Neural Correlates of Processing Negative and Sexually Arousing Pictures

Science.gov (United States)

Bailey, Kira; West, Robert; Mullaney, Kellie M.

2012-01-01

Recent work has questioned whether the negativity bias is a distinct component of affective picture processing. The current study was designed to determine whether there are different neural correlates of processing positive and negative pictures using event-related brain potentials. The early posterior negativity and late positive potential were greatest in amplitude for erotic pictures. Partial Least Squares analysis revealed one latent variable that distinguished erotic pictures from neutral and positive pictures and another that differentiated negative pictures from neutral and positive pictures. The effects of orienting task on the neural correlates of processing negative and erotic pictures indicate that affective picture processing is sensitive to both stimulus-driven, and attentional or decision processes. The current data, together with other recent findings from our laboratory, lead to the suggestion that there are distinct neural correlates of processing negative and positive stimuli during affective picture processing. PMID:23029071

Maternal transfer of mercury to songbird eggs.

Science.gov (United States)

Ackerman, Joshua T; Hartman, C Alex; Herzog, Mark P

2017-11-01

We evaluated the maternal transfer of mercury to eggs in songbirds, determined whether this relationship differed between songbird species, and developed equations for predicting mercury concentrations in eggs from maternal blood. We sampled blood and feathers from 44 house wren (Troglodytes aedon) and 34 tree swallow (Tachycineta bicolor) mothers and collected their full clutches (n = 476 eggs) within 3 days of clutch completion. Additionally, we sampled blood and feathers from 53 tree swallow mothers and randomly collected one egg from their clutches (n = 53 eggs) during mid to late incubation (6-10 days incubated) to evaluate whether the relationship varied with the timing of sampling the mother's blood. Mercury concentrations in eggs were positively correlated with mercury concentrations in maternal blood sampled at (1) the time of clutch completion for both house wrens (R 2  = 0.97) and tree swallows (R 2  = 0.97) and (2) during mid to late incubation for tree swallows (R 2  = 0.71). The relationship between mercury concentrations in eggs and maternal blood did not differ with the stage of incubation when maternal blood was sampled. Importantly, the proportion of mercury transferred from mothers to their eggs decreased substantially with increasing blood mercury concentrations in tree swallows, but increased slightly with increasing blood mercury concentrations in house wrens. Additionally, the proportion of mercury transferred to eggs at the same maternal blood mercury concentration differed between species. Specifically, tree swallow mothers transferred 17%-107% more mercury to their eggs than house wren mothers over the observed mercury concentrations in maternal blood (0.15-1.92 μg/g ww). In contrast, mercury concentrations in eggs were not correlated with those in maternal feathers and, likewise, mercury concentrations in maternal blood were not correlated with those in feathers (all R 2  mercury concentrations from maternal blood to eggs

Mercury in Nelson's Sparrow subspecies at breeding sites.

Directory of Open Access Journals (Sweden)

Virginia L Winder

Full Text Available BACKGROUND: Mercury is a persistent, biomagnifying contaminant that can cause negative effects on ecosystems. Marshes are often areas of relatively high mercury methylation and bioaccumulation. Nelson's Sparrows (Ammodramus nelsoni use marsh habitats year-round and have been documented to exhibit tissue mercury concentrations that exceed negative effects thresholds. We sought to further characterize the potential risk of Nelson's Sparrows to mercury exposure by sampling individuals from sites within the range of each of its subspecies. METHODOLOGY/PRINCIPAL FINDINGS: From 2009 to 2011, we captured adult Nelson's Sparrows at sites within the breeding range of each subspecies (A. n. nelsoni: Grand Forks and Upham, North Dakota; A. n. alterus: Moosonee, Ontario; and A. n. subvirgatus: Grand Manan Island, New Brunswick and sampled breast feathers, the first primary feather (P1, and blood for total mercury analysis. Mean blood mercury in nelsoni individuals captured near Grand Forks ranged from 0.84 ± 0.37 to 1.65 ± 1.02 SD ppm among years, between 2.0 and 4.9 times as high as concentrations at the other sites (P<0.01. Breast feather mercury did not vary among sites within a given sampling year (site means ranged from 0.98 ± 0.69 to 2.71 ± 2.93 ppm. Mean P1 mercury in alterus (2.96 ± 1.84 ppm fw was significantly lower than in any other sampled population (5.25 ± 2.24-6.77 ± 3.51 ppm; P ≤ 0.03. CONCLUSIONS/SIGNIFICANCE: Our study further characterized mercury in Nelson's Sparrows near Grand Forks; we documented localized and potentially harmful mercury concentrations, indicating that this area may represent a biological mercury hotspot. This finding warrants further research to determine if wildlife populations of conservation or recreational interest in this area may be experiencing negative effects due to mercury exposure. We present preliminary conclusions about the risk of each sampled population to mercury exposure.

Mercury in Nelson's Sparrow Subspecies at Breeding Sites

Science.gov (United States)

Winder, Virginia L.; Emslie, Steven D.

2012-01-01

Background Mercury is a persistent, biomagnifying contaminant that can cause negative effects on ecosystems. Marshes are often areas of relatively high mercury methylation and bioaccumulation. Nelson's Sparrows (Ammodramus nelsoni) use marsh habitats year-round and have been documented to exhibit tissue mercury concentrations that exceed negative effects thresholds. We sought to further characterize the potential risk of Nelson's Sparrows to mercury exposure by sampling individuals from sites within the range of each of its subspecies. Methodology/Principal Findings From 2009 to 2011, we captured adult Nelson's Sparrows at sites within the breeding range of each subspecies (A. n. nelsoni: Grand Forks and Upham, North Dakota; A. n. alterus: Moosonee, Ontario; and A. n. subvirgatus: Grand Manan Island, New Brunswick) and sampled breast feathers, the first primary feather (P1), and blood for total mercury analysis. Mean blood mercury in nelsoni individuals captured near Grand Forks ranged from 0.84±0.37 to 1.65±1.02 SD ppm among years, between 2.0 and 4.9 times as high as concentrations at the other sites (Pmercury did not vary among sites within a given sampling year (site means ranged from 0.98±0.69 to 2.71±2.93 ppm). Mean P1 mercury in alterus (2.96±1.84 ppm fw) was significantly lower than in any other sampled population (5.25±2.24–6.77±3.51 ppm; P≤0.03). Conclusions/Significance Our study further characterized mercury in Nelson's Sparrows near Grand Forks; we documented localized and potentially harmful mercury concentrations, indicating that this area may represent a biological mercury hotspot. This finding warrants further research to determine if wildlife populations of conservation or recreational interest in this area may be experiencing negative effects due to mercury exposure. We present preliminary conclusions about the risk of each sampled population to mercury exposure. PMID:22384194

Intake of mercury through fish consumption

International Nuclear Information System (INIS)

Sarmani, S.B.; Kiprawi, A.Z.; Ismail, R.B.; Hassan, R.B.; Wood, A.K.; Rahman, S.A.

1995-01-01

Fish has been known as a source of non-occupational mercury exposure to fish consuming population groups, and this is shown by the high hair mercury levels. In this study, hair samples collected from fishermen and their families, and commercial marine fishes were analyzed for mercury and methylmercury by neutron activation and gas chromatography. The results showed a correlation between hair mercury levels and fish consumption patterns. The levels of mercury found in this study were similar to those reported by other workers for fish consuming population groups worldwide. (author)

Speciated atmospheric mercury in the marine boundary layer of the Bohai Sea and Yellow Sea

Science.gov (United States)

Wang, Chunjie; Ci, Zhijia; Wang, Zhangwei; Zhang, Xiaoshan; Guo, Jia

2016-04-01

The objectives of this study are to identify the spatial and temporal distributions of gaseous elemental mercury (GEM), reactive gaseous mercury (RGM), and fine particulate mercury (HgP2.5) in the marine boundary layer (MBL) of the Bohai Sea (BS) and Yellow Sea (YS), and to investigate the relationships between mercury species and meteorological parameters. The mean concentrations of GEM, RGM, and HgP2.5 were 2.03 ng m-3, 2.5 pg m-3, and 8.2 pg m-3 in spring, and 2.09 ng m-3, 4.3 pg m-3, and 8.3 pg m-3 in fall. Reactive mercury (RGM + HgP2.5) represented RGM + HgP2.5), which indicated that most mercury export in the MBL was GEM and the direct outflow of reactive mercury was very small. Moreover, GEM concentrations over the BS were generally higher than those over the YS both in spring and fall. Although RGM showed a homogeneous distribution over the BS and YS both in spring and fall, the mean RGM concentration in fall was significantly higher than that in spring. In contrast, the spatial distribution of HgP2.5 generally reflected a gradient with high levels near the coast of China and low levels in the open sea, suggesting the significant atmospheric mercury outflow from China. Interestingly, the mean RGM concentrations during daytime were significantly higher than those during nighttime both in spring and fall, while the opposite results were observed for HgP2.5. Additionally, RGM positively correlates with air temperature while negatively correlates with relative humidity. In conclusion, the elevated atmospheric mercury levels in the BS and YS compared to other open seas suggested that the human activities had a significant influence on the oceanic mercury cycle downwind of China.

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

Science.gov (United States)

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.

Genetic effects of organic mercury compounds

Energy Technology Data Exchange (ETDEWEB)

Ramel, C

1967-01-01

Studies on the genetic and developmental effects of organic mercury compounds on lilies, drosophila, and ice were carried out. It was found that chromosomal and developmental abnormalities were correlated with the administration of mercury compounds.

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

Distribution and elevated soil pools of mercury in an acidic subtropical forest of southwestern China

International Nuclear Information System (INIS)

Zhou, Jun; Wang, Zhangwei; Zhang, Xiaoshan; Chen, Jian

2015-01-01

Tieshanping catchment in southwest China was supposed to a large pool of atmospheric mercury. This work was aimed to examine THg (total mercury) concentrations, pools and influence factors in the acidic forest. THg concentrations were highly elevated in the study area, which was significantly depended on TOM (total organic matter) concentrations and altitudinal elevation, whereas negatively correlated with soil pH. The pools of mercury accumulated in soils were correlated strongly with the stocks of TOM and altitude, ranged from 5.9 to 32 mg m −2 and averaged 14.5 mg m −2 , indicating that the acidic forest was a great sink of atmospheric mercury in southwest China. THg concentrations in stream waters decreased with altitude increasing and regression analyses showed that soil/air exchange flux would be increased with the decrease of altitude. Present results suggest that elevation increasing decreases THg losses as low THg concentrations in runoffs and volatilization from soils. - Highlights: • Soil THg pools and influence factors were studied at an acidic catchment in southwestern China. • THg concentrations was increased significantly with TOM concentrations and altitude increasing, decreased with pH. • THg pools in soils were highly elevated and deepened on TOM pools and altitude. • Difference in THg output by volatilization and runoff was a major reason for THg distribution at different altitudes. - Mercury pools increased with altitude increasing as mercury lost more at low elevation area in acidic subtropical forest

Mercury levels, reproduction, and hematology in western grebes from three California Lakes, USA

Energy Technology Data Exchange (ETDEWEB)

Elbert, R.A.; Anderson, D.W. [Univ. of California, Davis, CA (United States). Wildlife, Fish, and Conservation Biology

1998-02-01

Twenty-three healthy adult western and Clark`s grebes (Aechmorphorus occidentalis and Aechmorphorus clarkii) were collected at three study sites in California, USA, in 1992: Clear Lake, Lake County; Eagle Lake, Lassen County; and Tule Lake, Siskiyou County. Liver, kidney, breast muscle, and brain were analyzed for total mercury (Hg) concentration (ppm wet weight), and blood was analyzed for various blood parameters. Clear Lake birds had greater Hg concentrations in kidney, breast muscle, and brain than birds from the other two lakes whereas liver concentrations were not statistically different. Average concentrations for Clear Lake birds were 2.74 ppm for liver, 2.06 ppm for kidney, 1.06 ppm for breast muscle, and 0.28 ppm for brain. The tissue levels of kidney, breast muscle, and brain at the other two study sites were one half the levels found at Clear Lake. These mean tissue levels were near, but below, those known to cause adverse effects. When data from all sites were merged, kidney, breast muscle, and brain concentrations are positively correlated to each other. Liver concentrations were not correlated to any other value. Brain Hg concentrations were also negatively correlated to blood potassium and blood phosphorus levels. Kidney Hg levels were positively correlated to percent blood heterophils and negatively correlated to percent eosinophils, suggesting that mercury levels might be affecting immune function. These biomarkers could not be related to any obvious ecological effects.

Kilometer-Scale Topographic Roughness of Mercury: Correlation with Geologic Features and Units

Science.gov (United States)

Kreslavsky, Mikhail A.; Head, James W.; Neumann, Gregory A.; Zuber, Maria T.; Smith, David E.

2014-01-01

We present maps of the topographic roughness of the northern circumpolar area of Mercury at kilometer scales. The maps are derived from range profiles obtained by the Mercury Laser Altimeter (MLA) instrument onboard the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission. As measures of roughness, we used the interquartile range of profile curvature at three baselines: 0.7 kilometers, 2.8 kilometers, and 11 kilometers. The maps provide a synoptic overview of variations of typical topographic textures. They show a dichotomy between the smooth northern plains and rougher, more heavily cratered terrains. Analysis of the scale dependence of roughness indicates that the regolith on Mercury is thicker than on the Moon by approximately a factor of three. Roughness contrasts within northern volcanic plains of Mercury indicate a younger unit inside Goethe basin and inside another unnamed stealth basin. These new data permit interplanetary comparisons of topographic roughness.

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.

Gaseous elemental mercury (GEM emissions from snow surfaces in northern New York.

Directory of Open Access Journals (Sweden)

J Alexander Maxwell

Full Text Available Snow surface-to-air exchange of gaseous elemental mercury (GEM was measured using a modified Teflon fluorinated ethylene propylene (FEP dynamic flux chamber (DFC in a remote, open site in Potsdam, New York. Sampling was conducted during the winter months of 2011. The inlet and outlet of the DFC were coupled with a Tekran Model 2537A mercury (Hg vapor analyzer using a Tekran Model 1110 two port synchronized sampler. The surface GEM flux ranged from -4.47 ng m(-2 hr(-1 to 9.89 ng m(-2 hr(-1. For most sample periods, daytime GEM flux was strongly correlated with solar radiation. The average nighttime GEM flux was slightly negative and was not well correlated with any of the measured meteorological variables. Preliminary, empirical models were developed to estimate GEM emissions from snow surfaces in northern New York. These models suggest that most, if not all, of the Hg deposited with and to snow is reemitted to the atmosphere.

Gaseous elemental mercury (GEM) emissions from snow surfaces in northern New York.

Science.gov (United States)

Maxwell, J Alexander; Holsen, Thomas M; Mondal, Sumona

2013-01-01

Snow surface-to-air exchange of gaseous elemental mercury (GEM) was measured using a modified Teflon fluorinated ethylene propylene (FEP) dynamic flux chamber (DFC) in a remote, open site in Potsdam, New York. Sampling was conducted during the winter months of 2011. The inlet and outlet of the DFC were coupled with a Tekran Model 2537A mercury (Hg) vapor analyzer using a Tekran Model 1110 two port synchronized sampler. The surface GEM flux ranged from -4.47 ng m(-2) hr(-1) to 9.89 ng m(-2) hr(-1). For most sample periods, daytime GEM flux was strongly correlated with solar radiation. The average nighttime GEM flux was slightly negative and was not well correlated with any of the measured meteorological variables. Preliminary, empirical models were developed to estimate GEM emissions from snow surfaces in northern New York. These models suggest that most, if not all, of the Hg deposited with and to snow is reemitted to the atmosphere.

Quantitative renal scintigraphy: anatomo-clinical and biological correlation (concerning 51 mercury 197 renal scintigraphs)

International Nuclear Information System (INIS)

Pinganaud, J.-M.

1976-01-01

To find out whether the renal mercury uptake measurement in urology is a satisfactory way to judge the separate functional value of the kidneys the records of 51 patients were examined. The exploration took place as follows: - injection of 300 μCi 197 HgCl 2 , - measurement of the radioactivity fixed on each kidney, three days later, by means of a gamma camera. Of these 51 uptake measurements only one result appears inconsistent by excess. All the others agree perfectly with comparative observations. On the whole a close correlation is found between the renal mercury uptake measurement and the various clinical, urographic and anatomical data obtained on this group of patients. The method seems to be ideal because reliable, harmless and repeatable. Where dosimetry is concerned an injected dose of 300μCi delivers 9mrad to each kidney, 6mrad to the ovaries. By way of comparison it is interesting to note that an intraveinous urograph with 5 exposures delivers 500mrad to the ovaries. It is considered safe to repeat the examination 3 to 4 times on one patient [fr

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.

Negatively correlated local and global stock externalities: tax or subsidy?

International Nuclear Information System (INIS)

Zili Yang

2006-01-01

Fossil fuel combustion generates both CO 2 and SO 2 . CO 2 is the most important greenhouse gas; SO 2 can cause serious local pollution. But it can alleviate the potential global warming because of negative radiative forcing. Such a phenomenon can be characterized as negatively correlated local and global stock externalities. In this paper, we set up an optimal control problem of negatively correlated local and global stock externality provision. The efficiency conditions for this problem are derived. These conditions modify the Samuelson rules for optimal provision of externalities. In addition, we examine several policy related scenarios of negatively correlated local and global stock externality provisions. Finally, we discuss policy implications and limitation of the theoretical results derived in this paper. We also indicate applications of the theoretical results here to empirical research, particularly to economic analysis of multiple-gas issues in climate change. (Author)

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

Preliminary study of the distribution of gaseous mercury species in the air of Guiyang city, China

Science.gov (United States)

Shang, L.; Feng, X.; Zheng, W.; Yan, H.

2003-05-01

Total gaseous mercury (TGM) in ambient air consists of Hg^0 and reactive gaseous mercury (RGM) in general. Although RGM only constitutes a small portion of TGM in the air, it contributes the most to both dry and wet deposition of mercury from the atmosphere. TGM and RGM concentrations in ambient air at one site of Guiyang City were determined in March 2002. TGM concentrations were monitored using an automated mercury vapor analyzer Tekran2537A, and RGM in ambient air was sampled using KCI coated tubular denuders. The sampled RGM denuders were analyzed using thermal desorption coupled with CVAFS detection. The average concentrations of TGM and RGM are 7.09 ng m^{-3} and 37.5pg m^{-3} respectively during the sampling period. The primary anthropogenic source for both Hg^0 and RGM is coal combustion in the study area. TGM concentrations are significantly elevated comparing to the global background values, whereas RGM concentrations are only slightly higher than the reported values in remote areas in Europe and US. RGM only constitutes 0.5% ofTGM in the air at the sampling period. There is a significant negative correlation between RGM concentration and relative humidity (RH), with a coefficient correlation of 0.39 (αRGM concentrations observed.

The secondary release of mercury in coal fly ash-based flue-gas mercury removal technology.

Science.gov (United States)

He, Jingfeng; Duan, Chenlong; Lei, Mingzhe; Zhu, Xuemei

2016-01-01

The secondary release of mercury from coal fly ash is a negative by-product from coal-fired power plants, and requires effective control to reduce environmental pollution. Analysing particle size distribution and composition of the coal fly ash produced by different mercury removing technologies indicates that the particles are generally less than 0.5 mm in size and are composed mainly of SiO2, Al2O3, and Fe2O3. The relationships between mercury concentration in the coal fly ash, its particle size, and loss of ignition were studied using different mercury removing approaches. The research indicates that the coal fly ash's mercury levels are significantly higher after injecting activated carbon or brominating activated carbon when compared to regular cooperating-pollution control technology. This is particularly true for particle size ranges of >0.125, 0.075-0.125, and 0.05-0.075 mm. Leaching experiments revealed the secondary release of mercury in discarded coal fly ash. The concentration of mercury in the coal fly ash increases as the quantity of injecting activated carbon or brominating activated carbon increases. The leached concentrations of mercury increase as the particle size of the coal fly ash increases. Therefore, the secondary release of mercury can be controlled by adding suitable activated carbon or brominating activated carbon when disposing of coal fly ash. Adding CaBr2 before coal combustion in the boiler also helps control the secondary release of mercury, by increasing the Hg(2+) concentration in the leachate. This work provides a theoretical foundation for controlling and removing mercury in coal fly ash disposal.

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

Biomarkers of mercury exposure at a mercury recycling facility in Ukraine.

Science.gov (United States)

Gibb, Herman Jones; Kozlov, Kostj; Buckley, Jessie Poulin; Centeno, Jose; Jurgenson, Vera; Kolker, Allan; Conko, Kathryn; Landa, Edward; Panov, Boris; Panov, Yuri; Xu, Hanna

2008-08-01

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 microg/g-Cr (urine), 2.58 microg/L (blood), 3.95 microg/g (hair), and 1.16 microg/g (nails). Occupational category was significantly correlated (p 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.

Understanding the effects of sulfur on mercury capture from coal-fired utility flue gases

Energy Technology Data Exchange (ETDEWEB)

Morris, E.A.; Morita, K.; Jia, C.Q. [University of Toronto, Toronto, ON (Canada)

2010-07-01

Coal combustion continues to be a major source of energy throughout the world and is the leading contributor to anthropogenic mercury emissions. Effective control of these emissions requires a good understanding of how other flue gas constituents such as sulfur dioxide (SO{sub 2}) and sulfur trioxide (SO{sub 3}) may interfere in the removal process. Most of the current literature suggests that SO{sub 2} hinders elemental mercury (Hg{sup 0}) oxidation by scavenging oxidizing species such as chlorine (Cl2) and reduces the overall efficiency of mercury capture, while there is evidence to suggest that SO{sub 2} with oxygen (O{sub 2}) enhances Hg{sup 0} oxidation by promoting Cl2 formation below 100{sup o}C. However, studies in which SO{sub 2} was shown to have a positive correlation with Hg{sup 0} oxidation in full-scale utilities indicate that these interactions may be heavily dependent on operating conditions, particularly chlorine content of the coal and temperature. While bench-scale studies explicitly targeting SO{sub 3} are scarce, the general consensus among full-scale coal-fired utilities is that its presence in flue gas has a strong negative correlation with mercury capture efficiency. The exact reason behind this observed correlation is not completely clear, however. While SO{sub 3} is an inevitable product of SO{sub 2} oxidation by O{sub 2}, a reaction that hinders Hg{sup 0} oxidation, it readily reacts with water vapor, forms sulfuric acid (H{sub 2 }SO{sub 4}) at the surface of carbon, and physically blocks active sites of carbon. On the other hand, H{sub 2}SO{sub 4} on carbon surfaces may increase mercury capacity either through the creation of oxidation sites on the carbon surface or through a direct reaction of mercury with the acid. However, neither of these beneficial impacts is expected to be of practical significance for an activated carbon injection system in a real coal-fired utility flue gas.

Mercury emission from a temperate lake during autumn turnover

International Nuclear Information System (INIS)

Wollenberg, Jennifer L.; Peters, Stephen C.

2009-01-01

Lakes in temperate regions stratify during summer and winter months, creating distinct layers of water differentiated by their physical and chemical characteristics. When lakes mix in autumn and spring, mercury cycling may be affected by the chemical changes that occur during mixing. Sampling was conducted in Lake Lacawac, Eastern Pennsylvania, USA, throughout the autumn of 2007 to characterize changes in emission of gaseous elemental mercury (Hg 0 ) from the lake surface and dissolved mercury profiles in the water column during mixing. Water chemistry and weather parameters were also measured, including dissolved organic carbon (DOC), iron, and solar radiation which have been shown to interact with mercury species. Results indicate that emission of Hg 0 from the lake to the atmosphere during turnover was controlled both by solar radiation and by surface water mercury concentration. As autumn turnover progressed through the months of October and November, higher mercury concentration water from the hypolimnion mixed with epilimnetic water, increasing mercury concentration in epilimnetic waters. Dissolved absorbance was significantly correlated with mercury concentrations and with iron, but DOC concentrations were essentially constant throughout the study period and did not exhibit a relationship with either dissolved mercury concentrations or emission rates. Positive correlations between dissolved mercury and iron and manganese also suggest a role for these elements in mercury transport within the lake, but iron and manganese did not demonstrate a relationship with emission rates. This research indicates that consideration of seasonal processes in lakes is important when evaluating mercury cycling in aquatic systems

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

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.

Bioaccumulation of mercury and polychlorinated dibenzo-p-dioxins and dibenzofurans in salty water organisms.

Science.gov (United States)

Liao, Pei-Yu; Liu, Chen-Wuing; Liu, Wen-Yao

2016-01-01

Mercury and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) accumulate in organisms through food webs and exert potentially toxic effects on aquatic organisms and humans. This study examined the levels of mercury and PCDD/Fs in organisms and sediment samples collected from a saltwater pond at the An-Shun site, a chloralkali factory that shut down in Tainan City, Taiwan. It was also a pentachlorophenol production plant. After the factories were shut down in the 1980s, mercury and PCDD/Fs contamination remained, posing severe health hazards. The correlation between PCDD/Fs congener accumulation patterns in distinct fish organs and the sediment was evaluated. Mercury and PCDD/Fs levels in all the fish samples exceeded food safety limits, and the concentrations of mercury and PCDD/Fs in each species were closely correlated (n = 12, Spearman's rank correlation [R] = 0.811, p mercury concentrations were positively but non-significantly correlated with the weight (n = 11, R = 0.741, p mercury concentration was correlated with organism weight and length, whereas the PCDD/Fs concentration was associated with organ lipid content. The study results are valuable for assessing the health risks associated with ingesting mercury- and PCFF/F-contaminated seafood from the study site.

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

-profile concentration maxima, however, the depth of the maxima are more varied than the total mercury profiles (150 - 700m). Also, our observed distribution of methylated mercury highly correlated with organic carbon remineralization rates (OCRR) in the North Pacific and Indian Oceans. Interestingly, we find the highest methylated mercury concentrations in the Southern Ocean, suggesting the possibility of unique mechanisms for methylmercury production, preservation, and degradation in polar ecosystems such as cold water temperatures, extended periods of sea ice cover, and annual atmospheric mercury depletion events. We are using these data to better link oceanic production of bioaccumulative mercury to models for atmospheric and oceanic transport and bioaccumulation. This will ultimately lead to a better understanding of mercury levels in consumable fish and shell fish.

Acclimation of subsurface microbial communities to mercury

DEFF Research Database (Denmark)

de Lipthay, Julia R; Rasmussen, Lasse D; Øregaard, Gunnar

2008-01-01

of mercury tolerance and functional versatility of bacterial communities in contaminated soils initially were higher for surface soil, compared with the deeper soils. However, following new mercury exposure, no differences between bacterial communities were observed, which indicates a high adaptive potential......We studied the acclimation to mercury of bacterial communities of different depths from contaminated and noncontaminated floodplain soils. The level of mercury tolerance of the bacterial communities from the contaminated site was higher than those of the reference site. Furthermore, the level...... of the subsurface communities, possibly due to differences in the availability of mercury. IncP-1 trfA genes were detected in extracted community DNA from all soil depths of the contaminated site, and this finding was correlated to the isolation of four different mercury-resistance plasmids, all belonging...

On the relationship between positive and negative affect: Their correlation and their co-occurrence.

Science.gov (United States)

Larsen, Jeff T; Hershfield, Hal E; Stastny, Bradley J; Hester, Neil

2017-03-01

Understanding the nature of emotional experience requires understanding the relationship between positive and negative affect. Two particularly important aspects of that relationship are the extent to which positive and negative affect are correlated with one another and the extent to which they co-occur. Some researchers have assumed that weak negative correlations imply greater co-occurrence (i.e., more mixed emotions) than do strong negative correlations, but others have noted that correlations may imply very little about co-occurrence. We investigated the relationship between the correlation between positive and negative affect and co-occurrence. Participants in each of 2 samples provided moment-to-moment happiness and sadness ratings as they watched an evocative film and listened to music. Results indicated (a) that 4 measures of the correlation between positive and negative affect were quite highly related to 1 another; (b) that the strength of the correlation between measures of mixed emotions varied considerably; (c) that correlational measures were generally (but not always) weakly correlated with mixed emotion measures; and (d) that bittersweet stimuli consistently led to elevations in mixed emotion measures but did not consistently weaken the correlation between positive and negative affect. Results highlight that the correlation between positive and negative affect and their co-occurrence are distinct aspects of the relationship between positive and negative affect. Such insight helps clarify the implications of existing work on age-related and cultural differences in emotional experience and sets the stage for greater understanding of the experience of mixed emotions. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Plasma homovanillic acid levels in schizophrenic patients: correlation with negative symptoms.

Science.gov (United States)

Dávila, Ricardo; Zumárraga, Mercedes; Basterreche, Nieves; Arrúe, Aurora; Anguiano, Juan B

2007-05-30

The relation between changes in the levels of plasma homovanillic acid (pHVA) and clinical evolution during neuroleptic treatment of schizophrenic patients has not been satisfactorily characterized, as a number of conflicting findings have been reported. Significant correlations have generally been found using the assessment of positive symptoms as an index of clinical outcome. Nevertheless, attempts to correlate pHVA concentrations with negative symptoms have yielded contradictory results. With a view to evaluating if different responses in negative symptoms are associated with distinct pHVA profiles, we examined the levels of pHVA in 46 neuroleptic-free schizophrenic patients and in these patients after neuroleptic treatment. Negative and positive symptoms were also addressed before and after treatment. Our results reveal that at least two classes of negative symptoms exist; the clinical evolution of the first class of negative symptoms parallels that of positive symptoms, and clinical improvement correlates with reduced dopaminergic activity. In contrast, in the second class, reduced dopaminergic activity is associated with a further deterioration of negative symptoms. These findings corroborate the heterogeneity of negative symptoms and may contribute to a better definition of endophenotypes in the schizophrenic syndrome.

Mercury soil surveys: a good reconnaissance tool

Energy Technology Data Exchange (ETDEWEB)

Stone, C.; Ruscetta, C.A.; Foley, D. (eds.)

1981-05-01

Three examples of mercury soil surveys are discussed, along with the gravity data. An excellent correlation was found in southern Arizona between buried structures revealed by gravity and mercury soil surveys. The advantages of the latter over the former as a reconnaissance tool are listed. (MHR)

Determination of Mercury Daily Intake and Hair-to-Blood Mercury Concentration Ratio in People Resident of the Coast of the Persian Gulf, Iran.

Science.gov (United States)

Okati, Narjes; Esmaili-Sari, Abbas

2018-01-01

The objectives of this study were to understand the mercury daily intake and hair-to-blood mercury ratio in fishermen and non-fishermen families in the coast of the Persian Gulf in Iran. The mean mercury concentration in the hair of fishermen and non-fishermen families was 5.76 and 2.27 μg/g, respectively. The mean mercury concentrations of RBCs were obtained for fishermen families and non-fishermen families: 35.96 and 17.18 μg/L, respectively. Hair mercury concentrations in 17% of people were higher than 10 μg/g, the No Observed Adverse Effects Level set by the World Health Organization. 78% of people had a blood mercury value > 5.8 μg/L, the standard level set by the U.S. Environmental Protection Agency. A significant correlation (r = 0.94, p = 0.000) was seen between log hair and RBCs mercury concentrations. The mean mercury daily intake for fishermen and non-fishermen families was 0.42 and 0.20 µg/kg BW per day, respectively. The mean mercury daily intake of fishermen families was higher than the provisional tolerable daily intake (0.23 µg/kg BW per day) suggested by the Joint Expert Committee on Food Additives. Mercury daily intake significantly correlated with fish consumption (r = 0.50, p = 0.000) and log hair mercury (r = 0.88, p = 0.000). The total mean of hair-to-blood mercury concentration ratio was 306. We conclude that the use of mercury concentrations in the hair and RBCs could have been suitable biomarkers for predicting mercury exposure of people with a high rate of fish consumption.

Atmospheric mercury inputs in montane soils increase with elevation: evidence from mercury isotope signatures.

Science.gov (United States)

Zhang, Hua; Yin, Run-sheng; Feng, Xin-bin; Sommar, Jonas; Anderson, Christopher W N; Sapkota, Atindra; Fu, Xue-wu; Larssen, Thorjørn

2013-11-25

The influence of topography on the biogeochemical cycle of mercury (Hg) has received relatively little attention. Here, we report the measurement of Hg species and their corresponding isotope composition in soil sampled along an elevational gradient transect on Mt. Leigong in subtropical southwestern China. The data are used to explain orography-related effects on the fate and behaviour of Hg species in montane environments. The total- and methyl-Hg concentrations in topsoil samples show a positive correlation with elevation. However, a negative elevation dependence was observed in the mass-dependent fractionation (MDF) and mass-independent fractionation (MIF) signatures of Hg isotopes. Both a MIF (Δ(199)Hg) binary mixing approach and the traditional inert element method indicate that the content of Hg derived from the atmosphere distinctly increases with altitude.

High activity carbon sorbents for mercury capture

Directory of Open Access Journals (Sweden)

Stavropoulos George G.

2006-01-01

Full Text Available High efficiency activated carbons have been prepared for removing mercury from gas streams. Starting materials used were petroleum coke, lignite, charcoal and olive seed waste, and were chemically activated with KOH. Produced adsorbents were primarily characterized for their porosity by N2 adsorption at 77 K. Their mercury retention capacity was characterized based on the breakthrough curves. Compared with typical commercial carbons, they have exhibited considerably enhanced mercury adsorption capacity. An attempt has been made to correlate mercury entrapment and pore structure. It has been shown that physical surface area is increased during activation in contrast to the mercury adsorption capacity that initially increases and tends to decrease at latter stages. Desorption of active sites may be responsible for this behavior.

Total mercury and methylmercury in fish fillets, water, and bed sediments from selected streams in the Delaware River basin, New Jersery, New York, and Pennsylvania, 1998-2001

Science.gov (United States)

Brightbill, Robin A.; Riva-Murray, Karen; Bilger, Michael D.; Byrnes, John D.

2004-01-01

Within the Delaware River Basin, fish-tissue samples were analyzed for total mercury (tHg). Water and bed-sediment samples were analyzed for tHg and methylmercury (MeHg), and methylation efficiencies were calculated. This study was part of a National Mercury Pilot Program conducted by the U.S. Geological Survey (USGS). The Delaware River Basin was chosen because it is part of the USGS National Water-Quality Assessment Program that integrates physical, chemical, and biological sampling efforts to determine status and trends in surface-water and ground-water resources. Of the 35 sites in the study, 31 were sampled for fish. The species sampled at these sites include smallmouth bass (Micropterus dolomieu), the target species, and where smallmouth bass could not be collected, brown trout (Salmo trutta), chain pickerel (Esox niger), largemouth bass (Micropterus salmoides), and rock bass (Ambloplites rupestris). There were a total of 32 fish samples; 7 of these exceeded the 0.3 ?g/g (micrograms per gram) wet-weight mercury (Hg) concentration set for human health by the U.S. Environmental Protection Agency and 27 of these exceeded the U.S. Fish and Wildlife Service criteria of 0.1 ?g/g wet weight for the protection of fish-eating birds and wildlife. Basinwide analysis of Hg in fish, water, and bed sediment showed tHg concentration in fillets correlated positively with population density, urban land cover, and impervious land surface. Negative correlations included wetland land cover, septic density, elevation, and latitude. Smallmouth bass from the urban sites had a higher median concentration of tHg than fish from agricultural, low intensity-agricultural, or forested sites. Concentrations of tHg and MeHg in water were higher in samples from the more urbanized areas of the basin and were positively correlated with urbanization and negatively correlated with forested land cover. Methylation efficiency of water was negatively correlated with urbanization. Bed

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

Mercury and water level fluctuations in lakes of northern Minnesota

Science.gov (United States)

Larson, James H.; Maki, Ryan P; Christensen, Victoria G.; Sandheinrich, Mark B.; LeDuc, Jaime F.; Kissane, Claire; Knights, Brent C.

2017-01-01

Large lake ecosystems support a variety of ecosystem services in surrounding communities, including recreational and commercial fishing. However, many northern temperate fisheries are contaminated by mercury. Annual variation in mercury accumulation in fish has previously been linked to water level (WL) fluctuations, opening the possibility of regulating water levels in a manner that minimizes or reduces mercury contamination in fisheries. Here, we compiled a long-term dataset (1997-2015) of mercury content in young-of-year Yellow Perch (Perca flavescens) from six lakes on the border between the U.S. and Canada and examined whether mercury content appeared to be related to several metrics of WL fluctuation (e.g., spring WL rise, annual maximum WL, and year-to-year change in maximum WL). Using simple correlation analysis, several WL metrics appear to be strongly correlated to Yellow Perch mercury content, although the strength of these correlations varies by lake. We also used many WL metrics, water quality measurements, temperature and annual deposition data to build predictive models using partial least squared regression (PLSR) analysis for each lake. These PLSR models showed some variation among lakes, but also supported strong associations between WL fluctuations and annual variation in Yellow Perch mercury content. The study lakes underwent a modest change in WL management in 2000, when winter WL minimums were increased by about 1 m in five of the six study lakes. Using the PLSR models, we estimated how this change in WL management would have affected Yellow Perch mercury content. For four of the study lakes, the change in WL management that occurred in 2000 likely reduced Yellow Perch mercury content, relative to the previous WL management regime.

Maternal transfer of contaminants in birds: Mercury and selenium concentrations in parents and their eggs

International Nuclear Information System (INIS)

Ackerman, Joshua T.; Eagles-Smith, Collin A.; Herzog, Mark P.; Hartman, C. Alex

2016-01-01

We conducted a detailed assessment of the maternal transfer of mercury and selenium to eggs in three bird species (n = 107 parents and n = 339 eggs), and developed predictive equations linking contaminant concentrations in eggs to those in six tissues of the mother (blood, muscle, liver, kidney, breast feathers, and head feathers). Mercury concentrations in eggs were positively correlated with mercury concentrations in each of the mother's internal tissues (R"2 ≥ 0.95), but generally not with feathers. For each species, the proportion of mercury transferred to eggs decreased as mercury concentrations in the mother increased. At the same maternal mercury concentration, the proportion of mercury transferred to eggs differed among species, such that Forster's tern (Sterna forsteri) and black-necked stilt (Himantopus mexicanus) females transferred more methylmercury to their eggs than American avocet (Recurvirostra americana) females. Selenium concentrations in eggs also were correlated with selenium concentrations in the mother's liver (R"2 = 0.87). Furthermore, mercury and selenium concentrations in tern eggs were positively correlated with those in the father (R"2 = 0.84). Incubating male terns had 21% higher mercury concentrations in blood compared to incubating females at the same egg mercury concentration. We provide equations to predict contaminant concentrations in eggs from each of the commonly sampled bird tissues. - Highlights: • We developed predictive equations linking contaminant concentrations in eggs to those in the mother. • Mercury concentrations in eggs were positively correlated with those in the mother. • The proportion of mercury transferred to eggs decreased as mercury in the mother increased. • The proportion of mercury transferred to eggs differed among species. • Selenium concentrations in eggs also were correlated with those in the mother's liver. - We examined the maternal transfer of mercury and selenium to eggs in

Mercury and selenium levels in 19 species of saltwater fish from New Jersey as a function of species, size, and season

Science.gov (United States)

Burger, Joanna; Gochfeld, Michael

2014-01-01

There are few data on risks to biota and humans from mercury levels in saltwater fish. This paper examines mercury and selenium levels in muscle of 19 species of fish caught by recreational fisherfolk off the New Jersey shore, as a function of species of fish, size, and season, and risk of mercury to consumers. Average mercury levels ranged from 0.01 ppm (wet weight) (Menhaden Brevoortia tyrannus) to 1.83 ppm (Mako Shark Isurus oxyrinchus). There were four categories of mercury levels: very high (only Mako), high (averaging 0.3–0.5 ppm, 3 species), medium (0.14–0.20 ppm, 10 species), and low (below 0.13 ppm, 5 species). Average selenium levels for the fish species ranged from 0.18 ppm to 0.58 ppm, and had lower variability than mercury (coefficient of variation=38.3 vs 69.1%), consistent with homeostatic regulation of this essential element. The correlation between mercury and selenium was significantly positive for five and negative for two species. Mercury levels showed significant positive correlations with fish size for ten species. Size was the best predictor of mercury levels. Selenium showed no consistent relationship to fish length. Over half of the fish species had some individual fish with mercury levels over 0.3 ppm, and a third had fish with levels over 0.5 ppm, levels that pose a human health risk for high end consumers. Conversely several fish species had no individuals above 0.5 ppm, and few above 0.3 ppm, suggesting that people who eat fish frequently, can reduce their risk from mercury by selecting which species (and which size) to consume. Overall, with the exception of shark, Bluefin Tuna (Thunnus thynnus), Bluefish (Pomatomus saltatrix) and Striped Bass (Morone saxatilis), the species sampled are generally medium to low in mercury concentration. Selenium:mercury molar ratios were generally above 1:1, except for the Mako shark. PMID:21292311

Circulating steroids negatively correlate with tinnitus.

Science.gov (United States)

Chrbolka, Pavel; Palúch, Zoltán; Hill, Martin; Alušík, Štefan

2017-07-01

While not a disease entity in itself; symptoms of tinnitus (from Latin tinnio - clink) accompany a number of diseases. Tinnitus prevalence increases with age, deteriorates one's quality of life, and may even result in suicidal behavior. Tinnitus develops in response to a variety of risk factors, otoxic substances, noise exposure, hearing disorders, and psychological alterations. Tinnitus is closely related to mood, depression, and psychological state. In the present study, we focused on alterations of the steroid metabolome and particularly neuroactive, neuroprotective, and immunomodulatory steroids in patients with tinnitus. The study group consisted of 28 patients without evidence of an organic cause of tinnitus as well as without associated diseases or the effect of ototoxic medications. All patients underwent a complete audiological assessment and laboratory tests including routine biochemical markers and quantification of circulating steroids using gas chromatography/mass spectrometry and immunoassays. To rule out a pathology in the cerebellopontine angle area, CT scan or MRI were performed. To diagnose stem lesions, evoked potentials were also measured. Pearson's correlations and multivariate regression were used to assess any links between tinnitus intensity and frequency on the one hand, and steroid levels on the other. Results indicated a significant and consistent negative correlation between tinnitus indices and intensity of adrenal steroidogenesis. The circulating steroid metabolome including hormones and neuroactive, neuroprotective, and immunomodulatory steroids negatively correlates with the degree of tinnitus due to hypothalamo-pituitary-adrenal axis malfunction. Our results may help explain the pathophysiology of tinnitus and improve its diagnosis. However, further studies are needed to verify our postulation. Copyright © 2017 Elsevier Inc. All rights reserved.

The Effect of Long Term Mercury Pollution on the Soil Microbial Community

DEFF Research Database (Denmark)

Müller, A.K.; Westergaard, K.; Christensen, Søren

2001-01-01

The effect of long-term exposure to mercury on the soil microbial community was investigated in soil from three different sites along a pollution gradient. The amount of total and bioavailable mercury was negatively correlated to the distance from the center of contamination. The size...... of the bacterial and protozoan populations was reduced in the most contaminated soil, whereas there was no significant difference in fungal biomass measured as chitinase activity. Based on the number of colony morphotypes, moreover, the culturable bacterial population was structurally less diverse and contained...... of the number and abundance of bands. The functional potential of the microbial population measured as sole carbon source utilization by Ecoplates® differed between the soils, but there was no change in the number of substrates utilized. The observed changes in the different soil microbial populations...

Variation in concentrations of three mercury (Hg) forms at a rural and a suburban site in New York State.

Science.gov (United States)

Choi, Hyun-Deok; Huang, Jiaoyan; Mondal, Sumona; Holsen, Thomas M

2013-03-15

Tekran® Hg speciation systems were used at a rural site (Huntington Forest, NY; HF) and a suburban site (Rochester, NY; ROC) to measure gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM), and fine particulate-bound mercury (PBM2.5) concentrations for two years (December 2007 to November 2009). Ancillary data were also available from the New York State Department of Environmental Conservation and the United States Environmental Protection Agency Clean Air Status and Trends Network. Seasonal GEM concentrations were similar at both sites and influenced by factors such as the planet boundary layer (PBL) height and mercury emissions from snow, soil, and point sources. In some seasons, O3 was negatively correlated with GEM at ROC and positively correlated with GEM at HF. At HF, O3 was correlated with GOM and was typically higher in the afternoon. The cause of this pattern may be photochemical reactions during the day, and the GOM diel pattern may also be due to deposition which is enhanced by dew formation during the night and early morning. PBM2.5 concentrations were higher in winter at both sites. This is indicative of local wood combustion for space heating in winter, increased sorption to particles at lower temperatures, and lower PBL in the winter. At the suburban site, 2 of 12 events with enhanced GEM/CO ratios were poorly correlated with SO2/GOM, implying that these two events were due either to long range transport or regional metallurgical industries in Canada. Copyright © 2012 Elsevier B.V. All rights reserved.

Conifer density within lake catchments predicts fish mercury concentrations in remote subalpine lakes

Science.gov (United States)

Eagles-Smith, Collin A.; Herring, Garth; Johnson, Branden L.; Graw, Rick

2016-01-01

Remote high-elevation lakes represent unique environments for evaluating the bioaccumulation of atmospherically deposited mercury through freshwater food webs, as well as for evaluating the relative importance of mercury loading versus landscape influences on mercury bioaccumulation. The increase in mercury deposition to these systems over the past century, coupled with their limited exposure to direct anthropogenic disturbance make them useful indicators for estimating how changes in mercury emissions may propagate to changes in Hg bioaccumulation and ecological risk. We evaluated mercury concentrations in resident fish from 28 high-elevation, sub-alpine lakes in the Pacific Northwest region of the United States. Fish total mercury (THg) concentrations ranged from 4 to 438 ng/g wet weight, with a geometric mean concentration (±standard error) of 43 ± 2 ng/g ww. Fish THg concentrations were negatively correlated with relative condition factor, indicating that faster growing fish that are in better condition have lower THg concentrations. Across the 28 study lakes, mean THg concentrations of resident salmonid fishes varied as much as 18-fold among lakes. We used a hierarchal statistical approach to evaluate the relative importance of physiological, limnological, and catchment drivers of fish Hg concentrations. Our top statistical model explained 87% of the variability in fish THg concentrations among lakes with four key landscape and limnological variables: catchment conifer density (basal area of conifers within a lake's catchment), lake surface area, aqueous dissolved sulfate, and dissolved organic carbon. Conifer density within a lake's catchment was the most important variable explaining fish THg concentrations across lakes, with THg concentrations differing by more than 400 percent across the forest density spectrum. These results illustrate the importance of landscape characteristics in controlling mercury bioaccumulation in fish.

Mercury Report-Children's exposure to elemental mercury

Science.gov (United States)

... 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 ...

Ecological and physiological parameters of mercury and cesium-137 accumulation in the raccoon

International Nuclear Information System (INIS)

Davis, A.H.

1981-01-01

Raccoons from 4 regions in the southeastern Coastal Plain were evaluated for mercury content. Mercury content of hair when used as an indicator of total body mercury content was significantly different among 3 of the 4 areas: Okefenokee Swamp, Eglin Air Force Base, and Sapelo Island on the Georgia Coast. Raccoons from Echols County Georgia were not significantly different from those of the Okefenokee. Mercury in the liver and kidney was significantly different between Okefenokee and Sapelo. There was a strong correlation between the age of the raccoon and the mercury in hair, with older animals having higher concentrations. This relationship was also valid for most other tissues. There was evidence that mercury content in some tissues was correlated with the season and the body condition of the raccoon. Mercury was not transferred through the placenta to the fetal raccoons. There was a strong relationship of mercury content to raccoon behavioral characteristics. Raccoon body weight was slightly different between the areas studied. Cesium-137 values in raccoons were significantly different between the Okefenokee and Sapelo Island. Cesium-137 content was correlated with raccoon age, body weight, and mercury content. Generally non-detectable levels of chlorinated hydrocarbons and PCB were found in Okefenokee raccoons. Mercury concentrations in crayfish were generally low but probably of importance in the raccoon food chain. The biological half life of mercury in brain, gonad, pancreas, spleen, heart, and lung was approximately 52 days. The half-life of mercury in muscle was 35 days. Mercury content of hair, liver, and kidney decreased at very slow rates, with biological half lives of 229, 108, and 138 days. This was probably due to the role of these tissues in clearance of mercury from the body, and to the molting pattern of raccoon hair

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

Geographic and seasonal variation in mercury exposure of the declining Rusty Blackbird

Science.gov (United States)

Samuel T. Edmonds; David C. Evers; Daniel A. Cristol; Claudia Mettke-Hofmann; Luke L. Powell

2010-01-01

Recent evidence suggests that mercury exposure has negative effects on the health of songbirds, and species that forage in wetlands may be at a greater risk of bioaccumulation of mercury than are those of other habitats. We examined mercury concentrations in blood and feathers from the wetland obligate and rapidly declining Rusty Blackbird (Euphagus carolinus) from...

Evaluation of passive sampling of gaseous mercury using different sorbing materials.

Science.gov (United States)

Lin, Huiming; Zhang, Wei; Deng, Chunyan; Tong, Yingdong; Zhang, Qianggong; Wang, Xuejun

2017-06-01

Atmospheric mercury monitoring is essential because of its potential human health and ecological impacts. Current automated monitoring systems include limitations such as high cost, complicated configuration, and electricity requirements. Passive samplers require no electric power and are more appropriate for screening applications and long-term monitoring. Sampling rate is a major factor to evaluate the performance of a passive sampler. In this study, laboratory experiments were carried out using an exposure chamber to search for high efficiency sorbents for gaseous mercury. Four types of sorbents, including sulfur-impregnated carbon (SIC), chlorine-impregnated carbon (CIC), bromine-impregnated carbon (BIC), and gold-coated sand (GCS) were evaluated under a wide range of meteorological parameters, including temperature, relative humidity, and wind speed. The results showed that the four sorbents all have a high sampling rate above 0.01 m 3 g -1  day -1 , and wind speed has a positive correlation with the sampling rate. Under different temperature and relative humidity, the sampling rate of SIC keeps stable. The sampling rate of CIC and BIC shows a negative correlation with temperature, and GCS is influenced by all the three meteorological factors. Furthermore, long-term experiments were carried out to investigate the uptake capacity of GCS and SIC. Uptake curves show that the mass amount of sorbent in a passive sampler can influence uptake capacity. In the passive sampler, 0.9 g SIC or 0.9 g GCS can achieve stable uptake efficiency for at least 110 days with gaseous mercury concentration at or below 2 ng/m 3 . For mercury concentration at or below 21 ng/m 3 , 0.9 g SIC can maintain stable uptake efficiency for 70 days, and 0.9 g GCS can maintain stability for 45 days.

Atmospheric mercury monitoring survey in Beijing, China.

Science.gov (United States)

Liu, Shili; Nadim, Farhad; Perkins, Chris; Carley, Robert J; Hoag, George E; Lin, Yuhan; Chen, Letian

2002-07-01

With the aid of one industrial, two urban, two suburban, and two rural sampling locations, diurnal patterns of total gaseous mercury (TGM) were monitored in January, February and September of 1998 in Beijing, China. Monitoring was conducted in six (two urban, two suburban, one rural and the industrial sites) of the seven sampling sites during January and February (winter) and in four (two urban, one rural, and the industrial sites) of the sampling locations during September (summer) of 1998. In the three suburban sampling stations, mean TGM concentrations during the winter sampling period were 8.6, 10.7, and 6.2 ng/m3, respectively. In the two urban sampling locations mean TGM concentrations during winter and summer sampling periods were 24.7, 8.3, 10, and 12.7 ng/m3, respectively. In the suburban-industrial and the two rural sampling locations, mean mercury concentrations ranged from 3.1-5.3 ng/m3 in winter to 4.1-7.7 ng/m3 in summer sampling periods. In the Tiananmen Square (urban), and Shijingshan (suburban) sampling locations the mean TGM concentrations during the summer sampling period were higher than winter concentrations, which may have been caused by evaporation of soil-bound mercury in warm periods. Continuous meteorological data were available at one of the suburban sites, which allowed the observation of mercury concentration variations associated with some weather parameters. It was found that there was a moderate negative correlation between the wind speed and the TGM concentration at this suburban sampling location. It was also found that during the sampling period at the same site, the quantity of TGM transported to or from the sampling site was mainly influenced by the duration and frequency of wind occurrence from certain directions.

Heterogeneous Distribution of Chromium on Mercury

Science.gov (United States)

Nittler, L. R.; Boujibar, A.; Crapster-Pregont, E.; Frank, E. A.; McCoy, T. J.; McCubbin, F. M.; Starr, R. D.; Vander Kaaden, K. E.; Vorburger, A.; Weider, S. Z.

2018-05-01

Mercury's surface has an average Cr/Si ratio of 0.003 (Cr 800 ppm), with at least a factor of 2 systematic uncertainty. Cr is heterogeneously distributed and correlated with Mg, Ca, S, and Fe and anti-correlated with Al.

Global Mercury Pathways in the Arctic Ecosystem

Science.gov (United States)

Lahoutifard, N.; Lean, D.

2003-12-01

The sudden depletions of atmospheric mercury which occur during the Arctic spring are believed to involve oxidation of gaseous elemental mercury, Hg(0), rendering it less volatile and more soluble. The Hg(II) oxidation product(s) are more susceptible to deposition, consistent with the observation of dramatic increases in snow mercury levels during depletion events. Temporal correlations with ozone depletion events and the proliferation of BrO radicals support the hypothesis that oxidation of Hg(0) occurs in the gas phase and results in its conversion to RGM (Reactive Gaseous Mercury). The mechanisms of Hg(0) oxidation and particularly Hg(II) reduction are as yet unproven. In order to evaluate the feasibility of proposed chemical processes involving mercury in the Arctic atmosphere and its pathway after deposition on the snow from the air, we investigated mercury speciation in air and snow pack at Resolute, Nunavut, Canada (latitude 75° N) prior to and during snow melt during spring 2003. Quantitative, real-time information on emission, air transport and deposition were combined with experimental studies of the distribution and concentrations of different mercury species, methyl mercury, anions, total organic carbon and total inorganic carbon in snow samples. The effect of solar radiation and photoreductants on mercury in snow samples was also investigated. In this work, we quantify mercury removed from the air, and deposited on the snow and the transformation to inorganic and methyl mercury.

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.

Dissolved gaseous mercury formation and mercury volatilization in intertidal sediments.

Science.gov (United States)

Cesário, Rute; Poissant, Laurier; Pilote, Martin; O'Driscoll, Nelson J; Mota, Ana M; Canário, João

2017-12-15

Intertidal sediments of Tagus estuary regularly experiences complex redistribution due to tidal forcing, which affects the cycling of mercury (Hg) between sediments and the water column. This study quantifies total mercury (Hg) and methylmercury (MMHg) concentrations and fluxes in a flooded mudflat as well as the effects on water-level fluctuations on the air-surface exchange of mercury. A fast increase in dissolved Hg and MMHg concentrations was observed in overlying water in the first 10min of inundation and corresponded to a decrease in pore waters, suggesting a rapid export of Hg and MMHg from sediments to the water column. Estimations of daily advective transport exceeded the predicted diffusive fluxes by 5 orders of magnitude. A fast increase in dissolved gaseous mercury (DGM) concentration was also observed in the first 20-30min of inundation (maximum of 40pg L -1 ). Suspended particulate matter (SPM) concentrations were inversely correlated with DGM concentrations. Dissolved Hg variation suggested that biotic DGM production in pore waters is a significant factor in addition to the photochemical reduction of Hg. Mercury volatilization (ranged from 1.1 to 3.3ngm -2 h -1 ; average of 2.1ngm -2 h -1 ) and DGM production exhibited the same pattern with no significant time-lag suggesting a fast release of the produced DGM. These results indicate that Hg sediment/water exchanges in the physical dominated estuaries can be underestimated when the tidal effect is not considered. Copyright © 2017 Elsevier B.V. All rights reserved.

Mercury dilution by autochthonous organic matter in a fertilized mangrove wetland.

Science.gov (United States)

Machado, Wilson; Sanders, Christian J; Santos, Isaac R; Sanders, Luciana M; Silva-Filho, Emmanoel V; Luiz-Silva, Wanilson

2016-06-01

A dated sediment core from a highly-fertilized mangrove wetland located in Cubatão (SE Brazil) presented a negative correlation between mercury (Hg) and organic carbon contents. This is an unusual result for a metal with well-known affinity to organic matter. A dilution of Hg concentrations by autochthonous organic matter explained this observation, as revealed by carbon stable isotopes signatures (δ(13)C). Mercury dilution by the predominant mangrove-derived organic matter counterbalanced the positive influences of algal-derived organic matter and clay contents on Hg levels, suggesting that deleterious effects of Hg may be attenuated. Considering the current paradigm on the positive effect of organic matter on Hg concentrations in coastal sediments and the expected increase in mangrove organic matter burial due to natural and anthropogenic stimulations of primary production, predictions on the influences of organic matter on Hg accumulation in mangrove wetlands deserve caution. Copyright © 2016 Elsevier Ltd. All rights reserved.

Genotypic differences in arsenic, mercury, lead and cadmium in milled rice (Oryza sativa L.).

Science.gov (United States)

Jiang, Shuli; Shi, Chunhai; Wu, Jianguo

2012-06-01

The contents of arsenic, mercury, lead and cadmium in milled rice were determined. Among 216 genotypes, the As, Hg, Pb and Cd contents were ranged from 5.06 to 296.45, 2.46 to 65.85, 4.16 to 744.95 and 5.91 to 553.40 ng/g, respectively. Six genotypes with lower contents of toxic metal elements were selected. The averages of As and Pb contents for indica rice were higher than those of japonica rice, while the averages of Hg and Cd contents were in contrast. Compared with white brown rice, the milled rice from black and red brown rice contained lower contents of four elements. Significant negative correlation was found between As content and alkaline spread value. Significant correlations were observed between As and aspartic acid (Asp) content, Hg and Asp or leucine contents, Pb and cysteine or methionine contents. Cd content was significantly negatively correlated with protein and 14 amino acid contents.

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 ...

Maternal transfer of contaminants in birds: Mercury and selenium concentrations in parents and their eggs

Science.gov (United States)

Ackerman, Joshua T.; Eagles-Smith, Collin A.; Herzog, Mark P.; Hartman, C. Alex

2016-01-01

We conducted a detailed assessment of the maternal transfer of mercury and selenium to eggs in three bird species (n = 107 parents and n = 339 eggs), and developed predictive equations linking contaminant concentrations in eggs to those in six tissues of the mother (blood, muscle, liver, kidney, breast feathers, and head feathers). Mercury concentrations in eggs were positively correlated with mercury concentrations in each of the mother's internal tissues (R2 ≥ 0.95), but generally not with feathers. For each species, the proportion of mercury transferred to eggs decreased as mercury concentrations in the mother increased. At the same maternal mercury concentration, the proportion of mercury transferred to eggs differed among species, such that Forster's tern (Sterna forsteri) and black-necked stilt (Himantopus mexicanus) females transferred more methylmercury to their eggs than American avocet (Recurvirostra americana) females. Selenium concentrations in eggs also were correlated with selenium concentrations in the mother's liver (R2 = 0.87). Furthermore, mercury and selenium concentrations in tern eggs were positively correlated with those in the father (R2 = 0.84). Incubating male terns had 21% higher mercury concentrations in blood compared to incubating females at the same egg mercury concentration. We provide equations to predict contaminant concentrations in eggs from each of the commonly sampled bird tissues.

Mercury exposure may influence fluctuating asymmetry in waterbirds

Science.gov (United States)

Herring, Garth; Eagles-Smith, Collin A.; Ackerman, Joshua T.

2017-01-01

Variation in avian bilateral symmetry can be an indicator of developmental instability in response to a variety of stressors, including environmental contaminants. The authors used composite measures of fluctuating asymmetry to examine the influence of mercury concentrations in 2 tissues on fluctuating asymmetry within 4 waterbird species. Fluctuating asymmetry increased with mercury concentrations in whole blood and breast feathers of Forster's terns (Sterna forsteri), a species with elevated mercury concentrations. Specifically, fluctuating asymmetry in rectrix feather 1 was the most strongly correlated structural variable of those tested (wing chord, tarsus, primary feather 10, rectrix feather 6) with mercury concentrations in Forster's terns. However, for American avocets (Recurvirostra americana), black-necked stilts (Himantopus mexicanus), and Caspian terns (Hydroprogne caspia), the authors found no relationship between fluctuating asymmetry and either whole-blood or breast feather mercury concentrations, even though these species had moderate to elevated mercury exposure. The results indicate that mercury contamination may act as an environmental stressor during development and feather growth and contribute to fluctuating asymmetry of some species of highly contaminated waterbirds.

Sources of speciated atmospheric mercury at a residential neighborhood impacted by industrial sources.

Science.gov (United States)

Manolopoulos, Helen; Snyder, David C; Schauer, James J; Hill, Jason S; Turner, Jay R; Olson, Mark L; Krabbenhoft, David P

2007-08-15

Speciated measurements of atmospheric mercury plumes were obtained at an industrially impacted residential area of East St. Louis, IL. These plumes were found to result in extremely high mercury concentrations at ground level that were composed of a wide distribution of mercury species. Ground level concentrations as high as 235 ng m(-3) for elemental mercury (Hg0) and 38 300 pg m(-3) for reactive mercury species (reactive gaseous (RGM) plus particulate (PHg) mercury) were measured. The highest mercury concentrations observed during the study were associated with plumes that contained high concentrations of all mercury species (Hg0, RGM, and PHg) and originated from a source located southwest of the sampling site. Variations in proportions of Hg0/RGM/PHg among plumes, with Hg0 dominating some plumes and RGM and/or PHg dominating others, were attributed to differences in emissions from different sources. Correlations between mercury plumes and elevated NO(x) were not observed; however, a correlation between elevated SO2 and mercury plumes was observed during some but not all plume events. Despite the presence of six coal-fired power plants within 60 km of the study site, wind direction data along with Hg/SO2 and Hg/NO(x) ratios suggest that high-concentration mercury plumes impacting the St. Louis-Midwest Particle Matter Supersite are attributable to local point sources within 5 km of the site.

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

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.

Global Mercury Observatory System (GMOS): measurements of atmospheric mercury in Celestun, Yucatan, Mexico during 2012.

Science.gov (United States)

Velasco, Antonio; Arcega-Cabrera, Flor; Oceguera-Vargas, Ismael; Ramírez, Martha; Ortinez, Abraham; Umlauf, Gunther; Sena, Fabrizio

2016-09-01

Within the Global Mercury Observation System (GMOS) project, long-term continuous measurements of total gaseous mercury (TGM) were carried out by a monitoring station located at Celestun, Yucatan, Mexico, a coastal site along the Gulf of Mexico. The measurements covered the period from January 28th to October 17th, 2012. TGM data, at the Celestun site, were obtained using a high-resolution mercury vapor analyzer. TGM data show values from 0.50 to 2.82 ng/m(3) with an annual average concentration of 1.047 ± 0.271 ng/m(3). Multivariate analyses of TGM and meteorological variables suggest that TGM is correlated with the vertical air mass distribution in the atmosphere, which is influenced by diurnal variations in temperature and relative humidity. Diurnal variation is characterized by higher nighttime mercury concentrations, which might be influenced by convection currents between sea and land. The back trajectory analysis confirmed that local sources do not significantly influence TGM variations. This study shows that TGM monitoring at the Celestun site fulfills GMOS goals for a background site.

Evaluation of dental amalgam mercury in human body by nuclear techniques

International Nuclear Information System (INIS)

Khddour, S.S.

2000-01-01

The levels of mercury in blood and hair samples of different groups of population belong to the same geographical areas have been investigated using neutron activation technique. The level of mercury in the blood samples ranged between 1.021 - 81.64 mg/l, while that in the hair samples ranged between 0.17 - 3.95 mg/l. T-test analysis showed higher levels of Hg in blood and hair of group having amalgam restorations comparing to other groups. This study also showed high correlation between the concentration of mercury in the blood of treated and untreated mothers and their newborn babies, where the correlation factors were 0.66 and 0.49 respectively. Correlation between the levels of Hg and Se in the blood was week. It can undoubtedly be concluded that amalgam restorations will contribute in increasing the level of mercury in blood, but although these levels exceed the maximum permissible limit in some samples, there were no any clinical side effects noticed. these levels also remained below the poisoning level.(Author)

Sources of speciated atmospheric mercury at a residential neighborhood impacted by industrial sources

Energy Technology Data Exchange (ETDEWEB)

Helen Manolopoulos; David C. Snyder; James J. Schauer; Jason S. Hill; Jay R. Turner; Mark L. Olson; David P. Krabbenhoft [University of Wisconsin-Madison, Madison, WI (United States). Environmental Chemistry and Technology Program

2007-08-15

Speciated measurements of atmospheric mercury plumes were obtained at an industrially impacted residential area of East St. Louis, IL. These plumes were found to result in extremely high mercury concentrations at ground level that were composed of a wide distribution of mercury species. Ground level concentrations as high as 235 ng m{sup -3} for elemental mercury (Hg{sup 0}) and 38,300 pg m{sup -3} for reactive mercury species (reactive gaseous (RGM) plus particulate (PHg) mercury) were measured. The highest mercury concentrations observed during the study were associated with plumes that contained high concentrations of all mercury species (Hg{sup 0}, RGM, and PHg) and originated from a source located southwest of the sampling site. Variations in proportions of Hg{sup 0}/RGM/PHg among plumes, with Hg{sup 0} dominating some plumes and RGM and/or PHg dominating others, were attributed to differences in emissions from different sources. Correlations between mercury plumes and elevated NOx were not observed; however, a correlation between elevated SO{sub 2} and mercury plumes was observed during some but not all plume events. Despite the presence of six coal-fired power plants within 60 km of the study site, wind direction data along with Hg/SO{sub 2} and Hg/NOx ratios suggest that high-concentration mercury plumes impacting the St. Louis-Midwest Particle Matter Supersite are attributable to local point sources within 5 km of the site. 35 refs., 5 figs.

Litterfall mercury deposition in Atlantic forest ecosystem from SE – Brazil

International Nuclear Information System (INIS)

Teixeira, Daniel C.; Montezuma, Rita C.; Oliveira, Rogério R.; Silva-Filho, Emmanoel V.

2012-01-01

Litterfall is believed to be the major flux of Hg to soils in forested landscapes, yet much less is known about this input on tropical environment. The Hg litterfall flux was measured during one year in Atlantic Forest fragment, located within Rio de Janeiro urban perimeter, in the Southeastern region of Brazil. The results indicated a mean annual Hg concentration of 238 ± 52 ng g −1 and a total annual Hg deposition of 184 ± 8.2 μg m −2 y −1 . The negative correlation observed between rain precipitation and Hg concentrations is probably related to the higher photosynthetic activity observed during summer. The total Hg concentration in leaves from the most abundant species varied from 60 to 215 ng g −1 . Hg concentration showed a positive correlation with stomatal and trichomes densities. These characteristics support the hypothesis that Tropical Forest is an efficient mercury sink and litter plays a key role in Hg dynamics. - Highlights: ► The litter production from an Atlantic Forest was measured by one year. ► Concentration and flux of mercury was measured from these litter samples. ► The Hg concentrations from 5 trees were taken. ► Correlations between the data found and meteorological and anatomical plant parameters were confronted. ► The high Hg values found and their distribution points to a great sequester potential from this biome. - Hg high values in litter are a pattern found at Tropical Forest, it seems to be correlated with physio-anatomical plant characteristics from this biome.

Mercury pollution in the ground of Saint-Petersburg

Energy Technology Data Exchange (ETDEWEB)

Malov, A.M. [FSSI Inst. of Toxicology FMBA of Russia, Saint-Petersburg (Russian Federation)

2008-07-01

The problem of mercury poisoning in St-Petersburg's industrial centre was investigated. First, mercury content was directly measured in ground samples taken at various depths. Mushrooms, which are abundant in every district of the city, were then collected from lawns, yards and parks. Mushrooms provide an accurate indication of mercury distribution in the upper layer of the ground because they get their nutrients from the environment. As such, the chemical composition of mushrooms depends on the composition of the substrate on which they grow, notably the composition of the ground soil and its mercury content. The purpose of the study was to determine the mercury content of the mushrooms growing in the centre of St-Petersburg and its suburbs. The mercury content of the samples was measured by using the cold vapor atomic absorption spectrometry method. The mercury content of the mushrooms collected ranged from 1.29 mg/kg to 0.010 mg/kg. There was some correlation of the 2 data sets for territorial mercury impurity. The mercury content in the blood of 2 comparable groups of women living in the central part of St-Petersburg and its suburbs was also compared. Although there was no one single patterns of mercury distribution in the ground of the city, the depth of 1.0 to 2.0 m was found to be the most polluted. It was concluded that both measuring methods could be used to determine mercury contamination, but each reflects the situation from a different perspective. 20 refs., 3 tabs.

Significance of fingernail and toenail mercury concentrations as biomarkers for prenatal methylmercury exposure in relation to segmental hair mercury concentrations.

Science.gov (United States)

Sakamoto, Mineshi; Chan, Hing M; Domingo, José L; Oliveira, Ricardo B; Kawakami, Shoichi; Murata, Katsuyuki

2015-01-01

To investigate the appropriateness of mercury (Hg) concentrations in fingernails and toenails at parturition for detecting prenatal exposure to methylmercury (MeHg). Total Hg concentrations were measured in 54 paired samples of fingernails, toenails, maternal blood, and maternal hair (1cm incremental segments from the scalp toward the tip) collected at 4th weeks of (early) pregnancy, and the same specimens and cord blood collected at parturition. Strong correlations were observed between Hg concentrations in fingernails and toenails at early pregnancy (r=0.923, pMercury concentrations in fingernails and toenails at parturition represented strong correlations with those in cord blood (r=0.803, pMercury in fingernails and toenails at early pregnancy reflected the maternal Hg body burden level approximately 5 months retroactively. At parturition, Hg levels in fingernails and toenails also showed strong correlations with those in cord blood. In addition, Hg levels in fingernails and toenails at parturition reflected more recent MeHg exposure, compared with those at early pregnancy. These results suggest that fingernails and toenails at parturition are useful biomarkers for prenatal MeHg exposure for mothers and fetuses, especially during the third-trimester of gestation. Copyright © 2014 Elsevier Inc. All rights reserved.

Factors influencing mercury in freshwater surface sediments of northeastern North America

Science.gov (United States)

Kamman, N.C.; Chalmers, A.; Clair, T.A.; Major, A.; Moore, R.B.; Norton, S.A.; Shanley, J.B.

2005-01-01

We report on an inventory and analysis of sediment mercury (Hg) concentrations from 579 sites across northeastern North America. Sediment Hg concentrations ranged from the limit of detection ca. 0.01-3.7 ??g g -1 (dry weight, d.w.), and the average concentration was 0.19 ??g g-1 (d.w.) Sediment methylmercury concentrations ranged from 0.15 to 21 ng g-1 (d.w.) and the mean concentration was 3.83 ng g -1 (d.w.). Total Hg concentrations (HgT) were greatest in lakes > reservoirs > rivers, although the proportion of Hg as methylmercury showed an inverse pattern. Total Hg was weakly and positively correlated with the sediment organic matter and percent of watershed as forested land, and weakly and negatively correlated with sediment solids content, drainage area, and agricultural land. Sediment methylmercury concentrations were weakly and positively correlated to wetland area, and weakly and negatively correlated to drainage area. Methylmercury, expressed as a percentage of HgT was positively correlated to agricultural land area. For sites with co-located sediment and fish-tissue sampling results, there was no relationship between sediment Hg and fish-tissue Hg. Finally, our data indicate that at least 44% of waters across the region have sediment HgT concentrations in excess of Canadian and United States minimum sediment contaminant guidelines for the protection of aquatic biota. ?? 2005 Springer Science+Business Media, Inc.

Mercury concentration in black flies Simulium spp. (Diptera, Simuliidae) from soft-water streams in Ontario, Canada

International Nuclear Information System (INIS)

Harding, K.M.; Gowland, J.A.; Dillon, P.J.

2006-01-01

Total Hg in Simulium spp. (Diptera, Simuliidae) was measured in 17 soft-water streams in the District of Muskoka and Haliburton County (Ontario, Canada) during 2003 and 2004. Black flies contained 0.07-0.64 μg/g total Hg (dry weight). The methylmercury concentration was measured in 6 samples of the 17, and ranged from 58% to 93% of total Hg. The concentration of total Hg is much higher than has been found in other filter feeding insects, and represents a significant potential source of Hg to fish. Mercury concentrations in Simulium spp. at different sites were strongly positively correlated with dissolved organic carbon, and the proportion of land within each catchment that was wetland. There was also a strong negative correlation with pH. By examining Hg concentration in filter feeding insects we have found a significant entry point for Hg and MeHg into the food web. - Accumulation of total mercury by black fly larvae is affected by stream pH, DOC and wetland area in the stream catchment

Mercury concentration in black flies Simulium spp. (Diptera, Simuliidae) from soft-water streams in Ontario, Canada

Energy Technology Data Exchange (ETDEWEB)

Harding, K.M. [Trent University, 1600 West Bank Drive, Peterborough, ON K9J 7B8 (Canada); Gowland, J.A. [Trent University, 1600 West Bank Drive, Peterborough, ON K9J 7B8 (Canada); Dillon, P.J. [Trent University, 1600 West Bank Drive, Peterborough, ON K9J 7B8 (Canada)]. E-mail: pdillon@trentu.ca

2006-10-15

Total Hg in Simulium spp. (Diptera, Simuliidae) was measured in 17 soft-water streams in the District of Muskoka and Haliburton County (Ontario, Canada) during 2003 and 2004. Black flies contained 0.07-0.64 {mu}g/g total Hg (dry weight). The methylmercury concentration was measured in 6 samples of the 17, and ranged from 58% to 93% of total Hg. The concentration of total Hg is much higher than has been found in other filter feeding insects, and represents a significant potential source of Hg to fish. Mercury concentrations in Simulium spp. at different sites were strongly positively correlated with dissolved organic carbon, and the proportion of land within each catchment that was wetland. There was also a strong negative correlation with pH. By examining Hg concentration in filter feeding insects we have found a significant entry point for Hg and MeHg into the food web. - Accumulation of total mercury by black fly larvae is affected by stream pH, DOC and wetland area in the stream catchment.

Mercury levels in eggs, embryos, and neonates of Trachemys callirostris (Testudines, Emydidae)

International Nuclear Information System (INIS)

Rendon Valencia, Beatriz; Zapata, Lina M; Bock, Brian C; Paez, Vivian P; Palacio, Jaime A.

2014-01-01

We quantified total mercury concentrations in eggshells, egg yolks, and embryos from 16 nests of the Colombian slider (Trachemys callirostris). Nests were collected in different stages of development, but estimated time of incubation in natural substrates was not correlated with mercury levels in the eggs, suggesting that mercury was not absorbed from the substrate, but more likely passed on to the embryos during folliculogenesis by the reproductive females who had bioaccumulated the mercury from environmental sources. Mean mercury concentrations were higher in embryos than in eggshells or egg yolks, indicating that embryos also bioaccumulate mercury present in other egg tissues. Intra-clutch variation in egg yolk mercury concentrations was relatively high. Egg yolk mercury concentrations were not associated with any of the fitness proxies we quantified for the nests (hatching success rates, initial neonate sizes and first-month juvenile growth rates). After five months of captive rearing in a mercury-free laboratory environment, 86 % of the juveniles had eliminated the mercury from their tissues.

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.

[Environment spatial distribution of mercury pollution in Songhua River upstream gold mining areas].

Science.gov (United States)

Zou, Ting-Ting; Wang, Ning; Zhang, Gang; Zhao, Dan-Dan

2010-09-01

Using Zeeman mercury spectrometer RA915+ monitoring the total gaseous mercury concentration were collected from gold mining area in Huadian, in the upper reaches of the Songhua River, during summer and autumn of 2008, where we simultaneously collected samples of air, water, sediment and soil. The research is focused on analyzing of the spatial and temporal distribution characteristics of atmospheric mercury pollution and the correlation with other environmental factors. The results show that: the concentration of atmospheric mercury in summer is higher than that in autumn and in the evening is higher than at noon, and it present a gradual decay with the distance to the gold mining area as the center point increasing. The distribution rule of mercury pollution of environmental factors in the gold mining area is: in sediment > in soil > in plant > in water, the characteristics of mercury pollution distribution in plant is: root > stem and leaf, and the content of mercury in plant in autumn is commonly higher than that in summer. This is thought due to the accumulation of pollutant element from soil during the growth of plant. The atmospheric mercury has a significant correlation with the root of plant, respectively 0.83 in summer and 0.97 in autumn.

Total mercury, organic mercury and selenium in liver and kidney of a South American coastal dolphin

International Nuclear Information System (INIS)

Seixas, Tercia G.; Kehrig, Helena do A.; Costa, Monica; Fillmann, Gilberto; Di Beneditto, Ana Paula M.; Secchi, Eduardo R.; Souza, Cristina M.M.; Malm, Olaf; Moreira, Isabel

2008-01-01

Selenium and total and organic mercury were determined in the liver and kidney of franciscana dolphin (Pontoporia blainvillei) incidentally caught in fishing nets along two Brazilian coastal areas (southeast and south). Regional differences in the concentrations of these contaminants were observed in P. blainvillei. Liver showed the highest organic and total mercury. In general, samples of individuals collected at the southern of Brazil had the highest concentrations of selenium and total and organic mercury. No significant gender differences were observed. Growth stage influenced the accumulation of these contaminants in both organs, and hepatic concentrations increased with the body length, according to the sampling area. Molar mercury and selenium concentrations in liver were significantly correlated, with a Se:Hg ratio close to 4. The among-site differences we found may be related to differences in preferred prey, bioavailability in the marine environment, environmental conditions, or these individuals may belong to distinct populations. - This study presents some useful data on the bioaccumulation of Hg, organic Hg and Se, and their inter-element relationships in a Brazilian small cetacean

Total mercury, organic mercury and selenium in liver and kidney of a South American coastal dolphin

Energy Technology Data Exchange (ETDEWEB)

Seixas, Tercia G. [Departamento de Quimica, PUC-Rio, 22453-900 Rio de Janeiro, RJ (Brazil); Laboratorio de Radioisotopos Eduardo Penna Franca, IBCCF-UFRJ, 21949-900 Rio de Janeiro, RJ (Brazil)], E-mail: tercia@rdc.puc-rio.br; Kehrig, Helena do A. [Laboratorio de Radioisotopos Eduardo Penna Franca, IBCCF-UFRJ, 21949-900 Rio de Janeiro, RJ (Brazil); Costa, Monica [Departamento de Oceanografia, CTG-UFPE, 50740-550 Recife, PE (Brazil); Fillmann, Gilberto [Departamento de Oceanografia, FURG, C.P. 474, 96201-900 Rio Grande, RS (Brazil); Di Beneditto, Ana Paula M. [Laboratorio de Ciencias Ambientais, CBB-UENF, 28013-602 Campos dos Goytacazes, RJ (Brazil); Secchi, Eduardo R. [Departamento de Oceanografia, FURG, C.P. 474, 96201-900 Rio Grande, RS (Brazil); Laboratorio de Tartarugas e Mamiferos Marinhos, Departamento de Oceanografia e Museu Oceanografico ' Prof. E.C. Rios' , FURG, 96201-900 Rio Grande, RS (Brazil); Souza, Cristina M.M. [Laboratorio de Ciencias Ambientais, CBB-UENF, 28013-602 Campos dos Goytacazes, RJ (Brazil); Malm, Olaf [Laboratorio de Radioisotopos Eduardo Penna Franca, IBCCF-UFRJ, 21949-900 Rio de Janeiro, RJ (Brazil); Moreira, Isabel [Departamento de Quimica, PUC-Rio, 22453-900 Rio de Janeiro, RJ (Brazil)

2008-07-15

Selenium and total and organic mercury were determined in the liver and kidney of franciscana dolphin (Pontoporia blainvillei) incidentally caught in fishing nets along two Brazilian coastal areas (southeast and south). Regional differences in the concentrations of these contaminants were observed in P. blainvillei. Liver showed the highest organic and total mercury. In general, samples of individuals collected at the southern of Brazil had the highest concentrations of selenium and total and organic mercury. No significant gender differences were observed. Growth stage influenced the accumulation of these contaminants in both organs, and hepatic concentrations increased with the body length, according to the sampling area. Molar mercury and selenium concentrations in liver were significantly correlated, with a Se:Hg ratio close to 4. The among-site differences we found may be related to differences in preferred prey, bioavailability in the marine environment, environmental conditions, or these individuals may belong to distinct populations. - This study presents some useful data on the bioaccumulation of Hg, organic Hg and Se, and their inter-element relationships in a Brazilian small cetacean.

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.

The mercury species and their association with carbonaceous compositions, bromine and iodine in PM2.5 in Shanghai.

Science.gov (United States)

Duan, Lian; Xiu, Guangli; Feng, Ling; Cheng, Na; Wang, Chenggang

2016-03-01

PM2.5 samples were collected in south Shanghai from November 2013 to October 2014. The species of particulate bounded mercury (PBM), including hydrochloric soluble particle-phase mercury (HPM), element soluble particle-phase mercury (EPM) and residual soluble particle-phase mercury (RPM), were determined in PM2.5. The chemical composition of PM2.5 including organic carbon (OC) and elemental carbon (EC), total bromine and iodine were also analyzed. The results showed that the annual average concentration of PBM was 0.30 ± 0.31 ng m(-3) and 0.34 ± 0.32 ng m(-3) in winter, 0.31 ± 0.19 ng m(-3) in spring, 0.30 ± 0.45 ng m(-3) in fall and 0.28 ± 0.17 ng m(-3) in summer. HPM took the highest fraction 51.2% in PBM, followed by RPM 27.7% and EPM 21.1%. EC positively correlated to particle mercury, especially in winter (r = 0.70), the same for OC in winter (r = 0.72), which indicated that the carbonaceous composition may affect the transformation of Hg in the atmosphere. Mercury species showed different correlations with bromine and iodine in the four seasons. The strongest correlation between bromine, iodine and mercury was found in spring and fall, respectively. Bromine showed the stronger correlation with total mercury and speciated particle mercury than iodine. In addition, the days were classified into haze and non-haze days based on the visibility and relative humidity, while the ratio of HPM in haze days was much higher than that in non-haze days. EC strongly correlated with PBM during haze and non-haze days while OC only positively correlated with PBM in non-haze days, this may indicate that the different carbonaceous part may affect PBM differently. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of methyl mercury exposure on the growth of juvenile common loons

Science.gov (United States)

Kenow, K.P.; Gutreuter, S.; Hines, R.K.; Meyer, M.W.; Fournier, F.; Karasov, W.H.

2003-01-01

We conducted a dose-response laboratory study to quantify the level of mercury exposure associated with negative effects on the development of common loon chicks reared in captivity from hatch to 105 days. A dose regimen was implemented that provided exposure levels that bracketed relevant exposure levels of methyl mercury found in loon chicks across North America. We observed no overt signs of mercury toxicosis and detected no significant effect of dietary mercury exposure on growth or food consumption. However, asymptotic mass was lower in chicks that hatched from eggs collected from nests on low pH lakes relative to eggs from neutral pH lakes. Rapid excretion of methyl mercury during feather growth likely provides loon chicks protection from methyl mercury toxicity and may explain the lack of convincing toxicological findings in this study. Lake-source effects suggest that in ovo exposure to methyl mercury or other factors related to lake pH have consequences on chick development.

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

A preliminary analysis of the Mariner 10 color ratio map of Mercury

Science.gov (United States)

Rava, Barry; Hapke, Bruce

1987-01-01

A preliminary geological analysis of the Mariner 10 orange/UV color ratio map of Mercury is given, assuming a basaltic crust. Certain errors in the map are pointed out. The relationship between color and terrain are distinctly non-lunar. Rays and ejecta are bluer than average on Mercury, whereas they are redder on the Moon. This fact, along with the lack of the ferrous band in Mercury's spectral reflectance and smaller albedo contrasts, implies that the crust is low in Fe and Ti. There is no correlation between color boundaries and the smooth plains on Mercury, in contrast with the strong correlation between color and maria-highlands contacts on the Moon. The smooth plains are not Mercurian analogs of lunar maria, and a lunar-type of second wave melting did not occur. Ambiguous correlations between color and topography indicate that older, redder materials underlie younger, bluer rocks in many places on the planet, implying that the last stages of volcanism involved low-Fe lavas covering higher-Fe rocks. There is some evidence of late Fe-rich pyroclastic activity.

Correlation of regional cerebral blood flow and positive/negative symptoms in schizophrenic patients: covariate SPM analysis

Energy Technology Data Exchange (ETDEWEB)

Lim, Ki Chun; Kim, J. S.; Kim, C. Y.; Lee, H. K.; Moon, D. H. [Ulsan University, Seoul (Korea, Republic of)

2002-07-01

We investigated the relations between rCBF and psychopathology in schizophrenic patients using a SPM99. Thirty-two patients(M/F:22/10, 25{+-}5,6yr) with active symptoms of schizophrenia and 15 age matched normal controls underwent Tc-99m ECD brain perfusion SPECT. Psychopathology of all patients were also assessed according to PANSS (positive and negative syndrome scale in schizophrenia). By covariate SPM analysis, specific areas where rCBF correlated with sum scores of positive/negative synptoms were identified. Regional CBF of schizophrenics was different in several cortical regions from normal controls. Sum scores of positive symptoms were positively correlated with rCBF of both rectal and inferior frontal gyri and right transverse temporal gyrus, and negatively correlated with rCBF of left lingual and right middle temporal gyri (p<0.01). Sum scores of negative symptoms were positively correlated with rCBF of both middle temporal gyri and negatively correlated with rCBF of right superior parietal lobule and medial frontal gyrus (p<0.01). Positive and negative symptoms of schizophrenia were correlated with rCBF change in different regions of cerebral association cortex.

Correlation of regional cerebral blood flow and positive/negative symptoms in schizophrenic patients: covariate SPM analysis

International Nuclear Information System (INIS)

Lim, Ki Chun; Kim, J. S.; Kim, C. Y.; Lee, H. K.; Moon, D. H.

2002-01-01

We investigated the relations between rCBF and psychopathology in schizophrenic patients using a SPM99. Thirty-two patients(M/F:22/10, 25±5,6yr) with active symptoms of schizophrenia and 15 age matched normal controls underwent Tc-99m ECD brain perfusion SPECT. Psychopathology of all patients were also assessed according to PANSS (positive and negative syndrome scale in schizophrenia). By covariate SPM analysis, specific areas where rCBF correlated with sum scores of positive/negative synptoms were identified. Regional CBF of schizophrenics was different in several cortical regions from normal controls. Sum scores of positive symptoms were positively correlated with rCBF of both rectal and inferior frontal gyri and right transverse temporal gyrus, and negatively correlated with rCBF of left lingual and right middle temporal gyri (p<0.01). Sum scores of negative symptoms were positively correlated with rCBF of both middle temporal gyri and negatively correlated with rCBF of right superior parietal lobule and medial frontal gyrus (p<0.01). Positive and negative symptoms of schizophrenia were correlated with rCBF change in different regions of cerebral association cortex

Accumulation of mercury in Typha domingensis under field conditions.

Science.gov (United States)

Lominchar, M A; Sierra, M J; Millán, R

2015-01-01

Typha species is a common wetland plant used in the treatment of urban and industrial effluents. But, despite their widespread implementation, there are not many studies based on the behaviour of this plant growing in an areas affected by mercury. The present work investigates the ability of Typha domingensis to accumulate mercury under field conditions. The study area was along the Valdeazogues river which flows through the Almadén mining district (Ciudad Real, Spain) that is considered the largest mercury reservoir in the world. The mercury concentration in different plant fractions was measured as well as the available and total concentration in the bottom sediments. The results showed that the highest mercury concentrations were found in the belowground organs. T. domingensis had a high efficiency to accumulate mercury in their organs although available metal concentrations in the environment did not exceed 0.16 mg kg(-1). Bioaccumulation factors (BAF) ranged between 121 and 3168 in roots. Furthermore, significant correlations were found between mercury concentration in all plant organs and Hg in sediments (both total and available). These results demonstrated that T. domingensis could be used as a biomonitor as well as in phytoextraction technology in areas affected by mercury. Copyright © 2014 Elsevier Ltd. All rights reserved.

Mercury's Lithospheric Magnetization

Science.gov (United States)

Johnson, C.; Phillips, R. J.; Philpott, L. C.; Al Asad, M.; Plattner, A.; Mast, S.; Kinczyk, M. J.; Prockter, L. M.

2017-12-01

Magnetic field data obtained by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft have been used to demonstrate the presence of lithospheric magnetization on Mercury. Larger amplitude fields resulting from the core dynamo and the strongly time-varying magnetospheric current systems are first estimated and subtracted from the magnetic field data to isolate lithospheric signals with wavelengths less than 500 km. These signals (hereafter referred to as data) are only observed at spacecraft altitudes less than 120 km, and are typically a few to 10 nT in amplitude. We present and compare equivalent source dipole magnetization models for latitudes 35°N to 75°N obtained from two distinct approaches to constrain the distribution and origin of lithospheric magnetization. First, models that fit either the data or the surface field predicted from a regional spherical harmonic representation of the data (see Plattner & Johnson abstract) and that minimize the root mean square (RMS) value of the magnetization are derived. Second, models in which the spatial distribution of magnetization required to fit the data is minimized are derived using the approach of Parker (1991). As seen previously, the largest amplitudes of lithospheric magnetization are concentrated around the Caloris basin. With this exception, across the northern hemisphere there are no overall correlations of magnetization with surface geology, although higher magnetizations are found in regions with darker surfaces. Similarly, there is no systematic correlation of magnetization signatures with crater materials, although there are specific instances of craters with interiors or ejecta that have magnetizations distinct from the surrounding region. For the latter case, we observe no correlation of the occurrence of these signatures with crater degradation state (a proxy for age). At the lowest spacecraft altitudes (source depths less than O(10 km) are unlikely in most regions

Interaction of ethanol and mercury body burden in the mouse

Energy Technology Data Exchange (ETDEWEB)

Dunn, J.D.

1978-01-01

The interaction of ethanol with mercury in the body resulting in increased exhalation of the metal was studied in the mouse. A persistent elimination of the metal in the breath was demonstrated after single, sublethal (<1 mgHg/Kg body weight) exposures to mercury vapor (Hg/sup 0/) or mercury II chloride (HgCl/sub 2/). The amount of mercury exhaled per unit time was enhanced by oral or parenteral administration of ethanol solutions. These modifications were investigated in dose-response studies in which the drug was administered in doses ranging from 0.2g to 5.5g/Kg to mice pretreated with mercury. The EC/sub 50/ for blood ethanol with respect to mercury exhalation was determined to be approximately 200 mg/dl corresponding to an output rate of approximately 0.1% of the simultaneous body burden in 30 min several days after mercury. A hypothesis that mercury expired by these animals was proportional to the body burden after mercury administration was addressed in experiments whereby mice given one of several doses of mercuric chloride (0.16 to 500 ..mu..g/Kg) were monitored for pulmonary mercury elimination for a fifteen day period. The high correlation obtained between the amount of mercury exhaled in a standard time period and the body burden by group indicated that breath sampling could be applied as an indicator of the mercury body burden which may not be limited to the mouse.

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...

Systematic bias of correlation coefficient may explain negative accuracy of genomic prediction.

Science.gov (United States)

Zhou, Yao; Vales, M Isabel; Wang, Aoxue; Zhang, Zhiwu

2017-09-01

Accuracy of genomic prediction is commonly calculated as the Pearson correlation coefficient between the predicted and observed phenotypes in the inference population by using cross-validation analysis. More frequently than expected, significant negative accuracies of genomic prediction have been reported in genomic selection studies. These negative values are surprising, given that the minimum value for prediction accuracy should hover around zero when randomly permuted data sets are analyzed. We reviewed the two common approaches for calculating the Pearson correlation and hypothesized that these negative accuracy values reflect potential bias owing to artifacts caused by the mathematical formulas used to calculate prediction accuracy. The first approach, Instant accuracy, calculates correlations for each fold and reports prediction accuracy as the mean of correlations across fold. The other approach, Hold accuracy, predicts all phenotypes in all fold and calculates correlation between the observed and predicted phenotypes at the end of the cross-validation process. Using simulated and real data, we demonstrated that our hypothesis is true. Both approaches are biased downward under certain conditions. The biases become larger when more fold are employed and when the expected accuracy is low. The bias of Instant accuracy can be corrected using a modified formula. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Off-line tests on pitting damage in mercury target

CERN Document Server

Futakawa, M; Ishikura, S; Kogawa, H; Tsai, C C

2003-01-01

A liquid-mercury target system for the MW-scale target is being developed in the world. The moment the proton beams bombard the target, stress waves will be imposed on the beam window and pressure waves will be generated in the mercury by the thermally shocked heat deposition. Provided that the negative pressure generates through its propagation in the mercury target and causes cavitation in the mercury, there is the possibility for the cavitation bubbles collapse to form pits on the interface between the mercury and the target vessel wall. In order to estimate the cavitation erosion damage due to pitting, two types of off-line tests were performed: Split Hopkinson Pressure Bar (SHPB), and Magnetic IMpact Testing Machine (MIMTM). The data on the piping damage at the high cycle impacts up to 10 million were given by the MIMTM. Additionally the data obtained were compared with classical vibratory horn tests. As a result, it is confirmed that the mean depth erosion is predictable using a homologous line in the s...

BEHAVIOR OF MERCURY DURING DWPF CHEMICAL PROCESS CELL PROCESSING

Energy Technology Data Exchange (ETDEWEB)

Zamecnik, J.; Koopman, D.

2012-04-09

The Defense Waste Processing Facility has experienced significant issues with the stripping and recovery of mercury in the Chemical Processing Cell (CPC). The stripping rate has been inconsistent, often resulting in extended processing times to remove mercury to the required endpoint concentration. The recovery of mercury in the Mercury Water Wash Tank has never been high, and has decreased significantly since the Mercury Water Wash Tank was replaced after the seventh batch of Sludge Batch 5. Since this time, essentially no recovery of mercury has been seen. Pertinent literature was reviewed, previous lab-scale data on mercury stripping and recovery was examined, and new lab-scale CPC Sludge Receipt and Adjustment Tank (SRAT) runs were conducted. For previous lab-scale data, many of the runs with sufficient mercury recovery data were examined to determine what factors affect the stripping and recovery of mercury and to improve closure of the mercury material balance. Ten new lab-scale SRAT runs (HG runs) were performed to examine the effects of acid stoichiometry, sludge solids concentration, antifoam concentration, form of mercury added to simulant, presence of a SRAT heel, operation of the SRAT condenser at higher than prototypic temperature, varying noble metals from none to very high concentrations, and higher agitation rate. Data from simulant runs from SB6, SB7a, glycolic/formic, and the HG tests showed that a significant amount of Hg metal was found on the vessel bottom at the end of tests. Material balance closure improved from 12-71% to 48-93% when this segregated Hg was considered. The amount of Hg segregated as elemental Hg on the vessel bottom was 4-77% of the amount added. The highest recovery of mercury in the offgas system generally correlated with the highest retention of Hg in the slurry. Low retention in the slurry (high segregation on the vessel bottom) resulted in low recovery in the offgas system. High agitation rates appear to result in lower

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.

[Mercury concentration of fish in Tokyo Bay and the surrounding sea area].

Science.gov (United States)

Zhang, R; Kashima, Y; Matsui, M; Okabe, T; Doi, R

2001-07-01

Total mercury in the muscles of three fish species was analyzed in fish caught in Tokyo Bay and the surrounding sea areas, Sagami Bay and Choshi. Tokyo Bay is a semi-closed sea area surrounded by Tokyo, Kanagawa and Chiba prefectures. Sagami Bay and Choshi are open to the Pacific Ocean. A total of 412 fish consisting of northern whiting (Sillago japonica), flatfish (Limanda yokohamae) and sardine (Sardinops melanosticta) were caught in these areas over a 6 months period from November 1998 to April 1999. Total mercury concentration ranged from 0.008-0.092 microgram/g (wet wt.) in northern whiting, 0.006-0.065 microgram/g in flatfish and 0.001-0.045 microgram/g in sardine. All concentrations were below the restriction limit of fish mercury in Japan, 0.4 microgram/g of total mercury concentration. A significant correlation was found between mercury concentrations and body length or body weight in northern whiting and flatfish, irrespective of the sea area. A correlation was also found between mercury concentration in fish and their feeding habits: among the 3 species caught in the same area, crustacean feeding northern whiting had the highest, polychaete feeding flatfish moderate, and plankton feeding sardine had the lowest mercury concentration. In a comparison of mercury concentration in the same species caught in different sea areas, a higher concentration was noted in fish caught in the semi-closed sea area of Tokyo Bay, than in fish caught in the open sea areas of Sagami Bay and Choshi. This difference was most marked in fish caught at the bottom of Tokyo Bay and we considered that the mercury concentration of seawater and sediment in these areas was the cause of mercury accumulation in fish. These findings suggest that improved water quality control and environmental monitoring is necessary in semi-closed sea areas such as Tokyo Bay.

Association of methionine requirement with methyl mercury resistant mutants of yeast

Energy Technology Data Exchange (ETDEWEB)

Singh, A.; Sherman, F.

1974-01-25

It has been known for several years that strains resistant to mercury can be obtained in several bacterial species. Soon after the correlation between resistance to antibiotics and to mercury was recognized, it was established that genetic elements conferring resistance to antibiotics, mercury and other heavy metals in Escherichia coli and Samonella typhimurium and Staphylococcus aureus reside on extrachromosomal resistance transfer factors or plasmids. Among fungi, mercury resistant strains of Botrytis cinerea, Penicillium notatum, Sclerotinia fructicola, Stemphylium sarcinaeforme, and Saccharomyces cerevisiae have been reported. In most cases, this was accomplished by training the normal strains for growth on media supplemented with successively increasing concentrations of mercury compounds, and in some cases the resistance was lost when subcultured on mercury-free media. It is noteworthy that in none of the mercury-adapted strains of fungi has the genetic basis of resistance been determined. In this report we describe a method of isolation and characterization of methyl mercury resistant mutants of S. cerevisiae. This study was undertaken with the view that the examination of physiological changes associated with genetically defined resistant mutants will be useful in studying the mechanisms of cellular detoxification of organic mercurials.

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.

Neural Correlates of Attitude Change Following Positive and Negative Advertisements

Science.gov (United States)

Kato, Junko; Ide, Hiroko; Kabashima, Ikuo; Kadota, Hiroshi; Takano, Kouji; Kansaku, Kenji

2009-01-01

Understanding changes in attitudes towards others is critical to understanding human behaviour. Neuropolitical studies have found that the activation of emotion-related areas in the brain is linked to resilient political preferences, and neuroeconomic research has analysed the neural correlates of social preferences that favour or oppose consideration of intrinsic rewards. This study aims to identify the neural correlates in the prefrontal cortices of changes in political attitudes toward others that are linked to social cognition. Functional magnetic resonance imaging (fMRI) experiments have presented videos from previous electoral campaigns and television commercials for major cola brands and then used the subjects' self-rated affinity toward political candidates as behavioural indicators. After viewing negative campaign videos, subjects showing stronger fMRI activation in the dorsolateral prefrontal cortex lowered their ratings of the candidate they originally supported more than did those with smaller fMRI signal changes in the same region. Subjects showing stronger activation in the medial prefrontal cortex tended to increase their ratings more than did those with less activation. The same regions were not activated by viewing negative advertisements for cola. Correlations between the self-rated values and the neural signal changes underscore the metric representation of observed decisions (i.e., whether to support or not) in the brain. This indicates that neurometric analysis may contribute to the exploration of the neural correlates of daily social behaviour. PMID:19503749

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

Mercury emission, control and measurement from coal combustion

Energy Technology Data Exchange (ETDEWEB)

Pan, Wei-Ping [North China Electric Power Univ., Beijing (China). School of Energy and Power Engineering; Western Kentucky Univ., Bowling Green, KY (United States). Inst. for Combustion Science and Environmental Technology; Cao, Yan [Western Kentucky Univ., Bowling Green, KY (United States). Inst. for Combustion Science and Environmental Technology; Zhang, Kai [North China Electric Power Univ., Beijing (China). School of Energy and Power Engineering

2013-07-01

Coal-fired electric power generation accounts for 65% of U.S. emissions of sulfur dioxide (SO2), 22% of nitrogen oxides (NOx), and 37% of mercury (Hg). The proposed Clear Air Interstate Rule (CAIR) and Clean Air Mercury Rule (CAMR) will attempt to regulate these emissions using a cap-and-trade program to replace a number of existing regulatory requirements that will impact this industry over the next decade. Mercury emissions remain the largest source that has not yet been efficiently controlled, in part because this is one of the most expensive to control. Mercury is a toxic, persistent pollutant that accumulates in the food chain. During the coal combustion process, when both sampling and accurate measurements are challenging, we know that mercury is present in three species: elemental, oxidized and particulate. There are three basic types of mercury measurement methods: Ontario Hydro Method, mercury continuous emission monitoring systems (CEMS) and sorbent-based monitoring. Particulate mercury is best captured by electrostatic precipitators (ESP). Oxidized mercury is best captured in wet scrubbers. Elemental mercury is the most difficult to capture, but selective catalytic reduction units (SCRs) are able to convert elemental mercury to oxidized mercury allowing it to be captured by wet flue gas desulfurization (FGD). This works well for eastern coals with high chlorine contents, but this does not work well on the Wyoming Powder River Basin (PRB) coals. However, no good explanation for its mechanism, correlations of chlorine content in coal with SCR performance, and impacts of higher chlorine content in coal on FGD re-emission are available. The combination of SCR and FGD affords more than an 80% reduction in mercury emissions in the case of high chlorine content coals. The mercury emission results from different coal ranks, boilers, and the air pollution control device (APCD) in power plant will be discussed. Based on this UAEPA new regulation, most power plants

Litterfall mercury dry deposition in the eastern USA

International Nuclear Information System (INIS)

Risch, Martin R.; DeWild, John F.; Krabbenhoft, David P.; Kolka, Randall K.; Zhang, Leiming

2012-01-01

Mercury (Hg) in autumn litterfall from predominately deciduous forests was measured in 3 years of samples from 23 Mercury Deposition Network sites in 15 states across the eastern USA. Annual litterfall Hg dry deposition was significantly higher (median 12.3 micrograms per square meter (μg/m 2 ), range 3.5–23.4 μg/m 2 ) than annual Hg wet deposition (median 9.6 μg/m 2 , range 4.4–19.7 μg/m 2 ). The mean ratio of dry to wet Hg deposition was 1.3–1. The sum of dry and wet Hg deposition averaged 21 μg/m 2 per year and 55% was litterfall dry deposition. Methylmercury was a median 0.8% of Hg in litterfall and ranged from 0.6 to 1.5%. Annual litterfall Hg and wet Hg deposition rates differed significantly and were weakly correlated. Litterfall Hg dry deposition differed among forest-cover types. This study demonstrated how annual litterfall Hg dry deposition rates approximate the lower bound of annual Hg dry fluxes. - Highlights: ► Annual litterfall mercury dry deposition was significantly higher than wet deposition. ► The mean ratio of dry to wet mercury deposition was 1.3–1. ► The sum of dry and wet mercury deposition averaged 55% litterfall dry deposition. ► Litterfall mercury deposition was highest in the oak-hickory forest-cover type. ► Methylmercury was a median 0.8% of mercury in litterfall and ranged to 1.5%. - A multi-year study of Mercury Deposition Network sites found that annual mercury dry deposition from litterfall in predominately deciduous forests exceeded annual mercury wet deposition in the eastern USA.

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 ...

Monitoring and assessment of mercury pollution in the vicinity of a chloralkali plant. IV. Bioconcentration of mercury in in situ aquatic and terrestrial plants at Ganjam, India.

Science.gov (United States)

Lenka, M; Panda, K K; Panda, B B

1992-02-01

In situ aquatic and terrestrial plants including a few vegetable and crop plants growing in and around a chloralkali plant at Ganjam, India were analyzed for concentrations of root and shoot mercury. The aquatic plants found to bioconcentrate mercury to different degrees included Marsilea spp., Spirodela polyrhiza, Jussiea repens, Paspalum scrobiculatam, Pistia stratiotes, Eichhornia crassipes, Hygrophila schulli, Monochoria hastata and Bacopa monniera. Among wild terrestrial plants Chloris barbata, Cynodon dactylon, Cyperus rotundus and Croton bonplandianum were found growing on heavily contaminated soil containing mercury as high as 557 mg/kg. Analysis of mercury in root and shoot of these plants in relation to the mercury levels in soil indicated a significant correlation between soil and plant mercury with the exception of C. bonplandianum. Furthermore, the tolerance to mercury toxicity was highest with C. barbata followed by C. dactylon and C. rotundus, in that order. The rice plants analyzed from the surrounding agricultural fields did not show any significant levels of bioconcentrated mercury. Of the different vegetables grown in a contaminated kitchen garden with mercury level at 8.91 mg/kg, the two leafy vegetables, namely cabbage (Brassica oleracea) and amaranthus (Amaranthus oleraceous), were found to bioconcentrate mercury at statistically significant levels. The overall study indicates that the mercury pollution is very much localized to the specific sites in the vicinity of the chloralkali plant.

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.

Red fox Vulpes vulpes (L., 1758) as a bioindicator of mercury contamination in terrestrial ecosystems of north-western Poland.

Science.gov (United States)

Kalisinska, Elzbieta; Lisowski, Piotr; Kosik-Bogacka, Danuta Izabela

2012-02-01

In this study, we determined the concentrations of total mercury (Hg) in samples of liver, kidney and skeletal muscle of 27 red foxes Vulpes vulpes (L., 1758) from north-western Poland, and examined the morphometric characteristics of the collected specimens. The analysis also included the relationship between Hg concentration and the fox size, and the suitability of individual organs as bioindicators in indirect evaluation of environmental mercury contamination. Determination of Hg concentration was performed by atomic absorption spectroscopy. In the analysed samples, the Hg concentration was low and the maximum value did not exceed 0.85 mgHg/kg dry weight (dw). There were no significant differences in Hg concentrations in the analysed material between males and females or between immature and adult groups. The median concentrations of Hg in the liver, kidney and skeletal muscle were 0.22, 0.11 and 0.05 mgHg/kg dw, respectively. The correlation coefficients were significant between the concentrations of mercury in the liver, kidney and skeletal muscle (positive) and between the kidney Hg concentration and kidney mass (negative). Taking into account our results and findings of other authors, it may be argued that the red fox exhibits a measurable response to mercury environmental pollution and meets the requirements of a bioindicator.

Off-line tests on pitting damage in mercury target

International Nuclear Information System (INIS)

Futakawa, Masatoshi; Kogawa, Hiroyuki; Ishikura, Shuichi; Ikeda, Yujiro

2003-03-01

A liquid-mercury target system for the MW-scale target is being developed in the world. The moment the proton beams bombard the target, stress waves will be imposed on the beam window and pressure waves will be generated in the mercury by the thermally shocked heat deposition. Provided that the negative pressure generates through its propagation in the mercury target and causes cavitation in the mercury, there is the possibility for the cavitation bubbles collapse to form pits on the interface between the mercury and the target vessel wall. In order to estimate the cavitation erosion damage due to pitting, two types of off-line tests were performed: Split Hopkinson Pressure Bar (SHPB), and Magnetic IMpact Testing Machine (MIMTM). The data on the piping damage at the high cycle impacts up to 10 million were given by the MIMTM. Additionally the data obtained were compared with classical vibratory horn tests. As a result, it is confirmed that the mean depth erosion is predictable using a homologous line in the steady state with mass loss independently of testing machines and the incubation period is very dependent on materials and imposed pressures. (author)

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

Enzymatic Mercury Detoxification: The Regulatory Protein MerR

CERN Multimedia

Ctortecka, B; Walsh, C T; Comess, K M

2002-01-01

Mercury ions and organomercurial reagents are extremely toxic due to their affinity for thiol groups. Many bacteria contain an elaborate detoxification system for a metabolic conversion of toxic Hg$^{2+}$ or organomercurials to less toxic elemental Hg$^0$. The main components of the enzymatic mercury detoxification (see Fig. 1) are the regulatory protein MerR (mercury responsive genetic switch), the organomercurial lyase MerB (cleavage of carbon mercury bonds), and the mercuric ion reductase MerA (reduction of mercuric ions). In these proteins Hg$^{2+}$ is usually coordinated by the thiol groups of cysteines. We utilize the nuclear quadrupole interaction (NQI) of ${\\rm^{199m}}$Hg detected by time differential perturbed angular correlation (TDPAC) to identify the Hg metal site geometries in these proteins in order to elucidate the molecular origin of the ultrasensitivity, selectivity and reaction mechanism of this detoxification system. The short lived TDPAC probe ${\\rm^{199m}}$Hg ($\\tau_{1/2} =$ 43 min) is su...

Monitoring of mercury concentration in atmosphere in Usti nad Labem

International Nuclear Information System (INIS)

Synek, V.; Baloch, T.; Otcenasek, J.; Kremlova, S.; Subrt, P.

2007-01-01

This study elaborates the observation of mercury pollution of the atmosphere in the city of Usti nad Labem. The biggest source of the polluting mercury in Usti nad Labem is the chlor-alkali production in the factory of Spolchemie Inc. The method of mercury determination applied is based on capturing the mercury contented in a volume of the air on an amalgamator and measuring the mercury by an atomic absorption spectrometer (Perkin -Elmer 4100ZL) equipped with a special adapter after a thermal release of the mercury from the amalgamator. The basic characteristics of this method were evaluated; e.g. the limit of detection and limit of determination are, respectively, 0.43 and 1.4 ng/m 3 , the relative expanded uncertainty is 28 %. The work gives results of long-term (1998-2006) observations in a few localities in Usti nad Labem situated in various distances from the mercury source (e.g. means of 28.6 and 14.1 ng/m3 were obtained, respectively, in places 350 and 700 m far from the electrolysis plant) and also in a different city (Duchcov). The cases with a higher mercury concentration are very frequent so the sets of the obtained results have lognormal distributions. This study statistically compares the total level and variability of the mercury concentrations in the time series. It also investigates their trends, correlations between them and meteorological influences upon the levels of mercury concentration in the air. The effect of the mercury emission from the chlor-alkali plant is dominant. It as the only factor determines when the cases with a high mercury concentration in the atmosphere occur. (author)

Mercury content in fish from newly impounded reservoirs

International Nuclear Information System (INIS)

Frick, K.

1992-12-01

During the seventies elevated mercury content in fish was observed in newly created reservoirs although background levels were normal. The initial rise of reservoir mercury levels is probably caused by the dramatically increased amount of organic matter originating from flooded top-soil and vegetation. Mercury is introduced in the food-chain by methylating bacteria that utilize the surplus of organic matter. This microbial methylation is probably also favoured by reductions in oxygen content and pH that accompanies the decomposition of organic material. It is difficult to make reliable estimates of the duration and maximum levels of the elevated mercury levels since the end result is affected by several biological and chemical processes in combination. Variations may occur on the basis of the type and amount of flooded organic and inorganic material, water chemistry, specific combination of fish and residence time of reservoir water. All available preventive and ameliorating measures are untried in reservoir water bodies, at least in large scale experiments. Vegetation and top-soil stripping could be efficient but also very costly. Liming is a possible method in cases of ongoing or expected acidification. Addition of selenium is a potentially powerful way of lowering the mercury content in fish and this method is well suited to neutral water bodies. Large reductions in fish mercury content have been documented, but since selenium also has been shown to have strong negative effects on biota this method is not yet recommended. (57 refs.)

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 ...

Mercury exposure may influence fluctuating asymmetry in waterbirds.

Science.gov (United States)

Herring, Garth; Eagles-Smith, Collin A; Ackerman, Joshua T

2017-06-01

Variation in avian bilateral symmetry can be an indicator of developmental instability in response to a variety of stressors, including environmental contaminants. The authors used composite measures of fluctuating asymmetry to examine the influence of mercury concentrations in 2 tissues on fluctuating asymmetry within 4 waterbird species. Fluctuating asymmetry increased with mercury concentrations in whole blood and breast feathers of Forster's terns (Sterna forsteri), a species with elevated mercury concentrations. Specifically, fluctuating asymmetry in rectrix feather 1 was the most strongly correlated structural variable of those tested (wing chord, tarsus, primary feather 10, rectrix feather 6) with mercury concentrations in Forster's terns. However, for American avocets (Recurvirostra americana), black-necked stilts (Himantopus mexicanus), and Caspian terns (Hydroprogne caspia), the authors found no relationship between fluctuating asymmetry and either whole-blood or breast feather mercury concentrations, even though these species had moderate to elevated mercury exposure. The results indicate that mercury contamination may act as an environmental stressor during development and feather growth and contribute to fluctuating asymmetry of some species of highly contaminated waterbirds. Environ Toxicol Chem 2017;36:1599-1605. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

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)

Neural correlates of attitude change following positive and negative advertisements

Directory of Open Access Journals (Sweden)

Junko Kato

2009-05-01

Full Text Available Understanding changes in attitudes towards others is critical to understanding human behaviour. Neuropolitical studies have found that the activation of emotion-related areas in the brain is linked to resilient political preferences, and neuroeconomic research has analysed the neural correlates of social preferences that favour or oppose consideration of intrinsic rewards. This study aims to identify the neural correlates in the prefrontal cortices of changes in political attitudes toward others that are linked to social cognition. Functional magnetic resonance imaging (fMRI experiments have presented videos from previous electoral campaigns and television commercials for major cola brands and then used the subjects’ self-rated affinity toward political candidates as behavioural indicators. After viewing negative campaign videos, subjects showing stronger fMRI activation in the dorsolateral prefrontal cortex lowered their ratings of the candidate they originally supported more than did those with smaller fMRI signal changes in the same region. Subjects showing stronger activation in the medial prefrontal cortex tended to increase their ratings more than did those with less activation. The same regions were not activated by viewing negative advertisements for cola. Correlations between the self-rated values and the neural signal changes underscore the metric representation of observed decisions (i.e., whether to support or not in the brain. This indicates that neurometric analysis may contribute to the exploration of the neural correlates of daily social behaviour.

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

[Mercury dynamics of several plants collected from the water-level fluctuation zone of the Three Gorges Reservoir area during flooding and its impact on water body].

Science.gov (United States)

Zhang, Xiang; Zhang, Cheng; Sun, Rong-guo; Wang, Ding-yong

2014-12-01

Submerged plants are a major source for the abnormal elevation of methylmercury in reservoir. Several specific plants (Echinochloa crusgalli, Cynodondactylon and Corn stover) were collected and inundated in a simulated aquatic environment in the laboratory for investigating the mercury (Hg) dynamics in plants and the release process into water, aiming to find out the properties of Hg dynamics of plants under inundation conditions and its impact on water body in the Water-Level Fluctuation Zone of the Three Gorges Reservoir Area. The results showed that the contents of total mercury in several plants were in the range of 9. 21-12.07 ng x g(-1), and the percentage content of methylmercury (MeHg) was about 1%-2%. The content of total mercury (THg) in plants gradually decreased, by 35.81%-55.96%, whereas that of the dissolved mercury (DHg) increased sharply, by 103.23% -232.15%, which indicated an emission of Hg from plants to water in the process of decomposition. Furthermore, the state of inundation provided sufficient conditions for the methylation process in plants and therefore caused an increase of the content of methylmercury in the plant residues, which was 3.04-6.63 times as much as the initial content. The concentration of dissolved methylmercury (DMeHg) in the overlying water also increased significantly by 14.84- 16.05 times compared with the initial concentration. Meanwhile, the concentration of dissolved oxygen (DO) in the overlying water was significantly and negatively correlated with DMeHg. On the other hand, the concentration of dissolved organic carbon (DOC) in the overlying water was significantly and positively correlated with DMeHg. During the whole inundation period, the increase of DHg in the overlying water accounted for 41.74% -47.01% of the total amount of THg emission, and there was a negative correlation between the content of THg in plant residues and that of DHg in the overlying water.

Mercury distribution in the main compartments of the eutrophic Lake Candia (Northern Italy

Directory of Open Access Journals (Sweden)

Gian Maria BEONE

2009-08-01

Full Text Available Total mercury (T-Hg and organic mercury (mainly methylmercury, MeHg concentrations in the most important compartments (water, sediment, macrophytes, zooplankton, mussels and fish of the shallow and eutrophic Lake Candia (Turin, Northern Italy were measured. The decreasing sequence of the T-Hg concentrations is as follows: cat-fish (143 μg kg-1 d.w., zooplankton (77 μg kg-1 d.w., Unio pictorum mancus (37.9 μg kg-1 d.w., macrophytes (28.9 μg kg-1 d.w.. The content of mercury in mussel tissues increased with the size of the animal, but the relationship between Hg concentration and tissue weight was negative, indicating that the rate of mercury accumulation was lower than the tissue growth rate. The amount of mercury accumulated in the mussels living in the lake sediments was estimated to be 0.54 μg m-2. The importance of mercury biomagnification is also discussed.

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.

The Lagoon of Ravenna (Italy). Characterisation of mercury-contaminated sediments

Energy Technology Data Exchange (ETDEWEB)

Fabbri, D.; Lombardo, M.; Trombini, C.; Vassura, I. [Laboratorio di Chimica Ambientale, Universita di Bologna, Ravenna (Italy); Felisatti, O. [Ambiente SpA, Ravenna (Italy)

1998-05-06

Between 1958 and 1973, the wetland called Pialassa Baiona near Ravenna (Italy) had been heavily polluted by industrial effluents, among which mercury represented the most hazardous contaminant. Three sediment cores representative of a channel and a pond in the southern area, close to the discharge point, were analysed. Up to 244 {mu}g/g (dry weight) of mercury were observed in the top 0-20 cm layer. Among various parameters under study, good correlation was found between mercury and redox properties of the sediment, sulphur and organic matter. Styrene/butadiene based polymers, produced by the same industrial area since 1958, were found to be an important component of organic matter. Despite the analogy with the Minamata case, mercury appears to be efficiently trapped by the sediment, probably in the form of sulphide and/or bound to the organic matter and so far it has not represented a hazard for public health as confirmed by the lack of epidemiological effects in Ravenna area due to exposure to mercury

Cadmium, mercury, zinc and selenium in ringed seals (Phoca hispida from Greenland and Svalbard

Directory of Open Access Journals (Sweden)

Run Dietz

1998-06-01

Full Text Available Muscle, liver, and kidney tissue from 456 ringed seals (Phoca hispida from eight areas in Greenland were analysed for cadmium, mercury, zinc and selenium. In general, cadmium concentrations were high in liver and kidney tissue, with geometric means of 7.79 and 33.5 μg/g (all data on wet weight basis, respectively. Muscle levels were considerably lower, at 0.067 μg/g. The concentration of mercury was relatively high in liver tissue with a geometric mean of 2.59 μg/g. Muscle and kidney mercury levels were somewhat lower, with geometric means of 0.210 and 0.956 μg/g, respectively. Cadmium and mercury levels were strongly dependent upon age and sampling area, as well as the interaction combinations, indicating that the accumulation of cadmium and mercury varies with age and area. Mercury accumulated in all three tissues throughout life, whereas cadmium in liver and kidneys peaked in the age group 5-10 years old where after it dropped significantly. Cadmium levels showed a tendency towards higher concentrations in the northern municipalities, which may be due to the higher cadmium levels in certain prey items in the northern areas. Mercury levels were higher in seals from East Greenland compared to West Greenland. Variations in feeding habits probably explain some of the differences in levels of cadmium and mercury in ringed seals from different geographical areas. Cadmium concentrations were correlated (both pairwise and partial in the three organs. This was true for mercury as well, whereas only half of the combinations were significant for zinc and selenium. Cadmium was strongly correlated to mercury in all three tissues and zinc only in liver and kidneys. Mercury was only correlated to selenium in liver and not to zinc. High concentrations of cadmium were found in the bile from 58 ringed seals, and were about 10-fold higher than in muscle. The concentration of mercury in bile was relatively low, being only one third of the

Mercury content in amalgam tattoos of human oral mucosa and its relation to local tissue reactions

Energy Technology Data Exchange (ETDEWEB)

Forsell, M.; Larsson, B.; Ljungqvist, A.; Carlmark, B.; Johansson, O

1998-02-01

Mucosal biopsies from 48 patients with and 9 without amalgam tattoos were analysed with respect to their mercury content, distribution of mercury in the tissue, and histological tissue reactions. The distribution of mercury was assessed by auto-metallography (AMG), a silver amplification technique. The mercury content was determined by energy dispersive X-ray fluorescence (EDXRF), a multielemental analysis. Mercury was observed in connective tissue where it was confined to fibroblasts and macrophages, in vessel walls and in structures with the histological character of nerve fibres. A correlation was found between the histopathological tissue reaction, the type of mercury deposition, the intensity of the AMG reaction, and the mercury content. Mercury was also found in patients with amalgam dental fittings but without amalgam tattoos. (au) 24 refs.

Mercury content in amalgam tattoos of human oral mucosa and its relation to local tissue reactions

International Nuclear Information System (INIS)

Forsell, M.; Larsson, B.; Ljungqvist, A.; Carlmark, B.; Johansson, O.

1998-01-01

Mucosal biopsies from 48 patients with and 9 without amalgam tattoos were analysed with respect to their mercury content, distribution of mercury in the tissue, and histological tissue reactions. The distribution of mercury was assessed by auto-metallography (AMG), a silver amplification technique. The mercury content was determined by energy dispersive X-ray fluorescence (EDXRF), a multielemental analysis. Mercury was observed in connective tissue where it was confined to fibroblasts and macrophages, in vessel walls and in structures with the histological character of nerve fibres. A correlation was found between the histopathological tissue reaction, the type of mercury deposition, the intensity of the AMG reaction, and the mercury content. Mercury was also found in patients with amalgam dental fittings but without amalgam tattoos. (au)

Observations of speciated atmospheric mercury at three sites in Nevada: Evidence for a free tropospheric source of reactive gaseous mercury

Science.gov (United States)

Weiss-Penzias, Peter; Gustin, Mae Sexauer; Lyman, Seth N.

2009-07-01

Air mercury (Hg) speciation was measured for 11 weeks (June-August 2007) at three sites simultaneously in Nevada, USA. Mean reactive gaseous Hg (RGM) concentrations were elevated at all sites relative to those reported for locations not directly influenced by known point sources. RGM concentrations at all sites displayed a regular diel pattern and were positively correlated with ozone (O3) and negatively correlated with elemental Hg (Hg0) and dew point temperature (Tdp). Superimposed on the diel changes were 2- to 7-day periods when RGM concentrations increased across all three sites, producing significant intersite correlations of RGM daily means (r = 0.53-0.76, p distribution (GFD) plots and determine trajectory residence times (TRT) in specific source boxes. The GFD for the upper-quartile RGM daily means at one site showed a contributing airflow regime from the high-altitude subtropics with little precipitation, while that developed for the lower-quartile RGM concentrations indicated predominantly lower-altitude westerly flow and precipitation. Daily mean TRT in a subtropical high-altitude source box (>2 km and RGM at two sites (r2 = 0.37 and 0.27, p RGM from the free troposphere is a potentially important component of Hg input to rural areas of the western United States.

Monitoring and assessment of mercury pollution in the vicinity of a chloralkali plant. III. Concentration and genotoxicity of mercury in the industrial effluent and contaminated water of Rushikulya estuary, India.

Science.gov (United States)

Panda, K K; Lenka, M; Panda, B B

1992-01-01

Aquatic mercury pollution of the Rushikulya estuary in the vicinity of the chloralkali plant at Ganjam, India was monitored over a period from October 1987 to May 1989. The concentrations of aquatic mercury in the water samples taken from the effluent channel and from different sites along the course of the estuary covering a distance of 2 km were periodically recorded and ranged from 0 to 0.5 mg/l. The bioconcentration and genotoxicity of aquatic mercury in the samples were assessed by the Allium micronucleus (MNC) assay. The frequency of cells with MNC was highly correlated not only with bioconcentrated mercury (root mercury) but also with the levels of aquatic mercury. The threshold assessment values such as effective concentration fifty (EC50) for root growth, lowest effective concentration tested (LECT), and highest ineffective concentration tested (HICT) for induction of MNC in Allium MNC assay for the present aquatic industrial mercury were determined to be 0.14, 0.06 and 0.02 mg/l, respectively.

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

Mercury in the Umbilical Cord: Implications for Risk Assessment for Minamata Disease

DEFF Research Database (Denmark)

Dalgård, Christine; Grandjean, Philippe; Jørgensen, Poul Jørgen

1994-01-01

Umbilical cord tissue was obtained from 50 births in the Faroe Islands, where high mercury intake is due to ingestion of pilot whale meat. The mercury concentration correlated significantly with the frequency of maternal whale meat dinners during pregnancy and with mercury concentrations in umbil...... mercury concentration of 4.95 nmol/g dry weight in Minamata would correspond to 668 nmol/l cord blood and 114 nmol/g maternal hair. These levels agree well with other evidence of susceptibility of the fetus to increased exposure to methylmercury....... in umbilical cord blood and in maternal hair. The results were compared with published values for mercury in umbilical cord tissue from 12 infants diagnosed with congenital methylmercury poisoning in Minamata, Japan. From the regression coefficients obtained in the Faroese samples, the median umbilical cord...

Formation of nanocolloidal metacinnabar in mercury-DOM-sulfide systems

Science.gov (United States)

Gerbig, Chase A.; Kim, Christopher S.; Stegemeier, John P.; Ryan, Joseph N.; Aiken, George R.

2011-01-01

Direct determination of mercury (Hg) speciation in sulfide-containing environments is confounded by low mercury concentrations and poor analytical sensitivity. Here we report the results of experiments designed to assess mercury speciation at environmentally relevant ratios of mercury to dissolved organic matter (DOM) (i.e., structure (EXAFS) spectroscopy. Aqueous Hg(II) and a DOM isolate were equilibrated in the presence and absence of 100 μM total sulfide. In the absence of sulfide, mercury adsorption to the resin increased as the Hg:DOM ratio decreased and as the strength of Hg-DOM binding increased. EXAFS analysis indicated that in the absence of sulfide, mercury bonds with an average of 2.4 ± 0.2 sulfur atoms with a bond length typical of mercury-organic thiol ligands (2.35 Å). In the presence of sulfide, mercury showed greater affinity for the C18 resin, and its chromatographic behavior was independent of Hg:DOM ratio. EXAFS analysis showed mercury–sulfur bonds with a longer interatomic distance (2.51–2.53 Å) similar to the mercury–sulfur bond distance in metacinnabar (2.53 Å) regardless of the Hg:DOM ratio. For all samples containing sulfide, the sulfur coordination number was below the ideal four-coordinate structure of metacinnabar. At a low Hg:DOM ratio where strong binding DOM sites may control mercury speciation (1.9 nmol mg–1) mercury was coordinated by 2.3 ± 0.2 sulfur atoms, and the coordination number rose with increasing Hg:DOM ratio. The less-than-ideal coordination numbers indicate metacinnabar-like species on the nanometer scale, and the positive correlation between Hg:DOM ratio and sulfur coordination number suggests progressively increasing particle size or crystalline order with increasing abundance of mercury with respect to DOM. In DOM-containing sulfidic systems nanocolloidal metacinnabar-like species may form, and these species need to be considered when addressing mercury biogeochemistry.

Impacts of Sublethal Mercury Exposure on Birds: A Detailed Review.

Science.gov (United States)

Whitney, Margaret C; Cristol, Daniel A

Mercury is a ubiquitous environmental contaminant known to accumulate in, and negatively affect, fish-eating and oceanic bird species, and recently demonstrated to impact some terrestrial songbirds to a comparable extent. It can bioaccumulate to concentrations of >1 μg/g in tissues of prey organisms such as fish and insects. At high enough concentrations, exposure to mercury is lethal to birds. However, environmental exposures are usually far below the lethal concentrations established by dosing studies.The objective of this review is to better understand the effects of sublethal exposure to mercury in birds. We restricted our survey of the literature to studies with at least some exposures >5 μg/g. The majority of sublethal effects were subtle and some studies of similar endpoints reached different conclusions. Strong support exists in the literature for the conclusion that mercury exposure reduces reproductive output, compromises immune function, and causes avoidance of high-energy behaviors. For some endpoints, notably certain measures of reproductive success, endocrine and neurological function, and body condition, there is weak or contradictory evidence of adverse effects and further study is required. There was no evidence that environmentally relevant mercury exposure affects longevity, but several of the sublethal effects identified likely do result in fitness reductions that could adversely impact populations. Overall, 72% of field studies and 91% of laboratory studies found evidence of deleterious effects of mercury on some endpoint, and thus we can conclude that mercury is harmful to birds, and the many effects on reproduction indicate that bird population declines may already be resulting from environmental mercury pollution.

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.

Using Sulfate-Amended Sediment Slurry Batch Reactors to Evaluate Mercury Methylation

International Nuclear Information System (INIS)

Harmon, S.M.

2003-01-01

In the methylated form, mercury represents a concern to public health primarily through the consumption of contaminated fish tissue. Research conducted on the methylation of mercury strongly suggests the process is microbial in nature and facilitated principally by sulfate-reducing bacteria. This study addressed the potential for mercury methylation by varying sulfate treatments and wetland-based soil in microbial slurry reactors with available inorganic mercury. Under anoxic laboratory conditions conducive to growth of naturally occurring sulfate-reducing bacteria in the soil, it was possible to evaluate how various sulfate additions influenced the methylation of inorganic mercury added to overlying water. Treatments included sulfate amendments ranging FR-om 25 to 500 mg/L (0.26 to 5.2 mM) above the soil's natural sulfate level. This study also provided an assessment of mercury methylation relative to sulfate-reducing bacterial population growth and subsequent sulfide production. Mercury methylation in sulfate treatments did not exceed that of the non-amended control during a 35-day incubation. However, increases in methylmercury concentration were linked to bacterial growth and sulfate reduction. A time lag in methylation in the highest treatment correlated with an equivalent lag in bacterial growth

Spatial and Ontogenetic Variation in Mercury in Lake Superior Basin Sea Lamprey (Petromyzon marinus).

Science.gov (United States)

Moses, Sara K; Polkinghorne, Christine N; Mattes, William P; Beesley, Kimberly M

2018-01-01

Mercury concentrations were measured in eggs, larvae, and adult spawning-phase sea lampreys (Petromyzon marinus) collected in tributaries of Lake Superior to investigate spatial and ontogenetic variation. There were significant differences in mercury concentrations between all three life stages, with levels highest in adults (mean = 3.01 µg/g), followed by eggs (mean = 0.942 µg/g), and lowest in larvae (mean = 0.455 µg/g). There were no significant differences in mercury concentrations by location for any life stage or by sex in adults. Mercury was not correlated with adult or larval lamprey length or mass. Mercury levels in adult lampreys exceeded U.S. and Canadian federal guidelines for human consumption. Mercury concentrations in all life stages exceeded criteria for the protection of piscivorous wildlife, posing a threat to local fish, birds, and mammals. High mercury levels in adult lampreys combined with their semelparous life history make them a potential source of lake-derived mercury to spawning streams.

Maternal Steller sea lion diets elevate fetal mercury concentrations in an area of population decline

Energy Technology Data Exchange (ETDEWEB)

Rea, Lorrie D., E-mail: lorrie.rea@alaska.gov [Division of Wildlife Conservation, Alaska Department of Fish and Game, Fairbanks, AK 99701 (United States); Castellini, J. Margaret, E-mail: maggie.c@alaska.edu [Wildlife Toxicology Laboratory, School of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, AK 99775 (United States); Correa, Lucero, E-mail: lucero.correa@alaska.gov [Division of Wildlife Conservation, Alaska Department of Fish and Game, Fairbanks, AK 99701 (United States); Wildlife Toxicology Laboratory, College of Natural Sciences and Mathematics, University of Alaska Fairbanks, Fairbanks, AK 99775 (United States); Fadely, Brian S., E-mail: brian.fadely@noaa.gov [National Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, WA 98115 (United States); O' Hara, Todd M., E-mail: tmohara@alaska.edu [Wildlife Toxicology Laboratory, College of Natural Sciences and Mathematics, University of Alaska Fairbanks, Fairbanks, AK 99775 (United States)

2013-06-01

Total mercury concentrations ([THg]) measured in western Aleutian Island Steller sea lion pup hair were the highest maximum [THg] documented in this endangered species to date. Some pups exceeded concentrations at which other fish-eating mammals can exhibit adverse neurological and reproductive effects (21% and 15% pups above 20 and 30 μg/g in hair, respectively). Of particular concern is fetal exposure to mercury during a particularly vulnerable stage of neurological development in late gestation. Hair and blood [THg] were highly correlated and 20% of pups sampled in the western Aleutian Islands of Alaska exceeded mammalian risk thresholds established for each of these tissues. Higher nitrogen isotope ratios suggested that pups accumulated the highest [THg] when their dams fed on higher trophic level prey during late gestation. - Highlights: • High total mercury concentrations in western Aleutian Island Steller sea lions • Some pups exceeded thresholds for adverse neurological and reproductive effects. • Fetal exposure to mercury during a vulnerable stage of neurological development • Mercury concentrations in hair were highly correlated with circulating blood levels. • High mercury levels in pups related to dams feeding on high trophic level prey.

Maternal Steller sea lion diets elevate fetal mercury concentrations in an area of population decline

International Nuclear Information System (INIS)

Rea, Lorrie D.; Castellini, J. Margaret; Correa, Lucero; Fadely, Brian S.; O'Hara, Todd M.

2013-01-01

Total mercury concentrations ([THg]) measured in western Aleutian Island Steller sea lion pup hair were the highest maximum [THg] documented in this endangered species to date. Some pups exceeded concentrations at which other fish-eating mammals can exhibit adverse neurological and reproductive effects (21% and 15% pups above 20 and 30 μg/g in hair, respectively). Of particular concern is fetal exposure to mercury during a particularly vulnerable stage of neurological development in late gestation. Hair and blood [THg] were highly correlated and 20% of pups sampled in the western Aleutian Islands of Alaska exceeded mammalian risk thresholds established for each of these tissues. Higher nitrogen isotope ratios suggested that pups accumulated the highest [THg] when their dams fed on higher trophic level prey during late gestation. - Highlights: • High total mercury concentrations in western Aleutian Island Steller sea lions • Some pups exceeded thresholds for adverse neurological and reproductive effects. • Fetal exposure to mercury during a vulnerable stage of neurological development • Mercury concentrations in hair were highly correlated with circulating blood levels. • High mercury levels in pups related to dams feeding on high trophic level prey

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

Mercury species in lymphoid and non-lymphoid tissues after exposure to methyl mercury: correlation with autoimmune parameters during and after treatment in susceptible mice

DEFF Research Database (Denmark)

Havarinasab, Said; Björn, Erik; Nielsen, Jesper Bo

2007-01-01

). This study aimed at exploring the effect of MeHg with regard to HgIA, and especially the immunological events after stopping treatment, correlated with the presence of MeHg and Hg(2+) in the organs. Treatment of A.SW mice for 30 days with 4.2 mg MeHg/L drinking water (corresponding to approximately 420...... during the initial 6 weeks after stopping treatment, while all other HgIA features including antichromatin antibodies declined to control levels after 2-4 weeks. This indicates differences in either dose requirement or induction mechanisms for the different HgIA parameters. The selective accumulation...... together with the local demethylation increases the organ Hg(2+) concentration. MeHg is a well-known immunosuppressive agent, while Hg(2+) is associated with immunostimulation and autoimmunity especially in genetically susceptible rodents, creating a syndrome, i.e. mercury-induced autoimmunity (HgIA...

Intra- and inter-basin mercury comparisons: Importance of basin scale and time-weighted methylmercury estimates

International Nuclear Information System (INIS)

Bradley, Paul M.; Journey, Celeste A.; Brigham, Mark E.; Burns, Douglas A.; Button, Daniel T.; Riva-Murray, Karen

2013-01-01

To assess inter-comparability of fluvial mercury (Hg) observations at substantially different scales, Hg concentrations, yields, and bivariate-relations were evaluated at nested-basin locations in the Edisto River, South Carolina and Hudson River, New York. Differences between scales were observed for filtered methylmercury (FMeHg) in the Edisto (attributed to wetland coverage differences) but not in the Hudson. Total mercury (THg) concentrations and bivariate-relationships did not vary substantially with scale in either basin. Combining results of this and a previously published multi-basin study, fish Hg correlated strongly with sampled water FMeHg concentration (ρ = 0.78; p = 0.003) and annual FMeHg basin yield (ρ = 0.66; p = 0.026). Improved correlation (ρ = 0.88; p < 0.0001) was achieved with time-weighted mean annual FMeHg concentrations estimated from basin-specific LOADEST models and daily streamflow. Results suggest reasonable scalability and inter-comparability for different basin sizes if wetland area or related MeHg-source-area metrics are considered. - Highlights: ► National scale mercury assessments integrate small scale study results. ► Basin scale differences and representativeness of fluvial mercury samples are concerns. ► Wetland area, not basin size, predicts inter-basin methylmercury variability. ► Time-weighted methylmercury estimates improve the prediction of mercury in basin fish. - Fluvial methylmercury concentration correlates with wetland area not basin scale and time-weighted estimates better predict basin top predator mercury than discrete sample estimates.

Remediation aspect of microbial changes of plant rhizosphere in mercury contaminated soil.

Science.gov (United States)

Sas-Nowosielska, Aleksandra; Galimska-Stypa, Regina; Kucharski, Rafał; Zielonka, Urszula; Małkowski, Eugeniusz; Gray, Laymon

2008-02-01

Phytoremediation, an approach that uses plants to remediate contaminated soil through degradation, stabilization or accumulation, may provide an efficient solution to some mercury contamination problems. This paper presents growth chamber experiments that tested the ability of plant species to stabilize mercury in soil. Several indigenous herbaceous species and Salix viminalis were grown in soil collected from a mercury-contaminated site in southern Poland. The uptake and distribution of mercury by these plants were investigated, and the growth and vitality of the plants through a part of one vegetative cycle were assessed. The highest concentrations of mercury were found at the roots, but translocation to the aerial part also occurred. Most of the plant species tested displayed good growth on mercury contaminated soil and sustained a rich microbial population in the rhizosphere. The microbial populations of root-free soil and rhizosphere soil from all species were also examined. An inverse correlation between the number of sulfur amino acid decomposing bacteria and root mercury content was observed. These results indicate the potential for using some species of plants to treat mercury contaminated soil through stabilization rather than extraction. The present investigation proposes a practical cost-effective temporary solution for phytostabilization of soil with moderate mercury contamination as well as the basis for plant selection.

Mercury cycling in surface water, pore water and sediments of Mugu Lagoon, CA, USA

Energy Technology Data Exchange (ETDEWEB)

Rothenberg, Sarah E. [Environmental Science and Engineering Program, Box 951772, University of California, Los Angeles, CA 90095-1772 (United States)], E-mail: rothenberg.sarah@gmail.com; Ambrose, Richard F. [Environmental Science and Engineering Program, Box 951772, University of California, Los Angeles, CA 90095-1772 (United States); Department of Environmental Health Sciences, Box 951772, University of California, Los Angeles, CA 90095-1772 (United States)], E-mail: rambrose@ucla.edu; Jay, Jennifer A. [Department of Civil and Environmental Engineering, Box 951593, University of California, Los Angeles, CA 90095-1593 (United States)], E-mail: jjay@seas.ucla.edu

2008-07-15

Mugu Lagoon is an estuary in southern California, listed as impaired for mercury. In 2005, we examined mercury cycling at ten sites within at most four habitats. In surface water (unfiltered and filtered) and pore water, the concentration of total mercury was correlated with methylmercury levels (R{sup 2} = 0.29, 0.26, 0.27, respectively, p < 0.05), in contrast to sediments, where organic matter and reduced iron levels were most correlated with methylmercury content (R{sup 2} = 0.37, 0.26, respectively, p < 0.05). Interestingly, levels for percent methylmercury of total mercury in sediments were higher than typical values for estuarine sediments (average 5.4%, range 0.024-38%, n = 59), while pore water methylmercury K{sub d} values were also high (average 3.1, range 2.0-4.2 l kg{sup -1}, n = 39), and the estimated methylmercury flux from sediments was low (average 1.7, range 0.14-5.3 ng m{sup -2} day{sup -1}, n = 19). Mercury levels in predatory fish tissue at Mugu are >0.3 ppm, suggesting biogeochemical controls on methylmercury mobility do not completely mitigate methylmercury uptake through the food web. - Trends in mercury cycling differed between habitats and within matrices at Mugu Lagoon.

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.

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

Correlates between feeding ecology and mercury levels in historical and modern arctic foxes (Vulpes lagopus.

Directory of Open Access Journals (Sweden)

Natalia Bocharova

Full Text Available Changes in concentration of pollutants and pathogen distribution can vary among ecotypes (e.g. marine versus terrestrial food resources. This may have important implications for the animals that reside within them. We examined 1 canid pathogen presence in an endangered arctic fox (Vulpes lagopus population and 2 relative total mercury (THg level as a function of ecotype ('coastal' or 'inland' for arctic foxes to test whether the presence of pathogens or heavy metal concentration correlate with population health. The Bering Sea populations on Bering and Mednyi Islands were compared to Icelandic arctic fox populations with respect to inland and coastal ecotypes. Serological and DNA based pathogen screening techniques were used to examine arctic foxes for pathogens. THg was measured by atomic absorption spectrometry from hair samples of historical and modern collected arctic foxes and samples from their prey species (hair and internal organs. Presence of pathogens did not correlate with population decline from Mednyi Island. However, THg concentration correlated strongly with ecotype and was reflected in the THg concentrations detected in available food sources in each ecotype. The highest concentration of THg was found in ecotypes where foxes depended on marine vertebrates for food. Exclusively inland ecotypes had low THg concentrations. The results suggest that absolute exposure to heavy metals may be less important than the feeding ecology and feeding opportunities of top predators such as arctic foxes which may in turn influence population health and stability. A higher risk to wildlife of heavy metal exposure correlates with feeding strategies that rely primarily on a marine based diet.

Correlates between feeding ecology and mercury levels in historical and modern arctic foxes (Vulpes lagopus).

Science.gov (United States)

Bocharova, Natalia; Treu, Gabriele; Czirják, Gábor Árpád; Krone, Oliver; Stefanski, Volker; Wibbelt, Gudrun; Unnsteinsdóttir, Ester Rut; Hersteinsson, Páll; Schares, Gereon; Doronina, Lilia; Goltsman, Mikhail; Greenwood, Alex D

2013-01-01

Changes in concentration of pollutants and pathogen distribution can vary among ecotypes (e.g. marine versus terrestrial food resources). This may have important implications for the animals that reside within them. We examined 1) canid pathogen presence in an endangered arctic fox (Vulpes lagopus) population and 2) relative total mercury (THg) level as a function of ecotype ('coastal' or 'inland') for arctic foxes to test whether the presence of pathogens or heavy metal concentration correlate with population health. The Bering Sea populations on Bering and Mednyi Islands were compared to Icelandic arctic fox populations with respect to inland and coastal ecotypes. Serological and DNA based pathogen screening techniques were used to examine arctic foxes for pathogens. THg was measured by atomic absorption spectrometry from hair samples of historical and modern collected arctic foxes and samples from their prey species (hair and internal organs). Presence of pathogens did not correlate with population decline from Mednyi Island. However, THg concentration correlated strongly with ecotype and was reflected in the THg concentrations detected in available food sources in each ecotype. The highest concentration of THg was found in ecotypes where foxes depended on marine vertebrates for food. Exclusively inland ecotypes had low THg concentrations. The results suggest that absolute exposure to heavy metals may be less important than the feeding ecology and feeding opportunities of top predators such as arctic foxes which may in turn influence population health and stability. A higher risk to wildlife of heavy metal exposure correlates with feeding strategies that rely primarily on a marine based diet.

Mercury levels in the Smooth Hammerhead Shark Sphyrna zygaena (Carcharhiniformes: Sphyrnidae from Northern Peru

Directory of Open Access Journals (Sweden)

Adriana Gonzalez-Pestana

2017-12-01

Full Text Available The smooth hammerhead shark Sphyrna zygaena (Linnaeus, 1758 is one of the elasmobranch species most used for human consumption in Peru. However, the level of mercury in hammerhead muscle tissue is unknown. This study assessed the level of mercury found in the muscle of hammerhead sharks and its relation with human health. Moreover, we evaluated the relationship between shark body size and mercury levels. We analyzed 27 muscle samples of neonates and juveniles captured in northern Peru. Mercury concentrations varied between 0.13 and 0.86 mg kg-1 wet weight. Moreover, we found a negative and significant relationship between shark body size and mercury levels. This study represents the first evaluation of mercury levels of sharks in Peru. Although the values found do not exceed levels recommended by the World Health Organization (< 1 mg kg-1, we recommend expanding this study to include other size classes of sharks as well as other marine resources used for human consumption.

Characteristics and source appointment of atmospheric particulate mercury over East China Sea: Implication on the deposition of atmospheric particulate mercury in marine environment.

Science.gov (United States)

Duan, Lian; Cheng, Na; Xiu, Guangli; Wang, Fujiang; Chen, Ying

2017-05-01

Total Suspended Particulate (TSP) samples were collected at Huaniao Island in northern East China Sea (ECS) from March 2012 to January 2013. Chemical analysis were conducted to measure the concentration of total particulate mercury (TPM) and speciated particulate mercury including HCl-soluble particulate mercury (HPM), elemental particulate mercury (EPM) and residual particulate mercury (RPM). The bromine (Br) and iodine (I) on particles were also detected. The mean concentration of TPM during the study period was 0.23 ± 0.15 ng m -3 , while the obviously seasonal variation was found that the concentrations of TPM in spring, summer, fall and winter were 0.34 ± 0.20 ng m -3 , 0.15 ± 0.03 ng m -3 , 0.15 ± 0.05 ng m -3 and 0.27 ± 0.26 ng m -3 , respectively. The statistically strong correlation of bromine and iodine to HPM was only found in spring with r = 0.81 and 0.77 (p mercury due to the deposition of mercury over the sea. The cluster of air mass across the sea had low concentration of HPM in winter, which suggested that the oxidation of mercury in winter might be related to other oxidants. During the whole sampling period, the air mass from the north of China contributed to the higher concentration of TPM in Huaniao Island. Copyright © 2016 Elsevier Ltd. All rights reserved.

Potential for Increased Mercury Accumulation in the Estuary Food Web

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Jay A Davis

2003-10-01

Full Text Available Present concentrations of mercury in large portions of San Francisco Bay (Bay, the Sacramento-San Joaquin Delta (Delta, and the Sacramento and San Joaquin rivers are high enough to warrant concern for the health of humans and wildlife. Large scale tidal wetland restoration is currently under consideration as a means of increasing populations of fish species of concern. Tidal wetland restoration activities may lead to increased concentrations of mercury in the estuarine food web and exacerbate the existing mercury problem. This paper evaluates our present ability to predict the local and regional effects of restoration actions on mercury accumulation in aquatic food webs. A sport fish consumption advisory is in place for the Bay, and an advisory is under consideration for the Delta and lower Sacramento and San Joaquin rivers. Mercury concentrations in eggs of several water bird species from the Bay have exceeded the lowest observed effect level. A variety of mercury sources, largely related to historic mercury and gold mining, is present in the watershed and has created a spatially heterogeneous distribution of mercury in the Bay-Delta Estuary. Mercury exists in the environment in a variety of forms and has a complex biogeochemical cycle. The most hazardous form, methylmercury, is produced at a relatively high rate in wetlands and newly flooded aquatic habitats. It is likely that distinct spatial variation on multiple spatial scales exists in net methylmercury production in Bay-Delta tidal wetlands, including variation within each tidal wetland, among tidal wetlands in the same region, and among tidal wetlands in different regions. Understanding this spatial variation and its underlying causes will allow environmental managers to minimize the negative effects of mercury bioaccumulation as a result of restoration activities. Actions needed to reduce the uncertainty associated with this issue include a long term, multifaceted research effort, long

Biosorption of mercury by capsulated and slime layer- forming Gram ...

African Journals Online (AJOL)

ONOS

2010-09-20

Sep 20, 2010 ... high negatively charged components, showed more than 1.5 fold increase as compared to capsulated ... Mercury is one of the most toxic heavy metals released in ... ion exchange, activated carbon adsorption and separation.

Avian mercury exposure and toxicological risk across western North America: A synthesis

Science.gov (United States)

Ackerman, Joshua T.; Eagles-Smith, Collin A.; Herzog, Mark; Hartman, Christopher; Peterson, Sarah; Evers, David C.; Jackson, Allyson K.; Elliott, John E.; Vander Pol, Stacy S.; Bryan, Colleen E.

2016-01-01

Methylmercury contamination of the environment is an important issue globally, and birds are useful bioindicators for mercury monitoring programs. The available data on mercury contamination of birds in western North America were synthesized. Original data from multiple databases were obtained and a literature review was conducted to obtain additional mercury concentrations. In total, 29219 original bird mercury concentrations from 225 species were compiled, and an additional 1712 mean mercury concentrations, representing 19998 individuals and 176 species, from 200 publications were obtained. To make mercury data comparable across bird tissues, published equations of tissue mercury correlations were used to convert all mercury concentrations into blood-equivalent mercury concentrations. Blood-equivalent mercury concentrations differed among species, foraging guilds, habitat types, locations, and ecoregions. Piscivores and carnivores exhibited the greatest mercury concentrations, whereas herbivores and granivores exhibited the lowest mercury concentrations. Bird mercury concentrations were greatest in ocean and salt marsh habitats and lowest in terrestrial habitats. Bird mercury concentrations were above toxicity benchmarks in many areas throughout western North America, and multiple hotspots were identified. Additionally, published toxicity benchmarks established in multiple tissues were summarized and translated into a common blood-equivalent mercury concentration. Overall, 66% of birds sampled in western North American exceeded a blood-equivalent mercury concentration of 0.2 μg/g wet weight (ww; above background levels), which is the lowest-observed effect level, 28% exceeded 1.0 μg/g ww (moderate risk), 8% exceeded 3.0 μg/g ww (high risk), and 4% exceeded 4.0 μg/g ww (severe risk). Mercury monitoring programs should sample bird tissues, such as adult blood and eggs, that are most-easily translated into tissues with well-developed toxicity benchmarks and that

Characteristics of total gaseous mercury concentrations at a coastal area of the Yangtze Delta, China.

Science.gov (United States)

Diao, Chunyan; Li, Jianfeng; Zhang, Bin; Tang, Shichuang

2017-03-01

In this study, we report on total gaseous mercury (TGM) field observations made in the rural area of Shanghai, Chongming Island, China, from September 2009 to April 2012. The average TGM was 2.65 ± 1.73 ng m -3 in Chongming Island, which is higher than the TGM background value of the Northern Hemisphere (1.5-1.7 ng m -3 ); this indicates that to some extent, the Chongming area has been affected by anthropogenic mercury emissions. The observed TGM follows a seasonal pattern; concentrations are highest in winter, followed by autumn, summer, and spring. There is also a clear diurnal variation in TGM. All peak values appear between 7:00 and 9:00 in all four seasons; this appears to be the result of the height change in the atmospheric boundary layer that occurs between day and night. TGM concentrations in Chongming remain high in the westerly wind direction, especially in the southwest direction because of its low frequency, so the greatest source contribution to TGM in Chongming lies to the northwest. Wind speed is also a significant factor affecting TGM, and was negatively correlated with TGM concentrations. TGM is also closely related to carbon monoxide (CO) concentrations, indicating that TGM is impacted by human activities. The slope of the linear fitting of TGM and CO demonstrates that the contribution of noncoal source emissions to TGM in summer is greater than in autumn, mainly because the high temperature and intensive sunlight in summer increase mercury emissions from natural sources. Except for some studies in the coastal areas (e.g., Kang Hwa Island by Kim et al., 2006, An-Myun Island by Kim et al., 2002, and Okinawa by Chan et al., 2008), data specifically for coastal areas are lacking. Monitoring of total gaseous mercury (TGM) in the rural area of Shanghai, Chongming Island, can help us understand mercury distribution.

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.

Mercury in Hair Is Inversely Related to Disease Associated Damage in Systemic Lupus Erythematosus

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William Crowe

2015-12-01

Full Text Available Systemic lupus erythematosus (SLE is an autoimmune inflammatory disease, and environmental factors are proposed to exacerbate existing symptoms. One such environmental factor is mercury. The aim of this study was to investigate the relationship between exposure to mercury (Hg and disease activity and disease associated damage in Total Hg concentrations in hair and urine were measured in 52 SLE patients. Dental amalgams were quantified. Disease activity was assessed using three indexes including the British Isles Lupus Assessment Group Index (BILAG. Disease associated damage was measured using the Systemic Lupus International Collaborating Clinics/American College of Rheumatology SLICC/ACR Damage Index. Pearson’s correlation identified a significant negative correlation between hair Hg and BILAG (r = −0.323, p = 0.029 and SLICC/ACR (r = −0.377, p = 0.038. Multiple regression analysis identified hair Hg as a significant predictor of disease associated damage as determined by SLICC/ACR (β = −0.366, 95% confidence interval (CI: −1.769, −0.155 p = 0.019. Urinary Hg was not related to disease activity or damage. Fish consumption is the primary route of MeHg exposure in humans and the inverse association of hair Hg with disease activity observed here might be explained by the anti-inflammatory effects of n-3 long chain polyunsaturated fatty acids also found in fish.

Mercury regulation, fate, transport, transformation, and abatement within cement manufacturing facilities: review.

Science.gov (United States)

Sikkema, Joel K; Alleman, James E; Ong, Say Kee; Wheelock, Thomas D

2011-09-15

The USEPA's 2010 mercury rule, which would reduce emissions from non-hazardous waste burning cement manufacturing facilities by an estimated 94%, represents a substantial regulatory challenge for the industry. These regulations, based on the performance of facilities that benefit from low concentrations of mercury in their feedstock and fuel inputs (e.g., limestone concentration was less than 25 ppb at each facility), will require non-compliant facilities to develop innovative controls. Control development is difficult because each facility's emissions must be assessed and simple correlation to mercury concentrations in limestone or an assumption of 'typically observed' mercury concentrations in inputs are unsupported by available data. Furthermore, atmospheric emissions are highly variable due to an internal control mechanism that captures and loops mercury between the high-temperature kiln and low-temperature raw materials mill. Two models have been reported to predict emissions; however, they have not been benchmarked against data from the internal components that capture mercury and do not distinguish between mercury species, which have different sorption and desorption properties. Control strategies include technologies applied from other industries and technologies developed specifically for cement facilities. Reported technologies, listed from highest to lowest anticipated mercury removal, include purge of collected dust or raw meal, changes in feedstocks and fuels, wet scrubbing, cleaning of mercury enriched dust, dry sorbent injection, and dry and semi-dry scrubbing. The effectiveness of these technologies is limited by an inadequate understanding of sorption, desorption, and mercury species involved in internal loop mercury control. To comply with the mercury rule and to improve current mercury control technologies and practices, research is needed to advance fundamental knowledge regarding mercury species sorption and desorption dynamics on materials

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.

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.

Total mercury levels in hair, toenail, and urine among women free from occupational exposure and their relations to renal tubular function

International Nuclear Information System (INIS)

Ohno, Tomoko; Sakamoto, Mineshi; Kurosawa, Tomoko; Dakeishi, Miwako; Iwata, Toyoto; Murata, Katsuyuki

2007-01-01

To investigate the relations among total mercury levels in hair, toenail, and urine, together with potential effects of methylmercury intake on renal tubular function, we determined their levels, and urinary N-acetyl-β-d-glucosaminidase activity (NAG) and α 1 -microglobulin (AMG) in 59 women free from occupational exposures, and estimated daily mercury intakes from fish and other seafood using a food frequency questionnaire. Mercury levels (mean+/-SD) in the women were 1.51+/-0.91μg/g in hair, 0.59+/-0.32μg/g in toenail, and 0.86+/-0.66μg/g creatinine in urine; and, there were positive correlations among them (P<0.001). The daily mercury intake of 9.15+/-7.84μg/day was significantly correlated with total mercury levels in hair, toenail, and urine (r=0.551, 0.537, and 0.604, P<0.001). Among the women, the NAG and AMG were positively correlated with both the daily mercury intake and mercury levels in hair, toenail, and urine (P<0.01); and, these relations were almost similar when using multiple regression analysis to adjust for possible confounders such as urinary cadmium (0.47+/-0.28μg/g creatinine) and smoking status. In conclusion, mercury resulting from fish consumption can explain total mercury levels in hair, toenail, and urine to some degree (about 30%), partly through the degradation into the inorganic form, and it may confound the renal tubular effect of other nephrotoxic agents. Also, the following equation may be applicable to the population neither with dental amalgam fillings nor with occupational exposures: [hair mercury (μg/g)]=2.44x[toenail mercury (μg/g)

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.

ICP OES and CV AAS in determination of mercury in an unusual fatal case of long-term exposure to elemental mercury in a teenager.

Science.gov (United States)

Lech, Teresa

2014-04-01

In this work, a case of deliberate self-poisoning is presented. A 14-year-old girl suddenly died during one of the several hospitalizations. Abdominal computer tomography showed a large number of metallic particles in the large intestine. Analysis of blood and internal organs for mercury and other toxic metals carried out by inductively coupled plasma optical emission spectrometry (ICP OES) revealed high concentrations of mercury in kidneys and liver (64,200 and 2470ng/g, respectively), less in stomach (90ng/g), and none in blood. Using cold vapor-atomic absorption spectrometry (CV AAS), high levels of mercury were confirmed in all examined materials, including blood (87ng/g), and additionally in hair. The results of analysis obtained by two techniques revealed that the exposure to mercury was considerable (some time later, it was stated that the mercury originated from thermometers that had been broken over the course of about 1 year, because of Münchausen syndrome). CV AAS is a more sensitive technique, particularly for blood samples (negative results using ICP OES), and tissue samples - with LOQ: 0.63ng/g of Hg (CV AAS) vis-à-vis 70ng/g of Hg (ICP OES). However, ICP OES may be used as a screening technique for autopsy material in acute poisoning by a heavy metal, even one as volatile as mercury. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

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.

Characterization of the binding capacity of mercurial species in Lactobacillus strains.

Science.gov (United States)

Alcántara, Cristina; Jadán-Piedra, Carlos; Vélez, Dinoraz; Devesa, Vicenta; Zúñiga, Manuel; Monedero, Vicente

2017-12-01

Metal sequestration by bacteria has been proposed as a strategy to counteract metal contamination in foodstuffs. Lactobacilli can interact with metals, although studies with important foodborne metals such as inorganic [Hg(II)] or organic (CH 3 Hg) mercury are lacking. Lactobacilli were evaluated for their potential to bind these contaminants and the nature of the interaction was assessed by the use of metal competitors, chemical and enzymatical treatments, and mutants affected in the cell wall structure. Lactobacillus strains efficiently bound Hg(II) and CH 3 Hg. Mercury binding by Lactobacillus casei BL23 was independent of cell viability. In BL23, both forms of mercury were cell wall bound. Their interaction was not inhibited by cations and it was resistant to chelating agents and protein digestion. Lactobacillus casei mutants affected in genes involved in the modulation of the negative charge of the cell wall anionic polymer lipoteichoic acid showed increased mercury biosorption. In these mutants, mercury toxicity was enhanced compared to wild-type bacteria. These data suggest that lipoteichoic acid itself or the physicochemical characteristics that it confers to the cell wall play a major role in mercury complexation. This is the first example of the biosorption of Hg(II) and CH 3 Hg in lactobacilli and it represents a first step towards their possible use as agents for diminishing mercury bioaccessibility from food at the gastrointestinal tract. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

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

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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

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, ...

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.

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.)

High Correlated Paternity Leads to Negative Effects on Progeny Performance in Two Mediterranean Shrub Species.

Directory of Open Access Journals (Sweden)

Sofia Nora

Full Text Available Anthropogenic habitat deterioration can promote changes in plant mating systems that subsequently may affect progeny performance, thereby conditioning plant recruitment for the next generation. However, very few studies yet tested mating system parameters other than outcrossing rates; and the direct effects of the genetic diversity of the pollen received by maternal plants (i.e. correlated paternity has often been overlooked. In this study, we investigated the relation between correlated paternity and progeny performance in two common Mediterranean shrubs, Myrtus communis and Pistacia lentiscus. To do so, we collected open-pollinated progeny from selected maternal plants, calculated mating system parameters using microsatellite genotyping and conducted sowing experiments under greenhouse and field conditions. Our results showed that some progeny fitness components were negatively affected by the high correlated paternity of maternal plants. In Myrtus communis, high correlated paternity had a negative effect on the proportion and timing of seedling emergence in the natural field conditions and in the greenhouse sowing experiment, respectively. In Pistacia lentiscus, seedling emergence time under field conditions was also negatively influenced by high correlated paternity and a progeny survival analysis in the field experiment showed greater mortality of seedlings from maternal plants with high correlated paternity. Overall, we found effects of correlated paternity on the progeny performance of Myrtus communis, a self-compatible species. Further, we also detected effects of correlated paternity on the progeny emergence time and survival in Pistacia lentiscus, an obligate outcrossed species. This study represents one of the few existing empirical examples which highlight the influence that correlated paternity may exert on progeny performance in multiple stages during early seedling growth.

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.

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.

Mercury species in lymphoid and non-lymphoid tissues after exposure to methyl mercury: Correlation with autoimmune parameters during and after treatment in susceptible mice

International Nuclear Information System (INIS)

Havarinasab, Said; Bjoern, Erik; Nielsen, Jesper B.; Hultman, Per

2007-01-01

Methylmercury (MeHg) is present in the environment as a result of the global cycling of mercury, although anthropogenic sources may dramatically increase the availability in confined geographical areas. Accumulation of MeHg in the aquatic food chain is the dominating way of exposure in mammals, which accumulate MeHg in all organs, including Brain. Demethylation has been described in the organs, especially in phagocytic cells, but mainly in the flora of the intestinal tract. While most of the inorganic mercury (Hg 2+ ) formed in the intestine is excreted, a fraction is reabsorbed which together with the local demethylation increases the organ Hg 2+ concentration. MeHg is a well-known immunosuppressive agent, while Hg 2+ is associated with immunostimulation and autoimmunity especially in genetically susceptible rodents, creating a syndrome, i.e. mercury-induced autoimmunity (HgIA). This study aimed at exploring the effect of MeHg with regard to HgIA, and especially the immunological events after stopping treatment, correlated with the presence of MeHg and Hg 2+ in the organs. Treatment of A.SW mice for 30 days with 4.2 mg MeHg/L drinking water (corresponding to approximately 420 μg Hg/kg body weight/day) caused all the HgIA features observed after primary treatment with inorganic Hg, except systemic immune complex deposits. The total Hg concentration was 5-fold higher in the kidneys as compared with lymph nodes, but the fraction of Hg 2+ was similar (17-20%). After stopping treatment, the renal and lymph node MeHg concentration declined according to first order kinetics during the initial 4-6 weeks, but then slower. A similar decline in the organ Hg 2+ concentration occurred during the initial 2 weeks after stopping treatment but then ceased, causing the Hg 2+ concentration to exceed that of MeHg in the lymph nodes and kidneys after 3 and 8 weeks, respectively. The selective increase in lymph node Hg 2+ fraction is likely to be due to demethylation of MeHg in the

Ship-Based Measurements of Atmospheric Mercury Concentrations over the Baltic Sea

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Hanna Hoglind

2018-02-01

Full Text Available Mercury is a toxic pollutant emitted from both natural sources and through human activities. A global interest in atmospheric mercury has risen ever since the discovery of the Minamata disease in 1956. Properties of gaseous elemental mercury enable long range transport, which can cause pollution even in pristine environments. Gaseous elemental mercury (GEM was measured from winter 2016 to spring 2017 over the Baltic Sea. A Tekran 2357A mercury analyser was installed aboard the research and icebreaking vessel Oden for the purpose of continuous measurements of gaseous mercury in ambient air. Measurements were performed during a campaign along the Swedish east coast and in the Bothnian Bay near Lulea during the icebreaking season. Data was evaluated from Gothenburg using plotting software, and back trajectories for air masses were calculated. The GEM average of 1.36 ± 0.054 ng/m3 during winter and 1.29 ± 0.140 ng/m3 during spring was calculated as well as a total average of 1.36 ± 0.16 ng/m3. Back trajectories showed a possible correlation of anthropogenic sources elevating the mercury background level in some areas. There were also indications of depleted air, i.e., air with lower concentrations than average, being transported from the Arctic to northern Sweden, resulting in a drop in GEM levels.

Fractal analysis of SEM images and mercury intrusion porosimetry data for the microstructural characterization of microcrystalline cellulose-based pellets

International Nuclear Information System (INIS)

Gomez-Carracedo, A.; Alvarez-Lorenzo, C.; Coca, R.; Martinez-Pacheco, R.; Concheiro, A.; Gomez-Amoza, J.L.

2009-01-01

The microstructure of theophylline pellets prepared from microcrystalline cellulose, carbopol and dicalcium phosphate dihydrate, according to a mixture design, was characterized using textural analysis of gray-level scanning electron microscopy (SEM) images and thermodynamic analysis of the cumulative pore volume distribution obtained by mercury intrusion porosimetry. Surface roughness evaluated in terms of gray-level non-uniformity and fractal dimension of pellet surface depended on agglomeration phenomena during extrusion/spheronization. Pores at the surface, mainly 1-15 μm in diameter, determined both the mechanism and the rate of theophylline release, and a strong negative correlation between the fractal geometry and the b parameter of the Weibull function was found for pellets containing >60% carbopol. Theophylline mean dissolution time from these pellets was about two to four times greater. Textural analysis of SEM micrographs and fractal analysis of mercury intrusion data are complementary techniques that enable complete characterization of multiparticulate drug dosage forms

Searching for Terrain Softening near Mercury's North Pole

Science.gov (United States)

Cobian, P. S.; Vilas, F.; Lederer, S. M.; Barlow, N. G.

2004-01-01

In 1999, following the initial discovery of radar bright craters near both poles of Mercury measured the depth-todiameter (d/D) ratios of 170 impact craters in Mariner 10 images covering four different regions on Mercury s surface. Rapid softening of crater structure, indicated by lower d/D ratios, could indicate the possibility of subsurface water ice in Mercury's terrain originating from an internal source in the planet. Their study included 3 specific radar bright craters suggested to contain ice. They concluded that no terrain softening was apparent, and a rapidly emplaced exogenic water source was the most likely source for the proposed ice in these craters. Recent radar observations of the Mercurian North pole have pinpointed many additional radar bright areas with a resolution 10x better than previous radar measurements, and which correlate with craters imaged by Mariner 10. These craters are correlated with regions that are permanently shaded from direct sunlight, and are consistent with observations of clean water ice. We have expanded the initial study by Barlow et al. to include d/D measurements of 12 craters newly identified as radar bright at latitudes poleward of +80o. The radar reflectivity resemblances to Mars south polar cap and echoes from three icy Galilean satellites suggest that these craters too may have polar ice on Mercury. The effect of subsurface H20 on impact craters is a decrease in its d/D ratio, and softening of crater rims over a period of time. The study of Barlow et al., focused on determining the d/D ratios of 170 impact craters in the Borealis (north polar), Tolstoj (equatorial), Kuiper (equatorial), and Bach (south polar) quadrangles. This work focuses on the newly discovered radar bright craters, investigating their d/D ratios as an expansion of the earlier work..We compare our results to the statistical results from Barlow et al. here. With the upcoming Messenger spacecraft mission to Mercury, this is an especially timely study

Toenail mercury and dyslipidemia: Interaction with selenium.

Science.gov (United States)

Park, Kyong; Seo, Eunmin

2017-01-01

Although compelling evidences from in vivo and in vitro studies exist, limited studies have examined the association between chronic mercury exposure and dyslipidemia. Particularly, data are sparse regarding the influence of selenium on this association of mercury with dyslipidemia in humans. The purpose of the current study was to examine the associations of toenail mercury with dyslipidemia and its components, and to examine whether selenium in toenails modifies these associations. We performed cross-sectional analyses using baseline data from a cohort in the Yeungnam area in South Korea, including 232 men and 269 women. Toenail mercury and selenium concentrations were quantified using neutron activation analysis, and fasting serum lipid measurements were obtained through the medical examination. Odds ratios of the prevalent hypercholesterolemia, hyper-LDL-cholesterolemia, hypo-HDL-cholesterolemia, hypertriglyceridemia, and dyslipidemia in correlation with mercury levels were calculated using multivariable logistic regression. The mean levels of toenail mercury were 0.47μg/g for men and 0.34μg/g for women. After adjustment for multiple confounding variables, participants in the highest tertile of toenail mercury levels had 4.08 (95% CI 1.09-15.32, p for trend=0.02) times higher risk of hyper-LDL-cholesterolemia, and 2.24 (95% CI 1.15-4.37, p for trend=0.004) times higher risk of dyslipidemia than those in the lowest tertile. Selenium is a significant effect-modifier for these associations; the highest tertile of toenail mercury were significantly associated with a higher risk of hypercholesterolemia (OR 5.25, 95% CI 1.04-26.38) and dyslipidemia (OR 2.98, 95% CI 1.16-7.66) compared to the lowest tertile at toenail selenium levels ≤0.685μg/g, while these associations became weak and non-significant, showing OR 0.98 and 95% CI 0.25-3.80 for hypercholesterolemia and OR 1.99 and 95% CI 0.73-5.45 for dyslipidemia at toenail selenium levels >0.685μg/g. We

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.

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

Local Impacts of Mercury Emissions from the Three Pennsylvania Coal Fired Power Plants.

Energy Technology Data Exchange (ETDEWEB)

Sullivan,T.; Adams,J.; Bender, M.; Bu, C.; Piccolo, N.; Campbell, C.

2008-02-01

The Clean Air Interstate Rule (CAIR) and the Clean Air Mercury Rule (CAMR) as proposed by the U.S. Environmental Protection Agency (EPA) when fully implemented will lead to reduction in mercury emissions from coal-fired power plants by 70 percent to fifteen tons per year by 2018. The EPA estimates that mercury deposition would be reduced 8 percent on average in the Eastern United States. The CAMR permits cap-and-trade approach that requires the nationwide emissions to meet the prescribed level, but do not require controls on each individual power plant. This has led to concerns that there may be hot-spots of mercury contamination near power plants. Partially because of this concern, many states including Pennsylvania have implemented, or are considering, state regulations that are stricter on mercury emissions than those in the CAMR. This study examined the possibility that coal-fired power plants act as local sources leading to mercury 'hot spots'. Soil and oak leaf samples from around three large U.S. coal-fired power plants in Western Pennsylvania were collected and analyzed for evidence of 'hot spots'. These three plants (Conemaugh, Homer City, and Keystone) are separated by a total distance of approximately 30 miles. Each emits over 500 pounds of mercury per year which is well above average for mercury emissions from coal plants in the U.S. Soil and oak leaf sampling programs were performed around each power plant. Sampling rings one-mile apart were used with eight or nine locations on each ring. The prevailing winds in the region are from the west. For this reason, sampling was conducted out to 10 miles from the Conemaugh plant which is southeast of the others. The other plants were sampled to a distance of five miles. The objectives were to determine if local mercury hot spots exist, to determine if they could be attributed to deposition of coal-fired power plant emissions, and to determine if they correlated with wind patterns. The study

Colour mapping of the Shakespeare (H-03) quadrangle of Mercury

Science.gov (United States)

Bott, N.; Doressoundiram, A.; Perna, D.; Zambon, F.; Carli, C.; Capaccioni, F.

2017-09-01

We will present a colour mapping of the Shakespeare (H-03) quadrangle of Mercury, as well as the spectral analysis and a preliminary correlation between the spectral properties and the geological units.

Impact of gold mining associated with mercury contamination in soil, biota sediments and tailings in Kenya.

Science.gov (United States)

Odumo, Benjamin Okang'; Carbonell, Gregoria; Angeyo, Hudson Kalambuka; Patel, Jayanti Purshottam; Torrijos, Manuel; Rodríguez Martín, José Antonio

2014-11-01

This work considered the environmental impact of artisanal mining gold activity in the Migori-Transmara area (Kenya). From artisanal gold mining, mercury is released to the environment, thus contributing to degradation of soil and water bodies. High mercury contents have been quantified in soil (140 μg kg(-1)), sediment (430 μg kg(-1)) and tailings (8,900 μg kg(-1)), as expected. The results reveal that the mechanism for transporting mercury to the terrestrial ecosystem is associated with wet and dry depositions. Lichens and mosses, used as bioindicators of pollution, are related to the proximity to mining areas. The further the distance from mining areas, the lower the mercury levels. This study also provides risk maps to evaluate potential negative repercussions. We conclude that the Migori-Transmara region can be considered a strongly polluted area with high mercury contents. The technology used to extract gold throughout amalgamation processes causes a high degree of mercury pollution around this gold mining area. Thus, alternative gold extraction methods should be considered to reduce mercury levels that can be released to the environment.

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.

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.

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

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.

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

Determination of mercury in air by adsorption on Hopcalite and by neutron activation analysis

International Nuclear Information System (INIS)

Leyni-Barbaz, D.; Zikovsky, L.; Poissant, L.

2002-01-01

A new method for the determination of mercury in air has been developed. It combines the adsorption of mercury on Hopcalite (a material approved for this purpose by the National Institute of Health of the United States) and its quantification by neutron activation. The concentrations of mercury in office air in Montreal, Canada, were determined by instrumental semiabsolute neutron activation analysis. They varied from 39 to 48 ng/m 3 . The results were compared with the concentrations of mercury in office air determined simultaneously at the same place by cold vapour atomic fluorescence spectrophotometry. A close correlation between the results of the 2 methods was obtained. The detection limit of our method is about 14 ng/m 3 . (author)

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

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.

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

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.

Changes in Hair Mercury Levels Among Women of Child-Bearing Age Following an Educational Intervention.

Science.gov (United States)

Raymond, Michelle; Christensen, Krista Y; Thompson, Brooke; Anderson, Henry

2017-06-01

Describe mercury exposures among women of childbearing age before and after an educational intervention. Women age 18 to 45 were recruited to participate in an educational intervention concerning fish consumption. Fish consumption habits and total mercury concentration in hair were assessed pre- and post-intervention. Regression models examined associations between mercury, fish consumption, and demographics. Overall, 234 women completed the study. On average, mercury concentrations increased by 0.01 ppm (parts per million) following the intervention, despite declines in fish consumption; however, women in the 90th percentile for mercury at baseline decreased concentrations significantly while maintaining high rates of fish consumption. Mercury concentrations were positively correlated with fish consumption and certain demographic characteristics. The intervention reached individuals most at-risk. Healthcare providers should discuss fish consumption habits with women to encourage consumption of low-risk fish, and identify women needing education and counseling.

Atmospheric speciation of mercury in two contrasting Southeastern US airsheds

Science.gov (United States)

Gabriel, Mark C.; Williamson, Derek G.; Brooks, Steve; Lindberg, Steve

Simultaneous measurement of gaseous elemental, reactive gaseous, and fine particulate mercury took place in Tuscaloosa AL, (urban airshed) and Cove Mountain, TN (non-urban airshed) during the summers of 2002 and 2003. The objective of this research was to (1) summarize the temporal distribution of each mercury specie at each site and compare to other speciation data sets developed by other researchers and (2) provide insight into urban and non-urban mercury speciation effects using various statistical methods. Average specie concentrations were as follows: 4.05 ng m -3 (GEM), 13.6 pg m -3 (RGM), 16.4 pg m -3 (Hg-p) for Tuscaloosa; 3.20 ng m -3 (GEM), 13.6 pg m -3 (RGM), 9.73 pg m -3 (Hg-p) for Cove Mountain. As a result of urban airshed impacts, short periods of high concentration for all mercury species was common in Tuscaloosa. At Cove Mountain a consistent mid-day rise and evening drop for mercury species was found. This pattern was primarily the result of un-impacted physical boundary layer movement, although, other potential impacts were ambient photochemistry and air-surface exchange of mercury. Meteorological parameters that are known to heavily impact mercury speciation were similar for the study period for Tuscaloosa and Cove Mountain except for wind speed (m s -1), which was higher at Cove Mountain. For both sites statistically significant ( p<0.0001), inverse relationships existed between wind speed and Hg 0 concentration. A weaker windspeed-Hg 0 correlation existed for Tuscaloosa. By analyzing Hg concentration—wind speed magnitude change at both sites it was found that wind speed at Cove Mountain had a greater influence on Hg 0 concentration variability than Tuscaloosa by a factor of 3. Using various statistical tests, we concluded that the nature of Tuscaloosa's atmospheric mercury speciation was the result of typical urban airshed impacts. Cove Mountain showed atmospheric mercury speciation characteristics indicative of a non-urban area along with

From Midges to Spiders: Mercury Biotransport in Riparian Zones Near the Buffalo River Area of Concern (AOC), USA.

Science.gov (United States)

Pennuto, C M; Smith, M

2015-12-01

Riparian communities can receive environmental contaminants from adjacent aquatic 'donor' habitats. We investigated mercury biotransport from aquatic to terrestrial habitats via aquatic insect emergence and uptake by riparian spiders at sites within and upstream of the Buffalo River Area of Concern (AOC), a site with known sediment Hg contamination. Mercury concentration in emerging midges was roughly 10× less than contaminated sediment levels with the AOC, but biomagnification factors from midges to spiders ranged from 2.0 to 2.65 between sites. There was a significantly negative body mass:total mercury relationship in spiders (p Spiders contained significantly more mercury than their midge prey and spiders upstream of the AOC had higher mercury concentrations than spiders from within the AOC. Collectively, these data indicate that riparian spiders can be good mercury sentinels in urban environments, and that riparian communities upstream from the AOC may be at greater risk to mercury than has been previously considered.

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

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.

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

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)

Altered miRNA expression in the cervix during pregnancy associated with lead and mercury exposure

Science.gov (United States)

Sanders, Alison P; Burris, Heather H; Just, Allan C; Motta, Valeria; Amarasiriwardena, Chitra; Svensson, Katherine; Oken, Emily; Solano-Gonzalez, Maritsa; Mercado-Garcia, Adriana; Pantic, Ivan; Schwartz, Joel; Tellez-Rojo, Martha M; Baccarelli, Andrea A; Wright, Robert O

2015-01-01

Aim: Toxic metals including lead and mercury are associated with adverse pregnancy outcomes. This study aimed to assess the association between miRNA expression in the cervix during pregnancy with lead and mercury levels. Materials & methods: We obtained cervical swabs from pregnant women (n = 60) and quantified cervical miRNA expression. Women's blood lead, bone lead and toenail mercury levels were analyzed. We performed linear regression to examine the association between metal levels and expression of 74 miRNAs adjusting for covariates. Results: Seventeen miRNAs were negatively associated with toenail mercury levels, and tibial bone lead levels were associated with decreased expression of miR-575 and miR-4286. Conclusion: The findings highlight miRNAs in the human cervix as novel responders to maternal chemical exposure during pregnancy. PMID:26418635

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.

Negative correlates of computer game play in adolescents.

Science.gov (United States)

Colwell, J; Payne, J

2000-08-01

There is some concern that playing computer games may be associated with social isolation, lowered self-esteem, and aggression among adolescents. Measures of these variables were included in a questionnaire completed by 204 year eight students at a North London comprehensive school. Principal components analysis of a scale to assess needs fulfilled by game play provided some support for the notion of 'electronic friendship' among boys, but there was no evidence that game play leads to social isolation. Play was not linked to self-esteem in girls, but a negative relationship was obtained between self-esteem and frequency of play in boys. However, self-esteem was not associated with total exposure to game play. Aggression scores were not related to the number of games with aggressive content named among three favourite games, but they were positively correlated with total exposure to game play. A multiple regression analysis revealed that sex and total game play exposure each accounted for a significant but small amount of the variance in aggression scores. The positive correlation between playing computer games and aggression provides some justification for further investigation of the causal hypothesis, and possible methodologies are discussed.

Gene–Environment Correlation Underlying the Association Between Parental Negativity and Adolescent Externalizing Problems

Science.gov (United States)

Marceau, Kristine; Horwitz, Briana N.; Ganiban, Jody M.; Reiss, David; Narusyte, Jurgita; Spotts, Erica L.; Neiderhiser, Jenae M.

2014-01-01

Studies of adolescent or parent-based twins suggest that gene–environment correlation (rGE) is an important mechanism underlying parent–adolescent relationships. However, information on how parents′ and children’s genes and environments influence correlated parent and child behaviors is needed to distinguish types of rGE. The present study used the novel Extended Children of Twins model to distinguish types of rGE underlying associations between negative parenting and adolescent (age 11–22 years) externalizing problems with a Swedish sample of 909 twin parents and their adolescent offspring and a U.S.-based sample of 405 adolescent siblings and their parents. Results suggest that evocative rGE, not passive rGE or direct environmental effects of parenting on adolescent externalizing, explains associations between maternal and paternal negativity and adolescent externalizing problems. PMID:23573986

Natural stable isotopic compositions of mercury in aerosols and wet precipitations around a coal-fired power plant in Xiamen, southeast China

Science.gov (United States)

Huang, Shuyuan; Sun, Lumin; Zhou, Tingjin; Yuan, Dongxing; Du, Bing; Sun, Xiuwu

2018-01-01

In this study, samples of 18 wet precipitations (WPs) and 38 aerosols were collected around a coal-fired power plant (CFPP) located in Xiamen, southeast China, which was equipped with a seawater flue gas desulfurization system. Total particulate mercury (TPM) in aerosol samples, and total mercury (WP-TM), dissolved mercury (WP-DM) and particulate mercury (WP-PM) in WP samples were analyzed for the natural isotopic compositions of mercury. For the first time, both mass dependent fractionation (MDF) and mass independent fractionation of odd (odd-MIF) and even (even-MIF) isotopes of WP-DM and WP-PM were reported and discussed. Both WP-TM and TPM displayed negative MDF and slightly positive even-MIF. Negative odd-MIF was observed in TPM and WP-PM, whereas positive odd-MIF was observed in WP-TM and WP-DM. It was found that the mercury budget in WP-PM samples was mainly controlled by atmospheric particles. Potential sources of mercury in samples were identified via analysis of mercury isotopic signatures and meteorological data with the NOAA HYSPLIT model. The results showed that TPM and WP-PM in solid samples were homologous and the isotopic compositions of WP-TM depended on those of WP-DM. The ratios of Δ199Hg/Δ201Hg resulting from photochemical reactions and positive Δ200Hg values (from -0.06‰ to 0.27‰) in all samples indicated that the mercury coming from local emission of the CFPP together with long-distance transportation were the two main contributing sources.

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(+),

The negative ultraslow potential, electrophysiological correlate of infarction in the human cortex.

Science.gov (United States)

Lückl, Janos; Lemale, Coline L; Kola, Vasilis; Horst, Viktor; Khojasteh, Uldus; Oliveira-Ferreira, Ana I; Major, Sebastian; Winkler, Maren K L; Kang, Eun-Jeung; Schoknecht, Karl; Martus, Peter; Hartings, Jed A; Woitzik, Johannes; Dreier, Jens P

2018-06-01

Spreading depolarizations are characterized by abrupt, near-complete breakdown of the transmembrane ion gradients, neuronal oedema, mitochondrial depolarization, glutamate excitotoxicity and activity loss (depression). Spreading depolarization induces either transient hyperperfusion in normal tissue; or hypoperfusion (inverse coupling = spreading ischaemia) in tissue at risk for progressive injury. The concept of the spreading depolarization continuum is critical since many spreading depolarizations have intermediate characteristics, as opposed to the two extremes of spreading depolarization in either severely ischaemic or normal tissue. In animals, the spreading depolarization extreme in ischaemic tissue is characterized by prolonged depolarization durations, in addition to a slow baseline variation termed the negative ultraslow potential. The negative ultraslow potential is initiated by spreading depolarization and similar to the negative direct current (DC) shift of prolonged spreading depolarization, but specifically refers to a negative potential component during progressive recruitment of neurons into cell death in the wake of spreading depolarization. We here first quantified the spreading depolarization-initiated negative ultraslow potential in the electrocorticographic DC range and the activity depression in the alternate current range after middle cerebral artery occlusion in rats. Relevance of these variables to the injury was supported by significant correlations with the cortical infarct volume and neurological outcome after 72 h of survival. We then identified negative ultraslow potential-containing clusters of spreading depolarizations in 11 patients with aneurysmal subarachnoid haemorrhage. The human platinum/iridium-recorded negative ultraslow potential showed a tent-like shape. Its amplitude of 45.0 (39.0, 69.4) mV [median (first, third quartile)] was 6.6 times larger and its duration of 3.7 (3.3, 5.3) h was 34.9 times longer than the negative DC

The Cut-off Value of Blood Mercury Concentration in Relation to Insulin Resistance

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Seok-Hoon Lee

2017-09-01

Full Text Available Background : Increased blood mercury concentration is associated with inflammation, and chronic inflammation can cause insulin resistance. We examined the cut-off value of blood mercury in relation to an increased score on the homeostasis model assessment for insulin resistance (HOMA-IR. Methods : We used data from the Korean National Health and Nutrition Examination Survey (2008–2010. Relevant data from 5,184 subjects (2,523 men and 2,661 women were analyzed cross-sectionally. General linear analysis was performed to evaluate the relationship between HOMA-IR score and blood mercury concentration. In addition, we determined the cut-off value of blood mercury concentration in relation to increased HOMA-IR score (> 2.34 using an ROC curve. Results : The mean value of blood mercury concentration in men and women was 5.88 μg/L and 4.11 μg/L, respectively. In men, comparing to the first quartile, HOMA-IR score increased significantly in the third and fourth blood mercury quartiles. In women, however, the increase in HOMA-IR score was not significant. The cut-off value that best represented the association between increased HOMA-IR score and blood mercury concentration in men was found to be 4.71 μg/L. Conclusion : Blood mercury concentration was associated with increased HOMA-IR score in men, and the cut-off value of blood mercury concentration that was correlated with increased HOMA-IR score was around 4.71 μg/L.

Assessment of mobility and bioavailability of mercury compounds in sewage sludge and composts.

Science.gov (United States)

Janowska, Beata; Szymański, Kazimierz; Sidełko, Robert; Siebielska, Izabela; Walendzik, Bartosz

2017-07-01

Content of heavy metals, including mercury, determines the method of management and disposal of sewage sludge. Excessive concentration of mercury in composts used as organic fertilizer may lead to accumulation of this element in soil and plant material. Fractionation of mercury in sewage sludge and composts provides a better understanding of the extent of mobility and bioavailability of the different mercury species and helps in more informed decision making on the application of sludge for agricultural purposes. The experimental setup comprises the composing process of the sewage sludge containing 13.1mgkg -1 of the total mercury, performed in static reactors with forced aeration. In order to evaluate the bioavailability of mercury, its fractionation was performed in sewage sludge and composts during the process. An analytical procedure based on four-stage sequential extraction was applied to determine the mercury content in the ion exchange (water soluble and exchangeable Hg), base soluble (Hg bound to humic and fulvic acid), acid soluble (Hg bound to Fe/Mn oxides and carbonates) and oxidizable (Hg bound to organic matter and sulphide) fractions. The results showed that from 50.09% to 64.55% of the total mercury was strongly bound to organo-sulphur and inorganic sulphide; that during composting, increase of concentrations of mercury compounds strongly bound with organic matter and sulphides; and that mercury content in the base soluble and oxidizable fractions was strongly correlated with concentration of dissolved organic carbon in those fractions. Copyright © 2017 Elsevier Inc. All rights reserved.

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.

Mercury use in small scale gold mining in Ghana: an assessment of its impact on miners

International Nuclear Information System (INIS)

Biagya, Robert Yakubu

2002-12-01

Small scale gold mining is responsible for about 5% of Ghana’s annual gold production. It is estimated that between 80,000 and 100,000 people are engaged in small scale gold mining either on part-time or permanent basis. Amalgamation is the preferred method used by small scale gold miners for extracting free gold from its ores. The rate at which mercury, an important input in this method, is discharged into the atmosphere and water bodies is alarming. This research describes the various mining and processing methods in small scale gold mining and the extent of mercury use and releases to the environment. It discusses mercury and its human and environmental effects. It defines the various forms of mercury, routes of exposure, toxic effects. The levels of exposure to mercury by all groups of small scale gold miners are determined, and the impacts on the miners and the environment are assessed. It concludes that: • Mercury is mainly released into the environment as a result of small scale gold mining through spillage of elemental mercury and evaporation of mercury from the amalgam and sponge gold when they are heated on open fire. • Mercury in environmental samples from small scale gold mining areas is well above standard limit values. • Mercury released into the environment through small scale gold mining impacts negatively on the miners themselves and the general environment. Finally, it recommends the need for the adoption of mercury emission reduction strategies for dealing with the mercury problem. (au)

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.

Selenium:Mercury Molar Ratios in Freshwater Fish from Tennessee: Individual, Species, and Geographical Variations have Implications for Management

Science.gov (United States)

Burger, Joanna; Gochfeld, Michael; Jeitner, C.; Donio, M.; Pittfield, T.

2014-01-01

Vertebrates, including humans, can experience adverse effects from mercury consumed in fish. Humans often prefer large predatory fish that bioaccumulate high mercury levels. Recent attention has focused on the role of selenium countering mercury toxicity, but there is little research on the selenium:mercury molar ratios in freshwater fish. We examine selenium:mercury molar ratios in freshwater fish from Tennessee at Poplar Creek which receives ongoing inputs of mercury from the Department of Energy’s Oak Ridge Y-12 facility. Our objective was to determine variation of the ratios within species that might affect the protectiveness of selenium against mercury toxicity. Within species, the ratio was correlated significantly and positively with fish length only for two species. There was great individual variation in the selenium:mercury molar ratio within each species, except striped bass. The lack of a clear relationship between the selenium:mercury molar ratio and fish length, and the intraspecific variation, suggests that it would be difficult to use the molar ratio in predicting either the risk from mercury toxicity or in devising consumption advisories. PMID:22456727

Distribution and assessment of residual mercury from gold mining in Changbai Mountain Range Northeastern China

Science.gov (United States)

Meng, D.; Wang, N.; Ai, J. C.; Zhang, G.; Liu, X. J.

2016-08-01

Gold mining was first initiated in Jiapigou area, Huadian city of Northeastern China about 200 years ago. Before 2006, the mercury amalgamation technique was used in the gold mining process, which led to severe mercury contamination. The aim of this paper is to explore the influences of residual mercury on the environment media after eliminating the amalgamation process to extract gold. The mercury concentrations of the atmosphere and the soil were determined in autumn of 2011 and spring of 2012. The soil environmental quality was assessed by the index of geoaccumulation. The results indicated that the maximum value of gaseous mercury was 25ng•m-3 in autumn and 19.5ng•m-3 in spring; the maximum value of mercury in the soil was 2.06mg•kg-1 in autumn and 2.51mg•kg-1in spring. It can be seen that the peak concentrations of the gaseous mercury happened at the gold mine area and tailings, while the peak mercury concentrations in the soil were located at the places near the mining sites and the residential area in the valley. Furthermore, the regression analysis of the total mercury contents between the atmosphere and the soil showed a significant correlation, which indicated that there was certain circulation of the mercury between the regional atmosphere and soil. In general, after the elimination of the amalgamation technique in gold extraction, the distance to the mercury source, the special conditions of hilly weather and landforms and the mercury exchange flux are the main factors of mercury contamination.

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

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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.

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

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.

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.

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

FINAL REPORT ON THE AQUATIC MERCURY ASSESSMENT STUDY

Energy Technology Data Exchange (ETDEWEB)

Halverson, N

2008-09-30

. Methylmercury ranged from 0.002 ng/l in Upper Three Runs to 2.60 ng/l in Tims Branch. Total mercury in the Savannah River ranged from 0.62 ng/l to 43.9 ng/l, and methylmercury ranged from 0.036 ng/l to 7.54 ng/l. Both total and methylmercury concentrations were consistently high in the river near the mouth of Steel Creek. Total mercury was positively correlated with methylmercury (r = 0.88). Total mercury bound to particulates ranged from 41% to 57% in the river and from 28% to 90% in the streams. Particulate methylmercury varied from 9% to 37% in the river and from 6% to 79% in the streams. Small temporary pools in the Savannah River swamp area near and around Fourmile Branch had the highest concentrations observed in the Savannah River watershed, reaching 1,890 ng/l for total mercury and 34.0 ng/l for methylmercury. The second study developed a mercury bioaccumulation factor (BAF) for the Savannah River near SRS. A BAF is the ratio of the concentration of mercury in fish flesh to the concentration of mercury in the water. BAFs are important in the TMDL process because target concentrations for mercury in water are computed from BAFs. Mercury BAFs are known to differ substantially among fish species, water bodies, and possibly seasons. Knowledge of such variation is needed to determine a BAF that accurately represents average and extreme conditions in the water body under study. Analysis of fish tissue and aqueous methylmercury samples collected at a number of locations and over several seasons in a 110 km (68 mile) reach of the Savannah River demonstrated that BAFs for each species under study varied by factors of three to eight. Influences on BAF variability were location, habitat and season-related differences in fish mercury levels and seasonal differences in methylmercury levels in the water. Overall (all locations, habitats, and seasons) average BAFs were 3.7 x 10{sup 6} for largemouth bass, 1.4 x 10{sup 6} for sunfishes, and 2.5 x 10{sup 6} for white catfish. This study

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...

Negative moods correlate with craving in female methamphetamine users enrolled in compulsory detoxification

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Shen Wenwen

2012-10-01

Full Text Available Abstract Background Methamphetamine (METH use, especially in females, has become a growing public health concern in China. In this study, we aimed to characterize the factors that contributed to drug craving in female METH users under isolated compulsory detoxification. We characterized factors contributing to craving such as duration of detoxification, history of drug use and self-reported mood state. Methods Subjects (N=113 undergoing a 1- to 3-year METH detoxification program were recruited from the Zhejiang Compulsory Detoxification Center for Women. The Questionnaire of METH-use Urge (QMU was used to evaluate the level of craving for METH. The Abbreviate Profile of Mood States (A-POMS was applied as an assessment for the negative mood disturbances. Results The participants were at a mean age of 25.2, primarily lowly educated and unemployed, and single. Smoking was the only route of METH administration at an average dose of 0.5 g/day, and 4 times/week. The reported craving level was positively correlated with the negative mood disturbances and the weekly dose of METH, but independent of the duration of detoxification. Furthermore, all five aspects of negative mood disturbances, including fatigue, bewilderment, anxiety, depression and hostility, were shown to positively correlate to the self-reported craving level after controlling for weekly dose of METH. Conclusions The data demonstrate a robust correlation between mood distress and craving for METH. Our results call for close evaluation of mood distress in treatment of METH users in China.

Dry deposition of gaseous oxidized mercury in Western Maryland.

Science.gov (United States)

Castro, Mark S; Moore, Chris; Sherwell, John; Brooks, Steve B

2012-02-15

The purpose of this study was to directly measure the dry deposition of gaseous oxidized mercury (GOM) in western Maryland. Annual estimates were made using passive ion-exchange surrogate surfaces and a resistance model. Surrogate surfaces were deployed for seventeen weekly sampling periods between September 2009 and October 2010. Dry deposition rates from surrogate surfaces ranged from 80 to 1512 pgm(-2)h(-1). GOM dry deposition rates were strongly correlated (r(2)=0.75) with the weekly average atmospheric GOM concentrations, which ranged from 2.3 to 34.1 pgm(-3). Dry deposition of GOM could be predicted from the ambient air concentrations of GOM using this equation: GOM dry deposition (pgm(-2)h(-1))=43.2 × GOM concentration-80.3. Dry deposition velocities computed using GOM concentrations and surrogate surface GOM dry deposition rates, ranged from 0.2 to 1.7 cms(-1). Modeled dry deposition rates were highly correlated (r(2)=0.80) with surrogate surface dry deposition rates. Using the overall weekly average surrogate surface dry deposition rate (369 ± 340 pg m(-2)h(-1)), we estimated an annual GOM dry deposition rate of 3.2 μg m(-2)year(-1). Using the resistance model, we estimated an annual GOM dry deposition rate of 3.5 μg m(-2)year(-1). Our annual GOM dry deposition rates were similar to the dry deposition (3.3 μg m(-2)h(-1)) of gaseous elemental mercury (GEM) at our site. In addition, annual GOM dry deposition was approximately 1/2 of the average annual wet deposition of total mercury (7.7 ± 1.9 μg m(-2)year(-1)) at our site. Total annual mercury deposition from dry deposition of GOM and GEM and wet deposition was approximately 14.4 μg m(-2)year(-1), which was similar to the average annual litterfall deposition (15 ± 2.1 μg m(-2)year(-1)) of mercury, which was also measured at our site. Copyright © 2012 Elsevier B.V. All rights reserved.

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

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.

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.

Daily atmospheric radionuclide observations and health impact estimation before and after the Fukushima-Daiichi nuclear accident: Five-year trends by Canadian monitoring stations - Ten-year trends of atmospheric lead-210 and the correlation to atmospheric mercury in the Canadian Arctic

Energy Technology Data Exchange (ETDEWEB)

Zhang, Weihua; Chen, Jing; Ungar, Kurt [Radiation Protection Bureau, Health Canada, 775 Brookfield Rd. Ottawa, K1A 1C1 (Canada)

2014-07-01

Mercury is a global threat to human and environmental health. Anthropogenic emissions of mercury have been larger than natural emissions since the start of the industrial age about 200 years ago. In the past decades, many studies have focused on monitoring and controlling anthropogenic emissions of mercury and their transport and transformation in the environment. In October 2013, the Minamata Convention on Mercury was formally adopted as international law. The new treaty aims to further cut mercury emissions and releases; it is the first global convention on environment and health. Coal burning for power generation and industrial use is one of the major sources of anthropogenic mercury emissions to the air. However, coal combustion processes produce significant quantities of dust containing not only mercury but also natural radionuclides that are released into the atmosphere. Like the case of mercury, those radionuclides can be transported over long distances, deposited on soil and oceans and accumulated in Arctic biota. Exposure to elevated levels of radiation is a health concern. This study analyses long-term trends of atmospheric lead-210 from Health Canada's radiological monitoring stations in the Arctic. Results are compared with ten-year records of atmospheric mercury reported by Environment Canada. A discussion is given on the correlation of long-range atmospheric transport of lead-210 and mercury from industrial sources, such as coal burning. It is expected that continuous decline of atmospheric mercury in the Arctic, especially with more and more countries signing the Minamata Convention, will result in a deceasing trend of atmospheric lead-210 from industrial sources as well. (authors)

Shipborne measurements of mercury in the marine boundary layer

Science.gov (United States)

Soerensen, A. L.; Skov, H.; Christensen, J.; Glasius, M.; Soerensen, B. T.; Steffen, A.; Jensen, B.; Christoffersen, C.; Madsen, H. W.; Johnson, M. S.

2008-12-01

Mercury accumulates in the human body, for example when consumed through fish and other aquatic animals. While it is poisonous to adults, only low doses are sufficient to cause severe effects in the development of foetuses where the source of mercury is through the mother's blood. From once being a problem restricted to certain populations, the negative effects of mercury consumption are becoming a global problem due to high anthropogenic emissions, long range transport in the atmosphere and bioaccumulation in the food chain after deposition. It is therefore important to understand the atmospheric photochemical pathways of mercury from source to sink. We have used a TEKRAN 2537A mercury vapor analyzer with a TEKRAN 1130 mercury speciation unit to measure gaseous elemental mercury (GEM) and reactive gaseous mercury (RGM) during an eight month circumnavigation of the Earth. This is the longest single track time series of mercury concentrations that we know of. This has offered the opportunity to give a global overview of the marine boundary layer (MBL) distribution of both GEM and RGM. Supplemented with earlier cruise measurements, we now have a broader knowledge of global GEM and RGM concentration in the MBL. The Galathea 3 cruise data offers new knowledge of the mechanisms causing the distribution patterns of GEM and RGM in the MBL. The first analysis of the Galathea 3 data indicates that measurements show a concentration difference between the northern and the southern hemispheres. In the northern hemisphere, the mean concentration in the free ocean is 2.06 ng/m3 and, including values down wind of Western Europe, an average value of 2.47 ng/m3 was found. Measurements in the southern hemisphere show a mean concentration of 1.24 ng/m3 and 1.57 ng/m3 where values close to the coast of West Africa are included. In contrast, the concentration levels of RGM are similar for the two hemispheres (northern hemisphere 3.40 pg/m3, southern hemisphere 3.95 pg/m3). Some

Mercury and flooding cycles in the Tapajos river basin, Brazilian Amazon: The role of periphyton of a floating macrophyte (Paspalum repens)

International Nuclear Information System (INIS)

Coelho-Souza, Sergio A.; Guimaraes, Jean R.D.; Miranda, Marcio R.; Poirier, Hugo; Mauro, Jane B.N.; Lucotte, Marc; Mergler, Donna

2011-01-01

Methylmercury (MeHg) increases mercury (Hg) toxicity and is biomagnified in the trophic chain contaminating riverine Amazon populations. Freshwater macrophyte roots are a main site of Hg methylation in different Brazilian environments. Paspalum repens periphyton was sampled in four floodplain lakes during the dry, rainy and wet seasons for measurement of total Hg (THg), MeHg, Hg methylation potentials, %C, %N, δ 13 C, δ 15 N and bacterial heterotrophic production as 3 H-leucine incorporation rate. THg concentration varied from 67 to 198 ng/g and the potential of Me 203 Hg formation was expressive (1-23%) showing that periphyton is an important matrix both in the accumulation of Hg and in MeHg production. The concentration of MeHg varied from 1 to 6 ng/g DW and was positively correlated with Me 203 Hg formation. Though methylmercury formation is mainly a bacterial process, no significant correlation was observed between the methylation potentials and bacterial production. The multiple regressions analyses suggested a negative correlation between THg and %C and %N and between methylation potential and δ 13 C. The discriminant analysis showed a significant difference in periphyton δ 15 N, δ 13 C and THg between seasons, where the rainy season presented higher δ 15 N and the wet period lighter δ 13 C, lower THg values and higher Me 203 Hg formation. This exploratory study indicates that the flooding cycle could influence the periphyton composition, mercury accumulation and methylmercury production. - Research highlights: → During rainy season mercury (Hg 2+ ) is carried out from terrestrial to aquatic systems by runoff. → Macrophyte roots accumulates Hg 2+ from suspended particulate matter (SPM). → Hg methylation increases during the wet season. → Flooded forest is a source of labile organic carbon and bioavailable Hg. → Macrophytes decompose during the dry season and made up terrestrial soil.

[Characteristics of mercury pollution in soil and atmosphere in Songhua River upstream Jia-pi-gou gold mining area].

Science.gov (United States)

Zhang, Gang; Wang, Ning; Wang, Yuan; Liu, Te; Ai, Jian-Chao

2012-09-01

In the studied area of Jia-pi-gou at the upstream area of Songhua River, algamation process has been applied as a dominant method to extract gold for more than one hundred and eighty years, resulting in severe mercury environmental pollution. The total mercury contents in the atmosphere and soil have been determined by mercury analyzer (Zeeman RA915+) and cold atomic absorption spectrophotometry (GB/T 17136-1997), respectively. To study the pollution characteristics of mercury in the soil and atmosphere, the mercury flux at the interface between the soil and the atmosphere of 4 sampling sites Lao-jin-chang, Er-dao-gou, Er-dao-cha and community of Jia-pi-gou have been determined with the method of dynamic flux chamber. Furthermore, linear regression analyses on the total mercury contents between soil and atmosphere have been carried out and the correlation coefficient of mercury exchange flux between soil and atmosphere and meteorological factors has been studied. The results are as follows: (1) The mean value of mercury content in the atmosphere is (71.08 +/- 38.22) ng x m(-3). (2) The mean value of mercury content in the soil is (0.913 1 +/- 0.040 8) mg x kg(-1); it shows remarkably positive correlation between the mercury contents in soil and in the atmosphere. (3) The mercury exchange flux between soil and atmosphere in different locations are Lao-jin-chang [(129.13 +/- 496.07) ng (m2 x h)(-1)], Er-dao-gou [(98.64 +/- 43.96) ng x (m2 x h)(-1)], Er-dao-cha [(23.17 +/- 171.23) ng x (m2 x h)(-1)], and community of Jia-pi-gou [(7.12 +/- 46.33) ng x (m2 x h)(-1)]. (4) Solar radiation is the major influential factor in the mercury exchange flux between the soil and atmosphere in Lao-jin-chang, Er-dao-cha and community of Jia-pi-gou. Solar radiation, air temperature and soil temperature jointly influence the process of the mercury exchange flux between the soil and atmosphere in Er-dao-gou. Under the disturbance of terrain, three noticeably distinctive trend features

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…

Mercury adsorption properties of sulfur-impregnated adsorbents

Science.gov (United States)

Hsi, N.-C.; Rood, M.J.; Rostam-Abadi, M.; Chen, S.; Chang, R.

2002-01-01

Carbonaceous and noncarbonaceous adsorbents were impregnated with elemental sulfur to evaluate the chemical and physical properties of the adsorbents and their equilibrium mercury adsorption capacities. Simulated coal combustion flue gas conditions were used to determine the equilibrium adsorption capacities for Hg0 and HgCl2 gases to better understand how to remove mercury from gas streams generated by coal-fired utility power plants. Sulfur was deposited onto the adsorbents by monolayer surface deposition or volume pore filling. Sulfur impregnation increased the total sulfur content and decreased the total and micropore surface areas and pore volumes for all of the adsorbents tested. Adsorbents with sufficient amounts of active adsorption sites and sufficient microporous structure had mercury adsorption capacities up to 4,509 ??g Hg/g adsorbent. Elemental sulfur, organic sulfur, and sulfate were formed on the adsorbents during sulfur impregnation. Correlations were established with R2>0.92 between the equilibrium Hg0/HgCl2 adsorption capacities and the mass concentrations of elemental and organic sulfur. This result indicates that elemental and organic sulfur are important active adsorption sites for Hg0 and HgCl2.

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.

Two new sources of reactive gaseous mercury in the free troposphere

Science.gov (United States)

Timonen, H.; Ambrose, J. L.; Jaffe, D. A.

2012-11-01

Mercury (Hg) is a neurotoxin that bioaccumulates in the food chain. Mercury is emitted to the atmosphere primarily in its elemental form, which has a long lifetime allowing global transport. It is known that atmospheric oxidation of gaseous elemental mercury (GEM) generates reactive gaseous mercury (RGM) which plays an important role in the atmospheric mercury cycle by enhancing the rate of mercury deposition to ecosystems. However, the primary GEM oxidants, and the sources and chemical composition of RGM are poorly known. Using speciated mercury measurements conducted at the Mt. Bachelor Observatory since 2005 we present two previously unidentified sources of RGM to the free troposphere (FT). Firstly, we observed elevated RGM concentrations, large RGM/GEM-ratios, and anti-correlation between RGM and GEM during Asian long-rang transport events, demonstrating that RGM is formed from GEM by in-situ oxidation in some anthropogenic pollution plumes in the FT. During the Asian pollution events the measured RGM/GEM-ratios reached peak values, up to ~0.20, which are significantly larger than ratios typically measured (RGM/GEM RGM levels - the highest reported in the FT - in clean air masses that were processed upwind of Mt. Bachelor Observatory over the Pacific Ocean. The high RGM concentrations (up to 700 pg m-3), high RGM/GEM-ratios (up to 1), and very low ozone levels during these events provide the first observational evidence indicating significant GEM oxidation in the lower FT. The identification of these processes changes our conceptual understanding of the formation and distribution of oxidized Hg in the global atmosphere.

Sensitive determination of trace mercury by UV-visible diffuse reflectance spectroscopy after complexation and membrane filtration-enrichment.

Science.gov (United States)

Yin, Changhai; Iqbal, Jibran; Hu, Huilian; Liu, Bingxiang; Zhang, Lei; Zhu, Bilin; Du, Yiping

2012-09-30

A simple, sensitive and selective solid phase reflectometry method is proposed for the determination of trace mercury in aqueous samples. The complexation reagent dithizone was firstly injected into the properly buffered solution with vigorous stirring, which started a simultaneous formation of nanoparticles suspension of dithizone and its complexation reaction with the mercury(II) ions to make Hg-dithizone nanoparticles. After a definite time, the mixture was filtered with membrane, and then quantified directly on the surface of the membrane by using integrating sphere accessory of the UV-visible spectrophotometer. The quantitative analysis was carried out at a wavelength of 485 nm since it yielded the largest difference in diffuse reflectance spectra before and after reaction with mercury(II).A good linear correlation in the range of 0.2-4.0 μg/L with a squared correlation coefficient (R(2)) of 0.9944 and a detection limit of 0.12 μg/L were obtained. The accuracy of the method was evaluated by the analysis of spiked mercury(II) concentrations determined using this method along with those determined by the atomic fluorescence mercury vapourmeter and the results obtained were in good agreement. The proposed method was applied to the determination of mercury in tap water and river water samples with the recovery in an acceptable range (95.7-105.3%). Copyright © 2012 Elsevier B.V. All rights reserved.

Reliability of environmental sampling culture results using the negative binomial intraclass correlation coefficient.

Science.gov (United States)

Aly, Sharif S; Zhao, Jianyang; Li, Ben; Jiang, Jiming

2014-01-01

The Intraclass Correlation Coefficient (ICC) is commonly used to estimate the similarity between quantitative measures obtained from different sources. Overdispersed data is traditionally transformed so that linear mixed model (LMM) based ICC can be estimated. A common transformation used is the natural logarithm. The reliability of environmental sampling of fecal slurry on freestall pens has been estimated for Mycobacterium avium subsp. paratuberculosis using the natural logarithm transformed culture results. Recently, the negative binomial ICC was defined based on a generalized linear mixed model for negative binomial distributed data. The current study reports on the negative binomial ICC estimate which includes fixed effects using culture results of environmental samples. Simulations using a wide variety of inputs and negative binomial distribution parameters (r; p) showed better performance of the new negative binomial ICC compared to the ICC based on LMM even when negative binomial data was logarithm, and square root transformed. A second comparison that targeted a wider range of ICC values showed that the mean of estimated ICC closely approximated the true ICC.

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

Potency of Mangrove Apple (Sonneratia alba as Mercury Bioindicator

Directory of Open Access Journals (Sweden)

Muhammad Reza Cordova

2017-12-01

Full Text Available The anthropogenic provide a negative impact on the surrounding environment. Mangrove species, such as Sonneratia alba would get the impact of anthropogenic activities, to accumulate the pollution of heavy metals. The aim of this study were to evaluate mercury accumulation in Mangrove Apple (S. alba and to analyze mangrove apple potency as mercury bioindicator. Samples were taken in April 2016 at Pari Island, Seribu Islands by purposive sampling. The results showed that the highest concentration of Hg in the Northern of Pari Island was found in the leaves and the lowest was in the fruit. The highest concentration of Hg in the Eastern of Pari Island was found in the leaves and lowest was in the fruit. The concentrations of Hg in the Eastern area higher the Northern area (significantly different. The accumulation of Hg mainly collected on the leaves with TF> 1, but the ability of S. alba trees absorb Hg in the environment showed a small value, namely BCF <1. The ability of S. alba in sediments, contaminated with mercury showed a high value of the leaves in the East Pari Island, but the fruit of S. alba both in the North and East of the Pari Island showed a small value.  Mangrove Apple leaves has a potency as mercury bioindicator organ.

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.

The intercrater plains of Mercury and the Moon: Their nature, origin and role in terrestrial planet evolution. Geologic mapping of Mercury and the Moon. Ph.D. Thesis

Science.gov (United States)

Leake, M. A.

1982-01-01

The geologic framework of the intercrater plains on Mercury and the Moon as determined through geologic mapping is presented. The strategies used in such mapping are discussed first. Then, because the degree of crater degradation is applied to both mapping and crater statistics, the correlation of degradation classification of lunar and Mercurian craters is thoroughly addressed. Different imaging systems can potentially affect this classification, and are therefore also discussed. The techniques used in mapping Mercury are discussed in Section 2, followed by presentation of the Geologic Map of Mercury in Section 3. Material units, structures, and relevant albedo and color data are discussed therein. Preliminary conclusions regarding plains' origins are given there. The last section presents the mapping analyses of the lunar intercrater plains, including tentative conclusions of their origin.

Quadrupole collective correlations and termination of the superdeformed bands in mercury

International Nuclear Information System (INIS)

Bonche, P.; Heenen, P.H.; Krieger, S.J.; Weiss, M.S.; Meyer, J.

1990-03-01

Fully self-consistent Generator Coordinate Method calculations have been performed on a basis of quadrupole constrained Hartree-Fock plus BCS wave functions for the five even mercury isotopes 190-198 Hg. The GCM results support conclusions drawn from previous HF+BCS calculations. The predicted evolution of superdeformed band head (shape isomer) properties as a function of the neutron number is consistent with the data. Using calculated transition matrix elements, we evaluate in-band versus out-of-band quadrupole decay and explain the sudden termination of the superdeformed band

The Impact of Impoundment on Mercury Bioaccumulation in Fish Downstream from a Newly Constructed Reservoir, Wujiang River, Southwest China.

Science.gov (United States)

Li, Sixin; Zhou, Lianfeng; Chang, Jianbo; Yang, Zhi; Hu, Juxiang; Hongjun, Wang

2017-11-01

Mercury concentrations in fish were investigated downstream from a newly impounded subtropical reservoir in August 2008. After 6-7 months of reservoir impoundment, mean mercury concentration in fish from downstream is significantly increased by 1.9 times. Not only carnivorous fish but also benthic fish had significantly higher total mercury concentrations than others. No significant correlation was found between total mercury concentrations and body length or weight of 13 fish species. Compared with the pre-impoundment, total mercury in fish from downstream is significantly increased by reservoir impoundment, but the increased rate is lower than those in subarctic and temperate areas. Fish samples surpassed the Chinese hygienic standard for tolerances of mercury in foods increased by 4.3%. More attention should be given to fish mercury levels from downstream sites to prevent possible adverse effects on the health of local people.

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.

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

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.

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

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.

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)

[Evaluation and source analysis of the mercury pollution in soils and vegetables around a large-scale zinc smelting plant].

Science.gov (United States)

Liu, Fang; Wang, Shu-Xiao; Wu, Qing-Ru; Lin, Hai

2013-02-01

The farming soil and vegetable samples around a large-scale zinc smelter were collected for mercury content analyses, and the single pollution index method with relevant regulations was used to evaluate the pollution status of sampled soils and vegetables. The results indicated that the surface soil and vegetables were polluted with mercury to different extent. Of the soil samples, 78% exceeded the national standard. The mercury concentration in the most severely contaminated area was 29 times higher than the background concentration, reaching the severe pollution degree. The mercury concentration in all vegetable samples exceeded the standard of non-pollution vegetables. Mercury concentration, in the most severely polluted vegetables were 64.5 times of the standard, and averagely the mercury concentration in the vegetable samples was 25.4 times of the standard. For 85% of the vegetable samples, the mercury concentration, of leaves were significantly higher than that of roots, which implies that the mercury in leaves mainly came from the atmosphere. The mercury concentrations in vegetable roots were significantly correlated with that in soils, indicating the mercury in roots was mainly from soil. The mercury emissions from the zinc smelter have obvious impacts on the surrounding soils and vegetables. Key words:zinc smelting; mercury pollution; soil; vegetable; mercury content

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

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.

Evidence for Surface and Subsurface Ice Inside Micro Cold-Traps on Mercury's North Pole

Science.gov (United States)

Rubanenko, L.; Mazarico, E.; Neumann, G. A.; Paige, D. A.

2017-01-01

The small obliquity of Mercury causes topographic depressions located near its poles to cast persistent shadows. Many [1, 9, 15] have shown these permanently shadowed regions (PSRs) may trap water ice for geologic time periods inside cold-traps. More recently, direct evidence for the presence of water ice deposits inside craters was remotely sensed in RADAR [5] and visible imagery [3]. Albedo measurements (reflectence at 1064 nm) obtained by the MErcury Space ENviroment GEochemistry and Ranging Laser Altimeter (MLA) found unusually bright and dark areas next to Mercury's north pole [7]. Using a thermal illumination model, Paige et al. [8] found the bright deposits are correlated with surface cold-traps, and the dark deposits are correlated with subsurface cold-traps. They suggested these anomalous deposits were brought to the surface by comets and were processed by the magnetospheric radiation flux, removing hydrogen and mixing C-N-O-S atoms to form a variety of molecules which will darken with time. Here we use a thermal illumination model to find the link between the cold-trap area fraction of a rough surface and its albedo. Using this link and the measurements obtained by MESSENGER we derive a surface and a subsurface ice distribution map on Mercury's north pole below the MESSENGER spatial resolution, approximately 500 m. We find a large fraction of the polar ice on Mercury resides inside micro cold-traps (of scales 10 - 100 m) distributed along the inter-crater terrain.

MERCURY IN FISHERY PRODUCTS FROM CENTRAL ADRIATIC SEA (OFFICIAL CONTROLS FROM 1995 TO 2009

Directory of Open Access Journals (Sweden)

C. Ciccarelli

2011-04-01

Full Text Available Thanks to its properties, methylmercury is the most bioavailable form of mercury compounds. In fact, it causes the most toxic effects on the immune, cardiovascular, renal and central nervous systems, in particular the fetal brain. Seafood consumption is recognized as being the largest environmental mercury source to most human populations. So, fishery products are the most important source of methylmercury exposure in human. As the mercury burden of fish increases for transference to upper trophic levels (biomagnification, piscivors have the potential to accumulate extremely high mercury loads, in the methylated form, 70 to 100% in the muscular tissues. Reg. CE 1881/2006 sets, lastly, allowed maximum levels of mercury in seafood. Several authors found out an increase of mercury levels with size of carnivorous fishes. But this relationship strictly depends on fish species, and is a result of the interaction between environmental and physiological effects. This paper describes the results of a monitoring of mercury levels in fishery products, from 1995 to 2009, before they were sold by auction in the Wholesale Fish Market in the town of San Benedetto del Tronto. The authors’aim was to set a correlation between increasing fish size (weight and loads of the metal up to maximum levels by law.

Effectiveness of Emission Controls to Reduce the Atmospheric Concentrations of Mercury.

Science.gov (United States)

Castro, Mark S; Sherwell, John

2015-12-15

Coal-fired power plants in the United States are required to reduce their emissions of mercury (Hg) into the atmosphere to lower the exposure of Hg to humans. The effectiveness of power-plant emission controls on the atmospheric concentrations of Hg in the United States is largely unknown because there are few long-term high-quality atmospheric Hg data sets. Here, we present the atmospheric concentrations of Hg and sulfur dioxide (SO2) measured from 2006 to 2015 at a relatively pristine location in western Maryland that is several (>50 km) kilometers downwind of power plants in Ohio, Pennsylvania, and West Virginia. Annual average atmospheric concentrations of gaseous oxidized mercury (GOM), SO2, fine particulate mercury (PBM2.5), and gaseous elemental mercury (GEM) declined by 75%, 75%, 43%, and 13%, respectively, and were strongly correlated with power-plant Hg emissions from the upwind states. These results provide compelling evidence that reductions in Hg emissions from power plants in the United States had their intended impact to reduce regional Hg pollution.

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.

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.

Methyl Mercury Production In Tropical Hydromorphic Soils: Impact Of Gold Mining.

Science.gov (United States)

Guedron, S.; Charlet, L.; Harris, J.; Grimaldi, M.; Cossa, D.

2007-12-01

Artisanal alluvial gold mining is important in many tropical developing countries and several million people are involved worldwide. The dominant use of mercury for gold amalgamation in this activity leads to mercury accumulation in soils, to sediment contamination and to methyl mercury (MMHg) bioaccumulation along the food chain. In this presentation we will present recent data on methyl mercury production in hydromorphic soils and tailing ponds from a former gold mining area located in French Guiana (South America). Comparison of specific fluxes between a pristine sub watershed and the contaminated watershed shows that former mining activities lead to a large enhancement of dissolved and particulate MMHg emissions at least by a factor of 4 and 6, respectively. MMHg production was identified in sediments from tailing ponds and in surrounding hydromorphic soils. Moreover, interstitial soil water and tailing pond water profiles sampled in an experimental tailing pond demonstrate the presence of a large MMHg production in the suboxic areas. Both tailing ponds and hydromorphic soils present geochemical conditions that are favorable to bacterial mercury methylation (high soil Hg content, high aqueous ferric iron and dissolved organic carbon concentrations). Although sulfate-reducing bacteria have been described as being the principal mercury methylating bacteria, the positive correlation between dissolved MMHg and ferrous iron concentrations argue for a significant role of iron-reducing bacteria. Identifications by sequencing fragments of 16S rRNA from total soil DNA support these interpretations. This study demonstrates that current and past artisanal gold mining in the tropics lead to methyl mercury production in contaminated areas. As artisanal activities are increasing with increasing gold prices, the bio- magnification of methyl mercury in fish presents an increasing threat to local populations whose diet relies on fish consumption.

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.

Rapid Monitoring of Mercury in Air from an Organic Chemical Factory in China Using a Portable Mercury Analyzer

Directory of Open Access Journals (Sweden)

Akira Yasutake

2011-01-01

Full Text Available A chemical factory, using a production technology of acetaldehyde with mercury catalysis, was located southeast of Qingzhen City in Guizhou Province, China. Previous research showed heavy mercury pollution through an extensive downstream area. A current investigation of the mercury distribution in ambient air, soils, and plants suggests that mobile mercury species in soils created elevated mercury concentrations in ambient air and vegetation. Mercury concentrations of up to 600 ng/m3 in air over the contaminated area provided evidence of the mercury transformation to volatile Hg(0. Mercury analysis of soil and plant samples demonstrated that the mercury concentrations in soil with vaporized and plant-absorbable forms were higher in the southern area, which was closer to the factory. Our results suggest that air monitoring using a portable mercury analyzer can be a convenient and useful method for the rapid detection and mapping of mercury pollution in advanced field surveys.

Aerobic Mercury-resistant bacteria alter Mercury speciation and retention in the Tagus Estuary (Portugal).

Science.gov (United States)

Figueiredo, Neusa L; Canário, João; O'Driscoll, Nelson J; Duarte, Aida; Carvalho, Cristina

2016-02-01

Aerobic mercury-resistant bacteria were isolated from the sediments of two highly mercury-polluted areas of the Tagus Estuary (Barreiro and Cala do Norte) and one natural reserve area (Alcochete) in order to test their capacity to transform mercury. Bacterial species were identified using 16S rRNA amplification and sequencing techniques and the results indicate the prevalence of Bacillus sp. Resistance patterns to mercurial compounds were established by the determination of minimal inhibitory concentrations. Representative Hg-resistant bacteria were further tested for transformation pathways (reduction, volatilization and methylation) in cultures containing mercury chloride. Bacterial Hg-methylation was carried out by Vibrio fluvialis, Bacillus megaterium and Serratia marcescens that transformed 2-8% of total mercury into methylmercury in 48h. In addition, most of the HgR bacterial isolates showed Hg(2+)-reduction andHg(0)-volatilization resulting 6-50% mercury loss from the culture media. In summary, the results obtained under controlled laboratory conditions indicate that aerobic Hg-resistant bacteria from the Tagus Estuary significantly affect both the methylation and reduction of mercury and may have a dual face by providing a pathway for pollution dispersion while forming methylmercury, which is highly toxic for living organisms. Copyright © 2015 Elsevier Inc. All rights reserved.

EDITORIAL: Mercury-free discharges for lighting

Science.gov (United States)

Haverlag, M.

2007-07-01

This special Cluster of articles in Journal of Physics D: Applied Physics covers the subject of mercury-free discharges that are being investigated by different light source researchers, as an alternative to existing mercury-containing lamps. The main driving force to move away from mercury-containing discharge light sources is connected to the environmentally unfriendly nature of mercury. After inhalation or direct contact, severe mercury exposure can lead to damage to human brain cells, the kidneys, the liver and the nervous system. For this reason, the use of mercury in products is becoming more and more restricted by different governmental bodies. In the lighting industry, however, many products still make use of mercury, for different reasons. The main reason is that mercury-containing products are, in most cases, more efficient than mercury-free products. For a realistic comparison of the environmental impact, the mercury-contamination due to electricity production must be taken into account, which depends on the type of fuel being used. For an average European fuel-mix, the amount of mercury that is released into the environment is around 29 μg kWh-1. This means that a typical 30 W TL lamp during a lifetime of 20,000 hours will release a total of about 20 mg mercury due to electricity production, which exceeds the total mercury dose in the lamp (more and more of which is being recycled) by a factor of 5-10 for a modern TL lamp. This illustrates that, quite apart from other environmental arguments like increased CO2 production, mercury-free alternatives that use more energy can in fact be detrimental for the total mercury pollution over the lifetime of the lamp. For this reason, the lighting industry has concentrated on lowering the mercury content in lamps as long as no efficient alternatives exist. Nevertheless, new initiatives for HID lamps and fluorescent lamps with more or less equal efficiency are underway, and a number of them are described in this

Intoxication with metallic mercury

International Nuclear Information System (INIS)

Fichte, B.; Assmann, H.; Ritzau, F.

1984-01-01

Intoxications by metallic mercury are extremely rare. Report of a patient, who tried to commit suicide by subcutaneous injection of 500 g of metallic mercury. He died 16 months later in the course of the intoxication. A short review is given of effects and reactions of metallic mercury in the human organism. (orig.) [de

Intoxication with metallic mercury

Energy Technology Data Exchange (ETDEWEB)

Fichte, B.; Ritzau, F.; Assmann, H.

1984-02-01

Intoxications by metallic mercury are extremely rare. Report is given of a patient who tried to commit suicide by subcutaneous injection of 500 g of metallic mercury. He died 16 months later in the course of the intoxication. A short review is given of effects and reactions of metallic mercury in the human organism.

Intoxication with metallic mercury

Energy Technology Data Exchange (ETDEWEB)

Fichte, B.; Assmann, H.; Ritzau, F.

1984-02-01

Intoxications by metallic mercury are extremely rare. Report is given of a patient, who tried to commit suicide by subcutaneous injection of 500 g of metallic mercury. He died 16 months later in the course of the intoxication. A short review is given of effects and reactions of metallic mercury in the human organism.

Mercury in dated Greenland marine sediments

DEFF Research Database (Denmark)

Asmund, G.; Nielsen, S.P.

2000-01-01

Twenty marine sediment cores from Greenland were analysed for mercury, and dated by the lead-210 method. In general the cores exhibit a mercury profile with higher mercury concentrations in the upper centimetres of the core. The cores were studied by linear regression of In Hg vs, age of the sedi......Twenty marine sediment cores from Greenland were analysed for mercury, and dated by the lead-210 method. In general the cores exhibit a mercury profile with higher mercury concentrations in the upper centimetres of the core. The cores were studied by linear regression of In Hg vs, age...... indicating that the mercury mainly originates from atmospheric washout. But the large variability indicates that other processes also influence the mercury flux to Arctic marine sediments. (C) 2000 Elsevier Science B.V. All rights reserved....

Accumulation factors of mercury in mushrooms from Zaborski Landscape Park, Poland.

Science.gov (United States)

Falandysz, Jerzy; Lipka, Krzysztof; Gucia, Magdalena; Kawano, Masahide; Strumnik, Katarzyna; Kannan, Kurunthachalam

2002-11-01

Total mercury concentrations were determined by cold-vapour atomic absorption spectroscopy (CV-AAS) in 117 samples of caps, 117 of stalks and 47 of whole fruiting bodies of 13 species of wild mushrooms and in 164 underlying soil substrate collected from Zaborski Landscape Park during 1997 and 1998. The study area is a background, forested site with rural landscape and no known local sources of mercury emission. Mean mercury concentrations in mushrooms varied widely (range: 50 +/- 20 to 3700 +/- 1700 ng/g, dry matter) depending on the site and mushroom species investigated. However, mercury concentrations in soil samples varied less (range: 3.0 +/- 3.0 to 43 +/- 17 ng/g dry matter). Fruiting bodies of Common Puffball (Lycoperdon perlatum) and King Bolete (Boletus edulis) contained the greatest concentrations of mercury of 3700 +/- 1700 and 2600 +/- 1200 ng/g dry matter, respectively. A positive correlation existed between mercury concentrations in the caps of Slippery Jack (Suillus luteus) and Fly Agaric (Amanita muscaria) (p Suillus grevillei) and King Bolete (B. edulis) and varied between 130 +/- 78 and 160 +/- 120, while for the other species BCFs were between 4.0 +/- 6.0 and 61 +/- 20 in caps, and 4.4 +/- 3.1 and 70 +/- 68 in stalks. The concentration ratios of Hg in cap to stalk were from 1.1 +/- 0.5 for Poison Pax (Paxillus involutus) to 2.7 +/- 1.7 in Larch Bolete (S. grevillei).

Mercury kinetics in marine zooplankton

International Nuclear Information System (INIS)

Fowler, S.W.; Heyraud, M.; LaRosa, J.

1976-01-01

Mercury, like many other heavy metals, is potentially available to marine animals by uptake directly from water and/or through the organisms food. Furthermore, bioavailability, assimilation and subsequent retention in biota may be affected by the chemical species of the element in sea water. While mercury is known to exist in the inorganic form in sea water, recent work has indicated that, in certain coastal areas, a good portion of the total mercury appears to be organically bound; however, the exact chemical nature of the organic fraction has yet to be determined. Methyl mercury may be one constituent of the natural organically bound fraction since microbial mechanisms for in situ methylation of mercury have been demonstrated in the aquatic environment. Despite the fact that naturally produced methyl mercury probably comprises only a small fraction of an aquatic ecosystem, the well-documented toxic effects of this organo-mercurial, caused by man-made introductions into marine food chains, make it an important compound to study

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.

Groundwater Modeling Of Mercury Pollution At A Former Mercury Cell Chlor Alkali Facility In Pavoldar, Kazakhstan

Science.gov (United States)

In Kazakhstan, there is a serious case of mercury pollution near the city of Pavlodar from an old mercury cell chlor-alkali plant. The soil, sediment, and water is severly contaminated with mercury and mercury compounds as a result of the industrial activity of this chemical pla...

Process for low mercury coal

Science.gov (United States)

Merriam, Norman W.; Grimes, R. William; Tweed, Robert E.

1995-01-01

A process for producing low mercury coal during precombustion procedures by releasing mercury through discriminating mild heating that minimizes other burdensome constituents. Said mercury is recovered from the overhead gases by selective removal.

Mercury's magnetic field and interior

International Nuclear Information System (INIS)

Connerney, J.E.P.; Ness, N.F.

1988-01-01

The magnetic-field data collected on Mercury by the Mariner-10 spacecraft present substantial evidence for an intrinsic global magnetic field. However, studies of Mercury's thermal evolution show that it is most likely that the inner core region of Mercury solidified or froze early in the planet's history. Thus, the explanation of Mercury's magnetic field in the framework of the traditional planetary dynamo is less than certain

Multi-model study of mercury dispersion in the atmosphere: vertical and interhemispheric distribution of mercury species

Directory of Open Access Journals (Sweden)

J. Bieser

2017-06-01

Full Text Available Atmospheric chemistry and transport of mercury play a key role in the global mercury cycle. However, there are still considerable knowledge gaps concerning the fate of mercury in the atmosphere. This is the second part of a model intercomparison study investigating the impact of atmospheric chemistry and emissions on mercury in the atmosphere. While the first study focused on ground-based observations of mercury concentration and deposition, here we investigate the vertical and interhemispheric distribution and speciation of mercury from the planetary boundary layer to the lower stratosphere. So far, there have been few model studies investigating the vertical distribution of mercury, mostly focusing on single aircraft campaigns. Here, we present a first comprehensive analysis based on various aircraft observations in Europe, North America, and on intercontinental flights. The investigated models proved to be able to reproduce the distribution of total and elemental mercury concentrations in the troposphere including interhemispheric trends. One key aspect of the study is the investigation of mercury oxidation in the troposphere. We found that different chemistry schemes were better at reproducing observed oxidized mercury patterns depending on altitude. High concentrations of oxidized mercury in the upper troposphere could be reproduced with oxidation by bromine while elevated concentrations in the lower troposphere were better reproduced by OH and ozone chemistry. However, the results were not always conclusive as the physical and chemical parameterizations in the chemistry transport models also proved to have a substantial impact on model results.

Mercury (Environmental Health Student Portal)

Science.gov (United States)

... in contact with) to mercury is by eating fish or shellfish that have high levels of mercury. You can also get sick from: Touching it Breathing it in Drinking contaminated water How can mercury ...

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.

Mercury

CERN Document Server

Balogh, André; Steiger, Rudolf

2008-01-01

Mercury, the planet closest to the Sun, is different in several respects from the other three terrestrial planets. In appearance, it resembles the heavily cratered surface of the Moon, but its density is high, it has a magnetic field and magnetosphere, but no atmosphere or ionosphere. This book reviews the progress made in Mercury studies since the flybys by Mariner 10 in 1974-75, based on the continued research using the Mariner 10 archive, on observations from Earth, and on increasingly realistic models of its interior evolution.

Environmental Sampling FY03 Annual Report - Understanding the Movement of Mercury on the INEEL

International Nuclear Information System (INIS)

Michael L. Abbott

2003-01-01

Environmental mercury measurements were started in Fy-01 at the Idaho National Engineering Laboratory (INEEL) to monitor downwind impacts from on-going waste treatment operations at the Idaho Nuclear Technology and Engineering Center (INTEC) and to improve our scientific understanding of mercury fate and transport in this region. This document provides a summary of the sampling done in FY04. Continuous total gaseous mercury (TGM) measurements were made using a Tekran Model 2537A mercury vapor analyzer during October 2002 and from February through July 2003. The equipment was deployed in a self-contained field trailer at the Experimental Field Station (EFS) four kilometers downwind (northeast) of INTEC. Mercury surface-to-air flux measurements were made in October 2002 and from February through May 2003 to better understand the fate of the estimated 1500 kg of mercury emitted from 36 years of calciner operations at INTEC and to improve our scientific understanding of mercury environmental cycling in this region. Flux was measured using an INEEL-designed dynamic flux chamber system with a Tekran automated dual sampling (TADS) unit. Diel flux was positively correlated with solar radiation (r = 0.65), air temperature (r = 0.64), and wind speed (r = 0.38), and a general linear model for flux prediction at the INEEL was developed. Reactive gaseous mercury (RGM) was measured at EFS in July using a Tekran Model 1130 mercury speciation unit. Based on comparisons with other published data around the U.S., mercury air concentrations and surface flux rates directly downwind from INTEC were not distinguishable from remote area (non-industrial) background levels during the monitoring period

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

Mercury and selenium relationship in a tropical estuarine fish

Directory of Open Access Journals (Sweden)

Ana Carolina Pizzochero

2015-11-01

Full Text Available Aquatic systems have been considered as final sinks for persistent and bioaccumulative toxicants (PBTs, such as metals and organohalogen compounds. Among the trace elements, non-essential metals deserve special attention due to their toxicity. In this context, mercury (Hg should be highlighted due to its toxic effects, which comprise neurotoxicity, nephrotoxicity, hepatotoxicity, genotoxicity, among others. Several studies have highlighted the selenium-mediated methylmercury detoxification process, via mercury selenide formation in tissues of marine vertebrates. Despite being an essential element, selenium may also be toxic in high concentrations. This study focused on Guanabara Bay (GB, a heavily polluted urban estuary in Rio de Janeiro state (Brazil, where the whitemouth croaker (Micropogonias furnieri provides a valuable fishery resource. Therefore, hepatic (Hg and Se and muscular (Hg concentrations of these elements were determined in GB whitemouth croakers. Mercury and selenium measurements were performed by cold vapor atomic absorption spectrometry (CV-AAS and electrothermal AAS (ET-AAS, respectively. Total mercury (THg concentrations in muscle (n=19 ranged from 184.9 to 858.6 (ng/g, while in liver they varied from 11.05 to 1188 (ng/g. Hepatic selenium concentrations ranged from 7820 to 40085 (ng/g. The hepatic Se:THg molar ratio ranged from 40,8 to 3102,5. The results showed a significant correlation between hepatic mercury and selenium levels, but the molar ratio suggests the absence of mercury selenide formation. Some of the Se concentrations found were above the threshold level for freshwater fish (12000 ng/g; however, it is not yet clear if these concentrations are toxic for marine fish as well. More studies are necessary for evaluating the impact of such exposure in fish from Guanabara Bay.

Spatial trends and impairment assessment of mercury in sport fish in the Sacramento-San Joaquin Delta watershed

International Nuclear Information System (INIS)

Melwani, A.R.; Bezalel, S.N.; Hunt, J.A.; Grenier, J.L.; Ichikawa, G.; Heim, W.; Bonnema, A.; Foe, C.; Slotton, D.G.; Davis, J.A.

2009-01-01

A three-year study was conducted to examine mercury in sport fish from the Sacramento-San Joaquin Delta. More than 4000 fish from 31 species were collected and analyzed for total mercury in individual muscle filets. Largemouth bass and striped bass were the most contaminated, averaging 0.40 μg/g, while redear sunfish, bluegill and rainbow trout exhibited the lowest (<0.15 μg/g) concentrations. Spatial variation in mercury was evaluated with an analysis of covariance model, which accounted for variability due to fish size and regional hydrology. Significant regional differences in mercury were apparent in size-standardized largemouth bass, with concentrations on the Cosumnes and Mokelumne rivers significantly higher than the central and western Delta. Significant prey-predator mercury correlations were also apparent, which may explain a significant proportion of the spatial variation in the watershed. - Regional differences in sport fish mercury were found in the Sacramento-San Joaquin Delta.

Method and apparatus for sampling atmospheric mercury

Science.gov (United States)

Trujillo, Patricio E.; Campbell, Evan E.; Eutsler, Bernard C.

1976-01-20

A method of simultaneously sampling particulate mercury, organic mercurial vapors, and metallic mercury vapor in the working and occupational environment and determining the amount of mercury derived from each such source in the sampled air. A known volume of air is passed through a sampling tube containing a filter for particulate mercury collection, a first adsorber for the selective adsorption of organic mercurial vapors, and a second adsorber for the adsorption of metallic mercury vapor. Carbon black molecular sieves are particularly useful as the selective adsorber for organic mercurial vapors. The amount of mercury adsorbed or collected in each section of the sampling tube is readily quantitatively determined by flameless atomic absorption spectrophotometry.

Does seasonal snowpacks enhance or decrease mercury contamination of high elevation ecosystems?

Science.gov (United States)

Pierce, A.; Fain, X.; Obrist, D.; Helmig, D.; Barth, C.; Jacques, H.; Chowanski, K.; Boyle, D.; William, M.

2009-12-01

Mercury (Hg) is an extremely toxic pollutant globally dispersed in the environment. Natural and anthropogenic sources emit Hg to the atmosphere, either as gaseous elemental mercury (GEM; Hg0) or as divalent mercury species. Due to the long lifetime of GEM mercury contamination is not limited to industrialized sites, but also a concern in remote areas such as high elevation mountain environments. During winter and spring 2009, we investigated the fate of atmospheric mercury deposited to mountain ecosystems in the Sierra Nevada (Sagehen station, California, USA) and the Rocky Mountains (Niwot Ridge station, Colorado, USA). At Sagehen, we monitored mercury in snow (surface snow sampling and snow pits), wet deposition, and stream water during the snow-dominated season. Comparison of Hg stream discharge to snow Hg wet deposition showed that only a small fraction of Hg wet deposition reached stream in the melt water. Furthermore, Hg concentration in soil transects (25 different locations) showed no correlations to wet deposition Hg loads due to pronounced altitudinal precipitation gradient suggesting that Hg deposited to the snowpack was not transferred to ecosystems. At Niwot Ridge, further characterization of the chemical transformation involving mercury species within snowpacks was achieved by 3-months of continuous monitoring of GEM and ozone concentrations in the snow air at eight depths from the soil-snow interface to the top of the up to 2 meter deep snowpack. Divalent mercury concentrations were monitored as well (surface snow sampling and snow pits). GEM levels in snow air exhibited strong diurnal pattern indicative of both oxidation and reduction processes. Low levels of divalent mercury concentrations in snow pack suggest that large fractions of Hg originally deposited as wet deposition was reemitted back to the atmosphere after reduction. Hence, these results suggest that the presence of a seasonal snowpack may decrease effective wet deposition of mercury and

Methods for dispensing mercury into devices

Science.gov (United States)

Grossman, Mark W.; George, William A.

1987-04-28

A process for dispensing mercury into devices which requires mercury. Mercury is first electrolytically separated from either HgO or Hg.sub.2 Cl.sub.2 and plated onto a cathode wire. The cathode wire is then placed into a device requiring mercury.

Determination of mercury and its fractionation products in samples from legacy use of mercury amalgam in gold processing in Randfontein, South Africa

Directory of Open Access Journals (Sweden)

Tshia Malehase

2016-09-01

Full Text Available This study aimed at determining the levels of total mercury (THg in tailings dams, soil, sediments and water samples collected in the vicinity of legacy mercury amalgam gold mines. Acid digestion was employed in sample digestion followed by analysis using CVAAS. Tailings dams, community and garden soil, and stream sediments were further investigated for mercury fractions using a five step sequential extraction procedure. The concentrations of THg in tailings dams, community and gardens soil were 0.890–6.755 μg/g, 0.431–0.968 μg/g and 0.471–1.019 μg/g, respectively and the concentrations of THg in the sediments obtained from tailings dams, streams and wetlands were 0.649–1.998 μg/g, 0.604–1.356 μg/g and 0.681–1.356 μg/g, respectively. The concentrations of THg, in aqueous samples obtained from tailings, streams and wetlands were 0.032–0.070 μg/l, 0.004–0.068 μg/l and 0.007–0.012 μg/l, respectively. The sequential extraction procedure showed that most Hg in the tailings dams was largely elemental Hg and Hg bound to sulphur. Soil and sediments were largely dominated by organic bound Hg. Moderate seasonal correlation was observed in tailings dams soil, but weak seasonal correlation in soils collected in the vicinity of tailings. However, a strong seasonal correlation was observed in sediments and water samples. The concentrations of Hg obtained largely existed in organic and sulphate bound Hg and there is elevated potential to methylate Hg.

Mercury erosion experiments for spallation target system

International Nuclear Information System (INIS)

Kinoshita, Hidetaka; Kaminaga, Masanori; Haga, Katsuhiro; Hino, Ryutaro

2003-01-01

The Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Research Organization (KEK) are promoting a plan to construct the spallation neutron source at the Tokai Research Establishment, JAERI, under the High-Intensity Proton Accelerator Project (J-PARC). A mercury circulation system has been designed so as to supply mercury to the target stably under the rated flow rate of 41 m 3 /hr. Then, it was necessary to confirm a mercury pump performance from the viewpoint of making the mercury circulation system feasible, and more, to investigate erosion rate under the mercury flow as well as an amount of mercury remained on the surface after drain from the viewpoints of mechanical strength relating to the lifetime and remote handling of mercury components. The mercury pump performance was tested under the mercury flow conditions by using an experimental gear pump, which had almost the same structure as a practical mercury pump to be expected in the mercury circulation system, and the erosion rates in a mercury pipeline as well as the amount of mercury remained on the surface were also investigated. The discharged flow rates of the experimental gear pump increased linearly with the rotation speed, so that the gear pump would work as the flow meter. Erosion rates obtained under the mercury velocity less than 1.6 m/s was found to be so small that decrease of pipeline wall thickness would be 390 μm after 30-year operation under the rated mercury velocity of 0.7 m/s. For the amount of remaining mercury on the pipeline, remaining rates of weight and volume were estimated at 50.7 g/m 2 and 3.74 Hg-cm 3 /m 2 , respectively. Applying these remaining rates of weight and volume to the mercury target, the remaining mercury was estimated at about 106.5 g and 7.9 cm 3 . Radioactivity of this remaining mercury volume was found to be three-order lower than that of the target casing. (author)

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...

Mercury flow experiments. 4th report Measurements of erosion rate caused by mercury flow

CERN Document Server

Kinoshita, H; Hino, R; Kaminaga, M

2002-01-01

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 we...

Mercury contamination and effects on survival of American avocet and black-necked stilt chicks in San Francisco Bay.

Science.gov (United States)

Ackerman, Joshua T; Takekawa, John Y; Eagles-Smith, Collin A; Iverson, Samuel A

2008-02-01

We evaluated whether mercury influenced survival of free-ranging American avocet (Recurvirostra americana) and black-necked stilt (Himantopus mexicanus) chicks in San Francisco Bay, California. Using radio telemetry, we radio-marked 158 avocet and 79 stilt chicks at hatching and tracked them daily until their fate was determined. We did not find strong support for an influence of in ovo mercury exposure on chick survival, despite observing a wide range of mercury concentrations in chick down feathers at hatching (0.40-44.31 microg g(-1) fw). We estimated that chick survival rates were reduced by nest monitoring. In contrast to the telemetry results, we found that mercury concentrations in down feathers of dead chicks were higher than those in randomly-sampled live chicks of similar age. However, capture site was the most important variable influencing mercury concentrations, followed by year, species, and hatching date. Although laboratory studies have demonstrated negative effects of environmentally relevant mercury concentrations on chick survival, our results concur with the small number of previous field studies that have not been able to detect reduced survival in the wild.

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

Mercury content in Hot Springs

Energy Technology Data Exchange (ETDEWEB)

Nakagawa, R

1974-01-01

A method of determination of mercury in hot spring waters by flameless atomic absorption spectrophotometry is described. Further, the mercury content and the chemical behavior of the elementary mercury in hot springs are described. Sulfide and iodide ions interfered with the determination of mercury by the reduction-vapor phase technique. These interferences could, however, be minimized by the addition of potassium permanganate. Waters collected from 55 hot springs were found to contain up to 26.0 ppb mercury. High concentrations of mercury have been found in waters from Shimoburo Springs, Aomori (10.0 ppb), Osorezan Springs, Aomori (1.3 approximately 18.8 ppb), Gosyogake Springs, Akita (26.0 ppb), Manza Springs, Gunma (0.30 approximately 19.5 ppb) and Kusatu Springs, Gunma (1.70 approximately 4.50 ppb). These hot springs were acid waters containing a relatively high quantity of chloride or sulfate.

Method and apparatus for monitoring mercury emissions

Science.gov (United States)

Durham, Michael D.; Schlager, Richard J.; Sappey, Andrew D.; Sagan, Francis J.; Marmaro, Roger W.; Wilson, Kevin G.

1997-01-01

A mercury monitoring device that continuously monitors the total mercury concentration in a gas. The device uses the same chamber for converting speciated mercury into elemental mercury and for measurement of the mercury in the chamber by radiation absorption techniques. The interior of the chamber is resistant to the absorption of speciated and elemental mercury at the operating temperature of the chamber.

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: ...

Mercury speciation and selenium in toothed-whale muscles

International Nuclear Information System (INIS)

Sakamoto, Mineshi; Itai, Takaaki; Yasutake, Akira; Iwasaki, Toshihide; Yasunaga, Genta; Fujise, Yoshihiro; Nakamura, Masaaki; Murata, Katsuyuki; Man Chan, Hing; Domingo, José L.; Marumoto, Masumi

2015-01-01

Mercury accumulates at high levels in marine mammal tissues. However, its speciation is poorly understood. The main goal of this investigation was to establish the relationships among mercury species and selenium (Se) concentrations in toothed-whale muscles at different mercury levels. The concentrations of total mercury (T-Hg), methylmercury (MeHg), inorganic mercury (I-Hg) and Se were determined in the muscles of four toothed-whale species: bottlenose dolphins (n=31), Risso's dolphins (n=30), striped dolphins (n=29), and short-finned pilot whales (n=30). In each species, the MeHg concentration increased with increasing T-Hg concentration, tending to reach a plateau. In contrast, the proportion of MeHg in T-Hg decreased from 90–100% to 20–40%. The levels of T-Hg and Se showed strong positive correlations. Se/I-Hg molar ratios rapidly decreased with the increase of I-Hg and reached almost 1 in all species. These results suggested that the demethylated MeHg immediately formed Se/I-Hg equimolar complex of mercury selenide (HgSe) in their muscles. In addition, an X-ray absorption fine structure analysis (XAFS) of a bottlenose dolphin muscle confirmed that the dominant chemical form of the Se/I-Hg equimolar complex was HgSe. HgSe was mainly localized in cells near the endomysium using electron probe microanalysis (EPMA). These results suggested that the demethylated MeHg finally deposits within muscle cells of bottlenose dolphin as an inert HgSe. - Highlights: • T-Hg, MeHg, I-Hg and Se were determined in the muscles of four toothed-whales. • MeHg increased with increasing T-Hg and tended to reach a plateau in all species. • Se/I-Hg molar ratios rapidly decreased with increase of I-Hg and reached almost 1. • XAFS of bottlenose dolphin muscle confirmed that HgSe was dominant chemical form. • EPMA of bottlenose dolphin muscle showed that HgSe deposited in muscle cells.

Mercury speciation and selenium in toothed-whale muscles

Energy Technology Data Exchange (ETDEWEB)

Sakamoto, Mineshi, E-mail: sakamoto@nimd.go.jp [National Institute for Minamata Disease, Hama 4058-18, Minamata, Kumamoto 867-0008 (Japan); Itai, Takaaki [Ehime University, Bunkyo 2-5, Matsuyama 790-8755 (Japan); Yasutake, Akira [National Institute for Minamata Disease, Hama 4058-18, Minamata, Kumamoto 867-0008 (Japan); Iwasaki, Toshihide [Tohoku National Fisheries Research Institute, 25-259 Shimomekurakubo, Aomori 031-0841 (Japan); Yasunaga, Genta; Fujise, Yoshihiro [Institute of Cetacean Research, 4-5 Toyomi, Tokyo 104-0055 (Japan); Nakamura, Masaaki [National Institute for Minamata Disease, Hama 4058-18, Minamata, Kumamoto 867-0008 (Japan); Murata, Katsuyuki [Akita University School of Medicine, Hondo 1-1-1, Akita 010-8543 (Japan); Man Chan, Hing [University of Ottawa, Marie-Curie, Ottawa, ON, Canada KIN 6N5 (Canada); Domingo, José L. [School of Medicine, IISPV, Universitat “Rovira i Virgili”, Reus (Spain); Marumoto, Masumi [National Institute for Minamata Disease, Hama 4058-18, Minamata, Kumamoto 867-0008 (Japan)

2015-11-15

Mercury accumulates at high levels in marine mammal tissues. However, its speciation is poorly understood. The main goal of this investigation was to establish the relationships among mercury species and selenium (Se) concentrations in toothed-whale muscles at different mercury levels. The concentrations of total mercury (T-Hg), methylmercury (MeHg), inorganic mercury (I-Hg) and Se were determined in the muscles of four toothed-whale species: bottlenose dolphins (n=31), Risso's dolphins (n=30), striped dolphins (n=29), and short-finned pilot whales (n=30). In each species, the MeHg concentration increased with increasing T-Hg concentration, tending to reach a plateau. In contrast, the proportion of MeHg in T-Hg decreased from 90–100% to 20–40%. The levels of T-Hg and Se showed strong positive correlations. Se/I-Hg molar ratios rapidly decreased with the increase of I-Hg and reached almost 1 in all species. These results suggested that the demethylated MeHg immediately formed Se/I-Hg equimolar complex of mercury selenide (HgSe) in their muscles. In addition, an X-ray absorption fine structure analysis (XAFS) of a bottlenose dolphin muscle confirmed that the dominant chemical form of the Se/I-Hg equimolar complex was HgSe. HgSe was mainly localized in cells near the endomysium using electron probe microanalysis (EPMA). These results suggested that the demethylated MeHg finally deposits within muscle cells of bottlenose dolphin as an inert HgSe. - Highlights: • T-Hg, MeHg, I-Hg and Se were determined in the muscles of four toothed-whales. • MeHg increased with increasing T-Hg and tended to reach a plateau in all species. • Se/I-Hg molar ratios rapidly decreased with increase of I-Hg and reached almost 1. • XAFS of bottlenose dolphin muscle confirmed that HgSe was dominant chemical form. • EPMA of bottlenose dolphin muscle showed that HgSe deposited in muscle cells.

Feedback mechanisms between snow and atmospheric mercury: Results and observations from field campaigns on the Antarctic plateau.

Science.gov (United States)

Spolaor, Andrea; Angot, Hélène; Roman, Marco; Dommergue, Aurélien; Scarchilli, Claudio; Vardè, Massimiliano; Del Guasta, Massimo; Pedeli, Xanthi; Varin, Cristiano; Sprovieri, Francesca; Magand, Olivier; Legrand, Michel; Barbante, Carlo; Cairns, Warren R L

2018-04-01

The Antarctic Plateau snowpack is an important environment for the mercury geochemical cycle. We have extensively characterized and compared the changes in surface snow and atmospheric mercury concentrations that occur at Dome C. Three summer sampling campaigns were conducted between 2013 and 2016. The three campaigns had different meteorological conditions that significantly affected mercury deposition processes and its abundance in surface snow. In the absence of snow deposition events, the surface mercury concentration remained stable with narrow oscillations, while an increase in precipitation results in a higher mercury variability. The Hg concentrations detected confirm that snowfall can act as a mercury atmospheric scavenger. A high temporal resolution sampling experiment showed that surface concentration changes are connected with the diurnal solar radiation cycle. Mercury in surface snow is highly dynamic and it could decrease by up to 90% within 4/6 h. A negative relationship between surface snow mercury and atmospheric concentrations has been detected suggesting a mutual dynamic exchange between these two environments. Mercury concentrations were also compared with the Br concentrations in surface and deeper snow, results suggest that Br could have an active role in Hg deposition, particularly when air masses are from coastal areas. This research presents new information on the presence of Hg in surface and deeper snow layers, improving our understanding of atmospheric Hg deposition to the snow surface and the possible role of re-emission on the atmospheric Hg concentration. Copyright © 2018 Elsevier Ltd. All rights reserved.

Determination of mercury and selenium in hair samples of Brazilian Indian populations living in the Amazonic region by NAA

International Nuclear Information System (INIS)

Vasconcellos, M.B.A.; Paletti, G.; Catharino, M.G.M.; Saiki, M.; Favaro, D.I.T.; Bode, P.; Ammerlaan, A.K.; Byrne, A.R.; Baruzzi, R.; Rodrigues, D.A.

2000-01-01

Biomonitoring of mercury contamination of Brazilian Indian population groups living in the Xingu Park, a reservation situated in the Amazonic region, has revealed very high levels of mercury in hair samples as compared to controls. Total mercury was determined by INAA in most of the tribes living in the Park and methylmercury was determined by CVAAS in samples with total mercury above 10 mg/kg. Due to the fact that selenium seems to protect animals against the toxic effects of methylmercury, it was considered also of interest to determine its concentrations in the hair samples with very high mercury levels. Selenium was determined by INAA via the short-lived radionuclide 77m Se (T 1/2 = 17.45 s). The correlations between selenium and mercury concentrations in Brazilian controls and in the Indian population groups are discussed. (author)

Return to Mercury: a global perspective on MESSENGER's first Mercury flyby.

Science.gov (United States)

Solomon, Sean C; McNutt, Ralph L; Watters, Thomas R; Lawrence, David J; Feldman, William C; Head, James W; Krimigis, Stamatios M; Murchie, Scott L; Phillips, Roger J; Slavin, James A; Zuber, Maria T

2008-07-04

In January 2008, the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft became the first probe to fly past the planet Mercury in 33 years. The encounter revealed that Mercury is a dynamic system; its liquid iron-rich outer core is coupled through a dominantly dipolar magnetic field to the surface, exosphere, and magnetosphere, all of which interact with the solar wind. MESSENGER images confirm that lobate scarps are the dominant tectonic landform and record global contraction associated with cooling of the planet. The history of contraction can be related to the history of volcanism and cratering, and the total contractional strain is at least one-third greater than inferred from Mariner 10 images. On the basis of measurements of thermal neutrons made during the flyby, the average abundance of iron in Mercury's surface material is less than 6% by weight.

Mercury: Aspects of its ecology and environmental toxicity. [physiological effects of mercury compound contamination of environment

Science.gov (United States)

Siegel, S. M.

1973-01-01

A study was conducted to determine the effects of mercury pollution on the environment. The possible sources of mercury contamination in sea water are identified. The effects of mercury on food sources, as represented by swordfish, are analyzed. The physiological effects of varying concentrations of mercury are reported. Emphasis is placed on the situation existing in the Hawaiian Islands.

Axial mercury segregation in direct current operated low-pressure argon-mercury gas discharges: Part I. Experimental

International Nuclear Information System (INIS)

Gielen, John W A M; Groot, Simon de; Mullen, Joost J A M van der

2004-01-01

Due to cataphoresis, axial segregation of mercury will occur when the gas discharge of a fluorescent lamp is operated by means of a direct current. A consequence of this is a non-uniform axial luminance distribution along the lamp. To determine the degree of axial mercury segregation experimentally, axial luminance distributions have been measured which are converted into axial mercury vapour pressure distributions by an appropriate calibration method. The mercury segregation has been investigated for variations in lamp tube radius (3.6-4.8 mm), argon buffer gas pressure (200-600 Pa) and lamp current (100-250 mA) at mercury vapour pressures set at the anode in the range from 0.2 to 9.0 Pa. From the experiments it has been concluded that the mercury vapour pressure gradient at any axial position for a certain lamp tube diameter, argon pressure and lamp current depends on the local mercury vapour pressure. This observation is in contrast to assumptions made in earlier modelling publications in which one mercury vapour pressure gradient is used for all axial positions. By applying a full factorial design, an empirical relation of the mercury segregation is found for any set of parameters inside the investigated parameter ranges

Mercury Sorption onto Malt Spent Rootlets

Science.gov (United States)

Manariotis, I. D.; Anagnostopoulos, V.; Karapanagioti, H. K.; Chrysikopoulos, C.

2011-12-01

Mercury is a metal of particular concern due to its toxicity even at relatively low concentrations. The maximum permissible level for mercury in drinking water set by the European Union is 0.001 mg/L. Mercury is released into the environment via four principal pathways: (1) natural processes; i.e. a volcanic eruption, (2) incidental to some other activity; i.e. coal burning power plants, (3) accidentally during the manufacture, breakage or disposal of products that have mercury put into them deliberately, and (4) direct use in industrial settings. The present study focuses on the removal of mercury (II) from aqueous solutions via sorption onto Malt Spent Rootlets (MSR). Batch experiments were conducted employing MSR with size ranging from 0.18 to 1 mm. The effects of pH, mercury concentration, contact time, and solid to liquid ratio on mercury sorption onto MSR were investigated. The highest mercury removal from the aqueous phase, of 41%, was observed at pH of 5.

Mercury Exposure: Protein Biomarkers of Mercury Exposure in Jaraqui Fish from the Amazon Region.

Science.gov (United States)

Vieira, José Cavalcante Souza; Braga, Camila Pereira; de Oliveira, Grasieli; Padilha, Cilene do Carmo Federici; de Moraes, Paula Martin; Zara, Luiz Fabricio; Leite, Aline de Lima; Buzalaf, Marília Afonso Rabelo; Padilha, Pedro de Magalhães

2018-05-01

This study presents data on the extraction and characterization of proteins associated with mercury in the muscle and liver tissues of jaraqui (Semaprochilodus spp.) from the Madeira River in the Brazilian Amazon. Protein fractionation was carried out by two-dimensional electrophoresis (2D-PAGE). Mercury determination in tissues, pellets, and protein spots was performed by graphite furnace atomic absorption spectrometry (GFAAS). Proteins in the spots that showed mercury were characterized by electrospray ionization tandem mass spectrometry (ESI-MS/MS). The highest mercury concentrations were found in liver tissues and pellets (426 ± 6 and 277 ± 4 μg kg -1 ), followed by muscle tissues and pellets (132 ± 4 and 86 ± 1 μg kg -1 , respectively). Mercury quantification in the protein spots allowed us to propose stoichiometric ratios in the range of 1-4 mercury atoms per molecule of protein in the protein spots. The proteins characterized in the analysis by ESI-MS/MS were keratin, type II cytoskeletal 8, parvalbumin beta, parvalbumin-2, ubiquitin-40S ribosomal S27a, 39S ribosomal protein L36 mitochondrial, hemoglobin subunit beta, and hemoglobin subunit beta-A/B. The results suggest that proteins such as ubiquitin-40S ribosomal protein S27a, which have specific domains, possibly zinc finger, can be used as biomarkers of mercury, whereas mercury and zinc present characteristics of soft acids.

Method for the removal and recovery of mercury

Science.gov (United States)

Easterly, Clay E.; Vass, Arpad A.; Tyndall, Richard L.

1997-01-01

The present invention is an enhanced method for the removal and recovery of mercury from mercury-contaminated matrices. The method involves contacting a mercury-contaminated matrix with an aqueous dispersant solution derived from specific intra-amoebic isolates to release the mercury from the mercury-contaminated matrix and emulsify the mercury; then, contacting the matrix with an amalgamating metal from a metal source to amalgamate the mercury to the amalgamating metal; removing the metallic source from the mercury-contaminated matrix; and heating the metallic source to vaporize the mercury in a closed system to capture the mercury vapors.

Isolation, screening and identification of mercury resistant bacteria from mercury contaminated soil

OpenAIRE

Kowalczyk Anna; Wilińska Magdalena; Chyc Marek; Bojko Monika; Latowski Dariusz

2016-01-01

New bacterial strains resistant to high concentration of mercury were obtained and character iz ed focusing on their potential application in bioremediation. The biological material was isolated from soil contaminated with mercury. The ability to removal of Hg from the liquid medium and the effect of the various pH and mercury concentrations in the environment on bacterial strains growth kinetics were tested. The selected strains were identified by analysis of the 16S ribosome subunit coding ...

Groundwater Modeling of Mercury Pollution at a Former Mercury Cell Chlor Alkali Facility in Pavlodar City, Kazakhstan

Science.gov (United States)

In northern Kazakhstan, there is a serious case of mercury pollution near the city of Pavlodar from an old mercury cell chlor-alkali plant. The soil, sediment, and water is severely contaminated with mercury and mercury compounds as a result of the industrial activity of this ch...

Phytoremediation of Ionic and Methyl Mercury Pollution

Energy Technology Data Exchange (ETDEWEB)

Meagher, Richard B.

2004-12-01

Phytoremediation is defined as the use of plants to extract, resist, detoxify, and/or sequester toxic environmental pollutants. The long-term goal of the proposed research is to develop and test highly productive, field-adapted plant species that have been engineered for the phytoremediation of mercury. A variety of different genes, which should enable plants to clean mercury polluted sites are being tested as tools for mercury phytoremediation, first in model laboratory plants and then in potential field species. Several of these genes have already been shown to enhance mercury phytoremediation. Mercury pollution is a serious, world-wide problem affecting the health of human and wildlife populations. Environmentally, the most serious mercury threat is the production of methylmercury (CH3Hg+) by native bacteria at mercury contaminated wetland sites. Methylmercury is inherently more toxic than metallic (Hg(0)) or ionic (Hg(II)) mercury, and because methylmercury is prolifically biomagnified up the food chain, it poses the most immediate danger to animal populations. We have successfully engineered two model plants, Arabidopsis and tobacco, to use the bacterial merB gene to convert methylmercury to less toxic ionic mercury and to use the bacterial merA gene to further detoxify ionic mercury to the least toxic form of mercury, metallic mercury. Plants expressing both MerA and MerB proteins detoxify methylmercury in two steps to the metallic form. These plants germinate, grow, and set seed at normal growth rates on levels of methylmercury or ionic mercury that are lethal to normal plants. Our newest efforts involve engineering plants with several additional bacterial and plant genes that allow for higher levels of mercury resistance and mercury hyperaccumulation. The potential for these plants to hyperaccumulate mercury was further advanced by developing constitutive, aboveground, and root-specific gene expression systems.

Mercury emission from crematories in Japan

Directory of Open Access Journals (Sweden)

M. Takaoka

2010-04-01

Full Text Available Anthropogenic sources of mercury emissions have a significant impact on global pollution. Therefore, finding uncharacterised sources and assessing the emissions from these sources are important. However, limited data are available worldwide on mercury emissions from crematories. In Japan, 99.9% of dead bodies are cremated, which is the highest percentage in the world, and more than 1600 crematories are in operation. We thus focused on emissions from crematories in Japan. The number of targeted facilities was seven, and we used continuous emission monitoring to measure the mercury concentrations and investigate mercury behaviour. The total mercury concentrations in stack gases were a few μg/Nm³ (normal cubic meters. Considering the time profile of mercury and its species in cremations, the findings confirmed that the mercury in stack gas originated from dental amalgam. The amount of mercury emissions was calculated using the total concentration and gas flow rate. Furthermore, the annual amount of mercury emission from crematories in Japan was estimated by using the total number of corpses. The emission amount was considerably lower than that estimated in the United Kingdom. From statistical analyses on population demographics and measurements, future total emissions from crematories were also predicted. As a result, the amount of mercury emitted by crematories will likely increase by 2.6-fold from 2007 to 2037.

Genetic effects of organic mercury compounds

Energy Technology Data Exchange (ETDEWEB)

Ramel, C

1967-01-01

Organic mercury compounds have a c-mitotic effect on plant cells that cause polyploidi. Studies were performed on Allium root cells. These investigations involved methyl mercury dicyandiamide, methyl mercury hydroxide, and phenyl mercury hydroxide. The lowest concentration necessary for a cytologically observable effect was about 0.05 ppM Hg for the methyl compounds. For the phenyl compound, the value was lower. Experiments were performed on Drosophila melanogaster. The question was whether the mercury would reach the gonads. Experimental data with mercury treated larvae indicated a chromosome disjunction. Data indicated a preferential segregation at the meiotic division might be involved. Experiments are being performed on mice inbred (CBA) in order to investigate teratogenic effects and dominant lethality caused by organic mercury compounds. The mutagenic effects of these compounds are studied on Neurospora Drosophila. No conclusive data is now available.

Phytoremediation of Ionic and Methyl Mercury Pollution

Energy Technology Data Exchange (ETDEWEB)

Meagher, Richard B.

2005-06-01

Phytoremediation is defined as the use of plants to extract, resist, detoxify, and/or sequester toxic environmental pollutants. The long-term goal of the proposed research is to develop and test highly productive, field-adapted plant species that have been engineered for the phytoremediation of mercury. A variety of different genes, which should enable plants to clean mercury polluted sites are being tested as tools for mercury phytoremediation, first in model laboratory plants and then in potential field species. Several of these genes have already been shown to enhance mercury phytoremediation. Mercury pollution is a serious, world-wide problem affecting the health of human and wildlife populations. Environmentally, the most serious mercury threat is the production of methylmercury (CH3Hg+) by native bacteria at mercury contaminated wetland sites. Methylmercury is inherently more toxic than metallic (Hg(0)) or ionic (Hg(II)) mercury, and because methylmercury is prolifically biomagnified up the food chain, it poses the most immediate danger to animal populations. We have successfully engineered two model plants, Arabidopsis and tobacco, to use the bacterial merB gene to convert methylmercury to less toxic ionic mercury and to use the bacterial merA gene to further detoxify ionic mercury to the least toxic form of mercury, metallic mercury. Plants expressing both MerA and MerB proteins detoxify methylmercury in two steps to the metallic form. These plants germinate, grow, and set seed at normal growth rates on levels of methylmercury or ionic mercury that are lethal to normal plants. Our newest efforts involve engineering plants with several additional bacterial and plant genes that allow for higher levels of mercury resistance and mercury hyperaccumulation. The potential for these plants to hyperaccumulate mercury was further advanced by developing constitutive, aboveground, and root-specific gene expression systems. Our current strategy is to engineer plants to

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.

MERCURY IN MARINE LIFE DATABASE

Science.gov (United States)

The purpose of the Mercury in Marine Life Project is to organize information on estuarine and marine species so that EPA can better understand both the extent of monitoring for mercury and level of mercury contamination in the biota of coastal environments. This report follows a ...

Possible interferences of mercury sulfur compounds with ethylated and methylated mercury species using HPLC-ICP-MS

International Nuclear Information System (INIS)

Wilken, R.D.; Nitschke, F.; Falter, R.

2003-01-01

The HPLC-ICP-MS coupling technique is able to separate and detect methyl, ethyl and inorganic mercury isotopes specifically. An identification of ethyl mercury(+) is not possible when the widely used sodium tetraethylborate derivatisation method in combination with GC-AFS/AAS or ICP-MS techniques is performed because it contains ethyl groups. An unidentified compound with the same retention time as ethyl mercury was found in the HPLC chromatograms of industrial sewage samples and humic-rich soils of microcosm experiments after applying water vapour distillation. We also observed such unidentified peaks in samples of heavily contaminated sites in Eastern Germany, separated by HPLC fractionation only. In the experiments described, different mercury sulfur adducts were synthesised and tested for their retention times in the HPLC-ICP-MS system. It was found that the compound CH 3 -S-Hg + showed the same retention time as the ethyl mercury standard. It is therefore possible that ethyl mercury detected in chromatography by comparison of the retention time could also be due to an adduct of a sulfur compound and a mercury species. CH 3 -S-Hg + should be tested in other chromatographic mercury speciation methods for this effect. This work can also be regarded as a contribution to the discussion of artificially occurring methyl mercury in sediments during sample preparation. (orig.)

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.

Total mercury, methylmercury and selenium in mercury polluted areas in the province Guizhou, China.

Science.gov (United States)

Horvat, Milena; Nolde, Natasa; Fajon, Vesna; Jereb, Vesna; Logar, Martina; Lojen, Sonja; Jacimovic, Radojko; Falnoga, Ingrid; Liya, Qu; Faganeli, Jadran; Drobne, Damjana

2003-03-20

The province of Guizhou in Southwestern China is currently one of the world's most important mercury production areas. Emissions of mercury from the province to the global atmosphere have been estimated to be approximately 12% of the world total anthropogenic emissions. The main objective of this study was to assess the level of contamination with Hg in two geographical areas of Guizhou province. Mercury pollution in the areas concerned originates from mercury mining and ore processing in the area of Wanshan, while in the area of Quingzhen mercury pollution originates from the chemical industry discharging Hg through wastewaters and emissions to the atmosphere due to coal burning for electricity production. The results of this study confirmed high contamination with Hg in soil, sediments and rice in the Hg mining area in Wanshan. High levels of Hg in soil and rice were also found in the vicinity of the chemical plant in Quingzhen. The concentrations of Hg decreased with distance from the main sources of pollution considerably. The general conclusion is that Hg contamination in Wanshan is geographically more widespread, due to deposition and scavenging of Hg from contaminated air and deposition on land. In Quingzhen Hg contamination of soil is very high close to the chemical plant but the levels reach background concentrations at a distance of several km. Even though the major source of Hg in both areas is inorganic Hg, it was observed that active transformation of inorganic Hg to organic Hg species (MeHg) takes place in water, sediments and soils. The concentration of Hg in rice grains can reach up to 569 microg/kg of total Hg of which 145 microg/kg was in MeHg form. The percentage of Hg as MeHg varied from 5 to 83%. The concentrations of selenium can reach up to 16 mg/kg in soil and up to 1 mg/g in rice. A correlation exists between the concentration of Se in soil and rice, indicating that a portion of Se is bioavailable to plants. No correlation between Hg and Se

Mercury pollution in Malaysia.

Science.gov (United States)

Hajeb, Parvaneh; Jinap, S; Ismail, Ahmad; Mahyudin, Nor Ainy

2012-01-01

Although several studies have been published on levels of mercury contamination of the environment, and of food and human tissues in Peninsular Malaysia, there is a serious dearth of research that has been performed in East Malaysia (Sabah and Sarawak). Industry is rapidly developing in East Malaysia, and, hence, there is a need for establishing baseline levels of mercury contamination in environmental media in that part of the country by performing monitoring studies. Residues of total mercury and inorganic in food samples have been determined in nearly all previous studies that have been conducted; however, few researchers have analyzed samples for the presence of methlymercury residues. Because methylmercury is the most toxic form of mercury, and because there is a growing public awareness of the risk posed by methylmercury exposure that is associated with fish and seafood consumption, further monitoring studies on methylmercury in food are also essential. From the results of previous studies, it is obvious that the economic development in Malaysia, in recent years, has affected the aquatic environment of the country. Primary areas of environmental concern are centered on the rivers of the west Peninsular Malaysian coast, and the coastal waters of the Straits of Malacca, wherein industrial activities are rapidly expanding. The sources of existing mercury input to both of these areas of Malaysia should be studied and identified. Considering the high levels of mercury that now exists in human tissues, efforts should be continued, and accelerated in the future, if possible, to monitor mercury contamination levels in the coastal states, and particularly along the west Peninsular Malaysian coast. Most studies that have been carried out on mercury residues in environmental samples are dated, having been conducted 20-30 years ago; therefore, the need to collect much more and more current data is urgent. Furthermore, establishing baseline levels of mercury exposure to

Correlation of circRNAs’ differential expression to negative- positive symptoms of patients with schizophrenia

Directory of Open Access Journals (Sweden)

Ling-ming KONG

2017-11-01

Full Text Available Objective To explore the correlation of circRNAs' expression level to the negative- and positive symptoms of patients with schizophrenia (SZ. Methods Gene chip screening was performed with the peripheral blood samples from each five of SZ patients and normal controls. Nine circRNAs showing differentiate expression were confirmed, and further verification was done by real-time fluorescence quantitative PCR in 102 SZ patients and 103 normal controls. All the SZ patients were assessed with Positive and Negative Symptom Scale (PANSS. Results It was revealed that the expression levels of circRNA_102101, circRNA_102315, circRNA_104597, circRNA_101835 and circRNA_101836 were significantly down-regulated (P<0.01 or P<0.05, and circRNA_103102 and circRNA_103704 were up-regulated in SZ group (P<0.01. The ΔCT value of circRNA_102101 and circRNA_103102 was positively correlated to the positive symptoms (P<0.01 or P<0.05, and the ΔCT value of circRNA_103704 also showed positive correlation with positive symptoms and general psychopathological symptoms (P<0.01 or P<0.05. The ΔCT values of circRNA_102101, circRNA_103102, circRNA_102315, circRNA_103704 and circRNA_102802 were correlated with thinking disorder (P<0.01 or P<0.05, and the ΔCT values of circRNA_102101, circRNA_103102, circRNA_104597, circRNA_103704 and circRNA_102802 were correlated with the activation (P<0.01 or P<0.05. The ΔCT values of circRNA_102101, circRNA_103102, circRNA_103704 and circRNA_102802 were positively correlated with paranoid (P<0.01 or P<0.05, and of circRNA_102101, circRNA_103102, circRNA_103704 and circRNA_102802 were markedly correlated with assault (P<0.01 or P<0.05. Therefore, circRNA_103704 was chosen into regressive equation of positive symptoms (P<0.01, and circRNA_103704 and circRNA_102315 were chosen into regressive equation of general pathological findings (P<0.01 or P<0.05. Conclusion The expression levels of circRNA_103704 and circRNA_103102 are obviously up

Mercury Information Clearinghouse

Energy Technology Data Exchange (ETDEWEB)

Chad A. Wocken; Michael J. Holmes; Dennis L. Laudal; Debra F. Pflughoeft-Hassett; Greg F. Weber; Nicholas V. C. Ralston; Stanley J. Miller; Grant E. Dunham; Edwin S. Olson; Laura J. Raymond; John H. Pavlish; Everett A. Sondreal; Steven A. Benson

2006-03-31

The Canadian Electricity Association (CEA) identified a need and contracted the Energy & Environmental Research Center (EERC) to create and maintain an information clearinghouse on global research and development activities related to mercury emissions from coal-fired electric utilities. With the support of CEA, the Center for Air Toxic Metals{reg_sign} (CATM{reg_sign}) Affiliates, and the U.S. Department of Energy (DOE), the EERC developed comprehensive quarterly information updates that provide a detailed assessment of developments in the various areas of mercury monitoring, control, policy, and research. A total of eight topical reports were completed and are summarized and updated in this final CEA quarterly report. The original quarterly reports can be viewed at the CEA Web site (www.ceamercuryprogram.ca). In addition to a comprehensive update of previous mercury-related topics, a review of results from the CEA Mercury Program is provided. Members of Canada's coal-fired electricity generation sector (ATCO Power, EPCOR, Manitoba Hydro, New Brunswick Power, Nova Scotia Power Inc., Ontario Power Generation, SaskPower, and TransAlta) and CEA, have compiled an extensive database of information from stack-, coal-, and ash-sampling activities. Data from this effort are also available at the CEA Web site and have provided critical information for establishing and reviewing a mercury standard for Canada that is protective of environment and public health and is cost-effective. Specific goals outlined for the CEA mercury program included the following: (1) Improve emission inventories and develop management options through an intensive 2-year coal-, ash-, and stack-sampling program; (2) Promote effective stack testing through the development of guidance material and the support of on-site training on the Ontario Hydro method for employees, government representatives, and contractors on an as-needed basis; (3) Strengthen laboratory analytical capabilities through

Radiation propagation in random media: From positive to negative correlations in high-frequency fluctuations

International Nuclear Information System (INIS)

Davis, Anthony B.; Mineev-Weinstein, Mark B.

2011-01-01

We survey research on radiation propagation or ballistic particle motion through media with randomly variable material density, and we investigate the topic with an emphasis on very high spatial frequencies. Our new results are based on a specific variability model consisting of a zero-mean Gaussian scaling noise riding on a constant value that is large enough with respect to the amplitude of the noise to yield overwhelmingly non-negative density. We first generalize known results about sub-exponential transmission from regular functions, which are almost everywhere continuous, to merely 'measurable' ones, which are almost everywhere discontinuous (akin to statistically stationary noises), with positively correlated fluctuations. We then use the generalized measure-theoretic formulation to address negatively correlated stochastic media without leaving the framework of conventional (continuum-limit) transport theory. We thus resolve a controversy about recent claims that only discrete-point process approaches can accommodate negative correlations, i.e., anti-clustering of the material particles. We obtain in this case the predicted super-exponential behavior, but it is rather weak. Physically, and much like the alternative discrete-point process approach, the new model applies most naturally to scales commensurate with the inter-particle distance in the material, i.e., when the notion of particle density breaks down due to Poissonian-or maybe not-so-Poissonian-number-count fluctuations occur in the sample volume. At the same time, the noisy structure must prevail up to scales commensurate with the mean-free-path to be of practical significance. Possible applications are discussed.

Mercury recycling in the United States in 2000

Science.gov (United States)

Brooks, William E.; Matos, Grecia R.

2005-01-01

Reclamation and recycling of mercury from used mercury- containing products and treatment of byproduct mercury from gold mining is vital to the continued, though declining, use of this metal. Mercury is reclaimed from mercury-containing waste by treatment in multistep high-temperature retorts-the mercury is volatized and then condensed for purification and sale. Some mercury-containing waste, however, may be landfilled, and landfilled material represents loss of a recyclable resource and a threat to the environment. Related issues include mercury disposal and waste management, toxicity and human health, and regulation of mercury releases in the environment. End-users of mercury-containing products may face fines and prosecution if these products are improperly recycled or not recycled. Local and State environmental regulations require adherence to the Resource Conservation and Recovery Act and the Comprehensive Environmental Response, Compensation, and Liability Act to regulate generation, treatment, and disposal of mercury-containing products. In the United States, several large companies and a number of smaller companies collect these products from a variety of sources and then reclaim and recycle the mercury. Because mercury has not been mined as a principal product in the United States since 1992, mercury reclamation from fabricated products has become the main source of mercury. Principal product mercury and byproduct mercury from mining operations are considered to be primary materials. Mercury may also be obtained as a byproduct from domestic or foreign gold-processing operations. In the early 1990s, U.S. manufacturers used an annual average that ranged from 500 to 600 metric tons of recycled and imported mercury for fabrication of automobile convenience switches, dental amalgam, fluorescent lamps, medical uses and thermometers, and thermostats. The amount now used for fabrication is estimated to be 200 metric tons per year or less. Much of the data on

Quarter 9 Mercury information clearinghouse final report

Energy Technology Data Exchange (ETDEWEB)

Laudal, D.L.; Miller, S.; Pflughoeft-Hassett, D.; Ralston, N.; Dunham, G.; Weber, G.

2005-12-15

The Canadian Electricity Association (CEA) identified a need and contracted the Energy & Environmental Research Center (EERC) to create and maintain an information clearinghouse on global research and development activities related to mercury emissions from coal-fired electric utilities. A total of eight reports were completed and are summarized and updated in this final CEA quarterly report. Selected topics were discussed in detail in each quarterly report. Issues related to mercury from coal-fired utilities include the general areas of measurement, control, policy, and transformations. Specific topics that have been addressed in previous quarterly reports include the following: Quarterly 1 - Sorbent Control Technologies for Mercury Control; Quarterly 2 - Mercury Measurement; Quarterly 3 - Advanced and Developmental Mercury Control Technologies; Quarterly 4 - Prerelease of Mercury from Coal Combustion By-Products; Quarterly 5 - Mercury Fundamentals; Quarterly 6 - Mercury Control Field Demonstrations; Quarterly 7 - Mercury Regulations in the United States: Federal and State; and Quarterly 8 - Commercialization Aspects of Sorbent Injection Technologies in Canada. In this last of nine quarterly reports, an update of these mercury issues is presented that includes a summary of each topic, with recent information pertinent to advances made since the quarterly reports were originally presented. In addition to a comprehensive update of previous mercury-related topics, a review of results from the CEA Mercury Program is provided. 86 refs., 11 figs., 8 tabs.

Phytoremediation of Ionic and Methyl Mercury Pollution

Energy Technology Data Exchange (ETDEWEB)

Meagher, Richard B.

2005-06-01

Phytoremediation is defined as the use of plants to extract, resist, detoxify, and/or sequester toxic environmental pollutants. The long-term goal of the proposed research is to develop and test highly productive, field-adapted plant species that have been engineered for the phytoremediation of mercury. A variety of different genes, which should enable plants to clean mercury polluted sites are being tested as tools for mercury phytoremediation, first in model laboratory plants and then in potential field species. Several of these genes have already been shown to enhance mercury phytoremediation. Mercury pollution is a serious, world-wide problem affecting the health of human and wildlife populations. Environmentally, the most serious mercury threat is the production of methylmercury (CH3Hg+) by native bacteria at mercury contaminated wetland sites. Methylmercury is inherently more toxic than metallic (Hg(0)) or ionic (Hg(II)) mercury, and because methylmercury is prolifically biomagnified up the food chain, it poses the most immediate danger to animal populations. We have successfully engineered two model plants, Arabidopsis and tobacco, to use the bacterial merB gene to convert methylmercury to less toxic ionic mercury and to use the bacterial merA gene to further detoxify ionic mercury to the least toxic form of mercury, metallic mercury. Plants expressing both MerA and MerB proteins detoxify methylmercury in two steps to the metallic form. These plants germinate, grow, and set seed at normal growth rates on levels of methylmercury or ionic mercury that are lethal to normal plants. Our newest efforts involve engineering plants with several additional bacterial and plant genes that allow for higher levels of mercury resistance and mercury hyperaccumulation. The potential for these plants to hyperaccumulate mercury was further advanced by developing constitutive, aboveground, and root-specific gene expression systems. Our current strategy is to engineer plants to

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

Objective: Toxic heavy metals are released to the environment constantly from unregulated electronic waste (e-waste) recycling in Guiyu, China, and thus may contribute to the elevation of mercury (Hg) and other heavy metals levels in human hair. We aimed to investigate concentrations of mercury in hair from Guiyu and potential risk factors and compared them with those from a control area where no e-waste processing occurs. Methods: A total of 285 human hair samples were collected from three villages (including Beilin, Xianma, and Huamei) of Guiyu (n=205) and the control area, Jinping district of Shantou city (n=80). All the volunteers were administered a questionnaire regarding socio-demographic characteristics and other possible factors contributed to hair mercury concentration. Hair mercury concentration was analyzed by hydride generation atomic fluorescence spectrometry (AFS). Results: Our results suggested that hair mercury concentrations in volunteers of Guiyu (median, 0.99; range, 0.18–3.98 μg/g) were significantly higher than those of Jinping (median, 0.59; range, 0.12–1.63 μg/g). We also observed a higher over-limit ratio (>1 μg/g according to USEPA) in Guiyu than in Jinping (48.29% vs. 11.25%, P<0.001). Logistic regression model showed that the variables of living house also served as an e-waste workshop, work related to e-waste, family income, time of residence in Guiyu, the distance between home and waste incineration, and fish intake were associated with hair mercury concentration. After multiple stepwise regression analysis, in the Guiyu samples, hair mercury concentration was found positively associated with the time residence in Guiyu (β=0.299, P<0.001), and frequency of shellfish intake (β=0.184, P=0.016); and negatively associated with the distance between home and waste incineration (β=−0.190, P=0.015) and whether house also served as e-waste workshop (β=−0.278, P=0.001). Conclusions: This study investigated human mercury exposure

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

Objective: Toxic heavy metals are released to the environment constantly from unregulated electronic waste (e-waste) recycling in Guiyu, China, and thus may contribute to the elevation of mercury (Hg) and other heavy metals levels in human hair. We aimed to investigate concentrations of mercury in hair from Guiyu and potential risk factors and compared them with those from a control area where no e-waste processing occurs. Methods: A total of 285 human hair samples were collected from three villages (including Beilin, Xianma, and Huamei) of Guiyu (n=205) and the control area, Jinping district of Shantou city (n=80). All the volunteers were administered a questionnaire regarding socio-demographic characteristics and other possible factors contributed to hair mercury concentration. Hair mercury concentration was analyzed by hydride generation atomic fluorescence spectrometry (AFS). Results: Our results suggested that hair mercury concentrations in volunteers of Guiyu (median, 0.99; range, 0.18–3.98 μg/g) were significantly higher than those of Jinping (median, 0.59; range, 0.12–1.63 μg/g). We also observed a higher over-limit ratio (>1 μg/g according to USEPA) in Guiyu than in Jinping (48.29% vs. 11.25%, P<0.001). Logistic regression model showed that the variables of living house also served as an e-waste workshop, work related to e-waste, family income, time of residence in Guiyu, the distance between home and waste incineration, and fish intake were associated with hair mercury concentration. After multiple stepwise regression analysis, in the Guiyu samples, hair mercury concentration was found positively associated with the time residence in Guiyu (β=0.299, P<0.001), and frequency of shellfish intake (β=0.184, P=0.016); and negatively associated with the distance between home and waste incineration (β=−0.190, P=0.015) and whether house also served as e-waste workshop (β=−0.278, P=0.001). Conclusions: This study investigated human mercury exposure

Minamata Convention on Mercury

Science.gov (United States)

On November 6, 2013 the United States signed the Minamata Convention on Mercury, a new multilateral environmental agreement that addresses specific human activities which are contributing to widespread mercury pollution

Total Mercury content of skin toning creams

African Journals Online (AJOL)

Administrator

2008-04-01

Apr 1, 2008 ... used it for cosmetics (Silberberg, 1995). Mercury- ... Cosmetic preparations containing mercury com- pounds are .... mercury determination by a modified version of an open .... level mercury exposure, which could lead to a.

Experimental dosing of wetlands with coagulants removes mercury from surface water and decreases mercury bioaccumulation in fish.

Science.gov (United States)

Ackerman, Joshua T; Kraus, Tamara E C; Fleck, Jacob A; Krabbenhoft, David P; Horwath, William R; Bachand, Sandra M; Herzog, Mark P; Hartman, C Alex; Bachand, Philip A M

2015-05-19

Mercury pollution is widespread globally, and strategies for managing mercury contamination in aquatic environments are necessary. We tested whether coagulation with metal-based salts could remove mercury from wetland surface waters and decrease mercury bioaccumulation in fish. In a complete randomized block design, we constructed nine experimental wetlands in California's Sacramento-San Joaquin Delta, stocked them with mosquitofish (Gambusia affinis), and then continuously applied agricultural drainage water that was either untreated (control), or treated with polyaluminum chloride or ferric sulfate coagulants. Total mercury and methylmercury concentrations in surface waters were decreased by 62% and 63% in polyaluminum chloride treated wetlands and 50% and 76% in ferric sulfate treated wetlands compared to control wetlands. Specifically, following coagulation, mercury was transferred from the filtered fraction of water into the particulate fraction of water which then settled within the wetland. Mosquitofish mercury concentrations were decreased by 35% in ferric sulfate treated wetlands compared to control wetlands. There was no reduction in mosquitofish mercury concentrations within the polyaluminum chloride treated wetlands, which may have been caused by production of bioavailable methylmercury within those wetlands. Coagulation may be an effective management strategy for reducing mercury contamination within wetlands, but further studies should explore potential effects on wetland ecosystems.

Experimental dosing of wetlands with coagulants removes mercury from surface water and decreases mercury bioaccumulation in fish

Science.gov (United States)

Ackerman, Joshua T.; Kraus, Tamara E.C.; Fleck, Jacob A.; Krabbenhoft, David P.; Horwarth, William R.; Bachand, Sandra M.; Herzog, Mark; Hartman, Christopher; Bachand, Philip A.M.

2015-01-01

Mercury pollution is widespread globally, and strategies for managing mercury contamination in aquatic environments are necessary. We tested whether coagulation with metal-based salts could remove mercury from wetland surface waters and decrease mercury bioaccumulation in fish. In a complete randomized block design, we constructed nine experimental wetlands in California’s Sacramento–San Joaquin Delta, stocked them with mosquitofish (Gambusia affinis), and then continuously applied agricultural drainage water that was either untreated (control), or treated with polyaluminum chloride or ferric sulfate coagulants. Total mercury and methylmercury concentrations in surface waters were decreased by 62% and 63% in polyaluminum chloride treated wetlands and 50% and 76% in ferric sulfate treated wetlands compared to control wetlands. Specifically, following coagulation, mercury was transferred from the filtered fraction of water into the particulate fraction of water which then settled within the wetland. Mosquitofish mercury concentrations were decreased by 35% in ferric sulfate treated wetlands compared to control wetlands. There was no reduction in mosquitofish mercury concentrations within the polyaluminum chloride treated wetlands, which may have been caused by production of bioavailable methylmercury within those wetlands. Coagulation may be an effective management strategy for reducing mercury contamination within wetlands, but further studies should explore potential effects on wetland ecosystems.

Determination of mercury in plant material

Energy Technology Data Exchange (ETDEWEB)

Pickard, J A; Martin, J T

1960-07-01

An analytical procedure used for the determination of traces of mercury in plant material is described. The conditions of combustion of organic matter are controlled to avoid loss of mercury and EDTA is used to reduce the values for apparent mercury on uncontaminated samples. Satisfactory recoveries of mercury added to apples, tomatoes and coffee are obtained. 10 references, 1 table.

[Mercury Distribution Characteristics and Atmospheric Mercury Emission Factors of Typical Waste Incineration Plants in Chongqing].

Science.gov (United States)

Duan, Zhen-ya; Su, Hai-tao; Wang, Feng-yang; Zhang, Lei; Wang, Shu-xiao; Yu, Bin

2016-02-15

Waste incineration is one of the important atmospheric mercury emission sources. The aim of this article is to explore the atmospheric mercury pollution level of waste incineration industry from Chongqing. This study investigated the mercury emissions from a municipal solid waste incineration plant and a medical waste incineration plant in Chongqing. The exhaust gas samples in these two incineration plants were obtained using USA EPA 30B method. The mercury concentrations in the fly ash and bottom ash samples were analyzed. The results indicated that the mercury concentrations of the municipal solid waste and medical waste incineration plant in Chongqing were (26.4 +/- 22.7) microg x m(-3) and (3.1 +/- 0.8) microg x m(-3) in exhaust gas respectively, (5279.2 +/- 798.0) microg x kg(-1) and (11,709.5 +/- 460.5) microg x kg(-1) in fly ash respectively. Besides, the distribution proportions of the mercury content from municipal solid waste and medical waste in exhaust gas, fly ash, and bottom ash were 34.0%, 65.3%, 0.7% and 32.3%, 67.5%, 0.2% respectively; The mercury removal efficiencies of municipal solid waste and medical waste incineration plants were 66.0% and 67.7% respectively. The atmospheric mercury emission factors of municipal solid waste and medical waste incineration plants were (126.7 +/- 109.0) microg x kg(-1) and (46.5 +/- 12.0) microg x kg(-1) respectively. Compared with domestic municipal solid waste incineration plants in the Pearl River Delta region, the atmospheric mercury emission factor of municipal solid waste incineration plant in Chongqing was lower.

The mixed waste focus area mercury working group: an integrated approach for mercury treatment and disposal

International Nuclear Information System (INIS)

Conley, T.B.; Morris, M.I.; Holmes-Burns, H.; Petersell, J.; Schwendiman, L.

1997-01-01

In May 1996, the U.S. Department of Energy (DOE) Mixed Waste Focus Area (MWFA) initiated the Mercury Work Group (HgWG), which was established to address and resolve the issues associated with mercury- contaminated mixed wastes. Three of the first four technology deficiencies identified during the MWFA technical baseline development process were related to mercury amalgamation, stabilization, and separation/removal. The HgWG will assist the MWFA in soliciting, identifying, initiating, and managing all the efforts required to address these deficiencies. The focus of the HgWG is to better establish the mercury-related treatment needs at the DOE sites, refine the MWFA technical baseline as it relates to mercury treatment, and make recommendations to the MWFA on how to most effectively address these needs. The team will initially focus on the sites with the most mercury-contaminated mixed wastes, whose representatives comprise the HgWG. However, the group will also work with the sites with less inventory to maximize the effectiveness of these efforts in addressing the mercury- related needs throughout the entire complex

Atmospheric mercury footprints of nations.

Science.gov (United States)

Liang, Sai; Wang, Yafei; Cinnirella, Sergio; Pirrone, Nicola

2015-03-17

The Minamata Convention was established to protect humans and the natural environment from the adverse effects of mercury emissions. A cogent assessment of mercury emissions is required to help implement the Minamata Convention. Here, we use an environmentally extended multi-regional input-output model to calculate atmospheric mercury footprints of nations based on upstream production (meaning direct emissions from the production activities of a nation), downstream production (meaning both direct and indirect emissions caused by the production activities of a nation), and consumption (meaning both direct and indirect emissions caused by final consumption of goods and services in a nation). Results show that nations function differently within global supply chains. Developed nations usually have larger consumption-based emissions than up- and downstream production-based emissions. India, South Korea, and Taiwan have larger downstream production-based emissions than their upstream production- and consumption-based emissions. Developed nations (e.g., United States, Japan, and Germany) are in part responsible for mercury emissions of developing nations (e.g., China, India, and Indonesia). Our findings indicate that global mercury abatement should focus on multiple stages of global supply chains. We propose three initiatives for global mercury abatement, comprising the establishment of mercury control technologies of upstream producers, productivity improvement of downstream producers, and behavior optimization of final consumers.

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.

Isolation, screening and identification of mercury resistant bacteria from mercury contaminated soil

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Kowalczyk Anna

2016-01-01

Full Text Available New bacterial strains resistant to high concentration of mercury were obtained and character iz ed focusing on their potential application in bioremediation. The biological material was isolated from soil contaminated with mercury. The ability to removal of Hg from the liquid medium and the effect of the various pH and mercury concentrations in the environment on bacterial strains growth kinetics were tested. The selected strains were identified by analysis of the 16S ribosome subunit coding sequenc es as Pseudomonas syringae. The analysis of Hg concentration in liquid medium as effect of microbial metabolism demonstrated that P. syringae is able to remove almost entire metal from medium after 120 hours of incubation. Obtained results revealed new ability of the isolated strain P. syringae. Analyzed properties of this soil bacteria species able to reduce concentration of Hg ors immobi lize this metal are promising for industrial wastewater treatment and bioremediation of the soils polluted especially by mercury lamps scrapping, measuring instruments, dry batteries, detonators or burning fuels made from crude oil, which may also contain mercury. Selected bacteria strains provide efficient and relatively low-cost bioremediation of the areas and waters contaminated with Hg.

Occupational Metallic Mercury Poisoning in Gilders

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M Vahabzadeh

2016-04-01

Full Text Available Occupational exposure to elemental mercury vapor usually occurs through inhalation during its utilizations. This leads to a variety of adverse health effects. In some Islamic cities, this type of poisoning may occur during gilding of shrines using elemental mercury with gold. Herein, we report on three male patients aged 20–53 years, who were diagnosed with occupational metallic mercury poisoning due to gilding of a shrine. All patients presented with neuro-psychiatric disorders such as anxiety, loss of memory and concentration, and sleep disorders with high urinary mercury concentrations of 326–760 μg/L upon referring, 3–10 days after cessation of elemental mercury exposure. Following chelating therapy, the patients recovered clinically and their mercury concentrations declined to non-toxic level (<25 μg/L. Health, environmental and labor authorities, as well as the gilders should be aware of the toxicity risk of exposure to metalic mercury during gilding in closed environments and act accordingly.

Sexual differences in the distribution and retention of organic and inorganic mercury in methyl mercury-treated rats

International Nuclear Information System (INIS)

Thomas, D.J.; Fisher, H.L.; Sumler, M.R.; Marcus, A.H.; Mushak, P.; Hall, L.L.

1986-01-01

At 56 days of age, male and female Long-Evans rats received 1 μmole of 203 Hg-labeled mercuric chloride per kilogram sc and total, organic, and inorganic mercury contents and concentrations in tissues were determined for up to 98 days postdosing. When expressed on a concentration basis, the only significant sexual difference was in the higher average concentration of organic mercury in the kidneys of females. When expressed on a tissue content basis, significant male-female differences in the kinetics (sex x time interactions) of organic mercury retention were found in kidney, brain, skeletal muscle, pelt, and whole body. Significant sex x time interactions in the concentrations of organic mercury were found in kidney, skeletal muscle, and whole body. Kinetics of retention and concentration of inorganic Hg in the pelt differed significantly for males and females. Discordance of degree of statistical significance of differences in mercury contents and concentrations reflected in part differences in relative body composition of males and females. Differences in integrated exposure were estimated by the female-to-male ratio of areas under retention curves. Reconstruction of whole body organic and inorganic mercury burdens from constituent tissues indicated that integrated exposures of males and females to inorganic mercury were equal but females had a lower integrated exposure to organic mercury. Integrated exposure of liver to either form of mercury was about equal in males and females. However, the integrated exposure of the brain of females to inorganic mercury was 2.19 times that of males suggest'ing a sexual difference in accumulation or retention of inorganic mercury in the nervous system

Field controlled experiments of mercury accumulation in crops from air and soil

Energy Technology Data Exchange (ETDEWEB)

Niu Zhenchuan [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Zhang Xiaoshan, E-mail: zhangxsh@rcees.ac.cn [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Wang Zhangwei, E-mail: wangzhw@rcees.ac.cn [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Ci Zhijia [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China)

2011-10-15

Field open top chambers (OTCs) and soil mercury (Hg) enriched experiments were employed to study the influence of Hg concentrations in air and soil on the Hg accumulation in the organs of maize (Zea mays L.) and wheat (Triticum aestivum L.). Results showed that Hg concentrations in foliages were correlated significantly (p < 0.05) with air Hg concentrations but insignificantly correlated with soil Hg concentrations, indicating that Hg in crop foliages was mainly from air. Hg concentrations in roots were generally correlated with soil Hg concentrations (p < 0.05) but insignificantly correlated with air Hg concentrations, indicating that Hg in crop roots was mainly from soil. No significant correlations were found between Hg concentrations in stems and those in air and soil. However, Hg concentrations in upper stems were usually higher than those in bottom stems, implying air Hg might have stronger influence than soil Hg on stem Hg accumulation. - Highlights: > Hg accumulation in crop organs was studied by OTCs and soil Hg enriched experiments. > Hg accumulation in foliages and roots was mainly from air and soil, respectively. > Air Hg had stronger influence than soil Hg on stem Hg accumulation. > Foliar Hg concentrations showed the trend of increase over growth stages. - Capsule Mercury accumulated in the aboveground organs of crop was mainly from the air.

Mercury cycling in a wastewater treatment plant treating waters with high mercury contents.

Science.gov (United States)

García-Noguero, Eva M.; García-Noguero, Carolina; Higueras, Pablo; Reyes-Bozo, Lorenzo; Esbrí, José M.

2015-04-01

The Almadén mercury mining district has been historically the most important producer of this element since Romans times to 2004, when both mining and metallurgic activities ceased as a consequence both of reserves exhaustion and persistent low prices for this metal. The reclamation of the main dump of the mine in 2007-2008 reduced drastically the atmospheric presence of the gaseous mercury pollutant in the local atmosphere. But still many areas, and in particular in the Almadén town area, can be considered as contaminated, and produce mercury releases that affect the urban residual waters. Two wastewater treatment plants (WWTP) where built in the area in year 2002, but in their design the projects did not considered the question of high mercury concentrations received as input from the town area. This communication presents data of mercury cycling in one of the WWTP, the Almadén-Chillón one, being the larger and receiving the higher Hg concentrations, due to the fact that it treats the waters coming from the West part of the town, in the immediate proximity to the mine area. Data were collected during a number of moments of activity of the plant, since April 2004 to nowadays. Analyses were carried out by means of cold vapor-atomic fluorescence spectroscopy (CV-AFS), using a PSA Millennium Merlin analytical device with gold trap. The detection limit is 0.1 ng/l. The calibration standards are prepared using the Panreac ICP Standard Mercury Solution (1,000±0,002 g/l Hg in HNO3 2-5%). Results of the surveys indicate that mercury concentrations in input and output waters in this plant has suffered an important descent since the cessation of mining and metallurgical activities, and minor reduction also after the reclamation of the main mine's dump. Since 2009, some minor seasonal variations are detected, in particular apparently related to accumulation during summer of mercury salts and particles, which are washed to the plant with the autumn's rains. Further

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.

Mercury-induced epigenetic transgenerational inheritance of abnormal neurobehavior is correlated with sperm epimutations in zebrafish.

Directory of Open Access Journals (Sweden)

Michael J Carvan

Full Text Available Methylmercury (MeHg is a ubiquitous environmental neurotoxicant, with human exposures predominantly resulting from fish consumption. Developmental exposure of zebrafish to MeHg is known to alter their neurobehavior. The current study investigated the direct exposure and transgenerational effects of MeHg, at tissue doses similar to those detected in exposed human populations, on sperm epimutations (i.e., differential DNA methylation regions [DMRs] and neurobehavior (i.e., visual startle and spontaneous locomotion in zebrafish, an established human health model. F0 generation embryos were exposed to MeHg (0, 1, 3, 10, 30, and 100 nM for 24 hours ex vivo. F0 generation control and MeHg-exposed lineages were reared to adults and bred to yield the F1 generation, which was subsequently bred to the F2 generation. Direct exposure (F0 generation and transgenerational actions (F2 generation were then evaluated. Hyperactivity and visual deficit were observed in the unexposed descendants (F2 generation of the MeHg-exposed lineage compared to control. An increase in F2 generation sperm epimutations was observed relative to the F0 generation. Investigation of the DMRs in the F2 generation MeHg-exposed lineage sperm revealed associated genes in the neuroactive ligand-receptor interaction and actin-cytoskeleton pathways being effected, which correlate to the observed neurobehavioral phenotypes. Developmental MeHg-induced epigenetic transgenerational inheritance of abnormal neurobehavior is correlated with sperm epimutations in F2 generation adult zebrafish. Therefore, mercury can promote the epigenetic transgenerational inheritance of disease in zebrafish, which significantly impacts its environmental health considerations in all species including humans.

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

Mercury Poisoning Linked to Skin Products

Science.gov (United States)

... Products For Consumers Home For Consumers Consumer Updates Mercury Poisoning Linked to Skin Products Share Tweet Linkedin ... and, in some situations, criminal prosecution. Dangers of Mercury Exposure to mercury can have serious health consequences. ...

LOCAL IMPACTS OF MERCURY EMISSIONS FROM COAL FIRED POWER PLANTS.

Energy Technology Data Exchange (ETDEWEB)

SULLIVAN, T.M.; BOWERMAN, B.; ADAMS, J.; LIPFERT, D.D.; MORRIS, S.M.; BANDO, A.; ET AL.

2004-03-30

deposition and fish content. Soil and vegetation sampling programs were performed around two mid-size coal fired power plants. The objectives were to determine if local mercury hot spots exist, to determine if they could be attributed to deposition of coal-fired power plant emissions, and to determine if they correlated with model predictions. These programs found the following: (1) At both sites, there was no correlation between modeled mercury deposition and either soil concentrations or vegetation concentrations. At the Kincaid plant, there was excess soil Hg along heavily traveled roads. The spatial pattern of soil mercury concentrations did not match the pattern of vegetation Hg concentrations at either plant. (2) At both sites, the subsurface (5-10 cm) samples the Hg concentration correlated strongly with the surface samples (0-5 cm). Average subsurface sample concentrations were slightly less than the surface samples, however, the difference was not statistically significant. (3) An unequivocal definition of background Hg was not possible at either site. Using various assumed background soil mercury concentrations, the percentage of mercury deposited within 10 km of the plant ranged between 1.4 and 8.5% of the RGM emissions. Based on computer modeling, Hg deposition was primarily RGM with much lower deposition from elemental mercury. Estimates of the percentage of total Hg deposition ranged between 0.3 and 1.7%. These small percentages of deposition are consistent with the empirical findings of only minor perturbations in environmental levels, as opposed to ''hot spots'', near the plants. The major objective of this study was to determine if there was evidence for ''hot spots'' of mercury deposition around coal-fired power plants. Although the term has been used extensively, it has never been defined. From a public health perspective, such a ''hot spot'' must be large enough to insure that it did not occur by

The impact of sewage irrigation on the uptake of mercury in corn plants (Zea mays) from suburban Beijing

International Nuclear Information System (INIS)

Rothenberg, S.E.; Du, X.; Zhu, Y.-G.; Jay, J.A.

2007-01-01

The impact of sewage irrigation on the uptake and translocation of mercury (Hg) in corn plants (Zea mays) was investigated. Corn plants were harvested the same day from two nearby fields in suburban Beijing, one irrigated historically with sewage effluent, and one irrigated solely with groundwater. Hg content was analyzed in the soil, roots and stems, while percent moisture and soil organic content were analyzed in the soil samples. The concentration of Hg in the soil and roots, and the soil organic content were not significantly different between the two fields, despite the historic practice of sewage irrigation. Hg content in roots was positively correlated with soil Hg concentration (r = 0.95, n = 6). The transfer coefficients between roots and stems were significantly higher in the control site (control: 2.06, sewage-irrigated: 0.44, p < 0.05), indicating that the barrier effect of the roots was not consistent between the two fields. - Hg content in the roots of corn plants (Zea mays) was positively correlated with soil Hg content, but negatively correlated with Hg content in stems

The impact of sewage irrigation on the uptake of mercury in corn plants (Zea mays) from suburban Beijing

Energy Technology Data Exchange (ETDEWEB)

Rothenberg, S.E. [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing, 100085 (China); Environmental Science and Engineering Program, Box 951772 CHS, University of California, Los Angeles, CA 90095-1772 (United States)], E-mail: srothenb@ucla.edu; Du, X.; Zhu, Y.-G. [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing, 100085 (China); Jay, J.A. [Department of Civil and Environmental Engineering, Box 951593 Boelter Hall, University of California, Los Angeles, CA 90095-1593 (United States)

2007-09-15

The impact of sewage irrigation on the uptake and translocation of mercury (Hg) in corn plants (Zea mays) was investigated. Corn plants were harvested the same day from two nearby fields in suburban Beijing, one irrigated historically with sewage effluent, and one irrigated solely with groundwater. Hg content was analyzed in the soil, roots and stems, while percent moisture and soil organic content were analyzed in the soil samples. The concentration of Hg in the soil and roots, and the soil organic content were not significantly different between the two fields, despite the historic practice of sewage irrigation. Hg content in roots was positively correlated with soil Hg concentration (r = 0.95, n = 6). The transfer coefficients between roots and stems were significantly higher in the control site (control: 2.06, sewage-irrigated: 0.44, p < 0.05), indicating that the barrier effect of the roots was not consistent between the two fields. - Hg content in the roots of corn plants (Zea mays) was positively correlated with soil Hg content, but negatively correlated with Hg content in stems.

Basic Information about Mercury

Science.gov (United States)

... or metallic mercury is a shiny, silver-white metal and is liquid at room temperature. It is ... releases can happen naturally. Both volcanoes and forest fires send mercury into the atmosphere. Human activities, however, ...

The fate of Mercury in Arctic regions: New understanding of atmospheric chemical processes and mercury stability in snow.

Science.gov (United States)

Steffen, A.; Ferrari, C.; Dommergue, A.; Scherz, T.; Lawson, G.; Leiatch, R.

2006-12-01

Mercury is a known toxic pollutant in the Arctic environment. Atmospheric mercury depletion events (AMDEs) have been studied in the Arctic since 1995. While advances in understanding this newly discovered cycling of mercury in the atmosphere have been made, much of the chemistry and the impact of this annually reoccurring event to the Arctic ecosystem are not well understood. Four years of continuous measurements at Alert, Canada of so-called reactive gaseous mercury (RGM) and mercury associated to particles (PHg) coupled with ongoing snow sampling have produced new information on the atmospheric chemistry and deposition of these mercury species to the Arctic. A distinct pattern during the springtime period in the distribution of these atmospheric mercury species has emerged. This pattern is characterized by the predominance of PHg concentration at the onset of the AMDEs. During the latter part of the AMDE season, there is an obvious swicth in the speciation of mercury to RGM as the main component during AMDEs. This swicth from PHg to RGM is clearly linked to a significant increase of mercury in the snow. In addition, concentrations of PHg are clearly linked with particles in the air that are primarily associated with Arctic haze. Recently, similar results have also been observed in Ny-Alesund (Svalbard). Further observations indicate that once deposited, the deposited mercury appears to evolve chemically in the snow. This change in mercury may impact the transfer of mercury to the environment during snow melt. These first time observed links between atmospheric conditions and subsequent deposition of mercury may help to ascertain the conditions throughout the Arctic as to when significant deposition of mercury will occur. It is proposed that should the concentration of atmospheric particles increase in the Arctic due to long range transport from emission sources, an increase in the deposition of mercury to this environment will increase during the springtime

Concentration of mercury and selenium in tissues of five cetacean species from Croatian coastal waters

Directory of Open Access Journals (Sweden)

Bilandžić Nina

2015-01-01

Full Text Available Mercury (Hg and selenium (Se concentrations were measured in muscle, liver, kidney, spleen and lung tissues of five cetacean species, three dolphin (Stenella coeruleoalba, Tursiops truncatus and Grampus griseus and two whale species (Balaenoptera physalus and Ziphius cavirostris, stranded along the Croatian coast during the period 1999-2002. Statistically significant differences in Hg concentrations in muscle, spleen and lung, and Se in liver and lung of the different dolphin species were observed. Mercury levels in liver and spleen and Se levels in liver differed between young and adult T. truncatus species. A significant positive correlation between different tissue types for Hg and Se concentrations was observed. In all tissues tested, the lowest Hg and Se concentrations were found in B. physalus. Mercury concentrations were positively correlated with Se in all tissues. The results present one of few studies related to lung and spleen tissues in these mammals, particularly in the Adriatic Sea. Since very little data are available, this research provides new data on concentrations of Hg and Se in five cetacean species from the Adriatic Sea basin.

Mercury

CERN Document Server

Mahoney, T J

2014-01-01

This gazetteer and atlas on Mercury lists, defines and illustrates every named (as opposed to merely catalogued) object and term as related to Mercury within a single reference work. It contains a glossary of terminology used, an index of all the headwords in the gazetteer, an atlas comprising maps and images with coordinate grids and labels identifying features listed in the gazetteer, and appendix material on the IAU nomenclature system and the transcription systems used for non-roman alphabets. This book is useful for the general reader, writers and editors dealing with astronomical themes, and those astronomers concerned with any aspect of astronomical nomenclature.

Mercury and flooding cycles in the Tapajos river basin, Brazilian Amazon: The role of periphyton of a floating macrophyte (Paspalum repens)

Energy Technology Data Exchange (ETDEWEB)

Coelho-Souza, Sergio A., E-mail: sacs@biof.ufrj.br [Lab. Tracadores Wolfgang C. Pfeiffer, SL 049, Instituto de Biofisica Carlos Chagas Filho/UFRJ, Bloco G, Centro de Ciencias e Saude, Ilha do Fundao, Rio de Janeiro, RJ, CEP 21949-902 (Brazil); Guimaraes, Jean R.D.; Miranda, Marcio R. [Lab. Tracadores Wolfgang C. Pfeiffer, SL 049, Instituto de Biofisica Carlos Chagas Filho/UFRJ, Bloco G, Centro de Ciencias e Saude, Ilha do Fundao, Rio de Janeiro, RJ, CEP 21949-902 (Brazil); Poirier, Hugo [Chaire de Reserche en Environment, Universite du Quebec a Montreal (UQaM), CP 8888, Montreal, H3C 3P8 (Canada); Mauro, Jane B.N. [Lab. Tracadores Wolfgang C. Pfeiffer, SL 049, Instituto de Biofisica Carlos Chagas Filho/UFRJ, Bloco G, Centro de Ciencias e Saude, Ilha do Fundao, Rio de Janeiro, RJ, CEP 21949-902 (Brazil); Lucotte, Marc [Chaire de Reserche en Environment, Universite du Quebec a Montreal (UQaM), CP 8888, Montreal, H3C 3P8 (Canada); Mergler, Donna [CINBIOSE, UQaM, CP 8888, succ. Centre-ville, Montreal, H3C 3P8 (Canada)

2011-06-15

Methylmercury (MeHg) increases mercury (Hg) toxicity and is biomagnified in the trophic chain contaminating riverine Amazon populations. Freshwater macrophyte roots are a main site of Hg methylation in different Brazilian environments. Paspalum repens periphyton was sampled in four floodplain lakes during the dry, rainy and wet seasons for measurement of total Hg (THg), MeHg, Hg methylation potentials, %C, %N, {delta}{sup 13}C, {delta}{sup 15}N and bacterial heterotrophic production as {sup 3}H-leucine incorporation rate. THg concentration varied from 67 to 198 ng/g and the potential of Me{sup 203}Hg formation was expressive (1-23%) showing that periphyton is an important matrix both in the accumulation of Hg and in MeHg production. The concentration of MeHg varied from 1 to 6 ng/g DW and was positively correlated with Me{sup 203}Hg formation. Though methylmercury formation is mainly a bacterial process, no significant correlation was observed between the methylation potentials and bacterial production. The multiple regressions analyses suggested a negative correlation between THg and %C and %N and between methylation potential and {delta}{sup 13}C. The discriminant analysis showed a significant difference in periphyton {delta}{sup 15}N, {delta}{sup 13}C and THg between seasons, where the rainy season presented higher {delta}{sup 15}N and the wet period lighter {delta}{sup 13}C, lower THg values and higher Me{sup 203}Hg formation. This exploratory study indicates that the flooding cycle could influence the periphyton composition, mercury accumulation and methylmercury production. - Research highlights: {yields} During rainy season mercury (Hg{sup 2+}) is carried out from terrestrial to aquatic systems by runoff. {yields} Macrophyte roots accumulates Hg{sup 2+} from suspended particulate matter (SPM). {yields} Hg methylation increases during the wet season. {yields} Flooded forest is a source of labile organic carbon and bioavailable Hg. {yields} Macrophytes

Mercury analysis in hair

DEFF Research Database (Denmark)

Esteban, Marta; Schindler, Birgit K; Jiménez-Guerrero, José A

2015-01-01

Human biomonitoring (HBM) is an effective tool for assessing actual exposure to chemicals that takes into account all routes of intake. Although hair analysis is considered to be an optimal biomarker for assessing mercury exposure, the lack of harmonization as regards sampling and analytical...... assurance program (QAP) for assessing mercury levels in hair samples from more than 1800 mother-child pairs recruited in 17 European countries. To ensure the comparability of the results, standard operating procedures (SOPs) for sampling and for mercury analysis were drafted and distributed to participating...... laboratories. Training sessions were organized for field workers and four external quality-assessment exercises (ICI/EQUAS), followed by the corresponding web conferences, were organized between March 2011 and February 2012. ICI/EQUAS used native hair samples at two mercury concentration ranges (0...

Serum acylated ghrelin is negatively correlated with the insulin resistance in the CODING study.

Directory of Open Access Journals (Sweden)

Peyvand Amini

Full Text Available Ghrelin is a 28-amino acid orexigenic peptide synthesized mainly in the stomach. Acute administration of ghrelin has been found to decrease insulin secretion. However, little data is available regarding whether ghrelin contributes to the long-term regulation of insulin resistance at the population level. The aim of this study is to investigate the association between circulating ghrelin and insulin resistance in a large population based study.A total of 2082 CODING study (Complex Diseases in the Newfoundland population: Environment and Genetics subjects were assessed. Subjects were of at least third generation Newfoundland descent, between the ages of 20 and 79 years, and had no serious metabolic, cardiovascular, or endocrine diseases. Ghrelin was measured with an Enzyme Immunoassay method. Insulin and fasting glucose were measured by Immulite 2500 autoanalyzer and Lx20 clinical chemistry analyzer, respectively. Homeostatic Model Assessment of β cell function (HOMA-β and Insulin Resistance (HOMA-IR and Quantitative Insulin-sensitivity Check Index (QUICKI were used for measurement of insulin resistance.Partial correlation analyses showed a significant negative correlation between circulating ghrelin and insulin level and insulin resistance in the entire cohort and also in men and women separately. The aforementioned correlation was independent of age, percentage of trunk fat and HDL-cholesterol. According to menopausal status, only pre-menopausal women revealed negative correlations.Our results suggest that except for postmenopausal women, high circulating ghrelin level is associated with lower insulin resistance in the general population.

Coal fired flue gas mercury emission controls

International Nuclear Information System (INIS)

Wu, Jiang; Pan, Weiguo; Cao, Yan; Pan, Weiping

2015-01-01

Mercury (Hg) is one of the most toxic heavy metals, harmful to both the environment and human health. Hg is released into the atmosphere from natural and anthropogenic sources and its emission control has caused much concern. This book introduces readers to Hg pollution from natural and anthropogenic sources and systematically describes coal-fired flue gas mercury emission control in industry, especially from coal-fired power stations. Mercury emission control theory and experimental research are demonstrated, including how elemental mercury is oxidized into oxidized mercury and the effect of flue gas contents on the mercury speciation transformation process. Mercury emission control methods, such as existing APCDs (air pollution control devices) at power stations, sorbent injection, additives in coal combustion and photo-catalytic methods are introduced in detail. Lab-scale, pilot-scale and full-scale experimental studies of sorbent injection conducted by the authors are presented systematically, helping researchers and engineers to understand how this approach reduces the mercury emissions in flue gas and to apply the methods in mercury emission control at coal-fired power stations.

Coal fired flue gas mercury emission controls

Energy Technology Data Exchange (ETDEWEB)

Wu, Jiang; Pan, Weiguo [Shanghai Univ. of Electric Power (China); Cao, Yan; Pan, Weiping [Western Kentucky Univ., Bowling Green, KY (United States)

2015-05-01

Mercury (Hg) is one of the most toxic heavy metals, harmful to both the environment and human health. Hg is released into the atmosphere from natural and anthropogenic sources and its emission control has caused much concern. This book introduces readers to Hg pollution from natural and anthropogenic sources and systematically describes coal-fired flue gas mercury emission control in industry, especially from coal-fired power stations. Mercury emission control theory and experimental research are demonstrated, including how elemental mercury is oxidized into oxidized mercury and the effect of flue gas contents on the mercury speciation transformation process. Mercury emission control methods, such as existing APCDs (air pollution control devices) at power stations, sorbent injection, additives in coal combustion and photo-catalytic methods are introduced in detail. Lab-scale, pilot-scale and full-scale experimental studies of sorbent injection conducted by the authors are presented systematically, helping researchers and engineers to understand how this approach reduces the mercury emissions in flue gas and to apply the methods in mercury emission control at coal-fired power stations.

Effects of Hypolimnetic Oxygenation on Mercury Cycling in Twin Lake, Washington

Science.gov (United States)

Beutel, M.; Dent, S.; Reed, B.; Moore, B.; Yonge, D.; Shallenberger, E.

2010-12-01

The accumulation of mercury in freshwater aquatic food webs is a widespread health concern. Nearly one-third of US lakes have fish consumption advisories in place due to elevated concentrations of mercury in fish tissue. Mercury, primarily from fossil fuel combustion, is widely deposited across the landscape in the form of ionic mercury. The deposited ionic mercury can be transformed to toxic methylmercury by anaerobic bacteria in anoxic waters and sediments. Once produced, methylmercury is taken up by algae and seston, and then biomagnified up the aquatic food web with levels increasing in successive trophic levels. This presentation summarizes three years (2008-2010) of mercury monitoring at North and South Twin Lakes, moderately deep (maximum depth ~15 m) meso-eutrophic lakes located on the Colville Indian Reservation in eastern Washington State. The objective of the study was to evaluate spatial and temporal patterns of the total and methyl mercury in the water column and zooplankton before and after the implementation of hypolimnetic oxygenation in North Twin Lake in 2009. The working hypothesis was that maintenance of an oxic hypolimnion would repress methylmercury enrichment in bottom waters, and subsequent uptake into zooplankton. Initial results confirm that oxygenation repressed hypolimnetic enrichment of methylmercury. In 2008, prior to oxygenation, peak levels of methylmercury in anaerobic bottom waters of North and South Twin Lakes were 0.4-0.6 ng/L. In 2009 levels were less than 0.05 ng/L in oxygenated North Twin Lake, but were again elevated in anaerobic bottom waters of South Twin Lake. Interestingly, during a two-week oxygenation test in North Twin Lake in the fall of 2008, bottom waters exhibited a short-term and reversible loss of methylmercury that correlated with a decrease in dissolved iron and manganese. Regarding zooplankton, total mercury was higher in zooplankton from oxygenated North Twin Lake relative to non-oxygenated South Twin Lake

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.

Mercury emission monitoring on municipal waste combustion

International Nuclear Information System (INIS)

Braun, H.; Gerig, A.

1991-01-01

In waste incineration, mercury is the only heavy metal to be released as a gas, mostly as mercury(II) chloride, because of its high volatility. Continuous emission monitoring is possible only when mercury occurs in its elemental form. This paper reports on various possibilities of converting Hg(II) into Hg(0) that has been studied and tested on a laboratory scale and in the TAMARA refuse incineration pilot facility. Continuous mercury emission measurement appears to be possible, provided mercury is converted in the flue gas condensate precipitated. The measuring results obtained on two municipal solid waste and on one sewage treatment sludge incineration plants show that the mercury monitor is a highly sensitive and selective continuously working instrument for mercury emission monitoring

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.

Volcanic mercury in Pinus canariensis

Science.gov (United States)

Rodríguez Martín, José Antonio; Nanos, Nikos; Miranda, José Carlos; Carbonell, Gregoria; Gil, Luis

2013-08-01

Mercury (Hg) is a toxic element that is emitted to the atmosphere by both human activities and natural processes. Volcanic emissions are considered a natural source of mercury in the environment. In some cases, tree ring records taken close to volcanoes and their relation to volcanic activity over time are contradictory. In 1949, the Hoyo Negro volcano (La Palma-Canary Islands) produced significant pyroclastic flows that damaged the nearby stand of Pinus canariensis. Recently, 60 years after the eruption, we assessed mercury concentrations in the stem of a pine which survived volcano formation, located at a distance of 50 m from the crater. We show that Hg content in a wound caused by pyroclastic impacts (22.3 μg kg-1) is an order of magnitude higher than the Hg concentrations measured in the xylem before and after the eruption (2.3 μg kg-1). Thus, mercury emissions originating from the eruption remained only as a mark—in pyroclastic wounds—and can be considered a sporadic and very high mercury input that did not affect the overall Hg input in the xylem. In addition, mercury contents recorded in the phloem (9.5 μg kg-1) and bark (6.0 μg kg-1) suggest that mercury shifts towards non-living tissues of the pine, an aspect that can be related to detoxification in volcanism-adapted species.

Volcanic mercury in Pinus canariensis.

Science.gov (United States)

Rodríguez Martín, José Antonio; Nanos, Nikos; Miranda, José Carlos; Carbonell, Gregoria; Gil, Luis

2013-08-01

Mercury (Hg) is a toxic element that is emitted to the atmosphere by both human activities and natural processes. Volcanic emissions are considered a natural source of mercury in the environment. In some cases, tree ring records taken close to volcanoes and their relation to volcanic activity over time are contradictory. In 1949, the Hoyo Negro volcano (La Palma-Canary Islands) produced significant pyroclastic flows that damaged the nearby stand of Pinus canariensis. Recently, 60 years after the eruption, we assessed mercury concentrations in the stem of a pine which survived volcano formation, located at a distance of 50 m from the crater. We show that Hg content in a wound caused by pyroclastic impacts (22.3 μg kg(-1)) is an order of magnitude higher than the Hg concentrations measured in the xylem before and after the eruption (2.3 μg kg(-1)). Thus, mercury emissions originating from the eruption remained only as a mark-in pyroclastic wounds-and can be considered a sporadic and very high mercury input that did not affect the overall Hg input in the xylem. In addition, mercury contents recorded in the phloem (9.5 μg kg(-1)) and bark (6.0 μg kg(-1)) suggest that mercury shifts towards non-living tissues of the pine, an aspect that can be related to detoxification in volcanism-adapted species.

Assessment of permeation quality of concrete through mercury intrusion porosimetry

International Nuclear Information System (INIS)

Kumar, Rakesh; Bhattacharjee, B.

2004-01-01

Permeation quality of laboratory cast concrete beams was determined through initial surface absorption test (ISAT). The pore system characteristics of the same concrete beam specimens were determined through mercury intrusion porosimetry (MIP). Data so obtained on the measured initial surface absorption rate of water by concrete and characteristics of pore system of concrete estimated from porosimetry results were used to develop correlations between them. Through these correlations, potential of MIP in assessing the durability quality of concrete in actual structure is demonstrated

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

Mercury emissions from municipal solid waste combustors

Energy Technology Data Exchange (ETDEWEB)

1993-05-01

This report examines emissions of mercury (Hg) from municipal solid waste (MSW) combustion in the United States (US). It is projected that total annual nationwide MSW combustor emissions of mercury could decrease from about 97 tonnes (1989 baseline uncontrolled emissions) to less than about 4 tonnes in the year 2000. This represents approximately a 95 percent reduction in the amount of mercury emitted from combusted MSW compared to the 1989 mercury emissions baseline. The likelihood that routinely achievable mercury emissions removal efficiencies of about 80 percent or more can be assured; it is estimated that MSW combustors in the US could prove to be a comparatively minor source of mercury emissions after about 1995. This forecast assumes that diligent measures to control mercury emissions, such as via use of supplemental control technologies (e.g., carbon adsorption), are generally employed at that time. However, no present consensus was found that such emissions control measures can be implemented industry-wide in the US within this time frame. Although the availability of technology is apparently not a limiting factor, practical implementation of necessary control technology may be limited by administrative constraints and other considerations (e.g., planning, budgeting, regulatory compliance requirements, etc.). These projections assume that: (a) about 80 percent mercury emissions reduction control efficiency is achieved with air pollution control equipment likely to be employed by that time; (b) most cylinder-shaped mercury-zinc (CSMZ) batteries used in hospital applications can be prevented from being disposed into the MSW stream or are replaced with alternative batteries that do not contain mercury; and (c) either the amount of mercury used in fluorescent lamps is decreased to an industry-wide average of about 27 milligrams of mercury per lamp or extensive diversion from the MSW stream of fluorescent lamps that contain mercury is accomplished.

A comparison of mercury levels in feathers and eggs of osprey (Pandion haliaetus) in the North American Great Lakes.

Science.gov (United States)

Hughes, K D; Ewins, P J; Clark, K E

1997-11-01

Osprey (Pandion haliaetus) eggs and chick feathers were collected for mercury analysis from nests at four Great Lakes study areas in Ontario (three "naturally formed" lakes in southern Ontario and one reservoir in northern Ontario) and two New Jersey study areas in 1991-1994. Adult osprey feathers were sampled from three Great Lakes study areas in 1991. Feathers sampled from chicks (approximately 28-35 days old) appear to be better indicators of local contaminant conditions since spatial patterns of mercury in known prey, yellow perch (Perca flavescens), also collected in these areas, were more similar to chick feathers than to eggs. Mercury levels were less variable in chick feathers than in eggs. Estimates of biomagnification factors using prey of known size at these areas were also less variable in feathers than in eggs. At naturally formed lakes, no significant correlation in mercury levels between eggs and chick feathers from the same nest was apparent, suggesting that the source of mercury contamination was not the same in these two tissues: mercury levels in eggs reflect mercury acquired on the breeding grounds, wintering grounds, and migratory route; mercury levels in chick feathers reflect local dietary conditions on the breeding grounds. Mercury levels in both osprey eggs and chick feathers were higher at the Ogoki Reservoir than at naturally formed lakes. Adult osprey feathers had higher mercury concentrations than chick feathers. Mercury levels in osprey eggs, chick feathers, and adult feathers did not approach levels associated with toxic reproductive effects.

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.

Mercury in a coastal marine environment

Energy Technology Data Exchange (ETDEWEB)

Burton, J D; Leatherland, T M

1971-06-18

The problem of mercury pollution was investigated in Southampton Water and the English Channel. Mercury was determined in five specimens of the mollusk, Mercenaria mercenaria. The concentrations in whole organisms, without shell, ranged from 0.18 to 0.57 p.p.m. The amounts of mercury in the river and estuarine waters were found to be low. Yet, samples from the surface of the bottom mud in different parts of the estuary had mercury contents ranging from 0.19 to 0.64 p.p.m. The role of sediments in the transport of mercury in food chains could be significant, particularly for bottom living, suspension feeding animals. 14 references, 1 table.

Mercury risk in poultry in the Wanshan Mercury Mine, China

International Nuclear Information System (INIS)

Yin, Runsheng; Zhang, Wei; Sun, Guangyi; Feng, Zhaohui; Hurley, James P.; Yang, Liyuan; Shang, Lihai; Feng, Xinbin

2017-01-01

In this study, total mercury (THg) and methylmercury (MeHg) concentrations in muscles (leg and breast), organs (intestine, heart, stomach, liver) and blood were investigated for backyard chickens, ducks and geese of the Wanshan Mercury Mine, China. THg in poultry meat products range from 7.9 to 3917.1 ng/g, most of which exceeded the Chinese national standard limit for THg in meat (50 ng/g). Elevated MeHg concentrations (0.4–62.8 ng/g) were also observed in meat products, suggesting that poultry meat can be an important human MeHg exposure source. Ducks and geese showed higher Hg levels than chickens. For all poultry species, the highest Hg concentrations were observed in liver (THg: 23.2–3917.1 ng/g; MeHg: 7.1–62.8 ng/g) and blood (THg: 12.3–338.0 ng/g; MeHg: 1.4–17.6 ng/g). We estimated the Hg burdens in chickens (THg: 15.3–238.1 μg; MeHg: 2.2–15.6 μg), ducks (THg: 15.3–238.1 μg; MeHg: 3.5–14.7 μg) and geese (THg: 83.8–93.4 μg; MeHg: 15.4–29.7 μg). To not exceed the daily intake limit for THg (34.2 μg/day) and MeHg (6 μg/day), we suggested that the maximum amount (g) for chicken leg, breast, heart, stomach, intestine, liver, and blood should be 1384, 1498, 2315, 1214, 1081, 257, and 717, respectively; the maximum amount (g) for duck leg, breast, heart, stomach, intestine, liver, and blood should be 750, 1041, 986, 858, 752, 134, and 573, respectively; and the maximum amount (g) for goose leg, breast, heart, stomach, intestine, liver, and blood should be 941, 1051, 1040, 1131, 964, 137, and 562, respectively. - Highlights: • Elevated mercury levels were observed in poultry from Wanshan Mercury Mine, China. • Ducks and geese showed higher mercury levels than chickens. • Liver and blood showed the highest mercury levels. • Poultry can be an important dietary Hg exposure source for local residents. - High levels of Hg associated with poultry surrounding the Wanshan Mercury Mine pose a great risk of Hg exposure to

Sorption of mercury on chemically synthesized polyaniline

International Nuclear Information System (INIS)

Remya Devi, P.S.; Verma, R.; Sudersanan, M.

2006-01-01

Sorption of inorganic mercury (Hg 2+ ) and methyl mercury, on chemically synthesized polyaniline, in 0.1-10N HCl solutions has been studied. Hg 2+ is strongly sorbed at low acidities and the extent of sorption decreases with increase in acidity. The sorption of methyl mercury is very low in the HCl concentration range studied. Sorption of Hg 2+ on polyaniline in 0.1-10N LiCl and H 2 SO 4 solutions has also been studied. The analysis of the data indicates that the sorption of Hg 2+ depends on the degree of protonation of polyaniline and the nature of mercury(II) chloride complexes in solution. X-ray photoelectron spectroscopy analysis (XPS) of polyaniline sorbed with mercury show that mercury is bound as Hg 2+ . Sorbed mercury is quantitatively eluted from polyaniline with 0.5N HNO 3 . Polyaniline can be used for separation and pre-concentration of inorganic mercury from aqueous samples. (author)

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.

Reference Atmosphere for Mercury

Science.gov (United States)

Killen, Rosemary M.

2002-01-01

We propose that Ar-40 measured in the lunar atmosphere and that in Mercury's atmosphere is due to current diffusion into connected pore space within the crust. Higher temperatures at Mercury, along with more rapid loss from the atmosphere will lead to a smaller column abundance of argon at Mercury than at the Moon, given the same crustal abundance of potassium. Because the noble gas abundance in the Hermean atmosphere represents current effusion, it is a direct measure of the crustal potassium abundance. Ar-40 in the atmospheres of the planets is a measure of potassium abundance in the interiors, since Ar-40 is a product of radiogenic decay of K-40 by electron capture with the subsequent emission of a 1.46 eV gamma-ray. Although the Ar-40 in the Earth's atmosphere is expected to have accumulated since the late bombardment, Ar-40 in the atmospheres of Mercury and the Moon is eroded quickly by photoionization and electron impact ionization. Thus, the argon content in the exospheres of the Moon and Mercury is representative of current effusion rather than accumulation over the lifetime of the planet.

Health Effects of Exposures to Mercury

Science.gov (United States)

... IRIS database Top of Page Elemental (Metallic) Mercury Effects Exposures to metallic mercury most often occur when metallic ... poor performance on tests of mental function Higher exposures may also cause kidney effects, respiratory failure and death. Note that metallic mercury ...

Legislation, standards and methods for mercury emissions control

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-04-15

Mercury is an element of growing global concern. The United Nations Environment Programme plans to finalise and ratify a new global legally-binding convention on mercury by 2013. Canada already has legislation on mercury emissions from coal-fired utilities and the USA has recently released the new Mercury and Air Toxics Standard. Although other countries may not have mercury-specific legislation as such, many have legislation which results in significant co-benefit mercury reduction due to the installation of effective flue-gas cleaning technologies. This report reviews the current situation and trends in mercury emission legislation and, where possible, discusses the actions that will be taken under proposed or impending standards globally and regionally. The report also reviews the methods currently applied for mercury control and for mercury emission measurement with emphasis on the methodologies most appropriate for compliance. Examples of the methods of mercury control currently deployed in the USA, Canada and elsewhere are included.