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Sample records for mercury-exposed amazonian children

  1. Hair mercury levels in Amazonian populations: spatial distribution and trends

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    Barbieri Flavia L

    2009-12-01

    Full Text Available Abstract Background Mercury is present in the Amazonian aquatic environments from both natural and anthropogenic sources. As a consequence, many riverside populations are exposed to methylmercury, a highly toxic organic form of mercury, because of their intense fish consumption. Many studies have analysed this exposure from different approaches since the early nineties. This review aims to systematize the information in spatial distribution, comparing hair mercury levels by studied population and Amazonian river basin, looking for exposure trends. Methods The reviewed papers were selected from scientific databases and online libraries. We included studies with a direct measure of hair mercury concentrations in a sample size larger than 10 people, without considering the objectives, approach of the study or mercury speciation. The results are presented in tables and maps by river basin, displaying hair mercury levels and specifying the studied population and health impact, if any. Results The majority of the studies have been carried out in communities from the central Amazonian regions, particularly on the Tapajós River basin. The results seem quite variable; hair mercury means range from 1.1 to 34.2 μg/g. Most studies did not show any significant difference in hair mercury levels by gender or age. Overall, authors emphasized fish consumption frequency as the main risk factor of exposure. The most studied adverse health effect is by far the neurological performance, especially motricity. However, it is not possible to conclude on the relation between hair mercury levels and health impact in the Amazonian situation because of the relatively small number of studies. Conclusions Hair mercury levels in the Amazonian regions seem to be very heterogenic, depending on several factors. There is no obvious spatial trend and there are many areas that have never been studied. Taking into account the low mercury levels currently handled as acceptable, the

  2. Mercury toxicity in the Amazon: contrast sensitivity and color discrimination of subjects exposed to mercury

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    A.R. Rodrigues

    2007-03-01

    Full Text Available We measured visual performance in achromatic and chromatic spatial tasks of mercury-exposed subjects and compared the results with norms obtained from healthy individuals of similar age. Data were obtained for a group of 28 mercury-exposed subjects, comprising 20 Amazonian gold miners, 2 inhabitants of Amazonian riverside communities, and 6 laboratory technicians, who asked for medical care. Statistical norms were generated by testing healthy control subjects divided into three age groups. The performance of a substantial proportion of the mercury-exposed subjects was below the norms in all of these tasks. Eleven of 20 subjects (55% performed below the norms in the achromatic contrast sensitivity task. The mercury-exposed subjects also had lower red-green contrast sensitivity deficits at all tested spatial frequencies (9/11 subjects; 81%. Three gold miners and 1 riverine (4/19 subjects, 21% performed worse than normal subjects making more mistakes in the color arrangement test. Five of 10 subjects tested (50%, comprising 2 gold miners, 2 technicians, and 1 riverine, performed worse than normal in the color discrimination test, having areas of one or more MacAdam ellipse larger than normal subjects and high color discrimination thresholds at least in one color locus. These data indicate that psychophysical assessment can be used to quantify the degree of visual impairment of mercury-exposed subjects. They also suggest that some spatial tests such as the measurement of red-green chromatic contrast are sufficiently sensitive to detect visual dysfunction caused by mercury toxicity.

  3. Mercury exposure in a high fish eating Bolivian Amazonian population with intense small-scale gold-mining activities.

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    Barbieri, Flavia Laura; Cournil, Amandine; Gardon, Jacques

    2009-08-01

    Methylmercury exposure in Amazonian communities through fish consumption has been widely documented in Brazil. There is still a lack of data in other Amazonian countries, which is why we conducted this study in the Bolivian Amazon basin. Simple random sampling was used from a small village located in the lower Beni River, where there is intense gold mining and high fish consumption. All participants were interviewed and hair samples were taken to measure total mercury concentrations. The hair mercury geometric mean in the general population was 3.02 microg/g (CI: 2.69-3.37; range: 0.42-15.65). Age and gender were not directly associated with mercury levels. Fish consumption showed a positive relation and so did occupation, especially small-scale gold mining. Hair mercury levels were lower than those found in Brazilian studies, but still higher than in non-exposed populations. It is necessary to assess mercury exposure in the Amazonian regions where data is still lacking, using a standardized indicator.

  4. Litter mercury deposition in the Amazonian rainforest

    International Nuclear Information System (INIS)

    Fostier, Anne Hélène; Melendez-Perez, José Javier; Richter, Larissa

    2015-01-01

    The objective of this work was to assess the flux of atmospheric mercury transferred to the soil of the Amazonian rainforest by litterfall. Calculations were based on a large survey of published and unpublished data on litterfall and Hg concentrations in litterfall samples from the Amazonian region. Litterfall based on 65 sites located in the Amazon rainforest averaged 8.15 ± 2.25 Mg ha"−"1 y"−"1. Average Hg concentrations were calculated from nine datasets for fresh tree leaves and ten datasets for litter, and a median concentration of 60.5 ng Hg g"−"1 was considered for Hg deposition in litterfall, which averaged 49 ± 14 μg m"−"2 yr"−"1. This value was used to estimate that in the Amazonian rainforest, litterfall would be responsible for the annual removing of 268 ± 77 Mg of Hg, approximately 8% of the total atmospheric Hg deposition to land. The impact of the Amazon deforestation on the Hg biogeochemical cycle is also discussed. - Highlights: • Based on published data we estimated the litterfall in the Amazonian rainforest. • All the published data on Hg concentration in leaves and litter from the region and some unpublished data are presented. • We calculated the litter mercury deposition. • We estimated the contribution of dry, wet and litter Hg deposition in the Amazonian rainforest. • We also discussed the impact of Amazon deforestation on the Hg biogeochemical cycle. - The Amazonian rainforest is responsible for removing at least 268 Mg Hg y"−"1, 8% of the total atmospheric mercury deposition to land.

  5. Mercury in fish from the Madeira River and health risk to Amazonian and riverine populations.

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    Soares, José Maria; Gomes, José M; Anjos, Marcelo R; Silveira, Josianne N; Custódio, Flavia B; Gloria, M Beatriz A

    2018-07-01

    The objective of this study was to quantify total mercury in highly popular Amazonian fish pacu, curimatã, jaraqui, and sardinha from the Madeira River and to estimate the exposure to methylmercury from fish consumption. The samples were obtained from two locations - Puruzinho Igarapé and Santa Rosa - near Humaitá, Amazonia, Brazil in two seasons of 2015 (high and low waters). The fish were identified, weighed and measured, and lipids were quantified. Total mercury was determined by gold amalgamation-atomic absorption spectrometry. Mean levels were used to calculate exposure of Amazonian and riverine populations. There was significant correlation (p < 0.05) between length × weight for all fish; length × lipid and weight × lipid were significant only for pacu. Total mercury levels varied along muscle tissue for the fish, except for sardinha; therefore muscle from the dorsal area along the fish were sampled, homogenized and used for analysis. The levels of total mercury varied from 0.01 to 0.46 mg/kg, with higher median levels in sardinha (0.24 mg/kg), followed by curimatã (0.16 mg/kg), jaraqui (0.13 mg/kg) and pacu (0.04 mg/kg), corresponding with the respective feeding habits along the trophic chain. Total mercury levels were not affected by the location of fish capture and by high and low waters seasons. Total mercury correlated significantly with length and weight for jaraqui and with length for sardinha (negative correlation). Total mercury levels in fish complied with legislation; however, exposures to methylmercury from fish consumption overpassed the safe intake reference dose for sardinha for Amazonians; however, for the riverine communities, all of the fish would cause potential health risk, mainly for children and women of childbearing age. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Qualitative assessment of visuospatial errors in mercury-exposed Amazonian children

    DEFF Research Database (Denmark)

    Chevrier, Cécile; Sullivan, Kimberly; White, Roberta F.

    2009-01-01

    -12 years (from Brazil and French Guiana). These outcomes were related to hair-mercury concentration as the biomarker of MeHg exposure (range = 0.5-63.8 μg/g). The combined analysis of data from two separate countries had two major goals: (1) to gain clues concerning the underlying neuropathological...

  7. Litter mercury deposition in the Amazonian rainforest.

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    Fostier, Anne Hélène; Melendez-Perez, José Javier; Richter, Larissa

    2015-11-01

    The objective of this work was to assess the flux of atmospheric mercury transferred to the soil of the Amazonian rainforest by litterfall. Calculations were based on a large survey of published and unpublished data on litterfall and Hg concentrations in litterfall samples from the Amazonian region. Litterfall based on 65 sites located in the Amazon rainforest averaged 8.15 ± 2.25 Mg ha(-1) y(-1). Average Hg concentrations were calculated from nine datasets for fresh tree leaves and ten datasets for litter, and a median concentration of 60.5 ng Hg g(-1) was considered for Hg deposition in litterfall, which averaged 49 ± 14 μg m(-2) yr(-1). This value was used to estimate that in the Amazonian rainforest, litterfall would be responsible for the annual removing of 268 ± 77 Mg of Hg, approximately 8% of the total atmospheric Hg deposition to land. The impact of the Amazon deforestation on the Hg biogeochemical cycle is also discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Novel biomarkers of mercury-induced autoimmune dysfunction: a Cross-sectional study in Amazonian Brazil

    Science.gov (United States)

    Motts, Jonathan A.; Shirley, Devon L.; Silbergeld, Ellen K.; Nyland, Jennifer F.

    2014-01-01

    Mercury is an ubiquitous environmental contaminant, causing both neurotoxicity and immunotoxicity. Given its ability to amalgamate gold, mercury is frequently used in small-scale artisanal gold mining. We have previously reported that elevated serum titers of antinuclear autoantibodies (ANA) are associated with mercury exposures of miners in gold mining. The goal of this project was to identify novel serum biomarkers of mercury-induced immunotoxicity and autoimmune dysregulation. We conducted an analysis of serum samples from a cross-sectional epidemiological study on miners working in Amazonian Brazil. In proteomic screening analyses, samples were stratified based on mercury concentrations and ANA titer and a subset of serum samples (N=12) were profiled using Immune Response Biomarker Profiling ProtoArray protein microarray for elevated autoantibodies. Of the up-regulated autoantibodies in the mercury-exposed cohort, potential target autoantibodies were selected based on relevance to pro-inflammatory and macrophage activation pathways. ELISAs were developed to test the entire sample cohort (N=371) for serum titers to the highest of these autoantibodies (anti-glutathione S-transferase alpha, GSTA1) identified in the high mercury/high ANA group. We found positive associations between elevated mercury exposure and up-regulated serum titers of 3760 autoantibodies as identified by ProtoArray. Autoantibodies identified as potential novel biomarkers of mercury-induced immunotoxicity include antibodies to the following proteins: GSTA1, tumor necrosis factor ligand superfamily member 13, linker for activation of T cells, signal peptide peptidase like 2B, stimulated by retinoic acid 13, and interferon induced transmembrane protein. ELISA analyses confirmed that mercury-exposed gold miners had significantly higher serum titers of anti-GSTA1 autoantibody [unadjusted odds ratio = 89.6; 95% confidence interval: 27.2, 294.6] compared to emerald miners (referent population

  9. Mercury Bioaccumulation in the Brazilian Amazonian Tucunares (Cichla sp., Cichlidae, Perciformes

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    Maria Josefina Reyna Kurtz

    2008-08-01

    Full Text Available There are emissions of mercury to the atmosphere, soil and rivers of the Brazilian Amazon stem from many sources. Once in the atmosphere, the metal is oxidized and immediately deposited. In the water, the transformation to methylmercury takes place mostly by the action of microorganisms. The formation of methylmercury increases the dispersion and bioavailability of the element in the aquatic environment. Methylmercury can be assimilated by plankton and enters the food chain. The concentration of mercury increases further up in the trophic levels of the chain and reaches the highest values in carnivorous fishes like tucunare. Therefore, mercury emissions cause the contamination of natural resources and increase risks to the health of regular fish consumers. The objective of this work was to study the bioaccumulation of mercury in tucunares (Cichla sp., top predators of the food chain. The fishes were collected at two locations representative of the Amazonian fluvial ecosystem, in the state of Pará, Brazil, in 1992 and 2001. One location is near a former informal gold mining area. The other is far from the mining area and is considered pristine. Average values of total mercury concentration and accumulation rates for four different collection groups were compared and discussed. Tucunares collected in 2001 presented higher mercury contents and accumulated mercury faster than tucunares collected in 1992 notwithstanding the decline of mining activities in this period. The aggravation of the mercury contamination with time not only in an area where informal gold mining was practiced but also far from this area is confirmed.

  10. Mercury Report-Children's exposure to elemental mercury

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    ... gov . Mercury Background Mercury Report Additional Resources Mercury Report - Children's Exposure to Elemental Mercury Recommend on Facebook ... I limit exposure to mercury? Why was the report written? Children attending a daycare in New Jersey ...

  11. Mercury-induced motor and sensory neurotoxicity: systematic review of workers currently exposed to mercury vapor.

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    Fields, Cheryl A; Borak, Jonathan; Louis, Elan D

    2017-11-01

    The neurotoxicity of elemental mercury (Hg 0 ) is well-recognized, but it is uncertain whether and for how long neurotoxicity persists; among studies that evaluated previously exposed workers, only one examined workers during and also years after exposure ceased. The aim of this review is to document the type, frequency, and dose-relatedness of objective neurological effects in currently exposed mercury workers and thereby provide first approximations of the effects one would have expected in previously exposed workers evaluated during exposure. We systematically reviewed studies of neurotoxicity in currently exposed mercury workers identified by searching MEDLINE (1950-2015), government reports, textbook chapters, and references cited therein; dental cohorts were not included. Outcomes on physical examination (PE), neurobehavioral (NB) tests, and electrophysiological studies were extracted and evaluated for consistency and dose-relatedness. Forty-five eligible studies were identified, comprising over 3000 workers chronically exposed to a range of Hg 0 concentrations (0.002-1.7 mg/m 3 ). Effects that demonstrated consistency across studies and increased frequency across urine mercury levels (200 μg/L, while NB testing is more appropriate for those with lower U Hg levels. They also provide benchmarks to which findings in workers with historical exposure can be compared.

  12. Oral and dental affections in mercury-exposed workers

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    Fahmy, M.S.

    1978-07-01

    A total of 222 mercury-exposed workers in the Chlor-Alkali plant in Kuwait were investigated for oral and dental affections. The levels of mercury-vapor ranged from 566.6 microgram/m3 to 0.3 microgram/m3 in different parts of the factory. The periods of exposure varied from 1 to 11 years. Although the level of mercury vapor in the air and the period of exposure proved to be the main factors as regards the oral signs and symptoms, the oral hygiene condition and the individual sensitivity played substantial roles. Oral affections were found not to be due to allergy to mercury.

  13. Evaluation of mercury levels in hair of children resident in artisanal gold mining area in the city of Chapada de Natividade-Tocantins

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    Mendes, Seyna Ueno R., E-mail: seynaueno@gmail.com [Universidade Federal do Tocantins (UFTO), Palmas,TO (Brazil). Coordenação de Medicina; Vasconcellos, Marina B.A.; Catharino, Marília Gabriela M., E-mail: mbvascon@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (CRPQ/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro do Reator de Pesquisa; Quinaglia, Gilson A.; Held, Barbara, E-mail: gquinaglia@sp.gov.br [Companhia Ambiental do Estado de São Paulo (CETESB), São Paulo, SP (Brazil). Setor de Análises Toxicológicas

    2017-07-01

    The objective of the work is to evaluate the mercury exposure of children living in an artisanal gold mining area and in a control area, without mining. A cross-sectional study was conducted with children living in the municipalities of Chapada de Natividade and Porto Nacional, in the State of Tocantins, where hair samples were collected for laboratorial analysis of mercury concentrations, comparing between municipalities, gender, monthly fish consumption, profession of parents and the presence of amalgam in dental restorations. The hair samples were analyzed by the methods of neutron activation analysis and also by means of the DMA (Direct Mercury Analyzer) equipment, in the last case being a partnership with CETESB. There was no evidence of mercury-related diseases in the studied children. The mean concentration of mercury in children in Chapada de Natividade was significantly higher than in Porto Nacional. Children exposed to artisanal gold mining areas have higher concentrations of mercury than children living in non- artisanal gold mining areas. There was no significant relationship between mercury concentrations and gender, monthly fish consumption, parental profession and amalgam presence in dental restorations. The results suggest that the children living in an area exposed to mining experience greater environmental exposure to mercury, regardless of their eating habits or gender. (author)

  14. Evaluation of mercury levels in hair of children resident in artisanal gold mining area in the city of Chapada de Natividade-Tocantins

    International Nuclear Information System (INIS)

    Mendes, Seyna Ueno R.; Vasconcellos, Marina B.A.; Catharino, Marília Gabriela M.; Quinaglia, Gilson A.; Held, Barbara

    2017-01-01

    The objective of the work is to evaluate the mercury exposure of children living in an artisanal gold mining area and in a control area, without mining. A cross-sectional study was conducted with children living in the municipalities of Chapada de Natividade and Porto Nacional, in the State of Tocantins, where hair samples were collected for laboratorial analysis of mercury concentrations, comparing between municipalities, gender, monthly fish consumption, profession of parents and the presence of amalgam in dental restorations. The hair samples were analyzed by the methods of neutron activation analysis and also by means of the DMA (Direct Mercury Analyzer) equipment, in the last case being a partnership with CETESB. There was no evidence of mercury-related diseases in the studied children. The mean concentration of mercury in children in Chapada de Natividade was significantly higher than in Porto Nacional. Children exposed to artisanal gold mining areas have higher concentrations of mercury than children living in non- artisanal gold mining areas. There was no significant relationship between mercury concentrations and gender, monthly fish consumption, parental profession and amalgam presence in dental restorations. The results suggest that the children living in an area exposed to mining experience greater environmental exposure to mercury, regardless of their eating habits or gender. (author)

  15. Genetic and demographic responses of mosquitofish (Gambusia holbrooki) populations exposed to mercury for multiple generations

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    Tatara, C.P.; Mulvey, M.; Newman, M.C.

    1999-12-01

    Genetic and demographic responses of mosquitofish were examined after multiple generations of exposure to mercury. Previous studies of acute lethal exposures of mosquitofish to either mercury or arsenic demonstrated a consistent correlation between time to death and genotype at the glucosephosphate isomerase-2 (Gpi-2) locus. A mesocosm study involving mosquitofish populations exposed to mercury for 111 d showed significant female sexual selection and fecundity selection at the Gpi-2 locus. Here the mesocosm study was extended to populations exposed to mercury for several (approx. four) generations. After 2 years, control and mercury-exposed populations met Hardy-Weinberg expectations and showed no evidence of genetic bottlenecks. The mean number of heterozygous loci did not differ significantly between the mercury-exposed and control populations. Significant differences in allele frequencies at the Gpi-2 locus were observed between the mercury-exposed and control populations. Relative to the initial and control allele frequencies, the GPI-2{sup 100} allele frequency was lower, the Gpi-2{sup 66} allele frequency increased, but the Gpi-2{sup 38} allele frequency did not change in mercury-exposed populations. No significant differences were found in standard length, weight, sex ratio, or age class ratio between the control and mercury-exposed populations. Allele frequency changes at the Gpi-2 locus suggest population-level response to chronic mercury exposure. Changes in allele frequency may be useful as indicators of population response to contaminants, provided that the population in question is well understood.

  16. Experimental Infection and Clearance of Coccidian Parasites in Mercury-Exposed Zebra Finches.

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    Ebers Smith, Jessica H; Cristol, Daniel A; Swaddle, John P

    2018-01-01

    Mercury is a globally distributed, persistent environmental contaminant that affects the health of many taxa. It can suppress the immune system, which often plays a role in defense against parasites. However, there have been few investigations of whether mercury affects the abilities of animals to resist parasitic infection. Here, we exposed zebra finches to a lifetime dietary exposure of methylmercury (1.2 μg/g wet weight) and experimentally infected them with coccidian parasites to examine the effect of methylmercury exposure on parasitic infection. The mercury-exposed birds did not have an altered immune response (heterophil:lymphocyte ratio) nor a reduced ability to clear the infection. However, mercury-exposed birds tended to have higher parasite loads at the time when we expected the greatest immune response (2-3 weeks post-infection). Although mercury did not greatly influence the infection-course of this parasite in captivity, responses may be more accentuated in the wild where birds face additional immune challenges.

  17. Mercury Levels in Women and Children from Interior Villages in Suriname, South America.

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    Ouboter, Paul E; Landburg, Gwendolyn; Satnarain, Gaitrie U; Starke, Sheryl Y; Nanden, Indra; Simon-Friedt, Bridget; Hawkins, William B; Taylor, Robert; Lichtveld, Maureen Y; Harville, Emily; Wickliffe, Jeffrey K

    2018-05-17

    Natural sources of mercury, historical gold mining, and contemporary artisanal and small-scale gold mining (ASGM) activities have led to mercury contamination in Suriname. Our primary objective was to evaluate mercury levels in hair of women and children from interior villages in Suriname where mercury levels in fish are elevated. We also estimated blood levels of mercury using an established mathematical conversion to facilitate comparison with other biomonitoring programs in the United States. Estimated levels of mercury in the blood of participants from Suriname were significantly higher than those in women from a heavy marine fish-consuming population in southeast Louisiana and estimates of the US national average. This includes women from Surinamese villages well upstream of ASGM activities. Since residents in these areas rely heavily on local fish, this is likely the source of their exposure to mercury. The levels in hair are similar to those seen in women from longitudinal studies finding neurological impairments in children exposed pre- and postnatally. Additional biomonitoring and neurodevelopmental assessments are warranted in these areas, as well as other areas of the Suriname. Mercury levels in hair (Suriname) and blood (southeast LA USA) were determined using cold vapor atomic absorption spectroscopy (CVAAS).

  18. Mercury Levels in Women and Children from Interior Villages in Suriname, South America

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    Paul E. Ouboter

    2018-05-01

    Full Text Available Natural sources of mercury, historical gold mining, and contemporary artisanal and small-scale gold mining (ASGM activities have led to mercury contamination in Suriname. Our primary objective was to evaluate mercury levels in hair of women and children from interior villages in Suriname where mercury levels in fish are elevated. We also estimated blood levels of mercury using an established mathematical conversion to facilitate comparison with other biomonitoring programs in the United States. Estimated levels of mercury in the blood of participants from Suriname were significantly higher than those in women from a heavy marine fish-consuming population in southeast Louisiana and estimates of the US national average. This includes women from Surinamese villages well upstream of ASGM activities. Since residents in these areas rely heavily on local fish, this is likely the source of their exposure to mercury. The levels in hair are similar to those seen in women from longitudinal studies finding neurological impairments in children exposed pre- and postnatally. Additional biomonitoring and neurodevelopmental assessments are warranted in these areas, as well as other areas of the Suriname. Mercury levels in hair (Suriname and blood (southeast LA USA were determined using cold vapor atomic absorption spectroscopy (CVAAS.

  19. Color discrimination impairment in workers exposed to mercury vapor.

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    Urban, Pavel; Gobba, Fabriziomaria; Nerudová, Jana; Lukás, Edgar; Cábelková, Zdena; Cikrt, Miroslav

    2003-08-01

    To study color discrimination impairment in workers exposed to elemental mercury (Hg) vapor. Twenty-four male workers from a chloralkali plant exposed to Hg vapor, aged 42+/-9.8 years, duration of exposure 14.7+/-9.7 years, were examined. The 8h TWA air-borne Hg concentration in workplace was 59 microg/m(3); mean Hg urinary excretion (HgU) was 20.5+/-19.3 microg/g creatinine; mean Hg urinary excretion after the administration of a chelating agent, sodium 2,3-dimercapto-1-propane-sulfonate (DMPS), was 751.9+/-648 microg/48h. Twenty-four age- and gender-matched control subjects were compared. Visual acuity, alcohol intake, smoking habits, and history of diseases or drugs potentially influencing color vision were registered. The Lanthony 15-Hue desaturated test (L-D15-d) was used to assess color vision. The results were expressed quantitatively as Bowman's Color Confusion Index (CCI), and qualitatively according to Verriest's classification of acquired dyschromatopsias. The CCI was significantly higher in the exposed group than in the control (mean CCI 1.15 versus 1.04; P=0.04). The proportion of subjects with errorless performance on the Lanthony test was significantly lower in the Hg exposed group compared to referents (52% versus 73%; P=0.035). The exposed group showed higher frequency of type III dyschromatopsias (blue-yellow confusion axis) in comparison with the control group (12.5% versus 8.3%), however, the difference did not reach statistical significance. Multiple regression did not show any significant relationship between the CCI, and age, alcohol consumption, or measures of exposure. In agreement with previous studies by Cavalleri et al. [Toxicol. Lett. 77 (1995) 351; Environ. Res. Sec. A 77 (1998) 173], the results of this study support the hypothesis that exposure to mercury vapor can induce sub-clinical color vision impairment. This effect was observed at an exposure level below the current biological limit for occupational exposure to mercury. This

  20. Fish are central in the diet of Amazonian riparians: should we worry about their mercury concentrations?

    International Nuclear Information System (INIS)

    Dorea, Jose G.

    2003-01-01

    The Amazon rain forest extends over an area of 7.8x10 6 km 2 in nine countries. It harbors a diverse human population distributed in dense cities and isolated communities with extreme levels of infrastructure. Amazonian forest people, either autochthons or frontier riparians (ribeirinhos) living in isolated areas, share the same environment for survival and nutritional status. The peculiarities of the hydrological cycle determine disease patterns, agricultural conditions, and food availability. Feeding strategies depend heavily on cassava products and fish. These two foods carry toxic substances such as linamarin (naturally present in cassava) and monomethyl mercury (MMHg) (bioconcentrated in fish flesh) that cause neurotoxic diseases in other parts of the world but not in Amazonia, where neurotoxic cases of food origin are rare and not related to these staples. While cassava detoxification processes may partly explain its safe consumption, the Hg concentrations in Amazonian fish are within traditionally safe limits for this population and contribute to an important metabolic interaction with cassava. The gold rush of the 1970s and 1980s brought large-scale environmental disruption and physical destruction of ecosystems at impact points, along with a heavy discharge of metallic Hg. The discharged Hg has not yet impacted on MMHg concentrations in fish or in hair of fish consumers. Hair Hg concentration, used as a biomarker of fish consumption, indicates that the Amazonian riparians are acquiring an excellent source of protein carrying important nutrients, the lack of which could aggravate their existing health problems. Therefore, in a scenario of insufficient health services and an unhealthy environment, food habits based on fish consumption are part of a successful survival strategy and recommendations for changes are not yet justifiable

  1. Fish are central in the diet of Amazonian riparians: should we worry about their mercury concentrations?

    Science.gov (United States)

    Dorea, Jose G

    2003-07-01

    The Amazon rain forest extends over an area of 7.8x10(6)km(2) in nine countries. It harbors a diverse human population distributed in dense cities and isolated communities with extreme levels of infrastructure. Amazonian forest people, either autochthons or frontier riparians (ribeirinhos) living in isolated areas, share the same environment for survival and nutritional status. The peculiarities of the hydrological cycle determine disease patterns, agricultural conditions, and food availability. Feeding strategies depend heavily on cassava products and fish. These two foods carry toxic substances such as linamarin (naturally present in cassava) and monomethyl mercury (MMHg) (bioconcentrated in fish flesh) that cause neurotoxic diseases in other parts of the world but not in Amazonia, where neurotoxic cases of food origin are rare and not related to these staples. While cassava detoxification processes may partly explain its safe consumption, the Hg concentrations in Amazonian fish are within traditionally safe limits for this population and contribute to an important metabolic interaction with cassava. The gold rush of the 1970s and 1980s brought large-scale environmental disruption and physical destruction of ecosystems at impact points, along with a heavy discharge of metallic Hg. The discharged Hg has not yet impacted on MMHg concentrations in fish or in hair of fish consumers. Hair Hg concentration, used as a biomarker of fish consumption, indicates that the Amazonian riparians are acquiring an excellent source of protein carrying important nutrients, the lack of which could aggravate their existing health problems. Therefore, in a scenario of insufficient health services and an unhealthy environment, food habits based on fish consumption are part of a successful survival strategy and recommendations for changes are not yet justifiable.

  2. [Genotoxic damage among artisanal and small-scale mining workers exposed to mercury].

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    Rosales-Rimache, Jaime A; Elizabeth Malca, Nancy; Alarcón, Jhonatan J; Chávez, Manuel; Gonzáles, Marco Antonio

    2013-01-01

    To determine the genotoxic damage among artisanal and small-scale mining workers exposed to mercury. Observational cross-sectional study which evaluated mercury-exposed workers (n=83), whose cells were collected by mouth swab for further staining, microscopic observance, micronuclei count, and other nuclear alterations. 24-hour urine was also collected for the determination of inorganic mercury. 68.7% of participants were male, the mean age being 43 ± 12,4 years (range: 16-76). The average time of occupational exposure to mercury was 12,1 ± 6,7 years, and the contact with mercury was 4,1 ± 3,6 kg per person per day. 93% of participants failed to wear personal protection gear while handling mercury. Results of biological monitoring showed that 17% of participants had concentrations of mercury in urine higher than 2,5 µg/L, this value being the detection limit of the measurement technique used. Results of the genotoxic evaluation evidenced that 15% of people with labor exposure to mercury presented micronuclei in mouth epithelial cells, and other indicators of nuclear alteration such as nucleoplasmic bridges, gemmation and binucleation were found, which are also considered genotoxic events associated to the exposure of physical or chemical risk agents. The finding of micronuclei in mouth epithelial cells reflects genotoxic damage associated to the labor exposure of mercury used in artisanal and small-scale mining activities.

  3. Mercury exposure, serum antinuclear/antinucleolar antibodies, and serum cytokine levels in mining populations in Amazonian Brazil: a cross-sectional study.

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    Gardner, Renee M; Nyland, Jennifer F; Silva, Ines A; Ventura, Ana Maria; de Souza, Jose Maria; Silbergeld, Ellen K

    2010-05-01

    Mercury is an immunotoxic substance that has been shown to induce autoimmune disease in rodent models, characterized by lymphoproliferation, overproduction of immunoglobulin (IgG and IgE), and high circulating levels of auto-antibodies directed at antigens located in the nucleus (antinuclear auto-antibodies, or ANA) or the nucleolus (antinucleolar auto-antibodies, or ANoA). We have reported elevated levels of ANA and ANoA in human populations exposed to mercury in artisanal gold mining, though other confounding variables that may also modulate ANA/ANoA levels were not well controlled. The goal of this study is to specifically test whether occupational and environmental conditions (other than mercury exposure) that are associated with artisanal gold mining affect the prevalence of markers of autoimmune dysfunction. We measured ANA, ANoA, and cytokine concentrations in serum and compared results from mercury-exposed artisanal gold miners to those from diamond and emerald miners working under similar conditions and with similar socio-economic status and risks of infectious disease. Mercury-exposed gold miners had higher prevalence of detectable ANA and ANoA and higher titers of ANA and ANoA as compared to diamond and emerald miners with no occupational mercury exposure. Also, mercury-exposed gold miners with detectable ANA or ANoA in serum had significantly higher concentrations of pro-inflammatory cytokines IL-1beta, TNF-alpha, and IFN-gamma in serum as compared to the diamond and emerald miners. This study provides further evidence that mercury exposure may lead to autoimmune dysfunction and systemic inflammation in affected populations. Copyright 2010 Elsevier Inc. All rights reserved.

  4. Mercury Hair Concentration among Primary School Children in Malaysia

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    Nurul Izzah Abdul Samad

    2017-12-01

    Full Text Available The main concern regarding mercury exposure is the adverse health effect on the developing nervous system. The objective of this cross-sectional study was to determine hair mercury levels and their association with socio-demographic characteristics, complaints about mercury poisoning symptoms and the fish consumption pattern among children in Malaysia. A cross-sectional study was conducted among 215 school children aged 11 years old. Hair was collected from the children and the total mercury was analyzed using oxygen combustion–gold amalgamation atomic absorption spectrophotometry. Anthropometric data, a fish consumption questionnaire and mercury poisoning symptoms were collected during a personal interview. The mean hair mercury level among primary school children was 0.63 ± 0.59 µg/g with the geometric mean of 0.47 µg/g. A total of 14% of respondents had hair mercury levels above 1 µg/g. A multiple binary logistic regression analysis outlined that fish consumption of at least one meal per week increased the likelihood of having a high mercury level (odds ratio (OR 3.7, 95% confidence interval (CI 1.3–10.4. This study confirms the existence of a mercury burden among Malaysian children and the level is high compared to other regional studies. This study provides important baseline data regarding the mercury level among children in Malaysia.

  5. Assessment of mercury exposure and malaria in a Brazilian Amazon riverine community

    International Nuclear Information System (INIS)

    Crompton, Peter; Ventura, Ana Maria; Souza, Jose Maria de; Santos, Elisabeth; Strickland, G. Thomas; Silbergeld, Ellen

    2002-01-01

    Small-scale gold mining in the Brazilian Amazon occurs in areas with high rates of malaria transmission. Amazonian populations can be exposed to mercury through direct contact with the mining process and/or through fish consumption. Because of data from experimental studies, we examined the potential for mercury to affect host response to malaria. A cross-sectional survey was done in Jacareacanga, a riverine community in Para state, in a region of intense alluvial gold mining. A sample of 205 persons was selected by cluster sampling from the total population of approximately 2000. A brief medical history and exam were conducted, malaria slides were obtained, and air samples were taken to measure mercury levels. The average hair mercury level was 8.6 μg/g, ranging from 0.3 to 83.2 μg/g. The most important predictors of elevated mercury levels were high fish consumption and low income. Although there was no prevalent malaria, the odds of reporting a past malaria infection was four times higher for those also reporting a history of working with mercury

  6. A review of events that expose children to elemental mercury in the United States Uma revisão dos eventos que expõem as crianças ao elemento mercúrio nos Estados Unidos

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    Robin Lee

    2010-03-01

    Full Text Available Concern for children exposed to elemental mercury prompted the Agency for Toxic Substances and Disease Registry and the Centers for Disease Control and Prevention to review the sources of elemental mercury exposures in children, describe the location and proportion of children affected, and make recommendations on how to prevent these exposures. In this review, we excluded mercury exposures from coal-burning facilities, dental amalgams, fish consumption, medical waste incinerators, or thimerosal-containing vaccines. We reviewed federal, state, and regional programs with data on mercury releases along with published reports of children exposed to elemental mercury in the United States. We selected all mercury-related events that were documented to expose (or potentially expose children. Primary exposure locations were at home, at school, and at others such as industrial property not adequately remediated or medical facilities. Exposure to small spills from broken thermometers was the most common scenario; however, reports of such exposures are declining. The information reviewed suggests that most releases do not lead to demonstrable harm if the exposure period is short and the mercury is properly cleaned up. Primary prevention should include health education and policy initiatives.Uma preocupação pela exposição de crianças ao elemento mercúrio estimulou a Agência para Substâncias Tóxicas e Registro de Doenças e os Centros para Controle e Prevenção de Doenças a rever as fontes de exposição a este elemento por crianças, descrever a locação e proporção de crianças afetadas e fazer recomendações de como prevenir essas exposições. Nesta análise, foi excluída a exposição a mercúrio em instalações de queima de carvão, amálgamas dentários, consumo de peixes, incineradores de lixo hospitalar ou vacinas contendo timerosal. Analisamos programas regionais, estaduais e federais com dados sobre liberação de merc

  7. Water Consumption as Source of Arsenic, Chromium, and Mercury in Children Living in Rural Yucatan, Mexico: Blood and Urine Levels.

    Science.gov (United States)

    Arcega-Cabrera, F; Fargher, L F; Oceguera-Vargas, I; Noreña-Barroso, E; Yánez-Estrada, L; Alvarado, J; González, L; Moo-Puc, R; Pérez-Herrera, N; Quesadas-Rojas, M; Pérez-Medina, S

    2017-10-01

    Studies investigating the correlation between metal content in water and metal levels in children are scarce worldwide, but especially in developing nations. Therefore, this study investigates the correlation between arsenic, chromium, and mercury concentrations in drinking and cooking water and in blood and urine samples collected from healthy and supposedly non-exposed children from a rural area in Yucatan, Mexico. Mercury in water shows concentrations above the recommended World Health Organization (WHO) value for drinking and cooking water. Also, 25% of the children show mercury in urine above the WHO recommended value. Multivariate analyses show a significant role for drinking and cooking water as a vector of exposure in children. Also, the factor analysis shows chronic exposure in the case of arsenic, as well as an ongoing detoxification process through urine in the case of mercury. Further studies should be done in order to determine other potential metal exposure pathways among children.

  8. Risk assessment of environmental exposure to mercury in the urban area of Alta Floresta, Mato Grosso State - Amazonian basin - Brazil; Avaliacao do risco potencial para a saude humana da exposicao ao mercurio na area urbana de Alta Floresta, Mato Grosso - Bacia Amazonica - Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Hacon, Sandra de Souza

    1996-07-01

    Mercury contamination in the Amazon basin is a consequence of the intensive and extensive use of metallic Hg in gold mining activities which use the amalgamation process. Mercury vapor is the main form of Hg released in the Amazonian ecosystem. However, some studies have shown that enhanced biotransformation of inorganic mercury into organic Hg is occurring. These two forms of Hg have some properties in common but differ in toxicity and metabolic behavior. Knowledge of the fate and transport of Hg in the Amazon basin is especially important for the assessment of the extent of contamination, as well as the characterization of exposed groups. the present study attempts to evaluate the Hg exposure scenario as well as to assess the quantitative risk (from Hg emission) for workers in gold-dealers' shops and for the general population in the urban area of Alta Floresta. The way that are was populated and the regional and local economy history, particularly in connection with the commercialization of gold in the region, are important factors in the study of the exposure scenario in Alta Floresta. Assessment of exposure pathways has shown that the adult and infant populations of Alta Floresta are exposed to low dose levels of Hg. Fish consumed locally shows high concentrations of Hg, ranging from 0,5 to 3,6 mg/kg. However, due to the low consumption of fish by the general population this exposure pathway has little effect on the health of the general public. Fishermen and their families are those most at risk from Hg intoxication. Workers in gold shops are another critical group, in relation to exposure to Hg vapor. As for the infant population, above 4 years old, inhalation of Hg vapor is the main source of the exposure, one exception being to children of fishermen whose pattern of fish consumption is similar to their parents. These are the two groups at risk from fish ingestion. Infants between 1 and 4 years of age are the group most likely to suffer adverse effects from

  9. Risk assessment of environmental exposure to mercury in the urban area of Alta Floresta, Mato Grosso State - Amazonian basin - Brazil; Avaliacao do risco potencial para a saude humana da exposicao ao mercurio na area urbana de Alta Floresta, Mato Grosso - Bacia Amazonica - Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Hacon, Sandra de Souza

    1996-07-01

    Mercury contamination in the Amazon basin is a consequence of the intensive and extensive use of metallic Hg in gold mining activities which use the amalgamation process. Mercury vapor is the main form of Hg released in the Amazonian ecosystem. However, some studies have shown that enhanced biotransformation of inorganic mercury into organic Hg is occurring. These two forms of Hg have some properties in common but differ in toxicity and metabolic behavior. Knowledge of the fate and transport of Hg in the Amazon basin is especially important for the assessment of the extent of contamination, as well as the characterization of exposed groups. the present study attempts to evaluate the Hg exposure scenario as well as to assess the quantitative risk (from Hg emission) for workers in gold-dealers' shops and for the general population in the urban area of Alta Floresta. The way that are was populated and the regional and local economy history, particularly in connection with the commercialization of gold in the region, are important factors in the study of the exposure scenario in Alta Floresta. Assessment of exposure pathways has shown that the adult and infant populations of Alta Floresta are exposed to low dose levels of Hg. Fish consumed locally shows high concentrations of Hg, ranging from 0,5 to 3,6 mg/kg. However, due to the low consumption of fish by the general population this exposure pathway has little effect on the health of the general public. Fishermen and their families are those most at risk from Hg intoxication. Workers in gold shops are another critical group, in relation to exposure to Hg vapor. As for the infant population, above 4 years old, inhalation of Hg vapor is the main source of the exposure, one exception being to children of fishermen whose pattern of fish consumption is similar to their parents. These are the two groups at risk from fish ingestion. Infants between 1 and 4 years of age are the group most likely to suffer adverse effects

  10. A Comparison of Urinary Mercury between Children with Autism Spectrum Disorders and Control Children

    Science.gov (United States)

    Wright, Barry; Pearce, Helen; Allgar, Victoria; Miles, Jeremy; Whitton, Clare; Leon, Irene; Jardine, Jenny; McCaffrey, Nicola; Smith, Rob; Holbrook, Ian; Lewis, John; Goodall, David; Alderson-Day, Ben

    2012-01-01

    Background Urinary mercury concentrations are used in research exploring mercury exposure. Some theorists have proposed that autism is caused by mercury toxicity. We set out to test whether mercury concentrations in the urine of children with autism were significantly increased or decreased compared to controls or siblings. Methods Blinded cohort analyses were carried out on the urine of 56 children with autism spectrum disorders (ASD) compared to their siblings (n = 42) and a control sample of children without ASD in mainstream (n = 121) and special schools (n = 34). Results There were no statistically significant differences in creatinine levels, in uncorrected urinary mercury levels or in levels of mercury corrected for creatinine, whether or not the analysis is controlled for age, gender and amalgam fillings. Conclusions This study lends no support for the hypothesis of differences in urinary mercury excretion in children with autism compared to other groups. Some of the results, however, do suggest further research in the area may be warranted to replicate this in a larger group and with clear measurement of potential confounding factors. PMID:22355303

  11. A comparison of urinary mercury between children with autism spectrum disorders and control children.

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    Barry Wright

    Full Text Available BACKGROUND: Urinary mercury concentrations are used in research exploring mercury exposure. Some theorists have proposed that autism is caused by mercury toxicity. We set out to test whether mercury concentrations in the urine of children with autism were significantly increased or decreased compared to controls or siblings. METHODS: Blinded cohort analyses were carried out on the urine of 56 children with autism spectrum disorders (ASD compared to their siblings (n = 42 and a control sample of children without ASD in mainstream (n = 121 and special schools (n = 34. RESULTS: There were no statistically significant differences in creatinine levels, in uncorrected urinary mercury levels or in levels of mercury corrected for creatinine, whether or not the analysis is controlled for age, gender and amalgam fillings. CONCLUSIONS: This study lends no support for the hypothesis of differences in urinary mercury excretion in children with autism compared to other groups. Some of the results, however, do suggest further research in the area may be warranted to replicate this in a larger group and with clear measurement of potential confounding factors.

  12. Mercury exposure in young children living in New York City.

    Science.gov (United States)

    Rogers, Helen S; Jeffery, Nancy; Kieszak, Stephanie; Fritz, Pat; Spliethoff, Henry; Palmer, Christopher D; Parsons, Patrick J; Kass, Daniel E; Caldwell, Kathy; Eadon, George; Rubin, Carol

    2008-01-01

    Residential exposure to vapor from current or previous cultural use of mercury could harm children living in rental (apartment) homes. That concern prompted the following agencies to conduct a study to assess pediatric mercury exposure in New York City communities by measuring urine mercury levels: New York City Department of Health and Mental Hygiene's (NYCDOHMH) Bureau of Environmental Surveillance and Policy, New York State Department of Health/Center for Environmental Health (NYSDOHCEH), Wadsworth Center's Biomonitoring Program/Trace Elements Laboratory (WC-TEL), and Centers for Disease Control and Prevention (CDC). A previous study indicated that people could obtain mercury for ritualistic use from botanicas located in Brooklyn, Manhattan, and the Bronx. Working closely with local community partners, we concentrated our recruiting efforts through health clinics located in potentially affected neighborhoods. We developed posters to advertise the study, conducted active outreach through local partners, and, as compensation for participation in the study, we offered a food gift certificate redeemable at a local grocer. We collected 460 urine specimens and analyzed them for total mercury. Overall, geometric mean urine total mercury was 0.31 microg mercury/l urine. One sample was 24 microg mercury/l urine, which exceeded the (20 microg mercury/l urine) NYSDOH Heavy Metal Registry reporting threshold for urine mercury exposure. Geometric mean urine mercury levels were uniformly low and did not differ by neighborhood or with any clinical significance by children's ethnicity. Few parents reported the presence of mercury at home, in a charm, or other item (e.g., skin-lightening creams and soaps), and we found no association between these potential sources of exposure and a child's urinary mercury levels. All pediatric mercury levels measured in this study were well below a level considered to be of medical concern. This study found neither self-reported nor measured

  13. The price of gold: mercury exposure in the Amazonian rain forest.

    Science.gov (United States)

    Branches, F J; Erickson, T B; Aks, S E; Hryhorczuk, D O

    1993-01-01

    Concern has surfaced over the recent discovery of human mercury exposure throughout the tropical rain forest of South America's Amazon River Basin. The probable source of mercury has been traced to gold mines located within the interior. The mining process involves the extraction of gold from ore by burning off a mercury additive, resulting in vaporization of elemental mercury into the surrounding environment. The purpose of this case series is to document mercury levels in miners and local villagers presenting with a history of exposure, or signs and symptoms consistent with mercury toxicity. Over a five year period (1986-91), the whole blood and urine mercury levels of 55 Brazilian patients demonstrating signs and symptoms consistent with mercury exposure were collected. Thirty-three (60%) of the subjects had direct occupational exposure to mercury via gold mining and refining. Whole blood mercury levels ranged from 0.4-13.0 micrograms/dL (mean 3.05 micrograms/dL). Spot urine levels ranged 0-151 micrograms/L (mean = 32.7 micrograms/L). Occupational mercury exposure is occurring in the Amazon River Basin. Interventions aimed at altering the gold mining process while protecting the workers and surrounding villagers from the source of exposure are essential. The impact of the gold mining industry on general environmental contamination has not been investigated.

  14. Renographic curve of persons exposed to mercury

    International Nuclear Information System (INIS)

    Kolenic, J.; Jurgova, T.; Zimacek, J.; Petrovicova, J.; Bilicky, J.

    1995-01-01

    In the group of 72 workers which were exposed to fumes of metallic mercury we evaluated possible nephrotoxic effect of Hg 0 . We also used nuclear renography for evaluation of kidney. Nephrotoxic effect of Hg 0 was proved by increased proteinuria and relatively frequent findings of pathological renogram. In the group with pathological renogram, elimination of Hg 0 in urine (1822.8 nmol.dm -3 ) was increased. In the group with normal finding the value was 883.7 nmol.dm -3 . These findings pointed at toxic effect of Hg 0 on kidney and suitability of radionuclide examination for disclosing of subclinical pathological changes. (authors)

  15. Exposure to mercury among Spanish preschool children: Trend from birth to age four

    Energy Technology Data Exchange (ETDEWEB)

    Llop, Sabrina, E-mail: llop_sab@gva.es [Foundation for the Promotion of Health and Biomedical Research in the Valencian Region, FISABIO-Public Health, Av. Catalunya 21, 46020 Valencia (Spain); Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid (Spain); Murcia, Mario [Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid (Spain); Foundation for the Promotion of Health and Biomedical Research in the Valencian Region, FISABIO-Public Health, Av. Catalunya 21, 46020 Valencia (Spain); Aguinagalde, Xabier [Laboratorio de Salud Pública de Alava, Santiago 11, 01002 Vitoria Gasteiz (Spain); Vioque, Jesus [Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid (Spain); Universidad Miguel Hernandez, Avenida de Alicante KM 87, 03550 Sant Joan d´Alacant (Spain); Rebagliato, Marisa [Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid (Spain); Medicine Department, Jaume I University, Av. Vicent Sos Baynat, s/n, 12071 Castelló de la Plana (Spain); Cases, Amparo [Foundation for the Promotion of Health and Biomedical Research in the Valencian Region, FISABIO-Public Health, Av. Catalunya 21, 46020 Valencia (Spain); Iñiguez, Carmen; Lopez-Espinosa, Maria-Jose [Foundation for the Promotion of Health and Biomedical Research in the Valencian Region, FISABIO-Public Health, Av. Catalunya 21, 46020 Valencia (Spain); Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid (Spain); Amurrio, Ascensión [Laboratorio de Salud Pública de Alava, Santiago 11, 01002 Vitoria Gasteiz (Spain); María Navarrete-Muñoz, Eva [Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid (Spain); Universidad Miguel Hernandez, Avenida de Alicante KM 87, 03550 Sant Joan d´Alacant (Spain); and others

    2014-07-15

    The purpose of this study is to describe the total hair mercury concentrations and their determinants in preschool Spanish children, as well as to explore the trend in mercury exposure from birth to the age four. This evolution has been scarcely studied in other birth cohort studies. The study population was 580 four year old children participating in the INMA (i.e. Childhood and Environment) birth cohort study in Valencia (2008–2009). Total mercury concentration at age four was measured in hair samples by atomic absorption spectrometry. Fish consumption and other covariates were obtained by questionnaire. Multivariate linear regression models were conducted in order to explore the association between mercury exposure and fish consumption, socio-demographic characteristics and prenatal exposure to mercury. The geometric mean was 1.10 µg/g (95%CI: 1.02, 1.19). Nineteen percent of children had mercury concentrations above the equivalent to the Provisional Tolerable Weekly Intake proposed by WHO. Mercury concentration was associated with increasing maternal age, fish consumption and cord blood mercury levels, as well as decreasing parity. Children whose mothers worked had higher mercury levels than those with non working mothers. Swordfish, lean fish and canned fish were the fish categories most associated with hair mercury concentrations. We observed a decreasing trend in mercury concentrations between birth and age four. In conclusion, the children participating in this study had high hair mercury concentrations compared to reported studies on children from other European countries and similar to other countries with high fish consumption. The INMA study design allows the evaluation of the exposure to mercury longitudinally and enables this information to be used for biomonitoring purposes and dietary recommendations. - Highlights: • The geometric mean of hair Hg concentrations was 1.10 µg/g. • 19% of children had Hg concentrations above the RfD proposed by

  16. Exposure to mercury among Spanish preschool children: Trend from birth to age four

    International Nuclear Information System (INIS)

    Llop, Sabrina; Murcia, Mario; Aguinagalde, Xabier; Vioque, Jesus; Rebagliato, Marisa; Cases, Amparo; Iñiguez, Carmen; Lopez-Espinosa, Maria-Jose; Amurrio, Ascensión; María Navarrete-Muñoz, Eva

    2014-01-01

    The purpose of this study is to describe the total hair mercury concentrations and their determinants in preschool Spanish children, as well as to explore the trend in mercury exposure from birth to the age four. This evolution has been scarcely studied in other birth cohort studies. The study population was 580 four year old children participating in the INMA (i.e. Childhood and Environment) birth cohort study in Valencia (2008–2009). Total mercury concentration at age four was measured in hair samples by atomic absorption spectrometry. Fish consumption and other covariates were obtained by questionnaire. Multivariate linear regression models were conducted in order to explore the association between mercury exposure and fish consumption, socio-demographic characteristics and prenatal exposure to mercury. The geometric mean was 1.10 µg/g (95%CI: 1.02, 1.19). Nineteen percent of children had mercury concentrations above the equivalent to the Provisional Tolerable Weekly Intake proposed by WHO. Mercury concentration was associated with increasing maternal age, fish consumption and cord blood mercury levels, as well as decreasing parity. Children whose mothers worked had higher mercury levels than those with non working mothers. Swordfish, lean fish and canned fish were the fish categories most associated with hair mercury concentrations. We observed a decreasing trend in mercury concentrations between birth and age four. In conclusion, the children participating in this study had high hair mercury concentrations compared to reported studies on children from other European countries and similar to other countries with high fish consumption. The INMA study design allows the evaluation of the exposure to mercury longitudinally and enables this information to be used for biomonitoring purposes and dietary recommendations. - Highlights: • The geometric mean of hair Hg concentrations was 1.10 µg/g. • 19% of children had Hg concentrations above the RfD proposed by

  17. Probabilistic mercury multimedia exposure assessment in small children and risk assessment.

    Science.gov (United States)

    Morisset, Typhaine; Ramirez-Martinez, Alejandra; Wesolek, Nathalie; Roudot, Alain-Claude

    2013-09-01

    Emissions of mercury in the environment have been decreasing for several years. However, mercury species are still found in different media (food, water, air and breast-milk). Due to mercury toxicity and typical behaviour in children, we have conducted a mercury exposure assessment in French babies, and small children aged 0 to 36months. Consumption and mercury concentration data were chosen for the exposure assessment. The Monte Carlo technique has been used to calculate the weekly exposure dose in order to integrate inter-individual variability and parameter uncertainty. Exposure values have been compared to toxicological reference values for health risk assessment. Inorganic mercury median exposure levels ranged from 0.160 to 1.649μg/kg of body weight per week (95th percentile (P95): 0.298-2.027µg/kg bw/week); elemental mercury median exposure level in children was 0.11ng/kg bw/week (P95: 28ng/kg bw/week); and methylmercury median exposure level ranged from 0.247 to 0.273µg/kg bw/week (P95: 0.425-0.463µg/kg bw/week). Only elemental mercury by inhalation route (indoor air) and methylmercury by ingestion (fish and breast-milk) seem to lead to a health risk in small children. These results confirm the importance of assessing total mercury concentration in media like breast-milk, indoor air and dust and methylmercury level in food, other than fish and seafood. In this way, informed monitoring plan and risk assessment in an at-risk sub-population can be set. © 2013 Elsevier Ltd. All rights reserved.

  18. Mercury exposure, malaria, and serum antinuclear/antinucleolar antibodies in amazon populations in Brazil: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Burek CL

    2004-11-01

    Full Text Available Abstract Background Mercury is an immunotoxic metal that induces autoimmune disease in rodents. Highly susceptible mouse strains such as SJL/N, A.SW, B10.S (H-2s develop multiple autoimmune manifestations after exposure to inorganic mercury, including lymphoproliferation, elevated levels of autoantibodies, overproduction of IgG and IgE, and circulating immune complexes in kidney and vasculature. A few studies have examined relationships between mercury exposures and adverse immunological reactions in humans, but there is little evidence of mercury-associated autoimmunity in humans. Methods To test the immunotoxic effects of mercury in humans, we studied communities in Amazonian Brazil with well-characterized exposures to mercury. Information was collected on diet, mercury exposures, demographic data, and medical history. Antinuclear and antinucleolar autoantibodies (ANA and ANoA were measured by indirect immunofluorescence. Anti-fibrillarin autoantibodies (AFA were measured by immunoblotting. Results In a gold mining site, there was a high prevalence of ANA and ANoA: 40.8% with detectable ANoA at ≥1:10 serum dilution, and 54.1% with detectable ANA (of which 15% had also detectable ANoA. In a riverine town, where the population is exposed to methylmercury by fish consumption, both prevalence and levels of autoantibodies were lower: 18% with detectable ANoA and 10.7% with detectable ANA. In a reference site with lower mercury exposures, both prevalence and levels of autoantibodies were much lower: only 2.0% detectable ANoA, and only 7.1% with detectable ANA. In the gold mining population, we also examined serum for AFA in those subjects with detectable ANoA (≥1:10. There was no evidence for mercury induction of this autoantibody. Conclusions This is the first study to report immunologic changes, indicative of autoimmune dysfunction in persons exposed to mercury, which may also reflect interactions with infectious disease and other factors.

  19. Risk factors for mercury exposure of children in a rural mining town in northern Chile.

    Directory of Open Access Journals (Sweden)

    Johan Ohlander

    Full Text Available Traditional gold mining is associated with mercury exposure. Especially vulnerable to its neurotoxic effects is the developing nervous system of a child. We aimed to investigate risk factors of mercury exposure among children in a rural mining town in Chile.Using a validated questionnaire distributed to the parents of the children, a priori mercury risk factors, potential exposure pathways and demographics of the children were obtained. Mercury levels were measured through analyzing fingernail samples. Logistic regression modeling the effect of risk factors on mercury levels above the 75(th percentile were made, adjusted for potential confounders.The 288 children had a mean age of 9.6 years (SD = 1.9. The mean mercury level in the study population was 0.13 µg/g (SD 0.11, median 0.10, range 0.001-0.86 µg/g. The strongest risk factor for children's odds of high mercury levels (>75(th percentile, 0.165 µg/g was to play inside a house where a family member worked with mercury (OR adjusted 3.49 95% CI 1.23-9.89. Additionally, children whose parents worked in industrial gold mining had higher odds of high mercury levels than children whose parents worked in industrial copper mining or outside mining activities.Mercury exposure through small-scale gold mining might affect children in their home environments. These results may further help to convince the local population of banning mercury burning inside the households.

  20. Environmental Mercury and Its Toxic Effects

    Directory of Open Access Journals (Sweden)

    Kevin M. Rice

    2014-03-01

    Full Text Available Mercury exists naturally and as a man-made contaminant. The release of processed mercury can lead to a progressive increase in the amount of atmospheric mercury, which enters the atmospheric-soil-water distribution cycles where it can remain in circulation for years. Mercury poisoning is the result of exposure to mercury or mercury compounds resulting in various toxic effects depend on its chemical form and route of exposure. The major route of human exposure to methylmercury (MeHg is largely through eating contaminated fish, seafood, and wildlife which have been exposed to mercury through ingestion of contaminated lower organisms. MeHg toxicity is associated with nervous system damage in adults and impaired neurological development in infants and children. Ingested mercury may undergo bioaccumulation leading to progressive increases in body burdens. This review addresses the systemic pathophysiology of individual organ systems associated with mercury poisoning. Mercury has profound cellular, cardiovascular, hematological, pulmonary, renal, immunological, neurological, endocrine, reproductive, and embryonic toxicological effects.

  1. Blood mercury concentration, fish consumption and anthropometry in Chinese children: A national study.

    Science.gov (United States)

    Gao, Zhen-Yan; Li, Min-Ming; Wang, Ju; Yan, Jin; Zhou, Can-Can; Yan, Chong-Huai

    2018-01-01

    This study sought to obtain national cross-sectional data for blood mercury levels and risk factors for mercury exposure in Chinese children aged 0 to 6years to provide evidence to support preventive measures for reducing childhood blood mercury levels. A multi-stage, stratified, clustered random sampling survey was conducted May 2013-Mar 2015. Shanghai, Jilin, Shanxi, Guangdong, Qinghai, Yunnan and Hubei, which are located in seven different geographical regions in China, were selected as the study field. A total of 14,202 children aged 0-6years participated in the study. Whole-blood venous samples (3ml) were collected from the subjects for mercury exposure assessment. The DMA-80 was applied for mercury detection, and a health questionnaire gathering information on related confounders was completed by the subjects' parents of the subjects after they received guidance from the investigators. A general linear model was used for the primary descriptive statistical analysis. Odds ratios (ORs) and 95%CIs for the risk factors were estimated using unconditional logistic regression. A total of 14,202 eligible samples were collected. The mean mercury level was 1.39μg/L. Other results were as follows: median 1.23μg/L, p25 0.86μg/L, p75 1.73μg/L, and GM 1.10μg/L. Of the seven geographical regions, Qinghai, in northwestern China, had a median mercury level of 0.37μg/L, which was significantly lower than the mercury level in Guangdong, in southeastern China (2.01μg/L). The median blood mercury level of children in suburban areas was 1.34μg/L, which was remarkably higher than that of children in rural areas (1.09μg/L). Dichotomous subgroups were generated using the median mercury concentration. Unconditional logistic regression analysis revealed that fish consumption may contribute to increased blood mercury levels (pmercury concentrations and the children's anthropometric characteristics (BMI; pmercury concentrations among Chinese children aged 0-6years were

  2. Mercury Exposure and Heart Diseases

    Science.gov (United States)

    Genchi, Giuseppe; Sinicropi, Maria Stefania; Carocci, Alessia; Lauria, Graziantonio; Catalano, Alessia

    2017-01-01

    Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system. PMID:28085104

  3. Mercury Exposure and Heart Diseases.

    Science.gov (United States)

    Genchi, Giuseppe; Sinicropi, Maria Stefania; Carocci, Alessia; Lauria, Graziantonio; Catalano, Alessia

    2017-01-12

    Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system.

  4. Mercury Exposure and Heart Diseases

    Directory of Open Access Journals (Sweden)

    Giuseppe Genchi

    2017-01-01

    Full Text Available Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system.

  5. Mercury Levels in Pregnant Women, Children, and Seafood from Mexico City

    Science.gov (United States)

    Basu, Niladri; Tutino, Rebecca; Zhang, Zhenzhen; Cantonwine, David E.; Goodrich, Jaclyn M.; Somers, Emily C.; Rodriguez, Lauren; Schnaas, Lourdes; Solano, Maritsa; Mercado, Adriana; Peterson, Karen; Sánchez, Brisa N.; Hernández-Avila, Mauricio; Hu, Howard; Téllez-Rojo, Martha Maria

    2014-01-01

    Background Mercury is a global contaminant of concern though little is known about exposures in México. Objectives To characterize mercury levels in pregnant women, children, and commonly consumed seafood samples. Methods Use resources of the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) birth cohorts to measure total mercury levels in archived samples from 348 pregnant women (blood from three trimesters and cord blood), 825 offspring (blood, hair, urine) and their mothers (hair), and 91 seafood and canned tuna samples from Mexico City. Results Maternal blood mercury levels correlated across three trimesters and averaged 3.4μg/L. Cord blood mercury averaged 4.7μg/L and correlated with maternal blood from trimester 3 (but not trimesters 1 and 2). In children, blood, hair and urine mercury levels correlated and averaged 1.8μg/L, 0.6μg/g, and 0.9μg/L, respectively. Hair mercury was 0.5μg/g in mothers and correlated with child's hair. Mean consumption of canned tuna, fresh fish, canned sardine, and shellfish was 3.1, 2.2, 0.5, and 1.0 times per month respectively in pregnant women. Mean mercury content in 7 of 23 seafood species and 5 of 9 canned tuna brands purchased exceeded the U.S. EPA guidance value of 0.3 μg/g. Conclusions Mercury exposures in pregnant women and children from Mexico City, via biomarker studies, are generally 3-5 times greater than values reported in population surveys from the U.S., Canada, and elsewhere. In particular, mercury levels in 29-39% of the maternal participants exceeded the biomonitoring guideline associated with the U.S. EPA reference dose for mercury. PMID:25262076

  6. Hair mercury concentrations of children and mothers in Korea: Implication for exposure and evaluation

    International Nuclear Information System (INIS)

    Kim, S.A.; Jeon, C.K.; Paek, D.M.

    2008-01-01

    Background: Mercury is a global pollutant that affects neurodevelopment of children. Objective: The objectives were to measure and evaluate mercury concentration of children and mothers, and its association with exposure. Methods: A cross-sectional assessment was done using questionnaires and hair mercury were analysed by Cold Vapor Atomic Absorption Spectrometry in the National Institute for Minamata Disease in Japan. Results: A total of 112 children and 111 mothers were included; mean age was 34 months and 32 years, respectively. 17.9 % of children and 34.2 % of mothers had concentrations greater than 1 parts per million (ppm) as reference level. Body weight at birth, feeding methods, maternal age, and maternal education level were significantly different in each group (p < .05). Mean maternal hair mercury level (0.91 ppm) was higher than children (0.74 ppm), and has a positive correlation between them (p < .05). 68.1% of children, 75% of pregnant period, 63.4% of lactating period, and 78.6% of last six months have been consuming fish. With multiple regression analysis, hair mercury levels in children aged less than 6 months had a linear relationship with body weight at birth, gestational weeks, feeding methods (breast- or bottle- feeding) and maternal educational level. While children aged over 6 months significantly differed with gender, frequency of fish servings per week, and frequency of maternal fish consumption in lactation period. And hair mercury levels had inverse linear relationship with maternal monthly income in this age group. Maternal mercury levels had linear relationship with maternal age. Conclusion: Mercury levels in children may be affected by their mothers due to similar dietary patterns. Further long-term large-scale and follow-up studies are needed

  7. Hair mercury concentrations of children and mothers in Korea: Implication for exposure and evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S.A. [Department of Environmental Health, School of Public Health, Seoul National University, Seoul (Korea, Republic of)], E-mail: heaven1@snu.ac.kr; Jeon, C.K.; Paek, D.M. [Department of Environmental Health, School of Public Health, Seoul National University, Seoul (Korea, Republic of)

    2008-08-25

    Background: Mercury is a global pollutant that affects neurodevelopment of children. Objective: The objectives were to measure and evaluate mercury concentration of children and mothers, and its association with exposure. Methods: A cross-sectional assessment was done using questionnaires and hair mercury were analysed by Cold Vapor Atomic Absorption Spectrometry in the National Institute for Minamata Disease in Japan. Results: A total of 112 children and 111 mothers were included; mean age was 34 months and 32 years, respectively. 17.9 % of children and 34.2 % of mothers had concentrations greater than 1 parts per million (ppm) as reference level. Body weight at birth, feeding methods, maternal age, and maternal education level were significantly different in each group (p < .05). Mean maternal hair mercury level (0.91 ppm) was higher than children (0.74 ppm), and has a positive correlation between them (p < .05). 68.1% of children, 75% of pregnant period, 63.4% of lactating period, and 78.6% of last six months have been consuming fish. With multiple regression analysis, hair mercury levels in children aged less than 6 months had a linear relationship with body weight at birth, gestational weeks, feeding methods (breast- or bottle- feeding) and maternal educational level. While children aged over 6 months significantly differed with gender, frequency of fish servings per week, and frequency of maternal fish consumption in lactation period. And hair mercury levels had inverse linear relationship with maternal monthly income in this age group. Maternal mercury levels had linear relationship with maternal age. Conclusion: Mercury levels in children may be affected by their mothers due to similar dietary patterns. Further long-term large-scale and follow-up studies are needed.

  8. Efficacy of succimer chelation of mercury at background exposures in toddlers: a randomized trial

    Science.gov (United States)

    Cao, Yang; Chen, Aimin; Jones, Robert L.; Radcliffe, Jerilynn; Dietrich, Kim N.; Caldwell, Kathleen L.; Peddada, Shyamal; Rogan, Walter J.

    2011-01-01

    Objective To examine whether succimer, a mercaptan compound known to reduce blood lead concentration in children, reduces blood mercury concentration. Study Design We used samples from a randomized clinical trial of succimer chelation for lead-exposed children. We measured mercury in pre-treatment samples from 767 children. We also measured mercury in blood samples drawn 1 week after treatment began (N=768) and in a 20% random sample of the children who received the maximum 3 courses of treatment (N=67). A bootstrap-based isotonic regression method was used to compare the trend over time in the difference between the adjusted mean mercury concentrations in the succimer group and the placebo group. Results The adjusted mean organic mercury concentration in the succimer group relative to the placebo group fell from 99% at baseline to 82% after three courses of treatment (p for trend = 0.048), but this resulted from the prevention of the age-related increase in the succimer group. Conclusion Succimer chelation for low level organic mercury exposure in children has limited efficacy. PMID:20889164

  9. High Maternal Blood Mercury Level Is Associated with Low Verbal IQ in Children.

    Science.gov (United States)

    Jeong, Kyoung Sook; Park, Hyewon; Ha, Eunhee; Shin, Jiyoung; Hong, Yun Chul; Ha, Mina; Park, Hyesook; Kim, Bung Nyun; Lee, Boeun; Lee, Soo Jeong; Lee, Kyung Yeon; Kim, Ja Hyeong; Kim, Yangho

    2017-07-01

    The objective of the present study was to investigate the relationship of IQ in children with maternal blood mercury concentration during late pregnancy. The present study is a component of the Mothers and Children's Environmental Health (MOCEH) study, a multi-center birth cohort project in Korea that began in 2006. The study cohort consisted of 553 children whose mothers underwent testing for blood mercury during late pregnancy. The children were given the Korean language version of the Wechsler Preschool and Primary Scale of Intelligence, revised edition (WPPSI-R) at 60 months of age. Multivariate linear regression analysis, with adjustment for covariates, was used to assess the relationship between verbal, performance, and total IQ in children and blood mercury concentration of mothers during late pregnancy. The results of multivariate linear regression analysis indicated that a doubling of blood mercury was associated with the decrease in verbal and total IQ by 2.482 (95% confidence interval [CI], 0.749-4.214) and 2.402 (95% CI, 0.526-4.279), respectively, after adjustment. This inverse association remained after further adjustment for blood lead concentration. Fish intake is an effect modifier of child IQ. In conclusion, high maternal blood mercury level is associated with low verbal IQ in children. © 2017 The Korean Academy of Medical Sciences.

  10. Seafood Consumption and Blood Mercury Concentrations in Jamaican Children With and Without Autism Spectrum Disorders

    Science.gov (United States)

    Samms-Vaughan, Maureen; Loveland, Katherine A.; Ardjomand-Hessabi, Manouchehr; Chen, Zhongxue; Bressler, Jan; Shakespeare-Pellington, Sydonnie; Grove, Megan L.; Bloom, Kari; Pearson, Deborah A.; Lalor, Gerald C.; Boerwinkle, Eric

    2014-01-01

    Mercury is a toxic metal shown to have harmful effects on human health. Several studies have reported high blood mercury concentrations as a risk factor for autism spectrum disorders (ASDs), while other studies have reported no such association. The goal of this study was to investigate the association between blood mercury concentrations in children and ASDs. Moreover, we investigated the role of seafood consumption in relation to blood mercury concentrations in Jamaican children. Based on data for 65 sex- and age-matched pairs (2–8 years), we used a General Linear Model to test whether there is an association between blood mercury concentrations and ASDs. After controlling for the child’s frequency of seafood consumption, maternal age, and parental education, we did not find a significant difference (P = 0.61) between blood mercury concentrations and ASDs. However, in both cases and control groups, children who ate certain types of seafood (i.e., salt water fish, sardine, or mackerel fish) had significantly higher (all P mercury concentration which were about 3.5 times that of children living in the US or Canada. Our findings also indicate that Jamaican children with parents who both had education up to high school are at a higher risk of exposure to mercury compared to children with at least one parent who had education beyond high school. Based on our findings, we recommend additional education to Jamaican parents regarding potential hazards of elevated blood mercury concentrations, and its association with seafood consumption and type of seafood. PMID:22488160

  11. Assessment of Mercury Bioaccumulation in Zebra Cichlid (Cichlasoma Nigrofasciatum Exposed to Sublethal Concentrations of Permethrin

    Directory of Open Access Journals (Sweden)

    Mahdi Banaee

    2014-12-01

    Full Text Available Background: Aquatic ecosystems are frequently subjected to contamination by toxic heavy metals and pesticides, yet very little is known about the influence of pesticides on bioaccumulation of heavy metals in aquatic organisms. Mercury is a toxic metal with no known biological benefit to organisms. Bioavailability of mercury in aquatic environments depends on biological and non-biological parameters including other pollutants. Therefore, the objectives of this research were to determine the effects of permethrin on bioaccumulation of mercury in zebra cichlid. Methods: Acute toxicity (LC50 of permethrin and mercury chloride was evaluated by estimating mortality in Probit Model in SPSS (version 19.0 IBM. In sub-lethal toxicity, zebra cichlid (Cichlasoma nigrofasciatum was exposed to various concentrations of permethrin (0.0, 0.40, 0.80, 1.20 and 1.60 µg.L-1 combined with 20 µg.L-1 mercury chloride for 15 days. At the end of the experiment, mercury concentrations were measured using ICP-OES-Perkin elmer (optima 7300-DV. Results: 96 h LC50 values of permethrin and mercury for C. nigrofasciatum were calculated to be 17.55 µg.L-1 and 140.38 µg.L-1, respectively. Our results clearly showed that the bioaccumulation of mercury in the specimens increased with increasing concentrations of permethrin to 1.20 and 1.60 µg.L-1. Conclusion: Increasing the concentration of permethrin had synergistic effects on the bioaccumulation of mercury in fish.

  12. Stress proteins and oxidative damage in a renal derived cell line exposed to inorganic mercury and lead

    International Nuclear Information System (INIS)

    Stacchiotti, Alessandra; Morandini, Fausta; Bettoni, Francesca; Schena, Ilaria; Lavazza, Antonio; Grigolato, Pier Giovanni; Apostoli, Pietro; Rezzani, Rita; Aleo, Maria Francesca

    2009-01-01

    A close link between stress protein up-regulation and oxidative damage may provide a novel therapeutic tool to counteract nephrotoxicity induced by toxic metals in the human population, mainly in children, of industrialized countries. Here we analysed the time course of the expression of several heat shock proteins, glucose-regulated proteins and metallothioneins in a rat proximal tubular cell line (NRK-52E) exposed to subcytotoxic doses of inorganic mercury and lead. Concomitantly, we used morphological and biochemical methods to evaluate metal-induced cytotoxicity and oxidative damage. In particular, as biochemical indicators of oxidative stress we detected reactive oxygen species (ROS) and nitrogen species (RNS), total glutathione (GSH) and glutathione-S-transferase (GST) activity. Our results clearly demonstrated that mercury increases ROS and RNS levels and the expressions of Hsp25 and inducible Hsp72. These findings are corroborated by evident mitochondrial damage, apoptosis or necrosis. By contrast, lead is unable to up-regulate Hsp72 but enhances Grp78 and activates nuclear Hsp25 translocation. Furthermore, lead causes endoplasmic reticulum (ER) stress, vacuolation and nucleolar segregation. Lastly, both metals stimulate the over-expression of MTs, but with a different time course. In conclusion, in NRK-52E cell line the stress response is an early and metal-induced event that correlates well with the direct oxidative damage induced by mercury. Indeed, different chaperones are involved in the specific nephrotoxic mechanism of these environmental pollutants and work together for cell survival.

  13. Mercury Levels in US Children and Women

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2003-04-01

    Full Text Available Data are presented from the 1999-2000 National Health and Nutrition Examination Survey (NHANES on the distribution of blood mercury levels and association with fish consumption in a representative sample of young children and women of reproductive age.

  14. Influence of socio-demographic and diet determinants on the levels of mercury in preschool children from a Mediterranean island

    International Nuclear Information System (INIS)

    Garí, Mercè; Grimalt, Joan O.; Torrent, Maties; Sunyer, Jordi

    2013-01-01

    Mercury levels measured in 302 hair samples of 4 year-old children from Menorca (western Mediterranean Sea) are reported. Their concentrations, arithmetic mean 1.4 μg/g, ranging between 0.040 μg/g and 10 μg/g, were higher than in other children inland populations but lower than in previously studied island cohorts, e.g. Faroe, Madeira and Seychelles. 20% of the samples were above the WHO recommended values. Higher concentrations in females than males were observed. Frequent consumption of fish and other seafood were significantly related to the observed mercury concentrations. Oily fish was the main source of this pollutant but shellfish and squid consumption were also associated with high mercury concentrations. Maternal smoking, occupational status or previous siblings were also found to significantly influence the levels of this pollutant. McCarthy Scales of Children's Abilities used to assess children's motor and cognitive abilities did not show association with mercury concentrations at 4 years of age. Highlights: •20% of children exceed the WHO guideline level of 2 μg/g of mercury in hair. •Higher mercury concentrations in female than male children are observed. •Oily fish is the main source of mercury within frequent-fish consumer children. •Higher parity is associated with lower mercury concentrations in children. •No associations between children's cognitive abilities and mercury levels are found. -- Oily fish and shellfish consumption, parity, maternal smoking and occupational status are the main determinants of mercury in four year-old children from Menorca Island (Mediterranean Sea)

  15. A cluster of pediatric metallic mercury exposure cases treated with meso-2,3-dimercaptosuccinic acid (DMSA)

    Science.gov (United States)

    Forman, J; Moline, J; Cernichiari, E; Sayegh, S; Torres, J C; Landrigan, M M; Hudson, J; Adel, H N; Landrigan, P J

    2000-06-01

    Nine children and their mother were exposed to vapors of metallic mercury. The source of the exposure appears to have been a 6-oz vial of mercury taken from a neighbor's home. The neighbor reportedly operated a business preparing mercury-filled amulets for practitioners of the Afro-Caribbean religion Santeria. At diagnosis, urinary mercury levels in the children ranged from 61 to 1,213 microg/g creatinine, with a geometric mean of 214.3 microg/m creatinine. All of the children were asymptomatic. To prevent development of neurotoxicity, we treated the children with oral meso-2,3-dimercaptosuccinic acid (DMSA). During chelation, the geometric mean urine level rose initially by 268% to 573.2 microg mercury/g creatinine (p<0.0005). At the 6-week follow-up examination after treatment, the geometric mean urine mercury level had fallen to 102.1 microg/g creatinine, which was 17.8% of the geometric mean level observed during treatment (p<0.0005) and 47.6% of the original baseline level (p<0.001). Thus, oral chelation with DMSA produced a significant mercury diuresis in these children. We observed no adverse side effects of treatment. DMSA appears to be an effective and safe chelating agent for treatment of pediatric overexposure to metallic mercury.

  16. Mercury pollution in the Upper Beni River, Amazonian basin : Bolivia

    OpenAIRE

    Maurice Bourgoin, Laurence; Quiroga, I.; Guyot, Jean-Loup; Malm, O.

    1999-01-01

    Mercury contamination caused by the amalgamation of gold in small-scale gold mining is an environmental problem of increasing concern, particularly in tropical regions like the Amazon, where a new boom of such gold mining started in the 1970s. In Brazil, research into these problems has been carried out for many years, but there is no available data for Bolivia. The present paper surveys mercury contamination of a Bolivian river system in the Amazon drainage basin, measured in water, fish, an...

  17. Cadmium and mercury exposure over time in Swedish children

    Energy Technology Data Exchange (ETDEWEB)

    Lundh, T., E-mail: Thomas.Lundh@med.lu.se [Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, SE−22185 Lund (Sweden); Axmon, A., E-mail: Anna.Axmon@med.lu.se [Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, SE−22185 Lund (Sweden); Skerfving, S., E-mail: Staffan.Skerfving@med.lu.se [Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, SE−22185 Lund (Sweden); Broberg, K., E-mail: Karin.Broberg@ki.se [Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, SE−22185 Lund (Sweden); Unit of Metals and Health, Institute of Environmental Medicine, Karolinska Institutet, Nobels väg 13, SE-171 77 Stockholm (Sweden)

    2016-10-15

    Purpose: Knowledge about changes in exposure to toxic metals over time remains very sparse, in particular for children, the most vulnerable group. Here, we assessed whether a reduction in environmental pollution with cadmium (Cd) and mercury (Hg) caused a change in exposure over time. In total, 1257 children (age 4–9) in two towns in Sweden were sampled once in 1986–2013. Blood concentrations of Cd (b-Cd; n=1120) and Hg (b-Hg; n=560) were determined. Results: The median b-Cd was 0.10 (geometric mean 0.10; range 0.010–0.61) μg/L and b-Hg was 0.91 (geometric mean 0.83; range 0.021–8.2) μg/L. Children living close to a smelter had higher b-Cd and b-Hg than those in urban and rural areas. There was no sex difference in b-Cd or b-Hg, and b-Cd and b-Hg showed no significant accumulation by age. b-Cd decreased only slightly (0.7% per year, p<0.001) over the study period. In contrast, b-Hg did show a clear decrease over the study period (3% per year, p<0.001). Conclusions: The exposure to Cd was very low but still might increase the risk of disease later in life. Moreover, b-Cd only showed a minor decrease, indicating that Cd pollution should be further restricted. b-Hg was relatively low and decreasing, probably because of reduced use of dental amalgam and lower Hg intake from fish. The b-Cd and b-Hg levels decreased much less than the levels of lead in the blood as previously found in the same children. - Highlights: • There are few studies of time trends for exposure to toxic metals, except for lead. • 1986–2013 we studied blood levels of cadmium and mercury in 1257 Swedish children. • The median blood concentration of cadmium was 0.10 μg/L, of mercury 0.83 μg/L. • Cadmium perhaps decreased by 0.7% per year, mercury by 3% per year. • Cadmium accumulation may result in toxic levels in elderly women.

  18. Mercury exposure in children: a review

    International Nuclear Information System (INIS)

    Counter, S. Allen; Buchanan, Leo H.

    2004-01-01

    Exposure to toxic mercury (Hg) is a growing health hazard throughout the world today. Recent studies show that mercury exposure may occur in the environment, and increasingly in occupational and domestic settings. Children are particularly vulnerable to Hg intoxication, which may lead to impairment of the developing central nervous system, as well as pulmonary and nephrotic damage. Several sources of toxic Hg exposure in children have been reported in biomedical literature: (1) methylmercury, the most widespread source of Hg exposure, is most commonly the result of consumption of contaminated foods, primarily fish; (2) ethylmercury, which has been the subject of recent scientific inquiry in relation to the controversial pediatric vaccine preservative thimerosal; (3) elemental Hg vapor exposure through accidents and occupational and ritualistic practices; (4) inorganic Hg through the use of topical Hg-based skin creams and in infant teething powders; (5) metallic Hg in dental amalgams, which release Hg vapors, and Hg 2+ in tissues. This review examines recent epidemiological studies of methylmercury exposure in children. Reports of elemental Hg vapor exposure in children through accidents and occupational practices, and the more recent observations of the increasing use of elemental Hg for magico-religious purposes in urban communities are also discussed. Studies of inorganic Hg exposure from the widespread use of topical beauty creams and teething powders, and fetal/neonatal Hg exposure from maternal dental amalgam fillings are reviewed. Considerable attention was given in this review to pediatric methylmercury exposure and neurodevelopment because it is the most thoroughly investigated Hg species. Each source of Hg exposure is reviewed in relation to specific pediatric health effects, particularly subtle neurodevelopmental disorders

  19. Biochemical parameters of pregnant rats and their offspring exposed to different doses of inorganic mercury in drinking water.

    Science.gov (United States)

    Oliveira, Cláudia S; Oliveira, Vitor A; Ineu, Rafael P; Moraes-Silva, Lucélia; Pereira, Maria E

    2012-07-01

    This work investigated the effects of low and high doses of inorganic mercury in drinking water on biochemical parameters of pregnant rats and their offspring. Female Wistar rats were treated during pregnancy with 0, 0.2, 0.5, 10 or 50 μg Hg(2+)/mL as HgCl(2). Rats were euthanized on day 20 of pregnancy. Pregnant rats presented a decrease in total water intake in all doses of mercury tested. At high doses, a decrease in the total food intake and in body weight gain was observed. Pregnant rats exposed to 50 μg Hg(2+)/mL presented an increase in kidney relative weight. Mercury exposure did not change serum urea and creatinine levels in any of the doses tested. Moreover, mercury exposure did not change porphobilinogen synthase activity of kidney, liver and placenta from pregnant rats in any of the doses tested, whereas fetuses of pregnant rats exposed to 50 μg Hg(2+)/mL presented an increase in the hepatic porphobilinogen synthase activity. In general, pregnant rats presented alterations due to HgCl(2) exposure in drinking water. However, only the dose 50 μg Hg(2+)/mL appeared to be enough to cross the blood-placenta barrier, since at this dose the fetuses presented change in the porphobilinogen synthase activity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Hair mercury and urinary cadmium levels in Belgian children and their mothers within the framework of the COPHES/DEMOCOPHES projects

    International Nuclear Information System (INIS)

    Pirard, Catherine; Koppen, Gudrun; De Cremer, Koen; Van Overmeire, Ilse; Govarts, Eva; Dewolf, Marie-Christine; Van De Mieroop, Els; Aerts, Dominique; Biot, Pierre; Casteleyn, Ludwine; Kolossa-Gehring, Marike; Schwedler, Gerda

    2014-01-01

    A harmonized human biomonitoring pilot study was set up within the frame of the European projects DEMOCOPHES and COPHES. In 17 European countries, biomarkers of some environmental pollutants, including urinary cadmium and hair mercury, were measured in children and their mothers in order to obtain European-wide comparison values on these chemicals. The Belgian participant population consisted in 129 school children (6–11 years) and their mothers (≤ 45 years) living in urban or rural areas of Belgium. The geometric mean levels for mercury in hair were 0.383 μg/g and 0.204 μg/g for respectively mothers and children. Cadmium in mother's and children's urine was detected at a geometric mean concentration of respectively 0.21 and 0.04 μg/l. For both biomarkers, levels measured in the mothers and their child were correlated. While the urinary cadmium levels increased with age, no trend was found for hair mercury content, except the fact that mothers hold higher levels than children. The hair mercury content increased significantly with the number of dental amalgam fillings, explaining partially the higher levels in the mothers by their higher presence rate of these amalgams compared to children. Fish or seafood consumption was the other main parameter determining the mercury levels in hair. No relationship was found between smoking status and cadmium or mercury levels, but the studied population included very few smokers. Urinary cadmium levels were higher in both mothers and children living in urban areas, while for mercury this difference was only significant for children. Our small population showed urinary cadmium and hair mercury levels lower than the health based guidelines suggested by the WHO or the JECFA (Joint FAO/WHO Expert Committee on Food Additives). Only 1% had cadmium level slightly higher than the German HBM-I value (1 μg/l for adults), and 9% exceeded the 1 μg mercury/g hair suggested by the US EPA. - Highlights: • Hair mercury and urinary

  1. Hair mercury and urinary cadmium levels in Belgian children and their mothers within the framework of the COPHES/DEMOCOPHES projects

    Energy Technology Data Exchange (ETDEWEB)

    Pirard, Catherine, E-mail: c.pirard@chu.ulg.ac.be [CHU of Liege, Laboratory of Clinical, Forensic and Environmental Toxicology, CHU (B35), 4000 Liege (Belgium); Koppen, Gudrun, E-mail: gudrun.koppen@vito.be [Flemish Institute of Technological Research, Environmental Risk and Health Unit, Boeretang 200, 2400 Mol (Belgium); De Cremer, Koen, E-mail: Koen.DeCremer@wiv-isp.be [Scientific Institute of Public Health, Juliette Wytsmanstraat 14, 1050 Brussels (Belgium); Van Overmeire, Ilse, E-mail: ilse.vanovermeire@wiv-isp.be [Scientific Institute of Public Health, Juliette Wytsmanstraat 14, 1050 Brussels (Belgium); Govarts, Eva, E-mail: eva.govarts@vito.be [Flemish Institute of Technological Research, Environmental Risk and Health Unit, Boeretang 200, 2400 Mol (Belgium); Dewolf, Marie-Christine, E-mail: marie_christine.dewolf@hainaut.be [Provincial Institute Hainaut Vigilance Sanitaire — Hainaut Hygiène Publique en (HVS-HPH), Boulevard Sainctelette, 55, 7000 Mons (Belgium); Van De Mieroop, Els, E-mail: Els.VanDeMieroop@pih.provant.be [Provincial Institute for Hygiene (PIH), Boomgaardstraat 22 bus 1, 2600 Antwerpen (Belgium); Aerts, Dominique, E-mail: dominique.aerts@milieu.belgie.be [Federal Public Service Health, Food Chain Safety and Environment, Place Victor Horta 40/10, 1060 Brussels (Belgium); Biot, Pierre, E-mail: pierre.biot@environnement.belgique.be [Federal Public Service Health, Food Chain Safety and Environment, Place Victor Horta 40/10, 1060 Brussels (Belgium); Casteleyn, Ludwine, E-mail: Ludwine.Casteleyn@med.kuleuven.be [University of Leuven, Center for Human Genetics, Herestraat 49, 3000 Leuven (Belgium); Kolossa-Gehring, Marike, E-mail: marike.kolossa@uba.de [Federal Environment Agency, Corrensplatz 1, 14195 Berlin (Germany); Schwedler, Gerda, E-mail: Gerda.Schwedler@uba.de [Federal Environment Agency, Corrensplatz 1, 14195 Berlin (Germany); and others

    2014-02-01

    A harmonized human biomonitoring pilot study was set up within the frame of the European projects DEMOCOPHES and COPHES. In 17 European countries, biomarkers of some environmental pollutants, including urinary cadmium and hair mercury, were measured in children and their mothers in order to obtain European-wide comparison values on these chemicals. The Belgian participant population consisted in 129 school children (6–11 years) and their mothers (≤ 45 years) living in urban or rural areas of Belgium. The geometric mean levels for mercury in hair were 0.383 μg/g and 0.204 μg/g for respectively mothers and children. Cadmium in mother's and children's urine was detected at a geometric mean concentration of respectively 0.21 and 0.04 μg/l. For both biomarkers, levels measured in the mothers and their child were correlated. While the urinary cadmium levels increased with age, no trend was found for hair mercury content, except the fact that mothers hold higher levels than children. The hair mercury content increased significantly with the number of dental amalgam fillings, explaining partially the higher levels in the mothers by their higher presence rate of these amalgams compared to children. Fish or seafood consumption was the other main parameter determining the mercury levels in hair. No relationship was found between smoking status and cadmium or mercury levels, but the studied population included very few smokers. Urinary cadmium levels were higher in both mothers and children living in urban areas, while for mercury this difference was only significant for children. Our small population showed urinary cadmium and hair mercury levels lower than the health based guidelines suggested by the WHO or the JECFA (Joint FAO/WHO Expert Committee on Food Additives). Only 1% had cadmium level slightly higher than the German HBM-I value (1 μg/l for adults), and 9% exceeded the 1 μg mercury/g hair suggested by the US EPA. - Highlights: • Hair mercury and

  2. Cardiac autonomic activity and blood pressure among Nunavik Inuit adults exposed to environmental mercury: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Poirier Paul

    2008-06-01

    Full Text Available Abstract Background Mercury is a contaminant that reaches high levels in Nunavik (North of Quebec. It is transformed into methylmercury (MeHg and accumulated in marine mammals and predator fish, an important part of the traditional Inuit diet. MeHg has been suggested to affect BP in adults and children while the influence on HRV has only been studied in children. We aimed to assess the impact of MeHg levels on HRV and BP in Inuit adults from Nunavik. Methods In the fall of 2004, the «Qanuippitaa?» Health Survey was conducted in Nunavik (Quebec, Canada and information on HRV was collected among 280 adults aged 40 years and older. Indicators of the time and frequency domains of HRV were derived from a 2-hour Holter recording. BP was measured according to the Canadian Coalition for High Blood Pressure technique. Pulse pressure (PP was the difference between systolic (SBP and diastolic blood pressure (DBP. Blood mercury concentration was used as exposure biomarker. Statistical analysis was conducted through linear regression and multivariable linear regression was used to control for confounders. Results Mercury was negatively correlated with low frequency (LF (r = -0.18; p = 0.02, the standard deviation of RR intervals (SDNN (r = -0.14; p = 0.047 and the coefficient of variation of RR intervals (CVRR (r = -0.18; p = 0.011 while correlations with other HRV parameters did not reach statistical significance. After adjusting for confounders, the association with LF (beta = -0.006; p = 0.93 became non significant. However, the association with SDANN became statistically significant (beta = -0.086; p = 0.026 and CVRR tended to decrease with blood mercury concentrations (beta = -0.057; p = 0.056. Mercury was positively correlated with SBP (r = 0.25; p Conclusion The results of this study suggest a deleterious impact of mercury on BP and HRV in adults. SBP and PP increased with blood mercury concentrations while SDANN decreased with blood mercury

  3. Histochemical demonstration of two mercury pools in trout tissues: mercury in kidney and liver after mercuric chloride exposure

    International Nuclear Information System (INIS)

    Baatrup, E.; Nielsen, M.G.; Danscher, G.

    1986-01-01

    Juvenile rainbow trout (Salmo gairdneri) were exposed to 100 ppb mercury (as HgCl 2 ) in the water for 14 days. Concentrations of mercury in water and fish organs were monitored using radiolabeled mercury. Tissues from kidney and liver were fixed, and sections were developed by autometallography, a method whereby accumulations of mercury sulfides and/or mercury selenides are silver amplified. In the kidney, mercury was found within lysosomes and extracellularly in the basal lamina of proximal tubules. In the liver, mercury was found within lysosomes of the hepatocytes. Additional groups of mercury-exposed trout were subjected to selenium (as Na 2 SeO 3 ), administered intraperitoneally 2 hr before fixation. Following this treatment, additional mercury could be visualized in the kidney circulatory system, including glomeruli, and in the nucleus and endoplasmic reticulum of liver cells. It is suggested that the mercury visualized prior to selenium treatment represents inorganic mercury, while additional mercury visualized after selenium administration represents an organic form

  4. Histochemical demonstration of two mercury pools in trout tissues: mercury in kidney and liver after mercuric chloride exposure

    DEFF Research Database (Denmark)

    Baatrup, E; Nielsen, M G; Danscher, G

    1987-01-01

    Juvenile rainbow trout (Salmo gairdneri) were exposed to 100 ppb mercury (as HgCl2) in the water for 14 days. Concentrations of mercury in water and fish organs were monitored using radiolabeled mercury. Tissues from kidney and liver were fixed, and sections were developed by autometallography......, a method whereby accumulations of mercury sulfides and/or mercury selenides are silver amplified. In the kidney, mercury was found within lysosomes and extracellularly in the basal lamina of proximal tubules. In the liver, mercury was found within lysosomes of the hepatocytes. Additional groups of mercury......-exposed trout were subjected to selenium (as Na2SeO3), administered intraperitoneally 2 hr before fixation. Following this treatment, additional mercury could be visualized in the kidney circulatory system, including glomeruli, and in the nucleus and endoplasmic reticulum of liver cells. It is suggested...

  5. Effect of PUFAs from Pteleopsis suberosa stem bark on androgenic enzymes, cellular ATP and prostatic acid phosphatase in mercury chloride – Exposed rat

    Directory of Open Access Journals (Sweden)

    J.K. Akintunde

    2017-09-01

    Full Text Available Occupational and environmental exposure to mercury causes varieties of adverse reproductive disorders in mammals. The present study was designed to investigate the unsaturated fatty acids of Pteleopsis suberosa stem bark extract (PTSSBE, evaluate its antioxidant properties and examine its biochemical targets on sub-acute mercury-induced testicular dysfunctions. Rats were divided into five groups of 10 animals each. Group I was given distilled water; group II, III, IV and V was orally administered with mercury at a dose of 3.75 mg/kg body weight. Group III, IV and V were co-treated with PTSSBE of 25, 50 and 100 mg/kg body weight respectively, for 10 days. Rats exposed to mercury significantly decreased the activities of catalase (CAT, lactate dehydrogenase (LDH, and the level of reduced glutathione (GSH, while the formation of malondialdehyde (MDA was increased. There was also a marked significant decrease (p < 0.05 in testicular activities of Δ5-3β-hydroxysteroid dehydrogenase and Δ5 17β-hydroxysteroid dehydrogenase. Moreover, the activities of prostatic acid phosphatase, total acid phosphatase and prostatic alkaline phosphatase, were significantly (p < 0.05 elevated in mercury treated rats. These effects were prevented by co-treatment with PTSSBE in mercury-induced testicular toxicity in rats. Aphrosidiac effects of Pteleopsis suberosa, may find clinical application in reproductive abnormalities. Isolation and translation of individual active ingredient would help to find new drugs to cure and/or prevent male infertility among mercury exposed workers.

  6. Distribution of mercury in guinea pig offspring after in utero exposure to mercury vapor during late gestation

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Minoru; Yamamura, Yukio; Sataoh, Hiroshi

    1986-04-01

    Organ distribution of mercury after in utero mercury vapor exposure was investigated in neonatal guinea pigs. Mother guinea pigs in late gestation were exposed to 0.2-0.3 mg/m/sup 3/ mercury vapor 2 h per day until giving birth. Mercury concentrations in neonatal brain, lungs, heart, kidneys, plasma and erythrocytes were much lower than those of maternal organs and tissues. Neonatal liver, however, showed a mercury concentration twice as high as maternal liver. Mercury concentration ratios of erythrocytes to plasma in offspring were quite different from those of mothers, being 0.2-0.4 for offspring, and 1.3-3.0 for mothers. These results suggested that mercury vapor metabolism in fetuses was quite different from that in their mothers. This may be due to the different blood circulation, as mercury vapor transferred through the placental barrier would be rapidly oxidized into ionic mercury in fetal liver and accumulated in the organ. The different mercury vapor metabolism may prevent fetal brain, which is rapidly developing, and thus vulnerable, from being exposed to excessive mercury vapor.

  7. Animal Cruelty by Children Exposed to Domestic Violence

    Science.gov (United States)

    Currie, Cheryl L.

    2006-01-01

    Objective: The first objective of this study was to determine if children exposed to domestic violence were significantly more likely to be cruel to animals than children not exposed to violence. The second was to determine if there were significant age and gender differences between children who were and were not cruel to animals. Method: A…

  8. Mercury in Your Environment

    Science.gov (United States)

    Basic information about mercury, how it gets in the air, how people are exposed to it and health effects associated with exposure; what EPA and other organizations are doing to limit exposures; what citizens should know to minimize exposures and to reduce mercury in the environment; and information about products that contain mercury.

  9. Nutritional Status among the Children of Age Group 5-14 Years in Selected Arsenic Exposed and Non-Exposed Areas of Bangladesh.

    Science.gov (United States)

    Rezaul Karim, Mohammad; Ahmad, Sk Akhtar

    2014-12-01

    To assess and compare the nutritional status of children aged 5-14 years in arsenic exposed and non- exposed areas. It was a cross sectional study conducted on 600 children of age 5-14 years from arsenic exposed and non-exposed areas in Bangladesh. Designed questionnaire and check list were used for collection of data. To estimate BMI necessary anthropometric measurements of the studied children were done. Dietary intakes of the study children were assessed using 24-hours recall method. The difference of socio-economic conditions between the children of exposed area and non-exposed area was not significant. On an average the body mass index was found to be significantly (p < 0.01) lower among the children of arsenic exposed area (49%) in comparison to that of children in non-exposed area (38%). Stunting (p < 0.01), wasting (p < 0.05) and underweight (p < 0.05) were significantly higher in exposed group in comparison to non-exposed group. No significant difference of nutrition intake was found between exposed and non-exposed children as well as thin and normal children. In this study children exposed to arsenic contaminated water were found to be suffered from lower nutritional status.

  10. Mercury Exposure in Ireland: Results of the DEMOCOPHES Human Biomonitoring Study

    Directory of Open Access Journals (Sweden)

    Elizabeth Cullen

    2014-09-01

    Full Text Available Background: Monitoring of human exposure to mercury is important due to its adverse health effects. This study aimed to determine the extent of mercury exposure among mothers and their children in Ireland, and to identify factors associated with elevated levels. It formed part of the Demonstration of a study to Coordinate and Perform Human Biomonitoring on a European Scale (DEMOCOPHES pilot biomonitoring study. Methods: Hair mercury concentrations were determined from a convenience sample of 120 mother/child pairs. Mothers also completed a questionnaire. Rigorous quality assurance within DEMOCOPHES guaranteed the accuracy and international comparability of results. Results: Mercury was detected in 79.2% of the samples from mothers, and 62.5% of children’s samples. Arithmetic mean levels in mothers (0.262 µg/g hair and children (0.149 µg /g hair did not exceed the US EPA guidance value. Levels were significantly higher for those with higher education, and those who consumed more fish. Conclusions: The study demonstrates the benefit of human biomonitoring for assessing and comparing internal exposure levels, both on a population and an individual basis. It enables the potential harmful impact of mercury to be minimised in those highly exposed, and can therefore significantly contribute to population health.

  11. Lead and mercury levels in an environmentally exposed population in the Central Brazil.

    Science.gov (United States)

    Jesus, Leda Diva Freitas de; Moreira, Maria de Fátima Ramos; Azevedo, Sayonara Vieira de; Borges, Renato Marçullo; Gomes, Regina Aderne de Almeida; Bergamini, Fernanda Pereira Baptista; Teixeira, Liliane Reis

    2018-03-01

    The objective was to assess the level of exposure to lead and mercury in a population in the Pantanal region in Mato Grosso State, Brazil. Blood lead (PbB) (n = 119) and urinary mercury (HgU) (n = 109) in local residents were measured by atomic absorption spectrometry. Comparison of means and correlations between variables used analysis of variance (ANOVA) and linear regression, respectively, with 95% confidence intervals. Mean PbB was 2.82 ± 1.53µg dL-1. The comparison of PbB stratified by collection site (p ≤ 0.01), work activity (p ≤ 0.01), and consumption of locally produced cow's milk (p ≤ 0.05) showed statistically significant differences. There were also positive associations between PbB and collection site (p ≤ 0.01), participants' profession (p ≤ 0.05), local milk (p ≤ 0.01), and source of drinking water (p ≤ 0.01). Mean HgU was 1.41 ± 0.98µg L-1. The levels only showed significant differences for participants' profession (p ≤ 0.01), and positive associations emerged between HgU and work activity (p ≤ 0.01) and body mass index (p ≤ 0.01). The samples showed low lead and mercury levels, similar to those found in other environmentally exposed populations. Despite these low concentrations, current knowledge on the toxicity of these metals shows that health effects can already be felt at levels that were previously considered safe, thus characterizing a health hazard.

  12. Hair mercury measurement in Egyptian autistic children | El-baz ...

    African Journals Online (AJOL)

    difficulties, and repetitive and stereotyped patterns of behavior, which comprise the three DSM-IV diagnostic criteria of autism. The aim of this work was to measure the concentration of total mercury trace elements in the hair of some Egyptian autistic children and to correlate these levels with severity of the disease. Methods: ...

  13. Nutritional Status among the Children of Age Group 5-14 Years in Selected Arsenic Exposed and Non-Exposed Areas of Bangladesh.

    Directory of Open Access Journals (Sweden)

    Mohammad Rezaul Karim

    2014-12-01

    Full Text Available To assess and compare the nutritional status of children aged 5-14 years in arsenic exposed and non- exposed areas.It was a cross sectional study conducted on 600 children of age 5-14 years from arsenic exposed and non-exposed areas in Bangladesh. Designed questionnaire and check list were used for collection of data. To estimate BMI necessary anthropometric measurements of the studied children were done. Dietary intakes of the study children were assessed using 24-hours recall method.The difference of socio-economic conditions between the children of exposed area and non-exposed area was not significant. On an average the body mass index was found to be significantly (p < 0.01 lower among the children of arsenic exposed area (49% in comparison to that of children in non-exposed area (38%. Stunting (p < 0.01, wasting (p < 0.05 and underweight (p < 0.05 were significantly higher in exposed group in comparison to non-exposed group. No significant difference of nutrition intake was found between exposed and non-exposed children as well as thin and normal children.In this study children exposed to arsenic contaminated water were found to be suffered from lower nutritional status.

  14. Mercury in breast milk - a health hazard for infants in gold mining areas?

    Science.gov (United States)

    Bose-O'Reilly, Stephan; Lettmeier, Beate; Roider, Gabriele; Siebert, Uwe; Drasch, Gustav

    2008-10-01

    Breast-feeding can be a source of mercury exposure for infants. The main concern up to now is methyl-mercury exposure of women at child-bearing age. Certain fish species have high levels of methyl-mercury leading to consumer's advisory guidelines in regard of fish consumption to protect infants from mercury exposure passing through breast milk. Little is known about the transfer of inorganic mercury passing through breast milk to infants. Epidemiological studies showed negative health effects of inorganic mercury in gold mining areas. Small-scale gold miners use mercury to extract the gold from the ore. Environmental and health assessments of gold mining areas in Indonesia, Tanzania and Zimbabwe showed a high exposure with inorganic mercury in these gold mining areas, and a negative health impact of the exposure to the miners and the communities. This paper reports about the analysis and the results of 46 breast milk samples collected from mercury-exposed mothers. The median level of 1.87mug/l is fairly high compared to other results from literature. Some breast milk samples showed very high levels of mercury (up to 149mug/l). Fourteen of the 46 breast milk samples exceed 4mug/l which is considered to be a "high" level. US EPA recommends a "Reference Dose" of 0.3mug inorganic mercury/kg body weight/day [United States Environmental Protection Agency, 1997. Volume V: Health Effects of Mercury and Mercury Compounds. Study Report EPA-452/R-97-007: US EPA]. Twenty-two of the 46 children from these gold mining areas had a higher calculated total mercury uptake. The highest calculated daily mercury uptake of 127mug exceeds by far the recommended maximum uptake of inorganic mercury. Further systematic research of mercury in breast milk from small-scale gold mining areas is needed to increase the knowledge about the bio-transfer of mercury from mercury vapour-exposed mothers passing through breast milk to the breast-fed infant.

  15. The influence of obesity on blood mercury levels for U.S. non-pregnant adults and children: NHANES 2007-2010.

    Science.gov (United States)

    Rothenberg, Sarah E; Korrick, Susan A; Fayad, Raja

    2015-04-01

    In animal studies obesity is associated with higher blood and tissue mercury concentrations; however human studies are lacking. Although the mechanism underlying this association is uncertain, obesity may alter the metabolism and distribution of methylmercury. We determined whether obesity influenced blood mercury levels, the majority of which was methylmercury, for U.S. non-pregnant adults (≥20 years) and children (2-19 years) after controlling for methylmercury intake through fish and shellfish consumption, and other confounders. We completed secondary data analysis of the National Health and Nutrition Examination Survey (NHANES) (2007-2010) for participants who consumed fish/shellfish within 24h of blood collection for mercury analysis. Weighted least squares regression models related blood mercury levels (the dependent variable) to methylmercury exposure (μg) from fish consumed in the previous 24h, body mass index (BMI) (for adults), BMI z-scores (for children), and other confounders. In adjusted models, blood mercury levels were inversely correlated with BMI for adults [β, 95% confidence interval (CI)=-0.54 (-0.90, -0.18)]. For children, blood mercury levels were inversely correlated with BMI z-scores but the trend was not significant [β (95% CI)=-0.016 (-0.066, 0.035)]. When obese adults or children were compared with those who were overweight/normal weight, blood mercury averaged 22% lower for obese adults (95% CI: -33%, -8.2%), while blood mercury did not differ significantly for obese children [β (95% CI)=-1.7% (-31%, +39%)]. After adjusting for the main, if not exclusive, exogenous source of methylmercury exposure (through fish/shellfish intake) and other confounders, our results support potential changes in the metabolism, distribution or excretion of methylmercury with increasing BMI (for adults). Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Mercury exposure, nutritional deficiencies and metabolic disruptions may affect learning in children

    Directory of Open Access Journals (Sweden)

    Patrick Lyn

    2009-10-01

    Full Text Available Abstract Among dietary factors, learning and behavior are influenced not only by nutrients, but also by exposure to toxic food contaminants such as mercury that can disrupt metabolic processes and alter neuronal plasticity. Neurons lacking in plasticity are a factor in neurodevelopmental disorders such as autism and mental retardation. Essential nutrients help maintain normal neuronal plasticity. Nutritional deficiencies, including deficiencies in the long chain polyunsaturated fatty acids eicosapentaenoic acid and docosahexaenoic acid, the amino acid methionine, and the trace minerals zinc and selenium, have been shown to influence neuronal function and produce defects in neuronal plasticity, as well as impact behavior in children with attention deficit hyperactivity disorder. Nutritional deficiencies and mercury exposure have been shown to alter neuronal function and increase oxidative stress among children with autism. These dietary factors may be directly related to the development of behavior disorders and learning disabilities. Mercury, either individually or in concert with other factors, may be harmful if ingested in above average amounts or by sensitive individuals. High fructose corn syrup has been shown to contain trace amounts of mercury as a result of some manufacturing processes, and its consumption can also lead to zinc loss. Consumption of certain artificial food color additives has also been shown to lead to zinc deficiency. Dietary zinc is essential for maintaining the metabolic processes required for mercury elimination. Since high fructose corn syrup and artificial food color additives are common ingredients in many foodstuffs, their consumption should be considered in those individuals with nutritional deficits such as zinc deficiency or who are allergic or sensitive to the effects of mercury or unable to effectively metabolize and eliminate it from the body.

  17. Mercury pOIsonIng

    African Journals Online (AJOL)

    A case of mercury poisoning is reported and clinical observations of 6 .... fish ingested and occupational exposure. .... exposed to mercury as a result of inadequate industrial safety standards, and ... WHO Tech Rep Ser 1980; No. 674: 102-115.

  18. Autometallographic tracing of mercury in frog liver

    International Nuclear Information System (INIS)

    Loumbourdis, N.S.; Danscher, G.

    2004-01-01

    The distribution of mercury in the liver of the frog Rana ridibunda with the autometallographic method was investigated. The mercury specific autometallographic (HgS/Se AMG ) technique is a sensitive histochemical approach for tracing mercury in tissues from mercury-exposed organisms. Mercury accumulates in vivo as mercury sulphur/mercury selenium nanocrystals that can be silver-enhanced. Thus, only a fraction of the Hg can be visualized. Six animals were exposed for one day and another group of six animals for 6 days in 1 ppm mercury (as HgCI 2 ) dissolved in fresh water. A third group of six animals, served as controls, were sacrificed the day of arrival at the laboratory. First, mercury appears in the blood plasma and erythrocytes. Next, mercury moves to hepatocytes and in the apical part of the cells, that facing bile canaliculi. In a next step, mercury appears in the endothelial and Kupffer cells. It seems likely that, the mercury of hepatocytes moves through bile canaliculi to the gut, most probably bound to glutathione and/or other similar ligands. Most probably, the endothelial and Kupffer cells comprise the first line of defense against metal toxicity. - Frogs can be good bioindicators of mercury

  19. Applying cost analyses to drive policy that protects children. Mercury as a case study

    Energy Technology Data Exchange (ETDEWEB)

    Leonardo Trasande; Clyde Schechter; Karla A. Haynes; Philip J. Landrigan [Mount Sinai School of Medicine, New York, NY (United States). Department of Community and Preventive Medicine

    2006-09-15

    Exposure in prenatal life to methylmercury (MeHg) has become the topic of intense debate in the United States after the Environmental Protection Agency (EPA) announced a proposal in 2004 to reverse strict controls on emissions of mercury from coal-fired power plants that had been in effect for the preceding 15 years. This proposal failed to incorporate any consideration of the health impacts on children that would result from increased mercury emissions. We assessed the impact on children's health of industrial mercury emissions and found that between 316,588 and 637,233 babies are born with mercury-related losses of cognitive function ranging from 0.2 to 5.13 points. We calculated that decreased economic productivity resulting from diminished intelligence over a lifetime results in an aggregate economic cost in each annual birth cohort of $8.7 billion annually. $1.3 billion of this cost is attributable to mercury emitted from American coal-fired power plants. Downward shifts in intellectual quotient (IQ) are also associated with 1566 excess cases of mental retardation annually. This number accounts for 3.2% of MR cases in the United States. If the lifetime excess cost of a case of MR is $1,248,648 in 2000 dollars, then the cost of these excess cases of MR is $2.0 billion annually. Preliminary data suggest that more stringent mercury policy options would prevent thousands of cases of MR and billions of dollars over the next 25 years.

  20. Epidemiologic confirmation that fruit consumption influences mercury exposure in riparian communities in the Brazilian Amazon

    International Nuclear Information System (INIS)

    Sousa Passos, Carlos Jose; Mergler, Donna; Fillion, Myriam; Lemire, Melanie; Mertens, Frederic; Guimaraes, Jean Remy Davee; Philibert, Aline

    2007-01-01

    Since deforestation has recently been associated with increased mercury load in the Amazon, the problem of mercury exposure is now much more widespread than initially thought. A previous exploratory study suggested that fruit consumption may reduce mercury exposure. The objectives of the study were to determine the effects of fruit consumption on the relation between fish consumption and bioindicators of mercury (Hg) exposure in Amazonian fish-eating communities. A cross-sectional dietary survey based on a 7-day recall of fish and fruit consumption frequency was conducted within 13 riparian communities from the Tapajos River, Brazilian Amazon. Hair samples were collected from 449 persons, and blood samples were collected from a subset of 225, for total and inorganic mercury determination by atomic absorption spectrometry. On average, participants consumed 6.6 fish meals/week and ate 11 fruits/week. The average blood Hg (BHg) was 57.1±36.3 μg/L (median: 55.1 μg/L), and the average hair-Hg (HHg) was 16.8±10.3 μg/g (median: 15.7 μg/g). There was a positive relation between fish consumption and BHg (r=0.48; P 2 =36.0%) and HHg levels (fish: β=1.2, P 2 =21.0%). ANCOVA models showed that for the same number of fish meals, persons consuming fruits more frequently had significantly lower blood and HHg concentrations. For low fruit consumers, each fish meal contributed 9.8 μg/L Hg increase in blood compared to only 3.3 μg/L Hg increase for the high fruit consumers. In conclusion, fruit consumption may provide a protective effect for Hg exposure in Amazonian riparians. Prevention strategies that seek to maintain fish consumption while reducing Hg exposure in fish-eating communities should be pursued

  1. Clinical findings on in utero exposed microcephalic children

    Energy Technology Data Exchange (ETDEWEB)

    Tabuchi, Akira; Hirai, Tsuyoshi; Nakagawa, Shigeru; Shimada, Katsunobu; Fujito, Junro

    1966-12-24

    Since animal experiments have shown that microcephaly is induced by fetal exposure to radiation and microcephaly has been found in children of mothers exposed to x-ray therapy during pregnancy (Murphy et al), the main cause of microcephaly in children exposed in utero to the A-bomb is considered to be ionizing radiation. Wood et al reported the increased incidence of microcephaly and mental retardation in children exposed in utero at proximal distances which they felt could not be attributed to any other known variable. ABCC has recently concluded that the effect of in utero exposure is primarily due to the immediate effect of radiation upon the fetuses although in A-bomb exposure the physical injury to the mother due to the A-bomb cannot be completely ignored. Our survey likewise revealed an increase of microcephaly in children exposed early in pregnancy at less than 15 weeks at closer distances than 1500 m. Thus, we presume that A-bomb radiation increases the incidence of microcephaly. 16 references, 8 tables.

  2. Biological monitoring involving children exposed to mercury from a barometer in a private residence

    NARCIS (Netherlands)

    Scheepers, P.T.J.; Ballegooij-Gevers, M. van; Jans, H.

    2014-01-01

    A small spill of approximately 3mL of mercury from a broken barometer in a residential setting resulted in blood values of 32mug/L in a boy of 9 months and 26mug/L in a girl of 2.5 years in samples collected within 6h after the start of the incident. A nanny who attempted to remove the spill had a

  3. Photodegradation of 17α-ethynylestradiol in aqueous solution exposed to a high-pressure mercury lamp (250 W)

    International Nuclear Information System (INIS)

    Liu, X.L.; Wu, F.; Deng, N.S.

    2003-01-01

    The photodegradation of 17α-ethynylestradiol (EE 2 ) induced by high-pressure mercury lamp (λ≥313, 250 W) in aqueous solution of EE 2 was investigated initially. The affecting factors on the photodegradation were studied and described in details, such as EE 2 initial concentration, Fe 3+ , algae, exposure time, and so on. The concentration of EE 2 in distilled water was mainly determined using fluorescence spectrophotometer. The photodegradation of EE 2 in aqueous solution exposed to high-pressure mercury lamp was evident and could be accelerated by Fe 3+ or algae (e.g. Anabaena cylindrica) in general. With the algae concentration increasing, photodegradation rate increased. In this paper, the mechanism of photocatalytic degradation of EE 2 by Fe 3+ or algae is discussed primarily. - Photodegradation increased with increasing concentrations of algae

  4. Spatial variation of mercury bioaccumulation in bats of Canada linked to atmospheric mercury deposition.

    Science.gov (United States)

    Chételat, John; Hickey, M Brian C; Poulain, Alexandre J; Dastoor, Ashu; Ryjkov, Andrei; McAlpine, Donald; Vanderwolf, Karen; Jung, Thomas S; Hale, Lesley; Cooke, Emma L L; Hobson, Dave; Jonasson, Kristin; Kaupas, Laura; McCarthy, Sara; McClelland, Christine; Morningstar, Derek; Norquay, Kaleigh J O; Novy, Richard; Player, Delanie; Redford, Tony; Simard, Anouk; Stamler, Samantha; Webber, Quinn M R; Yumvihoze, Emmanuel; Zanuttig, Michelle

    2018-06-01

    Wildlife are exposed to neurotoxic mercury at locations distant from anthropogenic emission sources because of long-range atmospheric transport of this metal. In this study, mercury bioaccumulation in insectivorous bat species (Mammalia: Chiroptera) was investigated on a broad geographic scale in Canada. Fur was analyzed (n=1178) for total mercury from 43 locations spanning 20° latitude and 77° longitude. Total mercury and methylmercury concentrations in fur were positively correlated with concentrations in internal tissues (brain, liver, kidney) for a small subset (n=21) of little brown bats (Myotis lucifugus) and big brown bats (Eptesicus fuscus), validating the use of fur to indicate internal mercury exposure. Brain methylmercury concentrations were approximately 10% of total mercury concentrations in fur. Three bat species were mainly collected (little brown bats, big brown bats, and northern long-eared bats [M. septentrionalis]), with little brown bats having lower total mercury concentrations in their fur than the other two species at sites where both species were sampled. On average, juvenile bats had lower total mercury concentrations than adults but no differences were found between males and females of a species. Combining our dataset with previously published data for eastern Canada, median total mercury concentrations in fur of little brown bats ranged from 0.88-12.78μg/g among 11 provinces and territories. Highest concentrations were found in eastern Canada where bats are most endangered from introduced disease. Model estimates of atmospheric mercury deposition indicated that eastern Canada was exposed to greater mercury deposition than central and western sites. Further, mean total mercury concentrations in fur of adult little brown bats were positively correlated with site-specific estimates of atmospheric mercury deposition. This study provides the largest geographic coverage of mercury measurements in bats to date and indicates that atmospheric

  5. Children exposed to war/terrorism.

    Science.gov (United States)

    Shaw, Jon A

    2003-12-01

    This paper reviews the prevalence of psychological morbidities in children who have been exposed to war-related traumas or terrorism as well as the diversity of war-related casualties and their associated psychological responses. The psychological responses to war-related stressors are categorized as (1) little or no reaction, (2) acute emotional and behavioral effects, and (3) long-term effects. Specific categories of war-related casualties discussed include refugee status, traumatic bereavement, effects of parental absence, and child soldiers. Psychological responses associated with terrorism and bioterrorism are presented. Lastly, mediators of the psychological response to war-related stressors are discussed, to include exposure effects, gender effects, parental, family and social factors, and child-specific factors. Children exposed to war-related stressors experience a spectrum of psychological morbidities including posttraumatic stress symptomatology, mood disorders, externalizing and disruptive behaviors, and somatic symptoms determined by exposure dose effect. Specific questions for future research are identified.

  6. Mercury alters initiation and construction of nests by zebra finches, but not incubation or provisioning behaviors.

    Science.gov (United States)

    Chin, Stephanie Y; Hopkins, William A; Cristol, Daniel A

    2017-11-01

    Mercury is an environmental contaminant that impairs avian reproduction, but the behavioral and physiological mechanisms underlying this effect are poorly understood. The objective of this study was to determine whether lifetime dietary exposure to mercury (1.2 µg/g wet weight in food) impacted avian parental behaviors, and how this might influence reproductive success. To distinguish between the direct effects of mercury on parents and offspring, we created four treatment groups of captive-bred zebra finches (Taeniopygia guttata), with control and mercury-exposed adults raising cross-fostered control or mercury-exposed eggs (from maternal transfer). Control parents were 23% more likely to fledge young than parents exposed to mercury, regardless of egg exposure. Mercury-exposed parents were less likely to initiate nests than controls and spent less time constructing them. Nests of mercury-exposed pairs were lighter, possibly due to an impaired ability to bring nest material into the nestbox. However, nest temperature, incubation behavior, and provisioning rate did not differ between parental treatments. Unexposed control eggs tended to have shorter incubation periods and higher hatching success than mercury-exposed eggs, but there was no effect of parental exposure on these parameters. We accidentally discovered that parent finches transfer some of their body burden of mercury to nestlings during feeding through secretion in the crop. These results suggest that, in mercury-exposed songbirds, pre-laying parental behaviors, combined with direct exposure of embryos to mercury, likely contribute to reduced reproductive success and should be considered in future studies. Further research is warranted in field settings, where parents are exposed to greater environmental challenges and subtle behavioral differences might have more serious consequences than were observed in captivity.

  7. Maternal ability to take care of children exposed to HIV

    Directory of Open Access Journals (Sweden)

    Julyana Gomes Freitas

    2013-07-01

    Full Text Available OBJECTIVE: to assess the ability of mothers to take care of children exposed to HIV, using the Assessment Scale of Care Skills for Children Exposed to HIV at Birth and to check the association between the scale dimensions and maternal characteristics. METHOD: this cross-sectional study involved 62 HIV+ mothers whose children of up to one year old had been exposed to the virus at birth. The Assessment Scale of Care Skills for Children Exposed to HIV at Birth consists of 52 items and five dimensions, indicating high, moderate or low care ability. RESULTS: 72.7% of the mothers appropriately offered zidovudine syrup; 86.0% were highly skilled to prepare and administer milk formula; 44.4% were moderately able to prepare and administer complementary feeding; 76.5% revealed high ability to administer prophylactic treatment against pneumonia and 95.3% demonstrated high abilities for clinical monitoring and immunization. Significant associations were found between some maternal variables and the scale dimensions. CONCLUSION: the scale permits the assessment of maternal care delivery to these children and the accomplishment of specific child health interventions.

  8. Nasal biopsies of children exposed to air pollutants.

    Science.gov (United States)

    Calderón-Garcidueñas, L; Rodriguez-Alcaraz, A; Valencia-Salazar, G; Mora-Tascareño, A; García, R; Osnaya, N; Villarreal-Calderón, A; Devlin, R B; Van Dyke, T

    2001-01-01

    Southwest Metropolitan Mexico City (SWMMC) atmosphere is a complex mixture of air pollutants, including ozone, particulate matter, and aldehydes. Children in SWMMC are exposed chronically and sequentially to numerous toxicants, and they exhibit significant nasal damage. The objective of this study was to assess p53 accumulation by immunohistochemistry in nasal biopsies of SWMMC children. We evaluated 111 biopsies from 107 children (83 exposed SWMMC children and 24 control children residents in a pollutant-compliant Caribbean island). Complete clinical histories and physical examinations, including an ear-nose-throat (ENT) exam were done. There was a significant statistical difference in the upper and lower respiratory symptomatology and ENT findings between control and exposed children (p < 0.001). Control children gave no respiratory symptomatology in the 3 months prior to the study; their biopsies exhibited normal ciliated respiratory epithelium and were p53-negative. SWMMC children complained of epistaxis, nasal obstruction. and crusting. Irregular areas of whitish-gray recessed mucosa over the inferior and middle turbinates were seen in 25% of SWMMC children, and their nasal biopsies displayed basal cell hyperplasia, decreased numbers of ciliated and goblet cells, neutrophilic epithelial infiltrates, squamous metaplasia. and mild dysplasia. Four of 21 SWMMC children with grossly abnormal mucosal changes exhibited strong transmural nuclear p53 staining in their nasal biopsies (p 0.005, odds ratio 26). In the context of lifetime exposures to toxic and potentially carcinogenic air pollutants, p53 nasal induction in children could potentially represent. a) a checkpoint response to toxic exposures, setting up a selective condition for p53 mutation, or b) a p53 mutation has already occurred as a result of such selection. Because the biological significance of p53 nuclear accumulation in the nasal biopsies of these children is not clear at this point, we strongly

  9. Biomarkers of kidney integrity in children and adolescents with dental amalgam mercury exposure: Findings from the Casa Pia children's amalgam trial

    International Nuclear Information System (INIS)

    Woods, James S.; Martin, Michael D.; Leroux, Brian G.; DeRouen, Timothy A.; Bernardo, Mario F.; Luis, Henrique S.; Leitao, Jorge G.; Kushleika, John V.; Rue, Tessa C.; Korpak, Anna M.

    2008-01-01

    Mercury is toxic to the kidney, and dental amalgam is a source of mercury exposure. Few studies have evaluated the effects of dental amalgam on kidney function in a longitudinal context in children. Here, we evaluated urinary concentrations of glutathione S-transferases (GSTs) α and π as biomarkers of renal proximal and distal tubular integrity, respectively, and albumin as a biomarker of glomerular integrity in children and adolescents 8-18 years of age over a 7-year course of dental amalgam treatment. Five hundred seven children, 8-12 years of age at baseline, participated in a clinical trial to evaluate the neurobehavioral and renal effects of dental amalgam in children. Subjects were randomized to either dental amalgam or resin composite treatments. Urinary GSTs α and π, albumin, and creatinine concentrations were measured at baseline and annually in all subjects. Results were evaluated using linear regression analysis. GST-α concentrations were similar between treatment groups and in each sex and race (white vs. non-white) group in each follow-up year. GST-π levels tended upward over the course of follow-up by four- to six-fold. This increase was seen in all groups irrespective of the treatment, race, or gender. Females had GST-π levels approximately twice those of males at all ages. Albumin concentrations were constant throughout the follow-up period and did not differ by treatment, although females had 39% higher albumin levels than males. Additionally, we found no significant effects of amalgam treatment on the proportion of children with microalbuminuria (>30 mg/g creatinine). These findings are relevant within the context of children's health risk assessment as relates to the safety of mercury exposure from dental amalgam on kidney function. These data also provide normative values for sensitive indices of renal functional integrity that may serve in the evaluation of children and adolescents with renal disorders

  10. Assessment of Hair Aluminum, Lead, and Mercury in a Sample of Autistic Egyptian Children: Environmental Risk Factors of Heavy Metals in Autism.

    Science.gov (United States)

    Mohamed, Farida El Baz; Zaky, Eman Ahmed; El-Sayed, Adel Bassuoni; Elhossieny, Reham Mohammed; Zahra, Sally Soliman; Salah Eldin, Waleed; Youssef, Walaa Yousef; Khaled, Rania Abdelmgeed; Youssef, Azza Mohamed

    2015-01-01

    The etiological factors involved in the etiology of autism remain elusive and controversial, but both genetic and environmental factors have been implicated. The aim of this study was to assess the levels and possible environmental risk factors and sources of exposure to mercury, lead, and aluminum in children with autism spectrum disorder (ASD) as compared to their matched controls. One hundred ASD children were studied in comparison to 100 controls. All participants were subjected to clinical evaluation and measurement of mercury, lead, and aluminum through hair analysis which reflects past exposure. The mean Levels of mercury, lead, and aluminum in hair of the autistic patients were significantly higher than controls. Mercury, lead, and aluminum levels were positively correlated with maternal fish consumptions, living nearby gasoline stations, and the usage of aluminum pans, respectively. Levels of mercury, lead, and aluminum in the hair of autistic children are higher than controls. Environmental exposure to these toxic heavy metals, at key times in development, may play a causal role in autism.

  11. Mercury Spill Responses - Five States, 2012-2015.

    Science.gov (United States)

    Wozniak, Ryan J; Hirsch, Anne E; Bush, Christina R; Schmitz, Stuart; Wenzel, Jeff

    2017-03-17

    Despite measures to educate the public about the dangers of elemental mercury, spills continue to occur in homes, schools, health care facilities, and other settings, endangering the public's health and requiring costly cleanup. Mercury is most efficiently absorbed by the lungs, and exposure to high levels of mercury vapor after a release can cause cough, sore throat, shortness of breath, nausea, vomiting, diarrhea, headaches, and visual disturbances (1). Children and fetuses are most susceptible to the adverse effects of mercury vapor exposure. Because their organ systems are still developing, children have increased respiratory rates, and they are closer to the ground where mercury vapors are most highly concentrated (2). To summarize key features of recent mercury spills and lessons learned, five state health departments involved in the cleanup (Iowa, Michigan, Missouri, North Carolina, and Wisconsin) compiled data from various sources on nonthermometer mercury spills from 2012 to 2015. The most common sites of contamination were residences, schools and school buses, health care facilities, and commercial and industrial facilities. Children aged mercury exposure. To protect the public's health after a mercury spill, it is important that local, state, and federal agencies communicate and coordinate effectively to ensure a quick response, and to minimize the spread of contamination. To reduce the number of mercury spills that occur in the United States, public health officials should increase awareness about exchange programs for mercury-containing items and educate school and health care workers about sources of mercury and how to dispose of them properly.

  12. Mercury uptake in vivo by normal and acatalasemic mice exposed to metallic mercury vapor (203Hg degrees) and injected with metallic mercury or mercuric chloride (203HgCl2)

    International Nuclear Information System (INIS)

    Ogata, M.; Kenmotsu, K.; Hirota, N.; Meguro, T.; Aikoh, H.

    1985-01-01

    Levels of mercury in the brain and liver of acatalasemic mice immediately following exposure to metallic mercury vapor or injection of metallic mercury were higher than those found in normal mice. Acatalasemic mice had decreased levels of mercury in the blood and kidneys when the levels were compared with those of normal mice, which indicated that catalase plays a role in oxidizing and taking up mercury. Thus, the brain/blood or liver/blood ratio of mercury concentration in acatalasemic mice was significantly higher than that of normal mice. These results suggest that metallic mercury in the blood easily passed through the blood-brain or blood-liver barrier. The levels of mercury distribution to the kidneys of normal and acatalasemic mice, 1 hr after injection of mercuric chloride solution, were higher than that of normal and acatalasemic mice, respectively, 1 hr after injection of metallic mercury

  13. Genomic damage in children accidentally exposed to ionizing radiation

    DEFF Research Database (Denmark)

    Fucic, A; Brunborg, G; Lasan, R

    2007-01-01

    During the last decade, our knowledge of the mechanisms by which children respond to exposures to physical and chemical agents present in the environment, has significantly increased. Results of recent projects and programmes focused on children's health underline a specific vulnerability of chil...... and efficient preventive measures, by means of a better knowledge of the early and delayed health effects in children resulting from radiation exposure....... of children to environmental genotoxicants. Environmental research on children predominantly investigates the health effects of air pollution while effects from radiation exposure deserve more attention. The main sources of knowledge on genome damage of children exposed to radiation are studies performed...... after the Chernobyl nuclear plant accident in 1986. The present review presents and discusses data collected from papers analyzing genome damage in children environmentally exposed to ionizing radiation. Overall, the evidence from the studies conducted following the Chernobyl accident, nuclear tests...

  14. High-field MRI and mercury release from dental amalgam fillings.

    Science.gov (United States)

    Mortazavi, S M J; Neghab, M; Anoosheh, S M H; Bahaeddini, N; Mortazavi, G; Neghab, P; Rajaeifard, A

    2014-04-01

    Mercury is among the most toxic nonradioactive elements which may cause toxicity even at low doses. Some studies showed release of mercury from dental amalgam fillings in individuals who used mobile phone. This study was conducted to assess the effect of high-field MRI on mercury release from dental amalgam filling. We studied two groups of students with identical tooth decays requiring a similar pattern of restorative dentistry. They were exposed to a magnetic flux density of 1.5 T produced by a MRI machine. 16 otherwise healthy students with identical dental decay participated in this study. They underwent similar restorative dentistry procedures and randomly divided into two groups of MRI-exposed and control arms. Urinary concentrations of mercury in the control subjects were measured before (hour 0) and 48 and 72 hrs after amalgam restoration, using cold vapor atomic absorption spectrometry. Urinary concentrations of mercury in exposed individuals were determined before (hour 0), and 24, 48, 72 and 96 hrs after amalgam restoration. Unlike control subjects, they underwent conventional brain MRI (15 min, 99 slices), 24 hrs after amalgam restoration. The mean±SD urinary mercury levels in MRI-exposed individuals increased linearly from a baseline value of 20.70±17.96 to 24.83±22.91 μg/L 72 hrs after MRI. In the control group, the concentration decreased linearly from 20.70±19.77 to 16.14±20.05 μg/L. The difference between urinary mercury in the exposed and control group, 72 hrs after MRI (96 h after restoration),was significant (p=0.046). These findings provide further support for the noxious effect of MRI (exposure to strong magnetic field)and release of mercury from dental amalgam fillings.

  15. High-Field MRI and Mercury Release from Dental Amalgam Fillings

    Directory of Open Access Journals (Sweden)

    SMJ Mortazavi

    2014-04-01

    Full Text Available Mercury is among the most toxic nonradioactive elements which may cause toxicity even at low doses. Some studies showed release of mercury from dental amalgam fillings in individuals who used mobile phone. This study was conducted to assess the effect of high-field MRI on mercury release from dental amalgam filling. We studied two groups of students with identical tooth decays requiring a similar pattern of restorative dentistry. They were exposed to a magnetic flux density of 1.5 T produced by a MRI machine. 16 otherwise healthy students with identical dental decay participated in this study. They underwent similar restorative dentistry procedures and randomly divided into two groups of MRI-exposed and control arms. Urinary concentrations of mercury in the control subjects were measured before (hour 0 and 48 and 72 hrs after amalgam restoration, using cold vapor atomic absorption spectrometry. Urinary concentrations of mercury in exposed individuals were determined before (hour 0, and 24, 48, 72 and 96 hrs after amalgam restoration. Unlike control subjects, they underwent conventional brain MRI (15 min, 99 slices, 24 hrs after amalgam restoration. The mean±SD urinary mercury levels in MRI-exposed individuals increased linearly from a baseline value of 20.70±17.96 to 24.83±22.91 μg/L 72 hrs after MRI. In the control group, the concentration decreased linearly from 20.70±19.77 to 16.14±20.05 μg/L. The difference between urinary mercury in the exposed and control group, 72 hrs after MRI (96 h after restoration,was significant (p=0.046. These findings provide further support for the noxious effect of MRI (exposure to strong magnetic fieldand release of mercury from dental amalgam fillings.

  16. The Effect of Mercury Vapor and the Role of Green Tea Extract on Brain Cells

    Directory of Open Access Journals (Sweden)

    Dhona Afriza

    2013-09-01

    Full Text Available Mercury is a wellknown toxic metal that is capable to induce free radical-induced oxidative stress. It can cause human disease including brain disorders. Objective: To identify the effect of mercury vapor inhalation on brain cells and the role of green tea extract (Camellia sinensis as antioxidant on the brain cells exposed to mercury. Methods: Fourty-eight male Mus musculus were divided into 8 groups, which were given treatment for 3 and 6 weeks. Group A did not receive any treatment and served as a negative control. Group B was a positive control exposed to Mercury. Group C was exposed to Mercury and treated with 26μg/g green tea extract. Group D was exposed to mercury and treated with 52μg/g green tea extract. All animals in the Group B, C, D were exposed to mercury through inhalation for 4 hours daily. The effect of mercury on the brain cells were examined histopathologically. Results: The numbers of necrotic cells counted in the green tea-treated mice group were significantly lower than those untreated group (p<0,05. Conclusion: Mercury vapor inhalation may cause necrosis on brain cells. Administration of green tea extract as an antioxidant reduced the amount of mercury-induced necrotic brain cells in mice.DOI: 10.14693/jdi.v20i2.151

  17. Cardiac autonomic activity and blood pressure among Nunavik Inuit adults exposed to environmental mercury: a cross-sectional study

    OpenAIRE

    Poirier Paul; Dewailly Eric; Valera Beatriz

    2008-01-01

    Abstract Background Mercury is a contaminant that reaches high levels in Nunavik (North of Quebec). It is transformed into methylmercury (MeHg) and accumulated in marine mammals and predator fish, an important part of the traditional Inuit diet. MeHg has been suggested to affect BP in adults and children while the influence on HRV has only been studied in children. We aimed to assess the impact of MeHg levels on HRV and BP in Inuit adults from Nunavik. Methods In the fall of 2004, the «Qanuip...

  18. Dental health of young children prenatally exposed to buprenorphine. A concern of child neglect?

    Science.gov (United States)

    Kivistö, K; Alapulli, H; Tupola, S; Alaluusua, S; Kivitie-Kallio, S

    2014-06-01

    To study the oral health and dental neglect of prenatally buprenorphine-exposed 3-year-old children. The study consisted of 51 children who as newborns tested positive for buprenorphine in a urine screen. The control group comprised 68 children previously unexposed to narcotics. The dentist examined the children and interviewed their guardians. Buprenorphine-exposed children exhibited significantly more early childhood caries than did the control group. Caries indices, the number of decayed, missing and filled teeth or tooth surfaces and decayed teeth were greater in the buprenorphine-exposed children than the control children (p = 0.004, p = 0.004, p = 0.001, respectively). In the buprenorphine group, more children showed visible plaque (p = 0.003) and fewer children were caries-free (p = 0.009) than in the control group. The control children's teeth were also brushed more often than the buprenorphine-exposed children's teeth (p = 0.001) and the parents were more involved in their children's tooth brushing than were those in the buprenorphine-exposed group (p = 0.035). More caries and dental neglect were found in buprenorphine-exposed children than in controls. These findings highlight the importance of routine dental appointments, caries screening and preventive care for children in substance-abusing families.

  19. Mercury accumulation plant Cyrtomium macrophyllum and its potential for phytoremediation of mercury polluted sites.

    Science.gov (United States)

    Xun, Yu; Feng, Liu; Li, Youdan; Dong, Haochen

    2017-12-01

    Cyrtomium macrophyllum naturally grown in 225.73 mg kg -1 of soil mercury in mining area was found to be a potential mercury accumulator plant with the translocation factor of 2.62 and the high mercury concentration of 36.44 mg kg -1 accumulated in its aerial parts. Pot experiments indicated that Cyrtomium macrophyllum could even grow in 500 mg kg -1 of soil mercury with observed inhibition on growth but no obvious toxic effects, and showed excellent mercury accumulation and translocation abilities with both translocation and bioconcentration factors greater than 1 when exposed to 200 mg kg -1 and lower soil mercury, indicating that it could be considered as a great mercury accumulating species. Furthermore, the leaf tissue of Cyrtomium macrophyllum showed high resistance to mercury stress because of both the increased superoxide dismutase activity and the accumulation of glutathione and proline induced by mercury stress, which favorited mercury translocation from the roots to the aerial parts, revealing the possible reason for Cyrtomium macrophyllum to tolerate high concentration of soil mercury. In sum, due to its excellent mercury accumulation and translocation abilities as well as its high resistance to mercury stress, the use of Cyrtomium macrophyllum should be a promising approach to remediating mercury polluted soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Psychopharmacologic treatment of children prenatally exposed to drugs of abuse.

    Science.gov (United States)

    Hulvershorn, Leslie A; Schroeder, Kristen M; Wink, Logan K; Erickson, Craig A; McDougle, Christopher J

    2015-05-01

    This pilot study compared the pharmacologic treatment history and clinical outcomes observed in pediatric outpatients with psychiatric disorders exposed to drugs of abuse in utero to those of an age-matched, sex-matched and psychiatric disorder-matched, non-drug-exposed group. In this matched cohort study, medical records of children treated at an academic, child and adolescent psychiatry outpatient clinic were reviewed. Children with caregiver-reported history of prenatal drug exposure were compared with a non-drug-exposed control group being cared for by the same providers. Patients were rated with the Clinical Global Impressions-Severity scale (CGI-S) throughout treatment. The changes in pre-treatment and post-treatment CGI-S scores and the total number of medication trials were determined between groups. The drug-exposed group (n = 30) had a higher total number of lifetime medication trials compared with the non-drug-exposed group (n = 28) and were taking significantly more total medications, at their final assessment. Unlike the non-drug-exposed group, the drug-exposed group demonstrated a lack of clinical improvement. These results suggest that in utero drug-exposed children may be more treatment-refractory to or experience greater side effects from the pharmacologic treatment of psychiatric disorders than controls, although we cannot determine if early environment or drugs exposure drives these findings. Copyright © 2015 John Wiley & Sons, Ltd.

  1. Chronic psychological effects of exposure to mercury vapour among chlorine-alkali plant workers.

    Science.gov (United States)

    Pranjić, N; Sinanović, O; Jakubović, R

    2003-01-01

    Quantitative assessment of nervous system function is essential in characterising the nature and extent of impairment in individuals experiencing symptoms following work-place mercury vapour exposure. The purpose of this study was the application of standardised tests of behavioural, psychomotor and memory function to understand the neuropsychological effects of mercury in occupationally exposed chlorine-alkali plant workers. The study comprised 45 workers at a chlorine-alkali plant with the mean age of 39.36 +/- 5.94 years, who had been exposed to daily inhalation of mercury vapour over long-term employment of 16.06 +/- 4.29 years. The cumulative mercury index was 155.32 +/- 95.02 micrograms/g creatinine, the mean of urinary mercury concentrations on the first day of the study was 119.50 +/- 157.24 micrograms/g creatinine, and the mean of urinary mercury concentrations 120 days after cessation of exposure was 21.70 +/- 26.07 micrograms/g creatinine. The analysis included tests of behavioural, psychomotor and memory function. The behavioural test battery consisted of: Environmental Worry Scale (EWS), Minnesota Modified Personal Inventory (MMPI-2), Purdue standard 25 minute test, and adapted, 10 minutes test, Bender's Visual-Motor Gestalt test (BGT), and Eysenck Personality Inventory (EPQ). The data were compared to a control group of 32 not directly exposed workers. In the mercury vapour exposed workers with relatively high level exposure to inorganic mercury vapour (TWA/TLV = 0.12 mg/m3/0.025 mg/m3) we identified somatic depression-hypochondria symptoms with higher scores for scales: hysteria (P introvert behaviour (EPQ, MMPI-2). The cognitive disturbances in mercury-exposed workers were identified as: concentration difficulty, psychomotor, perceptual and motor coordination disturbances, and brain effects. We identified fine tremor of the hands in 34 out of 45 mercury-exposed workers (BGT). The results point to a relationship between the duration of mercury

  2. Mercury

    Science.gov (United States)

    ... that mercuric chloride and methylmercury are possible human carcinogens. top How does mercury affect children? Very young ... billion parts of drinking water (2 ppb). The Food and Drug Administration (FDA) has set a maximum ...

  3. Radioactive mercury distribution in biological fluids and excretion in human subjects after inhalation of mercury vapor

    International Nuclear Information System (INIS)

    Cherian, M.G.; Hursh, J.B.; Clarkson, T.W.; Allen, J.

    1978-01-01

    The distribution of mercury in red blood cells (RBCs) and plasma, and its excretion in urine and feces are described in five human subjects during the first 7 days following inhalation of radioactive mercury vapor. A major portion (98%) of radioactive mercury in whole blood is initially accumulated in the RBCs and is transferred partly to the plasma compartment until the ratio of mercury in RBCs to plasma is about 2 within 20 h. The cumulative urinary and fecal excretion of mercury for 7 days is about 11.6% of the retained dose, and is closely related to the percent decline in body burden of mercury. There is little correlation between either the urinary excretion and plasma radioactivity of mercury, or the specific activities of urine and plasma mercury, suggesting a mechanism other than a direct glomerular filtration involved in the urinary excretion of recently exposed mercury. These studies suggest that blood mercury levels can be used as an index of recent exposure, while urinary levels may be an index of renal concentration of mercury. However, there is no reliable index for mercury concentration in the brain

  4. Predictors of incident tuberculosis in HIV-exposed children in ...

    African Journals Online (AJOL)

    Objective: To examine the predictors of tuberculosis infection in HIV-exposed children. Design: A longitudinal cohort study nested within a randomised controlled trial. Setting: Antenatal clinics in Dar-es-Salaam, Tanzania. Subjects: Children born to 875 HIV-infected women in Tanzania. Results: A total of 82 children ...

  5. Mercury release from deforested soils triggered by base cation enrichment

    International Nuclear Information System (INIS)

    Farella, N.; Lucotte, M.; Davidson, R.; Daigle, S.

    2006-01-01

    The Brazilian Amazon has experienced considerable colonization in the last few decades. Family agriculture based on slash-and-burn enables millions of people to live in that region. However, the poor nutrient content of most Amazonian soils requires cation-rich ashes from the burning of the vegetation biomass for cultivation to be successful, which leads to forest ecosystem degradation, soil erosion and mercury contamination. While recent studies have suggested that mercury present in soils was transferred towards rivers upon deforestation, little is known about the dynamics between agricultural land-use and mercury leaching. In this context, the present study proposes an explanation that illustrates how agricultural land-use triggers mercury loss from soils. This explanation lies in the competition between base cations and mercury in soils which are characterized by a low adsorption capacity. Since these soils are naturally very poor in base cations, the burning of the forest biomass suddenly brings high quantities of base cations to soils, destabilizing the previous equilibrium amongst cations. Base cation enrichment triggers mobility in soil cations, rapidly dislocating mercury atoms. This conclusion comes from principal component analyses illustrating that agricultural land-use was associated with base cation enrichment and mercury depletion. The overall conclusions highlight a pernicious cycle: while soil nutrient enrichment actually occurs through biomass burning, although on a temporary basis, there is a loss in Hg content, which is leached to rivers, entering the aquatic chain, and posing a potential health threat to local populations. Data presented here reflects three decades of deforestation activities, but little is known about the long-term impact of such a disequilibrium. These findings may have repercussions on our understanding of the complex dynamics of deforestation and agriculture worldwide

  6. Decreased vaccine antibody titers following exposure to multiple metals and metalloids in e-waste-exposed preschool children.

    Science.gov (United States)

    Lin, Xinjiang; Xu, Xijin; Zeng, Xiang; Xu, Long; Zeng, Zhijun; Huo, Xia

    2017-01-01

    We explored acquired immunity resulting from vaccination in 3 to 7-year-old children, chronically exposed to multiple heavy metals and metalloids, in an e-waste recycling area (Guiyu, China). Child blood levels of ten heavy metals and metalloids, including lead (Pb), arsenic (As), mercury (Hg), chromium (Cr), cadmium (Cd), manganese (Mn), nickel (Ni), copper (Cu), zinc (Zn) and selenium (Se), and seven vaccine antibodies (diphtheria, pertussis, tetanus, hepatitis B, Japanese encephalitis, polio, measles) were measured. The exposed group had higher levels of blood Pb, Mn, Cu, Zn and Cr compared to the reference group (P 10 μg/dL) and high blood Cu and Zn (upper median value of each group) to be inversely associated with seven antibody titers. Antibody titers increased with age, BMI, high blood Mn (>15 μg/L), and high blood Cd and Ni (upper median value of each group). Results suggest multiple heavy metal and metalloid exposure, especially to Pb, Zn and Cu, may be a risk factor inhibiting the development of child immunity, resulting in decreased child antibody levels against vaccines. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Technical report: mercury in the environment: implications for pediatricians.

    Science.gov (United States)

    Goldman, L R; Shannon, M W

    2001-07-01

    Mercury is a ubiquitous environmental toxin that causes a wide range of adverse health effects in humans. Three forms of mercury (elemental, inorganic, and organic) exist, and each has its own profile of toxicity. Exposure to mercury typically occurs by inhalation or ingestion. Readily absorbed after its inhalation, mercury can be an indoor air pollutant, for example, after spills of elemental mercury in the home; however, industry emissions with resulting ambient air pollution remain the most important source of inhaled mercury. Because fresh-water and ocean fish may contain large amounts of mercury, children and pregnant women can have significant exposure if they consume excessive amounts of fish. The developing fetus and young children are thought to be disproportionately affected by mercury exposure, because many aspects of development, particularly brain maturation, can be disturbed by the presence of mercury. Minimizing mercury exposure is, therefore, essential to optimal child health. This review provides pediatricians with current information on mercury, including environmental sources, toxicity, and treatment and prevention of mercury exposure.

  8. Impact of exposure to low levels of mercury on the health of dental workers

    Directory of Open Access Journals (Sweden)

    Leda Freitas Jesus

    2016-09-01

    Full Text Available This work evaluated the impact of exposure to mercury on the health of workers comparing dentists and dental assistants exposed to mercury by handling amalgam in a public dental clinic with a reference group which, in private offices, did not make use of the metal in their professional routine. Data collection included mercury levels in urine and air samples determined by cold vapor atomic absorption spectrometry, questionnaires and direct observation. The difference between urine and air samples in both groups was statistically significant while mercury levels in air and urine showed positive associations. Mercury concentration in urine correlated with gender, practice time, and age of workers. Half of those exposed had complaints compatible with mercury contamination. Among the exposed, the most common complaints were cognitive and neurocognitive symptoms. Correlations between symptoms and exposure time and also number of amalgam fillings placed per week were positive. Amalgam handling resulted in environmental and biological contamination by mercury.

  9. Unmet Health Care Needs among Children Exposed to Parental Incarceration.

    Science.gov (United States)

    Turney, Kristin

    2017-05-01

    Objectives The incarceration rate in the United States has increased rapidly since the mid-1970s and, accordingly, a large number of children are exposed to parental incarceration. Research finds that parental incarceration is associated with deleterious physical and mental health outcomes among children, but little is known about these children's health care access. Methods I used data from the 2011-2012 National Survey of Children's Health (N = 95,531), a population-based and nationally representative survey of non-institutionalized children ages 0-17 in the United States, to estimate the association between exposure to parental incarceration and children's unmet health care needs. Results In logistic regression models that adjust for an array of demographic and socioeconomic characteristics, children exposed to parental incarceration, compared to their counterparts, have 1.26 (95% CI 1.02-1.54) times the odds of having any unmet health care need. Analyses that disaggregate by type of unmet health care need (mental, dental, vision, mental health, or other) suggest this association is driven by a greater likelihood of unmet mental health care needs (OR 1.60; 95% CI 1.04-2.46). Conclusions Children exposed to parental incarceration, a vulnerable group especially at risk of physical and mental health problems, face challenges to health care access, especially mental health care access. Given that parental incarceration is concentrated among those children most in need of health care, parental incarceration may exacerbate existing inequalities in unmet health care needs.

  10. Heterogeneous effects of market integration on sub-adult body size and nutritional status among the Shuar of Amazonian Ecuador.

    Science.gov (United States)

    Urlacher, Samuel S; Liebert, Melissa A; Josh Snodgrass, J; Blackwell, Aaron D; Cepon-Robins, Tara J; Gildner, Theresa E; Madimenos, Felicia C; Amir, Dorsa; Bribiescas, Richard G; Sugiyama, Lawrence S

    2016-07-01

    Market integration (MI)-increasing production for and consumption from a market-based economy-is drastically altering traditional ways of life and environmental conditions among indigenous Amazonian peoples. The effects of MI on the biology and health of Amazonian children and adolescents, however, remain unclear. This study examines the impact of MI on sub-adult body size and nutritional status at the population, regional and household levels among the Shuar of Amazonian Ecuador. Anthropometric data were collected between 2005-2014 from 2164 Shuar (aged 2-19 years) living in two geographic regions differing in general degree of MI. High-resolution household economic, lifestyle and dietary data were collected from a sub-sample of 631 participants. Analyses were performed to investigate relationships between body size and year of data collection, region and specific aspects of household MI. Results from temporal and regional analyses suggest that MI has a significant and overall positive impact on Shuar body size and nutritional status. However, household-level results exhibit nuanced and heterogeneous specific effects of MI underlying these overarching relationships. This study provides novel insight into the complex socio-ecological pathways linking MI, physical growth and health among the Shuar and other indigenous Amazonian populations.

  11. Hydroelectric reservoir inundation (Rio Madeira Basin, Amazon) and changes in traditional lifestyle: impact on growth and neurodevelopment of pre-school children.

    Science.gov (United States)

    Marques, Rejane C; Dórea, José G; McManus, Concepta; Leão, Renata S; Brandão, Katiane G; Marques, Rayson C; Vieira, Igor H Ito; Guimarães, Jean-Remy D; Malm, Olaf

    2011-04-01

    To assess the dependence on fish consumption of families and its impact on nutritional status and neurodevelopment of pre-school children. Cross-sectional study that measured children's hair mercury (HHg) as an indicator of family fish consumption, growth (anthropometric Z-scores, WHO standards) and neurological (Gesell developmental scores (GDS)) development. Traditional living conditions among families residing in the area adjacent to the Samuel Dam (Western Amazon) hydroelectric reservoir. Two hundred and forty-nine pre-school children (1-59 months of age) from families transitioning from the traditional Amazonian lifestyle. Family fish consumption was significantly correlated with children's HHg concentration (Spearman's r=0.246, P85), multiple regression analysis showed that fish consumption (as HHg) had no impact on GDS, but that some variables did interact significantly with specific domains (motor and language development). The study showed that the families' shift in fish consumption had no negative impact on the growth of young children and that ensuing methylmercury exposure has not been a noticeable neurodevelopmental hindrance.

  12. Mercury exposure in Ireland

    DEFF Research Database (Denmark)

    Cullen, Elizabeth; Evans, David S; Davidson, Fred

    2014-01-01

    of a study to Coordinate and Perform Human Biomonitoring on a European Scale (DEMOCOPHES) pilot biomonitoring study. METHODS: Hair mercury concentrations were determined from a convenience sample of 120 mother/child pairs. Mothers also completed a questionnaire. Rigorous quality assurance within DEMOCOPHES...... guaranteed the accuracy and international comparability of results. RESULTS: Mercury was detected in 79.2% of the samples from mothers, and 62.5% of children's samples. Arithmetic mean levels in mothers (0.262 µg/g hair) and children (0.149 µg /g hair) did not exceed the US EPA guidance value. Levels were...

  13. Assessment of chronic neuropsychological effects of mercury vapour poisoning in chloral-alkali plant workers.

    Science.gov (United States)

    Pranjić, Nurka; Sinanović, Osman; Karamehić, Jasenko; Jakubović, Rusid

    2002-12-01

    A prospective case study was conducted in the Department of Occupational Medicine, Tuzla. The purpose of this study was to indicate negative effects from occupational exposure to mercury on behavioural and mental health, memory and psychomotor function that was tested in 46 chloral-alkali plant workers (mean age was 38. 8+/- 5. 7 years; mean age of occupational history 16. 5+/- 6. 0 years). Data on toxicological monitoring on atomic absorption spectrometer, and data on mental health were collected, psychiatric and other subjective symptoms, and behavioural, psychomotor and memory function tested. The data were compared to control group, 32 healthy non exposed workers. The study was designed to assess blood and urine mercury levels and length of occupational exposure and investigate its relationships to effects on the mental health. The mean air mercury levels were 0.23 mg/m3, the mean blood mercury concentrations was 3. 6 mg/ dl and the mean urine mercury concentrations were 151.7 +/- 180.4 mg/l. In 25 (53%) workers exposed to mercury vapour was identified Depression-Hypochondrias Syndrome (p trend 2. 9 mg/ dl, or urine mercury levels > 87 mg/l workers exposed to mercury vapour knew that toxic effects in body resulted in loosing some of intellectual abilities, and that people who handle chemicals had an increased health risk (ESW questionnaire). The occupational mercury exposed workers had introvert behaviour (EPQ). Aggressiveness was found in 71.7% workers. The cognitive disturbances: short-term memory loss, difficult to concentrate on tasks which require attention and thinking, were significantly differed compared to those of controls (p trend < 0. 001). In 24 (52%) exposed to mercury workers we have determined ego strength loss and regressive defensive mechanisms (LB). Handwriting disturbances-micrography we have identified in 27 (58.7%) workers.

  14. Heterogeneous effects of market integration on subadult body size and nutritional status among the Shuar of Amazonian Ecuador

    Science.gov (United States)

    Urlacher, Samuel S.; Liebert, Melissa A.; Snodgrass, J. Josh; Blackwell, Aaron D.; Cepon-Robins, Tara J.; Gildner, Theresa E.; Madimenos, Felicia C.; Amir, Dorsa; Bribiescas, Richard G.; Sugiyama, Lawrence S.

    2016-01-01

    Background Market integration (MI) – increasing production for and consumption from a market-based economy – is drastically altering traditional ways of life and environmental conditions among indigenous Amazonian peoples. The effects of MI on the biology and health of Amazonian children and adolescents, however, remain unclear. Aim This study examines the impact of MI on subadult body size and nutritional status at the population, regional, and household levels among the Shuar of Amazonian Ecuador. Subjects and Methods Anthropometric data were collected between 2005 and 2014 from 2,164 Shuar (age 2-19 years) living in two geographic regions differing in general degree of MI. High-resolution household economic, lifestyle, and dietary data were collected from a subsample of 631 participants. Analyses were performed to investigate relationships between body size and year of data collection, region, and specific aspects of household MI. Results Results from temporal and regional analyses suggest that MI has a significant and overall positive impact on Shuar body size and nutritional status. However, household-level results exhibit nuanced and heterogeneous specific effects of MI underlying these overarching relationships. Conclusion This study provides novel insight into the complex socio-ecological pathways linking MI, physical growth, and health among the Shuar and other indigenous Amazonian populations. PMID:27230632

  15. Fat and muscle mass in different groups of pre-pubertal and pubertal rural children. Cross-cultural comparisons between Sahelian (rural Senegal) and Amazonian (Beni River, Bolivia) children.

    Science.gov (United States)

    Benefice, Eric; Luna Monrroy, Selma J; Lopez Rodriguez, Ronald W; Ndiaye, Gnagna

    2011-07-01

    An increase in fat accretion is essential for triggering the puberty spurt. Hence, nutritional constraints may influence puberty timing. To measure changes in fat and muscle mass in children living in natural environments but with different nutritional exposures. Cross-comparisons of children from rural Senegal and lowland (Amazonian) Bolivia were carried out. Anthropometric measurements of stature, weight, four subcutaneous skin-folds (triceps, biceps, subscapular, supra-iliac) and arm circumference were made. Children were divided into two age groups (5-9.9-year-olds or 'pre pubescents' (n = 381) and 10-15-year-olds or 'pubescents' (n = 692)). Senegalese girls menstruated later than Bolivian girls and Senegalese boys also matured later than Bolivian boys. Bolivian children displayed more fat and muscle before puberty and during puberty than the Senegalese. They also had more fat deposited on the trunk. There were substantial differences in living conditions and nutritional patterns between both locations. In Senegal, nutritional stress is likely to appear early during in utero life and to persist throughout the growth period, including puberty. This leads to a deficit in fat accretion before and during puberty that is associated with a considerable delay in puberty occurrence. In Bolivia, such stress is far less severe. Variability in puberty should be analysed taking into account these differences.

  16. Human accumulation of mercury in Greenland

    DEFF Research Database (Denmark)

    Johansen, Poul; Mulvad, Gert; Pedersen, Henning Sloth

    2007-01-01

    In the Arctic, the traditional diet exposes its people to a high intake of mercury especially from marine mammals. To determine whether the mercury is accumulated in humans, we analyzed autopsy samples of liver, kidney and spleen from adult ethnic Greenlanders who died between 1990 and 1994 from...... a wide range of causes, natural and violent. Liver, kidney and spleen samples from between 33 and 71 case subjects were analyzed for total mercury and methylmercury, and liver samples also for selenium. Metal levels in men and women did not differ and were not related to age except in one case, i.......e. for total mercury in liver, where a significant declining concentration with age was observed. The highest total mercury levels were found in kidney followed by liver and spleen. Methylmercury followed the same pattern, but levels were much lower, constituting only 19% of the total mercury concentration...

  17. Human accumulation of mercury in Greenland

    DEFF Research Database (Denmark)

    Johansen, P.; Mulvad, G.; Pedersen, H. S.

    2007-01-01

    a wide range of causes, natural and violent. Liver, kidney and spleen samples from between 33 and 71 case subjects were analyzed for total mercury and methylmercury, and liver samples also for selenium. Metal levels in men and women did not differ and were not related to age except in one case, i......In the Arctic, the traditional diet exposes its people to a high intake of mercury especially from marine mammals. To determine whether the mercury is accumulated in humans, we analyzed autopsy samples of liver, kidney and spleen from adult ethnic Greenlanders who died between 1990 and 1994 from.......e. for total mercury in liver, where a significant declining concentration with age was observed. The highest total mercury levels were found in kidney followed by liver and spleen. Methylmercury followed the same pattern, but levels were much lower, constituting only 19% of the total mercury concentration...

  18. Impact of synbiotic diets including inulin, Bacillus coagulans and Lactobacillus plantarum on intestinal microbiota of rat exposed to cadmium and mercury

    Directory of Open Access Journals (Sweden)

    Dornoush Jafarpour

    2015-09-01

    Full Text Available The aim of this study was to investigate the efficacy of two probiotics and a prebiotic (inulin on intestinal microbiota of rats exposed to cadmium and mercury. Fifty-four male Wistar rats were randomly divided into nine groups. All groups except control group were fed standard rat chow with 5% inulin and treated as follows: i control (standard diet, ii Lactobacillus plantarum- treated group (1×109 CFU/day, iii Bacillus coagulans-treated group (1×109 spores/day, iv cadmium-treated group (200 μg/rat/day, v L. plantarum and cadmium-treated group, vi B. coagulans and cadmium-treated group, vii mercury-treated group (10 μg/rat/day, viii L. plantarum and mercurytreated group, ix B. coagulans and mercurytreated group. Cadmium, mercury and probiotics were daily gavaged to individual rats for 42 days. Treatment effects on intestinal microbiota composition of rats were determined. Data showed that cadmium and mercury accumulation in rat intestine affected the gastrointestinal tract and had a reduction effect on all microbial counts (total aerobic bacteria, total anaerobic bacteria, total Lactic acid bacteria, L. plantarum and B. coagulans counts compared to the control group. It was also observed that application of synbiotics in synbiotic and heavy metals-treated groups had a significant effect and increased the number of fecal bacteria compared to the heavy metals groups. Based on our study, it can be concluded that L. plantarum and B. coagulans along with prebiotic inulin play a role in protection against cadmium and mercury inhibitory effect and have the potential to be a beneficial supplement in rats’ diets.

  19. Micronuclei frequency in children exposed to environmental mutagens: a review

    DEFF Research Database (Denmark)

    Neri, Monica; Fucic, Aleksandra; Knudsen, Lisbeth E

    2003-01-01

    Cytogenetic monitoring has been traditionally used for the surveillance of populations exposed to genotoxic agents. In recent years sensitivity problems emerged in surveys of populations exposed to low levels of mutagens, and therefore alternative approaches have been explored. Biomonitoring....... The limited number of published papers indicates that the conduct of properly designed studies on the effect of environmental pollutants in children may be difficult. This review confirmed the usefulness of MN assay in biomonitoring studies conducted in children, revealing that in many circumstances...

  20. Diagnostic and therapeutic methods for occupational mercury poisoning

    International Nuclear Information System (INIS)

    Liu Zhanqi; Wang Xiuqin; Luo Futang

    2003-01-01

    A method of diagnosing and treating occupational mercury poisoning is reviewed in this paper. The treating measures for the chelating syndrome are also described. Based on his exposure history, urinary mercury, and clinical symptom, the employee who exposed occupationally to mercury can be diagnosed to a certain degree according to the related diagnostic standards. The chelating agent, such as meso-2, 3-dimercapto-succinicacid (DMSA), is used for mercury-lustrating treatment. By reducing the chelating agent dose and supplying necessary trace element, the side effect of chelating treatment is decreased. (authors)

  1. Health and environmental assessment of mercury exposure in a gold mining community in Western Mindanao, Philippines.

    Science.gov (United States)

    Cortes-Maramba, Nelia; Reyes, Jose Paciano; Francisco-Rivera, Ana Trinidad; Akagi, Hirokatsu; Sunio, Rose; Panganiban, Lynn Crisanta

    2006-10-01

    The small-scale gold mining activities using mercury began in the late 1980s in Sibutad, Western Mindanao. It is located very near the Murcielagos Bay with tailing ponds directly discharging into bodies of water. This cross-sectional study aimed to determine the health and environmental effects of gold mining activities on the community. Residents were randomly selected and classified into two groups, namely, the directly exposed and indirectly exposed populations using a set inclusion criteria. Complete medical and laboratory examinations were performed. Environmental and biologic samples were collected for total mercury and methylmercury determinations. The results showed that the directly exposed group had significantly higher mean blood total mercury and methylmercury levels in comparison with the indirectly exposed population. Although there were no significant differences between hair total mercury and methylmercury levels, there was a trend for higher levels of these biomarkers among the directly exposed residents as compared with the unexposed group. The absence of statistically significant differences may be attributable to the small sample size. Ambient air quality monitoring for mercury exceeded the allowable levels. However, levels of mercury in drinking water and sediments were within allowable limits. Frequency of gastrointestinal complaints was significantly associated with elevated hair methylmercury levels (p=0.02). Also, there appears to be a trend towards higher blood total mercury levels and frequency of gastrointestinal complaints (p=0.09). An interesting finding in this study was the increasing incidence of elevated diastolic blood pressure with elevated hair total mercury levels (p=0.07). Mercury storage at home is a risk factor.

  2. Chemical Form Matters: Differential Accumulation of Mercury Following Inorganic and Organic Mercury Exposures in Zebrafish Larvae

    Energy Technology Data Exchange (ETDEWEB)

    Korbas, Malgorzata; MacDonald, Tracy C.; Pickering, Ingrid J.; George, Graham N.; Krone, Patrick H. (Saskatchewan)

    2013-04-08

    Mercury, one of the most toxic elements, exists in various chemical forms each with different toxicities and health implications. Some methylated mercury forms, one of which exists in fish and other seafood products, pose a potential threat, especially during embryonic and early postnatal development. Despite global concerns, little is known about the mechanisms underlying transport and toxicity of different mercury species. To investigate the impact of different mercury chemical forms on vertebrate development, we have successfully combined the zebrafish, a well-established developmental biology model system, with synchrotron-based X-ray fluorescence imaging. Our work revealed substantial differences in tissue-specific accumulation patterns of mercury in zebrafish larvae exposed to four different mercury formulations in water. Methylmercury species not only resulted in overall higher mercury burdens but also targeted different cells and tissues than their inorganic counterparts, thus revealing a significant role of speciation in cellular and molecular targeting and mercury sequestration. For methylmercury species, the highest mercury concentrations were in the eye lens epithelial cells, independent of the formulation ligand (chloride versus L-cysteine). For inorganic mercury species, in absence of L-cysteine, the olfactory epithelium and kidney accumulated the greatest amounts of mercury. However, with L-cysteine present in the treatment solution, mercuric bis-L-cysteineate species dominated the treatment, significantly decreasing uptake. Our results clearly demonstrate that the common differentiation between organic and inorganic mercury is not sufficient to determine the toxicity of various mercury species.

  3. Fate and Transport of Mercury in Environmental Media and Human Exposure

    Science.gov (United States)

    Kim, Moon-Kyung

    2012-01-01

    Mercury is emitted to the atmosphere from various natural and anthropogenic sources, and degrades with difficulty in the environment. Mercury exists as various species, mainly elemental (Hg0) and divalent (Hg2+) mercury depending on its oxidation states in air and water. Mercury emitted to the atmosphere can be deposited into aqueous environments by wet and dry depositions, and some can be re-emitted into the atmosphere. The deposited mercury species, mainly Hg2+, can react with various organic compounds in water and sediment by biotic reactions mediated by sulfur-reducing bacteria, and abiotic reactions mediated by sunlight photolysis, resulting in conversion into organic mercury such as methylmercury (MeHg). MeHg can be bioaccumulated through the food web in the ecosystem, finally exposing humans who consume fish. For a better understanding of how humans are exposed to mercury in the environment, this review paper summarizes the mechanisms of emission, fate and transport, speciation chemistry, bioaccumulation, levels of contamination in environmental media, and finally exposure assessment of humans. PMID:23230463

  4. DMPS (DIMAVAL) as a challenge test to assess the mercury and arsenic body/kidney load in humans and as a treatment of mercury toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Aposhian, H.V.; Maiorino, R.M.; Aposhian, M.M. [Univ. of Arizona, Tucson, AZ (United States); Hurlbut, K.M. [Rocky Mountain Poison Control Center, Denver, CO (United States)] [and others

    1996-12-31

    Mercury is an element which, with its compounds, is hazardous and is found in hazardous wastes. In Order to develop suitable diagnostic and therapeutic agents for mercury exposure, we have sought alternative test systems. We have used the chelating agent 2,3-dimercaptopropane-1-sulfonate (DMPS, DIMAVAL{reg_sign}) for estimating the body burden of mercury in normal humans and in dental personnel in a developing country, and for detoxifying humans with mercurous chloride exposure. Use of the DMPS-mercury challenge test has shown that two-thirds of the mercury excreted in the urine of volunteers with dental amalgams appears to be derived from the mercury vapor released from their amalgams. The DMPS challenge test (300 mg, by mouth, after an 11 hr fast) was useful for monitoring dental personnel for mercury vapor exposure. The DMPS challenge test was given to 11 factory workers who make a skin lotion that contains mercurous chloride, 8 users of the skin lotion, and 9 controls. The increases in urinary Hg resulting from the DMPS challenge were 45, 87, and 38-fold, respectively. The results demonstrate that in humans exposed to mercurous chloride, the DMPS-mercury challenge test is of value for a more realistic estimation of mobilizable Hg. DMPS should be considered for use to determine mercury body burdens and to treat humans exposed to mercury and its compounds via exposure to hazardous wastes. 42 refs., 2 figs., 5 tabs.

  5. Life satisfaction and school performance of children exposed to classic and cyber peer bullying.

    Science.gov (United States)

    Bilić, Vesna; Flander, Gordana Buljan; Rafajac, Branko

    2014-03-01

    This paper analyses the relationship between the exposure of school children to various forms of peer bullying (classic/cyber) and their life satisfaction in the domain of school, family, friends and school performance. The sample included 562 children from rural and urban areas of Croatia who were attending the seventh and the eighth grade of primary school. Results show that children were more often exposed to classic forms of peer bullying, especially verbal, and then physical bullying. On the other hand, cyber bullying most often comprises harassment in forums, blogs, chats or social networks, then on the web, by e-mail and mobile phone. Almost half of the examinees knew the identity of the bully, while a minority believes that bullies are the same ones who also physically abuse them at school. We found that children exposed to all forms of both classic and cyber bullying, unlike their peers who do not have such experience, show less satisfaction with friends, while those exposed to physical and cyber bullying show dissatisfaction with their family, too. However no statistically significant difference was found in their satisfaction with school. Children exposed to physical bullying showed poorer school performance, poorer achievement in Croatian and math, while children exposed to verbal and cyber bullying and children who were not exposed to such forms of bullying showed no differences in their school achievement.

  6. Mercury accumulation in native mammals of the Southeast

    Energy Technology Data Exchange (ETDEWEB)

    Cumbie, P.M.; Jenkins, J.H.

    1974-01-01

    Mercury levels in tissues of mammals collected in Georgia, Florida, and South Carolina were compared using hair mercury concentration as an index of total mercury content. Bobcats (Lynx rufus), raccoons (Procyon lotor), opossum (Didelphis marsupialis) and gray fox (Urocyon cinereoargenteus) from the Lower Coastal Plain of Georgia had higher mercury levels than specimens from the Upper Coastal Plain or Piedmont. The highest individual mercury levels in raccoons and bobcats occurred in specimens from the Georgia Lower Coastal Plain flatwoods. Skeletal muscle and liver of individual raccoons and bobcats taken in the coastal flatwoods exceeded the 0.5 ppm limit for mercury in human foodstuffs. No pattern of mercury accumulation was detected in white-tailed deer (Odocoileus virginianus). Hair analysis revealed elevated mercury levels in mammals from a region exposed to mercury pollution. Mercury levels in wildlife exhibit a pattern similar to that of certain fallout radioisotopes such as /sub 137/Cs. These observations indicate that significant biomagnification of mercury may occur in native mammals in certain southeastern habitats. 28 references, 6 tables.

  7. Mercury accumulation and its distribution to metallothionein in mouse brain after sub-chronic pulse exposure to mercury vapor

    Energy Technology Data Exchange (ETDEWEB)

    Yasutake, A. [Biochemistry Section, National Institute for Minamata Disease, Minamata, Kumamoto 867-0008 (Japan); Sawada, M.; Shimada, A. [Department of Veterinary Pathology, Tottori University, 4-101 Koyamacho, Minami, Tottori 680-0945 (Japan); Satoh, M. [Department of Hygienics, Gifu Pharmaceutical University, 5-6-1 Mitahora-higashi, Gifu 502-8585 (Japan); Tohyama, C. [Environmental Health Sciences Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan)

    2004-09-01

    Previously we found that exposure to mercury vapor effectively induced metallothionein (MT) biosynthesis in rat brain. Although the induction of not only MT-I/II but also MT-III was evident, the induction rate of the latter was much lower than that of the former. The brain of an MT-null mouse lacks MT-I/II, but has MT-III. Here we examined the effects of sub-chronic pulse exposure to mercury vapor on the brain MT in MT-null mice and their wild type controls. MT-null and wild type mice were preliminarily exposed to mercury vapor for 2 weeks at 0.1 mg Hg/m{sup 3} for 1 h/day for 3 days a week, and then exposed for 11 weeks at 4.1 mg Hg/m{sup 3} for 30 min/day for 3 days a week. This exposure caused no toxic signs such as abnormal behavior or loss of body weight gain in the mice of either strain throughout the experimental period. Twenty-four hours after the termination of the exposure, mice were sacrificed and brain samples were subjected to mercury analysis, MT assay, and pathological examination. The MT-null mice showed lower accumulation of mercury in the brain than the wild type mice. Mercury exposure resulted in a 70% increase of brain MT in the wild type mice, which was mostly accounted for by the increase in MT-I/II. On the other hand, the brain MT in the MT-null mice increased by 19%, suggesting less reactivity of the MT-III gene to mercury vapor. Although histochemical examination revealed silver-mercury grains in the cytoplasm of nerve cells and glial cells throughout the brains of both strains, no significant difference was observed between the two strains. (orig.)

  8. Detecting Airborne Mercury by Use of Palladium Chloride

    Science.gov (United States)

    Ryan, Margaret; Shevade, Abhijit; Kisor, Adam; Homer, Margie; Jewell, April; Manatt, Kenneth; Torres, Julia; Soler, Jessica; Taylor, Charles

    2009-01-01

    Palladium chloride films have been found to be useful as alternatives to the gold films heretofore used to detect airborne elemental mercury at concentrations of the order of parts per billion (ppb). Somewhat more specifically, when suitably prepared palladium chloride films are exposed to parts-per-billion or larger concentrations of airborne mercury, their electrical resistances change by amounts large enough to be easily measurable. Because airborne mercury adversely affects health, it is desirable to be able to detect it with high sensitivity, especially in enclosed environments in which there is a risk of leakage of mercury from lamps or other equipment. The detection of mercury by use of gold films involves the formation of gold/mercury amalgam. Gold films offer adequate sensitivity for detection of airborne mercury and could easily be integrated into an electronic-nose system designed to operate in the temperature range of 23 to 28 C. Unfortunately, in order to regenerate a gold-film mercury sensor, one must heat it to a temperature of 200 C for several minutes in clean flowing air. In preparation for an experiment to demonstrate the present sensor concept, palladium chloride was deposited from an aqueous solution onto sets of gold electrodes and sintered in air to form a film. Then while using the gold electrodes to measure the electrical resistance of the films, the films were exposed, at a temperature of 25 C, to humidified air containing mercury at various concentrations from 0 to 35 ppb (see figure). The results of this and other experiments have been interpreted as signifying that sensors of this type can detect mercury in room-temperature air at concentrations of at least 2.5 ppb and can readily be regenerated at temperatures <40 C.

  9. From "Buzzword" to Best Practice: Applying Intersectionality to Children Exposed to Intimate Partner Violence.

    Science.gov (United States)

    Etherington, Nicole; Baker, Linda

    2016-03-07

    Empirical studies on the impact of intimate partner violence (IPV) on children have burgeoned over the last three decades. Notably absent from existing approaches to studying children exposed to IPV, however, is attention to how various positionalities intersect to impact the experiences of children and their families. In fact, while the importance of an intersectional framework for understanding IPV has been discussed for over two decades, little or no attention has been given to issues of children's exposure to IPV. In this article, we examine the current state of the literature on children exposed to IPV through an exploratory meta-analysis, finding limited application of intersectionality and a focus on discrete categories of difference. We then demonstrate why and how an intersectional framework should be applied to children exposed to IPV, with specific strategies for research and policy. We suggest a child-centered approach that recognizes diversity among children exposed to IPV, extending the challenge to traditional "one-size-fits-all" models to include an intersectionality-informed stance. © The Author(s) 2016.

  10. Mercury and neuromotor function among children in a rural town in Chile.

    Science.gov (United States)

    Ohlander, Johan; Huber, Stella Maria; Schomaker, Michael; Heumann, Christian; Schierl, Rudolf; Michalke, Bernhard; Jenni, Oskar G; Caflisch, Jon; Muñoz, Daniel Moraga; von Ehrenstein, Ondine S; Radon, Katja

    2016-01-01

    Mercury (Hg) exposure from artisanal gold mining has adverse effects on the neuromotor function in adults. However, few studies have examined this relationship in children. To investigate the impact of Hg exposure on children's neuromotor function. Cross-sectional data on Hg risk factors and demographics were collected from n = 288 children (response = 68.9%). Based on complete cases (CCs) (n = 130) and multiple imputations (n = 288), associations between fingernail Hg and four different neuromotor function components were calculated using multiple logistic regression adjusted for confounders. Of the children, 11.1, 14.9, 63.9, and 10.4% had pathologic pure motor skills, adaptive fine motor skills, adaptive gross motor skills, and static balance, respectively. No significant association between fingernail Hg and any neuromotor component was found. However, Hg burning in the household was significantly associated with children's pathologic pure motor skills (OR 3.07 95% CI 1.03-9.18). Elemental Hg exposure in the household might have adverse long-term effects on children's pure motor skills.

  11. Anthropogenic mercury deposition to arctic lake sediments

    Energy Technology Data Exchange (ETDEWEB)

    Hermanson, M.H. [Westchester University, Westchester, PA (United States). Dept. of Health

    1998-01-01

    The history of atmospheric mercury inputs to remote arctic regions can be measured in lake sediment cores using lead-210 chronology. In the investigation, total mercury deposition is measured in sediments from Imitavik and Annak Lakes on the Belcher Islands in southeastern Hudson Bay, an area in the southern Canadian Arctic with no history of local industrial or agricultural sources of contamination. Both lakes received background and atmospheric inputs of mercury while Annak also received mercury from raw domestic sewage from the Hamlet of Sanikiluaq, a growing Inuit community of about 550 established in the late 1960s. Results from Imitavik show that anthropogenic mercury inputs, apparently transported through the atmosphere, began to appear in the mid-eighteenth century, and continued to the 1990s. Annak had a similar mercury history until the late 1960s when disposal of domestic sewage led to increased sediment and contaminant accumulation. The high input of mercury to Annak confirms that Sanikiluaq residents are exposed to mercury through native food sources. 39 refs., 7 figs., 3 tabs.

  12. Determination of mercury in dentists through Neutron activation analysis

    International Nuclear Information System (INIS)

    Padilla M, M.A.; Granados C, F.

    1999-01-01

    It was determined the mercury levels in urine through Neutron activation analysis to 25 dentists who have been exposed to mercury by several time periods, because of the routine manipulations of amalgams. The determined concentrations of mercury were less to 10 μ g Hg/l of urine. The results were founded inside the safety limits reported in the literature. The mercury levels in the dentists are associated with a wide variety of factors that contribute to their exposure as: number of years of dental practice, number of amalgams manipulated between others. (Author)

  13. Development Enamel Defects in Children Prenatally Exposed to Anti-Epileptic Drugs

    DEFF Research Database (Denmark)

    Jacobsen, Pernille Endrup; Henriksen, Tine Brink; Haubek, Dorte

    2013-01-01

    Objective Some anti-epileptic drugs (AED) have well-known teratogenic effects. The aim of the present study was to elucidate the effect of prenatal exposure to AED and the risk of enamel defects in the primary and permanent dentition. Methods A total of 38 exposed and 129 non-exposed children, 6......–10 years of age, were recruited from the Aarhus Birth Cohort and the Department of Neurology, Viborg Regional Hospital, Denmark. Medication during pregnancy was confirmed by the Danish Prescription Database. All children had their teeth examined and outcomes in terms of enamel opacities and enamel...... hypoplasia were recorded. Results Children prenatally exposed to AED have an increased prevalence of enamel hypoplasia (11% vs. 4%, odds ratio (OR) = 3.6 [95% confidence interval (CI): 0.9 to 15.4]), diffuse opacities (18% vs. 7%, OR = 3.0; [95% CI: 1.0 to 8.7, p3) white opacities (18...

  14. Environmental and human exposure assessment monitoring of communities near an abandoned mercury mine in the Philippines: a toxic legacy.

    Science.gov (United States)

    Maramba, Nelia P C; Reyes, Jose Paciano; Francisco-Rivera, Ana Trinidad; Panganiban, Lynn Crisanta R; Dioquino, Carissa; Dando, Nerissa; Timbang, Rene; Akagi, Hirokatsu; Castillo, Ma Teresa; Quitoriano, Carmela; Afuang, Maredith; Matsuyama, Akito; Eguchi, Tomomi; Fuchigami, Youko

    2006-10-01

    sites, namely Tagburos and Honda Bay, exceeded the EPA Region 9 Primary Remediation Goal recommended values for total mercury for residential purposes (NV>23 mg/kg). The hand to mouth activity among infants and children is another significant route for mercury exposure. Statistically significant results were obtained for infants when comparing the results after one year of monitoring for methylmercury levels in hair for both exposed and control sub-groups. Likewise, comparing the initial and final hair methylmercury levels among pregnant women/mothers in the exposed group showed statistically significant (p<0.05) results. Comparing the exposed and control sub-groups' mercury hair levels per sub-group showed statistically significant results among the following: (a) initial and final total mercury hair levels among children, (b) initial and final methylmercury hair levels among children, (c) final total mercury hair levels among pregnant women, (d) initial and final total mercury hair levels among mothers, and (e) initial and final methyl hair levels among mothers.

  15. Docosahexaenoic acid counteracts attenuation of CD95-induced cell death by inorganic mercury

    Energy Technology Data Exchange (ETDEWEB)

    Gill, Randall [Department of Immunology and Microbiology, Wayne State University, Detroit MI (United States); Lanni, Lydia; Jen, K.-L. Catherine [Department of Nutrition and Food Science, Wayne State University, Detroit MI (United States); McCabe, Michael J. [Department of Environmental Medicine, University of Rochester, Rochester NY (United States); Rosenspire, Allen, E-mail: arosenspire@wayne.edu [Department of Immunology and Microbiology, Wayne State University, Detroit MI (United States)

    2015-01-01

    In the United States the principal environmental exposure to mercury is through dietary consumption of sea food. Although the mechanism by which low levels of mercury affect the nervous system is not well established, epidemiological studies suggest that low level exposure of pregnant women to dietary mercury can adversely impact cognitive development in their children, but that Docosahexaenoic acid (DHA), the most prominent n-polyunsaturated fatty acid (n-PUFA) present in fish may counteract negative effects of mercury on the nervous system. Aside from effects on the nervous system, epidemiological and animal studies have also suggested that low level mercury exposure may be a risk factor for autoimmune disease. However unlike the nervous system where a mechanism linking mercury to impaired cognitive development remains elusive, we have previously suggested a potential mechanism linking low level mercury exposures to immune system dysfunction and autoimmunity. In the immune system it is well established that disruption of CD95 mediated apoptosis leads to autoimmune disease. We have previously shown in vitro as well as in vivo that in lymphocytes burdened with low levels of mercury, CD95 mediated cell death is impaired. In this report we now show that DHA counteracts the negative effect of mercury on CD95 signaling in T lymphocytes. T cells which have been pre-exposed to DHA are able to cleave pro-caspase 3 and efficiently signal programmed cell death through the CD95 signaling pathway, whether or not they are burdened with low levels of mercury. Thus DHA may lower the risk of autoimmune disease after low level mercury exposures. - Highlights: • Inorganic mercury (Hg{sup 2+}) interferes with CD95 mediated cell death in Jurkat T cells • DHA restores the ability of CD95 to signal cell death in Hg{sup 2+} intoxicated T cells • The restoration of CD95 mediated cell death by DHA is correlated with increased activation of Caspase 3.

  16. Docosahexaenoic acid counteracts attenuation of CD95-induced cell death by inorganic mercury

    International Nuclear Information System (INIS)

    Gill, Randall; Lanni, Lydia; Jen, K.-L. Catherine; McCabe, Michael J.; Rosenspire, Allen

    2015-01-01

    In the United States the principal environmental exposure to mercury is through dietary consumption of sea food. Although the mechanism by which low levels of mercury affect the nervous system is not well established, epidemiological studies suggest that low level exposure of pregnant women to dietary mercury can adversely impact cognitive development in their children, but that Docosahexaenoic acid (DHA), the most prominent n-polyunsaturated fatty acid (n-PUFA) present in fish may counteract negative effects of mercury on the nervous system. Aside from effects on the nervous system, epidemiological and animal studies have also suggested that low level mercury exposure may be a risk factor for autoimmune disease. However unlike the nervous system where a mechanism linking mercury to impaired cognitive development remains elusive, we have previously suggested a potential mechanism linking low level mercury exposures to immune system dysfunction and autoimmunity. In the immune system it is well established that disruption of CD95 mediated apoptosis leads to autoimmune disease. We have previously shown in vitro as well as in vivo that in lymphocytes burdened with low levels of mercury, CD95 mediated cell death is impaired. In this report we now show that DHA counteracts the negative effect of mercury on CD95 signaling in T lymphocytes. T cells which have been pre-exposed to DHA are able to cleave pro-caspase 3 and efficiently signal programmed cell death through the CD95 signaling pathway, whether or not they are burdened with low levels of mercury. Thus DHA may lower the risk of autoimmune disease after low level mercury exposures. - Highlights: • Inorganic mercury (Hg 2+ ) interferes with CD95 mediated cell death in Jurkat T cells • DHA restores the ability of CD95 to signal cell death in Hg 2+ intoxicated T cells • The restoration of CD95 mediated cell death by DHA is correlated with increased activation of Caspase 3

  17. Mercury and autoimmunity: implications for occupational and environmental health

    International Nuclear Information System (INIS)

    Silbergeld, Ellen K.; Silva, Ines A.; Nyland, Jennifer F.

    2005-01-01

    Mercury (Hg) has long been recognized as a neurotoxicant; however, recent work in animal models has implicated Hg as an immunotoxicant. In particular, Hg has been shown to induce autoimmune disease in susceptible animals with effects including overproduction of specific autoantibodies and pathophysiologic signs of lupus-like disease. However, these effects are only observed at high doses of Hg that are above the levels to which humans would be exposed through contaminated fish consumption. While there is presently no evidence to suggest that Hg induces frank autoimmune disease in humans, a recent epidemiological study has demonstrated a link between occupational Hg exposure and lupus. In our studies, we have tested the hypothesis that Hg does not cause autoimmune disease directly, but rather that it may interact with triggering events, such as genetic predisposition, exposure to antigens, or infection, to exacerbate disease. Treatment of mice that are not susceptible to Hg-induced autoimmune disease with very low doses and short term exposures of inorganic Hg (20-200 μg/kg) exacerbates disease and accelerates mortality in the graft versus host disease model of chronic lupus in C57Bl/6 x DBA/2 mice. Furthermore, low dose Hg exposure increases the severity and prevalence of experimental autoimmune myocarditis (induced by immunization with cardiac myosin peptide in adjuvant) in A/J mice. To test our hypothesis further, we examined sera from Amazonian populations exposed to Hg through small-scale gold mining, with and without current or past malaria infection. We found significantly increased prevalence of antinuclear and antinucleolar antibodies and a positive interaction between Hg and malaria. These results suggest a new model for Hg immunotoxicity, as a co-factor in autoimmune disease, increasing the risks and severity of clinical disease in the presence of other triggering events, either genetic or acquired

  18. Mercury reduces avian reproductive success and imposes selection: an experimental study with adult- or lifetime-exposure in zebra finch.

    Directory of Open Access Journals (Sweden)

    Claire W Varian-Ramos

    Full Text Available Mercury is a global pollutant that biomagnifies in food webs, placing wildlife at risk of reduced reproductive fitness and survival. Songbirds are the most diverse branch of the avian evolutionary tree; many are suffering persistent and serious population declines and we know that songbirds are frequently exposed to mercury pollution. Our objective was to determine the effects of environmentally relevant doses of mercury on reproductive success of songbirds exposed throughout their lives or only as adults. The two modes of exposure simulated philopatric species versus dispersive species, and are particularly relevant because of the heightened mercury-sensitivity of developing nervous systems. We performed a dosing study with dietary methylmercury in a model songbird species, the zebra finch (Taeniopygia guttata, at doses from 0.3 - 2.4 parts per million. Birds were exposed to mercury either as adults only or throughout their lives. All doses of mercury reduced reproductive success, with the lowest dose reducing the number of independent offspring produced in one year by 16% and the highest dose, representing approximately half the lethal dose for this species, causing a 50% reduction. While mercury did not affect clutch size or survivorship, it had the most consistent effect on the proportion of chicks that fledged from the nest, regardless of mode of exposure. Among birds exposed as adults, mercury caused a steep increase in the latency to re-nest after loss of a clutch. Birds exposed for their entire lifetimes, which were necessarily the offspring of dosed parents, had up to 50% lower reproductive success than adult-exposed birds at low doses of methylmercury, but increased reproductive success at high doses, suggesting selection for mercury tolerance at the highest level of exposure. Our results indicate that mercury levels in prey items at contaminated sites pose a significant threat to populations of songbirds through reduced reproductive

  19. Mercury Reduces Avian Reproductive Success and Imposes Selection: An Experimental Study with Adult- or Lifetime-Exposure in Zebra Finch

    Science.gov (United States)

    Varian-Ramos, Claire W.; Swaddle, John P.; Cristol, Daniel A.

    2014-01-01

    Mercury is a global pollutant that biomagnifies in food webs, placing wildlife at risk of reduced reproductive fitness and survival. Songbirds are the most diverse branch of the avian evolutionary tree; many are suffering persistent and serious population declines and we know that songbirds are frequently exposed to mercury pollution. Our objective was to determine the effects of environmentally relevant doses of mercury on reproductive success of songbirds exposed throughout their lives or only as adults. The two modes of exposure simulated philopatric species versus dispersive species, and are particularly relevant because of the heightened mercury-sensitivity of developing nervous systems. We performed a dosing study with dietary methylmercury in a model songbird species, the zebra finch (Taeniopygia guttata), at doses from 0.3 – 2.4 parts per million. Birds were exposed to mercury either as adults only or throughout their lives. All doses of mercury reduced reproductive success, with the lowest dose reducing the number of independent offspring produced in one year by 16% and the highest dose, representing approximately half the lethal dose for this species, causing a 50% reduction. While mercury did not affect clutch size or survivorship, it had the most consistent effect on the proportion of chicks that fledged from the nest, regardless of mode of exposure. Among birds exposed as adults, mercury caused a steep increase in the latency to re-nest after loss of a clutch. Birds exposed for their entire lifetimes, which were necessarily the offspring of dosed parents, had up to 50% lower reproductive success than adult-exposed birds at low doses of methylmercury, but increased reproductive success at high doses, suggesting selection for mercury tolerance at the highest level of exposure. Our results indicate that mercury levels in prey items at contaminated sites pose a significant threat to populations of songbirds through reduced reproductive success. PMID

  20. Children exposed to domestic violences assessment and psychopathology /

    OpenAIRE

    Olaya Guzmán, Beatriz

    2010-01-01

    Descripció del recurs: 17-06-2010 Exposure to domestic violence is a current, complex concern with negative aftermath on the child's mental health. Aim: to answer the following questions about the effects that this exposure has on children's mental health: a) what should be assessed; b) what kind of psychopathology do outpatient exposed children have; c) which characteristics of the situation are more influential; and d) what is the role of parenting styles. Method: A retrospective cohort ...

  1. Evolution of Socioeconomic Conditions and Its Relation to Spatial-Temporal Changes of Giardiasis and Helminthiasis in Amazonian Children.

    Science.gov (United States)

    Delfino, B M; Campos, R G; Pereira, T M; Mantovani, S A S; Oliart-Guzmán, H; Martins, A C; Braña, A M; Branco, F L C C; Filgueira-Júnior, J A; Santos, A P; Araújo, T S; Oliveira, C S M; Ramalho, A A; Muniz, P T; Codeço, C T; da Silva-Nunes, M

    2016-12-01

    This study analyzed the evolution of socioeconomic, sanitary, and personal factors as well as spatiotemporal changes in the prevalence of helminthiasis and giardiasis in urban Amazonian children between 2003 and 2011. Child age, lack of sanitation, and lack of access to bottled water were identified as significant associated factors for helminthiasis and giardiasis. There was an overall improvement in socioeconomic and sanitary conditions in the city resulting in decreased helminth prevalences from 12.42 to 9.63% between 2003 and 2010, but the prevalence increased to 15.03% in 2011 due to migratory movement and unstable sanitary conditions. As for Giardiasis, socioeconomic and environmental changes were not enough to reduce prevalence (16% in 2003 and 23% in 2011). Spatial analysis identified a significant cluster for helminthiasis in an area of poor housing conditions. Control programs in the Amazon need to target high-risk areas focusing changes in sanitation, water usage, and health education.

  2. Health and environmental impact of mercury in the Philippines using nuclear techniques

    International Nuclear Information System (INIS)

    Cortes-Maramba, Nelia; Reyes, J.P.; Panganiban, L.C.P.; Francisco-Rivera, Ana Trinidad; Suplido, M.L.; Akagi, Hirokatsu

    2002-01-01

    Mercury pollution in most parts of the regions in the world are caused by release into the environment of metallic mercury used in the recovery of gold by an amalgamation technique with subsequent mercury emission into the atmosphere by blowtorching operations. Significant small-scale gold mining operations in other countries such as Tanzania, Philippines, Indonesia, China and Vietnam have been reported with roughly 10 million people estimated to be involved in these activities Artisanal gold mining activities using mercury has proliferated in various parts of the country since the early 1980's. In Southern Philippines, it is estimated that a small-scale gold processor utilizes one kilogram of mercury every week or an average of fifty-two kgs/1yr. Production is estimated at 30 kilograms of gold per day. It has been estimated that 140 tons of mercury flux has been dumped directly into the river systems from small-scale gold mining operations in one of the gold rush areas in the country. In the 1980's, gold rush activities intensified in Northeastern Mindanao providing livelihood opportunities to about 80,000-120,000 people at the height of mining activities in the area. In gold mining areas it should be noted that transformation in the natural environment of inorganic mercury to methylmercury occurs which can easily bio-accumulate in fish and other organisms through the aquatic food chains. Therefore, there are two main exposure pathways of mercury contamination that can affect the human population in gold mining areas. First, gold miners and workers are exposed to inorganic mercury due to direct inhalation of mercury during gold recovery processes and second, people living along the river systems and depending on riverine products for food sources can be exposed to methylmercury mainly through fish consumption. Presently, environmental and health monitoring conducted by several government agencies in the recent past were limited to the determination of total

  3. Voices of Contact: Politics of Language in Urban Amazonian Ecuador

    Science.gov (United States)

    Wroblewski, Michael

    2010-01-01

    This dissertation is a study of diverse linguistic resources and contentious identity politics among indigenous Amazonian Kichwas in the city of Tena, Ecuador. Tena is a rapidly developing Amazonian provincial capital city with a long history of interethnic and interlinguistic contact. In recent decades, the course of indigenous Kichwa identity…

  4. Uptake of inorganic mercury by human locus ceruleus and corticomotor neurons: implications for amyotrophic lateral sclerosis

    Science.gov (United States)

    2013-01-01

    Background Environmental toxins are suspected to play a role in the pathogenesis of amyotrophic lateral sclerosis (ALS). In an attempt to determine which pathways these toxins can use to enter motor neurons we compared the distribution of mercury in the CNS of a human and of mice that had been exposed to inorganic mercury. Results In the human who had been exposed to metallic mercury, mercury was seen predominantly in the locus ceruleus and corticomotor neurons, as well as in scattered glial cells. In mice that had been exposed to mercury vapor or mercuric chloride, mercury was present in lower motor neurons in the spinal cord and brain stem. Conclusions In humans, inorganic mercury can be taken up predominantly by corticomotor neurons, possibly when the locus ceruleus is upregulated by stress. This toxin uptake into corticomotor neurons is in accord with the hypothesis that ALS originates in these upper motor neurons. In mice, inorganic mercury is taken up predominantly by lower motor neurons. The routes toxins use to enter motor neurons depends on the nature of the toxin, the duration of exposure, and possibly the amount of stress (for upper motor neuron uptake) and exercise (for lower motor neuron uptake) at the time of toxin exposure. PMID:24252585

  5. Correlation between urinary concentrations of malondialdehyde and DNA damage in people exposed to mercury = Correlación entre la concentración urinaria de malondialdehído y daño en el ADN de personas expuestas a mercurio

    Directory of Open Access Journals (Sweden)

    Castaño Arias, Paula Andrea

    2014-03-01

    Full Text Available Objective: To determine whether the extent of DNA damage is correlated with the concentration of malondialdehyde (MDA in urine of individuals occupationally exposed and unexposed to mercury Methods: We evaluated 64 medical records (32 reference group and 32 exposed group, they were matched byage, smoke and alcohol consumption. For analysis, comet assay data (olive tail moment, % DNA in the tail and tail length, levels of urinary MDA and urinary mercury were taken. We compared the concentrations of MDA and the changes in the comet assay between the groups and the correlation between these variables. Results: MDA concentrations were higher in exposed than in referents (median 1.28 vs 0.51μmol/L, respectively and further damage to the comet assay (mean of tail % DNA: 27.37 vs. 0.31, median of Olivetail moment 8.29 vs olive 0.056; median of tail length 35 vs. 3.0, respectively.However there was a poor correlation between urinary MDA and genetic damage(r<0.11. Conclusion: No evidence was obtainedwith higher concentrations of MDA in urine provide additional genetic damage, but there was more DNA damage and higher concentrations of MDA in individuals occupationally exposed to mercury.

  6. Risk and resilience trajectories in war-exposed children across the first decade of life.

    Science.gov (United States)

    Halevi, Galit; Djalovski, Amir; Vengrober, Adva; Feldman, Ruth

    2016-10-01

    Although the effects of early-onset trauma on susceptibility to psychopathology are well-acknowledged, no study to date has followed risk and resilience trajectories in war-exposed young children over lengthy periods and charted predictors of individual pathways. In this prospective longitudinal study, we followed 232 children, including 148 exposed to repeated wartime trauma and 84 controls, at three time points: early childhood (1.5-5 years), middle childhood (5-8 years), and late childhood (9-11 years). Children were diagnosed at each time point and four trajectories defined: children exhibiting no pathology at any time point, those displaying early pathology that later remitted, those showing initial resilience followed by late pathology, and children presenting chronic pathology across the entire first decade. Maternal behavioral containment during trauma evocation and child social engagement during free play were observed in early childhood and maternal emotional distress self-reported across time. War-exposed children showed significantly higher rates of psychopathology, with 81% exhibiting pathology at some point during childhood. In middle childhood, exposed children displayed more posttraumatic stress disorders (PTSD), anxiety disorders, and attention-deficit/hyperactivity disorders (ADHD), and in late childhood more PTSD, conduct/oppositional defiant disorders, and ADHD. War-exposed children had more comorbid psychopathologies and number of comorbidities increased with age. Notably, war-exposure increased prevalence of chronic pathology by 24-fold. Maternal factors, including mother's uncontained style and emotional distress, increased risk for early and chronic psychopathology, whereas reduced child social engagement augmented risk for late pathology. Early-onset chronic stress does not heal naturally, and its effects appear to exacerbate over time, with trauma-exposed children presenting a more comorbid, chronic, and externalizing profile as they

  7. Elimination of mercury in health care facilities.

    Science.gov (United States)

    2000-03-01

    Mercury is a persistent, bioaccumulative toxin that has been linked to numerous health effects in humans and wildlife. It is a potent neurotoxin that may also harm the brain, kidneys, and lungs. Unborn children and young infants are at particular risk for brain damage from mercury exposure. Hospitals' use of mercury in chemical solutions, thermometers, blood pressure gauges, batteries, and fluorescent lamps makes these facilities large contributors to the overall emission of mercury into the environment. Most hospitals recognize the dangers of mercury. In a recent survey, four out of five hospitals stated that they have policies in place to eliminate the use of mercury-containing products. Sixty-two percent of them require vendors to disclose the presence of mercury in chemicals that the hospitals purchase. Only 12 percent distribute mercury-containing thermometers to new parents. Ninety-two percent teach their employees about the health and environmental effects of mercury, and 46 percent teach all employees how to clean up mercury spills. However, the same study showed that many hospitals have not implemented their policies. Forty-two percent were not aware whether they still purchased items containing mercury. In addition, 49 percent still purchase mercury thermometers, 44 percent purchase mercury gastrointestinal diagnostic equipment, and 64 percent still purchase mercury lab thermometers.

  8. PERSONAL FEATURES OF CHILDREN AND ADOLESCENTS ILL WITH RESPIRATORY TUBERCULOSIS EXPOSED AND NOT EXPOSED TO THE SOURCE OF INFECTION

    Directory of Open Access Journals (Sweden)

    N. V. Zolotova

    2017-01-01

    Full Text Available Specific personal features of 296 children and adolescents exposed to tuberculosis and those with unidentified exposure were comparatively analyzed. Children with unidentified exposure demonstrated psychic tension, poor self-control, poorly developed social communication skills which determined disruptive interpersonal relations and uneasy personal growth. Children exposed to tuberculosis in their families were characterized by judging didactive position towards their neighbors which was formed by dysfunctional patterns of relations in their parental families. Adolescent with unidentified exposure manifested the contrast combination of pre-morbid personal attitudes which had certain etiologic contribution to the development of borderline neurotic states. The higher level of destructive reactions in the interpersonal communication was observed in the adolescents exposed to tuberculosis in their families. Identified personal features are considered to be psychological factors determining the hyperactivation of adaptive systems at the pre-morbid state and consequent development of structural functional disorders in various systems of the host, as well as providing impact on the course of tuberculosis.

  9. Assessment of the mercury emissions from burning mining waste dumps

    Directory of Open Access Journals (Sweden)

    Barbara Białecka

    2016-04-01

    occur and to which the environment and local inhabitants can be exposed, it is important to define the size of the emission of mercury compounds from these objects. Despite the potential threats so far no measurements of mercury concentration which would a llow quantifying this phenomenon have been done. The analyses presented in this article fill this gap. Additionally, initial calculation of annual mercury emissions from burning coal mining waste dumps in Poland is presented.

  10. Landfill is an important atmospheric mercury emission source

    Institute of Scientific and Technical Information of China (English)

    FENG Xinbin; TANG Shunlin; LI Zhonggen; WANG Shaofeng; LIANG Lian

    2004-01-01

    Since municipal wastes contain refuses with high mercury contents, incineration of municipal wastes becomes the major anthropogenic atmospheric mercury emission source. In China, landfills are however the main way to dispose of municipal wastes. Total gaseous mercury (TGM) concentrations in landfill gas of Gaoyan sanitary landfill located in suburb of Guiyang City were monitored using a high temporal resolved automated mercury analyzer, and mono-methylmercury (MMHg) and dimethylmercury (DMHg) concentrations in landfill gas were also measured using GC coupled with the cold vapor atomic fluorescence (CVAFS) method. Meanwhile, the TGM exchange fluxes between exposed waste and air and the soil surface of the landfill and air, were measured using low Hg blank quartz flux chamber coupled with high temporal resolved automated mercury analyzer technique. TGM concentrations in landfill gas from half year filling area averaged out at 665.52±291.25 ng/m3, which is comparable with TGM concentrations from flue gas of a small coal combustion boiler in Guiyang. The average MMHg and DMHg concentrations averaged out at 2.06±1.82 ng/m3 and 9.50±5.18 ng/m3, respectively. It is proven that mercury emission is the predominant process at the surfaces of both exposed wastes and soil of landfill. Landfills are not only TGM emission source, but also methylmercury emission source to the ambient air. There are two ways to emit mercury to the air from landfills, one is with the landfill gas through landfill gas duct, and the other through soil/air exchange. The Hg emission processes from landfills are controlled by meteorological parameters.

  11. How People Domesticated Amazonian Forests

    NARCIS (Netherlands)

    Levis, C.; Flores, Bernardo; Moreira, Priscilla; Luize, Bruno G.; Alves, Rubana; Franco-Moraes, Juliano; Lins, Juliana; Konings, Evelien; Pena Claros, M.; Bongers, F.; Costa, Flavia; Clement, Charles

    2018-01-01

    For millennia, Amazonian peoples have managed forest resources, modifying the natural environment in subtle and persistent ways. Legacies of past human occupation are striking near archaeological sites, yet we still lack a clear picture of how human management practices resulted in the domestication

  12. Study of high levels indoor air mercury contamination from mercury amalgam use in dentistry

    International Nuclear Information System (INIS)

    Khwaja, M.A.; Abbasi, M.S.; Mehmood, F.; Jahangir, S.

    2014-01-01

    In 2005, United Nations Environment Programme (UNEP) estimated that 362 tonnes of dental mercury are consumed annually worldwide. Dental mercury amalgams also called silver fillings and amalgam fillings are widely done. These fillings gave off mercury vapours. Estimated average absorbed concentrations of mercury vapours from dental fillings vary from 3,000 to 17,000 ng Hg. Mercury (Hg) also known as quick silver is an essential constituent of dental amalgam. It is a toxic substance of global concern. A persistent pollutant, mercury is not limited to its source but it travels, on time thousands of kilometers away from the source. Scientific evidence, including, UNEP Global Mercury report, establishes mercury as an extremely toxic substance, which is a major threat to wildlife, ecosystem and human health, at a global scale. Children are more at risk from mercury poisoning which affects their neurological development and brain. Mercury poisoning diminishes memory, attention, thinking and sight. In the past, a number of studies at dental sites in many countries have been carried out and reported which have been reviewed and briefly described. This paper describes and discusses the recent investigations, regarding mercury vapours level in air, carried out at 18 dental sites in Pakistan and other countries. It is evident from the data of 42 dental sites in 17 countries, including, selected dental sites in five main cities of Pakistan, described and discussed in this paper that at most dental sites in many countries including Pakistan, the indoor mercury vapours levels exceed far above the permissible limit, recommended for safe physical and mental health. At these sites, public, in general, and the medical, paramedical staff and vulnerable population, in particular, are at most serious risk to health resulting from exposure to toxic and hazardous mercury. (author)

  13. Effects of lead, cadmium, arsenic, and mercury co-exposure on children's intelligence quotient in an industrialized area of southern China.

    Science.gov (United States)

    Pan, Shangxia; Lin, Lifeng; Zeng, Fan; Zhang, Jianpeng; Dong, Guanghui; Yang, Boyi; Jing, You; Chen, Shejun; Zhang, Gan; Yu, Zhiqiang; Sheng, Guoying; Ma, Huimin

    2018-04-01

    Exposure to metal(loid)s can lead to adverse effects on nervous system in children. However, little is known about the possible interaction effects of simultaneous exposure to multiple metal(loid)s on children's intelligence. In addition, relationship between blood lead concentrations (lead (Pb), cadmium (Cd), arsenic (As) and mercury (Hg) in blood (BPb, BCd, BAs, BHg) and urine (UPb, UCd, UAs, UHg) were assessed, as well as children's intelligence quotient (IQ). A significant decrease in IQ scores was identified in children from the industrialized town (p < .05), who had statistically higher geometric mean concentrations of BPb, BCd, UPb, UCd and UHg (65.89, 1.93, 4.04, 1.43 and 0.37 μg/L, respectively) compared with children from the reference town (37.21, 1.07, 2.14, 1.02 and 0.30 μg/L, respectively, p < .05). After adjusting confounders, only BPb had a significant negative association with IQ (B = -0.10, 95% confidence interval: -0.15 to -0.05, p < .001), which indicated that IQ decreased 0.10 points when BPb increased 1 μg/L. Significant negative interactions between BAs and BHg, positive interaction between UPb and UCd on IQ were observed (p < .10), and BPb <100 μg/L still negatively affected IQ (p < .05). Our findings suggest that although only BPb causes a decline in children's IQ when simultaneously exposed to these four metal(loid)s at relatively low levels, interactions between metal(loid)s on children's IQ should be paid special attention, and the reference standard in China of 100 μg/L BPb for children above 5 years old should be revised. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Assessment of chronic neuropsychological effects of mercury vapour poisoning in chloral-alkali plant workers

    Directory of Open Access Journals (Sweden)

    Nurka Pranjić

    2002-02-01

    Full Text Available A prospective case study was conducted in the Department of Occupational Medicine, Tuzla. The purpose of this study was to indicate negative effects from occupational exposure to mercury on behavioural and mental health, memory and psychomotor function that was tested in 46 chloral-alkali plant workers (mean age was 38. 8+/- 5. 7 years; mean age of occupational history 16. 5+/- 6. 0 years. Data on toxicological monitoring on atomic absorption spectrometer, and data on mental health were collected, psychiatric and other subjective symptoms, and behavioural, psychomotor and memory function tested. The data were compared to control group, 32 healthy non exposed workers. The study was designed to assess blood and urine mercurylevels and length of occupational exposure and investigate its relationships to effects on the mental health. The mean air mercury levels were 0.23 mg/m3, the mean blood mercury concentrations was 3. 6 mg/ dl and the mean urine mercuryconcentrations were 151.7 +/- 180.4 mg/l. In 25 (53% workers exposed to mercury vapour was identified Depression-Hypochondrias Syndrome (p trend < 0. 001 with higher scores for scales: Hysteria (p trend <0. 001, Schizoid and Psychoastenia (MMPI. All psychological parameters were in highly significantly correlations with mercury levels and length of occupational exposure. Pathological parameters were possible general identified if the concentration of blood mercury levels are >2. 9 mg/ dl, or urine mercury levels > 87 mg/l workers exposed to mercury vapour knew that toxic effects in body resulted in loosing some of intellectual abilities, and that people who handle chemicals had an increased health risk (ESW questionnaire. The occupational mercury exposed workers had introvert behaviour (EPQ. Aggressiveness was found in 71.7% workers. The cognitive disturbances: short-term memory loss, difficult to concentrate on tasks which require attention and thinking

  15. Brazil's Amazonian dams: Ecological and socioeconomic impacts

    Science.gov (United States)

    Fearnside, P. M.

    2016-12-01

    Brazil's 2015-2024 Energy Expansion Plan calls for 11 hydroelectric dams with installed capacity ≥ 30 MW in the country's Amazon region. Dozens of other large dams are planned beyond this time horizon, and dams with environmental and socioeconomic impacts. Loss of forest to flooding is one, the Balbina and Tucuruí Dams being examples (each 3000 km2). If the Babaquara/Altamira Dam is built it will flood as much forest as both of these combined. Some planned dams imply loss of forest in protected areas, for example on the Tapajós River. Aquatic and riparian ecosystems are lost, including unique biodiversity. Endemic fish species in rapids on the Xingu and Tapajós Rivers are examples. Fish migrations are blocked, such as the commercially important "giant catfish" of the Madeira River. Dams emit greenhouse gases, including CO2 from the trees killed and CH4 from decay under anoxic conditions at the bottom of reservoirs. Emissions can exceed those from fossil-fuel generation, particularly over the 20-year period during which global emissions must be greatly reduced to meet 1.5-2°C limit agreed in Paris. Carbon credit for dams under the Climate Convention causes further net emission because the dams are not truly "additional." Anoxic environments in stratified reservoirs cause methylation of mercury present in Amazonian soils, which concentrates in fish, posing a health risk to human consumers. Population displacement is a major impact; for example, the Marabá Dam would displace 40,000 people, mostly traditional riverside dwellers (ribeirinhos). Various dams impact indigenous peoples, such as the Xingu River dams (beginning with Belo Monte) and the São Luiz do Tapajós and Chacorão Dams on the Tapajós River. Brazil has many energy options other than dams. Much energy use has little benefit for the country, such as exporting aluminum. Electric showerheads use 5% of the country's power. Losses in transmission lines (20%) are far above global averages and can be

  16. Modulation of vasodilator response via the nitric oxide pathway after acute methyl mercury chloride exposure in rats.

    Science.gov (United States)

    Omanwar, S; Saidullah, B; Ravi, K; Fahim, M

    2013-01-01

    Mercury exposure induces endothelial dysfunction leading to loss of endothelium-dependent vasorelaxation due to decreased nitric oxide (NO) bioavailability via increased oxidative stress. Our aim was to investigate whether acute treatment with methyl mercury chloride changes the endothelium-dependent vasodilator response and to explore the possible mechanisms behind the observed effects. Wistar rats were treated with methyl mercury chloride (5 mg/kg, po.). The methyl mercury chloride treatment resulted in an increased aortic vasorelaxant response to acetylcholine (ACh). In methyl-mercury-chloride-exposed rats, the % change in vasorelaxant response of ACh in presence of Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME; 10(-4) M) was significantly increased, and in presence of glybenclamide (10(-5) M), the response was similar to that of untreated rats, indicating the involvement of NO and not of endothelium-derived hyperpolarizing factor (EDHF). In addition, superoxide dismutase (SOD) + catalase treatment increased the NO modulation of vasodilator response in methyl-mercury-chloride-exposed rats. Our results demonstrate an increase in the vascular reactivity to ACh in aorta of rats acutely exposed to methyl mercury chloride. Methyl mercury chloride induces nitric oxide synthase (NOS) and increases the NO production along with inducing oxidative stress without affecting the EDHF pathway.

  17. Modulation of Vasodilator Response via the Nitric Oxide Pathway after Acute Methyl Mercury Chloride Exposure in Rats

    Directory of Open Access Journals (Sweden)

    S. Omanwar

    2013-01-01

    Full Text Available Mercury exposure induces endothelial dysfunction leading to loss of endothelium-dependent vasorelaxation due to decreased nitric oxide (NO bioavailability via increased oxidative stress. Our aim was to investigate whether acute treatment with methyl mercury chloride changes the endothelium-dependent vasodilator response and to explore the possible mechanisms behind the observed effects. Wistar rats were treated with methyl mercury chloride (5 mg/kg, po.. The methyl mercury chloride treatment resulted in an increased aortic vasorelaxant response to acetylcholine (ACh. In methyl-mercury-chloride-exposed rats, the % change in vasorelaxant response of ACh in presence of Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME; 10-4 M was significantly increased, and in presence of glybenclamide (10-5 M, the response was similar to that of untreated rats, indicating the involvement of NO and not of endothelium-derived hyperpolarizing factor (EDHF. In addition, superoxide dismutase (SOD + catalase treatment increased the NO modulation of vasodilator response in methyl-mercury-chloride-exposed rats. Our results demonstrate an increase in the vascular reactivity to ACh in aorta of rats acutely exposed to methyl mercury chloride. Methyl mercury chloride induces nitric oxide synthase (NOS and increases the NO production along with inducing oxidative stress without affecting the EDHF pathway.

  18. Visual selective attention is impaired in children prenatally exposed to opioid agonist medication.

    Science.gov (United States)

    Konijnenberg, Carolien; Melinder, Annika

    2015-01-01

    To examine whether prenatal exposure to opioid agonist medication is associated with visual selective attention and general attention problems in early childhood. Twenty-two children (mean age = 52.17 months, SD = 1.81) prenatally exposed to methadone, 9 children (mean age = 52.41 months, SD = 1.42) prenatally exposed to buprenorphine and 25 nonexposed comparison children (mean age = 51.44 months, SD = 1.31) were tested. Visual selective attention was measured with a Tobii 1750 Eye Tracker using a spatial negative priming paradigm. Attention problems were measured using the Child Behavior Checklist. The comparison group demonstrated a larger spatial negative priming effect (mean = 23.50, SD = 45.50) than the exposed group [mean = -6.84, SD = 86.39, F(1,50) = 5.91, p = 0.019, η(2) = 0.11]. No difference in reported attention problems was found [F(1,51) = 1.63, p = 0.21, η(2) = 0.03]. Neonatal abstinence syndrome and prenatal exposure to marijuana were found to predict slower saccade latencies in the exposed group (b = 54.55, SE = 23.56, p = 0.03 and b = 88.86, SE = 32.07, p = 0.01, respectively). Although exposed children did not appear to have attention deficits in daily life, lower performance on the SNP task indicates subtle alteration in the attention system. © 2014 S. Karger AG, Basel.

  19. Carbon dynamics and ecosystem diversity of Amazonian peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Laehteenoja, O.

    2011-07-01

    The overall aim was to initiate peatland research in Amazonia, which has been referred to as 'one of the large white spots on the global peatland map'. Specifically, the study was to clarify how common peat accumulation is on Amazonian floodplains, and how extensive and thick peat deposits can be encountered. Secondly, the intention was to study how rapidly Amazonian peatlands sequester carbon, and how much carbon they store and thirdly, to gain some understanding of the diversity of peatland ecosystem types and of the processes forming these ecosystems

  20. Oxidative stress and repetitive element methylation changes in artisanal gold miners occupationally exposed to mercury

    Directory of Open Access Journals (Sweden)

    Diana M. Narváez

    2017-09-01

    Full Text Available Mercury (Hg exposure is a public health concern due to its persistence in the environment and its high toxicity. Such toxicity has been associated with the generation of oxidative stress in occupationally exposed subjects, such as artisanal gold miners. In this study, we characterize occupational exposure to Hg by measuring blood, urine and hair levels, and investigate oxidative stress and DNA methylation associated with gold mining. To do this, samples from 53 miners and 36 controls were assessed. We show higher levels of oxidative stress marker 8-OHdG in the miners. Differences in LINE1 and Alu(Yb8 DNA methylation between gold miners and control group are present in peripheral blood leukocytes. LINE1 methylation is positively correlated with 8-OHdG levels, while XRCC1 and LINE1 methylation are positively correlated with Hg levels. These results suggest an effect of Hg on oxidative stress and DNA methylation in gold miners that may have an impact on miners’ health.

  1. Analysis of mercury and selenium in biological samples by neutron activation analysis

    International Nuclear Information System (INIS)

    Catharino, Marilia Gabriela Miranda

    2002-01-01

    In the present work, hair samples from populations suspected of contamination by mercury, in the localities of Serra do Navio, Vila Nova and Tartarugalzinho, in the State of Amapa, were analyzed. Hair samples of children under odontopediatric treatment were also analyzed for mercury, in order to study the possibility of transfer of mercury from the dental amalgam and also to obtain data of hair mercury in a control population of children. Another step of the work was the development of a method for the determination of selenium, by using the short-lived radioisotope 77 mSe. After the certification of the method it was applied to the analysis of hair, nails and a vitamin supplement. A comparison was made with the results obtain ed by using the long-lived radioisotope of selenium, 75 Se. The results obtained for mercury in the hair samples of populations living in the State of Amapa have shown that the mercury concentrations in these populations are much higher than in the controls. As for the hair samples of children under treatment with mercury amalgam, no significant differences were found in the concentrations of mercury after the treatment. On the other hand, these data were important to obtain data for a control population of children. The results obtained by using the radioisotope 77 mSe showed that the method developed was suitable for the analyzed matrixes and the results were similar to the ones obtained by employing the usual AANI method, with the radioisotope 75 Se. (author)

  2. Scorpion envenoming in Morona Santiago, Amazonian Ecuador: Molecular phylogenetics confirms involvement of the Tityus obscurus group.

    Science.gov (United States)

    Román, Juan P; García, Fernanda; Medina, Doris; Vásquez, Manolo; García, José; Graham, Matthew R; Romero-Alvarez, Daniel; Pardal, Pedro P de Oliveira; Ishikawa, Edna A Y; Borges, Adolfo

    2018-02-01

    Scorpion envenoming by species in the genus Tityus is hereby reported from rural locations in the Amazonian province of Morona Santiago, southeastern Ecuador. Twenty envenoming cases (18 patients under 15 years of age) including one death (a 4-year-old male) were recorded at the Macas General Hospital, Morona Santiago, between January 2015 and December 2016 from the counties of Taisha (n=17), Huamboyo (n=1), Palora (n=1), and Logroño (n=1). An additional fatality from 2014 (a 3-year-old female from Nayantza, Taisha county) is also reported. Leukocytosis and low serum potassium levels were detected in most patients. We observed a significant negative correlation between leukocytosis and hypokalemia. Scorpions involved in three accidents from Macuma, Taisha County, were identified as genetically related to Tityus obscurus from the Brazilian Amazonian region based on comparison of mitochondrial DNA sequences encoding cytochrome oxidase subunit I. These cases, along with previously reported envenoming from northern Manabí, reinforce the notion that scorpionism is a health hazard for children in Ecuador and emphasizes the need to supply effective antivenoms against local species, which are not currently available. The genetic affinity of the Ecuadorian specimens with T. obscurus may underlay toxinological, clinical, and venom antigenic relationships among Amazonian scorpions that deserves further exploration for designing therapeutic strategies to treat scorpionism in the region. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Metal components analysis of metallothionein-III in the brain sections of metallothionein-I and metallothionein-II null mice exposed to mercury vapor with HPLC/ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Kameo, Satomi; Nakai, Kunihiko; Kurokawa, Naoyuki; Satoh, Hiroshi [Tohoku University, Graduate School of Medicine, Aoba-ku, Sendai (Japan); Kanehisa, Tomokazu; Naganuma, Akira [Tohoku University, Graduate School of Pharmaceutical Sciences, Sendai (Japan)

    2005-04-01

    Mercury vapor is effectively absorbed via inhalation and easily passes through the blood-brain barrier; therefore, mercury poisoning with primarily central nervous system symptoms occurs. Metallothionein (MT) is a cysteine-rich metal-binding protein and plays a protective role in heavy-metal poisoning and it is associated with the metabolism of trace elements. Two MT isoforms, MT-I and MT-II, are expressed coordinately in all mammalian tissues, whereas MT-III is a brain-specific member of the MT family. MT-III binds zinc and copper physiologically and is seemed to have important neurophysiological and neuromodulatory functions. The MT functions and metal components of MTs in the brain after mercury vapor exposure are of much interest; however, until now they have not been fully examined. In this study, the influences of the lack of MT-I and MT-II on mercury accumulation in the brain and the changes of zinc and copper concentrations and metal components of MTs were examined after mercury vapor exposure by using MT-I, II null mice and 129/Sv (wild-type) mice as experimental animals. MT-I, II null mice and wild-type mice were exposed to mercury vapor or an air stream for 2 h and were killed 24 h later. The brain was dissected into the cerebral cortex, the cerebellum, and the hippocampus. The concentrations of mercury in each brain section were determined by cold vapor atomic absorption spectrometry. The concentrations of mercury, copper, and zinc in each brain section were determined by inductively coupled plasma mass spectrometry (ICP-MS). The mercury accumulated in brains after mercury vapor exposure for MT-I, II null mice and wild-type mice. The mercury levels of MT-I, II null mice in each brain section were significantly higher than those of wild-type mice after mercury vapor exposure. A significant change of zinc concentrations with the following mercury vapor exposure for MT-I, II null mice was observed only in the cerebellum analyzed by two-way analysis of

  4. Release of mercury halides from KCl denuders in the presence of ozone

    Directory of Open Access Journals (Sweden)

    S. N. Lyman

    2010-09-01

    Full Text Available KCl-coated denuders have become a standard method for measurement of gaseous oxidized mercury, but their performance has not been exhaustively evaluated, especially in field conditions. In this study, KCl-coated and uncoated quartz denuders loaded with HgCl2 and HgBr2 lost 29–55% of these compounds, apparently as elemental mercury, when exposed to ozone (range of 6–100 ppb tested. This effect was also observed for denuders loaded with gaseous oxidized mercury at a field site in Nevada (3–37% of oxidized mercury lost. In addition, collection efficiency decreased by 12–30% for denuders exposed to 50 ppb ozone during collection of HgCl2. While data presented were obtained from laboratory tests and as such do not exactly simulate field sampling conditions, these results indicate that the KCl denuder oxidized mercury collection method may not be as robust as previously thought. This work highlights needs for further testing of this method, clear identification of gaseous oxidized mercury compounds in the atmosphere, and development of field calibration methods for these compounds.

  5. Relationship between mercury in kidney, blood, and urine in environmentally exposed individuals, and implications for biomonitoring

    Energy Technology Data Exchange (ETDEWEB)

    Akerstrom, Magnus, E-mail: magnus.akerstrom@amm.gu.se [Department of Occupational and Environmental Medicine, Sahlgrenska University Hospital and Academy, University of Gothenburg, Gothenburg (Sweden); Barregard, Lars [Department of Occupational and Environmental Medicine, Sahlgrenska University Hospital and Academy, University of Gothenburg, Gothenburg (Sweden); Lundh, Thomas [Department of Occupational and Environmental Medicine, Lund University Hospital, Lund University, Lund (Sweden); Sallsten, Gerd [Department of Occupational and Environmental Medicine, Sahlgrenska University Hospital and Academy, University of Gothenburg, Gothenburg (Sweden)

    2017-04-01

    Background: Individuals without occupational exposure are exposed to mercury (Hg) from diet and dental amalgam. The kidney is a critical organ, but there is limited information regarding the relationship between Hg in kidney (K-Hg), urine (U-Hg), blood (B-Hg), and plasma (P-Hg). Objectives: The aim was to determine the relationship between K-Hg, U-Hg, B-Hg, and P-Hg among environmentally exposed individuals, estimate the biological half-time of K-Hg, and provide information useful for biomonitoring of Hg. Methods: Kidney cortex biopsies and urine and blood samples were collected from 109 living kidney donors. Total Hg concentrations were determined and the relationships between K-Hg, U-Hg, P-Hg, and B-Hg were investigated in regression models. The half-time of K-Hg was estimated from the elimination constant. Results: There were strong associations between K-Hg and all measures of U-Hg and P-Hg (r{sub p} = 0.65–0.84, p < 0.001), while the association with B-Hg was weaker (r{sub p} = 0.29, p = 0.002). Mean ratios between K-Hg (in μg/g) and U-Hg/24h (in μg) and B-Hg (in μg/L) were 0.22 and 0.19 respectively. Estimates of the biological half-time varied between 30 and 92 days, with significantly slower elimination in women. Adjusting overnight urine samples for dilution using urinary creatinine resulted in less bias in relation to K-Hg or U-Hg/24h, compared with other adjustment techniques. Conclusions: The relationship between K-Hg and U-Hg is approximately linear. K-Hg can be estimated using U-Hg and gender. Women have longer half-time of Hg in kidney compared to men. Adjusting overnight urine samples for creatinine concentration resulted in less bias. - Highlights: • The first study of the relation between Hg in kidney, blood and urine at low U-Hg • Simultaneous samples were collected from healthy kidney donors. • There was a linear relationship between mercury in kidney and urine. • Kidney Hg can be estimated using U-Hg and gender. • Women have

  6. Relationship between mercury in kidney, blood, and urine in environmentally exposed individuals, and implications for biomonitoring

    International Nuclear Information System (INIS)

    Akerstrom, Magnus; Barregard, Lars; Lundh, Thomas; Sallsten, Gerd

    2017-01-01

    Background: Individuals without occupational exposure are exposed to mercury (Hg) from diet and dental amalgam. The kidney is a critical organ, but there is limited information regarding the relationship between Hg in kidney (K-Hg), urine (U-Hg), blood (B-Hg), and plasma (P-Hg). Objectives: The aim was to determine the relationship between K-Hg, U-Hg, B-Hg, and P-Hg among environmentally exposed individuals, estimate the biological half-time of K-Hg, and provide information useful for biomonitoring of Hg. Methods: Kidney cortex biopsies and urine and blood samples were collected from 109 living kidney donors. Total Hg concentrations were determined and the relationships between K-Hg, U-Hg, P-Hg, and B-Hg were investigated in regression models. The half-time of K-Hg was estimated from the elimination constant. Results: There were strong associations between K-Hg and all measures of U-Hg and P-Hg (r p = 0.65–0.84, p < 0.001), while the association with B-Hg was weaker (r p = 0.29, p = 0.002). Mean ratios between K-Hg (in μg/g) and U-Hg/24h (in μg) and B-Hg (in μg/L) were 0.22 and 0.19 respectively. Estimates of the biological half-time varied between 30 and 92 days, with significantly slower elimination in women. Adjusting overnight urine samples for dilution using urinary creatinine resulted in less bias in relation to K-Hg or U-Hg/24h, compared with other adjustment techniques. Conclusions: The relationship between K-Hg and U-Hg is approximately linear. K-Hg can be estimated using U-Hg and gender. Women have longer half-time of Hg in kidney compared to men. Adjusting overnight urine samples for creatinine concentration resulted in less bias. - Highlights: • The first study of the relation between Hg in kidney, blood and urine at low U-Hg • Simultaneous samples were collected from healthy kidney donors. • There was a linear relationship between mercury in kidney and urine. • Kidney Hg can be estimated using U-Hg and gender. • Women have longer half

  7. Mercury cycling in peatland watersheds. Chapter 11.

    Science.gov (United States)

    Randall K. Kolka; Carl P.J. Mitchell; Jeffrey D. Jeremiason; Neal A. Hines; David F. Grigal; Daniel R. Engstrom; Jill K. Coleman-Wasik; Edward A. Nater; Edward B. Swain; Bruce A. Monson; Jacob A. Fleck; Brian Johnson; James E. Almendinger; Brian A. Branfireun; Patrick L. Brezonik; James B. Cotner

    2011-01-01

    Mercury (Hg) is of great environmental concern due to its transformation into the toxic methylmercury (MeHg) form that bioaccumulates within the food chain and causes health concerns for both humans and wildlife (U.S. Environmental Protection Agency 2002). Mercury can affect neurological development in fetuses and young children. In adults, exposure to Hg can lead to...

  8. Presence of mercury in natural gas

    International Nuclear Information System (INIS)

    Gijselman, P.B.

    1991-01-01

    This paper describes the occupational health programme used to ensure that NAM and contractor personnel of the Nederlandse Aardolie Mij (NAM) exposed to mercury, common in Dutch gas, are adequately protected through the correct use of Personal Protective Equipment (PPE), proper instruction and suitable work procedures. To avoid health damage due to mercury exposure during maintenance and shutdown activities the occupational health department of NAM set up a programme covering 3 activities: monitoring of atmospheric air; sampling of inspired air during work, and measurement of mercury excretion in urine of workers instruction of company and contractor personnel consultancy during preparation of work instructions. The monitoring program showed that, through correct use of PPE, staff do not exhibit mercury concentration levels exceeding the human toxicity limit (100 ug/g creatinine) even after exposure to mercury vapor concentrations above the TLV of 0.5 mg/m 3 . The correct use of PPE is a result of the instruction programme which also promotes increased awareness for personnel of the harmful effects of mercury. Finally, the provision of consultancy during the preparation of work instructions has contributed to various measures; for instance, staff wearing plastic (Viton) protective suits may not work longer than 2 hours continuously to avoid heat exhaustion

  9. Language Outcomes at 12 Years for Children Exposed Prenatally to Cocaine

    Science.gov (United States)

    Lewis, Barbara A.; Minnes, Sonia; Short, Elizabeth J.; Min, Meeyoung O.; Wu, Miaoping; Lang, Adelaide; Weishampel, Paul; Singer, Lynn T.

    2013-01-01

    Purpose: In this study, the authors aimed to examine the long-term effects of prenatal cocaine exposure (PCE) on the language development of 12-year-old children using a prospective design, controlling for confounding prenatal drug exposure and environmental factors. Method: Children who were exposed to cocaine in utero (PCE; "n" = 183)…

  10. Effect of radiofrequency radiation from Wi-Fi devices on mercury release from amalgam restorations.

    Science.gov (United States)

    Paknahad, Maryam; Mortazavi, S M J; Shahidi, Shoaleh; Mortazavi, Ghazal; Haghani, Masoud

    2016-01-01

    Dental amalgam is composed of approximately 50% elemental mercury. Despite concerns over the toxicity of mercury, amalgam is still the most widely used restorative material. Wi-Fi is a rapidly using local area wireless computer networking technology. To the best of our knowledge, this is the first study that evaluates the effect of exposure to Wi-Fi signals on mercury release from amalgam restorations. Standard class V cavities were prepared on the buccal surfaces of 20 non-carious extracted human premolars. The teeth were randomly divided into 2 groups (n = 10). The control group was stored in non-environment. The specimens in the experimental groups were exposed to a radiofrequency radiation emitted from standard Wi Fi devices at 2.4 GHz for 20 min. The distance between the Wi-Fi router and samples was 30 cm and the router was exchanging data with a laptop computer that was placed 20 m away from the router. The concentration of mercury in the artificial saliva in the groups was evaluated by using a cold-vapor atomic absorption Mercury Analyzer System. The independent t test was used to evaluate any significant differences in mercury release between the two groups. The mean (±SD) concentration of mercury in the artificial saliva of the Wi-Fi exposed teeth samples was 0.056 ± .025 mg/L, while it was only 0.026 ± .008 mg/L in the non-exposed control samples. This difference was statistically significant (P =0.009). Exposure of patients with amalgam restorations to radiofrequency radiation emitted from conventional Wi-Fi devices can increase mercury release from amalgam restorations.

  11. The effect of mercury on baseline corticosterone in a breeding songbird.

    Science.gov (United States)

    Maddux, Sarah L; Cristol, Daniel A; Varian-Ramos, Claire W; Bradley, Eric L

    2015-02-01

    Although songbirds accumulate mercury at rates equivalent to better-studied aquatic avian species, effects of mercury bioaccumulation in songbirds remain understudied. Little is known about the effects of mercury on endocrine physiology, but recent evidence indicates that mercury may disrupt the function of the hypothalamic-pituitary-adrenal axis. Both field-based correlational studies and a recent dosing experiment suggest that mercury exposure alters levels of the primary avian stress hormone, CORT. We sampled zebra finches that had been dosed with 0, 0.5, or 1.0 ppm dietary methylmercury for baseline CORT twice; once during pairing and once after successfully fledging young. Circulating levels of CORT were not significantly affected by mercury exposure. However, our findings indicate potentially important differences in CORT responses between the sexes when exposed to environmentally relevant doses of mercury across the nesting cycle.

  12. SRXRF study of trace elements in hippocampus of pup rats after prenatal and postnatal exposure to low-level mercury

    International Nuclear Information System (INIS)

    Zhang Fang; Feng Weiyue; Chai Zhifang; Wang Meng; Shi Junwen; Huang Yuying; He Wei

    2005-01-01

    Since the pollution of mercury in the environment still keeps high, more and more concerns over mercury toxicity are focused on the potential risk associated with relatively low-dose and long-term mercury exposure in the environment. It is well known that fetus and developing children are the susceptive victims of mercury damage. Therefore, high attention is focused on whether the prenatal and postnatal exposure to relatively low level of mercury will be harmful to children development. Some epidemiological studies reported that the methylmercury-related neuropsychological deficits were mainly found in the domains of cognitional parts, such as language, attention, memory, and so forth, Our previous study found out that high level of mercury was accumulated in the pup hippocampus after their prenatal and postnatal exposure to low dose of inorganic mercury. Synchrotron radiation X-ray fluorescence technique (SRXRF) is characterized of its simultaneous determination of multi-elements, high sensitivity, small sampling amount and microanalysis. SRXRF does not cause the damage of irradiated samples. Thus, it makes possible to measure the distributions of trace elements in a selected area. In this study, in order to study the effects of low-level mercury exposure to pup rat brain, some oxidation-related elements, e.g. Cu, Fe and Mn in pup hippocampus after in utero and weaning exposure to low-level inorganic mercury were determined by SRXRF. The experiment was performed at a synchrotron radiation facility at Institute of High Energy Physics. And the spot size of the beam irradiating on the sample was adjusted to about 100 x 200 μm 2 , Each spot was irradiated for about 100 s. The spectra were analyzed by the AXIL program. Additionally, the activities of some important antioxidant enzymes, such as GSH-Px, SOD, CAT, were also measured together with the content of malondialdehyde (MDA). The results showed that mercury exposure could lead to significant increase of both

  13. Mitochondrial DNA mapping of social-biological interactions in Brazilian Amazonian African-descendant populations

    Directory of Open Access Journals (Sweden)

    Bruno Maia Carvalho

    2008-01-01

    Full Text Available The formation of the Brazilian Amazonian population has historically involved three main ethnic groups, Amerindian, African and European. This has resulted in genetic investigations having been carried out using classical polymorphisms and molecular markers. To better understand the genetic variability and the micro-evolutionary processes acting in human groups in the Brazilian Amazon region we used mitochondrial DNA to investigate 159 maternally unrelated individuals from five Amazonian African-descendant communities. The mitochondrial lineage distribution indicated a contribution of 50.2% from Africans (L0, L1, L2, and L3, 46.6% from Amerindians (haplogroups A, B, C and D and a small European contribution of 1.3%. These results indicated high genetic diversity in the Amerindian and African lineage groups, suggesting that the Brazilian Amazonian African-descendant populations reflect a possible population amalgamation of Amerindian women from different Amazonian indigenous tribes and African women from different geographic regions of Africa who had been brought to Brazil as slaves. The present study partially mapped the historical biological and social interactions that had occurred during the formation and expansion of Amazonian African-descendant communities.

  14. Mercury

    International Nuclear Information System (INIS)

    Vilas, F.; Chapman, C.R.; Matthews, M.S.

    1988-01-01

    Papers are presented on future observations of and missions to Mercury, the photometry and polarimetry of Mercury, the surface composition of Mercury from reflectance spectrophotometry, the Goldstone radar observations of Mercury, the radar observations of Mercury, the stratigraphy and geologic history of Mercury, the geomorphology of impact craters on Mercury, and the cratering record on Mercury and the origin of impacting objects. Consideration is also given to the tectonics of Mercury, the tectonic history of Mercury, Mercury's thermal history and the generation of its magnetic field, the rotational dynamics of Mercury and the state of its core, Mercury's magnetic field and interior, the magnetosphere of Mercury, and the Mercury atmosphere. Other papers are on the present bounds on the bulk composition of Mercury and the implications for planetary formation processes, the building stones of the planets, the origin and composition of Mercury, the formation of Mercury from planetesimals, and theoretical considerations on the strange density of Mercury

  15. Mercury uptake and accumulation by four species of aquatic plants

    International Nuclear Information System (INIS)

    Skinner, Kathleen; Wright, Nicole; Porter-Goff, Emily

    2007-01-01

    The effectiveness of four aquatic plants including water hyacinth (Eichornia crassipes), water lettuce (Pistia stratiotes), zebra rush (Scirpus tabernaemontani) and taro (Colocasia esculenta) were evaluated for their capabilities in removing mercury from water. The plants were exposed to concentrations of 0 mg/L, 0.5 mg/L or 2 mg/L of mercury for 30 days. Assays were conducted using both Microtox[reg] (water) and cold vapor Atomic Absorption Spectroscopy (AAS) (roots and water). The Microtox[reg] results indicated that the mercury induced acute toxicity had been removed from the water. AAS confirmed an increase of mercury within the plant root tissue and a corresponding decrease of mercury in the water. All species of plants appeared to reduce mercury concentrations in the water via root uptake and accumulation. Water lettuce and water hyacinth appeared to be the most effective, followed by taro and zebra rush, respectively. - Four species of aquatic plants reduced mercury in water

  16. Mercury uptake and accumulation by four species of aquatic plants

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, Kathleen [Department of Biology, Russell Sage College, 45 Ferry Street, Troy, NY 12180 (United States)]. E-mail: skinnk@sage.edu; Wright, Nicole [NEIWPCC-NYSDEC, 625 Broadway, 4th Floor, Albany, NY 12233-3502 (United States)]. E-mail: ndwright@gw.dec.state.ny.us; Porter-Goff, Emily [Department of Biology, Russell Sage College, 45 Ferry Street, Troy, NY 12180 (United States)

    2007-01-15

    The effectiveness of four aquatic plants including water hyacinth (Eichornia crassipes), water lettuce (Pistia stratiotes), zebra rush (Scirpus tabernaemontani) and taro (Colocasia esculenta) were evaluated for their capabilities in removing mercury from water. The plants were exposed to concentrations of 0 mg/L, 0.5 mg/L or 2 mg/L of mercury for 30 days. Assays were conducted using both Microtox[reg] (water) and cold vapor Atomic Absorption Spectroscopy (AAS) (roots and water). The Microtox[reg] results indicated that the mercury induced acute toxicity had been removed from the water. AAS confirmed an increase of mercury within the plant root tissue and a corresponding decrease of mercury in the water. All species of plants appeared to reduce mercury concentrations in the water via root uptake and accumulation. Water lettuce and water hyacinth appeared to be the most effective, followed by taro and zebra rush, respectively. - Four species of aquatic plants reduced mercury in water.

  17. Heterogeneous oxidation of mercury in simulated post combustion conditions

    Energy Technology Data Exchange (ETDEWEB)

    Glenn A. Norton; Hongqun Yang; Robert C. Brown; Dennis L. Laudal; Grant E. Dunham; John Erjavec [Iowa State University, Ames, IA (United States). Center for Sustainable Environmental Technologies

    2003-01-01

    Heterogeneous mercury oxidation was studied by exposing whole fly ash samples and magnetic, nonmagnetic, and size-classified fly ash fractions to elemental mercury vapor in simulated flue gas streams. Fly ash from sub-bituminous Wyodak-Anderson PRB coal and bituminous Blacksville coal were used. Scanning electron microscopy, X-ray diffraction, thermogravimetric analyses, and BET N{sub 2} isothermal sorption analyses were performed to characterize the fly ash samples. Mercury speciation downstream from the ash was determined using the Ontario Hydro method. Results showed that the presence of fly ash was critical for mercury oxidation, and the surface area of the ash appears to be an important parameter. However, for a given fly ash, there were generally no major differences in catalytic oxidation potential between different fly ash fractions. This includes fractions enriched in unburned carbon and iron oxides. The presence of NO{sub 2}, HCl, and SO{sub 2} resulted in greater levels of mercury oxidation, while NO inhibited mercury oxidation. The gas matrix affected mercury oxidation more than the fly ash composition. 21 refs., 10 figs., 2 tabs.

  18. Biological and environmental risk factors of children exposed or not to environmental tobacco pollution

    Directory of Open Access Journals (Sweden)

    Alice Stenzel de Pina Ferreira

    2017-12-01

    Full Text Available We aimed to investigate the biological and environmental risk facotrs of children exposed or not to environmental tobacco pollution (ETP. A cross-sectional study with 670 children of both sexes, aged between eight and 12 years, from schools located in Anápolis (GO. We used an adapted questionnaire directed to parents/guardians. The parents of children of the non-exposed to ETP group (NETP were more educated. The group of children exposed to ETP (EETP had a higher history of respiratory disease. The EETP resides with a smoker, commonly fathers, who smoke up to 20 cigarretes a day. The EETP lived in houses with fewer windows, less air circulation and more registries of mold. The EETP presents more respiratory diseases and unfavourable socioeconomic conditions. Therefore, there is a need for more care for the exposure and the environment where they live. Health professionals and educators should promote protection, education and stimulate the abandonment of parent smoking.

  19. Observations On Some Upper Amazonian Wetlands of Southeastern Peru

    Science.gov (United States)

    Householder, J. E.; Muttiah, R.; Khanal, S.

    2007-05-01

    Upper Amazonian wetlands represent little studied, poorly understood, and grossly under protected systems. Scientific investigation of Amazonian wetlands is in its infancy; nor is there much known about their ecological services. Regionally, wetlands form a ubiquitous and significant component of floodplain habitat fed by perennial springs as well as overland runoff. Locally, wetland vegetation forms bewilderingly complex vegetation mosaics that seem to be governed by local topography and hydrology. Drawing upon intensive field campaigns and remotely sensed imagery, we summarize the results and experiences gathered in wetlands of southeastern Peru.

  20. Current Mercury Exposure from Artisanal and Small-Scale Gold Mining in Bombana, Southeast Sulawesi, Indonesia-Future Significant Health Risks.

    Science.gov (United States)

    Sakakibara, Masayuki; Sera, Koichiro

    2017-02-08

    The rapid expansion of the artisanal and small-scale gold mining (ASGM) industry in developing countries has marginalized the local communities in poverty, and resulted in occupational exposure to mercury via the gold extraction process. We investigated the mercury exposure of the mining workers lived inside and outside the mining area. Based on the occupations of the contributors, the hair samples were divided into three subgroups: directly exposed, indirectly exposed, and a control. A total of 81 hair samples were analyzed by particle-induced X-ray emission spectrometry. The median mercury concentration was highest in the hair from the directly exposed group (12.82 μg/g hair) (control group median: 4.8 μg/g hair, p mining area but who are not engaged in mercury-based gold extraction.

  1. Mercury uptake and accumulation by four species of aquatic plants.

    Science.gov (United States)

    Skinner, Kathleen; Wright, Nicole; Porter-Goff, Emily

    2007-01-01

    The effectiveness of four aquatic plants including water hyacinth (Eichornia crassipes), water lettuce (Pistia stratiotes), zebra rush (Scirpus tabernaemontani) and taro (Colocasia esculenta) were evaluated for their capabilities in removing mercury from water. The plants were exposed to concentrations of 0 mg/L, 0.5 mg/L or 2 mg/L of mercury for 30 days. Assays were conducted using both Microtox (water) and cold vapor Atomic Absorption Spectroscopy (AAS) (roots and water). The Microtox results indicated that the mercury induced acute toxicity had been removed from the water. AAS confirmed an increase of mercury within the plant root tissue and a corresponding decrease of mercury in the water. All species of plants appeared to reduce mercury concentrations in the water via root uptake and accumulation. Water lettuce and water hyacinth appeared to be the most effective, followed by taro and zebra rush, respectively.

  2. Lower life satisfaction related to materialism in children frequently exposed to advertising.

    Science.gov (United States)

    Opree, Suzanna J; Buijzen, Moniek; Valkenburg, Patti M

    2012-09-01

    Research among adults suggests that materialism and life satisfaction negatively influence each other, causing a downward spiral. So far, cross-sectional research among children has indicated that materialistic children are less happy, but causality remains uncertain. This study adds to the literature by investigating the longitudinal relation between materialism and life satisfaction. We also investigated whether their relation depended on children's level of exposure to advertising. A sample of 466 children (aged 8-11; 55% girls) participated in a 2-wave online survey with a 1-year interval. We asked children questions about material possessions, life satisfaction, and advertising. We used structural equation modeling to study the relationship between these variables. For the children in our sample, no effect of materialism on life satisfaction was observed. However, life satisfaction did have a negative effect on materialism. Exposure to advertising facilitated this effect: We only found an effect of life satisfaction on materialism for children who were frequently exposed to advertising. Among 8- to 11-year-old children, life satisfaction leads to decreased materialism and not the other way around. However, this effect only holds for children who are frequently exposed to television advertising. It is plausible that the material values portrayed in advertising teach children that material possessions are a way to cope with decreased life satisfaction. It is important to reduce this effect, because findings among adults suggest that materialistic children may become less happy later in life. Various intervention strategies are discussed.

  3. Clastogenic factors in the plasma of children exposed at Chernobyl

    International Nuclear Information System (INIS)

    Emerit, I.; Levy, A.; Cernjavski, L.; Alaoui-Youssefi, A.; Pogossian, A.; Quastel, M.; Goldsmith, J.; Merkin, L.; Riklis, E.

    1997-01-01

    Clastogenic factors (CFs), as they were described previously in accidentally or therapeutically irradiated persons, in A-bomb survivors and in liquidators of the Chernobyl nuclear power plant, were also detected in the plasma of Chernobyl-exposed children. A high percentage of plasma ultrafiltrates from 170 children, immigrated to Israel in 1990, exerted clastogenic effects in test cultures set up with blood from healthy donors. The differences were highly significant in comparison to children immigrated from 'clean' cities of the former Soviet Union or children born in Israel. The percentage of CF-positive children and the mean values of the adjusted clastogenic scores (ACS) were higher for those coming from Gomel and Mozyr, which are high exposure sites (IAEA measurements), compared to those coming from Kiev. There was no correlation between residual 137-Caesium body burden and presence of CFs. However, both measurements were not done at the same time (in 1990 and 1992-1994, respectively). Also no relationship could be revealed between enlargement of the thyroid gland and CF-positivity. CFs are not only observed after irradiation, but in a variety of chronic inflammatory diseases with autoimmune reactions. They were also described in the congenital breakage syndromes, which are hereditary diseases with the highest cancer incidence in humans. Whether the clastogenic effects continuously produced by circulating CFs represent a risk factor for malignant late effects deserves further study and follow-up. Since CF formation and CF action are mediated by superoxide radicals, prophylactic treatment with antioxidants may be suggested for Chernobyl-exposed children, whose plasma induces a strongly positive CF-test

  4. Occupational Exposure to Mercury among Workers in a Fluorescent Lamp Factory, Quisna Industrial Zone, Egypt

    Directory of Open Access Journals (Sweden)

    MA Al-Batanony

    2013-07-01

    Full Text Available Background: With the fast growth in the market of fluorescent lamps, particularly compact fluorescent light, the associated risk of mercury exposure, which is an essential component in all types of fluorescent lamps, has received increasing public attention worldwide. Even low doses of mercury are toxic. Objective: To study the health consequences of occupational exposure to mercury in workers of a fluorescent lamp factory. Methods: In a cross-sectional study 138 workers of a florescent lamp factory and 151 people who had no occupational exposure to mercury (the comparison group were studied. Environmental study of mercury and noise levels was done. For all participants a neurobehavioral test battery was administered, spirometry was performed and air conduction audiometry was done. Urinary mercury level was also measured for all participants. Results: Prominent symptoms among workers exposed to mercury included tremors, emotional lability, memory changes, neuromuscular changes, and performance deficits in tests of cognitive function. Among the exposed group, the mean urinary mercury level was significantly higher in those who had personality changes or had manifestations of mercury toxicity. With increasing duration of employment and urinary mercury level, the performance of participants in neurobehavioral test battery and spirometric parameters deteriorated. Conclusion: Neurobehavioral test battery must be used for studying subclinical central nervous system dysfunction in those with chronic exposure to mercury. The test is especially useful for evaluating the severity of mercury effects in epidemiological studies. This study also reinforces the need for effective preventive programs for florescent lamp industry workplaces especially in developing countries with the lowest unhygienic work conditions.

  5. Prediction of mercury bioavailability to common carp (Cyprinus carpio L.) using the diffusive gradient in thin film technique.

    Science.gov (United States)

    Pelcová, Pavlína; Vičarová, Petra; Ridošková, Andrea; Dočekalová, Hana; Kopp, Radovan; Mareš, Jan; Poštulková, Eva

    2017-11-01

    The mercury bioaccumulation by common carp (Cyprinus carpio L.) tissues (gills, skin, eyes, scales, muscle, brain, kidneys, liver, and spleen) and the capability of the diffusive gradient in thin film (DGT) technique to predict bioavailability of mercury for individual carp's tissues were evaluated. Carp and DGT units were exposed to increasing concentrations of mercury (Hg 2+ : 0 μg L -1 , 0.5 μg L -1 , 1.5 μg L -1 and 3.0 μg L -1 ) in fish tanks for 14 days. In the uncontaminated fish group, the highest mercury concentration was determined in the muscle tissues and, in fish groups exposed to mercury, the highest mercury concentration was determined in the detoxification (kidneys) and input (gills) organs. A strong and positive correlation between the rate of mercury uptake by the DGT technique and the rate of mercury accumulation by fish tissues (gills, skin, scales, and eyes) was observed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Posttraumatic Stress Disorder in Infants and Young Children Exposed to War-Related Trauma

    Science.gov (United States)

    Feldman, Ruth; Vengrober, Adva

    2011-01-01

    Objective: Although millions of the world's children are growing up amidst armed conflict, little research has described the specific symptom manifestations and relational behavior in young children exposed to wartime trauma or assessed factors that chart pathways of risk and resilience. Method: Participants included 232 Israeli children 1.5 to 5…

  7. Distribution and excretion of inhaled mercury vapour

    Energy Technology Data Exchange (ETDEWEB)

    Gage, J C

    1961-01-01

    Rats have been exposed for varying periods to an atmosphere containing 1 mg/cu.m. mercury vapor. The toxic effects produced showed resemblances to signs of mercurialism in man. An attempt has been made to study the kinetics of absorption and excretion of mercury from measurements of the amounts excreted and stored in the tissues. The efficiency of absorption of mercury by the rat lung is about 50%. A small proportion is excreted into the gut. After about 10 days of continuous exposure a steady state is reached in which excretion balances absorption. During short exposures the turnover of mercury in all tissues except brain is fairly rapid and most of the mercury is cleared from the body within a week after exposure. The urinary excretion of mercury, during the initial stage of storage in the tissues and the final stage of clearance, shows divergencies from the simple exponential pattern; there appears to be a delay mechanism in the kidney which, in intermittent exposures, may result in the occurrence of peak excretion during periods of non-exposure. After more prolonged exposures the mercury in the kidney appears to be converted to a form which is only very slowly excreted. The significance of the urinary excretion of mercury by man after industrial exposure to mercury vapour is discussed. The rat experiments suggest that single measurements will give only limited information concerning industrial conditions, but that an approximate assessment of the total absorbed during a working week would be obtained if it were possible to make a seven-day collection of urine. Repeated measurements after exposure would yield information on the duration of exposure and would have some diagnostic value.

  8. Pulmonary CT findings in acute mercury vapour exposure

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Manabu; Sato, Kimihiko; Heianna, Jyouiti; Hirano, Yoshinori; Omachi, Kohiti; Izumi, Jyunichi; Watarai, Jiro

    2001-01-01

    AIM: We describe the pulmonary computed tomography (CT) findings in acute mercury poisoning. MATERIALS AND METHODS: Initial (n= 8) and follow-up (n= 6) chest CT examinations in eight patients exposed to mercury vapour while cutting pipes in a sulphuric acid plant were reviewed. Of the eight patients, two were asymptomatic and had normal CT results, two were asymptomatic but had abnormalities on CT, and four had both acute symptoms and positive CT results. The patients were all men whose ages ranged from 37 to 54 years (mean, 49 years). RESULTS: Poorly defined nodules were present in five of six patients with positive CT findings, present alone in two patients or as part of a mixed pattern in three. They were random in distribution. Alveolar consolidation (n= 3) and areas of ground-glass opacity (n= 4) were observed and were more prominent in the most severely affected patients with the highest blood and urine level of mercury, predominantly in the upper and/or middle zone. These abnormal findings on CT resolved with (n= 1) or without (n= 5) steroid therapy. Pathological findings (n= 1) demonstrated acute interstitial changes predominantly with oedema. CONCLUSION: We report CT findings in eight patients acutely exposed to mercury vapour. The pulmonary injury was reversible on CT in these cases. Hashimoto, M. (2001)

  9. Out-of-home placement to age 18 years in children exposed to a postpartum mental disorder

    DEFF Research Database (Denmark)

    Vigod, Simone N; Laursen, Thomas Munk; Ranning, Anne

    2018-01-01

    comprising 1 868 467 births (1982-2012) were used to determine how the timing of maternal illness onset influences out-of-home placement risk up to age 18 years among children exposed to a maternal mental disorder. RESULTS: Compared to children unexposed to maternal mental illness, risk was higher......OBJECTIVES: Little is known about risk of custody loss or out-of-home placement among children whose mothers experience postpartum mental disorders, and whether this risk differs from that of children whose mothers had earlier onset of their mental disorder. METHODS: National Danish registers.......49/1000 person-years; 3.93, 3.50-4.41). Risk was even higher for children exposed to a maternal mental disorder when illness onset was more than 1-year predelivery (9.11/1000 person-years; 5.48, 5.32-5.66). CONCLUSION: Risk of out-home placement in children exposed to mothers with a new-onset postpartum mental...

  10. Reactive gaseous mercury is generated from chloralkali factories resulting in extreme concentrations of mercury in hair of workers

    Science.gov (United States)

    Occupational exposure of chloralkali workers to highly concentrated mercury (Hg) vapour has been linked to an increased risk of renal dysfunction and behavioural changes. It is generally believed that these workers are exposed to elemental Hg, which is used in abundance during th...

  11. 76 FR 67761 - Establishment of the Attorney General's National Task Force on Children Exposed to Violence

    Science.gov (United States)

    2011-11-02

    ... the Attorney General's National Task Force on Children Exposed to Violence AGENCY: Office of Juvenile.... SUMMARY: The Attorney General's National Task Force on Children Exposed to Violence (the Task Force) is....C., App. 2. The Task Force will provide the Attorney General with valuable advice on a broad array...

  12. Transport, transformation and risks of mercury in the environment

    International Nuclear Information System (INIS)

    Gombos, B.; Kupka, J.

    1992-01-01

    The meaning of mercury in the assessment of the environmental conditions results from the increase in the concentration of mercury from natural sources in the atmosphere and that from the anthropogenic processes which one met especially in the civilized areas of Europe. Conversion and migration mechanisms in the environment are pointed out and judged from the hygienic viewpoint, taking into consideration the site of Rudnany in Eastern Slowaky where, for a long time, mercurial .. has been exploited and processed. The theses mentioned in the article are supported by the experimental data won in the studies. Clinical symptons of micromercurialism were not found in the people exposed to mercury for a long time. The hygienic situation in Rudnany can be improved by careful technical preventive measures and by changing the technological methods of production. (BBR) [de

  13. Mental health interventions for children exposed to disasters and terrorism.

    Science.gov (United States)

    Pfefferbaum, Betty; Newman, Elana; Nelson, Summer D

    2014-02-01

    The purpose of this review is to describe interventions used with children who are exposed to disasters and terrorism and to present information about the potential benefits of these interventions. A literature search conducted in January 2013 using relevant databases and literature known to the authors that was not generated by the search yielded a total of 85 studies appropriate for review. Intervention approaches used with children exposed to disasters and terrorism included preparedness interventions, psychological first aid, psychological debriefing, psychoeducation, cognitive behavioral techniques, exposure and narrative techniques, eye movement desensitization and reprocessing, and traumatic grief interventions. The investigation of these interventions is complex, and studies varied in methodological rigor (e.g., sample size, the use of control groups, outcomes measured). Given the limitations in the currently available empirical information, this review integrates the literature, draws tentative conclusions about the current state of knowledge, and suggests future directions for study.

  14. Low CD4+ T-cell levels and B-cell apoptosis in vertically HIV-exposed noninfected children and adolescents.

    Science.gov (United States)

    Miyamoto, Maristela; Pessoa, Silvana D; Ono, Erika; Machado, Daisy M; Salomão, Reinaldo; Succi, Regina C de M; Pahwa, Savita; de Moraes-Pinto, Maria Isabel

    2010-12-01

    Lymphocyte subsets, activation markers and apoptosis were assessed in 20 HIV-exposed noninfected (ENI) children born to HIV-infected women who were or not exposed to antiretroviral (ARV) drugs during pregnancy and early infancy. ENI children and adolescents were aged 6-18 years and they were compared to 25 age-matched healthy non-HIV-exposed children and adolescents (Control). ENI individuals presented lower CD4(+) T cells/mm(3) than Control group (control: 1120.3 vs. ENI: 876.3; t-test, p = 0.030). ENI individuals had higher B-cell apoptosis than Control group (Control: 36.6%, ARV exposed: 82.3%, ARV nonexposed: 68.5%; Kruskal-Wallis, p ENI and in Control children and adolescents. Subtle long-term immune alterations might persist among ENI individuals, but the clinical consequences if any are unknown, and these children require continued monitoring.

  15. Ethnic Kawasaki Disease Risk Associated with Blood Mercury and Cadmium in U.S. Children

    Science.gov (United States)

    Yeter, Deniz; Portman, Michael A.; Aschner, Michael; Farina, Marcelo; Chan, Wen-Ching; Hsieh, Kai-Sheng; Kuo, Ho-Chang

    2016-01-01

    Kawasaki disease (KD) primarily affects children <5 years of age (75%–80%) and is currently the leading cause of acquired heart disease in developed nations. Even when residing in the West, East Asian children are 10 to 20 times more likely to develop KD. We hypothesized cultural variations influencing pediatric mercury (Hg) exposure from seafood consumption may mediate ethnic KD risk among children in the United States. Hospitalization rates of KD in US children aged 0–4 years (n = 10,880) and blood Hg levels in US children aged 1–5 years (n = 713) were determined using separate US federal datasets. Our cohort primarily presented with blood Hg levels <0.1 micrograms (µg) per kg bodyweight (96.5%) that are considered normal and subtoxic. Increased ethnic KD risk was significantly associated with both increasing levels and detection rates of blood Hg or cadmium (Cd) in a linear dose-responsive manner between ethnic African, Asian, Caucasian, and Hispanic children in the US (p ≤ 0.05). Increasing low-dose exposure to Hg or Cd may induce KD or contribute to its later development in susceptible children. However, our preliminary results require further replication in other ethnic populations, in addition to more in-depth examination of metal exposure and toxicokinetics. PMID:26742052

  16. Neuropsychological dysfunction related to earlier occupational exposure to mercury vapor

    Directory of Open Access Journals (Sweden)

    E.C. Zachi

    2007-03-01

    Full Text Available We assessed the neuropsychological test performances of 26 patients (mean age = 41.5 ± 6.1 years; mean years of education = 9.8 ± 1.8; 20 males diagnosed with chronic occupational mercurialism who were former workers at a fluorescent lamp factory. They had been exposed to elemental mercury for an average of 10.2 ± 3.8 years and had been away from this work for 6 ± 4.7 years. Mean urinary mercury concentrations 1 year after cessation of work were 1.8 ± 0.9 µg/g creatinine. Twenty control subjects matched for age, gender, and education (18 males were used for comparison. Neuropsychological assessment included attention, inhibitory control, verbal and visual memory, verbal fluency, manual dexterity, visual-spatial function, executive function, and semantic knowledge tests. The Beck Depression Inventory and the State and Trait Inventory were used to assess depression and anxiety symptoms, respectively. The raw score for the group exposed to mercury indicated slower information processing speed, inferior performance in psychomotor speed, verbal spontaneous recall memory, and manual dexterity of the dominant hand and non-dominant hand (P < 0.05. In addition, the patients showed increased depression and anxiety symptoms (P < 0.001. A statistically significant correlation (Pearson was demonstrable between mean urinary mercury and anxiety trait (r = 0.75, P = 0.03. The neuropsychological performances of the former workers suggest that occupational exposure to elemental mercury has long-term effects on information processing and psychomotor function, with increased depression and anxiety also possibly reflecting the psychosocial context.

  17. PERCEPTIONS AND REPRESENTATIONS OF THE FOREIGN AUTHOR ABOUT AMAZONIAN MAN: AN ANALYSIS UNDER THE CATEGORIES OF GEOGRAPHY

    Directory of Open Access Journals (Sweden)

    Klondy Lúcia de Oliveira Agra

    2013-07-01

    Full Text Available In this article, I analyze, with aid of the concepts guide for the geographical science, two works by Americans over the Brazilian Amazon. Amazon Town of Charles Wagley, and the travel journal of American George E. Hafstad. Works which exposes the Brazilian Amazon and way of life of its people, describing in detail actions, habits, thoughts and beliefs, way of acting man Amazonian descriptions that form a backdrop of compositions and orientations of Amazon to the world. The main objective of this paper is to check the perceptions and representations of foreign researchers to translate Amazon contexts and scenarios to your community, with the help of the notions of space, place, landscape and territory. Interest in the analysis of these materials is due to singular description of Amazonian details that demonstrate the concern of foreign technicians involved with research in the Brazilian Amazon, between the years 1940 to 1950, with reading contexts and scenarios and detailed translation of the analyzed reality to their community, and also by the possibility of observation and demystification of misunderstandings made by these researchers and the rescue of cultural and historical values of this region.

  18. Emotions and personality traits in former mercury miners

    Directory of Open Access Journals (Sweden)

    Darja Kobal Grum

    2005-02-01

    Full Text Available The aim of this study is to evaluate the impact of long-term occupational exposure to elemental mercury vapor (Hg° on the personality traits of ex-mercury miners. The study groups included 53 ex-mercury miners previously exposed to Hg° and 53 age-matched controls. Their previous occupational exposure, as well as some biological indices of actual non-occupational exposure, were evaluated. Miners and controls completed the self-reporting Eysenck Personality Questionnaire (EPQ and the Emotional States Questionnaire (ESQ. Group differences were analyzed through the application of ANOVA software. The relationship between the indices of previous occupational exposure and the observed personality traits was evaluated by machine learning methods (regression trees. The mercury miners were intermittently exposed to Hg° in intervals – cycles for a period of 7-31 years at air Hg° concentrations ranging from 0.14 to 0.45 mg/m3. The miners' mean cycle urine mercury (U-Hg level (range 20–120 μg/L and cumulative U-Hg level (range 1286–21390 μg/L were very high. The present non-occupational exposure to mercury was very low in both groups. The low extraversion and lie scores shown by EPQ suggest that miners are more introverted and sincere. The results obtained from ESQ indicate that mercury miners tend to be more depressive, more rigid in expressing their emotions (indifference, and are likely to have more negative self-concepts than the controls. The tendency towards emotional rigidity, negative self-concept, and partly also introversion seems to be associated with some biological indices of occupational Hg° exposure, but not the lower score of lie found in miners. Higher occupational Hg° exposure (cycles U-Hg level > 38.7 mg/L in interaction with moderate alcohol consumption (<26 ml/day seems to have had a decisive influence on the development of miners' depression. Despite the limitations, long-term intermittent, substantial exposure to Hg° in

  19. Mercury accumulation in placenta and foetal membranes. A study of dental workers and their babies

    Energy Technology Data Exchange (ETDEWEB)

    Wannag, A; Skjaerasen, J

    1975-01-01

    To investigate the hazards of exposure to levels of elementary mercury lower than the present TLV value (0.05 mg/m/sup 3/) a group of dental workers and a nonexposed group were studied. The amount of mercury in blood from mothers and babies at the time of delivery was similar. The exposed group had increased mercury content in placenta and fetal membranes. Mercury accumulation in these organs might serve as a protection for the fetus against mercury exposure. Since exposure to sub-TLV concentrations of elemental mercury during pregnancy will not be reflected in blood mercury content at the time of delivery, the amount of mercury in placenta and fetal membranes might serve as a biological indicator of such exposure.

  20. A review of mercury exposure among artisanal small-scale gold miners in developing countries

    DEFF Research Database (Denmark)

    Kristensen, Anders Kasper Bruun; Thomsen, Jane Frølund; Mikkelsen, Sigurd

    2014-01-01

    Extraction of gold using mercury has been a way out of poverty for millions of people in developing countries. Artisanal small-scale gold mining (ASGM) has expanded during the last decades and is often carried out under primitive conditions. Thus, workers in this industry may be exposed to high...... levels of mercury and suffer from toxic effects from mercury exposure. The objective of this review was to provide an outline of the studies available on elemental mercury exposure among artisanal small-scale gold miners....

  1. Out-of-home placement to age 18 years in children exposed to a postpartum mental disorder.

    Science.gov (United States)

    Vigod, Simone N; Laursen, Thomas Munk; Ranning, Anne; Nordentoft, Merete; Munk-Olsen, Trine

    2018-04-17

    Little is known about risk of custody loss or out-of-home placement among children whose mothers experience postpartum mental disorders, and whether this risk differs from that of children whose mothers had earlier onset of their mental disorder. National Danish registers comprising 1 868 467 births (1982-2012) were used to determine how the timing of maternal illness onset influences out-of-home placement risk up to age 18 years among children exposed to a maternal mental disorder. Compared to children unexposed to maternal mental illness, risk was higher for children exposed to a maternal mental disorder whose mothers had a first contact for a mental disorder in the 0-12 months of predelivery (8.17/1000 person-years; aIRR 4.56, 95% CI 4.08-5.09), the first 3 months postpartum (4.60/1000 person-years; 3.55, 2.95-4.26) and 4-12 months postpartum (6.49/1000 person-years; 3.93, 3.50-4.41). Risk was even higher for children exposed to a maternal mental disorder when illness onset was more than 1-year predelivery (9.11/1000 person-years; 5.48, 5.32-5.66). Risk of out-home placement in children exposed to mothers with a new-onset postpartum mental disorder is almost as high as in children whose mothers have long-standing illness. A better understanding of the trajectories of these mothers and children is warranted. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. A preliminary study on health effects in villagers exposed to mercury in a small-scale artisanal gold mining area in Indonesia.

    Science.gov (United States)

    Bose-O'Reilly, Stephan; Schierl, Rudolf; Nowak, Dennis; Siebert, Uwe; William, Jossep Frederick; Owi, Fradico Teorgi; Ir, Yuyun Ismawati

    2016-08-01

    Cisitu is a small-scale gold mining village in Indonesia. Mercury (Hg) is used to extract gold from ore, heavily polluting air, soil, fish and rice paddy fields with Hg. Rice in Cisitu is burdened with mercury. The main staple food of the inhabitants of Cisitu is this polluted rice. Villagers were concerned that the severe diseases they observed in the community might be related to their mining activities, including high mercury exposure. Case report of the medical examinations and the mercury levels in urine and hair of 18 people with neurological symptoms. Typical signs and symptoms of chronic mercury intoxication were found (excessive salivation, sleep disturbances, tremor, ataxia, dysdiadochokinesia, pathological coordination tests, gray to bluish discoloration of the oral cavity and proteinuria). Mercury levels in urine were increased in eight patients (>7µg Hg/L urine). All 18 people had increased hair levels (>1µg Hg/g hair). 15 patients exhibited several, and sometimes numerous, symptoms in addition to having moderately to highly elevated levels of mercury in their specimens. These patients were classified as intoxicated. The situation in Cisitu is special, with rice paddy fields being irrigated with mercury-contaminated water and villagers consuming only local food, especially mercury-contaminated rice. Severe neurological symptoms and increased levels of mercury in urine and hair support are possibly caused by exposure to inorganic mercury in air, and the consumption of mercury-contaminated fish and rice. The mercury exposure needs to be reduced and treatment provided. Further research is needed to test the hypothesis that mercury-contaminated rice from small-scale gold mining areas might cause mercury intoxication. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Hair mercury and urinary cadmium levels in Belgian children and their mothers within the framework of the COPHES/DEMOCOPHES projects

    DEFF Research Database (Denmark)

    Pirard, Catherine; Koppen, Gudrun; De Cremer, Koen

    2014-01-01

    A harmonized human biomonitoring pilot study was set up within the frame of the European projects DEMOCOPHES and COPHES. In 17 European countries, biomarkers of some environmental pollutants, including urinary cadmium and hair mercury, were measured in children and their mothers in order to obtai...

  4. Mercury Disposition in Suckling Rats: Comparative Assessment Following Parenteral Exposure to Thiomersal and Mercuric Chloride

    Science.gov (United States)

    Blanuša, Maja; Orct, Tatjana; Vihnanek Lazarus, Maja; Sekovanić, Ankica; Piasek, Martina

    2012-01-01

    Due to the facts that thiomersal-containing vaccine is still in use in many developing countries, and all forms of mercury have recognised neurotoxic, nephrotoxic, and other toxic effects, studies on disposition of ethylmercury and other mercury forms are still justified, especially at young age. Our investigation aimed at comparing mercury distribution and rate of excretion in the early period of life following exposure to either thiomersal (TM) or mercuric chloride (HgCl2) in suckling rats. Three experimental groups were studied: control, TM, and HgCl2, with 12 to18 pups in each. Both forms of mercury were administered subcutaneously in equimolar quantities (0.81 μmol/kg b.w.) three times during the suckling period (on the days of birth 7, 9, and 11) to mimic the vaccination regimen in infants. After the last administration of TM or HgCl2, total mercury retention and excretion was assessed during following six days. In TM-exposed group mercury retention was higher in the brain, enteral excretion was similar, and urinary excretion was much lower compared to HgCl2-exposed sucklings. More research is still needed to elucidate all aspects of toxicokinetics and most harmful neurotoxic potential of various forms of mercury, especially in the earliest period of life. PMID:22899883

  5. Umbilical cord blood and placental mercury, selenium and selenoprotein expression in relation to maternal fish consumption

    OpenAIRE

    Gilman, Christy L.; Soon, Reni; Sauvage, Lynnae; Ralston, Nicholas V.C.; Berry, Marla J.

    2015-01-01

    Seafood is an important source of nutrients for fetal neurodevelopment. Most individuals are exposed to the toxic element mercury through seafood. Due to the neurotoxic effects of mercury, United States government agencies recommend no more than 340 g (12 oz) per week of seafood consumption during pregnancy. However, recent studies have shown that selenium, also abundant in seafood, can have protective effects against mercury toxicity. In this study, we analyzed mercury and selenium levels an...

  6. Posttraumatic play in young children exposed to terrorism: An empirical study.

    Science.gov (United States)

    Cohen, Esther; Chazan, Saralea; Lerner, Moran; Maimon, Efrat

    2010-03-01

    The phenomenon of "posttraumatic play" (PTP) has received much clinical recognition and little empirical support. The objective of this study was to examine various aspects of PTP in young children exposed to terror events and their relation to posttraumatic stress disorder (PTSD). Individual play sessions, conducted with 29 young Israeli children directly exposed to terrorism (M age = 5.47, SD = 1.34) and 25 matched unexposed children (M age = 5.62, SD = 0.87), were coded using the Children's Play Therapy Instrument-Adaptation for Terror Research (CPTI-ATR; S.E. Chazan & E. Cohen, 2003). Analyses using these ratings showed (a) significant differences between the two groups, (b) significant associations with the caregiver's reports on child's exposure, and (c) significant associations with the caregiver's reports on the child's PTSD symptoms. Play activity ratings of predominant negative affects, frequent acting-out/morbid themes, lowered developmental level, and reduced awareness of the child of him- or herself as a player significantly predicted more PTSD symptoms. PTP which included more coping strategies classified as "overwhelmed reexperiencing" and less "reenactment with soothing" was associated with a higher level of PTSD. Play analysis with the CPTI-ATR may be helpful in identifying PTSD in children and also guide the selection of therapeutic techniques. Copyright © 2010 Michigan Association for Infant Mental Health.

  7. Effect of mercury chloride to number of melano-macrophage centers on the kidney of carp fish (Cyprinus carpio)

    Science.gov (United States)

    Mubarokah, L.; Tjahjaningsih, W.; Sulmartiwi, L.

    2018-04-01

    Mercury chloride can cause immunotoxic effects on fish. The accumulation or aggregate of melano-macrophages centers (MMCs) in the kidney is a feature of cellular immune response, so it can be used as a bioindicator of heavy metal toxicity in waters. This research aims to determine an effect of heavy metal exposure concentration of mercury chloride (HgCl2) on a number of MMCs from common carp kidney. This research using four treatments of mercury chloride: 0 ppm, 0.01 ppm, 0.05 ppm and 0.1 ppm. The main parameters were the number of MMCs in kidney common carp. Supporting parameter was behavior change, water quality and concentration of mercury in the water and kidney. The results of the research showed that the concentration the heavy metal exposure concentration of mercury chloride (HgCl2) affected the number of MMCs from common carp (Cyprinus carpio) kidney. The number of MMCs in the kidney of common carp exposed to mercury chloride 0.01 ppm, 0.05 ppm and 0.1 ppm increased compared to carp was not exposed to mercury chloride (0 ppm).

  8. Placentation in the Amazonian manatee (Trichechus inunguis)

    DEFF Research Database (Denmark)

    Carter, A M; Miglino, M A; Ambrosio, C E

    2008-01-01

    Evidence from several sources supports a close phylogenetic relationship between elephants and sirenians. To explore whether this was reflected in similar placentation, we examined eight delivered placentae from the Amazonian manatee using light microscopy and immunohistochemistry. In addition, t...

  9. determination of mercury content in milk powder

    International Nuclear Information System (INIS)

    Jovchev, M.; Grigorov, T.; Apostolov, D.

    1985-01-01

    Four samples of humanized full cream cow milk powder of Bulgarian origin for new-born, sucklings, small children and soured milk powder were activated for 18-24 h in a neutron flux of 5.10 12 , resp. 2.10 13 n/cm 2 .sec in quartz ampules. The samples were activated without preliminary lyophilization, thus avoiding possible mistakes from mercury losses. Ag-110m, being eliminated in the amalgam, was not an obstacle to the mercury determination. The results obtained for the mercury content are in the same order as in other investigations and many times lower than the admissible norm for foodstuffs - 50 ppb

  10. Respiratory damage in children exposed to urban pollution.

    Science.gov (United States)

    Calderón-Garcidueñas, Lilian; Mora-Tiscareño, Antonieta; Fordham, Lynn A; Valencia-Salazar, Gildardo; Chung, Charles J; Rodriguez-Alcaraz, Antonio; Paredes, Rogelio; Variakojis, Daina; Villarreal-Calderón, Anna; Flores-Camacho, Lourdes; Antunez-Solis, Angelina; Henríquez-Roldán, Carlos; Hazucha, Milan J

    2003-08-01

    Southwest Metropolitan Mexico City (SWMMC) children are chronically exposed to complex mixtures of air pollutants. In a cross-sectional arm of our study, we investigated the association between exposure to SWMMC atmosphere and nasal abnormalities, hyperinflation, and interstitial markings assessed by chest X-rays, lung function changes, several serum cytokines, and endothelin-1 in 174 children aged 5-17 years vs. 27 control children residents in low-polluted areas. Control children had no nasal lesions, and only one child showed an abnormal chest X-ray. SWMMC children exhibited nasal abnormalities (22%), hyperinflation (67%), interstitial markings (49%), and a mild restrictive pattern by spirometry (10%). Interstitial markings were associated with a decrease in predicted values of FEF(25-75), FEF(75), and the FEV(1)/FVC ratio. Boys had a higher probability of developing interstitial markings with age (P = 0.004). Blood smear findings included toxic granulations in neutrophils and schistocytes. SWMMC children had more serum IL10 and IL6 and less IL8 than controls. In a longitudinal arm of our study, we found a significant seasonal drop in FVC and FEV(1) associated with a 6-month period of high ozone and PM(10) levels. Our data strongly suggest that a lifelong exposure to urban air pollution causes respiratory damage in children. Moreover, a cytokine network becomes imbalanced, with a shift towards upregulation of anti-inflammatory cytokines. Consequently, these children are potentially at risk for developing chronic lung disease and other systemic effects later in life. Copyright 2003 Wiley-Liss, Inc.

  11. A Miocene hyperdiverse crocodylian community reveals peculiar trophic dynamics in proto-Amazonian mega-wetlands

    Science.gov (United States)

    Salas-Gismondi, Rodolfo; Flynn, John J.; Baby, Patrice; Tejada-Lara, Julia V.; Wesselingh, Frank P.; Antoine, Pierre-Olivier

    2015-01-01

    Amazonia contains one of the world's richest biotas, but origins of this diversity remain obscure. Onset of the Amazon River drainage at approximately 10.5 Ma represented a major shift in Neotropical ecosystems, and proto-Amazonian biotas just prior to this pivotal episode are integral to understanding origins of Amazonian biodiversity, yet vertebrate fossil evidence is extraordinarily rare. Two new species-rich bonebeds from late Middle Miocene proto-Amazonian deposits of northeastern Peru document the same hyperdiverse assemblage of seven co-occurring crocodylian species. Besides the large-bodied Purussaurus and Mourasuchus, all other crocodylians are new taxa, including a stem caiman—Gnatusuchus pebasensis—bearing a massive shovel-shaped mandible, procumbent anterior and globular posterior teeth, and a mammal-like diastema. This unusual species is an extreme exemplar of a radiation of small caimans with crushing dentitions recording peculiar feeding strategies correlated with a peak in proto-Amazonian molluscan diversity and abundance. These faunas evolved within dysoxic marshes and swamps of the long-lived Pebas Mega-Wetland System and declined with inception of the transcontinental Amazon drainage, favouring diversification of longirostrine crocodylians and more modern generalist-feeding caimans. The rise and demise of distinctive, highly productive aquatic ecosystems substantially influenced evolution of Amazonian biodiversity hotspots of crocodylians and other organisms throughout the Neogene. PMID:25716785

  12. Mercury and Air Toxic Element Impacts of Coal Combustion By-Product Disposal and Utilizaton

    Energy Technology Data Exchange (ETDEWEB)

    David Hassett; Loreal Heebink; Debra Pflughoeft-Hassett; Tera Buckley; Erick Zacher; Mei Xin; Mae Sexauer Gustin; Rob Jung

    2007-03-31

    The University of North Dakota Energy & Environmental Research Center (EERC) conducted a multiyear study to evaluate the impact of mercury and other air toxic elements (ATEs) on the management of coal combustion by-products (CCBs). The ATEs evaluated in this project were arsenic, cadmium, chromium, lead, nickel, and selenium. The study included laboratory tasks to develop measurement techniques for mercury and ATE releases, sample characterization, and release experiments. A field task was also performed to measure mercury releases at a field site. Samples of fly ash and flue gas desulfurization (FGD) materials were collected preferentially from full-scale coal-fired power plants operating both without and with mercury control technologies in place. In some cases, samples from pilot- and bench-scale emission control tests were included in the laboratory studies. Several sets of 'paired' baseline and test fly ash and FGD materials collected during full-scale mercury emission control tests were also included in laboratory evaluations. Samples from mercury emission control tests all contained activated carbon (AC) and some also incorporated a sorbent-enhancing agent (EA). Laboratory release experiments focused on measuring releases of mercury under conditions designed to simulate CCB exposure to water, ambient-temperature air, elevated temperatures, and microbes in both wet and dry conditions. Results of laboratory evaluations indicated that: (1) Mercury and sometimes selenium are collected with AC used for mercury emission control and, therefore, present at higher concentrations than samples collected without mercury emission controls present. (2) Mercury is stable on CCBs collected from systems both without and with mercury emission controls present under most conditions tested, with the exception of vapor-phase releases of mercury exposed to elevated temperatures. (3) The presence of carbon either from added AC or from unburned coal can result in mercury

  13. Impaired cross-talk between the thioredoxin and glutathione systems is related to ASK-1 mediated apoptosis in neuronal cells exposed to mercury.

    Science.gov (United States)

    Branco, Vasco; Coppo, Lucia; Solá, Susana; Lu, Jun; Rodrigues, Cecília M P; Holmgren, Arne; Carvalho, Cristina

    2017-10-01

    Mercury (Hg) compounds target both cysteine (Cys) and selenocysteine (Sec) residues in peptides and proteins. Thus, the components of the two major cellular antioxidant systems - glutathione (GSH) and thioredoxin (Trx) systems - are likely targets for mercurials. Hg exposure results in GSH depletion and Trx and thioredoxin reductase (TrxR) are prime targets for mercury. These systems have a wide-range of common functions and interaction between their components has been reported. However, toxic effects over both systems are normally treated as isolated events. To study how the interaction between the glutathione and thioredoxin systems is affected by Hg, human neuroblastoma (SH-SY5Y) cells were exposed to 1 and 5μM of inorganic mercury (Hg 2+ ), methylmercury (MeHg) or ethylmercury (EtHg) and examined for TrxR, GSH and Grx levels and activities, as well as for Trx redox state. Phosphorylation of apoptosis signalling kinase 1 (ASK1), caspase-3 activity and the number of apoptotic cells were evaluated to investigate the induction of Trx-mediated apoptotic cell death. Additionally, primary cerebellar neurons from mice depleted of mitochondrial Grx2 (mGrx2D) were used to examine the link between Grx activity and Trx function. Results showed that Trx was affected at higher exposure levels than TrxR, especially for EtHg. GSH levels were only significantly affected by exposure to a high concentration of EtHg. Depletion of GSH with buthionine sulfoximine (BSO) severely increased Trx oxidation by Hg. Notably, EtHg-induced oxidation of Trx was significantly enhanced in primary neurons of mGrx2D mice. Our results suggest that GSH/Grx acts as backups for TrxR in neuronal cells to maintain Trx turnover during Hg exposure, thus linking different mechanisms of molecular and cellular toxicity. Finally, Trx oxidation by Hg compounds was associated to apoptotic hallmarks, including increased ASK-1 phosphorylation, caspase-3 activation and increased number of apoptotic cells

  14. Investigations of mercury concentrations in infant organs; Untersuchungen zur Quecksilberkonzentration in Organen von Kindern

    Energy Technology Data Exchange (ETDEWEB)

    Schlosser, C.

    2001-07-01

    Study of the mercury concentration of organs (kidneys, liver, brain, spleen, thyroid, pituitary gland, thymus) of 32 dead children, aged 0.1 - 15 years. Comparison with mercury concentration in adults. Emphasis is given on the role of dental amalgam. Study of age dependence of mercury contamination.

  15. Mercury-induced hepatotoxicity in zebrafish: in vivo mechanistic insights from transcriptome analysis, phenotype anchoring and targeted gene expression validation

    Directory of Open Access Journals (Sweden)

    Mathavan Sinnakaruppan

    2010-03-01

    Full Text Available Abstract Background Mercury is a prominent environmental contaminant that causes detrimental effects to human health. Although the liver has been known to be a main target organ, there is limited information on in vivo molecular mechanism of mercury-induced toxicity in the liver. By using transcriptome analysis, phenotypic anchoring and validation of targeted gene expression in zebrafish, mercury-induced hepatotoxicity was investigated and a number of perturbed cellular processes were identified and compared with those captured in the in vitro human cell line studies. Results Hepato-transcriptome analysis of mercury-exposed zebrafish revealed that the earliest deregulated genes were associated with electron transport chain, mitochondrial fatty acid beta-oxidation, nuclear receptor signaling and apoptotic pathway, followed by complement system and proteasome pathway, and thereafter DNA damage, hypoxia, Wnt signaling, fatty acid synthesis, gluconeogenesis, cell cycle and motility. Comparative meta-analysis of microarray data between zebrafish liver and human HepG2 cells exposed to mercury identified some common toxicological effects of mercury-induced hepatotoxicity in both models. Histological analyses of liver from mercury-exposed fish revealed morphological changes of liver parenchyma, decreased nucleated cell count, increased lipid vesicles, glycogen and apoptotic bodies, thus providing phenotypic evidence for anchoring of the transcriptome analysis. Validation of targeted gene expression confirmed deregulated gene-pathways from enrichment analysis. Some of these genes responding to low concentrations of mercury may serve as toxicogenomic-based markers for detection and health risk assessment of environmental mercury contaminations. Conclusion Mercury-induced hepatotoxicity was triggered by oxidative stresses, intrinsic apoptotic pathway, deregulation of nuclear receptor and kinase activities including Gsk3 that deregulates Wnt signaling

  16. Mother-child interaction and cognitive development in children prenatally exposed to methadone or buprenorphine.

    Science.gov (United States)

    Konijnenberg, Carolien; Sarfi, Monica; Melinder, Annika

    2016-10-01

    To assess the influence of mother-child interaction on children's cognitive development in a group of children prenatally exposed to methadone or buprenorphine. The study is part of a prospective longitudinal project investigating the development of children born to women in opioid maintenance therapy (OMT). The sample includes 67 children born between 2005 and 2007, 35 of which prenatally exposed to either methadone or buprenorphine and 32 non-exposed comparison children. Both groups scored within the normal range of development. However, the OMT group scored significantly lower on measures of cognitive development and mother-child interaction compared to the comparison group. Cognitive development was found to be affected by both group status, F(1,54)=5.65, p=0.02, η(2)=0.10 and mother-child interaction F(1,54)=5.26, p=0.03, η(2)=0.09. Behavioral inhibition (statue), sensorimotor function (imitating hand positions), and short-term memory (sentences) was influenced by group status while narrative memory and vocabulary were found to be more influenced by mother-child interaction. Different risk factors may influence different cognitive functions in children of women in OMT. Specifically, language-related cognitive skills may be more related to mother-child interaction while performance in higher cognitive functions requiring precise control over sensorimotor responses may be more sensitive to other factors such as prenatal OMT exposure, genetics, and/or prenatal exposure to other substances. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. Fracture risk by HIV infection status in perinatally HIV-exposed children.

    Science.gov (United States)

    Siberry, George K; Li, Hong; Jacobson, Denise

    2012-03-01

    The objective of this study was to examine the incidence of fractures in HIV-infected children and comparable HIV-exposed, uninfected (HEU) children in a multicenter, prospective cohort study (PACTG 219/219C) in the United States. The main outcome was first fracture during the risk period. Nine fractures occurred in 7 of 1326 HIV-infected and 2 of 649 HEU children, corresponding to incidence rates of 1.2 per 1000 person-years and 1.1 per 1000 person-years, respectively. The incidence rate ratio was 1.1 (95% CI 0.2, 5.5). There was no evidence of a substantially increased risk of fracture in HIV-infected compared to HEU children.

  18. Mercury biomagnification and the trophic structure of the ichthyofauna from a remote lake in the Brazilian Amazon

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo-Silva, Claudio Eduardo, E-mail: ceass@biof.ufrj.br [Laboratório de Radioisótopos Eduardo Penna, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Cidade Universitária, Av. Carlos Chagas Filho s/n, bloco G, Sala 60, Subsolo, Ilha do Fundão, Rio de Janeiro, RJ (Brazil); Almeida, Ronaldo [Instituto Natureza e Cultura, Universidade Federal do Amazonas, Rua 1 de Maio. Colegiado de Ciências Agrárias, Benjamin Constant, Colônia, AM (Brazil); Carvalho, Dario P. [Laboratório de Radioisótopos Eduardo Penna, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Cidade Universitária, Av. Carlos Chagas Filho s/n, bloco G, Sala 60, Subsolo, Ilha do Fundão, Rio de Janeiro, RJ (Brazil); Ometto, Jean P.H.B. [Instituto Nacional de Pesquisas Espaciais, Centro de Ciências do Sistema Terrestre, Avenida dos Astronautas, 1758, Jardim da Granja, São José dos Campos, SP (Brazil); Camargo, Plínio B. de [Laboratório de Ecologia Isotópica, Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Avenida Centenário, 303, São Dimas, Piracicaba, SP (Brazil); and others

    2016-11-15

    The present study assesses mercury biomagnification and the trophic structure of the ichthyofauna from the Puruzinho Lake, Brazilian Amazon. In addition to mercury determination, the investigation comprised the calculation of Trophic Magnification Factor (TMF) and Trophic Magnification Slope (TMS), through the measurements of stable isotopes of carbon (δ{sup 13}C) and nitrogen (δ{sup 15}N) in fish samples. These assessments were executed in two different scenarios, i.e., considering (1) all fish species or (2) only the resident fish (excluding the migratory species). Bottom litter, superficial sediment and seston were the sources used for generating the trophic position (TP) data used in the calculation of the TMF. Samples from 84 fish were analysed, comprising 13 species, which were categorized into four trophic guilds: iliophagous, planktivorous, omnivorous and piscivorous fish. The δ{sup 13}C values pointed to the separation of the ichthyofauna into two groups. One group comprised iliophagous and planktivorous species, which are linked to the food chains of phytoplankton and detritus. The other group was composed by omnivorous and piscivorous fish, which are associated to the trophic webs of phytoplankton, bottom litter, detritus, periphyton, as well as to food chains of igapó (blackwater-flooded Amazonian forests). The TP values suggest that the ichthyofauna from the Puruzinho Lake is part of a short food web, with three well-characterized trophic levels. Mercury concentrations and δ{sup 13}C values point to multiple sources for Hg input and transfer. The similarity in Hg levels and TP values between piscivorous and planktivorous fish suggests a comparable efficiency for the transfer of this metal through pelagic and littoral food chains. Regarding the two abovementioned scenarios, i.e., considering (1) the entire ichthyofauna and (2) only the resident species, the TMF values were 5.25 and 4.49, as well as the TMS values were 0.21 and 0.19, respectively

  19. Mercury biomagnification and the trophic structure of the ichthyofauna from a remote lake in the Brazilian Amazon

    International Nuclear Information System (INIS)

    Azevedo-Silva, Claudio Eduardo; Almeida, Ronaldo; Carvalho, Dario P.; Ometto, Jean P.H.B.; Camargo, Plínio B. de

    2016-01-01

    The present study assesses mercury biomagnification and the trophic structure of the ichthyofauna from the Puruzinho Lake, Brazilian Amazon. In addition to mercury determination, the investigation comprised the calculation of Trophic Magnification Factor (TMF) and Trophic Magnification Slope (TMS), through the measurements of stable isotopes of carbon (δ 13 C) and nitrogen (δ 15 N) in fish samples. These assessments were executed in two different scenarios, i.e., considering (1) all fish species or (2) only the resident fish (excluding the migratory species). Bottom litter, superficial sediment and seston were the sources used for generating the trophic position (TP) data used in the calculation of the TMF. Samples from 84 fish were analysed, comprising 13 species, which were categorized into four trophic guilds: iliophagous, planktivorous, omnivorous and piscivorous fish. The δ 13 C values pointed to the separation of the ichthyofauna into two groups. One group comprised iliophagous and planktivorous species, which are linked to the food chains of phytoplankton and detritus. The other group was composed by omnivorous and piscivorous fish, which are associated to the trophic webs of phytoplankton, bottom litter, detritus, periphyton, as well as to food chains of igapó (blackwater-flooded Amazonian forests). The TP values suggest that the ichthyofauna from the Puruzinho Lake is part of a short food web, with three well-characterized trophic levels. Mercury concentrations and δ 13 C values point to multiple sources for Hg input and transfer. The similarity in Hg levels and TP values between piscivorous and planktivorous fish suggests a comparable efficiency for the transfer of this metal through pelagic and littoral food chains. Regarding the two abovementioned scenarios, i.e., considering (1) the entire ichthyofauna and (2) only the resident species, the TMF values were 5.25 and 4.49, as well as the TMS values were 0.21 and 0.19, respectively. These findings

  20. The mercury burden of the Czech population: An integrated approach.

    Science.gov (United States)

    Puklová, Vladimíra; Krsková, Andrea; Cerná, Milena; Cejchanová, Mája; Rehůrková, Irena; Ruprich, Jirí; Kratzer, Karel; Kubínová, Růzena; Zimová, Magdaléna

    2010-07-01

    In this paper an integrated approach in assessment of the population exposure from various sources of total mercury (THg) oral intake in the Czech Republic is presented. The information on total mercury levels in diet, drinking water, surface urban soil and body fluids and tissues stem from the Czech national Environmental Health Monitoring System (EHMS) operated since 1994. The THg concentration was determined by the special atomic absorption spectrophotometer AMA 254. The data on THg content in food from the sales network were collected in 12 cities. The estimated average dietary intake representing more than 95% of weight of usual diet composition ranged 1-2% of the JECFA/FAO WHO provisional tolerable weekly intake (PTWI) value for total mercury (5 microg/kg b.w./week). Data on drinking water quality stem from the nationwide monitoring database. The content of THg in drinking water is generally low; only 0.2% of the Czech population supplied with drinking water from the distribution networks (total of 92% of the population) has a mercury intake from drinking water higher than 1% PTWI and not exceeding 5% PTWI. The estimation of potential mercury intake by unintentional consumption of soil in small children was based on THg content in surface soil of a total of 324 nursery schools in 24 cities and towns. Median value was 0.16 mg/kg. Human biomonitoring was performed in 9 Czech cities. In 2007, the mercury median values in blood of adults (N=412) were 0.85 and 0.89 microg/l in males and in females, respectively; urine median value in adults was 1.10 microg/g creatinine. In 2008, the blood median value in children (N=324) amounted to 0.35 microg/l; urine median value is 0.16 microg/g creatinine. In children's hair the median THg value was 0.18 microg/g. The correlation between fish consumption and blood THg levels was observed in both adults and children. Also the biomonitoring outputs did not reveal a substantial burden of the population. Copyright 2010 Elsevier

  1. [Current dietary exposure to mercury during pregnancy and childhood, and public health recommendations].

    Science.gov (United States)

    Llop, Sabrina; Ibarlucea, Jesús; Sunyer, Jordi; Ballester, Ferran

    2013-01-01

    Exposure to high levels of mercury during vulnerable periods (such as pregnancy and childhood) may have serious consequences for cognitive development, as observed after acute poisoning episodes in Japan and Irak. The main source of mercury exposure in the general population is consumption of certain types of fish. There is growing concern about the possible neurotoxic effects of mercury, especially in younger children in populations where fish intake is moderate to high. The scientific evidence to date is inconclusive. In Spain, the Childhood and Environment (Infancia y Medio Ambiente [INMA]) project has provided information on levels of prenatal exposure to mercury among 1800 newborns from Valencia, Sabadell, Asturias and Guipúzcoa. In general, levels were high, being above the World Health Organization's recommended dose in 24% of children and above the recommended levels of the U.S. Environmental Protection Agency in 64%. However, the results did not indicate a significant association between prenatal mercury exposure and delayed cognitive development during the second year of life. Various agencies have developed recommendations on fish consumption for pregnant women and children, due to the presence of mercury. These recommendations should be strengthened, since there is general consensus among all regional and national public administrations that fish is an essential source of nutrients for development in the early stages of life. Copyright © 2012 SESPAS. Published by Elsevier Espana. All rights reserved.

  2. Child stunting is associated with weaker human capital among native Amazonians.

    Science.gov (United States)

    Undurraga, Eduardo A; Behrman, Jere R; Emmett, Susan D; Kidd, Celeste; Leonard, William R; Piantadosi, Steven T; Reyes-García, Victoria; Sharma, Abhishek; Zhang, Rebecca; Godoy, Ricardo A

    2018-01-01

    We assessed associations between child stunting, recovery, and faltering with schooling and human capital skills in a native Amazonian society of horticulturalists-foragers (Tsimane'). We used cross-sectional data (2008) from 1262 children aged 6 to 16 years in 53 villages to assess contemporaneous associations between three height categories: stunted (height-for-age Z score, HAZ-1), and three categories of human capital: completed grades of schooling, test-based academic skills (math, reading, writing), and local plant knowledge. We used annual longitudinal data (2002-2010) from all children (n = 853) in 13 villages to estimate the association between changes in height categories between the first and last years of measure and schooling and academic skills. Stunting was associated with 0.4 fewer completed grades of schooling (∼24% less) and with 13-15% lower probability of showing any writing or math skills. Moderate stunting was associated with ∼20% lower scores in local plant knowledge and 9% lower probability of showing writing skills, but was not associated with schooling or math and writing skills. Compared with nonstunted children, children who became stunted had 18-21% and 15-21% lower probabilities of showing math and writing skills, and stunted children had 0.4 fewer completed grades of schooling. Stunted children who recovered showed human capital outcomes that were indistinguishable from nonstunted children. The results confirm adverse associations between child stunting and human capital skills. Predictors of growth recovery and faltering can affect human capital outcomes, even in a remote, economically self-sufficient society. © 2017 Wiley Periodicals, Inc.

  3. Recognition of Facial Expressions of Mixed Emotions in School-Age Children Exposed to Terrorism

    Science.gov (United States)

    Scrimin, Sara; Moscardino, Ughetta; Capello, Fabia; Altoe, Gianmarco; Axia, Giovanna

    2009-01-01

    This exploratory study aims at investigating the effects of terrorism on children's ability to recognize emotions. A sample of 101 exposed and 102 nonexposed children (mean age = 11 years), balanced for age and gender, were assessed 20 months after a terrorist attack in Beslan, Russia. Two trials controlled for children's ability to match a facial…

  4. Mercury levels of yellowfin tuna (Thunnus albacares) are associated with capture location.

    Science.gov (United States)

    Nicklisch, Sascha C T; Bonito, Lindsay T; Sandin, Stuart; Hamdoun, Amro

    2017-10-01

    Mercury is a toxic compound to which humans are exposed by consumption of fish. Current fish consumption advisories focus on minimizing the risk posed by the species that are most likely to have high levels of mercury. Less accounted for is the variation within species, and the potential role of the geographic origin of a fish in determining its mercury level. Here we surveyed the mercury levels in 117 yellowfin tuna caught from 12 different locations worldwide. Our results indicated significant variation in yellowfin tuna methylmercury load, with levels that ranged from 0.03 to 0.82 μg/g wet weight across individual fish. Mean mercury levels were only weakly associated with fish size (R 2  mercury load, and argue for better traceability of fish to improve the accuracy of exposure risk predictions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Seafood substitutions obscure patterns of mercury contamination in Patagonian toothfish (Dissostichus eleginoides or "Chilean sea bass".

    Directory of Open Access Journals (Sweden)

    Peter B Marko

    Full Text Available Seafood mislabeling distorts the true abundance of fish in the sea, defrauds consumers, and can also cause unwanted exposure to harmful pollutants. By combining genetic data with analyses of total mercury content, we have investigated how species substitutions and fishery-stock substitutions obscure mercury contamination in Patagonian toothfish (Dissostichus eleginoides, also known as "Chilean sea bass". Patagonian toothfish show wide variation in mercury concentrations such that consumers may be exposed to either acceptable or unacceptable levels of mercury depending on the geographic origins of the fish and the allowable limits of different countries. Most notably, stocks of Patagonian toothfish in Chile accumulate significantly more mercury than stocks closer to the South Pole, including the South Georgia/Shag Rocks stock, a fishery certified by the Marine Stewardship Council (MSC as sustainably fished. Consistent with the documented geography of mercury contamination, our analysis showed that, on average, retail fish labeled as MSC-certified Patagonian toothfish had only half the mercury of uncertified fish. However, consideration of genetic data that were informative about seafood substitutions revealed a complex pattern of contamination hidden from consumers: species substitutions artificially inflated the expected difference in mercury levels between MSC-certified and uncertified fish whereas fishery stock substitutions artificially reduced the expected difference in mercury content between MSC-certified and uncertified fish that were actually D. eleginoides. Among MSC-certified fish that were actually D. eleginoides, several with exogenous mtDNA haplotypes (i.e., not known from the certified fishery had mercury concentrations on par with uncertified fish from Chile. Overall, our analysis of mercury was consistent with inferences from the genetic data about the geographic origins of the fish, demonstrated the potential negative impact of

  6. In vitro evaluation of dietary compounds to reduce mercury bioavailability.

    Science.gov (United States)

    Jadán-Piedra, Carlos; Vélez, Dinoraz; Devesa, Vicenta

    2018-05-15

    Mercury in foods, in inorganic form [Hg(II)] or as methylmercury (CH 3 Hg), can have adverse effects. Its elimination from foods is not technologically viable. To reduce human exposure, possible alternatives might be based on reducing its intestinal absorption. This study evaluates the ability of 23 dietary components to reduce the amount of mercury that is absorbed and reaches the bloodstream (bioavailability). We determined their effect on uptake of mercury in Caco-2 cells, a model of intestinal epithelium, exposed to Hg(II) and CH 3 Hg standards and to swordfish bioaccessible fractions. Cysteine, homocysteine, glutathione, quercetin, albumin and tannic reduce bioavailability of both mercury species. Fe(II), lipoic acid, pectin, epigallocatechin and thiamine are also effective for Hg(II). Some of these strategies also reduce Hg bioavailability in swordfish (glutathione, cysteine, homocysteine). Moreover, extracts and supplements rich in these compounds are also effective. This knowledge may help to define dietary strategies to reduce in vivo mercury bioavailability. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Medicinal plants of the Achuar (Jivaro) of Amazonian Ecuador: ethnobotanical survey and comparison with other Amazonian pharmacopoeias.

    Science.gov (United States)

    Giovannini, Peter

    2015-04-22

    This paper presents the first ethnobotanical survey conducted among the Achuar (Jivaro), indigenous people living in Amazonian Ecuador and Peru. The aims of this study are: (a) to present and discuss Achuar medicinal plant knowledge in the context of the epidemiology of this population (b) to compare the use of Achuar medicinal plants with the uses reported among the Shuar Jivaro and other Amazonian peoples. The author conducted field research in 9 indigenous villages in the region of Morona Santiago and Pastaza in Ecuador. Semi-structured interviews on local illnesses and herbal remedies were carried out with 82 informants and plant specimens were collected and later identified in Quito. A literature research was conducted on the medicinal species reported by Achuar people during this study. The most reported medicinal plants are species used by the Achuar to treat diarrhoea, parasites infection, fractures, wounds, and snakebites. Informants reported the use of 134 medicinal species for a total of 733 recorded use-reports. Of these 134 species, 44 are reported at least 3 times for one or more specific disease condition for a total of 56 uses. These species are considered a core kit of medicinal plants of the Achuar of Ecuador. Most of these medicinal species are widely used in the Amazon rainforest and in many other parts of Latin America. The author documented a core kit of 44 medicinal plants used among the Achuar of Ecuador and found that this core set of medicinal plants reflects local epidemiological concerns and the pharmacopoeias of the Shuar and other Amazonian groups. These findings suggest that inter-group diffusion of medicinal plant knowledge had a prominent role in the acquisition of current Achuar knowledge of medicinal plants. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  8. Mercury Exposure in a Riverside Amazon Population, Brazil: A Study of the Ototoxicity of Methylmercury

    Directory of Open Access Journals (Sweden)

    Hoshino, Ana

    2015-02-01

    Full Text Available Introduction Mercury poisoning causes hearing loss in humans and animals. Acute and long-term exposures produce irreversible peripheral and central auditory system damage, and mercury in its various forms of presentation in the environment is ototoxic. Objective We investigated the otoacoustic emissions responses in a riverside population exposed to environmental mercury by analyzing the inhibitory effect of the medial olivocochlear system (MOCS on transient otoacoustic emissions (TEOAE. Methods The purpose of the research was to evaluate the entire community independently of variables of sex and age. All of the participants were born and lived in a riverside community. After otolaryngologic evaluation, participants were received tympanometry, evaluation of contralateral acoustic reflexes, pure tone audiometry, and recording of TEOAEs with nonlinear click stimulation. Hair samples were collect to measure mercury levels. Results There was no significant correlation between the inhibitory effect of the MOCS, age, and the level of mercury in the hair. Conclusions The pathophysiological effects of chronic exposure may be subtle and nonspecific and can have a long period of latency; therefore, it will be important to monitor the effects of mercury exposure in the central auditory system of the Amazon population over time. Longitudinal studies should be performed to determine whether the inhibitory effect of the MOCS on otoacoustic emissions can be an evaluation method and diagnostic tool in populations exposed to mercury.

  9. PERCEPTION OF MERCURY RISK INFORMATION

    Science.gov (United States)

    Approximately 8% of American women have blood Mercury levels exceeding the EPA reference dose (a dose below which symptoms would be unlikely). The children of these women are at risk of neurological deficits (lower IQ scores) primarily because of the mother's consumption of conta...

  10. A Miocene hyperdiverse crocodylian community reveals peculiar trophic dynamics in proto-Amazonian mega-wetlands.

    Science.gov (United States)

    Salas-Gismondi, Rodolfo; Flynn, John J; Baby, Patrice; Tejada-Lara, Julia V; Wesselingh, Frank P; Antoine, Pierre-Olivier

    2015-04-07

    Amazonia contains one of the world's richest biotas, but origins of this diversity remain obscure. Onset of the Amazon River drainage at approximately 10.5 Ma represented a major shift in Neotropical ecosystems, and proto-Amazonian biotas just prior to this pivotal episode are integral to understanding origins of Amazonian biodiversity, yet vertebrate fossil evidence is extraordinarily rare. Two new species-rich bonebeds from late Middle Miocene proto-Amazonian deposits of northeastern Peru document the same hyperdiverse assemblage of seven co-occurring crocodylian species. Besides the large-bodied Purussaurus and Mourasuchus, all other crocodylians are new taxa, including a stem caiman-Gnatusuchus pebasensis-bearing a massive shovel-shaped mandible, procumbent anterior and globular posterior teeth, and a mammal-like diastema. This unusual species is an extreme exemplar of a radiation of small caimans with crushing dentitions recording peculiar feeding strategies correlated with a peak in proto-Amazonian molluscan diversity and abundance. These faunas evolved within dysoxic marshes and swamps of the long-lived Pebas Mega-Wetland System and declined with inception of the transcontinental Amazon drainage, favouring diversification of longirostrine crocodylians and more modern generalist-feeding caimans. The rise and demise of distinctive, highly productive aquatic ecosystems substantially influenced evolution of Amazonian biodiversity hotspots of crocodylians and other organisms throughout the Neogene. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  11. A Cartoon-Based Measure of PTSD Symptomatology in Children Exposed to a Disaster

    Science.gov (United States)

    Elklit, Ask; Nielsen, Louise Hjort; Lasgaard, Mathias; Duch, Christina

    2013-01-01

    Research on childhood posttraumatic stress disorder (PTSD) is sparse. This is partly due to the limited availability of empirically validated measures for children who are insecure readers. The present study examined the reliability and validity of a cartoon-based measure of PTSD symptoms in children exposed to a disaster. Cartoons were generated…

  12. Mercury emissions from coal combustion in Silesia, analysis using geostatistics

    Science.gov (United States)

    Zasina, Damian; Zawadzki, Jaroslaw

    2015-04-01

    Data provided by the UNEP's report on mercury [1] shows that solid fuel combustion in significant source of mercury emission to air. Silesia, located in southwestern Poland, is notably affected by mercury emission due to being one of the most industrialized Polish regions: the place of coal mining, production of metals, stone mining, mineral quarrying and chemical industry. Moreover, Silesia is the region with high population density. People are exposed to severe risk of mercury emitted from both: industrial and domestic sources (i.e. small household furnaces). Small sources have significant contribution to total emission of mercury. Official and statistical analysis, including prepared for international purposes [2] did not provide data about spatial distribution of the mercury emitted to air, however number of analysis on Polish public power and energy sector had been prepared so far [3; 4]. The distribution of locations exposed for mercury emission from small domestic sources is interesting matter merging information from various sources: statistical, economical and environmental. This paper presents geostatistical approach to distibution of mercury emission from coal combustion. Analysed data organized in 2 independent levels: individual, bottom-up approach derived from national emission reporting system [5; 6] and top down - regional data calculated basing on official statistics [7]. Analysis, that will be presented, will include comparison of spatial distributions of mercury emission using data derived from sources mentioned above. Investigation will include three voivodeships of Poland: Lower Silesian, Opole (voivodeship) and Silesian using selected geostatistical methodologies including ordinary kriging [8]. References [1] UNEP. Global Mercury Assessment 2013: Sources, Emissions, Releases and Environmental Transport. UNEP Chemicals Branch, Geneva, Switzerland, 2013. [2] NCEM. Poland's Informative Inventory Report 2014. NCEM at the IEP-NRI, 2014. http

  13. Biomarkers of mercury exposure in two eastern Ukraine cities

    Science.gov (United States)

    Gibb, H.; Haver, C.; Kozlov, K.; Centeno, J.A.; Jurgenson, V.; Kolker, A.; Conko, K.M.; Landa, E.R.; Xu, H.

    2011-01-01

    This study evaluates biomarkers of mercury exposure among residents of Horlivka, a city in eastern Ukraine located in an area with geologic and industrial sources of environmental mercury, and residents of Artemivsk, a nearby comparison city outside the mercury-enriched area. Samples of urine, blood, hair, and nails were collected from study participants, and a questionnaire was administered to obtain data on age, gender, occupational history, smoking, alcohol consumption, fish consumption, tattoos, dental amalgams, home heating system, education, source of drinking water, and family employment in mines. Median biomarker mercury concentrations in Artemivsk were 0.26 ??g/g-Cr (urine), 0.92 ??g/L (blood), 0.42 ??g/g (hair), 0.11 ??g/g (toenails), and 0.09 ??g/g (fingernails); median concentrations in Horlivka were 0.15 ??g/g-Cr (urine), 1.01 ??g/L (blood), 0.14 ??g/g (hair), 0.31 ??g/g (toenails), and 0.31 ??g/g (fingernails). Biomarkers of mercury exposure for study participants from Horlivka and Artemivsk are low in comparison with occupationally exposed workers at a mercury recycling facility in Horlivka and in comparison with exposures known to be associated with clinical effects. Blood and urinary mercury did not suggest a higher mercury exposure among Horlivka residents as compared with Artemivsk; however, three individuals living in the immediate vicinity of the mercury mines had elevated blood and urinary mercury, relative to overall results for either city. For a limited number of residents from Horlivka (N = 7) and Artemivsk (N = 4), environmental samples (vacuum cleaner dust, dust wipes, soil) were collected from their residences. Mercury concentrations in vacuum cleaner dust and soil were good predictors of blood and urinary mercury. Copyright ?? 2011 JOEH, LLC.

  14. Toxic Effects of Mercury on the Cardiovascular and Central Nervous Systems

    Directory of Open Access Journals (Sweden)

    Bruna Fernandes Azevedo

    2012-01-01

    Full Text Available Environmental contamination has exposed humans to various metal agents, including mercury. This exposure is more common than expected, and the health consequences of such exposure remain unclear. For many years, mercury was used in a wide variety of human activities, and now, exposure to this metal from both natural and artificial sources is significantly increasing. Many studies show that high exposure to mercury induces changes in the central nervous system, potentially resulting in irritability, fatigue, behavioral changes, tremors, headaches, hearing and cognitive loss, dysarthria, incoordination, hallucinations, and death. In the cardiovascular system, mercury induces hypertension in humans and animals that has wide-ranging consequences, including alterations in endothelial function. The results described in this paper indicate that mercury exposure, even at low doses, affects endothelial and cardiovascular function. As a result, the reference values defining the limits for the absence of danger should be reduced.

  15. Toxic Effects of Mercury on the Cardiovascular and Central Nervous Systems

    Science.gov (United States)

    Fernandes Azevedo, Bruna; Barros Furieri, Lorena; Peçanha, Franck Maciel; Wiggers, Giulia Alessandra; Frizera Vassallo, Paula; Ronacher Simões, Maylla; Fiorim, Jonaina; Rossi de Batista, Priscila; Fioresi, Mirian; Rossoni, Luciana; Stefanon, Ivanita; Alonso, María Jesus; Salaices, Mercedes; Valentim Vassallo, Dalton

    2012-01-01

    Environmental contamination has exposed humans to various metal agents, including mercury. This exposure is more common than expected, and the health consequences of such exposure remain unclear. For many years, mercury was used in a wide variety of human activities, and now, exposure to this metal from both natural and artificial sources is significantly increasing. Many studies show that high exposure to mercury induces changes in the central nervous system, potentially resulting in irritability, fatigue, behavioral changes, tremors, headaches, hearing and cognitive loss, dysarthria, incoordination, hallucinations, and death. In the cardiovascular system, mercury induces hypertension in humans and animals that has wide-ranging consequences, including alterations in endothelial function. The results described in this paper indicate that mercury exposure, even at low doses, affects endothelial and cardiovascular function. As a result, the reference values defining the limits for the absence of danger should be reduced. PMID:22811600

  16. Posttraumatic Stress Disorder in Children Exposed to Man-Made Disasters.

    Science.gov (United States)

    Manix, Mary M.

    This paper reviews the literature published in the last 10 years that focused on posttraumatic stress disorder (PTSD) in children exposed to man-made disasters such as war, school shootings, and the Oklahoma City bombing. As mass violence continues in society, mental health professionals need to be prepared to treat child victims of such…

  17. Large-scale projects in the amazon and human exposure to mercury: The case-study of the Tucuruí Dam.

    Science.gov (United States)

    Arrifano, Gabriela P F; Martín-Doimeadios, Rosa C Rodríguez; Jiménez-Moreno, María; Ramírez-Mateos, Vanesa; da Silva, Núbia F S; Souza-Monteiro, José Rogério; Augusto-Oliveira, Marcus; Paraense, Ricardo S O; Macchi, Barbarella M; do Nascimento, José Luiz M; Crespo-Lopez, Maria Elena

    2018-01-01

    The Tucuruí Dam is one of the largest dams ever built in the Amazon. The area is not highly influenced by gold mining as a source of mercury contamination. Still, we recently noted that one of the most consumed fishes (Cichla sp.) is possibly contaminated with methylmercury. Therefore, this work evaluated the mercury content in the human population living near the Tucuruí Dam. Strict exclusion/inclusion criteria were applied for the selection of participants avoiding those with altered hepatic and/or renal functions. Methylmercury and total mercury contents were analyzed in hair samples. The median level of total mercury in hair was above the safe limit (10µg/g) recommended by the World Health Organization, with values up to 75µg/g (about 90% as methylmercury). A large percentage of the participants (57% and 30%) showed high concentrations of total mercury (≥ 10µg/g and ≥ 20µg/g, respectively), with a median value of 12.0µg/g. These are among the highest concentrations ever detected in populations living near Amazonian dams. Interestingly, the concentrations are relatively higher than those currently shown for human populations highly influenced by gold mining areas. Although additional studies are needed to confirm the possible biomagnification and bioaccumulation of mercury by the dams in the Amazon, our data already support the importance of adequate impact studies and continuous monitoring. More than 400 hydropower dams are operational or under construction in the Amazon, and an additional 334 dams are presently planned/proposed. Continuous monitoring of the populations will assist in the development of prevention strategies and government actions to face the problem of the impacts caused by the dams. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Mercury in the environment : a primer

    Energy Technology Data Exchange (ETDEWEB)

    Lourie, B; Glenn, W [ed.; Ogilvie, K; Everhardus, E; Friesen, K; Rae, S

    2003-06-01

    This report provides an overview of the occurrence and effects of mercury in the environment and its impacts on human health. Low levels of mercury occur naturally everywhere in the environment in plants, animals, rocks and air. Incidental emissions occur when natural mercury is released to the environment through human activity. In Canada, coal burning and metal processing are the two largest point sources of atmospheric mercury emissions. Energy facilities have the option to invest in expensive control technologies for coal plants, or they can generate electricity from alternative energy sources. Energy conservation, however, offers the greatest overall benefits for the environment and the public. Mercury can also be released when products containing mercury (such as electrical switches, thermostats, dental amalgam, and thermometers) are broken while in use, or when they are crushed in garbage trucks and dumped in landfills. Source separation is the best way to reduce waste-related emissions. Once mercury is released to the natural environment, it can be transported long distances through air or watercourses. It is volatile, therefore evaporates readily to the atmosphere where it may do one of three things: it may fall out near the point where it was emitted; it may be transported long distances to some point downwind; or, it may enter the global atmospheric mercury pool where it will circle the globe for a year or more within the Earth's major weather systems before being deposited. Data from Canada's National Pollutant Release Inventory indicates that mercury releases and transfers total 28,674 kg per year. The most critical component of the mercury cycle is the conversion of inorganic forms of mercury to the organic compound methylmercury which is more toxic to humans. Most concern about mercury focuses on lakes and other aquatic ecosystems. Fish in hydroelectric reservoirs have been found to contain elevated methylmercury levels because natural mercury in the

  19. Neurodevelopmental delay in children exposed in utero to hyperemesis gravidarum.

    Science.gov (United States)

    Fejzo, Marlena S; Magtira, Aromalyn; Schoenberg, Frederic Paik; Macgibbon, Kimber; Mullin, Patrick M

    2015-06-01

    The purpose of this study is to determine the frequency of emotional, behavioral, and learning disorders in children exposed in utero to hyperemesis gravidarum (HG) and to identify prognostic factors for these disorders. Neurodevelopmental outcomes of 312 children from 203 mothers with HG were compared to neurodevelopmental outcomes from 169 children from 89 unaffected mothers. Then the clinical profiles of patients with HG and a normal child outcome were compared to the clinical profiles of patients with HG and a child with neurodevelopmental delay to identify prognostic factors. Binary responses were analyzed using either a Chi-square or Fisher Exact test and continuous responses were analyzed using a t-test. Children exposed in utero to HG have a 3.28-fold increase in odds of a neurodevelopmental diagnosis including attention disorders, learning delay, sensory disorders, and speech and language delay (Pneurodevelopmental delay. We found no evidence for increased risk of 13 emotional, behavioral, and learning disorders, including autism, intellectual impairment, and obsessive-compulsive disorder. However, the study was not sufficiently powered to detect rare conditions. Medications, treatments, and preterm birth were not associated with an increased risk for neurodevelopmental delay. Women with HG are at a significantly increased risk of having a child with neurodevelopmental delay. Common antiemetic treatments were not linked to neurodevelopmental delay, but early symptoms may play a role. There is an urgent need to address whether aggressive treatment that includes vitamin and nutrient supplementation in women with early symptoms of severe nausea of pregnancy decreases the risk of neurodevelopmental delay. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  20. Systemic inflammation, endothelial dysfunction, and activation in clinically healthy children exposed to air pollutants.

    Science.gov (United States)

    Calderón-Garcidueñas, L; Villarreal-Calderon, R; Valencia-Salazar, G; Henríquez-Roldán, C; Gutiérrez-Castrellón, P; Torres-Jardón, R; Osnaya-Brizuela, N; Romero, L; Torres-Jardón, R; Solt, A; Reed, W

    2008-03-01

    Mexico City children are chronically exposed to significant concentrations of air pollutants and exhibit chronic respiratory-tract inflammation. Epidemiological, controlled human exposures, laboratory-based animal models, and in vitro/in vivo studies have shown that inflammatory, endothelial dysfunction, and endothelial damage mediators are upregulated upon exposure to particulate matter (PM). Endothelial dysfunction is a critical event in cardiovascular disease. The focus of this work was to investigate whether exposure to ambient air pollution including PM(2.5) produces systemic inflammation and endothelial injury in healthy children. We measured markers of endothelial activation, and inflammatory mediators in 52 children age 8.6+/-0.1 yr, residents of Mexico City (n: 28) or of Polotitlán (n: 24), a city with low levels of pollutants. Mexico City children had significant increases in inflammatory mediators and vasoconstrictors, including tumor necrosis factor (TNF)alpha, prostaglandin (PG) E2, C-reactive protein, interleukin-1beta, and endothelin-1. There was a significant anti-inflammatory response, and a downregulation of vascular adhesion molecule-1, intercellular adhesion molecule-1 and -2, and selectins sE and sL. Results from linear regression found TNF a positively associated with 24- and 48-h cumulative levels of PM(2.5), while the 7-d PM(2.5) value was negatively associated with the numbers of white blood cells in peripheral blood in highly exposed children. Systemic subclinical inflammation, increased endothelin- 1, and significant downregulation of soluble adhesion molecules are seen in Mexico City children. Children chronically exposed to fine PM above the standard could be at risk of developing cardiovascular diseases, atherosclerosis, stroke, and other systemic effects later in life.

  1. Mercury Exposure and Health Problems in Urban Artisanal Gold Mining (UAGM in Makassar, South Sulawesi, Indonesia

    Directory of Open Access Journals (Sweden)

    Hasriwiani Habo Abbas

    2017-06-01

    Full Text Available Urban artisanal gold mining (UAGM in Makassar, South Sulawesi, Indonesia, has been run by a number of urban gold workers with gold jewelry manufacture as its core activity. The wastes generated from goldsmiths’ activities were further processed by the gold smelters to recover fine gold particles. Smelting gold doré, amalgamation, and burning out the amalgam were the mercury-based gold process usually applied in their work. While working the gold workers are, therefore, potentially exposed to a source of mercury pollution that may cause health problems because of working without proper protection. The aims of this research are to characterize the process of urban artisanal gold mining with the potential mercury exposures during the process, and to assess the health of the gold workers. The results showed that the gold workers had a low educational background, but a relatively high income. The total mercury concentration of gold workers was higher than the control group. They were exposed to intoxicatingly high levels of mercury with the average total mercury concentrations of 6.6 and 10.8 µg/g in the hair of indirect and direct exposed workers, respectively. The health assessment showed that 85% of the gold workers suffered neurological symptoms, such as tremors, and 44%–56% of them experienced restricted fields of vision, slow reflexes, sensory disturbances, unbalanced rigidity, and ataxia. The results also showed that the working years have reasonable correlation with the sum of the positive findings in the 10 neurological symptoms.

  2. Fixed-bed studies of the interactions between mercury and coal combustion fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Dunham, Grant E.; DeWall, Raymond A. [Energy and Environmental Research Center, 15 North 23rd Street, Grand Forks, ND 58203 (United States); Senior, Constance L. [Reaction Engineering International, 77 West 200 South, Suite 210, Salt Lake City, UT 84101 (United States)

    2003-08-15

    Sixteen different fly ash samples, generated from both pilot-scale and full-scale combustion systems, were exposed to a simulated flue gas containing either elemental mercury or HgCl{sub 2} in a bench-scale reactor system at the Energy and Environmental Research Center to evaluate the interactions and determine the effects of temperature, mercury species, and ash type on adsorption of mercury and oxidation of elemental mercury. The fly ash samples were characterized for surface area, loss on ignition, and forms of iron in the ash. While many of the ash samples oxidized elemental mercury, not all of the samples that oxidized mercury also captured elemental mercury. However, no capture of elemental mercury was observed without accompanying oxidation. Generally, oxidation of elemental mercury increased with increasing amount of magnetite in the ash. However, one high-carbon subbituminous ash with no magnetite showed considerable mercury oxidation that may have been due to unburned carbon. Surface area as well as the nature of the surface appeared to be important for oxidation and adsorption of elemental mercury. The capacity of the ash samples for HgCl{sub 2} was similar to that for elemental mercury. There was a good correlation between the capacity for HgCl{sub 2} and the surface area; capacity decreased with increasing temperature.

  3. Reduced Future Precipitation Makes Permanence of Amazonian Carbon Sinks Questionable

    Science.gov (United States)

    Arora, V.

    2011-12-01

    The tropical forests of the Amazon, considered as a tipping element in Earth's climate system, provide several ecosystem services including the maintenance of favourable regional climatic conditions in the region and storage of large amounts of carbon in their above- and below-ground pools. While it is nearly impossible, at present, to put a dollar value on these ecosystem services, the developed countries have started paying large sums of money to developing countries in the tropics to reduce deforestation. Norway recently committed up to $1 billion to the Amazon fund. The United Nations' Reducing Emissions from Deforestation and forest Degradation (REDD) program also financially supports national activities of 13 countries worldwide. The primary assumption inherent in paying for avoiding deforestation is that avoided land use change emissions contribute towards climate change mitigation. In addition, the standing forests that are spared deforestation contribute towards additional carbon sinks associated with the CO2 fertilization effect. Implicit in this reasoning is the understanding that the carbon sinks provided by avoided deforestation have some "permanence" associated with them, at least in the order of 50-100 years. Clearly, if "avoided deforestation" is essentially "delayed deforestation" then the benefits will not be long lasting. More importantly, changes in climate have the potential to adversely affect the permanence of carbon sinks, whether they are being paid for or not. This presentation will address the question of "permanence" by analyzing simulations of the second generation Canadian Earth system model (CanESM2) that are contributing results to the upcoming fifth Coupled Modeled Intercomparison Project (CMIP5). CanESM2 results for the future RCP 2.6, 4.5 and 8.5 scenarios show, that due to reduced future precipitation, the Amazonian region remains a net source of carbon over the 21st century in all scenarios. The carbon losses during the recent

  4. Drug and Alcohol Exposed Children: Implications for Special Education for Students Identified as Behaviorally Disordered.

    Science.gov (United States)

    Bauer, Anne M.

    1991-01-01

    This article reviews the literature on children prenatally exposed to drugs and alcohol, the potential impact on the educational and social services systems, and implications for programing for children identified as behaviorally disordered. (Author/JDD)

  5. Use of amazonian anthropogenic soils: Comparison between Caboclos communities and Tikunas indigenous group

    International Nuclear Information System (INIS)

    Torres Sanabria, Camilo; Cuartas Ricaurte, Jorge Armando

    2013-01-01

    In general terms, Amazonian soils are infertile and have several constraints for agricultural production. However, use by ancient human societies since pre-columbian times has driven landscape transformation of massive areas and development of anthropogenic soils called Terra Preta do Indio (TP) or Amazonian Dark Earths (ADE). ADE characterization, in terms of fertility and composition, has allowed the development of intensive agricultural activities over time. The current use of ADE for the Brazilian amazon peasants (Caboclos) is different from the indigenous communities in Colombia. The indigenous people in Colombia (Tikunas) no use this type of soils on behalf of cultural restrictions that avoid the use of ancient places. We are comparing the institutional conditions, migrations, social characterization and cultural factors that determine the use/no-use of these soils by the Amazonian societies.

  6. Determination of mercury by cold-vapor technique in several tissues of treated American red crayfish (Procambarus clarkii)

    Energy Technology Data Exchange (ETDEWEB)

    Del Ramo, J.; Pastor, A.; Diaz-Mayans, J.; Medina, J.; Torreblanca, A.

    1988-01-01

    Adult intermolt specimens of American red crayfish (Procambarus clarkii) collected from Lake Albufera (Valencia, Spain), were exposed to mercury during 96 h. The Hg-concentrations used were 50, 100, and 250 ..mu..g Hg/l as Cl/sub 2/Hg. The content of mercury in muscle, midgut gland, antennal glands and gills was investigated. Determinations of mercury were made by cold-vapor technique and AAS. The mercury levels in all examined tissues increased significantly with increasing Hg-concentration in the water.

  7. Mercury

    Science.gov (United States)

    Mercury is an element that is found in air, water and soil. It has several forms. Metallic mercury is a shiny, silver-white, odorless liquid. If ... with other elements to form powders or crystals. Mercury is in many products. Metallic mercury is used ...

  8. Correlation between mercury and selenium concentrations in Indian hair from Rondĵnia State, Amazon region, Brazil.

    Science.gov (United States)

    Soares, Mônica Campos; Sarkis, Jorge Eduardo Souza; Müller, Regina Céli Sarkis; Brabo, Edilson Silva; Santos, Elizabete Oliveira

    2002-03-15

    Total mercury and selenium concentrations were determined in hair samples collected from Wari (Pacaás Novos) Indians living in Doutor Tanajura village, Gujará-Mirim city, Rondĵnia State. The mercury concentrations in some samples are much higher than the values determined in samples from individuals not exposed to mercury contamination, occupationally or environmentally. The selenium concentrations are in the normal range. A correlation was observed between the mercury and selenium concentration and the values of the molar ratio approach 1 at low Hg concentrations. This fact is related to the equimolar complex formed by [(Hg-Se)n]m-Seleprotein P, which can decrease the bioavailable mercury in the organism.

  9. Mercury in various tissues of fish caught downstream of a wood pulp factory in the Kammerfoss River, South Norway

    International Nuclear Information System (INIS)

    Steinnes, E.; Haastein, T.; Norheim, G.; Froeslie, A.

    1976-01-01

    The mercury content of perch (Perca fluviatilis) and brown trout (Salmo trutta) was studied during a 5-year period after the ban on phenyl mercury in 1970. Muscular concentrations of about 1μg Hg/g were found, compared with 3-6μg Hg/g found in 1968. Organ distribution studies indicated that high concentrations of mercury may be found in the liver and kidney of fish exposed to high mercury pollution. (author)

  10. Psychological therapies for children and adolescents exposed to trauma.

    Science.gov (United States)

    Gillies, Donna; Maiocchi, Licia; Bhandari, Abhishta P; Taylor, Fiona; Gray, Carl; O'Brien, Louise

    2016-10-11

    Children and adolescents who have experienced trauma are at high risk of developing post-traumatic stress disorder (PTSD) and other negative emotional, behavioural and mental health outcomes, all of which are associated with high personal and health costs. A wide range of psychological treatments are used to prevent negative outcomes associated with trauma in children and adolescents. To assess the effects of psychological therapies in preventing PTSD and associated negative emotional, behavioural and mental health outcomes in children and adolescents who have undergone a traumatic event. We searched the Cochrane Common Mental Disorders Group's Specialised Register to 29 May 2015. This register contains reports of relevant randomised controlled trials from The Cochrane Library (all years), EMBASE (1974 to date), MEDLINE (1950 to date) and PsycINFO (1967 to date). We also checked reference lists of relevant studies and reviews. We did not restrict the searches by date, language or publication status. All randomised controlled trials of psychological therapies compared with a control such as treatment as usual, waiting list or no treatment, pharmacological therapy or other treatments in children or adolescents who had undergone a traumatic event. Two members of the review group independently extracted data. We calculated odds ratios for binary outcomes and standardised mean differences for continuous outcomes using a random-effects model. We analysed data as short-term (up to and including one month after therapy), medium-term (one month to one year after therapy) and long-term (one year or longer). Investigators included 6201 participants in the 51 included trials. Twenty studies included only children, two included only preschool children and ten only adolescents; all others included both children and adolescents. Participants were exposed to sexual abuse in 12 trials, to war or community violence in ten, to physical trauma and natural disaster in six each and to

  11. Evolutionary patterns of range size, abundance and species richness in Amazonian angiosperm trees

    Directory of Open Access Journals (Sweden)

    Kyle Dexter

    2016-09-01

    Full Text Available Amazonian tree species vary enormously in their total abundance and range size, while Amazonian tree genera vary greatly in species richness. The drivers of this variation are not well understood. Here, we construct a phylogenetic hypothesis that represents half of Amazonian tree genera in order to contribute to explaining the variation. We find several clear, broad-scale patterns. Firstly, there is significant phylogenetic signal for all three characteristics; closely related genera tend to have similar numbers of species and similar mean range size and abundance. Additionally, the species richness of genera shows a significant, negative relationship with the mean range size and abundance of their constituent species. Our results suggest that phylogenetically correlated intrinsic factors, namely traits of the genera themselves, shape among lineage variation in range size, abundance and species richness. We postulate that tree stature may be one particularly relevant trait. However, other traits may also be relevant, and our study reinforces the need for ambitious compilations of trait data for Amazonian trees. In the meantime, our study shows how large-scale phylogenies can help to elucidate, and contribute to explaining, macroecological and macroevolutionary patterns in hyperdiverse, yet poorly understood regions like the Amazon Basin.

  12. Leukemia incidence among individuals exposed in utero, children of atomic bomb survivors, and their controls; Hiroshima and Nagasaki, 1945-79

    International Nuclear Information System (INIS)

    Ishimaru, Toranosuke; Ichimaru, Michito; Mikami, Motoko.

    1982-03-01

    The incidence of leukemia has been analyzed in relation to the fetal dose of individuals exposed in utero, and the parental gonadal dose of individuals born to atomic bomb survivors and controls in the two fixed RERF cohorts. Among 3,636 in utero exposed children and controls, 3 leukemia cases have been identified through 1979. No excess risk of leukemia for in utero exposed children is apparent. For children born to exposed parents and controls, 36 leukemia cases have been identified in the years 1946-79 among 50,689 study subjects where the parental gonadal dose is available. Again, no excess risk of leukemia exists. (author)

  13. Neuropsychological alterations in mercury intoxication persist several years after exposure

    Directory of Open Access Journals (Sweden)

    Elaine Cristina Zachi

    Full Text Available Abstract Elemental mercury is a liquid toxic metal widely used in industry. Occupational exposure occurs mainly via inhalation. Previously, neuropsychological assessment detected deficits in former workers of a fluorescent lamp plant who had been exposed to elemental mercury vapor and were away from exposure for several years at the time of examination. Objectives: The purpose of this work was to reexamine these functions after 18 months in order to evaluate their progression. Methods: Thirteen participants completed tests of attention, inhibitory control, verbal/visual memory, psychomotor speed, verbal fluency, visuomotor ability, executive function, semantic knowledge, and depression and anxiety inventories on 2 separate occasions. Results: At baseline, the former workers indicated slower psychomotor and information processing speed, verbal spontaneous recall memory impairment, and increased depression and anxiety symptoms compared to controls (P<0.05. Paired comparisons of neuropsychological functioning within the exposed group at baseline and 1.5 years later showed poorer immediate memory performance (P<0.05. There were no differences on other measures. Conclusions: Although the literature show signs of recovery of functions, the neuropsychological effects related to mercury exposure are found to persist for many years.

  14. Got Mercury?

    Science.gov (United States)

    Meyers, Valerie E.; McCoy, J. Torin; Garcia, Hector D.; James, John T.

    2009-01-01

    Many of the operational and payload lighting units used in various spacecraft contain elemental mercury. If these devices were damaged on-orbit, elemental mercury could be released into the cabin. Although there are plans to replace operational units with alternate light sources, such as LEDs, that do not contain mercury, mercury-containing lamps efficiently produce high quality illumination and may never be completely replaced on orbit. Therefore, exposure to elemental mercury during spaceflight will remain possible and represents a toxicological hazard. Elemental mercury is a liquid metal that vaporizes slowly at room temperature. However, it may be completely vaporized at the elevated operating temperatures of lamps. Although liquid mercury is not readily absorbed through the skin or digestive tract, mercury vapors are efficiently absorbed through the respiratory tract. Therefore, the amount of mercury in the vapor form must be estimated. For mercury releases from lamps that are not being operated, we utilized a study conducted by the New Jersey Department of Environmental Quality to calculate the amount of mercury vapor expected to form over a 2-week period. For longer missions and for mercury releases occurring when lamps are operating, we conservatively assumed complete volatilization of the available mercury. Because current spacecraft environmental control systems are unable to remove mercury vapors, both short-term and long-term exposures to mercury vapors are possible. Acute exposure to high concentrations of mercury vapors can cause irritation of the respiratory tract and behavioral symptoms, such as irritability and hyperactivity. Chronic exposure can result in damage to the nervous system (tremors, memory loss, insomnia, etc.) and kidneys (proteinurea). Therefore, the JSC Toxicology Group recommends that stringent safety controls and verifications (vibrational testing, etc.) be applied to any hardware that contains elemental mercury that could yield

  15. Locus ceruleus neurons in people with autism contain no histochemically-detectable mercury.

    Science.gov (United States)

    Pamphlett, Roger; Kum Jew, Stephen

    2016-02-01

    Exposure to environmental mercury has been proposed to play a part in autism. Mercury is selectively taken up by the human locus ceruleus, a region of the brain that has been implicated in autism. We therefore looked for the presence of mercury in the locus ceruleus of people who had autism, using the histochemical technique of autometallography which can detect nanogram amounts of mercury in tissues. In addition, we sought evidence of damage to locus ceruleus neurons in autism by immunostaining for hyperphosphorylated tau. No mercury was found in any neurons of the locus ceruleus of 6 individuals with autism (5 male, 1 female, age range 16-48 years). Mercury was present in locus ceruleus neurons in 7 of 11 (64%) age-matched control individuals who did not have autism, which is significantly more than in individuals with autism. No increase in numbers of locus ceruleus neurons containing hyperphosphorylated tau was detected in people with autism. In conclusion, most people with autism have not been exposed early in life to quantities of mercury large enough to be found later in adult locus ceruleus neurons. Human locus ceruleus neurons are sensitive indicators of mercury exposure, and mercury appears to remain in these neurons indefinitely, so these findings do not support the hypothesis that mercury neurotoxicity plays a role in autism.

  16. Interspecific and intraspecific variation in selenium:mercury molar ratios in saltwater fish from the Aleutians: Potential protection on mercury toxicity by selenium

    Science.gov (United States)

    Burger, Joanna; Gochfeld, Michael; Jeitner, Christian; Donio, Mark; Pittfield, Taryn

    2014-01-01

    A number of factors affect the consumption risk from mercury in fish, including mercury levels, seasonal patterns of mercury concentrations, human consumption patterns, and sensitive populations (e.g. pregnant women, fetuses, young children, and yet unknown genetic factors). Recently the protective effects of selenium on methylmercury toxicity have been publicized, particularly for saltwater fish. We examine levels of mercury and selenium in several species of fish and seabirds from the Aleutians (Alaska), determine selenium:mercury molar ratios, and examine species-specific and individual variation in the ratios as a means of exploring the use of the ratio in risk assessment and risk management. Variation among species was similar for mercury and selenium. There was significant inter-specific and intraspecific variation in selenium:mercury molar ratios for fish, and for birds. The mean selenium:mercury molar ratios for all fish and bird species were above 1, meaning there was an excess of selenium relative to mercury. It has been suggested that an excess of selenium confers some protective advantage for salt water fish, although the degree of excess necessary is unclear. The selenium:mercury molar ratio was significantly correlated negatively with total length for most fish species, but not for dolly varden. Some individuals of Pacific cod, yellow irish lord, rock greenling, Pacific halibut, dolly varden, and to a lesser extent, flathead sole, had selenium:mercury ratios below 1. No bird muscle had an excess of mercury (ratio below 1), and only glaucous-winged gull and pigeon guillemot had ratios between 1 and 5. There was a great deal of variation in selenium:mercury molar ratios within fish species, and within bird species, making it difficult and impractical to use these ratios in risk assessment or management, for fish advisories, or for consumers, particularly given the difficulty of interpreting the ratios. PMID:22664537

  17. Assessment of Heavy Metals on Occupationally Exposed Workers from Hair Analysis

    Directory of Open Access Journals (Sweden)

    E. Damastuti

    2017-12-01

    Full Text Available The use of human hair as a tool in assessing changes and abnormalities in human bodies has been increasing for last decades since it may reflect the health status or environmental condition of habitation or working place of individuals as well as population groups. Compared to other body tissue or fluids, hair provides an ease of elemental analysis especially in reflecting the long-term exposure. This research was conducted to determine the elemental content especially heavy metals, since they are bioaccumulated in human body organs and impact human health, in hair of workshop workers and traffic services officers as exposed groups and its comparison with control group and references data for assessing of occupational exposure. Thirty-five automotive workshop workers and 32 traffic services officers’ hair specimens were collected in Bandung, while hair specimens of the control group were collected from 43 healthy individuals. The elemental concentrations in hair specimen were analyzed using neutron activation analysis (NAA for mercury and chromium, and atomic absorption spectrometry (AAS for lead and arsenic.  The accuracy of the method was evaluated using GBW 07601 human hair certified reference material (CRM and it was found to give good results in accordance with the certificate values. It was found that chromium, lead, and arsenic hair concentration in exposed groups (0.88, 10.7, and 0.051 mg/kg, respectively were higher than in control group (0.27, 4.52, and 0.045 mg/kg, respectively, while mercury hair concentration of traffic services officers were higher than control group but mercury hair concentration of automotive workshop workers were lower than in control group (1.41 mg/kg. The t-test statistical results shown that mercury concentrations in one exposed group did not differ significantly from the control, but other exposed groups showed otherwise. The level of mercury in hair is strongly attributed not only to environmental

  18. Amazonian Dark Earths: pathways to sustainable development in tropical rainforests?

    Directory of Open Access Journals (Sweden)

    Morgan Schmidt

    2013-04-01

    Full Text Available Fertile dark anthrosols associated with pre-Columbian settlement across the Amazon Basin have sparked wide interest for their potential contribution to sustainable use and management of tropical soils and ecosystems. In the Upper Xingu region of the southern Amazon, research on archaeological settlements and among contemporary descendant populations provides critical new data on the formation and use of anthrosols. These findings provide a basis for describing the variability of soil modifications that result from diverse human activities and a general model for the formation of Amazonian anthrosols. They underscore the potential for indigenous systems of knowledge and resource management to inform efforts for conservation and sustainable development of Amazonian ecosystems.

  19. The effects of mercury exposure on the surface morphology of gill filaments in Perna perna (Mollusca: Bivalvia)

    CSIR Research Space (South Africa)

    Gregory, MA

    1999-01-01

    Full Text Available each animal were analysed for mercury using an atomic absorption spectrometer. Mercury concentration increased from 0.13 (pre-immersion) to 87 mu g/g after day 24. Surface morphology remained normal for all animals in tank 2 and for those exposed to Hg...

  20. Extremely long-distance seed dispersal by an overfished Amazonian frugivore.

    Science.gov (United States)

    Anderson, Jill T; Nuttle, Tim; Saldaña Rojas, Joe S; Pendergast, Thomas H; Flecker, Alexander S

    2011-11-22

    Throughout Amazonia, overfishing has decimated populations of fruit-eating fishes, especially the large-bodied characid, Colossoma macropomum. During lengthy annual floods, frugivorous fishes enter vast Amazonian floodplains, consume massive quantities of fallen fruits and egest viable seeds. Many tree and liana species are clearly specialized for icthyochory, and seed dispersal by fish may be crucial for the maintenance of Amazonian wetland forests. Unlike frugivorous mammals and birds, little is known about seed dispersal effectiveness of fishes. Extensive mobility of frugivorous fish could result in extremely effective, multi-directional, long-distance seed dispersal. Over three annual flood seasons, we tracked fine-scale movement patterns and habitat use of wild Colossoma, and seed retention in the digestive tracts of captive individuals. Our mechanistic model predicts that Colossoma disperses seeds extremely long distances to favourable habitats. Modelled mean dispersal distances of 337-552 m and maximum of 5495 m are among the longest ever reported. At least 5 per cent of seeds are predicted to disperse 1700-2110 m, farther than dispersal by almost all other frugivores reported in the literature. Additionally, seed dispersal distances increased with fish size, but overfishing has biased Colossoma populations to smaller individuals. Thus, overexploitation probably disrupts an ancient coevolutionary relationship between Colossoma and Amazonian plants.

  1. Strategies for monitoring outcomes in HIV-exposed uninfected children in the United Kingdom

    Directory of Open Access Journals (Sweden)

    Claire eThorne

    2016-05-01

    Full Text Available Surveillance of pregnancies in women living with HIV is carried out on a national basis in the United Kingdom (UK through the National Study of HIV in Pregnancy and Childhood (NSHPC. There are currently around 1100-1200 HIV-exposed uninfected (HEU infants born every year in the UK, where vertical transmission of HIV now occurs in fewer than five in every 1000 pregnancies. By the end of 2014, there was a cumulative total of more than 15,000 HEU children with any combination antiretroviral therapy (cART exposure and more than 5,000 with cART exposure from conception in the UK. HEU infants are increasingly being exposed to newer antiretroviral drugs for which less is known regarding both short and longer-term safety. In this commentary, we describe the approaches that have been taken to explore health outcomes in HEU children born in the UK. This includes the Children exposed to AntiRetroviral Therapy (CHART Study, which was a consented follow-up study carried out in 2002-2005 of HEU children born in 1996-2004. The CHART Study showed that 4% of HEU children enrolled had a major health or development problem in early childhood; this was within expected UK norms but the study was limited by small numbers and short-term follow-up. However, the problems with recruitment and retention that were encountered within the CHART Study demonstrated that comprehensive, clinic-based follow-up was not a feasible approach for long-term assessment of HEU children in the UK. We describe an alternative approach developed to monitor some aspects of their long-term health, involving the flagging of HEU infants for death and cancer registration with the UK Office for National Statistics. Some of the ethical concerns regarding investigation of long-term outcomes of in utero and perinatal exposure to antiretrovirals including those relating to consent and confidentiality are also discussed.

  2. Estimating the global conservation status of more than 15,000 Amazonian tree species

    OpenAIRE

    ter Steege, H.; et al., [Unknown; Duivenvoorden, J.F.

    2015-01-01

    Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened ...

  3. Subcutaneous mercury injection by a child: A histopathology case report

    Directory of Open Access Journals (Sweden)

    Deepti Sukheeja

    2014-01-01

    Full Text Available Intentional subcutaneous injection of mercury by mentally healthy children is rare. Usually, it is seen as a part of suicidal attempt in severely depressed patients or by athletes to enhance their performance. We report a case of a 15-year-old child, inspired by a movie, who deliberately self-injected mercury subcutaneously into his forearm that led to the formation of a non-healing ulcer. Histopathology of the biopsy confirmed the diagnosis. A surgical procedure was thereby performed to treat the ulcer and reduce the blood and urinary levels of mercury. However, the patient did not develop clinical signs of chronic poisoning, proving that subcutaneous mercury injection has a low risk of systemic toxicity, and that histopathology plays an important role in diagnosis.

  4. 'Rogue' cells observed in children exposed to radiation from the Chernobyl accident

    International Nuclear Information System (INIS)

    Sevan'kaev, A.V.; Tsyb, A.F.; Zhloba, A.A.; Moiseenko, V.V.; Skrjabin, A.M.; Climov, V.M.

    1993-01-01

    Eight 'rogue' lymphocyte metaphases containing a large number of aberrant chromosomes were noted during a survey of chromosomal damage in 328 Belarussian children. The study population comprised children of families living in territory contaminated by radiation from the Chernobyl accident. The majority of the sample had been evacuated within 1 week from very heavily polluted territory to areas that had received much less fallout. Two hundred cells were scored per subject and one rogue cell was found in a child exposed in utero; one in a child conceived after the accident and six in the postnatally exposed group. The possibility that the damage was due to exposure to radio-iodine concentrated in the thyroid gland, or to radiation from incorporated hot particles' of an alpha or beta/gamma emitter is discussed. It is concluded that the damage to these cells is unlikely to have been caused by radiation. (Author)

  5. Fetal growth and preterm birth in children exposed to maternal or paternal rheumatoid arthritis. A nationwide cohort study

    DEFF Research Database (Denmark)

    Rom, Ane L; Wu, Chunsen; Olsen, Jørn

    2014-01-01

    OBJECTIVE: To assess indicators of fetal growth and risk of preterm birth in children of parents with rheumatoid arthritis (RA). METHODS: Through linkage of Danish national registries, we identified all children born in Denmark between 1977 and 2008. We used general linear regression models...... to estimate mean differences in indicators of fetal growth among children with a parent with RA compared to unexposed children. Odds ratios (ORs) and 95% confidence intervals (95% CIs) of preterm birth were calculated using a logistic regression model. RESULTS: Of the 1,917,723 children included, a total...... of 13,556 children were exposed to maternal RA or maternal preclinical RA. Children exposed to maternal RA (n = 2,101) had approximately similar length, head circumference, and abdominal circumference at birth compared with children of mothers without RA. Birth weight was 87 gm lower (mean difference...

  6. Integrating Mercury Science and Policy in the Marine Context: Challenges and Opportunities

    Science.gov (United States)

    Lambert, Kathleen F.; Evers, David C.; Warner, Kimberly A.; King, Susannah L.; Selin, Noelle E.

    2014-01-01

    Mercury is a global pollutant and presents policy challenges at local, regional, and global scales. Mercury poses risks to the health of people, fish, and wildlife exposed to elevated levels of mercury, most commonly from the consumption of methylmercury in marine and estuarine fish. The patchwork of current mercury abatement efforts limits the effectiveness of national and multi-national policies. This paper provides an overview of the major policy challenges and opportunities related to mercury in coastal and marine environments, and highlights science and policy linkages of the past several decades. The U.S. policy examples explored here point to the need for a full life cycle approach to mercury policy with a focus on source reduction and increased attention to: (1) the transboundary movement of mercury in air, water, and biota; (2) the coordination of policy efforts across multiple environmental media; (3) the cross-cutting issues related to pollutant interactions, mitigation of legacy sources, and adaptation to elevated mercury via improved communication efforts; and (4) the integration of recent research on human and ecological health effects into benefits analyses for regulatory purposes. Stronger science and policy integration will benefit national and international efforts to prevent, control, and minimize exposure to methylmercury. PMID:22901766

  7. A 3 Year-Old Male Child Ingested Approximately 750 Grams of Elemental Mercury

    Directory of Open Access Journals (Sweden)

    Metin Uysalol

    2016-08-01

    Full Text Available Background: The oral ingestion of elemental mercury is unlikely to cause systemic toxicity, as it is poorly absorbed through the gastrointestinal system. However, abnormal gastrointestinal function or anatomy may allow elemental mercury into the bloodstream and the peritoneal space. Systemic effects of massive oral intake of mercury have rarely been reported. Case Report: In this paper, we are presenting the highest ingle oral intake of elemental mercury by a child aged 3 years. A Libyan boy aged 3 years ingested approximately 750 grams of elemental mercury and was still asymptomatic. Conclusion: The patient had no existing disease or abnormal gastrointestinal function or anatomy. The physical examination was normal. His serum mercury level was 91 μg/L (normal: <5 μg/L, and he showed no clinical manifestations. Exposure to mercury in children through different circumstances remains a likely occurrence.

  8. Stress reactivity in war-exposed young children with and without posttraumatic stress disorder: relations to maternal stress hormones, parenting, and child emotionality and regulation.

    Science.gov (United States)

    Feldman, Ruth; Vengrober, Adva; Eidelman-Rothman, Moranne; Zagoory-Sharon, Orna

    2013-11-01

    The current study examined biomarkers of stress in war-exposed young children and addressed maternal and child factors that may correlate with children's stress response. Participants were 232 Israeli children aged 1.5-5 years, including 148 children exposed to continuous war. Similarly, 56 were diagnosed with posttraumatic stress disorder (PTSD) and 92 were defined as exposed-no-PTSD. Child cortisol (CT) and salivary alpha amylase (sAA), biomarkers of the hypothalamic-pituitary-adrenal and sympathetic-adrenal-medullary arms of the stress response, were measured at baseline, following challenge, and at recovery. Maternal CT and sAA, PTSD symptoms, and reciprocal parenting, and child negative emotionality and regulatory strategies were assessed. Differences between war-exposed children and controls emerged, but these were related to child PTSD status. Children with PTSD exhibited consistently low CT and sAA, exposed-no-PTSD displayed consistently high CT and sAA, and controls showed increase in CT following challenge and decrease at recovery and low sAA. Exposed children showed higher negative emotionality; however, whereas exposed-no-PTSD children employed comfort-seeking strategies, children with PTSD used withdrawal. Predictors of child CT included maternal CT, PTSD symptoms, low reciprocity, and negative emotionality. Findings suggest that high physiological arousal combined with approach strategies may be associated with greater resilience in the context of early trauma.

  9. A Bilingual Experiment in the Amazonian Jungle of Peru

    Science.gov (United States)

    Wise, Mary Ruth

    1971-01-01

    In the Amazonian jungle of Peru 240 Indian leaders representing 20 different South American Indian language groups are successfully teaching their own people to read and write, first in their mother tongue and then in Spanish. (Author/EB)

  10. Fostering Resilience in Children Exposed to Domestic Violence: Practical Strategies EC Staff Can Put into Action

    Science.gov (United States)

    Stephens, Karen

    2010-01-01

    Children enmeshed in violence don't experience a relaxed, predictable, or trusting home life. In fact, children exposed to home violence often experience symptoms of post-traumatic stress disorder (PTSD) just as adults do after enduring violence. Domestic violence robs children of their childhood. And while early childhood staff can't erase the…

  11. Pre-LBA Anglo-Brazilian Amazonian Climate Observation Study (ABRACOS) Data

    Data.gov (United States)

    National Aeronautics and Space Administration — The data set presents the principal data from the Anglo-BRazilian Amazonian Climate Observation Study (ABRACOS) (Gash et al. 1996) and provides quality controlled...

  12. Pre-LBA Anglo-Brazilian Amazonian Climate Observation Study (ABRACOS) Data

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: The data set presents the principal data from the Anglo-BRazilian Amazonian Climate Observation Study (ABRACOS) (Gash et al. 1996) and provides quality...

  13. Assessment of occupational exposure of dental professionals to mercury in dental offices of a public primary health care in Maringá, Paraná State, Brazil - 10.4025/actascihealthsci.v34ispec.13428

    Directory of Open Access Journals (Sweden)

    André Gasparetto

    2012-12-01

    Full Text Available In order to evaluate the occupational exposure of dental professionals to metallic mercury in dental offices of a public primary health care in the city of Maringá, Brazil, samples of blood and urine were collected from 149 dental professionals (group exposed, and 51 healthy adults similar for age and gender of the exposed group (control group in September and October, 2008. Urinary mercury was determined using atomic absorption spectrophotometry, urea and creatinine in blood and urine by UV/VIS spectrophotometry and analysis of physical, chemical and microbiological characteristics of the urine by reactive bands. The program ‘Statistic’ version 7.1 and the software R version 2.6.2 were used for the statistical calculations. Urinary mercury was 2.08 ± 2.11 µg g-1 creatinine in workers exposed to mercury and 0.36 ± 0.62 µg g-1 creatinine in the control group (p -1 creatinine; 11% of these professionals (n = 16 had mercury levels above the reference value (5.0 µg g-1 creatinine, whereas the maximum value found was 13 µg g-1 creatinine. The dental professionals of public primary health care in the city of Maringa was exposed to metallic mercury at levels 5.8 times higher than the non-exposed subjects.  

  14. Life Satisfaction and School Performance of Children Exposed to Classic and Cyber Peer Bullying

    OpenAIRE

    Bilić, Vesna; Buljan Flander, Gordana; Rafajac, Branko

    2014-01-01

    This paper analyses the relationship between the exposure of school children to various forms of peer bullying (classic/cyber) and their life satisfaction in the domain of school, family, friends and school performance. The sample included 562 children from rural and urban areas of Croatia who were attending the seventh and the eighth grade of primary school. Results show that children were more often exposed to classic forms of peer bullying, especially verbal, and then physical bullying. On...

  15. Isozyme characterization of Capsicum accessions from the Amazonian Colombian collection

    Directory of Open Access Journals (Sweden)

    Lorena Quintero Barrera

    2005-01-01

    Full Text Available Two hundred and sixty-one accessions of the genus Capsicum were obtained from the Colombian Amazonian germplasm bank at Amazonian Institute of Scientific Research (Sinchi and were evaluated with five polymorphic enzymatic systems, including esterase (EST, peroxidase (PRX, 6-phosphogluconate dehydrogenase (6-PGDH, aspartate amino transferase (GOT, and malic enzyme (ME. Using a cluster analysis (UPGMA the genetic variability of these accessions were characterized. Grouping of the species C. baccatum and C. pubescens were observed, while the species C. annuum, C. chinense and C. frutescens did not group independently, a result that has been previously reported in isoenzyme analyses of this genus. Several accessions were deemed of particular interest for future ecological and evolutive studies. Key words: Colombia, Capsicum, germplasm bank, isoenzymes, peppers.

  16. Association of oxidative stress with arsenic methylation in chronic arsenic-exposed children and adults

    International Nuclear Information System (INIS)

    Xu Yuanyuan; Wang Yi; Zheng Quanmei; Li Xin; Li Bing; Jin Yaping; Sun Xiance; Sun Guifan

    2008-01-01

    Though oxidative stress is recognized as an important pathogenic mechanism of arsenic, and arsenic methylation capacity is suggested to be highly involved in arsenic-related diseases, the association of arsenic methylation capacity with arsenic-induced oxidative stress remains unclear. To explore oxidative stress and its association with arsenic methylation, cross-sectional studies were conducted among 208 high and 59 low arsenic-exposed subjects. Levels of urinary arsenic species [inorganic arsenic (iAs), monomethylated arsenic (MMA) and dimethylated arsenic (DMA)] were determined by hydride generation atomic absorption spectrometry. Proportions of urinary arsenic species, the first methylation ratio (FMR) and the secondary methylation ratio (SMR) were used as indicators for arsenic methylation capacity. Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentrations were analyzed by enzyme-linked immunosorbent assay kits. Reduced glutathione (GSH) levels and superoxide dismutase (SOD) activity in whole blood were determined to reflect anti-oxidative status. The high arsenic-exposed children and adults were significantly increased in urinary 8-OHdG concentrations but decreased in blood GSH levels compared with the low exposed children and adults. In multiple linear regression models, blood GSH levels and urinary 8-OHdG concentrations of arsenic-exposed children and adults showed strong associations with the levels of urinary arsenic species. Arsenic-exposed subjects in the lower and the upper quartiles of proportions of urinary arsenic species, FMR or SMR were significantly different in urinary 8-OHdG, blood GSH and SOD. The associations of arsenic methylation capacity with 8-OHdG, GSH and SOD were also observed in multivariate regression analyses. These results may provide linkage between arsenic methylation capacity and oxidative stress in humans and suggest that adverse health effects induced by arsenic are related to arsenic methylation through oxidative stress

  17. Comparative sensitivity of European native (Anodonta anatina) and exotic (Corbicula fluminea) bivalves to mercury

    Science.gov (United States)

    Oliveira, Patrícia; Lopes-Lima, Manuel; Machado, Jorge; Guilhermino, Lúcia

    2015-12-01

    Pollution is believed to be an important factor modulating the competition between exotic invasive bivalves and their native competitors. Thus, the objective of the present study was to compare the sensitivity of the European native Anodonta anatina and the exotic invasive species Corbicula fluminea to mercury, a ubiquitous environmental contaminant of high concern. In laboratory acute bioassays, adult organisms of both species were exposed independently to mercury for 96 h (31-500 μg/L). The criteria indicative of toxicity were mortality and biomarkers of oxidative stress and damage, neurotoxicity, and energy production changes. Mercury induced mortality in A. anatina (72 h-LC10 and 72 h-LC50 of 14.0 μg/L and 49.6 μg/L, respectively) but not in C. fluminea. The ability of C. fluminea to maintaining the shell closed for considerable periods of time when exposed to high concentrations of mercury and the effective activation (up to 63 μg/L) of mechanisms against the oxidative stress caused by mercury may have contributed to its relatively low sensitivity. In the range of concentrations tested, mercury had no significant effects on the other parameters analysed in C. fluminea. Overall, the findings of the present study, suggest that in real scenarios of competition between C. fluminea and A. anatina populations, the presence of mercury may modulate the process, acting in favour of the exotic species because it is less sensitive to this environmental contaminant than the native bivalve. The results of the present study highlight the need of further investigation on the effects of mercury on the competition between exotic invasive species and their native competitors, especially the effects potentially induced by long-term exposure to low concentrations of this metal, the mechanisms involved in the tolerance to mercury-induced stress, and the potential post-exposure recovery of both exotic invasive and native bivalves. This knowledge is most important for

  18. Female reproductive health in two lamp factories: effects of exposure to inorganic mercury vapour and stress factors.

    OpenAIRE

    De Rosis, F; Anastasio, S P; Selvaggi, L; Beltrame, A; Moriani, G

    1985-01-01

    To evaluate the possible influence of mercury vapour on female reproduction, 153 women working in a mercury vapour lamp factory have been compared with 193 women employed in another factory of the same company, where mercury was not used. Both groups of subjects were exposed to stress factors (noise, rhythms of production, and shift work). The production process has been analysed by inspection of the plants and by collective discussions with "homogeneous groups" of workers; a retrospective in...

  19. Feeding mice with diets containing mercury-contaminated fish flesh from French Guiana: a model for the mercurial intoxication of the Wayana Amerindians

    Directory of Open Access Journals (Sweden)

    Rossignol Rodrigue

    2008-10-01

    Full Text Available Abstract Background In 2005, 84% of Wayana Amerindians living in the upper marshes of the Maroni River in French Guiana presented a hair mercury concentration exceeding the limit set up by the World Health Organization (10 μg/g. To determine whether this mercurial contamination was harmful, mice have been fed diets prepared by incorporation of mercury-polluted fish from French Guiana. Methods Four diets containing 0, 0.1, 1, and 7.5% fish flesh, representing 0, 5, 62, and 520 ng methylmercury per g, respectively, were given to four groups of mice for a month. The lowest fish regimen led to a mercurial contamination pressure of 1 ng mercury per day per g of body weight, which is precisely that affecting the Wayana Amerindians. Results The expression of several genes was modified with mercury intoxication in liver, kidneys, and hippocampus, even at the lowest tested fish regimen. A net genetic response could be observed for mercury concentrations accumulated within tissues as weak as 0.15 ppm in the liver, 1.4 ppm in the kidneys, and 0.4 ppm in the hippocampus. This last value is in the range of the mercury concentrations found in the brains of chronically exposed patients in the Minamata region or in brains from heavy fish consumers. Mitochondrial respiratory rates showed a 35–40% decrease in respiration for the three contaminated mice groups. In the muscles of mice fed the lightest fish-containing diet, cytochrome c oxidase activity was decreased to 45% of that of the control muscles. When mice behavior was assessed in a cross maze, those fed the lowest and mid-level fish-containing diets developed higher anxiety state behaviors compared to mice fed with control diet. Conclusion We conclude that a vegetarian diet containing as little as 0.1% of mercury-contaminated fish is able to trigger in mice, after only one month of exposure, disorders presenting all the hallmarks of mercurial contamination.

  20. Planet Mercury

    Science.gov (United States)

    1974-01-01

    Mariner 10's first image of Mercury acquired on March 24, 1974. During its flight, Mariner 10's trajectory brought it behind the lighted hemisphere of Mercury, where this image was taken, in order to acquire important measurements with other instruments.This picture was acquired from a distance of 3,340,000 miles (5,380,000 km) from the surface of Mercury. The diameter of Mercury (3,031 miles; 4,878 km) is about 1/3 that of Earth.Images of Mercury were acquired in two steps, an inbound leg (images acquired before passing into Mercury's shadow) and an outbound leg (after exiting from Mercury's shadow). More than 2300 useful images of Mercury were taken, both moderate resolution (3-20 km/pixel) color and high resolution (better than 1 km/pixel) black and white coverage.

  1. Developmental dental defects in children exposed to PCBs

    Energy Technology Data Exchange (ETDEWEB)

    Jan, J. [Ljubljana Univ. (Slovenia). Fac. of Medicine; Sovcikova, E.; Kovrizhnykh, I.; Wimmerova, S.; Trnovec, T. [Slovak Medical Univ., Bratislava (Slovakia). Inst. of Preventive and Clinical Medicine; Kocan, A. [Institute of Preventive and Clinical Medicine, Bratislava (Slovakia). Dept. of Toxic Organic Pollutants

    2004-09-15

    Developing enamel is sensitive to a wide range of local and systemic disturbances. Because of the absolute metabolic stability of its structure, changes in enamel during its development are permanent in nature. Polychlorinated biphenyls (PCB) have been shown to disturb tooth development in experimental animals, but only limited amounts of data exist on their adverse effects in humans. Dental changes such as mottled, chipped, carious, and neonatal teeth have been reported in accidentally exposed humans. Nevertheless, co-contamination with polychlorinated dibenzo-furans (PCDFs) was largely responsible for the overall toxicity4. Alaluusua et al. found that developmental dental defects were correlated with the total exposure to polychlorinated aromatic hydrocarbons via mother's milk. The correlation was strong with exposure to prevailing levels of polychlorinated dibenzo-p-dioxins (PCDD) and furans (PCDF) but weak with exposure to PCBs alone. In our previous study we have shown developmental dental defects in children exposed to PCBs alone6, suggesting that the developing human teeth are vulnerable to PCBs. In the Michalovce region of eastern Slovakia, PCBs from a chemical plant manufacturing Delors contaminated the surrounding district7. The total serum PCB levels in samples from the general population there exceeded by several times the background levels in subjects living in a comparable unexposed Svidnik district. PCB levels in breast milk samples in the Michalovce region were the highest in Slovakia. Levels of toxic polychlorinated aromatics (PCDFs, PCNs, and planar PCBs) in technical Delors were high. The aim of this study was to evaluate the effects of long-term exposure to PCBs, measured at the individual level, on developmental dental defects in children in eastern Slovakia.

  2. Performance on neurological development tests by riverine children with moderate mercury exposure in Amazonia, Brazil Desempenho de crianças ribeirinhas da Amazônia, Brasil, expostas moderadamente ao mercúrio em testes para avaliação de desenvolvimento neurológico

    Directory of Open Access Journals (Sweden)

    Lydia Maria Bocayuva Tavares

    2005-08-01

    Full Text Available The nervous system can be damaged when the population is exposed to methyl mercury (MeHg by ingesting fish, and children deserve special attention due to their increased susceptibility as compared to adults. A comparative cross-sectional study was performed in order to investigate the use of a battery of neurological development tests in two groups of 209 riverine children from 3 to 7 years old: a group exposed to moderate levels of MeHg (n = 75 and a control group (n = 134. The study included a questionnaire, the collection of scalp hair samples for determination of total mercury concentration, and performance on a test for evaluating neurological function in children. Riverine children presented higher exposure to MeHg (mean hair Hg = 5.37 ± 3.35µg.g-1 in comparison to the control group (mean Hg = 2.08 ± 1.37µg.g-1. Both groups showed a high proportion of children with what was considered "non-normal" performance, suggesting that the results could not be related to mercury exposure and that this type of test presented limitations for use with river-dwelling Amazon communities.O sistema nervoso pode ser afetado quando as pessoas, notadamente crianças, estão expostas ao metilmercúrio pela ingestão de peixes. Foi desenvolvido um estudo seccional, comparativo, para avaliar o desempenho de dois grupos de crianças ribeirinhas de 3 a 7 anos de idade na realização de uma bateria de testes de desenvolvimento neurológico. Um grupo estudo composto de crianças expostas a moderados níveis de mercúrio (n = 75 e um grupo controle (n = 134 de crianças que diferiam do primeiro grupo por uma ingestão menor de peixe. O estudo incluiu questionário, coleta de amostras de cabelo para determinação de mercúrio total e avaliação do desempenho das crianças na realização dos testes. As crianças do grupo estudo apresentaram maior média de concentração de mercúrio no cabelo (5,37 ± 3,35µg.g-1 em comparação com o grupo controle (2,08 ± 1

  3. Mercury (Hg) burden in children: The impact of dental amalgam

    International Nuclear Information System (INIS)

    Al-Saleh, Iman; Al-Sedairi, Al anoud

    2011-01-01

    The risks and benefits of using mercury (Hg) in dental amalgam have long been debated. This study was designed to estimate Hg body burden and its association with dental amalgam fillings in 182 children (ages: 5-15 years) living in Taif City. Hg was measured in urine (UHg), hair (HHg) and toenails (NHg) by the Atomic Absorption Spectrophotometer with Vapor Generator Accessory system. Urinary Hg levels were calculated as both micrograms per gram creatinine (μg/g creatinine) and micrograms per liter (μg/L). We found that children with amalgam fillings (N = 106) had significantly higher UHg-C levels than children without (N = 76), with means of 3.763 μg/g creatinine versus 3.457 μg/g creatinine, respectively (P = 0.019). The results were similar for UHg (P = 0.01). A similar pattern was also seen for HHg, with means of 0.614 μg/g (N = 97) for children with amalgam versus 0.242 μg/g (N = 74) for those without amalgam fillings (P = 0). Although the mean NHg was higher in children without amalgam (0.222 μg/g, N = 61) versus those with (0.163 μg/g, N = 101), the relationship was not significant (P = 0.069). After adjusting for many confounders, the multiple logistic regression model revealed that the levels of UHg-C and HHg were 2.047 and 5.396 times higher, respectively, in children with dental amalgam compared to those without (P < 0.01). In contrast, a significant inverse relationship was seen between NHg levels and dental amalgam fillings (P = 0.003). Despite the controversy surrounding the health impact of dental amalgam, this study showed some evidence that amalgam-associated Hg exposure might be related with symptoms of oral health, such as aphthous ulcer, white patches, and a burning-mouth sensation. Further studies are needed to reproduce these findings. The present study showed that significant numbers of children with or without amalgam had Hg levels exceeding the acceptable reference limits. The detrimental neurobehavioral and/or nephrotoxic effects of

  4. Mercury (Hg) burden in children: The impact of dental amalgam

    Energy Technology Data Exchange (ETDEWEB)

    Al-Saleh, Iman, E-mail: iman@kfshrc.edu.sa [Biological and Medical Research Department, King Faisal Specialist Hospital and Research Centre, PO Box: 3354, Riyadh 11211 (Saudi Arabia); Al-Sedairi, Al anoud [Department of Zoology, College of Science, King Saud University, PO Box: 24452, Riyadh 11495 (Saudi Arabia)

    2011-07-15

    The risks and benefits of using mercury (Hg) in dental amalgam have long been debated. This study was designed to estimate Hg body burden and its association with dental amalgam fillings in 182 children (ages: 5-15 years) living in Taif City. Hg was measured in urine (UHg), hair (HHg) and toenails (NHg) by the Atomic Absorption Spectrophotometer with Vapor Generator Accessory system. Urinary Hg levels were calculated as both micrograms per gram creatinine ({mu}g/g creatinine) and micrograms per liter ({mu}g/L). We found that children with amalgam fillings (N = 106) had significantly higher UHg-C levels than children without (N = 76), with means of 3.763 {mu}g/g creatinine versus 3.457 {mu}g/g creatinine, respectively (P = 0.019). The results were similar for UHg (P = 0.01). A similar pattern was also seen for HHg, with means of 0.614 {mu}g/g (N = 97) for children with amalgam versus 0.242 {mu}g/g (N = 74) for those without amalgam fillings (P = 0). Although the mean NHg was higher in children without amalgam (0.222 {mu}g/g, N = 61) versus those with (0.163 {mu}g/g, N = 101), the relationship was not significant (P = 0.069). After adjusting for many confounders, the multiple logistic regression model revealed that the levels of UHg-C and HHg were 2.047 and 5.396 times higher, respectively, in children with dental amalgam compared to those without (P < 0.01). In contrast, a significant inverse relationship was seen between NHg levels and dental amalgam fillings (P = 0.003). Despite the controversy surrounding the health impact of dental amalgam, this study showed some evidence that amalgam-associated Hg exposure might be related with symptoms of oral health, such as aphthous ulcer, white patches, and a burning-mouth sensation. Further studies are needed to reproduce these findings. The present study showed that significant numbers of children with or without amalgam had Hg levels exceeding the acceptable reference limits. The detrimental neurobehavioral and

  5. Mercury

    NARCIS (Netherlands)

    de Vries, Irma

    2017-01-01

    Mercury is a naturally occurring metal that exists in several physical and chemical forms. Inorganic mercury refers to compounds formed after the combining of mercury with elements such as chlorine, sulfur, or oxygen. After combining with carbon by covalent linkage, the compounds formed are called

  6. Neonate exposure to thimerosal mercury from hepatitis B vaccines.

    Science.gov (United States)

    Dórea, José G; Marques, Rejane C; Brandão, Katiane G

    2009-08-01

    Infant exposure to ethylmercury (EtHg) has not only increased but is starting earlier as a result of the current immunization schedule that uses thimerosal-containing vaccines (TCVs). Although vaccination schedule varies considerably between countries, infants in less-developed countries continue to be exposed to EtHg derived from more affordable TCVs. We studied the exposure of newborns to EtHg from hepatitis B vaccines; hospital records (21,685) were summarized for the years 2001 to 2005 regarding date of birth, vaccination date, and birth weight. Most of the vaccinations occurred in the first 24 hours postdelivery; over the 5 years, there was an increase in vaccinations within hours of birth (same day), from 7.4% (2001) to 87.8% (2005). Nearly 94.6% of infants are now being vaccinated within the first 24 hours. Range of mercury exposure spread from 4.2 to 21.1 microg mercury/kg body weight for those receiving TCVs with the highest thimerosal concentration; these exposure levels are conservative for 2% of children receiving vaccines within 2 to 3 postnatal days, when they are still going through physiological postnatal weight loss. Because of the particular timing (transitioning from in utero to ex utero metabolism) and specific aspects of exposure (i.e., parenteral mode, bypassing gastroenteric barriers) and dose (related to vaccine manufacturer and with variation in birth weight), this study reveals critical issues that can modulate toxicokinetics and toxicodynamics of organomercurials in neonates.

  7. DIFFUSION AND PERCEPTION OF MERCURY RISK INFORMATION

    Science.gov (United States)

    Approximately 8% of American women have blood Mercury levels exceeding the EPA reference dose (a dose below which symptoms would be unlikely). The children of these women are at risk of neurological deficits (lower IQ scores) primarily because of the mother’s consumption of...

  8. Genotoxicity in earthworm after combined treatment of ionising radiation and mercury

    International Nuclear Information System (INIS)

    Ryu, Tae Ho; Kim, Jin Kyu; An, Kwang-Guk

    2014-01-01

    This study was performed to investigate the acute genotoxic effects of mercury and radiation on earthworms (Eisenia fetida). The levels of DNA damage and the repair kinetics in the coelomocytes of E. fetida treated with mercuric chloride (HgCl 2 ) and ionising radiation (gamma rays) were analysed by means of the comet assay. For detection of DNA damage and repair, E. fetida was exposed to HgCl 2 (0-160 mg kg -1 ) and irradiated with gamma rays (0-50 Gy) in vivo. The increase in DNA damage depended on the concentration of mercury or dose of radiation. The results showed that the more the oxidative stress induced by mercury and radiation the longer the repair time that was required. When a combination of HgCl 2 and gamma rays was applied, the cell damage was much higher than those treated with HgCl 2 or radiation alone, which indicated that the genotoxic effects were increased after the combined treatment of mercury and radiation. (authors)

  9. Determination of mercury in dentists through Neutron activation analysis; Determinacion de mercurio en odontologos mediante Analisis por activacion neutronica

    Energy Technology Data Exchange (ETDEWEB)

    Padilla M, M.A.; Granados C, F. [Instituto Nacional de Investigaciones Nucleares, Departamento de Quimica, A.P. 18-1027, C.P. 11801 Mexico D.F. (Mexico)

    2000-07-01

    It was determined the mercury levels in urine through Neutron activation analysis to 25 dentists who have been exposed to mercury by several time periods, because of the routine manipulations of amalgams. The determined concentrations of mercury were less to 10 {mu} g Hg/l of urine. The results were founded inside the safety limits reported in the literature. The mercury levels in the dentists are associated with a wide variety of factors that contribute to their exposure as: number of years of dental practice, number of amalgams manipulated between others. (Author)

  10. Compact Fluorescent Lights, Mercury, and the Landfill

    Science.gov (United States)

    2009-09-01

    danger is for women of childbearing age, pregnant women, nursing mothers, and young children. The exposure of unborn and young children can harm the...acceptable exposure limits for women of childbearing years and those who are pregnant or nursing . In USEPA’s 1997 Mercury Study Report to Congress, it was...known to be contaminated at higher levels, such as shark , swordfish, tilefish, and king mackerel. USEPA also hosts a web-based compilation of fish

  11. Origin and domestication of native Amazonian crops

    OpenAIRE

    Clément, R. Charles; De Cristo-Araujo, Michelly; Coppens D'Eeckenbrugge, Géo; Alves Pereira, Allessandro; Picanço-Rodrigues, Doriane

    2010-01-01

    Molecular analyses are providing new elements to decipher the origin, domestication and dispersal of native Amazonian crops in an expanding archaeological context. Solid molecular data are available for manioc (Manihot esculenta), cacao (Theobroma cacao), pineapple (Ananas comosus), peach palm (Bactris gasipaes) and guaraná (Paullinia cupana), while hot peppers (Capsicum spp.), inga (Inga edulis), Brazil nut (Bertholletia excelsa) and cupuassu (Theobroma grandiflorum) are being studied. Emerg...

  12. Validation of assessment tools for identifying trauma symptomatology in young children exposed to trauma

    DEFF Research Database (Denmark)

    Schandorph Løkkegaard, Sille; Elmose, Mette; Elklit, Ask

    There is a lack of Danish validated, developmentally sensitive assessment tools for preschool and young school children exposed to psychological trauma. Consequently, young traumatised children are at risk of not being identified. The purpose of this project is to validate three assessment tools...... that identify trauma symptomatology in young children; a caregiver interview called the Diagnostic Infant and Preschool Assessment (DIPA), a structured play test called the Odense Child Trauma Screening (OCTS), and a child questionnaire called the Darryl Cartoon Test. Three validity studies were conducted...

  13. Genetic effects in children exposed in prenatal period to ionizing radiation after the Chornobyl nuclear power plant accident.

    Science.gov (United States)

    Stepanova, Ye I; Vdovenko, V Yu; Misharina, Zh A; Kolos, V I; Mischenko, L P

    2016-12-01

    To study the genetic effects in children exposed to radiation in utero as a result of the Chornobyl nuclear power plant accident accounting the total radiation doses and equivalent radiation doses to the red bone marrow. Incidence of minor developmental anomalies was studied in children exposed to radiation in utero (study group) and in the control group (1144 subjects surveyed in total). Cytogenetic tests using the method of differential G-banding of chromosomes were conducted in 60 children of both study and control groups (10-12-year-olds) and repeatedly in 39 adolescents (15-17-year-olds). A direct correlation was found between the number of minor developmental anomalies and fetal dose of radiation, and a reverse one with fetal gestational age at the time of radiation exposure. Incidence of chromosomal damage in somatic cells of 10-12-year-old children exposed prenatally was associated with radiation dose to the red bone marrow. The repeated testing has revealed that an increased level of chromosomal aberrations was preserved in a third of adolescents. The persons exposed to ionizing radiation at prenatal period should be attributed to the group of carcinogenic risk due to persisting increased levels of chromosome damage. This article is a part of a Special Issue entitled "The Chornobyl Nuclear Accident: Thirty Years After".

  14. Lower birth weight and increased body fat at school age in children prenatally exposed to modern pesticides: a prospective study

    Directory of Open Access Journals (Sweden)

    Grandjean Philippe

    2011-09-01

    Full Text Available Abstract Background Endocrine disrupting chemicals have been hypothesized to play a role in the obesity epidemic. Long-term effects of prenatal exposure to non-persistent pesticides on body composition have so far not been investigated. The purpose of this study was to assess possible effects of prenatal exposure to currently used pesticides on children's growth, endocrine and reproductive function. Methods In a prospective study of 247 children born by women working in greenhouses in early pregnancy, 168 were categorized as prenatally exposed to pesticides. At three months (n = 203 and at 6 to11 years of age (n = 177 the children underwent a clinical examination and blood sampling for analysis of IGF-I, IGFBP3 and thyroid hormones. Body fat percentage at age 6 to11 years was calculated from skin fold measurements. Pesticide related associations were tested by linear multiple regression analysis, adjusting for relevant confounders. Results Compared to unexposed children birth weight and weight for gestational age were lower in the highly exposed children: -173 g (-322; -23, -4.8% (-9.0; -0.7 and medium exposed children: -139 g (-272; -6, -3.6% (-7.2; -0.0. Exposed (medium and highly together children had significantly larger increase in BMI Z-score (0.55 SD (95% CI: 0.1; 1.0 from birth to school age and highly exposed children had 15.8% (0.2; 34.6 larger skin folds and higher body fat percentage compared to unexposed. If prenatally exposed to both pesticides and maternal smoking (any amount, the sum of four skin folds was 46.9% (95% CI: 8.1; 99.5 and body fat percentage 29.1% (95% CI: 3.0; 61.4 higher. There were subtle associations between exposure and TSH Z-score -0.66(-1.287; -0.022 and IGF-I Z-score (girls: -0.62(-1.0; -0.22, boys: 0.38(-0.03; 0.79, but not IGFBP3. Conclusions Occupational exposure to currently used pesticides may have adverse effects in spite of the added protection offered to pregnant women. Maternal exposure to

  15. Evidence of suppression of onchocerciasis transmission in the Venezuelan Amazonian focus.

    Science.gov (United States)

    Botto, Carlos; Basañez, María-Gloria; Escalona, Marisela; Villamizar, Néstor J; Noya-Alarcón, Oscar; Cortez, José; Vivas-Martínez, Sarai; Coronel, Pablo; Frontado, Hortencia; Flores, Jorge; Graterol, Beatriz; Camacho, Oneida; Tovar, Yseliam; Borges, Daniel; Morales, Alba Lucia; Ríos, Dalila; Guerra, Francisco; Margeli, Héctor; Rodriguez, Mario Alberto; Unnasch, Thomas R; Grillet, María Eugenia

    2016-01-27

    The World Health Organization (WHO) has set goals for onchocerciasis elimination in Latin America by 2015. Most of the six previously endemic countries are attaining this goal by implementing twice a year (and in some foci, quarterly) mass ivermectin (Mectizan®) distribution. Elimination of transmission has been verified in Colombia, Ecuador and Mexico. Challenges remain in the Amazonian focus straddling Venezuela and Brazil, where the disease affects the hard-to-reach Yanomami indigenous population. We provide evidence of suppression of Onchocerca volvulus transmission by Simulium guianense s.l. in 16 previously hyperendemic Yanomami communities in southern Venezuela after 15 years of 6-monthly and 5 years of 3-monthly mass ivermectin treatment. Baseline and monitoring and evaluation parasitological, ophthalmological, entomological and serological surveys were conducted in selected sentinel and extra-sentinel communities of the focus throughout the implementation of the programme. From 2010 to 2012-2015, clinico-parasitological surveys indicate a substantial decrease in skin microfilarial prevalence and intensity of infection; accompanied by no evidence (or very low prevalence and intensity) of ocular microfilariae in the examined population. Of a total of 51,341 S. guianense flies tested by PCR none had L3 infection (heads only). Prevalence of infective flies and seasonal transmission potentials in 2012-2013 were, respectively, under 1% and 20 L3/person/transmission season. Serology in children aged 1-10 years demonstrated that although 26 out of 396 (7%) individuals still had Ov-16 antibodies, only 4/218 (2%) seropositives were aged 1-5 years. We report evidence of recent transmission and morbidity suppression in some communities of the focus representing 75% of the Yanomami population and 70% of all known communities. We conclude that onchocerciasis transmission could be feasibly interrupted in the Venezuelan Amazonian focus.

  16. Neuropsychological alterations in mercury intoxication persist several years after exposure.

    Science.gov (United States)

    Zachi, Elaine Cristina; Taub, Anita; Faria, Marcília de Araújo Medrado; Ventura, Dora Fix

    2008-01-01

    Elemental mercury is a liquid toxic metal widely used in industry. Occupational exposure occurs mainly via inhalation. Previously, neuropsychological assessment detected deficits in former workers of a fluorescent lamp plant who had been exposed to elemental mercury vapor and were away from exposure for several years at the time of examination. The purpose of this work was to reexamine these functions after 18 months in order to evaluate their progression. Thirteen participants completed tests of attention, inhibitory control, verbal/visual memory, psychomotor speed, verbal fluency, visuomotor ability, executive function, semantic knowledge, and depression and anxiety inventories on 2 separate occasions. At baseline, the former workers indicated slower psychomotor and information processing speed, verbal spontaneous recall memory impairment, and increased depression and anxiety symptoms compared to controls (Precovery of functions, the neuropsychological effects related to mercury exposure are found to persist for many years.

  17. 49 CFR 173.164 - Mercury (metallic and articles containing mercury).

    Science.gov (United States)

    2010-10-01

    ... ounces) of mercury per package; (iv) Tubes which are completely jacketed in sealed leakproof metal cases... 49 Transportation 2 2010-10-01 2010-10-01 false Mercury (metallic and articles containing mercury... Than Class 1 and Class 7 § 173.164 Mercury (metallic and articles containing mercury). (a) For...

  18. Health and environmental impact of mercury in the Philippines using nuclear techniques. Highlights and achievements

    International Nuclear Information System (INIS)

    Cortes-Maramba, Nelia

    2002-01-01

    This is the first comprehensive health evaluation made by the Department of Health of the mining community's exposure to total and methyl mercury. Previous studies have mainly focused more on the health risks associated with occupational exposure to mercury. Other sources of mercury exposure such as diet and other environmental media was not investigated and the population studied did not include high risk groups such as pregnant women and children

  19. Mercury Contamination in an Indicator Fish Species from Andean Amazonian Rivers Affected by Petroleum Extraction.

    Science.gov (United States)

    Webb, Jena; Coomes, Oliver T; Mainville, Nicolas; Mergler, Donna

    2015-09-01

    Elevated mercury (Hg) concentrations in fish from Amazonia have been associated with gold-mining, hydroelectric dams and deforestation but few studies consider the role of petroleum extraction. Hg levels were determined in fish samples collected in three river basins in Ecuador and Peru with contrasting petroleum exploitation and land-use characteristics. The non-migratory, piscivorous species, Hoplias malabaricus, was used as a bioindicator. The rate of Hg increase with body weight for this species was significantly higher on the Corrientes River, near the site of a recent oil spill, than on the other two rivers. In the absence of substantial deforestation and other anthropogenic sources in the Corrientes River basin, this finding suggests that oil contamination in Andean Amazonia may have a significant impact on Hg levels in fish.

  20. Recovery of mercury from mercury compounds via electrolytic methods

    Science.gov (United States)

    Grossman, Mark W.; George, William A.

    1988-01-01

    A process for electrolytically recovering mercury from mercury compounds is provided. In one embodiment, Hg is recovered from Hg.sub.2 Cl.sub.2 employing as the electrolyte solution a mixture of HCl and H.sub.2 O. In another embodiment, Hg is electrolytically recovered from HgO wherein the electrolyte solution is comprised of glacial acetic acid and H.sub.2 O. Also provided is an apparatus for producing isotopically enriched mercury compounds in a reactor and then transporting the dissolved compounds into an electrolytic cell where mercury ions are electrolytically reduced and elemental mercury recovered from the mercury compounds.

  1. The health after effects on children exposed to Chernobyl radiation fallout

    International Nuclear Information System (INIS)

    Contis, G.

    2002-01-01

    The purpose of this paper is to describe some of the long-term health consequences that are now being detected in Ukrainian adolescents who, as children, were exposed to Chornobyl radiation fallout fifteen years ago. The information presented will emphasize the importance of ensuring that nuclear power plants are built and operated with all the safeguards needed to prevent a recurrence of the Chornobyl disaster

  2. The Mercury Problem in Artisanal and Small-Scale Gold Mining.

    Science.gov (United States)

    Esdaile, Louisa J; Chalker, Justin M

    2018-05-11

    Mercury-dependent artisanal and small-scale gold mining (ASGM) is the largest source of mercury pollution on Earth. In this practice, elemental mercury is used to extract gold from ore as an amalgam. The amalgam is typically isolated by hand and then heated-often with a torch or over a stove-to distill the mercury and isolate the gold. Mercury release from tailings and vaporized mercury exceed 1000 tonnes each year from ASGM. The health effects on the miners are dire, with inhaled mercury leading to neurological damage and other health issues. The communities near these mines are also affected due to mercury contamination of water and soil and subsequent accumulation in food staples, such as fish-a major source of dietary protein in many ASGM regions. The risks to children are also substantial, with mercury emissions from ASGM resulting in both physical and mental disabilities and compromised development. Between 10 and 19 million people use mercury to mine for gold in more than 70 countries, making mercury pollution from ASGM a global issue. With the Minamata Convention on Mercury entering force this year, there is political motivation to help overcome the problem of mercury in ASGM. In this effort, chemists can play a central role. Here, the problem of mercury in ASGM is reviewed with a discussion on how the chemistry community can contribute solutions. Introducing portable and low-cost mercury sensors, inexpensive and scalable remediation technologies, novel methods to prevent mercury uptake in fish and food crops, and efficient and easy-to-use mercury-free mining techniques are all ways in which the chemistry community can help. To meet these challenges, it is critical that new technologies or techniques are low-cost and adaptable to the remote and under-resourced areas in which ASGM is most common. The problem of mercury pollution in ASGM is inherently a chemistry problem. We therefore encourage the chemistry community to consider and address this issue that

  3. Estimating the global conservation status of more than 15,000 Amazonian tree species

    Science.gov (United States)

    ter Steege, Hans; Pitman, Nigel C. A.; Killeen, Timothy J.; Laurance, William F.; Peres, Carlos A.; Guevara, Juan Ernesto; Salomão, Rafael P.; Castilho, Carolina V.; Amaral, Iêda Leão; de Almeida Matos, Francisca Dionízia; de Souza Coelho, Luiz; Magnusson, William E.; Phillips, Oliver L.; de Andrade Lima Filho, Diogenes; de Jesus Veiga Carim, Marcelo; Irume, Mariana Victória; Martins, Maria Pires; Molino, Jean-François; Sabatier, Daniel; Wittmann, Florian; López, Dairon Cárdenas; da Silva Guimarães, José Renan; Mendoza, Abel Monteagudo; Vargas, Percy Núñez; Manzatto, Angelo Gilberto; Reis, Neidiane Farias Costa; Terborgh, John; Casula, Katia Regina; Montero, Juan Carlos; Feldpausch, Ted R.; Honorio Coronado, Euridice N.; Montoya, Alvaro Javier Duque; Zartman, Charles Eugene; Mostacedo, Bonifacio; Vasquez, Rodolfo; Assis, Rafael L.; Medeiros, Marcelo Brilhante; Simon, Marcelo Fragomeni; Andrade, Ana; Camargo, José Luís; Laurance, Susan G. W.; Nascimento, Henrique Eduardo Mendonça; Marimon, Beatriz S.; Marimon, Ben-Hur; Costa, Flávia; Targhetta, Natalia; Vieira, Ima Célia Guimarães; Brienen, Roel; Castellanos, Hernán; Duivenvoorden, Joost F.; Mogollón, Hugo F.; Piedade, Maria Teresa Fernandez; Aymard C., Gerardo A.; Comiskey, James A.; Damasco, Gabriel; Dávila, Nállarett; García-Villacorta, Roosevelt; Diaz, Pablo Roberto Stevenson; Vincentini, Alberto; Emilio, Thaise; Levis, Carolina; Schietti, Juliana; Souza, Priscila; Alonso, Alfonso; Dallmeier, Francisco; Ferreira, Leandro Valle; Neill, David; Araujo-Murakami, Alejandro; Arroyo, Luzmila; Carvalho, Fernanda Antunes; Souza, Fernanda Coelho; do Amaral, Dário Dantas; Gribel, Rogerio; Luize, Bruno Garcia; Pansonato, Marcelo Petrati; Venticinque, Eduardo; Fine, Paul; Toledo, Marisol; Baraloto, Chris; Cerón, Carlos; Engel, Julien; Henkel, Terry W.; Jimenez, Eliana M.; Maas, Paul; Mora, Maria Cristina Peñuela; Petronelli, Pascal; Revilla, Juan David Cardenas; Silveira, Marcos; Stropp, Juliana; Thomas-Caesar, Raquel; Baker, Tim R.; Daly, Doug; Paredes, Marcos Ríos; da Silva, Naara Ferreira; Fuentes, Alfredo; Jørgensen, Peter Møller; Schöngart, Jochen; Silman, Miles R.; Arboleda, Nicolás Castaño; Cintra, Bruno Barçante Ladvocat; Valverde, Fernando Cornejo; Di Fiore, Anthony; Phillips, Juan Fernando; van Andel, Tinde R.; von Hildebrand, Patricio; Barbosa, Edelcilio Marques; de Matos Bonates, Luiz Carlos; de Castro, Deborah; de Sousa Farias, Emanuelle; Gonzales, Therany; Guillaumet, Jean-Louis; Hoffman, Bruce; Malhi, Yadvinder; de Andrade Miranda, Ires Paula; Prieto, Adriana; Rudas, Agustín; Ruschell, Ademir R.; Silva, Natalino; Vela, César I. A.; Vos, Vincent A.; Zent, Eglée L.; Zent, Stanford; Cano, Angela; Nascimento, Marcelo Trindade; Oliveira, Alexandre A.; Ramirez-Angulo, Hirma; Ramos, José Ferreira; Sierra, Rodrigo; Tirado, Milton; Medina, Maria Natalia Umaña; van der Heijden, Geertje; Torre, Emilio Vilanova; Vriesendorp, Corine; Wang, Ophelia; Young, Kenneth R.; Baider, Claudia; Balslev, Henrik; de Castro, Natalia; Farfan-Rios, William; Ferreira, Cid; Mendoza, Casimiro; Mesones, Italo; Torres-Lezama, Armando; Giraldo, Ligia Estela Urrego; Villarroel, Daniel; Zagt, Roderick; Alexiades, Miguel N.; Garcia-Cabrera, Karina; Hernandez, Lionel; Huamantupa-Chuquimaco, Isau; Milliken, William; Cuenca, Walter Palacios; Pansini, Susamar; Pauletto, Daniela; Arevalo, Freddy Ramirez; Sampaio, Adeilza Felipe; Valderrama Sandoval, Elvis H.; Gamarra, Luis Valenzuela

    2015-01-01

    Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict that most of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century. PMID:26702442

  4. Atlantic Bottlenose Dolphins (Tursiops truncatus as A Sentinel for Exposure to Mercury in Humans: Closing the Loop

    Directory of Open Access Journals (Sweden)

    John S. Reif

    2015-11-01

    Full Text Available Mercury (Hg is a ubiquitous global contaminant with important public health implications. Mercury is released from a variety of anthropogenic, industrial processes, enters the earth's atmosphere and is re-deposited onto the earth’s surface in rainfall. Much of this Hg enters the oceans which cover the majority of the earth’s surface. In the marine environment, inorganic Hg is converted to the most toxic form of the element, methylmercury, and biomagnified through the trophic levels of the food web. The bottlenose dolphin (Tursiops truncatus is the apex predator in many estuarine and coastal ecosystems. Due to their long life span and trophic position, bottlenose dolphins bioaccumulate high concentrations of contaminants including Hg, thus making them an important sentinel species for ecosystem and public health. Bottlenose dolphins in Florida bioaccumulate high concentrations of Hg in their blood, skin and internal organs. The concentrations of Hg in blood and skin of bottlenose dolphins of the Indian River Lagoon, FL (IRL are among the highest reported world-wide. In previous studies, we demonstrated associations between concentrations of total Hg in the blood and skin of IRL dolphins and markers of endocrine, renal, hepatic, hematologic and immune system dysfunction. The predominant manifestation of exposure to mercury in humans is neurotoxicity. During the 1950s and 1960s, residents of Minamata bay, Japan were exposed to high concentrations of methyl mercury as the result of ingestion of fish and shellfish that had become contaminated in this infamous environmental disaster. Affected adults had severe motor and sensory abnormalities often leading to death. Methyl mercury crosses the placenta during pregnancy. Children exposed in utero were born with multiple congenital anomalies and also suffered from neurologic disorders. Significantly, local cats that consumed Hg contaminated fish developed severe signs of neurotoxicity which led to

  5. Autoantibodies associated with prenatal and childhood exposure to environmental chemicals in faroese children

    DEFF Research Database (Denmark)

    Osuna, Christa E; Grandjean, Philippe; Weihe, Pál

    2014-01-01

    to both neural (neurofilaments, cholineacetyltransferase, astrocyte glial fibrillary acidic protein, and myelin basic protein) and non-neural (actin, desmin, and keratin) antigens were measured and the associations of these autoantibody concentrations with chemical exposures were assessed using linear...... of autoantibodies. However, it is not known if autoantibodies similarly will be generated and detectable in humans following toxicant exposures. Therefore, we conducted a pilot study to investigate if autoantibodies specific for neural and non-neural antigens could be detected in children at age 7 years who have...... been exposed to environmental chemicals. Both prenatal and age-7 exposures to mercury, PCBs, and PFCs were measured in 38 children in the Faroe Islands who were exposed to widely different levels of these chemicals due to their seafood-based diet. Concentrations of IgM and IgG autoantibodies specific...

  6. Awakening the Biodiversity Potential Trough ST&I Investments in the Sector of Amazonian Biotechnology

    Directory of Open Access Journals (Sweden)

    Fabiana dos Santos e Souza Frickmann

    2013-04-01

    Full Text Available The biotechnological development conciliated to Amazonian biodiversity represents a big potential for richness to Brazil. This study analyses the Brazilian investments in ST&I Amazonia’s, utilizing as indicator for that, the resources applied in R&D and the patent appli;cations coming from Amazon, which were filed with the National Institute of Industrial Property during the period from 2003 to 2008. The objective is to analyze how where such investments applied by the Ministry of Science, Technology, and Innovation (MCTI, and which was their impact over the biotechnological inventions of Amazonian origin. In the results, we observed that R$ 1,308.09 million was invested in ST&I in Amazonia. The Amazonian state that attracted the larger part of such resources was Amazonas and 153 patent applications were identified coming from the state of Amazonas; out of which, 56% derived from companies of the Manaus Industrial Pole, and 9% originated from biomedical and alimentary sectors.

  7. Evidence-Based Psychosocial Treatments for Children and Adolescents Exposed to Traumatic Events

    Science.gov (United States)

    Silverman, Wendy K.; Ortiz, Claudio D.; Viswesvaran, Chockalingham; Burns, Barbara J.; Kolko, David J.; Putnam, Frank W.; Amaya-Jackson, Lisa

    2008-01-01

    The article reviews the current status (1993-2007) of psychosocial treatments for children and adolescents who have been exposed to traumatic events. Twenty-one treatment studies are evaluated using criteria from Nathan and Gorman (2002) along a continuum of methodological rigor ranging from Type 1 to Type 6. All studies were, at a minimum, robust…

  8. Fish complementarity is associated to forests in Amazonian streams

    Directory of Open Access Journals (Sweden)

    Carolina Rodrigues Bordignon

    Full Text Available The functional structure of communities is commonly measured by the variability in functional traits, which may demonstrate complementarity or redundancy patterns. In this study, we tested the influence of environmental variables on the functional structure of fish assemblages in Amazonian streams within a deforestation gradient. We calculated six ecomorphological traits related to habitat use from each fish species, and used them to calculate the net relatedness index (NRI and the nearest taxon index (NTI. The set of species that used the habitat differently (complementary or overdispersed assemblages occurred in sites with a greater proportion of forests. The set of species that used the habitat in a similar way (redundant or clustered assemblages occurred in sites with a greater proportion of grasses in the stream banks. Therefore, the deforestation of entire watersheds, which has occurred in many Amazonian regions, may be a central factor for the functional homogenization of fish fauna.

  9. Carbon Dioxide Physiological Forcing Dominates Projected Eastern Amazonian Drying

    Science.gov (United States)

    Richardson, T. B.; Forster, P. M.; Andrews, T.; Boucher, O.; Faluvegi, G.; Fläschner, D.; Kasoar, M.; Kirkevâg, A.; Lamarque, J.-F.; Myhre, G.; Olivié, D.; Samset, B. H.; Shawki, D.; Shindell, D.; Takemura, T.; Voulgarakis, A.

    2018-03-01

    Future projections of east Amazonian precipitation indicate drying, but they are uncertain and poorly understood. In this study we analyze the Amazonian precipitation response to individual atmospheric forcings using a number of global climate models. Black carbon is found to drive reduced precipitation over the Amazon due to temperature-driven circulation changes, but the magnitude is uncertain. CO2 drives reductions in precipitation concentrated in the east, mainly due to a robustly negative, but highly variable in magnitude, fast response. We find that the physiological effect of CO2 on plant stomata is the dominant driver of the fast response due to reduced latent heating and also contributes to the large model spread. Using a simple model, we show that CO2 physiological effects dominate future multimodel mean precipitation projections over the Amazon. However, in individual models temperature-driven changes can be large, but due to little agreement, they largely cancel out in the model mean.

  10. Pesticide use and biodiversity conservation in the Amazonian agricultural frontier.

    Science.gov (United States)

    Schiesari, Luis; Waichman, Andrea; Brock, Theo; Adams, Cristina; Grillitsch, Britta

    2013-06-05

    Agricultural frontiers are dynamic environments characterized by the conversion of native habitats to agriculture. Because they are currently concentrated in diverse tropical habitats, agricultural frontiers are areas where the largest number of species is exposed to hazardous land management practices, including pesticide use. Focusing on the Amazonian frontier, we show that producers have varying access to resources, knowledge, control and reward mechanisms to improve land management practices. With poor education and no technical support, pesticide use by smallholders sharply deviated from agronomical recommendations, tending to overutilization of hazardous compounds. By contrast, with higher levels of technical expertise and resources, and aiming at more restrictive markets, large-scale producers adhered more closely to technical recommendations and even voluntarily replaced more hazardous compounds. However, the ecological footprint increased significantly over time because of increased dosage or because formulations that are less toxic to humans may be more toxic to other biodiversity. Frontier regions appear to be unique in terms of the conflicts between production and conservation, and the necessary pesticide risk management and risk reduction can only be achieved through responsibility-sharing by diverse stakeholders, including governmental and intergovernmental organizations, NGOs, financial institutions, pesticide and agricultural industries, producers, academia and consumers.

  11. Mercury's Sodium Exosphere: Observations during the MESSENGER Orbital Phase

    Science.gov (United States)

    Killen, Rosemary M.; Cassidy, Timothy A.; Vervack, Ronald J., Jr.; Burger, Matthew H.; Merkel, Aimee W.; Sarantos, Menelaos; Sprague, Ann L.; McClintock, William E.; Benna, Mehdi; Solomon, Sean C.

    2012-01-01

    The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft entered into orbit about Mercury on March 18,2011. We now have approximately five Mercury years of data from orbit. Prior to the MESSENGER mission, Mercury's surface-bounded exosphere was known to contain H, He, Na. K, and Ca. The Ultraviolet and Visible Spectrometer (UVVS) began routine orbital observations of both the dayside and nightside exosphere on March 29. 2011, measuring altitude profiles for all previously detected neutral species except for He and K. We focus here on what we have learned about the sodium exosphere: its spatial, seasonal, and sporadic variation. Observations to date permit delineation of the relative roles of photon-stimulated desorption (PSD) and impact vaporization (IV) from seasonal and spatial effects, as well as of the roles of ions both as sputtering agents and in their possible role to enhance the efficiency of PSD. Correlations of Mercury's neutral sodium exosphere with measurements from MESSENGER's Magnetometer (MAG) and Energetic Particle and Plasma Spectrometer (EPPS) provide insight into the roles of ions and electrons. Models incorporating MAG observations provide a basis for identifying the location and area of the surface exposed to solar wind plasma, and EPPS observations reveal episodic populations of energetic electrons in the magnetosphere and the presence of planetary He(+), 0(+), and Na(+),

  12. Manganese and Mercury Levels in Water, Sediments, and Children Living Near Gold-Mining Areas of the Nangaritza River Basin, Ecuadorian Amazon.

    Science.gov (United States)

    González-Merizalde, Max V; Menezes-Filho, José A; Cruz-Erazo, Claudia Teresa; Bermeo-Flores, Santos Amable; Sánchez-Castillo, María Obdulia; Hernández-Bonilla, David; Mora, Abrahan

    2016-08-01

    Artisanal and small-scale gold-mining activities performed in mountain areas of the Southern Ecuadorian Amazon have incorporated several heavy metals into the aquatic systems, thus increasing the risk of exposure in populations living in adjacent zones. Therefore, the objective of this study was to evaluate the contamination levels of mercury (Hg) and manganese (Mn) in several rivers of the Nangaritza River basin and assess the exposure in school-aged children residing near the gold-mining zones. River water and sediment samples were collected from a highly contaminated (HEx) and a moderately contaminated (MEx) zones. Hair Mn (MnH) and urinary Hg (HgU) levels were determined in school-aged children living in both zones. High concentrations of dissolved Mn were found in river waters of the HEx zone (between 2660 and 3990 µg l(-1)); however, Hg levels, in general, were lower than the detection limit (DL; MnH in children of the HEx and MEx zones were 5.5 and 3.4 µg g(-1), respectively, whereas the median values of HgU concentrations in children living in the HEx and MEx zones were 4.4 and 0.62 µg g-creat(-1), respectively. Statistically significant differences were observed between both biomarkers in children from the HEx and MEx zones. In addition, boys presented significantly greater MnH levels in both zones. The greater MnH values were found in children living in alluvial areas, whereas children living in the high mountain areas, where some ore-processing plants are located close to or inside houses and schools, had the greater HgU concentrations. In summary, the data reported in this paper highlights that artisanal and small-scale gold-mining activities can not only produce mercurial contamination, that can also release other heavy metals (such as Mn) that may pose a risk to human health.

  13. Lung inflammation biomarkers and lung function in children chronically exposed to arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Olivas-Calderón, Edgar, E-mail: edgar_olivascalderon@hotmail.com [Department of Environmental Health, Biomedical Research Center, School of Medicine, University of Coahuila, Torreon, Coahuila (Mexico); School of Medicine, University Juarez of Durango, Gomez Palacio, Durango (Mexico); Recio-Vega, Rogelio, E-mail: rrecio@yahoo.com [Department of Environmental Health, Biomedical Research Center, School of Medicine, University of Coahuila, Torreon, Coahuila (Mexico); Gandolfi, A. Jay, E-mail: gandolfi@pharmacy.arizona.edu [Southwest Environmental Health Science Center, University of Arizona, Tucson, AZ (United States); Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ (United States); Lantz, R. Clark, E-mail: lantz@email.arizona.edu [Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ (United States); Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ (United States); González-Cortes, Tania, E-mail: taniagc2201@hotmail.com [Department of Environmental Health, Biomedical Research Center, School of Medicine, University of Coahuila, Torreon, Coahuila (Mexico); Gonzalez-De Alba, Cesar, E-mail: cesargonzalezalba@hotmail.com [Department of Environmental Health, Biomedical Research Center, School of Medicine, University of Coahuila, Torreon, Coahuila (Mexico); Froines, John R., E-mail: jfroines@ucla.edu [Center for Environmental and Occupational Health, School of Public Health, University of California at Los Angeles, Los Angeles, CA (United States); Espinosa-Fematt, Jorge A., E-mail: dr.jorge.espinosa@gmail.com [School of Medicine, University Juarez of Durango, Gomez Palacio, Durango (Mexico)

    2015-09-01

    Evidence suggests that exposure to arsenic in drinking water during early childhood or in utero has been associated with an increase in respiratory symptoms or diseases in the adulthood, however only a few studies have been carried out during those sensitive windows of exposure. Recently our group demonstrated that the exposure to arsenic during early childhood or in utero in children was associated with impairment in the lung function and suggested that this adverse effect could be due to a chronic inflammation response to the metalloid. Therefore, we designed this cross-sectional study in a cohort of children associating lung inflammatory biomarkers and lung function with urinary As levels. A total of 275 healthy children were partitioned into four study groups according with their arsenic urinary levels. Inflammation biomarkers were measured in sputum by ELISA and the lung function was evaluated by spirometry. Fifty eight percent of the studied children were found to have a restrictive spirometric pattern. In the two highest exposed groups, the soluble receptor for advanced glycation end products' (sRAGE) sputum level was significantly lower and matrix metalloproteinase-9 (MMP-9) concentration was higher. When the biomarkers were correlated to the urinary arsenic species, negative associations were found between dimethylarsinic (DMA), monomethylarsonic percentage (%MMA) and dimethylarsinic percentage (%DMA) with sRAGE and positive associations between %DMA with MMP-9 and with the MMP-9/tissue inhibitor of metalloproteinase (TIMP-1) ratio. In conclusion, chronic arsenic exposure of children negatively correlates with sRAGE, and positively correlated with MMP-9 and MMP-9/TIMP-1 levels, and increases the frequency of an abnormal spirometric pattern. Arsenic-induced alterations in inflammatory biomarkers may contribute to the development of restrictive lung diseases. - Highlights: • First study in children evaluating lung inflammatory biomarkers and As levels

  14. High levels of maternally transferred mercury disrupt magnetic responses of snapping turtle hatchlings (Chelydra serpentina).

    Science.gov (United States)

    Landler, Lukas; Painter, Michael S; Coe, Brittney Hopkins; Youmans, Paul W; Hopkins, William A; Phillips, John B

    2017-09-01

    The Earth's magnetic field is involved in spatial behaviours ranging from long-distance migration to non-goal directed behaviours, such as spontaneous magnetic alignment (SMA). Mercury is a harmful pollutant most often generated from anthropogenic sources that can bio-accumulate in animal tissue over a lifetime. We compared SMA of hatchling snapping turtles from mothers captured at reference (i.e., low mercury) and mercury contaminated sites. Reference turtles showed radio frequency-dependent SMA along the north-south axis, consistent with previous studies of SMA, while turtles with high levels of maternally inherited mercury failed to show consistent magnetic alignment. In contrast, there was no difference between reference and mercury exposed turtles on standard performance measures. The magnetic field plays an important role in animal orientation behaviour and may also help to integrate spatial information from a variety of sensory modalities. As a consequence, mercury may compromise the performance of turtles in a wide variety of spatial tasks. Future research is needed to determine the threshold for mercury effects on snapping turtles, whether mercury exposure compromises spatial behaviour of adult turtles, and whether mercury has a direct effect on the magnetoreception mechanism(s) that mediate SMA or a more general effect on the nervous system. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Behavioral and musical characteristics of the children who are exposed to child maltreatment and poverty in South Korea: a survey.

    Science.gov (United States)

    Kim, Jinah; Kim, Kwanghyuk

    2014-06-01

    A preliminary survey was conducted on primary school aged children (N=302) between seven to twelve years of age, who attend the local Community Child Centers (CCC) in the economically deprived areas of Jeollabukdo in South Korea for the purpose of identifying the children who have been exposed to on-going child maltreatment and poverty, and their needs. Both standardized and non-standardized self-report types of surveys were carried out and completed by both the children and the teachers of the CCC. As would be expected, emotional and behavioral problems are more pronounced by the children who are exposed to child maltreatment and poverty compared to the children who were not exposed to these adversities, or who were not poor. The more severely abused children in terms of frequency and co-occurrence of different abuses appear to display more behavioral problems than less severely abused children. Teachers reported that the children who were able to play a musical instrument and had arts therapy experiences appear to have less behavioral problems, particularly delinquent and aggressive behavior in comparison to the children who did not have such ability and experiences. Through the survey, it was possible to identify the children in need of therapeutic intervention and discover clinically relevant information. Clinical implications will be discussed further. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Mercury in Arctic snow: Quantifying the kinetics of photochemical oxidation and reduction

    Energy Technology Data Exchange (ETDEWEB)

    Mann, E.A. [Department of Environmental Science, Acadia University, Wolfville, NS (Canada); Environmental Science Programme, Memorial University of Newfoundland, St. John' s, NL (Canada); Mallory, M.L. [Department of Biology, Acadia University, Wolfville, NS (Canada); Ziegler, S.E. [Environmental Science Programme, Memorial University of Newfoundland, St. John' s, NL (Canada); Tordon, R. [Environment Canada, Dartmouth, NS (Canada); O' Driscoll, N.J., E-mail: nelson.odriscoll@acadiau.ca [Department of Environmental Science, Acadia University, Wolfville, NS (Canada)

    2015-03-15

    Controlled experiments were performed with frozen and melted Arctic snow to quantify relationships between mercury photoreaction kinetics, ultra violet (UV) radiation intensity, and snow ion concentrations. Frozen (− 10 °C) and melted (4 °C) snow samples from three Arctic sites were exposed to UV (280–400 nm) radiation (1.26–5.78 W · m{sup −2}), and a parabolic relationship was found between reduction rate constants in frozen and melted snow with increasing UV intensity. Total photoreduced mercury in frozen and melted snow increased linearly with greater UV intensity. Snow with the highest concentrations of chloride and iron had larger photoreduction and photooxidation rate constants, while also having the lowest Hg(0) production. Our results indicate that the amount of mercury photoreduction (loss from snow) is the highest at high UV radiation intensities, while the fastest rates of mercury photoreduction occurred at both low and high intensities. This suggests that, assuming all else is equal, earlier Arctic snow melt periods (when UV intensities are less intense) may result in less mercury loss to the atmosphere by photoreduction and flux, since less Hg(0) is photoproduced at lower UV intensities, thereby resulting in potentially greater mercury transport to aquatic systems with snowmelt. - Highlights: • Mercury photochemical kinetics were studied in frozen and melted Arctic snow. • UV-induced photoreduction and photooxidation rate constants were quantified. • Chloride ion, iron, and DOC influence mercury photoreactions in snow. • Frozen and melted snow have different mercury photoreduction characteristics. • Kinetic information provided can be used to model mercury fate in the Arctic.

  17. Mercury in Arctic snow: Quantifying the kinetics of photochemical oxidation and reduction

    International Nuclear Information System (INIS)

    Mann, E.A.; Mallory, M.L.; Ziegler, S.E.; Tordon, R.; O'Driscoll, N.J.

    2015-01-01

    Controlled experiments were performed with frozen and melted Arctic snow to quantify relationships between mercury photoreaction kinetics, ultra violet (UV) radiation intensity, and snow ion concentrations. Frozen (− 10 °C) and melted (4 °C) snow samples from three Arctic sites were exposed to UV (280–400 nm) radiation (1.26–5.78 W · m −2 ), and a parabolic relationship was found between reduction rate constants in frozen and melted snow with increasing UV intensity. Total photoreduced mercury in frozen and melted snow increased linearly with greater UV intensity. Snow with the highest concentrations of chloride and iron had larger photoreduction and photooxidation rate constants, while also having the lowest Hg(0) production. Our results indicate that the amount of mercury photoreduction (loss from snow) is the highest at high UV radiation intensities, while the fastest rates of mercury photoreduction occurred at both low and high intensities. This suggests that, assuming all else is equal, earlier Arctic snow melt periods (when UV intensities are less intense) may result in less mercury loss to the atmosphere by photoreduction and flux, since less Hg(0) is photoproduced at lower UV intensities, thereby resulting in potentially greater mercury transport to aquatic systems with snowmelt. - Highlights: • Mercury photochemical kinetics were studied in frozen and melted Arctic snow. • UV-induced photoreduction and photooxidation rate constants were quantified. • Chloride ion, iron, and DOC influence mercury photoreactions in snow. • Frozen and melted snow have different mercury photoreduction characteristics. • Kinetic information provided can be used to model mercury fate in the Arctic

  18. Studies on the determination of mercury in human beard shavings by neutron-activation and γ-ray analysis

    International Nuclear Information System (INIS)

    Pritchard, J.G.; Saied, S.O.

    1986-01-01

    The determination of mercury by instrumental neutron-activation analysis has been studied with particular emphasis on hair as the matrix. The well known analytical standards orchard leaves and Bowen's kale have been compared and the value 0.164 +-0.013 p.p.m. found for the level of mercury in Bowen's kale. Hence, the likely accuracy is +- 8% when matrices similar to Bowen's kale are analysed for mercury by the method described. All factors affecting the precision are discussed. Powdered hair and the standards were shown to be easily homogenisable; however, beard shavings were found to be generally inhomogeneous with respect to mercury distribution, especially when the mercury content was much in excess of ca. 2 p.p.m. owing to exposure of subjects to mercury in the professional working environment. The beard shavings of non-occupationally exposed human beings contained 0.1 to 1.5 p.p.m. of mercury. Difficulties with the establishment of a mercury mass standard for use with the method are discussed. (author)

  19. Fire-free land use in pre-1492 Amazonian savannas.

    Science.gov (United States)

    Iriarte, José; Power, Mitchell J; Rostain, Stéphen; Mayle, Francis E; Jones, Huw; Watling, Jennifer; Whitney, Bronwen S; McKey, Doyle B

    2012-04-24

    The nature and scale of pre-Columbian land use and the consequences of the 1492 "Columbian Encounter" (CE) on Amazonia are among the more debated topics in New World archaeology and paleoecology. However, pre-Columbian human impact in Amazonian savannas remains poorly understood. Most paleoecological studies have been conducted in neotropical forest contexts. Of studies done in Amazonian savannas, none has the temporal resolution needed to detect changes induced by either climate or humans before and after A.D. 1492, and only a few closely integrate paleoecological and archaeological data. We report a high-resolution 2,150-y paleoecological record from a French Guianan coastal savanna that forces reconsideration of how pre-Columbian savanna peoples practiced raised-field agriculture and how the CE impacted these societies and environments. Our combined pollen, phytolith, and charcoal analyses reveal unexpectedly low levels of biomass burning associated with pre-A.D. 1492 savanna raised-field agriculture and a sharp increase in fires following the arrival of Europeans. We show that pre-Columbian raised-field farmers limited burning to improve agricultural production, contrasting with extensive use of fire in pre-Columbian tropical forest and Central American savanna environments, as well as in present-day savannas. The charcoal record indicates that extensive fires in the seasonally flooded savannas of French Guiana are a post-Columbian phenomenon, postdating the collapse of indigenous populations. The discovery that pre-Columbian farmers practiced fire-free savanna management calls into question the widely held assumption that pre-Columbian Amazonian farmers pervasively used fire to manage and alter ecosystems and offers fresh perspectives on an emerging alternative approach to savanna land use and conservation that can help reduce carbon emissions.

  20. Introduction of Molecular Building Blocks to Improve the Stability of Metal-Organic Frameworks for Efficient Mercury Removal.

    Science.gov (United States)

    Jiang, Shu-Yi; He, Wen-Wen; Li, Shun-Li; Su, Zhong-Min; Lan, Ya-Qian

    2018-05-08

    With expanding human needs, many heavy metals were mined, smelted, processed, and manufactured for commercialization, which caused serious environmental pollutions. Currently, many adsorption materials are applied in the field of adsorption of heavy metals. Among them, the principle of many mercury adsorbents is based on the interaction between mercury and sulfur. Here, a S-containing metal-organic framework NENU-400 was synthesized for effective mercury extraction. Unfortunately, the skeleton of NENU-400 collapsed easily when exposed to the mercury liquid solution. To improve the stability, a synthetic strategy installing molecular building blocks (MBBs) into the channels was used. Modified by the MBBs, a more stable nanoporous framework was synthesized, which not only exhibits a high capacity of saturation mercury uptake but also shows high selectivity and efficient recyclability.

  1. Blood Mercury Level and Its Determinants among Dental Practitioners in Hamadan, Iran

    Directory of Open Access Journals (Sweden)

    M. Vahedi

    2010-06-01

    Full Text Available Objective: Exposure to mercury can occur in occupational and environmental settings.During clinical work with dental amalgam, the dental personnel are exposed to both metallic mercury and mercury vapor. The aim of the present study was to investigate bloodmercury level (BML and its determinants among dentists practicing in Hamadan city,Iran.Materials and Methods: This cross sectional study was done on all dental practitioners of Hamadan (n=43. Dentists were asked to complete a questionnaire, and then 5 ml bloodsamples were obtained from them. After preparation, mercury concentration of each sample was measured by cold vapor atomic absorption device. Pearson correlation test and regression models served for statistical analysis.Results: The mean blood concentration of mercury was 6.3 μg/l (SD=1.31 range 4.15-8.93. BML was positively associated with age, years in practice, working hours per day,number of amalgam restorations per day, number of amalgam removal per week, sea foodconsumption, working years in present office, using amalgam powder, using diamond bur for amalgam removal, dry sterilization of amalgam contaminated instruments, and deficient air ventilation.Conclusion: BML of dentists in Hamadan was higher than standards. Working hours and number of amalgam restorations per day were significantly correlated with blood mercury.

  2. River transport of mercury from artisanal and small-scale gold mining and risks for dietary mercury exposure in Madre de Dios, Peru.

    Science.gov (United States)

    Diringer, Sarah E; Feingold, Beth J; Ortiz, Ernesto J; Gallis, John A; Araújo-Flores, Julio M; Berky, Axel; Pan, William K Y; Hsu-Kim, Heileen

    2015-02-01

    Artisanal and small-scale gold mining (ASGM) is a major contributor to deforestation and the largest anthropogenic source of atmospheric mercury worldwide. Despite significant information on the direct health impacts of mercury to ASGM miners, the impact of mercury contamination on downstream communities has not been well characterized, particularly in Peru's Madre de Dios region. In this area, ASGM has increased significantly since 2000 and has led to substantial political and social controversy. This research examined the spatial distribution and transport of mercury through the Madre de Dios River with distance from ASGM activity. This study also characterized risks for dietary mercury exposure to local residents who depend on fish from the river. River sediment, suspended solids from the water column, and fish samples were collected in 2013 at 62 sites near 17 communities over a 560 km stretch of the Madre de Dios River and its major tributaries. In areas downstream of known ASGM activity, mercury concentrations in sediment, suspended solids, and fish within the Madre de Dios River were elevated relative to locations upstream of mining. Fish tissue mercury concentrations were observed at levels representing a public health threat, with greater than one-third of carnivorous fish exceeding the international health standard of 0.5 mg kg(-1). This study demonstrates that communities located hundreds of kilometers downstream of ASGM activity, including children and indigenous populations who may not be involved in mining, are at risk of dietary mercury exposure that exceed acceptable body burdens. This report represents the first systematic study of the region to aid policy decision-making related to ASGM activities in Peru.

  3. Total mercury and methyl-mercury contents and accumulation in polar microbial mats.

    Science.gov (United States)

    Camacho, Antonio; Rochera, Carlos; Hennebelle, Raphaëlle; Ferrari, Christophe; Quesada, Antonio

    2015-03-15

    Although polar regions are considered isolated and pristine areas, the organisms that inhabit these zones are exposed to global pollution. Heavy metals, such as mercury, are global pollutants and can reach almost any location on Earth. Mercury may come from natural, volcanic or geological sources, or result from anthropogenic sources, in particular industrial or mining activities. In this study, we have investigated one of the most prominent biological non-marine communities in both polar regions, microbial mats, in terms of their Hg and methyl-mercury (MeHg) concentrations and accumulation capacities. The main hypotheses posed argued on the importance of different factors, and to test them, we have measured Hg concentrations in microbial mats that were collected from 6 locations in different ecological situations. For this purpose, the direct anthropogenic impacts, volcanic influences, proximity to the seashore, latitudinal gradients and C contents were investigated. Our results show that, other than the direct anthropogenic influence, none of the other hypotheses alone satisfactorily explains the Hg content in microbial mats. In contrast, the MeHg contents were noticeably different between the investigated locations, with a higher proportion of MeHg on the McMurdo Ice Shelf (Antarctica) and a lower proportion on Ward Hunt Island (High Arctic). Furthermore, our results from in situ experiments indicated that the microbial mats from South Shetland Islands could quickly accumulate (48 h) Hg when Hg dissolved salts were supplied. Over short-term periods, these mats do not transform Hg into MeHg under field conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. New evidence for surface water ice in small-scale cold traps and in three large craters at the north polar region of Mercury from the Mercury Laser Altimeter

    Science.gov (United States)

    Deutsch, Ariel N.; Neumann, Gregory A.; Head, James W.

    2017-09-01

    The Mercury Laser Altimeter (MLA) measured surface reflectance, rs, at 1064 nm. On Mercury, most water-ice deposits have anomalously low rs values indicative of an insulating layer beneath which ice is buried. Previous detections of surface water ice (without an insulating layer) were limited to seven possible craters. Here we map rs in three additional permanently shadowed craters that host radar-bright deposits. Each crater has a mean rs value >0.3, suggesting that water ice is exposed at the surface without an overlying insulating layer. We also identify small-scale cold traps (rs >0.3 and permanent shadows have biannual maximum surface temperatures <100 K. We suggest that a substantial amount of Mercury's water ice is not confined to large craters but exists within microcold traps, within rough patches and intercrater terrain.

  5. Mercury and Your Health

    Science.gov (United States)

    ... the Risk of Exposure to Mercury Learn About Mercury What is Mercury What is Metallic mercury? Toxicological Profile ToxFAQs Mercury Resources CDC’s National Biomonitoring Program Factsheet on Mercury ...

  6. Effects of methyl mercury exposure on pancreatic beta cell development and function.

    Science.gov (United States)

    Schumacher, Lauren; Abbott, Louise C

    2017-01-01

    Methyl mercury is an environmental contaminant of worldwide concern. Since the discovery of methyl mercury exposure due to eating contaminated fish as the underlying cause of the Minamata disaster, the scientific community has known about the sensitivity of the developing central nervous system to mercury toxicity. Warnings are given to pregnant women and young children to limit consumption of foods containing methyl mercury to protect the embryonic, fetal and postnatally developing central nervous system. However, evidence also suggests that exposure to methyl mercury or various forms of inorganic mercury may also affect development and function of other organs. Numerous reports indicate a worldwide increase in diabetes, particularly type 2 diabetes. Quite recently, methyl mercury has been shown to have adverse effects on pancreatic beta (β) cell development and function, resulting in insulin resistance and hyperglycemia and may even lead to the development of diabetes. This review discusses possible mechanisms by which methyl mercury exposure may adversely affect pancreatic β cell development and function, and the role that methyl mercury exposure may have in the reported worldwide increase in diabetes, particularly type 2 diabetes. While additional information is needed regarding associations between mercury exposure and specific mechanisms of the pathogenesis of diabetes in the human population, methyl mercury's adverse effects on the body's natural sources of antioxidants suggest that one possible therapeutic strategy could involve supplementation with antioxidants. Thus, it is important that additional investigation be undertaken into the role of methyl mercury exposure and reduced pancreatic β cell function. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  7. Preliminary study of selenium and mercury distribution in some porcine tissues and their subcellular fractions by NAA and HG-AFS

    International Nuclear Information System (INIS)

    Jiujiang Zhao; Chunying Chen; Peiqun Zhang; Zhifang Chai

    2004-01-01

    Selenium and mercury distribution in porcine tissues and their subcellular fractions from a mercury-polluted area of Guizhou Province and from a not mercury-exposed area of Beijing in China have been studied with neutron activation analysis and hydride generation-atomic fluorescence spectrometry. Both the selenium and mercury levels are higher in Guizhou porcine tissues and their subcellular fractions than those in Beijing. These two elements are highly enriched in kidney and liver of Guizhou pig, while selenium is only enriched in the kidney of Beijing pig. Exposure of mercury may result in redistribution of Se and Hg in vivo. The Hg/Se molar ratio of the subcellular fractions is very low in the case of relatively low mercury level and gradually reaches to a high constant value with increasing level of mercury, which implies that selenium and mercury may form some special complexes in the organisms. (author)

  8. RISK PERCEPTION AND DIFFUSION OF MERCURY RISK INFORMATION

    Science.gov (United States)

    The most recent NHANES data reveals that approximately 8% of American women have blood Mercury levels exceeding the EPA reference dose (a dose below which symptoms would be unlikely). The children of these women are at risk of neurological deficits (lower IQ scores) primarily bec...

  9. Malignant tumors in people exposed as children to atomic bomb in Nagasaki

    International Nuclear Information System (INIS)

    Ikeda, Takayoshi; Matsuo, Takeshi; Mori, Yo; Nonaka, Masaru; Oribe, Takashi

    1976-01-01

    In order to determine both the conditions under which malignant tumors occurred and the pathological specificity of those tumors in people exposed as children (at the age of 0-9) to the atomic bomb in Nagasaki, a comparative study was made of malignant tumors (including brain tumor but excluding leukemia) in 88 exposed cases taken from the data of the committee for the statistical analysis of tumors in Nagasaki and from other literature, and in unexposed cases of malignancy. The following items were analyzed; the distance from the bombed area (doses), the age at the time that the disease occurred, the latent period, the annual incidence of disease, the site of tumor, and the type of tissue. The results are summarized as follows, although they are inconclusive because of the small number of cases. The incidence of malignant lymphoma, cancer of the tyroid gland, brain tumor, sarcoma, and cancer of the ovary had a tendency to be higher in the exposed cases than in the unexposed cases. From the standpoint of sex, there was a tendency that cancer of the stomach and malignant lymphoma occurred more often in females than in males. On the other hand, sarcoma and brain tumor were seen more often in males. From the standpoint of the relationships among these factors: the distance from the bombed area, the latent period, and the type of tumor, it was suggested that cancer of the thyroid gland, brain tumor and cancer of the stomach were observed especially in cases which had been exposed as children. In addition, it was considered that the influence of not only a short distance from the bombed area but also a middle distance from that area can not be neglected. (Namekawa, K.)

  10. Mercury and other element exposure to tree swallows (Tachycineta bicolor) nesting on Lostwood National Wildlife Refuge, North Dakota

    International Nuclear Information System (INIS)

    Custer, Thomas W.; Custer, Christine M.; Johnson, Kevin M.; Hoffman, David J.

    2008-01-01

    Elevated mercury concentrations in water were reported in the prairie wetlands at Lostwood National Wildlife Refuge, ND. In order to determine whether wildlife associated with these wetlands was exposed to and then accumulated higher mercury concentrations than wildlife living near more permanent wetlands (e.g. lakes), tree swallow (Tachycineta bicolor) eggs and nestlings were collected from nests near seasonal wetlands, semi-permanent wetlands, and lakes. Mercury concentrations in eggs collected near seasonal wetlands were higher than those collected near semi-permanent wetlands or lakes. In contrast, mercury concentrations in nestling livers did not differ among wetland types. Mercury and other element concentrations in tree swallow eggs and nestlings collected from all wetlands were low. As suspected from these low concentrations, mercury concentrations in sample eggs were not a significant factor explaining the hatching success of the remaining eggs in each clutch. - Mercury concentrations in tree swallows nesting in the prairie wetlands at Lostwood National Wildlife Refuge were not elevated

  11. Determination of mercury and selenium in biological materials by neutron activation analysis method

    International Nuclear Information System (INIS)

    Catharino, Marilia G.M.; Vasconcellos, Marina B.A.; Moreira, Edson G.; Cipriano, Roseli; Saiki, Mitiko

    2000-01-01

    Mercury presents a great number of applications, however, many mercury compounds are highly toxic and may cause diseases or even death. Other element of interest is selenium, as some studies have shown that it may reduce the toxic effects of mercury and other toxic elements, due to its ability to bind to these elements. In this work the mercury concentration in the 'Spiked Human Hair' IAEA-085 and 'Unspiked Human Hair' IAEA-086 certified reference materials, in hair samples of children under dental treatment and in hair samples of an Amazon Region population, subject to mercurial contamination was determined. Selenium determination was done using 77m Se and 75 Se radioisotopes. The selenium concentration was determined also in the (IAEA-085, IAEA-086, 'Dogfish Liver' DOLT-1 and 'Dogfish Muscle' DORM-1) certified reference materials, vitamin supplement and nail clipping samples. (author)

  12. Higher Education and Urban Migration for Community Resilience: Indigenous Amazonian Youth Promoting Place-Based Livelihoods and Identities in Peru

    Science.gov (United States)

    Steele, Diana

    2018-01-01

    This paper offers an ethnographic analysis of indigenous Peruvian Amazonian youth pursuing higher education through urban migration to contribute to the resilience of their communities, place-based livelihoods, and indigenous Amazonian identities. Youth and their communities promoted education and migration as powerful tools in the context of…

  13. SEMINAL PLASMA LEVELS OF LEAD AND MERCURY IN INFERTILE MALES IN BENIN CITY, NIGERIA

    Directory of Open Access Journals (Sweden)

    Emokpae MA

    2016-01-01

    Full Text Available Background/objectives: Studies on environmental exposure to toxic metals and their effects on male reproductive function are scare in our setting. This study evaluates the levels of lead and mercury in seminal plasma of infertile males who are non-occupationally exposed in Benin City, Nigeria and to determine the relationship between seminal quality and these toxic metals. Materials and Methods: A total of 80 subjects participated in this study which includes 60 infertile males on routine visit to the infertility clinics in Benin City and 20 fertile males as controls. The concentration of lead in seminal plasma was assayed by atomic absorption spectrophotometer while the concentration of mercury was measured using inductively coupled plasma Mass spectrometry. Semen analyses were performed using standard techniques as recommended by World Health Organization. Results: Mean seminal plasma lead and mercury levels were significantly higher (p<0.001 in infertile males compared with controls. Mercury and lead correlated negatively (p<0.001 with sperm count, progressive motility, total motility and morphology but not with semen volume. There was no significant correlation between toxic metals and sperm indices in fertile males (controls. Conclusion: The levels of the studied toxic metals were higher in seminal plasma of infertile males and appear to have adverse effect on seminal indices in non -occupationally exposed males.

  14. Ultrastructural nasal pathology in children chronically and sequentially exposed to air pollutants.

    Science.gov (United States)

    Calderón-Garcidueñas, L; Valencia-Salazar, G; Rodríguez-Alcaraz, A; Gambling, T M; García, R; Osnaya, N; Villarreal-Calderón, A; Devlin, R B; Carson, J L

    2001-02-01

    Southwest Metropolitan Mexico City (SWMMC) children are repeatedly exposed to a complex mixture of air pollutants, including ozone, particulate matter, and aldehydes. Nasal biopsies taken from these children exhibit a wide range of histopathologic alterations: marked changes in ciliated and goblet cell populations, basal cell hyperplasia, squamous metaplasia, and mild dysplasias. We studied the ultrastructural features of 15 nasal biopsies obtained from clinically healthy children 4 to 15 yr of age, growing up in SWMMC. The results were compared with nasal biopsies from 11 children growing up in Veracruz and exposed to low pollutant levels. Ultrathin sections of nasal biopsies revealed an unremarkable mucociliary epithelium in control children, whereas SWMMC children showed an epithelium comprised of variable numbers of basal, ciliated, goblet, and squamous metaplastic as well as intermediate cells. Nascent ciliated cells, as evidenced by the presence of migratory kinetosomes, were common, as were ciliary abnormalities, including absent central microtubules, supernumerary central and peripheral tubules, ciliary microtubular discontinuities, and compound cilia. Dyskinesia associated with these abnormal cilia was suggested by the altered orientation of the central microtubules in closely adjacent cilia. A transudate was evident between epithelial cells, suggesting potential deficiencies in epithelial junction integrity. Particulate matter was present in heterolysosomal bodies in epithelial cells and it was also deposited in intercellular spaces. The severe structural alteration of the nasal epithelium together with the prominent acquired ciliary defects are likely the result of chronic airway injury in which ozone, particulate matter, and aldehydes are thought to play a crucial role. The nasal epithelium in SWMMC children is fundamentally disordered, and their mucociliary defense mechanisms are no longer intact. A compromised nasal epithelium has less ability to

  15. Assessment of mercury content in Panga (Pangasius hypophthalmus).

    Science.gov (United States)

    Rodríguez, María; Gutiérrez, Ángel J; Rodríguez, Natividad; Rubio, Carmen; Paz, Soraya; Martín, Verónica; Revert, Consuelo; Hardisson, Arturo

    2018-04-01

    Panga (Pangasius hypophthalmus), originating from Vietnam, is one of the most consumed fish because of its low cost, mild taste and presentation (fillets without skin and bones). Nevertheless, due to the high levels of contamination of the rivers where it lives, and to the fact that the panga is a predator, whereby it will accumulate a higher mercury concentration, the main objectives of the present study were to evaluate the toxic risk from mercury ingestion as a result of the consumption of this fish. A total of 80 frozen panga samples natural and marinade from different commercial establishments have been analyzed using cold vapour atomic absorption spectrophotometry (CV-AAS). The results obtained show a wide range of mercury concentrations between 0.10 and 0.69 mg/kg, with an average value of 0.22 mg/kg. In addition, it has been found that the average mercury concentration in the marinated presentation (0.18 mg/kg) is higher than that obtained in the natural panga (0.16 mg/kg). However, no significant differences were found between commercial establishments or in the presentation formats, with the conclusion that they did not influence the mercury content in the samples. Assuming a weekly consumption of 350 g of panga, the contribution rate to Tolerable Weekly Intake (TWI) of mercury (4 μg/kg bw/week) is 32% and 27.5% for women and men, respectively. Based on the results obtained in this study, an exhaustive control of the mercury content in this type of fish is necessary. In addition, a consumption restriction to children will be established. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Characterisation and modelling of mercury speciation in urban air affected by gold mining - assessment of bioavailability

    Directory of Open Access Journals (Sweden)

    Cukrowska E. M.

    2013-04-01

    Full Text Available The growing global concern over the release of mercury to the environment has prompted specific inventories that quantify mercury emissions from various sources. Investigations of atmospheric mercury have been mostly done on gaseous species. Although, to assess human expose to mercury, especially in urban areas, the inhalable dust should be included in a study. The Witwatersrand Basin in South Africa is one of the most important gold mining regions in the world. Mercury (Hg, which occurs in gold-bearing ores, was also used for gold recoveries in previous centuries (19th and early 20th century and presently in illegal artisanal mining. The consequences of these mining activities were the release of Hg to the environment, mainly due to AMD from tailings dumps which are presently reprocessed. The city of Johannesburg is a multimillion population exposed strongly to industrial pollution. The aim of this study was to determine the magnitude of mercury pollution in this urban area and assess its bioavailability. The gaseous samples were collected by trapping mercury on various gold traps. Dust samples were collected from a ground and on inhalation levels (1–2 m above a ground. They were later separated into different fractions by micro sieving. Bioavailability of mercury in inhalable dust (25 μm was tested by leaching collected samples with artificial lung fluid (ALF, pH 4.5, Gray’s solution (pH 7.4 and water. The leaching conditions were selected to mimic lungs environment (incubator at 30°C, time 24 hrs, rotation of samples 150 rpm. Total concentrations of mercury in dust fractions were also determined after microwave digestion. The results showed extremely high concentration levels of mercury in air and dust in industrial areas. Especially high levels were found around presently reprocessed old gold tailings dumps, up to 900 000 μgl–1. The levels dropped significantly in CBD area but still showing elevated concentrations up to 10 μgl−1

  17. Rethinking mercury: the role of selenium in the pathophysiology of mercury toxicity.

    Science.gov (United States)

    Spiller, Henry A

    2018-05-01

    There is increasing evidence that the pathophysiological target of mercury is in fact selenium, rather than the covalent binding of mercury to sulfur in the body's ubiquitous sulfhydryl groups. The role of selenium in mercury poisoning is multifaceted, bidirectional, and central to understanding the target organ toxicity of mercury. An initial search was performed using Medline/PubMed, Toxline, Google Scholar, and Google for published work on mercury and selenium. These searches yielded 2018 citations. Publications that did not evaluate selenium status or evaluated environmental status (e.g., lake or ocean sediment) were excluded, leaving approximately 500 citations. This initial selection was scrutinized carefully and 117 of the most relevant and representative references were selected for use in this review. Binding of mercury to thiol/sulfhydryl groups: Mercury has a lower affinity for thiol groups and higher affinity for selenium containing groups by several orders of magnitude, allowing for binding in a multifaceted way. The established binding of mercury to thiol moieties appears to primarily involve the transport across membranes, tissue distribution, and enhanced excretion, but does not explain the oxidative stress, calcium dyshomeostasis, or specific organ injury seen with mercury. Effects of mercury on selenium and the role this plays in the pathophysiology of mercury toxicity: Mercury impairs control of intracellular redox homeostasis with subsequent increased intracellular oxidative stress. Recent work has provided convincing evidence that the primary cellular targets are the selenoproteins of the thioredoxin system (thioredoxin reductase 1 and thioredoxin reductase 2) and the glutathione-glutaredoxin system (glutathione peroxidase). Mercury binds to the selenium site on these proteins and permanently inhibits their function, disrupting the intracellular redox environment. A number of other important possible target selenoproteins have been identified

  18. Quality control of analyses of mercury in hair

    International Nuclear Information System (INIS)

    Lind, B.; Friberg, L.; Bigras, L.; Kirkbride, J.; Kennedy, P.; Kjellstroem, T.

    1988-01-01

    A quality control programme for mercury determinations in hair was developed within a study of 'Mental effects of prenatal methylmercury exposure in New Zealand children'. Hair was obtained from seven females with a mercury concentration of about 0.5-4 μg Hg/g. The hair was cut into 1-5 cm pieces and pulverized by liquid nitrogen grinding using a ring mill. In order to obtain a series of QC samples with varying Hg concentrations, different amounts of powder from all the samples and a reference sample of pulverized hair (11.2 μg Hg/g) were mixed. The mercury concentrations in the original samples and the mixtures were determined by radiochemical neutron activation analysis (RNAA). In total four laboratories participated in the interlaboratory comparison. All laboratories used the cold vapor AAS technique and Hg monitor model 1235, LDC for determinations after wet digestion of the samples. (orig./RB)

  19. Mercury Exposure and Heart Rate Variability: A Systematic Review

    Science.gov (United States)

    Gribble, Matthew O.; Cheng, Alan; Berger, Ronald D.; Rosman, Lori; Guallar, Eliseo

    2015-01-01

    Background Mercury affects the nervous system and has been implicated in altering heart rhythm and function. We sought to better define its role in modulating heart rate variability, a well-known marker of cardiac autonomic function. Design Systematic review. Methods We searched PubMed, Embase, TOXLINE and DART databases without language restriction. We report findings as a qualitative systematic review because heterogeneity in study design and assessment of exposures and outcomes across studies, as well as other methodological limitations of the literature, precluded a quantitative meta-analysis. Results We identified 12 studies of mercury exposure and heart rate variability in human populations (10 studies involving primarily environmental methylmercury exposure and two studies involving occupational exposure to inorganic mercury) conducted in Japan, the Faroe Islands, Canada, Korea, French Polynesia, Finland and Egypt. The association of prenatal mercury exposure with lower high-frequency band scores (thought to reflect parasympathetic activity) in several studies, in particular the inverse association of cord blood mercury levels with the coefficient of variation of the R-R intervals and with low frequency and high frequency bands at 14 years of age in the Faroe Islands birth cohort study, suggests that early mercury exposure could have a long-lasting effect on cardiac parasympathetic activity. Studies with later environmental exposures to mercury in children or in adults were heterogeneous and did not show consistent associations. Conclusions The evidence was too limited to draw firm causal inferences. Additional research is needed to elucidate the effects of mercury on cardiac autonomic function, particularly as early-life exposures might have lasting impacts on cardiac parasympathetic function. PMID:26231507

  20. Prevalence and determinants of airflow limitation in urban and rural children exposed to cooking fuels in South-East Nigeria.

    Science.gov (United States)

    Oguonu, Tagbo; Obumneme-Anyim, Ijeoma N; Eze, Joy N; Ayuk, Adaeze C; Okoli, Chinyere V; Ndu, Ikenna K

    2018-03-15

    Background Biofuels and other cooking fuels are used in households in low- and middle-income countries. Aim To investigate the impact of cooking fuels on lung function in children in urban and rural households in South-East Nigeria. Methods The multi-stage sampling method was used to enroll children exposed to cooking fuel in the communities. Lung function values FEV1, FVC and the FEV1/FVC ratio, were measured with ndd EasyOne R spirometer. Airflow limitation was determined with FEV1/FVC Z-score values at -1.64 as the lower limit of normal (LLN5). The Global Lung Function Initiative 2012 software was used to calculate the lung function indices. Results The median age (range) of the 912 children enrolled was 10.6 years (6-18). Altogether, 468 (51.6%) children lived in rural areas. Seven hundred and thirty-seven (80.7%) were directly exposed to cooking fuels (418/737, 56.5% in rural areas). Wood and kerosene were the dominant fuels in rural and urban households. The respective mean Z-scores of the exposed children in rural and urban were zFEV1 -0.62, FVC -0.21, FEV1/FVC -0.83 and zFEV1 -0.57, zFVC -0.14, FEV1/FVC -0.75. Few (5.2%, 38/737) of the children had airflow limitation. Most of them (60.5%, 25/38) lived in the rural community; the lowest FEV1/FVC Z-scores were those of exposed to a combination of fuels. Conclusion Exposure to cooking fuels affects lung function in children with airway limitation in a small proportion, Control measures are advocated to reduce the morbidity related to cooking fuels exposure.

  1. Mercury Quick Facts: Health Effects of Mercury Exposure

    Science.gov (United States)

    ... 2012 What are the Health Effects of Mercury Exposure? The health effects that can be caused by breathing mercury depend ... they breathe faster and have smaller lungs. Health effects caused by long-term exposure to mercury vapors • • Anxiety • • Excessive shyness • • Anorexia • • Sleeping ...

  2. Mercury contamination and exposure assessment of fishery products in Korea.

    Science.gov (United States)

    Yang, Hye-Ran; Kim, Na-Young; Hwang, Lae-Hong; Park, Ju-Sung; Kim, Jung-Hun

    2015-01-01

    In this study, total (T-Hg) and methyl mercury (Me-Hg) contamination was investigated in fishery products including canned fish, fish sauces, dried bonito and frozen tuna sashimi, collected from retail markets in Korea, to assess dietary exposure. Direct mercury analyser and gas chromatography-electron captured detector were employed to measure T-Hg and Me-Hg, respectively. The highest T-Hg and Me-Hg contamination was present in tuna sashimi, followed by dried bonito, respectively. Canned tuna showed more frequent detection and higher content than other canned fishery products. The weekly exposure estimate indicates that exposure to mercury from fishery products is safe, showing 2.59% provisional tolerable weekly intake (PTWI) for T-Hg, 1.82% PTWI for Me-Hg and 4.16% reference dose for Me-Hg. However, it should be addressed to monitor the mercury contamination in fish and fishery products regularly, to safeguard vulnerable population such as children, to limit intake of these food products.

  3. Mercury balance analysis

    International Nuclear Information System (INIS)

    Maag, J.; Lassen, C.; Hansen, E.

    1996-01-01

    A detailed assessment of the consumption of mercury, divided into use areas, was carried out. Disposal and emissions to the environment were also qualified. The assessment is mainly based on data from 1992 - 1993. The most important source of emission of mercury to air is solid waste incineration which is assessed in particular to be due to the supply of mercury in batteries (most likely mercury oxide batteries from photo equipment) and to dental fillings. The second most important source of mercury emission to air is coal-fired power plants which are estimated to account for 200-500 kg of mercury emission p.a. Other mercury emissions are mainly related to waste treatment and disposal. The consumption of mercury is generally decreasing. During the period from 1982/83 - 1992-93, the total consumption of mercury in Denmark was about halved. This development is related to the fact that consumption with regard to several important use areas (batteries, dental fillings, thermometers etc.) has been significantly reduced, while for other purposes the use of mercury has completely, or almost disappeared, i.e. (fungicides for seed, tubes etc.). (EG)

  4. Mercury Phase II Study - Mercury Behavior in Salt Processing Flowsheet

    International Nuclear Information System (INIS)

    Jain, V.; Shah, H.; Wilmarth, W. R.

    2016-01-01

    Mercury (Hg) in the Savannah River Site Liquid Waste System (LWS) originated from decades of canyon processing where it was used as a catalyst for dissolving the aluminum cladding of reactor fuel. Approximately 60 metric tons of mercury is currently present throughout the LWS. Mercury has long been a consideration in the LWS, from both hazard and processing perspectives. In February 2015, a Mercury Program Team was established at the request of the Department of Energy to develop a comprehensive action plan for long-term management and removal of mercury. Evaluation was focused in two Phases. Phase I activities assessed the Liquid Waste inventory and chemical processing behavior using a system-by-system review methodology, and determined the speciation of the different mercury forms (Hg+, Hg++, elemental Hg, organomercury, and soluble versus insoluble mercury) within the LWS. Phase II activities are building on the Phase I activities, and results of the LWS flowsheet evaluations will be summarized in three reports: Mercury Behavior in the Salt Processing Flowsheet (i.e. this report); Mercury Behavior in the Defense Waste Processing Facility (DWPF) Flowsheet; and Mercury behavior in the Tank Farm Flowsheet (Evaporator Operations). The evaluation of the mercury behavior in the salt processing flowsheet indicates, inter alia, the following: (1) In the assembled Salt Batches 7, 8 and 9 in Tank 21, the total mercury is mostly soluble with methylmercury (MHg) contributing over 50% of the total mercury. Based on the analyses of samples from 2H Evaporator feed and drop tanks (Tanks 38/43), the source of MHg in Salt Batches 7, 8 and 9 can be attributed to the 2H evaporator concentrate used in assembling the salt batches. The 2H Evaporator is used to evaporate DWPF recycle water. (2) Comparison of data between Tank 21/49, Salt Solution Feed Tank (SSFT), Decontaminated Salt Solution Hold Tank (DSSHT), and Tank 50 samples suggests that the total mercury as well as speciated

  5. On the origin of Amazonian landscapes and biodiversity: a synthesis

    NARCIS (Netherlands)

    Wesselingh, F.P.; Hoorn, C.; Kroonenberg, S.B.; Antonelli, A.; Lundberg, J.G.; Vonhof, H.B.; Hooghiemstra, H.; Hoorn, M.; Wesselingh, F.P.

    2010-01-01

    In northern South America the Cenozoic was a period of intense tectonic and climatic interaction that resulted in a dynamic Amazonian landscape dominated by lowlands with local and shield-derived rivers. These drainage systems constantly changed shape and size. During the entire Cenozoic, the

  6. Neurotoxic impact of mercury on the central nervous system evaluated by neuropsychological tests and on the autonomic nervous system evaluated by dynamic pupillometry.

    Science.gov (United States)

    Milioni, Ana Luiza V; Nagy, Balázs V; Moura, Ana Laura A; Zachi, Elaine C; Barboni, Mirella T S; Ventura, Dora F

    2017-03-01

    Mercury vapor is highly toxic to the human body. The present study aimed to investigate the occurrence of neuropsychological dysfunction in former workers of fluorescent lamps factories that were exposed to mercury vapor (years after cessation of exposure), diagnosed with chronic mercurialism, and to investigate the effects of such exposure on the Autonomic Nervous System (ANS) using the non-invasive method of dynamic pupillometry. The exposed group and a control group matched by age and educational level were evaluated by the Beck Depression Inventory and with the computerized neuropsychological battery CANTABeclipse - subtests of working memory (Spatial Span), spatial memory (Spatial Recognition Memory), visual memory (Pattern Recognition Memory) and action planning (Stockings of Cambridge). The ANS was assessed by dynamic pupillometry, which provides information on the operation on both the sympathetic and parasympathetic functions. Depression scores were significantly higher among the former workers when compared with the control group. The exposed group also showed significantly worse performance in most of the cognitive functions assessed. In the dynamic pupillometry test, former workers showed significantly lower response than the control group in the sympathetic response parameter (time of 75% of pupillary recovery at 10cd/m 2 luminance). Our study found indications that are suggestive of cognitive deficits and losses in sympathetic autonomic activity among patients occupationally exposed to mercury vapor. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Determination of Mercury in Fish: A Low-Cost Implementation of Cold-Vapor Atomic Absorbance for the Undergraduate Environmental Chemistry Laboratory

    Science.gov (United States)

    Niece, Brian K.; Hauri, James F.

    2013-01-01

    Mercury is a known neurotoxin that is particularly harmful to children and unborn fetuses. Consumption of contaminated fish is one major route of mercury exposure. This laboratory experiment gives students an opportunity to measure mercury concentrations in store-bought seafood and compare the results to suggested exposure limits. The U.S.…

  8. MERCURY (Hg CONTENT OF MEAT TILAPIA FISH (Oreochromis niloticus WERE CULTIVATED IN PALANGKA RAYA CITY

    Directory of Open Access Journals (Sweden)

    Ciptadi

    2015-11-01

    Full Text Available Tilapia fish as Palangkarayan food are mostly cultivated in the river which exposed by mercury. To get information whether the fish have been contaminated by mercury, the mercury determination of tilapia fish meat cultivated in Kahayan river was carried out. The fish were analyzed based on age and the cultivation environment that are fishes cages in Kahayan river and isolated pond from streams of Kahayan river are also studied. The concentration of mercury in the flesh of tilapia with 5-7 months, kept in cages used to identify the content of mercury in fish tilapia cages in Kahayan river. The concentration of mercury in the flesh of tilapia reared in ponds aims to compare the mercury content in the tilapia in ponds the same age were used as comparison. The level of mercury in the samples was measured using a Mercury Analyzer. Data concentration of mercury in the flesh of tilapia were analyzed using analysis of variance (ANOVA: single factor with a significance level (α of 5%. The results showed that tilapia fish meat from the cages in the Kahayan river with age of 5-7 months contain mercury as much as 0.0145 ± 0.0005 ppm to 0.017 ± 0.001 ppm, which were lower than the maximum limit of mercury contamination in fish and processed products regulated by ISO 7387 in 2009 of 0.5 ppm. The the analysis of variance showed that the mercury content in tilapia fish meat was different by age and place of cultivation. The content of mercury in the tilapia fish meat increase with the increase of their age. The mercury content in tilapia fish cultivated in the isolated pond lower than that of in the tilapia fish meat cultivated in cages of 0.0115 ± 0.0005 ppm

  9. Phylogenetic insights into the diversity of homocytous cyanobacteria from Amazonian rivers.

    Science.gov (United States)

    Genuário, Diego Bonaldo; Vaz, Marcelo Gomes Marçal Vieira; Melo, Itamar Soares de

    2017-11-01

    The Amazon Rainforest holds great tropical biodiversity, mainly because of its favourable climatic conditions. The high temperatures, luminosity and humidity coupled with the nutritional simplicity of cyanobacteria allow undiscovered diversity to flourish within this group of microorganisms. Some efforts to reveal this diversity have been attempted; however, most were focused on the microscopic observation of environmental samples without any genetic information. Very few studies focusing on morphological, ecological and molecular criteria have been conducted, and none have been devoted to homocytous cyanobacteria forms in Amazonia region. Therefore, the genetic relationships amongst strains retrieved from this ecosystem with regard to other environments from Brazil and the world have not been tested and, consequently, the Amazonian strains would naturally be assumed as novel to science. To examine these relationships, cultured homocytous cyanobacteria isolated from two Amazonian rivers (Amazonas and Solimões) were evaluated using a phylogenetic perspective, considering the 16S rRNA gene sequence. A total of eleven homocytous cyanobacterial strains were isolated. Morphologically, they were identified as Pseudanabaena, Leptolyngbya, Planktothrix and Phormidium, but genetically they were included in the typical clusters of Planktothrix, Pseudanabaena, Cephalothrix, Pantanalinema and Alkalinema. These three latter genera have been detected in other Brazilian ecosystems only (Pantanal, Atlantic Rainforest and Pampa), while those remaining have been extensively found in many parts of the world. The data provided here indicate that Amazonian rivers support a homocytous cyanobacterial diversity previously reported from other geographical and ecological environments. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Uptake of elemental mercury and activity of catalase in rat, hamster, guinea-pig, normal and acatalasemic mice

    International Nuclear Information System (INIS)

    Eide, I.; Syversen, T.L.M.

    1982-01-01

    Uptake of elemental mercury after inhalation (3.5 mg/m 3 ) and the activity of catalase in brain, liver, kidney and blood were investigated in rat, hamster, guinea-pig, and normal and acatalasemic mice. The uptake of mercury in the species investigated varied considerably, being highest in the two strains of mice, followed by rat and hamster, and lowest in the guinea-pig. The uptake seemed to be more dependent on pulmonary ventilation than on the activity of catalase. The two strains of mice were exposed to a wide range of mercury concentrations in air (0.002-3.5 mg/m 3 ). The content of mercury in brain, liver and kidney was linearly dependent on the mercury concentration in the air, whereas in blood this relationship was exponential. At the lower concentraions of mercury in the inhaled air, the mercury level in blood was significantly lower, and in kidney higher in the acatalasemic mice compared to the normal ones. In acatalasemic mice the mercury content in the liver has higher at all concentrations investigated, whereas in brain no difference between the two strains was found. (author)

  11. Mercury and Lead Levels in Common Soaps from Local Markets in Mashhad, Iran

    Directory of Open Access Journals (Sweden)

    Anahita Alizadeh

    2017-06-01

    Full Text Available Background: The potential toxicity of human exposure was investigated to heavy metals from diverse sources but few or none was on Iranian soaps. Hence, we aimed to determine the presence of lead and mercury in selected soaps commonly used in Mashhad, northeastern Iran. Methods: Different common brands of cosmetic, hygiene and contraband soaps were purchased from retail market of Mashhad in 2016. Levels of these metals were determined using atomic absorption spectroscopy technique. Results: All samples had the mercury and lead levels but did not exceed the maximum acceptable level (1 µg/g for mercury and 20 µg/g for lead recommended by FDA. The mean levels of mercury were 0.02, 0.08 and 0.23 µg/g, respectively in cosmetic, hygiene and contraband soaps. These levels for lead were 0.10, 0.19 and 0.13 µg/g. The highest mercury and lead levels were detected in Halazoon contraband and P hygiene brands, respectively. Conclusion: The content of mercury and lead in common soaps is currently not a concern in this city. However, as human body may be exposed to several toxic metals from different care products simultaneously, cumulative toxic effects of these metals must be considered important.

  12. Tradeoffs between immune function and childhood growth among Amazonian forager-horticulturalists.

    Science.gov (United States)

    Urlacher, Samuel S; Ellison, Peter T; Sugiyama, Lawrence S; Pontzer, Herman; Eick, Geeta; Liebert, Melissa A; Cepon-Robins, Tara J; Gildner, Theresa E; Snodgrass, J Josh

    2018-04-24

    Immune function is an energetically costly physiological activity that potentially diverts calories away from less immediately essential life tasks. Among developing organisms, the allocation of energy toward immune function may lead to tradeoffs with physical growth, particularly in high-pathogen, low-resource environments. The present study tests this hypothesis across diverse timeframes, branches of immunity, and conditions of energy availability among humans. Using a prospective mixed-longitudinal design, we collected anthropometric and blood immune biomarker data from 261 Amazonian forager-horticulturalist Shuar children (age 4-11 y old). This strategy provided baseline measures of participant stature, s.c. body fat, and humoral and cell-mediated immune activity as well as subsample longitudinal measures of linear growth (1 wk, 3 mo, 20 mo) and acute inflammation. Multilevel analyses demonstrate consistent negative effects of immune function on growth, with children experiencing up to 49% growth reduction during periods of mildly elevated immune activity. The direct energetic nature of these relationships is indicated by ( i ) the manifestation of biomarker-specific negative immune effects only when examining growth over timeframes capturing active competition for energetic resources, ( ii ) the exaggerated impact of particularly costly inflammation on growth, and ( iii ) the ability of children with greater levels of body fat (i.e., energy reserves) to completely avoid the growth-inhibiting effects of acute inflammation. These findings provide evidence for immunologically and temporally diverse body fat-dependent tradeoffs between immune function and growth during childhood. We discuss the implications of this work for understanding human developmental energetics and the biological mechanisms regulating variation in human ontogeny, life history, and health.

  13. Distribution and retention of organic and inorganic mercury in methyl mercury-treated neonatal rats

    International Nuclear Information System (INIS)

    Thomas, D.J.; Fisher, H.L.; Sumler, M.R.; Hall, L.L.; Mushak, P.

    1988-01-01

    Seven-day-old Long Evans rats received one mumol of 203 Hg-labeled methyl mercury/kg sc and whole body retention and tissue distribution of organic and inorganic mercury were examined for 32 days postdosing. Neonates cleared mercury slowly until 10 days postdosing when the clearance rate abruptly increased. During the interval when whole body clearance of mercury was extremely slow, methyl mercury was metabolized to inorganic mercury. Peak concentration of mercury in kidney occurred at 2 days postdosing. At 32 days postdosing, 8% of mercury in kidney was in an organic from. Liver mercury concentration peaked at 2 days postdosing and organic mercury accounted for 38% at 32 days postdosing. Brain concentrations of mercury peaked at 2 days postdosing. At 10 days postdosing, organic mercury accounted for 86% of the brain mercury burden, and, at 32 days postdosing, for 60%. The percentage of mercury body burden in pelt rose from 30 to 70% between 1 and 10 days postdosing. At 32 days postdosing pelt contained 85% of the body burden of mercury. At all time points, about 95% of mercury in pelt was in an organic form. Compartmental analysis of these data permitted development of a model to describe the distribution and excretion of organic and inorganic mercury in methyl mercury-treated neonatal rats

  14. Toxic metal levels in children residing in a smelting craft village in Vietnam: a pilot biomonitoring study.

    Science.gov (United States)

    Sanders, Alison P; Miller, Sloane K; Nguyen, Viet; Kotch, Jonathan B; Fry, Rebecca C

    2014-02-04

    In Vietnam, environmental pollution caused by small-scale domestic smelting of automobile batteries into lead ingot is a growing concern. The village of Nghia Lo is a smelting craft village located roughly 25 km southeast of Hanoi in the Red River Delta. Despite the concern of toxic metal exposure in the village, biomonitoring among susceptible populations, such as children, has not been previously conducted. The aim of this study was to determine the body burden of toxic metals in children residing in a smelting craft village. Twenty children from Nghia Lo, Vietnam, ages 18 months to four years were selected for capillary whole blood and toenail biomonitoring. Whole blood lead levels (BLLs) were measured using a portable lead analyzer, and toenail levels of arsenic, cadmium, chromium, lead, manganese, and mercury were analyzed with inductively coupled plasma-mass spectrometry. The findings show that all of the 20 children had detectable BLLs, and every child had levels that exceeded the Centers for Disease Control and Prevention guideline level of 5 μg/dL. Eighty percent of tested subjects had BLLs higher than 10 μg/dL. Five children (25%) had BLLs greater than 45 μg/dL, the level of recommended medical intervention. In addition to blood lead, all of the children had detectable levels of arsenic, cadmium, chromium, lead, manganese, and mercury in toenail samples. Notably, average toenail lead, manganese, and mercury levels were 157 μg/g, 7.41 μg/g, and 2.63 μg/g respectively, well above levels previously reported in children. Significant Spearman's rank correlations showed that there were relationships between blood and toenail lead levels (r = 0.65, p craft villages in Vietnam are co-exposed to toxic metals. There is an urgent need for mitigation to control metal exposure related to domestic smelting.

  15. Dried Blood Spot Test for HIV Exposed Infants and Children and Their Anti-Retro Viral Treatment Status in Selected Hospitals in Ethiopia.

    Science.gov (United States)

    Wondafrash, Beyene; Hiko, Desta

    2016-01-01

    Infants and children living with HIV receive antiretroviral treatment often late, are exposed to opportunistic infection and quickly develop AIDS. Few hospitals are providing ART service after Dried Blood Spot (DBS)test.The objective of this study is to assess the status of infants and children linked to ART. Descriptive cross-sectional study was conducted in hospitals. Data of 138 infants and children exposed to HIV were collected from registration books and data bases from 2009 to 2011. Data were analyzed using SPSS version 16. Chi-squared test and p-value were computed. In-depth interviews were conducted with key informants. Ninety-eight (71%) infants and children exposed to HIV were diagnosed for HIV infection of which 68(69.4%) initiated ART. Twenty four (35.3%) initiated ART one month after HIV screening results. Thirty-three (50.0%) and 23(35.3%) infants and children dropped from and adhered to ART respectively. Eleven (16.2%) of them who initiated ART died within the study period. HIV infection status (p-value=0.003), dropping from ART (p-value=0.002) and death after ART initiation (p-value=0.010) showed significance with mothers' PMTCT service status. Seven in ten HIV-exposed infants and children were diagnosed with HIV, and almost all of them initiated ART. The overall turnaround time was 10 days. Based up on mothers' PMTCT service status, there was a significant difference among HIV-exposed infants and children in acquiring HIV infection from mothers during pregnancy (p-value=0.003) and dropping from ART (p-value=0.010). There were challenges in sample collection and transportation. Early HIV screening during pregnancy and PMTCT service should be strengthened.

  16. Composition and diversity of northwestern Amazonian rainforests in a geoecological context

    NARCIS (Netherlands)

    Duivenvoorden, J.F.; Duque, A.J.; Hoorn, C.; Wesselingh, F.P.

    2010-01-01

    The northwestern Amazonian landscape includes most of the representative landscape units that characterize Amazonia, and for this reason it constitutes an excellent place to investigate relationships between the abiotic environment (geology, geomorphology, soils) and biodiversity. In this review we

  17. Glutathione enzyme and selenoprotein polymorphisms associate with mercury biomarker levels in Michigan dental professionals

    Energy Technology Data Exchange (ETDEWEB)

    Goodrich, Jaclyn M.; Wang, Yi [Department of Environmental Health Sciences, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States); Gillespie, Brenda [Department of Biostatistics, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States); Werner, Robert [Department of Environmental Health Sciences, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States); Department of Physical Medicine and Rehabilitation, University of Michigan, 325 E. Eisenhower Parkway Suite 100, Ann Arbor, MI 48108 (United States); Franzblau, Alfred [Department of Environmental Health Sciences, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States); Basu, Niladri, E-mail: niladri@umich.edu [Department of Environmental Health Sciences, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States)

    2011-12-15

    Mercury is a potent toxicant of concern to both the general public and occupationally exposed workers (e.g., dentists). Recent studies suggest that several genes mediating the toxicokinetics of mercury are polymorphic in humans and may influence inter-individual variability in mercury accumulation. This work hypothesizes that polymorphisms in key glutathione synthesizing enzyme, glutathione s-transferase, and selenoprotein genes underlie inter-individual differences in mercury body burden as assessed by analytical mercury measurement in urine and hair, biomarkers of elemental mercury and methylmercury, respectively. Urine and hair samples were collected from a population of dental professionals (n = 515), and total mercury content was measured. Average urine (1.06 {+-} 1.24 ug/L) and hair mercury levels (0.49 {+-} 0.63 ug/g) were similar to national U.S. population averages. Taqman assays were used to genotype DNA from buccal swab samples at 15 polymorphic sites in genes implicated in mercury metabolism. Linear regression modeling assessed the ability of polymorphisms to modify the relationship between mercury biomarker levels and exposure sources (e.g., amalgams, fish consumption). Five polymorphisms were significantly associated with urine mercury levels (GSTT1 deletion), hair mercury levels (GSTP1-105, GSTP1-114, GSS 5 Prime ), or both (SEPP1 3 Prime UTR). Overall, this study suggests that polymorphisms in selenoproteins and glutathione-related genes may influence elimination of mercury in the urine and hair or mercury retention following exposures to elemental mercury (via dental amalgams) and methylmercury (via fish consumption). -- Highlights: Black-Right-Pointing-Pointer We explore the influence of 15 polymorphisms on urine and hair Hg levels. Black-Right-Pointing-Pointer Urine and hair Hg levels in dental professionals were similar to the US population. Black-Right-Pointing-Pointer GSTT1 and SEPP1 polymorphisms associated with urine Hg levels. Black

  18. Glutathione enzyme and selenoprotein polymorphisms associate with mercury biomarker levels in Michigan dental professionals

    International Nuclear Information System (INIS)

    Goodrich, Jaclyn M.; Wang, Yi; Gillespie, Brenda; Werner, Robert; Franzblau, Alfred; Basu, Niladri

    2011-01-01

    Mercury is a potent toxicant of concern to both the general public and occupationally exposed workers (e.g., dentists). Recent studies suggest that several genes mediating the toxicokinetics of mercury are polymorphic in humans and may influence inter-individual variability in mercury accumulation. This work hypothesizes that polymorphisms in key glutathione synthesizing enzyme, glutathione s-transferase, and selenoprotein genes underlie inter-individual differences in mercury body burden as assessed by analytical mercury measurement in urine and hair, biomarkers of elemental mercury and methylmercury, respectively. Urine and hair samples were collected from a population of dental professionals (n = 515), and total mercury content was measured. Average urine (1.06 ± 1.24 ug/L) and hair mercury levels (0.49 ± 0.63 ug/g) were similar to national U.S. population averages. Taqman assays were used to genotype DNA from buccal swab samples at 15 polymorphic sites in genes implicated in mercury metabolism. Linear regression modeling assessed the ability of polymorphisms to modify the relationship between mercury biomarker levels and exposure sources (e.g., amalgams, fish consumption). Five polymorphisms were significantly associated with urine mercury levels (GSTT1 deletion), hair mercury levels (GSTP1-105, GSTP1-114, GSS 5′), or both (SEPP1 3′UTR). Overall, this study suggests that polymorphisms in selenoproteins and glutathione-related genes may influence elimination of mercury in the urine and hair or mercury retention following exposures to elemental mercury (via dental amalgams) and methylmercury (via fish consumption). -- Highlights: ► We explore the influence of 15 polymorphisms on urine and hair Hg levels. ► Urine and hair Hg levels in dental professionals were similar to the US population. ► GSTT1 and SEPP1 polymorphisms associated with urine Hg levels. ► Accumulation of Hg in hair following exposure from fish was modified by genotype. ► GSTP1, GSS

  19. Uptake and accumulation of mercury from dental amalgam in the common goldfish, Carassius auratus

    International Nuclear Information System (INIS)

    Kennedy, C.J.

    2003-01-01

    Exposure of fish to concentrations of dental amalgam typically found in waste discharge leads to mercury accumulation in tissues. - In this study, the bioavailability and accumulation of mercury from external environmental exposure to mixed, cured, milled, sieved and proportioned dental amalgam was examined in the common goldfish, Carassius auratus. Fish were exposed to dental amalgam (particle size range from <0.10 to 3.15 mm) in order to represent the particle size and distribution of that found within the typical dental office wastewater discharge stream. Experimental amalgam water loadings were 0 g/l, 0.5 g/l and 1 g/l in glass aquaria at 15 deg. C for 28 days. Fish tissues were sampled at 5 min and 28 days of exposure, and the liver, brain, muscle and whole body analyzed for total mercury using cold vapor atomic fluorescence spectroscopy. Mercury was found in several tissues examined and generally increased with exposure to higher amounts of dental amalgam. The highest levels were found in the whole body (17.68±5.73 μg/g) followed by the liver (0.80±0.16 μg/g) and muscle (0.47±0.16 μg/g). The lowest concentrations were seen in the brain (0.28±0.19 μg/g). Compared to controls, concentrations in the whole body, muscle and liver in fish exposed for 28 days to the highest concentration of amalgam were 200-, 233-, and 40-fold higher, respectively. This study shows that mercury from an environmental exposure to representative samples of dental amalgam typically found within the dental wastewater discharge stream is bioavailable to fish and may accumulate in internal tissues

  20. Uptake and accumulation of mercury from dental amalgam in the common goldfish, Carassius auratus

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, C.J

    2003-03-01

    Exposure of fish to concentrations of dental amalgam typically found in waste discharge leads to mercury accumulation in tissues. - In this study, the bioavailability and accumulation of mercury from external environmental exposure to mixed, cured, milled, sieved and proportioned dental amalgam was examined in the common goldfish, Carassius auratus. Fish were exposed to dental amalgam (particle size range from <0.10 to 3.15 mm) in order to represent the particle size and distribution of that found within the typical dental office wastewater discharge stream. Experimental amalgam water loadings were 0 g/l, 0.5 g/l and 1 g/l in glass aquaria at 15 deg. C for 28 days. Fish tissues were sampled at 5 min and 28 days of exposure, and the liver, brain, muscle and whole body analyzed for total mercury using cold vapor atomic fluorescence spectroscopy. Mercury was found in several tissues examined and generally increased with exposure to higher amounts of dental amalgam. The highest levels were found in the whole body (17.68{+-}5.73 {mu}g/g) followed by the liver (0.80{+-}0.16 {mu}g/g) and muscle (0.47{+-}0.16 {mu}g/g). The lowest concentrations were seen in the brain (0.28{+-}0.19 {mu}g/g). Compared to controls, concentrations in the whole body, muscle and liver in fish exposed for 28 days to the highest concentration of amalgam were 200-, 233-, and 40-fold higher, respectively. This study shows that mercury from an environmental exposure to representative samples of dental amalgam typically found within the dental wastewater discharge stream is bioavailable to fish and may accumulate in internal tissues.

  1. Lower birth weight and increased body fat at school age in children prenatally exposed to modern pesticides: A prospective study

    DEFF Research Database (Denmark)

    Wohlfahrt-Veje, Christine; Main, Katharina Maria; Schmidt, Ida Maria

    2011-01-01

    of prenatal exposure to currently used pesticides on children's growth, endocrine and reproductive function. METHOD: In a prospective study of 247 children born by women working in greenhouses in early pregnancy, 168 were categorized as prenatally exposed to pesticides. At three months (n=203) and at 6 to11......: Occupational exposure to currently used pesticides may have adverse effects in spite of the added protection offered to pregnant women. Maternal exposure to combinations of modern, non-persistent pesticides during early pregnancy was associated with affected growth, both prenatally and postnatally. We found...... a biphasic association with lower weight at birth followed by increased body fat accumulation from birth to school age. We cannot rule out some residual confounding due to differences in social class, although this was adjusted for. Associations were stronger in highly exposed than in medium exposed children...

  2. Mercury exposure in Munduruku Indians from the community of Sai Cinza, state of Para, Brazil

    International Nuclear Information System (INIS)

    Oliveira Santos, Elisabeth C. de; Maura de Jesus, Iracina; Camara, Volney e M.; Brabo, Edilson; Brito Loureiro, Edvaldo C.; Mascarenhas, Artur; Weirich, Judith; Ragio Luiz, Ronir; Cleary, David

    2002-01-01

    The objective of this cross-sectional study was to evaluate mercury exposure and health status among Munduruku Indians from the community of Sai inza, State of Para, Brazil. The population studied included 330 Indians, who submitted to a questionnaire, clinical exams, and collection of hair, blood, urine, and feces. Mercury was measured in hair and fish. Although no person was found to have overt mercury intoxication, the mean levels of mercury in hair were elevated (14.45 μg/g for children from 7 to 12 years ld, 15.70 μg/g for women between 14 and 44 years old, and 14.1 μg/g or the remaining population). Mercury levels in fish were below levels recommended by the World Health Organization, but rates of fish consumption ere high. These results place this indigenous population as a group under risk of mercury toxicity from the gold production

  3. Method for removal and stabilization of mercury in mercury-containing gas streams

    Science.gov (United States)

    Broderick, Thomas E.

    2005-09-13

    The present invention is directed to a process and apparatus for removing and stabilizing mercury from mercury-containing gas streams. A gas stream containing vapor phase elemental and/or speciated mercury is contacted with reagent, such as an oxygen-containing oxidant, in a liquid environment to form a mercury-containing precipitate. The mercury-containing precipitate is kept or placed in solution and reacts with one or more additional reagents to form a solid, stable mercury-containing compound.

  4. Mercury-impacted scrap metal: Source and nature of the mercury.

    Science.gov (United States)

    Finster, Molly E; Raymond, Michelle R; Scofield, Marcienne A; Smith, Karen P

    2015-09-15

    The reuse and recycling of industrial solid wastes such as scrap metal is supported and encouraged both internationally and domestically, especially when such wastes can be used as substitutes for raw material. However, scrap metal processing facilities, such as mini-mills, have been identified as a source of mercury (Hg) emissions in the United States. This research aims to better define some of the key issues related to the source and nature of mercury in the scrap metal waste stream. Overall, it is difficult to pinpoint the key mercury sources feeding into scrap metal recycling facilities, quantify their associated mercury concentrations, or determine which chemical forms are most significant. Potential sources of mercury in scrap metal include mercury switches from discarded vehicles, electronic-based scrap from household appliances and related industrial systems, and Hg-impacted scrap metal from the oil and gas industry. The form of mercury associated with scrap metal varies and depends on the source type. The specific amount of mercury that can be adsorbed and retained by steel appears to be a function of both metallurgical and environmental factors. In general, the longer the steel is in contact with a fluid or condensate that contains measurable concentrations of elemental mercury, the greater the potential for mercury accumulation in that steel. Most mercury compounds are thermally unstable at elevated temperatures (i.e., above 350 °C). As such, the mercury associated with impacted scrap is expected to be volatilized out of the metal when it is heated during processing (e.g., shredding or torch cutting) or melted in a furnace. This release of fugitive gas (Hg vapor) and particulates, as well as Hg-impacted bag-house dust and control filters, could potentially pose an occupational exposure risk to workers at a scrap metal processing facility. Thus, identifying and characterizing the key sources of Hg-impacted scrap, and understanding the nature and extent

  5. The performance of children prenatally exposed to HIV on the A-not-B Task in Kilifi, Kenya : A preliminary study

    NARCIS (Netherlands)

    Abubakar, A.; Holding, P.; van Baar, A.L.; Newton, C.R.J.C.; van de Vijver, F.J.R.; Espy, K.A.

    2013-01-01

    The aim of the study was to investigate early executive functioning in young children from 6–35 months of age. The study involved 319 randomly selected children from the community, 17 HIV exposed but uninfected children and 31 HIV infected ARV-naive children. A variation of the A-not-B task was

  6. Mercury contamination extraction

    Science.gov (United States)

    Fuhrmann, Mark [Silver Spring, MD; Heiser, John [Bayport, NY; Kalb, Paul [Wading River, NY

    2009-09-15

    Mercury is removed from contaminated waste by firstly applying a sulfur reagent to the waste. Mercury in the waste is then permitted to migrate to the reagent and is stabilized in a mercury sulfide compound. The stable compound may then be removed from the waste which itself remains in situ following mercury removal therefrom.

  7. Human mercury exposure associated with small-scale gold mining in Burkina Faso.

    Science.gov (United States)

    Tomicic, Catherine; Vernez, David; Belem, Tounaba; Berode, Michèle

    2011-06-01

    In Burkina Faso, gold ore is one of the main sources of income for an important part of the active population. Artisan gold miners use mercury in the extraction, a toxic metal whose human health risks are well known. The aim of the present study was to assess mercury exposure as well as to understand the exposure determinants of gold miners in Burkinabe small-scale mines. The examined gold miners' population on the different selected gold mining sites was composed by persons who were directly and indirectly related to gold mining activities. But measurement of urinary mercury was performed on workers most susceptible to be exposed to mercury. Thus, occupational exposure to mercury was evaluated among ninety-three workers belonging to eight different gold mining sites spread in six regions of Burkina Faso. Among others, work-related exposure determinants were taken into account for each person during urine sampling as for example amalgamating or heating mercury. All participants were medically examined by a local medical team in order to identify possible symptoms related to the toxic effect of mercury. Mercury levels were high, showing that 69% of the measurements exceeded the ACGIH (American Conference of Industrial Hygienists) biological exposure indice (BEI) of 35 μg per g of creatinine (μg/g-Cr) (prior to shift) while 16% even exceeded 350 μg/g-Cr. Basically, unspecific but also specific symptoms related to mercury toxicity could be underlined among the persons who were directly related to gold mining activities. Only one-third among the studied subpopulation reported about less than three symptoms possibly associated to mercury exposure and nearly half of them suffered from at least five of these symptoms. Ore washers were more involved in the direct handling of mercury while gold dealers in the final gold recovery activities. These differences may explain the overexposure observed in gold dealers and indicate that the refining process is the major source

  8. Global Trends in Mercury Management

    Science.gov (United States)

    Choi, Kyunghee

    2012-01-01

    The United Nations Environmental Program Governing Council has regulated mercury as a global pollutant since 2001 and has been preparing the mercury convention, which will have a strongly binding force through Global Mercury Assessment, Global Mercury Partnership Activities, and establishment of the Open-Ended Working Group on Mercury. The European Union maintains an inclusive strategy on risks and contamination of mercury, and has executed the Mercury Export Ban Act since December in 2010. The US Environmental Protection Agency established the Mercury Action Plan (1998) and the Mercury Roadmap (2006) and has proposed systematic mercury management methods to reduce the health risks posed by mercury exposure. Japan, which experienced Minamata disease, aims vigorously at perfection in mercury management in several ways. In Korea, the Ministry of Environment established the Comprehensive Plan and Countermeasures for Mercury Management to prepare for the mercury convention and to reduce risks of mercury to protect public health. PMID:23230466

  9. A new mercury-accumulating Mucor hiemalis strain EH8 from cold sulfidic spring water biofilms.

    Science.gov (United States)

    Hoque, Enamul; Fritscher, Johannes

    2016-10-01

    Here, we report about a unique aquatic fungus Mucor hiemalisEH8 that can remove toxic ionic mercury from water by intracellular accumulation and reduction into elemental mercury (Hg 0 ). EH8 was isolated from a microbial biofilm grown in sulfidic-reducing spring water sourced at a Marching's site located downhill from hop cultivation areas with a history of mercury use. A thorough biodiversity survey and mercury-removal function analyses were undertaken in an area of about 200 km 2 in Bavaria (Germany) to find the key biofilm and microbe for mercury removal. After a systematic search using metal removal assays we identified Marching spring's biofilm out of 18 different sulfidic springs' biofilms as the only one that was capable of removing ionic Hg from water. EH8 was selected, due to its molecular biological identification as the key microorganism of this biofilm with the capability of mercury removal, and cultivated as a pure culture on solid and in liquid media to produce germinating sporangiospores. They removed 99% of mercury from water within 10-48 h after initial exposure to Hg(II). Scanning electron microscopy demonstrated occurrence of intracellular mercury in germinating sporangiospores exposed to mercury. Not only associated with intracellular components, but mercury was also found to be released and deposited as metallic-shiny nanospheres. Electron-dispersive x-ray analysis of such a nanosphere confirmed presence of mercury by the HgM α peak at 2.195 keV. Thus, a first aquatic eukaryotic microbe has been found that is able to grow even at low temperature under sulfur-reducing conditions with promising performance in mercury removal to safeguard our environment from mercury pollution. © 2016 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  10. Oxidative DNA damage and repair in children exposed to low levels of arsenic in utero and during early childhood: Application of salivary and urinary biomarkers

    International Nuclear Information System (INIS)

    Hinhumpatch, Pantip; Navasumrit, Panida; Chaisatra, Krittinee; Promvijit, Jeerawan; Mahidol, Chulabhorn; Ruchirawat, Mathuros

    2013-01-01

    The present study aimed to assess arsenic exposure and its effect on oxidative DNA damage and repair in young children exposed in utero and continued to live in arsenic-contaminated areas. To address the need for biological specimens that can be acquired with minimal discomfort to children, we used non-invasive urinary and salivary-based assays for assessing arsenic exposure and early biological effects that have potentially serious health implications. Levels of arsenic in nails showed the greatest magnitude of difference between exposed and control groups, followed by arsenic concentrations in saliva and urine. Arsenic levels in saliva showed significant positive correlations with other biomarkers of arsenic exposure, including arsenic accumulation in nails (r = 0.56, P < 0.001) and arsenic concentration in urine (r = 0.50, P < 0.05). Exposed children had a significant reduction in arsenic methylation capacity indicated by decreased primary methylation index and secondary methylation index in both urine and saliva samples. Levels of salivary 8-OHdG in exposed children were significantly higher (∼ 4-fold, P < 0.01), whereas levels of urinary 8-OHdG excretion and salivary hOGG1 expression were significantly lower in exposed children (∼ 3-fold, P < 0.05), suggesting a defect in hOGG1 that resulted in ineffective cleavage of 8-OHdG. Multiple regression analysis results showed that levels of inorganic arsenic (iAs) in saliva and urine had a significant positive association with salivary 8-OHdG and a significant negative association with salivary hOGG1 expression. - Highlights: • The effects of arsenic exposure in utero and through early childhood were studied. • Arsenic-exposed children had a reduction in arsenic methylation capacity. • Exposed children had more DNA damage, observed as elevated salivary 8-OHdG. • Lower salivary hOGG1 in exposed children indicated impairment of 8-OHdG repair. • Salivary and urinary 8-OHdG levels were discordant

  11. Lung radiology and pulmonary function of children chronically exposed to air pollution.

    Science.gov (United States)

    Calderón-Garcidueñas, Lilian; Mora-Tiscareño, Antonieta; Fordham, Lynn A; Chung, Charles J; Valencia-Salazar, Gildardo; Flores-Gómez, Silvia; Solt, Anna C; Gomez-del Campo, Alberto; Jardón-Torres, Ricardo; Henríquez-Roldán, Carlos; Hazucha, Milan J; Reed, William

    2006-09-01

    We analyzed the chest radiographs (CXRs) of 249 clinically healthy children, 230 from southwest Mexico City and 19 from Tlaxcala. In contrast to children from Tlaxcala, children from southwest Mexico City were chronically exposed to ozone levels exceeding the U.S. National Ambient Air Quality Standards for an average of 4.7 hr/day and to concentrations of particulate matter (PM) with aerodynamic diameters children demonstrated bilateral hyperinflation (151 of 230) and increased linear markings (121 of 230) . Hyperinflation and interstitial markings were significantly more common in Mexico City children (p < 0.0002 and 0.00006 respectively) . Mexico City boys had a higher probability of developing interstitial markings with age (p = 0.004) . Computed tomography (CT) scans were obtained in 25 selected Mexico City children with abnormal CXRs. Mild bronchial wall thickening was seen in 10 of 25, prominent central airways in 4 of 25, air trapping in 8 of 21, and pulmonary nodules in 2 of 21. Only 7.8% of Mexico City children had abnormal lung function tests based on predicted values. These findings are consistent with bronchiolar, peribronchiolar, and/or alveolar duct inflammation, possibly caused by ozone, PM, and lipopolysaccharide exposure. The epidemiologic implications of these findings are important for children residing in polluted environments, because bronchiolar disease could lead to chronic pulmonary disease later in life.

  12. Lead, mercury, and cadmium exposure and attention deficit hyperactivity disorder in children

    International Nuclear Information System (INIS)

    Kim, Stephani; Arora, Monica; Fernandez, Cristina; Landero, Julio; Caruso, Joseph; Chen, Aimin

    2013-01-01

    Background: There is limited research examining the relationship between lead (Pb) exposure and medically diagnosed attention deficit hyperactivity disorder (ADHD) in children. The role of mercury (Hg) and cadmium (Cd) exposures in ADHD development is even less clear. Objectives: To examine the relationship between Pb, Hg, and Cd and ADHD in children living inside and outside a Lead Investigation Area (LIA) of a former lead refinery in Omaha, NE. Methods: We carried out a case-control study with 71 currently medically diagnosed ADHD cases and 58 controls from a psychiatric clinic and a pediatric clinic inside and outside of the LIA. The participants were matched on age group (5–8, 9–12 years), sex, race (African American or Caucasians and others), and location (inside or outside LIA). We measured whole blood Pb, total Hg, and Cd using inductively coupled plasma mass spectrometry. Results: Inside the LIA, the 27 cases had blood Pb geometric mean (GM) 1.89 µg/dL and the 41 controls had 1.51 µg/dL. Outside the LIA, the 44 cases had blood Pb GM 1.02 µg/dL while the 17 controls had 0.97 µg/dL. After adjustment for matching variables and maternal smoking, socioeconomic status, and environmental tobacco exposure, each natural log unit blood Pb had an odds ratio of 2.52 with 95% confidence interval of 1.07–5.92. Stratification by the LIA indicated similar point estimate but wider CIs. No associations were observed for Hg or Cd. Conclusions: Postnatal Pb exposure may be associated with higher risk of clinical ADHD, but not the postnatal exposure to Hg or Cd. -- Highlights: • Blood Pb levels are associated with ADHD diagnosis in children. • No association was found between blood Cd or Hg levels and ADHD. • Children living close to hazardous waste site need to reduce metal exposure

  13. Lead, mercury, and cadmium exposure and attention deficit hyperactivity disorder in children

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Stephani [Division of Epidemiology and Biostatistics, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH 45267 (United States); Arora, Monica [Department of Psychiatry, Creighton University School of Medicine, Omaha, NE 68131 (United States); Fernandez, Cristina [Department of Pediatrics, Creighton University School of Medicine, Omaha, NE 68131 (United States); Landero, Julio; Caruso, Joseph [Metallomics Center, Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221 (United States); Chen, Aimin, E-mail: aimin.chen@uc.edu [Division of Epidemiology and Biostatistics, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH 45267 (United States)

    2013-10-15

    Background: There is limited research examining the relationship between lead (Pb) exposure and medically diagnosed attention deficit hyperactivity disorder (ADHD) in children. The role of mercury (Hg) and cadmium (Cd) exposures in ADHD development is even less clear. Objectives: To examine the relationship between Pb, Hg, and Cd and ADHD in children living inside and outside a Lead Investigation Area (LIA) of a former lead refinery in Omaha, NE. Methods: We carried out a case-control study with 71 currently medically diagnosed ADHD cases and 58 controls from a psychiatric clinic and a pediatric clinic inside and outside of the LIA. The participants were matched on age group (5–8, 9–12 years), sex, race (African American or Caucasians and others), and location (inside or outside LIA). We measured whole blood Pb, total Hg, and Cd using inductively coupled plasma mass spectrometry. Results: Inside the LIA, the 27 cases had blood Pb geometric mean (GM) 1.89 µg/dL and the 41 controls had 1.51 µg/dL. Outside the LIA, the 44 cases had blood Pb GM 1.02 µg/dL while the 17 controls had 0.97 µg/dL. After adjustment for matching variables and maternal smoking, socioeconomic status, and environmental tobacco exposure, each natural log unit blood Pb had an odds ratio of 2.52 with 95% confidence interval of 1.07–5.92. Stratification by the LIA indicated similar point estimate but wider CIs. No associations were observed for Hg or Cd. Conclusions: Postnatal Pb exposure may be associated with higher risk of clinical ADHD, but not the postnatal exposure to Hg or Cd. -- Highlights: • Blood Pb levels are associated with ADHD diagnosis in children. • No association was found between blood Cd or Hg levels and ADHD. • Children living close to hazardous waste site need to reduce metal exposure.

  14. The Performance of Children Prenatally Exposed to HIV on the A-Not-B Task in Kilifi, Kenya: A Preliminary Study

    Directory of Open Access Journals (Sweden)

    Charles. R. J. C. Newton

    2013-09-01

    Full Text Available The aim of the study was to investigate early executive functioning in young children from 6–35 months of age. The study involved 319 randomly selected children from the community, 17 HIV exposed but uninfected children and 31 HIV infected ARV-naive children. A variation of the A-not-B task was used. While there were no group differences in total correct, perseverative errors, nor maximum error run, a significant percentage of children were unable to complete the task as a consequence of the children becoming overtly distressed or refusing to continue. In a multivariate analysis we observed that the significant predictors of non-completion were HIV exposure (both infected and exposed and being under 24 months of age. These patterns of results indicate that future work with a broader array of tasks need to look at the association of HIV and EF tasks and potential contribution of factors such as emotion regulation, persistence and motivation on performance on EF tasks.

  15. Hair Mercury Level is Associated with Anemia and Micronutrient Status in Children Living Near Artisanal and Small-Scale Gold Mining in the Peruvian Amazon.

    Science.gov (United States)

    Weinhouse, Caren; Ortiz, Ernesto J; Berky, Axel J; Bullins, Paige; Hare-Grogg, John; Rogers, Laura; Morales, Ana-Maria; Hsu-Kim, Heileen; Pan, William K

    2017-12-01

    Anemia has been widely studied in global health contexts because of severe nutritional deficiency, and more recently, inflammatory status, but chemical exposures are rarely considered. Until recently, "anemia" was used synonymously with "iron deficiency anemia (IDA)" in global health settings. However, only 50% of anemia cases worldwide are IDA. Environmental toxicology studies of anemia risk have generally focused on populations in developed countries, albeit with high exposure to environmental toxicants, such as lead or cadmium. In the developing world, toxicant exposures commonly coexist with other risk factors for anemia. In particular, artisanal and small-scale gold mining (ASGM) communities are at risk for dietary methylmercury exposure through contaminated fish consumption, and for anemia due to food insecurity and infectious and chronic diseases. Here, we report analysis of total hair mercury content, hemoglobin, and serum micronutrient levels in children association between total mercury and hemoglobin (β = -0.12 g/dL, P = 0.06) that persisted (β = -0.14 g/dL, P = 0.04) after adjusting for age, sex, anthropometrics, and vitamin B 12 in multivariate regression. This study provides preliminary evidence that methylmercury exposure is associated with anemia, which is especially relevant to children living near ASGM.

  16. Mercurial poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Gorton, B

    1924-01-01

    Cats which had been kept in a thermometer factory to catch rats were afflicted with mercury poisoning. So were the rats they were supposed to eat. The symptoms of mercury poisoning were the same in both species. The source of mercury for these animals is a fine film of the metal which coats floors, a result of accidental spills during the manufacturing process.

  17. Legacies of Amazonian dark earths on forest composition, structure and dynamics

    NARCIS (Netherlands)

    Quintero Vallejo, E.M.

    2015-01-01

    Summary

    Amazonian forest is seen as the archetype of pristine forests, untouched by humans, but this romantic view is far from reality. In recent years, there is increasing evidence of long and extensive landscape modification by humans. Processes of permanent inhabitation,

  18. The proportion of unhealthy foodstuffs children are exposed to at the checkout of convenience supermarkets.

    Science.gov (United States)

    Horsley, Jason A; Absalom, Katie Ar; Akiens, Evie M; Dunk, Robert J; Ferguson, Alice M

    2014-11-01

    To investigate the proportion of foods that are unhealthy to which children are exposed at the checkout of convenience supermarkets. We performed a cross-sectional survey of foodstuffs displayed at the checkout. Products displayed at or below children's eye-level were designated as healthy, unhealthy or unclassifiable using the Food Standards Agency's scoring criteria. Thirteen convenience supermarkets from the three leading UK supermarket chains were selected on the basis of proximity to the town hall in Sheffield, England. Convenience supermarkets were defined as branches of supermarket chains that were identified as being other than superstores on their company's store locator website. In almost all of the convenience supermarkets surveyed, the main healthy product on display was sugar-free chewing gum. On average, when chewing gum was not included as a foodstuff, 89% of the products on display at the checkouts of convenience supermarkets were unhealthy using the Food Standards Agency's criteria. One store was a notable outlier, providing only fruit and nuts at its checkout. The overwhelming majority of products to which children are exposed at the convenience supermarket checkout are unhealthy. This is despite all the supermarket chains surveyed having signed up to the UK Government's 'responsibility deal'.

  19. Intellectual function in Mexican children living in a mining area and environmentally exposed to manganese.

    Science.gov (United States)

    Riojas-Rodríguez, Horacio; Solís-Vivanco, Rodolfo; Schilmann, Astrid; Montes, Sergio; Rodríguez, Sandra; Ríos, Camilo; Rodríguez-Agudelo, Yaneth

    2010-10-01

    Excessive exposure to manganese (Mn), an essential trace element, has been shown to be neurotoxic, especially when inhaled. Few studies have examined potential effects of Mn on cognitive functions of environmentally exposed children. This study was intended to estimate environmental exposure to Mn resulting from mining and processing and to explore its association with intellectual function of school-age children. Children between 7 and 11 years of age from the Molango mining district in central Mexico (n = 79) and communities with similar socioeconomic conditions that were outside the mining district (n = 93) participated in the cross-sectional evaluation. The revised version of the Wechsler Intelligence Scale for Children adapted for the Mexican population was applied. Concentrations of Mn in blood (MnB) and hair (MnH) were used as biomarkers of exposure. Exposed children had significantly higher median values for MnH (12.6 μg/g) and MnB (9.5 μg/L) than did nonexposed children (0.6 μg/g and 8.0 μg/L, respectively). MnH was inversely associated with Verbal IQ [β = -0.29; 95% confidence interval (CI), -0.51 to -0.08], Performance IQ (β = -0.08; 95% CI, -0.32 to 0.16), and Total Scale IQ (β = -0.20; 95% CI, -0.42 to 0.02). MnB was inversely but nonsignificantly associated with Total and Verbal IQ score. Age and sex significantly modified associations of MnH, with the strongest inverse associations in young girls and little evidence of associations in boys at any age. Associations with MnB did not appear to be modified by sex but appeared to be limited to younger study participants. The findings from this study suggest that airborne Mn environmental exposure is inversely associated with intellectual function in young school-age children.

  20. Amazonian indigenous settlement and local development in Pastaza, Ecuador

    Directory of Open Access Journals (Sweden)

    Ruth I. Arias-Gutiérrez

    2016-07-01

    Full Text Available In six Amazonian indigenous communities that call to their selves as membership of nación Kichwa, located in Pastaza province, in Ecuador, it is analyzed the process of inhabitation, population characteristics, how much the territory is enough for food requirements for the indigenous families, and their use of land, to determine important factors to improve strategies for local sustainable development. It is considered important because Ecuador has constitutional protection for plural ethnicity and it is looking for improving a new productivity matrix that let down extraction and contamination and raise another matrix based on knowledge and richness from natural renewable resources. Survey used statistics information, qualitative analysis around reality in process, participant research, documentary analysis, oral history and surveys to leadership and family`s chiefs. Results confirm that communities hold standing their identity and knowledge systems of the Amazonian environment, whose conservation they need. Those are factors to be included in local development strategies that let people become safe from effects of extractives activities that are dangerous for culture and environment, in the geographic and biological diversity of the high Ecuadorian Amazonia.

  1. Growth and development of children prenatally exposed to telbivudine administered for the treatment of chronic hepatitis B in their mothers.

    Science.gov (United States)

    Zeng, Huihui; Cai, Haodong; Wang, Ying; Shen, Ying

    2015-04-01

    We studied the growth and development of children prenatally exposed to telbivudine used to treat chronic hepatitis B virus (HBV) infection in their mothers. Maternal abnormalities during pregnancy and delivery and infant congenital anomalies, physical development status, developmental quotient (DQ), HBV vertical transmission status, and HBV vaccination outcomes of 54 infants were evaluated (2010-2013). No fetal abnormalities were observed during pregnancy or delivery. Postpartum, three infants (5.56%) had abnormalities: ankyloglossia, cutaneous hemangioma, and vaginal canal leak. Height and weight were within the normal range at birth and at 6 weeks, but were higher than the reference at 12 months (pchildren (68.52%), abnormal or suspicious for a developmental delay (15.19%, 41/270) in 17 children (31.48%), and indicated a developmental delay (4.07%, 11/270) in seven children (12.96%). There were no significant differences in developmental delay between children prenatally exposed to telbivudine and controls (p>0.05). HBV vertical transmission was successfully blocked in all infants. The effective HBV vaccination rate was 98.15% (53/54). The growth and development of children prenatally exposed to telbivudine was normal, indicating that telbivudine treatment during pregnancy is safe and effective. Copyright © 2015. Published by Elsevier Ltd.

  2. [Association between intracellular zinc levels and nutritional status in HIV-infected and uninfected children exposed to the virus].

    Science.gov (United States)

    Gómez G, Erika María; Maldonado C, María Elena; Rojas L, Mauricio; Posada J, Gladys

    2015-01-01

    Malnutrition, growth retardation and opportunistic infections outlast the metabolic, immune and gastrointestinal disorders produced by HIV. Zinc deficiency has been associated with deteriorating nutritional status, growth failure, and risk of infection. The aim of this study is to determine the association between zinc levels in peripheral blood mononuclear cells (PBMC) and the nutritional status of HIV-infected and uninfected children exposed to the virus. An analytical, observational, cross-sectional study was conducted on 17 infected and 17 exposed children, aged 2-10 years. Anthropometric measurements, clinical and nutritional history, 24h recall, measurement of physical activity, and zinc in PBMC by flow cytometry analysis were recorded. Height according to age, energy consumption and adequacy of energy, protein and dietary zinc were significantly higher in children exposed to the virus compared to those infected with HIV (P .05). However, the median levels of zinc in monocytes of infected patients was higher (218.6) compared to the control group (217.0). No association was found between zinc intake and levels of intracellular zinc. The deterioration of nutritional status and growth retardation in children were associated with HIV, but not with the levels of intracellular zinc. The dietary intake of this nutrient was not associated with levels of zinc in monocytes or CD4 + and CD4- lymphocytes. Copyright © 2015. Publicado por Elsevier España, S.L.U.

  3. Origin and Domestication of Native Amazonian Crops

    Directory of Open Access Journals (Sweden)

    Doriane Picanço-Rodrigues

    2010-01-01

    Full Text Available Molecular analyses are providing new elements to decipher the origin, domestication and dispersal of native Amazonian crops in an expanding archaeological context. Solid molecular data are available for manioc (Manihot esculenta, cacao (Theobroma cacao, pineapple (Ananas comosus, peach palm (Bactris gasipaes and guaraná (Paullinia cupana, while hot peppers (Capsicum spp., inga (Inga edulis, Brazil nut (Bertholletia excelsa and cupuassu (Theobroma grandiflorum are being studied. Emergent patterns include the relationships among domestication, antiquity (terminal Pleistocene to early Holocene, origin in the periphery, ample pre-Columbian dispersal and clear phylogeographic population structure for manioc, pineapple, peach palm and, perhaps, Capsicum peppers. Cacao represents the special case of an Amazonian species possibly brought into domestication in Mesoamerica, but close scrutiny of molecular data suggests that it may also have some incipiently domesticated populations in Amazonia. Another pattern includes the relationships among species with incipiently domesticated populations or very recently domesticated populations, rapid pre- or post-conquest dispersal and lack of phylogeographic population structure, e.g., Brazil nut, cupuassu and guaraná. These patterns contrast the peripheral origin of most species with domesticated populations with the subsequent concentration of their genetic resources in the center of the basin, along the major white water rivers where high pre-conquest population densities developed. Additional molecular genetic analyses on these and other species will allow better examination of these processes and will enable us to relate them to other historical ecological patterns in Amazonia.

  4. Modification of Depression by COMT val[superscript 158]Met Polymorphism in Children Exposed to Early Severe Psychosocial Deprivation

    Science.gov (United States)

    Drury, Stacy S.; Theall, Katherine P.; Smyke, Anna T.; Keats, Bronya J. B.; Egger, Helen L.; Nelson, Charles A.; Fox, Nathan A.; Marshall, Peter J.; Zeanah, Charles H.

    2010-01-01

    Objective: To examine the impact of the catechol-O-methyltransferase (COMT) val[superscript 158]met allele on depressive symptoms in young children exposed to early severe social deprivation as a result of being raised in institutions. Methods: One hundred thirty six children from the Bucharest Early Intervention Project (BEIP) were randomized…

  5. Atmospheric mercury in Changbai Mountain area, northeastern China II. The distribution of reactive gaseous mercury and particulate mercury and mercury deposition fluxes.

    Science.gov (United States)

    Wan, Qi; Feng, Xinbin; Lu, Julia; Zheng, Wei; Song, Xinjie; Li, Ping; Han, Shijie; Xu, Hao

    2009-08-01

    Reactive gaseous mercury (RGM) and particulate mercury (Hgp) concentrations in ambient air from a remote site at Changbai Mountain area in northeastern China were intermittently monitored from August 2005 to July 2006 totaling 93 days representing fall, winter-spring and summer season, respectively. Rainwater and snow samples were collected during a whole year, and total mercury (THg) in rain samples were used to calculate wet depositional flux. A throughfall method and a model method were used to estimate dry depositional flux. Results showed mean concentrations of RGM and Hgp are 65 and 77 pg m(-3). Compared to background concentrations of atmospheric mercury species in Northern Hemisphere, RGM and Hgp are significantly elevated in Changbai area. Large values for standard deviation indicated fast reactivity and a low residence time for these mercury species. Seasonal variability is also important, with lower mercury levels in summer compared to other seasons, which is attributed to scavenging by rainfall and low local mercury emissions in summer. THg concentrations ranged from 11.5 to 15.9 ng L(-1) in rainwater samples and 14.9-18.6 ng L(-1) in throughfall samples. Wet depositional flux in Changbai area is calculated to be 8.4 microg m(-2) a(-1), and dry deposition flux is estimated to be 16.5 microg m(-2) a(-1) according to a throughfall method and 20.2 microg m(-2) a(-1) using a model method.

  6. Sunlight mediated seasonality in canopy structure and photosynthetic activity of Amazonian rainforests

    International Nuclear Information System (INIS)

    Bi, Jian; Knyazikhin, Yuri; Choi, Sungho; Park, Taejin; Barichivich, Jonathan; Ciais, Philippe; Fu, Rong; Ganguly, Sangram; Hall, Forrest; Hilker, Thomas; Huete, Alfredo; Jones, Matthew; Kimball, John; Lyapustin, Alexei I; Mõttus, Matti; Nemani, Ramakrishna R; Piao, Shilong; Poulter, Benjamin; Saleska, Scott R

    2015-01-01

    Resolving the debate surrounding the nature and controls of seasonal variation in the structure and metabolism of Amazonian rainforests is critical to understanding their response to climate change. In situ studies have observed higher photosynthetic and evapotranspiration rates, increased litterfall and leaf flushing during the Sunlight-rich dry season. Satellite data also indicated higher greenness level, a proven surrogate of photosynthetic carbon fixation, and leaf area during the dry season relative to the wet season. Some recent reports suggest that rainforests display no seasonal variations and the previous results were satellite measurement artefacts. Therefore, here we re-examine several years of data from three sensors on two satellites under a range of sun positions and satellite measurement geometries and document robust evidence for a seasonal cycle in structure and greenness of wet equatorial Amazonian rainforests. This seasonal cycle is concordant with independent observations of solar radiation. We attribute alternative conclusions to an incomplete study of the seasonal cycle, i.e. the dry season only, and to prognostications based on a biased radiative transfer model. Consequently, evidence of dry season greening in geometry corrected satellite data was ignored and the absence of evidence for seasonal variation in lidar data due to noisy and saturated signals was misinterpreted as evidence of the absence of changes during the dry season. Our results, grounded in the physics of radiative transfer, buttress previous reports of dry season increases in leaf flushing, litterfall, photosynthesis and evapotranspiration in well-hydrated Amazonian rainforests. (letter)

  7. Sustainable development, social organization and environment in the Amazonian Area

    International Nuclear Information System (INIS)

    Vieco, Juan Jose

    2001-01-01

    The effects of the development on the environment and the culture in regions like the Amazonian are one of the most dramatic examples that can be in what refers to the physical disappearance of numerous cultures, as well as of their integration to the national society and their rising loss of cultural identity and the devastating consequences that have had the development politicians on the different Amazon ecosystems. The construction of a sustainable development for the region has to evaluate the different societies that have existed and they exist as for the use, handling and exploitation of the natural resources. This paper will be approached this problem in three Amazon societies: the cacique territory, the tribal societies and the societies in formation in the colonization regions. It will be done an analysis and a critic of the development concept and of the consequences that it has had their application so much in the indigenous towns as in the Amazon ecosystems, as well as their relationship with the current characterization of the Amazonian area

  8. Pollution by Arsenic, Mercury and other Heavy Metals in Sunchulli mining district of Apolobamba (Bolivia)

    Science.gov (United States)

    Terán Mita, Tania; Faz Cano, Angel; Muñoz, Maria Angeles; Millán Gómez, Rocio; Chincheros Paniagua, Jaime

    2010-05-01

    In Bolivia, metal mining activities since historical times have been one of the most important sources of environmental pollution. This is the case of the National Area of Apolobamba Integrated Management (ANMIN of Apolobamba) in La Paz, Bolivia, where intense gold mining activities have been carried out from former times to the present, with very little gold extraction and very primitive mineral processing technology; in fact, mercury is still being used in the amalgam processes of the gold concentration, which is burned outdoors to recover the gold. Sunchullí is a representative mining district in ANMIN of Apolobamba where mining activity is mainly gold extraction and its water effluents go to the Amazonian basin; in this mining district the productivity of extracted mineral is very low but the processes can result in heavy-metal contamination of the air, water, soils and plants. Due to its high toxicity, the contamination by arsenic and mercury create the most critical environmental problems. In addition, some other heavy metals may also be present such as lead, copper, zinc and cadmium. These heavy metals could be incorporated in the trophic chain, through the flora and the fauna, in their bio-available and soluble forms. Inhabitants of this area consume foodcrops, fish from lakes and rivers and use the waters for the livestock, domestic use, and irrigation. The aim of this work was to evaluate the heavy metals pollution by gold mining activities in Sunchullí area. In Sunchullí two representative zones were distinguished and sampled. Zone near the mining operation site was considered as affected by mineral extraction processes, while far away zones represented the non affected ones by the mining operation. In each zone, 3 plots were established; in each plot, 3 soil sampling points were selected in a random manner and analysed separately. In each sampling point, two samples were taken, one at the surface, from 0-5 cm depth (topsoil), and the other between 5

  9. Descarte de lámparas ahorradoras de energía y su relación con la exposición a mercurio. Caso: Bella Vista, estado Aragua, Venezuela | Discard of energy-saving bulbs and relationship with mercury exposure. Case: Bella Vista, Aragua state, Venezuela

    Directory of Open Access Journals (Sweden)

    Andreína Reyes

    2018-01-01

    Full Text Available Mercury is a toxic element used in the manufacture of energy-saving bulbs, which is a source of pollution both for the environment and humans when they are improperly disposed of. Mercury entering the organism is mainly eliminated by urinary excretion. The discard of energy-saving bulbs and its relation with mercury environmental exposure in Bella Vista population (Aragua, Venezuela was studied. Research was descriptive, correlational, cross-sectional and field. For a group of 36 possibly exposed and 37 control group individuals, the discarding methods for energy-saving bulbs were identified, mercury levels in urine by cold vapor spectrophotometry and creatinine levels by Jaffe modified method were quantified. Permissive limit for non-exposed persons is 5 μg Hg/g creatinine. Signs and symptoms associated with exposure to mercury were described and the variable discard of energy-saving bulbs with urinary mercury levels was related. An analysis of variance was applied on the results of urine mercury levels classified by study group (possibly exposed and control and age groups, with statistically significant differences for urine mercury levels classified according to study groups (p = 0.001 but not for age group (p = 0.946.

  10. Toward a Unified Understanding of Mercury and Methylated Mercury from the World's Oceans

    Science.gov (United States)

    McNutt, M. K.; Krabbenhoft, D. P.; Landing, W. M.; Sunderland, E. M.

    2012-12-01

    Marine fish and shellfish are the main source of toxic methylmercury exposure for humans. As recently as decade ago, very limited aqueous methylated mercury data were available from marine settings, resulting in a generally poor understanding of the processes controlling mercury in pelagic marine food webs. Recent oceanographic cruises have significantly improved availability of reliable measurements of methylated mercury and total mercury in seawater. This presentation will focus on vertical seawater profiles collected to depths 1000 m from three recent sampling efforts in collaboration with the CLIVAR Repeat Hydrography Program sponsored by NOAA including: 1) the northeastern Pacific (P16N cruise from Honolulu, Hawaii to Kodiak, Alaska); (2) the southern Indian Ocean (I5 cruise from Cape Town, South Africa, to Fremantle, Australia); and, (3) the Southern Ocean cruise (S4P from McMurdo, Antarctica, to Punta Arenas, Chile). Analytical results presented were all derived from the USGS Mercury Research Lab (http://wi.water.usgs.gov/mercury-lab). Supporting data derived from these cruises on water mass ages, nutrients, carbon and dissolved oxygen provide an opportunity to develop a stronger understanding of the biogeochemical factors controlling oceanic distributions of mercury and methylated mercury. Whole-water, median total mercury, and methylated mercury concentrations for the northern Pacific, southern Indian, and Southern Ocean were 1.10, 0.80, and 1.65 pM, , and 0.11, 0.08, and 0.32 pM, respectively. For all three oceans, vertical profiles of total mercury generally show the lowest concentrations in the surface mixed layer, and concentration maxima at the 700-1000 m depths. Surface depletion of total mercury is attributed to photo-chemical reduction and evasion of gaseous elemental mercury as well as scavenging by settling particulate matter, the main vector of transport to the subsurface ocean. Methylated mercury in all the ocean profiles reveal distinct mid

  11. Environmental change and the carbon balance of Amazonian forests

    International Nuclear Information System (INIS)

    Aragao, Luiz E.O.C.; Poulter, Benjamin

    2014-01-01

    Extreme climatic events and land-use change are known to influence strongly the current carbon cycle of Amazonia, and have the potential to cause significant global climate impacts. This review intends to evaluate the effects of both climate and anthropogenic perturbations on the carbon balance of the Brazilian Amazon and to understand how they interact with each other. By analysing the outputs of the Intergovernmental Panel for Climate Change (IPCC) Assessment Report 4 (AR4) model ensemble, we demonstrate that Amazonian temperatures and water stress are both likely to increase over the 21. Century. Curbing deforestation in the Brazilian Amazon by 62% in 2010 relative to the 1990's mean decreased the Brazilian Amazon's deforestation contribution to global land use carbon emissions from 17% in the 1990's and early 2000's to 9% by 2010. Carbon sources in Amazonia are likely to be dominated by climatic impacts allied with forest fires (48.3% relative contribution) during extreme droughts. The current net carbon sink (net biome productivity, NBP) of +0.16 (ranging from +0.11 to +0.21) PgCyear-1 in the Brazilian Amazon, equivalent to 13.3% of global carbon emissions from land-use change for 2008, can be negated or reversed during drought years [NBP=-0.06 (-0.31 to +0.01) PgCyear -1 ]. Therefore, reducing forest fires, in addition to reducing deforestation, would be an important measure for minimizing future emissions. Conversely, doubling the current area of secondary forests and avoiding additional removal of primary forests would help the Amazonian gross forest sink to offset approximately 42% of global land-use change emissions. We conclude that a few strategic environmental policy measures are likely to strengthen the Amazonian net carbon sink with global implications. Moreover, these actions could increase the resilience of the net carbon sink to future increases in drought frequency. (authors)

  12. Environmental change and the carbon balance of Amazonian forests.

    Science.gov (United States)

    Aragão, Luiz E O C; Poulter, Benjamin; Barlow, Jos B; Anderson, Liana O; Malhi, Yadvinder; Saatchi, Sassan; Phillips, Oliver L; Gloor, Emanuel

    2014-11-01

    Extreme climatic events and land-use change are known to influence strongly the current carbon cycle of Amazonia, and have the potential to cause significant global climate impacts. This review intends to evaluate the effects of both climate and anthropogenic perturbations on the carbon balance of the Brazilian Amazon and to understand how they interact with each other. By analysing the outputs of the Intergovernmental Panel for Climate Change (IPCC) Assessment Report 4 (AR4) model ensemble, we demonstrate that Amazonian temperatures and water stress are both likely to increase over the 21st Century. Curbing deforestation in the Brazilian Amazon by 62% in 2010 relative to the 1990s mean decreased the Brazilian Amazon's deforestation contribution to global land use carbon emissions from 17% in the 1990s and early 2000s to 9% by 2010. Carbon sources in Amazonia are likely to be dominated by climatic impacts allied with forest fires (48.3% relative contribution) during extreme droughts. The current net carbon sink (net biome productivity, NBP) of +0.16 (ranging from +0.11 to +0.21) Pg C year(-1) in the Brazilian Amazon, equivalent to 13.3% of global carbon emissions from land-use change for 2008, can be negated or reversed during drought years [NBP = -0.06 (-0.31 to +0.01) Pg C year(-1) ]. Therefore, reducing forest fires, in addition to reducing deforestation, would be an important measure for minimizing future emissions. Conversely, doubling the current area of secondary forests and avoiding additional removal of primary forests would help the Amazonian gross forest sink to offset approximately 42% of global land-use change emissions. We conclude that a few strategic environmental policy measures are likely to strengthen the Amazonian net carbon sink with global implications. Moreover, these actions could increase the resilience of the net carbon sink to future increases in drought frequency. © 2014 The Authors. Biological Reviews © 2014 Cambridge Philosophical

  13. Exploring eco-hydrological consequences of the Amazonian ecosystems under climate and land-use changes in the 21st century

    Science.gov (United States)

    Zhang, K.; Castanho, A. D.; Moghim, S.; Bras, R. L.; Coe, M. T.; Costa, M. H.; Levine, N. M.; Longo, M.; McKnight, S.; Wang, J.; Moorcroft, P. R.

    2012-12-01

    Deforestation and drought have imposed regional-scale perturbations onto Amazonian ecosystems and are predicted to cause larger negative impacts on the Amazonian ecosystems and associated regional carbon dynamics in the 21st century. However, global climate models (GCMs) vary greatly in their projections of future climate change in Amazonia, giving rise to uncertainty in the expected fate of the Amazon over the coming century. In this study, we explore the possible eco-hydrological consequences of the Amazonian ecosystems under projected climate and land-use changes in the 21st century using two state-of-the-art terrestrial ecosystem models—Ecosystem Demography Model 2.1(ED2.1) and Integrated Biosphere Simulator model (IBIS)—driven by three representative, bias-corrected climate projections from three IPCC GCMs (NCARPCM1, NCARCCSM3 and HadCM3), coupled with two land-use change scenarios (a business-as-usual and a strict governance scenario). We also analyze the relative roles of climate change, CO2 fertilization, land-use change and fire in driving the projected composition and structure of the Amazonian ecosystems. Our results show that CO2 fertilization enhances vegetation productivity and above-ground biomass (AGB) in the region, while land-use change and fire cause AGB loss and the replacement of forests by the savanna-like vegetation. The impacts of climate change depend strongly on the direction and severity of projected precipitation changes in the region. In particular, when intensified water stress is superimposed on unregulated deforestation, both ecosystem models predict large-scale dieback of Amazonian rainforests.

  14. Excretion and distribution of mercury in rats, antidotes for mercury and effects of egg production and fertility of hens after mercury administration

    Energy Technology Data Exchange (ETDEWEB)

    Ulfvarson, U

    1973-01-01

    The results of investigations of the distribution and excretion of organic and inorganic mercury compounds in albino rats and white leghorn hens conducted over a period of ten years are surveyed. The storage of mercury in eggs as well as its effects on the egg-lay-frequency and hatchability of the eggs have also been studied. All investigated mercury compounds were labelled with the radioactive mercury isotope /sup 203/Hg and the mercury level was measured with a scintillation technique. Since antidotes used in the treatment of mercury poisoning influence not only the excretion of mercury, but also its distribution in the body, the effects of nine antidotes on the metabolism of different mercury compounds were also investigated. The results of the survey are presented graphically. 6 references, 15 figures, 1 table.

  15. Analysis of mercury and selenium in biological samples by neutron activation analysis; Analise de mercurio e selenio em materiais biologicos pelo metodo de analise por ativacao com neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Catharino, Marilia Gabriela Miranda

    2002-07-01

    In the present work, hair samples from populations suspected of contamination by mercury, in the localities of Serra do Navio, Vila Nova and Tartarugalzinho, in the State of Amapa, were analyzed. Hair samples of children under odontopediatric treatment were also analyzed for mercury, in order to study the possibility of transfer of mercury from the dental amalgam and also to obtain data of hair mercury in a control population of children. Another step of the work was the development of a method for the determination of selenium, by using the short-lived radioisotope {sup 77}mSe. After the certification of the method it was applied to the analysis of hair, nails and a vitamin supplement. A comparison was made with the results obtain ed by using the long-lived radioisotope of selenium, {sup 75}Se. The results obtained for mercury in the hair samples of populations living in the State of Amapa have shown that the mercury concentrations in these populations are much higher than in the controls. As for the hair samples of children under treatment with mercury amalgam, no significant differences were found in the concentrations of mercury after the treatment. On the other hand, these data were important to obtain data for a control population of children. The results obtained by using the radioisotope {sup 77}mSe showed that the method developed was suitable for the analyzed matrixes and the results were similar to the ones obtained by employing the usual AANI method, with the radioisotope {sup 75}Se. (author)

  16. Mercury's exosphere: observations during MESSENGER's First Mercury flyby.

    Science.gov (United States)

    McClintock, William E; Bradley, E Todd; Vervack, Ronald J; Killen, Rosemary M; Sprague, Ann L; Izenberg, Noam R; Solomon, Sean C

    2008-07-04

    During MESSENGER's first Mercury flyby, the Mercury Atmospheric and Surface Composition Spectrometer measured Mercury's exospheric emissions, including those from the antisunward sodium tail, calcium and sodium close to the planet, and hydrogen at high altitudes on the dayside. Spatial variations indicate that multiple source and loss processes generate and maintain the exosphere. Energetic processes connected to the solar wind and magnetospheric interaction with the planet likely played an important role in determining the distributions of exospheric species during the flyby.

  17. Phenolic constituents and antioxidant activity of geopropolis from two species of amazonian stingless bees

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ellen Cristina Costa da; Muniz, Magno Perea; Nunomura, Rita de Cassia Saraiva, E-mail: ellensilva@yahoo.com.br [Departamento de Quimica, Instituto de Ciencias Exatas, Universidade Federal do Amazonas, Manaus, AM (Brazil); Nunomura, Sergio Massayoshi [Departamento de Produtos Naturais, Instituto Nacional de Pesquisas da Amazonia, Manaus, AM (Brazil); Zilse, Gislene Almeida Carvalho [Departamento de Biodiversidade, Instituto Nacional de Pesquisas da Amazonia, Manaus, AM (Brazil)

    2013-09-01

    We investigated the phenolic constituents and antioxidant activity of geopropolis from two species of stingless Amazonian bees, Melipona interrupta and Melipona seminigra. The chemical investigation of geopropolis from Melipona interrupta led to the isolation of 5,7,4'-trihydroxyflavonone, 3,5,6,7,4'-pentahydroxyflavonol, naringenine-4'-O-{beta}-D-glucopyranoside and myricetin-3-O-{beta}-D-glucopyranoside. Their structures were assigned based on spectroscopic analyses, including two-dimensional NMR techniques. Antioxidant activity of methanol and ethanol extracts of M. interrupta and M. seminigra were measured using the 1,2-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging assay. This is also the first work reporting the chemical investigation of stingless bee species from the Amazonian region. (author)

  18. Mercury heavy-metal-induced physiochemical changes and genotoxic alterations in water hyacinths [Eichhornia crassipes (Mart.)].

    Science.gov (United States)

    Malar, Srinivasan; Sahi, Shivendra Vikram; Favas, Paulo J C; Venkatachalam, Perumal

    2015-03-01

    Mercury heavy metal pollution has become an important environmental problem worldwide. Accumulation of mercury ions by plants may disrupt many cellular functions and block normal growth and development. To assess mercury heavy metal toxicity, we performed an experiment focusing on the responses of Eichhornia crassipes to mercury-induced oxidative stress. E. crassipes seedlings were exposed to varying concentrations of mercury to investigate the level of mercury ions accumulation, changes in growth patterns, antioxidant defense mechanisms, and DNA damage under hydroponics system. Results showed that plant growth rate was significantly inhibited (52 %) at 50 mg/L treatment. Accumulation of mercury ion level were 1.99 mg/g dry weight, 1.74 mg/g dry weight, and 1.39 mg/g dry weight in root, leaf, and petiole tissues, respectively. There was a decreasing trend for chlorophyll a, b, and carotenoids with increasing the concentration of mercury ions. Both the ascorbate peroxidase and malondialdehyde contents showed increased trend in leaves and roots up to 30 mg/L mercury treatment and slightly decreased at the higher concentrations. There was a positive correlation between heavy metal dose and superoxide dismutase, catalase, and peroxidase antioxidative enzyme activities which could be used as biomarkers to monitor pollution in E. crassipes. Due to heavy metal stress, some of the normal DNA bands were disappeared and additional bands were amplified compared to the control in the random amplified polymorphic DNA (RAPD) profile. Random amplified polymorphic DNA results indicated that genomic template stability was significantly affected by mercury heavy metal treatment. We concluded that DNA changes determined by random amplified polymorphic DNA assay evolved a useful molecular marker for detection of genotoxic effects of mercury heavy metal contamination in plant species.

  19. White matter hyperintensities, systemic inflammation, brain growth, and cognitive functions in children exposed to air pollution.

    Science.gov (United States)

    Calderón-Garcidueñas, Lilian; Mora-Tiscareño, Antonieta; Styner, Martin; Gómez-Garza, Gilberto; Zhu, Hongtu; Torres-Jardón, Ricardo; Carlos, Esperanza; Solorio-López, Edelmira; Medina-Cortina, Humberto; Kavanaugh, Michael; D'Angiulli, Amedeo

    2012-01-01

    Air pollution exposures are linked to neuroinflammation and neuropathology in young urbanites. Forty percent of exposed children and young adults exhibit frontal tau hyperphosphorylation and 51% have amyloid-β diffuse plaques compared to 0% in low pollution controls. In older adults, white matter hyperintensities (WMH) are associated with cognitive deficits while inflammatory markers correlate with greater atrophy than expected for age. We investigated patterns of WMH, magnetic resonance imaging (MRI) volume growth, blood inflammatory mediators, and cognition in matched children from two urban cohorts: one severely and one minimally exposed to air pollution. Baseline and one year follow-up measurements of cognitive abilities, brain MRI volumes, and blood were collected in 20 Mexico City (MC) children (10 with WMH+, and 10 without WMH-) and 10 matched controls (WMH-). MC WMH- children display the profile of classical pro-inflammatory defensive responses: high interleukin 12, production of powerful pro-inflammatory cytokines, and low concentrations of key cytokines and chemokines associated with neuroprotection. MC WMH+ children exhibit a response involved in resolution of inflammation, immunoregulation, and tissue remodeling. The MC WMH+ group responded to the air pollution-associated brain volumetric alterations with white and grey matter volume increases in temporal, parietal, and frontal regions and better cognitive performance compared to MC WMH-. We conclude that complex modulation of cytokines and chemokines influences children's central nervous system structural and volumetric responses and cognitive correlates resulting from environmental pollution exposures. Identification of biomarkers associating systemic inflammation to brain growth is critical for detecting children at higher risk for cognitive deficits and neurodegeneration, thereby warranting early implementation of neuroprotective measures.

  20. Developmental effects of mercury on Etheostoma caeruleum and E. spectabile: Predictable biomarkers of stress

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, J.R. [Southeast Missouri State Univ., Cape Girardeau, MO (United States). Dept. of Biology

    1995-12-31

    Etheostoma caeruleum and E. spectabile are sympatric teleostean species of the Family Percidae. The ova diameters and incubation times are different: E. caeruleum (1.9mm and 12-d), E. spectabile (1.2mm and 8-d). For both species, cleavage stage (4--8 cell), mid-blastula, mid-neurula, and early-eye stage embryos were exposed to + {minus}1 a 24-h static-renewal test of 0, 10, 20, 40, 60, 80, 100 {micro}gHg {sup ++}L{sup {minus}1} to assess the effects of stage-specific initial mercury exposure on the embryo-larval responses. In addition, cleavage stage embryos were exposed to a 1-d, 2-d, and 4-d static-renewal toxicity test to determine the influence that exposure duration to mercury has on embryolarval responses. Five replicates of 10 embryos each were incubated at 18 C for each concentration and exposure variation. Embryos were allowed to develop until all had hatched or died. Four embryonic responses were assessed for each species and exposure protocol: 96-h LC50, AB50, SH50 and VH50. The typical nonstressor specific terata were noted for each species with an increase in percent of embryos expressing abnormal developmental patterns with increase mercury concentrations and severity of exposure. These included dwarfism, cephalic complications, ophthalmic abnormalities, cardiovascular abnormalities, various edema, and haemorrhagia. Hatching success and viability of hatch were likewise reduced with increasing severity of exposure and mercury concentration. Previously undetected terata that were observed in the first hatch included scoliosis, lordosis, kyphosis, synarthrodic jaws, and grossly enlarged yolk sacs.

  1. Gene Responses in the Central Nervous System of Zebrafish Embryos Exposed to the Neurotoxicant Methyl Mercury

    NARCIS (Netherlands)

    Ho, Nga Yu; Yang, Lixin; Legradi, J.B.; Armant, Olivier; Takamiya, Masanari; Rastegar, Sepand; Strähle, Uwe

    2013-01-01

    Methyl mercury (MeHg) is a neurotoxicant with adverse effects on the development of the nervous system from fish to man. Despite a detailed understanding of the molecular mechanisms by which MeHg affects cellular homeostasis, it is still not clear how MeHg causes developmental neurotoxicity. We

  2. Eficácia da vacina Sabin em crianças subnutridas da Amazônia The efficacy of oral polio vaccine in malnourished Amazonian children

    Directory of Open Access Journals (Sweden)

    Klaus E. Stewien

    1985-02-01

    Full Text Available A eficácia da vacina Sabin foi determinada em 106 crianças normais e subnutridas da Amazônia, após a administração de uma e duas doses de vacina oral (trivalente. Após a aplicação de uma dose de vacina, verificou-se que apenas 9% das crianças com subnutrição pregressa (crônica e 43% das crianças normais formaram anticorpos neutralizantes (protetores contra dois ou três tipos de poliovírus (p = 0,04. Após duas doses de vacina, os níveis de imunidade dos dois grupos de crianças estudadas acusaram, respectivamente, 32% e 75% (p = 0,001. Estes resultados mostram que a resposta imunitária à vacina Sabin foi sensivelmente inferior no grupo das crianças subnutridas, do que no das crianças normais. Em decorrência disto, será necessário administrar um número maior de doses de vacina oral àquelas crianças, a fim de que níveis satisfatórios de imunidade contra a poliomielite sejam atingidos em toda a população infantil.Various hypotheses have been proposed to explain the diminished efficacy of the oral polio vaccine in underdeveloped tropical regions. In this study, the influence of mild to moderate chronic malnutrition on the development of antibodies to the 3 types of polioviruses was investigated in Brazilian Amazonian children. Vaccines were administered to 106 normal and stunted children, between 5 to 14 months of age, who were not suffering from acute malnutrition (wasting, in poor peri-urban slum areas of Manaus (AM and São Luis (MA during the National Poliomyelitis Vaccination Campaigns of 1981 and 1982. Two weeks after vaccination, blood was collected by digital puncture and the prevalence of neutralizing antibodies for the 3 types of polioviruses was determined in serum at a dilution of 1:8. In children who had received one dose of the vaccine, 43% of normal children had antibodies to 2 or 3 types of polioviruses, against only 9% of stunted children (p = .04. In children who had received 2 doses of vaccine, 75

  3. A mercury transport and fate model (LM2-mercury) for mass budget assessment of mercury cycling in Lake Michigan

    Science.gov (United States)

    LM2-Mercury, a mercury mass balance model, was developed to simulate and evaluate the transport, fate, and biogeochemical transformations of mercury in Lake Michigan. The model simulates total suspended solids (TSS), disolved organic carbon (DOC), and total, elemental, divalent, ...

  4. Mercury Emission Measurement in Coal-Fired Boilers by Continuous Mercury Monitor and Ontario Hydro Method

    Science.gov (United States)

    Zhu, Yanqun; Zhou, Jinsong; He, Sheng; Cai, Xiaoshu; Hu, Changxin; Zheng, Jianming; Zhang, Le; Luo, Zhongyang; Cen, Kefa

    2007-06-01

    The mercury emission control approach attaches more importance. The accurate measurement of mercury speciation is a first step. Because OH method (accepted method) can't provide the real-time data and 2-week time for results attained, it's high time to seek on line mercury continuous emission monitors(Hg-CEM). Firstly, the gaseous elemental and oxidized mercury were conducted to measure using OH and CEM method under normal operation conditions of PC boiler after ESP, the results between two methods show good consistency. Secondly, through ESP, gaseous oxidized mercury decrease a little and particulate mercury reduce a little bit, but the elemental mercury is just the opposite. Besides, the WFGD system achieved to gaseous oxidized mercury removal of 53.4%, gaseous overall mercury and elemental mercury are 37.1% and 22.1%, respectively.

  5. Mercury and trace element contents of Donbas coals and associated mine water in the vicinity of Donetsk, Ukraine

    Science.gov (United States)

    Kolker, A.; Panov, B.S.; Panov, Y.B.; Landa, E.R.; Conko, K.M.; Korchemagin, V.A.; Shendrik, T.; McCord, J.D.

    2009-01-01

    Mercury-rich coals in the Donets Basin (Donbas region) of Ukraine were sampled in active underground mines to assess the levels of potentially harmful elements and the potential for dispersion of metals through use of this coal. For 29 samples representing c11 to m3 Carboniferous coals, mercury contents range from 0.02 to 3.5 ppm (whole-coal dry basis). Mercury is well correlated with pyritic sulfur (0.01 to 3.2 wt.%), with an r2 of 0.614 (one outlier excluded). Sulfides in these samples show enrichment of minor constituents in late-stage pyrite formed as a result of interaction of coal with hydrothermal fluids. Mine water sampled at depth and at surface collection points does not show enrichment of trace metals at harmful levels, indicating pyrite stability at subsurface conditions. Four samples of coal exposed in the defunct open-cast Nikitovka mercury mines in Gorlovka have extreme mercury contents of 12.8 to 25.5 ppm. This coal was formerly produced as a byproduct of extracting sandstone-hosted cinnabar ore. Access to these workings is unrestricted and small amounts of extreme mercury-rich coal are collected for domestic use, posing a limited human health hazard. More widespread hazards are posed by the abandoned Nikitovka mercury processing plant, the extensive mercury mine tailings, and mercury enrichment of soils extending into residential areas of Gorlovka.

  6. Increased oxidative stress in preschool children exposed to passive smoking.

    Science.gov (United States)

    Yıldırım, Faruk; Sermetow, Kabil; Aycicek, Ali; Kocyigit, Abdurrahim; Erel, Ozcan

    2011-01-01

    To study the effect of passive cigarette smoking on plasma oxidative and antioxidative status in passive smoking preschool children and to compare them with controls. Thirty-four passive smoking (five to 50 cigarettes per day) preschool children (study group) and 32 controls who had never been exposed to cigarette smoke were randomly chosen from children aged from 4 to 6 years. Urinary cotinine and plasma indicators of oxidative and antioxidative status, i.e., total oxidant status (TOS), total antioxidant capacity (TAC), and oxidative stress index (OSI), were determined. Mean environmental cigarette consumption was 22±13 cigarettes per day in passive smoking children. Mean urinary cotinine levels were 77.6±41.4 ng/mL and 11.9±2.3 ng/mL in the study and control groups, respectively (p < 0.001). Mean plasma TAC levels were 0.95±0.13 mmol Trolox equivalent/L and 1.01±0.09 mmol Trolox equivalent/L, respectively (p = 0.039). Mean plasma TOS levels were 28.6±7.9 µmol H2O2 equivalent/L and 18.5±6.3 µmol H2O2 equivalent/L, respectively (p < 0.001). Mean OSI levels were 3.08±0.98 arbitrary units and 1.84±0.64 arbitrary units, respectively (p < 0.001). A small amount of cigarette smoke (five to 10 cigarettes per day) causes considerable oxidative stress. There were significant correlations between number of cigarettes consumed and oxidant status and OSI levels. Passive smoke is a potent oxidant in preschool children. Its deleterious effects are not limited just to heavy passive smoking, but also occur with exposure to small amounts of smoke.

  7. Development assessment of HIV exposed children aged 6-18 months: a cohort study from North India.

    Science.gov (United States)

    Rajan, Remya; Seth, Anju; Mukherjee, Sharmila B; Chandra, Jagdish

    2017-11-01

    HIV exposed children are vulnerable to developmental delay irrespective of their HIV status due to combined effect of risk factors like poverty, prenatal drug exposure, stress and chronic illness in family and malnutrition. This cohort study assessed the development of 50 HIV exposed children aged 6-18 months at a Pediatric Centre of Excellence in HIV care in India. The development was assessed using Development Assessment Scale for Indian Infants (DASII) at enrolment, 3 and 6 months later. The development quotient (DQ) scores and proportion of children with developmental delay (DQ ≤ 70) were compared among two sub-groups, HIV infected (HI) and HIV exposed uninfected (HEU) children. The various social and clinical factors affecting development were studied by univariate and multivariate analysis. Prevalence of developmental delay was 2.4% in the HEU (n = 41), and 33.3% in HI (n = 9). The DQ of HI was significantly lower than that of HEU at all three assessments. The DQ of HI were also significantly lower compared to the HEU at ages 12.1-18 months (83.37 ± 20.73 vs 94.68 ± 5.13, p = 0.005) and 18.1-24 months (84.55 ± 15.35 vs 94.63 ± 5.86, p = 0.006) respectively. The development of HEU was adversely affected by lower socioeconomic status and presence of wasting. In addition, development of HI was also adversely influenced by presence of stunting and opportunistic infections, advanced disease stage and shorter ART duration. We conclude that with optimum care, HEU can have a normal development, while a considerable proportion of HI may continue to have delayed development.

  8. Biomarkers of mercury exposure at a mercury recycling facility in Ukraine

    Science.gov (United States)

    Gibb, H.J.; Kozlov, K.; Buckley, J.P.; Centeno, J.; Jurgenson, V.; Kolker, A.; Conko, K.; Landa, E.; Panov, B.; Panov, Y.; Xu, H.

    2008-01-01

    This study evaluates biomarkers of occupational mercury exposure among workers at a mercury recycling operation in Gorlovka, Ukraine. The 29 study participants were divided into three occupational categories for analysis: (1) those who worked in the mercury recycling operation (Group A, n = 8), (2) those who worked at the facility but not in the yard where the recycling was done (Group B, n = 14), and (3) those who did not work at the facility (Group C, n = 7). Urine, blood, hair, and nail samples were collected from the participants, and a questionnaire was administered to obtain data on age, gender, occupational history, smoking, alcohol consumption, fish consumption, tattoos, dental amalgams, home heating system, education, source of drinking water, and family employment in the former mercury mine/smelter located on the site of the recycling facility. Each factor was tested in a univariate regression with total mercury in urine, blood, hair, and nails. Median biomarker concentrations were 4.04 ??g/g-Cr (urine), 2.58 ??g/L (blood), 3.95 ??g/g (hair), and 1.16 ??g/g (nails). Occupational category was significantly correlated (p < 0.001) with both blood and urinary mercury concentrations but not with hair or nail mercury. Four individuals had urinary mercury concentrations in a range previously found to be associated with subtle neurological and subjective symptoms (e.g., fatigue, loss of appetite, irritability), and one worker had a urinary mercury concentration in a range associated with a high probability of neurological effects and proteinuria. Comparison of results by occupational category found that workers directly involved with the recycling operation had the highest blood and urinary mercury levels. Those who worked at the facility but were not directly involved with the recycling operation had higher levels than those who did not work at the facility. Copyright ?? 2008 JOEH, LLC.

  9. Concentration of mercury in wheat samples stored with mercury tablets as preservative

    International Nuclear Information System (INIS)

    Lalit, B.Y.; Ramachandran, T.V.

    1977-01-01

    Tablets consisting of mercury in the form of a dull grey powder made by triturating mercury with chalk and sugar are used in Indian household for storing food-grains. The contamination of wheat samples by mercury, when stored with mercury tablets for period of upto four years has been assessed by using non-destructive neutron activation analysis. The details of the analytical procedure used have also been briefly described. The concentration of mercury in wheat increases with storage period. Loss of weight of mercury tablet is proportional to the storage period to a first approximation. In the present experiment, the average weight loss at the and end of first year was 0.009716 g corresponding to 6 ppm in wheat. (T.G.)

  10. Mercury Flow Through the Mercury-Containing Lamp Sector of the Economy of the United States

    Science.gov (United States)

    Goonan, Thomas G.

    2006-01-01

    Introduction: This Scientific Investigations Report examines the flow of mercury through the mercury-containing lamp sector of the U.S. economy in 2001 from lamp manufacture through disposal or recycling. Mercury-containing lamps illuminate commercial and industrial buildings, outdoor areas, and residences. Mercury is an essential component in fluorescent lamps and high-intensity discharge lamps (high-pressure sodium, mercury-vapor, and metal halide). A typical fluorescent lamp is composed of a phosphor-coated glass tube with electrodes located at either end. Only a very small amount of the mercury is in vapor form. The remainder of the mercury is in the form of either liquid mercury metal or solid mercury oxide (mercury oxidizes over the life of the lamp). When voltage is applied, the electrodes energize the mercury vapor and cause it to emit ultraviolet energy. The phosphor coating absorbs the ultraviolet energy, which causes the phosphor to fluoresce and emit visible light. Mercury-containing lamps provide more lumens per watt than incandescent lamps and, as a result, require from three to four times less energy to operate. Mercury is persistent and toxic within the environment. Mercury-containing lamps are of environmental concern because they are widely distributed throughout the environment and are easily broken in handling. The magnitude of lamp sector mercury emissions, estimated to be 2.9 metric tons per year (t/yr), is small compared with the estimated mercury losses of the U.S. coal-burning and chlor-alkali industries, which are about 70 t/yr and about 90 t/yr, respectively.

  11. Mercury Toxicity and Contamination of Households from the Use of Skin Creams Adulterated with Mercurous Chloride (Calomel

    Directory of Open Access Journals (Sweden)

    Lori Copan

    2015-09-01

    Full Text Available Inorganic mercury, in the form of mercurous chloride, or calomel, is intentionally added to some cosmetic products sold through informal channels in Mexico and the US for skin lightening and acne treatment. These products have led to multiple cases of mercury poisoning but few investigations have addressed the contamination of cream users’ homes. We report on several cases of mercury poisoning among three Mexican-American families in California from use of mercury-containing skin creams. Each case resulted in widespread household contamination and secondary contamination of family members. Urine mercury levels in cream users ranged from 37 to 482 µg/g creatinine and in non-users from non-detectable to 107 µg/g creatinine. Air concentrations of up to 8 µg/m3 of mercury within homes exceeded the USEPA/ATSDR health-based guidance and action level of <1.0 μg/m3. Mercury contamination of cream users’ homes presented a multi-pathway exposure environment to residents. Homes required extensive decontamination, including disposal of most household items, to achieve acceptable air levels. The acceptable air levels used were not designed to consider multi-pathway exposure scenarios. These findings support that the calomel is able to change valence form to elemental mercury and volatilize once exposed to the skin or surfaces in the indoor environment.

  12. Estimating mercury emissions from a zinc smelter in relation to China's mercury control policies

    International Nuclear Information System (INIS)

    Wang, S.X.; Song, J.X.; Li, G.H.; Wu, Y.; Zhang, L.; Wan, Q.; Streets, D.G.; Chin, Conrad K.; Hao, J.M.

    2010-01-01

    Mercury concentrations of flue gas at inlet/outlet of the flue gas cleaning, electrostatic demister, reclaiming tower, acid plant, and mercury contents in zinc concentrate and by-products were measured in a hydrometallurgical zinc smelter. The removal efficiency of flue gas cleaning, electrostatic demister, mercury reclaiming and acid plant was about 17.4%, 30.3%, 87.9% and 97.4% respectively. Flue gas cleaning and electrostatic demister captured 11.7% and 25.3% of the mercury in the zinc concentrate, respectively. The mercury reclaiming tower captured 58.3% of the mercury in the zinc concentrate. About 4.2% of the mercury in the zinc concentrate was captured by the acid plant. Consequently, only 0.8% of the mercury in the zinc concentrate was emitted to the atmosphere. The atmospheric mercury emission factor was 0.5 g t -1 of zinc produced for the tested smelter, indicating that this process offers the potential to effectively reduce mercury emissions from zinc smelting. - Modern scale production equipped with acid plant and Hg reclaiming tower will significantly reduce Hg emissions from zinc smelters in China.

  13. Health and environmental impact of mercury in the Philippines using nuclear techniques

    International Nuclear Information System (INIS)

    Cortex-Maramba, Nelia; Trinidad Francisco-Rivera, Ana; Manglicmot, Ailyn; Santos, Flora; Akagi, Hirokatsu

    2001-01-01

    Artisanal gold mining activities using mercury has proliferated in various parts of the country since the early 1980's. In Southern Philippines, it is estimated that a small-scale gold processor utilizes one kilogram of mercury every week or an average of fifty-two kgs./yr. Production is estimated at 30 kilograms of gold per day. It has been estimated that 140 tons of mercury flux have been dumped directly into the river systems from small-scale gold mining operations in one of the gold rush areas in the country. Small-scale mining operations have affected tributaries and water systems in the country that also relies heavily on fishing as a source of livelihood as well as the daily food fare among the low-income sectors in the area. Aside from this, cattle livestock and agricultural production have also been affected by these mining activities because of contamination of the irrigation and water systems. Presently, environmental and health monitoring conducted by several government agencies in the recent past were limited to the determination of total mercury only. Previous studies undertaken focused mainly on the exposure of adults and workers to mercury during mining/processing operations. Environmental quality monitoring showed total mercury sediment levels ranged from 0.55 ug/g dry weight while water samples from river systems exhibited mercury levels from 0.0728-0.0784 ppb. Fish samples collected showed levels ranging from 1.07-438.8 ppb for total mercury and 0.71-377.18 ppb for methyl mercury. Methyl mercury content in fish ranged from 56-99%. Laboratory results showed that total mercury hair samples in schoolchildren ranged from 0.278-20.393 ppm while methyl mercury levels were from 0.191-18.469 ppm. Methyl mercury represented 45.96%-99.81% of the total mercury levels in hair. Total blood mercury levels ranged from 0.757-56.88 ppb while methyl mercury blood levels ranged from 1.36-46.73 ppb. Summary of physical examination results showed that predominant

  14. Aggression by Children Exposed to IPV: Exploring the Role of Child Depressive Symptoms, Trauma-Related Symptoms, & Warmth in Family Relationships.

    Science.gov (United States)

    Piotrowski, Caroline C; Cameranesi, Margherita

    2018-06-01

    Multi-informant reports of aggression by siblings in families with and without a history of IPV were compared. Associations between aggressive behavior and child depressive and trauma-related symptoms, as well as maternal and sibling warmth were also explored. Mothers, observers and the siblings themselves reported on aggressive behaviour. Mothers reported on child trauma-related symptoms while children provided self-report on depressive symptoms and mother-child and sibling warmth. The frequency of observed aggression did not differ across groups on average, although more sibling dyads exposed to IPV engaged in aggression than those not exposed. Child reports of sibling aggression did not differ across groups but mothers reported significantly less aggressive behavior by children exposed to IPV than those not exposed. Regression results indicated that depressive and trauma-related symptoms were significant risk factors for aggression, while the role of mother-child and sibling warmth was more complex. Results were discussed within a developmental psychopathology framework.

  15. Exposure to dietary mercury alters cognition and behavior of zebra finches.

    Science.gov (United States)

    Swaddle, John P; Diehl, Tessa R; Taylor, Capwell E; Fanaee, Aaron S; Benson, Jessica L; Huckstep, Neil R; Cristol, Daniel A

    2017-04-01

    Environmental stressors can negatively affect avian cognitive abilities, potentially reducing fitness, for example by altering response to predators, display to mates, or memory of locations of food. We expand on current knowledge by investigating the effects of dietary mercury, a ubiquitous environmental pollutant and known neurotoxin, on avian cognition. Zebra finches Taeniopygia guttata were dosed for their entire lives with sub-lethal levels of mercury, at the environmentally relevant dose of 1.2 parts per million. In our first study, we compared the dosed birds with controls of the same age using tests of three cognitive abilities: spatial memory, inhibitory control, and color association. In the spatial memory assay, birds were tested on their ability to learn and remember the location of hidden food in their cage. The inhibitory control assay measured their ability to ignore visible but inaccessible food in favor of a learned behavior that provided the same reward. Finally, the color association task tested each bird's ability to associate a specific color with the presence of hidden food. Dietary mercury negatively affected spatial memory ability but not inhibitory control or color association. Our second study focused on three behavioral assays not tied to a specific skill or problem-solving: activity level, neophobia, and social dominance. Zebra finches exposed to dietary mercury throughout their lives were subordinate to, and more active than, control birds. We found no evidence that mercury exposure influenced our metric of neophobia. Together, these results suggest that sub-lethal exposure to environmental mercury selectively harms neurological pathways that control different cognitive abilities, with complex effects on behavior and fitness.

  16. Children prenatally exposed to maternal anxiety devote more attentional resources to neutral pictures.

    Science.gov (United States)

    van den Heuvel, Marion I; Henrichs, Jens; Donkers, Franc C L; Van den Bergh, Bea R H

    2017-10-22

    Maternal anxiety during pregnancy can negatively affect fetal neurodevelopment, predisposing the offspring to a higher risk of behavioral and emotional problems later in life. The current study investigates the association between maternal anxiety during pregnancy and child affective picture processing using event-related brain potentials (ERPs). Mothers reported anxiety during the second trimester using the anxiety subscale of the Symptom Checklist (SCL-90). At age 4 years, child affective picture processing (N = 86) was measured by recording ERPs during viewing of neutral, pleasant, and unpleasant pictures selected from the International Affective Pictures System. The late positive potential (LPP)-an ERP component reflecting individual differences in affective processing-was used as child outcome. The expected positive association between maternal anxiety and LPP amplitude for unpleasant pictures was not found. Nevertheless, we found a positive association between maternal anxiety during pregnancy and LPP amplitudes for neutral pictures in the middle and late time window at anterior locations (all p anxiety and gestational age at birth and after FDR correction for multiple comparisons. Our study provides neurophysiological evidence that children prenatally exposed to higher maternal anxiety devote more attentional resources to neutral pictures, but not to unpleasant pictures. Possibly, these children show enhanced vigilance for threat when viewing neutral pictures. Although useful in dangerous environments, this enhanced vigilance may predispose children prenatally exposed to higher maternal anxiety to developing behavioral and/or emotional problems later in life. A video abstract of this article can be viewed at: https://www.youtube.com/watch?v=kEzYi6IS2HA. © 2017 John Wiley & Sons Ltd.

  17. Glutathione level after long-term occupational elemental mercury exposure

    International Nuclear Information System (INIS)

    Kobal, Alfred Bogomir; Prezelj, Marija; Horvat, Milena; Krsnik, Mladen; Gibicar, Darija; Osredkar, Josko

    2008-01-01

    Many in vitro and in vivo studies have elucidated the interaction of inorganic mercury (Hg) and glutathione. However, human studies are limited. In this study, we investigated the potential effects of remote long-term intermittent occupational elemental Hg vapour (Hg o ) exposure on erythrocyte glutathione levels and some antioxidative enzyme activities in ex-mercury miners in the period after exposure. The study included 49 ex-mercury miners divided into subgroups of 28 still active, Hg o -not-exposed miners and 21 elderly retired miners, and 41 controls, age-matched to the miners subgroup. The control workers were taken from 'mercury-free works'. Reduced glutathione (GSH) and oxidized disulphide glutathione (GSSG) concentrations in haemolysed erythrocytes were determined by capillary electrophoresis, while total glutathione (total GSH) and the GSH/GSSG ratio were calculated from the determined values. Catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) activities in erythrocytes were measured using commercially available reagent kits, while urine Hg (U-Hg) concentrations were determined by cold vapour atomic absorption (CVAAS). No correlation of present U-Hg levels, GSH, GSSG, and antioxidative enzymes with remote occupational biological exposure indices were found. The mean CAT activity in miners and retired miners was significantly higher (p o could be an inductive and additive response to maintain the balance between GSH and antioxidative enzymes in interaction with the Hg body burden accumulated during remote occupational exposure, which does not represent a severely increased oxidative stress

  18. Accessibility of Early Infant Diagnostic Services by Under-5 Years and HIV Exposed Children in Muheza District, North-East Tanzania

    Directory of Open Access Journals (Sweden)

    Veneranda M. Bwana

    2018-05-01

    Full Text Available Introduction: Early infant diagnosis (EID of Human Immunodeficiency Virus (HIV provides an opportunity for follow up of HIV exposed children for early detection of infection and timely access to antiretroviral treatment. We assessed predictors for accessing HIV diagnostic services among under-five children exposed to HIV infection in Muheza district, Tanzania.Methods: A cross sectional facility-based study among mother/guardian-child pairs of HIV exposed children was conducted from June 2015 to June 2016. Using a structured questionnaire, we collected information on HIV status, socio-demographic characteristics and other relevant data. Multiple regression analyses were used to investigate associations of potential predictors of accessing EID services.Results: A total of 576 children with their respective mothers/guardians were recruited. Of the 576 mothers/guardians, 549 (95.3% were the biological mothers with a median age of 34 years (inter-quartile range: 30–38 years. The median age of the 576 children was 15 months (inter- quartile range: 8.5–38.0 months. A total of 251 (43.6% children were born to mothers with unknown HIV status at conception. Only 329 (57.1% children accessed EID between 4 and 6 weeks of age. Children born to mothers with unknown HIV status at conception (AOR = 0.6, 95% CI 0.4–0.8 and those with ages 13–59 months (AOR = 0.4, 95% CI 0.2–0.6 were the significant predictors of missed opportunity to access EID. Children living with the head of household with at least a high education level had higher chances of accessing EID (AOR = 1.8, 95% CI 1.1–3.3. Their chances of accessing EID services was three-fold higher among mothers/guardians with good knowledge of HIV infection prevention of mother to child transmission (AOR = 3.2, 95% CI 2.0–5.2 than those with poor knowledge. Mothers/guardians living in rural areas had poorer knowledge of HIV infection prevention of mother to child transmission (AOR = 0.6, 95% CI 0

  19. Is Chelation Therapy Efficient for the Treatment of Intravenous Metallic Mercury Intoxication?

    Czech Academy of Sciences Publication Activity Database

    Pelclová, D.; Vlčková, Š.; Bezdíček, O.; Vaněčková, M.; Urban, P.; Ridzoň, P.; Diblik, P.; Navrátil, Tomáš; Klusáčková, P.; Vlček, K.; Benešová, O.; Třeštík, P.; Homolka, J.; Zakharov, S.

    2017-01-01

    Roč. 120, č. 6 (2017), s. 628-633 ISSN 1742-7835 Institutional support: RVO:61388955 Keywords : elemental mercury * injection * children Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 3.176, year: 2016

  20. Metallic mercury recycling. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Beck, M.A.

    1994-07-01

    Metallic mercury is known to be a hazardous material and is regulated as such. The disposal of mercury, usually by landfill, is expensive and does not remove mercury from the environment. Results from the Metallic Mercury Recycling Project have demonstrated that metallic mercury is a good candidate for reclamation and recycling. Most of the potential contamination of mercury resides in the scum floating on the surface of the mercury. Pinhole filtration was demonstrated to be an inexpensive and easy way of removing residues from mercury. The analysis method is shown to be sufficient for present release practices, and should be sufficient for future release requirements. Data from tests are presented. The consistently higher level of activity of the filter residue versus the bulk mercury is discussed. Recommendations for the recycling procedure are made.

  1. Metallic mercury recycling. Final report

    International Nuclear Information System (INIS)

    Beck, M.A.

    1994-01-01

    Metallic mercury is known to be a hazardous material and is regulated as such. The disposal of mercury, usually by landfill, is expensive and does not remove mercury from the environment. Results from the Metallic Mercury Recycling Project have demonstrated that metallic mercury is a good candidate for reclamation and recycling. Most of the potential contamination of mercury resides in the scum floating on the surface of the mercury. Pinhole filtration was demonstrated to be an inexpensive and easy way of removing residues from mercury. The analysis method is shown to be sufficient for present release practices, and should be sufficient for future release requirements. Data from tests are presented. The consistently higher level of activity of the filter residue versus the bulk mercury is discussed. Recommendations for the recycling procedure are made

  2. Mercury(II) and methyl mercury speciation on Streptococcus pyogenes loaded Dowex Optipore SD-2

    International Nuclear Information System (INIS)

    Tuzen, Mustafa; Uluozlu, Ozgur Dogan; Karaman, Isa; Soylak, Mustafa

    2009-01-01

    A solid phase extraction procedure based on speciation of mercury(II) and methyl mercury on Streptococcus pyogenes immobilized on Dowex Optipore SD-2 has been established. Selective and sequential elution with 0.1 mol L -1 HCl for methyl mercury and 2 mol L -1 HCl for mercury(II) were performed at pH 8. The determination of mercury levels was performed by cold vapour atomic absorption spectrometry (CVAAS). Optimal analytical conditions including pH, amounts of biosorbent, sample volumes, etc., were investigated. The influences of the some alkaline and earth alkaline ions and some transition metals on the recoveries were also investigated. The capacity of biosorbent for mercury(II) and methyl mercury was 4.8 and 3.4 mg g -1 . The detection limit (3 sigma) of the reagent blank for mercury(II) and methyl mercury was 2.1 and 1.5 ng L -1 . Preconcentration factor was calculated as 25. The relative standard deviations of the procedure were below 7%. The validation of the presented procedure is performed by the analysis of standard reference material (NRCC-DORM 2 Dogfish Muscle). The procedure was successfully applied to the speciation of mercury(II) and methyl mercury in natural water and environmental samples.

  3. Mercury(II) and methyl mercury speciation on Streptococcus pyogenes loaded Dowex Optipore SD-2

    Energy Technology Data Exchange (ETDEWEB)

    Tuzen, Mustafa, E-mail: m.tuzen@gmail.com [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey); Uluozlu, Ozgur Dogan [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey); Karaman, Isa [Gaziosmanpasa University, Faculty of Science and Arts, Biology Department, 60250 Tokat (Turkey); Soylak, Mustafa [Erciyes University, Faculty of Science and Arts, Chemistry Department, 38039 Kayseri (Turkey)

    2009-09-30

    A solid phase extraction procedure based on speciation of mercury(II) and methyl mercury on Streptococcus pyogenes immobilized on Dowex Optipore SD-2 has been established. Selective and sequential elution with 0.1 mol L{sup -1} HCl for methyl mercury and 2 mol L{sup -1} HCl for mercury(II) were performed at pH 8. The determination of mercury levels was performed by cold vapour atomic absorption spectrometry (CVAAS). Optimal analytical conditions including pH, amounts of biosorbent, sample volumes, etc., were investigated. The influences of the some alkaline and earth alkaline ions and some transition metals on the recoveries were also investigated. The capacity of biosorbent for mercury(II) and methyl mercury was 4.8 and 3.4 mg g{sup -1}. The detection limit (3 sigma) of the reagent blank for mercury(II) and methyl mercury was 2.1 and 1.5 ng L{sup -1}. Preconcentration factor was calculated as 25. The relative standard deviations of the procedure were below 7%. The validation of the presented procedure is performed by the analysis of standard reference material (NRCC-DORM 2 Dogfish Muscle). The procedure was successfully applied to the speciation of mercury(II) and methyl mercury in natural water and environmental samples.

  4. Spatial trends in leaf size of Amazonian rainforest trees

    Science.gov (United States)

    Malhado, A. C. M.; Malhi, Y.; Whittaker, R. J.; Ladle, R. J.; Ter Steege, H.; Phillips, O. L.; Butt, N.; Aragão, L. E. O. C.; Quesada, C. A.; Araujo-Murakami, A.; Arroyo, L.; Peacock, J.; Lopez-Gonzalez, G.; Baker, T. R.; Anderson, L. O.; Almeida, S.; Higuchi, N.; Killeen, T. J.; Monteagudo, A.; Neill, D.; Pitman, N.; Prieto, A.; Salomão, R. P.; Vásquez-Martínez, R.; Laurance, W. F.

    2009-08-01

    Leaf size influences many aspects of tree function such as rates of transpiration and photosynthesis and, consequently, often varies in a predictable way in response to environmental gradients. The recent development of pan-Amazonian databases based on permanent botanical plots has now made it possible to assess trends in leaf size across environmental gradients in Amazonia. Previous plot-based studies have shown that the community structure of Amazonian trees breaks down into at least two major ecological gradients corresponding with variations in soil fertility (decreasing from southwest to northeast) and length of the dry season (increasing from northwest to south and east). Here we describe the geographic distribution of leaf size categories based on 121 plots distributed across eight South American countries. We find that the Amazon forest is predominantly populated by tree species and individuals in the mesophyll size class (20.25-182.25 cm2). The geographic distribution of species and individuals with large leaves (>20.25 cm2) is complex but is generally characterized by a higher proportion of such trees in the northwest of the region. Spatially corrected regressions reveal weak correlations between the proportion of large-leaved species and metrics of water availability. We also find a significant negative relationship between leaf size and wood density.

  5. Risk factors as moderators of recovery during and after interventions for children exposed to interparental violence

    NARCIS (Netherlands)

    Overbeek, M.M.; de Schipper, J.C.; Lamers-Winkelman, F.; Schuengel, C.

    2014-01-01

    High family risk was tested as an impediment to recovery in children exposed to interparental violence (IPV) participating in community-based intervention. Characteristics of IPV were also explored as moderators for the effect of an IPV-focused intervention over a common factors intervention.

  6. 77 FR 39264 - Meeting of the Attorney General's National Task Force on Children Exposed to Violence

    Science.gov (United States)

    2012-07-02

    ... research; and extensive input from experts, advocates, and impacted families and communities nationwide... Juvenile Justice & Delinquency Prevention, Office of Justice Programs, 810 7th Street NW., Washington, DC... Force on Children Exposed to Violence DFO, Office of Juvenile Justice and Delinquency Prevention, Office...

  7. Thiosulphate assisted phytoextraction of mercury contaminated soils at the Wanshan Mercury Mining District, Southwest China

    Directory of Open Access Journals (Sweden)

    J. Wang

    2013-10-01

    Full Text Available Wanshan, known as the “Mercury Capital” of China, is located in the Southwest of China. Due to the extensive mining and smelting works in the Wanshan area, the local ecosystem has been serious contaminated with mercury. In the present study, a number of soil samples were taken from the Wanshan mercury mining area and the mercury fractionations in soils were analyzed using sequential extraction procedure technique. The obtained results showed that the dominate mercury fractions (represent 95% of total mercury were residual and organic bound mercury. A field trial was conducted in a mercury polluted farmland at the Wanshan mercury mine. Four plant species Brassica juncea Czern. et Coss.var. ASKYC (ASKYC, Brassica juncea Czern. et Coss.var.DPDH (DPDH, Brassica juncea Czern. et Coss.var.CHBD(CHBD, Brassica juncea Czern. et Coss.var.LDZY (LDZY were tested their ability to extract mercury from soil with thiosulphate amendment. The results indicated that the mercury concentration in the roots and shoots of the four plants were significantly increased with thiosulphate treatment. The mercury phytoextraction yield of ASKYC, DPDH, CHBD and LDZY were 92, 526, 294 and 129 g/ha, respectively

  8. Thiosulphate assisted phytoextraction of mercury contaminated soils at the Wanshan Mercury Mining District, Southwest China

    Directory of Open Access Journals (Sweden)

    J Wang

    2013-10-01

    Full Text Available Wanshan, known as the “Mercury Capital” of China, is located in the Southwest of China. Due to the extensive mining and smelting works in the Wanshan area, the local ecosystem has been serious contaminated with mercury. In the present study, a number of soil samples were taken from the Wanshan mercury mining area and the mercury fractionations in soils were analyzed using sequential extraction procedure technique. The obtained results showed that the dominate mercury fractions (represent 95% of total mercury were residual and organic bound mercury. A field trial was conducted in a mercury polluted farmland at the Wanshan mercury mine. Four plant species Brassica juncea Czern. et Coss.var. ASKYC (ASKYC, Brassica juncea Czern. et Coss.var.DPDH (DPDH, Brassica juncea Czern. et Coss.var.CHBD(CHBD, Brassica juncea Czern. et Coss.var.LDZY (LDZY were tested their ability to extract mercury from soil with thiosulphate amendment. The results indicated that the mercury concentration in the roots and shoots of the four plants were significantly increased with thiosulphate treatment. The mercury phytoextraction yield of ASKYC, DPDH, CHBD and LDZY were 92, 526, 294 and 129 g/ha, respectively.

  9. Evaluation of urine mercury level of dentists in Tehran and its influencial factors

    Directory of Open Access Journals (Sweden)

    Tabatabaei M.

    2006-08-01

    Full Text Available Background and Aim: Dentists are exposed to mercury from dental amalgam in their routine occupational practice. Excess exposure to mercury is harmful and the measurement of mercury content of urine is a reliable and valid assessment of the level of mercury exposure from dental amalgam. The aim of this study was the measurement of urine mercury in dentists of Tehran and assessment of some possible related factors. Materials and Methods: This cross-sectional study was performed randomly on 211 dentists in all regions in Tehran city (center, north, south, west, and east between 1381 and 1383. Dentists were asked to give a sample of urine in the day of visit and to complete a questionnaire consisting of variables such as age, working history, handling of amalgam, environmental parameters and general health situation. Urine samples were analyzed by cold vapour atomic absorption spectrophotometry. Data were analyzed by Kruskall Walis, Kendall and Mann Whitney tests, with p<0.05 as the limit of significance. Results: The mean of urine mercury content in Tehran dentists was 3.1 (± 3.95 which was lower than the international TLV (Threshold Limit Value. There was a significant relation between urine mercury level and working hours per day (P=0.006. This relation was observed with working hours per week too (P=0.006. In general dentists, there was a positive relation between urine mercury and age (0.008 as well as the practicing years (P=0.034. A significant relation was found between urine mercury and the number of amalgam repairs and replacements in restorative specialists (p=0.039. There was a significant relation between the number of amalgam fillings in the mouth and urine mercury in general practitioners (p=0.027. The type of amalgam (predosed capsules or bulk powder had a significant effect on the urine mercury content (P=0.001. There was no significant relation between urine mercury and other variables of the study such as the squeezing of

  10. Mercury CEM Calibration

    Energy Technology Data Exchange (ETDEWEB)

    John Schabron; Joseph Rovani; Mark Sanderson

    2008-02-29

    Mercury continuous emissions monitoring systems (CEMS) are being implemented in over 800 coal-fired power plant stacks. The power industry desires to conduct at least a full year of monitoring before the formal monitoring and reporting requirement begins on January 1, 2009. It is important for the industry to have available reliable, turnkey equipment from CEM vendors. Western Research Institute (WRI) is working closely with the Electric Power Research Institute (EPRI), the National Institute of Standards and Technology (NIST), and the Environmental Protection Agency (EPA) to facilitate the development of the experimental criteria for a NIST traceability protocol for dynamic elemental mercury vapor generators. The generators are used to calibrate mercury CEMs at power plant sites. The Clean Air Mercury Rule (CAMR) which was published in the Federal Register on May 18, 2005 requires that calibration be performed with NIST-traceable standards (Federal Register 2007). Traceability procedures will be defined by EPA. An initial draft traceability protocol was issued by EPA in May 2007 for comment. In August 2007, EPA issued an interim traceability protocol for elemental mercury generators (EPA 2007). The protocol is based on the actual analysis of the output of each calibration unit at several concentration levels ranging initially from about 2-40 {micro}g/m{sup 3} elemental mercury, and in the future down to 0.2 {micro}g/m{sup 3}, and this analysis will be directly traceable to analyses by NIST. The document is divided into two separate sections. The first deals with the qualification of generators by the vendors for use in mercury CEM calibration. The second describes the procedure that the vendors must use to certify the generator models that meet the qualification specifications. The NIST traceable certification is performance based, traceable to analysis using isotope dilution inductively coupled plasma/mass spectrometry performed by NIST in Gaithersburg, MD. The

  11. Phenolic constituents and antioxidant activity of geopropolis from two species of amazonian stingless bees

    International Nuclear Information System (INIS)

    Silva, Ellen Cristina Costa da; Muniz, Magno Perêa; Nunomura, Rita de Cássia Saraiva; Nunomura, Sergio Massayoshi; Zilse, Gislene Almeida Carvalho

    2013-01-01

    We investigated the phenolic constituents and antioxidant activity of geopropolis from two species of stingless Amazonian bees, Melipona interrupta and Melipona seminigra. The chemical investigation of geopropolis from Melipona interrupta led to the isolation of 5,7,4’-trihydroxyflavonone, 3,5,6,7,4’-pentahydroxyflavonol, naringenine-4’-O-β-D-glucopyranoside and myricetin-3-O-β-D-glucopyranoside. Their structures were assigned based on spectroscopic analyses, including two-dimensional NMR techniques. Antioxidant activity of methanol and ethanol extracts of M. interrupta and M. seminigra were measured using the 1,2-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging assay. This is also the first work reporting the chemical investigation of stingless bee species from the Amazonian region. (author)

  12. Phenolic constituents and antioxidant activity of geopropolis from two species of amazonian stingless bees

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ellen Cristina Costa da; Muniz, Magno Perea; Nunomura, Rita de Cassia Saraiva, E-mail: ellensilva@yahoo.com.br [Departamento de Quimica, Instituto de Ciencias Exatas, Universidade Federal do Amazonas, Manaus, AM (Brazil); Nunomura, Sergio Massayoshi [Departamento de Produtos Naturais, Instituto Nacional de Pesquisas da Amazonia, Manaus, AM (Brazil); Zilse, Gislene Almeida Carvalho [Departamento de Biodiversidade, Instituto Nacional de Pesquisas da Amazonia, Manaus, AM (Brazil)

    2013-09-01

    We investigated the phenolic constituents and antioxidant activity of geopropolis from two species of stingless Amazonian bees, Melipona interrupta and Melipona seminigra. The chemical investigation of geopropolis from Melipona interrupta led to the isolation of 5,7,4'-trihydroxyflavonone, 3,5,6,7,4'-pentahydroxyflavonol, naringenine-4'-O-{beta}-D-glucopyranoside and myricetin-3-O-{beta}-D-glucopyranoside. Their structures were assigned based on spectroscopic analyses, including two-dimensional NMR techniques. Antioxidant activity of methanol and ethanol extracts of M. interrupta and M. seminigra were measured using the 1,2-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging assay. This is also the first work reporting the chemical investigation of stingless bee species from the Amazonian region. (author)

  13. A new Amazonian species from the Drosophila annulimana species group (Diptera, Drosophilidae

    Directory of Open Access Journals (Sweden)

    Marco S. Gottschalk

    2012-12-01

    Full Text Available Drosophila caxiuana sp. nov., Drosophila subgenus, is described and illustrated. This new species was collected in the Amazonian Biome (Caquajó river, Portel, Pará, Brazil and is an atypical species to the group due the unusual morphology of the male terminalia.

  14. Accumulation of mercury in selected plant species grown in soils contaminated with different mercury compounds

    International Nuclear Information System (INIS)

    Su, Yi; Han, Fengxiang; Shiyab, Safwan; Chen, Jian; Monts, David L.

    2007-01-01

    The objective of our research is to screen and search for suitable plant species for phyto-remediation of mercury-contaminated soil. Currently our effort is specifically focused on mercury removal from the U.S. Department of Energy (DOE) sites, where mercury contamination is a major concern. In order to cost effectively implement mercury remediation efforts, it is necessary now to obtain an improved understanding of biological means of removing mercury and mercury compounds.. Phyto-remediation is a technology that uses various plants to degrade, extract, contain, or immobilize contaminants from soil and water. In particular, phyto-extraction is the uptake of contaminants by plant roots and translocation within the plants to shoots or leaves. Contaminants are generally removed by harvesting the plants. We have investigated phyto-extraction of mercury from contaminated soil by using some of the known metal-accumulating plants since no natural plant species with mercury hyper-accumulating properties has yet been identified. Different natural plant species have been studied for mercury uptake, accumulation, toxicity and overall mercury removal efficiency. Various mercury compounds, such as HgS, HgCl 2 , and Hg(NO 3 ) 2 , were used as contaminant sources. Different types of soil were examined and chosen for phyto-remediation experiments. We have applied microscopy and diffuse reflectance spectrometry as well as conventional analytical chemistry to monitor the phyto-remediation processes of mercury uptake, translocation and accumulation, and the physiological impact of mercury contaminants on selected plant species. Our results indicate that certain plant species, such as beard grass (Polypogon monospeliensis), accumulated a very limited amount of mercury in the shoots ( 2 powder, respectively; no visual stress symptoms were observed. We also studied mercury phyto-remediation using aged soils that contained HgS, HgCl 2 , or Hg(NO 3 ) 2 . We have found that up to hundreds

  15. Mercury and selenium in European catfish (Silurus glanis) from Northern Italian Rivers: can molar ratio be a predictive factor for mercury toxicity in a top predator?

    Science.gov (United States)

    Squadrone, S; Benedetto, A; Brizio, P; Prearo, M; Abete, M C

    2015-01-01

    The study of mercury and selenium bioaccumulation in fish is crucially important for evaluating the extent of contamination in freshwater environments, and the possible health risk posed for humans when the antagonistic interactions of these two elements are considered. Several factors affect the risk of mercury intake from fish consumption, including mercury levels, human consumption patterns, and sensitive populations (e.g., pregnant women, foetuses, young children and unknown genetic factors). The protective effects of selenium on mercury toxicity have been extensively publicised in recent years, particularly targeting fish consumers. In this study, mercury (Hg) and selenium (Se) concentrations were determined in the muscle of European catfish (Silurus glanis) collected from North Italian Rivers. Differences in mercury and selenium levels, as a function of size, gender and location were investigated. Hg was strongly related to length, gender and location, while Se levels are not dependent on fish size or location. The mean Se/Hg molar ratio was strongly affected by location, and significantly related to length and age. Selenium was in molar excess of mercury in all sites, with a rank order of mean Se/Hg molar ratio of the Parma River (2.55)>Po River (1.71)>Tanaro River (1.66)>Bormida River (1.36). However, in 37% of analyzed samples, Hg exceeded the maximum level set by 1881/2006/EC and 629/2008/EC in fish muscle. The molar ratio of Se/Hg was 0.5mg/kg), and therefore the mean molar ratio cannot be considered as a safety criterion in top predator fish. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. A search for mutations affecting protein structure in children of proximally and distally exposed atomic bomb survivors

    International Nuclear Information System (INIS)

    Neel, J.V.; Satoh, Chiyoko; Hamilton, H.B.; Otake, Masanori; Goriki, Kazuaki; Kageoka, Takeshi; Fujita, Mikio; Neriishi, Shotaro; Asakawa, Jun-ichi.

    1981-07-01

    A total of 289,868 locus tests based on 28 different protein phenotypes, employing one-dimensional electrophoresis to detect variant proteins, has yielded one probable mutation in the offspring of 'proximally exposed' parents, who received an estimated average gonadal exposure dose of between 31 and 39 rem from the atomic bombs in Hiroshima and Nagasaki. There were no mutations in 208,196 locus tests involving children of 'distally exposed' parents, who had essentially no radiation exposure. (author)

  17. Applicability of two mobile analysers for mercury in urine in small-scale gold mining areas.

    Science.gov (United States)

    Baeuml, Jennifer; Bose-O'Reilly, Stephan; Lettmeier, Beate; Maydl, Alexandra; Messerer, Katalin; Roider, Gabriele; Drasch, Gustav; Siebert, Uwe

    2011-12-01

    Mercury is still used in developing countries to extract gold from the ore in small-scale gold mining areas. This is a major health hazard for people living in mining areas. The concentration of mercury in urine was analysed in different mining areas in Zimbabwe, Indonesia and Tanzania. First the urine samples were analysed by CV-AAS (cold vapour atomic absorption spectrometry) during the field projects with a mobile mercury analyser (Lumex(®) or Seefelder(®)) and secondly, in a laboratory with a stationary CV-AAS mercury analyser (PerkinElmer(®)). Caused by the different systems (reduction agent either SnCl(2) (Lumex(®) or Seefelder(®))) or NaBH(4) (PerkinElmer(®)), with the mobile analysers only the inorganic mercury was obtained and with the stationary system the total mercury concentration was measured. The aims of the study were whether the results obtained in field with the mobile equipments can be compared with the stationary reference method in the laboratory and allow the application of these mobile analysers in screening studies on concerned populations to select those, who are exposed to critical mercury levels. Overall, the concentrations obtained with the two mobile systems were approximately 25% lower than determined with the stationary system. Nevertheless, both mobile systems seem to be very useful for screening of volunteers in field. Moreover, regional staff may be trained on such analysers to perform screening tests by themselves. Copyright © 2011 Elsevier GmbH. All rights reserved.

  18. Methyl mercury, but not inorganic mercury, associated with higher blood pressure during pregnancy.

    Science.gov (United States)

    Wells, Ellen M; Herbstman, Julie B; Lin, Yu Hong; Hibbeln, Joseph R; Halden, Rolf U; Witter, Frank R; Goldman, Lynn R

    2017-04-01

    Prior studies addressing associations between mercury and blood pressure have produced inconsistent findings; some of this may result from measuring total instead of speciated mercury. This cross-sectional study of 263 pregnant women assessed total mercury, speciated mercury, selenium, and n-3 polyunsaturated fatty acids in umbilical cord blood and blood pressure during labor and delivery. Models with a) total mercury or b) methyl and inorganic mercury were evaluated. Regression models adjusted for maternal age, race/ethnicity, prepregnancy body mass index, neighborhood income, parity, smoking, n-3 fatty acids and selenium. Geometric mean total, methyl, and inorganic mercury concentrations were 1.40µg/L (95% confidence interval: 1.29, 1.52); 0.95µg/L (0.84, 1.07); and 0.13µg/L (0.10, 0.17), respectively. Elevated systolic BP, diastolic BP, and pulse pressure were found, respectively, in 11.4%, 6.8%, and 19.8% of mothers. In adjusted multivariable models, a one-tertile increase of methyl mercury was associated with 2.83mmHg (0.17, 5.50) higher systolic blood pressure and 2.99mmHg (0.91, 5.08) higher pulse pressure. In the same models, an increase of one tertile of inorganic mercury was associated with -1.18mmHg (-3.72, 1.35) lower systolic blood pressure and -2.51mmHg (-4.49, -0.53) lower pulse pressure. No associations were observed with diastolic pressure. There was a non-significant trend of higher total mercury with higher systolic blood pressure. We observed a significant association of higher methyl mercury with higher systolic and pulse pressure, yet higher inorganic mercury was significantly associated with lower pulse pressure. These results should be confirmed with larger, longitudinal studies. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Elemental Impurities in Nigerian Pediatric Syrups: Mercury in Violation of Standard Guidelines.

    Science.gov (United States)

    Orisakwe, Orish Ebere; Roberts, Irosanga Itamuno; Bagbi, Baribefe Monday

    2016-01-01

    Studies on the human exposure to elemental impurities like antimony, tin, and mercury pharmaceutical products in the African environment are scarce and limited. In this study, we determined the concentrations of these elemental impurities in 28 different brands of commonly used pediatric syrups, purchased randomly from patent medicine retail outlets in Port Harcourt, Rivers State, Nigeria. The aim of this study was to compare the antimony, tin, and mercury levels in these pediatric syrups with the recommended limits of United States Pharmacopeia. Twenty-eight different pediatric syrups were randomly sampled and purchased using the market basket protocol from pharmacy shops in Port Harcourt, Rivers State, Nigeria in December 2010. Syrups were ashed before digestion using concentrated aqua regia, HCl: HNO3 (3:1), and antimony, tin, and mercury were analyzed using Unicam Atomic Absorption Spectrophotometer (AAS) Model 929. The ranges of heavy metal content in these pediatric syrups were 0.54-1.27, 0.86-2.56, and 0.97-5.13 μg/g for antimony, tin, and mercury, respectively. About 75% of the syrups exceeded the United States Pharmacopeia mercury limit of 1.5 μg/g. The estimated or calculated amounts of antimony, tin, and mercury in the 3 most likely administered syrups were 17.15, 64.20, and 34.60 μg of antimony, tin, and mercury, respectively. The daily intake or estimated amount from the ingestion of syrups excluding background exposure (μg metal·kg body weight·d) for a 15-kg child were 1.17, 2.31, and 4.28 for antimony, tin, and mercury, respectively. Mercury content in pediatric syrups may constitute a significant source of heavy metal exposure to children and may be of public health importance in Nigeria.

  20. Mercury and halogens in coal--Their role in determining mercury emissions from coal combustion

    Science.gov (United States)

    Kolker, Allan; Quick, Jeffrey C.; Senior, Connie L.; Belkin, Harvey E.

    2012-01-01

    Mercury is a toxic pollutant. In its elemental form, gaseous mercury has a long residence time in the atmosphere, up to a year, allowing it to be transported long distances from emission sources. Mercury can be emitted from natural sources such as volcanoes, or from anthropogenic sources, such as coal-fired powerplants. In addition, all sources of mercury on the Earth's surface can re-emit it from land and sea back to the atmosphere, from which it is then redeposited. Mercury in the atmosphere is present in such low concentrations that it is not considered harmful. Once mercury enters the aquatic environment, however, it can undergo a series of biochemical transformations that convert a portion of the mercury originally present to methylmercury, a highly toxic organic form of mercury that accumulates in fish and birds. Many factors contribute to creation of methylmercury in aquatic ecosystems, including mercury availability, sediment and nutrient load, bacterial influence, and chemical conditions. In the United States, consumption of fish with high levels of methylmercury is the most common pathway for human exposure to mercury, leading the U.S. Environmental Protection Agency (EPA) to issue fish consumption advisories in every State. The EPA estimates that 50 percent of the mercury entering the atmosphere in the United States is emitted from coal-burning utility powerplants. An EPA rule, known as MATS (for Mercury and Air Toxics Standards), to reduce emissions of mercury and other toxic pollutants from powerplants, was signed in December 2011. The rule, which is currently under review, specifies limits for mercury and other toxic elements, such as arsenic, chromium, and nickel. MATS also places limits on emission of harmful acid gases, such as hydrochloric acid and hydrofluoric acid. These standards are the result of a 2010 detailed nationwide program by the EPA to sample stack emissions and thousands of shipments of coal to coal-burning powerplants. The United

  1. Modeling Mercury in Proteins

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Jeremy C [ORNL; Parks, Jerry M [ORNL

    2016-01-01

    Mercury (Hg) is a naturally occurring element that is released into the biosphere both by natural processes and anthropogenic activities. Although its reduced, elemental form Hg(0) is relatively non-toxic, other forms such as Hg2+ and, in particular, its methylated form, methylmercury, are toxic, with deleterious effects on both ecosystems and humans. Microorganisms play important roles in the transformation of mercury in the environment. Inorganic Hg2+ can be methylated by certain bacteria and archaea to form methylmercury. Conversely, bacteria also demethylate methylmercury and reduce Hg2+ to relatively inert Hg(0). Transformations and toxicity occur as a result of mercury interacting with various proteins. Clearly, then, understanding the toxic effects of mercury and its cycling in the environment requires characterization of these interactions. Computational approaches are ideally suited to studies of mercury in proteins because they can provide a detailed picture and circumvent issues associated with toxicity. Here we describe computational methods for investigating and characterizing how mercury binds to proteins, how inter- and intra-protein transfer of mercury is orchestrated in biological systems, and how chemical reactions in proteins transform the metal. We describe quantum chemical analyses of aqueous Hg(II), which reveal critical factors that determine ligand binding propensities. We then provide a perspective on how we used chemical reasoning to discover how microorganisms methylate mercury. We also highlight our combined computational and experimental studies of the proteins and enzymes of the mer operon, a suite of genes that confers mercury resistance in many bacteria. Lastly, we place work on mercury in proteins in the context of what is needed for a comprehensive multi-scale model of environmental mercury cycling.

  2. A dose-effect analysis of children's exposure to dental amalgam and neuropsychological function: the New England Children's Amalgam Trial.

    Science.gov (United States)

    Bellinger, David C; Trachtenberg, Felicia; Daniel, David; Zhang, Annie; Tavares, Mary A; McKinlay, Sonja

    2007-09-01

    The New England Children's Amalgam Trial (NECAT) was a five-year randomized trial of 534 6- to 10-year-old children that compared the neuropsychological outcomes of those whose caries were restored using dental amalgam with the outcomes of those those whose caries were restored using mercury-free resin-based composite. The primary intention-to-treat analyses did not reveal significant differences between the treatment groups on the primary or secondary outcomes of the administered psychological tests: Full-Scale IQ score on the Wechsler Intelligence Scale for Children-Third Edition, General Memory Index of the Wide Range Assessment of Memory and Learning, and Visual-Motor Composite of the Wide Range Assessment of Visual Motor Abilities. To determine whether treatment group assignment, a dichotomous measure of exposure, was sufficiently sensitive to detect associations between mercury exposure and these outcomes, the authors conducted analyses to evaluate the associations between the primary and secondary outcomes and two continuously distributed indexes of potential exposure, surface-years of amalgam and urinary mercury excretion. Neither index of mercury exposure was significantly associated with any of the three outcomes. The authors found no evidence that exposure to mercury from dental amalgam was associated with any adverse neuropsychological effects over the five-year period after placement of amalgam restorations. Analyses of the outcomes of the NECAT study indicate that use of dental amalgam was not associated with an increase in children's risk of experiencing neuropsychological dysfunction.

  3. Diminished Mercury Emission From Water Surfaces by Duckweed (Lemna minor)

    Science.gov (United States)

    Wollenberg, J. L.; Peters, S. C.

    2007-12-01

    Aquatic plants of the family Lemnaceae (generally referred to as duckweeds) are a widely distributed type of floating vegetation in freshwater systems. Under suitable conditions, duckweeds form a dense vegetative mat on the water surface, which reduces light penetration into the water column and decreases the amount of exposed water surface. These two factors would be expected to reduce mercury emission by limiting a) direct photoreduction of Hg(II), b) indirect reduction via coupled DOC photooxidation-Hg(II) reduction, and c) gas diffusion across the water-air interface. Conversely, previous studies have demonstrated transpiration of Hg(0) by plants, so it is therefore possible that the floating vegetative mat would enhance emission via transpiration of mercury vapor. The purpose of this experiment was to determine whether duckweed limits mercury flux to the atmosphere by shading and the formation of a physical barrier to diffusion, or whether it enhances emission from aquatic systems via transpiration of Hg(0). Deionized water was amended with mercury to achieve a final concentration of approximately 35 ng/L and allowed to equilibrate prior to the experiment. Experiments were conducted in rectangular polystyrene flux chambers with measured UV-B transmittance greater than 60% (spectral cutoff approximately 290 nm). Light was able to penetrate the flux chamber from the sides as well as the top throughout the experiment, limiting the effect of shading by duckweed on the water surface. Flux chambers contained 8L of water with varying percent duckweed cover, and perforated plastic sheeting was used as an abiotic control. Exposures were conducted outside on days with little to no cloud cover. Real time mercury flux was measured using atomic absorption (Mercury Instruments UT-3000). Total solar and ultraviolet radiation, as well as a suite of meteorological parameters, were also measured. Results indicate that duckweed diminishes mercury emission from the water surface

  4. Mercury is Moon's brother

    International Nuclear Information System (INIS)

    Ksanfomalifi, L.V.

    1976-01-01

    The latest information on Mercury planet is presented obtained by studying the planet with the aid of radar and space vehicles. Rotation of Mercury about its axis has been discovered; within 2/3 of its year it executes a complete revolution about its axis. In images obtained by the ''Mariner-10'' Mercurys surface differs little from that of the Moon. The ''Mariner-10'' has also discovered the Mercurys atmosphere, which consists of extremely rarefied helium. The helium is continuously supplied to the planet by the solar wind. The Mercury's magnetic field has been discovered, whose strength is 35 x 10 -4 at the Equator and 70 x 10 -4 E at the poles. The inclination of the dipole axis to the Mercury's rotation axis is 7 deg

  5. Mercury nano-trap for effective and efficient removal of mercury(II) from aqueous solution

    Science.gov (United States)

    Li, Baiyan; Zhang, Yiming; Ma, Dingxuan; Shi, Zhan; Ma, Shengqian

    2014-11-01

    Highly effective and highly efficient decontamination of mercury from aqueous media remains a serious task for public health and ecosystem protection. Here we report that this task can be addressed by creating a mercury ‘nano-trap’ as illustrated by functionalizing a high surface area and robust porous organic polymer with a high density of strong mercury chelating groups. The resultant porous organic polymer-based mercury ‘nano-trap’ exhibits a record-high saturation mercury uptake capacity of over 1,000 mg g-1, and can effectively reduce the mercury(II) concentration from 10 p.p.m. to the extremely low level of smaller than 0.4 p.p.b. well below the acceptable limits in drinking water standards (2 p.p.b.), and can also efficiently remove >99.9% mercury(II) within a few minutes. Our work therefore presents a new benchmark for mercury adsorbent materials and provides a new perspective for removing mercury(II) and also other heavy metal ions from contaminated water for environmental remediation.

  6. Environmental costs of mercury pollution

    Energy Technology Data Exchange (ETDEWEB)

    Hylander, Lars D. [Department of Earth Sciences, Air and Water Science, Uppsala University, Villavaegen 16, S-752 36 Uppsala (Sweden); Goodsite, Michael E. [Department of Chemistry, Environmental Chemistry Research Group, University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark)

    2006-09-01

    Mercury (Hg) has been used for millennia in many applications, primarily in artisanal mining and as an electrode in the chlor-alkali industry. It is anthropogenically emitted as a pollutant from coal fired power plants and naturally emitted, primarily from volcanoes. Its unique chemical characteristics enable global atmospheric transport and it is deposited after various processes, ultimately ending up in one of its final sinks, such as incorporated into deep sediment or bioaccumulated, primarily in the marine environment. All forms of Hg have been established as toxic, and there have been no noted biological benefits from the metal. Throughout time, there have been notable incidents of Hg intoxication documented, and the negative health effects have been documented to those chronically or acutely exposed. Today, exposure to Hg is largely diet or occupationally dependent, however, many are exposed to Hg from their amalgam fillings. This paper puts a tentative monetary value on Hg polluted food sources in the Arctic, where local, significant pollution sources are limited, and relates this to costs for strategies avoiding Hg pollution and to remediation costs of contaminated sites in Sweden and Japan. The case studies are compiled to help policy makers and the public to evaluate whether the benefits to the global environment from banning Hg and limiting its initial emission outweigh the benefits from its continued use or lack of control of Hg emissions. The cases we studied are relevant for point pollution sources globally and their remediation costs ranged between 2500 and 1.1 million US$ kg{sup -1} Hg isolated from the biosphere. Therefore, regulations discontinuing mercury uses combined with extensive flue gas cleaning for all power plants and waste incinerators is cost effective. (author)

  7. The development of the Amazonian mega-wetland (Miocene; Brazil, Colombia, Peru, Bolivia)

    NARCIS (Netherlands)

    Hoorn, C.; Wesselingh, F.P.; Hovikoski, J.; Guerrero, J.; Hoorn, C.; Wesselingh, F.P.

    2010-01-01

    The scenery of Western Amazonia once consisted of fluvial systems that originated on the Amazonian Craton and were directed towards the sub-Andean zone and the Caribbean. In the course of the Early Miocene these fluvial systems were largely replaced by lakes, swamps, tidal channels and marginal

  8. Isotopes as validation tools for predictions of the impact of Amazonian deforestation on climate and regional hydrology

    International Nuclear Information System (INIS)

    Henderson-Sellers, A.; Chambers, S.; McGuffie, K.

    2002-01-01

    Isotopic analysis and modelling of the Amazon Basin have both been reported for about thirty years. Isotopic data have been used to explain important characteristics of Amazonian hydrologic cycling by means of simple models. To date there has been no attempt to use isotopic data to evaluate global climate models employed to predict the possible impacts of Amazonian deforestation. This paper reviews the history of isotopic analysis and simulations of deforestation in the Amazon and initiates isotopic evaluation of GCMs. It is shown that one widely reported simulation set gives seasonal transpiration and re-evaporated canopy interception budgets different from those derived from isotopic analysis. It is found that temporal changes (1965 to 1990) in wet season deuterium excess differences between Belem and Manaus are consistent with GCM results only if there has been a relative increase in evaporation from non-fractionating water sources over this period. We propose synergistic future interactions among the climate/hydrological modelling and isotopic analysis communities in order to improve confidence in simulations of Amazonian deforestation. (author)

  9. In vitro regeneration of Amazonian pineapple (Ananas comosus plants ecotype Gobernadora

    Directory of Open Access Journals (Sweden)

    Héctor Alexander Blanco Flores

    2017-01-01

    Full Text Available There are a number of pineapple (Ananas comosus cultivars and ecotypes of local commercial importance in Venezuela, among them the Amazonian ones, cultivated mainly by the aboriginal Piaroa, are of relevance. They sow the propagules, which restricts the availability of material for large-scale cultivation. This limitation was approached by plant tissue culture for in vitro propagation of Amazonian pineapple plants, Gobernadora ecotype, through somatic embryogenesis (ES and adventitious organogenesis (OA. Basal and intermediate sections of leaves were tested. Only the leaf base sections (FBS were morphogenically induced. The highest number of vitroplants (1.58 plants / explant was obtained from the embryogenic callus induced in MS medium with Picloram 10 mg.L-1 + Thidiazuron 2 mg.L-1, transferred to MS medium without hormones. In the organogenic process, the highest number of plants/explants (5 was obtained directly in MS with naphthaleneacetic acid 5 mg.L-1 + benzylaminopurine 0.25 mg.L-1, transferred to MS. The latter being the best in vitro culture system due to its productivity and for being a method that minimizes somaclonal variation.

  10. Mercury contamination, a potential threat to the globally endangered aquatic warbler Acrocephalus paludicola.

    Science.gov (United States)

    Pacyna, Aneta Dorota; Martínez, Carlos Zumalacárregui; Miguélez, David; Jiguet, Frédéric; Polkowska, Żaneta; Wojczulanis-Jakubas, Katarzyna

    2017-12-01

    Mercury (Hg) contamination is considered a global concern for humans and wildlife, and although the number of studies dealing with that issue continues to increase, some taxonomic groups such as small passerine birds are largely understudied. In this paper, concentration of mercury in the aquatic warbler (Acrocephalus paludicola) feathers, a globally threatened passerine species, was examined. The concentration differences between two ages and sexes were investigated. The comparison of feathers taken on autumn migrants of two age categories act as a comparison of the species' exposure within the two different areas (European breeding or African wintering grounds). The average Hg concentration for all sampled individuals [2.32 μg/g dw (range 0.38-12.76)] is relatively high, compared with values found in other passerine species. An age difference was found, with first-year individuals displaying higher mercury concentrations than adults. This indicates that birds are exposed to mercury pollution during the breeding season, i.e., in the continental floodplains of eastern Europe. The average Hg concentration in feathers grown on the breeding grounds was 3.88 ± 2.59 μg/g dw, closer to the critical value of 5 μg/g dw, which is considered to impair the health of individuals. The findings suggest that mercury pollution may constitute a threat so far neglected for the endangered aquatic warbler.

  11. Mercury toxicokinetics-dependency on strain and gender

    International Nuclear Information System (INIS)

    Ekstrand, Jimmy; Nielsen, Jesper B.; Havarinasab, Said; Zalups, Rudolfs K.; Soederkvist, Peter; Hultman, Per

    2010-01-01

    Mercury (Hg) exposure from dental amalgam fillings and thimerosal in vaccines is not a major health hazard, but adverse health effects cannot be ruled out in a small and more susceptible part of the exposed population. Individual differences in toxicokinetics may explain susceptibility to mercury. Inbred, H-2-congenic A.SW and B10.S mice and their F1- and F2-hybrids were given HgCl 2 with 2.0 mg Hg/L drinking water and traces of 203 Hg. Whole-body retention (WBR) was monitored until steady state after 5 weeks, when the organ Hg content was assessed. Despite similar Hg intake, A.SW males attained a 20-30% significantly higher WBR and 2- to 5-fold higher total renal Hg retention/concentration than A.SW females and B10.S mice. A selective renal Hg accumulation but of lower magnitude was seen also in B10.S males compared with females. Differences in WBR and organ Hg accumulation are therefore regulated by non-H-2 genes and gender. Lymph nodes lacked the strain- and gender-dependent Hg accumulation profile of kidney, liver and spleen. After 15 days without Hg A.SW mice showed a 4-fold higher WBR and liver Hg concentration, but 11-fold higher renal Hg concentration, showing the key role for the kidneys in explaining the slower Hg elimination in A.SW mice. The trait causing higher mercury accumulation was not dominantly inherited in the F1 hybrids. F2 mice showed a large inter-individual variation in Hg accumulation, showing that multiple genetic factors influence the Hg toxicokinetics in the mouse. The genetically heterogeneous human population may therefore show a large variation in mercury toxicokinetics.

  12. Mercury flow experiments. 4th report: Measurements of erosion rate caused by mercury flow

    International Nuclear Information System (INIS)

    Kinoshita, Hidetaka; Kaminaga, Masanori; Haga, Katsuhiro; Hino, Ryutaro

    2002-06-01

    The Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Research Organization (KEK) are promoting a construction plan of the Material-Life Science Facility, which is consisted of a Muon Science Facility and a Neutron Scattering Facility, in order to open up the new science fields. The Neutron Scattering Facility will be utilized for advanced fields of Material and Life science using high intensity neutron generated by the spallation reaction of a 1 MW pulsed proton beam and mercury target. Design of the spallation mercury target system aims to obtain high neutron performance with high reliability and safety. Since the target system is using mercury as the target material and contains large amount of radioactive spallation products, it is necessary to estimate reliability for strength of instruments in a mercury flow system during lifetime of the facility. Piping and components in the mercury flow system would be damaged by erosion with mercury flow, since these components will be weak by thickness decreasing. This report presents experimental results of wall thickness change by erosion using a mercury experimental loop. In the experiments, an erosion test section and coupons were installed in the mercury experimental loop, and their wall thickness was measured with an ultra sonic thickness gage after every 1000 hours. As a result, under 0.7 m/s of mercury velocity condition which is slightly higher than the practical velocity in mercury pipelines, the erosion is about 3 μm in 1000 hours. The wall thickness decrease during facility lifetime of 30 years is estimated to be less than 0.5 mm. According to the experimental result, it is confirmed that the effect of erosion on component strength is extremely small. Moreover, a measurement of residual mercury on the piping surface was carried out. As a result, 19 g/m 2 was obtained as the residual mercury for the piping surface. According to this result, estimated amount of residual mercury for

  13. Adaptive and Defensive Strategies in Post-Traumatic Play of Young Children Exposed to Violent Attacks

    Science.gov (United States)

    Chazan, Saralea; Cohen, Esther

    2010-01-01

    Twenty-three children, aged four to eight years, who had been exposed to violent attacks, were videotaped in individual 40-minute play sessions. These play narratives were recorded by a student researcher trained in narrative analysis and play therapy. She then sorted these play vignettes into three patterns of post-traumatic play, defined in the…

  14. Amazonian Buriti oil: chemical characterization and antioxidant potential

    Energy Technology Data Exchange (ETDEWEB)

    Speranza, P.; Oliveira Falcao, A. de; Alves Macedo, J.; Silva, L.H.M. da; Rodrigues, A.M. da C.; Alves Macedo, G.

    2016-07-01

    Buriti oil is an example of an Amazonian palm oil of economic importance. The local population uses this oil for the prevention and treatment of different diseases; however, there are few studies in the literature that evaluate its properties. In this study, detailed chemical and antioxidant properties of Buriti oil were determined. The predominant fatty acid was oleic acid (65.6%) and the main triacylglycerol classes were tri-unsaturated (50.0%) and di-unsaturated-mono-saturated(39.3%) triacylglycerols. The positional distribution of the classes of fatty acids on the triacylglycerol backbone indicated a saturated and unsaturated fatty acid relationship similar in the three-triacylglycerol positions. All tocopherol isomers were present, with a total content of 2364.1 mg·kg−1. α-tocopherol constitutes 48% of the total tocopherol content, followed by γ- tocopherol (45%). Total phenolic (107.0 mg gallic acid equivalent·g−1 oil) and β-carotene (781.6 mg·kg−1) were particularly high in this oil. The highest antioxidant activity against the free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) was obtained at an oil concentration of 50 mg·mL−1 (73.15%). The antioxidant activity evaluated by the Oxygen Radical Absorbance Capacity (ORAC) was 95.3 μmol Trolox equivalent·g−1 oil. These results serve to present Buriti oil as an Amazonian resource for cosmetic, food and pharmaceuticals purposes. (Author)

  15. Concentration of mercury in wheat samples stored with mercury tablets as preservative. [Neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Lalit, B Y; Ramachandran, T V [Bhabha Atomic Research Centre, Bombay (India). Air Monitoring Section

    1977-01-01

    Tablets consisting of mercury in the form of a dull grey powder made by triturating mercury with chalk and sugar are used in Indian household for storing food-grains. The contamination of wheat samples by mercury, when stored with mercury tablets for period of upto four years has been assessed by using non-destructive neutron activation analysis. The details of the analytical procedure used have also been briefly described. The concentration of mercury in wheat increases with storage period. Loss of weight of mercury tablet is proportional to the storage period to a first approximation. In the present experiment, the average weight loss at the and end of first year was 0.009716 g corresponding to 6 ppm in wheat.

  16. MRP2 and the Handling of Mercuric Ions in Rats Exposed Acutely to Inorganic and Organic Species of Mercury

    Science.gov (United States)

    Bridges, Christy C.; Joshee, Lucy; Zalups, Rudolfs K.

    2011-01-01

    Mercuric ions accumulate preferentially in renal tubular epithelial cells and bond with intracellular thiols. Certain metal-complexing agents have been shown to promote extraction of mercuric ions via the multidrug resistance-associated protein 2 (MRP2). Following exposure to a non-toxic dose of inorganic mercury (Hg2+), in the absence of complexing agents, tubular cells are capable of exporting a small fraction of intracellular Hg2+ through one or more undetermined mechanisms. We hypothesize that MRP2 plays a role in this export. To test this hypothesis, Wistar (control) and TR− rats were injected intravenously with a non-nephrotoxic dose of HgCl2 (0.5 μmol/kg) or CH3HgCl (5 mg/kg), containing [203Hg], in the presence or absence of cysteine (Cys; 1.25 μmol/kg or 12.5 mg/kg, respectively). Animals were sacrificed 24 h after exposure to mercury and the content of [203Hg] in blood, kidneys, liver, urine and feces was determined. In addition, uptake of Cys-S-conjugates of Hg2+ and methylmercury (CH3Hg+) was measured in inside-out membrane vesicles prepared from either control Sf9 cells or Sf9 cells transfected with human MRP2. The amount of mercury in the total renal mass and liver was significantly greater in TR− rats than in controls. In contrast, the amount of mercury in urine and feces was significantly lower in TR− rats than in controls. Data from membrane vesicles indicate that Cys-S-conjugates of Hg2+ and CH3Hg+ are transportable substrates of MRP2. Collectively, these data indicate that MRP2 plays a role in the physiological handling and elimination of mercuric ions from the kidney. PMID:21134393

  17. Hematological Changes Induced by Mercury Ions and Ionizing Radiation in Experimental Animals

    International Nuclear Information System (INIS)

    Kim, Jin-Kyu; Lee, Yun-Jong; Choi, Dae-Seong; Kim, Ji-Hyang; Cebulska-Wasilewska, Antonina

    2006-01-01

    Toxic metals such as lead, chromium, cadmium, mercury and arsenic are widely found in our environment. Humans are exposed to these metals from numerous sources, including contaminated air, water, soil and food. Mercury, one of the most diffused and hazardous organ specific environmental contaminants, exists in a wide variety of physical and chemical states, each of which has unique characteristics for a target organ specificity. Although reports indicate that mercury induces deleterious damage, little is known about its effects on living organisms. Ionizing radiation, an extensively used therapeutic modality in oncology, not only eradicates neoplastic cells but also generates inevitable side effects for normal tissues. Such biological effects are made through the production of reactive oxygen species which include a superoxide anion, a hydroxyl radical and a hydrogen peroxide. These reactive species may contribute to the radiation-induced cytotoxicity (e.g., chromosome aberrations, protein oxidation, and muscle injury) and to the metabolic and morphologic changes (e.g., increased muscle proteolysis and changes in the central nervous system) in animals and humans. In the present study, radioimmunoassay of the cortisol in the serum and the analysis of the hematological components and enzymes related to a tissue injury were carried out to evaluate the effects of mercury chloride in comparison with those of ionizing radiation

  18. Hematological Changes Induced by Mercury Ions and Ionizing Radiation in Experimental Animals

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin-Kyu; Lee, Yun-Jong; Choi, Dae-Seong [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Kim, Ji-Hyang [Biotechnology Research Institute, Seoul (Korea, Republic of); Cebulska-Wasilewska, Antonina [The Henryk Niewodniczanski Institute of Nuclear Physics, Krakow (Poland)

    2006-07-01

    Toxic metals such as lead, chromium, cadmium, mercury and arsenic are widely found in our environment. Humans are exposed to these metals from numerous sources, including contaminated air, water, soil and food. Mercury, one of the most diffused and hazardous organ specific environmental contaminants, exists in a wide variety of physical and chemical states, each of which has unique characteristics for a target organ specificity. Although reports indicate that mercury induces deleterious damage, little is known about its effects on living organisms. Ionizing radiation, an extensively used therapeutic modality in oncology, not only eradicates neoplastic cells but also generates inevitable side effects for normal tissues. Such biological effects are made through the production of reactive oxygen species which include a superoxide anion, a hydroxyl radical and a hydrogen peroxide. These reactive species may contribute to the radiation-induced cytotoxicity (e.g., chromosome aberrations, protein oxidation, and muscle injury) and to the metabolic and morphologic changes (e.g., increased muscle proteolysis and changes in the central nervous system) in animals and humans. In the present study, radioimmunoassay of the cortisol in the serum and the analysis of the hematological components and enzymes related to a tissue injury were carried out to evaluate the effects of mercury chloride in comparison with those of ionizing radiation.

  19. Energetic planning in isolated Amazonian communities using geographical information system; Planejamento energetico em regioes isoladas da Amazonia utilizando sistemas de informacoes geograficas

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Arthur [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Programa de Pos-Graduacao de Engenharia Eletrica; Rocha, Brigida R.P.; Monteiro, Jose H.A.; Gaspar, Gabriella C.M. [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Dept. de Engenharia Eletrica e de Computacao; Aarao Junior, Raimundo N.N. [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Dept. de Engenharia Mecanica

    2004-07-01

    This paper proposes a system of electric planning in isolated Amazonian communities. For those communities, we propose the use of decentralized systems of electric energy with biomass as fuel. We also propose a computer system of electric planning with geographical information systems for its facilities of integrating geographical information, so useful in an Amazonian context. (author)

  20. Solubility of helium in mercury for bubbling technology of the spallation neutron mercury target

    International Nuclear Information System (INIS)

    Hasegawa, S.; Naoe, T.; Futakawa, M.

    2010-01-01

    The pitting damage of mercury target container that originates in the pressure wave excited by the proton beam incidence becomes a large problem to reach the high-power neutron source in JSNS and SNS. The lifetime of mercury container is decreased remarkably by the pitting damage. As one of solutions, the pressure wave is mitigated by injecting the helium micro bubbles in mercury. In order to inject the helium micro bubbles into mercury, it is important to understand the characteristic of micro bubbles in mercury. The solubility of mercury-helium system is a key factor to decide bubbling conditions, because the disappearance behavior, i.e. the lifetime of micro bubbles, depends on the solubility. In addition, the bubble generation method is affected by it. Moreover, the experimental data related to the solubility of helium in mercury hardly exist. In this work, the solubility was obtained experimentally by measuring precisely the pressure drop of the gas that is facing to mercury surface. The pressure drop was attributed to the helium dissolution into mercury. Based on the measured solubility, the lifetime of micro bubbles and the method of the bubble generation is estimated using the solubility data.

  1. Mercury CEM Calibration

    Energy Technology Data Exchange (ETDEWEB)

    John F. Schabron; Joseph F. Rovani; Susan S. Sorini

    2007-03-31

    The Clean Air Mercury Rule (CAMR) which was published in the Federal Register on May 18, 2005, requires that calibration of mercury continuous emissions monitors (CEMs) be performed with NIST-traceable standards. Western Research Institute (WRI) is working closely with the Electric Power Research Institute (EPRI), the National Institute of Standards and Technology (NIST), and the Environmental Protection Agency (EPA) to facilitate the development of the experimental criteria for a NIST traceability protocol for dynamic elemental mercury vapor generators. The traceability protocol will be written by EPA. Traceability will be based on the actual analysis of the output of each calibration unit at several concentration levels ranging from about 2-40 ug/m{sup 3}, and this analysis will be directly traceable to analyses by NIST using isotope dilution inductively coupled plasma/mass spectrometry (ID ICP/MS) through a chain of analyses linking the calibration unit in the power plant to the NIST ID ICP/MS. Prior to this project, NIST did not provide a recommended mercury vapor pressure equation or list mercury vapor pressure in its vapor pressure database. The NIST Physical and Chemical Properties Division in Boulder, Colorado was subcontracted under this project to study the issue in detail and to recommend a mercury vapor pressure equation that the vendors of mercury vapor pressure calibration units can use to calculate the elemental mercury vapor concentration in an equilibrium chamber at a particular temperature. As part of this study, a preliminary evaluation of calibration units from five vendors was made. The work was performed by NIST in Gaithersburg, MD and Joe Rovani from WRI who traveled to NIST as a Visiting Scientist.

  2. Exposure to Inorganic Mercury Causes Oxidative Stress, Cell Death, and Functional Deficits in the Motor Cortex.

    Science.gov (United States)

    Teixeira, Francisco B; de Oliveira, Ana C A; Leão, Luana K R; Fagundes, Nathália C F; Fernandes, Rafael M; Fernandes, Luanna M P; da Silva, Márcia C F; Amado, Lilian L; Sagica, Fernanda E S; de Oliveira, Edivaldo H C; Crespo-Lopez, Maria E; Maia, Cristiane S F; Lima, Rafael R

    2018-01-01

    Mercury is a toxic metal that can be found in the environment in three different forms - elemental, organic and inorganic. Inorganic mercury has a lower liposolubility, which results in a lower organism absorption and reduced passage through the blood-brain barrier. For this reason, exposure models that use inorganic mercury in rats in order to evaluate its effects on the central nervous system are rare, especially in adult subjects. This study investigated if a chronic exposure to low doses of mercury chloride (HgCl2), an inorganic form of mercury, is capable of promoting motor alterations and neurodegenerative in the motor cortex of adult rats. Forty animals were exposed to a dose of 0.375 mg/kg/day, for 45 days. They were then submitted to motor evaluation and euthanized to collect the motor cortex. Measurement of mercury deposited in the brain parenchyma, evaluation of oxidative balance, quantification of cellular cytotoxicity and apoptosis and density of mature neurons and astrocytes of the motor cortex were performed. It was observed that chronic exposure to inorganic mercury caused a decrease in balance and fine motor coordination, formation of mercury deposits and oxidative stress verified by the increase of lipoperoxidation and nitrite concentration and a decrease of the total antioxidant capacity. In addition, we found that this model of exposure to inorganic mercury caused cell death by cytotoxicity and induction of apoptosis with a decreased number of neurons and astrocytes in the motor cortex. Our results provide evidence that exposure to inorganic mercury in low doses, even in spite of its poor ability to cross biological barriers, is still capable of inducing motor deficits, cell death by cytotoxicity and apoptosis, and oxidative stress in the motor cortex of adult rats.

  3. Exposure to Inorganic Mercury Causes Oxidative Stress, Cell Death, and Functional Deficits in the Motor Cortex

    Directory of Open Access Journals (Sweden)

    Francisco B. Teixeira

    2018-05-01

    Full Text Available Mercury is a toxic metal that can be found in the environment in three different forms – elemental, organic and inorganic. Inorganic mercury has a lower liposolubility, which results in a lower organism absorption and reduced passage through the blood–brain barrier. For this reason, exposure models that use inorganic mercury in rats in order to evaluate its effects on the central nervous system are rare, especially in adult subjects. This study investigated if a chronic exposure to low doses of mercury chloride (HgCl2, an inorganic form of mercury, is capable of promoting motor alterations and neurodegenerative in the motor cortex of adult rats. Forty animals were exposed to a dose of 0.375 mg/kg/day, for 45 days. They were then submitted to motor evaluation and euthanized to collect the motor cortex. Measurement of mercury deposited in the brain parenchyma, evaluation of oxidative balance, quantification of cellular cytotoxicity and apoptosis and density of mature neurons and astrocytes of the motor cortex were performed. It was observed that chronic exposure to inorganic mercury caused a decrease in balance and fine motor coordination, formation of mercury deposits and oxidative stress verified by the increase of lipoperoxidation and nitrite concentration and a decrease of the total antioxidant capacity. In addition, we found that this model of exposure to inorganic mercury caused cell death by cytotoxicity and induction of apoptosis with a decreased number of neurons and astrocytes in the motor cortex. Our results provide evidence that exposure to inorganic mercury in low doses, even in spite of its poor ability to cross biological barriers, is still capable of inducing motor deficits, cell death by cytotoxicity and apoptosis, and oxidative stress in the motor cortex of adult rats.

  4. Alkaline Comet Assay and Micronucleus Test Parameters in Children Exposed to Diagnostic X-Ray Examination

    International Nuclear Information System (INIS)

    Gajski, G.; Geric, M.; Garaj-Vrhovac, V.; Milkovic, Dj.; Beck, N.; Ranogajec-Komor, M.; Miljanic, S.; Knezevic, Z.

    2011-01-01

    Chest radiograms represent the basic radiological examination of thorax and are the most frequently performed radiological diagnostic procedure in the child population. Understanding the risks of low doses of radiation is an important aspect in the risk benefit analysis in paediatric populations. To provide the best care for the young patients the effects of radiation should be minimized thus chest X-rays must be performed by highest standards to ensure that the young patient has the lowest risk possible. Since children are the most sensitive to radiation, there is a need for follow up of the young populations that receive these X-ray diagnostic examinations. Follow up would be especially advisable for children that are at higher risk of radiation induced damage, for example children with a predisposition to DNA damage, or for children that are constantly exposed to numerous radiological examinations due to their illness. In that manner, present study was undertaken to evaluate application of different dosimetry systems in conjunction with alkaline comet assay and micronucleus test for the assessment of different types of DNA and chromosomal alterations in child population exposed to acute diagnostic X-rays examination. For that purpose doses were measured using thermoluminescence (TL) and radiophotoluminescent (RPL) dosimetry systems. The study demonstrated that immediately after exposure to diagnostic X-irradiation, mean percentage of DNA in tail of the comets, which is indirect measures of DNA damage, was significantly changed. The same was noticed for mean total number of micronuclei as well. It was shown that children with pulmonary diseases subjected to diagnostic procedure develop a significant increase in mean total number of each measured parameter which are the biomarkers of genetic damage for carcinogenesis, than prior to diagnostic procedure and that interindividual differences exist for each monitored child. Our results show that genetic damage arises

  5. Study on total mercury and methylmercury levels in hair and tissues of typical human populations exposed to mercury in China by NAA and GC(EC)

    International Nuclear Information System (INIS)

    Chai Chifang; Qian Qinfang; Feng Weiyu; Sun Jianguo; Li Xinji; Lu Yilun; Zhang Xioumei; Zhang Shen

    1992-01-01

    Since the first Research Coordination Meeting in Vienna, 10-13 June 1991, China has been putting the research emphasis on two aspects for studying mercury exposure to the population. The first is a methodology for methylmercury analysis. The second is the collection and analysis of representative hair samples. The main activities during this study period are summarized in this paper. 8 tabs

  6. A population-based study of how children are exposed to saliva in KwaZulu-Natal Province, South Africa: implications for the spread of saliva-borne pathogens to children

    Science.gov (United States)

    Butler, L. M.; Neilands, T. B.; Mosam, A.; Mzolo, S.; Martin, J. N.

    2014-01-01

    Summary Objectives In sub-Saharan Africa, many viral infections, including Epstein–Barr virus, cytomegalovirus, Kaposi’s sarcoma-associated herpesvirus and hepatitis B are acquired in childhood. While saliva is an important transmission conduit for these viruses, little is known about how saliva is passed to African children. We endeavoured to identify the range and determinants of acts by which African children are exposed to saliva. Methods To identify the range of acts by which African children are exposed to saliva, we conducted focus groups, semi-structured interviews and participant observations in an urban and a rural community in South Africa. To measure the prevalence and determinants of the identified acts, we administered a questionnaire to a population-based sample of caregivers. Results We identified 12 caregiving practices that expose a child’s oral–respiratory mucosa, cutaneous surfaces or anal–rectal mucosa to saliva. Several acts were heretofore not described in the contemporary literature (e.g., caregiver inserting finger lubricated with saliva into child’s rectum to relieve constipation). Among 896 participants in the population-based survey, many of the acts were commonly practised by all respondent types (mothers, fathers, grandmothers and siblings). The most common were premastication of food, sharing sweets and premastication of medicinal plants that are spit onto a child’s body. Conclusions African children are exposed to saliva through a variety of acts, practised by a variety of caregivers, with no single predominant practice. This diversity poses challenges for epidemiologic work seeking to identify specific saliva-passing practices that transmit viruses. Most acts could be replaced by other actions and are theoretically preventable. PMID:20149165

  7. Lead, mercury, and cadmium exposure and attention deficit hyperactivity disorder in children.

    Science.gov (United States)

    Kim, Stephani; Arora, Monica; Fernandez, Cristina; Landero, Julio; Caruso, Joseph; Chen, Aimin

    2013-10-01

    There is limited research examining the relationship between lead (Pb) exposure and medically diagnosed attention deficit hyperactivity disorder (ADHD) in children. The role of mercury (Hg) and cadmium (Cd) exposures in ADHD development is even less clear. To examine the relationship between Pb, Hg, and Cd and ADHD in children living inside and outside a Lead Investigation Area (LIA) of a former lead refinery in Omaha, NE. We carried out a case-control study with 71 currently medically diagnosed ADHD cases and 58 controls from a psychiatric clinic and a pediatric clinic inside and outside of the LIA. The participants were matched on age group (5-8, 9-12 years), sex, race (African American or Caucasians and others), and location (inside or outside LIA). We measured whole blood Pb, total Hg, and Cd using inductively coupled plasma mass spectrometry. Inside the LIA, the 27 cases had blood Pb geometric mean (GM) 1.89 µg/dL and the 41 controls had 1.51 µg/dL. Outside the LIA, the 44 cases had blood Pb GM 1.02 µg/dL while the 17 controls had 0.97 µg/dL. After adjustment for matching variables and maternal smoking, socioeconomic status, and environmental tobacco exposure, each natural log unit blood Pb had an odds ratio of 2.52 with 95% confidence interval of 1.07-5.92. Stratification by the LIA indicated similar point estimate but wider CIs. No associations were observed for Hg or Cd. Postnatal Pb exposure may be associated with higher risk of clinical ADHD, but not the postnatal exposure to Hg or Cd. © 2013 Published by Elsevier Inc.

  8. Sexual differences in the excretion of organic and inorganic mercury by methyl mercury-treated rats

    International Nuclear Information System (INIS)

    Thomas, D.J.; Fisher, H.L.; Sumler, M.R.; Mushak, P.; Hall, L.L.

    1987-01-01

    Adult male and female Long Evans rats received 1 mumole of methyl ( 203 Hg) mercuric chloride per kilogram sc. Whole-body retention of mercury and excretion of organic and inorganic mercury in urine and feces were monitored for 98 days after dosing. Females cleared mercury from the body more rapidly than did males. The major route of mercury excretion was feces. By 98 days after dosing, cumulative mercury excretion in feces accounted for about 51% of the dose in males and about 54% of the dose in females. For both sexes, about 33% of the dose was excreted in feces as inorganic mercury. Cumulative excretion of organic mercury in feces accounted for about 18 and 21% of the dose in males and females, respectively. Urinary excretion of mercury was quantitatively a smaller route for mercury clearance but important sexual differences in loss by this route were found. Over the 98-day experimental period, males excreted in urine about 3.2% of the dose and females excreted 7.5%. Cumulative organic Hg excretion in urine accounted for 1.8% of the dose in males and 5.3% of the dose in females. These sexual differences in urinary and fecal excretion of organic and inorganic mercury following methyl mercury treatment were consistent with previous reports of sexual differences in mercury distribution and retention in methyl mercury-treated rats, particularly sexual differences in organic mercury uptake and retention in the kidney. Relationships between body burdens of organic or inorganic Hg and output of these forms of Hg in urine and feces were also found to be influenced by the interval after MeHg treatment and by sex. Relationship between concentration of Hg in liver and feces and in kidney and urine differed for organic and inorganic Hg and depended upon sexual status and interval after MeHg treatment

  9. The role of Amazonian anthropogenic soils in shifting cultivation: learning from farmers’ rationales

    NARCIS (Netherlands)

    Braga Junqueira, A.; Almekinders, C.J.M.; Stomph, T.J.; Clement, C.R.; Struik, P.C.

    2016-01-01

    We evaluated farmers’ rationales to understand their decision making in relation to the use of fertile anthropogenic soils, i.e., Amazonian dark earths (ADE), and for dealing with changes in shifting cultivation in Central Amazonia. We analyzed qualitative information from 196 interviews with

  10. 76 FR 13851 - National Emission Standards for Hazardous Air Pollutants: Mercury Emissions From Mercury Cell...

    Science.gov (United States)

    2011-03-14

    ... National Emission Standards for Hazardous Air Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali...-5] RIN 2060-AN99 National Emission Standards for Hazardous Air Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants AGENCY: Environmental Protection Agency (EPA). ACTION: Supplemental...

  11. Mercury in Nordic ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Munthe, John; Waengberg, Ingvar (IVL Swedish Environmental Research Inst., Stockholm (SE)); Rognerud, Sigurd; Fjeld, Eirik (Norwegian Inst. for Water Research (NIVA), Oslo (Norway)); Verta, Matti; Porvari, Petri (Finnish Environment Inst. (SYKE), Helsinki (Finland)); Meili, Markus (Inst. of Applied Environmental Research (ITM), Stockholm (Sweden))

    2007-12-15

    This report provides a first comprehensive compilation and assessment of available data on mercury in air, precipitation, sediments and fish in the Nordic countries. The main conclusion is that mercury levels in Nordic ecosystems continue to be affected by long-range atmospheric transport. The geographical patterns of mercury concentrations in both sediments and fish are also strongly affected by ecosystem characteristics and in some regions possibly by historical pollution. An evaluation of geographical variations in mercury concentrations in precipitation indicates that the influence from anthropogenic sources from Central European areas is still significant. The annual variability of deposition is large and dependant of precipitation amounts. An evaluation of data from stations around the North Sea has indicated a significant decrease in mercury concentrations in precipitation indicating a continuous decrease of emissions in Europe (Waengberg et al., 2007). For mercury in air (TGM), the geographical pattern is less pronounced indicating the influence of mercury emissions and distribution over a larger geographical area (i.e. hemispherical transport). Comparison of recent (surficial) and historical lake sediments show significantly elevated concentrations of mercury most likely caused by anthropogenic atmospheric deposition over the past century. The highest pollution impact was observed in the coastal areas of southern Norway, in south western Finland and in Sweden from the coastal areas in the southwest across the central parts to the north-east. The general increase in recent versus old sediments was 2-5 fold. Data on mercury in Nordic freshwater fish was assembled and evaluated with respect to geographical variations. The fish data were further compared with temporal and spatial trends in mercury deposition and mercury contamination of lake sediments in order to investigate the coupling between atmospheric transport and deposition of mercury and local mercury

  12. Hair mercury concentrations and associated factors in an electronic waste recycling area, Guiyu, China

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Wenqing [Department of Preventive Medicine, Shantou University Medical College, Shantou 515041, Guangdong (China); Chen, Yaowen [Central Laboratory of Shantou University, Shantou 515063, Guangdong (China); Huang, Yue; Wang, Xiaoling [Department of Preventive Medicine, Shantou University Medical College, Shantou 515041, Guangdong (China); Zhang, Gairong [Central Laboratory of Shantou University, Shantou 515063, Guangdong (China); Luo, Jiayi [Department of Preventive Medicine, Shantou University Medical College, Shantou 515041, Guangdong (China); Wu, Kusheng, E-mail: kswu@stu.edu.cn [Department of Preventive Medicine, Shantou University Medical College, Shantou 515041, Guangdong (China)

    2014-01-15

    and suggested elevated hair mercury concentrations in an e-waste recycling area, Guiyu, China. Living in Guiyu for a long time and work related to e-waste may primarily contribute to the high hair mercury concentrations. -- Highlights: • Mercury levels in hair samples from Guiyu and risk factors were assessed. • The recruitments from Guiyu were exposed to high levels of mercury. • Primitive e-waste recycling resulted in high mercury exposure of local people.

  13. Hair mercury concentrations and associated factors in an electronic waste recycling area, Guiyu, China

    International Nuclear Information System (INIS)

    Ni, Wenqing; Chen, Yaowen; Huang, Yue; Wang, Xiaoling; Zhang, Gairong; Luo, Jiayi; Wu, Kusheng

    2014-01-01

    and suggested elevated hair mercury concentrations in an e-waste recycling area, Guiyu, China. Living in Guiyu for a long time and work related to e-waste may primarily contribute to the high hair mercury concentrations. -- Highlights: • Mercury levels in hair samples from Guiyu and risk factors were assessed. • The recruitments from Guiyu were exposed to high levels of mercury. • Primitive e-waste recycling resulted in high mercury exposure of local people

  14. Understanding the mercury reduction issue: the impact of mercury on the environment and human health.

    Science.gov (United States)

    Kao, Richard T; Dault, Scott; Pichay, Teresa

    2004-07-01

    Mercury has been used in both medicine and dentistry for centuries. Recent media attention regarding the increased levels of mercury in dietary fish, high levels of mercury in air emissions, and conjecture that certain diseases may be caused by mercury exposure has increased public awareness of the potential adverse health effects of high doses of mercury. Dentistry has been criticized for its continued use of mercury in dental amalgam for both public health and environmental reasons. To address these concerns, dental professionals should understand the impact of the various levels and types of mercury on the environment and human health. Mercury is unique in its ability to form amalgams with other metals. Dental amalgam--consisting of silver, copper, tin, and mercury--has been used as a safe, stable, and cost-effective restorative material for more than 150 years. As a result of this use, the dental profession has been confronted by the public on two separate health issues concerning the mercury content in amalgam. The first issue is whether the mercury amalgamated with the various metals to create dental restorations poses a health issue for patients. The second is whether the scraps associated with amalgam placement and the removal of amalgam restorations poses environmental hazards which may eventually have an impact on human health. Despite the lack of scientific evidence for such hazards, there is growing pressure for the dental profession to address these health issues. In this article, the toxicology of mercury will be reviewed and the impact of amalgam on health and the environment will be examined.

  15. Amazonian-aged fluvial system and associated ice-related features in Terra Cimmeria, Mars

    NARCIS (Netherlands)

    Adeli, Solmaz; Hauber, Ernst; Kleinhans, Maarten; Le Deit, Laetitia; Platz, Thomas; Fawdon, Peter; Jaumann, Ralf

    2016-01-01

    The Martian climate throughout the Amazonian is widely believed to have been cold and hyper-arid, very similar to the current conditions. However, ubiquitous evidence of aqueous and glacial activity has been recently reported, including channels that can be tens to hundreds of kilometres long,

  16. Prenatal mercury exposure, maternal seafood consumption and associations with child language at five years.

    Science.gov (United States)

    Vejrup, Kristine; Brandlistuen, Ragnhild Eek; Brantsæter, Anne Lise; Knutsen, Helle Katrine; Caspersen, Ida Henriette; Alexander, Jan; Lundh, Thomas; Meltzer, Helle Margrete; Magnus, Per; Haugen, Margaretha

    2018-01-01

    Methyl mercury (MeHg) is a well-known neurotoxin and evidence suggests that also low level exposure may affect prenatal neurodevelopment. Uncertainty exists as to whether the maternal MeHg burden in Norway might affect child neurodevelopment. To evaluate the association between prenatal mercury exposure, maternal seafood consumption and child language and communication skills at age five. The study sample comprised 38,581 mother-child pairs in the Norwegian Mother and Child Cohort Study. Maternal mercury blood concentration in gestational week 17 was analysed in a sub-sample of 2239 women. Prenatal mercury exposure from maternal diet was calculated from a validated FFQ answered in mid-pregnancy. Mothers reported children's language and communications skills at age five by a questionnaire including questions from the Ages and Stages Questionnaire (ASQ), the Speech and Language Assessment Scale (SLAS) and the Twenty Statements about Language-Related Difficulties (language 20). We performed linear regression analyses adjusting for maternal characteristics, nutritional status and socioeconomic factors. Median maternal blood mercury concentration was 1.03μg/L, dietary mercury exposure was 0.15μg/kgbw/wk, and seafood intake was 217g/wk. Blood mercury concentrations were not associated with any language and communication scales. Increased dietary mercury exposure was significantly associated with improved SLAS scores when mothers had a seafood intake below 400g/wk in the adjusted analysis. Sibling matched analysis showed a small significant adverse association between those above the 90th percentile dietary mercury exposure and the SLAS scores. Maternal seafood intake during pregnancy was positively associated with the language and communication scales. Low levels of prenatal mercury exposure were positively associated with language and communication skills at five years. However, the matched sibling analyses suggested an adverse association between mercury and child

  17. Fallen leaves on the water-bed: diurnal camouflage of three night active fish species in an Amazonian streamlet

    Directory of Open Access Journals (Sweden)

    Ivan Sazima

    Full Text Available Resemblance to dead leaves is a well known type of camouflage recorded for several small vertebrates that dwell in the leaf and root litter on the ground. We present here instances of such resemblance in three species of nocturnal fishes (Siluriformes and Gymnotiformes that spend the daytime among submersed root-tangle with leaf litter in Amazonian streams. All three species are very difficult to spot visually, due both to their shape and colors which blend with the substrate, as well as to the heterogeneous nature of their cover. Two species were recorded to lie on their sides, which adds to their resemblance to dead leaves. When disturbed, one species may drift like a waterlogged leaf, whereas another moves upwards the root-tangle, exposing its fore body above the water surface. We regard their leaf-like shapes, cryptic colors, and escape movements as a convergence in defensive responses to visually hunting aquatic vertebrates, most likely diurnal predaceous fishes.

  18. The adaptive response of lichens to mercury exposure involves changes in the photosynthetic machinery

    International Nuclear Information System (INIS)

    Nicolardi, Valentina; Cai, Giampiero; Parrotta, Luigi; Puglia, Michele; Bianchi, Laura; Bini, Luca; Gaggi, Carlo

    2012-01-01

    Lichens are an excellent model to study the bioaccumulation of heavy metals but limited information is available on the molecular mechanisms occurring during bioaccumulation. We investigated the changes of the lichen proteome during exposure to constant concentrations of mercury. We found that most of changes involves proteins of the photosynthetic pathway, such as the chloroplastic photosystem I reaction center subunit II, the oxygen-evolving protein and the chloroplastic ATP synthase β-subunit. This suggests that photosynthesis is a target of the toxic effects of mercury. These findings are also supported by changes in the content of photosynthetic pigments (chlorophyll a and b, and β-carotene). Alterations to the photosynthetic machinery also reflect on the structure of thylakoid membranes of algal cells. Response of lichens to mercury also involves stress-related proteins (such as Hsp70) but not cytoskeletal proteins. Results suggest that lichens adapt to mercury exposure by changing the metabolic production of energy. - Highlights: ► Lichens exposed to Hg° vapors accumulate this metal irreversibly. ► Hg° interferes with physiological processes of the epiphytic lichen Evernia prunastri. ► Hg° promotes changes in the concentration of photosynthetic pigments. ► Hg° treatment causes changes in the ultrastructure of the photobiont plastids. ► Hg° induces changes in the protein machinery involved in the photosynthesis pathway. - Mercury affects the photosynthetic protein machinery of lichens.

  19. Getting Mercury out of Schools.

    Science.gov (United States)

    1999

    This guide was prepared while working with many Massachusetts schools to remove items that contain mercury and to find suitable alternatives. It contains fact sheets on: mercury in science laboratories and classrooms, mercury in school buildings and maintenance areas, mercury in the medical office and in medical technology classrooms in vocational…

  20. Mercury risk assessment combining internal and external exposure methods for a population living near a municipal solid waste incinerator.

    Science.gov (United States)

    Deng, Chunyan; Xie, Han; Ye, Xuejie; Zhang, Haoran; Liu, Maodian; Tong, Yindong; Ou, Langbo; Yuan, Wen; Zhang, Wei; Wang, Xuejun

    2016-12-01

    Risk assessments for human health have been conducted for municipal solid waste incinerators (MSWIs) in many western countries, whereas only a few risk assessments have been performed for MSWIs in developing countries such as China where the use of waste incineration is increasing rapidly. To assess the mercury exposure risks of a population living near the largest MSWI in South China, we combined internal exposure and external exposure assessment with an individual-specific questionnaire. The mercury concentrations in air, soil, and locally collected food around the MSWI were assessed. The total mercury (T-Hg) and methylmercury (MeHg) of 447 blood samples from a control group, residential exposure group, and MSWI workers were measured. The internal and external exposures of the subject population were analyzed. Significant difference in MeHg concentrations was observed between the control group and the exposed group, between the control group and the MSWI workers, and between the exposed group and the MSWI workers (median levels: 0.70 μg/L, 0.81 μg/L, and 1.02 μg/L for the control group, exposed group, and MSWI workers, respectively). The MeHg/T-Hg ratio was 0.51 ± 0.19, 0.59 ± 0.17 and 0.58 ± 0.25, respectively. Multiple linear regression analysis indicated that MeHg concentrations were positively correlated with the gaseous mercury in the air. Combining internal and external exposure assessment showed that the direct contribution of MSWI emissions was minor compared with the dietary contribution. The external and internal exposures were well matched with each other. This study also suggested that an integrated method combining internal and external exposure assessment with an individual-specific questionnaire is feasible to assess the risks for a population living near a MSWI. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Disparities in Children’s Blood Lead and Mercury Levels According to Community and Individual Socioeconomic Positions

    Science.gov (United States)

    Lim, Sinye; Ha, Mina; Hwang, Seung-Sik; Son, Mia; Kwon, Ho-Jang

    2015-01-01

    We aimed to examine the associations between blood lead and mercury levels and individual and community level socioeconomic positions (SEPs) in school-aged children. A longitudinal cohort study was performed in 33 elementary schools in 10 cities in Korea. Among a total of 6094 children included at baseline, the final study population, 2281 children followed-up biennially, were analyzed. The geometric mean (GM) levels of blood lead were 1.73 μg/dL (range 0.02–9.26) and 1.56 μg/dL (range 0.02–6.83) for male and female children, respectively. The blood lead levels were significantly higher in males, children living in rural areas, and those with lower individual SEP. The GM levels of blood mercury were 2.07 μg/L (range 0.09–12.67) and 2.06 μg/L (range 0.03–11.74) for males and females, respectively. Increased blood mercury levels were significantly associated with urban areas, higher individual SEP, and more deprived communities. The risk of high blood lead level was significantly higher for the lower individual SEP (odds ratio (OR) 2.18, 95% confidence interval (CI) 1.36–3.50 in the lowest educational attainment of the father), with a significant dose-response relationship observed after adjusting for the community SEP. The association between high blood lead levels and lower individual SEP was much stronger in the more deprived communities (OR 2.88, 95% CI 1.27–6.53) than in the less deprived communities (OR 1.40, 95% CI 0.76–2.59), and showed a significant decreasing trend during the follow-up only in the less deprived communities. The risk of high blood mercury levels was higher in higher individual SEP (OR 0.64, 95% CI 0.40–1.03 in the lowest educational attainment of the father), with a significant dose-response relationship noted. Significant decreasing trends were observed during the follow-up both in the less and more deprived communities. From a public health point-of-view, community level intervention with different approaches for

  2. Effect of mercury on the fish (Alburnus alburnus) chemoreceptor taste buds. A scanning electron microscopic study

    Energy Technology Data Exchange (ETDEWEB)

    Pevzner, R.A.; Hernadi, L.; Salanki, J.

    1986-01-01

    Taste buds (TBS) were investigated by scanning electron microscopy on various parts of the oral cavity of the bleak. (Alburnus alburnus) after differently long exposures to mercury (300 ..mu..g/1 Hg/sup + +/). This low concentration of mercury did not result in lethal effect on the bleak even after 19 days long exposure, but produced morphological changes on the TBs, which showed duration dependency. The first sign of the morphological alteration on the TBs was observed after three days long exposure, when the microridge system of the epithelial cells became damaged and the mucus secretion increased on the apical surfaces of the TBs. On the TBs exposed for 10 days swollen microvilliar tips of the sensory cells could be observed besides the damage of the epithelial microridge system. On the TBs exposed for 19 days degenerative changes were detected on the microvilliar system of both the supporting and receptor cells. By this time completely degenerated TBs were frequently observed.

  3. Risk of hearing loss in children exposed to gentamicin for the treatment of sepsis in young infancy: A community based cohort study in pakistan

    International Nuclear Information System (INIS)

    Iftikhar, U.; Ali, S.A.; Tikmani, S.S.; Zaidi, A.K.; Azam, S.I.; Saleem, S.

    2013-01-01

    Objective: To determine the safety of gentamicin when used in a community setting to treat neonatal sepsis. Methods: The study was conducted in peri-urban areas of Karachi from September 2009 to April 2010. The exposed group consisted of children 6 months to 3 years of age who were treated for sepsis during 0-2 months of age in the community, with a regimen that included gentamicin for at least five days. The control group included children from the same area who never received gentamicin. The outcome measure was hearing loss, which was assessed by Brainstem Evoked Response Audiometry. Results: Of the 255 children enrolled, 125 (49%) received gentamicin, while 130 (51%) were not exposed to gentamicin. Children in the gentamicin exposed group were not at increased risk for hearing loss compared to controls (n=30; 30.9% vs. n=33; 31.4%, RR 0.98; 95% CI: 0.60-1.61). Children with history of ear discharge (RR 1.7) and children with family history of deafness (RR 2.0) were more at risk for having hearing loss. Conclusion: No association was found between hearing loss and gentamicin exposure in a community setting for the management of sepsis in the first two months of life. (author)

  4. Exploring Empathy and Callous-Unemotional Traits as Predictors of Animal Abuse Perpetrated by Children Exposed to Intimate Partner Violence.

    Science.gov (United States)

    Hartman, Christie; Hageman, Tina; Williams, James Herbert; Mary, Jason St; Ascione, Frank R

    2016-07-01

    We explored the relation between empathy, callous-unemotional (CU) traits, and animal abuse in a sample of 290 seven- to twelve-year-old children whose mothers were exposed to intimate partner violence (IPV). The sample comprises mostly Latino and White participants, and 55% of the children's mothers were born outside the United States (primarily Mexico). To our knowledge, among studies examining child-perpetrated animal abuse, this study is the first to examine empathy levels and one of only a few to examine CU traits. When comparing Griffith Empathy Measure (empathy) and Inventory of Callous-Unemotional Traits (callous-unemotional [CU] traits) scores with those from studies of White schoolchildren, our sample scored lower on affective empathy, higher on cognitive empathy, and lower for overall CU scores as well as Callous and Unemotional subscales. Of 290 children, 47 (16.2%) harmed an animal at least once according to either mother or child report. There were no significant sex or age differences between Abuse and No Abuse groups. The Abuse group scored significantly higher on affective empathy, CU, and Callousness/Unemotional subscales, and significantly lower on cognitive empathy. However, in regression analyses that controlled for income, only lower cognitive empathy and higher CU significantly predicted having abused an animal. In summary, low cognitive empathy (but not affective empathy) and CU traits may serve as reliable predictors of child animal abuse. However, replication of these results is necessary. A larger sample with a high percentage of Latino children whose mothers were exposed to IPV, along with a non-exposed comparison group, would be ideal.

  5. The influences of CO2 fertilization and land use change on the total aboveground biomass in Amazonian tropical forest

    Science.gov (United States)

    Castanho, A. D.; Zhang, K.; Coe, M. T.; Costa, M. H.; Moorcroft, P. R.

    2012-12-01

    Field observations from undisturbed old-growth Amazonian forest plots have recently reported on the temporal variation of many of the physical and chemical characteristics such as: physiological properties of leaves, above ground live biomass, above ground productivity, mortality and turnover rates. However, although this variation has been measured, it is still not well understood what mechanisms control the observed temporal variability. The observed changes in time are believed to be a result of a combination of increasing atmospheric CO2 concentration, climate variability, recovery from natural disturbance (drought, wind blow, flood), and increase of nutrient availability. The time and spatial variability of the fertilization effect of CO2 on above ground biomass will be explored in more detail in this work. A precise understanding of the CO2 effect on the vegetation is essential for an accurate prediction of the future response of the forest to climate change. To address this issue we simultaneously explore the effects of climate variability, historical CO2 and land-use change on total biomass and productivity using two different Dynamic Global Vegetation Models (DGVM). We use the Integrated Biosphere Simulator (IBIS) and the Ecosystem Demography Model 2.1 (ED2.1). Using land use changes database from 1700 - 2008 we reconstruct the total carbon balance in the Amazonian forest in space and time and present how the models predict the forest as carbon sink or source and explore why the model and field data diverge from each other. From 1970 to 2005 the Amazonian forest has been exposed to an increase of approximately 50 ppm in the atmospheric CO2 concentration. Preliminary analyses with the IBIS and ED2.1 dynamic vegetation model shows the CO2 fertilization effect could account for an increase in above ground biomass of 0.03 and 0.04 kg-C/m2/yr on average for the Amazon basin, respectively. The annual biomass change varies temporally and spatially from about 0

  6. Human and ecological remediation goals for soil mercury at East Fork Poplar Creek, Oak Ridge, TN

    International Nuclear Information System (INIS)

    Zafran, F.A.; Cornaby, B.W.; Hadden, C.T.

    1995-01-01

    Mercury, used in the past production of enriched lithium by the Department of Energy, is the principal chemical of concern in the 14-mile floodplain of East Fork Poplar Creek (EFPC). SAIC has developed risk-based remediation goal options (RGOS) for mercury in EFPC soils to protect the most sensitive human receptors. The existing chronic oral RfD for mercury is based on exposure of laboratory species to mercuric chloride. However, speciation and leaching/availability studies (conducted by EPA EMSL and Oak Ridge National Laboratory) indicated less soluble and less toxic mercury species, principally mercuric sulfide, with measurable quantities of metallic mercury also present, predominate in EFPC floodplain soils. SAIC derived human health RGOs using deterministic and probabilistic methods and incorporated the probability density function for bioavailability of mercury species from leaching/availability data generated by ORNL. Monte Carlo simulation was used in uncertainty analysis and supported the derivation of a protective, but realistic risk-based remediation goal of 400 mg mercury/kg soil. For ecological risk assessment, RGOs were based on risks through food chains from contaminants in soil. The authors describe a terrestrial food-chain model of contaminant transfer to primary producers, first-order consumers, mid-level predators, and top-level predators. The model uses published toxicity data, site-specific contaminant concentrations, and bioaccumulation factors calculated from measured body burdens of floodplain organisms to compute RGOs for various combinations of exposure parameters. Model calculations show that under reasonably conservative conditions, mid-level predators have the highest exposures relative to dietary limits and, therefore, require the lowest soil-mercury RGOs. Mercury concentrations of ∼500 mg/kg are protective of the receptor populations exposed through food chains at this site

  7. Mercury in mercury(II)-spiked soils is highly susceptible to plant bioaccumulation.

    Science.gov (United States)

    Hlodák, Michal; Urík, Martin; Matúš, Peter; Kořenková, Lucia

    2016-01-01

    Heavy metal phytotoxicity assessments usually use soluble metal compounds in spiked soils to evaluate metal bioaccumulation, growth inhibition and adverse effects on physiological parameters. However, exampling mercury phytotoxicity for barley (Hordeum vulgare) this paper highlights unsuitability of this experimental approach. Mercury(II) in spiked soils is extremely bioavailable, and there experimentally determined bioaccumulation is significantly higher compared to reported mercury bioaccumulation efficiency from soils collected from mercury-polluted areas. Our results indicate this is not affected by soil sorption capacity, thus soil ageing and formation of more stable mercuric complexes with soil fractions is necessary for reasonable metal phytotoxicity assessments.

  8. The Amazonian Craton and its influence on past fluvial systems (Mesozoic-Cenozoic, Amazonia)

    NARCIS (Netherlands)

    Hoorn, C.; Roddaz, M.; Dino, R.; Soares, E.; Uba, C.; Ochoa-Lozano, D.; Mapes, R.; Hoorn, C.; Wesselingh, F.P.

    2010-01-01

    The Amazonian Craton is an old geological feature of Archaean/Proterozoic age that has determined the character of fluvial systems in Amazonia throughout most of its past. This situation radically changed during the Cenozoic, when uplift of the Andes reshaped the relief and drainage patterns of

  9. Below a Historic Mercury Mine: Non-linear Patterns of Mercury Bioaccumulation in Aquatic Organisms

    Science.gov (United States)

    Haas, J.; Ichikawa, G.; Ode, P.; Salsbery, D.; Abel, J.

    2001-12-01

    Unlike most heavy metals, mercury is capable of bioaccumulating in aquatic food-chains, primarily because it is methylated by bacteria in sediment to the more toxic methylmercury form. Mercury concentrations in a number of riparian systems in California are highly elevated as a result of historic mining activities. These activities included both the mining of cinnabar in the coastal ranges to recover elemental mercury and the use of elemental mercury in the gold fields of the Sierra Nevada Mountains. The most productive mercury mining area was the New Almaden District, now a county park, located in the Guadalupe River drainage of Santa Clara County, where cinnabar was mined and retorted for over 100 years. As a consequence, riparian systems in several subwatersheds of the Guadalupe River drainage are contaminated with total mercury concentrations that exceed state hazardous waste criteria. Mercury concentrations in fish tissue frequently exceed human health guidelines. However, the potential ecological effects of these elevated mercury concentrations have not been thoroughly evaluated. One difficulty is in extrapolating sediment concentrations to fish tissue concentrations without accounting for physical and biological processes that determine bioaccumulation patterns. Many processes, such as methylation and demethylation of mercury by bacteria, assimilation efficiency in invertebrates, and metabolic rates in fish, are nonlinear, a factor that often confounds attempts to evaluate the effects of mercury contamination on aquatic food webs. Sediment, benthic macroinvertebrate, and fish tissue samples were collected in 1998 from the Guadalupe River drainage in Santa Clara County at 13 sites upstream and downstream from the historic mining district. Sediment and macroinvertebrate samples were analyzed for total mercury and methylmercury. Fish samples were analyzed for total mercury as whole bodies, composited by species and size. While linear correlations of sediment

  10. Mercury pollution in Wuchuan mercury mining area, Guizhou, Southwestern China: the impacts from large scale and artisanal mercury mining.

    Science.gov (United States)

    Li, Ping; Feng, Xinbin; Qiu, Guangle; Shang, Lihai; Wang, Shaofeng

    2012-07-01

    To evaluate the environmental impacts from large scale mercury mining (LSMM) and artisanal mercury mining (AMM), total mercury (THg) and methyl mercury (MeHg) were determined in mine waste, ambient air, stream water and soil samples collected from Wuchuan mercury (Hg) mining area, Guizhou, Southwestern China. Mine wastes from both LSMM and AMM contained high THg concentrations, which are important Hg contamination sources to the local environment. Total gaseous mercury (TGM) concentrations in the ambient air near AMM furnaces were highly elevated, which indicated that AMM retorting is a major source of Hg emission. THg concentrations in the stream water varied from 43 to 2100 ng/L, where the elevated values were mainly found in the vicinity of AMM and mine waste heaps of LSMM. Surface soils were seriously contaminated with Hg, and land using types and organic matter played an important role in accumulation and transportation of Hg in soil. The results indicated heavy Hg contaminations in the study area, which were resulted from both LSMM and AMM. The areas impacted by LSMM were concentrated in the historical mining and smelting facilities, while Hg pollution resulted from AMM can be distributed anywhere in the Hg mining area. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Mercury Conditions for the MESSENGER Mission Simulated in High- Solar-Radiation Vacuum Tests

    Science.gov (United States)

    Wong, Wayne A.

    2003-01-01

    The MESSENGER (Mercury Surface, Space Environment, Geochemistry, and Ranging) spacecraft, planned for launch in March 2004, will perform two flybys of Mercury before entering a year-long orbit of the planet in September 2009. The mission will provide opportunities for detailed characterization of the surface, interior, atmosphere, and magnetosphere of the closest planet to the Sun. The NASA Glenn Research Center and the MESSENGER spacecraft integrator, the Johns Hopkins University Applied Physics Laboratory, have partnered under a Space Act Agreement to characterize a variety of critical components and materials under simulated conditions expected near Mercury. Glenn's Vacuum Facility 6, which is equipped with a solar simulator, can simulate the vacuum and high solar radiation anticipated in Mercury orbit. The MESSENGER test hardware includes a variety of materials and components that are being characterized during the Tank 6 vacuum tests, where the hardware will be exposed to up to 11 suns insolation, simulating conditions expected in Mercury orbit. In 2002, ten solar vacuum tests were conducted, including beginning of life, end of life, backside exposure, and solar panel thermal shock cycling tests. Components tested include candidate solar array panels, sensors, thermal shielding materials, and communication devices. As an example, for the solar panel thermal shock cycling test, two candidate solar array panels were suspended on a lift mechanism that lowered the panels into a liquid-nitrogen-cooled box. After reaching -140 C, the panels were then lifted out of the box and exposed to the equivalent of 6 suns (8.1 kilowatts per square meters). After five cold soak/heating cycles were completed successfully, there was no apparent degradation in panel performance. An anticipated 100-hr thermal shield life test is planned for autumn, followed by solar panel flight qualification tests in winter. Glenn's ongoing support to the MESSENGER program has been instrumental in

  12. Amazonian Amphibian Diversity Is Primarily Derived from Late Miocene Andean Lineages

    Science.gov (United States)

    Santos, Juan C; Coloma, Luis A; Summers, Kyle; Caldwell, Janalee P; Ree, Richard; Cannatella, David C

    2009-01-01

    The Neotropics contains half of remaining rainforests and Earth's largest reservoir of amphibian biodiversity. However, determinants of Neotropical biodiversity (i.e., vicariance, dispersals, extinctions, and radiations) earlier than the Quaternary are largely unstudied. Using a novel method of ancestral area reconstruction and relaxed Bayesian clock analyses, we reconstructed the biogeography of the poison frog clade (Dendrobatidae). We rejected an Amazonian center-of-origin in favor of a complex connectivity model expanding over the Neotropics. We inferred 14 dispersals into and 18 out of Amazonia to adjacent regions; the Andes were the major source of dispersals into Amazonia. We found three episodes of lineage dispersal with two interleaved periods of vicariant events between South and Central America. During the late Miocene, Amazonian, and Central American-Chocoan lineages significantly increased their diversity compared to the Andean and Guianan-Venezuelan-Brazilian Shield counterparts. Significant percentage of dendrobatid diversity in Amazonia and Chocó resulted from repeated immigrations, with radiations at Venezuelan Highlands, and Guiana Shield have undergone extended in situ diversification at near constant rate since the Oligocene. The effects of Miocene paleogeographic events on Neotropical diversification dynamics provided the framework under which Quaternary patterns of endemism evolved. PMID:19278298

  13. Behaviour of mercury compounds in soil

    Energy Technology Data Exchange (ETDEWEB)

    Booer, J R

    1944-01-01

    The uses of inorganic compounds of mercury for the control of plant pests is reviewed, and a summary of the relevant chemical and physical properties of the compounds concerned is given. On chemical evidence a working hypothesis is propounded showing that all compounds may be expected to decompose into metallic mercury. A pot technique is described by means of which a correlation can be obtained between the effective mercury content of a given soil sample and the rate of growth of wheat seedlings. The mathematical treatment of the results is described, and the validity of the pot technique is verified by statistical analysis of results. Using the pot technqiue it is shown that volatilization losses are insignificant but that mercury is slowly rendered ineffective by the formation of mercuric sulphide. The effect of sulphur-reducing bacteria is considered and the influence of Vibrio desulphuricans on mercury is studied in detail. Experimental evidence obtained by the pot technique is produced to show that mercurous chloride slowly decomposes in the soil giving mercury and mercuric chloride, mercuric chloride rapidly decomposes into mercury and mercurous chloride, and other inorganic compounds decompose directly into mercury. The working hypothesis is substantiated in all major aspects. The uses and properties of the organo-mercury compounds are then discussed. Type compounds selected are ethyl mercury phosphate, phenyl mercury acetate and methoxyethyl mercury acetate. Using the pot technique it is shown that the formation of organo-mercury clays takes place and that these clays decompose giving metallic mercury. A mechanism is suggested.

  14. Mercury in the environment : a review

    International Nuclear Information System (INIS)

    Goodarzi, F.

    2000-01-01

    Both geogenic and anthropogenic sources are responsible for the input of mercury into the environment. However, mercury comes mostly from geogenic sources and is found naturally in air, water and soil. Crustal degassing results in emission of mercury into the atmosphere. Mercury in water and soil is due mostly to input from sedimentary rocks. Mercury in lake sediments is related mainly to input by country rock and anthropogenic activities such as agriculture. The mercury content of coal is similar to or less than the amount found in the earths crust. Natural charcoal is also able to capture mercury at low temperature combustion. The amount of mercury emitted from the stack of coal-fired power plants is related to the nature of the milled coal and its mineralogical and elemental content. Mercury emissions originating from the combustion of coal from electric utility power plants are considered to be among the greatest contributors to global mercury air emissions. In order to quantify the impact the electric power industry has on the environment, information regarding mercury concentrations in coal and their speciation is needed. For this reason the author examined the behaviour of mercury in three coal samples ashed at increasing temperatures. Mercury removal from coal-fired power plants ranges from 10 to 50 per cent by fabric filters and 20 to 95 per cent by FGD systems. This data will help in regulating emissions of hazardous air pollutants from electric utility steam generating units and will potentially provide insight into the industry's contribution to the global mercury burden. 50 refs

  15. Calls to Florida Poison Control Centers about mercury: Trends over 2003-2013.

    Science.gov (United States)

    Gribble, Matthew O; Deshpande, Aniruddha; Stephan, Wendy B; Hunter, Candis M; Weisman, Richard S

    2017-11-01

    The aim of this analysis was to contrast trends in exposure-report calls and informational queries (a measure of public interest) about mercury to the Florida Poison Control Centers over 2003-2013. Poison-control specialists coded calls to Florida Poison Control Centers by substance of concern, caller demographics, and whether the call pertained to an exposure event or was an informational query. For the present study, call records regarding mercury were de-identified and provided along with daily total number of calls for statistical analysis. We fit Poisson models using generalized estimating equations to summarize changes across years in counts of daily calls to Florida Poison Control Centers, adjusting for month. In a second stage of analysis, we further adjusted for the total number of calls each day. We also conducted analyses stratified by age of the exposed. There was an overall decrease over 2003-2013 in the number of total calls about mercury [Ratio per year: 0.89, 95% CI: (0.88, 0.90)], and calls about mercury exposure [Ratio per year: 0.84, 95% CI: (0.83, 0.85)], but the number of informational queries about mercury increased over this time [Ratio per year: 1.15 (95% CI: 1.12, 1.18)]. After adjusting for the number of calls of that type each day (e.g., call volume), the associations remained similar: a ratio of 0.88 (95% CI: 0.87, 0.89) per year for total calls, 0.85 (0.83, 0.86) for exposure-related calls, and 1.17 (1.14, 1.21) for informational queries. Although, the number of exposure-related calls decreased, informational queries increased over 2003-2013. This might suggest an increased public interest in mercury health risks despite a decrease in reported exposures over this time period. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Axial mercury segregation in direct current operated low-pressure argon-mercury gas discharge: Part II. Model

    International Nuclear Information System (INIS)

    Gielen, John W A M; Groot, Simon de; Dijk, Jan van; Mullen, Joost J A M van der

    2004-01-01

    In a previous paper we had presented experimental results on mercury segregation due to cataphoresis in direct current operated low-pressure argon-mercury gas discharges. In this paper, we present our model to describe cataphoretic segregation in argon (or another noble gas)-mercury discharges. The model is based on the balance equations for mass and momentum and includes electrophoresis effects of electrons on mercury. Good agreement is found between the experimental results and model calculations. The model confirms our experimental observation that the mercury vapour pressure gradient depends on the local mercury vapour pressure. Furthermore, the model predicts the reversal of the direction of the transport of mercury under certain conditions (the phenomenon known as retrograde cataphoresis)

  17. Mercury in Canadian crude oil

    International Nuclear Information System (INIS)

    Hollebone, B.P.

    2005-01-01

    Estimates for average mercury concentrations in crude oil range widely from 10 ng/g of oil to 3,500 ng/g of oil. With such a broad range of estimates, it is difficult to determine the contributions of the petroleum sector to the total budget of mercury emissions. In response to concerns that the combustion of petroleum products may be a major source of air-borne mercury pollution, Environment Canada and the Canadian Petroleum Products Institute has undertaken a survey of the average total mercury concentration in crude oil processed in Canadian refineries. In order to calculate the potential upper limit of total mercury in all refined products, samples of more than 30 different types of crude oil collected from refineries were measured for their concentration of mercury as it enters into a refinery before processing. High temperature combustion, cold vapour atomic absorption and cold vapour atomic fluorescence were the techniques used to quantify mercury in the samples. The results of the study provide information on the total mass of mercury present in crude oil processed in Canada each year. Results can be used to determine the impact of vehicle exhaust emissions to the overall Canadian mercury emission budget. 17 refs., 2 tabs., 2 figs

  18. MESSENGER: Exploring Mercury's Magnetosphere

    Science.gov (United States)

    Slavin, James A.

    2008-01-01

    The MESSENGER mission to Mercury offers our first opportunity to explore this planet's miniature magnetosphere since Mariner 10's brief fly-bys in 1974-5. Mercury's magnetosphere is unique in many respects. The magnetosphere of Mercury is the smallest in the solar system with its magnetic field typically standing off the solar wind only - 1000 to 2000 km above the surface. For this reason there are no closed dri-fi paths for energetic particles and, hence, no radiation belts; the characteristic time scales for wave propagation and convective transport are short possibly coupling kinetic and fluid modes; magnetic reconnection at the dayside magnetopause may erode the subsolar magnetosphere allowing solar wind ions to directly impact the dayside regolith; inductive currents in Mercury's interior should act to modify the solar In addition, Mercury's magnetosphere is the only one with its defining magnetic flux tubes rooted in a planetary regolith as opposed to an atmosphere with a conductive ionosphere. This lack of an ionosphere is thought to be the underlying reason for the brevity of the very intense, but short lived, approx. 1-2 min, substorm-like energetic particle events observed by Mariner 10 in Mercury's magnetic tail. In this seminar, we review what we think we know about Mercury's magnetosphere and describe the MESSENGER science team's strategy for obtaining answers to the outstanding science questions surrounding the interaction of the solar wind with Mercury and its small, but dynamic magnetosphere.

  19. Hair Mercury Levels in Six Iranian Sub-populations for Estimation of Methylmercury Exposure: A Mini-review

    Directory of Open Access Journals (Sweden)

    Abbas Esmaili-Sari

    2012-01-01

    Full Text Available Background: Mercury is widespread and persistent in the environment. One organicform of mercury, Methylmercury (MeHg, can accumulate in the food chain in aquaticecosystems and lead to high concentrations of MeHg in fish, which, when consumed byhumans, can result in an increased risk of adverse effects. Currently, the Joint FAO/WHOExpert Committee on Food Additives (JECFA has established provisional tolerableweekly intakes (PTWIs for total mercury at 5 μg/kg body weight and for methylmercury at1.6 μg/kg body weight. Mercury concentration in blood or hair has been widely used forestimation of methylmercury exposure.Materials and Methods: In this review article, we calculated methylmercury exposurefrom hair mercury levels among six subpopulations (i.e. students, dentists, dental nurses,women with amalgam fillings, pregnant women in Mahshahr, and Women of a port town,Mahshahr, Iran. Some of the experiments had been performed by this group in previousyears.Results: The mean exposure level (μg/kg bw/day in three Iranian groups (dentists,pregnant women, and women in Mahshahr was higher than RfD and PTWIs.Conclusion: As people are exposed to methylmercury mainly through their diet,especially from fish and other marine species, pregnant women should reduce fishconsumption, especially predatory fish, and dentists should use preventive measures (likemasks and gloves.

  20. Mercury's Dynamic Magnetic Tail

    Science.gov (United States)

    Slavin, James A.

    2010-01-01

    The Mariner 10 and MESSENGER flybys of Mercury have revealed a magnetosphere that is likely the most responsive to upstream interplanetary conditions of any in the solar system. The source of the great dynamic variability observed during these brief passages is due to Mercury's proximity to the Sun and the inverse proportionality between reconnection rate and solar wind Alfven Mach number. However, this planet's lack of an ionosphere and its small physical dimensions also contribute to Mercury's very brief Dungey cycle, approx. 2 min, which governs the time scale for internal plasma circulation. Current observations and understanding of the structure and dynamics of Mercury's magnetotail are summarized and discussed. Special emphasis will be placed upon such questions as: 1) How much access does the solar wind have to this small magnetosphere as a function of upstream conditions? 2) What roles do heavy planetary ions play? 3) Do Earth-like substorms take place at Mercury? 4) How does Mercury's tail respond to extreme solar wind events such coronal mass ejections? Prospects for progress due to advances in the global magnetohydrodynamic and hybrid simulation modeling and the measurements to be taken by MESSENGER after it enters Mercury orbit on March 18, 2011 will be discussed.