WorldWideScience

Sample records for exposure point concentrations

  1. View point of medical exposure

    International Nuclear Information System (INIS)

    Akahane, Keiichi

    2008-01-01

    This text contains the following subjects. (1) Introduction, (2) Progress of medical examinations by radiation, (2-1) Decision of applying radiation, (2-2) Irradiation method, (2-3) Irradiation dose, (3) Exposure at medical examinations by radiation, (3-1) Dose to express the exposure, (3-2) Dose at medical exposure, (4) Types of medical examinations by radiation, (4-1) Radiation diagnosis, (4-2) Radiation therapy, (4-3) Nuclear medicine, (5) Radiation effects, (5-1) Types of radiation effect, (5-2) Effects of medical exposure, (6) Present status of medical examination by radiation, (6-1) Actual status of medical exposure, (6-2) Medical examinations by radiation in Japan, (7) Assessment of medical exposure, (7-1) Exposure dose, (7-2) Papers on radiation risk, and (7-3) Radiation protection. (K.Y.)

  2. A point focusing double parabolic trough concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Murphree, Quincy C. [Kentucky Mountain Bible College, Vancleve, KY (United States)

    2001-07-01

    This article shows that a point focusing solar concentrator can be made from two reflective parabolic troughs, a primary and a secondary, by orienting their longitudinal axes in perpendicular directions and separating them by the difference of their focal lengths along the optical axis. This offers a new alternative to the conventional 3-D paraboloidal concentrator permitting more flexibility in designs for applications requiring high concentrations. Both advantages and disadvantages are discussed. The intensity concentration ratio distribution is calculated in the focal plane and has elliptically shaped contours due to the inherent compensation of errant rays by the concave secondary. The ratio of the major to minor axes was 2.61 for the case considered, resulting in a concentration {approx}2.61 times that of a comparable concentrator without the compensation afforded by a concave secondary. Still, geometrical constraints limit the concentration to about 2000 suns for mirror quality errors of 5 mr. Optimisation of the compensation effect holds potential for improved performance for other concentrator designs. Finally, the functional dependence of the peak concentration and shading factor upon design parameters are presented. (Author)

  3. Maternal exposure to metals—Concentrations and predictors of exposure

    International Nuclear Information System (INIS)

    Callan, A.C.; Hinwood, A.L.; Ramalingam, M.; Boyce, M.; Heyworth, J.; McCafferty, P.; Odland, J.Ø.

    2013-01-01

    A variety of metals are important for biological function but have also been shown to impact health at elevated concentrations, whereas others have no known biological function. Pregnant women are a vulnerable population and measures to reduce exposure in this group are important. We undertook a study of maternal exposure to the metals, aluminium, arsenic, copper, cobalt, chromium, lithium, manganese, nickel, selenium, tin, uranium and zinc in 173 participants across Western Australia. Each participant provided a whole blood and urine sample, as well as drinking water, residential soil and dust samples and completed a questionnaire. In general the concentrations of metals in all samples were low with the notable exception of uranium (blood U mean 0.07 µg/L, range <0.01–0.25 µg/L; urinary U mean 0.018 µg/g creatinine, range <0.01–0.199 µg/g creatinine). Factors that influenced biological concentrations were consumption of fish which increased urinary arsenic concentrations, hobbies (including mechanics and welding) which increased blood manganese concentrations and iron/folic acid supplement use which was associated with decreased concentrations of aluminium and nickel in urine and manganese in blood. Environmental concentrations of aluminium, copper and lithium were found to influence biological concentrations, but this was not the case for other environmental metals concentrations. Further work is underway to explore the influence of diet on biological metals concentrations in more detail. The high concentrations of uranium require further investigation. -- Highlights: • High concentrations of uranium with respect to international literature. • Environmental concentrations of Al, Cu and Li influenced urinary concentrations. • Exposure to mechanics/welding hobbies increased blood Mn concentrations. • Iron/Folic acid supplements reduced biological concentrations of Al, Ni and Mn

  4. Maternal exposure to metals—Concentrations and predictors of exposure

    Energy Technology Data Exchange (ETDEWEB)

    Callan, A.C., E-mail: a.callan@ecu.edu.au [Centre for Ecosystem Management, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA 6027 (Australia); Hinwood, A.L.; Ramalingam, M.; Boyce, M. [Centre for Ecosystem Management, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA 6027 (Australia); Heyworth, J. [School Population Health, The University of Western Australia, 35 Stirling Highway Crawley, WA 6009 (Australia); McCafferty, P. [ChemCentre, PO Box 1250, Bentley, WA 6983 (Australia); Odland, J.Ø. [Department of Community Medicine, University of Tromsø, N-9037 Tromsø (Norway)

    2013-10-15

    A variety of metals are important for biological function but have also been shown to impact health at elevated concentrations, whereas others have no known biological function. Pregnant women are a vulnerable population and measures to reduce exposure in this group are important. We undertook a study of maternal exposure to the metals, aluminium, arsenic, copper, cobalt, chromium, lithium, manganese, nickel, selenium, tin, uranium and zinc in 173 participants across Western Australia. Each participant provided a whole blood and urine sample, as well as drinking water, residential soil and dust samples and completed a questionnaire. In general the concentrations of metals in all samples were low with the notable exception of uranium (blood U mean 0.07 µg/L, range <0.01–0.25 µg/L; urinary U mean 0.018 µg/g creatinine, range <0.01–0.199 µg/g creatinine). Factors that influenced biological concentrations were consumption of fish which increased urinary arsenic concentrations, hobbies (including mechanics and welding) which increased blood manganese concentrations and iron/folic acid supplement use which was associated with decreased concentrations of aluminium and nickel in urine and manganese in blood. Environmental concentrations of aluminium, copper and lithium were found to influence biological concentrations, but this was not the case for other environmental metals concentrations. Further work is underway to explore the influence of diet on biological metals concentrations in more detail. The high concentrations of uranium require further investigation. -- Highlights: • High concentrations of uranium with respect to international literature. • Environmental concentrations of Al, Cu and Li influenced urinary concentrations. • Exposure to mechanics/welding hobbies increased blood Mn concentrations. • Iron/Folic acid supplements reduced biological concentrations of Al, Ni and Mn.

  5. Point-of-care estimation of haemoglobin concentration in neonates ...

    African Journals Online (AJOL)

    Objective. The HemoCue is a point-of-care analytical system for haemoglobin concentration (Hb) measurement. Point-of-care testing has been validated in hospitals and outpatient departments to assist with urgent patient management by providing rapid laboratory test results. Method. In this prospective study we compared ...

  6. EXPOSURE TO CONCENTRATED AMBIENT PARTICLES (CAPS): REVIEW

    Science.gov (United States)

    Epidemiologic studies support a participation of fine particulate matter (PM) with a diameter of 0.1 to 2.5 microm in the effects of air pollution particles on human health. The ambient fine particle concentrator is a recently developed technology that can enrich the mass of ambi...

  7. Lead concentrations and risk exposure assessment in surface soils ...

    African Journals Online (AJOL)

    Lead concentrations and risk exposure assessment in surface soils at residential lands previously used for auto-mechanic and auto-welding activities in Port Harcourt, Nigeria. ... Journal of Applied Sciences and Environmental Management.

  8. Effects of repeated skin exposure to low nickel concentrations

    DEFF Research Database (Denmark)

    Nielsen, N H; Menné, T; Kristiansen, J

    1999-01-01

    and nickel allergy, either on normal or on SLS-treated forearm skin. The present study strongly suggests that the changes observed were specific to nickel exposure. Standardized methods to assess trace to moderate nickel exposure on the hands, and the associated effects in nickel-sensitized subjects......We studied the effects of repeated daily exposure to low nickel concentrations on the hands of patients with hand eczema and nickel allergy. The concentrations used were chosen to represent the range of trace to moderate occupational nickel exposure. The study was double-blinded and placebo...... controlled. Patients immersed a finger for 10 min daily into a 10-p.p.m. nickel concentration in water for the first week, and during the second week into a 100-p.p.m. nickel concentration. This regimen significantly increased (P = 0.05) local vesicle formation and blood flow (P = 0.03) as compared...

  9. Toluene metabolism during exposure to varying concentrations combined with exercise

    DEFF Research Database (Denmark)

    Bælum, Jesper; Døssing, M; Hansen, S H

    1987-01-01

    . In Study A, four males were exposed to clean air and to constant and varying concentrations of toluene in combination with rest and with 100 W exercise in 140 min. Exercise increased end exposure excretion rate of HA and O-cr by 47 and 114%, respectively. After exposure, all excess HA was excreted within 4...... weight and smoking habits, thus influencing the metabolite concentration standardised in relation to creatinine. It is concluded that both metabolites are estimates of toluene exposure. O-cr is more specific than HA, but the individual variation in excretion of both metabolites is large, and when...

  10. Effect of prolonged exposure to low antigen concentration for sensitization

    International Nuclear Information System (INIS)

    Och, Francois M.M. van; Vandebriel, Rob J.; Jong, Wim H. de; Loveren, Henk van

    2003-01-01

    The local lymph node assay (LLNA) is an assay in mice to identify potential allergens. Compounds that do not induce a stimulation index (SI)≥3 are not considered sensitizers. Of the chemicals that do, the SI of 3 is used as a benchmark, and indicates the sensitizing potency of a chemical. Compared to the exposure duration of the LLNA (3 days), real life exposure often lasts for months or years. We therefore investigated whether prolonged exposure to sensitizers at concentrations that do not induce a SI≥3 in the LLNA, were able to surpass this threshold. Mice were treated for 2 months at 7-day intervals with a range of concentrations of the known allergens ethyl-p-aminobenzoate (benzocaine, BENZ), 2,4-dinitrochlorobenzene (DNCB), and tetramethyl thiuram disulfide (TMTD). Both proliferative activity and cytokine production were established at day 60. Neither BENZ nor TMTD showed a significant increase in the proliferation rate compared to vehicle controls. Only DNCB at concentrations originally above the EC 3 a significant increase in proliferation was seen after prolonged exposure. No significant effect on IFN-γ and IL-4 production was observed for all three compounds compared. These findings indicate that for classification of sensitizers the shorter exposure period employed in the standard LLNA is sufficient, and longer periods of exposure have no bearing on this classification

  11. Health effects of airborne exposures from concentrated animal feeding operations

    DEFF Research Database (Denmark)

    Heederik, Dick; Sigsgaard, Torben; Thorne, Peter S

    2006-01-01

    effects related to low-level gas and particulate emissions. Most information comes from studies among workers in CAFO installations. Research over the last decades has shown that microbial exposures, especially endotoxin exposure, are related to deleterious respiratory health effects, of which cross......-shift lung function decline and accelerated decline over time are the most pronounced effects. Studies in naïve subjects and workers have shown respiratory inflammatory responses related to the microbial load. This working group, which was part of the Conference on Environmental Health Impacts...... but also on potential health effects from microbial exposures, concentrating on susceptible subgroups, especially asthmatic children and the elderly, since these exposures have been shown to be related to respiratory health effects among workers in CAFOs. Udgivelsesdato: 2007-Feb...

  12. Serum lipid and lipoprotein concentrations following exposure to ozone

    Energy Technology Data Exchange (ETDEWEB)

    Vaughan, W J; Adamson, G L; Lindgren, F T; Schooley, J.C.

    1984-07-01

    The effects of exposure to ozone (O/sub 3/) on concentrations of serum lipids and lipoproteins were investigated. Male and female guinea pigs were exposed to O/sub 3/ at 1 ppm for two weeks. Serum concentrations of cholesterol, triglycerides, low density (LDL) and very low density (VLDL) lipoproteins were elevated after O/sub 3/ exposure, particularly in males. During O/sub 3/ exposure the food intake per day decreased (for a constant body weight), suggesting that metabolic rate and possibly basal metabolic rate was lower. Lung wet weights increased during O/sub 3/ exposure by 87% for males and 45% for females. When individual lung weight/body weight ratios were correlated with cholesterol and LDL values from the same animal, a high correlation is found for males (r . 0.81, P less than 0.05), suggesting that there may be a relationship between lipoprotein elevations and lung damage for males. Because elevated concentrations of lipids and lipoproteins in humans increase the risk of coronary heart disease (CHD), the lipoprotein results suggest that an epidemiological study of the incidence of CHD with metropolitan O/sub 3/ levels may be warranted.

  13. Lead concentrations and risk exposure assessment in surface soils ...

    African Journals Online (AJOL)

    This study investigated lead concentrations in < 250 μm and < 75 μm of deposited dust and< 2000 μm, < 250 μm, and < 75 μm of surface soils at undeveloped residential lands leased to auto-mechanic artisans for a minimum of ten years and estimated exposure risk for children that will reside on the polluted lands after the ...

  14. Sensor-triggered sampling to determine instantaneous airborne vapor exposure concentrations.

    Science.gov (United States)

    Smith, Philip A; Simmons, Michael K; Toone, Phillip

    2018-06-01

    It is difficult to measure transient airborne exposure peaks by means of integrated sampling for organic chemical vapors, even with very short-duration sampling. Selection of an appropriate time to measure an exposure peak through integrated sampling is problematic, and short-duration time-weighted average (TWA) values obtained with integrated sampling are not likely to accurately determine actual peak concentrations attained when concentrations fluctuate rapidly. Laboratory analysis for integrated exposure samples is preferred from a certainty standpoint over results derived in the field from a sensor, as a sensor user typically must overcome specificity issues and a number of potential interfering factors to obtain similarly reliable data. However, sensors are currently needed to measure intra-exposure period concentration variations (i.e., exposure peaks). In this article, the digitized signal from a photoionization detector (PID) sensor triggered collection of whole-air samples when toluene or trichloroethylene vapors attained pre-determined levels in a laboratory atmosphere generation system. Analysis by gas chromatography-mass spectrometry of whole-air samples (with both 37 and 80% relative humidity) collected using the triggering mechanism with rapidly increasing vapor concentrations showed good agreement with the triggering set point values. Whole-air samples (80% relative humidity) in canisters demonstrated acceptable 17-day storage recoveries, and acceptable precision and bias were obtained. The ability to determine exceedance of a ceiling or peak exposure standard by laboratory analysis of an instantaneously collected sample, and to simultaneously provide a calibration point to verify the correct operation of a sensor was demonstrated. This latter detail may increase the confidence in reliability of sensor data obtained across an entire exposure period.

  15. Maternal exposure to alkali, alkali earth, transition and other metals: Concentrations and predictors of exposure

    International Nuclear Information System (INIS)

    Hinwood, A.L.; Stasinska, A.; Callan, A.C.; Heyworth, J.; Ramalingam, M.; Boyce, M.; McCafferty, P.; Odland, J.Ø.

    2015-01-01

    Most studies of metals exposure focus on the heavy metals. There are many other metals (the transition, alkali and alkaline earth metals in particular) in common use in electronics, defense industries, emitted via combustion and which are naturally present in the environment, that have received limited attention in terms of human exposure. We analysed samples of whole blood (172), urine (173) and drinking water (172) for antimony, beryllium, bismuth, cesium, gallium, rubidium, silver, strontium, thallium, thorium and vanadium using ICPMS. In general most metals concentrations were low and below the analytical limit of detection with some high concentrations observed. Few factors examined in regression models were shown to influence biological metals concentrations and explained little of the variation. Further study is required to establish the source of metals exposures at the high end of the ranges of concentrations measured and the potential for any adverse health impacts in children. - This study has demonstrated exposure to alkali, alkali earth and transition metals in pregnant women with factors such as breastfeeding, fish oil use and diet affecting exposures

  16. Evaluation of cumulative PCB exposure estimated by a job exposure matrix versus PCB serum concentrations

    Science.gov (United States)

    Ruder, Avima M.; Succop, Paul; Waters, Martha A.

    2015-01-01

    Although polychlorinated biphenyls (PCBs) have been banned in many countries for more than three decades, exposures to PCBs continue to be of concern due to their long half-lives and carcinogenic effects. In National Institute for Occupational Safety and Health studies, we are using semiquantitative plant-specific job exposure matrices (JEMs) to estimate historical PCB exposures for workers (n=24,865) exposed to PCBs from 1938 to 1978 at three capacitor manufacturing plants. A subcohort of these workers (n=410) employed in two of these plants had serum PCB concentrations measured at up to four times between 1976 and 1989. Our objectives were to evaluate the strength of association between an individual worker’s measured serum PCB levels and the same worker’s cumulative exposure estimated through 1977 with the (1) JEM and (2) duration of employment, and to calculate the explained variance the JEM provides for serum PCB levels using (3) simple linear regression. Consistent strong and statistically significant associations were observed between the cumulative exposures estimated with the JEM and serum PCB concentrations for all years. The strength of association between duration of employment and serum PCBs was good for highly chlorinated (Aroclor 1254/HPCB) but not less chlorinated (Aroclor 1242/LPCB) PCBs. In the simple regression models, cumulative occupational exposure estimated using the JEMs explained 14–24 % of the variance of the Aroclor 1242/LPCB and 22–39 % for Aroclor 1254/HPCB serum concentrations. We regard the cumulative exposure estimated with the JEM as a better estimate of PCB body burdens than serum concentrations quantified as Aroclor 1242/LPCB and Aroclor 1254/HPCB. PMID:23475397

  17. Caffeine dependence in rats: effects of exposure duration and concentration.

    Science.gov (United States)

    Dingle, Rachel N; Dreumont-Boudreau, Sarah E; Lolordo, Vincent M

    2008-09-03

    Groups of rats were chronically exposed to a 1.0-g/L caffeine solution for 5, 10, 15 or 20 days. Upon removal of caffeine, rats were given brief exposure to a novel flavour CS (withdrawal CS) followed by 12 days of plain water and then brief exposure to a second flavour CS (neutral CS). Only rats exposed to 20 days of caffeine strongly preferred the neutral CS to the withdrawal CS in a 2-bottle test. In Experiment 2, groups of rats were chronically exposed to caffeine at one of four concentrations (1.0, 0.5, 0.25, or 0.125 g/L) for 21 days, after which withdrawal and neutral CSs were established. Only rats that drank the highest caffeine concentration, 1.0 g/L, preferred the neutral CS to the withdrawal CS. This suggests that long exposure to a strong caffeine solution is required in order to induce dependence in rats such that a CS associated with the withdrawal of caffeine becomes avoided.

  18. Exposure to hydrocarbon concentrations while commuting or exercising in Dublin.

    Science.gov (United States)

    O'Donoghue, R T; Gill, L W; McKevitt, R J; Broderick, B

    2007-01-01

    In Ireland, several studies have monitored the air pollution due to traffic in both urban and rural environments. However, few studies have attempted to quantify the relative exposure to traffic derived HC pollutants between different modes of commuter transport. In this study, the difference in pollution exposure between bus and cycling commuters on a route in Dublin was compared by sampling for five vehicle related hydrocarbons: benzene, 1,3-butadiene, acetylene, ethane and ethylene. Samples were collected during both morning and afternoon rush hour periods using a fixed speed pump to gain representative concentrations across the whole journey. Journey times were also measured, as were typical breathing rates in order to calculate the overall dose of pollutant inhaled on the journey. Results clearly picked up significantly higher pollutant concentrations in the bus compared to cycling and also revealed elevated concentrations on the congested side of the road compared to the side moving against the traffic. However, when respiration rates and travel times were taken into account to reveal the mass of pollutants inhaled over the course of a journey, the pattern was reversed, showing slightly enhanced levels of hydrocarbons for the cyclist compared to the bus passenger. In addition, the concentrations of these compounds (excluding ethane), were ascertained at playing pitches in the vicinity of a heavily trafficked suburban motorway and in Dublin city centre. Although the concentrations were relatively low at all sites, when breathing rates were taken into consideration, the average inhaled weights of pollutants were, on occasion, higher than those average values observed for both bus and bicycle commuters.

  19. Toward a comprehensive theory of radiation-induced swelling and creep - the point defect concentrations

    International Nuclear Information System (INIS)

    Mansur, L.K.; Yoo, M.H.

    1979-01-01

    The theory of void swelling and irradiation creep is now fairly comprehensive. A unifying concept on which most of this understanding rests is that of the rate theory point defect concentrations. Several basic aspects of this unifying conept are reviewed. These relate to local fluctuations in point defect concentrations produced by cascades, the effects of thermal and radiation-produced divacancies, and the effects of point defect trapping

  20. Point-of-care estimation of haemoglobin concentration in all age ...

    African Journals Online (AJOL)

    Point-of-care estimation of haemoglobin concentration in all age groups in clinical ... and the results were compared using standard scatter and difference plots. ... Hb measurements with a smaller sample volume, improved turnaround time, ...

  1. Influence of point defects' concentration on the ZnO matrix – a ...

    African Journals Online (AJOL)

    Numerical simulations of the effect of the presence of point defects in the matrix of ZnO were carried out using MATLAB computation procedure. The variation of impurity atom concentration with the energy gap was simulated. The plot obtained exhibited an exponential increase in energy gap with respect to the concentration ...

  2. Airborne concentrations of toxic metals resulting from the use of low melting point lead alloys to construct radiotherapy shielding

    International Nuclear Information System (INIS)

    McCullough, E.C.; Senjem, D.H.

    1981-01-01

    Determinations of airborne concentrations of lead, cadmium, bismuth, and tin were made above vessels containing a fusible lead alloy (158 0 F melting point) commonly used for construction of radiotherapy blocks. Fume concentrations were determined by collection on a membrane filter and analysis by atomic absorption spectrophotometry. Samples were obtained for alloy temperatures of 200 0 , 400 0 , and 600 0 F. In all instances, concentrations were much lower than the applicable occupational limits for continuous exposure. The results of this study indicate that the use of a vented hood as a means of reducing air concentrations of toxic metals above and near vessels containing low temperature melting point lead allows commonly used in construction of radiotherapy shields appears unjustifiable. However, proper handling procedures should be observed to avoid entry into the body via alternate pathways (e.g., ingestion or skin absorption). Transmission data of a non-cadmium containing lead alloy with a melting point of 203 0 F was ascertained and is reported on

  3. Does multigenerational exposure to hormetic concentrations of imidacloprid precondition aphids for increased insecticide tolerance?

    Science.gov (United States)

    Rix, Rachel R; Cutler, G Christopher

    2018-02-01

    Hormetic preconditioning, whereby exposure to mild stress primes an organism to better tolerate subsequent stress, is well documented. It is unknown if exposure to hormetic concentrations of insecticide can trans-generationally prime insects to better tolerate insecticide exposure, or whether exposure to hormetic concentrations of insecticide can induce mutations in genes responsible for insecticide resistance. Using the aphid Myzus persicae (Sulzer) and the insecticide imidacloprid as a model, we examined if exposure to mildly toxic and hormetic concentrations of imidacloprid reduced aphid susceptibility to insecticides across four generations, and whether such exposures induced mutations in the imidacloprid binding site in post-synaptic nicotinic acetylcholine receptors. Chronic, multigenerational exposure of aphids to hormetic concentrations of imidacloprid primed offspring to better survive exposure to certain concentrations of imidacloprid, but not exposure to spirotetramat, an insecticide with a different mode of action. Exposure to hormetic and mildly toxic concentrations of imidacloprid did not result in mutations in any of the examined nicotinic acetylcholine receptor subunits. Our findings demonstrate that exposure to hormetic concentrations of insecticide can prime insects to better withstand subsequent chemical stress, but this is dependent upon the insecticide exposure scenario, and may be subtle over generations. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  4. Influence of the size of facets on point focus solar concentrators

    Energy Technology Data Exchange (ETDEWEB)

    Riveros-Rosas, David [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, Col. Copilco, Coyoacan, CP 04510 DF (Mexico); Sanchez-Gonzalez, Marcelino [Centro Nacional de Energias Renovables, c/Somera 7-9, CP 28026 Madrid (Spain); Arancibia-Bulnes, Camilo A.; Estrada, Claudio A. [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, Priv. Xochicalco s/n, Morelos (Mexico)

    2011-03-15

    It is a common practice in the development of point focus solar concentrators to use multiple identical reflecting facets, as a practical and economic alternative for the design and construction of large systems. This kind of systems behaves in a different manner than continuous paraboloidal concentrators. A theoretical study is carried out to understand the effect of the size of facets and of their optical errors in multiple facet point focus solar concentrating systems. For this purpose, a ray tracing program was developed based on the convolution technique, in which the brightness distribution of the sun and the optical errors of the reflecting surfaces are considered. The study shows that both the peak of concentration and the optimal focal distance of the system strongly depend on the size of the facets, and on their optical errors. These results are useful to help concentrator developers to have a better understanding of the relationship between manufacturing design restrictions and final optical behavior. (author)

  5. Personal carbon monoxide exposures of preschool children in Helsinki, Finland - comparison to ambient air concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Alm, S.; Mukala, K.; Tittanen, P.; Jantunen, M.J. [KTL National Public Health Institute, Kuopio (Finland). Dept. of Environmental Health

    2001-07-01

    The associations of personal carbon monoxide (CO) exposures with ambient air CO concentrations measured at fixed monitoring sites, were studied among 194 children aged 3-6yr in four downtown and four suburban day-care centers in Helsinki, Finland. Each child carried a personal CO exposure monitor between 1 and 4 times for a time period of between 20 and 24h. CO concentrations at two fixed monitoring sites were measured simultaneously. The CO concentrations measured at the fixed monitoring sites were usually lower (mean maximum 8-h concentration: 0.9 and 2.6mgm{sup -3}) than the personal CO exposure concentrations (mean maximum 8-h concentration: 3.3mgm{sup -3}).The fixed site CO concentrations were poor predictors of the personal CO exposure concentrations. However, the correlations between the personal CO exposure and the fixed monitoring site CO concentrations increased (-0.03 -- -0.12 to 0.13-0.16) with increasing averaging times from 1 to 8h. Also, the fixed monitoring site CO concentrations explained the mean daily or weekly personal CO exposures of a group of simultaneously measured children better than individual exposure CO concentrations. This study suggests that the short-term CO personal exposure of children cannot be meaningfully assessed using fixed monitoring sites. (author)

  6. Effects Of Exposure To Sublethal Concentrations Of Azadirachta ...

    African Journals Online (AJOL)

    The physiological impairment on the fingerlings of Clarias gariepinus when exposed to sublethal concentrations of Azadirachta Indica was investigated. The fish were exposed to concentrations of 1.25, 2.50, 5.0, 10.0, 20.0 ML -1 for the period of 12 weeks. The crude protein content decreased with increased concentration ...

  7. Lead Concentrations and Risk Exposure Assessment in Surface ...

    African Journals Online (AJOL)

    ADOWIE PERE

    µm, < 250 µm, and < 75 µm of surface soils at undeveloped residential lands leased to ... mechanic yards may still be point sources of lead ..... therefore need to conduct a source apportionment ... heavy metals in soil profiles of automobile.

  8. Speciation and Determination of Low Concentration of Iron in Beer Samples by Cloud Point Extraction

    Science.gov (United States)

    Khalafi, Lida; Doolittle, Pamela; Wright, John

    2018-01-01

    A laboratory experiment is described in which students determine the concentration and speciation of iron in beer samples using cloud point extraction and absorbance spectroscopy. The basis of determination is the complexation between iron and 2-(5-bromo-2- pyridylazo)-5-diethylaminophenol (5-Br-PADAP) as a colorimetric reagent in an aqueous…

  9. Zero-point energy of N perfectly conducting concentric cylindrical shells

    International Nuclear Information System (INIS)

    Tatur, K.; Woods, L.M.

    2008-01-01

    The zero-point (Casimir) energy of N perfectly conducting, infinitely long, concentric cylindrical shells is calculated utilizing the mode summation technique. The obtained convergent expression is studied as a function of size, curvature and number of shells. Limiting cases, such as infinitely close shells or infinite radius shells are also investigated

  10. Distribution of exposure concentrations and doses for constituents of environmental tobacco smoke

    Energy Technology Data Exchange (ETDEWEB)

    LaKind, J.S. [LaKind Associates (United States); Ginevan, M.E. [M.E. Ginevan and Associates (United States); Naiman, D.Q. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Mathematical Sciences; James, A.C. [A.C. James and Associates (United States); Jenkins, R.A. [Oak Ridge National Lab., TN (United States); Dourson, M.L.; Felter, S.P. [TERA (United States); Graves, C.G.; Tardiff, R.G. [Sapphire Group, Inc., Bethesda, MD (United States)

    1999-06-01

    The ultimate goal of the research reported in this series of three articles is to derive distributions of doses of selected environmental tobacco smoke (ETS)-related chemicals for nonsmoking workers. This analysis uses data from the 16-City Study collected with personal monitors over the course of one workday in workplaces where smoking occurred. In this article, the authors describe distributions of ETS chemical concentrations and the characteristics of those distributions for the workplace exposure. Next, they present population parameters relevant for estimating dose distributions and the methods used for estimating those dose distributions. Finally, they derive distributions of doses of selected ETS-related constituents obtained in the workplace for people in smoking work environments. Estimating dose distributions provided information beyond the usual point estimate of dose and showed that the preponderance of individuals exposed to ETS in the workplace were exposed at the low end of the dose distribution curve. The results of this analysis include estimations of hourly maxima and time-weighted average (TWA) doses of nicotine from workplace exposures to ETS and doses derived from modeled lung burdens of ultraviolet-absorbing particulate matter (UVPM) and solanesol resulting from workplace exposures to ETS (extrapolated from 1 day to 1 year).

  11. Personal exposure to grass pollen: relating inhaled dose to background concentration

    DEFF Research Database (Denmark)

    Peel, Robert George; Hertel, Ole; Smith, Matt

    2013-01-01

    Background: Very few studies on human exposure to allergenic pollen have been conducted using direct methods, with background concentrations measured at city center monitoring stations typically taken as a proxy for exposure despite the inhomogeneous nature of atmospheric pollen concentrations. A...

  12. Different relationships between personal exposure and ambient concentration by particle size.

    Science.gov (United States)

    Guak, Sooyoung; Lee, Kiyoung

    2018-04-06

    Ambient particulate matter (PM) concentrations at monitoring stations were often used as an indicator of population exposure to PM in epidemiological studies. The correlation between personal exposure and ambient concentrations of PM varied because of diverse time-activity patterns. The aim of this study was to determine the relationship between personal exposure and ambient concentrations of PM 10 and PM 2.5 with minimal impact of time-activity pattern on personal exposure. Performance of the MicroPEM, v3.2 was evaluated by collocation with central ambient air monitors for PM 10 and PM 2.5 . A field technician repeatedly conducted measurement of 24 h personal exposures to PM 10 and PM 2.5 with a fixed time-activity pattern of office worker over 26 days in Seoul, Korea. The relationship between the MicroPEM and the ambient air monitor showed good linearity. Personal exposure and ambient concentrations of PM 2.5 were highly correlated with a fixed time-activity pattern compared with PM 10 . The finding implied a high infiltration rate of PM 2.5 and low infiltration rate of PM 10 . The relationship between personal exposure and ambient concentrations of PM 10 and PM 2.5 was different for high level episodes. In the Asian dust episode, staying indoors could reduce personal exposure to PM 10 . However, personal exposure to PM 2.5 could not be reduced by staying indoors during the fine dust advisory episode.

  13. A novel method of measuring the concentration of anaesthetic vapours using a dew-point hygrometer.

    Science.gov (United States)

    Wilkes, A R; Mapleson, W W; Mecklenburgh, J S

    1994-02-01

    The Antoine equation relates the saturated vapour pressure of a volatile substance, such as an anaesthetic agent, to the temperature. The measurement of the 'dew-point' of a dry gas mixture containing a volatile anaesthetic agent by a dew-point hygrometer permits the determination of the partial pressure of the anaesthetic agent. The accuracy of this technique is limited only by the accuracy of the Antoine coefficients and of the temperature measurement. Comparing measurements by the dew-point method with measurements by refractometry showed systematic discrepancies up to 0.2% and random discrepancies with SDS up to 0.07% concentration in the 1% to 5% range for three volatile anaesthetics. The systematic discrepancies may be due to errors in available data for the vapour pressures and/or the refractive indices of the anaesthetics.

  14. A numerical analysis on forming limits during spiral and concentric single point incremental forming

    Science.gov (United States)

    Gipiela, M. L.; Amauri, V.; Nikhare, C.; Marcondes, P. V. P.

    2017-01-01

    Sheet metal forming is one of the major manufacturing industries, which are building numerous parts for aerospace, automotive and medical industry. Due to the high demand in vehicle industry and environmental regulations on less fuel consumption on other hand, researchers are innovating new methods to build these parts with energy efficient sheet metal forming process instead of conventionally used punch and die to form the parts to achieve the lightweight parts. One of the most recognized manufacturing process in this category is Single Point Incremental Forming (SPIF). SPIF is the die-less sheet metal forming process in which the single point tool incrementally forces any single point of sheet metal at any process time to plastic deformation zone. In the present work, finite element method (FEM) is applied to analyze the forming limits of high strength low alloy steel formed by single point incremental forming (SPIF) by spiral and concentric tool path. SPIF numerical simulations were model with 24 and 29 mm cup depth, and the results were compare with Nakajima results obtained by experiments and FEM. It was found that the cup formed with Nakajima tool failed at 24 mm while cups formed by SPIF surpassed the limit for both depths with both profiles. It was also notice that the strain achieved in concentric profile are lower than that in spiral profile.

  15. The Los Angeles TEAM Study: personal exposures, indoor-outdoor air concentrations, and breath concentrations of 25 volatile organic compounds.

    Science.gov (United States)

    Wallace, L; Nelson, W; Ziegenfus, R; Pellizzari, E; Michael, L; Whitmore, R; Zelon, H; Hartwell, T; Perritt, R; Westerdahl, D

    1991-04-01

    The U.S. Environmental Protection Agency and the California Air Resources Board studied the exposures of 51 residents of Los Angeles, California, to 25 volatile organic chemicals (VOCs) in air and drinking water in 1987. A major goal of the study was to measure personal, indoor, and outdoor air concentrations, and breath concentrations of VOCs in persons living in households that had previously been measured in 1984. Other goals were to confirm the marked day-night and seasonal differences observed in 1984; to determine room-to-room variability within homes; to determine source emission rates by measuring air exchange rates in each home; and to extend the coverage of chemicals by employing additional sampling and analysis methods. A total of 51 homes were visited in February of 1987, and 43 of these were revisited in July of 1987. The results confirmed previous TEAM Study findings of higher personal and indoor air concentrations than outdoor concentrations of all prevalent chemicals (except carbon tetrachloride); higher personal, indoor, and outdoor air concentrations in winter than in summer; and (in winter only) higher outdoor concentrations at night than in the daytime. New findings included the following: (1) room-to-room variability of 12-hour average concentrations was very small, indicating that a single monitor may be adequate for estimating indoor concentrations over this time span; (2) "whole-house" source emission rates were relatively constant during both seasons, with higher rates for odorous chemicals such as p-dichlorobenzene and limonene (often used in room air fresheners) than for other classes of chemicals; (3) breath concentrations measured during morning and evening were similar for most participants, suggesting the suitability of breath measurements for estimating exposure in the home; (4) limited data obtained on two additional chemicals-toluene and methylene chloride-indicated that both were prevalent at fairly high concentrations and that

  16. Cross-site comparisons of concentration-discharge relationships reveal climate-driven chemostatic set points

    Science.gov (United States)

    Godsey, S.; Kirchner, J. W.

    2017-12-01

    Streamflow solute concentrations often vary predictably with flows, providing insight into processes controlling solute generation and export. Previous work by the authors showed that log-transformed concentration-discharge relationships of weathering-derived solutes in 59 headwater catchments had relatively low slopes, implying that these watersheds behaved almost like chemostats. That is, their rates of solute production and/or mobilization were nearly proportional to water fluxes, on both event and inter-annual time scales. Here we re-examine these findings using data from roughly 1000 catchments, ranging from ˜10 to >1,000,000 sq. km in drainage area, and spanning a wide range of lithologic and climatic settings.Concentration-discharge relationships among this much larger set of much larger catchments are broadly consistent with the chemostatic behavior described above. However, site-to-site variations in mean concentrations among these catchments are negatively correlated with long-term average precipitation and discharge, suggesting dilution of stream concentrations under long-term leaching of the critical zone. Thus, on event and inter-annual time scales, stream solute concentrations are chemostatically buffered by groundwater storage and fast chemical reactions (such as ion exchange), but on much longer time scales, the catchment's chemostatic "set point" is determined by climatically driven critical zone evolution. We present examples illustrating short-term and long-term controls on water quality consistent with variations in weather and climate, and discuss their implications.

  17. PREMOR: a point reactor exposure model computer code for survey analysis of power plant performance

    International Nuclear Information System (INIS)

    Vondy, D.R.

    1979-10-01

    The PREMOR computer code was written to exploit a simple, two-group point nuclear reactor power plant model for survey analysis. Up to thirteen actinides, fourteen fission products, and one lumped absorber nuclide density are followed over a reactor history. Successive feed batches are accounted for with provision for from one to twenty batches resident. The effect of exposure of each of the batches to the same neutron flux is determined

  18. PREMOR: a point reactor exposure model computer code for survey analysis of power plant performance

    Energy Technology Data Exchange (ETDEWEB)

    Vondy, D.R.

    1979-10-01

    The PREMOR computer code was written to exploit a simple, two-group point nuclear reactor power plant model for survey analysis. Up to thirteen actinides, fourteen fission products, and one lumped absorber nuclide density are followed over a reactor history. Successive feed batches are accounted for with provision for from one to twenty batches resident. The effect of exposure of each of the batches to the same neutron flux is determined.

  19. Relation of whole blood carboxyhemoglobin concentration to ambient carbon monoxide exposure estimated using regression.

    Science.gov (United States)

    Rudra, Carole B; Williams, Michelle A; Sheppard, Lianne; Koenig, Jane Q; Schiff, Melissa A; Frederick, Ihunnaya O; Dills, Russell

    2010-04-15

    Exposure to carbon monoxide (CO) and other ambient air pollutants is associated with adverse pregnancy outcomes. While there are several methods of estimating CO exposure, few have been evaluated against exposure biomarkers. The authors examined the relation between estimated CO exposure and blood carboxyhemoglobin concentration in 708 pregnant western Washington State women (1996-2004). Carboxyhemoglobin was measured in whole blood drawn around 13 weeks' gestation. CO exposure during the month of blood draw was estimated using a regression model containing predictor terms for year, month, street and population densities, and distance to the nearest major road. Year and month were the strongest predictors. Carboxyhemoglobin level was correlated with estimated CO exposure (rho = 0.22, 95% confidence interval (CI): 0.15, 0.29). After adjustment for covariates, each 10% increase in estimated exposure was associated with a 1.12% increase in median carboxyhemoglobin level (95% CI: 0.54, 1.69). This association remained after exclusion of 286 women who reported smoking or being exposed to secondhand smoke (rho = 0.24). In this subgroup, the median carboxyhemoglobin concentration increased 1.29% (95% CI: 0.67, 1.91) for each 10% increase in CO exposure. Monthly estimated CO exposure was moderately correlated with an exposure biomarker. These results support the validity of this regression model for estimating ambient CO exposures in this population and geographic setting.

  20. Chemical concentrations, exposures, health risks by census tract from National Scale Air Toxics Assessment (NATA)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Chemical concentrations, exposures, health risks by census tract for the United States from National Scale Air Toxics Assessment (NATA). This dataset is associated...

  1. EXPOSURE TO ENVIRONMENTALLY RELEVANT CONCENTRATIONS OF DIFFERENT NONYLPHENOL FORMULATIONS IN JAPANESE MEDAKA

    Science.gov (United States)

    The time course of exposure to p-nonylphenol (NP) from two different sources was compared to equivalent exposures of 17-b-estradiol (E2) and a solvent control (ethanol: EtOH). Japanese medaka were exposed for 4 days to a nominal concentration of 20 ?g/l of either NP-I (Schenectad...

  2. Estimated exposures to perfluorinated compounds in infancy predict attenuated vaccine antibody concentrations at age 5-years

    DEFF Research Database (Denmark)

    Grandjean, Philippe; Heilmann, Carsten; Weihe, Pal

    2017-01-01

    Perfluorinated alkylate substances (PFASs) are highly persistent and may cause immunotoxic effects. PFAS-associated attenuated antibody responses to childhood vaccines may be affected by PFAS exposures during infancy, where breastfeeding adds to PFAS exposures. Of 490 members of a Faroese birth...... cohort, 275 and 349 participated in clinical examinations and provided blood samples at ages 18 months and 5 years. PFAS concentrations were measured at birth and at the clinical examinations. Using information on duration of breastfeeding, serum-PFAS concentration profiles during infancy were estimated......, with decreases by up to about 20% for each two-fold higher exposure, while associations for serum concentrations at ages 18 months and 5 years were weaker. Modeling of serum-PFAS concentration showed levels for age 18 months that were similar to those measured. Concentrations estimated for ages 3 and 6 months...

  3. 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.

  4. Concentrations and assessment of exposure to siloxanes and synthetic musks in personal care products from China

    International Nuclear Information System (INIS)

    Lu Yan; Yuan Tao; Wang Wenhua; Kannan, Kurunthachalam

    2011-01-01

    We investigated the concentrations and profiles of 15 siloxanes (four cyclic siloxanes, D 4 -D 7 ; 11 linear siloxanes, L 4 -L 14 ), four synthetic musks (two polycyclic musks, HHCB and AHTN; two nitro musks, MX and MK), and HHCB-lactone, in 158 personal care products marketed in China. Siloxanes were detected in 88% of the samples analyzed, at concentrations as high as 52.6 mg g -1 ; Linear siloxanes were the predominant compounds. Among synthetic musks, more than 80% of the samples contained at least one of these compounds, and their total concentrations were as high as 1.02 mg g -1 . HHCB was the predominant musk in all of the samples analyzed, on average, accounting for 52% of the total musk concentrations. Based on the median concentrations of siloxanes and musks and the average daily usage amounts of consumer products, dermal exposure rates in adults were calculated to be 3.69 and 3.38 mg d -1 for siloxanes and musks, respectively. - Highlights: → Siloxanes and synthetic musks are determined in personal care products. → Highest siloxane concentration was 52.6 mg g -1 . → Highest musk concentration was 1.02 mg g -1 . → Daily dermal exposure rates of siloxanes and musks were in mg levels. → Dermal exposure is a major pathway of human exposure to siloxanes and musks. - Dermal application of several personal care products is a major source of human exposure to cyclic and linear siloxanes.

  5. Isopleths of surface concentration and surface exposure rate due to a radioactive cloud released from a stack

    International Nuclear Information System (INIS)

    Kobayashi, Hideo; Yabuta, Hajimu; Katagiri, Hiroshi; Obata, Kazuichi; Kokubu, Morinobu

    1982-03-01

    Various calculations are made to estimate the distributions of concentration and γ-exposure rate due to a radioactive cloud released from a point source to the atmosphere. In this report, the isopleths of concentration and γ-exposure rate which were calculated are given in graphs to enable rapid prediction of the influence of released radioactive material in the emergency situation. Recently there are facilities which are equipped with a system to display the calculation results on CRT; but such practice is rather rare. By placing the calculated isopleths of reduction scale 1/25000 or 1/50000 on the usual map, any facilities without the CRT system can readily estimate the influence of an accidental release. The graphs of isopleths are given with the release height (11 values of 0 to 200 m at about 20 m intervals) and the atmospheric stability (6 classes) as parameters. Calculations of γ-exposure rates were made using the computer code GAMPUL developed by T. Hayashi and T. Shiraishi. In the calculation of radioactive concentrations and γ-exposure rates, the vertical diffusion depths, σsub(z), exceeding 1000 m are taken to be 1000 m according to the Meteorological Guide for the Safety Analysis of Power Reactor (J.AEC). The comparison between with and without this limitation in σsub(z) is made in the case of downwind axial surface distributions. (author)

  6. Is there a threshold concentration of cat allergen exposure on respiratory symptoms in adults?

    NARCIS (Netherlands)

    Chen, C.M.; Thiering, E.; Zock, J.P.; Villani, S.; Olivieri, M.; Modig, L.; Jarvis, D.; Norbäck, D.; Verlato, G.; Heinrich, J.

    2015-01-01

    Background and Objective: Cat allergen concentrations higher than 8 μg/g in settled house dust, have been suggested to provoke exacerbation of allergic respiratory symptoms. However, whether the 8μg/g of indoor cat allergen concentration is indeed the minimal exposure required for triggering the

  7. Estimated exposures to perfluorinated compounds in infancy predict attenuated vaccine antibody concentrations at age 5-years.

    Science.gov (United States)

    Grandjean, Philippe; Heilmann, Carsten; Weihe, Pal; Nielsen, Flemming; Mogensen, Ulla B; Timmermann, Amalie; Budtz-Jørgensen, Esben

    2017-12-01

    Perfluorinated alkylate substances (PFASs) are highly persistent and may cause immunotoxic effects. PFAS-associated attenuated antibody responses to childhood vaccines may be affected by PFAS exposures during infancy, where breastfeeding adds to PFAS exposures. Of 490 members of a Faroese birth cohort, 275 and 349 participated in clinical examinations and provided blood samples at ages 18 months and 5 years. PFAS concentrations were measured at birth and at the clinical examinations. Using information on duration of breastfeeding, serum-PFAS concentration profiles during infancy were estimated. As outcomes, serum concentrations of antibodies against tetanus and diphtheria vaccines were determined at age 5. Data from a previous cohort born eight years earlier were available for pooled analyses. Pre-natal exposure showed inverse associations with the antibody concentrations five years later, with decreases by up to about 20% for each two-fold higher exposure, while associations for serum concentrations at ages 18 months and 5 years were weaker. Modeling of serum-PFAS concentration showed levels for age 18 months that were similar to those measured. Concentrations estimated for ages 3 and 6 months showed the strongest inverse associations with antibody concentrations at age 5 years, particularly for tetanus. Joint analyses showed statistically significant decreases in tetanus antibody concentrations by 19-29% at age 5 for each doubling of the PFAS exposure in early infancy. These findings support the notion that the developing adaptive immune system is particularly vulnerable to immunotoxicity during infancy. This vulnerability appears to be the greatest during the first 6 months after birth, where PFAS exposures are affected by breast-feeding.

  8. Social Disparities in Exposure to Point-of-Sale Cigarette Marketing

    Directory of Open Access Journals (Sweden)

    Mohammad Siahpush

    2016-12-01

    Full Text Available While most ecological studies have shown that higher levels of point-of-sale (POS cigarette marketing are associated with larger proportions of residents from lower socioeconomic and minority backgrounds in neighborhoods, there are no studies that examine individual-level social disparities in exposure to POS cigarette marketing among smokers in the United States. Our aim was to examine these disparities in a Midwestern metropolitan area in the United States. We conducted a telephone survey to collect data on 999 smokers. Cigarette marketing was measured by asking respondents three questions about noticing advertisements, promotions, and displays of cigarettes within their respective neighborhoods. The questions were combined to create a summated scale. We estimated ordered logistic regression models to examine the association of sociodemographic variables with exposure to POS cigarette marketing. Adjusted results showed that having a lower income (p < 0.003 and belonging to a race/ethnicity other than “non-Hispanic White” (p = 0.011 were associated with higher levels of exposure to POS cigarette marketing. The results highlight social disparities in exposure to POS cigarette marketing in the United States, which can potentially be eliminated by banning all forms of cigarette marketing.

  9. Effects of glyphosate exposure on sperm concentration in rodents: A systematic review and meta-analysis.

    Science.gov (United States)

    Cai, Wenyan; Ji, Ying; Song, Xianping; Guo, Haoran; Han, Lei; Zhang, Feng; Liu, Xin; Zhang, Hengdong; Zhu, Baoli; Xu, Ming

    2017-10-01

    Correlation between exposure to glyphosate and sperm concentrations is important in reproductive toxicity risk assessment for male reproductive functions. Many studies have focused on reproductive toxicity on glyphosate, however, results are still controversial. We conducted a systematic review of epidemiological studies on the association between glyphosate exposure and sperm concentrations of rodents. The aim of this study is to explore the potential adverse effects of glyphosate on reproductive function of male rodents. Systematic and comprehensive literature search was performed in MEDLINE, TOXLINE, Embase, WANFANG and CNKI databases with different combinations of glyphosate exposure and sperm concentration. 8 studies were eventually identified and random-effect model was conducted. Heterogeneity among study results was calculated via chi-square tests. Ten independent experimental datasets from these eight studies were acquired to synthesize the random-effect model. A decrease in sperm concentrations was found with mean difference of sperm concentrations(MDsperm)=-2.774×10 6 /sperm/g/testis(95%CI=-0.969 to -4.579) in random-effect model after glyphosate exposure. There was also a significant decrease after fitting the random-effect model: MDsperm=-1.632×10 6 /sperm/g/testis (95%CI=-0.662 to -2.601). The results of meta-analysis support the hypothesis that glyphosate exposure decreased sperm concentration in rodents. Therefore, we conclude that glyphosate is toxic to male rodent's reproductive system. Copyright © 2017. Published by Elsevier B.V.

  10. Sequential Measurement of Intermodal Variability in Public Transportation PM2.5 and CO Exposure Concentrations.

    Science.gov (United States)

    Che, W W; Frey, H Christopher; Lau, Alexis K H

    2016-08-16

    A sequential measurement method is demonstrated for quantifying the variability in exposure concentration during public transportation. This method was applied in Hong Kong by measuring PM2.5 and CO concentrations along a route connecting 13 transportation-related microenvironments within 3-4 h. The study design takes into account ventilation, proximity to local sources, area-wide air quality, and meteorological conditions. Portable instruments were compacted into a backpack to facilitate measurement under crowded transportation conditions and to quantify personal exposure by sampling at nose level. The route included stops next to three roadside monitors to enable comparison of fixed site and exposure concentrations. PM2.5 exposure concentrations were correlated with the roadside monitors, despite differences in averaging time, detection method, and sampling location. Although highly correlated in temporal trend, PM2.5 concentrations varied significantly among microenvironments, with mean concentration ratios versus roadside monitor ranging from 0.5 for MTR train to 1.3 for bus terminal. Measured inter-run variability provides insight regarding the sample size needed to discriminate between microenvironments with increased statistical significance. The study results illustrate the utility of sequential measurement of microenvironments and policy-relevant insights for exposure mitigation and management.

  11. The effects of oil sands wastewater on fish resulting from exposure to sub-lethal concentrations

    International Nuclear Information System (INIS)

    Birkholz, D.A.; Goudey, J.S.; Balch, G.C.; Nelson, L.R.; MacKinnon, M.

    1995-01-01

    Rainbow trout, Oncorhynchus mykiss, were exposed to sub-lethal concentrations of oil sands wastewater in flow through laboratory experiments as well as to artificial ponds containing sub-lethal concentrations of tailings pond water and fine tails in order to study the viability of the wet landscape remediation option. Large (200--300 g) fish were used for all the exposures in this preliminary study and the following data were collected: blood cell counts, sex hormone concentrations, sexual maturation, stress protein concentrations, PAH-metabolites in bile, condition factors, liver somatic indices, mixed function oxygenase induction, PAHs in muscle, external condition and the condition of internal organs. The data obtained from this study revealed no adverse effects upon fish during extended field exposures. Given similar exposure conditions in the release waters of a wet landscape reclamation, the data suggest that there may be no adverse effects upon fish, however, longer term studies, other indicator organisms and additional chronic tests should be conducted

  12. Spatial variation of particle number concentration in school microscale environments and its impact on exposure assessment.

    Science.gov (United States)

    Salimi, Farhad; Mazaheri, Mandana; Clifford, Sam; Crilley, Leigh R; Laiman, Rusdin; Morawska, Lidia

    2013-05-21

    It has not yet been established whether the spatial variation of particle number concentration (PNC) within a microscale environment can have an effect on exposure estimation results. In general, the degree of spatial variation within microscale environments remains unclear, since previous studies have only focused on spatial variation within macroscale environments. The aims of this study were to determine the spatial variation of PNC within microscale school environments, in order to assess the importance of the number of monitoring sites on exposure estimation. Furthermore, this paper aims to identify which parameters have the largest influence on spatial variation as well as the relationship between those parameters and spatial variation. Air quality measurements were conducted for two consecutive weeks at each of the 25 schools across Brisbane, Australia. PNC was measured at three sites within the grounds of each school, along with the measurement of meteorological and several other air quality parameters. Traffic density was recorded for the busiest road adjacent to the school. Spatial variation at each school was quantified using coefficient of variation (CV). The portion of CV associated with instrument uncertainty was found to be 0.3, and, therefore, CV was corrected so that only noninstrument uncertainty was analyzed in the data. The median corrected CV (CVc) ranged from 0 to 0.35 across the schools, with 12 schools found to exhibit spatial variation. The study determined the number of required monitoring sites at schools with spatial variability and tested the deviation in exposure estimation arising from using only a single site. Nine schools required two measurement sites and three schools required three sites. Overall, the deviation in exposure estimation from using only one monitoring site was as much as 1 order of magnitude. The study also tested the association of spatial variation with wind speed/direction and traffic density, using partial

  13. Comparison of point-of-care methods for preparation of platelet concentrate (platelet-rich plasma).

    Science.gov (United States)

    Weibrich, Gernot; Kleis, Wilfried K G; Streckbein, Philipp; Moergel, Maximilian; Hitzler, Walter E; Hafner, Gerd

    2012-01-01

    This study analyzed the concentrations of platelets and growth factors in platelet-rich plasma (PRP), which are likely to depend on the method used for its production. The cellular composition and growth factor content of platelet concentrates (platelet-rich plasma) produced by six different procedures were quantitatively analyzed and compared. Platelet and leukocyte counts were determined on an automatic cell counter, and analysis of growth factors was performed using enzyme-linked immunosorbent assay. The principal differences between the analyzed PRP production methods (blood bank method of intermittent flow centrifuge system/platelet apheresis and by the five point-of-care methods) and the resulting platelet concentrates were evaluated with regard to resulting platelet, leukocyte, and growth factor levels. The platelet counts in both whole blood and PRP were generally higher in women than in men; no differences were observed with regard to age. Statistical analysis of platelet-derived growth factor AB (PDGF-AB) and transforming growth factor β1 (TGF-β1) showed no differences with regard to age or gender. Platelet counts and TGF-β1 concentration correlated closely, as did platelet counts and PDGF-AB levels. There were only rare correlations between leukocyte counts and PDGF-AB levels, but comparison of leukocyte counts and PDGF-AB levels demonstrated certain parallel tendencies. TGF-β1 levels derive in substantial part from platelets and emphasize the role of leukocytes, in addition to that of platelets, as a source of growth factors in PRP. All methods of producing PRP showed high variability in platelet counts and growth factor levels. The highest growth factor levels were found in the PRP prepared using the Platelet Concentrate Collection System manufactured by Biomet 3i.

  14. Motoneuron axon pathfinding errors in zebrafish: Differential effects related to concentration and timing of nicotine exposure

    International Nuclear Information System (INIS)

    Menelaou, Evdokia; Paul, Latoya T.; Perera, Surangi N.; Svoboda, Kurt R.

    2015-01-01

    Nicotine exposure during embryonic stages of development can affect many neurodevelopmental processes. In the developing zebrafish, exposure to nicotine was reported to cause axonal pathfinding errors in the later born secondary motoneurons (SMNs). These alterations in SMN axon morphology coincided with muscle degeneration at high nicotine concentrations (15–30 μM). Previous work showed that the paralytic mutant zebrafish known as sofa potato exhibited nicotine-induced effects onto SMN axons at these high concentrations but in the absence of any muscle deficits, indicating that pathfinding errors could occur independent of muscle effects. In this study, we used varying concentrations of nicotine at different developmental windows of exposure to specifically isolate its effects onto subpopulations of motoneuron axons. We found that nicotine exposure can affect SMN axon morphology in a dose-dependent manner. At low concentrations of nicotine, SMN axons exhibited pathfinding errors, in the absence of any nicotine-induced muscle abnormalities. Moreover, the nicotine exposure paradigms used affected the 3 subpopulations of SMN axons differently, but the dorsal projecting SMN axons were primarily affected. We then identified morphologically distinct pathfinding errors that best described the nicotine-induced effects on dorsal projecting SMN axons. To test whether SMN pathfinding was potentially influenced by alterations in the early born primary motoneuron (PMN), we performed dual labeling studies, where both PMN and SMN axons were simultaneously labeled with antibodies. We show that only a subset of the SMN axon pathfinding errors coincided with abnormal PMN axonal targeting in nicotine-exposed zebrafish. We conclude that nicotine exposure can exert differential effects depending on the levels of nicotine and developmental exposure window. - Highlights: • Embryonic nicotine exposure can specifically affect secondary motoneuron axons in a dose-dependent manner.

  15. Motoneuron axon pathfinding errors in zebrafish: Differential effects related to concentration and timing of nicotine exposure

    Energy Technology Data Exchange (ETDEWEB)

    Menelaou, Evdokia; Paul, Latoya T. [Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803 (United States); Perera, Surangi N. [Joseph J. Zilber School of Public Health, University of Wisconsin — Milwaukee, Milwaukee, WI 53205 (United States); Svoboda, Kurt R., E-mail: svobodak@uwm.edu [Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803 (United States); Joseph J. Zilber School of Public Health, University of Wisconsin — Milwaukee, Milwaukee, WI 53205 (United States)

    2015-04-01

    Nicotine exposure during embryonic stages of development can affect many neurodevelopmental processes. In the developing zebrafish, exposure to nicotine was reported to cause axonal pathfinding errors in the later born secondary motoneurons (SMNs). These alterations in SMN axon morphology coincided with muscle degeneration at high nicotine concentrations (15–30 μM). Previous work showed that the paralytic mutant zebrafish known as sofa potato exhibited nicotine-induced effects onto SMN axons at these high concentrations but in the absence of any muscle deficits, indicating that pathfinding errors could occur independent of muscle effects. In this study, we used varying concentrations of nicotine at different developmental windows of exposure to specifically isolate its effects onto subpopulations of motoneuron axons. We found that nicotine exposure can affect SMN axon morphology in a dose-dependent manner. At low concentrations of nicotine, SMN axons exhibited pathfinding errors, in the absence of any nicotine-induced muscle abnormalities. Moreover, the nicotine exposure paradigms used affected the 3 subpopulations of SMN axons differently, but the dorsal projecting SMN axons were primarily affected. We then identified morphologically distinct pathfinding errors that best described the nicotine-induced effects on dorsal projecting SMN axons. To test whether SMN pathfinding was potentially influenced by alterations in the early born primary motoneuron (PMN), we performed dual labeling studies, where both PMN and SMN axons were simultaneously labeled with antibodies. We show that only a subset of the SMN axon pathfinding errors coincided with abnormal PMN axonal targeting in nicotine-exposed zebrafish. We conclude that nicotine exposure can exert differential effects depending on the levels of nicotine and developmental exposure window. - Highlights: • Embryonic nicotine exposure can specifically affect secondary motoneuron axons in a dose-dependent manner.

  16. Sleep disturbances in treatment-seeking OCD-patients: Changes after concentrated exposure treatment.

    Science.gov (United States)

    Nordahl, Håkon; Havnen, Audun; Hansen, Bjarne; Öst, Lars-Göran; Kvale, Gerd

    2018-04-01

    Research indicates that patients with Obsessive Compulsive Disorder (OCD) frequently suffer from comorbid sleep difficulties, and that these difficulties often are not clinically recognized and diagnosed. There has been limited research investigating if comorbid sleep difficulties impair treatment outcome for OCD and if the sleep difficulties change following OCD-treatment. Thirty-six patients with obsessive compulsive disorder underwent concentrated exposure treatment delivered in a group over four consecutive days and were assessed with measures of OCD, depressive symptoms and sleep disturbance at three different time points (pre, post and 6 months follow-up). The sample was characterized by a high degree of comorbidity with other psychiatric disorders. At pre-treatment nearly 70% of the patients reported sleep difficulties indicative of primary insomnia. The results showed that patients had large reductions of OCD-symptoms as well as significant improvements in sleep disturbance assessed after treatment, and that these improvements were maintained at follow-up. Sleep disturbance did not impair treatment outcome, on the contrary patients with higher degree of sleep disturbance at pre-treatment had better outcome on OCD-symptoms after treatment. The results indicated that the majority of the OCD sample suffered from sleep disturbances and that these sleep disturbances were significantly reduced following adequate treatment of OCD without specific sleep interventions. However, a proportion of the patients suffered from residual symptoms of insomnia after treatment. © 2017 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

  17. Social Disparities in Exposure to Point-of-Sale Cigarette Marketing.

    Science.gov (United States)

    Siahpush, Mohammad; Farazi, Paraskevi A; Kim, Jungyoon; Michaud, Tzeyu L; Yoder, Aaron M; Soliman, Ghada; Tibbits, Melissa K; Nguyen, Minh N; Shaikh, Raees A

    2016-12-21

    While most ecological studies have shown that higher levels of point-of-sale (POS) cigarette marketing are associated with larger proportions of residents from lower socioeconomic and minority backgrounds in neighborhoods, there are no studies that examine individual-level social disparities in exposure to POS cigarette marketing among smokers in the United States. Our aim was to examine these disparities in a Midwestern metropolitan area in the United States. We conducted a telephone survey to collect data on 999 smokers. Cigarette marketing was measured by asking respondents three questions about noticing advertisements, promotions, and displays of cigarettes within their respective neighborhoods. The questions were combined to create a summated scale. We estimated ordered logistic regression models to examine the association of sociodemographic variables with exposure to POS cigarette marketing. Adjusted results showed that having a lower income ( p marketing. The results highlight social disparities in exposure to POS cigarette marketing in the United States, which can potentially be eliminated by banning all forms of cigarette marketing.

  18. Concentrations and assessment of exposure to siloxanes and synthetic musks in personal care products from China

    Energy Technology Data Exchange (ETDEWEB)

    Lu Yan [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Wadsworth Center, New York State Department of Health and Department of Environmental Health Sciences, School of Public Health, State University of New York at Albany, Empire State Plaza, PO Box 509, Albany, NY 12201-0509 (United States); Yuan Tao; Wang Wenhua [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Kannan, Kurunthachalam, E-mail: kkannan@wadsworth.org [Wadsworth Center, New York State Department of Health and Department of Environmental Health Sciences, School of Public Health, State University of New York at Albany, Empire State Plaza, PO Box 509, Albany, NY 12201-0509 (United States); International Joint Research Center for Persistent Toxic Substances, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China)

    2011-12-15

    We investigated the concentrations and profiles of 15 siloxanes (four cyclic siloxanes, D{sub 4}-D{sub 7}; 11 linear siloxanes, L{sub 4}-L{sub 14}), four synthetic musks (two polycyclic musks, HHCB and AHTN; two nitro musks, MX and MK), and HHCB-lactone, in 158 personal care products marketed in China. Siloxanes were detected in 88% of the samples analyzed, at concentrations as high as 52.6 mg g{sup -1}; Linear siloxanes were the predominant compounds. Among synthetic musks, more than 80% of the samples contained at least one of these compounds, and their total concentrations were as high as 1.02 mg g{sup -1}. HHCB was the predominant musk in all of the samples analyzed, on average, accounting for 52% of the total musk concentrations. Based on the median concentrations of siloxanes and musks and the average daily usage amounts of consumer products, dermal exposure rates in adults were calculated to be 3.69 and 3.38 mg d{sup -1} for siloxanes and musks, respectively. - Highlights: > Siloxanes and synthetic musks are determined in personal care products. > Highest siloxane concentration was 52.6 mg g{sup -1}. > Highest musk concentration was 1.02 mg g{sup -1}. > Daily dermal exposure rates of siloxanes and musks were in mg levels. > Dermal exposure is a major pathway of human exposure to siloxanes and musks. - Dermal application of several personal care products is a major source of human exposure to cyclic and linear siloxanes.

  19. Predicting arsenic concentrations in groundwater of San Luis Valley, Colorado: implications for individual-level lifetime exposure assessment.

    Science.gov (United States)

    James, Katherine A; Meliker, Jaymie R; Buttenfield, Barbara E; Byers, Tim; Zerbe, Gary O; Hokanson, John E; Marshall, Julie A

    2014-08-01

    Consumption of inorganic arsenic in drinking water at high levels has been associated with chronic diseases. Risk is less clear at lower levels of arsenic, in part due to difficulties in estimating exposure. Herein we characterize spatial and temporal variability of arsenic concentrations and develop models for predicting aquifer arsenic concentrations in the San Luis Valley, Colorado, an area of moderately elevated arsenic in groundwater. This study included historical water samples with total arsenic concentrations from 595 unique well locations. A longitudinal analysis established temporal stability in arsenic levels in individual wells. The mean arsenic levels for a random sample of 535 wells were incorporated into five kriging models to predict groundwater arsenic concentrations at any point in time. A separate validation dataset (n = 60 wells) was used to identify the model with strongest predictability. Findings indicate that arsenic concentrations are temporally stable (r = 0.88; 95 % CI 0.83-0.92 for samples collected from the same well 15-25 years apart) and the spatial model created using ordinary kriging best predicted arsenic concentrations (ρ = 0.72 between predicted and observed validation data). These findings illustrate the value of geostatistical modeling of arsenic and suggest the San Luis Valley is a good region for conducting epidemiologic studies of groundwater metals because of the ability to accurately predict variation in groundwater arsenic concentrations.

  20. The effects of temperature and pressure on airborne exposure concentrations when performing compliance evaluations using ACGIH TLVs and OSHA PELs.

    Science.gov (United States)

    Stephenson, D J; Lillquist, D R

    2001-04-01

    Occupational hygienists perform air sampling to characterize airborne contaminant emissions, assess occupational exposures, and establish allowable workplace airborne exposure concentrations. To perform these air sampling applications, occupational hygienists often compare an airborne exposure concentration to a corresponding American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) or an Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL). To perform such comparisons, one must understand the physiological assumptions used to establish these occupational exposure limits, the relationship between a workplace airborne exposure concentration and its associated TLV or PEL, and the effect of temperature and pressure on the performance of an accurate compliance evaluation. This article illustrates the correct procedure for performing compliance evaluations using airborne exposure concentrations expressed in both parts per million and milligrams per cubic meter. In so doing, a brief discussion is given on the physiological assumptions used to establish TLVs and PELs. It is further shown how an accurate compliance evaluation is fundamentally based on comparison of a measured work site exposure dose (derived from the sampling site exposure concentration estimate) to an estimated acceptable exposure dose (derived from the occupational exposure limit concentration). In addition, this article correctly illustrates the effect that atmospheric temperature and pressure have on airborne exposure concentrations and the eventual performance of a compliance evaluation. This article also reveals that under fairly moderate conditions of temperature and pressure, 30 degrees C and 670 torr, a misunderstanding of how varying atmospheric conditions affect concentration values can lead to a 15 percent error in assessing compliance.

  1. National-scale exposure prediction for long-term concentrations of particulate matter and nitrogen dioxide in South Korea.

    Science.gov (United States)

    Kim, Sun-Young; Song, Insang

    2017-07-01

    The limited spatial coverage of the air pollution data available from regulatory air quality monitoring networks hampers national-scale epidemiological studies of air pollution. The present study aimed to develop a national-scale exposure prediction model for estimating annual average concentrations of PM 10 and NO 2 at residences in South Korea using regulatory monitoring data for 2010. Using hourly measurements of PM 10 and NO 2 at 277 regulatory monitoring sites, we calculated the annual average concentrations at each site. We also computed 322 geographic variables in order to represent plausible local and regional pollution sources. Using these data, we developed universal kriging models, including three summary predictors estimated by partial least squares (PLS). The model performance was evaluated with fivefold cross-validation. In sensitivity analyses, we compared our approach with two alternative approaches, which added regional interactions and replaced the PLS predictors with up to ten selected variables. Finally, we predicted the annual average concentrations of PM 10 and NO 2 at 83,463 centroids of residential census output areas in South Korea to investigate the population exposure to these pollutants and to compare the exposure levels between monitored and unmonitored areas. The means of the annual average concentrations of PM 10 and NO 2 for 2010, across regulatory monitoring sites in South Korea, were 51.63 μg/m3 (SD = 8.58) and 25.64 ppb (11.05), respectively. The universal kriging exposure prediction models yielded cross-validated R 2 s of 0.45 and 0.82 for PM 10 and NO 2 , respectively. Compared to our model, the two alternative approaches gave consistent or worse performances. Population exposure levels in unmonitored areas were lower than in monitored areas. This is the first study that focused on developing a national-scale point wise exposure prediction approach in South Korea, which will allow national exposure assessments and

  2. Blood lead exposure concentrations in mottled ducks (Anas fulvigula) on the upper Texas coast

    Science.gov (United States)

    McDowell, Stephen K.; Conway, Warren C.; Haukos, David A.; Moon, Jena A.; Comer, Christopher E.; Hung, I-Kuai

    2015-01-01

    The mottled duck (Anas fulvigula) is a non-migratory waterfowl species dependent upon coastal marsh systems, including those on the Texas Chenier Plain National Wildlife Refuge (NWR) Complex, and considered a regional indicator species of marsh habitat quality. Research from the early 1970s, 1990s, and early-2000s indicated that mottled ducks continued to exhibit elevated wing-bone lead (Pb) concentrations, decades after implementation of non-toxic shot regulations. However, wing-bone concentrations reflect lifetime accumulation of Pb, whereas blood Pb concentrations reflect more recent exposure. To identify current potentially relevant temporal windows of Pb exposure, we collected 260 blood samples from mottled ducks during summer (n=124) and winter (n=136) from 2010–2012 on the Texas Chenier Plain NWR Complex. We quantified baseline blood Pb concentrations for all ages of mottled ducks, and hypothesized that blood lead concentrations would remain elevated above background levels (200 µg L–1) despite the 1983 and 1991 lead shot bans. Blood Pb concentrations ranged from below detection limits to >12,000 µg L–1, where >200 µg L–1 was associated with exposure levels above background concentrations. Male mottled ducks had the greatest blood Pb concentrations (30 times greater than females) with concentrations greater during winter than summer. Likewise, the proportion of exposed (>200 µg L–1) females increased from 14%–47% from summer to winter, respectively. Regardless of sex, adult mottled duck blood Pb concentrations were five times greater than juveniles, particularly during winter. We identified five plausible models that influenced blood Pb levels where year, site, and interactions among age*sex*season and between age*season were included in the top-ranked models. Frequency of exposure was greatest during winter, increasing from 12% in summer to 55% in winter, indicating that a temporal exposure window to environmental Pb exists between nesting

  3. Parental Concern about Environmental Chemical Exposures and Children's Urinary Concentrations of Phthalates and Phenols.

    Science.gov (United States)

    Pell, Tripler; Eliot, Melissa; Chen, Aimin; Lanphear, Bruce P; Yolton, Kimberly; Sathyanarayana, Sheela; Braun, Joseph M

    2017-07-01

    To examine whether parents' concerns about environmental chemical exposures were associated with urinary phthalate and phenol concentrations in their school-age children. In a prospective cohort of 218 mother-child pairs from Cincinnati, Ohio (2010-2014), we measured 11 phthalate metabolites and 5 phenols in urine samples when children were age 8 years and used questionnaire data from caregivers. We estimated the covariate-adjusted percent difference in phthalates and phenols among children of parents who expressed concern about environmental chemical exposures compared with children whose parents did not. Concentrations of 4 phthalates, bisphenol S, and bisphenol A were lower among children whose parents expressed concern about environmental chemicals (n = 122) compared with those who did not (n = 96). Di-2-ethylhexyl phthalate metabolites, bisphenol S, and bisphenol A concentrations were 23% (95% CI -38, -5), 37% (95% CI -49, -21), and 13% (95% CI -26, 3) lower, respectively, among children whose parents expressed concern compared with those whose parents did not. Triclosan concentrations were 35% greater (95% CI -2, 87) among children whose parents expressed concern compared with children whose parents did not. Parental concern about environmental chemicals was associated with lower childhood urine concentrations of several phthalates and phenols; unexpectedly, parental concern was associated with greater triclosan concentrations. These results suggest that parental concern may be an important factor in mitigating children's phthalate and phenol exposures. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Performance and exposure indices of rats exposed to low concentrations of lead.

    Science.gov (United States)

    Cory-Slechta, D A; Weiss, B; Cox, C

    1985-04-01

    To further characterize the lower end of the function relating lead exposure and biological exposure indices to behavior, male weanling rats were exposed chronically to drinking solutions containing 25 ppm sodium acetate (controls) or 25 ppm lead acetate. Behavioral training began when the animals reached 50 days of age, and performance on a fixed-interval 1-min schedule of food reinforcement was then assessed over 90 experimental sessions (136 days). This exposure produced overall response rate increases over the first 40 sessions that were similar to those observed previously with higher concentrations of lead. Response rates of the two groups tended to merge subsequently. The increased overall response rates in the treated group derived primarily from an increased frequency of shorter interresponse times (IRTs) and increased running rates (calculated without the postreinforcement interval). Blood lead (PbB) and zinc protoporphyrin (ZPP) values were determined following sessions 30, 60, and 90. PbB values of the lead-exposed group averaged 15 to 20 micrograms/dl throughout the study; ZPP did not differ. The mean brain lead value of the treated group was 0.07 micrograms Pb/g. Blood-brain ratios (1.38 to 4.06) were substantially greater than those previously observed at higher exposures. These data extend to even lower exposures, and lower blood lead concentrations, the effective concentration for behavioral effects, and further emphasize the importance of the sensitivity of the endpoint in assessing behavioral toxicity.

  5. Exposure buildup factors for a cobalt-60 point isotropic source for single and two layer slabs

    International Nuclear Information System (INIS)

    Chakarova, R.

    1992-01-01

    Exposure buildup factors for point isotropic cobalt-60 sources are calculated by the Monte Carlo method with statistical errors ranging from 1.5 to 7% for 1-5 mean free paths (mfp) thick water and iron single slabs and for 1 and 2 mfp iron layers followed by water layers 1-5 mfp thick. The computations take into account Compton scattering. The Monte Carlo data for single slab geometries are approximated by Geometric Progression formula. Kalos's formula using the calculated single slab buildup factors may be applied to reproduce the data for two-layered slabs. The presented results and discussion may help when choosing the manner in which the radiation field gamma irradiation units will be described. (author)

  6. Exposure to fine particulate, black carbon, and particle number concentration in transportation microenvironments

    Science.gov (United States)

    Morales Betancourt, R.; Galvis, B.; Balachandran, S.; Ramos-Bonilla, J. P.; Sarmiento, O. L.; Gallo-Murcia, S. M.; Contreras, Y.

    2017-05-01

    This research determined intake dose of fine particulate matter (PM2.5), equivalent black carbon (eBC), and number of sub-micron particles (Np) for commuters in Bogotá, Colombia. Doses were estimated through measurements of exposure concentration, a surrogate of physical activity, as well as travel times and speeds. Impacts of travel mode, traffic load, and street configuration on dose and exposure were explored. Three road segments were selected because of their different traffic loads and composition, and dissimilar street configuration. The transport modes considered include active modes (walking and cycling) and motorized modes (bus, car, taxi, and motorcycle). Measurements were performed simultaneously in the available modes at each road segment. High average eBC concentrations were observed throughout the campaign, ranging from 20 to 120 μgm-3 . Commuters in motorized modes experienced significantly higher exposure concentrations than pedestrians and bicyclists. The highest average concentrations of PM2.5, eBC , and Np were measured inside the city's Bus Rapid Transit (BRT) system vehicles. Pedestrians and bicycle users in an open street configuration were exposed to the lowest average concentrations of PM2.5 and eBC , six times lower than those experienced by commuters using the BRT in the same street segment. Pedestrians experienced the highest particulate matter intake dose in the road segments studied, despite being exposed to lower concentrations than commuters in motorized modes. Average potential dose of PM2.5 and eBC per unit length traveled were nearly three times higher for pedestrians in a street canyon configuration compared to commuters in public transport. Slower travel speed and elevated inhalation rates dominate PM dose for pedestrians. The presence of dedicated bike lanes on sidewalks has a significant impact on reducing the exposure concentration for bicyclists compared to those riding in mixed traffic lanes. This study proposes a simple

  7. Significance of lenticular opacity from the view point of the exposure dose of A-bomb radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, S [Sugimoto Hospital, Hiroshima (Japan)

    1975-04-01

    Two cases of lenticular opacity were discussed from the view point of exposure dose of A-bomb radiation. Case 1: female, 22 year and 5 months old when she was exposured to A-bomb radiation. The presumed exposure dose was 482.0 rad. Cataract due to A-bomb radiation. Case 2: female, 21 years and 6 months old when she was exposured to A-bomb radiation. The presumed exposure dose was more than 1,000 rad. Cataract due to A-bomb radiation and incipient cataract senilis. It was reported here that there was a marked difference in opacity findings of cataract due to A-bomb radiation in accordance with difference in exposure dose of radiation. It was also presumed from the findings of incipient cataract senilis that with increasing exposure dose, the aging phenomenon was promoted.

  8. Point Spectroscopy System for Noncontact and Noninvasive Prediction of Transcutaneous Bilirubin Concentration

    Science.gov (United States)

    Ong, P. E.; K. C Huong, Audrey

    2017-08-01

    This paper presents the use of a point spectroscopy system to determine one’s transcutaneous bilirubin level using Modified Lambert Beer model and the developed fitting routine. This technique required a priori knowledge of extinction coefficient of bilirubin and hemoglobin components in the wavelength range of 440-500 nm for the prediction of the required parameter value. This work was conducted on different skin sites of six healthy Asians namely on the thenar region of the palm of their hand, back of the hand, posterior and anterior forearm. The obtained results revealed the lowest mean transcutaneous bilirubin concentration of 0.44±0.3 g/l predicted for palm site while the highest bilirubin level of 0.98±0.2 g/l was estimated for posterior forearm. These values were also compared with that presented in the literature. This study found considerably good consistency in the value predicted for different subjects especially at the thenar region of the palm. This work concluded that the proposed system and technique may be suitably served as an alternative means to noncontact and noninvasive measurement of one’s transcutaneous bilirubin level at palm site.

  9. Brominated flame retardants in children's toys: concentration, composition, and children's exposure and risk assessment.

    Science.gov (United States)

    Chen, She-Jun; Ma, Yun-Juan; Wang, Jing; Chen, Da; Luo, Xiao-Jun; Mai, Bi-Xian

    2009-06-01

    Brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), decabromodiphenyl ethane (DBDPE), and polybrominated biphenyls (PBBs) were found in children's toys purchased from South China. The median BFR concentrations in the hard plastic toys were 53,000, 5540 ng/g, 101.1 ng/g, and 27.9 ng/g, fortotal PBDEs, DBDPE, BTBPE, and PBBs, respectively,which were notably higher than values in other toys. The PBDE concentrations were below the threshold limit (1000 ppm) required bythe European Commission's Restriction of Hazardous Substances (RoHS) and Waste Electrical and Electronic Equipment (WEEE) directives in all of the toys, except for one hard plastic toy with a total PBDE concentration of 5,344,000 ng/g. The BFR profiles in the toys were consistent with the patterns of their current production and consumption in China, where PBDEs, specifically decaBDE product, were the dominant BFR, followed by the emerging DBDPE. The relatively high concentrations of octa- and nonaBDEs in the foam toys and the results of principal component analysis (PCA) may suggest the decomposition of highly brominated BDEs during the manufacturing processes of the toys. Daily total PBDE exposures associated with toys via inhalation, mouthing, dermal contact, and oral ingestion ranged from 82.6 to 8992 pg/kg bw-day for children of 3 months to 14 years of age. Higher exposures, predominantly contributed through the mouthing pathway, were observed for infants and toddlers than for the other subgroups. In most cases, children's BFR exposure via the toys likely accounts for a small proportion of their daily BFR exposure, and the hazard quotients for noncancer risk evaluation were far below 1. To the author's knowledge, this is the first study to examine the concentrations of BFRs in toys, and the potential exposures to children.

  10. Effect of exposure history on microbial herbicide degradation in an aerobic aquifer affected by a point source

    DEFF Research Database (Denmark)

    Tuxen, Nina; de Lipthay, J.R.; Albrechtsen, Hans-Jørgen

    2002-01-01

    sampling points from within the plume, and neither BAM, bentazone, nor isoproturon was degraded in any sampling point. A linear correlation (R2 g 0.83) between pre-exposure and amount of herbicide degraded within 50 days was observed for the phenoxy acids, mecoprop and dichlorprop. An improved model fit...

  11. Isoniazid concentrations in hair and plasma area-under-the-curve exposure among children with tuberculosis.

    Directory of Open Access Journals (Sweden)

    Vidya Mave

    Full Text Available We measured hair and plasma concentrations of isoniazid among sixteen children with tuberculosis who underwent personal or video-assisted directly observed therapy and thus had 100% adherence. This study therefore defined typical isoniazid exposure parameters after two months of treatment among fully-adherent patients in both hair and plasma (plasma area under the concentration-time curve, AUC, estimated using pharmacokinetic data collected 0, 2, 4, and 6 hours after drug administration. We found that INH levels in hair among highly-adherent individuals did not correlate well with plasma AUC or trough concentrations, suggesting that each measure may provide incremental and complementary information regarding drug exposure in the context of TB treatment.

  12. Determination of Measurement Points in Urban Environments for Assessment of Maximum Exposure to EMF Associated with a Base Station

    Directory of Open Access Journals (Sweden)

    Agostinho Linhares

    2014-01-01

    Full Text Available A base station (BS antenna operates in accordance with the established exposure limits if the values of electromagnetic fields (EMF measured in points of maximum exposure are below these limits. In the case of BS in open areas, the maximum exposure to EMF probably occurs in the antenna’s boresight direction, from a few tens to a few hundred meters away. This is not a typical scenery for urban environments. However, in the line of sight (LOS situation, the region of maximum exposure can still be analytically estimated with good results. This paper presents a methodology for the choice of measurement points in urban areas in order to assess compliance with the limits for exposure to EMF.

  13. Young people's exposure to point-of-sale tobacco products and promotions.

    Science.gov (United States)

    Stead, M; Eadie, D; MacKintosh, A M; Best, C; Miller, M; Haseen, F; Pearce, J R; Tisch, C; Macdonald, L; MacGregor, A; Amos, A; van der Sluijs, W; Frank, J W; Haw, S

    2016-07-01

    Point of sale (POS) displays are one of the most important forms of tobacco marketing still permitted in many countries. Reliable methods for measuring exposure to such displays are needed in order to assess their potential impact, particularly on smoking attitudes and uptake among young people. In this study we use a novel method for evaluating POS exposure based on young people's use of retail outlets and recall of tobacco displays and observational data on the characteristics of displays. Observational audit of retail outlets (n = 96) and school-based pupil survey (n = 1482) in four Scottish communities reflecting different levels of social deprivation and urbanisation, conducted in 2013 before legislation to remove POS displays was implemented in supermarkets. Measures were taken of: visibility and placement of tobacco displays; internal and external advertising; display unit size, branding and design; visibility of pack warnings; proximity of tobacco products to products of potential interest to children and young people; pupils' self-reported frequency of visiting retail outlets; and pupils' recall of tobacco displays. Variation in POS exposure across social and demographic groups was assessed. Displays were highly visible within outlets and, in over half the stores, from the public footway outside. Tobacco products were displayed in close proximity to products of interest to children (e.g. confectionery, in 70% of stores). Eighty percent of pupils recalled seeing tobacco displays, with those from deprived areas more likely to recall displays in small shops. When confectioners, tobacconists and newsagents (CTNs) and grocery/convenience stores (two of the outlet types most often visited by young people) were examined separately, average tobacco display unit sizes were significantly larger in those outlets in more deprived areas. POS displays remain a key vector in most countries for advertising tobacco products, and it is important to develop robust

  14. Nonsmoker Exposure to Secondhand Cannabis Smoke. III. Oral Fluid and Blood Drug Concentrations and Corresponding Subjective Effects.

    Science.gov (United States)

    Cone, Edward J; Bigelow, George E; Herrmann, Evan S; Mitchell, John M; LoDico, Charles; Flegel, Ronald; Vandrey, Ryan

    2015-09-01

    The increasing use of highly potent strains of cannabis prompted this new evaluation of human toxicology and subjective effects following passive exposure to cannabis smoke. The study was designed to produce extreme cannabis smoke exposure conditions tolerable to drug-free nonsmokers. Six experienced cannabis users smoked cannabis cigarettes [5.3% Δ(9)-tetrahydrocannabinol (THC) in Session 1 and 11.3% THC in Sessions 2 and 3] in a closed chamber. Six nonsmokers were seated alternately with smokers during exposure sessions of 1 h duration. Sessions 1 and 2 were conducted with no ventilation and ventilation was employed in Session 3. Oral fluid, whole blood and subjective effect measures were obtained before and at multiple time points after each session. Oral fluid was analyzed by ELISA (4 ng/mL cutoff concentration) and by LC-MS-MS (limit of quantitation) for THC (1 ng/mL) and total THCCOOH (0.02 ng/mL). Blood was analyzed by LC-MS-MS (0.5 ng/mL) for THC, 11-OH-THC and free THCCOOH. Positive tests for THC in oral fluid and blood were obtained for nonsmokers up to 3 h following exposure. Ratings of subjective effects correlated with the degree of exposure. Subjective effect measures and amounts of THC absorbed by nonsmokers (relative to smokers) indicated that extreme secondhand cannabis smoke exposure mimicked, though to a lesser extent, active cannabis smoking. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. 1H NMR metabolomics of earthworm exposure to sub-lethal concentrations of phenanthrene in soil

    International Nuclear Information System (INIS)

    Brown, Sarah A.E.; McKelvie, Jennifer R.; Simpson, Andre J.; Simpson, Myrna J.

    2010-01-01

    1 H NMR metabolomics was used to monitor earthworm responses to sub-lethal (50-1500 mg/kg) phenanthrene exposure in soil. Total phenanthrene was analyzed via soxhlet extraction, bioavailable phenanthrene was estimated by hydroxypropyl-β-cyclodextrin (HPCD) and 1-butanol extractions and sorption to soil was assessed by batch equilibration. Bioavailable phenanthrene (HPCD-extracted) comprised ∼65-97% of total phenanthrene added to the soil. Principal component analysis (PCA) showed differences in responses between exposed earthworms and controls after 48 h exposure. The metabolites that varied with exposure included amino acids (isoleucine, alanine and glutamine) and maltose. PLS models indicated that earthworm response is positively correlated to both total phenanthrene concentration and bioavailable (HPCD-extracted) phenanthrene in a freshly spiked, unaged soil. These results show that metabolomics is a powerful, direct technique that may be used to monitor contaminant bioavailability and toxicity of sub-lethal concentrations of contaminants in the environment. These initial findings warrant further metabolomic studies with aged contaminated soils. - 1 H NMR metabolomics is used to directly monitor metabolic responses of Eisenia fetida after 48 h of exposure to sub-lethal concentrations of phenanthrene in soil.

  16. Urinary bisphenol A concentrations and their implications for human exposure in several Asian countries.

    Science.gov (United States)

    Zhang, Zifeng; Alomirah, Husam; Cho, Hyeon-Seo; Li, Yi-Fan; Liao, Chunyang; Minh, Tu Binh; Mohd, Mustafa Ali; Nakata, Haruhiko; Ren, Nanqi; Kannan, Kurunthachalam

    2011-08-15

    Bisphenol A (BPA) is an industrial chemical used in the manufacture of polycarbonate plastics and epoxy resins. Due to the potential of this compound to disrupt normal endocrinal functions, concerns over human exposure to BPA have been raised. Although several studies have reported human exposure to BPA in Western nations, little is known about exposure in Asian countries. In this study, we determined total urinary BPA concentrations (free plus conjugated) in 296 urine samples (male/female: 153/143) collected from the general population in seven Asian countries, China, India, Japan, Korea, Kuwait, Malaysia, and Vietnam, using high-performance liquid chromatography (HPLC) tandem mass spectrometry (MS/MS). On the basis of urinary BPA concentrations, we estimated the total daily intake. The results indicated that BPA was detected in 94.3% of the samples analyzed, at concentrations ranging from Malaysia (1.06 ng/mL, 2.31 μg/g), and Japan (0.95 ng/mL, 0.58 μg/g). Among the five age groups studied (≤ 19, 20-29, 30-39, 40-49, and ≥ 50 years), the highest median concentration of BPA was found in urine samples from the age group of ≤ 19 years. There was no significant difference in BPA concentrations between genders (male and female) or domicile of residence (rural and urban). The estimated median daily intakes of BPA for the populations in Kuwait, Korea, India, China, Vietnam, Malaysia, and Japan were 5.19, 3.69, 2.90, 2.13, 2.01, 1.80, and 1.61 μg/day, respectively. The estimated daily intake of BPA in the seven Asian countries was significantly lower than the tolerable daily intake recommended by the U.S. Environmental Protection Agency. This is the first study to document the occurrence of and human exposure to BPA in several Asian countries.

  17. Exposure of Norwegian toddlers to perfluoroalkyl substances (PFAS): The association with breastfeeding and maternal PFAS concentrations.

    Science.gov (United States)

    Papadopoulou, Eleni; Sabaredzovic, Azemira; Namork, Ellen; Nygaard, Unni C; Granum, Berit; Haug, Line S

    2016-09-01

    High exposure to perfluoroalkyl substances (PFASs) has been associated with adverse health effects in children. PFASs exposure pathways of toddlers might differ from those of infants and adults, and the investigations on determinants of PFASs exposure in early childhood are scarce. Our aims were to examine the PFAS blood concentrations in Norwegian toddlers and to assess their relationship with maternal PFAS concentrations in pregnancy and breastfeeding duration. We determined PFAS concentrations in 112 plasma samples of 3-year-old children collected at 2010-2011 and 99 maternal serum samples collected around delivery at 2007-2008. PFAS concentrations in children were regressed on duration of breastfeeding, and the effect modification by maternal prenatal PFAS concentrations was examined in 55 mother-child pairs. Six PFASs were quantifiable in >50% of both maternal and children samples. Positive and significant correlations ranging between 0.50 and 0.66 were found between maternal and child concentrations of the same PFAS congeners. Nevertheless, toddlers had higher total PFAS blood concentrations than their mothers, due to higher concentrations of PFOA, PFNA and PFHxS. Every month of breastfeeding was associated with an increase of 3.3% (95% Confidence Intervals (CI): 0.8-5.8) for PFOS, 4.7% (95%CI: 2.8-6.6) for PFOA and 6.1% (95% CI: 2.6-9.7) for PFHpS in toddlers' plasma and a dose-response association was found, after adjustment for confounders. However, PFNA and PFUnDA concentrations in children were not associated with either maternal concentrations or breastfeeding duration. Our findings suggest that transplacental transfer, prenatally, and breastfeeding, postanatally, are among the main determinants of PFOS, PFOA, PFHxS and PFHpS concentrations in toddlers, while that was not the case for PFNA and PFUnDA. Nevertheless, due to the small number of mother child-pairs in our study, our results should be interpreted with caution. Copyright © 2016 Elsevier Ltd

  18. Nickel concentrations in fingernails as a measure of occupational exposure to nickel

    DEFF Research Database (Denmark)

    Peters, K; Gammelgaard, Bente; Menné, T

    1991-01-01

    in nails (p less than 0.001). The difference between the 2 levels was also significant (p less than 0.001). No correlation between the nickel concentration in fingernails and the duration of exposure could be demonstrated. It was concluded that the higher the nickel level in the fingernails, the greater...... is the possibility that the person is occupationally exposed to nickel. Nail analysis is suggested as a measure of occupational exposure to nickel.......The nickel concentration in fingernails from 2 groups of people occupationally exposed to nickel was determined. In one group, comprising 83 persons moderately exposed to nickel, the mean +/- standard deviation (SD) was 29.2 micrograms/g +/- 56.7 micrograms/g and the median 13.8 micrograms/g (range...

  19. Mercury exposure in terrestrial birds far downstream of an historical point source

    International Nuclear Information System (INIS)

    Jackson, Allyson K.; Evers, David C.; Folsom, Sarah B.; Condon, Anne M.; Diener, John; Goodrick, Lizzie F.; McGann, Andrew J.; Schmerfeld, John; Cristol, Daniel A.

    2011-01-01

    Mercury (Hg) is a persistent environmental contaminant found in many freshwater and marine ecosystems. Historical Hg contamination in rivers can impact the surrounding terrestrial ecosystem, but there is little known about how far downstream this contamination persists. In 2009, we sampled terrestrial forest songbirds at five floodplain sites up to 137 km downstream of an historical source of Hg along the South and South Fork Shenandoah Rivers (Virginia, USA). We found that blood total Hg concentrations remained elevated over the entire sampling area and there was little evidence of decline with distance. While it is well known that Hg is a pervasive and long-lasting aquatic contaminant, it has only been recently recognized that it also biomagnifies effectively in floodplain forest food webs. This study extends the area of concern for terrestrial habitats near contaminated rivers for more than 100 km downstream from a waterborne Hg point source. - Highlights: → We report blood mercury levels for terrestrial songbirds downstream of contamination. → Blood mercury levels remain elevated above reference for at least 137 km downstream. → Trends vary based on foraging guild and migration strategy. → Mercury affects terrestrial biota farther downstream than previously documented. - Blood mercury levels of forest songbirds remain elevated above reference levels for at least 137 km downstream of historical point source.

  20. Mercury exposure in terrestrial birds far downstream of an historical point source

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Allyson K., E-mail: allyson.jackson@briloon.org [Biodiversity Research Institute, 19 Flaggy Meadow Road, Gorham, ME 04038 (United States); Institute for Integrative Bird Behavior Studies, Department of Biology, College of William and Mary, PO Box 8795, Williamsburg, VA 23187 (United States); Evers, David C.; Folsom, Sarah B. [Biodiversity Research Institute, 19 Flaggy Meadow Road, Gorham, ME 04038 (United States); Condon, Anne M. [U.S. Fish and Wildlife Service, 6669 Short Lane, Gloucester, VA 23061 (United States); Diener, John; Goodrick, Lizzie F. [Biodiversity Research Institute, 19 Flaggy Meadow Road, Gorham, ME 04038 (United States); McGann, Andrew J. [Institute for Integrative Bird Behavior Studies, Department of Biology, College of William and Mary, PO Box 8795, Williamsburg, VA 23187 (United States); Schmerfeld, John [U.S. Fish and Wildlife Service, 6669 Short Lane, Gloucester, VA 23061 (United States); Cristol, Daniel A. [Institute for Integrative Bird Behavior Studies, Department of Biology, College of William and Mary, PO Box 8795, Williamsburg, VA 23187 (United States)

    2011-12-15

    Mercury (Hg) is a persistent environmental contaminant found in many freshwater and marine ecosystems. Historical Hg contamination in rivers can impact the surrounding terrestrial ecosystem, but there is little known about how far downstream this contamination persists. In 2009, we sampled terrestrial forest songbirds at five floodplain sites up to 137 km downstream of an historical source of Hg along the South and South Fork Shenandoah Rivers (Virginia, USA). We found that blood total Hg concentrations remained elevated over the entire sampling area and there was little evidence of decline with distance. While it is well known that Hg is a pervasive and long-lasting aquatic contaminant, it has only been recently recognized that it also biomagnifies effectively in floodplain forest food webs. This study extends the area of concern for terrestrial habitats near contaminated rivers for more than 100 km downstream from a waterborne Hg point source. - Highlights: > We report blood mercury levels for terrestrial songbirds downstream of contamination. > Blood mercury levels remain elevated above reference for at least 137 km downstream. > Trends vary based on foraging guild and migration strategy. > Mercury affects terrestrial biota farther downstream than previously documented. - Blood mercury levels of forest songbirds remain elevated above reference levels for at least 137 km downstream of historical point source.

  1. Impacts of Mercury Pollution Controls on Atmospheric Mercury Concentration and Occupational Mercury Exposure in a Hospital.

    Science.gov (United States)

    Li, Ping; Yang, Yan; Xiong, Wuyan

    2015-12-01

    Mercury (Hg) and Hg-containing products are used in a wide range of settings in hospitals. Hg pollution control measures were carried out in the pediatric ward of a hospital to decrease the possibility of Hg pollution occurring and to decrease occupational Hg exposure. Total gaseous Hg (TGM) concentrations in the pediatric ward and hair and urine Hg concentrations for the pediatric staff were determined before and after the Hg pollution control measures had been implemented. A questionnaire survey performed indicated that the pediatric staff had little understanding of Hg pollution and that appropriate disposal techniques were not always used after Hg leakage. TGM concentrations in the pediatric ward and urine Hg (UHg) concentrations for the pediatric staff were 25.7 and 22.2% lower, respectively, after the Hg pollution control measures had been implemented than before, which indicated that the control measures were effective. However, TGM concentrations in the pediatric ward remained significantly higher than background concentrations and UHg concentrations for the pediatric staff were remained significantly higher than the concentrations in control group, indicating continued existence of certain Hg pollution.

  2. Binational Arsenic Exposure Survey: Methodology and Estimated Arsenic Intake from Drinking Water and Urinary Arsenic Concentrations

    Directory of Open Access Journals (Sweden)

    Robin B. Harris

    2012-03-01

    Full Text Available The Binational Arsenic Exposure Survey (BAsES was designed to evaluate probable arsenic exposures in selected areas of southern Arizona and northern Mexico, two regions with known elevated levels of arsenic in groundwater reserves. This paper describes the methodology of BAsES and the relationship between estimated arsenic intake from beverages and arsenic output in urine. Households from eight communities were selected for their varying groundwater arsenic concentrations in Arizona, USA and Sonora, Mexico. Adults responded to questionnaires and provided dietary information. A first morning urine void and water from all household drinking sources were collected. Associations between urinary arsenic concentration (total, organic, inorganic and estimated level of arsenic consumed from water and other beverages were evaluated through crude associations and by random effects models. Median estimated total arsenic intake from beverages among participants from Arizona communities ranged from 1.7 to 14.1 µg/day compared to 0.6 to 3.4 µg/day among those from Mexico communities. In contrast, median urinary inorganic arsenic concentrations were greatest among participants from Hermosillo, Mexico (6.2 µg/L whereas a high of 2.0 µg/L was found among participants from Ajo, Arizona. Estimated arsenic intake from drinking water was associated with urinary total arsenic concentration (p < 0.001, urinary inorganic arsenic concentration (p < 0.001, and urinary sum of species (p < 0.001. Urinary arsenic concentrations increased between 7% and 12% for each one percent increase in arsenic consumed from drinking water. Variability in arsenic intake from beverages and urinary arsenic output yielded counter intuitive results. Estimated intake of arsenic from all beverages was greatest among Arizonans yet participants in Mexico had higher urinary total and inorganic arsenic concentrations. Other contributors to urinary arsenic concentrations should be evaluated.

  3. Exposure to low mercury concentration in vivo impairs myocardial contractile function

    International Nuclear Information System (INIS)

    Furieri, Lorena Barros; Fioresi, Mirian; Junior, Rogerio Faustino Ribeiro; Bartolome, Maria Visitacion; Fernandes, Aurelia Araujo; Cachofeiro, Victoria; Lahera, Vicente; Salaices, Mercedes; Stefanon, Ivanita; Vassallo, Dalton Valentim

    2011-01-01

    Increased cardiovascular risk after mercury exposure has been described but cardiac effects resulting from controlled chronic treatment are not yet well explored. We analyzed the effects of chronic exposure to low mercury concentrations on hemodynamic and ventricular function of isolated hearts. Wistar rats were treated with HgCl 2 (1st dose 4.6 μg/kg, subsequent dose 0.07 μg/kg/day, im, 30 days) or vehicle. Mercury treatment did not affect blood pressure (BP) nor produced cardiac hypertrophy or changes of myocyte morphometry and collagen content. This treatment: 1) in vivo increased left ventricle end diastolic pressure (LVEDP) without changing left ventricular systolic pressure (LVSP) and heart rate; 2) in isolated hearts reduced LV isovolumic systolic pressure and time derivatives, and β-adrenergic response; 3) increased myosin ATPase activity; 4) reduced Na + -K + ATPase (NKA) activity; 5) reduced protein expression of SERCA and phosphorylated phospholamban on serine 16 while phospholamban expression increased; as a consequence SERCA/phospholamban ratio reduced; 6) reduced sodium/calcium exchanger (NCX) protein expression and α-1 isoform of NKA, whereas α-2 isoform of NKA did not change. Chronic exposure for 30 days to low concentrations of mercury does not change BP, heart rate or LVSP but produces small but significant increase of LVEDP. However, in isolated hearts mercury treatment promoted contractility dysfunction as a result of the decreased NKA activity, reduction of NCX and SERCA and increased PLB protein expression. These findings offer further evidence that mercury chronic exposure, even at small concentrations, is an environmental risk factor affecting heart function. - Highlights: → Unchanges blood pressure, heart rate, systolic pressure. → Increases end diastolic pressure. → Promotes cardiac contractility dysfunction. → Decreases NKA activity, NCX and SERCA, increases PLB protein expression. → Small concentrations constitutes

  4. Results of gas exposure experiments for determination of HF concentrations injurious to plants

    Energy Technology Data Exchange (ETDEWEB)

    Guderian, R

    1971-01-01

    Gas exposure experiments were performed under greenhouse conditions to determine the effects of hydrogen fluoride on the growth capacity, yield and quality of plants. Damage to plants was assessed after HF concentrations of 0.85-25 ..mu..g/m/sup 3/. The effects of definite HF quantities on plants are described and relative sensitivities of 17 deciduous trees, 9 evergreens, 24 agricultural garden plants and 17 ornamental plants are presented. 2 references, 7 tables.

  5. Effects of essential oil exposure on salivary estrogen concentration in perimenopausal women.

    Science.gov (United States)

    Shinohara, Kazuyuki; Doi, Hirokazu; Kumagai, Chizu; Sawano, Erika; Tarumi, Wataru

    2017-01-01

    The menopausal transition is the time from the onset of menstrual changes until one year after the final menstrual period. During this phase, perimenopausal women experience a variety of health-related symptoms, which seemingly derive from declining level of estrogen secretion. It has long been recognized that some essential oils have the efficacy of alleviating menopausal symptoms. On the basis of this, it is possible that these essential oils have the potency to facilitate estrogen secretion in women. The present study investigated this possibility by examining if the olfactory exposure to the essential oil increase salivary estrogen concentration. We tested the effect of ten essential oils; clary sage, frankincense, geranium, lavender, jasmine absolute, neroli, rose otto, ylang ylang, orange and roman chamomile, which are thought to relieve perimenopasal symptoms. The results have shown increase of salivary estrogen concentration induced by exposure to geranium and rose otto compared to control odor. Together with the previous studies, the present study may give support to the notion that olfactory exposure to some essential oils can influence salivary concentration of estrogen.

  6. Characteristics of carbonyl compounds in public vehicles of Beijing city: Concentrations, sources, and personal exposures

    Science.gov (United States)

    Pang, Xiaobing; Mu, Yujing

    The characteristics of carbonyl compounds (carbonyls) including concentrations, major sources, and personal exposure were investigated for 29 vehicles including taxi, bus and subway in Beijing. It was found that the taxis (Xiali, TA) and buses (Huanghe, BA) fueled by gasoline with longer service years had the higher indoor carbonyl levels (178±42.7 and 188±31.6 μg m -3) while subways energized by electricity without exhaust and the jingwa buses (BB) driven in the suburb had the lower levels with total concentrations of 98.5±26.3 and 92.1±20.3 μg m -3, respectively. Outdoor carbonyls of taxi cars and buses were nearly at the same level with their total concentrations varying from 80 to 110 μg m -3. The level of outdoor subways carbonyls was equal with the ambient air levels. Exhaust leakage, indoor material emissions, photochemical formation, and infiltration of outdoor air were considered to be the major sources to in-vehicle carbonyls. Personal exposures and cancer risk to formaldehyde and acetaldehyde were calculated for professional bus and taxi drivers, respectively. Taxi drivers had the highest cancer risk with personal exposure to formaldehyde and acetaldehyde of 212 and 243 μg day -1, respectively. The public concern should pay considerable attention to professional drivers' health.

  7. The effect of points and audio on concentration, engagement, enjoyment, learning, motivation, and classroom dynamics using Kahoot!

    DEFF Research Database (Denmark)

    Wang, Alf Inge; Lieberoth, Andreas

    2016-01-01

    There are many examples on the use of game-based learning in and outside the classroom, along with evaluation of their effect in terms of engagement, learning, classroom dynamics, concentration, motivation and enjoyment. Most of the research in this area focuses on evaluations of the use of game...... that produce a positive effect on engagement, motivation, enjoyment, concentration, classroom dynamics and learning. In this paper, we present an experiment where we investigated how the use of points and audio affect the learning environment. Specifically, the paper presents results from an experiment where...... points and audio. The results from the experiment reveal that there are some significant differences whether audio and points are used in game-based learning in the areas of concentration, engagement, enjoyment, and motivation. The most surprising finding was how the classroom dynamics was positively...

  8. Point and planar LIF for velocity-concentration correlations in a jet in cross flow

    DEFF Research Database (Denmark)

    Meyer, Knud Erik; Özcan, Oktay; Larsen, Poul Scheel

    2002-01-01

    Simultaneous measurements of velocities and concentration with Planar Laser Induced Fluorescense (PLIF) combined with Particle Image Velocimetry (PIV) are compared to similar measurements with pointwise Laser Induced Fluorescense (LIF) made with a slightly modified standard Laser Doppler Anemometer......, since these involve areas with high velocity- and concentration gradients, which in turn amplifies the effect of a finite measurement volume in the two measurement systems. In addition, the concentration measurement was realized by injecting clean water into the dye seeded main flow. This "inverse...

  9. Recreational Exposure to Low Concentrations of Microcystins During an Algal Bloom in a Small Lake

    Directory of Open Access Journals (Sweden)

    Yung-Sung Cheng

    2008-06-01

    Full Text Available We measured microcystins in blood from people at risk for swallowing water or inhaling spray while swimming, water skiing, jet skiing, or boating during an algal bloom. We monitored water samples from a small lake as a Microcystis aeruginosa bloom developed. We recruited 97 people planning recreational activities in that lake and seven others who volunteered to recreate in a nearby bloom-free lake. We conducted our field study within a week of finding a 10-μg/L microcystin concentration. We analyzed water, air, and human blood samples for water quality, potential human pathogens, algal taxonomy, and microcystin concentrations. We interviewed study participants for demographic and current health symptom information. Water samples were assayed for potential respiratory viruses (adenoviruses and enteroviruses, but none were detected. We did find low concentrations of Escherichia coli, indicating fecal contamination. We found low levels of microcystins (2 μg/L to 5 μg/L in the water and (<0.1 ng/m3 in the aerosol samples. Blood levels of microcystins for all participants were below the limit of detection (0.147μg/L. Given this low exposure level, study participants reported no symptom increases following recreational exposure to microcystins. This is the first study to report that water-based recreational activities can expose people to very low concentrations of aerosol-borne microcystins; we recently conducted another field study to assess exposures to higher concentrations of these algal toxins.

  10. Concentration dependent transcriptome responses of zebrafish embryos after exposure to cadmium, cobalt and copper.

    Science.gov (United States)

    Sonnack, Laura; Klawonn, Thorsten; Kriehuber, Ralf; Hollert, Henner; Schäfers, Christoph; Fenske, Martina

    2017-12-01

    Environmental metals are known to cause harmful effects to fish of which many molecular mechanisms still require elucidation. Particularly concentration dependence of gene expression effects is unclear. Focusing on this matter, zebrafish embryo toxicity tests were used in combination with transcriptomics. Embryos were exposed to three concentrations of copper (CuSO 4 ), cadmium (CdCl 2 ) and cobalt (CoSO 4 ) from just after fertilization until the end of the 48hpf pre- and 96hpf post-hatch stage. The RNA was then analyzed on Agilent's Zebrafish (V3, 4×44K) arrays. Enrichment for GO terms of biological processes illustrated for cadmium that most affected GO terms were represented in all three concentrations, while for cobalt and copper most GO terms were represented in the lowest test concentration only. This suggested a different response to the non-essential cadmium than cobalt and copper. In cobalt and copper treated embryos, many developmental and cellular processes as well as the Wnt and Notch signaling pathways, were found significantly enriched. Also, different exposure concentrations affected varied functional networks. In contrast, the largest clusters of enriched GO terms for all three concentrations of cadmium included responses to cadmium ion, metal ion, xenobiotic stimulus, stress and chemicals. However, concentration dependence of mRNA levels was evident for several genes in all metal exposures. Some of these genes may be indicative of the mechanisms of action of the individual metals in zebrafish embryos. Real-time quantitative RT-PCR (qRT-PCR) verified the microarray data for mmp9, mt2, cldnb and nkx2.2a. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Optimization of a Point Focus Concentration Photovoltaic System with Passive Cooling

    International Nuclear Information System (INIS)

    Chenlo, F.

    2015-01-01

    The objective of this work is modeling the temperature of photovoltaic (PV) solar cells operating in concentration systems with circular geometry and coupled to a heat sink plate for passive cooling. The proposed thermal behavior model analyses the temperature surface distribution of both PV solar cell and heat sink plate as function of light concentration. The model also allows analyzing the influence of other parameters such as uniform and non-uniform variation of the heat sink plate thickness or variation of the thermal transmission coefficient. The optimal range of the concentration factor is studied using simple models for the PV solar cell efficiency and Fresnel lens concentrator performance together with a function of costs applied to medium concentration silicon crystalline PV cells and high efficiency and high concentration multi-junction PV cells. Finally, experimental main parameters and its procedures measurement for concentration systems are presented. Modeling results show that the use of a high conductivity disk thermally coupled between the rear side of the cell and the cooling plate reduces the working cell temperature. Results also indicates that use of a light redirecting prism by total internal reflection of sunlight, reduces optical losses due to concentrator defects and chromatic aberration and increases the angle tracking error acceptance without having to increase the area of the PV solar cell

  12. Aquatic Exposure Predictions of Insecticide Field Concentrations Using a Multimedia Mass-Balance Model.

    Science.gov (United States)

    Knäbel, Anja; Scheringer, Martin; Stehle, Sebastian; Schulz, Ralf

    2016-04-05

    Highly complex process-driven mechanistic fate and transport models and multimedia mass balance models can be used for the exposure prediction of pesticides in different environmental compartments. Generally, both types of models differ in spatial and temporal resolution. Process-driven mechanistic fate models are very complex, and calculations are time-intensive. This type of model is currently used within the European regulatory pesticide registration (FOCUS). Multimedia mass-balance models require fewer input parameters to calculate concentration ranges and the partitioning between different environmental media. In this study, we used the fugacity-based small-region model (SRM) to calculate predicted environmental concentrations (PEC) for 466 cases of insecticide field concentrations measured in European surface waters. We were able to show that the PECs of the multimedia model are more protective in comparison to FOCUS. In addition, our results show that the multimedia model results have a higher predictive power to simulate varying field concentrations at a higher level of field relevance. The adaptation of the model scenario to actual field conditions suggests that the performance of the SRM increases when worst-case conditions are replaced by real field data. Therefore, this study shows that a less complex modeling approach than that used in the regulatory risk assessment exhibits a higher level of protectiveness and predictiveness and that there is a need to develop and evaluate new ecologically relevant scenarios in the context of pesticide exposure modeling.

  13. Intercomparison of model predictions of tritium concentrations in soil and foods following acute airborne HTO exposure

    International Nuclear Information System (INIS)

    Barry, P.J.; Watkins, B.M.; Belot, Y.; Davis, P.A.; Edlund, O.; Galeriu, D.; Raskob, W.; Russell, S.; Togawa, O.

    1998-01-01

    This paper describes the results of a model intercomparision exercise for predicting tritium transport through foodchains. Modellers were asked to assume that farmland was exposed for one hour to an average concentration in air of 10 4 MBq tritium m -3 . They were given the initial soil moisture content and 30 days of hourly averaged historical weather and asked to predict HTO and OBT concentrations in foods at selected times up to 30 days later when crops were assumed to be harvested. Two fumigations were postulated, one at 10.00 h (i.e., in day-light), and the other at 24.00 h (i.e., in darkness).Predicted environmental media concentrations after the daytime exposure agreed within an order of magnitude in most cases. Important sources of differences were variations in choices of numerical values for transport parameters. The different depths of soil layers used in the models appeared to make important contributions to differences in predictions for the given scenario. Following the night-time exposure, however, greater differences in predicted concentrations appeared. These arose largely because of different ways key processes were assumed to be affected by darkness. Uptake of HTO by vegetation and the rate it is converted to OBT were prominent amongst these processes. Further research, experimental data and modelling intercomparisons are required to resolve some of these issues. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  14. Repeat exposure to ciguatoxin leads to enhanced and sustained thermoregulatory, pain threshold and motor activity responses in mice: relationship to blood ciguatoxin concentrations.

    Science.gov (United States)

    Bottein Dechraoui, Marie-Yasmine; Rezvani, Amir H; Gordon, Christopher J; Levin, Edward D; Ramsdell, John S

    2008-04-03

    Ciguatera is a common illness in tropical and subtropical regions that manifests in complex and long-lived symptoms which are more severe in subsequent exposures. This study measures central and peripheral neurologic signs, in parallel with blood toxin levels, in mice exposed once or twice (at 3 days interval) to a sublethal dose of ciguatoxin P-CTX-1 (0.26ng/g via i.p.). Mice were implanted with radiotransmitters to monitor motor activity and core temperature. A single exposure to ciguatoxin elicited an immediate and transient decrease in motor activity and temperature, and subsequent long-lasting thermoregulatory dysfunction resulting in stabilized body temperature around 36.0 degrees C with no observable circadian rhythm. The hypothermic response and the reduced activity were enhanced with a second exposure with 30% of the mice dying within 7h. Measurement of the peripheral nervous system by the tail flick assay revealed increased latency with a single ciguatoxin exposure, and a greater effect following the second exposure. Toxin was measurable in blood up to 3 days following the first exposure; at the 1h time point the concentrations were significantly elevated after a second exposure. These findings indicate an early response to ciguatoxin manifest in a central response to lower body temperature and reduce motor activity and a more persistent effect on the peripheral system leading to spinal heat antinociception and delayed fever-like response. The greater neurological response to a second ciguatoxin exposure was associated with elevated concentrations of ciguatoxin in the blood solely over the first hour of exposure. In conclusion, a single exposure to toxin exerts a significant neurological response which may be enhanced with subsequent exposure.

  15. Benzonphenone-type UV filters in urine of Chinese young adults: Concentration, source and exposure

    International Nuclear Information System (INIS)

    Gao, Chong-jing; Liu, Li-yan; Ma, Wan-li; Zhu, Ning-zheng; Jiang, Ling; Li, Yi-Fan; Kannan, Kurunthachalam

    2015-01-01

    Benzophenone (BP)-type UV filters are commonly used in our daily life. 2-hydroxy-4-methoxy benzophenone (BP-3), 4-hydroxy benzophenone (4-HBP), 2,4-dihydroxy benzophenone (BP-1), 2,2′,4,4′-tetrahydroxy benzophenone (BP-2) and 2,2′-dihydroxy-4-methoxy benzophenone (BP-8) were measured in urine samples from Chinese young adults. The results indicated that Chinese young adults were widely exposed to BP-3, BP-1, and 4-HBP, with the median concentrations of 0.55, 0.21, and 0.08 ng/mL, respectively. No significant difference was found between males and females, between urban and rural population. The correlations between urinary concentrations provided important indications for sources and metabolic pathways of target compounds. The estimated daily excretion doses of BP-3, 4-HBP, BP-1, BP-2 and BP-8 were 27.2, 2.24, 5.86, 0.76 and 0.30 ng/kg-bw/day, respectively. The ratio of exposure to excretion must be considered for the exposure assessment with chemicals based on urine measurement. This is the first nationwide study on BP-derivatives with young adults in China. - Highlights: • Five BP-derivatives in urine were analyzed for Chinese young adults over China. • No difference was found between males and females, between urban and rural groups. • Concentration correlation provide indications for sources and metabolic pathways. • Ratio of exposure to excretion must be considered for the exposure assessment. - Benzophenone (BP)-type UV filters were frequently detected in urine samples from Chinese young adults, indicating their wide applications in China

  16. Source attribution of human campylobacteriosis at the point of exposure by combining comparative exposure assessment and subtype comparison based on comparative genomic fingerprinting.

    Directory of Open Access Journals (Sweden)

    André Ravel

    Full Text Available Human campylobacteriosis is a common zoonosis with a significant burden in many countries. Its prevention is difficult because humans can be exposed to Campylobacter through various exposures: foodborne, waterborne or by contact with animals. This study aimed at attributing campylobacteriosis to sources at the point of exposure. It combined comparative exposure assessment and microbial subtype comparison with subtypes defined by comparative genomic fingerprinting (CGF. It used isolates from clinical cases and from eight potential exposure sources (chicken, cattle and pig manure, retail chicken, beef, pork and turkey meat, and surface water collected within a single sentinel site of an integrated surveillance system for enteric pathogens in Canada. Overall, 1518 non-human isolates and 250 isolates from domestically-acquired human cases were subtyped and their subtype profiles analyzed for source attribution using two attribution models modified to include exposure. Exposure values were obtained from a concurrent comparative exposure assessment study undertaken in the same area. Based on CGF profiles, attribution was possible for 198 (79% human cases. Both models provide comparable figures: chicken meat was the most important source (65-69% of attributable cases whereas exposure to cattle (manure ranked second (14-19% of attributable cases, the other sources being minor (including beef meat. In comparison with other attributions conducted at the point of production, the study highlights the fact that Campylobacter transmission from cattle to humans is rarely meat borne, calling for a closer look at local transmission from cattle to prevent campylobacteriosis, in addition to increasing safety along the chicken supply chain.

  17. Source attribution of human campylobacteriosis at the point of exposure by combining comparative exposure assessment and subtype comparison based on comparative genomic fingerprinting.

    Science.gov (United States)

    Ravel, André; Hurst, Matt; Petrica, Nicoleta; David, Julie; Mutschall, Steven K; Pintar, Katarina; Taboada, Eduardo N; Pollari, Frank

    2017-01-01

    Human campylobacteriosis is a common zoonosis with a significant burden in many countries. Its prevention is difficult because humans can be exposed to Campylobacter through various exposures: foodborne, waterborne or by contact with animals. This study aimed at attributing campylobacteriosis to sources at the point of exposure. It combined comparative exposure assessment and microbial subtype comparison with subtypes defined by comparative genomic fingerprinting (CGF). It used isolates from clinical cases and from eight potential exposure sources (chicken, cattle and pig manure, retail chicken, beef, pork and turkey meat, and surface water) collected within a single sentinel site of an integrated surveillance system for enteric pathogens in Canada. Overall, 1518 non-human isolates and 250 isolates from domestically-acquired human cases were subtyped and their subtype profiles analyzed for source attribution using two attribution models modified to include exposure. Exposure values were obtained from a concurrent comparative exposure assessment study undertaken in the same area. Based on CGF profiles, attribution was possible for 198 (79%) human cases. Both models provide comparable figures: chicken meat was the most important source (65-69% of attributable cases) whereas exposure to cattle (manure) ranked second (14-19% of attributable cases), the other sources being minor (including beef meat). In comparison with other attributions conducted at the point of production, the study highlights the fact that Campylobacter transmission from cattle to humans is rarely meat borne, calling for a closer look at local transmission from cattle to prevent campylobacteriosis, in addition to increasing safety along the chicken supply chain.

  18. Measures to reduce occupational radiation exposure in PET facilities from nurses' point of view

    International Nuclear Information System (INIS)

    Miyazawa, Keiko; Takahashi, Juri; Mochiduki, Yoshikazu

    2006-01-01

    In parallel with the increase in the number of institutions having PET facilities, the number of nurse working in these facilities has also increased, and the issue of occupational radiation exposure has assumed ever greater importance. In our clinic, since nurses have started to administer FDG intravenous injections, their annual radiation exposure has amounted to 4.8 - 7.1 mSv. To reduce their annual radiation exposure to less than 5 mSv, we identified sources of increased exposure and considered countermeasures based on this information. By implementing countermeasures such as improvements in daily working conditions and ways to avoid various troubles, it was possible to reduce the annual radiation exposure of all nurses to less than 5 mSv. Our experience demonstrates that to provide a working environment with a minimum of occupational radiation exposure, educational training and enhancement of knowledge and technical skills are vital. (author)

  19. Concentrations of environmental organic contaminants in meat and meat products and human dietary exposure: A review.

    Science.gov (United States)

    Domingo, José L

    2017-09-01

    Meat and meat products is one of the most relevant food groups in an important number of human diets. Recently, the IARC, based on results of a number of epidemiological studies, classified the consumptions of red meat and processed meat as "probably carcinogenic to humans" and as "carcinogenic to humans", respectively. It was suggested that the substances responsible of the potential carcinogenicity would be mainly generated during meat processing, such as curing and smoking, or when meat is heated at high temperatures. However, the exposure to environmental pollutants through meat consumption was not discussed. The purpose of the present paper was to review recent studies reporting the concentrations of PCDD/Fs, DL-PCBs and PAHs in meat and meat products, as well as the human exposure to these pollutants through the diet. It is concluded that the health risks derived from exposure to carcinogenic environmental contaminants must be considered in the context of each specific diet, which besides meat and meat products, includes other foodstuffs containing also chemical pollutants, some of them with carcinogenic potential. Anyhow, meat and meat products are not the main food group responsible of the dietary exposure to carcinogenic (or probably carcinogenic) environmental organic pollutants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Gestational exposure to high perchlorate concentrations in drinking water and neonatal thyroxine levels.

    Science.gov (United States)

    Amitai, Yona; Winston, Gary; Sack, Joseph; Wasser, Janice; Lewis, Matthew; Blount, Benjamin C; Valentin-Blasini, Liza; Fisher, Nirah; Israeli, Avi; Leventhal, Alex

    2007-09-01

    To assess the effect of gestational perchlorate exposure through drinking water on neonatal thyroxine (T(4)). T(4) values were compared among newborns in Ramat Hasharon, Israel, whose mothers resided in suburbs where drinking water contained perchlorate water exclusively (as determined by a telephone interview) were analyzed as a subset. Serum perchlorate levels in blood from donors residing in the area were used as proxy indicators of exposure. Neonatal T(4) values (mean +/- SD) in the very high, high, and low exposure groups were 13.9 +/- 3.8, 13.9 +/- 3.4, and 14.0 +/- 3.5 microg/dL, respectively (p = NS). Serum perchlorate concentrations in blood from donors residing in areas corresponding to these groups were 5.99 +/- 3.89, 1.19 +/- 1.37, and 0.44 +/- 0.55 microg/L, respectively. T(4) levels of neonates with putative gestational exposure to perchlorate in drinking water were not statistically different from controls. This study finds no change in neonatal T(4) levels despite maternal consumption of drinking water that contains perchlorate at levels in excess of the Environmental Protection Agency (EPA) drinking water equivalent level (24.5 microg/L) based on the National Research Council reference dose (RfD) [0.7 microg/(kg.day)]. Therefore the perchlorate RfD is likely to be protective of thyroid function in neonates of mothers with adequate iodide intake.

  1. Time-dependent Taylor–Aris dispersion of an initial point concentration

    DEFF Research Database (Denmark)

    Vedel, Søren; Hovad, Emil; Bruus, Henrik

    2014-01-01

    -specific theoretical results, and furthermore predict new phenomena. In particular, for the transient phase before the well-described steady Taylor–Aris limit is reached, we find anomalous diffusion with a dependence of the temporal scaling exponent on the initial release point, generalizing this finding in specific...... cases. During this transient we furthermore identify maxima in the values of the dispersion coefficient which exceed the Taylor–Aris value by amounts that depend on channel geometry, initial point release position, velocity profile and Péclet number. We show that these effects are caused by a difference...

  2. A three-dimensional point process model for the spatial distribution of disease occurrence in relation to an exposure source

    DEFF Research Database (Denmark)

    Grell, Kathrine; Diggle, Peter J; Frederiksen, Kirsten

    2015-01-01

    We study methods for how to include the spatial distribution of tumours when investigating the relation between brain tumours and the exposure from radio frequency electromagnetic fields caused by mobile phone use. Our suggested point process model is adapted from studies investigating spatial...... the Interphone Study, a large multinational case-control study on the association between brain tumours and mobile phone use....

  3. Low concentrations of metal mixture exposures have adverse effects on selected biomarkers of Xenopus laevis tadpoles

    Energy Technology Data Exchange (ETDEWEB)

    Yologlu, Ertan, E-mail: ertanyologlu82@gmail.com [Adiyaman University, Faculty of Education, Department of Science Education, 02040 Adiyaman (Turkey); Ozmen, Murat [Inonu University, Laboratory of Environmental Toxicology, Department of Biology, Faculty of Arts & Science, 44280 Malatya (Turkey)

    2015-11-15

    Highlights: • Selected metal mixtures were evaluated for toxicity of safety limit concentrations. • Xenopus laevis tadpoles were used as model test organism. • Combinations of LC{sub 50} and LC{sub 50}/2 caused 100% lethality for some metals. • Metals did not change metallothionein levels in low concentrations. • Selected enzyme activities showed induction after low concentration exposures. - Abstract: Polluted ecosystems may contain mixtures of metals, such that the combinations of metals, even in low concentrations, may cause adverse effects. In the present study, we focused on toxic effects of mixtures of selected metals, the LC{sub 50} values, and also their safety limit in aquatic systems imposed by the European legislation using a model organism. Xenopus laevis tadpoles were used as test organisms. They were exposed to metals or their combinations due to 96-h LC{sub 50} values. Glutathione S-transferase (GST), glutathione reductase (GR), acetylcholinesterase (AChE), carboxylesterase (CaE), glutathione peroxidase (GPx), and catalase (CAT) levels were evaluated. Metallothionein concentrations were also determined. The LC{sub 50}s for Cd, Pb, and Cu were calculated as 5.81 mg AI/L, 123.05 mg AI/L, and 0.85 mg AI/L, respectively. Low lethality ratios were observed with unary exposure of each metal in lower concentrations. Double or triple combinations of LC{sub 50} and LC{sub 50}/2 concentrations caused 100% lethality with Cd + Cu and Pb + Cd + Cu mixtures, while the Pb + Cu mixture also caused high lethal ratios. The selected enzyme activities were significantly affected by metals or mixtures, and dose-related effects were determined. The metallothionein levels generally increased as related to concentration in unary metals and mixtures. Acceptable limit values of unary metals and mixtures did not significantly change metallothionein levels. The results suggest that oxidative stress-related mechanisms are involved in the toxicity induced by selected

  4. Derived air concentration for high exposure plutonium : revised values based on ICRP -30 recommendations

    International Nuclear Information System (INIS)

    Sharma, Lata; Janardhanan, S.; Krishnamurthi, T.N.

    1983-01-01

    Derived Air Concentration (DAC) limits for plutonium isotopic mixtures, as obtained from reprocessing of spent fuel heavy water reactors, are presented in this paper. DAC for the mixtures is expressed in terms of alpha activity of plutonium. Growth of 241 Am in the product is taken into consideration. Current recommedations on DAC limits for individual Pu isotopes, as laid down in ICRP-30 report, are used for estimating DAC for the mixture. DACsub(α) for high exposure plutonium is found to be less by a factor of 2-3, when compared with the limit for 239 Pu. As a result, detection and alarm limits for air monitoring instruments should be scaled down while handling high exposure plutonium. (author)

  5. Derived air concentration for high exposure plutonium : revised values based on ICRP -30 recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, L.; Janardhanan, S.; Krishnamurthi, T.N. (Bhabha Atomic Research Centre, Bombay (India). Health Physics Div.)

    Derived Air Concentration (DAC) limits for plutonium isotopic mixtures, as obtained from reprocessing of spent fuel heavy water reactors, are presented in this paper. DAC for the mixtures is expressed in terms of alpha activity of plutonium. Growth of /sup 241/Am in the product is taken into consideration. Current recommedations on DAC limits for individual Pu isotopes, as laid down in ICRP-30 report, are used for estimating DAC for the mixture. DACsub(..cap alpha..) for high exposure plutonium is found to be less by a factor of 2-3, when compared with the limit for /sup 239/Pu. As a result, detection and alarm limits for air monitoring instruments should be scaled down while handling high exposure plutonium.

  6. Exposure to ambient PM2.5 concentrations and cognitive function among older Mexican adults.

    Science.gov (United States)

    Salinas-Rodríguez, Aarón; Fernández-Niño, Julián Alfredo; Manrique-Espinoza, Betty; Moreno-Banda, Grea Litai; Sosa-Ortiz, Ana Luisa; Qian, Zhengmin Min; Lin, Hualiang

    2018-04-25

    Recent epidemiological research has shown that exposure to fine particulate pollution (PM 2.5 ) is associated with a reduction in cognitive function in older adults. However, primary evidence comes from high-income countries, and no specific studies have been conducted in low and middle-income countries where higher air pollution levels exist. To estimate the association between the exposure to PM 2.5 and cognitive function in a nationally representative sample of older Mexican adults and the associated effect modifiers. Data for this study were taken from the National Survey of Health and Nutrition in Mexico carried out in 2012. A total of 7986 older adults composed the analytical sample. Cognitive function was assessed using two tests: semantic verbal fluency and three-word memory. The annual concentration of PM 2.5 was calculated using satellite data. Association between exposure to PM 2.5 and cognitive function was estimated using two-level logistic and linear regression models. In adjusted multilevel regression models, each 10 μg/m 3 increase in ambient PM 2.5 raised the odds of a poorer cognitive function using the three-word memory test (OR = 1.37, 95% CI: 1.08, 1.74), and reduced the number of valid animal named in the verbal fluency test (β = -0.72, 95% CI: -1.05, -0.40). Stratified analyses did not yield any significant modification effects of age, sex, indoor pollution, urban/rural dwelling, education, smoking and other factors. This study supports an association between exposure to PM 2.5 concentrations and cognitive function in older adults. This is particularly relevant to low- and middle-income countries, which are marked by a rapid growth of their aging population and high levels of air pollution. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. The molecular basis of simple relationships between exposure concentration and toxic effects with time.

    Science.gov (United States)

    Tennekes, Henk A; Sánchez-Bayo, Francisco

    2013-07-05

    Understanding the toxicity of chemicals to organisms requires considering the molecular mechanisms involved as well as the relationships between exposure concentration and toxic effects with time. Our current knowledge about such relationships is mainly explained from a toxicodynamic and toxicokinetic perspective. This paper re-introduces an old approach that takes into account the biochemical mode of action and their resulting biological effects over time of exposure. Empirical evidence demonstrates that the Druckrey-Küpfmüller toxicity model, which was validated for chemical carcinogens in the early 1960s, is also applicable to a wide range of toxic compounds in ecotoxicology. According to this model, the character of a poison is primarily determined by the reversibility of critical receptor binding. Chemicals showing irreversible or slowly reversible binding to specific receptors will produce cumulative effects with time of exposure, and whenever the effects are also irreversible (e.g. death) they are reinforced over time; these chemicals have time-cumulative toxicity. Compounds having non-specific receptor binding, or involving slowly reversible binding to some receptors that do not contribute to toxicity, may also be time-dependent; however, their effects depend primarily on the exposure concentration, with time playing a minor role. Consequently, the mechanism of toxic action has important implications for risk assessment. Traditional risk approaches cannot predict the impacts of toxicants with time-cumulative toxicity in the environment. New assessment procedures are needed to evaluate the risk that the latter chemicals pose on humans and the environment. An example is shown to explain how the risk of time-dependent toxicants is underestimated when using current risk assessment protocols. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  8. Environmental concentrations of fibers with fluoro-edenitic composition and population exposure in Biancavilla (Sicily, Italy

    Directory of Open Access Journals (Sweden)

    Biagio Maria Bruni

    2014-06-01

    Full Text Available INTRODUCTION. The town of Biancavilla (Sicily was included in the National Priorities List of Contaminated Sites due to environmental dispersion of amphibole fibers owing to the extraction of materials from a local quarry. The present report summarizes results from several, hitherto unpublished, environmental surveys carried out in the area, as well as from published analyses of the chemistry and composition of fibers. METHODS. Data included here comprises environmental fiber concentrations by scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS analysis in soil, indoor and outdoor air, personal monitoring, as well as a chemical characterization of the fibers. The full chemical structure and spectroscopic characterization of fibers were obtained through a multi-analytical approach: SEM-EDS, X-ray powder diffraction (XRPD, as well as Mössbauer (MS and Fourier transform infrared (FT-IR spectroscopies. RESULTS. Data analyzed provided a spatial and temporal picture of fiber concentrations in Biancavilla, and a qualitative assessment of population exposure. Results suggest that until 2000, the population had been exposed to high levels of amphibole fibers. Mitigation measures adopted since 2001, gradually reduced exposure levels to about 0.10.4 ff/l. Previous studies on fibrous amphiboles from Biancavilla reported considerable chemical variability. Differences in composition, especially concerning the presence of Si, Ca, Fe, and Na, were found both within and between samples. Compared to the previously investigated prismatic fluoro-edenite, these fibrous fluorine amphiboles consistently showed higher average values of Si and Fe content, whereas Ca was significantly lower, which we consider a distinctive characteristic of the fluorine fibrous variety. CONCLUSIONS. The population of Biancavilla had been highly exposed to a suite of fibrous amphiboles for over 50 years. Dust mitigation measures have gradually reduced exposure, but

  9. Concentrator optical characterization using computer mathematical modelling and point source testing

    Science.gov (United States)

    Dennison, E. W.; John, S. L.; Trentelman, G. F.

    1984-01-01

    The optical characteristics of a paraboloidal solar concentrator are analyzed using the intercept factor curve (a format for image data) to describe the results of a mathematical model and to represent reduced data from experimental testing. This procedure makes it possible not only to test an assembled concentrator, but also to evaluate single optical panels or to conduct non-solar tests of an assembled concentrator. The use of three-dimensional ray tracing computer programs to calculate the mathematical model is described. These ray tracing programs can include any type of optical configuration from simple paraboloids to array of spherical facets and can be adapted to microcomputers or larger computers, which can graphically display real-time comparison of calculated and measured data.

  10. Concentrations and Exposure Evaluation of Metals in Diverse Food Items from Chengdu, China.

    Science.gov (United States)

    Wang, Rong; Zhong, Bifeng; Pi, Lu; Xie, Fuyu; Chen, Mengqin; Ding, Sanglan; Su, Shijun; Li, Zhi; Gan, Zhiwei

    2018-01-01

    A total of 520 food samples belonging to 29 food types and 63 drinking water were collected in Chengdu market of China in 2014 to investigate the concentrations of 11 metals, and to assess the related exposure to the local consumers by estimating the hazard quotient and carcinogenic risk (CR). The results showed that metals concentrations in drinking water were below the limit values suggested by the Ministry of Health of the People's Republic of China, and FAO/WHO (Food and Agriculture Organization of the United Nations/World Health Organization). While As, Cd, and Cr were found at concentrations higher than the limit values in some of the foodstuffs. Children in Chengdu intake more metals compared to adults, with the same order of Mn > Zn > Cu > Sr > Cr > Ni > As > Cd > Pb > Co > Sb. Among all of the diverse food, rice, flour, and fish and seafood were the primary sources to intake metals for Chengdu residents. Residents in Chengdu are subjected to both carcinogenic and non-carcinogenic risks based on the calculated HI and CR values, especially for children. Finally, total daily metals intakes for both children and adults were calculated based on the current study and our previous studies, including consumption of food and drinking water and intake of outdoor and indoor dust. Dietary exposure is the predominant exposure route to metals for Chengdu residents, accounting for more than 75.8% of the total daily metals intakes for both children and adults.

  11. Instruments to measure radon activity concentration or exposure to radon. Interlaboratory comparison 2011

    International Nuclear Information System (INIS)

    Foerster, Elisabeth; Beck, Thomas; Buchroeder, Helmut; Doering, Joachim; Schmidt, Volkmar

    2011-10-01

    According to the Directive 96/29/EURATOM the monitoring of occupational radiation exposures shall base on individual measurements carried out by an approved dosimetric service. Pursuant to the European Directive an approved dosimetric service is a body responsible for the calibration, reading or interpretation of individual monitoring devices.., whose capacity to act in this respect is recognized by the competent authorities. This concept will also be applied to radon services issuing passive radon measurement devices. Passive radon measurement devices 1 using solid state nuclear track detectors or electrets are recommended for individual monitoring of exposures to radon. German regulations lay down that radon measuring devices are appropriate for purposes of occupational radiation monitoring if the devices are issued by recognized radon measurement services, and the measurement service submits devices of the same type issued for radon monitoring to regular intercomparisons conducted by BfS. A radon measuring service is recognized by the competent authority if it proves its organizational and technical competence, e. g. by accreditation. These regulations have been introduced in the area of occupational radiation exposures. Nevertheless, it is recommended that radon measuring services which carry out radon measurements in other areas (e.g. dwellings) should subject themselves to these measures voluntarily. The interlaboratory comparisons comprise the organization, exposure, and evaluation of measurements of radon activity concentration or exposure to radon. The comparisons only concern radon-222; radon-220 is not in the scope. Radon services being interested can get further information from the website www.bfs.de/de/ion/radon/fachinfomessung/vergleichspruefungen.html and from the European Information System on Proficiency Testing Schemes (eptis) available in the internet. (orig.)

  12. Instruments to measure radon-222 activity concentration or exposure to radon-222. Intercomparison 2014

    International Nuclear Information System (INIS)

    Foerster, Elisabeth; Beck, Thomas; Buchroeder, Helmut; Doering, Joachim; Schmidt, Volkmar

    2014-10-01

    According to the Directive 96/29/EURATOM the monitoring of occupational radiation exposures shall base on individual measurements carried out by an approved dosimetric service. Pursuant to the European Directive an approved dosimetric service is a body responsible for the calibration, reading or interpretation of individual monitoring devices.., whose capacity to act in this respect is recognized by the competent authorities. This concept will also be applied to radon services issuing passive radon measurement devices. Passive radon measurement devices 1 using solid state nuclear track detectors or electrets are recommended for individual monitoring of exposures to radon. German regulations lay down that radon measuring devices are appropriate for purposes of occupational radiation monitoring if the devices are issued by recognized radon measurement services, and the measurement service submits devices of the same type issued for radon monitoring to regular intercomparisons conducted by the Bundesamt fuer Strahlenschutz (BfS). A radon measuring service is recognized by the competent authority if it proves its organisational and technical competence, e. g. by accreditation. These regulations have been introduced in the area of occupational radiation exposures. Nevertheless, it is recommended that radon measuring services which carry out radon measurements in other areas (e.g. dwellings) should subject themselves to these measures voluntarily. The interlaboratory comparisons comprise the organization, exposure, and evaluation of measurements of radon activity concentration or exposure to radon. The comparisons only concern radon-222; radon-220 is not in the scope. Radon services being interested can get further information from the European Information System on Proficiency Testing Schemes (EPTIS) and from the BfS websites.

  13. Programming of mouse obesity by maternal exposure to concentrated ambient fine particles.

    Science.gov (United States)

    Chen, Minjie; Wang, Xiaoke; Hu, Ziying; Zhou, Huifen; Xu, Yanyi; Qiu, Lianglin; Qin, Xiaobo; Zhang, Yuhao; Ying, Zhekang

    2017-06-23

    Many diseases including obesity may originate through alterations in the early-life environment that interrupts fetal development. Increasing evidence has shown that exposure to ambient fine particles (PM 2.5 ) is associated with abnormal fetal development. However, its long-term metabolic effects on offspring have not been systematically investigated. To determine if maternal exposure to PM 2.5 programs offspring obesity, female C57Bl/6j mice were exposed to filtered air (FA) or concentrated ambient PM 2.5 (CAP) during pre-conception, pregnancy, and lactation, and the developmental and metabolic responses of offspring were assessed. The growth trajectory of offspring revealed that maternal exposure to CAP significantly decreased offspring birth weight but increased body weight of adult male but not female offspring, and the latter was expressed as increased adiposity. These adult male offspring had increased food intake, but were sensitive to exogenous leptin. Their hypothalamic expression of Socs3 and Pomc, two target genes of leptin, was not changed, and the hypothalamic expression of NPY, an orexigenic peptide that is inhibited by leptin, was significantly increased. These decreases in central anorexigenic signaling were accompanied by reduced plasma leptin and its expression in adipose tissues, the primary source of circulating leptin. In contrast, maternal exposure did not significantly change any of these indexes in adult female offspring. Pyrosequencing demonstrated that the leptin promoter methylation of adipocytes was significantly increased in CAP-exposed male but not female offspring. Our data indicate that maternal exposure to ambient PM 2.5 programs obesity in male offspring probably through alterations in the methylation of the promoter region of the leptin gene.

  14. Effect on Hyalella azteca after pulse exposure to environmentally realistic concentrations of permethrin

    DEFF Research Database (Denmark)

    Pedersen, Signe; Palmqvist, Annemette; Forbes, Valery E.

    . H. azteca is widely distributed through North America where it is common as a food source for birds, fish and large invertebrates and is therefore considered as an ecologically important organism. In addition H. azteca has been extensively used as a test organism and is generally sensitive...... realistic pulse exposure and concentration of a pyrethroid pesticide, permethrin, on the freshwater amphipod Hyalella azteca. Permethrin is a pyrethroid insecticide used in mosquito control and to control a wide range of insect pests on various crops and is known to be highly toxic to aquatic invertebrates...

  15. Effects of maternal smoking and exposure to methylmercury on brain-derived neurotrophic factor concentrations in umbilical cord serum

    DEFF Research Database (Denmark)

    Spulber, Stefan; Rantamäki, Tomi; Nikkilä, Outi

    2010-01-01

    . The cohort consisted of 395 singleton births (206 boys and 189 girls), gestational age ranging from 38 to 42 weeks. Serum BDNF was measured by sandwich ELISA. Maternal smoking habits and other relevant factors were obtained by interviewing the mothers. The exposure to MeHg was estimated from Hg...... concentrations in cord blood, whereas exposure to PCB was estimated based on maternal serum concentrations. Only MeHg exposure affected the serum BDNF, which decreased in a concentration-dependent manner in girls born to nonsmoking mothers. Maternal smoking significantly increased BNDF in girls but not in boys....... For further statistical analyses, we used the serum BDNF concentration as a continuous outcome variable in supervised regression models. Serum BDNF concentration increased with gestational age, increased by maternal smoking, decreased slightly with MeHg exposure, and maternal smoking enhanced the decrease...

  16. Genotoxic effects of daily personal exposure to particle mass and number concentrations on buccal cells

    Science.gov (United States)

    de Almeida, Daniela S.; da Costa, Silvano César; Ribeiro, Marcos; Moreira, Camila A. B.; Beal, Alexandra; Squizzato, Rafaela; Rudke, Anderson Paulo; Rafee, Sameh Adib Abou; Martins, Jorge A.; Palioto, Graciana Freitas; Kumar, Prashant; Martins, Leila D.

    2018-03-01

    The aim of this study is to assess personal exposure to Particle Number Concentrations (PNC) in four size ranges between 0.3 and 10 μm, and particulate matter (PM1; PM2.5; PM4; PM10) in order to evaluate possible genotoxic effects through a comet assay in buccal cells. A convenience cohort of 30 individuals from a Brazilian medium-sized city was selected. These individuals aged between 20 and 61 and worked in typical job categories (i.e., administrative, commerce, education, general services and transport). They were recruited to perform personal exposure measurements during their typical daily routine activities, totaling 240 h of sampling. The 8-h average mass concentrations in air for volunteers ranged from 2.4 to 31.8 μg m-3 for PM1, 4.2-45.1 μg m-3 for PM2.5, 7.9-66.1 μg m-3 for PM4 and from 23.1 to 131.7 μg m-3 for PM10. The highest PNC variation was found for 0.3-0.5 range, between 14 and 181 particles cm-3, 1 to 14 particles cm-3 for the 0.5-1.0 range, 0.2 to 2 particles cm-3 for the 1.0-2.5 range, and 0.06 to 0.7 particles cm-3 for the 2.5-10 range. Volunteers in the 'education' category experienced the lowest inhaled dose of PM2.5, as opposed to those involved in 'commercial' activities with the highest doses for PM10 (1.63 μg kg-1 h-1) and PM2.5 (0.61 μg kg-1 h-1). The predominant cause for these high doses was associated with the proximity of the workplace to the street and vehicle traffic. The comet assay performed in buccal cells indicated that the volunteers in 'commerce' category experienced the highest damage to their DeoxyriboNucleic Acid (DNA) compared with the control category (i.e. 'education'). These results indicate the variability in personal exposure of the volunteers in different groups, and the potential damage to DNA was much higher for those spending time in close proximity to the vehicle sources (e.g. commercial services) leading to exposure to a higher fraction of fine particles. This study builds understanding on the exposure

  17. Performance and cost benefits associated with nonimaging secondary concentrators used in point-focus dish solar thermal applications

    Science.gov (United States)

    Ogallagher, J.; Winston, R.

    1987-09-01

    Using nonimaging secondary concentrators in point-focus applications may permit the development of more cost-effective concentrator systems by either improving performance or reducing costs. Secondaries may also increase design flexibility. The major objective of this study was to develop as complete an understanding as possible of the quantitative performance and cost effects associated with deploying nonimaging secondary concentrators at the focal zone of point-focus solar thermal concentrators. A performance model was developed that uses a Monte Carlo ray-trace procedure to determine the focal plane distribution of a paraboloidal primary as a function of optical parameters. It then calculates the corresponding optimized concentration and thermal efficiency as a function of temperature with and without the secondary. To examine the potential cost benefits associated with secondaries, a preliminary model for the rational optimization of performance versus cost trade-offs was developed. This model suggests a possible 10 to 20 percent reduction in the cost of delivered energy when secondaries are used. This is a lower limit, and the benefits may even be greater if using a secondary permits the development of inexpensive primary technologies for which the performance would not otherwise be viable.

  18. Exploratory Investigation of Bacteroides fragilis Transcriptional Response during In vitro Exposure to Subinhibitory Concentration of Metronidazole

    Science.gov (United States)

    de Freitas, Michele C. R.; Resende, Juliana A.; Ferreira-Machado, Alessandra B.; Saji, Guadalupe D. R. Q.; de Vasconcelos, Ana T. R.; da Silva, Vânia L.; Nicolás, Marisa F.; Diniz, Cláudio G.

    2016-01-01

    Bacteroides fragilis, member from commensal gut microbiota, is an important pathogen associated to endogenous infections and metronidazole remains a valuable antibiotic for the treatment of these infections, although bacterial resistance is widely reported. Considering the need of a better understanding on the global mechanisms by which B. fragilis survive upon metronidazole exposure, we performed a RNA-seq transcriptomic approach with validation of gene expression results by qPCR. Bacteria strains were selected after in vitro subcultures with subinhibitory concentration (SIC) of the drug. From a wild type B. fragilis ATCC 43859 four derivative strains were selected: first and fourth subcultures under metronidazole exposure and first and fourth subcultures after drug removal. According to global gene expression analysis, 2,146 protein coding genes were identified, of which a total of 1,618 (77%) were assigned to a Gene Ontology term (GO), indicating that most known cellular functions were taken. Among these 2,146 protein coding genes, 377 were shared among all strains, suggesting that they are critical for B. fragilis survival. In order to identify distinct expression patterns, we also performed a K-means clustering analysis set to 15 groups. This analysis allowed us to detect the major activated or repressed genes encoding for enzymes which act in several metabolic pathways involved in metronidazole response such as drug activation, defense mechanisms against superoxide ions, high expression level of multidrug efflux pumps, and DNA repair. The strains collected after metronidazole removal were functionally more similar to those cultured under drug pressure, reinforcing that drug-exposure lead to drastic persistent changes in the B. fragilis gene expression patterns. These results may help to elucidate B. fragilis response during metronidazole exposure, mainly at SIC, contributing with information about bacterial survival strategies under stress conditions in their

  19. Brominated flame retardants in black plastic kitchen utensils: Concentrations and human exposure implications.

    Science.gov (United States)

    Kuang, Jiangmeng; Abdallah, Mohamed Abou-Elwafa; Harrad, Stuart

    2018-01-01

    Concerns exist that restricted brominated flame retardants (BFRs) present in waste polymers may have, as a result of recycling, inadvertently contaminated items not required to meet flame retardancy regulations (e.g. plastic kitchen utensils). To investigate the extent to which kitchen utensils are contaminated with BFRs and the potential for resultant human exposure, we collected 96 plastic kitchen utensils and screened for Br content using a hand-held X-ray fluorescence (XRF) spectrometer. Only 3 out of 27 utensils purchased after 2011 contained detectable concentrations of Br (≥3μg/g). In contrast, Br was detected in 31 out of the 69 utensils purchased before 2011. Eighteen utensils with Br content higher than 100μg/g, and 12 new utensils were selected for GC-MS analysis of BFRs. BFRs targeted were polybrominated diphenyl ethers (PBDEs) BDE-28, 47, 99, 100, 153, 154, 183 and 209, and novel BFRs (NBFRs) pentabromoethylbenzene (PBEB), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), bis(2-ethylhexyl)-3,4,5,6-tetrabromo-phthalate (BEH-TEBP) and decabromodiphenyl ethane (DBDPE). The ability of XRF to act as a surrogate metric of BFR concentration was indicated by a significant (Spearman coefficient=0.493; p=0.006) positive relationship between Br and ΣBFR concentration. Measurements of ΣBFRs were always exceeded by those of Br. This may be due partly to the presence of BFRs not targeted in our study and also to reduced extraction efficiency of BFRs from utensils. Of our target BFRs, BDE-209 was the most abundant one in most samples, but an extremely high concentration (1000μg/g) of BTBPE was found in one utensil. Simulated cooking experiments were conducted to investigate BFR transfer from selected utensils (n=10) to hot cooking oil, with considerable transfer (20% on average) observed. Estimated median exposure via cooking with BFR contaminated utensils was 60ng/day for total BFRs. In contrast, estimated

  20. Physiologically based pharmacokinetic modeling of human exposure to perfluorooctanoic acid suggests historical non drinking-water exposures are important for predicting current serum concentrations.

    Science.gov (United States)

    Worley, Rachel Rogers; Yang, Xiaoxia; Fisher, Jeffrey

    2017-09-01

    Manufacturing of perfluorooctanoic acid (PFOA), a synthetic chemical with a long half-life in humans, peaked between 1970 and 2002, and has since diminished. In the United States, PFOA is detected in the blood of >99% of people tested, but serum concentrations have decreased since 1999. Much is known about exposure to PFOA in drinking water; however, the impact of non-drinking water PFOA exposure on serum PFOA concentrations is not well characterized. The objective of this research is to apply physiologically based pharmacokinetic (PBPK) modeling and Monte Carlo analysis to evaluate the impact of historic non-drinking water PFOA exposure on serum PFOA concentrations. In vitro to in vivo extrapolation was utilized to inform descriptions of PFOA transport in the kidney. Monte Carlo simulations were incorporated to evaluate factors that account for the large inter-individual variability of serum PFOA concentrations measured in individuals from North Alabama in 2010 and 2016, and the Mid-Ohio River Valley between 2005 and 2008. Predicted serum PFOA concentrations were within two-fold of experimental data. With incorporation of Monte Carlo simulations, the model successfully tracked the large variability of serum PFOA concentrations measured in populations from the Mid-Ohio River Valley. Simulation of exposure in a population of 45 adults from North Alabama successfully predicted 98% of individual serum PFOA concentrations measured in 2010 and 2016, respectively, when non-drinking water ingestion of PFOA exposure was included. Variation in serum PFOA concentrations may be due to inter-individual variability in the disposition of PFOA and potentially elevated historical non-drinking water exposures. Published by Elsevier Inc.

  1. Stochastic modelling for biodosimetry: Predicting the chromosomal response to radiation at different time points after exposure

    Science.gov (United States)

    Deperas-Standylo, Joanna; Gudowska-Nowak, Ewa; Ritter, Sylvia

    2014-07-01

    Cytogenetic data accumulated from the experiments with peripheral blood lymphocytes exposed to densely ionizing radiation clearly demonstrate that for particles with linear energy transfer (LET) >100 keV/ μm the derived relative biological effectiveness (RBE) will strongly depend on the time point chosen for the analysis. A reasonable prediction of radiation-induced chromosome damage and its distribution among cells can be achieved by exploiting Monte Carlo methodology along with the information about the radius of the penetrating ion-track and the LET of the ion beam. In order to examine the relationship between the track structure and the distribution of aberrations induced in human lymphocytes and to clarify the correlation between delays in the cell cycle progression and the aberration burden visible at the first post-irradiation mitosis, we have analyzed chromosome aberrations in lymphocytes exposed to Fe-ions with LET values of 335 keV/ μm and formulated a Monte Carlo model which reflects time-delay in mitosis of aberrant cells. Within the model the frequency distributions of aberrations among cells follow the pattern of local energy distribution and are well approximated by a time-dependent compound Poisson statistics. The cell-division cycle of undamaged and aberrant cells and chromosome aberrations are modelled as a renewal process represented by a random sum of (independent and identically distributed) random elements S N = ∑ N i=0 X i . Here N stands for the number of particle traversals of cell nucleus, each leading to a statistically independent formation of X i aberrations. The parameter N is itself a random variable and reflects the cell cycle delay of heavily damaged cells. The probability distribution of S N follows a general law for which the moment generating function satisfies the relation Φ S N = Φ N ( Φ X i ). Formulation of the Monte Carlo model which allows to predict expected fluxes of aberrant and non-aberrant cells has been based

  2. Concentrations versus amounts of biomarkers in urine: a comparison of approaches to assess pyrethroid exposure

    Directory of Open Access Journals (Sweden)

    Bouchard Michèle

    2008-11-01

    Full Text Available Abstract Background Assessment of human exposure to non-persistent pesticides such as pyrethroids is often based on urinary biomarker measurements. Urinary metabolite levels of these pesticides are usually reported in volume-weighted concentrations or creatinine-adjusted concentrations measured in spot urine samples. It is known that these units are subject to intra- and inter-individual variations. This research aimed at studying the impact of these variations on the assessment of pyrethroid absorbed doses at individual and population levels. Methods Using data obtained from various adult and infantile populations, the intra and inter-individual variability in the urinary flow rate and creatinine excretion rate was first estimated. Individual absorbed doses were then calculated using volume-weighted or creatinine-adjusted concentrations according to published approaches and compared to those estimated from the amounts of biomarkers excreted in 15- or 24-h urine collections, the latter serving as a benchmark unit. The effect of the units of measurements (volume-weighted or creatinine adjusted concentrations or 24-h amounts on results of the comparison of pyrethroid biomarker levels between two populations was also evaluated. Results Estimation of daily absorbed doses of permethrin from volume-weighted or creatinine-adjusted concentrations of biomarkers was found to potentially lead to substantial under or overestimation when compared to doses reconstructed directly from amounts excreted in urine during a given period of time (-70 to +573% and -83 to +167%, respectively. It was also shown that the variability in creatinine excretion rate and urinary flow rate may introduce a bias in the case of between population comparisons. Conclusion The unit chosen to express biomonitoring data may influence the validity of estimated individual absorbed dose as well as the outcome of between population comparisons.

  3. Experimental human exposure to inhaled grain dust and ammonia: towards a model of concentrated animal feeding operations.

    Science.gov (United States)

    Sigurdarson, Sigurdur T; O'Shaughnessy, Patrick T; Watt, Janet A; Kline, Joel N

    2004-10-01

    Ammonia and endotoxin-rich dust are present in high concentrations in swine confinement facilities; exposure to this environment is linked to workers' respiratory problems. We hypothesized that experimental exposure to ammonia and dust would impair pulmonary function, and that these exposures would be synergistic. We exposed six normal subjects and eight subjects with mild asthma to ammonia (16-25 ppm) and/or endotoxin-rich grain dust (4 mg/m3). Pulmonary function and exhaled NOx were measured before and after exposure. There was no significant change in pulmonary function in the normal subjects following any of the exposure conditions. Among asthmatics, a significant transient decrease in FEV1 was induced by grain dust, but was not altered by ammonia; increased bronchial hyperreactivity was also noted in this group. In a vulnerable population, exposure to grain dust results in transient airflow obstruction. Short-term exposure to ammonia does not increase this response.

  4. Comparison of point-of-care versus central laboratory measurement of hematocrit, hemoglobin, and electrolyte concentrations.

    Science.gov (United States)

    Gavala, Alexandra; Myrianthefs, Pavlos

    We aimed to investigate the accuracy of certain laboratory examinations obtained by the ABG analyzer (ROCHE AVL OMNI S) as compared to hospital central laboratory (CL). We prospectively collected data obtained from the same arterial blood sample regarding hematocrit, hemoglobin, potassium, and sodium. ABG analyzer results were significantly lower (p < 0.0001) compared to CL values thus values between the two methods are not interchangeable. The mean bias for Hb, Na + and K + were within accepted by US Clinical Laboratory Improvement Amendment (USCLIA) differences (cut-off points) but not for Ht. In 8.0%, 17.5%, 37.5% and 56.0% of Hb, Na + , K + and Ht measurements respectively and 29.75% in sum the differences were over the USCLIA accepted limits. ABG analyzer significantly underestimate the values of Hb, Ht, Na + and K + , compared to CL and almost 30% of all examined parameters were beyond USCLIA accepted biases. ABG analyzer significantly underestimates the values of Hb, Ht, Na + and K + compared to CL and almost 30% for all examined parameters are beyond USCLIA accepted biases. These data do not support widespread or even careful use of POCT for making diagnostic and treatment decisions until technology improves and results in improved outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. PBTK modeling demonstrates contribution of dermal and inhalation exposure components to end-exhaled breath concentrations of naphthalene.

    Science.gov (United States)

    Kim, David; Andersen, Melvin E; Chao, Yi-Chun E; Egeghy, Peter P; Rappaport, Stephen M; Nylander-French, Leena A

    2007-06-01

    Dermal and inhalation exposure to jet propulsion fuel 8 (JP-8) have been measured in a few occupational exposure studies. However, a quantitative understanding of the relationship between external exposures and end-exhaled air concentrations has not been described for occupational and environmental exposure scenarios. Our goal was to construct a physiologically based toxicokinetic (PBTK) model that quantitatively describes the relative contribution of dermal and inhalation exposures to the end-exhaled air concentrations of naphthalene among U.S. Air Force personnel. The PBTK model comprised five compartments representing the stratum corneum, viable epidermis, blood, fat, and other tissues. The parameters were optimized using exclusively human exposure and biological monitoring data. The optimized values of parameters for naphthalene were a) permeability coefficient for the stratum corneum 6.8 x 10(-5) cm/hr, b) permeability coefficient for the viable epidermis 3.0 x 10(-3) cm/hr, c) fat:blood partition coefficient 25.6, and d) other tissue:blood partition coefficient 5.2. The skin permeability coefficient was comparable to the values estimated from in vitro studies. Based on simulations of workers' exposures to JP-8 during aircraft fuel-cell maintenance operations, the median relative contribution of dermal exposure to the end-exhaled breath concentration of naphthalene was 4% (10th percentile 1% and 90th percentile 11%). PBTK modeling allowed contributions of the end-exhaled air concentration of naphthalene to be partitioned between dermal and inhalation routes of exposure. Further study of inter- and intraindividual variations in exposure assessment is required to better characterize the toxicokinetic behavior of JP-8 components after occupational and/or environmental exposures.

  6. Applicability of a Single Time Point Strategy for the Prediction of Area Under the Concentration Curve of Linezolid in Patients

    DEFF Research Database (Denmark)

    Srinivas, Nuggehally R; Syed, Muzeeb

    2016-01-01

    Background and Objectives: Linezolid, a oxazolidinone, was the first in class to be approved for the treatment of bacterial infections arising from both susceptible and resistant strains of Gram-positive bacteria. Since overt exposure of linezolid may precipitate serious toxicity issues......, therapeutic drug monitoring (TDM) may be required in certain situations, especially in patients who are prescribed other co-medications. Methods: Using appropriate oral pharmacokinetic data (single dose and steady state) for linezolid, both maximum plasma drug concentration (Cmax) versus area under the plasma...... concentration–time curve (AUC) and minimum plasma drug concentration (Cmin) versus AUC relationship was established by linear regression models. The predictions of the AUC values were performed using published mean/median Cmax or Cmin data and appropriate regression lines. The quotient of observed and predicted...

  7. Limited Sampling Strategy for Accurate Prediction of Pharmacokinetics of Saroglitazar: A 3-point Linear Regression Model Development and Successful Prediction of Human Exposure.

    Science.gov (United States)

    Joshi, Shuchi N; Srinivas, Nuggehally R; Parmar, Deven V

    2018-03-01

    Our aim was to develop and validate the extrapolative performance of a regression model using a limited sampling strategy for accurate estimation of the area under the plasma concentration versus time curve for saroglitazar. Healthy subject pharmacokinetic data from a well-powered food-effect study (fasted vs fed treatments; n = 50) was used in this work. The first 25 subjects' serial plasma concentration data up to 72 hours and corresponding AUC 0-t (ie, 72 hours) from the fasting group comprised a training dataset to develop the limited sampling model. The internal datasets for prediction included the remaining 25 subjects from the fasting group and all 50 subjects from the fed condition of the same study. The external datasets included pharmacokinetic data for saroglitazar from previous single-dose clinical studies. Limited sampling models were composed of 1-, 2-, and 3-concentration-time points' correlation with AUC 0-t of saroglitazar. Only models with regression coefficients (R 2 ) >0.90 were screened for further evaluation. The best R 2 model was validated for its utility based on mean prediction error, mean absolute prediction error, and root mean square error. Both correlations between predicted and observed AUC 0-t of saroglitazar and verification of precision and bias using Bland-Altman plot were carried out. None of the evaluated 1- and 2-concentration-time points models achieved R 2 > 0.90. Among the various 3-concentration-time points models, only 4 equations passed the predefined criterion of R 2 > 0.90. Limited sampling models with time points 0.5, 2, and 8 hours (R 2 = 0.9323) and 0.75, 2, and 8 hours (R 2 = 0.9375) were validated. Mean prediction error, mean absolute prediction error, and root mean square error were prediction of saroglitazar. The same models, when applied to the AUC 0-t prediction of saroglitazar sulfoxide, showed mean prediction error, mean absolute prediction error, and root mean square error model predicts the exposure of

  8. Exposure to sublethal concentrations of copper changes biochemistry parameters in silver catfish, Rhamdia quelen, Quoy & Gaimard.

    Science.gov (United States)

    Pretto, Alexandra; Loro, Vania Lucia; Silva, Vera M Machado; Salbego, Joseânia; de Menezes, Charlene Cavalheiro; Souza, Carine de Freitas; Gioda, Carolina Rosa; Baldisserotto, Bernardo

    2014-04-01

    The effects of Cu exposure on catalase (CAT) and acetylcholinesterase (AChE) activity, formation of thiobarbituric acid-reactive species (TBARS) and metabolic parameters were evaluated in silver catfish (Rhamdia quelen). The fish were exposed for 45 days to 0, 16 and 29 μg/L Cu. The fish that were exposed to Cu exhibited lower TBARS levels in the muscle and higher TBARS levels in the liver. They also showed lower CAT activity in the liver and lower AChE activity in the brain and muscle. Higher glucose and lactate and lower protein plasma levels were observed in the fish exposed to Cu. The changes in the hepatic metabolic parameters were Cu concentration dependent. In the muscle, lower glycogen and higher lactate levels were observed in the fish exposed to Cu. Alterations in the metabolic parameters showed a preference for the anaerobic pathway of energy production and liver protein catabolism to supply the energy demand.

  9. Purification and concentration of lead samples in biological monitoring of occupational exposures

    Directory of Open Access Journals (Sweden)

    A Rahimi-Froushani

    2006-04-01

    Full Text Available Background and Aims:Lead is an important environmental constituent widely used in industrialprocesses for production of synthetic materials and therefore can be released in the environmentcausing public exposure especially around the industrial residence area. For evaluation of humanexposure to trace toxic metal of Pb (II, environmental and biological monitoring are essentialprocesses, in which, preparation of such samples is one of the most time-consuming and errorproneaspects prior to analysis. The use of solid-phase extraction (SPE has grown and is a fertiletechnique of sample preparation as it provides better results than those produced by liquid-liquidextraction (LLE. The aim of this study was to investigate factors influencing sample pretreatmentfor trace analysis of lead in biological samples for evaluation of occupational exposure.Method :To evaluate factors influencing quantitative analysis scheme of lead, solid phaseextraction using mini columns filled with XAD-4 resin was optimized with regard to sample pH,ligand concentration, loading flow rate, elution solvent, sample volume (up to 500 ml, elutionvolume, amount of resins, and sample matrix interferences.Results :Lead was retained on solid sorbent and eluted followed by simple determination ofanalytes by using flame atomic absorption spectrometery. Obtained recoveries of the metal ionwere more than 92%. The amount of the analyte detected after simultaneous pre-concentrationwas basically in agreement with the added amounts. The optimized procedure was also validatedwith three different pools of spiked urine samples and showed a good reproducibility over sixconsecutive days as well as six within-day experiments. The developed method promised to beapplicable for evaluation of other metal ions present in different environmental and occupationalsamples as suitable results were obtained for relative standard deviation (less than 10%.Conclusion:This optimized method can be considered to be

  10. Occupational Exposure to Trichloroethylene and Serum Concentrations of IL-6, IL-10, and TNF-alpha

    Science.gov (United States)

    Bassig, Bryan A.; Zhang, Luoping; Tang, Xiaojiang; Vermeulen, Roel; Shen, Min; Smith, Martyn T.; Qiu, Chuangyi; Ge, Yichen; Ji, Zhiying; Reiss, Boris; Hosgood, H. Dean; Liu, Songwang; Bagni, Rachel; Guo, Weihong; Purdue, Mark; Hu, Wei; Yue, Fei; Li, Laiyu; Huang, Hanlin; Rothman, Nathaniel; Lan, Qing

    2015-01-01

    To evaluate the immunotoxicity of trichloroethylene (TCE), we conducted a cross-sectional molecular epidemiology study in China of workers exposed to TCE. We measured serum levels of IL-6, IL-10, and TNF-α, which play a critical role in regulating various components of the immune system, in 71 exposed workers and 78 unexposed control workers. Repeated personal exposure measurements were taken in workers before blood collection using 3 M organic vapor monitoring badges. Compared to unexposed workers, the serum concentration of IL-10 in workers exposed to TCE was decreased by 70% (P = 0.001) after adjusting for potential confounders. Further, the magnitude of decline in IL-10 was >60% and statistically significant in workers exposed to <12 ppm as well as in workers with exposures ≥ 12 ppm of TCE, compared to unexposed workers. No significant differences in levels of IL-6 or TNF-α were observed among workers exposed to TCE compared to unexposed controls. Given that IL-10 plays an important role in immunologic processes, including mediating the Th1/Th2 balance, our findings provide additional evidence that TCE is immunotoxic in humans. PMID:23798002

  11. Considerations for effect site pharmacokinetics to estimate drug exposure: concentrations of antibiotics in the lung.

    Science.gov (United States)

    Rodvold, Keith A; Hope, William W; Boyd, Sara E

    2017-10-01

    Bronchoalveolar lavage (BAL) and microdialysis have become the most reliable and relevant methods for measuring lung concentrations of antibiotics, with the majority of BAL studies involving either healthy adult subjects or patients undergoing diagnostic bronchoscopy. Emphasis on the amount of drug that reaches the site of infection is increasingly recognized as necessary to determine whether a dose selection will translate to good clinical outcomes in the treatment of patients with pneumonia. Observed concentrations and/or parameters of exposure (e.g. area-under-the-curve) need to be incorporated with pharmacokinetic-pharmacodynamic indices so that rational dose selection can be identified for specific pathogens and types of pneumonic infection (community-acquired vs hospital-acquired bacterial pneumonia, including ventilator-associated bacterial pneumonia). Although having measured plasma or lung concentration-time data from critically ill patients to incorporate into pharmacokinetic-pharmacodynamic models is very unlikely during drug development, it is essential that altered distribution, augmented renal clearance, and renal or hepatic dysfunction should be considered. Notably, the number of published studies involving microdialysis and intrapulmonary penetration of antibiotics has been limited and mainly involve beta-lactam agents, levofloxacin, and fosfomycin. Opportunities to measure in high-resolution effect site spatial pharmacokinetics (e.g. with MALDI-MSI or PET imaging) and in vivo continuous drug concentrations (e.g. with aptamer-based probes) now exist. Going forward these studies could be incorporated into antibiotic development programs for pneumonia in order to further increase the probability of candidate success. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Geospatial exposure to point-of-sale tobacco: real-time craving and smoking-cessation outcomes.

    Science.gov (United States)

    Kirchner, Thomas R; Cantrell, Jennifer; Anesetti-Rothermel, Andrew; Ganz, Ollie; Vallone, Donna M; Abrams, David B

    2013-10-01

    Little is known about the factors that drive the association between point-of-sale marketing and behavior, because methods that directly link individual-level use outcomes to real-world point-of-sale exposure are only now beginning to be developed. Daily outcomes during smoking cessation were examined as a function of both real-time geospatial exposure to point-of-sale tobacco (POST) and subjective craving to smoke. Continuous individual geospatial location data collected over the first month of a smoking-cessation attempt in 2010-2012 (N=475) were overlaid on a POST outlet geodatabase (N=1060). Participants' mobility data were used to quantify the number of times they came into contact with a POST outlet. Participants recorded real-time craving levels and smoking status via ecological momentary assessment (EMA) on cellular telephones. The final data set spanned a total of 12,871 days of EMA and geospatial tracking. Lapsing was significantly more likely on days with any POST contact (OR=1.19, 95% CI=1.18, 1.20), and increasingly likely as the number of daily POST contacts increased (OR=1.07, 95% CI=1.06, 1.08). Overall, daily POST exposure was significantly associated with lapsing when craving was low (OR=1.22, 95% CI=1.20, 1.23); high levels of craving were more directly associated with lapse outcomes. These data shed light on the way mobility patterns drive a dynamic interaction between individuals and the POST environment, demonstrating that quantification of individuals' exposure to POST marketing can be used to identify previously unrecognized patterns of association among individual mobility, the built environment, and behavioral outcomes. © 2013 American Journal of Preventive Medicine.

  13. A nine-point pH titration method to determine low-concentration VFA in municipal wastewater.

    Science.gov (United States)

    Ai, Hainan; Zhang, Daijun; Lu, Peili; He, Qiang

    2011-01-01

    Characterization of volatile fatty acid (VFA) in wastewater is significant for understanding the wastewater nature and the wastewater treatment process optimization based on the usage of Activated Sludge Models (ASMs). In this study, a nine-point pH titration method was developed for the determination of low-concentration VFA in municipal wastewater. The method was evaluated using synthetic wastewater containing VFA with the concentration of 10-50 mg/l and the possible interfering buffer systems of carbonate, phosphate and ammonium similar to those in real municipal wastewater. In addition, the further evaluation was conducted through the assay of real wastewater using chromatography as reference. The results showed that the recovery of VFA in the synthetic wastewater was 92%-102 and the coefficient of variance (CV) of reduplicate measurements 1.68%-4.72%. The changing content of the buffering substances had little effect on the accuracy of the method. Moreover, the titration method was agreed with chromatography in the determination of VFA in real municipal wastewater with R(2)= 0.9987 and CV =1.3-1.7. The nine-point pH titration method is capable of satisfied determination of low-concentration VFA in municipal wastewater.

  14. Trends in Pinus ponderosa foliar pigment concentration due to chronic exposure of ozone and acid rain

    International Nuclear Information System (INIS)

    Neuman, L.; Houpis, J.; Anderson, P.

    1991-01-01

    To determine the effects of ozone and acid rain on mature Ponderosa pine trees, Lawrence Livermore National Lab. has collaborated with University of California Berkeley, University of California Davis, California State University Chico, and the US Forest Service at the latter's Chico Tree Improvement Center. Foliar tissue from mature grafted scions of Pinus ponderosa were exposed to two times ambient ozone for ten months and to acid rain (3.0 pH) weekly for 10 weeks using branch exposure chambers. Pigment extracts were analyzed spectrophotometrically for concentrations of chlorophylls a and b, and carotenoid pigments, at 662 nm, 644 nm, and 470 nm, respectively. Pigment concentrations were expressed on a surface area basis. Preliminary results revealed that chlorophyll a showed a downward trend due to the ozone treatment. Acid rain caused no effects on these three pigments, however, chlorophyll b showed an upward trend due to the interaction of ozone and acid rain. The carotenoid pigments showed no changes due to the treatments either singly, or in combination

  15. A single sip of a strong alcoholic beverage causes exposure to carcinogenic concentrations of acetaldehyde in the oral cavity.

    Science.gov (United States)

    Linderborg, Klas; Salaspuro, Mikko; Väkeväinen, Satu

    2011-09-01

    The aim of this study was to explore oral exposure to carcinogenic (group 1) acetaldehyde after single sips of strong alcoholic beverages containing no or high concentrations of acetaldehyde. Eight volunteers tasted 5 ml of ethanol diluted to 40 vol.% with no acetaldehyde and 40 vol.% calvados containing 2400 μM acetaldehyde. Salivary acetaldehyde and ethanol concentrations were measured by gas chromatography. The protocol was repeated after ingestion of ethanol (0.5 g/kg body weight). Salivary acetaldehyde concentration was significantly higher after sipping calvados than after sipping ethanol at 30s both with (215 vs. 128 μmol/l, psipping of the alcoholic beverages. Carcinogenic concentrations of acetaldehyde are produced from ethanol in the oral cavity instantly after a small sip of strong alcoholic beverage, and the exposure continues for at least 10 min. Acetaldehyde present in the beverage has a short-term effect on total acetaldehyde exposure. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Effect of Exposure to Hyperoxic, Hypobaric, and Hyperbaric Environments on Concentrations of Selected Aerobic and Anaerobic Fecal Flora of Mice

    Science.gov (United States)

    Gillmore, James D.; Gordon, Francis B.

    1975-01-01

    Alterations in selected aerobic and anaerobic fecal microflora of the mouse were determined during exposure to hyperoxic and normoxic hypo- and hyperbaric environments. Examination of fecal cultures obtained during exposure for 6 weeks to either 60 or 77% oxygen concentration at 1 atmosphere absolute revealed little alteration in the aerobic or anaerobic flora. There appeared to be only a retardation in the reduction of the Klebsiella-Enterobacter flora which normally occurs after weaning. During exposure to hypobaric environments (100% O2, 0.2 atmosphere absolute), significant alterations in concentrations of Escherichia coli, slow lactose fermenters, Klebsiella-Enterobacter, and enterococci were found in some instances. All alterations were toward increased concentrations. Variations in concentrations of different colony types of obligately anaerobic gram-positive (anGPR) and gram-negative (anGNR) rods cultured during the same experiments also occurred. One colony type of anGPR appeared to decrease while a second type increased in numbers. Concentrations of three colony types of anGNR were generally, but not always, increased. During hyperbaric exposure (2.8% O2, 7.5 atmospheres absolute), increased concentrations of Klebsiella-Enterobacter, E. coli, slow lactose fermenters and enterococci were also noted. Changes in numbers of both colony types of anGPR, when occurring, were in the direction of lower numbers. Alteration in numbers of anGNR were in both directions but were more frequent in the direction of higher numbers. After return to normal air for 4 weeks of either hypo- or hyperbaric exposure, fecal concentrations of all organisms tended to revert toward control values with the exception of the anGPR which remained in lower concentrations after termination of the hyperbaric exposure. These observations indicate that, despite the great variation in the fecal flora among individual mice, it is possible to discover the effects induced by altered gaseous

  17. Traffic exposure in a population with high prevalence type 2 diabetes - Do medications influence concentrations of C-reactive protein?

    International Nuclear Information System (INIS)

    Rioux, Christine L.; Tucker, Katherine L.; Brugge, Doug; Gute, David M.; Mwamburi, Mkaya

    2011-01-01

    Type 2 Diabetes (T2D) and particulate air pollution are associated with inflammatory dysregulation. We assessed the modifying effects of diabetes medications on the association of C-reactive protein (CRP), a marker of inflammation, and traffic exposure in adults with T2D (n = 379). CRP concentrations were significantly positively associated with residence ≤100 m of a roadway, >100 m and ≤200 m of a roadway and increased traffic density for individuals using insulin. For individuals using oral hypoglycemic medications (OHAs), CRP was significantly negatively associated with residence >100 m - ≤200 m of a roadway and multiple roadway exposure in an interaction model. Among people with diabetes, individuals on insulin appear to be most vulnerable to the effects of traffic exposure. Disease severity among insulin users may promote the pro-inflammatory response to traffic exposure, though diabetes medications may also modify the response. Possible anti-inflammatory effects of OHAs with traffic exposure merit further evaluation. - Highlights: →We examine traffic exposure in a population with high rates of Type 2 Diabetes. →Differences in CRP were evaluated by traffic levels, medication use and type. →Those on insulin had significantly higher CRP with traffic exposure. →Interaction models demonstrated lower CRP with traffic exposure and OHA use. →Diabetes medications may modify the response to traffic exposure. - Among people with diabetes, individuals on insulin appear to be most vulnerable to the effects of traffic exposure. Diabetes medications may modify the response to traffic.

  18. Traffic exposure in a population with high prevalence type 2 diabetes - Do medications influence concentrations of C-reactive protein?

    Energy Technology Data Exchange (ETDEWEB)

    Rioux, Christine L., E-mail: christine.rioux@tufts.edu [Department of Public Health and Community Medicine, Tufts University, 136 Harrison Avenue, Boston, MA 02111 (United States); Tucker, Katherine L. [Department of Health Science, Northeastern University, Boston, MA (United States); Brugge, Doug [Department of Public Health and Community Medicine, Tufts University, 136 Harrison Avenue, Boston, MA 02111 (United States); Gute, David M. [Department of Civil and Environmental Engineering, Tufts University, Medford, MA (United States); Mwamburi, Mkaya [Department of Public Health and Community Medicine, Tufts University, 136 Harrison Avenue, Boston, MA 02111 (United States)

    2011-08-15

    Type 2 Diabetes (T2D) and particulate air pollution are associated with inflammatory dysregulation. We assessed the modifying effects of diabetes medications on the association of C-reactive protein (CRP), a marker of inflammation, and traffic exposure in adults with T2D (n = 379). CRP concentrations were significantly positively associated with residence {<=}100 m of a roadway, >100 m and {<=}200 m of a roadway and increased traffic density for individuals using insulin. For individuals using oral hypoglycemic medications (OHAs), CRP was significantly negatively associated with residence >100 m - {<=}200 m of a roadway and multiple roadway exposure in an interaction model. Among people with diabetes, individuals on insulin appear to be most vulnerable to the effects of traffic exposure. Disease severity among insulin users may promote the pro-inflammatory response to traffic exposure, though diabetes medications may also modify the response. Possible anti-inflammatory effects of OHAs with traffic exposure merit further evaluation. - Highlights: >We examine traffic exposure in a population with high rates of Type 2 Diabetes. >Differences in CRP were evaluated by traffic levels, medication use and type. >Those on insulin had significantly higher CRP with traffic exposure. >Interaction models demonstrated lower CRP with traffic exposure and OHA use. >Diabetes medications may modify the response to traffic exposure. - Among people with diabetes, individuals on insulin appear to be most vulnerable to the effects of traffic exposure. Diabetes medications may modify the response to traffic.

  19. A panel study of airborne particulate matter concentration and impaired cardiopulmonary function in young adults by two different exposure measurement

    Science.gov (United States)

    Hu, Li-Wen; Qian, Zhengmin (Min); Bloom, Michael S.; Nelson, Erik J.; Liu, Echu; Han, Bin; Zhang, Nan; Liu, Yimin; Ma, Huimin; Chen, Duo-Hong; Yang, Bo-Yi; Zeng, Xiao-Wen; Chen, Wen; Komppula, Mika; Leskinen, Ari; Hirvonen, Maija-Riitta; Roponen, Marjut; Jalava, Pasi; Bai, Zhipeng; Dong, Guang-Hui

    2018-05-01

    This study sought to clarify the correlation of individual exposure measurements and PM2.5 measurements collected at regulatory monitoring sites in short-term panel study settings. To achieve this goal, 30 young, healthy adult participants were assigned to three groups with 4 samplers in each group to collect individual exposures during four weekends in March 2016. Participants also completed cardiopulmonary function tests during the same periods. For comparison, ambient air pollution data were obtained from the Air Pollution Surveillance Network in Guangzhou, China. The 8-h ambient pollutant averages and group sampler concentrations were used as separate indicators of air pollution exposure. Results showed that the 8-h mean concentration of personal PM2.5 exposure was 65.09 ± 22.18 μg/m3, which was 24.34 μg/m3 statistically higher than the ambient concentrations over the same period (p < 0.05). However, these concentrations were strongly correlated (Spearman's r = 0.937, p < 0.01). Separate mixed-effect models were fit for ambient and personal exposures to estimate their associations with cardiopulmonary outcomes. Higher PM2.5 and PM10 exposures were related to lower lung function of maximal mid-expiratory flow (MMEF). A 10 μg/m3 higher PM was associated with 0.11 L/S to 0.52 L/S lower MMEF. No effects on cardiovascular function were found. In conclusion, personal PM2.5 exposure might be higher than ambient concentrations. Young, healthy adults in urban areas may experience reduced lung function (lower MMEF), even after just 8 h of exposure to PM2.5 and PM10.

  20. Electronic equilibrium as a function of depth in tissue from cobalt-60 point source exposures

    International Nuclear Information System (INIS)

    Myrick, J.A.

    1994-08-01

    The Nuclear Regulatory Commission has set the basic criteria for assessing skin dose stemming from hot particle contaminations. Compliance with 10 CFR 20.101 requires that exposure to the skin be evaluated over a 1 cm 2 area at a depth of 0.007 cm. Skin exposure can arise from both the beta and gamma components of radioactive particles and gamma radiation can contribute significantly to skin doses. The gamma component of dose increases dramatically when layers of protective clothing are interposed between the hot particle source and the skin, and in cases where the hot particle is large in comparison to the range of beta particles. Once the protective clothing layer is thicker than the maximum range of the beta particles, skin dose is due solely to gamma radiation. Charged particle equilibrium is not established at shallow depths. The degree of electronic equilibrium establishment must be assessed for shallow doses to prevent the over-assessment of skin dose because conventional fluence-to-dose conversion factors are not applicable. To assess the effect of electronic equilibrium, selected thicknesses of tissue equivalent material were interposed between radiochromic dye film and a 60 Co hot particle source and dose was measured as a function of depth. These measured values were then compared to models which are used to calculate charged particle equilibrium. The Miller-Reece model was found to agree closely with the experimental data while the Lantz-Lambert model overestimated dose at shallow depths

  1. The Dose–Response Association between Nitrogen Dioxide Exposure and Serum Interleukin-6 Concentrations

    Directory of Open Access Journals (Sweden)

    Jennifer L. Perret

    2017-05-01

    Full Text Available Systemic inflammation is an integral part of chronic obstructive pulmonary disease (COPD, and air pollution is associated with cardiorespiratory mortality, yet the interrelationships are not fully defined. We examined associations between nitrogen dioxide (NO2 exposure (as a marker of traffic-related air pollution and pro-inflammatory cytokines, and investigated effect modification and mediation by post-bronchodilator airflow obstruction (post-BD-AO and cardiovascular risk. Data from middle-aged participants in the Tasmanian Longitudinal Health Study (TAHS, n = 1389 were analyzed by multivariable logistic regression, using serum interleukin (IL-6, IL-8 and tumor necrosis factor-α (TNF-α as the outcome. Mean annual NO2 exposure was estimated at residential addresses using a validated satellite-based land-use regression model. Post-BD-AO was defined by post-BD forced expiratory ratio (FEV1/FVC < lower limit of normal, and cardiovascular risk by a history of either cerebrovascular or ischaemic heart disease. We found a positive association with increasing serum IL-6 concentration (geometric mean 1.20 (95% CI: 1.1 to 1.3, p = 0.001 per quartile increase in NO2. This was predominantly a direct relationship, with little evidence for either effect modification or mediation via post-BD-AO, or for the small subgroup who reported cardiovascular events. However, there was some evidence consistent with serum IL-6 being on the causal pathway between NO2 and cardiovascular risk. These findings raise the possibility that the interplay between air pollution and systemic inflammation may differ between post-BD airflow obstruction and cardiovascular diseases.

  2. Exposure to Point-of-Sale Marketing of Cigarettes and E-Cigarettes as Predictors of Smoking Cessation Behaviors.

    Science.gov (United States)

    Mantey, Dale S; Pasch, Keryn E; Loukas, Alexandra; Perry, Cheryl L

    2017-11-06

    Cue-reactivity theory suggests smoking-related visual cues such as point-of-sale (POS) marketing (e.g., advertising, product displays) may undermine cessation attempts by causing an increase in nicotine cravings among users. This study examined the relationship between recall of exposure to POS marketing and subsequent cessation behaviors among young adult cigarette smokers. Participants included 813 18-29 year old (m=21.1, sd=2.70) current cigarette smokers attending 24 Texas colleges. Multivariable logistic regression models examined the impact of baseline self-reported exposure to cigarette and e-cigarette advertising and product displays, on using e-cigarettes for cessation and successful cigarette cessation at 6-month follow-up. Two-way interactions between product-specific advertising and between product-specific displays were examined to determine if the marketing of one product strengthened the cue-reactivity of the other. Baseline covariates included socio-demographic factors, past quit attempts, intentions to quit smoking, and nicotine dependence. Exposure to e-cigarette displays was associated with lower odds of cigarette smoking cessation, controlling for covariates and conventional cigarette display exposure. E-cigarette advertising was positively associated with use of e-cigarettes for cigarette cessation among participants exposed to low (i.e., at least one standard deviation below the mean) levels of cigarette advertising. Cigarette advertising was associated with use of e-cigarettes for cigarette cessation only among those exposed to low levels of e-cigarette advertising. Exposure to cigarette displays was not associated with either outcome. Smoking-related cues at POS may undermine successful cigarette cessation. Exposure to product displays decrease odds of cessation. Advertising exposure increased odds for using e-cigarettes for cessation attempts, but may have guided smokers towards an unproven cessation aid. By examining the interaction of

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-08-25

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

  5. Using a chemistry transport model to account for the spatial variability of exposure concentrations in epidemiologic air pollution studies.

    Science.gov (United States)

    Valari, Myrto; Menut, Laurent; Chatignoux, Edouard

    2011-02-01

    Environmental epidemiology and more specifically time-series analysis have traditionally used area-averaged pollutant concentrations measured at central monitors as exposure surrogates to associate health outcomes with air pollution. However, spatial aggregation has been shown to contribute to the overall bias in the estimation of the exposure-response functions. This paper presents the benefit of adding features of the spatial variability of exposure by using concentration fields modeled with a chemistry transport model instead of monitor data and accounting for human activity patterns. On the basis of county-level census data for the city of Paris, France, and a Monte Carlo simulation, a simple activity model was developed accounting for the temporal variability between working and evening hours as well as during transit. By combining activity data with modeled concentrations, the downtown, suburban, and rural spatial patterns in exposure to nitrogen dioxide, ozone, and PM2.5 (particulate matter [PM] pollution on total nonaccidental mortality for the 4-yr period from 2001 to 2004. It was shown that the time series of the exposure surrogates developed here are less correlated across co-pollutants than in the case of the area-averaged monitor data. This led to less biased exposure-response functions when all three co-pollutants were inserted simultaneously in the same regression model. This finding yields insight into pollutant-specific health effects that are otherwise masked by the high correlation among co-pollutants.

  6. Black carbon concentrations in California vehicles and estimation of in-vehicle diesel exhaust particulate matter exposures

    Science.gov (United States)

    Fruin, Scott A.; Winer, Arthur M.; Rodes, Charles E.

    This research assessed in-vehicle exposures to black carbon (BC) as an indicator of diesel particulate matter (DPM) exposures. Approximately 50 h of real-time Aethalometer BC measurements were made inside vehicles driven on freeway and arterial loops in Los Angeles and Sacramento. Video tapes of the driver's view were transcribed to record the traffic conditions, vehicles followed, and vehicle occupant observations, and these results were tested for their associations with BC concentration. In-vehicle BC concentrations were highest when directly following diesel-powered vehicles, particularly those with low exhaust pipe locations. The lowest BC concentrations were observed while following gasoline-powered passenger cars, on average no different than not following any vehicle. Because diesel vehicles were over-sampled in the field study, results were not representative of real-world driving. To calculate representative exposures, in-vehicle BC concentrations were grouped by the type of vehicle followed, for each road type and congestion level. These groupings were then re-sampled stochastically, in proportion to the fraction of statewide vehicle miles traveled (VMT) under each of those conditions. The approximately 6% of time spent following diesel vehicles led to 23% of the in-vehicle BC exposure, while the remaining exposure was due to elevated roadway BC concentrations. In-vehicle BC exposures averaged 6 μg m -3 in Los Angeles and the Bay Area, the regions with the highest congestion and the majority of the state's VMT. The statewide average in-vehicle BC exposure was 4 μg m -3, corresponding to DPM concentrations of 7-23 μg m -3, depending on the Aethalometer response to elemental carbon (EC) and the EC fraction of the DPM. In-vehicle contributions to overall DPM exposures ranged from approximately 30% to 55% of total DPM exposure on a statewide population basis. Thus, although time spent in vehicles was only 1.5 h day -1 on average, vehicles may be the most

  7. Deoxyriboside determination and cytofluorometric test in rats at different points of time after radiation exposure

    International Nuclear Information System (INIS)

    Aleksandrov, S.N.; Bazanova, N.V.; Prokudina, E.A.; Safronova, V.G.; Yagunov, A.S.

    1976-01-01

    Whole-body X- or γ-irradiation with doses ranging from 200 to 400 rad is easily identifiable in rats within the succeeding days by determining the deoxyriboside level in blood and urine because of the almost linear correlation between the change of concentration and the dose level in the range under consideration. Within 4 weeks postirradiation the dose received may also be determined by measuring the intensity of ultraviolet fluorescence of the peripheral blood leukocytes. Subsequently, only a qualitative distinction between exposed and unexposed animals was still possible by means of this test up to the end of the investigation period. (author)

  8. Total arsenic concentrations in toenails quantified by two techniques provide a useful biomarker of chronic arsenic exposure in drinking water

    International Nuclear Information System (INIS)

    Adair, Blakely M.; Hudgens, Edward E.; Schmitt, Michael T.; Calderon, Rebecca L.; Thomas, David J.

    2006-01-01

    Accurate quantitation of any contaminant of interest is critical for exposure assessment and metabolism studies that support risk assessment. A preliminary step in an arsenic exposure assessment study in Nevada quantified total arsenic (TAs) concentrations in tissues as biomarkers of exposure. Participants in this study (n=95) were at least 45 years old, had lived in the area for more than 20 years, and were exposed to a wide range of arsenic concentrations in drinking water (3-2100ppb). Concentrations of TAs in blood, urine, and toenails determined by hydride generation-atomic fluorescence spectrometry (HG-AFS) ranged from below detection to 0.03, 0.76, and 12ppm, respectively; TAs in blood rarely exceeded the limit of detection. For comparison, TAs in toenails determined by neutron activation analysis (NAA) ranged from below detection to 16ppm. Significant (P 2 =0.3557 HG-AFS, adjusted r 2 =0.3922 NAA); TAs concentrations in urine were not described by drinking water As (adjusted r 2 =0.0170, P=0.1369). Analyses of TAs in toenails by HGAFS and NAA yielded highly concordant estimates (r=0.7977, P<0.0001). These results suggest that toenails are a better biomarker of chronic As exposure than urine in the current study, because the sequestration of As in toenails provides an integration of exposure over time that does not occur in urine

  9. Personal exposures to VOC in the upper end of the distribution—relationships to indoor, outdoor and workplace concentrations

    Science.gov (United States)

    Edwards, Rufus D.; Schweizer, Christian; Jantunen, Matti; Lai, Hak Kan; Bayer-Oglesby, Lucy; Katsouyanni, Klea; Nieuwenhuijsen, Mark; Saarela, Kristiina; Sram, Radim; Künzli, Nino

    Evaluation of relationships between median residential indoor, indoor workplace and population exposures may obscure potential strategies for exposure reduction. Evaluation of participants with personal exposures above median levels in the EXPOLIS study in Athens, Helsinki, Oxford and Prague illustrated that these participants frequently showed a different relationship to indoor and workplace levels than that shown by the population median. Thus, prioritization of environments for control measures based on median exposures may exclude important areas where effectively focused control measures are possible, and may therefore have little impact on the highest and most harmful exposures. Further, personal exposures at the upper end of the distribution may exceed the US EPA inhalation reference concentration (Rfc), illustrated here using hexane, naphthalene and benzene. For example upper 90th percentile personal exposures to benzene in Athens and Prague were 64 and 27 μg m -3 with peak exposures of 217 and 38 μg m -3, respectively for non-ETS exposed participants relative to an Rfc of 30 μg m -3. Strategies to reduce exposures to individual compounds, therefore, may benefit from focus on the high end of the distribution to identify activities and behaviors that result in elevated exposures. Control strategies targeting activities that lead to exposures in the upper end of the distribution would reduce the variability associated with population median values by bringing the upper end of the exposure distribution closer to median values. Thus, compliance with health-based standards would be more protective of the higher exposed fraction of the population, in whom health effects would be more expected.

  10. Effects of stunning with different carbon dioxide concentrations and exposure times on suckling lamb meat quality.

    Science.gov (United States)

    Bórnez, R; Linares, M B; Vergara, H

    2009-03-01

    Forty-nine Manchega breed male suckling lambs were used to determine the effect of different stunning methods (using two different CO2 concentrations and exposure times) on lamb meat quality. The lambs were allocated to five stunning treatments including four CO2 treatments [80% CO2 for 90s (G1); 90% CO2 for 90s (G2); 90% CO2 for 60s (G3); 80% CO2 for 60s (G4)] and an electrically stunned control group (G5). The gas-stunning treatments did not cause neither haematomas nor blood splash in the carcasses. Meat quality was evaluated by testing pH, colour (L(∗), a(∗), b(∗), chroma, hue values), water holding capacity (WHC), cooking loss (CL), shear force (SF), drip loss (DL) and total aerobic bacteria. Statistical differences in pH at 24h post-mortem, colour, WHC and CL were not found among groups. After 7 days post-mortem, there were statistical differences among groups in pH (highest in G4 and G5) and in DL (highest in G1). There were differences in SF due to stunning method evident after 72h and 7 days ageing. The statistical differences (Plambs since a highest stability with ageing time on meat quality was found using 90% CO2.

  11. [Geographic distribution and exposure population of drinking water with high concentration of arsenic in China].

    Science.gov (United States)

    Zhang, L; Chen, C

    1997-09-01

    According to the data obtained from the "National Survey on Drinking Water Quality and Waterborne Diseases", the geographic distribution and exposure population of high arsenic drinking water were reported. From the data of more than 28,800 water samples, we found 9.02 million people drinking the water with As concentration of 0.030-0.049 mg/L, 3.34 million people having their water of 0.050-0.099 mg/L and 2.29 million people having water of > 0.1 mg/L. A total of 14.6 million people, about 1.5% of the surveyed population was exposed to As (> 0.030 mg/L) from drinking water. 80% of high-As-drinking water was groundwater. The situation of As in drinking water in provinces, autonomous regions and municipalities were listed. The locations of sampling site where water As exceeded the national standard for drinking water were illustrated.

  12. Exposure to early adversity: Points of cross-species translation that can lead to improved understanding of depression.

    Science.gov (United States)

    Andersen, Susan L

    2015-05-01

    The relationship between developmental exposure to adversity and affective disorders is reviewed. Adversity discussed herein includes physical and sexual abuse, neglect, or loss of a caregiver in humans. While these stressors can occur at any point during development, the unique temporal relationship to specific depressive symptoms was the focus of discussion. Further influences of stress exposure during sensitive periods can vary by gender and duration of abuse as well. Data from animal studies are presented to provide greater translational and causal understanding of how sensitive periods, different types of psychosocial stressors, and sex interact to produce depressive-like behaviors. Findings from maternal separation, isolation rearing, chronic variable stress, and peer-peer rearing paradigms clarify interpretation about how various depressive behaviors are influenced by age of exposure. Depressive behaviors are broken down into the following categories: mood and affect, anhedonia, energy, working memory, sleep-wake, appetite changes, suicide, and general malaise. Cross-species evidence from humans, nonhuman primates, rats, and mice within each of these categories is discussed. In conclusion, sensitive periods for affective-related behaviors (anxiety, mood, and controllability) occur earlier in life, while other aspects of depression are associated with adversity later during adolescence.

  13. Mimicking exposures to acute and lifetime concentrations of inhaled silver nanoparticles by two different in vitro approaches

    Directory of Open Access Journals (Sweden)

    Fabian Herzog

    2014-08-01

    Full Text Available In the emerging market of nano-sized products, silver nanoparticles (Ag NPs are widely used due to their antimicrobial properties. Human interaction with Ag NPs can occur through the lung, skin, gastrointestinal tract, and bloodstream. However, the inhalation of Ag NP aerosols is a primary concern. To study the possible effects of inhaled Ag NPs, an in vitro triple cell co-culture model of the human alveolar/airway barrier (A549 epithelial cells, human peripheral blood monocyte derived dendritic and macrophage cells together with an air–liquid interface cell exposure (ALICE system was used in order to reflect a real-life exposure scenario. Cells were exposed at the air–liquid interface (ALI to 0.03, 0.3, and 3 µg Ag/cm2 of Ag NPs (diameter 100 nm; coated with polyvinylpyrrolidone: PVP. Ag NPs were found to be highly aggregated within ALI exposed cells with no impairment of cell morphology. Furthermore, a significant increase in release of cytotoxic (LDH, oxidative stress (SOD-1, HMOX-1 or pro-inflammatory markers (TNF-α, IL-8 was absent. As a comparison, cells were exposed to Ag NPs in submerged conditions to 10, 20, and 30 µg Ag/mL. The deposited dose per surface area was estimated by using a dosimetry model (ISDD to directly compare submerged vs ALI exposure concentrations after 4 and 24 h. Unlike ALI exposures, the two highest concentrations under submerged conditions promoted a cytotoxic and pro-inflammatory response after 24 h. Interestingly, when cell cultures were co-incubated with lipopolysaccharide (LPS, no synergistic inflammatory effects were observed. By using two different exposure scenarios it has been shown that the ALI as well as the suspension conditions for the lower concentrations after 4 h, reflecting real-life concentrations of an acute 24 h exposure, did not induce any adverse effects in a complex 3D model mimicking the human alveolar/airway barrier. However, the highest concentrations used in the ALI setup, as well

  14. Ambient concentrations and personal exposure to polycyclic aromatic hydrocarbons (PAH) in an urban community with mixed sources of air pollution

    Science.gov (United States)

    ZHU, XIANLEI; FAN, ZHIHUA (TINA); WU, XIANGMEI; JUNG, KYUNG HWA; OHMAN-STRICKLAND, PAMELA; BONANNO, LINDA J.; LIOY, PAUL J.

    2014-01-01

    Assessment of the health risks resulting from exposure to ambient polycyclic aromatic hydrocarbons (PAH) is limited by a lack of environmental exposure data among the general population. This study characterized personal exposure and ambient concentrations of PAH in the Village of Waterfront South (WFS), an urban community with many mixed sources of air toxics in Camden, New Jersey, and CopeWood/Davis Streets (CDS), an urban reference area located ~1 mile east of WFS. A total of 54 and 53 participants were recruited from non-smoking households in WFS and CDS, respectively. In all, 24-h personal and ambient air samples were collected simultaneously in both areas on weekdays and weekends during summer and winter. The ambient PAH concentrations in WFS were either significantly higher than or comparable to those in CDS, indicating the significant impact of local sources on PAH pollution in WFS. Analysis of diagnostic ratios and correlation suggested that diesel truck traffic, municipal waste combustion and industrial combustion were the major sources in WFS. In such an area, ambient air pollution contributed significantly to personal PAH exposure, explaining 44–96% of variability in personal concentrations. This study provides valuable data for examining the impact of local ambient PAH pollution on personal exposure and therefore potential health risks associated with environmental PAH pollution. PMID:21364704

  15. Interaction of exposure concentration and duration in determining the apoptosis of testis in rats after cigarette smoke inhalation

    Directory of Open Access Journals (Sweden)

    Lijuan He

    2016-07-01

    Full Text Available The effects of differences in smoke concentration and exposure duration in Sprague Dawley rats to determine variation in type and severity of the testis apoptosis were evaluated. The daily dosages were 10, 20 and 30 non-filter cigarettes for a period of 2, 4, 6, 8 and 12 weeks. Mainstream smoke exposure suppressed body weight gain in all regimens. A dose-related increase in plasma nicotine concentration was observed in smoke-exposed groups for 4, 6, 8 and 12 week regimens. Histopathological examination of the exposed groups showed disturbances in the stages of spermatogenesis, tubules atrophying and these appeared to be dose-related. Cytoplasmic caspase-3 immunostaining was detected both in Sertoli cells and germ cells in smoke-exposure groups. An increase in TUNEL-positive cells of testicular cells was observed after 6 weeks of cigarette exposure. The results indicate that cigarette exposure concentration and duration have interaction effect to induce apoptosis in the rat testes.

  16. Estimated exposures to perfluorinated compounds in infancy predict attenuated vaccine antibody concentrations at age 5-years

    DEFF Research Database (Denmark)

    Grandjean, Philippe; Heilmann, Carsten; Weihe, Pal

    2017-01-01

    Perfluorinated alkylate substances (PFASs) are highly persistent and may cause immunotoxic effects. PFAS-associated attenuated antibody responses to childhood vaccines may be affected by PFAS exposures during infancy, where breastfeeding adds to PFAS exposures. Of 490 members of a Faroese birth...... the notion that the developing adaptive immune system is particularly vulnerable to immunotoxicity during infancy. This vulnerability appears to be the greatest during the first 6 months after birth, where PFAS exposures are affected by breast-feeding....

  17. Assimilation of concentration measurements for retrieving multiple point releases in atmosphere: A least-squares approach to inverse modelling

    Science.gov (United States)

    Singh, Sarvesh Kumar; Rani, Raj

    2015-10-01

    The study addresses the identification of multiple point sources, emitting the same tracer, from their limited set of merged concentration measurements. The identification, here, refers to the estimation of locations and strengths of a known number of simultaneous point releases. The source-receptor relationship is described in the framework of adjoint modelling by using an analytical Gaussian dispersion model. A least-squares minimization framework, free from an initialization of the release parameters (locations and strengths), is presented to estimate the release parameters. This utilizes the distributed source information observable from the given monitoring design and number of measurements. The technique leads to an exact retrieval of the true release parameters when measurements are noise free and exactly described by the dispersion model. The inversion algorithm is evaluated using the real data from multiple (two, three and four) releases conducted during Fusion Field Trials in September 2007 at Dugway Proving Ground, Utah. The release locations are retrieved, on average, within 25-45 m of the true sources with the distance from retrieved to true source ranging from 0 to 130 m. The release strengths are also estimated within a factor of three to the true release rates. The average deviations in retrieval of source locations are observed relatively large in two release trials in comparison to three and four release trials.

  18. Large Industrial Point Sources in Italy: a focus on mercury concentrations resulting from three seasonal ship-borne measurements

    Directory of Open Access Journals (Sweden)

    Bencardino M.

    2013-04-01

    Full Text Available In Italy there are 25 Large Industrial Point Sources whose mercury emissions in air exceed the established threshold of 10 kg year−1. Many of these mercury point sources, mostly distributed along the Italian coastal area, are located at sites qualified as National Interest Rehabilitation Sites because of documented contamination in qualitative and/or quantitative terms and of potential health impact. Atmospheric mercury emissions related to Italian Large Industrial Point Sources, with a value of 1.04 Mg·yr−1 for 2007, have a not negligible contribution, accounting, on their own, for more than 10% of the total mercury emissions resulting from all activity sectors at a national level. Among others, thermal power stations, pig iron and steel as well as basic inorganic chemical production, result to be the main contributing industrial activities. In order to assess how mercury species concentrations and distribution in the Marine Boundary Layer (MBL change with vicinity to large industrial sites, measurements of atmospheric mercury were performed during three oceanographic campaigns aboard the Research Vessel (R.V. Urania of the Italian CNR. Collection of GEM, GOM and PBM was conducted across the Adriatic sea, during autumn 2004 (27th of October to 12th of November and summer 2005 (17th to 29th of June, and across the Tyrrhenian sea during autumn 2007 (12th of September to 1st October. Analysis were carried out with reference to the period in which the R.V. Urania has stopped close to the main Italian industrial contaminated sites. Explorative statistical parameters of atmospheric mercury species were computed over each single stop-period and then compared with the overall cruise campaign measurements. Results are herein presented and discussed.

  19. Cytotoxicity of TiO{sub 2} nanoparticles towards freshwater sediment microorganisms at low exposure concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Kumari, Jyoti; Kumar, Deepak; Mathur, Ankita; Naseer, Arif; Kumar, Ravi Ranjan [Centre for Nanobiotechnology, VIT University, Vellore 632014 (India); Thanjavur Chandrasekaran, Prathna [Department of Materials Engineering, Indian Institute of Science, Bangalore (India); Chaudhuri, Gouri; Pulimi, Mrudula [Centre for Nanobiotechnology, VIT University, Vellore 632014 (India); Raichur, Ashok M. [Department of Materials Engineering, Indian Institute of Science, Bangalore (India); Department of Chemical Technology, University of Johannesburg (South Africa); Babu, S. [School of Bio Sciences and Technology, VIT University, Vellore (India); Chandrasekaran, Natarajan [Centre for Nanobiotechnology, VIT University, Vellore 632014 (India); Nagarajan, R. [Department of Chemical Engineering, IIT Madras, Chennai (India); Mukherjee, Amitava, E-mail: amit.mookerjea@gmail.com [Centre for Nanobiotechnology, VIT University, Vellore 632014 (India)

    2014-11-15

    There is a persistent need to assess the effects of TiO{sub 2} nanoparticles on the aquatic ecosystem owing to their increasing usage in consumer products and risk of environmental release. The current study is focused on TiO{sub 2} nanoparticle-induced acute toxicity at sub-ppm level (≤1 ppm) on the three different freshwater sediment bacterial isolates and their consortium under two different irradiation (visible light and dark) conditions. The consortium of the bacterial isolates was found to be less affected by the exposure to the nanoparticles compared to the individual cells. The oxidative stress contributed considerably towards the cytotoxicity under both light and dark conditions. A statistically significant increase in membrane permeability was noted under the dark conditions as compared to the light conditions. The optical and fluorescence microscopic images showed aggregation and chain formation of the bacterial cells, when exposed to the nanoparticles. The electron microscopic (SEM, TEM) observations suggested considerable damage of cells and bio-uptake of nanoparticles. The exopolysaccrides (EPS) production and biofilm formation were noted to increase in the presence of the nanoparticles, and expression of the key genes involved in biofilm formation was studied by RT-PCR. - Highlights: • Toxicity of NPs towards freshwater sediment bacteria at sub-ppm concentrations. • Decreased toxicity of the nanoparticles in the consortium of microorganisms. • Enhanced bacterial resistance through EPS and biofilm formation in the presence of NPs. • Considerable surface damage of cells and internalization of NPs. • Gene expression analyses related to biofilm formation in the presence of NPs.

  20. Cytotoxicity of TiO2 nanoparticles towards freshwater sediment microorganisms at low exposure concentrations

    International Nuclear Information System (INIS)

    Kumari, Jyoti; Kumar, Deepak; Mathur, Ankita; Naseer, Arif; Kumar, Ravi Ranjan; Thanjavur Chandrasekaran, Prathna; Chaudhuri, Gouri; Pulimi, Mrudula; Raichur, Ashok M.; Babu, S.; Chandrasekaran, Natarajan; Nagarajan, R.; Mukherjee, Amitava

    2014-01-01

    There is a persistent need to assess the effects of TiO 2 nanoparticles on the aquatic ecosystem owing to their increasing usage in consumer products and risk of environmental release. The current study is focused on TiO 2 nanoparticle-induced acute toxicity at sub-ppm level (≤1 ppm) on the three different freshwater sediment bacterial isolates and their consortium under two different irradiation (visible light and dark) conditions. The consortium of the bacterial isolates was found to be less affected by the exposure to the nanoparticles compared to the individual cells. The oxidative stress contributed considerably towards the cytotoxicity under both light and dark conditions. A statistically significant increase in membrane permeability was noted under the dark conditions as compared to the light conditions. The optical and fluorescence microscopic images showed aggregation and chain formation of the bacterial cells, when exposed to the nanoparticles. The electron microscopic (SEM, TEM) observations suggested considerable damage of cells and bio-uptake of nanoparticles. The exopolysaccrides (EPS) production and biofilm formation were noted to increase in the presence of the nanoparticles, and expression of the key genes involved in biofilm formation was studied by RT-PCR. - Highlights: • Toxicity of NPs towards freshwater sediment bacteria at sub-ppm concentrations. • Decreased toxicity of the nanoparticles in the consortium of microorganisms. • Enhanced bacterial resistance through EPS and biofilm formation in the presence of NPs. • Considerable surface damage of cells and internalization of NPs. • Gene expression analyses related to biofilm formation in the presence of NPs

  1. CONSISTENT INFLAMMATORY RESPONSE FOLLOWING EXPOSURE TO CONCENTRATED AMBIENT PARTICLES (CAPS) DURING FALL SEASON IN WISTAR-KYOTO RATS

    Science.gov (United States)

    CONSISTENT INFLAMMATORY RESPONSE FOLLOWING EXPOSURE TO CONCENTRATED AMBIENT PARTICLES (CAPs) DURING FALL SEASON IN WISTAR-KYOTO RATS.UP Kodavanti, MC Schladweiler, AD Ledbetter, LC Walsh, PS Gilmour, MI Gilmour, WP Watkinson, JP Nolan, JH Richards, D Andrews, DL Costa. US EPA...

  2. Influence of radon-daughter exposure rate and uranium ore dust concentration on occurrence of lung tumors

    International Nuclear Information System (INIS)

    Cross, F.T.; Palmer, R.F.; Busch, R.H.

    1980-01-01

    Groups of male SPF Wistar rats were exposed concurrently to several levels of radon daughters and uranium ore dust to study the effect of these variables on pulmonary disease states. Clinical pathology data at 1 yr postexposure indicate no significant differences among exposed animals when compared with controls. Preliminary histopathologic data suggest a trend toward increasing lung tumor risk as the exposure rate is decreased (constant total dose), but the differences are not statistically significant at the 0.05 level. A similar trend occurs with decrease in ore dust concentration (except for the 2560-WLM exposure group), but these differences are also not significant at the 0.05 level. The tumor risk is significantly (0.05 level) increased as the exposure level increases from approximately 320 and 640 WLM to 2560 WLM at the high ore dust concentration

  3. Numerical and experimental analysis of a point focus solar collector using high concentration imaging PMMA Fresnel lens

    International Nuclear Information System (INIS)

    Xie, W.T.; Dai, Y.J.; Wang, R.Z.

    2011-01-01

    Research highlights: → We studied a point focus Fresnel solar collector using different cavity receivers. → The collector heat removal factors are derived to find the optimal cavity shape. → Numerical and experimental analysis shows that the conical cavity is optimum. -- Abstract: A high concentration imaging Fresnel solar collector provided with different cavity receivers was developed and its behavior was investigated. Round copper pipes winded into different spring shapes were used as receiver by placing in the cylindrical cavity to absorb concentrated solar energy and transfer it to a heat transfer fluid (HTF). The collector efficiency factor and collector heat removal factor were derived for the cavity receivers to find out heat transfer mechanism and to propose an effective way for evaluating the performance of Fresnel solar collector and determining the optimal cavity structure. The problem of Fresnel solar collector with synthetic heat transfer oil flow was simulated and analyzed to investigate heat loss from different cavity receivers. Solar irradiation as well as convection and heat transfer in the circulating fluid and between the internal surfaces of the cavity and the environment are considered in the model. The temperature distribution over its area as well as the collector thermal efficiency at nominal flow rate was used in order to validate the simulation results. It was found that the simulated temperature distribution during operation and the average collector efficiency are in good agreement with the experimental data. Finally, the optimal shape of solar cavity receiver, as well as its thermal performance, are deeply analyzed and discussed.

  4. Prenatal exposure to lead and cognitive deficit in 7- and 14-year-old children in the presence of concomitant exposure to similar molar concentration of methylmercury

    DEFF Research Database (Denmark)

    Yorifuji, Takashi; Debes, Frodi; Weihe, Pal

    2011-01-01

    1986-1987 from whom lead was measured in cord-blood. A total of 896 cohort subjects participated in a clinical examination at age 7 and 808 subjects in a second examination at age 14. We evaluated the association between cord-blood lead concentrations and cognitive deficits (attention/working memory......, language, visuospatial, and memory) using multiple regression models. Overall, the lead concentration showed no clear pattern of association. However, in subjects with a low methylmercury exposure, after inclusion of statistical interaction terms, lead-associated adverse effects on cognitive functions were...

  5. EXPOSURE TO ENVIRONMENTALLY RELEVANT CONCENTRATIONS OF DIFFERENT NONYLPHENOL FORMULATIONS IN JAPANESE MEDAKA. (R827098)

    Science.gov (United States)

    The time course of exposure to p-nonylphenol (NP) from two different sources was compared to equalivent exposures of 17--estradiol (E2) and a solvent control (ethanol; EtOH). Japanese medaka were exposed for 4 days to a nomina...

  6. The Feasibility of Using Lead in Hair Concentration in Monitoring Environmental Exposure in Children

    NARCIS (Netherlands)

    Wibowo, A.A.E.; Brunekreef, B.; Lebret, E.; Pieters, H.

    1980-01-01

    The feasibility of lead in hair as an indicator of lead exposure has been compared to that of lead in blood and zinc protoporphyrin in blood levels in 1-3 year-old children living within 1 km of a lead smelter. Lead exposure was measured as lead in house dust, outdoor and indoor lead in air

  7. Assessment of Heavy Metals Concentration in Soils at Selected Points on Roads and Sites Around Nairobi Using EDXRF Spectrometer

    International Nuclear Information System (INIS)

    Wanjala, O. F.; Rathore, I.V.S.; Murungi, J.

    2016-01-01

    Increased exhaust emissions (gaseous and particulate), fuel leakage, damping and wear and tear of vehicle parts have resulted in environmental pollution by heavy metals especially along major roads with high traffic. This calls for constant monitoring to make sure that the levels of heavy metals do not go above the threshold limits recommended due to their adverse health effects on human beings, plants and animals. This research project focused on determining the present concentrations of heavy metals (Pb, Zn, Cu, and Ni) in soils at selected points on roads around Nairobi and some selected sites with respect to distance off-road and depth. The soil samples collected were ground into fine particles of size less than 100m and prepared into pellet form for analysis using Energy Dispersive X-ray fluorescence spectrometry. This analytic technique is fast, non-destructive and enables simultaneous determination of the concentrations of many elements in a sample with high sensitivity. It consists of a Si(Li) detector with energy resolution between 170eV to 190eV at 5.9KeV, MnKα-lines and a radioisotope source 109Cd (T1/2 =461.4 days) for sample excitation leading to emission of characteristic X-rays. Quantitative analysis was done using a software program called Quantitative X-ray Analysis System with a sub-routine program called Quantitative Analysis of Environmental Samples to finally obtain the concentrations of the different elements in the samples. The levels of the heavy metals obtained from the selected sampling sites C.Gar, K. Gar, K.R, G.B.P and Nai were 82.2±7.6, g/g to 236.1±9.2, g/g Pb, 273±9.2, g/g to 794±26, g/gZn, 32.4±4.8, g/g to 221.8±6.8, g/g Cu, and 10.72.7, g/g to 33±4.8, g/g Ni. From the results, it was found that the concentrations of Pb, Zn, Cu, and Ni were very high at the garages followed by parking places for buses and heavy commercial vehicles and lastly at roundabouts. The concentrations of heavy metals on the selected roads at Roy, Cab

  8. Point-of-care procalcitonin test to reduce antibiotic exposure in patients hospitalized with acute exacerbation of COPD

    DEFF Research Database (Denmark)

    Corti, Caspar; Fally, Markus; Fabricius-Bjerre, Andreas

    2016-01-01

    BACKGROUND: This study was conducted to investigate whether point-of-care (POC) procalcitonin (PCT) measurement can reduce redundant antibiotic treatment in patients hospitalized with acute exacerbation of COPD (AECOPD). METHODS: One-hundred and twenty adult patients admitted with AECOPD were...... in the PCT-arm vs 8.5 (IQR 1-11) days in the control arm (P=0.0169, Wilcoxon) for the intention-to-treat population. The proportion of patients using antibiotics for ≥5 days within the 28-day follow-up was 41.9% (PCT-arm) vs 67.2% (P=0.006, Fisher's exact) in the intention-to-treat population. For the per...... no apparent difference. CONCLUSION: Our study shows that the implementation of a POC PCT-guided algorithm can be used to substantially reduce antibiotic exposure in patients hospitalized with AECOPD, with no apparent harm....

  9. Concentrations of polycyclic aromatic hydrocarbons in resuspendable fraction of settled bus dust and its implications for human exposure

    International Nuclear Information System (INIS)

    Gao, Peng; Liu, Sa; Feng, Yujie; Lin, Nan; Lu, Binyu; Zhang, Zhaohan; Cui, Fuyi; Xing, Baoshan; Hammond, S. Katharine

    2015-01-01

    This preliminary study measured Polycyclic Aromatic Hydrocarbons (PAHs) concentrations in the resuspendable fraction of settled dust on 39 bus lines, to evaluate the impact of engine type (gasoline and compressed natural gas) on exposure for commuters and drivers. Benzo(b)fluoranthene(BbF) was the predominant PAH in resuspendable fraction of settled bus dust. The concentration of total PAHs was 92.90 ± 116.00 μg/g (range: 0.57–410) in gasoline buses and 3.97 ± 1.81 (range: 2.01–9.47) in compressed natural gas (CNG) buses. Based on Benzo[a]pyrene (BaP) equivalent concentrations for the sum of 16 PAHs, the average daily dose (ADD) via dust ingestion and dermal contact was calculated. The ADD of PAHs was higher for commuters and drivers in gasoline-powered buses than in buses using CNG buses. For both short and long duration journeys, young commuters were exposed to higher levels of PAHs via dust ingestion and dermal contact than adult commuters. - Highlights: • Resuspendable fraction of settled dust from microenvironment of buses in Harbin monitored for PAHs exposure assessment. • Higher levels of PAHs pollutants at gasoline-powered buses than at compressed natural gas-powered buses. • Non-occupational and occupational exposures in the microenvironment of buses are assessed. - Occupational and non-occupational exposure to PAHs from the microenvironment of bus

  10. {sup 1}H NMR metabolomics of earthworm exposure to sub-lethal concentrations of phenanthrene in soil

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Sarah A.E.; McKelvie, Jennifer R.; Simpson, Andre J. [Department of Physical and Environmental Sciences, University of Toronto, 1265 Military Trail Toronto, Ontario, M1C 1A4 (Canada); Simpson, Myrna J., E-mail: myrna.simpson@utoronto.c [Department of Physical and Environmental Sciences, University of Toronto, 1265 Military Trail Toronto, Ontario, M1C 1A4 (Canada)

    2010-06-15

    {sup 1}H NMR metabolomics was used to monitor earthworm responses to sub-lethal (50-1500 mg/kg) phenanthrene exposure in soil. Total phenanthrene was analyzed via soxhlet extraction, bioavailable phenanthrene was estimated by hydroxypropyl-beta-cyclodextrin (HPCD) and 1-butanol extractions and sorption to soil was assessed by batch equilibration. Bioavailable phenanthrene (HPCD-extracted) comprised approx65-97% of total phenanthrene added to the soil. Principal component analysis (PCA) showed differences in responses between exposed earthworms and controls after 48 h exposure. The metabolites that varied with exposure included amino acids (isoleucine, alanine and glutamine) and maltose. PLS models indicated that earthworm response is positively correlated to both total phenanthrene concentration and bioavailable (HPCD-extracted) phenanthrene in a freshly spiked, unaged soil. These results show that metabolomics is a powerful, direct technique that may be used to monitor contaminant bioavailability and toxicity of sub-lethal concentrations of contaminants in the environment. These initial findings warrant further metabolomic studies with aged contaminated soils. - {sup 1}H NMR metabolomics is used to directly monitor metabolic responses of Eisenia fetida after 48 h of exposure to sub-lethal concentrations of phenanthrene in soil.

  11. Professional ski waxers' exposure to PFAS and aerosol concentrations in gas phase and different particle size fractions.

    Science.gov (United States)

    Nilsson, Helena; Kärrman, Anna; Rotander, Anna; van Bavel, Bert; Lindström, Gunilla; Westberg, Håkan

    2013-04-01

    Previous reports show that professional ski waxers have elevated blood levels of perfluorinated substances (PFAS) such as perfluorooctanoate (PFOA) and are exposed to very high concentrations of PFAS in air during ski waxing. Aerosol exposure increases the risk of cardiovascular disease, and PFOA is a potential hormonal disruptor and carcinogen, and can affect the fatty acid metabolism. Animal studies have shown that 8:2 FTOH can undergo biotransformation to PFOA. For the first time, this study presents an occupational scenario of professional ski waxers who are exposed to extremely high dust levels as well as per- and polyfluorinated compounds. Personal and fixed measurements of total aerosol, inhalable and respirable fractions were performed during World Cup events 2007-2010. The occupational exposure limit (OEL) is exceeded in 37% of the personal measurements with concentrations up to 15 mg m(-3) in air. There are differences between personal and area total aerosol concentrations with levels from personal measurements twice as high as those from the area measurements. The personal levels for FTOH ranged up to 996 μg m(-3) (mean = 114 μg m(-3)) and for PFOA up to 4.89 μg m(-3) (mean = 0.53 μg m(-3)) in ENV+ sorbent samples as compared to the general exposure levels from air reaching only low ng m(-3) (PFAS is not in compliance with the occupational exposure standards and by far exceed the general populations' exposure. Preventive measures must be taken to minimize the exposure in this occupational group.

  12. Effect of 'PC Game Room' use and polycyclic aromatic hydrocarbon exposure on plasma testosterone concentrations in young male Koreans.

    Science.gov (United States)

    Kim, Heon; Kang, Jong-Won; Ku, Seung-Yup; Kim, Seok Hyun; Cho, Soo-Hun; Koong, Sung-Soo; Kim, Yong-Dae; Lee, Chul-Ho

    2005-03-01

    'PC Game Rooms' were first popularized in Korea, although the concept is now becoming popular worldwide. PC Game Rooms provide users with high-performance PC connected to the high-speed internet, and access to computer games. However, PC Game Room users are exposed to various hazardous agents such as cigarette smoke in a confined environment, and thus it is likely that excessive PC Game Room use involves abnormal exposure to polycyclic aromatic hydrocarbons (PAH) as well as being associated with disturbed sleep or circadian rhythm. In this cross-sectional study, the exposure to PAH was evaluated by measuring urinary 1-hydroxypyrene (1-OHP) and 2-naphthol. The correlations between PC Game Room use and PAH exposure and plasma testosterone and LH levels were analysed in 208 young male Koreans. Urinary 1-OHP concentrations increased (P = 0.0001) and plasma testosterone levels decreased (P = 0.0153) significantly with increased duration of PC Game Room use. Correlation analysis showed that plasma testosterone concentrations were significantly negatively correlated with urinary 1-OHP (r = -0.22, P = 0.0012) and 2-naphthol (r = -0.15, P = 0.0308) concentrations. Moreover, these associations persisted after adjusting for other independent variables. However, the duration of PC Game Room use itself was not found to be an independent significant determinant of plasma testosterone level. Rather, PC Game Room use increased PAH exposure, which decreased plasma testosterone level. The younger age group (15-19 years) showed a more prominent decrease in plasma testosterone concentrations with increasing duration of PC Game Room use than the older age group (20-24 years) (r2 = 0.355, P = 0.0301 versus r2 = 0.213, P = 0.0001). These results imply that the excessive use of PC Game Rooms is related to an adverse impact on sex hormonal status in young male Koreans via PAH exposure. This effect was more prominent in the younger age group.

  13. Acute Exposure to Perchlorethylene alters Rat Visual Evoked Potentials in Relation to Brain Concentration

    Science.gov (United States)

    These experiments sought to establish a dose-effect relationship between the concentration of perchloroethylene (PCE) in brain tissue and concurrent changes in visual function. A physiologically-based pharmacokinetic (PBPK) model was implemented to predict concentrations of PCE ...

  14. A biological indicator of inorganic arsenic exposure using the sum of urinary inorganic arsenic and monomethylarsonic acid concentrations

    Science.gov (United States)

    Hata, Akihisa; Kurosawa, Hidetoshi; Endo, Yoko; Yamanaka, Kenzo; Fujitani, Noboru; Endo, Ginji

    2016-01-01

    Objectives: The sum of urinary inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) concentrations is used for the biological monitoring of occupational iAs exposure. Although DMA is a major metabolite of iAs, it is an inadequate index because high DMA levels are present in urine after seafood consumption. We estimated the urinary iAs+MMA concentration corresponding to iAs exposure. Methods: We used data from two arsenic speciation analyses of urine samples from 330 Bangladeshi with oral iAs exposure and 172 Japanese workers without occupational iAs exposure using high-performance liquid chromatography with inductively coupled plasma mass spectrometry. Results: iAs, MMA, and DMA, but not arsenobetaine (AsBe), were detected in the urine of the Bangladeshi subjects. The correlation between iAs+MMA+DMA and iAs+MMA was obtained as log (iAs+MMA) = 1.038 log (iAs+MMA+DMA) -0.658. Using the regression formula, the iAs+MMA value was calculated as 2.15 and 7.5 μg As/l, corresponding to 3 and 10 μg As/m3 of exposures, respectively. In the urine of the Japanese workers, arsenic was mostly excreted as AsBe. We used the 95th percentile of iAs+MMA (12.6 μg As/l) as the background value. The sum of the calculated and background values can be used as a biological indicator of iAs exposure. Conclusion: We propose 14.8 and 20.1 μg As/l of urinary iAs+MMA as the biological indicators of 3 and 10 μg As/m3 iAs exposure, respectively. PMID:27010090

  15. Germination of fungal conidia after exposure to low concentration ozone atmospheres.

    Science.gov (United States)

    The germinability of conidia of Alternaria alternata, Aspergillus flavus, Aspergillus niger, Penicillium digitatum, Penicillium expansum, or Penicillium italicum was determined periodically during exposure for approximately 100 days to a humid atmosphere of air alone or air containing 150 ppb ozone ...

  16. In vivo plasma concentration for lindane after 6 hour exposure in human skin

    Data.gov (United States)

    U.S. Environmental Protection Agency — Dataset is a time course description of lindane disappearance in blood plasma after dermal exposure in human volunteers. This dataset is associated with the...

  17. BLOOD AND BRAIN CONCENTRATIONS OF BIFENTHRIN CORRELATE WITH DECREASED MOTOR ACTIVITY INDEPENDENT OF TIME OF EXPOSURE

    Science.gov (United States)

    Pyrethroids are neurotoxic insecticides used in a variety of agricultural and household activities. Due to the phase-out of organophosphate pesticides, the use of pyrethroids has increased. The potential for human exposure to pyrethroids has prompted pharmacodynamic and pharmac...

  18. ESTIMATED RATE OF FATAL AUTOMOBILE ACCIDENTS ATTRIBUTABLE TO ACUTE SOLVENT EXPOSURE AT LOW INHALED CONCENTRATIONS

    Science.gov (United States)

    Acute solvent exposures may contribute to automobile accidents because they increase reaction time and decrease attention, in addition to impairing other behaviors. These effects resemble those of ethanol consumption, both with respect to behavioral effects and neurological mecha...

  19. Performance of honey bee colonies under a long-lasting dietary exposure to sublethal concentrations of the neonicotinoid insecticide thiacloprid.

    Science.gov (United States)

    Siede, Reinhold; Faust, Lena; Meixner, Marina D; Maus, Christian; Grünewald, Bernd; Büchler, Ralph

    2017-07-01

    Substantial honey bee colony losses have occurred periodically in the last decades. The drivers for these losses are not fully understood. The influence of pests and pathogens are beyond dispute, but in addition, chronic exposure to sublethal concentrations of pesticides has been suggested to affect the performance of honey bee colonies. This study aims to elucidate the potential effects of a chronic exposure to sublethal concentrations (one realistic worst-case concentration) of the neonicotinoid thiacloprid to honey bee colonies in a three year replicated colony feeding study. Thiacloprid did not significantly affect the colony strength. No differences between treatment and control were observed for the mortality of bees, the infestation with the parasitic mite Varroa destructor and the infection levels of viruses. No colony losses occurred during the overwintering seasons. Furthermore, thiacloprid did not influence the constitutive expression of the immunity-related hymenoptaecin gene. However, upregulation of hymenoptaecin expression as a response to bacterial challenge was less pronounced in exposed bees than in control bees. Under field conditions, bee colonies are not adversely affected by a long-lasting exposure to sublethal concentrations of thiacloprid. No indications were found that field-realistic and higher doses exerted a biologically significant effect on colony performance. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

  20. Blood vitamin D(3) metabolite concentrations of adult female bearded dragons (Pogona vitticeps) remain stable after ceasing UVb exposure.

    Science.gov (United States)

    Oonincx, D G A B; van de Wal, M D; Bosch, G; Stumpel, J B G; Heijboer, A C; van Leeuwen, J P T M; Hendriks, W H; Kik, M

    2013-07-01

    Vitamin D deficiency can lead to several health problems collectively called metabolic bone disease (MBD). One commonly kept reptile species prone to develop MBD if managed incorrectly is the bearded dragon (Pogona vitticeps). This study aimed to determine the extent to which adult female bearded dragons fed a diet low in vitamin D can use stored vitamin D and its metabolites to maintain plasma 25(OH)D(3) and 1,25(OH)(2)D(3) concentrations after discontinuing UVb exposure. Blood samples of healthy adult female bearded dragons, exposed to UVb radiation for over 6 months were collected (day 0) after which UVb exposure was discontinued for 83 days and blood was collected. Blood plasma was analysed for concentrations of total Ca, total P, ionized Ca, uric acid, 25(OH)D(3) and 1,25(OH)(2)D(3). There was no significant change in plasma 25(OH)D(3) and 1,25(OH)(2)D(3) concentrations during the study. While total Ca and P in whole blood was found to significantly decrease over time (P dragons, previously exposed to UVb, are able to maintain blood vitamin D metabolite concentrations when UVb exposure is discontinued for a period of up to 83 days. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Molecular toxicity of cerium oxide nanoparticles to the freshwater alga Chlamydomonas reinhardtii is associated with supra-environmental exposure concentrations

    Science.gov (United States)

    Taylor, Nadine S.; Merrifield, Ruth; Williams, Tim D.; Chipman, J. Kevin; Lead, Jamie R.; Viant, Mark R.

    2016-01-01

    Abstract Ceria nanoparticles (NPs) are widely used as fuel catalysts and consequently are likely to enter the environment. Their potential impacts on. biota at environmentally relevant concentrations, including uptake and toxicity, remain to be elucidated and quantitative data on which to assess risk are sparse. Therefore, a definitive assessment of the molecular and phenotypic effects of ceria NPs was undertaken, using well-characterised mono-dispersed NPs as their toxicity is likely to be higher, enabling a conservative hazard assessment. Unbiased transcriptomics and metabolomics approaches were used to investigate the potential toxicity of tightly constrained 4–5 nm ceria NPs to the unicellular green alga, Chlamydomonas reinhardtii, a sentinel freshwater species. A wide range of exposure concentrations were investigated from predicted environmental levels, to support hazard assessment, to supra-environmental levels to provide insight into molecular toxicity pathways. Ceria NPs were internalised into intracellular vesicles within C. reinhardtii, yet caused no significant effect on algal growth at any exposure concentration. Molecular perturbations were only detected at supra-environmental ceria NP-concentrations, primarily down-regulation of photosynthesis and carbon fixation with associated effects on energy metabolism. For acute exposures to small mono-dispersed particles, it can be concluded there should be little concern regarding their dispersal into the environment for this trophic level. PMID:25740379

  2. Source characterization and exposure modeling of gas-phase polycyclic aromatic hydrocarbon (PAH) concentrations in Southern California

    Science.gov (United States)

    Masri, Shahir; Li, Lianfa; Dang, Andy; Chung, Judith H.; Chen, Jiu-Chiuan; Fan, Zhi-Hua (Tina); Wu, Jun

    2018-03-01

    Airborne exposures to polycyclic aromatic hydrocarbons (PAHs) are associated with adverse health outcomes. Because personal air measurements of PAHs are labor intensive and costly, spatial PAH exposure models are useful for epidemiological studies. However, few studies provide adequate spatial coverage to reflect intra-urban variability of ambient PAHs. In this study, we collected 39-40 weekly gas-phase PAH samples in southern California twice in summer and twice in winter, 2009, in order to characterize PAH source contributions and develop spatial models that can estimate gas-phase PAH concentrations at a high resolution. A spatial mixed regression model was constructed, including such variables as roadway, traffic, land-use, vegetation index, commercial cooking facilities, meteorology, and population density. Cross validation of the model resulted in an R2 of 0.66 for summer and 0.77 for winter. Results showed higher total PAH concentrations in winter. Pyrogenic sources, such as fossil fuels and diesel exhaust, were the most dominant contributors to total PAHs. PAH sources varied by season, with a higher fossil fuel and wood burning contribution in winter. Spatial autocorrelation accounted for a substantial amount of the variance in total PAH concentrations for both winter (56%) and summer (19%). In summer, other key variables explaining the variance included meteorological factors (9%), population density (15%), and roadway length (21%). In winter, the variance was also explained by traffic density (16%). In this study, source characterization confirmed the dominance of traffic and other fossil fuel sources to total measured gas-phase PAH concentrations while a spatial exposure model identified key predictors of PAH concentrations. Gas-phase PAH source characterization and exposure estimation is of high utility to epidemiologist and policy makers interested in understanding the health impacts of gas-phase PAHs and strategies to reduce emissions.

  3. Chronic arsenic exposure increases TGFalpha concentration in bladder urothelial cells of Mexican populations environmentally exposed to inorganic arsenic

    International Nuclear Information System (INIS)

    Valenzuela, Olga L.; Germolec, Dori R.; Borja-Aburto, Victor H.; Contreras-Ruiz, Jose; Garcia-Vargas, Gonzalo G.; Razo, Luz M. del

    2007-01-01

    Inorganic arsenic (iAs) is a well-established carcinogen and human exposure has been associated with a variety of cancers including those of skin, lung, and bladder. High expression of transforming growth factor alpha (TGF-α) has associated with local relapses in early stages of urinary bladder cancer. iAs exposures are at least in part determined by the rate of formation and composition of iAs metabolites (MAs III , MAs V , DMAs III , DMAs V ). This study examines the relationship between TGF-α concentration in exfoliated bladder urothelial cells (BUC) separated from urine and urinary arsenic species in 72 resident women (18-51 years old) from areas exposed to different concentrations of iAs in drinking water (2-378 ppb) in central Mexico. Urinary arsenic species, including trivalent methylated metabolites were measured by hydride generation atomic absorption spectrometry method. The concentration of TGF-α in BUC was measured using an ELISA assay. Results show a statistically significant positive correlation between TGF-α concentration in BUC and each of the six arsenic species present in urine. The multivariate linear regression analyses show that the increment of TGF-α levels in BUC was importantly associated with the presence of arsenic species after adjusting by age, and presence of urinary infection. People from areas with high arsenic exposure had a significantly higher TGF-α concentration in BUC than people from areas of low arsenic exposure (128.8 vs. 64.4 pg/mg protein; p < 0.05). Notably, exfoliated cells isolated from individuals with skin lesions contained significantly greater amount of TGF-α than cells from individuals without skin lesions: 157.7 vs. 64.9 pg/mg protein (p = 0.003). These results suggest that TGF-α in exfoliated BUC may serve as a susceptibility marker of adverse health effects on epithelial tissue in arsenic-endemic areas

  4. In utero exposure to a low concentration of diesel exhaust affects spontaneous locomotor activity and monoaminergic system in male mice

    Directory of Open Access Journals (Sweden)

    Odagiri Takashi

    2010-03-01

    Full Text Available Abstract Background Epidemiological studies have suggested that suspended particulate matter (SPM causes detrimental health effects such as respiratory and cardiovascular diseases, and that diesel exhaust particles from automobiles is a major contributor to SPM. It has been reported that neonatal and adult exposure to diesel exhaust damages the central nervous system (CNS and induces behavioral alteration. Recently, we have focused on the effects of prenatal exposure to diesel exhaust on the CNS. In this study, we examined the effects of prenatal exposure to low concentration of diesel exhaust on behaviour and the monoaminergic neuron system. Spontaneous locomotor activity (SLA and monoamine levels in the CNS were assessed. Methods Mice were exposed prenatally to a low concentration of diesel exhaust (171 μg DEP/m3 for 8 hours/day on gestational days 2-16. SLA was assessed for 3 days in 4-week-old mice by analysis of the release of temperature-associated infrared rays. At 5 weeks of age, the mice were sacrificed and the brains were used for analysis by high-performance liquid chromatography (HPLC. Results and Discussion Mice exposed to a low concentration of diesel exhaust showed decreased SLA in the first 60 minutes of exposure. Over the entire test period, the mice exposed prenatally to diesel exhaust showed decreased daily SLA compared to that in control mice, and the SLA in each 3 hour period was decreased when the lights were turned on. Neurotransmitter levels, including dopamine and noradrenaline, were increased in the prefrontal cortex (PFC in the exposure group compared to the control group. The metabolites of dopamine and noradrenaline also increased in the PFC. Neurotransmitter turnover, an index of neuronal activity, of dopamine and noradrenaline was decreased in various regions of the CNS, including the striatum, in the exposure group. The serum corticosterone level was not different between groups. The data suggest that decreased

  5. Concentrations of phthalates and bisphenol A in Norwegian foods and beverages and estimated dietary exposure in adults.

    Science.gov (United States)

    Sakhi, Amrit K; Lillegaard, Inger Therese L; Voorspoels, Stefan; Carlsen, Monica H; Løken, Elin B; Brantsæter, Anne L; Haugen, Margaretha; Meltzer, Helle M; Thomsen, Cathrine

    2014-12-01

    Phthalates and bisphenol A (BPA) are ubiquitous in our environment. These chemicals have been characterized as endocrine disruptors that can cause functional impairment of development and reproduction. Processed and packaged foods are among the major sources of human exposure to these chemicals. No previous report showing the levels of these chemicals in food items purchased in Norway is available. The aim of the present study was to determine the concentration of ten different phthalates and BPA in foods and beverages purchased on the Norwegian market and estimate the daily dietary exposure in the Norwegian adult population. Commonly consumed foods and beverages in Norway were purchased in a grocery store and analysed using gas- and liquid chromatography coupled with mass spectrometry. Daily dietary exposures to these chemicals in the Norwegian adult population were estimated using the latest National dietary survey, Norkost 3 (2010-2011). This study showed that phthalates and BPA are found in all foods and beverages that are common to consume in Norway. The detection frequency of phthalates in the food items varied from 11% for dicyclohexyl phthalate (DCHP) to 84% for di-iso-nonyl phthalate (DiNP), one of the substitutes for bis(2-ethylhexyl) phthalate (DEHP). BPA was found in 54% of the food items analysed. Among the different phthalates, the highest concentrations were found for DEHP and DiNP in the food items. Estimated dietary exposures were also equally high and dominated by DEHP and DiNP (400-500 ng/kg body weight (bw)/day), followed by di-iso-butyl phthalate (DiBP), di-n-butyl phthalate (DnBP), di-n-octyl phthalate (DnOP) and di-iso-decyl phthalate (DiDP) (30-40 ng/kg bw/day). Dimethyl phthalate (DMP), diethylphthalate (DEP) and DCHP had the lowest concentrations and the exposures were around 10-20 ng/kg bw/day. Estimated dietary exposure to BPA was 5 ng/kg bw/day. In general, levels of phthalates and BPA in foods and beverages from the Norwegian market

  6. Effect of prenatal exposure to different salt concentration on the third month's weight and blood pressure in wistar rat

    International Nuclear Information System (INIS)

    Fereidoun, H.

    2009-01-01

    In utero alterations in fluid and electrolyte endocrine systems may result in permanent effects on offspring. A low sodium intake during prenatal life jeopardizes growth in young rats, prenatal high-salt diet in Sprague-Dawley rats caused an increase in MAP at postnatal day 30. The objective of this study was to determine the effect of prenatal exposure to different salt concentrations on the third month's weight and blood pressure in Wistar rat. This study was performed at the Department of Physiology, Isfahan University of Medical Science, Isfahan, Iran, over a period from 1998 to 2003. Six groups of rat, 1 male and 5 female in each group were exposed to 0.5, 1, 1.4, 1.6, 1.8 and 2 percent of salt concentrations during pre-pregnancy, pregnancy and lactation period, another test group consumed distilled water and control group used Isfahan tap water, other living conditions for all groups were similar. Exposure to different salt concentrations on the third month's weight and blood pressure was evaluated. Prenatal exposure to 0.5 and 1% salt concentrations gives birth to more alive and healthy infants, and third month's weight increased significantly, but blood pressure was not influenced significantly. Salt concentrations higher than 1% increased the maternal and infant mortality rate and blood pressure significantly, but some concentrations decreased third month's weight significantly. Level of dietary salt during intrauterine development can influence on the number of alive and healthy infants, birth weight, third month' weight and blood pressure significantly. There is no need to introduce a salt restricted diet in prenatal care, a balanced diet in sodium during pregnancy is recommended, high salt diet creates harmful effect. (author)

  7. Mean total arsenic concentrations in chicken 1989-2000 and estimated exposures for consumers of chicken.

    OpenAIRE

    Lasky, Tamar; Sun, Wenyu; Kadry, Abdel; Hoffman, Michael K

    2004-01-01

    The purpose of this study was to estimate mean concentrations of total arsenic in chicken liver tissue and then estimate total and inorganic arsenic ingested by humans through chicken consumption. We used national monitoring data from the Food Safety and Inspection Service National Residue Program to estimate mean arsenic concentrations for 1994-2000. Incorporating assumptions about the concentrations of arsenic in liver and muscle tissues as well as the proportions of inorganic and organic a...

  8. Pesticide exposure assessment in flowing waters – results for predicted environmental concentrations in some brooks in Germany

    DEFF Research Database (Denmark)

    Trapp, M.T.; Guerniche, D.G.; Bach, M.B.

    2010-01-01

    was to predict initial environmental concentrations in flowing water bodies after spray drift exposure. Based on this the downstream development of these concentrations over space and time with regard to dispersion processes was simulated (PECtwa, Time over Threshold). An adequate GIS-based software......The “Georisk”- project of the German Federal Environmental Agency forms the scientific basis for an integration of more realistic landscape based scenarios into the process of pesticide registration. Here, first results of geodata-based simulations are presented. The objective of the simulations...

  9. Mobilisation of heavy metals into the urine by CaEDTA: relation to erythrocyte and plasma concentrations and exposure indicators.

    OpenAIRE

    Araki, S; Aono, H; Murata, K

    1986-01-01

    To investigate the effects of calcium disodium ethylenediamine tetra-acetate (CaEDTA) on the urinary excretion, erythrocyte, and plasma concentrations and exposure indicators of seven heavy metals, CaEDTA was administered by intravenous infusion to 20 workers exposed to lead, zinc, and copper. The workers' blood lead concentrations ranged from 22 to 59 micrograms/dl (mean 38 micrograms/dl (1.8 mumol/l]. The 24 hour urinary excretion of metals after CaEDTA administration (mobilisation yield) w...

  10. Comparative analysis of the transcriptome responses of zebrafish embryos after exposure to low concentrations of cadmium, cobalt and copper.

    Science.gov (United States)

    Sonnack, Laura; Klawonn, Thorsten; Kriehuber, Ralf; Hollert, Henner; Schäfers, Christoph; Fenske, Martina

    2018-03-01

    Metal toxicity is a global environmental challenge. Fish are particularly prone to metal exposure, which can be lethal or cause sublethal physiological impairments. The objective of this study was to investigate how adverse effects of chronic exposure to non-toxic levels of essential and non-essential metals in early life stage zebrafish may be explained by changes in the transcriptome. We therefore studied the effects of three different metals at low concentrations in zebrafish embryos by transcriptomics analysis. The study design compared exposure effects caused by different metals at different developmental stages (pre-hatch and post-hatch). Wild-type embryos were exposed to solutions of low concentrations of copper (CuSO 4 ), cadmium (CdCl 2 ) and cobalt (CoSO 4 ) until 96h post-fertilization (hpf) and microarray experiments were carried out to determine transcriptome profiles at 48 and 96hpf. We found that the toxic metal cadmium affected the expression of more genes at 96hpf than 48hpf. The opposite effect was observed for the essential metals cobalt and copper, which also showed enrichment of different GO terms. Genes involved in neuromast and motor neuron development were significantly enriched, agreeing with our previous results showing motor neuron and neuromast damage in the embryos. Our data provide evidence that the response of the transcriptome of fish embryos to metal exposure differs for essential and non-essential metals. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Early prenatal androgen exposure reduces testes size and sperm concentration in sheep without altering neuroendocrine differentiation and masculine sexual behavior.

    Science.gov (United States)

    Scully, C M; Estill, C T; Amodei, R; McKune, A; Gribbin, K P; Meaker, M; Stormshak, F; Roselli, C E

    2018-01-01

    Prenatal androgens are largely responsible for growth and differentiation of the genital tract and testis and for organization of the control mechanisms regulating male reproductive physiology and behavior. The aim of the present study was to evaluate the impact of inappropriate exposure to excess testosterone (T) during the first trimester of fetal development on the reproductive function, sexual behavior, and fertility potential of rams. We found that biweekly maternal T propionate (100 mg) treatment administered from Day 30-58 of gestation significantly decreased (P < 0.05) postpubertal scrotal circumference and sperm concentration. Prenatal T exposure did not alter ejaculate volume, sperm motility and morphology or testis morphology. There was, however, a trend for more T-exposed rams than controls to be classified as unsatisfactory potential breeders during breeding soundness examinations. Postnatal serum T concentrations were not affected by prenatal T exposure, nor was the expression of key testicular genes essential for spermatogenesis and steroidogenesis. Basal serum LH did not differ between treatment groups, nor did pituitary responsiveness to GnRH. T-exposed rams, like control males, exhibited vigorous libido and were sexually attracted to estrous females. In summary, these results suggest that exposure to exogenous T during the first trimester of gestation can negatively impact spermatogenesis and compromise the reproductive fitness of rams. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Dermal absorption of benzo[a]pyrene into human skin from soil: Effect of artificial weathering, concentration, and exposure duration.

    Science.gov (United States)

    Peckham, Trevor K; Shirai, Jeffry H; Bunge, Annette L; Lowney, Yvette W; Ruby, Michael V; Kissel, John C

    2017-11-01

    In vitro assessments of 14 C-benzo[a]pyrene (BaP) absorption through human epidermis were conducted with the sub-63-μm fraction of four test soils containing different amounts of organic and black carbon. Soils were artificially weathered for eight weeks and applied to epidermis at nominal BaP concentrations of 3 and 10 mg/kg for 8 or 24 h. Experiments were also conducted at 24 h with unweathered soils and with BaP deposited onto skin from acetone at a comparable chemical load. For the weathered soils, absorption was independent of the amount of organic or black carbon, the mass in the receptor fluid was proportional to exposure duration but independent of concentration, and the mass recovered in the skin after washing was proportional to concentration and independent of exposure time. Results from the weathered and unweathered soils were similar except for the mass recovered in the washed skin, which was lower for the weathered soil only at the higher concentration. We hypothesize that chemical concentrations exceeded the BaP sorption capacity accessible within the artificial weathering timeframe for all soils tested, and that BaP mass in the washed skin was dominated by particles that were not removed by washing. Fluxes into and through skin from soils were lower by an order of magnitude than from acetone-deposited BaP.

  13. Stomatal response of Pinus sylvestriformis to elevated CO2 concentrations during the four years of exposure

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yu-mei; HAN Shi-jie; LIU Ying; JIA Xia

    2005-01-01

    Four-year-old Pinus sylvestriformis were exposed for four growing seasons in open top chambers to ambient CO2 concentration (approx. 350 μmol·mol-1) and high CO2 concentrations (500 and 700 μmol·mol-1) at Research Station of Changbai Mountain Forest Ecosystems, Chinese Academy of Sciences at Antu Town, Jilin Province, China (42oN, 128oE). Stomatal response to elevated CO2 concentrations was examined by stomatal conductance (gs), ratio of intercellular to ambient CO2 concentration (ci/ca) and stomatal number. Reciprocal transfer experiments of stomatal conductance showed that stomatal conductance in high-[CO2]-grown plants increased in comparison with ambient-[CO2]-grown plants when measured at their respective growth CO2 concentration and at the same measurement CO2 concentration (except a reduction in 700 μmol·mol-1 CO2 grown plants compared with plants on unchambered field when measured at growth CO2 concentration and 350 μmol·mol-1CO2). High-[CO2]-grown plants exhibited lower ci/ca ratios than ambient-[CO2]-grown plants when measured at their respective growth CO2 concentration. However, ci/ca ratios increased for plants grown in high CO2 concentrations compared with control plants when measured at the same CO2 concentration. There was no significant difference in stomatal number per unit long needle between elevated and ambient CO2. However, elevated CO2 concentrations reduced the total stomatal number of whole needle by the decline of stomatal line and changed the allocation pattern of stomata between upper and lower surface of needle.

  14. Marine diet and tobacco exposure affects mercury concentrations in pregnant women (I from Baja California Sur, Mexico

    Directory of Open Access Journals (Sweden)

    Ramón Gaxiola-Robles

    2014-01-01

    Full Text Available Seafood provides essential polyunsaturated fatty acids (PUFA and other nutrients to pregnant women and their fetus(es while a diet rich in finfish can be a major pathway of monomethyl mercury (MeHg+ exposure. We measured total mercury concentration ([THg] in hair samples provided by 75 women in Baja California Sur (BCS to assess its relationship with age, parity, tobacco smoke exposure, and diet based on survey methodologies. Generalized linear models (GLM were used to explain the possible association of the different variables with [THg] in hair. Median [THg] in hair was 1.52 μg g−1, ranging from 0.12 to 24.19 μg g−1 and varied significantly by segment. Approximately 72% (54/75 of those evaluated exceed 1 μg g−1 [THg] and 8% (6/75 exceed 5 μg g−1 [THg] in hair. Although frequency of fish consumption contributed significantly to explaining hair [THg], fish consumption only explained 43% of [THg] in a GLM incorporating tobacco exposure and body mass index. This study establishes possible relationships among multiple potential sources of exposure and other factors related to [THg] in hair of women in the prenatal period. A more detailed examination of other sources of exposure and factors contributing to [THg] is warranted.

  15. Chronic exposure to low concentrations of lead induces metabolic disorder and dysbiosis of the gut microbiota in mice.

    Science.gov (United States)

    Xia, Jizhou; Jin, Cuiyuan; Pan, Zihong; Sun, Liwei; Fu, Zhengwei; Jin, Yuanxiang

    2018-08-01

    Lead (Pb) is one of the most prevalent toxic, nonessential heavy metals that can contaminate food and water. In this study, effects of chronic exposure to low concentrations of Pb on metabolism and gut microbiota were evaluated in mice. It was observed that exposure of mice to 0.1mg/L Pb, supplied via drinking water, for 15weeks increased hepatic TG and TCH levels. The levels of some key genes related to lipid metabolism in the liver increased significantly in Pb-treated mice. For the gut microbiota, at the phylum level, the relative abundance of Firmicutes and Bacteroidetes changed obviously in the feces and the cecal contents of mice exposed to 0.1mg/L Pb for 15weeks. In addition, 16s rRNA gene sequencing further discovered that Pb exposure affected the structure and richness of the gut microbiota. Moreover, a 1 H NMR metabolic analysis unambiguously identified 31 metabolites, and 15 metabolites were noticeably altered in 0.1mg/L Pb-treated mice. Taken together, the data indicate that chronic Pb exposure induces dysbiosis of the gut microbiota and metabolic disorder in mice. Chronic Pb exposure induces metabolic disorder, dysbiosis of the gut microbiota and hepatic lipid metabolism disorder in mice. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Plasma fibrinogen and factor VII concentrations in adults after prenatal exposure to famine

    NARCIS (Netherlands)

    Roseboom, T. J.; van der Meulen, J. H.; Ravelli, A. C.; Osmond, C.; Barker, D. J.; Bleker, O. P.

    2000-01-01

    To assess the effect of maternal malnutrition during different stages of gestation on plasma concentrations of fibrinogen and factor VII, we investigated 725 people, aged 50 years, born around the time of the Dutch famine 1944-5. After adjustment for sex, plasma fibrinogen concentrations differed by

  17. Evaluation of an Electrochemical Point-of-Care Meter for Measuring Glucose Concentration in Blood from Periparturient Dairy Cattle.

    Science.gov (United States)

    Megahed, A A; Hiew, M W H; Townsend, J R; Messick, J B; Constable, P D

    2015-01-01

    The Precision Xtra(®) meter is a promising low cost electrochemical point-of-care unit for measuring blood glucose concentration ([gluc]) in cattle blood. The meter uses an algorithm that assumes the intra-erythrocyte [gluc] equals the plasma [gluc] on a molal basis, and that the hematocrit is similar in humans and cattle. The primary objective was to determine the accuracy of the meter for measuring plasma [gluc] in dairy cattle. Secondary objectives were to characterize the influence of hematocrit and sample temperature on the measured value for [gluc]. A total of 106 periparturient Holstein-Friesian cattle. Blood and plasma samples (1,109) were obtained and Deming regression and Bland-Altman plots were used to determine the accuracy of the meter against the reference method (plasma hexokinase assay). Multivariable regression and linear regression were used to determine the effect of hematocrit and sample temperature on the plasma [gluc] measured by the meter. Intra-erythrocyte [gluc] was 18% of plasma [gluc] on a molar basis. Sample temperature had a significant linear effect on plasma [gluc] as measured by the meter for 3/5 plasma samples when measured [gluc] > 160 mg/dL. The meter utilizes an algorithm that is optimized for human blood and is inaccurate when applied to bovine blood. Until a cattle-specific algorithm is developed, we recommend using plasma as the analyte instead of blood and calculating plasma [gluc] using the equation: [gluc] = 0.66 × [gluc]p-meter + 15, where [gluc]p-meter is the value reported by the meter. If blood is measured, then we recommend using the equation: [gluc] = 0.90 × [gluc]b-meter + 15. Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  18. Concentrations of legacy and novel brominated flame retardants in indoor dust in Melbourne, Australia: An assessment of human exposure.

    Science.gov (United States)

    McGrath, Thomas J; Morrison, Paul D; Ball, Andrew S; Clarke, Bradley O

    2018-04-01

    Polybrominated diphenyl ethers (PBDEs) and novel brominated flame retardants (NBFR) have been used in a range of polymers to inhibit the spread of fires but also have a propensity to migrate out of consumer materials and contaminate indoor dust. In this study, a total of 57 dust samples were collected from 12 homes, eight offices and eight vehicles in Melbourne, Australia and analysed for eight PBDEs (-28, -47, -99, -100, -153, -154, -183 and -209) and seven NBFRs (PBT, PBEB, HBB, EH-TBB, BEH-TEBP, BTBPE and DBDPE) to determine human exposure risks from dust ingestion. Samples were analysed using selective pressurized liquid extraction (S-PLE) and gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). Legacy and replacement flame retardants were detected in all samples with overall ∑PBDE concentrations ranging from 120 to 1700,000 ng/g (median 2100 ng/g) and ∑NBFRs ranging from 1.1 to 10,000 ng/g (median 1800 ng/g). BDE-209 and DBDPE were the dominant compounds in dust samples, followed by congeners associated with commercial Penta-BDE formulations (-47, -99, -100, -153 and -154) and then EH-TBB of the FireMaster 550 and BZ-54 products. ∑Penta-BDE concentrations were elevated in office samples compared with homes and vehicles, while EH-TBB and BDE-209 measured higher concentrations in vehicles compared with their respective levels in homes and offices. Risk assessment estimates revealed the majority of exposure to occur in the home for both adults and toddlers in the City of Melbourne. Generally, body weight adjusted exposure to PBDEs and NBFRs was predicted to be 1 to 2 orders of magnitude higher for toddlers than adults. Estimated rates of BDE-47, -99, -153 and -209 ingestion were each 2 orders of magnitude or more below the USEPA's prescribed oral reference dose values (RfDs) for typical exposure scenarios. However, exposure rates for BDE-47 and -99 reached as high as 52 and 95% of RfDs, respectively, for adults and 4.4 and 7

  19. [Exposure to point-of-sale tobacco displays in Argentina: evidence from the 2013 National Risk Factor Survey].

    Science.gov (United States)

    Morello, Paola; Ondarsuhu, Dolores; Galante, Mariana; O'Donnell, Victoria; Konfino, Jonatan

    2017-01-01

    To describe the population that reports to have visited tobacco points of sale (POS) in Argentina and their perception of tobacco advertising. We used data from the 2013 National Risk Factor Survey. We included 31 167 respondents (96% of the total) who attended a store that sells cigarettes in the previous 30 days. Overall, 54.1% (67.3% of current smokers, 55.1% of former smokers and 49% of non smokers) referred having seen tobacco advertising at the POS. Males (OR=1.2) and current smokers (OR=1.9 vs. non smokers) were more likely to report having seen tobacco advertising at the POS. Those who were exposed to second hand smoke in bars and restaurants (OR=1.2) were also more likely to have seen advertising. We found that younger people (age 18 - 24) were more likely to be exposed (OR=2.8 vs older than 65). Among smokers, those who referred to have seen the advertising were more likely to have tried to quit smoking during the previous year. It is important to regulate advertising at the POS to limit exposure, particularly among young people.

  20. Exposure to point-of-sale tobacco displays in Argentina: evidence from the 2013 National Risk Factor Survey

    Directory of Open Access Journals (Sweden)

    Paola Morello

    2017-03-01

    Full Text Available Objective. To describe the population that reports to have visited tobacco points of sale (POS in Argentina and their perception of tobacco advertising. Materials and methods. We used data from the 2013 National Risk Factor Survey. Results. We included 31 167 respondents (96% of the total who attended a store that sells cigarettes in the previous 30 days. Overall, 54.1% (67.3% of current smokers, 55.1% of former smokers and 49% of non smokers referred having seen tobacco advertising at the POS. Males (OR=1.2 and current smokers (OR=1.9 vs. non smokers were more likely to report having seen tobacco advertising at the POS. Those who were exposed to second hand smoke in bars and restaurants (OR=1.2 were also more likely to have seen advertising. We found that younger people (age 18 – 24 were more likely to be exposed (OR=2.8 vs older than 65. Among smokers, those who referred to have seen the advertising were more likely to have tried to quit smoking during the previous year. Conclusions. It is important to regulate advertising at the POS to limit exposure, particularly among young people.

  1. Evaluation of cetacean exposure to organotin compounds in Brazilian waters through hepatic total tin concentrations

    International Nuclear Information System (INIS)

    Dorneles, Paulo R.; Lailson-Brito, Jose; Fernandez, Marcos A.S.; Vidal, Lara G.; Barbosa, Lupercio A.; Azevedo, Alexandre F.; Fragoso, Ana B.L.; Torres, Joao P.M.; Malm, Olaf

    2008-01-01

    In Brazil, there is no restriction to the use of organotins (OTs). Previous investigations have shown that hepatic ΣSn in cetaceans is predominantly organic. Hepatic ΣSn concentrations were determined by GFAAS in 67 cetaceans (13 species) that stranded on Rio de Janeiro (RJ) and Espirito Santo (ES) states. Concentrations (in ng/g wet wt.) of marine tucuxis (n = 20) from the highly contaminated Guanabara Bay (in RJ) varied from 1703 to 9638. Concentrations of three marine tucuxi foetuses and one newborn calf (all from Guanabara Bay) varied between 431 and 2107. Contrastingly, the maximum level among 19 oceanic dolphins was 346, and 15 out of these 19 specimens presented concentrations below detection limit. The levels of Sn in six marine tucuxis from a less contaminated area (ES) varied from below detection limit to 744. Comparing to the literature, coastal cetaceans from Brazil appear to be highly exposed to OTs. - Cetaceans from Brazil are highly exposed to organotin compounds

  2. Evaluation of cetacean exposure to organotin compounds in Brazilian waters through hepatic total tin concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Dorneles, Paulo R. [Laboratorio de Radioisotopos Eduardo Penna Franca, Instituto de Biofisica Carlos Chagas Filho, CCS, Universidade Federal do Rio de Janeiro (Brazil); Laboratorio de Mamiferos Aquaticos (MAQUA), Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro (Brazil)], E-mail: dornelespr@gmail.com; Lailson-Brito, Jose [Laboratorio de Radioisotopos Eduardo Penna Franca, Instituto de Biofisica Carlos Chagas Filho, CCS, Universidade Federal do Rio de Janeiro (Brazil); Laboratorio de Mamiferos Aquaticos (MAQUA), Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro (Brazil)], E-mail: lailson@uerj.br; Fernandez, Marcos A.S. [Laboratorio de Oceanografia Quimica, Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro (Brazil)], E-mail: hallfz@uerj.br; Vidal, Lara G. [Laboratorio de Mamiferos Aquaticos (MAQUA), Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro (Brazil)], E-mail: vidallara@yahoo.com.br; Barbosa, Lupercio A. [Instituto ORCA, Vila Velha, ES (Brazil)], E-mail: lupercio@orca.org.br; Azevedo, Alexandre F. [Laboratorio de Mamiferos Aquaticos (MAQUA), Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro (Brazil)], E-mail: alexandre.maqua@gmail.com; Fragoso, Ana B.L. [Laboratorio de Mamiferos Aquaticos (MAQUA), Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro (Brazil)], E-mail: abfragoso@gmail.com; Torres, Joao P.M. [Laboratorio de Radioisotopos Eduardo Penna Franca, Instituto de Biofisica Carlos Chagas Filho, CCS, Universidade Federal do Rio de Janeiro (Brazil)], E-mail: jptorres@biof.ufrj.br; Malm, Olaf [Laboratorio de Radioisotopos Eduardo Penna Franca, Instituto de Biofisica Carlos Chagas Filho, CCS, Universidade Federal do Rio de Janeiro (Brazil)], E-mail: olaf@biof.ufrj.br

    2008-12-15

    In Brazil, there is no restriction to the use of organotins (OTs). Previous investigations have shown that hepatic {sigma}Sn in cetaceans is predominantly organic. Hepatic {sigma}Sn concentrations were determined by GFAAS in 67 cetaceans (13 species) that stranded on Rio de Janeiro (RJ) and Espirito Santo (ES) states. Concentrations (in ng/g wet wt.) of marine tucuxis (n = 20) from the highly contaminated Guanabara Bay (in RJ) varied from 1703 to 9638. Concentrations of three marine tucuxi foetuses and one newborn calf (all from Guanabara Bay) varied between 431 and 2107. Contrastingly, the maximum level among 19 oceanic dolphins was 346, and 15 out of these 19 specimens presented concentrations below detection limit. The levels of Sn in six marine tucuxis from a less contaminated area (ES) varied from below detection limit to 744. Comparing to the literature, coastal cetaceans from Brazil appear to be highly exposed to OTs. - Cetaceans from Brazil are highly exposed to organotin compounds.

  3. Concentrated pitch discrimination modulates auditory brainstem responses during contralateral noise exposure.

    Science.gov (United States)

    Ikeda, Kazunari; Sekiguchi, Takahiro; Hayashi, Akiko

    2010-03-31

    This study examined a notion that auditory discrimination is a requisite for attention-related modulation of the auditory brainstem response (ABR) during contralateral noise exposure. Given that the right ear was exposed continuously with white noise at an intensity of 60-80 dB sound pressure level, tone pips at 80 dB sound pressure level were delivered to the left ear through either single-stimulus or oddball procedures. Participants conducted reading (ignoring task) and counting target tones (attentive task) during stimulation. The oddball but not the single-stimulus procedures elicited task-related modulations in both early (ABR) and late (processing negativity) event-related potentials simultaneously. The elicitation of the attention-related ABR modulation during contralateral noise exposure is thus considered to require auditory discrimination and have the corticofugal nature evidently.

  4. Associations between plasma concentrations of PCB 28 and possible indoor exposure sources in Danish school children and mothers.

    Science.gov (United States)

    Egsmose, Emilie Lund; Bräuner, Elvira Vaclavik; Frederiksen, Marie; Mørck, Thit Aarøe; Siersma, Volkert Dirk; Hansen, Pernille Winton; Nielsen, Flemming; Grandjean, Philippe; Knudsen, Lisbeth E

    2016-02-01

    Polychlorinated biphenyls (PCBs) are ubiquitously present in the environment and are suspected of carcinogenic, neurotoxic and immunotoxic effects. Significantly higher plasma concentrations of the congener PCB 28 occur in children compared to adults. Exposure in schools may contribute to this difference. To determine whether increased blood plasma concentrations of PCB 28 in Danish school children and mothers are associated with living in homes or attending schools constructed in the PCB period (1959-1977). PCB 28 was analyzed in plasma samples from 116 children aged 6-11years and 143 mothers living in an urban and a rural area in Denmark and participating in the European pilot project DEMOCOPHES (Demonstration of a study to COordinate and Perform Human Biomonitoring on a European Scale). In Denmark, PCBs were used in construction in the period 1950-1977, and year of construction or renovation of the homes and schools was used as a proxy for indoor PCB exposure. Linear regression models were used to assess the association between potential PCB exposure from building materials and lipid adjusted concentrations of PCB 28 in plasma, with and without adjustment for potential confounders. Among the 116 children and 143 mothers, we were able to specify home construction period in all but 4 children and 5 mothers leaving 111 children and 138 mothers for our analyses. The median lipid adjusted plasma PCB 28 concentration was 3 (range: 1-28) ng/g lipid in the children and 2 (range: 1-8) ng/g lipid in the mothers. Children living in homes built in the PCB period had significantly higher lipid adjusted plasma PCB 28 concentrations compared to children living in homes built before or after the PCB period. Following adjustment for covariates, PCB 28 concentrations in children were 40 (95% CI: 13; 68) percent higher than concentrations of children living in homes constructed at other times. Furthermore, children attending schools built or substantially refurbished in the PCB

  5. Risk assessment of exposure to radon concentration in indoor atmosphere and drinking water of Shimoga city, Karnataka, India

    International Nuclear Information System (INIS)

    Rangaswamy, D.R.; Sannappa, J.; Srinivasa, E.

    2016-01-01

    The exposure of population to natural sources of radiation has become an important issue in terms of radiological protection. The major contribution of dose from natural radiation in normal background regions arises due to inhalation of alpha-emitting radon and thoron, and their progenies, which are ubiquitous in both indoor and outdoor environs. The aim of the present study is to measure indoor radon, thoron and their progeny levels in the dwellings of Shimoga city and radon concentration in drinking water and to estimate the annual effective dose. The indoor concentration of radon, thoron and their progeny was measured using Solid-State Nuclear Track Detectors (SSNTDs) based twin chamber dosimeter cups. The 222 Rn concentration in drinking water was estimated by the Emanometry technique

  6. Determination of rare earth elements in products of Chadormalu iron ore concentrator plant (Iran) from beneficiation point of view

    International Nuclear Information System (INIS)

    Jorjani, E.; Bagherieh, A. H.; Rezai, B.

    2007-01-01

    :Different samples have been prepared from different products in Chadormalu iron ore concentrator plant: Low intensity magnetite separators concentrate (magnetite concentrate), reverse flotation tail (final hematite concentrate), flotation concentrate (apatite concentrate), final tail (L.I. M.S. tail + reverse flotation concentrate + apatite flotation tail). The samples were used for rare earth elements (REEs) distribution and origin studies. The assay of REEs was determined by ICP-MS spectrometry. The amount of total (light and heavy) REEs were 9631, 291, 199, 2236 ppm and the distributions were 19.3, 3.6, 10.1, 67% in flotation concentrate (apatite concentrate), reverse flotation tail (hematite concentrate), magnetite concentrate and total tail respectively. About 19.3% of total REEs were distributed in apatite concentrate with an assay of 9631 ppm. Therefore, further studies have been conducted on this product. According to the Xray studies the minerals of fluoroapatite, ankerite and calcite are the main mineral phases in apatite concentrate which the apatite is dominant among them. The scanning electron microscopy studies were shown that the high amount of REEs distributed on fluoroapatite mineral. The results have clearly shown that the apatite concentrate that is a by product of iron dressing in Chadormalu plant, with a low economical value and left without any further treatment, can be used as a significant source of REEs. According to this characterization studies, the recovery of a mixed rare earth oxide from fluoroapatite is possible either with the treatment of liquors from the total dissolution of the ore in nitric acid or with the proposed treatment of the phosphogypsum by-product from the conventional sulphuric acid route and the recovery of rare earth oxides from phosphoric acid sludges that the detailed flowsheet needs further extraction work

  7. Environmental and occupational exposure to bisphenol A and endometriosis: urinary and peritoneal fluid concentration levels.

    Science.gov (United States)

    Simonelli, Angela; Guadagni, Rossella; De Franciscis, Pasquale; Colacurci, Nicola; Pieri, Maria; Basilicata, Pascale; Pedata, Paola; Lamberti, Monica; Sannolo, Nicola; Miraglia, Nadia

    2017-01-01

    The study aimed to give a first data set of bisphenol A (BPA) levels in the peritoneal fluid of patients suffering from endometriosis and to investigate the relationship between BPA exposure and endometriosis. A questionnaire investigating the occupational context, life environment, and habits was administered to 68 patients suffering from endometriosis and 60 endometriosis-free subjects (control group). Urine and peritoneal fluids samples were collected and analysed by GC/MSMS for BPA dosage. Some of the investigated environmental/lifestyle risk factors (closeness to industries/activities at risk) were associated with an increase in endometriosis; smoking resulted as protective factor; others (use of food plastic boxes) did not seem to influence the onset of pathology. The association between the occupational exposure summarising all examined risk factors (working activity, personal protective equipment, seniority) and endometriosis was statistically significant (χ 2  = 5.252, p = 0.02). Contrasting results were obtained when specific activities were examined. Detectable urinary BPA levels were found in all analysed samples (patients: 1.17-12.68 pg/µl; mean ± SD, 5.31 ± 3.36 pg/µl; control group: 1.28-2.35 pg/µl; mean ± SD, 1.64 ± 0.49 pg/µl; median; 1.46 pg/µl), with a statistically significant difference between patients and controls, showing an association between BPA exposure and endometriosis. Only a few subjects from the control group supplied peritoneal fluid; hence, no comparison test with patients (range 0.39-1.46 pg/µl; mean ± SD, 0.67 ± 0.30 pg/µl; median, 0.58 pg/µl) was carried out. Results highlight the potential association between BPA exposure and endometriosis, as well as the current lack of knowledge regarding occupational exposure to BPA and the need of epidemiological studies focused on single activities/occupations, such as housewives, cleaners, students.

  8. Effect of prolonged exposure to sublethal concentrations of DDT and DDE on protein expression in human pancreatic beta cells.

    Science.gov (United States)

    Pavlikova, Nela; Smetana, Pavel; Halada, Petr; Kovar, Jan

    2015-10-01

    Pollution of the environment represents one of less explored potential reasons for the worldwide epidemic of type 2 diabetes. One of the most prevalent organochlorine pollutants remains the pesticide DDT and its degradation product DDE. Despite some epidemiologic correlations between levels of DDT and DDE in human organism and the prevalence of diabetes, there is almost no information about the exact targets of these compounds inside pancreatic beta cells. To detect functional areas of pancreatic beta cells that could be affected by exposure to DDT and DDE, we analyzed changes in protein expression in the NES2Y human pancreatic beta cell line exposed to three sublethal concentrations (0.1 μM, 1 μM, 10 μM) of DDT and DDE for 1 month. Protein separation and identification was achieved using high-resolution 2D-electrophoresis, computer analysis and mass spectrometry. With these techniques, four proteins were found downregulated after exposure to 10 μM DDT: three cytoskeletal proteins (cytokeratin 8, cytokeratin 18 and actin) and one protein involved in glycolysis (alpha-enolase). Two proteins were downregulated after exposure to 10 μM DDE: cytokeratin 18 and heterogenous nuclear ribonucleoprotein H1 (HNRH1). These changes correlate with previously described effects of other stress conditions (e.g. exposure to palmitate, hyperglycemia, imidazoline derivative, and cytokines) on protein expression in pancreatic beta cells. We conclude that cytoskeletal proteins and their processing, glucose metabolism, and mRNA processing may represent targets affected by exposure to conditions hostile to pancreatic beta cells, including exposure to DDT and DDE. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Effect of prolonged exposure to sublethal concentrations of DDT and DDE on protein expression in human pancreatic beta cells

    Energy Technology Data Exchange (ETDEWEB)

    Pavlikova, Nela, E-mail: nela.pavlikova@lf3.cuni.cz [Department of Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague (Czech Republic); Smetana, Pavel [Department of Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague (Czech Republic); Halada, Petr [Laboratory of Molecular Structure Characterization, Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague (Czech Republic); Kovar, Jan [Department of Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague (Czech Republic)

    2015-10-15

    Pollution of the environment represents one of less explored potential reasons for the worldwide epidemic of type 2 diabetes. One of the most prevalent organochlorine pollutants remains the pesticide DDT and its degradation product DDE. Despite some epidemiologic correlations between levels of DDT and DDE in human organism and the prevalence of diabetes, there is almost no information about the exact targets of these compounds inside pancreatic beta cells. To detect functional areas of pancreatic beta cells that could be affected by exposure to DDT and DDE, we analyzed changes in protein expression in the NES2Y human pancreatic beta cell line exposed to three sublethal concentrations (0.1 μM, 1 μM, 10 μM) of DDT and DDE for 1 month. Protein separation and identification was achieved using high-resolution 2D-electrophoresis, computer analysis and mass spectrometry. With these techniques, four proteins were found downregulated after exposure to 10 μM DDT: three cytoskeletal proteins (cytokeratin 8, cytokeratin 18 and actin) and one protein involved in glycolysis (alpha-enolase). Two proteins were downregulated after exposure to 10 μM DDE: cytokeratin 18 and heterogenous nuclear ribonucleoprotein H1 (HNRH1). These changes correlate with previously described effects of other stress conditions (e.g. exposure to palmitate, hyperglycemia, imidazoline derivative, and cytokines) on protein expression in pancreatic beta cells. We conclude that cytoskeletal proteins and their processing, glucose metabolism, and mRNA processing may represent targets affected by exposure to conditions hostile to pancreatic beta cells, including exposure to DDT and DDE. - Highlights: • Epidemiologic studies connect pollution with incidence of diabetes mellitus. • We explored the effect of DDT and DDE on protein expression in the NES2Y pancreatic beta cell line. • One month exposure to three sublethal concentrations of DDT and DDE was employed. • Expression of alpha-enolase, actin

  10. Effect of prolonged exposure to sublethal concentrations of DDT and DDE on protein expression in human pancreatic beta cells

    International Nuclear Information System (INIS)

    Pavlikova, Nela; Smetana, Pavel; Halada, Petr; Kovar, Jan

    2015-01-01

    Pollution of the environment represents one of less explored potential reasons for the worldwide epidemic of type 2 diabetes. One of the most prevalent organochlorine pollutants remains the pesticide DDT and its degradation product DDE. Despite some epidemiologic correlations between levels of DDT and DDE in human organism and the prevalence of diabetes, there is almost no information about the exact targets of these compounds inside pancreatic beta cells. To detect functional areas of pancreatic beta cells that could be affected by exposure to DDT and DDE, we analyzed changes in protein expression in the NES2Y human pancreatic beta cell line exposed to three sublethal concentrations (0.1 μM, 1 μM, 10 μM) of DDT and DDE for 1 month. Protein separation and identification was achieved using high-resolution 2D-electrophoresis, computer analysis and mass spectrometry. With these techniques, four proteins were found downregulated after exposure to 10 μM DDT: three cytoskeletal proteins (cytokeratin 8, cytokeratin 18 and actin) and one protein involved in glycolysis (alpha-enolase). Two proteins were downregulated after exposure to 10 μM DDE: cytokeratin 18 and heterogenous nuclear ribonucleoprotein H1 (HNRH1). These changes correlate with previously described effects of other stress conditions (e.g. exposure to palmitate, hyperglycemia, imidazoline derivative, and cytokines) on protein expression in pancreatic beta cells. We conclude that cytoskeletal proteins and their processing, glucose metabolism, and mRNA processing may represent targets affected by exposure to conditions hostile to pancreatic beta cells, including exposure to DDT and DDE. - Highlights: • Epidemiologic studies connect pollution with incidence of diabetes mellitus. • We explored the effect of DDT and DDE on protein expression in the NES2Y pancreatic beta cell line. • One month exposure to three sublethal concentrations of DDT and DDE was employed. • Expression of alpha-enolase, actin

  11. Influence of geometry of thermal manikins on concentration distribution and personal exposure

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor; Kaczmarczyk, Jan

    2007-01-01

    The analyses performed in this paper reveal that a breathing thermal manikin with realistic simulation of respiration including breathing cycle, pulmonary ventilation rate, frequency and breathing mode, gas concentration, humidity and temperature of exhaled air and human body shape and surface...... temperature is sensitive enough to perform reliable measurement of characteristics of air as inhaled by occupants. The temperature, humidity, and pollution concentration in the inhaled air can be measured accurately with a thermal manikin without breathing simulation if they are measured at the upper lip...... at a distance of simulation of breathing, especially of exhalation, is needed for studying the transport of exhaled air between occupants. A method...

  12. Reduced gene expression levels after chronic exposure to high concentrations of air pollutants

    Czech Academy of Sciences Publication Activity Database

    Rössner ml., Pavel; Tulupová, Elena; Rössnerová, Andrea; Líbalová, Helena; Hoňková, Kateřina; Gmuender, H.; Pastorková, Anna; Švecová, Vlasta; Topinka, Jan; Šrám, Radim

    2015-01-01

    Roč. 780, oct (2015), s. 60-70 ISSN 0027-5107 R&D Projects: GA MŽP(CZ) SP/1B3/8/08; GA MŠk(CZ) LO1508; GA ČR GA13-13458S; GA MŠk 2B08005 Institutional support: RVO:68378041 Keywords : chronic exposure * air pollution * gene expression profiles * human health * particulate matter * polycyclic aromatic hydrocarbons Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 2.581, year: 2015

  13. Interdependence of initial cell density, drug concentration and exposure time revealed by real-time impedance spectroscopic cytotoxicity assay

    DEFF Research Database (Denmark)

    Caviglia, Claudia; Zor, Kinga; Canepa, Silvia

    2015-01-01

    We investigated the combined effect of the initial cell density (12 500, 35 000, 75 000, and 100 000 cells cm−2) and concentration of the anti-cancer drug doxorubicin on HeLa cells by performing timedependent cytotoxicity assays using real-time electrochemical impedance spectroscopy. A correlation...... between the rate of cell death and the initial cell seeding density was found at 2.5 μM doxorubicin concentration, whereas this was not observed at 5 or 100 μM. By sensing the changes in the cell–substrate interaction using impedance spectroscopy under static conditions, the onset of cytotoxicity...... was observed 5 h earlier than when using a standard colorimetric end-point assay (MTS) which measures changes in the mitochondrial metabolism. Furthermore, with the MTS assay no cytotoxicity was observed after 15 h of incubation with 2.5 μM doxorubicin, whereas the impedance showed at this time point cell...

  14. Activity concentrations of K, Th, Ra and radiation exposure levels in ...

    African Journals Online (AJOL)

    use

    Available online at http://www.academicjournals.org/AJEST ... average absorbed dose rate for the five quarries was found to be 541.4 nGyh-1 1m above the ground level while .... conversion factors for converting the activity concentrations of.

  15. Correlation between odour concentration and odour intensity from exposure to environmental odour

    Science.gov (United States)

    Yusoff, Syafinah; Qamaruz Zaman, Nastaein

    2017-08-01

    The encroachment of industries, agricultural activities and husbandries to the community area had been a major concern of late, especially in regards to the escalating reports of odour nuisances. A study was performed with the objective of establishing correlation between odour concentration and odour intensity, as an improved method to determine odour nuisances in the community. Universiti Sains Malaysia Engineering Campus was chosen as the study location, due to its vicinity to several odour sources including paper mill, palm oil mill and poultry farm. The odour survey was based on VDI 3940, to determine the level of odour intensity with the corresponding odour concentration measured using an infield olfactometer. The correlation between both methods shows a significant correlation by using Pearson Correlation with a level of confidence of 99.9 percent. The graph plotted between intensity and concentration shows the R2 value of 0.40 which indicated a good correlation between both methods, despite having a high variance and low in consistency. Therefore, this study concludes that the determination of odour concentration should be complemented with odour intensity in order to recognize the true impact of odour nuisance in a community.

  16. Behavior toxicity to Caenorhabditis elegans transferred to the progeny after exposure to sulfamethoxazole at environmentally relevant concentrations

    Institute of Scientific and Technical Information of China (English)

    Zhenyang Yu; Lei Jiang; Daqiang Yin

    2011-01-01

    Sulfamethoxazole (SMX) is one of the most common detected antibiotics in the environment. In order to study whether SMX can affect behavior and growth and whether these effects could be transferred to the progeny, Caenorhabditis elegans was exposed at environmentally relevant concentrations for 24, 48, 72 and 96 hr, respectively. After exposure, the exposed parent generation (Po) was measured for behavior and growth indicators, which were presented as percentage of controls (POC). Then their corresponding unexposed progeny (F1) was separated and measured for the same indicators. The lowest POC for Po after 96 hr-exposure at 100 mg/L were 37.8%, 12.7%, 45.8% and 70.1% for body bending frequency (BBF), reversal movement (RM), Omega turns (OT) and body length (BL), respectively. And F1 suffered defects with the lowest POC as 55.8%, 24.1%, 48.5% and 60.7% for BBF, RM, OT and BL, respectively. Defects in both Po and F1 showed a time- and concentration-dependent fashion and behavior indicators showed better sensitivity than growth indicator. The observed effects on F1 demonstrated the transferable properties of SMX. Defects of SMX at environmental concentrations suggested that it is necessary to perform further systematical studies on its ecological risk in actual conditions.

  17. Maternal exposure to carbamazepine at environmental concentrations can cross intestinal and placental barriers

    Energy Technology Data Exchange (ETDEWEB)

    Kaushik, Gaurav, E-mail: kausgaur@isu.edu [Department of Biological Sciences, Idaho State University, Stop 8007, 921 S 8th Ave, Pocatello, ID 83209-8007 (United States); Department of Medical Pathology and Laboratory Medicine, University of California at Davis, Davis, CA 95817 (United States); Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children, Northern California, 2425 Stockton Boulevard, Sacramento, CA 95817 (United States); Huber, David P., E-mail: hubedavi@isu.edu [Department of Biological Sciences, Idaho State University, Stop 8007, 921 S 8th Ave, Pocatello, ID 83209-8007 (United States); Aho, Ken, E-mail: ahoken@isu.edu [Department of Biological Sciences, Idaho State University, Stop 8007, 921 S 8th Ave, Pocatello, ID 83209-8007 (United States); Finney, Bruce, E-mail: finney@isu.edu [Department of Biological Sciences, Idaho State University, Stop 8007, 921 S 8th Ave, Pocatello, ID 83209-8007 (United States); Bearden, Shawn, E-mail: bearshaw@isu.edu [Department of Biological Sciences, Idaho State University, Stop 8007, 921 S 8th Ave, Pocatello, ID 83209-8007 (United States); Zarbalis, Konstantinos S., E-mail: kzarbalis@ucdavis.edu [Department of Medical Pathology and Laboratory Medicine, University of California at Davis, Davis, CA 95817 (United States); Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children, Northern California, 2425 Stockton Boulevard, Sacramento, CA 95817 (United States); Thomas, Michael A., E-mail: mthomas@isu.edu [Department of Biological Sciences, Idaho State University, Stop 8007, 921 S 8th Ave, Pocatello, ID 83209-8007 (United States)

    2016-05-27

    Psychoactive pharmaceuticals have been found as teratogens at clinical dosage during pregnancy. These pharmaceuticals have also been detected in minute (ppb) concentrations in drinking water in the US, and are environmental contaminants that may be complicit in triggering neurological disorders in genetically susceptible individuals. Previous studies have determined that psychoactive pharmaceuticals (fluoxetine, venlafaxine and carbamazepine) at environmentally relevant concentrations enriched sets of genes regulating development and function of the nervous system in fathead minnows. Altered gene sets were also associated with potential neurological disorders, including autism spectrum disorders (ASD). Subsequent in vitro studies indicated that psychoactive pharmaceuticals altered ASD-associated synaptic protein expression and gene expression in human neuronal cells. However, it is unknown if environmentally relevant concentrations of these pharmaceuticals are able to cross biological barriers from mother to fetus, thus potentially posing risks to nervous system development. The main objective of this study was to test whether psychoactive pharmaceuticals (fluoxetine, venlafaxine, and carbamazepine) administered through the drinking water at environmental concentrations to pregnant mice could reach the brain of the developing embryo by crossing intestinal and placental barriers. We addressed this question by adding {sup 2}H-isotope labeled pharmaceuticals to the drinking water of female mice for 20 days (10 pre-and 10 post–conception days), and quantifying {sup 2}H-isotope enrichment signals in the dam liver and brain of developing embryos using isotope ratio mass spectrometry. Significant levels of {sup 2}H enrichment was detected in the brain of embryos and livers of carbamazepine-treated mice but not in those of control dams, or for fluoxetine or venlafaxine application. These results provide the first evidence that carbamazepine in drinking water and at

  18. Maternal exposure to carbamazepine at environmental concentrations can cross intestinal and placental barriers

    International Nuclear Information System (INIS)

    Kaushik, Gaurav; Huber, David P.; Aho, Ken; Finney, Bruce; Bearden, Shawn; Zarbalis, Konstantinos S.; Thomas, Michael A.

    2016-01-01

    Psychoactive pharmaceuticals have been found as teratogens at clinical dosage during pregnancy. These pharmaceuticals have also been detected in minute (ppb) concentrations in drinking water in the US, and are environmental contaminants that may be complicit in triggering neurological disorders in genetically susceptible individuals. Previous studies have determined that psychoactive pharmaceuticals (fluoxetine, venlafaxine and carbamazepine) at environmentally relevant concentrations enriched sets of genes regulating development and function of the nervous system in fathead minnows. Altered gene sets were also associated with potential neurological disorders, including autism spectrum disorders (ASD). Subsequent in vitro studies indicated that psychoactive pharmaceuticals altered ASD-associated synaptic protein expression and gene expression in human neuronal cells. However, it is unknown if environmentally relevant concentrations of these pharmaceuticals are able to cross biological barriers from mother to fetus, thus potentially posing risks to nervous system development. The main objective of this study was to test whether psychoactive pharmaceuticals (fluoxetine, venlafaxine, and carbamazepine) administered through the drinking water at environmental concentrations to pregnant mice could reach the brain of the developing embryo by crossing intestinal and placental barriers. We addressed this question by adding "2H-isotope labeled pharmaceuticals to the drinking water of female mice for 20 days (10 pre-and 10 post–conception days), and quantifying "2H-isotope enrichment signals in the dam liver and brain of developing embryos using isotope ratio mass spectrometry. Significant levels of "2H enrichment was detected in the brain of embryos and livers of carbamazepine-treated mice but not in those of control dams, or for fluoxetine or venlafaxine application. These results provide the first evidence that carbamazepine in drinking water and at typical

  19. Blood cadmium concentrations and environmental exposure sources in newcomer South and East Asian women in the Greater Toronto Area, Canada

    International Nuclear Information System (INIS)

    Wiseman, C.L.S.; Parnia, A.; Chakravartty, D.; Archbold, J.; Zawar, N.; Copes, R.; Cole, D.C.

    2017-01-01

    Background: Immigrant women are often identified as being particularly vulnerable to environmental exposures and health effects. The availability of biomonitoring data on newcomers is limited, thus, presenting a challenge to public health practitioners in the identification of priorities for intervention. Objectives: In fulfillment of data needs, the purpose of this study was to characterize blood concentrations of cadmium (Cd) among newcomer women of reproductive age (19–45 years of age) living in the Greater Toronto Area (GTA), Canada and to assess potential sources of environmental exposures. Methods: A community-based model, engaging peer researchers from the communities of interest, was used for recruitment and follow-up purposes. Blood samples were taken from a total of 211 newcomer women from South and East Asia, representing primary, regional origins of immigrants to the GTA, and environmental exposure sources were assessed via telephone survey. Metal concentrations were measured in blood samples (diluted with 0.5% (v/v) ammonium hydroxide and 0.1% (v/v) octylphenol ethoxylate) using a quadrupole ICP-MS. Survey questions addressed a wide range of environmental exposure sources, including dietary and smoking patterns and use of nutritional supplements, herbal products and cosmetics. Results: A geometric mean (GM) blood Cd concentration of 0.39 µg/L (SD:±2.07 µg/L) was determined for study participants (min/max: <0.045 µg /L (LOD)/2.36 µg/L). Several variables including low educational attainment (Relative Ratio (RR) (adjusted)=1.50; 95% CI 1.17–1.91), milk consumption (RR (adjusted)=0.86; 95% CI 0.76–0.97), and use of zinc supplements (RR (adjusted)=0.76; 95% CI 0.64–0.95) were observed to be significantly associated with blood Cd concentrations in the adjusted regression model. The variable domains socioeconomic status (R 2 adj =0.11) and country of origin (R 2 adj =0.236) were the strongest predictors of blood Cd. Conclusion: Blood Cd

  20. Blood cadmium concentrations and environmental exposure sources in newcomer South and East Asian women in the Greater Toronto Area, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Wiseman, C.L.S., E-mail: clare.wiseman@utoronto.ca [School of the Environment, University of Toronto (Canada); Dalla Lana School of Public Health, University of Toronto (Canada); Parnia, A.; Chakravartty, D. [Dalla Lana School of Public Health, University of Toronto (Canada); Archbold, J. [Toronto Public Health (Canada); Zawar, N. [Dalla Lana School of Public Health, University of Toronto (Canada); Copes, R. [Dalla Lana School of Public Health, University of Toronto (Canada); Public Health Ontario (Canada); Cole, D.C. [School of the Environment, University of Toronto (Canada); Dalla Lana School of Public Health, University of Toronto (Canada)

    2017-04-15

    Background: Immigrant women are often identified as being particularly vulnerable to environmental exposures and health effects. The availability of biomonitoring data on newcomers is limited, thus, presenting a challenge to public health practitioners in the identification of priorities for intervention. Objectives: In fulfillment of data needs, the purpose of this study was to characterize blood concentrations of cadmium (Cd) among newcomer women of reproductive age (19–45 years of age) living in the Greater Toronto Area (GTA), Canada and to assess potential sources of environmental exposures. Methods: A community-based model, engaging peer researchers from the communities of interest, was used for recruitment and follow-up purposes. Blood samples were taken from a total of 211 newcomer women from South and East Asia, representing primary, regional origins of immigrants to the GTA, and environmental exposure sources were assessed via telephone survey. Metal concentrations were measured in blood samples (diluted with 0.5% (v/v) ammonium hydroxide and 0.1% (v/v) octylphenol ethoxylate) using a quadrupole ICP-MS. Survey questions addressed a wide range of environmental exposure sources, including dietary and smoking patterns and use of nutritional supplements, herbal products and cosmetics. Results: A geometric mean (GM) blood Cd concentration of 0.39 µg/L (SD:±2.07 µg/L) was determined for study participants (min/max: <0.045 µg /L (LOD)/2.36 µg/L). Several variables including low educational attainment (Relative Ratio (RR) (adjusted)=1.50; 95% CI 1.17–1.91), milk consumption (RR (adjusted)=0.86; 95% CI 0.76–0.97), and use of zinc supplements (RR (adjusted)=0.76; 95% CI 0.64–0.95) were observed to be significantly associated with blood Cd concentrations in the adjusted regression model. The variable domains socioeconomic status (R{sup 2}{sub adj}=0.11) and country of origin (R{sup 2}{sub adj}=0.236) were the strongest predictors of blood Cd. Conclusion

  1. Effects of benzo(a)pyrene exposure on the ATPase activity and calcium concentration in the hippocampus of neonatal rats.

    Science.gov (United States)

    Yang, Kai; Chen, Chengzhi; Cheng, Shuqun; Cao, Xianqing; Tu, Baijie

    2017-03-30

    To investigate whether postnatal benzo(a)pyrene (B(a)P) exposure caused the impairments on the process of neurodevelopment and the alteration in the calcium medium in the neonatal rats. Eighty neonatal Sprague Dawley (SD) rats were randomly divided into 5 groups (untreated control group, vehicle group, 0.02 mg/kg, 0.2 mg/kg and 2 mg/kg B(a)P-exposed group). Rats were treated with B(a)P by the intragastric administration from postnatal day (PND) 4 to 25. Morris water maze (MWM) was employed to observe the spatial memory of rats. The activity of calcium adenosine triphosphatase (Ca2+-ATPase), sodium-potassium adenosine triphosphatase (Na+-K+-ATPase) and calcium-magnesium adenosine triphosphatase (Ca2+-Mg2+-ATPase) in the hippocampus were detected by commercial kits. Fura-2 pentakis(acetoxymethyl) (Fura-2/AM) probe and reactive oxygen species (ROS) reagent kit were used for measuring the concentration of Ca2+ and ROS in the hippocampus synapse, respectively. Rats exposed to B(a)P resulted in the deficits in the spatial memory manifested by the increased escape latency and decreased number of crossing platform and time spent in target quadrant in comparison with the control groups. Benzo(a)pyrene exposure caused the significant decrease in the ATPase activity in the hippocampus and caused Ca2+ overload in the synaptic, besides, the ROS concentration increased significantly which may further induce neurobehavioral impairment of the neonatal rats. Our findings suggest that postnatal B(a)P exposure may cause the neurobehavioral impairments in the neonatal rats, which were mediated by the decreased ATPase activity and elevated Ca2+ concentration. Int J Occup Med Environ Health 2017;30(2):203-211. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  2. Mobilisation of heavy metals into the urine by CaEDTA: relation to erythrocyte and plasma concentrations and exposure indicators.

    Science.gov (United States)

    Araki, S; Aono, H; Murata, K

    1986-09-01

    To investigate the effects of calcium disodium ethylenediamine tetra-acetate (CaEDTA) on the urinary excretion, erythrocyte, and plasma concentrations and exposure indicators of seven heavy metals, CaEDTA was administered by intravenous infusion to 20 workers exposed to lead, zinc, and copper. The workers' blood lead concentrations ranged from 22 to 59 micrograms/dl (mean 38 micrograms/dl (1.8 mumol/l]. The 24 hour urinary excretion of metals after CaEDTA administration (mobilisation yield) was on average 13 times the background excretion for lead, 11 times for zinc, 3.8 times for manganese, 3.4 times for cadmium, 1.3 times for copper, and 1.1 times for chromium; no significant increase was found for mercury. The mobilisation yield of lead (MPb) was significantly correlated with whole blood and erythrocyte concentrations and the urinary excretion of lead but not with its plasma concentration; similarly, the mobilisation yield of cadmium was significantly correlated with its erythrocyte concentration. In addition, MPb was significantly correlated with intra-erythrocytic enzyme delta-aminolaevulinic acid dehydratase activity and urinary coproporphyrin excretion. The relation between the mobilisation yield of heavy metals and their body burden (and toxic signs) is discussed in the light of these findings.

  3. Using equilibrium passive dosing to maintain stable exposure concentrations of triclosan in a 6-week toxicity test

    DEFF Research Database (Denmark)

    Sobek, A.; Ribbenstedt, A.; Mustajärvi, L.

    2015-01-01

    toxicity tests. Yet, the European Commission’s criteria for chemicals’ risk assessments aim at protecting higher levels in the environment. To achieve protection of populations and ecosystems, reliable long-term ecotoxicologial tests are needed. In this study, we used equilibrium passive dosing to maintain...... stable exposure concentrations of triclosan (log Kow 4.8) in a 6-week multigeneration test with the benthic copepod Nitocra spinipes. The tests were performed in 10 mL vials casted with 1000 mg of silicone (DC 1-2577). Based on a previous pilot study, three triclosan concentrations were selected...... and tested (15 μg L-1; 30 μg L-1; 60 μg L-1) as well as a control (no triclosan). At test beginning, each vial contained 12 individuals consisting of 3 individuals from four different life stages. The test includes feeding with phytoplankton three times a week, which can lead to declining freely dissolved...

  4. Associations between plasma concentrations of PCB 28 and possible indoor exposure sources in Danish school children and mothers

    DEFF Research Database (Denmark)

    Egsmose, Emilie Lund; Bräuner, Elvira Vaclavik; Frederiksen, Marie

    2016-01-01

    Background: Polychlorinated biphenyls (PCBs) are ubiquitously present in the environment and are suspected ofcarcinogenic, neurotoxic and immunotoxic effects. Significantly higher plasma concentrations of the congener PCB 28 occur in children compared to adults. Exposure in schools may contribute...... to this difference. Objective: To determine whether increased blood plasma concentrations of PCB 28 in Danish school children andmothers are associated with living in homes or attending schools constructed in the PCB period (1959–1977). Methods: PCB 28 was analyzed in plasma samples from 116 children aged 6–11 years...... and 143 mothers living inan urban and a rural area in Denmark and participating in the European pilot project DEMOCOPHES (Demonstrationof a study to COordinate and Perform Human Biomonitoring on a European Scale). In Denmark, PCBs wereused in construction in the period 1950–1977, and year of construction...

  5. Concentrations, sources and human health risk of inhalation exposure to air toxics in Edmonton, Canada.

    Science.gov (United States)

    Bari, Md Aynul; Kindzierski, Warren B

    2017-04-01

    With concern about levels of air pollutants in recent years in the Capital Region of Alberta, an investigation of ambient concentrations, sources and potential human health risk of hazardous air pollutants (HAPs) or air toxics was undertaken in the City of Edmonton over a 5-year period (2009-2013). Mean concentrations of individual HAPs in ambient air including volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs) and trace metals ranged from 0.04 to 1.73 μg/m 3 , 0.01-0.54 ng/m 3 , and 0.05-3.58 ng/m 3 , respectively. Concentrations of benzene, naphthalene, benzo(a)pyrene (BaP), arsenic, manganese and nickel were far below respective annual Alberta Ambient Air Quality Objectives. Carcinogenic and non-carcinogenic risk of air toxics were also compared with risk levels recommended by regulatory agencies. Positive matrix factorization identified six air toxics sources with traffic as the dominant contributor to total HAPs (4.33 μg/m 3 , 42%), followed by background/secondary organic aerosol (SOA) (1.92 μg/m 3 , 25%), fossil fuel combustion (0.92 μg/m 3 , 11%). On high particulate air pollution event days, local traffic was identified as the major contributor to total HAPs compared to background/SOA and fossil fuel combustion. Carcinogenic risk values of traffic, background/SOA and metals industry emissions were above the USEPA acceptable level (1 × 10 -6 ), but below a tolerable risk (1 × 10 -4 ) and Alberta benchmark (1 × 10 -5 ). These findings offer useful preliminary information about current ambient air toxics levels, dominant sources and their potential risk to public health; and this information can support policy makers in the development of appropriate control strategies if required. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Paternal exposure to environmental 17-alpha-ethinylestradiol concentrations modifies testicular transcription, affecting the sperm transcript content and the offspring performance in zebrafish.

    Science.gov (United States)

    Valcarce, David G; Vuelta, Elena; Robles, Vanesa; Herráez, Maria Paz

    2017-12-01

    The synthetic estrogen 17-α-ethinylestradiol (EE2), a major constituent in contraceptive pills, is an endocrine disrupting chemical (EDC) present in the aquatic environment at concentrations of ng/L. Developmental exposure to these low concentrations in fish can induce several disorders. Zebrafish (Danio rerio) is a perfect organism for monitoring the effects of environmental contaminants. Our hypothesis is that changes promoted by EE2 in the germ line of male adults could be transmitted to the unexposed progeny. We exposed male zebrafish to 2.5, 5 and 10ng/L of EE2 during spermatogenesis and mated them with untreated females. Detailed progeny development was studied concentrating to survival, hatching and malformations. Due to the high incidence of lymphedemas within larvae, we performed qPCR analysis of genes involved in lymphatic development (vegfc and vegfr3) and endothelial cell migration guidance (cxcr4a and cxcl12b). Estrogen receptor (ER) transcript presence was also evaluated in sperm, testis and embryos. Progenies showed a range of disorders although at a low incidence: skeletal distortions, uninflated swimbladder, lymphedema formation, cartilage deformities and otolith tethering. Swimming evaluation revealed less active locomotion. All these processes are related to pathways involving ERs (esr1, esr2a and esr2b). mRNA analysis revealed that environmental EE2 causes the up-regulation of esr1 an esr2b in testis and the increase of esr2b transcripts in sperm pointing to a link between lymphedema in embryos and ER expression impairment. We demonstrate that the effects induced by environmental toxicants can be paternally inherited and point to the changes on the sperm transcriptome as the responsible mechanism. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Triton X-114 based cloud point extraction: a thermoreversible approach for separation/concentration and dispersion of nanomaterials in the aqueous phase.

    Science.gov (United States)

    Liu, Jing-fu; Liu, Rui; Yin, Yong-guang; Jiang, Gui-bin

    2009-03-28

    Capable of preserving the sizes and shapes of nanomaterials during the phase transferring, Triton X-114 based cloud point extraction provides a general, simple, and cost-effective route for reversible concentration/separation or dispersion of various nanomaterials in the aqueous phase.

  8. Assessing bottled water nitrate concentrations to evaluate total drinking water nitrate exposure and risk of birth defects.

    Science.gov (United States)

    Weyer, Peter J; Brender, Jean D; Romitti, Paul A; Kantamneni, Jiji R; Crawford, David; Sharkey, Joseph R; Shinde, Mayura; Horel, Scott A; Vuong, Ann M; Langlois, Peter H

    2014-12-01

    Previous epidemiologic studies of maternal exposure to drinking water nitrate did not account for bottled water consumption. The objective of this National Birth Defects Prevention Study (NBDPS) (USA) analysis was to assess the impact of bottled water use on the relation between maternal exposure to drinking water nitrate and selected birth defects in infants born during 1997-2005. Prenatal residences of 1,410 mothers reporting exclusive bottled water use were geocoded and mapped; 326 bottled water samples were collected and analyzed using Environmental Protection Agency Method 300.0. Median bottled water nitrate concentrations were assigned by community; mothers' overall intake of nitrate in mg/day from drinking water was calculated. Odds ratios for neural tube defects, limb deficiencies, oral cleft defects, and heart defects were estimated using mixed-effects models for logistic regression. Odds ratios (95% CIs) for the highest exposure group in offspring of mothers reporting exclusive use of bottled water were: neural tube defects [1.42 (0.51, 3.99)], limb deficiencies [1.86 (0.51, 6.80)], oral clefts [1.43 (0.61, 3.31)], and heart defects [2.13, (0.87, 5.17)]. Bottled water nitrate had no appreciable impact on risk for birth defects in the NBDPS.

  9. Exposure of commuters to carbon monoxide in Mexico City II. Comparison of in-vehicle and fixed-site concentrations.

    Science.gov (United States)

    Fernandez-Bremauntz, A A; Ashmore, M R

    1995-01-01

    The objective of this paper is to compare measurements of carbon monoxide taken concurrently inside vehicles and at fixed-site monitoring stations (FSMs), in order to assess if the FSM stations can be used to estimate commuters' exposure to this pollutant. During the study period ambient CO concentrations were very high. Five selected stations reported concentrations in excess of the Mexican (13 ppm) and United States (9 ppm) 8-hour standards for CO. Since, for all modes of transportation, the in-vehicle concentrations were always larger than the concurrent ambient concentrations, the differences between them were always positive and the ratios were always greater than one. Average, in-vehicle/ambient ratios for each mode of transportation were: automobile, 5.2; minivan, 5.2; minibus, 4.3; bus, 3.1; trolleybus 3.0; and metro, 2.2. A series of simple regression models with a moderate predictive power (R2 = 0.47 to 0.71) were developed for metro, bus, minibus, and automobile commuters. The models include the FSM measurements and also, depending on the mode of transportation, other variables, such as vehicular speed, the route of travel, and the wind speed. In the future, the models should be validated in two ways to determine their predictive power. First, they should be verified against additional samples taken under similar conditions; and second, their applications under different conditions should be explored through sampling during a different season of the year or on other commuting routes.

  10. Exposure to high glutamate concentration activates aerobic glycolysis but inhibits ATP-linked respiration in cultured cortical astrocytes.

    Science.gov (United States)

    Shen, Yao; Tian, Yueyang; Shi, Xiaojie; Yang, Jianbo; Ouyang, Li; Gao, Jieqiong; Lu, Jianxin

    2014-08-01

    Astrocytes play a key role in removing the synaptically released glutamate from the extracellular space and maintaining the glutamate below neurotoxic level in the brain. However, high concentration of glutamate leads to toxicity in astrocytes, and the underlying mechanisms are unclear. The purpose of this study was to investigate whether energy metabolism disorder, especially impairment of mitochondrial respiration, is involved in the glutamate-induced gliotoxicity. Exposure to 10-mM glutamate for 48 h stimulated glycolysis and respiration in astrocytes. However, the increased oxygen consumption was used for proton leak and non-mitochondrial respiration, but not for oxidative phosphorylation and ATP generation. When the exposure time extended to 72 h, glycolysis was still activated for ATP generation, but the mitochondrial ATP-linked respiration of astrocytes was reduced. The glutamate-induced astrocyte damage can be mimicked by the non-metabolized substrate d-aspartate but reversed by the non-selective glutamate transporter inhibitor TBOA. In addition, the glutamate toxicity can be partially reversed by vitamin E. These findings demonstrate that changes of bioenergetic profile occur in cultured cortical astrocytes exposed to high concentration of glutamate and highlight the role of mitochondria respiration in glutamate-induced gliotoxicity in cortical astrocytes. Copyright © 2014 John Wiley & Sons, Ltd.

  11. Can the exposure of Apis mellifera (Hymenoptera, Apiadae) larvae to a field concentration of thiamethoxam affect newly emerged bees?

    Science.gov (United States)

    Friol, Priscila Sepúlveda; Catae, Aline Fernanda; Tavares, Daiana Antonia; Malaspina, Osmar; Roat, Thaisa Cristina

    2017-10-01

    The use of insecticides on crops can affect non-target insects, such as bees. In addition to the adult bees, larvae can be exposed to the insecticide through contaminated floral resources. Therefore, this study aimed to investigate the possible effects of the exposure of A. mellifera larvae to a field concentration of thiamethoxam (0.001 ng/μL thiamethoxam) on larval and pupal survival and on the percentage of adult emergence. Additionally, its cytotoxic effects on the digestive cells of midgut, Malpighian tubules cells and Kenyon cells of the brain of newly emerged A. mellifera bees were analyzed. The results showed that larval exposure to this concentration of thiamethoxam did not influence larval and pupal survival or the percentage of adult bee emergence. However, this exposure caused ultra-structural alterations in the target and non-target organs of newly emerged bees. The digestive cell of bees that were exposed to the insecticide exhibited a basal labyrinth without long and thin channels and compromised mitochondria. In Malpighian tubules cells, disorganized basal labyrinth, dilated mitochondria with a deformed shape and a loss of cristae, and disorganized microvilli were observed. The results showed that the exposed bees presented Kenyon cells with alterations in the nucleus and mitochondria. These alterations indicate possible tissue degeneration, demonstrating the cytotoxicity of thiamethoxam in the target and non-target organs of newly emerged bees. Such results suggest cellular organelle impairment that can compromise cellular function of the midgut cells, Malpighian tubules cells and Kenyon cells, and, consequently, can compromise the longevity of the bees of the whole colony. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Association between arsenic exposure from a coal-burning power plant and urinary arsenic concentrations in Prievidza District, Slovakia

    Energy Technology Data Exchange (ETDEWEB)

    Ranft, U.; Miskovic, P.; Pesch, B.; Jakubis, P.; Fabianova, E.; Keegan, T.; Hergemoller, A.; Jakubis, M.; Nieuwenhuijsen, M.J. [University of Dusseldorf, Dusseldorf (Germany)

    2003-06-01

    To assess the arsenic exposure of a population living in the vicinity of a coal-burning power plant with high arsenic emission in the Prievidza District, Slovakia, 548 spot urine samples were speciated for inorganic As (As-inorg), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), and their sum (As-sum). The urine samples were collected from the population of a case-control study on nonmelanoma skin cancer (NMSC). A total of 411 samples with complete As speciations and sufficient urine quality and without fish consumption were used for statistical analysis. Although current environmental As exposure and urinary As concentrations were low (median As in soil within 5 km distance to the power plant, 41 {mu}g/g; median urinary As-sum, 5.8 {mu}g/L), there was a significant but weak association between As in soil and urinary As-sum (r = 0.21, p {lt} 0.01). We performed a multivariate regression analysis to calculate adjusted regression coefficients for environmental As exposure and other determinants of urinary As. Persons living in the vicinity of the plant had 27% higher As-sum values (p {lt} 0.01), based on elevated concentrations of the methylated species. A 32% increase of MMA occurred among subjects who consumed homegrown food (p {lt} 0.001). NMSC cases had significantly higher levels of As-sum, DMA, and As-inorg. The methylation index As-inorg/(MMA + DMA) was about 20% lower among cases (p {lt} 0.05) and in men (p {lt} 0.05) compared with controls and females, respectively.

  13. Microarray analysis in the zebrafish (Danio rerio) liver and telencephalon after exposure to low concentration of 17alpha-ethinylestradiol

    Energy Technology Data Exchange (ETDEWEB)

    Martyniuk, Christopher J. [Centre for Advanced Research in Environmental Genomics, 30 Marie Curie, Department of Biology, University of Ottawa, Ottawa, Ontario, K1N 6N5 (Canada); Gerrie, Emily R. [Centre for Advanced Research in Environmental Genomics, 30 Marie Curie, Department of Biology, University of Ottawa, Ottawa, Ontario, K1N 6N5 (Canada); Popesku, Jason T. [Centre for Advanced Research in Environmental Genomics, 30 Marie Curie, Department of Biology, University of Ottawa, Ottawa, Ontario, K1N 6N5 (Canada); Ekker, Marc [Centre for Advanced Research in Environmental Genomics, 30 Marie Curie, Department of Biology, University of Ottawa, Ottawa, Ontario, K1N 6N5 (Canada); Trudeau, Vance L. [Centre for Advanced Research in Environmental Genomics, 30 Marie Curie, Department of Biology, University of Ottawa, Ottawa, Ontario, K1N 6N5 (Canada)]. E-mail: trudeauv@uottawa.ca

    2007-08-15

    17alpha-ethinylestradiol (EE2) is detected in sewage effluent at concentrations that can disrupt normal reproductive function in fish. The objectives of this study were to identify novel genomic responses to EE2 exposure using microarray and real-time RT-PCR analysis in the liver and telencephalon of male zebrafish. Zebrafish were exposed to an environmentally relevant nominal concentration of 10 ng/L EE2 for a 21-day period. In the liver, common biomarkers for estrogenic exposure such as vitellogenin 1 and 3 (vtg1; vtg3), estrogen receptor alpha (esr1), and apolipoprotein A1 (apoA1) mRNA were identified by microarray analysis as being differentially regulated. Real-time RT-PCR confirmed that vtg1 was induced {approx}700-fold, vtg3 was induced {approx}100-fold and esr1 was induced {approx}20-fold. As determined by microarray analysis, ATPase Na+/K+ alpha 1a.4 (atp1a1a.4) and ATPase Na+/K+ beta 1a (atp1b1a) mRNA were down-regulated in the liver. Gene ontology (GO) analysis revealed that there were common biological processes and molecular functions regulated by EE2 in both tissues (e.g. electron transport and cell communication) but there were tissue specific changes in gene categories. For example, genes involved in protein metabolism, carbohydrate metabolism were down-regulated in the liver but were induced in the telencephalon. This study demonstrates that (1) tissues exhibit different gene responses to low EE2 exposure; (2) there are pronounced genomic effects in the liver and (3) multi-tissue gene profiling is needed to improve understanding of the effects of human pharmaceuticals on aquatic organisms.

  14. Lethal concentration (CL50 of un-ionized ammonia for pejerrey larvae in acute exposure

    Directory of Open Access Journals (Sweden)

    Piedras Sérgio Renato Noguez

    2006-01-01

    Full Text Available Ammonia results from decomposition of effluents organic matter, e.g. feed wastes and fish faeces. Its un-ionized form can be toxic because diffuses easily through fish respiratory membranes, damaging gill epithelium and impairing gas exchanges. The objective of this work was determining the 96-hour CL50 of un-ionized ammonia for newly hatched pejerrey Odontesthes bonariensis larvae. Trials were set up completely randomized design, with three different concentration of un-ionized ammonia (0.57, 0.94, and 1.45 mg L-1 NH3-N and a control treatment (n = 3. Experimental units were 20-L, aerated aquaria stocked with 20 larvae (average weight 3.9 mg. Pejerrey larvae exposed to un-ionized ammonia during 96 hours present 50% mortality at 0.71 mg L-1 NH3-N.

  15. Decreasing aqueous mercury concentrations to achieve safe levels in fish: examining the water-fish relationship in two point-source contaminated streams

    Energy Technology Data Exchange (ETDEWEB)

    Mathews, Teresa J [ORNL; Southworth, George R [ORNL; Peterson, Mark J [ORNL; Roy, W Kelly [ORNL; Ketelle, Richard H [ORNL; Valentine, Charles S [ORNL; Gregory, Scott M [ORNL

    2013-01-01

    East Fork Poplar Creek (EFPC) and White Oak Creek (WOC) are two mercury-contaminated streams located on the Department of Energy s Oak Ridge Reservation in east Tennessee. East Fork Poplar Creek is the larger and more contaminated of the two, with average aqueous mercury (Hg) concentrations exceeding those in reference streams by several hundred-fold. Remedial actions over the past 20 years have decreased aqueous Hg concentrations in EFPC by 85 %. Fish fillet concentrations, however, have not responded to this decrease in aqueous Hg and remain above the U.S. Environmental Protection Agency s ambient water quality criterion (AWQC) of 0.3 mg/kg. The lack of correlation between aqueous and fish tissue Hg concentrations in this creek has led to questions regarding the usefulness of target aqueous Hg concentrations and strategies for future remediation efforts. White Oak Creek has a similar contamination history but aqueous Hg concentrations in WOC are an order of magnitude lower than in EFPC. Despite the lower aqueous Hg concentrations, fish fillet concentrations in WOC have also been above the AWQC, making the most recent aqueous Hg target of 200 ng/L in EFPC seem unlikely to result in an effective decrease in fillet Hg concentrations. Recent monitoring efforts in WOC, however, suggest an aqueous total Hg threshold above which Hg bioaccumulation in fish may not respond. This new information could be useful in guiding remedial actions in EFPC and in other point-source contaminated streams.

  16. Personal exposure to PM2.5, black smoke and NO2 in Copenhagen: relationship to bedroom and outdoor concentrations covering seasonal variation.

    Science.gov (United States)

    Sørensen, Mette; Loft, Steffen; Andersen, Helle Vibeke; Raaschou-Nielsen, Ole; Skovgaard, Lene Theil; Knudsen, Lisbeth E; Nielsen, Ivan V; Hertel, Ole

    2005-09-01

    Epidemiological studies have found negative associations between human health and particulate matter in urban air. In most studies outdoor monitoring of urban background has been used to assess exposure. In a field study, personal exposure as well as bedroom, front door and background concentrations of PM(2.5), black smoke (BS), and nitrogen dioxide (NO(2)) were measured during 2-day periods in 30 subjects (20-33 years old) living and studying in central parts of Copenhagen. The measurements were repeated in the four seasons. Information on indoor exposure sources such as environmental tobacco smoke (ETS) and burning of candles was collected by questionnaires. The personal exposure, the bedroom concentration and the front door concentration was set as outcome variable in separate models and analysed by mixed effect model regression methodology, regarding subject levels as a random factor. Seasons were defined as a dichotomised grouping of outdoor temperature (above and below 8 degrees C). For NO(2) there was a significant association between personal exposure and both the bedroom, the front door and the background concentrations, whereas for PM(2.5) and BS only the bedroom and the front door concentrations, and not the background concentration, were significantly associated to the personal exposure. The bedroom concentration was the strongest predictor of all three pollution measurements. The association between the bedroom and front door concentrations was significant for all three measurements, and the association between the front door and the background concentrations was significant for PM(2.5) and NO(2), but not for BS, indicating greater spatial variation for BS than for PM(2.5) and NO(2). For NO(2), the relationship between the personal exposure and the front door concentration was dependent upon the "season", with a stronger association in the warm season compared with the cold season, and for PM(2.5) and BS the same tendency was seen. Time exposed to

  17. IMBALANCE OF DNA METHYLATION, BOTH HYPERMETHYLATION AND HYPOMETHYLATION, OCCUR AFTER EXPOSURE OF HUMAN CELLS TO NANOMOLAR CONCENTRATIONS OF ARSENITE IN CULTURE.

    Science.gov (United States)

    Imbalance of DNA methylation, BOTH hypermethylation and hypomethylation, occur after exposure of human cells to nanomolar concentrations of arsenite in culture.We and others have hypothesized that a mechanism of arsenic carcinogenesis could involve alteration of DNA methy...

  18. Probabilistic reconstruction of internal exposure for nuclear power plant workers using air concentration measurements

    International Nuclear Information System (INIS)

    Linkov, I.; Burmistrov, D.

    2000-01-01

    Air surveys, whole-body counting, bioassays or combination of these measurements can be utilized for purposes or assessing internal doses to determine compliance with occupational dose equivalent limits. Air sampling with a little support provided by whole body counting and/or bioassays was often relied on in dose calculations. The utility of air sampling for internal dose reconstruction is addressed in this paper through the probabilistic analysis of environmental factors and their impact on dose estimates. In this paper we attempt to reconstruct an internal dose due to inhalation of beta + gamma emitting radionuclides for a contractual electrician, Mr. X. The data available for reconstruction of internal dose for Mr. X was found to be highly variable and uncertain. Uncertainty describes a lack of knowledge about a parameter, this lack of knowledge theoretically can be reduced, e.g., if more measurements were to be taken (for example, estimated activities for alpha-emitting radionuclides are uncertain due to the influence of naturally-occurring alpha-emitters). Variability describes the existence of different values that represent different environmental conditions (for example, the air concentrations of radionuclides may vary over time because of the different tasks performed by workers in the area). Variability can not be reduced by additional data collection because the varying values reflect the variable nature of the environment, not a lack of data. The high variability in measured air concentrations in the restricted areas of a LWR nuclear power plant where he worked do not allow adequate reconstruction of his individual internal dose using deterministic methods and therefore probabilistic methods are desirable. The guidance for probabilistic assessment developed by the United States Environmental Protection Agency as well as recommendations of the National Council of Radiation Protection provide an adequate framework for probabilistic reconstruction of

  19. 10 CFR Appendix C to Part 835 - Derived Air Concentration (DAC) for Workers From External Exposure During Immersion in a Cloud of...

    Science.gov (United States)

    2010-01-01

    ... Exposure During Immersion in a Cloud of Airborne Radioactive Material C Appendix C to Part 835 Energy... Concentration (DAC) for Workers From External Exposure During Immersion in a Cloud of Airborne Radioactive...-infinite cloud of airborne radioactive material. The DACs listed in this appendix may be modified to allow...

  20. Use of a centrifugation-based, point-of-care device for production of canine autologous bone marrow and platelet concentrates.

    Science.gov (United States)

    Thoesen, Michael S; Berg-Foels, Wendy S Vanden; Stokol, Tracy; Rassnick, Kenneth M; Jacobson, May S; Kevy, Sherwin V; Todhunter, Rory J

    2006-10-01

    To analyze a centrifugation-based, point-of-care device that concentrates canine platelets and bone marrow-derived cells. 19 adult sexually intact dogs. Anticoagulated peripheral blood (60 mL) and 60 mL of anticoagulated bone marrow aspirate (BMA) were concentrated by centrifugation with the centrifugation-based, point-of-care device to form a platelet and a bone marrow concentrate (BMC) from 11 dogs. Blood samples were analyzed on the basis of hemograms, platelet count, and PCV. The BMA and BMC were analyzed to determine PCV, total nucleated cell count, RBC count, and differential cell counts. The BMC stromal cells were cultured in an osteoinductive medium. Eight additional dogs were used to compare the BMC yield with that in which heparin was infused into the bone marrow before aspiration. The centrifugation-based, point-of-care device concentrated platelets by 6-fold over baseline (median recovery, 63.1%) with a median of 1,336 x 10(3) platelets/microL in the 7-mL concentrate. The nucleated cells in BMCs increased 7-fold (median recovery, 42.9%) with a median of 720 x 10(3) cells/microL in the 4-mL concentrate. The myeloid nucleated cells and mononuclear cells increased significantly in BMCs with a significant decrease in PCV, compared with that of BMAs. Stromal cell cultures expressed an osteoblastic phenotype in culture. Infusion of heparin into the bone marrow eliminated clot formation and created less variation in the yield (median recovery, 61.9%). Bone marrow-derived cell and platelet-rich concentrates may form bone if delivered in an engineered graft, thus decreasing the need for cancellous bone grafts.

  1. A proteomic study using zebra mussels (D. polymorpha) exposed to benzo(α)pyrene: the role of gender and exposure concentrations.

    Science.gov (United States)

    Riva, Consuelo; Binelli, Andrea; Rusconi, Francesco; Colombo, Graziano; Pedriali, Alessandra; Zippel, Renata; Provini, Alfredo

    2011-07-01

    It has recently been established that the use of proteomics can be a useful tool in the field of ecotoxicology. Despite the fact that the mussel Dreissena polymorpha is a valuable bioindicator for freshwater ecosystems, the application of a proteomic approach with this organism has not been deeply investigated. To this end, several zebra mussel specimens were subjected to a 7-day exposure of two different concentrations (0.1 and 2 μg L⁻¹) of the model pollutant benzo[α]pyrene (B[α]P). Changes in protein expression profiles were investigated in gill cytosolic fractions from control/exposed male and female mussels using 2-DE electrophoresis. B[α]P bioaccumulation in mussel soft tissue was also assessed to validate exposure to the selected chemical. We evaluated overall changes in expression profiles for 28 proteins in exposed mussels, 16 and 12 of which were, respectively, over- and under-expressed. Surprisingly, the comparative analysis of protein data sets showed no proteins that varied commonly between the two different B[α]P concentrations. Spots of interest were manually excised and analysed by MALDI-TOF/TOF mass spectrometry. The most significant proteins that were identified as altered were related to oxidative stress, signal transduction, cellular structure and metabolism. This preliminary study indicates the feasibility of a proteomic approach with the freshwater mussel D. polymorpha and provides a starting point for similar investigations. Our results confirm the need to increase the number of invertebrate proteomic studies in order to increase the following: their representation in databases and the successful identification of their most relevant proteins. Finally, additional studies investigating the role of gender and protein modulation are warranted. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Apocynin prevents vascular effects caused by chronic exposure to low concentrations of mercury.

    Directory of Open Access Journals (Sweden)

    Danize A Rizzetti

    Full Text Available UNLABELLED: Mercury increases the risk of cardiovascular disease and oxidative stress and alters vascular reactivity. This metal elicits endothelial dysfunction causing decreased NO bioavailability via increased oxidative stress and contractile prostanoid production. NADPH oxidase is the major source of reactive oxygen species (ROS in the vasculature. Our aim was to investigate whether treatment with apocynin, an NADPH oxidase inhibitor, prevents the vascular effects caused by chronic intoxication with low concentrations of mercury. Three-month-old male Wistar rats were treated for 30 days with a intramuscular injections (i.m. of saline; b HgCl(2 (i.m. 1(st dose: 4.6 µg/kg, subsequent doses: 0.07 µg/kg/day; c Apocynin (1.5 mM in drinking water plus saline i.m.; and d Apocynin plus HgCl(2. The mercury treatment resulted in 1 an increased aortic vasoconstrictor response to phenylephrine and reduced endothelium-dependent responses to acetylcholine; 2 the increased involvement of ROS and vasoconstrictor prostanoids in response to phenylephrine, whereas the endothelial NO modulation of such responses was reduced; and 3 the reduced activity of aortic superoxide dismutase (SOD and glutathione peroxidase (GPx and increased plasma malondialdehyde (MDA levels. Treatment with apocynin partially prevented the increased phenylephrine responses and reduced the endothelial dysfunction elicited by mercury treatment. In addition, apocynin treatment increased the NO modulation of vasoconstrictor responses and aortic SOD activity and reduced plasma MDA levels without affecting the increased participation of vasoconstrictor prostanoids observed in aortic segments from mercury-treated rats. CONCLUSIONS: Mercury increases the vasoconstrictor response to phenylephrine by reducing NO bioavailability and increasing the involvement of ROS and constrictor prostanoids. Apocynin protects the vessel from the deleterious effects caused by NADPH oxidase, but not from those

  3. Alterations of tissue metallothionein and vitellogenin concentrations in tropical cup oysters (Saccostrea sp.) following short-term (96 h) exposure to cadmium

    International Nuclear Information System (INIS)

    Moncaleano-Niño, Angela M.; Barrios-Latorre, Sergio A.; Poloche-Hernández, Javier F.; Becquet, Vanessa; Huet, Valérie; Villamil, Luisa; Thomas-Guyon, Hélène; Ahrens, Michael J.; Luna-Acosta, Andrea

    2017-01-01

    Highlights: • The cup oyster Saccostrea sp. is present in Santa Marta, Colombian Caribbean. • 96 h exposure of oysters to Cd increased metallothionein concentrations in digestive glands up to 2-fold. • 96 h exposure of oysters to Cd decreased vitellogenin concentrations in gonads up to 6-fold. • Metallothionein and vitellogenin tissue concentrations correlated with whole tissue Cd concentrations. • Significant changes in metallothionein and vitellogenin levels were only evident at Cd concentrations above 100 μg/L. - Abstract: Metallothioneins and vitellogenins are low molecular weight proteins that have been used widely in environmental monitoring as biomarkers of exposure and damage to metals and estrogenic compounds, respectively. In the present study, the responses of metallothionein and vitellogenin tissue concentrations were measured following acute (96 h) aqueous exposures to cadmium in Saccostrea sp., a tropical cup oyster native to the Western Pacific Ocean that has recently established itself in the Caribbean Sea. Adult oysters (1.5–5.0 cm shell length) collected from the municipal marina of Santa Marta, Colombia (Caribbean Sea) and acclimated for 5 days in the laboratory, were exposed to Cd at five concentrations (0, 1, 10, 100 and 1000 μg/L) and their tissues (gills, digestive gland and adductor muscle) were analyzed in pools of 5 individuals (3 replicates per concentration). Metallothioneins in digestive glands of oysters exposed to Cd concentrations ≥ 100 μg/L showed a significant increase, from 8.0 to 14.8 μg MT/mg total protein, whereas metallothionein concentrations in gills increased to lesser extent, and no differences were observed in adductor muscle. Metallothionein concentrations in digestive gland and gills correlated directly with whole soft tissue Cd concentrations (ranging from 2 to 297 μg/g dw Cd). Vitellogenin in homogenates of oyster gonad tissue, after 96 h of exposure to 1000 μg/L Cd, were significantly lower (0

  4. Alterations of tissue metallothionein and vitellogenin concentrations in tropical cup oysters (Saccostrea sp.) following short-term (96 h) exposure to cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Moncaleano-Niño, Angela M.; Barrios-Latorre, Sergio A.; Poloche-Hernández, Javier F. [Department of Biological Sciences, Universidad de Bogota Jorge Tadeo Lozano, Carrera 4 No. 22-61, Bogota (Colombia); Becquet, Vanessa; Huet, Valérie [Littoral Environnement et Sociétés (LIENSs) – UMR 7266, CNRS-Université de La Rochelle, Bâtiment ILE 2, rue Olympe de Gouges, 17 000 La Rochelle (France); Villamil, Luisa [Department of Biological Sciences, Universidad de Bogota Jorge Tadeo Lozano, Carrera 4 No. 22-61, Bogota (Colombia); Thomas-Guyon, Hélène [Littoral Environnement et Sociétés (LIENSs) – UMR 7266, CNRS-Université de La Rochelle, Bâtiment ILE 2, rue Olympe de Gouges, 17 000 La Rochelle (France); Ahrens, Michael J., E-mail: michael.ahrens@utadeo.edu.co [Department of Biological Sciences, Universidad de Bogota Jorge Tadeo Lozano, Carrera 4 No. 22-61, Bogota (Colombia); Luna-Acosta, Andrea [Department of Biological Sciences, Universidad de Bogota Jorge Tadeo Lozano, Carrera 4 No. 22-61, Bogota (Colombia)

    2017-04-15

    Highlights: • The cup oyster Saccostrea sp. is present in Santa Marta, Colombian Caribbean. • 96 h exposure of oysters to Cd increased metallothionein concentrations in digestive glands up to 2-fold. • 96 h exposure of oysters to Cd decreased vitellogenin concentrations in gonads up to 6-fold. • Metallothionein and vitellogenin tissue concentrations correlated with whole tissue Cd concentrations. • Significant changes in metallothionein and vitellogenin levels were only evident at Cd concentrations above 100 μg/L. - Abstract: Metallothioneins and vitellogenins are low molecular weight proteins that have been used widely in environmental monitoring as biomarkers of exposure and damage to metals and estrogenic compounds, respectively. In the present study, the responses of metallothionein and vitellogenin tissue concentrations were measured following acute (96 h) aqueous exposures to cadmium in Saccostrea sp., a tropical cup oyster native to the Western Pacific Ocean that has recently established itself in the Caribbean Sea. Adult oysters (1.5–5.0 cm shell length) collected from the municipal marina of Santa Marta, Colombia (Caribbean Sea) and acclimated for 5 days in the laboratory, were exposed to Cd at five concentrations (0, 1, 10, 100 and 1000 μg/L) and their tissues (gills, digestive gland and adductor muscle) were analyzed in pools of 5 individuals (3 replicates per concentration). Metallothioneins in digestive glands of oysters exposed to Cd concentrations ≥ 100 μg/L showed a significant increase, from 8.0 to 14.8 μg MT/mg total protein, whereas metallothionein concentrations in gills increased to lesser extent, and no differences were observed in adductor muscle. Metallothionein concentrations in digestive gland and gills correlated directly with whole soft tissue Cd concentrations (ranging from 2 to 297 μg/g dw Cd). Vitellogenin in homogenates of oyster gonad tissue, after 96 h of exposure to 1000 μg/L Cd, were significantly lower (0

  5. The effect of points and audio on concentration, engagement, enjoyment, learning, motivation, and classroom dynamics using Kahoot!

    DEFF Research Database (Denmark)

    Wang, Alf Inge; Lieberoth, Andreas

    2016-01-01

    There are many examples on the use of game-based learning in and outside the classroom, along with evaluation of their effect in terms of engagement, learning, classroom dynamics, concentration, motivation and enjoyment. Most of the research in this area focuses on evaluations of the use of game-...... affected by use of audio. A total of 593 students participated in this experiment with a gender distribution of 44% female and 56 male students. Contribution: Factorial design method, lit review...

  6. A Modeling Investigation of Human Exposure to Select Traffic-Related Air Pollutants in the Tampa Area: Spatiotemporal Distributions of Concentrations, Social Distributions of Exposures, and Impacts of Urban Design on Both

    Science.gov (United States)

    Yu, Haofei

    Increasing vehicle dependence in the United States has resulted in substantial emissions of traffic-related air pollutants that contribute to the deterioration of urban air quality. Exposure to urban air pollutants trigger a number of public health concerns, including the potential of inequality of exposures and health effects among population subgroups. To better understand the impact of traffic-related pollutants on air quality, exposure, and exposure inequality, modeling methods that can appropriately characterize the spatiotemporally resolved concentration distributions of traffic-related pollutants need to be improved. These modeling methods can then be used to investigate the impacts of urban design and transportation management choices on air quality, pollution exposures, and related inequality. This work will address these needs with three objectives: 1) to improve modeling methods for investigating interactions between city and transportation design choices and air pollution exposures, 2) to characterize current exposures and the social distribution of exposures to traffic-related air pollutants for the case study area of Hillsborough County, Florida, and 3) to determine expected impacts of urban design and transportation management choices on air quality, air pollution exposures, and exposure inequality. To achieve these objectives, the impacts of a small-scale transportation management project, specifically the '95 Express' high occupancy toll lane project, on pollutant emissions and nearby air quality was investigated. Next, a modeling method capable of characterizing spatiotemporally resolved pollutant emissions, concentrations, and exposures was developed and applied to estimate the impact of traffic-related pollutants on exposure and exposure inequalities among several population subgroups in Hillsborough County, Florida. Finally, using these results as baseline, the impacts of sprawl and compact urban forms, as well as vehicle fleet electrification

  7. Concentrations of polycyclic aromatic hydrocarbons in resuspendable fraction of settled bus dust and its implications for human exposure.

    Science.gov (United States)

    Gao, Peng; Liu, Sa; Feng, Yujie; Lin, Nan; Lu, Binyu; Zhang, Zhaohan; Cui, Fuyi; Xing, Baoshan; Hammond, S Katharine

    2015-03-01

    This preliminary study measured Polycyclic Aromatic Hydrocarbons (PAHs) concentrations in the resuspendable fraction of settled dust on 39 bus lines, to evaluate the impact of engine type (gasoline and compressed natural gas) on exposure for commuters and drivers. Benzo(b)fluoranthene(BbF) was the predominant PAH in resuspendable fraction of settled bus dust. The concentration of total PAHs was 92.90 ± 116.00 μg/g (range: 0.57-410) in gasoline buses and 3.97 ± 1.81 (range: 2.01-9.47) in compressed natural gas (CNG) buses. Based on Benzo[a]pyrene (BaP) equivalent concentrations for the sum of 16 PAHs, the average daily dose (ADD) via dust ingestion and dermal contact was calculated. The ADD of PAHs was higher for commuters and drivers in gasoline-powered buses than in buses using CNG buses. For both short and long duration journeys, young commuters were exposed to higher levels of PAHs via dust ingestion and dermal contact than adult commuters. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Calculation of NO2 concentration in air from the point source Tepláreň Košice

    Directory of Open Access Journals (Sweden)

    Jozef Mačala

    2007-06-01

    Full Text Available The most threatened part of environment is air and its pollution increases rapidly. In the local rate, the weight of air pollution increases by reason of a more intensive influence on the human population. The problem is significant mostly in urban areas, places with the biggest concentration of peoples, industry and transport. The greatest producers of air pollution are various parts of industry, heat production and traffic. For a complex valuation, the influence of particular parts of industry is needed to know the sources of air pollution in the specific area. Only with a knowledge, it is possible to evaluate a spotted area in terms of air quality.

  9. Antioxidant gene expression and metabolic responses of earthworms (Eisenia fetida) after exposure to various concentrations of hexabromocyclododecane.

    Science.gov (United States)

    Shi, Yajuan; Xu, Xiangbo; Chen, Juan; Liang, Ruoyu; Zheng, Xiaoqi; Shi, Yajing; Wang, Yurong

    2018-01-01

    Hexabromocyclododecane (HBCD), a ubiquitous suspected contaminant, is one of the world's most prominent brominated flame retardants (BFRs). In the present study, earthworms (Eisenia fetida) were exposed to HBCD. The expression of selected antioxidant enzyme genes was measured, and the metabolic responses were assessed using nuclear magnetic resonance (NMR) to identify the molecular mechanism of the antioxidant stress reaction and the metabolic reactions of earthworms to HBCD. A significant up-regulation (p  0.05). Principal component analysis (PCA) of the metabolic responses showed that all groups could be clearly differentiated, and the highest concentration dose group was the most distant from the control group. Except for fumarate, the measured metabolites, which included adenosine triphosphate (ATP), valine, lysine, glycine, betaine and lactate, revealed significant (p earthworm exposure studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Driving simulator sickness: Impact on driving performance, influence of blood alcohol concentration, and effect of repeated simulator exposures.

    Science.gov (United States)

    Helland, Arne; Lydersen, Stian; Lervåg, Lone-Eirin; Jenssen, Gunnar D; Mørland, Jørg; Slørdal, Lars

    2016-09-01

    Simulator sickness is a major obstacle to the use of driving simulators for research, training and driver assessment purposes. The purpose of the present study was to investigate the possible influence of simulator sickness on driving performance measures such as standard deviation of lateral position (SDLP), and the effect of alcohol or repeated simulator exposure on the degree of simulator sickness. Twenty healthy male volunteers underwent three simulated driving trials of 1h's duration with a curvy rural road scenario, and rated their degree of simulator sickness after each trial. Subjects drove sober and with blood alcohol concentrations (BAC) of approx. 0.5g/L and 0.9g/L in a randomized order. Simulator sickness score (SSS) did not influence the primary outcome measure SDLP. Higher SSS significantly predicted lower average speed and frequency of steering wheel reversals. These effects seemed to be mitigated by alcohol. Higher BAC significantly predicted lower SSS, suggesting that alcohol inebriation alleviates simulator sickness. The negative relation between the number of previous exposures to the simulator and SSS was not statistically significant, but is consistent with habituation to the sickness-inducing effects, as shown in other studies. Overall, the results suggest no influence of simulator sickness on SDLP or several other driving performance measures. However, simulator sickness seems to cause test subjects to drive more carefully, with lower average speed and fewer steering wheel reversals, hampering the interpretation of these outcomes as measures of driving impairment and safety. BAC and repeated simulator exposures may act as confounding variables by influencing the degree of simulator sickness in experimental studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. The thermal expansion of gold: point defect concentrations and pre-melting in a face-centred cubic metal.

    Science.gov (United States)

    Pamato, Martha G; Wood, Ian G; Dobson, David P; Hunt, Simon A; Vočadlo, Lidunka

    2018-04-01

    On the basis of ab initio computer simulations, pre-melting phenomena have been suggested to occur in the elastic properties of hexagonal close-packed iron under the conditions of the Earth's inner core just before melting. The extent to which these pre-melting effects might also occur in the physical properties of face-centred cubic metals has been investigated here under more experimentally accessible conditions for gold, allowing for comparison with future computer simulations of this material. The thermal expansion of gold has been determined by X-ray powder diffraction from 40 K up to the melting point (1337 K). For the entire temperature range investigated, the unit-cell volume can be represented in the following way: a second-order Grüneisen approximation to the zero-pressure volumetric equation of state, with the internal energy calculated via a Debye model, is used to represent the thermal expansion of the 'perfect crystal'. Gold shows a nonlinear increase in thermal expansion that departs from this Grüneisen-Debye model prior to melting, which is probably a result of the generation of point defects over a large range of temperatures, beginning at T / T m > 0.75 (a similar homologous T to where softening has been observed in the elastic moduli of Au). Therefore, the thermodynamic theory of point defects was used to include the additional volume of the vacancies at high temperatures ('real crystal'), resulting in the following fitted parameters: Q = ( V 0 K 0 )/γ = 4.04 (1) × 10 -18  J, V 0 = 67.1671 (3) Å 3 , b = ( K 0 ' - 1)/2 = 3.84 (9), θ D = 182 (2) K, ( v f /Ω)exp( s f / k B ) = 1.8 (23) and h f = 0.9 (2) eV, where V 0 is the unit-cell volume at 0 K, K 0 and K 0 ' are the isothermal incompressibility and its first derivative with respect to pressure (evaluated at zero pressure), γ is a Grüneisen parameter, θ D is the Debye temperature, v f , h f and s f are the vacancy formation volume, enthalpy and entropy

  12. The Association of Exposure to Point-of-Sale Tobacco Marketing with Quit Attempt and Quit Success: Results from a Prospective Study of Smokers in the United States

    Science.gov (United States)

    Siahpush, Mohammad; Shaikh, Raees A.; Smith, Danielle; Hyland, Andrew; Cummings, K. Michael; Sikora Kessler, Asia; Dodd, Michael D.; Carlson, Les; Meza, Jane; Wakefield, Melanie

    2016-01-01

    The aim was to assess the association of exposure to point-of-sale (POS) tobacco marketing with quit attempt and quit success in a prospective study of smokers in the United States. Data were collected via telephone-interview on exposure to POS tobacco marketing, sociodemographic and smoking-related variables from 999 smokers in Omaha, Nebraska, in the United States. Exposure to POS tobacco marketing was measured by asking respondents three questions about noticing pack displays, advertisements, and promotions in their respective neighborhoods stores. These three variables were combined into a scale of exposure to POS tobacco marketing. About 68% of the respondents participated in a six-month follow-up phone interview and provided data on quit attempts and smoking cessation. At the six-month follow-up, 39.9% of respondents reported to have made a quit attempt, and 21.8% of those who made a quit attempt succeeded in quitting. Exposure to POS marketing at baseline was not associated with the probability of having made a quit attempt as reported at the six-month follow-up (p = 0.129). However, higher exposure to POS marketing was associated with a lower probability of quit success among smokers who reported to have attempted to quit smoking at six-month follow-up (p = 0.006). Exposure to POS tobacco marketing is associated with lower chances of successfully quitting smoking. Policies that reduce the amount of exposure to POS marketing might result in higher smoking cessation rates. PMID:26861379

  13. The Association of Exposure to Point-of-Sale Tobacco Marketing with Quit Attempt and Quit Success: Results from a Prospective Study of Smokers in the United States

    Directory of Open Access Journals (Sweden)

    Mohammad Siahpush

    2016-02-01

    Full Text Available The aim was to assess the association of exposure to point-of-sale (POS tobacco marketing with quit attempt and quit success in a prospective study of smokers in the United States. Data were collected via telephone-interview on exposure to POS tobacco marketing, sociodemographic and smoking-related variables from 999 smokers in Omaha, Nebraska, in the United States. Exposure to POS tobacco marketing was measured by asking respondents three questions about noticing pack displays, advertisements, and promotions in their respective neighborhoods stores. These three variables were combined into a scale of exposure to POS tobacco marketing. About 68% of the respondents participated in a six-month follow-up phone interview and provided data on quit attempts and smoking cessation. At the six-month follow-up, 39.9% of respondents reported to have made a quit attempt, and 21.8% of those who made a quit attempt succeeded in quitting. Exposure to POS marketing at baseline was not associated with the probability of having made a quit attempt as reported at the six-month follow-up (p = 0.129. However, higher exposure to POS marketing was associated with a lower probability of quit success among smokers who reported to have attempted to quit smoking at six-month follow-up (p = 0.006. Exposure to POS tobacco marketing is associated with lower chances of successfully quitting smoking. Policies that reduce the amount of exposure to POS marketing might result in higher smoking cessation rates.

  14. The Association of Exposure to Point-of-Sale Tobacco Marketing with Quit Attempt and Quit Success: Results from a Prospective Study of Smokers in the United States.

    Science.gov (United States)

    Siahpush, Mohammad; Shaikh, Raees A; Smith, Danielle; Hyland, Andrew; Cummings, K Michael; Kessler, Asia Sikora; Dodd, Michael D; Carlson, Les; Meza, Jane; Wakefield, Melanie

    2016-02-06

    The aim was to assess the association of exposure to point-of-sale (POS) tobacco marketing with quit attempt and quit success in a prospective study of smokers in the United States. Data were collected via telephone-interview on exposure to POS tobacco marketing, sociodemographic and smoking-related variables from 999 smokers in Omaha, Nebraska, in the United States. Exposure to POS tobacco marketing was measured by asking respondents three questions about noticing pack displays, advertisements, and promotions in their respective neighborhoods stores. These three variables were combined into a scale of exposure to POS tobacco marketing. About 68% of the respondents participated in a six-month follow-up phone interview and provided data on quit attempts and smoking cessation. At the six-month follow-up, 39.9% of respondents reported to have made a quit attempt, and 21.8% of those who made a quit attempt succeeded in quitting. Exposure to POS marketing at baseline was not associated with the probability of having made a quit attempt as reported at the six-month follow-up (p = 0.129). However, higher exposure to POS marketing was associated with a lower probability of quit success among smokers who reported to have attempted to quit smoking at six-month follow-up (p = 0.006). Exposure to POS tobacco marketing is associated with lower chances of successfully quitting smoking. Policies that reduce the amount of exposure to POS marketing might result in higher smoking cessation rates.

  15. Reduction of 3-methoxytyramine concentrations in the caudate nucleus of rats after exposure to high-energy iron particles: evidence for deficits in dopaminergic neurons

    International Nuclear Information System (INIS)

    Hunt, W.A.; Dalton, T.K.; Joseph, J.A.; Rabin, B.M.

    1990-01-01

    Exposure to low doses of high-energy iron particles can alter motor behavior. The ability of rats to hang from a wire has been reported to be significantly degraded after exposure to doses as low as 0.5 Gy. In addition, deficits in the ability of acetylcholine to regulate dopamine release in the caudate nucleus (an area in the brain important for motor function) have been found. The concentrations of 3-methoxytyramine (3-MT), a metabolite of dopamine whose concentrations reflect dopamine release in vivo, were measured after rats were exposed to different doses of high-energy iron particles to gain further information about the effect of radiation on the dopaminergic system. Concentrations of 3-MT were significantly reduced 3 days after exposure to 5 Gy but returned to control values by 8 days. After 6 months, concentrations were again less than control values. Exposure to 5 Gy of high-energy electrons or gamma photons had no effect 3 days after exposure. Very high doses of electrons were needed to alter 3-MT concentrations. One hundred grays of electrons decreased 3-MT 30 min after irradiation but levels returned to control values by 60 min. Gamma photons had no effect after doses up to 200 Gy. These results provide further evidence that exposure to heavy particles can degrade motor behavior through an action on dopaminergic mechanisms and that this can occur after doses much lower than those needed for low-LET radiation

  16. Lead concentration in meat from lead-killed moose and predicted human exposure using Monte Carlo simulation.

    Science.gov (United States)

    Lindboe, M; Henrichsen, E N; Høgåsen, H R; Bernhoft, A

    2012-01-01

    Lead-based hunting ammunitions are still common in most countries. On impact such ammunition releases fragments which are widely distributed within the carcass. In Norway, wild game is an important meat source for segments of the population and 95% of hunters use lead-based bullets. In this paper, we have investigated the lead content of ground meat from moose (Alces alces) intended for human consumption in Norway, and have predicted human exposure through this source. Fifty-two samples from different batches of ground meat from moose killed with lead-based bullets were randomly collected. The lead content was measured by atomic absorption spectroscopy. The lead intake from exposure to moose meat over time, depending on the frequency of intake and portion size, was predicted using Monte Carlo simulation. In 81% of the batches, lead levels were above the limit of quantification of 0.03 mg kg(-1), ranging up to 110 mg kg(-1). The mean lead concentration was 5.6 mg kg(-1), i.e. 56 times the European Commission limit for lead in meat. For consumers eating a moderate meat serving (2 g kg(-1) bw), a single serving would give a lead intake of 11 µg kg(-1) bw on average, with maximum of 220 µg kg(-1) bw. Using Monte Carlo simulation, the median (and 97.5th percentile) predicted weekly intake of lead from moose meat was 12 µg kg(-1) bw (27 µg kg(-1) bw) for one serving per week and 25 µg kg(-1) bw (45 µg kg(-1) bw) for two servings per week. The results indicate that the intake of meat from big game shot with lead-based bullets imposes a significant contribution to the total human lead exposure. The provisional tolerable weekly intake set by the World Health Organization (WHO) of 25 µg kg(-1) bw is likely to be exceeded in people eating moose meat on a regular basis. The European Food Safety Authority (EFSA) has recently concluded that adverse effects may be present at even lower exposure doses. Hence, even occasional consumption of big game meat with lead levels as

  17. Decreasing aqueous mercury concentrations to meet the water quality criterion in fish: examining the water-fish relationship in two point-source contaminated streams.

    Science.gov (United States)

    Mathews, Teresa J; Southworth, George; Peterson, Mark J; Roy, W Kelly; Ketelle, Richard H; Valentine, Charles; Gregory, Scott

    2013-01-15

    East Fork Poplar Creek (EF) and White Oak Creek (WC) are two mercury-contaminated streams located on the United States (U.S.) Department of Energy Oak Ridge Reservation in East Tennessee. East Fork Poplar Creek is the larger and more contaminated of the two, with average aqueous mercury (Hg) concentrations exceeding those in reference streams by several hundred-fold. Remedial actions over the past 20 years have decreased aqueous Hg concentrations in EF by 85% (from >1600 ng/L to Fish fillet concentrations, however, have not responded to this decrease in aqueous Hg and remain above the U.S. Environmental Protection Agency National Recommended Water Quality Criteria (NRWQC) of 0.3 mg/kg. The lack of correlation between aqueous and fish tissue Hg concentrations in this creek has led to questions regarding the usefulness of target aqueous Hg concentrations and strategies for future remediation efforts. White Oak Creek has a similar contamination history but aqueous Hg concentrations in WC are an order of magnitude lower than in EF. Despite the lower aqueous Hg concentrations (fish fillet concentrations in WC have also been above the NRWQC, making the aqueous Hg remediation goal of 200 ng/L in EF seem unlikely to result in an effective decrease in fillet Hg concentrations. Recent monitoring efforts in WC, however, suggest an aqueous total Hg threshold above which Hg bioaccumulation in fish may not respond. This new information could be useful in guiding remedial actions in EF and in other point-source contaminated streams. Published by Elsevier B.V.

  18. 'Real-world' compensatory behaviour with low nicotine concentration e-liquid: subjective effects and nicotine, acrolein and formaldehyde exposure.

    Science.gov (United States)

    Dawkins, Lynne; Cox, Sharon; Goniewicz, Maciej; McRobbie, Hayden; Kimber, Catherine; Doig, Mira; Kośmider, Leon

    2018-06-07

    To compare the effects of i) high versus low nicotine concentration e-liquid, ii) fixed versus adjustable power and iii) the interaction between the two on: a) vaping behaviour, b) subjective effects, c) nicotine intake, and d) exposure to acrolein and formaldehyde in e-cigarette users vaping in their everyday setting. Counterbalanced, repeated measures with four conditions: i) low nicotine (6 mg/mL)/fixed power; ii) low nicotine/adjustable power; iii) high nicotine (18 mg/mL)/fixed power; iv) high nicotine/adjustable power. London and the South East, England. Twenty experienced e-cigarette users (recruited between September 2016 and February 2017) vaped ad libitum using an eVic Supreme™ with a 'Nautilus Aspire' tank over four weeks (one week per condition). Puffing patterns (daily puff number [PN], puff duration [PD], inter-puff interval [IPI]), mL of e-liquid consumed, changes to power (where permitted), and subjective effects (urge to vape, nicotine withdrawal symptoms) were measured in each condition. Nicotine intake was measured via salivary cotinine. 3-hydroxypropylmercapturic acid (3-HPMA), a metabolite of the toxicant acrolein, and formate, a metabolite of the carcinogen formaldehyde, were measured in urine. There was a significant nicotine concentration x power interaction for PD (p<0.01). PD was longer with low nicotine/fixed power compared with i) high nicotine/fixed power (p< 0.001 and ii) low nicotine/adjustable power (p< 0.01). PN and liquid consumed were higher in the low versus high nicotine condition (main effect of nicotine, p<0.05). Urge to vape and withdrawal symptoms were lower, and nicotine intake was higher, in the high nicotine condition (main effects of nicotine: p<0.01). Whilst acrolein levels did not differ, there was a significant nicotine x power interaction for formaldehyde (p<0.05). Use of a lower nicotine concentration e-liquid may be associated with compensatory behaviour (e.g., higher number and duration of puffs) and increases

  19. Spatial analysis of concentrations of multiple air pollutants using NASA DISCOVER-AQ aircraft measurements: Implications for exposure assessment.

    Science.gov (United States)

    Lee, Hyung Joo; Chatfield, Robert B; Bell, Michelle L

    2018-01-01

    In recent years, multipollutant approaches have been employed to investigate the association with health outcomes to better represent real-world conditions than more traditional analysis that considers a single pollutant. With regard to the exposure assessment of a mixture of air pollutants, it is critical to understand the spatial variability in multipollutant relations in order to assess their potential health implications. In this study, we investigated the spatial relations of multiple pollutant concentrations (i.e., NO x , NO y , black carbon, carbon monoxide, acetaldehyde, formaldehyde, toluene, xylenes/ethylbenzene, ozone, water-soluble organic carbon, and aerosol extinction) observed from the P-3B aircraft in the 2011 NASA field campaign in Baltimore/Washington D.C. areas during July 2011. The between-pollutant Pearson correlations and Z-scores (calculated from log-transformed concentrations) between near-highways and non-highways and between near-urban centers and non-urban centers varied by pollutant pair and space. We found generally lower correlations between NO x and other pollutants for near-highways (average r = 0.36) than for non-highways (average r = 0.41) and also for non-urban centers (average r = 0.37) than for near-urban centers (average r = 0.41). This indicated that the temporal associations between NO x and health outcomes might be less affected by other pollutants, which were also related to same health outcomes, for near-highways and non-urban centers. The analysis of between-pollutant Z-scores showed varying spatial relations for popular traffic-related pollutants with the Z-score differences of 0.43 (NO x -carbon monoxide), 0.29 (NO x -black carbon), and 0.17 (black carbon-carbon monoxide) between near-highways and non-highways. This result exhibited heterogeneous traffic-related pollutant mixtures with the proximity to highways, potentially leading to the diverse extent of health associations. Furthermore, a mixed effects model

  20. Thermal equilibrium concentration of intrinsic point defects in heavily doped silicon crystals - Theoretical study of formation energy and formation entropy in area of influence of dopant atoms-

    Science.gov (United States)

    Kobayashi, K.; Yamaoka, S.; Sueoka, K.; Vanhellemont, J.

    2017-09-01

    It is well known that p-type, neutral and n-type dopants affect the intrinsic point defect (vacancy V and self-interstitial I) behavior in single crystal Si. By the interaction with V and/or I, (1) growing Si crystals become more V- or I-rich, (2) oxygen precipitation is enhanced or retarded, and (3) dopant diffusion is enhanced or retarded, depending on the type and concentration of dopant atoms. Since these interactions affect a wide range of Si properties ranging from as-grown crystal quality to LSI performance, numerical simulations are used to predict and to control the behavior of both dopant atoms and intrinsic point defects. In most cases, the thermal equilibrium concentrations of dopant-point defect pairs are evaluated using the mass action law by taking only the binding energy of closest pair to each other into account. The impacts of dopant atoms on the formation of V and I more distant than 1st neighbor and on the change of formation entropy are usually neglected. In this study, we have evaluated the thermal equilibrium concentrations of intrinsic point defects in heavily doped Si crystals. Density functional theory (DFT) calculations were performed to obtain the formation energy (Ef) of the uncharged V and I at all sites in a 64-atom supercell around a substitutional p-type (B, Ga, In, and Tl), neutral (C, Ge, and Sn) and n-type (P, As, and Sb) dopant atom. The formation (vibration) entropies (Sf) of free I, V and I, V at 1st neighboring site from B, C, Sn, P and As atoms were also calculated with the linear response method. The dependences of the thermal equilibrium concentrations of trapped and total intrinsic point defects (sum of free I or V and I or V trapped with dopant atoms) on the concentrations of B, C, Sn, P and As in Si were obtained. Furthermore, the present evaluations well explain the experimental results of the so-called ;Voronkov criterion; in B and C doped Si, and also the observed dopant dependent void sizes in P and As doped Si

  1. Effect of exposure to hyperoxic, hypobaric, and hyperbaric environments on concentrations of selected and aerobic and anaerobic fecal flora of mice.

    Science.gov (United States)

    Gillmore, J D; Gordon, F B

    1975-03-01

    Alterations in selected aerobic and anaerobic fecal microflora of the mouse were determined during exposure to hyperoxic and normoxic hypo- and hyperbaric environments. Examination of fecal cultures obtained during exposure for 6 weeks to either 60 or 77% oxygen concentration 1 atmosphere absolute revealed little alteration in the aerobic or anaerobic flora. There appeared to be only a retardation in the reduction of the Klebsiella-Enterobacter flora which normally occurs after weaning. During exposure to hypobaric environments (100% O-2, 0.2 atmosphere absolute), significant alterations in concentrations of Escherichia coli, slow lactose fermenters, Klebsiella-Enterobacter, and enterococci were found in some instances. All alterations were toward increased concentrations. Variations in concentrations of different colony types of obligately anaerobic gram-positive (anGPR) and gram-negative (anGNR) rods cultured during the same experiments also occurred. One colony type of anGPR appeared to decrease while a second type increased in numbers. Concentrations of three colony types of anGNR were generally, but not always, increased. During hyperbaric exposure (2.8% O-2, 7.5 atmospheres absolute), increased concentrations of Klebsiella-Enterobacter, E. coli, slow lactose fermenters and enterococci were also noted. Changes in numbers of both colony types of anGPR, when occurring, were in the direction of lower numbers. Alteration in numbers of anGNR were in both directions but were more frequent in the direction of higher numbers. After return to normal air for 4 weeks of either hypo- or hyperbaric exposure, fecal concentrations of all organisms tended to revert toward control values with the exception of the anGPR which remained in lower concentrations after termination of the hyperbaric exposure. These observations indicate that, despite the great variation in the fecal flora among individual mice, it is possible to discover the effects induced by altered gaseous

  2. Short-term exposure with high concentrations of pristine microplastic particles leads to immobilisation of Daphnia magna.

    Science.gov (United States)

    Rehse, Saskia; Kloas, Werner; Zarfl, Christiane

    2016-06-01

    Recent studies revealed that freshwaters are not only polluted by chemicals, but also by persistent synthetic material like microplastics (plastic particles pollutants or release additives. Although there is rising concern about the pollution of freshwaters by microplastics, knowledge about their potential effects on organisms is limited. For a better understanding of their risks, it is crucial to unravel which characteristics influence their effects on organisms. Analysing effects by the mere particles is the first step before including more complex interactions e.g. with associated chemicals. The aim of this study was to analyse potential physical effects of microplastics on one representative organism for limnic zooplankton (Daphnia magna). We investigated whether microplastics can be ingested and whether their presence causes adverse effects after short-term exposure. Daphnids were exposed for up to 96 h to 1-μm and 100-μm polyethylene particles at concentrations between 12.5 and 400 mg L(-1). Ingestion of 1-μm particles led to immobilisation increasing with dose and time with an EC50 of 57.43 mg L(-1) after 96 h. 100-μm particles that could not be ingested by the daphnids had no observable effects. These results underline that, considering high concentrations, microplastic particles can already induce adverse effects in limnic zooplankton. Although it needs to be clarified if these concentrations can be found in the environment these results are a basis for future impact analysis, especially in combination with associated chemicals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Murine strain differences and the effects of zinc on cadmium concentrations in tissues after acute cadmium exposure

    Energy Technology Data Exchange (ETDEWEB)

    King, L.M. [ARS USDA, Germplasm and Gamete Physiology Lab., Beltsville, MD (United States); Anderson, M.B. [Dept. of Anatomy, Tulane Univ. School of Medicine, New Orleans, LA (United States); Sikka, S.C. [Dept. of Urology, Tulane Univ. School of Medicine, New Orleans, LA (United States); George, W.J. [Dept. of Pharmacology, Tulane Univ. School of Medicine, New Orleans, LA (United States)

    1998-10-01

    The role of strain differences in cadmium tissue distribution was studied using sensitive (129/J) and resistant (A/J) mice. These murine strains have previously been shown to differ in their susceptibility to cadmium-induced testicular toxicity. Cadmium concentration was measured in testis, epididymis, seminal vesicle, liver, and kidney at 24 h after cadmium chloride exposure (4, 10, and 20 {mu}mol/kg CdCl{sub 2}). The 129/J mice exhibited a significant increase in cadmium concentration in testis, epididymis, and seminal vesicle at all cadmium doses used, compared to A/J mice. However, cadmium concentrations in liver and kidney were not different between the strains, at any dose, indicating that cadmium uptake is similar in these organs at 24 h. These murine strains demonstrate similar hepatic and renal cadmium uptake but significantly different cadmium accumulation in the reproductive organs at 24 h. The mechanism of the protective effect of zinc on cadmium toxicity was studied by assessing the impact of zinc acetate (ZnAc) treatment on cadmium concentrations in 129/J mice after 24 h. Zinc pretreatment (250 {mu}mol/kg ZnAc), given 24 h prior to 20 {mu}mol/kg CdCl{sub 2} administration, significantly decreased the amount of cadmium in the testis, epididymis, and seminal vesicle of 129/J mice, and significantly increased the cadmium content of the liver after 24 h. Cadmium levels in the kidney were unaffected at this time. Zinc pretreatment also prevented the cadmium-induced decrease in testicular sperm concentration and epididymal sperm motility seen in 129/J mice. These findings suggest that the differences in the two murine strains may be attributed partly to the differential accumulation of cadmium in murine gonads. This may be caused by strain differences in the specificity of cadmium transport mechanisms. The protective role of zinc in cadmium-induced testicular toxicity in the sensitive strain may be due to an interference in the cadmium uptake by susceptible

  4. Considerations for automated machine learning in clinical metabolic profiling: Altered homocysteine plasma concentration associated with metformin exposure.

    Science.gov (United States)

    Orlenko, Alena; Moore, Jason H; Orzechowski, Patryk; Olson, Randal S; Cairns, Junmei; Caraballo, Pedro J; Weinshilboum, Richard M; Wang, Liewei; Breitenstein, Matthew K

    2018-01-01

    With the maturation of metabolomics science and proliferation of biobanks, clinical metabolic profiling is an increasingly opportunistic frontier for advancing translational clinical research. Automated Machine Learning (AutoML) approaches provide exciting opportunity to guide feature selection in agnostic metabolic profiling endeavors, where potentially thousands of independent data points must be evaluated. In previous research, AutoML using high-dimensional data of varying types has been demonstrably robust, outperforming traditional approaches. However, considerations for application in clinical metabolic profiling remain to be evaluated. Particularly, regarding the robustness of AutoML to identify and adjust for common clinical confounders. In this study, we present a focused case study regarding AutoML considerations for using the Tree-Based Optimization Tool (TPOT) in metabolic profiling of exposure to metformin in a biobank cohort. First, we propose a tandem rank-accuracy measure to guide agnostic feature selection and corresponding threshold determination in clinical metabolic profiling endeavors. Second, while AutoML, using default parameters, demonstrated potential to lack sensitivity to low-effect confounding clinical covariates, we demonstrated residual training and adjustment of metabolite features as an easily applicable approach to ensure AutoML adjustment for potential confounding characteristics. Finally, we present increased homocysteine with long-term exposure to metformin as a potentially novel, non-replicated metabolite association suggested by TPOT; an association not identified in parallel clinical metabolic profiling endeavors. While warranting independent replication, our tandem rank-accuracy measure suggests homocysteine to be the metabolite feature with largest effect, and corresponding priority for further translational clinical research. Residual training and adjustment for a potential confounding effect by BMI only slightly modified

  5. Radon concentration in The Netherlands

    International Nuclear Information System (INIS)

    Meijer, R.J. de; Put, L.W.; Veldhuizen, A.

    1986-02-01

    In 1000 dwellings, which can be assumed to be an reasonable representation of the average Dutch dwellings, time averaged radon concentrations, radon daughter concentrations and gamma-exposure tempi are determined during a year with passive dosemeters. They are also determined outdoor at circa 200 measure points. (Auth.)

  6. Exposure to sublethal concentrations of tributyltin reduced survival, growth, and 20-hydroxyecdysone levels in a marine mysid.

    Science.gov (United States)

    Kim, Bo-Mi; Saravanan, Manoharan; Lee, Do-Hee; Kang, Jung-Hoon; Kim, Moonkoo; Jung, Jee-Hyun; Rhee, Jae-Sung

    2018-06-07

    Tributyltin (TBT) is as an antifouling organotin compound used in boat paints. Although organotin-based antifouling agents have been banned on a global scale, the mode of action of TBT has been studied in numerous aquatic species because of its toxicity, persistence, bioaccumulation potential, and endocrine-disrupting characteristics. In this study, we conducted 96-h acute toxicity tests wherein we exposed juvenile and adult marine mysids to waterborne TBT. Over 4 weeks of exposure, mortality was dose-dependently increased in juveniles and adult mysids. To test sublethal effects of TBT on juvenile development, newborn juvenile mysids were exposed to 1, 5, or 10 ng L -1  TBT for 4 weeks. Subsequently, we measured morphological growth parameters and quantified the hormone ecdysterone (20-hydroxyecdysone: 20E), which controls molting in mysids. The lengths of the whole body, antennal scale, exopod, endopod, and telson were significantly smaller in the 5 and/or 10 ng L -1 TBT-exposed juvenile mysids than in control and DMSO-exposed groups. Levels of 20E were significantly lower at 5 and 10 ng L -1  TBT exposures. Additionally, the number of newly hatched juveniles was significantly lower from females previously exposed to 10 ng L -1  TBT. Our results indicate sublethal concentrations of TBT have inhibitory effects on the survival, growth, and production of juveniles. The lower 20E levels could be strongly associated with TBT-triggered inhibition. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Hair cortisol concentrations and cortisol stress reactivity predict PTSD symptom increase after trauma exposure during military deployment.

    Science.gov (United States)

    Steudte-Schmiedgen, Susann; Stalder, Tobias; Schönfeld, Sabine; Wittchen, Hans-Ulrich; Trautmann, Sebastian; Alexander, Nina; Miller, Robert; Kirschbaum, Clemens

    2015-09-01

    Previous evidence on endocrine risk markers for posttraumatic stress disorder (PTSD) has been inconclusive. Here, we report results of the first prospective study to investigate whether long-term hair cortisol levels and experimentally-induced cortisol stress reactivity are predictive of the development of PTSD symptomatology in response to trauma during military deployment. Male soldiers were examined before deployment to Afghanistan and at a 12-month post-deployment follow-up using dimensional measures for psychopathological symptoms. The predictive value of baseline (i) hair cortisol concentrations (HCC, N=90) and (ii) salivary cortisol stress reactivity (measured by the Trier Social Stress Test, N=80) for the development of PTSD symptomatology after being exposed to new-onset traumatic events was analyzed. Baseline cortisol activity significantly predicted PTSD symptom change from baseline to follow-up upon trauma exposure. Specifically, our results consistently revealed that lower HCC and lower cortisol stress reactivity were predictive of a greater increase in PTSD symptomatology in soldiers who had experienced new-onset traumatic events (explaining 5% and 10.3% of variance, respectively). Longitudinal analyses revealed an increase in HCC from baseline to follow-up and a trend for a negative relationship between HCC changes and the number of new-onset traumatic events. Additional pre-deployment analyses revealed that trauma history was reflected in lower HCC (at trend level) and that HCC were negatively related to stressful load. Our data indicate that attenuated cortisol secretion is a risk marker for subsequent development of PTSD symptomatology upon trauma exposure. Future studies are needed to confirm our findings in other samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Infection of the malaria mosquito, Anopheles gambiae, with two species of entomopathogenic fungi: effects of concentration, co-formulation, exposure time and persistence

    Directory of Open Access Journals (Sweden)

    Lwetoijera Dickson W

    2009-12-01

    Full Text Available Abstract Background Entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana isolates have been shown to infect and reduce the survival of mosquito vectors. Methods Here four different bioassays were conducted to study the effect of conidia concentration, co-formulation, exposure time and persistence of the isolates M. anisopliae ICIPE-30 and B. bassiana I93-925 on infection and survival rates of female Anopheles gambiae sensu stricto. Test concentrations and exposure times ranged between 1 × 107 - 4 × 1010 conidia m-2 and 15 min - 6 h. In co-formulations, 2 × 1010 conidia m-2 of both fungus isolates were mixed at ratios of 4:1, 2:1, 1:1,1:0, 0:1, 1:2 and 1:4. To determine persistence, mosquitoes were exposed to surfaces treated 1, 14 or 28 d previously, with conidia concentrations of 2 × 109, 2 × 1010 or 4 × 1010. Results Mosquito survival varied with conidia concentration; 2 × 1010 conidia m-2 was the concentration above which no further reductions in survival were detectable for both isolates of fungus. The survival of mosquitoes exposed to single and co-formulated treatments was similar and no synergistic or additive effects were observed. Mosquitoes were infected within 30 min and longer exposure times did not result in a more rapid killing effect. Fifteen min exposure still achieved considerable mortality rates (100% mortality by 14 d of mosquitoes, but at lower speed than with 30 min exposure (100% mortality by 9 d. Conidia remained infective up to 28 d post-application but higher concentrations did not increase persistence. Conclusion Both fungus isolates are effective and persistent at low concentrations and short exposure times.

  9. Acute 7,12-dimethylbenz[a]anthracene exposure causes differential concentration-dependent follicle depletion and gene expression in neonatal rat ovaries

    Energy Technology Data Exchange (ETDEWEB)

    Madden, Jill A. [Department of Animal Science, Iowa State University, Ames, IA 50011 (United States); Hoyer, Patricia B. [Department of Physiology, University of Arizona, Tucson, AZ 85724 (United States); Devine, Patrick J. [INRS—Institut Armand-Frappier Research Centre, University of Quebec, Laval, QC H7V 1B7 (Canada); Keating, Aileen F., E-mail: akeating@iastate.edu [Department of Animal Science, Iowa State University, Ames, IA 50011 (United States); Department of Physiology, University of Arizona, Tucson, AZ 85724 (United States)

    2014-05-01

    Chronic exposure to the polycyclic aromatic hydrocarbon 7,12-dimethylbenz[a]anthracene (DMBA), generated during combustion of organic matter including cigarette smoke, depletes all ovarian follicle types in the mouse and rat, and in vitro models mimic this effect. To investigate the mechanisms involved in follicular depletion during acute DMBA exposure, two concentrations of DMBA at which follicle depletion has (75 nM) and has not (12.5 nM) been observed were investigated. Postnatal day four F344 rat ovaries were maintained in culture for four days before a single exposure to vehicle control (1% DMSO; CT) or DMBA (12 nM; low-concentration or 75 nM; high-concentration). After four or eight additional days of culture, DMBA-induced follicle depletion was evaluated via follicle enumeration. Relative to control, DMBA did not affect follicle numbers after 4 days of exposure, but induced large primary follicle loss at both concentrations after 8 days; while, the low-concentration DMBA also caused secondary follicle depletion. Neither concentration affected primordial or small primary follicle number. RNA was isolated and quantitative RT-PCR performed prior to follicle loss to measure mRNA levels of genes involved in xenobiotic metabolism (Cyp2e1, Gstmu, Gstpi, Ephx1), autophagy (Atg7, Becn1), oxidative stress response (Sod1, Sod2) and the phosphatidylinositol 3-kinase (PI3K) pathway (Kitlg, cKit, Akt1) 1, 2 and 4 days after exposure. With the exception of Atg7 and cKit, DMBA increased (P < 0.05) expression of all genes investigated. Also, BECN1 and pAKT{sup Thr308} protein levels were increased while cKIT was decreased by DMBA exposure. Taken together, these results suggest an increase in DMBA bioactivation, add to the mechanistic understanding of DMBA-induced ovotoxicity and raise concern regarding female low concentration DMBA exposures. - Highlights: • Acute DMBA exposures induce large primary and/or secondary follicle loss. • Acute DMBA exposure did not impact

  10. Acute 7,12-dimethylbenz[a]anthracene exposure causes differential concentration-dependent follicle depletion and gene expression in neonatal rat ovaries

    International Nuclear Information System (INIS)

    Madden, Jill A.; Hoyer, Patricia B.; Devine, Patrick J.; Keating, Aileen F.

    2014-01-01

    Chronic exposure to the polycyclic aromatic hydrocarbon 7,12-dimethylbenz[a]anthracene (DMBA), generated during combustion of organic matter including cigarette smoke, depletes all ovarian follicle types in the mouse and rat, and in vitro models mimic this effect. To investigate the mechanisms involved in follicular depletion during acute DMBA exposure, two concentrations of DMBA at which follicle depletion has (75 nM) and has not (12.5 nM) been observed were investigated. Postnatal day four F344 rat ovaries were maintained in culture for four days before a single exposure to vehicle control (1% DMSO; CT) or DMBA (12 nM; low-concentration or 75 nM; high-concentration). After four or eight additional days of culture, DMBA-induced follicle depletion was evaluated via follicle enumeration. Relative to control, DMBA did not affect follicle numbers after 4 days of exposure, but induced large primary follicle loss at both concentrations after 8 days; while, the low-concentration DMBA also caused secondary follicle depletion. Neither concentration affected primordial or small primary follicle number. RNA was isolated and quantitative RT-PCR performed prior to follicle loss to measure mRNA levels of genes involved in xenobiotic metabolism (Cyp2e1, Gstmu, Gstpi, Ephx1), autophagy (Atg7, Becn1), oxidative stress response (Sod1, Sod2) and the phosphatidylinositol 3-kinase (PI3K) pathway (Kitlg, cKit, Akt1) 1, 2 and 4 days after exposure. With the exception of Atg7 and cKit, DMBA increased (P < 0.05) expression of all genes investigated. Also, BECN1 and pAKT Thr308 protein levels were increased while cKIT was decreased by DMBA exposure. Taken together, these results suggest an increase in DMBA bioactivation, add to the mechanistic understanding of DMBA-induced ovotoxicity and raise concern regarding female low concentration DMBA exposures. - Highlights: • Acute DMBA exposures induce large primary and/or secondary follicle loss. • Acute DMBA exposure did not impact

  11. Relative performance of different exposure modeling approaches for sulfur dioxide concentrations in the air in rural western Canada

    Directory of Open Access Journals (Sweden)

    Kim Hyang-Mi

    2008-07-01

    Full Text Available Abstract Background The main objective of this paper is to compare different methods for predicting the levels of SO2 air pollution in oil and gas producing area of rural western Canada. Month-long average air quality measurements were collected over a two-year period (2001–2002 at multiple locations, with some side-by-side measurements, and repeated time-series at selected locations. Methods We explored how accurately location-specific mean concentrations of SO2 can be predicted for 2002 at 666 locations with multiple measurements. Means of repeated measurements on the 666 locations in 2002 were used as the alloyed gold standard (AGS. First, we considered two approaches: one that uses one measurement from each location of interest; and the other that uses context data on proximity of monitoring sites to putative sources of emission in 2002. Second, we imagined that all of the previous year's (2001's data were also available to exposure assessors: 9,464 measurements and their context (month, proximity to sources. Exposure prediction approaches we explored with the 2001 data included regression modeling using either mixed or fixed effects models. Third, we used Bayesian methods to combine single measurements from locations in 2002 (not used to calculate AGS with different priors. Results The regression method that included both fixed and random effects for prediction (Best Linear Unbiased Predictor had the best agreement with the AGS (Pearson correlation 0.77 and the smallest mean squared error (MSE: 0.03. The second best method in terms of correlation with AGS (0.74 and MSE (0.09 was the Bayesian method that uses normal mixture prior derived from predictions of the 2001 mixed effects applied in the 2002 context. Conclusion It is likely that either collecting some measurements from the desired locations and time periods or predictions of a reasonable empirical mixed effects model perhaps is sufficient in most epidemiological applications. The

  12. An Experimental Study of Effects on Schoolchildren of Exposure to Point-of-Sale Cigarette Advertising and Pack Displays

    Science.gov (United States)

    Wakefield, Melanie; Germain, Daniella; Durkin, Sarah; Henriksen, Lisa

    2006-01-01

    By creating a sense of familiarity with tobacco, cigarette advertising and bold packaging displays in stores where children often visit may help to pre-dispose them to smoking. A total of 605 ninth-grade students were randomly allocated to view a photograph of a typical convenience store point-of-sale which had been digitally manipulated to show…

  13. Correlation between glucose concentrations in serum, plasma, and whole blood measured by a point-of-care glucometer and serum glucose concentration measured by an automated biochemical analyzer for canine and feline blood samples.

    Science.gov (United States)

    Tauk, Barbara S; Drobatz, Kenneth J; Wallace, Koranda A; Hess, Rebecka S

    2015-06-15

    To investigate the correlation between glucose concentrations in serum, plasma, and whole blood measured by a point-of-care glucometer (POCG) and serum glucose concentration measured by a biochemical analyzer. Prospective clinical study. 96 blood samples from 80 dogs and 90 blood samples from 65 cats. Serum, plasma, and whole blood were obtained from each blood sample. The glucose concentrations in serum, plasma, and whole blood measured by a POCG were compared with the serum glucose concentration measured by a biochemical analyzer by use of the Lin concordance correlation coefficient (ρc) and Bland-Altman plots. For both canine and feline samples, glucose concentrations in serum and plasma measured by the POCG were more strongly correlated with the serum glucose concentration measured by the biochemical analyzer (ρc, 0.98 for both canine serum and plasma; ρc, 0.99 for both feline serum and plasma) than was that in whole blood (ρc, 0.62 for canine samples; ρc, 0.90 for feline samples). The mean difference between the glucose concentrations determined by the biochemical analyzer and the POCG in serum, plasma, and whole blood was 0.4, 0.3, and 31 mg/dL, respectively, for canine samples and 7, 6, and 32 mg/dL, respectively, for feline samples. Results indicated that use of a POCG to measure glucose concentrations in serum or plasma may increase the accuracy and reliability of diagnostic and treatment decisions associated with glucose homeostasis disorders in dogs and cats.

  14. Outdoor performance analysis of a 1090× point-focus Fresnel high concentrator photovoltaic/thermal system with triple-junction solar cells

    International Nuclear Information System (INIS)

    Xu, Ning; Ji, Jie; Sun, Wei; Han, Lisheng; Chen, Haifei; Jin, Zhuling

    2015-01-01

    Graphical abstract: A high concentrator photovoltaic/thermal (HCPV/T) system based on point-focus Fresnel lens has been set up in this work. The concentrator has a geometric concentration ratio of 1090× and uniform irradiation distribution can be obtained on solar cells. The system produces both electricity and heat. Performance of the system has been investigated based on the outdoor measurement in a clear day. The HCPV/T system presents an instantaneous electrical efficiency of 28% and a highest instantaneous thermal efficiency of 54%, respectively. Experimental results show that direct irradiation affects the electrical performance of the system dominantly. Fitting results of electrical performance offer simple and reliable methods to analyze the system performance. - Highlights: • A point-focus Fresnel lens photovoltaic/thermal system is proposed and studied. • The system presents an instantaneous electrical efficiency of 28%. • The system has a highest instantaneous thermal efficiency of 54%. • Direct irradiation has the dominant effect on the electrical performance. • Fitting results offer simple and reliable methods to analyze system performances. - Abstract: A high concentrator photovoltaic/thermal (HCPV/T) system based on point-focus Fresnel lens has been set up in this work. The concentrator has a geometric concentration ratio of 1090× and uniform irradiation distribution can be obtained on solar cells. The system produces both electricity and heat. Performance of the system has been investigated based on the outdoor measurement in a clear day. The HCPV/T system presents an instantaneous electrical efficiency of 28% and a highest instantaneous thermal efficiency of 54%, which means the overall efficiency of the system can be more than 80%. A mathematical model for calculating cell temperature is proposed to solve difficult measurement of cell temperature in a system. Moreover, characteristics of electrical performance under various direct

  15. EFFECTS OF SUBCHRONIC EXPOSURE TO CONCENTRATED AMBIENT PARTICULATES ON ELECTROCARDIOGRAM AND HEART RATE VARIABILITY IN SPONTANEOUSLY HYPERTENSIVE RATS

    Science.gov (United States)

    Epidemiological studies have linked air pollution exposure to adverse respiratory health effects, especially in individuals with inflammatory airways disease. Symptomatic asthmatics appear to be at greatest risk. We previously demonstrated that exposure of rats to particulate...

  16. Ozone pollution and ozone biomonitoring in European cities. Part I: Ozone concentrations and cumulative exposure indices at urban and suburban sites

    DEFF Research Database (Denmark)

    Klumpp, A.; Ansel, W.; Klumpp, G.

    2006-01-01

    In the frame of a European research project on air quality in urban agglomerations, data on ozone concentrations from 23 automated urban and suburban monitoring stations in 11 cities from seven countries were analysed and evaluated. Daily and summer mean and maximum concentrations were computed...... based on hourly mean values, and cumulative ozone exposure indices (Accumulated exposure Over a Threshold of 40 ppb (AOT40), AOT20) were calculated. The diurnal profiles showed a characteristic pattern in most city centres, with minimum values in the early morning hours, a strong rise during the morning......, by contrast, maximum values were lower and diurnal variation was much smaller. Based on ozone concentrations as well as on cumulative exposure indices, a clear north-south gradient in ozone pollution, with increasing levels from northern and northwestern sites to central and southern European sites...

  17. Risk behaviors in a rural community with a known point-source exposure to chronic wasting disease

    Directory of Open Access Journals (Sweden)

    Weeks Jennifer

    2008-06-01

    Full Text Available Abstract Background The emergence and continuing spread of Chronic Wasting Disease (CWD in cervids has now reached 14 U.S. states, two Canadian provinces, and South Korea, producing a potential for transmission of CWD prions to humans and other animals globally. In 2005, CWD spread for the first time from the Midwest to more densely populated regions of the East Coast. As a result, a large cohort of individuals attending a wild game feast in upstate New York were exposed to a deer that was subsequently confirmed positive for CWD. Methods Eighty-one participants who ingested or otherwise were exposed to a deer with chronic wasting disease at a local New York State sportsman's feast were recruited for this study. Participants were administered an exposure questionnaire and agreed to follow-up health evaluations longitudinally over the next six years. Results Our results indicate two types of risks for those who attended the feast, a Feast Risk and a General Risk. The larger the number of risk factors, the greater the risk to human health if CWD is transmissible to humans. Long-term surveillance of feast participants exposed to CWD is ongoing. Conclusion The risk data from this study provide a relative scale for cumulative exposure to CWD-infected tissues and surfaces, and those in the upper tiers of cumulative risk may be most at risk if CWD is transmissible to humans.

  18. Remote Sensing of Sub-Surface Suspended Sediment Concentration by Using the Range Bias of Green Surface Point of Airborne LiDAR Bathymetry

    Directory of Open Access Journals (Sweden)

    Xinglei Zhao

    2018-04-01

    Full Text Available Suspended sediment concentrations (SSCs have been retrieved accurately and effectively through waveform methods by using green-pulse waveforms of airborne LiDAR bathymetry (ALB. However, the waveform data are commonly difficult to analyze. Thus, this paper proposes a 3D point-cloud method for remote sensing of SSCs in calm waters by using the range biases of green surface points of ALB. The near water surface penetrations (NWSPs of green lasers are calculated on the basis of the green and reference surface points. The range biases (ΔS are calculated by using the corresponding NWSPs and beam-scanning angles. In situ measured SSCs (C and range biases (ΔS are used to establish an empirical C-ΔS model at SSC sampling stations. The SSCs in calm waters are retrieved by using the established C-ΔS model. The proposed method is applied to a practical ALB measurement performed by Optech Coastal Zone Mapping and Imaging LiDAR. The standard deviations of the SSCs retrieved by the 3D point-cloud method are less than 20 mg/L.

  19. Personal exposure to PM2,5, black smoke and NO2 in Copenhagen: relationship to bedroom and outdoor concentrations covering seasonal variation

    DEFF Research Database (Denmark)

    Sørensen, M.; Loft, S.; Andersen, H. V.

    2005-01-01

    concentrations of PM(2.5), black smoke (BS), and nitrogen dioxide (NO(2)) were measured during 2-day periods in 30 subjects (20-33 years old) living and studying in central parts of Copenhagen. The measurements were repeated in the four seasons. Information on indoor exposure sources such as environmental......Epidemiological studies have found negative associations between human health and particulate matter in urban air. In most studies outdoor monitoring of urban background has been used to assess exposure. In a field study, personal exposure as well as bedroom, front door and background...

  20. A single exposure to a sublethal pediocin concentration initiates a resistance-associated temporal cell envelope and general stress response in Listeria monocytogenes

    DEFF Research Database (Denmark)

    Laursen, Martin Frederik; Bahl, Martin Iain; Licht, Tine Rask

    2015-01-01

    was to determine if exposure to sublethal concentrations of pediocin-containing Lactobacillus plantarum WHE 92 supernatant could prime L. monocytogenes for resistance. By transcriptomic analysis, we found two, 55 and 539 genes differentially expressed after 10, 60 and 180 min of exposure to L. plantarum WHE 92...... resistant than wild types to L. plantarum WHE 92 supernatant. LisRK, SigB and SigL regulation and genes associated with resistance are involved in the temporal adaptive response to pediocin and all three regulatory systems affect pediocin resistance. Thus, a single exposure to a sublethal pediocin...

  1. Effects of two-hour exposure to environmental and high concentrations of methylmercury on the transcriptome of the macrophyte Elodea nuttallii.

    Science.gov (United States)

    Beauvais-Flück, Rebecca; Slaveykova, Vera I; Cosio, Claudia

    2018-01-01

    The effects of two methylmercury (CH 3 Hg + , MeHg) concentrations, representative of environmental level and extreme contamination, were investigated on the macrophyte Elodea nuttallii during a 2h-exposure combining transcriptomic (RNA-Seq), physiological endpoints (pigment contents, activity of anti-oxidative stress enzymes) and bioaccumulation. Exposure to MeHg induced the up- and down-regulation of numerous genes (4389 and 16853 for 10ngL -1 and 10μgL -1 MeHg exposure, respectively) involved in sugar, amino acid and secondary metabolism (e.g. cinnamic acid, flavonoids) at both concentrations. Genes coding for photosynthesis, membrane integrity, metal homeostasis, water transport and anti-oxidative enzymes were additionally up- and down-regulated at the higher concentration. At the physiological level, exposure to both MeHg concentrations resulted in a strong increase of anthocyanin content in shoots. Chlorophyll content and antioxidant enzyme activities were unchanged. The data suggest that the macrophyte was able to efficiently cope with the stress resulting from MeHg exposure, possibly by using anthocyanin as anti-oxidant and S-rich amino acids (such as cysteine and methionine) as chelators. Transcriptomics analysis enabled gaining novel insights on molecular effects of MeHg in primary producers, which are one of the main entry pathway of hazardous MeHg in aquatic food webs. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Copper-Based Aquatic Algaecide Adsorption and Accumulation Kinetics: Influence of Exposure Concentration and Duration for Controlling the Cyanobacterium Lyngbya wollei.

    Science.gov (United States)

    Bishop, West M; Lynch, Clayton L; Willis, Ben E; Cope, W Gregory

    2017-09-01

    Filamentous mat-forming cyanobacteria are increasingly impairing uses of freshwater resources. To effectively manage, a better understanding of control measures is needed. Copper (Cu)-based algaecide formulations are often applied to reactively control nuisance cyanobacterial blooms. This laboratory research assessed typical field exposure scenarios for the ability of Cu to partition to, and accumulate in Lyngbya wollei. Exposure factors (Cu concentration × duration) of 4, 8, 16, 24, 32 h were tested across three aqueous Cu concentrations (1, 2, 4 ppm). Results indicated that internally accumulated copper correlated with control of L. wollei, independent of adsorbed copper. L. wollei control was determined by filament viability and chlorophyll a concentrations. Similar exposure factors elicited similar internalized copper levels and consequent responses of L. wollei. Ultimately, a "concentration-exposure-time" (CET) model was created to assist water resource managers in selecting an appropriate treatment regime for a specific in-water infestation. By assessing the exposure concentration and duration required to achieve the internal threshold of copper (i.e., critical burden) that elicits control, water management objectives can be achieved while simultaneously decreasing the environmental loading of copper and potential for non-target species risks.

  3. [Effect of ear point embedding on plasma and effect site concentrations of propofol-remifentanil in elderly patients after target-controlled induction].

    Science.gov (United States)

    Zheng, Xiaochun; Wan, Liling; Gao, Fei; Chen, Jianghu; Tu, Wenshao

    2017-08-12

    To observe the clinical effect of ear point embedding on plasma and effect site concentrations of propofol-remifentanil in elderly patients who underwent abdominal external hernia surgery at the time of consciousness and pain disappearing by target-controlled infusion (TCI) and bispectral index (BIS). Fifty patients who underwent elective abdominal hernia surgery were randomly assigned into an observation group and a control group, 25 cases in each one. In the observation group, 30 minutes before anesthesia induction, Fugugou (Extra), Gan (CO 12 ), Pizhixia (AT 4 ), and Shenmen (TF 4 ) were embedded by auricular needles until the end of surgery, 10 times of counter press each point. In the control group, the same amount of auricular tape was applied until the end of surgery at the same points without stimulation 30 minutes before anesthesia induction. Patients in the two groups were given total intravenous anesthesia, and BIS was monitored by BIS anesthesia depth monitor. Propofol was infused by TCI at a beginning concentration of 1.5μg/L and increased by 0.3μg/L every 30s until the patients lost their consciousness. After that, remifentanil was infused by TCI at a beginning concentration of 2.0μg/L and increased by 0.3μg/L every 30s until the patients had no body reaction to pain stimulation (orbital reflex). Indices were recorded, including mean arterial pressure (MAP), heart rate (HR) and the BIS values, at the time of T 0 (entering into the operation room), T 1 (losing consciousness) and T 2 (pain relief), the plasma and effect site concentrations of propofol at T 1 , the plasma and effect site concentrations of remifentanil at T 2 . After surgery we recorded the total amounts of propofol and remifentanil, surgery time and anesthesia time. At T 1 and T 2 , MAP and HR of the observation group were higher than those of the control group ( P effect site concentrations of propofol in the observation group were significantly lower than those in the control group

  4. Cloud point extraction-flame atomic absorption spectrometry for pre-concentration and determination of trace amounts of silver ions in water samples

    Directory of Open Access Journals (Sweden)

    Xiupei Yang

    2017-03-01

    Full Text Available A cloud point extraction (CPE method was used as a pre-concentration strategy prior to the determination of trace levels of silver in water by flame atomic absorption spectrometry (FAAS The pre-concentration is based on the clouding phenomena of non-ionic surfactant, triton X-114, with Ag (I/diethyldithiocarbamate (DDTC complexes in which the latter is soluble in a micellar phase composed by the former. When the temperature increases above its cloud point, the Ag (I/DDTC complexes are extracted into the surfactant-rich phase. The factors affecting the extraction efficiency including pH of the aqueous solution, concentration of the DDTC, amount of the surfactant, incubation temperature and time were investigated and optimized. Under the optimal experimental conditions, no interference was observed for the determination of 100 ng·mL−1 Ag+ in the presence of various cations below their maximum concentrations allowed in this method, for instance, 50 μg·mL−1 for both Zn2+ and Cu2+, 80 μg·mL−1 for Pb2+, 1000 μg·mL−1 for Mn2+, and 100 μg·mL−1 for both Cd2+ and Ni2+. The calibration curve was linear in the range of 1–500 ng·mL−1 with a limit of detection (LOD at 0.3 ng·mL−1. The developed method was successfully applied for the determination of trace levels of silver in water samples such as river water and tap water.

  5. [Optimization of benzalkonium chloride concentration in 0.0015% tafluprost ophthalmic solution from the points of ocular surface safety and preservative efficacy].

    Science.gov (United States)

    Asada, Hiroyuki; Takaoka-Shichijo, Yuko; Nakamura, Masatsugu; Kimura, Akio

    2010-06-01

    Optimization of benzalkonium chloride (alkyl dimethylbenzylammonium chloride: BAK) concentration as preservative in 0.0015% tafluprost ophthalmic solution (Tapros 0.0015% ophthalmic solution), an anti-glaucoma medicine, was examined from the points of ocular surface safety and preservative efficacy. BAKC(12), which is dodecyl dimethylbenzylammonium chloride, and BAKmix, which is the mixture of dodecyl, tetradecyl and hexadecyl dimethylbenzylammonium chloride were used in this study. The effects of BAKC(12) concentrations and the BAK types, BAKC(12) and BAKmix, in tafluprost ophthalmic solution on ocular surface safety were evaluated using the in vitro SV 40-immobilized human corneal epithelium cell line (HCE-T). Following treatments of Tafluprost ophthalmic solutions with BAKC(12), its concentration dependency was observed on cell viability of HCE-T. The cell viability of HCE-T after treatment of these solutions with 0.001% to 0.003% BAKC(12) for 5 minutes were the same level as that after treatment of the solution without BAK. Tafluprost ophthalmic solution with 0.01% BAKC(12) was safer for the ocular surface than the same solution with 0.01% BAKmix. Preservatives-effectiveness tests of tafluprost ophthalmic solutions with various concentrations of BAKC(12) were performed according to the Japanese Pharmacopoeia (JP), and solutions with more than 0.0005% BAKC(12) conformed to JP criteria. It was concluded that 0.0005% to 0.003% of BAKC(12) in tafluprost ophthalmic solution was optimal, namely, well-balanced from the points of ocular surface safety and preservative efficacy.

  6. Cloud point extraction-flame atomic absorption spectrometry for pre-concentration and determination of trace amounts of silver ions in water samples.

    Science.gov (United States)

    Yang, Xiupei; Jia, Zhihui; Yang, Xiaocui; Li, Gu; Liao, Xiangjun

    2017-03-01

    A cloud point extraction (CPE) method was used as a pre-concentration strategy prior to the determination of trace levels of silver in water by flame atomic absorption spectrometry (FAAS) The pre-concentration is based on the clouding phenomena of non-ionic surfactant, triton X-114, with Ag (I)/diethyldithiocarbamate (DDTC) complexes in which the latter is soluble in a micellar phase composed by the former. When the temperature increases above its cloud point, the Ag (I)/DDTC complexes are extracted into the surfactant-rich phase. The factors affecting the extraction efficiency including pH of the aqueous solution, concentration of the DDTC, amount of the surfactant, incubation temperature and time were investigated and optimized. Under the optimal experimental conditions, no interference was observed for the determination of 100 ng·mL -1 Ag + in the presence of various cations below their maximum concentrations allowed in this method, for instance, 50 μg·mL -1 for both Zn 2+ and Cu 2+ , 80 μg·mL -1 for Pb 2+ , 1000 μg·mL -1 for Mn 2+ , and 100 μg·mL -1 for both Cd 2+ and Ni 2+ . The calibration curve was linear in the range of 1-500 ng·mL -1 with a limit of detection (LOD) at 0.3 ng·mL -1 . The developed method was successfully applied for the determination of trace levels of silver in water samples such as river water and tap water.

  7. Ammonia concentrations in canine whole blood, EDTA-anticoagulated whole blood, and plasma measured by use of a point-of-care ammonia meter.

    Science.gov (United States)

    Odunayo, Adesola; Tobias, Karen M; Okafor, Chika C; Flatland, Bente

    2017-11-01

    OBJECTIVE To investigate the use of canine whole blood (WB) for measurement of ammonia concentration by use of a point-of-care ammonia meter and to compare results of measuring ammonia concentrations in WB, EDTA-anticoagulated WB, and plasma. ANIMALS 40 client-owned dogs. PROCEDURES A blood sample (2 mL) was obtained from each dog. One drop of WB was immediately applied to a test strip for evaluation with an ammonia meter. The remainder of the blood sample was placed in an EDTA-containing tube, and 1 drop of EDTA-anticoagulated WB was applied to a test strip. The remaining EDTA-anticoagulated WB sample was centrifuged, and the plasma was harvested and placed on ice. One drop of plasma was applied to a test strip; the remainder of the plasma sample was transported on ice and used for ammonia measurement with a reference laboratory instrument. All samples were tested within 1 hour after sample collection. Results were evaluated to detect significant differences in ammonia concentration. RESULTS Ammonia concentrations did not differ significantly between WB and EDTA-anticoagulated WB and between plasma samples measured with the meter and reference laboratory instrument. However, median ammonia concentration was significantly higher in plasma than in WB or EDTA-anti-coagulated WB. CONCLUSIONS AND CLINICAL RELEVANCE Anticoagulant-free WB was a valid sample for measurement by use of the ammonia meter. Plasma samples had higher ammonia concentrations than did WB samples. Results for each sample type should be interpreted by use of specimen- and method-specific reference intervals.

  8. Lessoning of radiation exposure. Radiation effect on humans and points to be noticed learned by Fukushima nuclear power plant accident

    International Nuclear Information System (INIS)

    Omori, Koichi

    2013-01-01

    Described are the process of medical measures taken along with the time after the Accident in the title (Mar. 12, 2011) and the present state (June, 2013) of Fukushima. The author at first presents the fundamental knowledge of radiation like unit, natural/medical doses, and the scale of the Accident compared with Chernobyl Accident (1986) involving observed diseases like thyroid cancer. On the day before the Accident, the Earthquake and Tsunami attacked Fukushima, and the University Hospital built up an anti-disaster medical headquarter. Until 15th, the hospital accepted about 500 persons for their contamination survey and subsequent de-contamination, then played a role for relaying 1,300 patients to other facilities and accepted 125 hospitalizations, during which communication by phone had been scarcely available, leading to complication and confusion. The radioisotope subjected to be noted was radioiodine earlier and then radiocesium. Emergent medical supports were conducted for various evacuation areas involving 20-30 km zone from the Plant by pediatric and infection teams with joint doctors from Thailand. The University had been defined to be the secondary emergent, expertized medical facility since 2001 and began to conduct the long-term project Fukushima Health Management Survey after the Accident for the fundamental and detailed studies of residents. The secondary facility at the emergency was inevitably the center of medicare as the primary hospitals were mostly in the radiological evacuation area and tertiary ones located afar. The University Hospital is now revising the formal manual for medical response to exposure. In Fukushima City, 60 km distant from the Plant, the ambient dose is about 0.5 mc-Sv and external exposure dose is lowering to 2-4 mSv/y. Decrease of medical staff like doctors and nurses is significant in the prefecture. (T.T.)

  9. GAMMA-CLOUD: a computer code for calculating gamma-exposure due to a radioactive cloud released from a point source

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, O [Chugoku Electric Power Co. Inc., Hiroshima (Japan); Sawaguchi, Y; Kaneko, M

    1979-03-01

    A computer code, designated GAMMA-CLOUD, has been developed by specialists of electric power companies to meet requests from the companies to have a unified means of calculating annual external doses from routine releases of radioactive gaseous effluents from nuclear power plants, based on the Japan Atomic Energy Commission's guides for environmental dose evaluation. GAMMA-CLOUD is written in FORTRAN language and its required capacity is less than 100 kilobytes. The average ..gamma..-exposure at an observation point can be calculated within a few minutes with comparable precision to other existing codes.

  10. One versus five-days of exposure to varying concentrations of B100 soya biodiesel exhaust reveals a threshold concentration for increased sensitivity to aconitine-induced arrhythmia

    Science.gov (United States)

    Although biodiesel (BD) is rapidly being considered as an alternative to diesel fuel, its health effects have not been thoroughly characterized. We previously used the aconitine challenge test to demonstrate that a single exposure to petroleum diesel exhaust (DE) increases the ri...

  11. Nondestructive pollution exposure assessment in the European hedgehog (Erinaceus europaeus): I. Relationships between concentrations of metals and arsenic in hair, spines, and soil.

    Science.gov (United States)

    D'Havé, Helga; Scheirs, Jan; Mubiana, Valentine Kayawe; Verhagen, Ron; Blust, Ronny; De Coen, Wim

    2005-09-01

    Conventional metal exposure assessment in terrestrial mammals is generally based on organ analyses of sacrificed animals. Few studies on mammals use nondestructive methodologies despite the growing ethical concern over the use of destructive sampling. Nondestructive methods involve minimal stress to populations and permit successive biomonitoring of the same populations and individuals. In the present study we assessed metal exposure of hedgehogs (Erinaceus europaeus) by investigating relationships between concentrations of metals (Ag, Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn) and As in soil samples and in hair and spines of hedgehogs. Samples were collected in seven study sites along a metal pollution gradient, characterized by decreasing total soil Ag, As, Cd, Cu, Ni, and Pb concentrations with increasing distance from a nonferrous metallurgic factory. For a number of elements, soil contamination was related both to distance to the smelter and to habitat. Soil concentrations were positively related to levels in hair and spines for Ag, As, Cd, and Pb and thus to hedgehog exposure. Metal concentrations in soil did not relate to metal concentrations in hair and spines for essential elements (e.g., Cu, Fe, Mn, Ni, and Zn), except Co in hair and soil. Our results demonstrate that, at least for nonessential elements, concentrations in soils can be used to predict contamination of these elements in hedgehogs or vice versa. Furthermore, hedgehog exposure increased toward the smelter and was higher for hedgehogs foraging in grasslands than for animals foraging in the forest. Moreover, we believe that hair and spines are promising tools in terrestrial wildlife exposure assessment studies of metals and As.

  12. EFFECTS OF COMMONLY USED COOKING PRACTICES ON TOTAL MERCURY CONCENTRATION IN FISH AND THEIR IMPACT ON EXPOSURE ASSESSMENTS

    Science.gov (United States)

    The effects of cooking practices commonly used by Native Americans on total mercury concentrations in fish were investigated. A preparation factor relating mercury concentrations in fish as prepared for consumption to mercury concentration data as measured in typical environmenta...

  13. Use of anti-Aedes aegypti salivary extract antibody concentration to correlate risk of vector exposure and dengue transmission risk in Colombia.

    Directory of Open Access Journals (Sweden)

    Berlin Londono-Renteria

    Full Text Available Norte de Santander is a region in Colombia with a high incidence of dengue virus (DENV. In this study, we examined the serum concentration of anti-Aedes salivary gland extract (SGE antibodies as a biomarker of DENV infection and transmission, and assessed the duration of anti-SGE antibody concentration after exposure to the vector ceased. We also determined whether SGE antibody concentration could differentiate between positive and negative DENV infected individuals and whether there are differences in exposure for each DENV serotype. We observed a significant decrease in the concentration of IgG antibodies at least 40 days after returning to an "Ae. aegypti-free" area. In addition, we found significantly higher anti-SGE IgG concentrations in DENV positive patients with some difference in exposure to mosquito bites among DENV serotypes. We conclude that the concentration of IgG antibodies against SGE is an accurate indicator of risk of dengue virus transmission and disease presence.

  14. Challenges in evaluating PM concentration levels, commuting exposure, and mask efficacy in reducing PM exposure in growing, urban communities in a developing country.

    Science.gov (United States)

    Patel, Disa; Shibata, Tomoyuki; Wilson, James; Maidin, Alimin

    2016-02-01

    Particulate matter (PM) contributes to an increased risk of respiratory and cardiovascular illnesses, cancer, and preterm birth complications. This project assessed PM exposure in Eastern Indonesia's largest city, where air quality has not been comprehensively monitored. We examined the efficacy of wearing masks as an individual intervention effort to reduce in-transit PM exposures. Handheld particulate counters were used to investigate ambient air quality for spatial analysis, as well as the differences in exposure to PM2.5 and PM10 (μg/m(3)) by different transportation methods [e.g. motorcycle (n=97), pete-pete (n=53), and car (n=55); note: n=1 means 1m(3) of air sample]. Mask efficacy to reduce PM exposure was evaluated [e.g. surgical masks (n=39), bandanas (n=52), and motorcycle masks (n=39)]. A Monte Carlo simulation was used to provide a range of uncertainty in exposure assessment. Overall PM10 levels (91±124 μg/m(3)) were elevated compared to the World Health Organization (WHO)'s 24-hour air quality guideline (50 μg/m(3)). While average PM2.5 levels (9±14 μg/m(3)) were below the WHO's guideline (25 μg/m(3)), measurements up to 139 μg/m(3) were observed. Compared to cars, average motorcycle and pete-pete PM exposures were four and three times higher for PM2.5, and 13 and 10 times higher for PM10, respectively. Only surgical masks were consistent in lowering PM2.5 and PM10 (pmasks. Individual interventions can effectively reduce individual PM exposures; however, policy interventions will be needed to improve the overall air quality and create safer transportation. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Prevalence of subclinical ketosis in dairy cattle in the Southwestern Iran and detection of cutoff point for NEFA and glucose concentrations for diagnosis of subclinical ketosis.

    Science.gov (United States)

    Asl, Ardavan Nowroozi; Nazifi, Saeed; Ghasrodashti, Abbas Rowshan; Olyaee, Ahad

    2011-06-01

    Subclinical ketosis (SCK) is simply a condition marked by increased levels of circulating ketone bodies without the presence of the clinical signs of ketosis. Subclinical ketosis can cause economic losses through decreased milk production and association with preparturient diseases. Limited information is available regarding the prevalence of SCK in dairy herds in Southwestern Iran. The objectives of this study were (i) determination of the cutoff point of nonesterified fatty acids (NEFAs) and glucose concentrations for diagnosis of SCK using receiver operating characteristic (ROC) analysis, and (ii) determination of prevalence of subclinical ketosis in apparently healthy dairy cattle in Southwestern Iran. From October to December 2009, a total of 100 clinically healthy multiparous Holstein cows (3-8 years old) were randomly selected from 16 dairy herds around Kazerun, Fars Province, Iran. The cows had two-six lactations, with body weight ranging from 500 to 650 kg. Blood samples for each cow were taken at 2, 4 and 6 weeks post parturition and 3-4h after the morning feeding. The optimal cutoff point was set, by the ROC method, to >0.26 mmol/L for NEFA, and ketosis in all of the 2, 4 and 6 weeks postpartum. The results suggest that, a cut-off point of 0.26 mmol/L for NEFA concentrations can be used during early lactation for diagnosis of subclinical ketosis and making management decisions for prevention and treatment. Glucose cannot be a good criterion for diagnosis of SCK and it does not appear to be useful for monitoring subclinical ketosis. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Distinct toxicological characteristics and mechanisms of Hg2+ and MeHg in Tetrahymena under low concentration exposure.

    Science.gov (United States)

    Liu, Cheng-Bin; Qu, Guang-Bo; Cao, Meng-Xi; Liang, Yong; Hu, Li-Gang; Shi, Jian-Bo; Cai, Yong; Jiang, Gui-Bin

    2017-12-01

    Inorganic divalent mercury complexes (Hg 2+ ) and monomethylmercury complexes (MeHg) are the main mercury species in aquatic systems and their toxicity to aquatic organisms is of great concern. Tetrahymena is a type of unicellular eukaryotic protozoa located at the bottom of food chain that plays a fundamental role in the biomagnification of mercury. In this work, the dynamic accumulation properties, toxicological characteristics and mechanisms of Hg 2+ and MeHg in five Tetrahymena species were evaluated in detail. The results showed that both Hg 2+ and MeHg were ingested and exhibited inhibitory effects on the proliferation or survival of Tetrahymena species. However, the ingestion rate of MeHg was significantly higher than that of Hg 2+ . The mechanisms responsible for the toxicity of MeHg and Hg 2+ were different, although both chemicals altered mitochondrial membrane potential (MMP). MeHg disrupted the integrity of membranes while Hg 2+ had detrimental effects on Tetrahymena as a result of the increased generation of reactive oxygen species (ROS). In addition, the five Tetrahymena species showed different capacities in accumulating Hg 2+ and MeHg, with T. corlissi exhibiting the highest accumulations. The study also found significant growth-promoting effect on T. corlissi under low concentration exposure (0.003 and 0.01μg Hg/mL (15 and 50nM)), suggesting different effect and mechanism that should be more closely examined when assessing the bioaccumulation and toxicity of mercury in aquatic ecosystems. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Applicability of a Single Time Point Strategy for the Prediction of Area Under the Concentration Curve of Linezolid in Patients: Superiority of Ctrough- over Cmax-Derived Linear Regression Models.

    Science.gov (United States)

    Srinivas, Nuggehally R; Syed, Muzeeb

    2016-03-01

    Linezolid, a oxazolidinone, was the first in class to be approved for the treatment of bacterial infections arising from both susceptible and resistant strains of Gram-positive bacteria. Since overt exposure of linezolid may precipitate serious toxicity issues, therapeutic drug monitoring (TDM) may be required in certain situations, especially in patients who are prescribed other co-medications. Using appropriate oral pharmacokinetic data (single dose and steady state) for linezolid, both maximum plasma drug concentration (Cmax) versus area under the plasma concentration-time curve (AUC) and minimum plasma drug concentration (Cmin) versus AUC relationship was established by linear regression models. The predictions of the AUC values were performed using published mean/median Cmax or Cmin data and appropriate regression lines. The quotient of observed and predicted values rendered fold difference calculation. The mean absolute error (MAE), root mean square error (RMSE), correlation coefficient (r), and the goodness of the AUC fold prediction were used to evaluate the two models. The Cmax versus AUC and trough plasma concentration (Ctrough) versus AUC models displayed excellent correlation, with r values of >0.9760. However, linezolid AUC values were predicted to be within the narrower boundary of 0.76 to 1.5-fold by a higher percentage by the Ctrough (78.3%) versus Cmax model (48.2%). The Ctrough model showed superior correlation of predicted versus observed values and RMSE (r = 0.9031; 28.54%, respectively) compared with the Cmax model (r = 0.5824; 61.34%, respectively). A single time point strategy of using Ctrough level is possible as a prospective tool to measure the AUC of linezolid in the patient population.

  18. The density of tobacco retailers and its association with attitudes toward smoking, exposure to point-of-sale tobacco advertising, cigarette purchasing, and smoking among New York youth.

    Science.gov (United States)

    Loomis, Brett R; Kim, Annice E; Busey, Andrew H; Farrelly, Matthew C; Willett, Jeffrey G; Juster, Harlan R

    2012-11-01

    Estimate the association between the density of licensed tobacco retailers (LTRs) and smoking-related attitudes and behaviors among middle and high school students in New York. The 2000-2008 New York Youth Tobacco Surveys were pooled (N=70,427) and linked with county-level density of LTRs and retailer compliance with laws restricting youth access to cigarettes. Logistic regressions tested for associations with attitudes toward smoking exposure to point-of-sale tobacco advertising, cigarette purchasing, and smoking prevalence. LTR density is associated with self-reported exposure to point-of-sale advertising in New York City (NYC) among all youth (OR=1.15; 95% CI: 1.02, 1.30) and nonsmokers (OR=1.14; 95% CI: 1.01, 1.30); youth believing that smoking makes them look cool, overall (OR=1.75; 95% CI: 1.22, 2.52) and among nonsmokers (OR=1.68; 95% CI: 1.11, 2.55); and a counter-intuitive negative relationship with frequent smoking in NYC (OR=0.50; 95% CI: 0.29, 0.84). Retailer compliance was negatively associated with youth reporting that a retail store is their usual source for cigarettes (OR=0.93; 95% CI: 0.88, 0.98). Restricting tobacco licenses and enforcing youth access laws are reasonable policy approaches for influencing youth smoking outcomes. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. The influence of short-term concentration peaks on exposure risks in the vicinity of an episodic release of hydrogen sulphide

    International Nuclear Information System (INIS)

    1981-01-01

    In order to propose a methodology by which the influence of short-term concentration peaks on exposure risks could be estimated in the vicinity of an atmospheric release of hydrogen sulphide (H 2 S), an extensive and up-to-date review of H 2 S toxicity was conducted, with emphasis on acute and sub-acute poisoning. The literature on animal studies and cases of human exposure were used to derive a lethal dose relationship(concentration-exposure time) appropriate for the general population. A statistical model was developed which calculates the probability of short-term concentrations exceeding the lethal level given the downwind range from the release, the short-term averaging time of interest, the long-term average concentration, and metereological and terrain conditions . Results were obtained for passive releases of H 2 S under a range of hypothetical conditions. Interpretation of these results is given in terms of the overall probability of lethal exposure during a 30-minute episode. The likely influence of heavy water plant gas dispersion systems is also addressed. (author)

  20. Association between secondhand smoke exposure and blood lead and cadmium concentration in community dwelling women: the fifth Korea National Health and Nutrition Examination Survey (2010-2012).

    Science.gov (United States)

    Jung, Se Young; Kim, Suyeon; Lee, Kiheon; Kim, Ju Young; Bae, Woo Kyung; Lee, Keehyuck; Han, Jong-Soo; Kim, Sarah

    2015-07-16

    To assess the association between secondhand smoke exposure and blood lead and cadmium concentration in women in South Korea. Population-based cross-sectional study. South Korea (Korea National Health and Nutrition Examination Survey V). 1490 non-smoking women who took part in the fifth Korea National Health and Nutrition Examination Survey (2010-2012), in which blood levels of lead and cadmium were measured. The primary outcome was blood levels of lead and cadmium in accordance with the duration of secondhand smoke exposure. The adjusted mean level of blood cadmium in women who were never exposed to secondhand smoke was 1.21 (0.02) µg/L. Among women who were exposed less than 1 h/day, the mean cadmium level was 1.13 (0.03) µg/L, and for those exposed for more than 1 h, the mean level was 1.46 (0.06) µg/L. In particular, there was a significant association between duration of secondhand smoke exposure at the workplace and blood cadmium concentration. The adjusted mean level of blood cadmium concentration in the never exposed women's group was less than that in the 1 h and more exposed group, and the 1 h and more at workplace exposed group: 1.20, 1.24 and 1.50 µg/L, respectively. We could not find any association between lead concentration in the blood and secondhand smoke exposure status. This study showed that exposure to secondhand smoke and blood cadmium levels are associated. Especially, there was a significant association at the workplace. Therefore, social and political efforts for reducing the exposure to secondhand smoke at the workplace are needed in order to promote a healthier working environment for women. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  1. [Dust concentration analysis in non-coal mining. Exposure evaluation based on measurements performed by occupational hygiene laboratories in the years 2001-2005 in Poland].

    Science.gov (United States)

    Bujak-Pietrek, Stella; Mikołajczyk, Urszula; Szadkowska-Stańczyk, Irena

    2011-01-01

    Non-coal mining includes the extraction of materials for construction (stone, gravel, sand and clay), chemical industry (salt and sulfur), metallurgy (metal ores, uranium and thorium) and other mining and quarrying. Regardless of the type of mining company one of the most common health hazards in this sector is exposure to high concentrations of dust occurring during the extraction of materials. Such activities as drilling, use of blasting agents, processing of raw material, its transportation and loading are the source of large amounts of dust containing crystalline silica. Data on exposure to dust, collected by industrial hygiene laboratories on the basis of dust concentration measurements in the work environment, were obtained from the sanitary inspection service. The analysis of dust concentrations at workplaces in non-coal mining covered the years 2001-2005. The average concentration of inhalable and respirable dust and the degree of results dispersion at workposts in different branches of non-coal mining (according to NACE rev1.1) were evaluated. Also there was estimated the percentage of surveys indicating dust concentrations above hygiene standards. Almost 5000 measurements of dust concentrations were performed in the years under study. The highest concentration of inhalable dust was noted for the production of salt (5.51 mg/m3), other mining and quarrying (4.30 mg/m3) and quarrying of slate (3.77 mg/m3). For respirable dust the highest concentrations were noted in other mining and quarrying (1.10 mg/m3), quarrying of slate (1.09 mg/m3) and quarrying of stone (0.81 mg/m3). Exposure to high concentrations of dust during the extraction of non-carbon is still an important hazard to human health. Almost for all workposts under study the excess of hygiene standards were observed.

  2. Personal exposures to NO2 in the EXPOLIS-study: relation to residential indoor, outdoor and workplace concentrations in Basel, Helsinki and Prague

    International Nuclear Information System (INIS)

    Kousa, A.; Rotko, T.; Alm, S.; Monn, C.

    2001-01-01

    Personal exposures, residential indoor, outdoor and workplace levels of nitrogen dioxide (NO 2 ) were measured for 262 urban adult (25-55 years) participants in three EXPOLIS centres (Basel, Switzerland; Helsinki, Finland; and Prague, Czech Republic) using passive samplers for 48-h sampling periods during 1996-1997. The average residential outdoor and indoor NO 2 levels were lowest in Helsinki (24 ± 12 and 18 ± 11 μgm -3 , respectively), highest in Prague (61 ± 20 and 43 ± 23μgm -3 ), with Basel in between (36 ± 13 and 27± 13μgm -3 ). Average workplace NO 2 levels, however, were highest in Basel (36 ± 24μgm -3 ), lowest in Helsinki (27 ± 15μgm -3 ), with Prague in between (30 ± 18μgm -3 ). A time-weighted microenvironmental exposure model explained 74% of the personal exposure variation in all centre and in average 88% of the exposures. Log-linear regression models, using residential outdoor measurements (fixed site monitoring) combined with residential and work characteristics (i.e. work location, using gas appliances and keeping windows open), explained 48% (37%) of the personal NO 2 exposure variation. Regression models based on ambient fixed site concentrations alone explained only 11-19% of personal NO 2 exposure variation. Thus, ambient fixed site monitoring alone was a poor predictor for personal NO 2 exposure variation, but adding personal questionnaire information can significantly improve the predicting power. (Author)

  3. Simultaneous exposure to concentrated ambient particles and acrolein causes cardiac effects mediated by parasympathetic modulation in mice

    Science.gov (United States)

    This study shows that exposure to CAPs and acrolein causes an increase in HRV that is mediated by the parasympathetic nervous system. Numerous studies show that short-term air pollution exposure modulates heart rate variability (HRV), which is an indicator of autonomic influence...

  4. Performance, acute health symptoms and physiological responses during exposure to high air temperature and carbon dioxide concentration

    DEFF Research Database (Denmark)

    liu, weiwei; Zhong, Weidi; Wargocki, Pawel

    2017-01-01

    saturation decreased significantly, while the percentage of adjacent inter-beat cardiac intervals differing by > 50 m (pNN50) decreased significantly, indicating elevated stress. The performance of addition and subtraction tasks decreased significantly during this exposure, as well. Increasing CO2 to 3000......Human subjects were exposed for 3 h in a climate chamber to the air temperature of 35 °C that is an action level, at which the working time needs to be diminished in China. The purpose was to put this action level to test by measuring physiological responses, subjective ratings and cognitive...... performance, and compare them with responses at temperature of 26 °C (reference exposure). Moreover, CO2 was increased to 3000 ppm (CO2 exposure) at 35 °C to further examine, whether this change will have any effect on the measured responses. Compared with the reference exposure, exposure to 35 °C caused...

  5. Sequential Neighborhood Effects: The Effect of Long-Term Exposure to Concentrated Disadvantage on Children's Reading and Math Test Scores.

    Science.gov (United States)

    Hicks, Andrew L; Handcock, Mark S; Sastry, Narayan; Pebley, Anne R

    2018-02-01

    Prior research has suggested that children living in a disadvantaged neighborhood have lower achievement test scores, but these studies typically have not estimated causal effects that account for neighborhood choice. Recent studies used propensity score methods to account for the endogeneity of neighborhood exposures, comparing disadvantaged and nondisadvantaged neighborhoods. We develop an alternative propensity function approach in which cumulative neighborhood effects are modeled as a continuous treatment variable. This approach offers several advantages. We use our approach to examine the cumulative effects of neighborhood disadvantage on reading and math test scores in Los Angeles. Our substantive results indicate that recency of exposure to disadvantaged neighborhoods may be more important than average exposure for children's test scores. We conclude that studies of child development should consider both average cumulative neighborhood exposure and the timing of this exposure.

  6. Study of radiation exposure rate on the measurement points in Kartini reactor hall as based to determine operation safety parameters (KBO)

    International Nuclear Information System (INIS)

    Mahrus Salam; Elisabeth Supriyatni; Fajar Panuntun

    2016-01-01

    In the operation of nuclear facility there are safety parameters, which is the value of the conservatively maximum limit to ensure that all of the uncertainty in the analysis of facility operations safety have been considered, such as uncertainty of measurement, response time and uncertainty calculation tool, and is get a long to others value of normal operating condition limits, in other words, there are still allowed or permitted. Calculation of the radiation exposure rate on five measurement points (50 cm above the water surface of reactor pool, above interim storage (bulk shielding), reactor deck, thermal column and sub critical facility) and to be compared to the operation safety parameters (KBO) of Kartini reactor. The exposure rate value is obtained by calculating the source term of radioactivity on the core, attenuation resulting from the radiation shielding and measurement distance. From the calculation obtained that the value of gamma exposure rate of 50 cm above the water surface of reactor pool is 96.91 mR/hr (KBO<100 mR/hr), on the deck of Bulk Shielding amounted to 1.70 mR/h (KBO<2.5 mR/hr), on the reactor deck amounted to 5.73 mR/hr (KBO<10 mR/hr), on the Thermal Column amounted to 2.73 mR/hr (KBO<10 mR/hr) and on the sub critical facility amounted to 1.148 mR/hr (KBO<2.5 mR/hr). The value of gamma exposure rate at 5 locations measurements are still less than the operation safety parameters (KBO), it means that the reactor is safe to be operated. (author)

  7. The effect of concentration and exposure time on 15N uptake and incorporation from urea and ammonium nitrate by spring barley in the initial growth period

    International Nuclear Information System (INIS)

    Matula, J.; Knop, K.

    1978-01-01

    The uptake and incorporation of 15 N from urea and ammonium nitrate by spring barley were studied in aquaculture at three nitrogen concentrations in complex nutrient solutions (28, 140 and 700 mg N per 1 litre) and for three lengths of exposure to 15 N-labelled nutrient solutions. The 'Diamant' variety plants were precultivated up to the stage of the 3rd to 4th leaf in a complex nutrient solution, and five days prior to exposure to 15 N-labelled solutions the plants were cultivated in a nutrient solution without nitrogen. At a concentration of 28 mg N per litre the course of urea absorption was similar to the absorption of ammonium nitrate, but at a lower level. The results suggest that urea uptake is basically controlled by the metabolic requirement, particularly at lower concentrations. Only at the highest concentrations of nitrogen in the nutrient solutions did the 15 N of urea and ammonium nitrate penetrate into the roots, passive uptake being preferred. The uptake of urea is controlled by the metabolic requirement but its availability for barley metabolism is lower. Ammonium nitrate NO 3 - was taken up at a lower rate than NH 4 + from the same compound. Nitrate nitrogen was transported relatively more intensively to the above-ground parts of barley. The increasing concentration of nitrogen and exposure to nutrient solutions induced a rise in the proportion of ethanol-soluble forms of nitrogen, particularly in the roots. (author)

  8. Passive dosing of triclosan in multi-generation tests with copepods - Stable exposure concentrations and effects at the low µg l-1 range

    DEFF Research Database (Denmark)

    Ribbenstedt, Anton; Mustajärvi, Lukas; Breitholtz, Magnus

    2017-01-01

    to test the applicability of passive dosing to maintain stable concentrations of the organochlorine bacteriocide triclosan in the water phase during a 6-week multi-generation population development test with the harpacticoid copepod Nitocra spinipes. Triclosan was loaded into silicone (1000 mg), which...... was used as passive dosing phase in the exposure vials. The distribution ratio for triclosan between silicone and water (Dsilicone-water ) was 10466 ± 1927. A population development test was conducted at three concentration levels of triclosan that were measured to be 3-5 µg L(-1) , 7-11 µg L(-1) and 16...... exerted on juvenile development. Progressively lower development index values in the populations exposed to increasing triclosan concentrations suggest developmental retardation. Our results further stress the need for chronic exposure during ecotoxicity testing in chemical risk assessment as even...

  9. Low-cost manufacturing of the point focus concentrating module and its key component, the Fresnel lens. Final subcontract report, 31 January 1991--6 May 1991

    Energy Technology Data Exchange (ETDEWEB)

    Saifee, T.; Konnerth, A. III [Solar Kinetics, Inc., Dallas, TX (United States)

    1991-11-01

    Solar Kinetics, Inc. (SKI) has been developing point-focus concentrating PV modules since 1986. SKI is currently in position to manufacture between 200 to 600 kilowatts annually of the current design by a combination of manual and semi-automated methods. This report reviews the current status of module manufacture and specifies the required approach to achieve a high-volume manufacturing capability and low cost. The approach taken will include process development concurrent with module design for automated manufacturing. The current effort reviews the major manufacturing costs and identifies components and processes whose improvements would produce the greatest effect on manufacturability and cost reduction. The Fresnel lens is one such key component. Investigating specific alternative manufacturing methods and sources has substantially reduced the lens costs and has exceeded the DOE cost-reduction goals. 15 refs.

  10. Determination of the exposure parameters that maximise the concentrations of the anaesthetic/sedative eugenol in rainbow trout (Oncorhynchus mykiss) skin-on fillet tissue

    Science.gov (United States)

    Meinertz, Jeffery R.; Porcher, Scott T.; Smerud, Justin R.

    2014-01-01

    Studies were conducted to determine the anaesthetic/sedative concentrations and durations that would maximize anaesthetic/sedative residue concentrations in rainbow trout (Oncorhynchus mykiss) skin-on fillet tissue. Rainbow trout (167–404 g) were exposed to 50 mg l−1 AQUI-S® 20E (10% active ingredient, eugenol) in 17°C freshwater for durations up to 1440 min, 100 and 250 mg l−1 AQUI-S® 20E for durations up to 240 min, and 500 and 1000 mg l−1 AQUI-S® 20E for durations up to 90 min. Fish exposed to 100 mg l−1 AQUI-S® 20E for durations of 30, 60, 120 and 240 min had the greatest eugenol concentrations in the fillet tissue, 50, 58, 54 and 62 µg g−1, respectively. All other exposure concentrations and durations resulted in significantly lower eugenol concentrations, i.e. all −1.

  11. Determination of the exposure parameters that maximise the concentrations of the anaesthetic/sedative eugenol in rainbow trout (Oncorhynchus mykiss) skin-on fillet tissue.

    Science.gov (United States)

    Meinertz, J R; Porcher, S T; Smerud, J R; Gaikowski, M P

    2014-01-01

    Studies were conducted to determine the anaesthetic/sedative concentrations and durations that would maximise anaesthetic/sedative residue concentrations in rainbow trout (Oncorhynchus mykiss) skin-on fillet tissue. Rainbow trout (167-404 g) were exposed to 50 mg l(-1) AQUI-S(®) 20E (10% active ingredient, eugenol) in 17°C freshwater for durations up to 1440 min, 100 and 250 mg l(-1) AQUI-S(®) 20E for durations up to 240 min, and 500 and 1000 mg l(-1) AQUI-S(®) 20E for durations up to 90 min. Fish exposed to 100 mg l(-1) AQUI-S(®) 20E for durations of 30, 60, 120 and 240 min had the greatest eugenol concentrations in the fillet tissue, 50, 58, 54 and 62 µg g(-1), respectively. All other exposure concentrations and durations resulted in significantly lower eugenol concentrations, i.e. all < 39 µg g(-1).

  12. Reduction of metal exposure of Daubenton's bats (Myotis daubentonii) following remediation of pond sediment as evidenced by metal concentrations in hair.

    Science.gov (United States)

    Flache, Lucie; Ekschmitt, Klemens; Kierdorf, Uwe; Czarnecki, Sezin; Düring, Rolf-Alexander; Encarnação, Jorge A

    2016-03-15

    Transfer of contaminants from freshwater sediments via aquatic insects to terrestrial predators is well documented in spiders and birds. Here, we analyzed the metal exposure of Myotis daubentonii using an urban pond as their preferred foraging area before and after a remediation measure (sediment dredging) at this pond. Six metal elements (Zn, Cu, Cr, Cd, Pb and Ni) were measured in the sediment of the pond, in EDTA extracts of the sediment and in hair samples of M. daubentonii foraging at the pond. Samples were taken before remediation in 2011 and after remediation in 2013. Metal concentrations were quantified by ICP-OES after miniaturized microwave assisted extraction. In 2011, the pond sediment exhibited a high contamination with nickel, a moderate contamination with copper and chromium and low contents of zinc, cadmium and lead. While sediment metal contents declined only weakly after remediation, a much more pronounced reduction in the concentrations of zinc, copper, chromium and lead concentrations was observed in bat hair. Our results suggest a marked decline in metal exposure of the bats foraging at the pond as a consequence of the remediation measure. It is concluded that Daubenton's bats are suitable bioindicators of metal contamination in aquatic environments, integrating metal exposure via prey insects over their entire foraging area. We further suggest that bat hair is a useful monitoring unit, allowing a non-destructive and non-invasive assessment of metal exposure in bats. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Safety and Effectiveness of Bone Marrow Cell Concentrate in the Treatment of Chronic Critical Limb Ischemia Utilizing a Rapid Point-of-Care System

    Directory of Open Access Journals (Sweden)

    Venkatesh Ponemone

    2017-01-01

    Full Text Available Critical limb ischemia (CLI is the end stage of lower extremity peripheral vascular disease (PVD in which severe obstruction of blood flow results in ischemic rest pain, ulcers and/or gangrene, and a significant risk of limb loss. This open-label, single-arm feasibility study evaluated the safety and therapeutic effectiveness of autologous bone marrow cell (aBMC concentrate in revascularization of CLI patients utilizing a rapid point-of-care device. Seventeen (17 no-option CLI patients with ischemic rest pain were enrolled in the study. Single dose of aBMC, prepared utilizing an intraoperative point-of-care device, the Res-Q™ 60 BMC system, was injected intramuscularly into the afflicted limb and patients were followed up at regular intervals for 12 months. A statistically significant improvement in Ankle Brachial Index (ABI, Transcutaneous Oxygen Pressure (TcPO2, mean rest pain and intermittent claudication pain scores, wound/ ulcer healing, and 6-minute walking distance was observed following aBMC treatment. Major amputation-free survival (mAFS rate and amputation-free rates (AFR at 12 months were 70.6% and 82.3%, respectively. In conclusion, aBMC injections were well tolerated with improved tissue perfusion, confirming the safety, feasibility, and preliminary effectiveness of aBMC treatment in CLI patients.

  14. Chronic exposure to low concentration of arsenic is immunotoxic to fish: Role of head kidney macrophages as biomarkers of arsenic toxicity to Clarias batrachus

    International Nuclear Information System (INIS)

    Datta, Soma; Ghosh, Debabrata; Saha, Dhira Rani; Bhattacharaya, Shelley; Mazumder, Shibnath

    2009-01-01

    The present study was aimed at elucidating the effect of chronic low-level arsenic exposure on the head kidney (HK) of Clarias batrachus and at determining the changes in head kidney macrophage (HKM) activity in response to arsenic exposure. Chronic exposure (30 days) to arsenic (As 2 O 3 , 0.50 μM) led to significant increase in arsenic content in the HK accompanied by reduction in both HKM number and head kidney somatic index (HKSI). Arsenic induced HK hypertrophy, reduction in melano-macrophage population and increased hemosiderin accumulation. Transmission electron microscopy of 30 days exposed HKM revealed prominent endoplasmic reticulum, chromatin condensation and loss in structural integrity of nuclear membrane. Head kidney macrophages from exposed fish demonstrated significant levels of superoxide anions but on infection with Aeromonas hydrophila were unable to clear the intracellular bacteria and died. Exposure-challenge experiments with A. hydrophila revealed that chronic exposure to micromolar concentration of arsenic interfered with the phagocytic potential of HKM, helped in intracellular survival of the ingested bacteria inside the HKM inducing significant HKM cytotoxicity. The immunosuppressive effect of arsenic was further evident from the ability of A. hydrophila to colonize and disseminate efficiently in exposed fish. Enzyme linked immunosorbent assay indicated that chronic exposure to arsenic suppressed the production of pro-inflammatory 'IL-1β like' factors from HKM. It is concluded that arsenic even at very low concentration is immunotoxic to fish and the changes observed in HKM may provide a useful early biomarker of low-level xenobiotic exposure

  15. Chronic exposure to low concentration of arsenic is immunotoxic to fish: Role of head kidney macrophages as biomarkers of arsenic toxicity to Clarias batrachus

    Energy Technology Data Exchange (ETDEWEB)

    Datta, Soma; Ghosh, Debabrata [Immunobiology Laboratory, School of Life Sciences, Visva Bharati University, Santiniketan 731 235 (India); Saha, Dhira Rani [Microscopy Laboratory, National Institute of Cholera and Enteric Diseases, P-33, Scheme XM, C.I.T. Road, Beliaghata, Kolkata 700 010 (India); Bhattacharaya, Shelley [Environmental Toxicology Laboratory, School of Life Sciences, Visva Bharati University, Santiniketan 731 235 (India); Mazumder, Shibnath [Immunobiology Laboratory, School of Life Sciences, Visva Bharati University, Santiniketan 731 235 (India)], E-mail: shibnath1@yahoo.co.in

    2009-04-09

    The present study was aimed at elucidating the effect of chronic low-level arsenic exposure on the head kidney (HK) of Clarias batrachus and at determining the changes in head kidney macrophage (HKM) activity in response to arsenic exposure. Chronic exposure (30 days) to arsenic (As{sub 2}O{sub 3}, 0.50 {mu}M) led to significant increase in arsenic content in the HK accompanied by reduction in both HKM number and head kidney somatic index (HKSI). Arsenic induced HK hypertrophy, reduction in melano-macrophage population and increased hemosiderin accumulation. Transmission electron microscopy of 30 days exposed HKM revealed prominent endoplasmic reticulum, chromatin condensation and loss in structural integrity of nuclear membrane. Head kidney macrophages from exposed fish demonstrated significant levels of superoxide anions but on infection with Aeromonas hydrophila were unable to clear the intracellular bacteria and died. Exposure-challenge experiments with A. hydrophila revealed that chronic exposure to micromolar concentration of arsenic interfered with the phagocytic potential of HKM, helped in intracellular survival of the ingested bacteria inside the HKM inducing significant HKM cytotoxicity. The immunosuppressive effect of arsenic was further evident from the ability of A. hydrophila to colonize and disseminate efficiently in exposed fish. Enzyme linked immunosorbent assay indicated that chronic exposure to arsenic suppressed the production of pro-inflammatory 'IL-1{beta} like' factors from HKM. It is concluded that arsenic even at very low concentration is immunotoxic to fish and the changes observed in HKM may provide a useful early biomarker of low-level xenobiotic exposure.

  16. Olive Oil Supplements Ameliorate Endothelial Dysfunction Caused by Concentrated Ambient Particulate Matter Exposure in Healthy Human Volunteers

    Science.gov (United States)

    Context: Exposure to ambient particulate matter (PM) induces endothelial dysfunction, a risk factor for clinical cardiovascular events and progression of atherosclerosis. Dietary supplements such as olive oil and fish oil have beneficial effects on endothelial function, and ther...

  17. Environmentally safe separation and pre-concentration of rhodium and ruthenium from spent nuclear fuel using mixed-micelle cloud point extraction and determination by ICP-MS

    International Nuclear Information System (INIS)

    Ranjit, M.; Meeravali, N.N.; Kumar, S.J.

    2010-01-01

    Full text: Recently, spend nuclear fuel waste of thermal and fast reactors are emerging as an alternative valuable resource for Rh, Ru and Pd. In addition, its presence causes the difficulty in the vitrification process. Hence, its safe extraction from these wastes has to be carried out by using the environmental friendly extraction procedure. In this study, we have reported the simple mixed-micelle cloud point extraction (MM-CPE) procedure for separation as well as pre-concentration of Rh, Ru and Pd. This MM-CPE is carried out preliminarily from aqueous chloride medium with Aliquat-336/Triton X-114 mixed-micelles in the absence and presence of tin(II) chloride. In presence of chloride medium alone, only Pd get extracted quantitatively, while extraction of Rh and Ru are negligible. In presence of tin chloride, the extraction of Rh and Ru increases and becomes quantitative, without affecting the extraction of Pd. The MM-CPE conditions are optimized under influence of variables such as HCI, Aliquat-336, Triton X-114 and tin chloride concentrations and incubation time and temperature. Under the optimized conditions, the accuracy of the procedure is verified by using recovery study carried out from real water samples. This work is under progress to apply real nuclear fuel waste samples

  18. Lack of the correlation between biochemical effects on rats and blood carboxyhemoglobin concentrations in various conditions of single acute exposure to carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Sokal, J.A.

    1975-01-01

    The relationship between conditions of exposure to carbon monoxide (CO) and biochemical effects was investigated in experiments on rats. The magnitude and the time of biochemical disturbances in the tissues resulting from two different exposures consisting of 1 vol. percent CO for 4 min and 0.4 vol. percent CO for 40 min respectively were compared. In both cases, at the end of exposure the same level of blood carboxyhemoglobin (COHb) (about 50 percent) was reached. The biochemical determinations in the blood (pH, glucose, lactate, pyruvate) and brain tissue (lactate, pyruvate) were carried out immediately after termination of the exposure and after the time periods of restitution. CO exposure resulted in a decreased blood pH, increased level of blood glucose, as well as that of lactate and pyruvate both in blood and brain tissue. These changes were much more pronounced following the longer-lesser exposure than after the shorter-intense one, although blood concentrations of COHb was the same. The observed phenomenon puts some light on the frequently encountered lack of the correlation between COHb level in blood and severity of CO intoxication in clinical practice.

  19. Repetitive Daily Point of Choice Prompts and Occupational Sit-Stand Transfers, Concentration and Neuromuscular Performance in Office Workers: An RCT

    Directory of Open Access Journals (Sweden)

    Lars Donath

    2015-04-01

    Full Text Available Objective: Prolonged office sitting time adversely affects neuromuscular and cardiovascular health parameters. As a consequence, the present study investigated the effects of prompting the use of height-adjustable working desk (HAWD on occupational sitting and standing time, neuromuscular outcomes and concentration in office workers. Methods: A single-blinded randomized controlled trial (RCT with parallel group design was conducted. Thirty-eight office workers were supplied with HAWDs and randomly assigned (Strata: physical activity (PA, BMI, gender, workload to a prompt (INT or non-prompt (CON group. INT received three daily screen-based prompts within 12 weeks. CON was only instructed once concerning the benefits of using HAWDs prior to the start of the study. Sitting and standing times were objectively assessed as primary outcomes for one entire working week using the ActiGraph wGT3X-BT at baseline (pre, after 6 (mid and 12 weeks (post. Concentration (d2-test, postural sway during upright stance (under single, dual and triple task and lower limb strength endurance (heel-rise were collected as secondary outcomes. Results: With large but not statistically significant within group effects from pre to post, INT increased weekly standing time at work by 9% (p = 0.22, d = 0.8 representing an increase from 7.2 h (4.8 to 9.7 (6.6 h (p = 0.07. Concentration and neuromuscular performance did not change from pre to post testing (0.23 < p < 0.95; 0.001 < ηp² < 0.05. Conclusion: Low-frequent and low cost screen-based point of choice prompts (3 per day within 12 weeks already result in notable increases of occupational standing time of approx. daily 30 min. These stimuli, however, did not relevantly affect neuromuscular outcomes.

  20. Factors influencing the outdoor concentration of carbonaceous aerosols at urban schools in Brisbane, Australia: Implications for children's exposure

    International Nuclear Information System (INIS)

    Crilley, L.R.; Ayoko, G.A.; Mazaheri, M.; Morawska, L.

    2016-01-01

    This comprehensive study aimed to determine the sources and driving factors of organic carbon (OC) and elemental carbon (EC) concentrations in ambient PM 2.5 in urban schools. Sampling was conducted outdoors at 25 schools in the Brisbane Metropolitan Area, Australia. Concentrations of primary and secondary OC were quantified using the EC tracer method, with secondary OC accounting for an average of 60%. Principal component analysis distinguished the contributing sources above the background and identified groups of schools with differing levels of primary and secondary carbonaceous aerosols. Overall, the results showed that vehicle emissions, local weather conditions and secondary organic aerosols (SOA) were the key factors influencing concentrations of carbonaceous component of PM 2.5 at these schools. These results provide insights into children's exposure to vehicle emissions and SOA at such urban schools. - Highlights: • We aimed to find the contributing sources to children's exposure at school. • Measured outdoor organic carbon and elemental carbon at 25 urban schools. • Schools varied in exposure to primary and secondary sources. • Secondary organic carbon the largest component of carbonaceous aerosols. • Vehicle emission levels at schools are primarily dependent on local traffic counts. - Key factors influencing concentrations of carbonaceous component of PM 2.5 at urban schools were found to be vehicle emissions, secondary organic aerosols and local weather conditions.

  1. The postantifungal effect and phospholipase production of oral Candida albicans from smokers, diabetics, asthmatics, denture wearers and healthy individuals following brief exposure to subtherapeutic concentrations of chlorhexidine gluconate.

    Science.gov (United States)

    Ellepola, Arjuna N B; Joseph, Bobby K; Khan, Z U

    2014-09-01

    Candida albicans is the major aetiological agent of oral candidosis and one of its important virulent factors is the production of extracellular phospholipases, which can be modulated by subtherapeutic concentrations of antifungal agents thus decreasing their pathogenicity. Hence, considering that chlorhexidine gluconate (CG) is a common antimicrobial mouthwash used in dentistry and that its concentration in the mouth reaches subtherapeutic levels during dosage intervals due to the diluent effect of saliva and cleansing effect of the oral musculature, the postantifungal effect (PAFE) and the phospholipase production of oral C. albicans following brief exposure to subtherapeutic concentrations of CG was studied. Fifty C. albicans planktonic oral isolates obtained from smokers, diabetics, asthmatics using steroid inhalers, partial denture wearers and healthy individuals were exposed to three subtherapeutic concentrations of CG (0.005%, 0.0025% and 0.00125%) for 1 h. Isolates unexposed to CG was the control group. Thereafter the antiseptic was removed and the PAFE and phospholipase production was determined by a turbidometric method and a plate assay using an egg yolk agar medium respectively. Mean PAFE (hours) of 50 oral isolates of C. albicans following 1-h exposure to 0.005%, 0.0025% and 0.00125% CG was 6.97, 1.85 and 0.62 respectively. The phospholipase production of these isolates was significantly suppressed with a percentage reduction of 21.68, 18.20 and 14.04% following exposure to 0.005%, 0.0025% and 0.00125% CG respectively. Brief exposure of C. albicans isolates to subtherapeutic concentrations of CG would wield an antifungal effect by suppressing growth and phospholipase production, thereby quelling its pathogenicity. © 2014 Blackwell Verlag GmbH.

  2. Concentrations of delta9-tetrahydrocannabinol and 11-nor-9-carboxytetrahydrocannabinol in blood and urine after passive exposure to Cannabis smoke in a coffee shop.

    Science.gov (United States)

    Röhrich, J; Schimmel, I; Zörntlein, S; Becker, J; Drobnik, S; Kaufmann, T; Kuntz, V; Urban, R

    2010-05-01

    Cannabinoid concentrations in blood and urine after passive exposure to cannabis smoke under real-life conditions were investigated in this study. Eight healthy volunteers were exposed to cannabis smoke for 3 h in a well-attended coffee shop in Maastricht, Netherlands. An initial blood and urine sample was taken from each volunteer before exposure. Blood samples were taken 1.5, 3.5, 6, and 14 h after start of initial exposure, and urine samples were taken after 3.5, 6, 14, 36, 60, and 84 h. The samples were subjected to immunoassay screening for cannabinoids and analyzed using gas chromatography-mass spectrometry (GC-MS) for Delta(9)-tetrahydrocannabinol (THC), 11-nor-hydroxy-Delta(9)-tetrahydrocannabinol (THC-OH), and 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (THC-COOH). It could be demonstrated that all volunteers absorbed THC. However, the detected concentrations were rather small. None of the urine samples produced immunoassay results above the cutoff concentration of 25 ng/mL. THC-COOH concentrations up to 5.0 and 7.8 ng/mL before and after hydrolysis, respectively, were found in the quantitative GC-MS analysis of urine. THC could be detected in trace amounts close to the detection limit of the used method in the first two blood samples after initial exposure (1.5 and 3.5 h). In the 6 h blood samples, THC was not detectable anymore. THC-COOH could be detected after 1.5 h and was still found in 3 out of 8 blood samples after 14 h in concentrations between 0.5 and 1.0 ng/mL.

  3. Neighbourhood exposure to point-of-sale price promotions for cigarettes is associated with financial stress among smokers: results from a population-based study.

    Science.gov (United States)

    Siahpush, Mohammad; Tibbits, Melissa; Soliman, Ghada A; Grimm, Brandon; Shaikh, Raees A; McCarthy, Molly; Wan, Neng; Ramos, Athena K; Correa, Antonia

    2017-11-01

    To examine the association between neighbourhood exposure to point-of-sale (POS) cigarette price promotions and financial stress among smokers in a Midwestern metropolitan area in the USA. Survey data from 888 smokers provided information on sociodemographic and smoking related variables. Financial stress was measured with the question: 'In the last six months, because of lack of money, was there a time when you were unable to buy food or pay any important bills on time, such as electricity, telephone, credit card, rent or your mortgage? (Yes/No).' Using audit data from 504 tobacco retailers, we estimated a score of POS price promotions for each respondent by summing the different types of promotion in each store in their neighbourhood, as defined by a 1-km roadway buffer. Adjusted results provided strong support for an association between higher scores of neighbourhood POS cigarette price promotions and a higher probability of financial stress (p=0.007). Exposure to POS cigarette price promotions is associated with financial stress. This finding, coupled with previous reports that smokers with financial stress are less likely to attempt to quit or succeed in quitting smoking, suggests that POS cigarette price promotions may act as an impediment to smoking cessation. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  4. Field evaluation of a new point-of-use faucet filter for preventing exposure to Legionella and other waterborne pathogens in health care facilities.

    Science.gov (United States)

    Baron, Julianne L; Peters, Tammy; Shafer, Raymond; MacMurray, Brian; Stout, Janet E

    2014-11-01

    Opportunistic waterborne pathogens (eg, Legionella, Pseudomonas) may persist in water distribution systems despite municipal chlorination and secondary disinfection and can cause health care-acquired infections. Point-of-use (POU) filtration can limit exposure to pathogens; however, their short maximum lifetime and membrane clogging have limited their use. A new faucet filter rated at 62 days was evaluated at a cancer center in Northwestern Pennsylvania. Five sinks were equipped with filters, and 5 sinks served as controls. Hot water was collected weekly for 17 weeks and cultured for Legionella, Pseudomonas, and total bacteria. Legionella was removed from all filtered samples for 12 weeks. One colony was recovered from 1 site at 13 weeks; however, subsequent tests were negative through 17 weeks of testing. Total bacteria were excluded for the first 2 weeks, followed by an average of 1.86 log reduction in total bacteria compared with controls. No Pseudomonas was recovered from filtered or control faucets. This next generation faucet filter eliminated Legionella beyond the 62 day manufacturers' recommended maximum duration of use. These new POU filters will require fewer change-outs than standard filters and could be a cost-effective method for preventing exposure to Legionella and other opportunistic waterborne pathogens in hospitals with high-risk patients. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  5. The effects of acute waterborne exposure to sublethal concentrations of molybdenum on the stress response in rainbow trout, Oncorhynchus mykiss.

    Directory of Open Access Journals (Sweden)

    Chelsea D Ricketts

    Full Text Available To determine if molybdenum (Mo is a chemical stressor, fingerling and juvenile rainbow trout (Oncorhynchus mykiss were exposed to waterborne sodium molybdate (0, 2, 20, or 1,000 mg l-1 of Mo and components of the physiological (plasma cortisol, blood glucose, and hematocrit and cellular (heat shock protein [hsp] 72, hsp73, and hsp90 in the liver, gills, heart, and erythrocytes and metallothionein [MT] in the liver and gills stress responses were measured prior to initiation of exposure and at 8, 24, and 96 h. During the acute exposure, plasma cortisol, blood glucose, and hematocrit levels remained unchanged in all treatments. Heat shock protein 72 was not induced as a result of exposure and there were no detectable changes in total hsp70 (72 and 73, hsp90, and MT levels in any of the tissues relative to controls. Both fingerling and juvenile fish responded with similar lack of apparent sensitivity to Mo exposure. These experiments demonstrate that exposure to waterborne Mo of up to 1,000 mg l(-1 did not activate a physiological or cellular stress response in fish. Information from this study suggests that Mo water quality guidelines for the protection of aquatic life are highly protective of freshwater fish, namely rainbow trout.

  6. The Effects of Acute Waterborne Exposure to Sublethal Concentrations of Molybdenum on the Stress Response in Rainbow Trout, Oncorhynchus mykiss

    Science.gov (United States)

    Ricketts, Chelsea D.; Bates, William R.; Reid, Scott D.

    2015-01-01

    To determine if molybdenum (Mo) is a chemical stressor, fingerling and juvenile rainbow trout (Oncorhynchus mykiss) were exposed to waterborne sodium molybdate (0, 2, 20, or 1,000 mg l-1 of Mo) and components of the physiological (plasma cortisol, blood glucose, and hematocrit) and cellular (heat shock protein [hsp] 72, hsp73, and hsp90 in the liver, gills, heart, and erythrocytes and metallothionein [MT] in the liver and gills) stress responses were measured prior to initiation of exposure and at 8, 24, and 96 h. During the acute exposure, plasma cortisol, blood glucose, and hematocrit levels remained unchanged in all treatments. Heat shock protein 72 was not induced as a result of exposure and there were no detectable changes in total hsp70 (72 and 73), hsp90, and MT levels in any of the tissues relative to controls. Both fingerling and juvenile fish responded with similar lack of apparent sensitivity to Mo exposure. These experiments demonstrate that exposure to waterborne Mo of up to 1,000 mg l-1 did not activate a physiological or cellular stress response in fish. Information from this study suggests that Mo water quality guidelines for the protection of aquatic life are highly protective of freshwater fish, namely rainbow trout. PMID:25629693

  7. Effects of vitamin D3 supplementation and UVb exposure on the growth and plasma concentration of vitamin D3 metabolites in juvenile bearded dragons (Pogona vitticeps).

    Science.gov (United States)

    Oonincx, D G A B; Stevens, Y; van den Borne, J J G C; van Leeuwen, J P T M; Hendriks, W H

    2010-06-01

    The effectiveness of dietary vitamin D3 and UVb exposure on plasma vitamin D metabolites in growing bearded dragons (Pogona vitticeps) was studied. A total of 84 (40 males and 44 females) newly hatched bearded dragons were allocated to six levels of oral vitamin D3 supplementation (0 to 400%) or six UVb exposure times (2 to 12 h). At 3 and 6 months of age, blood samples were obtained from each animal and analysed for 25(OH)D3 and 1,25(OH)2D3. At 3 months of age, plasma concentrations of 25(OH)D3 did not increase with increasing vitamin D3 supplementation unlike the 1,25(OH)2D3. At 6 months of age, plasma concentrations of both 25(OH)D(3) and 1,25(OH)2D3 increased with increasing vitamin D(3) supplementation. Plasma concentrations in UVb-exposed animals were 18 times higher for 25(OH)D3 (178.4+/-9.0 vs. 9.9+/-1.3 nmol/L) and 5.3 times higher for 1,25(OH)2D3 (1.205+/-0.100 vs. 0.229+/-0.025 nmol/L) than in vitamin D(3) supplemented animals at 6 months of age. This study shows that 2h of UVb exposure enables adequate physiological concentrations of plasma vitamin D metabolites to be maintained in growing bearded dragons. Oral supplementation of vitamin D(3) is ineffective in raising plasma concentrations of 25(OH)D3 and 1,25(OH)2D3 to concentrations observed in UVb-exposed animals. 2010 Elsevier Inc. All rights reserved.

  8. Reduction of metal exposure of Daubenton's bats (Myotis daubentonii) following remediation of pond sediment as evidenced by metal concentrations in hair

    Energy Technology Data Exchange (ETDEWEB)

    Flache, Lucie, E-mail: Lucie.Flache@bio.uni-giessen.de [Mammalian Ecology Group, Department of Animal Ecology and Systematics, Justus Liebig University of Giessen, Heinrich-Buff-Ring 26, D-35392 Giessen (Germany); Ekschmitt, Klemens [Animal Ecology, Department of Animal Ecology and Systematics, Justus Liebig University of Giessen, Heinrich-Buff-Ring 26, D-35392 Giessen (Germany); Kierdorf, Uwe [Department of Biology, University of Hildesheim, Universitätsplatz 1, D-31141 Hildesheim (Germany); Czarnecki, Sezin; Düring, Rolf-Alexander [Institute of Soil Science and Soil Conservation, Justus Liebig University of Giessen, Heinrich-Buff-Ring 26, D-35392 Giessen (Germany); Encarnação, Jorge A. [Mammalian Ecology Group, Department of Animal Ecology and Systematics, Justus Liebig University of Giessen, Heinrich-Buff-Ring 26, D-35392 Giessen (Germany)

    2016-03-15

    Transfer of contaminants from freshwater sediments via aquatic insects to terrestrial predators is well documented in spiders and birds. Here, we analyzed the metal exposure of Myotis daubentonii using an urban pond as their preferred foraging area before and after a remediation measure (sediment dredging) at this pond. Six metal elements (Zn, Cu, Cr, Cd, Pb and Ni) were measured in the sediment of the pond, in EDTA extracts of the sediment and in hair samples of M. daubentonii foraging at the pond. Samples were taken before remediation in 2011 and after remediation in 2013. Metal concentrations were quantified by ICP-OES after miniaturized microwave assisted extraction. In 2011, the pond sediment exhibited a high contamination with nickel, a moderate contamination with copper and chromium and low contents of zinc, cadmium and lead. While sediment metal contents declined only weakly after remediation, a much more pronounced reduction in the concentrations of zinc, copper, chromium and lead concentrations was observed in bat hair. Our results suggest a marked decline in metal exposure of the bats foraging at the pond as a consequence of the remediation measure. It is concluded that Daubenton's bats are suitable bioindicators of metal contamination in aquatic environments, integrating metal exposure via prey insects over their entire foraging area. We further suggest that bat hair is a useful monitoring unit, allowing a non-destructive and non-invasive assessment of metal exposure in bats. - Highlights: • Changes in metal exposure of bats due to remediation measure are documented. • Bats are suitable bioindicators of metal pollution. • Bat hair is a useful monitoring unit in such studies.

  9. Reduction of metal exposure of Daubenton's bats (Myotis daubentonii) following remediation of pond sediment as evidenced by metal concentrations in hair

    International Nuclear Information System (INIS)

    Flache, Lucie; Ekschmitt, Klemens; Kierdorf, Uwe; Czarnecki, Sezin; Düring, Rolf-Alexander; Encarnação, Jorge A.

    2016-01-01

    Transfer of contaminants from freshwater sediments via aquatic insects to terrestrial predators is well documented in spiders and birds. Here, we analyzed the metal exposure of Myotis daubentonii using an urban pond as their preferred foraging area before and after a remediation measure (sediment dredging) at this pond. Six metal elements (Zn, Cu, Cr, Cd, Pb and Ni) were measured in the sediment of the pond, in EDTA extracts of the sediment and in hair samples of M. daubentonii foraging at the pond. Samples were taken before remediation in 2011 and after remediation in 2013. Metal concentrations were quantified by ICP-OES after miniaturized microwave assisted extraction. In 2011, the pond sediment exhibited a high contamination with nickel, a moderate contamination with copper and chromium and low contents of zinc, cadmium and lead. While sediment metal contents declined only weakly after remediation, a much more pronounced reduction in the concentrations of zinc, copper, chromium and lead concentrations was observed in bat hair. Our results suggest a marked decline in metal exposure of the bats foraging at the pond as a consequence of the remediation measure. It is concluded that Daubenton's bats are suitable bioindicators of metal contamination in aquatic environments, integrating metal exposure via prey insects over their entire foraging area. We further suggest that bat hair is a useful monitoring unit, allowing a non-destructive and non-invasive assessment of metal exposure in bats. - Highlights: • Changes in metal exposure of bats due to remediation measure are documented. • Bats are suitable bioindicators of metal pollution. • Bat hair is a useful monitoring unit in such studies.

  10. Measurement of the radioactive concentration in consumer's goods containing natural uranium and thorium and evaluation of the exposure by their utilization

    International Nuclear Information System (INIS)

    Yoshida, Masahiro; Satou, Shigerou; Ohhata, Tsutomu; Watanabe, Masatoshi; Ohyama, Ryutaro; Furuya, Hirotaka; Endou, Akira

    2005-01-01

    A number of consumer's goods which contain natural uranium and thorium are circulated in the familiar living environment. Based on various kinds of information sources, 20 kinds of these consumer's goods were collected and their radioactive concentrations were measured by using ICP-MS and Ge semiconductor detector. As this result, it was found that the concentrations of uranium and thorium in the consumer's goods used at home and industries were below 34 Bq/g and below 270 Bq/g, respectively. Next, the concentrations of daughter nuclides were not so different from the ones of uranium or thorium, which showed that the secular radioactive equilibrium held between both concentrations. In addition, the radiation exposures for public consumer were evaluated when four kinds of typical consumer's goods frequently used in daily life are utilized. The results computed by MCNP-4C code were below 250 μSv/y. (author)

  11. Human exposure to brominated flame retardants through dust in different indoor environments: Identifying the sources of concentration differences in hair from men and women.

    Science.gov (United States)

    Li, Junqi; Dong, Zheng; Wang, Ying; Bao, Junsong; Yan, Yijun; Liu, Anming; Jin, Jun

    2018-08-01

    Brominated flame retardants (BFRs) can accumulate in humans and are associated with adverse health effects. The study was conducted to determine the differences in Polybrominated diphenyl ethers (PBDEs) and alternative brominated flame retardant (Alt-BFR) concentrations between men and women. We analyzed hair samples from 14 male and 20 female university students, paired dust samples from their dormitories (10 for males and 8 for females), and six dust samples from university teaching buildings. The total PBDE concentrations in hair from females were significantly (three times) higher (p = 0.012) than that from males (means 372 and 109 ng/g, respectively). The mean total PBDE concentrations in classroom and dormitory dust were 36100 and 2012 ng/g, respectively. The PBDE patterns were different in the male and female hair samples, as were the patterns in the classroom and dormitory dust. There are no reports concerning human exposure to BFRs through dust that was assessed considering academic and residential environments simultaneously. The differences between BFR exposure for males and females and the differences between BFR concentrations in hair samples from males and females were consistent for 71.4% of the compounds. However, using only dormitory dust in the calculations gave consistent differences only for 28.6% of the compounds, suggesting that the BFR concentration differences in hair were mainly because females spent much more time than males in classrooms. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Secondhand smoke exposure within semi-open air cafes and tobacco specific 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) concentrations among nonsmoking employees.

    Science.gov (United States)

    Vardavas, Constantine I; Karabela, Maria; Agaku, Israel T; Matsunaga, Yuko; Myridakis, Antonis; Kouvarakis, Antonis; Stephanou, Euripides G; Lymperi, Maria; Behrakis, Panagiotis K

    2014-10-01

    Secondhand smoke (SHS) is a defined occupational hazard. The association though between SHS exposure in semi-open air venues and tobacco specific carcinogen uptake is an area of debate. A cross sectional survey of 49 semi-open air cafes in Athens, Greece was performed during the summer of 2008, prior to the adoption of the national smoke free legislation. All venues had at least 1 entire wall open to allow for free air exchange. Indoor concentrations of particulate matter smaller than 2.5 microns (PM2.5) attributable to SHS were assessed during a work shift, while 1 non-smoking employee responsible for indoor and outdoor table service from each venue provided a post work shift urine sample for analysis of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL). Post work shift NNAL concentrations were correlated with work shift PM2.5 concentrations attributable to SHS (r = 0.376, p = 0.0076). Urinary NNAL concentrations among employees increased by 9.5%, per 10 μg/m(3) increase in PM2.5 concentrations attributable to SHS after controlling for the time of day and day of week. These results indicate that the commonly proposed practice of maintaining open sliding walls as a means of free air exchange does not lead to the elimination of employee exposure to tobacco specific carcinogens attributable to workplace SHS.

  13. Prenatal cigarette smoke exposure: Pregnancy outcome and gestational changes in plasma nicotine concentration, hematocrit, and carboxyhemoglobin in a newly standardized rat model

    International Nuclear Information System (INIS)

    Farkas, Svetlana; Hussein, Jabeen; Ariano, Robert E.; Sitar, Daniel S.; Hasan, Shabih U.

    2006-01-01

    Epidemiological studies support an association between perinatal cigarette smoke (CS) exposure and a number of severe pre- and postnatal complications. However, the mechanisms through which CS enhances such risks largely remain unknown. One of the reasons for our inability to discover such mechanisms has been the unavailability of a clinically relevant and physiologically concordant animal model. A number of studies have previously used nicotine (Nic) as surrogate for CS. We sought to (1) establish the amount of CS exposure to achieve plasma Nic concentrations observed among moderate to heavy smokers (20-60 ng/ml) (2) investigate the temporal changes in plasma Nic concentrations, carboxyhemoglobin, and hematocrit with advancing pregnancy, and (3) elucidate the effects of CS exposure on pregnancy outcome. Pregnant Sprague-Dawley rats were exposed to various doses of CS or room air (Sham) from days 6 to 21 of gestation. Exposure to 6000 ml/day of CS led to very high plasma Nic concentrations and increased maternal and fetal mortality (P < 0.001). The plasma Nic concentrations remained higher than those observed in moderate smokers until the CS dose was reduced to 1000 ml/day and showed dose-dependent temporal changes with advancing gestational age. Significant increases in carboxyhemoglobin and hematocrit were observed in the CS group as compared with the Sham group (P < 0.001). In addition, prenatally CS exposed fetuses had lower birth weight as compared with the Sham group (P = 0.04). Our current study establishes a newly standardized and physiologically relevant model to investigate the mechanisms of CS-mediated adverse effects during the critical period of fetal development

  14. Increased albumin excretion in industrial workers due to shift work rather than to prolonged exposure to low concentrations of chlorinated hydrocarbons.

    OpenAIRE

    Boogaard, P J; Caubo, M E

    1994-01-01

    OBJECTIVES--It has been reported that groups of workers in petrochemical industries who have been exposed to low concentrations of chemicals for prolonged periods have an increased urinary albumin excretion compared with unexposed controls. This increase, however, seemed to be unrelated to the extent, duration, and type of exposure. The aim of the present study was to investigate the suggestion that the small increase in albumin excretion might be due to differences in physical workload betwe...

  15. Antioxidant Activity and Thermal Stability of Oleuropein and Related Phenolic Compounds of Olive Leaf Extract after Separation and Concentration by Salting-Out-Assisted Cloud Point Extraction

    Directory of Open Access Journals (Sweden)

    Konstantinos Stamatopoulos

    2014-04-01

    Full Text Available A fast, clean, energy-saving, non-toxic method for the stabilization of the antioxidant activity and the improvement of the thermal stability of oleuropein and related phenolic compounds separated from olive leaf extract via salting-out-assisted cloud point extraction (CPE was developed using Tween 80. The process was based on the decrease of the solubility of polyphenols and the lowering of the cloud point temperature of Tween 80 due to the presence of elevated amounts of sulfates (salting-out and the separation from the bulk solution with centrifugation. The optimum conditions were chosen based on polyphenols recovery (%, phase volume ratio (Vs/Vw and concentration factor (Fc. The maximum recovery of polyphenols was in total 95.9%; Vs/Vw was 0.075 and Fc was 15 at the following conditions: pH 2.6, ambient temperature (25 °C, 4% Tween 80 (w/v, 35% Na2SO4 (w/v and a settling time of 5 min. The total recovery of oleuropein, hydroxytyrosol, luteolin-7-O-glucoside, verbascoside and apigenin-7-O-glucoside, at optimum conditions, was 99.8%, 93.0%, 87.6%, 99.3% and 100.0%, respectively. Polyphenolic compounds entrapped in the surfactant-rich phase (Vs showed higher thermal stability (activation energy (Ea 23.8 kJ/mol compared to non-entrapped ones (Ea 76.5 kJ/mol. The antioxidant activity of separated polyphenols remained unaffected as determined by the 1,1-diphenyl-2-picrylhydrazyl method.

  16. Impact of Indocyanine Green Concentration, Exposure Time, and Degree of Dissolution in Creating Toxic Anterior Segment Syndrome: Evaluation in a Rabbit Model

    Directory of Open Access Journals (Sweden)

    Tamer Tandogan

    2016-01-01

    Full Text Available Purpose. To investigate the role of indocyanine green (ICG dye as a causative material of toxic anterior segment syndrome (TASS in an experimental rabbit model. Method. Eight eyes of four rabbits were allocated to this study. Capsular staining was performed using ICG dye, after which the anterior chamber was irrigated with a balanced salt solution. The effects of different concentrations (control, 0.25, 0.5, and 1.0%, exposure times (10 and 60 seconds, and the degree of dissolution (differently vortexed were investigated. The analysis involved anterior segment photography, ultrasound pachymetry, prostaglandin assay (PGE2 Parameter Assay, R&D systems, Inc., and scanning electron microscopy of each iris. Result. There was no reaction in the control eye. A higher aqueous level of PGE2 and more severe inflammatory reaction were observed in cases of eyes with higher concentration, longer exposure time, and poorly dissolved dye. Additionally, scanning electron microscopy revealed larger and coarser ICG particles. Conclusion. TASS occurrence may be associated with the concentration, exposure time, and degree of dissolution of ICG dye during cataract surgery.

  17. A Study on Pharmacokinetics of Bosentan with Systems Modeling, Part 1: Translating Systemic Plasma Concentration to Liver Exposure in Healthy Subjects.

    Science.gov (United States)

    Li, Rui; Niosi, Mark; Johnson, Nathaniel; Tess, David A; Kimoto, Emi; Lin, Jian; Yang, Xin; Riccardi, Keith A; Ryu, Sangwoo; El-Kattan, Ayman F; Maurer, Tristan S; Tremaine, Larry M; Di, Li

    2018-04-01

    Understanding liver exposure of hepatic transporter substrates in clinical studies is often critical, as it typically governs pharmacodynamics, drug-drug interactions, and toxicity for certain drugs. However, this is a challenging task since there is currently no easy method to directly measure drug concentration in the human liver. Using bosentan as an example, we demonstrate a new approach to estimate liver exposure based on observed systemic pharmacokinetics from clinical studies using physiologically based pharmacokinetic modeling. The prediction was verified to be both accurate and precise using sensitivity analysis. For bosentan, the predicted pseudo steady-state unbound liver-to-unbound systemic plasma concentration ratio was 34.9 (95% confidence interval: 4.2, 50). Drug-drug interaction (i.e., CYP3A and CYP2B6 induction) and inhibition of hepatic transporters (i.e., bile salt export pump, multidrug resistance-associated proteins, and sodium-taurocholate cotransporting polypeptide) were predicted based on the estimated unbound liver tissue or plasma concentrations. With further validation and refinement, we conclude that this approach may serve to predict human liver exposure and complement other methods involving tissue biopsy and imaging. Copyright © 2018 by The American Society for Pharmacology and Experimental Therapeutics.

  18. A simple method for point-of-need extraction, concentration and rapid multi-mycotoxin immunodetection in feeds using aqueous two-phase systems.

    Science.gov (United States)

    Soares, Ruben R G; Azevedo, Ana M; Fernandes, Pedro; Chu, Virginia; Conde, João P; Aires-Barros, M Raquel

    2017-08-18

    The rapid detection of mycotoxins in feed samples is becoming an increasingly relevant challenge for the food production sector, in order to effectively enforce current regulations and assure food and feed safety. To achieve rapid mycotoxin detection, several biosensing strategies have been published, many reaching assay times of the order of a few minutes. However, the vast majority of these rely on sample preparation based on volatile organic solvents, often comprising complex multi-step procedures and devoid of clean-up and/or concentration effects. Here, a novel sample preparation methodology based on a green, non-toxic and inexpensive polyethylene glycol-sodium citrate aqueous two-phase system is reported, providing single-step extraction and concentration of three target mycotoxins within 20min: aflatoxin B1 (AFB1), ochratoxin A (OTA) and deoxynivalenol (DON). With point-of-need applications in mind, the extraction procedure was optimized and validated using a rapid multi-toxin microfluidic competitive immunoassay. The assay was successfully tested with spiked complex solid matrices including corn, soy, chickpea and sunflower-based feeds and limits of detection of 4.6ngg -1 ±15.8%, 24.1ngg -1 ±8.1% and 129.7ngg -1 ±53.1% (±CV) were obtained in corn for AFB1, OTA and DON, respectively. These sensitivities are fit-for-purpose at the required regulatory and recommended limits for animal feed, providing an effective and safe semi-quantitative mycotoxin analysis that can be performed in the field. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Simultaneous determination of antimony and boron in beverage and dairy products by flame atomic absorption spectrometry after separation and pre-concentration by cloud-point extraction.

    Science.gov (United States)

    Altunay, Nail; Gürkan, Ramazan

    2016-01-01

    A new cloud-point extraction (CPE) method was developed for the pre-concentration and simultaneous determination of Sb(III) and B(III) by flame atomic absorption spectrometry (FAAS). The method was based on complexation of Sb(III) and B(III) with azomethine-H in the presence of cetylpyridinium chloride (CPC) as a signal-enhancing agent, and then extraction into the micellar phase of Triton X-114. Under optimised conditions, linear calibration was obtained for Sb(III) and B(III) in the concentration ranges of 0.5-180 and 2.5-600 μg l(-1) with LODs of 0.15 and 0.75 μg l(-1), respectively. Relative standard deviations (RSDs) (25 and 100 μg l(-1) of Sb(III) and B(III), n = 6) were in a range of 2.1-3.8% and 1.9-2.3%, respectively. Recoveries of spiked samples of Sb(III) and B(III) were in the range of 98-103% and 99-102%, respectively. Measured values for Sb and B in three standard reference materials were within the 95% confidence limit of the certified values. Also, the method was used for the speciation of inorganic antimony. Sb(III), Sb(V) and total Sb were measured in the presence of excess boron before and after pre-reduction with an acidic mixture of KI-ascorbic acid. The method was successfully applied to the simultaneous determination of total Sb and B in selected beverage and dairy products.

  20. Effects of simultaneous ozone exposure and nitrogen loads on carbohydrate concentrations, biomass, and growth of young spruce trees (Picea abies)

    International Nuclear Information System (INIS)

    Thomas, V.F.D.; Braun, S.; Flueckiger, W.

    2005-01-01

    Spruce saplings were grown under different nitrogen fertilization regimes in eight chamberless fumigation systems, which were fumigated with either charcoal-filtered (F) or ambient air (O 3 ). After the third growing season trees were harvested for biomass and non-structural carbohydrate analysis. Nitrogen had an overall positive effect on the investigated plant parameters, resulting in increased shoot elongation, biomass production, fine root soluble carbohydrate concentrations, and also slightly increased starch concentrations of stems and roots. Only needle starch concentrations and fine root sugar alcohol concentrations were decreased. Ozone fumigation resulted in needle discolorations and affected most parameters negatively, including decreased shoot elongation and decreased starch concentrations in roots, stems, and needles. In fine roots, however, soluble carbohydrate concentrations remained unaffected or increased by ozone fumigation. The only significant interaction was an antagonistic effect on root starch concentrations, where higher nitrogen levels alleviated the negative impact of ozone. - Simultaneous ozone fumigation and nitrogen fertilization have no synergistic impacts on carbohydrate concentrations, biomass, or growth of Picea abies saplings

  1. Multigeneration exposure of the springtail Folsomia candida to phenanthrone: from dose-response relationships to threshold concentrations.

    NARCIS (Netherlands)

    Paumen, M.L.; Steenbergen, E.; Kraak, M.H.S.; Straalen, N.M. van; Gestel, C.A.M. van

    2008-01-01

    Results of life-cycle toxicity experiments are supposed to be indicative for long-term effects of exposure to toxicants. Several studies, however, have shown that adaptation or extinction of populations exposed for several generations may occur. The aim of this study was therefore to determine if

  2. Multigeneration exposure of the springtail Folsomia candida to phenanthrene: from dose-response relationships to threshold concentrations.

    NARCIS (Netherlands)

    Leon Paumen, M.; Steenbergen, E.; Kraak, M.H.S.; van Straalen, N.M.; van Gestel, C.A.M.

    2008-01-01

    Results of life-cycle toxicity experiments are supposed to be indicative for long-term effects of exposure to toxicants. Several studies, however, have shown that adaptation or extinction of populations exposed for several generations may occur. The aim of this study was therefore to determine if

  3. Multigeneration exposure of the springtail Folsomia candida to phenanthrene: From dose-response relationships to threshold concentrations

    NARCIS (Netherlands)

    Leon Paumen, M.; Steenbergen, E.; Kraak, M.H.S.; van Straalen, N.M.; van Gestel, C.A.M.

    2008-01-01

    Results of life-cycle toxicity experiments are supposed to be indicative for long-term effects of exposure to toxicants. Several studies, however, have shown that adaptation or extinction of populations exposed for several generations may occur. The aim of this study was therefore to determine if

  4. Measuring tobacco smoke exposure: quantifying nicotine/cotinine concentration in biological samples by colorimetry, chromatography and immunoassay methods.

    Science.gov (United States)

    Dhar, Preeti

    2004-04-01

    Procedures to assess tobacco smoke exposure are reviewed and biomarkers used for determining the smoking status of an individual are compared. Methods used to extract these biomarkers from saliva, urine, and blood and the advantages and disadvantages of the assays are discussed. Finally, the procedures used to measure the levels of cortisol, a stress hormone speculated to be linked to nicotine metabolism, are discussed.

  5. CORRELATED PULMONARY AND SYSTEMIC EFFECTS IN SPONTANEOUSLY HYPERTENSIVE RATS FOLLOWING ACUTE EXPOSURES TO CONCENTRATED AMBIENT PARTICLES (CAPS)

    Science.gov (United States)

    The increase in plasma fibrinogen, a risk factor for cardiovascular disease (CVD), has recently been associated with exposures to particulate air pollution (PM) in humans. We have shown a similar pattern of fibrinogen increases in rats exposed to emission PM. The purpose of thi...

  6. Impacts of Transit-Oriented Compact-Growth on Air Pollutant Concentrations and Exposures in the Tampa Region

    Science.gov (United States)

    2018-03-31

    Amy L. Stuart (ORCID # 0000-0003-1229-493) The objective of this study was to model the potential impacts of alternative transit-oriented urban design scenarios on community exposures to roadway air pollution. We used a modeling framework developed p...

  7. Concentration risk

    Directory of Open Access Journals (Sweden)

    Matić Vesna

    2016-01-01

    Full Text Available Concentration risk has been gaining a special dimension in the contemporary financial and economic environment. Financial institutions are exposed to this risk mainly in the field of lending, mostly through their credit activities and concentration of credit portfolios. This refers to the concentration of different exposures within a single risk category (credit risk, market risk, operational risk, liquidity risk.

  8. Characterization of Missouri surface waters near point sources of pollution reveals potential novel atmospheric route of exposure for bisphenol A and wastewater hormonal activity pattern.

    Science.gov (United States)

    Kassotis, Christopher D; Alvarez, David A; Taylor, Julia A; vom Saal, Frederick S; Nagel, Susan C; Tillitt, Donald E

    2015-08-15

    Surface water contamination by chemical pollutants increasingly threatens water quality around the world. Among the many contaminants found in surface water, there is growing concern regarding endocrine disrupting chemicals, based on their ability to interfere with some aspect of hormone action in exposed organisms, including humans. This study assessed water quality at several sites across Missouri (near wastewater treatment plants and airborne release sites of bisphenol A) based on hormone receptor activation potencies and chemical concentrations present in the surface water. We hypothesized that bisphenol A and ethinylestradiol would be greater in water near permitted airborne release sites and wastewater treatment plant inputs, respectively, and that these two compounds would be responsible for the majority of activities in receptor-based assays conducted with water collected near these sites. Concentrations of bisphenol A and ethinylestradiol were compared to observed receptor activities using authentic standards to assess contribution to total activities, and quantitation of a comprehensive set of wastewater compounds was performed to better characterize each site. Bisphenol A concentrations were found to be elevated in surface water near permitted airborne release sites, raising questions that airborne releases of BPA may influence nearby surface water contamination and may represent a previously underestimated source to the environment and potential for human exposure. Estrogen and androgen receptor activities of surface water samples were predictive of wastewater input, although the lower sensitivity of the ethinylestradiol ELISA relative to the very high sensitivity of the bioassay approaches did not allow a direct comparison. Wastewater-influenced sites also had elevated anti-estrogenic and anti-androgenic equivalence, while sites without wastewater discharges exhibited no antagonist activities. Published by Elsevier B.V.

  9. Exposure of honey bees (Apis mellifera) to different classes of insecticides exhibit distinct molecular effect patterns at concentrations that mimic environmental contamination.

    Science.gov (United States)

    Christen, Verena; Fent, Karl

    2017-07-01

    Pesticides are implicated in the decline of honey bee populations. Many insecticides are neurotoxic and act by different modes of actions. Although a link between insecticide exposure and changed behaviour has been made, molecular effects underlying these effects are poorly understood. Here we elucidated molecular effects at environmental realistic concentrations of two organophosphates, chlorpyrifos and malathion, the pyrethroid cypermethrin, and the ryanodine receptor activator, chlorantraniliprole. We assessed transcriptional alterations of selected genes at three exposure times (24 h, 48 h, 72 h) in caged honey bees exposed to different concentrations of these compounds. Our targeted gene expression concept focused on several transcripts, including nicotinic acetylcholine receptor α 1 and α 2 (nAChRα1, nAChRα2) subunits, the multifunctional gene vitellogenin, immune system related genes of three immune system pathways, genes belonging to the detoxification system and ER stress genes. Our data indicate a dynamic pattern of expressional changes at different exposure times. All four insecticides induced strong alterations in the expression of immune system related genes suggesting negative implications for honey bee health, as well as cytochrome P450 enzyme transcripts suggesting an interference with metabolism. Exposure to neurotoxic chlorpyrifos, malathion and cypermethrin resulted in up-regulation of nAChRα1 and nAChRα2. Moreover, alterations in the expression of vitellogenin occurred, which suggests implications on foraging activity. Chlorantraniliprole induced ER stress which may be related to toxicity. The comparison of all transcriptional changes indicated that the expression pattern is rather compound-specific and related to its mode of action, but clusters of common transcriptional changes between different compounds occurred. As transcriptional alterations occurred at environmental concentrations our data provide a molecular basis for observed

  10. Embryonic Methamphetamine Exposure Inhibits Methamphetamine Cue Conditioning and Reduces Dopamine Concentrations in Adult N2 Caenorhabditis elegans.

    Science.gov (United States)

    Katner, Simon N; Neal-Beliveau, Bethany S; Engleman, Eric A

    2016-01-01

    Methamphetamine (MAP) addiction is substantially prevalent in today's society, resulting in thousands of deaths and costing billions of dollars annually. Despite the potential deleterious consequences, few studies have examined the long-term effects of embryonic MAP exposure. Using the invertebrate nematode Caenorhabditis elegans allows for a controlled analysis of behavioral and neurochemical changes due to early developmental drug exposure. The objective of the current study was to determine the long-term behavioral and neurochemical effects of embryonic exposure to MAP in C. elegans. In addition, we sought to improve our conditioning and testing procedures by utilizing liquid filtration, as opposed to agar, and smaller, 6-well testing plates to increase throughput. Wild-type N2 C. elegans were embryonically exposed to 50 μM MAP. Using classical conditioning, adult-stage C. elegans were conditioned to MAP (17 and 500 μM) in the presence of either sodium ions (Na+) or chloride ions (Cl-) as conditioned stimuli (CS+/CS-). Following conditioning, a preference test was performed by placing worms in 6-well test plates spotted with the CS+ and CS- at opposite ends of each well. A preference index was determined by counting the number of worms in the CS+ target zone divided by the total number of worms in the CS+ and CS- target zones. A food conditioning experiment was also performed in order to determine whether embryonic MAP exposure affected food conditioning behavior. For the neurochemical experiments, adult worms that were embryonically exposed to MAP were analyzed for dopamine (DA) content using high-performance liquid chromatography. The liquid filtration conditioning procedure employed here in combination with the use of 6-well test plates significantly decreased the time required to perform these experiments and ultimately increased throughput. The MAP conditioning data found that pairing an ion with MAP at 17 or 500 μM significantly increased the preference

  11. Effect of oxidant concentration, exposure time, and seed particles on secondary organic aerosol chemical composition and yield

    Directory of Open Access Journals (Sweden)

    A. T. Lambe

    2015-03-01

    This similarity in turn suggests that both in the flow reactor and in chambers, SOA chemical composition at low OH exposure is governed primarily by gas-phase OH oxidation of the precursors rather than heterogeneous oxidation of the condensed particles. In general, SOA yields measured in the flow reactor are lower than measured in chambers for the range of equivalent OH exposures that can be measured in both the flow reactor and chambers. The influence of sulfate seed particles on isoprene SOA yield measurements was examined in the flow reactor. The studies show that seed particles increase the yield of SOA produced in flow reactors by a factor of 3 to 5 and may also account in part for higher SOA yields obtained in the chambers, where seed particles are routinely used.

  12. A Systematic Review and Meta-Analysis of the Campylobacter spp. Prevalence and Concentration in Household Pets and Petting Zoo Animals for Use in Exposure Assessments.

    Science.gov (United States)

    Pintar, Katarina D M; Christidis, Tanya; Thomas, M Kate; Anderson, Maureen; Nesbitt, Andrea; Keithlin, Jessica; Marshall, Barbara; Pollari, Frank

    2015-01-01

    Animal contact is a potential transmission route for campylobacteriosis, and both domestic household pet and petting zoo exposures have been identified as potential sources of exposure. Research has typically focussed on the prevalence, concentration, and transmission of zoonoses from farm animals to humans, yet there are gaps in our understanding of these factors among animals in contact with the public who don't live on or visit farms. This study aims to quantify, through a systematic review and meta-analysis, the prevalence and concentration of Campylobacter carriage in household pets and petting zoo animals. Four databases were accessed for the systematic review (PubMed, CAB direct, ProQuest, and Web of Science) for papers published in English from 1992-2012, and studies were included if they examined the animal population of interest, assessed prevalence or concentration with fecal, hair coat, oral, or urine exposure routes (although only articles that examined fecal routes were found), and if the research was based in Canada, USA, Europe, Australia, and New Zealand. Studies were reviewed for qualitative synthesis and meta-analysis by two reviewers, compiled into a database, and relevant studies were used to create a weighted mean prevalence value. There were insufficient data to run a meta-analysis of concentration values, a noted study limitation. The mean prevalence of Campylobacter in petting zoo animals is 6.5% based on 7 studies, and in household pets the mean is 24.7% based on 34 studies. Our estimated concentration values were: 7.65x103cfu/g for petting zoo animals, and 2.9x105cfu/g for household pets. These results indicate that Campylobacter prevalence and concentration are lower in petting zoo animals compared with household pets and that both of these animal sources have a lower prevalence compared with farm animals that do not come into contact with the public. There is a lack of studies on Campylobacter in petting zoos and/or fair animals in

  13. "It Looks Like an Adult Sweetie Shop": Point-of-Sale Tobacco Display Exposure and Brand Awareness in Scottish Secondary School Students.

    Science.gov (United States)

    van der Sluijs, Winfried; Haseen, Farhana; Miller, Martine; MacGregor, Andy; Sharp, Clare; Amos, Amanda; Best, Catherine; Stead, Martine; Eadie, Douglas; Pearce, Jamie; Frank, John; Haw, Sally

    2016-10-01

    As further restrictions have been placed on tobacco advertising and promotions, point-of-sale (PoS) displays of cigarettes in shops have become an increasingly important source of young people's exposure to tobacco products. This study explored the relationship between PoS displays of cigarettes and brand awareness among secondary school students in Scotland. Cross-sectional school surveys (n = 1406) and focus groups (n = 86) were conducted with S2 (13-14 years) and S4 (15-16 years) students in four schools of differing socioeconomic status in 2013, prior to the PoS display ban in large shops. Adjusted negative binomial regression analysis examined associations between brand awareness and exposure variables (visiting tobacco retailers, noticing displays of tobacco products). Students visiting small shops more frequently (relative rate ratio [RRR] 1.19, 95% confidence interval [CI] 1.01-1.41) and those who noticed cigarette displays in small shops (RRR 1.24, 95% CI 1.03-1.51) and large supermarkets (RRR 1.15, 95% CI 1.01-1.30) had higher brand awareness. The focus groups supported these findings. Participants described PoS tobacco displays as being eye-catching, colorful and potentially attractive to young people. This mixed-methods study showed that higher cigarette brand awareness was significantly associated with regularly visiting small shops and noticing PoS displays in small and large shops, even when students' smoking status, smoking in their social networks, leisure activities, and demographics were included as confounding variables. This highlights the importance of PoS displays of tobacco products in increasing brand awareness, which is known to increase youth smoking susceptibility, and thus the importance of implementing PoS display bans in all shops. As increasing restrictions have been placed on tobacco promotion in many countries, PoS displays of cigarettes in shops have become an important source of young people's exposure to tobacco products and

  14. “It Looks Like an Adult Sweetie Shop”: Point-of-Sale Tobacco Display Exposure and Brand Awareness in Scottish Secondary School Students

    Science.gov (United States)

    van der Sluijs, Winfried; Miller, Martine; MacGregor, Andy; Sharp, Clare; Amos, Amanda; Best, Catherine; Stead, Martine; Eadie, Douglas; Pearce, Jamie; Frank, John; Haw, Sally

    2016-01-01

    Introduction: As further restrictions have been placed on tobacco advertising and promotions, point-of-sale (PoS) displays of cigarettes in shops have become an increasingly important source of young people’s exposure to tobacco products. This study explored the relationship between PoS displays of cigarettes and brand awareness among secondary school students in Scotland. Methods: Cross-sectional school surveys (n = 1406) and focus groups (n = 86) were conducted with S2 (13–14 years) and S4 (15–16 years) students in four schools of differing socioeconomic status in 2013, prior to the PoS display ban in large shops. Adjusted negative binomial regression analysis examined associations between brand awareness and exposure variables (visiting tobacco retailers, noticing displays of tobacco products). Results: Students visiting small shops more frequently (relative rate ratio [RRR] 1.19, 95% confidence interval [CI] 1.01–1.41) and those who noticed cigarette displays in small shops (RRR 1.24, 95% CI 1.03–1.51) and large supermarkets (RRR 1.15, 95% CI 1.01–1.30) had higher brand awareness. The focus groups supported these findings. Participants described PoS tobacco displays as being eye-catching, colorful and potentially attractive to young people. Conclusions: This mixed-methods study showed that higher cigarette brand awareness was significantly associated with regularly visiting small shops and noticing PoS displays in small and large shops, even when students’ smoking status, smoking in their social networks, leisure activities, and demographics were included as confounding variables. This highlights the importance of PoS displays of tobacco products in increasing brand awareness, which is known to increase youth smoking susceptibility, and thus the importance of implementing PoS display bans in all shops. Implications: As increasing restrictions have been placed on tobacco promotion in many countries, PoS displays of cigarettes in shops have become

  15. A study on modeling nitrogen dioxide concentrations using land-use regression and conventionally used exposure assessment methods

    Science.gov (United States)

    Choi, Giehae; Bell, Michelle L.; Lee, Jong-Tae

    2017-04-01

    The land-use regression (LUR) approach to estimate the levels of ambient air pollutants is becoming popular due to its high validity in predicting small-area variations. However, only a few studies have been conducted in Asian countries, and much less research has been conducted on comparing the performances and applied estimates of different exposure assessments including LUR. The main objectives of the current study were to conduct nitrogen dioxide (NO2) exposure assessment with four methods including LUR in the Republic of Korea, to compare the model performances, and to estimate the empirical NO2 exposures of a cohort. The study population was defined as the year 2010 participants of a government-supported cohort established for bio-monitoring in Ulsan, Republic of Korea. The annual ambient NO2 exposures of the 969 study participants were estimated with LUR, nearest station, inverse distance weighting, and ordinary kriging. Modeling was based on the annual NO2 average, traffic-related data, land-use data, and altitude of the 13 regularly monitored stations. The final LUR model indicated that area of transportation, distance to residential area, and area of wetland were important predictors of NO2. The LUR model explained 85.8% of the variation observed in the 13 monitoring stations of the year 2009. The LUR model outperformed the others based on leave-one out cross-validation comparing the correlations and root-mean square error. All NO2 estimates ranged from 11.3-18.0 ppb, with that of LUR having the widest range. The NO2 exposure levels of the residents differed by demographics. However, the average was below the national annual guidelines of the Republic of Korea (30 ppb). The LUR models showed high performances in an industrial city in the Republic of Korea, despite the small sample size and limited data. Our findings suggest that the LUR method may be useful in similar settings in Asian countries where the target region is small and availability of data is

  16. Environmentally relevant concentrations of di(2-ethylhexyl)phthalate exposure alter larval growth and locomotion in medaka fish via multiple pathways.

    Science.gov (United States)

    Yang, Wen-Kai; Chiang, Li-Fen; Tan, Shi-Wei; Chen, Pei-Jen

    2018-06-01

    Di(2-ethylhexyl)phthalate (DEHP) is a commonly used plasticizer, with evidence of ubiquitous human exposure and widespread occurrence in the aquatic environment. It is an emerging environmental pollutant with regulatory priority; however, most studies have focused on the toxicity of DEHP related to endocrine disruption and reproduction in mammals. The ecotoxicological impact of phthalates (e.g., DEHP) on early life stages of fish under environmentally relevant concentrations of chronic exposure remains unclear. In this study, 7-day post-hatching fry of medaka fish (Oryzias latipes) underwent 21-day continuous exposure to DEHP solutions at 20, 100 and 200 μg/L to assess the effects on fish development and locomotion and related toxic mechanisms. Larval mortality was low with DEHP (20-200 μg/L) within 21 days, but such exposure significantly reduced fish body weight and length and altered swimming behavior. At 21 days, DEHP exposure resulted in specific patterns of larval locomotion (e.g., increased maximum velocity and absolute turn angle) and dose-dependently increased the mRNA expression of acetylcholinesterase (ache) but did not alter AChE activity. Transcriptional expression of antioxidants such as superoxide dismutase, catalase, glutathione peroxidase, and glutathione S-transferase and peroxisome proliferation-activated receptor and retinoid X receptor genes was significantly suppressed with 21-day DEHP exposure (20-200 μg/L), with marginal alteration in reactive oxygen species levels and antioxidant activities within the dosing period. As well, DEHP altered the mRNA expression of p53-regulated apoptosis pathways, such as upregulated p53, p21 and bcl-2 and downregulated caspase-3 expression, with increased enzymatic activity of caspase-3 in larvae. Our results suggest that toxic mechanisms of waterborne DEHP altered fish growth and locomotion likely via a combined effect of oxidative stress, neurotoxicity and apoptosis pathways. Copyright © 2018

  17. Exposure to the Holocaust and World War II concentration camps during late adolescence and adulthood is not associated with increased risk for dementia at old age.

    Science.gov (United States)

    Ravona-Springer, Ramit; Beeri, Michal Schnaider; Goldbourt, Uri

    2011-01-01

    Holocaust and Nazi concentration camp survivors were subjects to prolonged and multi-dimensional trauma and stress. The aim of the present study was to assess the association between exposure to such trauma during late adolescence and adulthood with dementia at old age. In 1963, approximately 10,000 male civil servants aged 40-71 participated in the Israel Ischemic Heart Disease (IIHD) study. Of them, 691 reported having survived Nazi concentration camps [concentration Camp Survivors (CCS)]. Additional 2316 participants were holocaust survivors but not concentration camp survivors (HSNCC) and 1688 were born in European countries but not exposed to the Holocaust (NH). Dementia was assessed in 1999-2000, over three decades later, in 1889 survivors of the original IIHD cohort; 139 of whom were CCS, 435 were HSNCC, and 236 were NH. Dementia prevalence was 11.5% in CCS, 12.6% in HSNCC, and 15.7% in NH. The odds ratio of dementia prevalence, estimated by age adjusted logistic regression, for CCS as compared to HSNCC was 0.97 (95% CI: 0.53-1.77), approximate Z = -0.10; p = 0.92. Further adjustment for socioeconomic status, diabetes mellitus, and other co-morbidity at midlife (coronary heart disease, lung, and kidney disease), and height did not change the results substantially. Thus, in subjects who survived until old age, late adolescence and adulthood exposure to extreme stress, as reflected by experiencing holocaust and Nazi concentration camps, was not associated with increased prevalence of dementia. Individuals who survived concentration camps and then lived into old age may carry survival advantages that are associated with protection from dementia and mortality.

  18. Hazard assessment of metals in invasive fish species of the Yamuna River, India in relation to bioaccumulation factor and exposure concentration for human health implications.

    Science.gov (United States)

    Singh, Atul K; Srivastava, Sharad C; Verma, Pankaj; Ansari, Abubakar; Verma, Ambrish

    2014-06-01

    Monitoring of heavy metals was conducted in the Yamuna River considering bioaccumulation factor, exposure concentration, and human health implications which showed contamination levels of copper (Cu), lead (Pb), nickel (Ni), and chromium (Cr) and their dispersion patterns along the river. Largest concentration of Pb in river water was 392 μg L(-1); Cu was 392 μg L(-1) at the extreme downstream, Allahabad and Ni was 146 μg L(-1) at midstream, Agra. Largest concentration of Cu was 617 μg kg(-1), Ni 1,621 μg kg(-1) at midstream while Pb was 1,214 μg kg(-1) at Allahabad in surface sediment. The bioconcentration of Cu, Pb, Ni, and Cr was observed where the largest accumulation of Pb was 2.29 μg kg(-1) in Oreochromis niloticus and 1.55 μg kg(-1) in Cyprinus carpio invaded at Allahabad while largest concentration of Ni was 174 μg kg(-1) in O. niloticus and 124 μg kg(-1) in C. carpio in the midstream of the river. The calculated values of hazard index (HI) for Pb was found more than one which indicated human health concern. Carcinogenic risk value for Ni was again high i.e., 17.02 × 10(-4) which was larger than all other metals studied. The results of this study indicated bioconcentration in fish due to their exposures to heavy metals from different routes which had human health risk implications. Thus, regular environmental monitoring of heavy metal contamination in fish is advocated for assessing food safety since health risk may be associated with the consumption of fish contaminated through exposure to a degraded environment.

  19. Are Retail Outlets Complying with National Legislation to Protect Children from Exposure to Tobacco Displays at Point of Sale? Results from the First Compliance Study in the UK.

    Directory of Open Access Journals (Sweden)

    Douglas Eadie

    Full Text Available From April 6th 2015, all small shops in the UK were required to cover up tobacco products at point of sale (POS to protect children from exposure. As part of a larger 5-year study to measure the impact of the legislation in Scotland, an audit was conducted to assess level and nature of compliance with the ban immediately following its introduction.A discreet observational audit was conducted 7-14 days post implementation which took measures of physical changes made to cover products, server/assistant practices, tobacco signage and advertising, and communication of price information. The audit was conducted in all small retail outlets (n = 83 selling tobacco in four communities in Scotland selected to represent different levels of urbanisation and social deprivation. Data were analysed descriptively.Compliance with the legislation was high, with 98% of shops removing tobacco from permanent display and non-compliance was restricted almost entirely to minor contraventions. The refurbishment of shops with new or adapted tobacco storage units resulted in the removal of nearly all commercial brand messages and images from POS, dropping from 51% to 4%. The majority of shops stored their tobacco in public-facing storage units (81%. Most shops also displayed at least one generic tobacco message (88%.Compliance with Scottish prohibitions on display of tobacco products in small retail outlets was high immediately after the legislation implementation date. However, although tobacco branding is no longer visible in retail outlets, tobacco storage units with generic tobacco messages are still prominent. This points towards a need to monitor how the space vacated by tobacco products is utilised and to better understand how the continuing presence of tobacco storage units influences people's awareness and understanding of tobacco and smoking. Countries with existing POS bans and who are considering such bans should pay particular attention to regulations

  20. Are Retail Outlets Complying with National Legislation to Protect Children from Exposure to Tobacco Displays at Point of Sale? Results from the First Compliance Study in the UK.

    Science.gov (United States)

    Eadie, Douglas; Stead, Martine; MacKintosh, Anne Marie; Murray, Susan; Best, Catherine; Pearce, Jamie; Tisch, Catherine; van der Sluijs, Winfried; Amos, Amanda; MacGregor, Andy; Haw, Sally

    2016-01-01

    From April 6th 2015, all small shops in the UK were required to cover up tobacco products at point of sale (POS) to protect children from exposure. As part of a larger 5-year study to measure the impact of the legislation in Scotland, an audit was conducted to assess level and nature of compliance with the ban immediately following its introduction. A discreet observational audit was conducted 7-14 days post implementation which took measures of physical changes made to cover products, server/assistant practices, tobacco signage and advertising, and communication of price information. The audit was conducted in all small retail outlets (n = 83) selling tobacco in four communities in Scotland selected to represent different levels of urbanisation and social deprivation. Data were analysed descriptively. Compliance with the legislation was high, with 98% of shops removing tobacco from permanent display and non-compliance was restricted almost entirely to minor contraventions. The refurbishment of shops with new or adapted tobacco storage units resulted in the removal of nearly all commercial brand messages and images from POS, dropping from 51% to 4%. The majority of shops stored their tobacco in public-facing storage units (81%). Most shops also displayed at least one generic tobacco message (88%). Compliance with Scottish prohibitions on display of tobacco products in small retail outlets was high immediately after the legislation implementation date. However, although tobacco branding is no longer visible in retail outlets, tobacco storage units with generic tobacco messages are still prominent. This points towards a need to monitor how the space vacated by tobacco products is utilised and to better understand how the continuing presence of tobacco storage units influences people's awareness and understanding of tobacco and smoking. Countries with existing POS bans and who are considering such bans should pay particular attention to regulations regarding the use

  1. Developmental exposure to low concentrations of two brominated flame retardants, BDE-47 and BDE-99, causes life-long behavioral alterations in zebrafish.

    Science.gov (United States)

    Glazer, Lilah; Wells, Corinne N; Drastal, Meghan; Odamah, Kathryn-Ann; Galat, Richard E; Behl, Mamta; Levin, Edward D

    2018-05-01

    Polybrominated diphenyl ethers (PBDEs) were widely used as flame retardants until the early 2000s, mainly in home furnishings and electronics. The persistence of PBDEs in the environment leads to continued ubiquitous exposure to low levels, with infants and children experiencing higher exposures than adults. Accumulating evidence suggest that low-level exposures during early life stages can affect brain development and lead to long-term behavioral impairments. We investigated the effects of zebrafish exposure to low doses of the two prominent PBDEs; 2,2',4,4',5,-Pentabromodiphenyl ether (BDE-99) and 2,2',4,4',-Tetrabromodiphenyl ether (BDE-47), during embryo-development on short- and long-term behavioral endpoints. We included the organophosphate pesticide chlorpyrifos (CPF) due to its well documented neurotoxicity across species from zebrafish to humans. Zebrafish embryos were exposed to the following individual treatments; 0.1% DMSO (vehicle control); 0.3μM CPF; 0.01, 0.03, 0.1, 0.3μM BDE-47; 0.003, 0.03, 0.3, 1, 3, 10, 20μM BDE-99 from 5 until 120h post fertilization (hpf). Low exposure levels were determined as those not causing immediate overt toxicity, and behavior assays were conducted in the low-level range. At 144 hpf the larvae were tested for locomotor activity. At approximately 6 months of age adult zebrafish were tested in a behavioral battery including assays for anxiety-related behavior, sensorimotor response and habituation, social interaction, and predator avoidance. In the short-term, larval locomotor activity was reduced in larvae treated with 0.3μM CPF and 0.1μM BDE-47. BDE-99 treatment caused non-monotonic dose effects, with 0.3μM causing hyperactivity and 1μM or higher causing hypoactivity. In the long-term, adult anxiety-related behavior was reduced in all treatments as measured in both the novel tank dive test and tap test. We show that exposure of zebrafish embryos to low concentrations of the brominated flame retardants BDE-47 and

  2. Chronic exposure to a low concentration of bisphenol A during follicle culture affects the epigenetic status of germinal vesicles and metaphase II oocytes.

    Science.gov (United States)

    Trapphoff, Tom; Heiligentag, Martyna; El Hajj, Nady; Haaf, Thomas; Eichenlaub-Ritter, Ursula

    2013-12-01

    To determine whether exposure to low concentrations of the endocrine disrupting chemical bisphenol A (BPA) during follicle culture and oocyte growth alters the methylation status of differentially methylated regions (DMRs) of imprinted genes and histone posttranslational modification patterns in mammalian oocytes. Comparative and control study. Experimental laboratory. C57/Bl6JxCBA/Ca mice. Exposure of oocytes to 3 nM or 300 nM BPA during follicle culture from preantral to antral stage. Methylation status of DMRs of maternally imprinted (Snrpn, Igf2r, and Mest) and paternally imprinted gene(s) (H19) in mouse germinal vesicle oocytes; trimethylation of histone H3K9, acetylation of histone H4K12, and distance between centromeres of sister chromatids in metaphase II oocytes. Exposure to 3 nM BPA was associated with slightly accelerated follicle development, statistically significant increases in allele methylation errors in DMRs of maternally imprinted genes, and statistically significant decreases in histone H3K9 trimethylation and interkinetochore distance. The disturbances in oocyte genomic imprinting and modification of posttranslational histone and centromere architecture provide the first link between low BPA exposures and induction of epigenetic changes that may contribute to chromosome congression failures and meiotic errors, and to altered gene expression that might affect health of the offspring. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  3. Differential osmotic pressure measurements of the concentration susceptibility of liquid 3He/4He mixtures near the lambda curve and tricritical point

    International Nuclear Information System (INIS)

    Gearhart, C.A. Jr.; Zimmermann, W. Jr.

    1979-01-01

    Values of the concentration susceptibility (partial x/partial Δ)/sub T/,P of liquid 3 He/ 4 He mixtures have been determined near the lambda curve and tricritical point from measurements of the differential osmotic pressure as a function of temperature T at four values of the 3 He mole fraction, x = 0.594, x = 0.644, x = 0.680, and x = 0.706. Here Δ = μ 3 - μ 4 is the difference between molar chemical potentials and P is the pressure. Our results for the two values of x less than the tricritical value x/sub t/ = 0.675 show pronounced peaks at the lambda transition. For 3 x 10 -4 -2 , where t equals [T - T/sub lambda/(x)]/T/sub lambda/(x), these peaks may be characterized both above and below the transition by the form (A/sub plus-or-minus//α/sub plus-or-minus/) (vertical-bart vertical-bar/sup -alpha/ +- - 1) + B/sub plus-or-minus/, with exponents α/sub plus-or-minus/ lying in the range from approx. 0.0 to approx. 0.2. Except perhaps for x -1 [T-T/sub t//T/sub t/)/vertical-barx-x/sub t//x/sub t/vertical-bar], where f and Ψ are functions determined by experiment and T/sub t/ = 0.867 K is the tricritical value of T. With the aid of this scaling relationship, the behavior of (partialx/partialΔ)/sub T/,P along curves of constant Δ near the lambda curve has been constucted from our data at constant x

  4. Exposure of sea bream (Sparus aurata) to toxic concentrations of benzo[a]pyrene: possible human health effect.

    Science.gov (United States)

    Zena, R; Speciale, A; Calabrò, C; Calò, M; Palombieri, D; Saija, A; Cimino, F; Trombetta, D; Lo Cascio, P

    2015-12-01

    Polycyclic aromatic hydrocarbons (PAHs) can accumulate in the food chain, due to their lipophilic properties. Fish can accumulate contaminants including PAHs and frequent consumption of such contaminated fish can pose risk to human health. The aim of this study was to clarify if acute exposure of sea bream (Sparus aurata, a fish species of great economic importance in the Atlantic and Mediterranean areas) to a PAH, benzo[a]pyrene (B[a]P), at a dose that can induce CYP1A and pathological changes in fish gills, liver and muscle, can induce accumulation in muscle. We investigated the cytotoxic effects (as changes in cell viability, DNA laddering and glutathione content) of in vitro exposure of human peripheral blood mononuclear cells (PBMCs) to organic extracts obtained from muscle of sea breams previously exposed via water to B[a]P (2mg/l, for 12, 24 and 72 h). At this level of exposure, B[a]P caused morphological changes, inflammatory response and CYP1A induction not only in sea bream gills and liver but also in muscle; furthermore, in fish muscle we observed a substantial B[a]P accumulation, which may be associated with the increased CYP1A activity in liver and especially in muscle. However, when PBMCs were exposed to organic extracts obtained from sea bream muscle contaminated with B[a]P, a toxic, although modest effect was revealed, consisting in a significant decrease in cell glutathione levels without alterations in cell viability and DNA laddering. This suggests that consumption of sea breams from B[a]P contaminated waters might represent a risk for human health. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Effect of doxycycline concentrations in chicken tissues as a consequence of permanent exposure to enrofloxacin traces in drinking water

    Directory of Open Access Journals (Sweden)

    Gbylik-Sikorska Małgorzata

    2016-09-01

    Full Text Available Introduction: The main problem in poultry farming is the difficulty in producing food of animal origin without using antibacterial agents. Because most antibacterial compounds are dispensed in water, some water supply systems can be contaminated by antibiotics which are then administered to the animals unintentionally. This can lead to unexpected increases in antibiotic residues in food of animal origin. The aim of the present study was to determine whether the constant exposure of chicken broilers to enrofloxacin affects the withdrawal time of a therapeutic doxycycline that is intentionally administered to the chickens.

  6. Improving Infant Exposure and Health Risk Estimates: Using Serum Data to Predict Polybrominated Diphenyl Ether Concentrations in Breast Milk

    Science.gov (United States)

    Women in the United States have breast milk concentrations of polybrominated diphenyl ethers (PBDEs) that are among the highest in the world, leading to concerns over the potential health implications to breastfeeding infants during critical stages of growth and development. Deve...

  7. Influence of different sanitizers on food contaminant bacteria: effect of exposure temperature, contact time, and product concentration

    Directory of Open Access Journals (Sweden)

    Cezar Augusto Beltrame

    2012-06-01

    Full Text Available The efficiency of four Sanitizers - peracetic acid, chlorhexidine, quaternary ammonium, and organic acids - was tested in this work using different bacteria recognized as a problem to meat industry, Salmonella sp., S. aureus, E. coli and L. monocytogenes. The effects of sanitizer concentration (0.2, 0.5, 0.6, 1.0, 1.1 and 1.4%, at different temperatures (10 and 45 °C and contact time (2, 10, 15, 18 and 25 minutes were evaluated. Tests in an industrial plant were also carried out considering previously obtained results. In a general way, peracetic acid presented higher efficiencies using low concentration (0.2% and contact time (2 minutes at 10 °C. The tests performed in industrial scale showed that peracetic acid presented a good performance in concentration and contact time lower than that suggested by the suppliers. The use of chlorhexidine and quaternary ammonium led to reasonable results at the indicated conditions, and organic acids were ineffective under concentration and contact time higher than those indicated by the suppliers in relation to Staphylococcus aureus. The results, in general, show that the choice for the most adequate sanitizer depends on the microorganism contaminant, the time available for sanitizer application, and also on the process cost.

  8. Probabilistic acute dietary exposure assessments to captan and tolylfluanid using several European food consumption and pesticide concentration databases

    DEFF Research Database (Denmark)

    Boon, Polly E.; Svensson, Kettil; Moussavian, Shahnaz

    2009-01-01

    to national food consumption surveys. In this way it is possible to exchange or merge concentration data between countries in situations of data scarcity. This electronic platform in connection with probabilistic software can be seen as a prototype of a data warehouse, including a harmonised approach...

  9. Characterization of Missouri surface waters near point sources of pollution reveals potential novel atmospheric route of exposure for bisphenol A and wastewater hormonal activity pattern

    Science.gov (United States)

    Kassotis, Christopher D.; Alvarez, David A.; Taylor, Julia A.; vom Saal, Frederick S.; Nagel, Susan C.; Tillitt, Donald E.

    2015-01-01

    Surface water contamination by chemical pollutants increasingly threatens water quality around the world. Among the many contaminants found in surface water, there is growing concern regarding endocrine disrupting chemicals, based on their ability to interfere with some aspect of hormone action in exposed organisms, including humans. This study assessed water quality at several sites across Missouri (near wastewater treatment plants and airborne release sites of bisphenol A) based on hormone receptor activation potencies and chemical concentrationspresent in the surface water. We hypothesized that bisphenol A and ethinylestradiol would be greater in water near permitted airborne release sites and wastewater treatment plant inputs, respectively, and that these two compounds would be responsible for the majority of activities in receptor-based assays conducted with water collected near these sites. Concentrations of bisphenol A and ethinylestradiol were compared to observed receptor activities using authentic standards to assess contribution to total activities, and quantitation of a comprehensive set of wastewater compounds was performed to better characterize each site. Bisphenol A concentrations were found to be elevated in surface water near permitted airborne release sites, raising questions that airborne releases of BPA may influence nearby surface water contamination and may represent a previously underestimated source to the environment and potential for human exposure. Estrogen and androgen receptor activities of surface water samples were predictive of wastewater input, although the lower sensitivity of the ethinylestradiol ELISA relative to the very high sensitivity of the bioassay approaches did not allow a direct comparison. Wastewater-influenced sites also had elevated anti-estrogenic and anti-androgenic equivalence, while sites without wastewater discharges exhibited no antagonist activities.

  10. Chronic low-level arsenite exposure through drinking water increases blood pressure and promotes concentric left ventricular hypertrophy in female mice.

    Science.gov (United States)

    Sanchez-Soria, Pablo; Broka, Derrick; Monks, Sarah L; Camenisch, Todd D

    2012-04-01

    Cardiovascular disease is the leading cause of death in the United States and worldwide. High incidence of cardiovascular diseases has been linked to populations with elevated arsenic content in their drinking water. Although this correlation has been established in many epidemiological studies, a lack of experimental models to study mechanisms of arsenic-related cardiovascular pathogenesis has limited our understanding of how arsenic exposure predisposes for development of hypertension and increased cardiovascular mortality. Our studies show that mice chronically exposed to drinking water containing 100 parts per billion (ppb) sodium arsenite for 22 weeks show an increase in both systolic and diastolic blood pressure. Echocardiographic analyses as well as histological assessment show concentric left ventricular hypertrophy, a primary cardiac manifestation of chronic hypertension. Live imaging by echocardiography shows a 43% increase in left ventricular mass in arsenic-treated animals. Relative wall thickness (RWT) was calculated showing that all the arsenic-exposed animals show an RWT greater than 0.45, indicating concentric hypertrophy. Importantly, left ventricular hypertrophy, although often associated with chronic hypertension, is an independent risk factor for cardiovascular-related mortalities. These results suggest that chronic low-level arsenite exposure promotes the development of hypertension and the comorbidity of concentric hypertrophy.

  11. A single exposure of sediment sulphate-reducing bacteria to oxytetracycline concentrations relevant to aquaculture enduringly disturbed their activity, abundance and community structure.

    Science.gov (United States)

    Fernández, M L; Granados-Chinchilla, F; Rodríguez, C

    2015-08-01

    Although feed medicated with antibiotics is widely used in animal production to prevent and treat bacterial infections, the effect of these drugs on nontarget anaerobic bacteria is unknown. We aimed to clarify whether a single exposure of sulphate-reducing bacteria (SRB) from a tilapia pond to oxytetracycline (OTC) concentrations relevant to aquaculture impacts their function, abundance and community structure. To demonstrate changes in SO4(2-) content, SRB abundance, dsrB copy number and SRB diversity, sediment mesocosms were spiked with 5, 25, 50 and 75 mg OTC kg(-1) and examined for 30 days by means of ion chromatography, qPCR, cultivation and fluorescent in situ hybridization (FISH). On day 3, we measured higher SO4(2-) concentrations (ca. two-fold) and a reduction in dsrB copy numbers of approximately 50% in the treatments compared to the controls. After 30 days, a subtle yet measurable enrichment of bacteria from the order Desulfovibrionales occurred in mesocosms receiving ≥ 50 mg OTC kg(-1), notwithstanding that SRB counts decreased two orders of magnitude. OTC was dynamically and reversibly converted into 4-epioxytetracycline and other related compounds in a dose-dependent manner during the experiment. A single exposure to rather high OTC concentrations triggered functional and structural changes in a SRB community that manifested quickly and persisted for a month. This study improves our limited knowledge on the ecotoxicology of antibiotics in anaerobic environments. © 2015 The Society for Applied Microbiology.

  12. Oxidative stress mediated toxicity of TiO2 nanoparticles after a concentration and time dependent exposure of the aquatic macrophyte Hydrilla verticillata.

    Science.gov (United States)

    Spengler, Annette; Wanninger, Lena; Pflugmacher, Stephan

    2017-09-01

    The present study focused on oxidative stress effects in the aquatic macrophyte Hydrilla verticillata after exposure to titanium dioxide nanoparticles (TiO 2 -NPs). Experiments were conducted with different TiO 2 -NPs and concentrations (0.1 mg/L and 10 mg/L) in a time-dependent manner (0 h, 24 h, 48 h, 96 h, 168 h). To assess various levels of the oxidative stress response in H. verticillata, the level of hydrogen peroxide (H 2 O 2 ), the ratio of reduced to oxidized glutathione (GSH/GSSG), and activities of the antioxidative enzymes catalase (CAT) and glutathione reductase (GR) were evaluated. Study results imply oxidative stress effects after TiO 2 -NP exposure as adaptations in plant metabolism became apparent to counteract increased ROS formation. All TiO 2 -NPs caused elevated activities of the enzymes CAT and GR. Moreover, decreased ratios of GSH/GSSG indicated an activation of GSH-dependent pathways counteracting ROS formation. Plants exposed to a bulk-sized control revealed a size-dependent influence on the antioxidative stress response. As H 2 O 2 level increases were solely detected after exposure to 10 mg/L TiO 2 -NPs and nano-exposed plants showed normalization in its antioxidative stress response after 168h of exposure, it can be suggested that macrophytes are able to cope with currently predicted low-level exposures to TiO 2 -NPs. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Passive exposure to tobacco smoke: saliva cotinine concentrations in a representative population sample of non-smoking schoolchildren

    Energy Technology Data Exchange (ETDEWEB)

    Jarvis, M J; Russell, M A; Feyerabend, C; Eiser, J R; Morgan, M; Gammage, P; Gray, E M

    1985-10-05

    Saliva cotinine concentrations in 569 non-smoking schoolchildren were strongly related to the smoking habits of their parents. When neither parent smoked the mean concentration was 0.44 ng/ml, rising to 3.38 ng/ml when both parents were cigarette smokers. Mothers smoking had a stronger influence than did fathers (p less than 0.01). In addition, there was a small independent effect of number of siblings who smoked (p less than 0.01). The dose of nicotine received from fathers smoking was estimated as equivalent to the active smoking of 30 cigarettes a year, that from mothers smoking as equivalent to smoking 50 cigarettes a year, and that from both parents smoking as equivalent to smoking 80 cigarettes a year. This unsolicited burden may be prolonged throughout childhood and poses a definite risk to health.

  14. Gamma exposure rate reduction and residual radium-226 concentrations resulting from decontamination activities conducted at the former uranium millsite in Shiprock, New Mexico

    International Nuclear Information System (INIS)

    Hans, J.M. Jr.; Hurst, T.L.

    1981-01-01

    Gamma radiation surveys and residual radium 226 soil samples were taken as part of the decontamination activities of the former Shiprock uranium mill site in New Mexico. In order to facilitate the decontamination activities, the mill site and its contaminated environs were divided into 6 major areas. Extensive data are presented in 2 appendices of the pre- and post-decontamination gamma ray exposure rates made on mill site, and of radium 226 concentrations in surface soil samples. A training program established on the mill site by the Navajo Engineering and Construction Authority is described

  15. Dose assessment from exposure to radon, thoron and their progeny concentrations in the dwellings of sub-mountainous region of Jammu and Kashmir, India

    International Nuclear Information System (INIS)

    Kaur, M.; Dr. B. R. Ambedkar National Institute of Technology, Jalandhar, Punjab; Kumar, A.; Mehra, R.; Mishra, R.

    2018-01-01

    The present work deals with the assessment of annual inhalation dose due to exposure of indoor radon, thoron and their progeny concentrations in the villages situated in sub-mountainous region of Jammu and Kashmir, India. The distribution of the data and the homogeneity of medians among different seasons and dwellings were assessed with the Shapiro-Wilk test and the Mann-Whitney test. The estimated total annual inhalation dose in these villages varied from 0.5 to 1.9 mSv year -1 which is less than the prescribed limit by ICRP (2008). Thus, the investigated area is safe from irradiation of radon, thoron and their progeny. (author)

  16. Effect of concentration, exposure time, temperature, and relative humidity on the toxicity of sulfur dioxide to the spores of Botrytis cinerea

    Energy Technology Data Exchange (ETDEWEB)

    Couey, H.M.; Uota, M.

    1961-12-01

    When spores of Botrytis cinerea are exposed to SO/sub 2/ gas, the subsequent reduction in spore germination is quantitatively proportional to the SO/sub 2/ concentration and the exposure time. The toxicity of SO/sub 2/ increases with increasing relative humidity. In an atmosphere of 96% RH, SO/sub 2/ is more than 20 times as effective as at 75% RH. The toxicity also increases about 1.5 times for each 10/sup 0/C rise in temperature between 0/sup 0/ and 30/sup 0/C. 8 references, 4 figures, 1 table.

  17. Experimental elicitation of contact allergy from a diazolidinyl urea-preserved cream in relation to anatomical region, exposure time and concentration

    DEFF Research Database (Denmark)

    Zachariae, Claus; Hall, Barbara; Cottin, Martine

    2005-01-01

    urea, ranging from 0.05% to 0.6%. A repeated open application-like exposure test was performed on volunteers and a control group with the test product containing increasing preservative concentrations, on arm, neck and face, sequentially, for 2 weeks or until dermatitis developed. The preservative...... depends on the anatomical region, increasing from the upper arm to neck and, possibly, to the face. The study design, beginning on the upper arm and moving on to the neck and face seems to be relevant for the study of reactions to cosmetic products. A clear dose-response relationship was seen regarding...

  18. Chronic exposure to low concentrations of strontium 90 affects bone physiology but not the hematopoietic system in mice.

    Science.gov (United States)

    Synhaeve, Nicholas; Wade-Gueye, Ndéye Marième; Musilli, Stefania; Stefani, Johanna; Grandcolas, Line; Gruel, Gaëtan; Souidi, Maâmar; Dublineau, Isabelle; Bertho, Jean-Marc

    2014-01-01

    The aim of this work was to delineate the effects of chronic ingestion of strontium 90 ((90) Sr) at low concentrations on the hematopoiesis and the bone physiology. A mouse model was used for that purpose. Parent animals ingested water containing 20 kBq l(-1) of (90) Sr two weeks before mating. Offspring were then continuously contaminated with (90) Sr through placental transfer during fetal life, through lactation after birth and through drinking water after weaning. At various ages between birth and 20 weeks, animals were tested for hematopoietic parameters such as blood cell counts, colony forming cells in spleen and bone marrow and cytokine concentrations in the plasma. However, we did not find any modification in (90) Sr ingesting animals as compared with control animals. By contrast, the analysis of bone physiology showed a modification of gene expression towards bone resorption. This was confirmed by an increase in C-telopeptide of collagen in the plasma of (90) Sr ingesting animals as compared with control animals. This modification in bone metabolism was not linked to a modification of the phosphocalcic homeostasis, as measured by calcium, phosphorus, vitamin D and parathyroid hormone in the blood. Overall these results suggest that the chronic ingestion of (90) Sr at low concentration in the long term may induce modifications in bone metabolism but not in hematopoiesis. Copyright © 2012 John Wiley & Sons, Ltd.

  19. Response of needle dark respiration of Pinus koraiensis and Pinus sylvestriformis to elevated CO2 concentrations for four growing seasons' exposure

    Institute of Scientific and Technical Information of China (English)

    ZHOU YuMei; HAN ShiJie; ZHANG HaiSen; XIN LiHua; ZHENG JunQiang

    2007-01-01

    The long-term effect of elevated CO2 concentrations on needle dark respiration of two coniferous species-Pinus koraiensis and Pinus sylvestriformis on the Changbai Mountain was investigated using open-top chambers. P. Koraiensis and P. Sylvestriformis were exposed to 700,500μmol·mol-1 CO2 and ambient CO2(approx.350 μmol·mol-1)for four growing seasons. Needle dark respiration was measurd during the second, third and fourth growing seasons' exposure to elevated CO2.The results showed that needle dark respiration rate increased for P. Koraiensis and P. Sylvestriformis grown at elevated CO2 concentrations during the second growing season, could be attributed to the change of carbohydrate and/or nitrogen content of needles. Needle dark respiration of P. Koraiensis was stimulated and that of P. Sylvestriformis was inhibited by elevated CO2 concentrations during the third growing season. Different response of the two tree species to elevated CO2 mainly resulted from the difference in the growth rate. Elevated CO2 concentrations inhibited needle dark respiration of both P. Koraiensis and P. Sylvestriformis during the fourth growing season. There was consistent trend between the short-term effect and the long-term effect of elevated CO2 on needle dark respiration in P. Sylvestriformis during the third growing season by changing measurement CO2 concentrations. However, the short-term effect was different from the long-term effect for P. Koraiensis. Response of dark respiration of P. Koraiensis and P. Sylvestriformis to elevated CO2 concentrations was related to the treatment time of CO2 and the stage of growth and development of plant. The change of dark respiration for the two tree species was determined by the direct effect of CO2 and long-term acclimation. The prediction of the long-term response of needle dark respiration to elevated CO2 concentration based on the short-term response is in dispute.

  20. Prolonged exposure of methicillin-resistant Staphylococcus aureus (MRSA) COL strain to increasing concentrations of oxacillin results in a multidrug-resistant phenotype

    DEFF Research Database (Denmark)

    Martins, Ana; Couto, Isabel; Aagaard, Lone

    2007-01-01

    Our previous studies demonstrated that exposure of a bacterium to increasing concentrations of an antibiotic would increase resistance to that antibiotic as a consequence of activating efflux pumps. This study utilises the same approach; however, it employs the methicillin-resistant Staphylococcus...... aureus (MRSA) COL strain, which is highly resistant to oxacillin (OXA). MRSA COL was adapted to 3200 mg/L of OXA. Changes in resistance to other antibiotics were evaluated and efflux pump activity during the adaptation process was determined. MRSA COL was exposed to stepwise two-fold increases of OXA....... At the end of each step, minimum inhibitory concentration determination for erythromycin (ERY) and other antibiotics was conducted. Reserpine (RES) was employed to evaluate whether resistance to ERY was dependent on efflux pump activity. Efflux pump activity was also evaluated using the ethidium bromide (EB...

  1. PHP47 - Early assessment of highly innovative medical technology: clinical and economical gains of point-of-care applications for measuring potassium concentrations

    NARCIS (Netherlands)

    van de Wetering, G.; Hummel, J. Marjan; van Montfort, Augustinus P.W.P.; Montfoort, A.; IJzerman, Maarten Joost

    2009-01-01

    OBJECTIVES: Innovative point-of-care diagnostics are likely to be having a strong impact on health care. The aim of this study is to conduct an early assessment of point-of-care chips. These chips can detect many particles and, consequently, many product-market combinations can be developed. This

  2. The role of socioeconomic factors in Black-White health inequities across the life course: Point-in-time measures, long-term exposures, and differential health returns.

    Science.gov (United States)

    Boen, Courtney

    2016-12-01

    Research links Black-White health disparities to racial differences in socioeconomic status (SES), but understanding of the role of SES in racial health gaps has been restricted by reliance on static measures of health and socioeconomic well-being that mask the dynamic quality of these processes and ignore the racialized nature of the SES-health connection. Utilizing twenty-three years of longitudinal data from the Panel Study of Income Dynamics (1984-2007), this study uses multilevel growth curve models to examine how multiple dimensions of socioeconomic well-being-including long-term economic history and differential returns to SES-contribute to the life course patterning of Black-White health disparities across two critical markers of well-being: body mass index (N = 9057) and self-rated health (N = 11,329). Findings indicate that long-term SES exerts a significant influence on both body mass index and self-rated health, net of point-in-time measures, and that Black-White health gaps are smallest in models that adjust for both long-term and current SES. I also find that Blacks and Whites receive differential health returns to increases in SES, which suggests that other factors-such as neighborhood segregation and exposure racial discrimination-may restrict Blacks from converting increases in SES into health improvements in the same way as Whites. Together, these processes contribute to the life course patterning of Black-White health gaps and raise concerns about previous misestimation of the role of SES in racial health disparities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Parental exposure to environmental concentrations of diuron leads to aneuploidy in embryos of the Pacific oyster, as evidenced by fluorescent in situ hybridization.

    Science.gov (United States)

    Barranger, Audrey; Benabdelmouna, Abdellah; Dégremont, Lionel; Burgeot, Thierry; Akcha, Farida

    2015-02-01

    Changes in normal chromosome numbers (i.e. aneuploidy) due to abnormal chromosome segregation may arise either spontaneously or as a result of chemical/radiation exposure, particularly during cell division. Coastal ecosystems are continuously subjected to various contaminants originating from urban, industrial and agricultural activities. Genotoxicity is common to several families of major environmental pollutants, including pesticides, which therefore represent a potential important environmental hazard for marine organisms. A previous study demonstrated the vertical transmission of DNA damage by subjecting oyster genitors to short-term exposure to the herbicide diuron at environmental concentrations during gametogenesis. In this paper, Fluorescent in situ hybridization (FISH) was used to further characterize diuron-induced DNA damage at the chromosomal level. rDNA genes (5S and 18-5.8-28S), previously mapped onto Crassostrea gigas chromosomes 4, 5 and 10, were used as probes on the interphase nuclei of embryo preparations. Our results conclusively show higher aneuploidy (hypo- or hyperdiploidy) level in embryos from diuron-exposed genitors, with damage to the three studied chromosomal regions. This study suggests that sexually developing oysters are vulnerable to diuron exposure, incurring a negative impact on reproductive success and oyster recruitment. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Parental exposure to environmental concentrations of diuron leads to aneuploidy in embryos of the Pacific oyster, as evidenced by fluorescent in situ hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Barranger, Audrey, E-mail: audrey.barranger@ifremer.fr [Ifremer, SG2M, Laboratory of Genetics and Pathology of Marine Molluscs, Avenue de Mus du Loup, 17390 La Tremblade (France); Ifremer, Department of Biogeochemistry and Ecotoxicology, Laboratory of Ecotoxicology, Rue de l’Ile d’Yeu, BP 21105, 44311 Nantes Cedex 03 (France); Benabdelmouna, Abdellah, E-mail: abdellah.benabdelmouna@ifremer.fr [Ifremer, SG2M, Laboratory of Genetics and Pathology of Marine Molluscs, Avenue de Mus du Loup, 17390 La Tremblade (France); Dégremont, Lionel [Ifremer, SG2M, Laboratory of Genetics and Pathology of Marine Molluscs, Avenue de Mus du Loup, 17390 La Tremblade (France); Burgeot, Thierry; Akcha, Farida [Ifremer, Department of Biogeochemistry and Ecotoxicology, Laboratory of Ecotoxicology, Rue de l’Ile d’Yeu, BP 21105, 44311 Nantes Cedex 03 (France)

    2015-02-15

    Highlights: • FISH was realized on oyster embryos from diuron-exposed genitors. • rDNA genes were used as probes on the interphase nuclei of embryo preparations. • Higher aneuploidy level was observed in embryos from diuron-exposed genitors. • Hypo- and hyperdiploid (triploid) nuclei were detected. - Abstract: Changes in normal chromosome numbers (i.e. aneuploidy) due to abnormal chromosome segregation may arise either spontaneously or as a result of chemical/radiation exposure, particularly during cell division. Coastal ecosystems are continuously subjected to various contaminants originating from urban, industrial and agricultural activities. Genotoxicity is common to several families of major environmental pollutants, including pesticides, which therefore represent a potential important environmental hazard for marine organisms. A previous study demonstrated the vertical transmission of DNA damage by subjecting oyster genitors to short-term exposure to the herbicide diuron at environmental concentrations during gametogenesis. In this paper, Fluorescent in situ hybridization (FISH) was used to further characterize diuron-induced DNA damage at the chromosomal level. rDNA genes (5S and 18-5.8-28S), previously mapped onto Crassostrea gigas chromosomes 4, 5 and 10, were used as probes on the interphase nuclei of embryo preparations. Our results conclusively show higher aneuploidy (hypo- or hyperdiploidy) level in embryos from diuron-exposed genitors, with damage to the three studied chromosomal regions. This study suggests that sexually developing oysters are vulnerable to diuron exposure, incurring a negative impact on reproductive success and oyster recruitment.

  5. Parental exposure to environmental concentrations of diuron leads to aneuploidy in embryos of the Pacific oyster, as evidenced by fluorescent in situ hybridization

    International Nuclear Information System (INIS)

    Barranger, Audrey; Benabdelmouna, Abdellah; Dégremont, Lionel; Burgeot, Thierry; Akcha, Farida

    2015-01-01

    Highlights: • FISH was realized on oyster embryos from diuron-exposed genitors. • rDNA genes were used as probes on the interphase nuclei of embryo preparations. • Higher aneuploidy level was observed in embryos from diuron-exposed genitors. • Hypo- and hyperdiploid (triploid) nuclei were detected. - Abstract: Changes in normal chromosome numbers (i.e. aneuploidy) due to abnormal chromosome segregation may arise either spontaneously or as a result of chemical/radiation exposure, particularly during cell division. Coastal ecosystems are continuously subjected to various contaminants originating from urban, industrial and agricultural activities. Genotoxicity is common to several families of major environmental pollutants, including pesticides, which therefore represent a potential important environmental hazard for marine organisms. A previous study demonstrated the vertical transmission of DNA damage by subjecting oyster genitors to short-term exposure to the herbicide diuron at environmental concentrations during gametogenesis. In this paper, Fluorescent in situ hybridization (FISH) was used to further characterize diuron-induced DNA damage at the chromosomal level. rDNA genes (5S and 18-5.8-28S), previously mapped onto Crassostrea gigas chromosomes 4, 5 and 10, were used as probes on the interphase nuclei of embryo preparations. Our results conclusively show higher aneuploidy (hypo- or hyperdiploidy) level in embryos from diuron-exposed genitors, with damage to the three studied chromosomal regions. This study suggests that sexually developing oysters are vulnerable to diuron exposure, incurring a negative impact on reproductive success and oyster recruitment

  6. Tissue lead concentration during chronic exposure of Pimephales promelas (fathead minnow) to lead nitrate in aquarium water.

    Science.gov (United States)

    Spokas, Eric G; Spur, Bernd W; Smith, Holly; Kemp, Francis W; Bogden, John D

    2006-11-01

    The fathead minnow is a useful species for evaluating the toxicity of wastewater effluents. While this fish is widely used for "survival" studies of metal toxicity, little or no work has been done on the tissue distribution of metals in fathead minnows. To determine the distribution of tissue lead, aquarium studies were conducted for several weeks with fish maintained in soft synthetic freshwater. Lead- (II) nitrate was added to three aquaria attaining concentrations of 20-30 ppb (aquarium B), 100-140 ppb (aquarium C), and roughly 200 ppb (aquarium D). Results were compared to controls (aquarium A). During the initial week, the majority of aquarium D fish died, whereas few deaths occurred in the other groups. Lead accumulation was dose- and tissue-dependent, with highest uptake by the gills. Gill concentrations of aquarium D fish averaged about 4-fold higherthan in skeleton or skin and muscle. In vitro, lead (2.5-25 ppm) caused dose-dependent reductions in the ratio of reduced glutathione/oxidized glutathione (GSH/GSSG) in gills incubated in physiological buffer. These findings demonstrate that fathead minnow gills bind and accumulate waterborne lead rapidly and preferentially and raise the possibility that gill lipid peroxidation contributes to lead toxicity at low water hardness.

  7. Radon concentration in drinking water and supplementary exposure in Baita-Stei mining area, Bihor county (Romania).

    Science.gov (United States)

    Moldovan, Mircea; Nita, Dan Constantin; Cucos-Dinu, Alexandra; Dicu, Tiberius; Bican-Brisan, Nicoleta; Cosma, Constantin

    2014-03-01

    The radon concentration was measured in the drinking water of public water supply and private wells located in the mining area of BăiŢa-Ştei, Bihor County, Romania. The measurements were performed using the LUK-VR system based on radon gas measurement with Lucas cell. The results show that the radon concentrations are within the range of 1.9-134.3 kBq m(-3) with an average value of 35.5 kBq m(-3) for well water, 18.5 kBq m(-3) for spring water and 6.9 kBq m(-3) for tap water. Comparing with previous data from the whole of Transylvania, the average value is two times higher, proving this zone to be a radon-prone area. From the results of this study the effective dose to the population is between 4.78 and 338.43 µSv y(-1). These doses are within the recommended limits of the world organisations.

  8. Urinary trans-trans muconic acid (exposure biomarker to benzene) and hippuric acid (exposure biomarker to toluene) concentrations in Mexican women living in high-risk scenarios of air pollution.

    Science.gov (United States)

    Pruneda-Alvarez, Lucía G; Ruíz-Vera, Tania; Ochoa-Martínez, Angeles C; Pérez-Maldonado, Iván N

    2017-11-02

    This study aimed to determine t,t-muconic acid (t,t-MA; exposure biomarker for benzene) and hippuric acid (HA; exposure biomarker for toluene) concentrations in the urine of women living in Mexico. In a cross-sectional study, apparently healthy women (n = 104) were voluntarily recruited from localities with a high risk of air pollution; t,t-MA and HA in urine were quantified using a high-performance liquid chromatography (HPLC) technique. Mean urinary levels of t,t-MA ranged from 680 to 1,310 μg/g creatinine. Mean values of HA ranged from 0.38 to 0.87 g/g creatinine. In conclusion, compared to data recently reported in literature, we found high urinary levels of t,t-MA and HA in assessed women participating in this study. We therefore deem the implementation of a strategy aimed at the reduction of exposure as a necessary measure for the evaluated communities.

  9. Measure of exposure of short-lived radon products using an alpha spectrometer for measuring indoor aerosol activity concentration and dose evaluation

    International Nuclear Information System (INIS)

    Berico, M.; Castellani, C. M.; Formignani, M.; Mariotti, F.

    2001-01-01

    A new italian law introduces the regulation of occupational exposure to radon. To evaluate the inhalation of radon daughters by the workers a sampling device has been assembled with the aim of evaluation of unattached and aerosol attached radon daughters' fractions. The instrument, based on selection of the aerosuspended particles by means of a wire screen type battery and subsequent collection on a total filter, allows to describe the behaviour of both fractions using defined temporal pattern of collecting particles and counting them by alpha spectroscopy. A measurement campaign to test the radon daughter dichotomous spectrometer in comparison with a commercial Radon Working Level meter, has been performed in a research laboratory of central Italy affected by high radon concentrations. The radon concentration during the measurement campaign has been also measured. The equilibrium factor F e q ad the attachment factor fp have been evaluated during 3 days campaign. Using the measured mean parameters (radon concentration, F e q, f p ) the dose evaluation for workers using dosimetric approach has been performed. A comparison between the epidemiologic approach, based on the radon concentration, and dosimetric approach is also presented [it

  10. Concentration and chemical status of arsenic in the blood of pregnant hamsters during critical embryogenesis. 1. Subchronic exposure to arsenate utilizing constant rate administration

    Energy Technology Data Exchange (ETDEWEB)

    Hanlon, D.P.; Ferm, V.H.

    1986-08-01

    The concentration, availability, and chemical status of radiolabeled arsenic has been determined in the blood of pregnant hamsters at the beginning (morning of Day 8) and the end (morning of Day 9) of the critical period of embryogenesis. Hamster dams were exposed to teratogenic doses of arsenate by means of osmotic minipumps implanted on the morning of Day 6 of the gestation period. Whole blood arsenic concentrations were the same for 48 and 72 hr postimplant. The arsenic concentration of plasma equaled that of red cells. Plasma arsenic was not bound to macromolecules and had the same chemical status 48 and 72 hr postimplant. Arsenate was the dominant form (67% of the total). However, the presence of dimethylarsinic acid and arsenite indicates that the pentavalent species was metabolized. Red cell arsenic was bound to macromolecules in the cell sap. Seventy percent of red cell sap arsenic was dialyzable 48 hr postimplant, but only 56% 72 hr postimplant. Arsenate was the dominant dialyzable red cell species on Day 8 and arsenite was the major dialyzable form on Day 9. The authors findings demonstrate a relationship between the maternal blood concentration and chemical status of arsenic and the presence of malformations resulting from a constant rate exposure of pregnant hamsters to arsenate via the osmotic minipump.

  11. Concentration and chemical status of arsenic in the blood of pregnant hamsters during critical embryogenesis. 1. Subchronic exposure to arsenate utilizing constant rate administration

    International Nuclear Information System (INIS)

    Hanlon, D.P.; Ferm, V.H.

    1986-01-01

    The concentration, availability, and chemical status of radiolabeled arsenic has been determined in the blood of pregnant hamsters at the beginning (morning of Day 8) and the end (morning of Day 9) of the critical period of embryogenesis. Hamster dams were exposed to teratogenic doses of arsenate by means of osmotic minipumps implanted on the morning of Day 6 of the gestation period. Whole blood arsenic concentrations were the same for 48 and 72 hr postimplant. The arsenic concentration of plasma equaled that of red cells. Plasma arsenic was not bound to macromolecules and had the same chemical status 48 and 72 hr postimplant. Arsenate was the dominant form (67% of the total). However, the presence of dimethylarsinic acid and arsenite indicates that the pentavalent species was metabolized. Red cell arsenic was bound to macromolecules in the cell sap. Seventy percent of red cell sap arsenic was dialyzable 48 hr postimplant, but only 56% 72 hr postimplant. Arsenate was the dominant dialyzable red cell species on Day 8 and arsenite was the major dialyzable form on Day 9. The authors findings demonstrate a relationship between the maternal blood concentration and chemical status of arsenic and the presence of malformations resulting from a constant rate exposure of pregnant hamsters to arsenate via the osmotic minipump

  12. Rapid Chondrocyte Isolation for Tissue Engineering Applications: The Effect of Enzyme Concentration and Temporal Exposure on the Matrix Forming Capacity of Nasal Derived Chondrocytes

    Directory of Open Access Journals (Sweden)

    Srujana Vedicherla

    2017-01-01

    Full Text Available Laboratory based processing and expansion to yield adequate cell numbers had been the standard in Autologous Disc Chondrocyte Transplantation (ADCT, Allogeneic Juvenile Chondrocyte Implantation (NuQu®, and Matrix-Induced Autologous Chondrocyte Implantation (MACI. Optimizing cell isolation is a key challenge in terms of obtaining adequate cell numbers while maintaining a vibrant cell population capable of subsequent proliferation and matrix elaboration. However, typical cell yields from a cartilage digest are highly variable between donors and based on user competency. The overall objective of this study was to optimize chondrocyte isolation from cartilaginous nasal tissue through modulation of enzyme concentration exposure (750 and 3000 U/ml and incubation time (1 and 12 h, combined with physical agitation cycles, and to assess subsequent cell viability and matrix forming capacity. Overall, increasing enzyme exposure time was found to be more detrimental than collagenase concentration for subsequent viability, proliferation, and matrix forming capacity (sGAG and collagen of these cells resulting in nonuniform cartilaginous matrix deposition. Taken together, consolidating a 3000 U/ml collagenase digest of 1 h at a ratio of 10 ml/g of cartilage tissue with physical agitation cycles can improve efficiency of chondrocyte isolation, yielding robust, more uniform matrix formation.

  13. Radionuclide concentrations in raw and purified phosphoric acids from Brazil and their processing wastes: implications for radiation exposures.

    Science.gov (United States)

    da Conceição, Fabiano Tomazini; Antunes, Maria Lúcia Pereira; Durrant, Steven F

    2012-02-01

    Radionuclides from the U and Th natural series are present in alkaline rocks, which are used as feedstock in Brazil for the production of raw phosphoric acid, which can be considered as a NORM (naturally occurring radioactive material). As a result of the purification of raw phosphoric acid to food-grade phosphoric acid, two by-products are generated, i.e., solid and liquid wastes. Taking this into account, the main aim of this study was to evaluate the fluxes of natural radionuclide in the production of food-grade phosphoric acids in Brazil, to determine the radiological impact caused by ingestion of food-grade phosphoric acid, and to evaluate the solid waste environmental hazards caused by its application in crop soils. Radiological characterization of raw phosphoric acid, food-grade phosphoric acid, solid waste, and liquid waste was performed by alpha and gamma spectrometry. The (238)U, (234)U, (226)Ra, and (232)Th activity concentrations varied depending on the source of raw phosphoric acid. Decreasing radionuclides activity concentrations in raw phosphoric acids used by the producer of the purified phosphoric acid were observed as follows: Tapira (raw phosphoric acid D) > Catalão (raw phosphoric acids B and C) > Cajati (raw phosphoric acid A). The industrial purification process produces a reduction in radionuclide activity concentrations in food-grade phosphoric acid in relation to raw phosphoric acid produced in plant D and single raw phosphoric acid used in recent years. The most common use of food-grade phosphoric acid is in cola soft drinks, with an average consumption in Brazil of 72 l per person per year. Each liter of cola soft drink contains 0.5 ml of food-grade phosphoric acid, which gives an annual average intake of 36 ml of food-grade phosphoric acid per person. Under these conditions, radionuclide intake through consumption of food-grade phosphoric acid per year per person via cola soft drinks is not hazardous to human health in Brazil

  14. A Case Study Application of the Aggregate Exposure Pathway (AEP) and Adverse Outcome Pathway (AOP) Frameworks to Facilitate the Integration of Human Health and Ecological End Points for Cumulative Risk Assessment (CRA)

    Science.gov (United States)

    Cumulative risk assessment (CRA) methods promote the use of a conceptual site model (CSM) to apportion exposures and integrate risk from multiple stressors. While CSMs may encompass multiple species, evaluating end points across taxa can be challenging due to data availability an...

  15. Degreening and cold storage of ‘Murcott’ tangor as function concentration and exposure time to ethylene

    Directory of Open Access Journals (Sweden)

    Maria Luiza Lye Jomori

    2014-02-01

    Full Text Available Degreening treatment has been applied in traditional countries exporters and consumers of fresh citrus to improve rind color of fruit cultivated in regions that no shown low temperature during maturation. In Brazil, this technique is performed empirically, without control of application conditions and fruit shown low extern quality. This study was carried out with the objective to determinate conditions to the technique of postharvest degreening of ‘Murcott’ orange, involving the application of exogenous ethylene. The concentrations 5 and 10 mL L-1 of ethylene was applied inside the chamber for 96 and 120 hours at 25oC and 90% RH. After treatments fruit were stored at 5°C during for 30 days, and after that, plus 3 days at 25ºC. Fruit were evaluated in four periods: after harvest; after degreening treatment, after cold storage and after 3 days at 25°C (simulated marketing. The variable analyzed were: skin color, soluble solids (SS, titratable acidity (TA, ratio (SS/TA, ascorbic acid, percentage of juice, chlorophyll and carotenoids content, chlorophyllase activity, respiratory rate and ethylene production. The treatments did not affect the soluble solids, titratable acidity, ratio, percentage of juice and ascorbic acid content. Fruit treated with ethylene showed increase of color index concomitant by higher chlorophyllase activity and lower chlorophyll content. There were no differences in the carotenoids content in the periods evaluated. Fruit treated with ethylene at both concentrations had higher ethylene production, whereas the dose of 10 mL L-1 favored the incidence of decay. Ethylene 5 mL L-1 for 96 hours is enough to trigger the process of degreening ‘ Murcott’ tangor and can be used to improve skin color of this cultivar.

  16. Effects of acute exposure to increased plasma branched-chain amino acid concentrations on insulin-mediated plasma glucose turnover in healthy young subjects.

    Science.gov (United States)

    Everman, Sarah; Mandarino, Lawrence J; Carroll, Chad C; Katsanos, Christos S

    2015-01-01

    Plasma branched-chain amino acids (BCAA) are inversely related to insulin sensitivity of glucose metabolism in humans. However, currently, it is not known whether there is a cause-and-effect relationship between increased plasma BCAA concentrations and decreased insulin sensitivity. To determine the effects of acute exposure to increased plasma BCAA concentrations on insulin-mediated plasma glucose turnover in humans. Ten healthy subjects were randomly assigned to an experiment where insulin was infused at 40 mU/m2/min (40U) during the second half of a 6-hour intravenous infusion of a BCAA mixture (i.e., BCAA; N = 5) to stimulate plasma glucose turnover or under the same conditions without BCAA infusion (Control; N = 5). In a separate experiment, seven healthy subjects were randomly assigned to receive insulin infusion at 80 mU/m2/min (80U) in association with the above BCAA infusion (N = 4) or under the same conditions without BCAA infusion (N = 3). Plasma glucose turnover was measured prior to and during insulin infusion. Insulin infusion completely suppressed the endogenous glucose production (EGP) across all groups. The percent suppression of EGP was not different between Control and BCAA in either the 40U or 80U experiments (P > 0.05). Insulin infusion stimulated whole-body glucose disposal rate (GDR) across all groups. However, the increase (%) in GDR was not different [median (1st quartile - 3rd quartile)] between Control and BCAA in either the 40U ([199 (167-278) vs. 186 (94-308)] or 80 U ([491 (414-548) vs. 478 (409-857)] experiments (P > 0.05). Likewise, insulin stimulated the glucose metabolic clearance in all experiments (P BCAA in either of the experiments (P > 0.05). Short-term exposure of young healthy subjects to increased plasma BCAA concentrations does not alter the insulin sensitivity of glucose metabolism.

  17. Concentrations of polybrominated diphenyl ethers (PBDEs) in central air-conditioner filter dust and relevance of non-dietary exposure in occupational indoor environments in Greece

    International Nuclear Information System (INIS)

    Besis, Athanasios; Katsoyiannis, Athanasios; Botsaropoulou, Elisavet; Samara, Constantini

    2014-01-01

    Polybrominated Diphenyl Ethers (PBDEs) are ubiquitous in the indoor environment owing to their use in consumer products and various studies around the world have found higher concentrations indoors than outdoors. Central air conditioner (A/C) systems have been widely used in many workplaces, therefore, studying of PBDEs in central A/C filter dust is useful to better understand the occurrences and health implications of PBDEs in indoor environments. The present study examined the occurrence of PBDEs in central A/C filter dust collected from various workplaces (n = 20) in Thessaloniki, Greece. The sum concentrations of 21 target congeners (∑ 21 PBDE) in A/C dust ranged between 84 and 4062 ng g −1 with a median value of 1092 ng g −1 , while BDE-209 was found to be the most abundant BDE congener. The daily intake via dust ingestion of PBDEs estimated for the employees of the occupational settings ranged from 3 to 45 ng day −1 (median 12 ng day −1 ). - Highlights: • PBDEs were investigated in dust of A/C filters in occupational settings in Thessaloniki, Greece. • BDE-209 was found to be the most abundant BDE congener. • High levels of PBDEs were found in a newspaper building, internet cafes and electronic shops. • PBDEs were attributable to the extensive presence and/or usage of electronic devices. • Exposure of employees to PBDEs via indoor dust ingestion was estimated at 12 ng day −1 . - PBDEs were for the first time measured in dust from central A/C filters in workplaces of Greece and their concentrations were used to estimate the non-dietary human exposure

  18. Effects of acute exposure to increased plasma branched-chain amino acid concentrations on insulin-mediated plasma glucose turnover in healthy young subjects.

    Directory of Open Access Journals (Sweden)

    Sarah Everman

    Full Text Available Plasma branched-chain amino acids (BCAA are inversely related to insulin sensitivity of glucose metabolism in humans. However, currently, it is not known whether there is a cause-and-effect relationship between increased plasma BCAA concentrations and decreased insulin sensitivity.To determine the effects of acute exposure to increased plasma BCAA concentrations on insulin-mediated plasma glucose turnover in humans.Ten healthy subjects were randomly assigned to an experiment where insulin was infused at 40 mU/m2/min (40U during the second half of a 6-hour intravenous infusion of a BCAA mixture (i.e., BCAA; N = 5 to stimulate plasma glucose turnover or under the same conditions without BCAA infusion (Control; N = 5. In a separate experiment, seven healthy subjects were randomly assigned to receive insulin infusion at 80 mU/m2/min (80U in association with the above BCAA infusion (N = 4 or under the same conditions without BCAA infusion (N = 3. Plasma glucose turnover was measured prior to and during insulin infusion.Insulin infusion completely suppressed the endogenous glucose production (EGP across all groups. The percent suppression of EGP was not different between Control and BCAA in either the 40U or 80U experiments (P > 0.05. Insulin infusion stimulated whole-body glucose disposal rate (GDR across all groups. However, the increase (% in GDR was not different [median (1st quartile - 3rd quartile] between Control and BCAA in either the 40U ([199 (167-278 vs. 186 (94-308] or 80 U ([491 (414-548 vs. 478 (409-857] experiments (P > 0.05. Likewise, insulin stimulated the glucose metabolic clearance in all experiments (P 0.05.Short-term exposure of young healthy subjects to increased plasma BCAA concentrations does not alter the insulin sensitivity of glucose metabolism.

  19. Effects of Low Ozone Concentrations and Short Exposure Times on the Mortality of Immature Stages of the Indian Meal Moth, Plodia Interpunctella (Lepidoptera: Pyralidae

    Directory of Open Access Journals (Sweden)

    Keivanloo Ensieh

    2014-07-01

    Full Text Available In Iran, the Indian meal moth, Plodia interpunctella (Hübner, is one of the most important pests of such stored products as date fruits and pistachio nuts. Ozone was applied as a gas at four concentrations (0, 2, 3, and 5 ppm for four different periods (30, 60, 90, and 120 min on the immature stages of P. interpunctella. The results indicated that by increasing the concentration and exposure time, the rate of mortality increased for all tested stages. This study showed that 12-day-old larvae were more susceptible than other stages when exposed to 5 ppm ozone for 120 min. The next in order of susceptibility were pupae, then 5-day-old larvae, and 17-dayold larvae had the highest sensitivity to ozonation. At the highest concentration of ozone, for the longest time, the least mortality rate was recorded for one-day-old eggs. According to the results, a reduction in the population density of P. interpunctella in laboratory experiments is promising. However, validation studies will be necessary to fully determine the potential of ozone as a replacement for the current post harvest chemical control of P. interpunctella on either pistachio nuts or date fruits.

  20. Chronic exposure to low environmental concentrations and legal aquaculture doses of antibiotics cause systemic adverse effects in Nile tilapia and provoke differential human health risk.

    Science.gov (United States)

    Limbu, Samwel M; Zhou, Li; Sun, Sheng-Xiang; Zhang, Mei-Ling; Du, Zhen-Yu

    2018-06-01

    Antibiotics used globally to treat human and animal diseases exist ubiquitously in the environment at low doses because of misuse, overdose and poor absorption after ingestion, coupled with their high-water solubility and degradation resistance. However, the systemic chronic effects of exposure to low environmental concentrations of antibiotics (LECAs) and legal aquaculture doses of antibiotics (LADAs) in fish and their human health risk are currently unknown. To investigate the in vivo chronic effects of exposure to LECAs and LADAs using oxytetracycline (OTC) and sulfamethoxazole (SMZ) in Nile tilapia (Oreochromis niloticus) and their human health risk. Twenty O. niloticus weighing 27.73 ± 0.81 g were exposed to water containing LECAs (OTC at 420 ng/L and SMZ at 260 ng/L) and diets supplemented with LADAs (OTC 80 mg/kg/day and SMZ 100 mg/kg/day) for twelve weeks. General physiological functions, metabolic activities, intestinal and hepatic health were systemically evaluated. The possible human health risks of the consumption of the experimental Nile tilapia fillets in adults and children were assessed by using risk quotient. After exposure, we observed retarded growth performance accompanied by reduced nutrients digestibility, feed efficiency, organ indices, and lipid body composition in treated fish. Antibiotics distorted intestinal morphological features subsequently induced microbiota dysbiosis and suppressed intestinal tight junction proteins. Exposure of fish to LECAs and LADAs induced oxidative stress, suppressed innate immunity, stimulated inflammatory and detoxification responses, concomitantly inhibited antioxidant capacity and caused lipid peroxidation in intestine and liver organs. Both LECAs and LADAs enhanced gluconeogenesis, inhibited lipogenesis and fatty acid beta oxidation in intestine and liver organs. The exposure of fish to LECAs and LADAs induced anaerobic glycolytic pathway and affected intestinal fat catabolism in intestine

  1. Maximum permissible body burdens and maximum permissible concentrations of radionuclides in air and in water for occupational exposure. Recommendations of the National Committee on Radiation Protection. Handbook 69

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1959-06-05

    The present Handbook and its predecessors stem from the Second International Congress of Radiology, held in Stockholm in 1928. At that time, under the auspices of the Congress, the International Commission on Radiological Protection (ICRP) was organized to deal initially with problems of X-ray protection and later with radioactivity protection. At that time 'permissible' doses of X-rays were estimated primarily in terms of exposures which produced erythema, the amount of exposure which would produce a defined reddening of the skin. Obviously a critical problem in establishing criteria for radiation protection was one of developing useful standards and techniques of physical measurement. For this reason two of the organizations in this country with a major concern for X-ray protection, the American Roentgen Ray Society and the Radiology Society of North America, suggested that the National Bureau of Standards assume responsibility for organizing representative experts to deal with the problem. Accordingly, early in 1929, an Advisory Committee on X-ray and Radium Protection was organized to develop recommendations on the protection problem within the United States and to formulate United States points of view for presentation to the International Commission on Radiological Protection. The organization of the U.S. Advisory Committee included experts from both the medical and physical science fields. The recommendations of this Handbook take into consideration the NCRP statement entitled 'Maximum Permissible Radiation Exposures to Man', published as an addendum to Handbook 59 on April 15, 1958. As noted above this study was carried out jointly by the ICRP and the NCRP, and the complete report is more extensive than the material contained in this Handbook.

  2. Maximum permissible body burdens and maximum permissible concentrations of radionuclides in air and in water for occupational exposure. Recommendations of the National Committee on Radiation Protection. Handbook 69

    International Nuclear Information System (INIS)

    1959-01-01

    The present Handbook and its predecessors stem from the Second International Congress of Radiology, held in Stockholm in 1928. At that time, under the auspices of the Congress, the International Commission on Radiological Protection (ICRP) was organized to deal initially with problems of X-ray protection and later with radioactivity protection. At that time 'permissible' doses of X-rays were estimated primarily in terms of exposures which produced erythema, the amount of exposure which would produce a defined reddening of the skin. Obviously a critical problem in establishing criteria for radiation protection was one of developing useful standards and techniques of physical measurement. For this reason two of the organizations in this country with a major concern for X-ray protection, the American Roentgen Ray Society and the Radiology Society of North America, suggested that the National Bureau of Standards assume responsibility for organizing representative experts to deal with the problem. Accordingly, early in 1929, an Advisory Committee on X-ray and Radium Protection was organized to develop recommendations on the protection problem within the United States and to formulate United States points of view for presentation to the International Commission on Radiological Protection. The organization of the U.S. Advisory Committee included experts from both the medical and physical science fields. The recommendations of this Handbook take into consideration the NCRP statement entitled 'Maximum Permissible Radiation Exposures to Man', published as an addendum to Handbook 59 on April 15, 1958. As noted above this study was carried out jointly by the ICRP and the NCRP, and the complete report is more extensive than the material contained in this Handbook

  3. Comparison of a Point-of-Care Glucometer and a Laboratory Autoanalyzer for Measurement of Blood Glucose Concentrations in Domestic Pigeons ( Columba livia domestica).

    Science.gov (United States)

    Mohsenzadeh, Mahdieh Sadat; Zaeemi, Mahdieh; Razmyar, Jamshid; Azizzadeh, Mohammad

    2015-09-01

    Biochemical analysis is necessary for diagnosis and monitoring of diseases in birds; however, the small volume of blood that can be safely obtained from small avian species often limits laboratory diagnostic testing. Consequently, a suitable methodology requiring only a small volume of blood must be used. This study was designed to compare blood glucose concentrations in domestic pigeons ( Columba livia domestica) as measured by a commercial, handheld, human glucometer and a standard autoanalyzer. During the first phase of the study, whole blood samples obtained from 30 domestic pigeons were used to measure the blood glucose concentration with a glucometer, the packed cell volume (PCV), and the total erythrocyte count (nRBC). Plasma separated from the each sample was then used to obtain the plasma glucose concentration with the autoanalyzer. During the second phase of the study, 30 pigeons were assigned to 2 equal groups (n = 15). Hypoglycemia or hyperglycemia was induced in each group by intravenous injection of insulin or glucose, respectively. Blood was collected and processed, and glucose concentrations, PCV, and nRBC were measured as previously described. Linear-regression models demonstrated a significant relationship between results measured by the glucometer and autoanalyzer results from normoglycemic (correlation coefficient [R] = 0.43, P = .02), hypoglycemic (R = 0.95; P < .001), and hyperglycemic (R = 0.81; P < .001) birds. The results of this study suggest that we can predict the real blood-glucose concentration of pigeons by using results obtained by a glucometer.

  4. Response of needle dark respiration of Pinus koraiensis and Pinus sylvestriformis to elevated CO2 concentra-tions for four growing seasons’ exposure

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The long-term effect of elevated CO2 concentrations on needle dark respiration of two coniferous spe- cies—Pinus koraiensis and Pinus sylvestriformis on the Changbai Mountain was investigated using open-top chambers. P. koraiensis and P. sylvestriformis were exposed to 700, 500 μmol·mol-1 CO2 and ambient CO2 (approx. 350 μmol·mol-1) for four growing seasons. Needle dark respiration was meas- ured during the second, third and fourth growing seasons’ exposure to elevated CO2. The results showed that needle dark respiration rate increased for P. koraiensis and P. sylvestriformis grown at elevated CO2 concentrations during the second growing season, could be attributed to the change of carbohydrate and/or nitrogen content of needles. Needle dark respiration of P. koraiensis was stimu- lated and that of P. sylvestriformis was inhibited by elevated CO2 concentrations during the third growing season. Different response of the two tree species to elevated CO2 mainly resulted from the difference in the growth rate. Elevated CO2 concentrations inhibited needle dark respiration of both P. koraiensis and P. sylvestriformis during the fourth growing season. There was consistent trend be- tween the short-term effect and the long-term effect of elevated CO2 on needle dark respiration in P. sylvestriformis during the third growing season by changing measurement CO2 concentrations. How- ever, the short-term effect was different from the long-term effect for P. koraiensis. Response of dark respiration of P. koraiensis and P. sylvestriformis to elevated CO2 concentrations was related to the treatment time of CO2 and the stage of growth and development of plant. The change of dark respiration for the two tree species was determined by the direct effect of CO2 and long-term acclimation. The prediction of the long-term response of needle dark respiration to elevated CO2 concentration based on the short-term response is in dispute.

  5. Indoor and outdoor sources of size-resolved mass concentration of particulate matter in a school gym-implications for exposure of exercising children.

    Science.gov (United States)

    Braniš, Martin; Safránek, Jiří; Hytychová, Adéla

    2011-05-01

    activity is the main source of indoor emission of coarse particles. The fourth factor involved only outdoor variables showing the resuspension of coarse ambient aerosol on dry and warm days without its seeming effect on the indoor coarse PM levels. Having in mind that high concentrations of both fine and coarse aerosol were frequently observed in the studied space, our results suggest that indoor exercise in polluted urbanized areas may increase the overall exposure and thus represent a potential health risk to young individuals during physical education at schools.

  6. Can insoluble polysaccharide concentration in dental plaque, sugar exposure and cariogenic microorganisms predict early childhood caries? A follow-up study.

    Science.gov (United States)

    Parisotto, T M; Stipp, R; Rodrigues, L K A; Mattos-Graner, R O; Costa, L S; Nobre-Dos-Santos, M

    2015-08-01

    Insoluble polysaccharide (IP) has been associated with caries prevalence in young children. However, the power of IP to predict ECC needs to be demonstrated. To assess the relationships between early childhood caries (ECC) and extracellular insoluble polysaccharides (IP) in dental plaque, sugar exposure and cariogenic microorganisms. Visible plaque on maxillary incisors was recorded, followed by caries diagnosis in 65 preschoolers (3-4 years) at baseline and after 1 year. Plaque was collected for mutans streptococci (MS), total microorganism (TM) and lactobacilli (LB) enumerations in selective media, as well as for IP analysis, which was later assessed by colorimetry. Sugar/sucrose exposure was assessed by a diet chart. Positive correlations were found among the prevalence of caries and MS, TM, LB, solid sucrose and visible dental plaque. Additionally, children with IP concentrations in dental plaque higher than 2.36 μg/mg (odds ratio-OR=6.8), with visible plaque on maxillary incisors (OR=4.3), harbouring LB (OR=13) and exposed to solid sugar more than twice/day (OR=5) showed higher risk of developing caries (pdental plaque and cariogenic microorganisms could predict caries development, partially explaining the ECC pattern. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Long-term exposure to gold nanoparticles accelerates larval metamorphosis without affecting mass in wood frogs (Lithobates sylvaticus) at environmentally relevant concentrations.

    Science.gov (United States)

    Fong, Peter P; Thompson, Lucas B; Carfagno, Gerardo L F; Sitton, Andrea J

    2016-09-01

    Nanoparticles are environmental contaminants of emerging concern. Exposure to engineered nanoparticles has been shown to have detrimental effects on aquatic organisms. The authors synthesized gold nanoparticles (18.1 ± 3.5 nm) and tested their effects on time to and weight at metamorphosis in wood frog (Lithobates sylvaticus) tadpoles, a species known to be sensitive to environmental stressors. Continuous exposure to all concentrations of gold nanoparticles (0.05 pM, 0.5 pM, and 5 pM in particles) for up to 55 d significantly reduced time to metamorphosis by as much as an average of 3 d (p metamorphosis. The approximately 18-nm gold nanoparticles used were metastable in dechlorinated tap water, resulting in a change in surface charge and aggregation over time, leading to negatively charged aggregates that were on the order of 60 nm to 110 nm. Nanoparticle aggregation could exacerbate the effect on time to metamorphosis. To the authors' knowledge, the present study is the first report on the effect of engineered nanoparticles of any kind on life-history variables in an amphibian, a taxonomic group that has been declining globally for at least 25 yr. Environ Toxicol Chem 2016;35:2304-2310. © 2016 SETAC. © 2016 SETAC.

  8. Serum concentrations of organochlorine compounds and predictors of exposure in children living in agricultural communities from South-Eastern Spain

    DEFF Research Database (Denmark)

    González-Alzaga, B.; Lacasaña, M.; Hernández, A. F.

    2017-01-01

    BACKGROUND: Information on exposure levels to organochlorine compounds (OCs) in child population is limited, despite their greater vulnerability to the adverse health effects of these chemicals. OBJECTIVE: To determine serum concentrations of 10 OCs (including organochlorine pesticides and polych...... are no longer used. Their presence in children serum can be explained by their high lipophilicity and environmental persistence, leading to contamination of fatty food. In this line, fish consumption seemed to be the most relevant determinant of OC levels found in our study....... and polychlorinated biphenyls -PCBs-) in children living in agricultural communities from Almería (South-Eastern Spain), and to identify the main predictors of exposure related to socio-economic characteristics, diet and lifestyle. METHODS: A cross-sectional study was conducted on 133 children aged 6-11 years...... selected from public schools of the study area. OCs compounds were determined in serum samples by GC/ECD. Anthropometric measures were obtained during sample collection. Information on sociodemographic characteristics, parental occupation, residential history, lifestyle and frequency of food consumption...

  9. Blood and hair mercury concentrations among Cree First Nations of Eeyou Istchee (Quebec, Canada): time trends, prenatal exposure and links to local fish consumption.

    Science.gov (United States)

    Ripley, Susannah; Robinson, Elizabeth; Johnson-Down, Louise; Andermann, Anne; Ayotte, Pierre; Lucas, Michel; Nieboer, Evert

    2018-12-01

    To describe exposure to methylmercury among Cree, focusing on women of childbearing age, we used data from 2 studies. Multiple regression was employed to examine associations between blood and hair mercury concentrations and consumption of locally harvested fish. Approximately 9.9% of non-pregnant women aged 15-44 y and 3.9% of pregnant women required follow-up according to Health Canada's blood mercury guidance value of 40 nmol/L. 8% of hair mercury observations in the non-pregnant women and 2.5% among pregnant women exceeded the equivalent threshold of 10 nmol/g. The geometric mean blood mercury concentration was 12.7 nmol/L in 1,429 persons aged 8 and over, and 17.7 nmol/L in adults aged 18 and older. The proportion of hair mercury concentrations greater than 12.5 nmol/g decreased in all age-sex groups when comparing the 2002-2009 data to published values for 1993-1994. Among women of childbearing age, local fish consumption was associated with increased blood and hair mercury concentrations. While over 90% of women of childbearing age in this population have acceptable levels of mercury, ongoing intake of mercury suggests that their consumption of fish with known high mercury content be minimised. Reducing consumption of fish known to be high in mercury content needs to be balanced with promoting ongoing connection to Cree culture and land-based activities that are also important determinants of health.

  10. Health Risk Impacts of Exposure to Airborne Metals and Benzo(a)Pyrene during Episodes of High PM10 Concentrations in Poland.

    Science.gov (United States)

    Widziewicz, Kamila; Rogula-Kozlowska, Wioletta; Loska, Krzysztof; Kociszewska, Karolina; Majewski, Grzegorz

    2018-01-01

    To check whether health risk impacts of exposure to airborne metals and Benzo(a) Pyrene during episodes of high PM10 concentrations lead to an increased number of lung cancer cases in Poland. In this work, we gathered data from 2002 to 2014 concerning the ambient concentrations of PM10 and PM10-bound carcinogenic Benzo(a)pyrene [B(a)P] and As, Cd, Pb, and Ni. With the use of the criterion of the exceedance in the daily PM10 mass concentration on at least 50% of all the analyzed stations, the PM10 maxima's were selected. Lung cancer occurrences in periods with and without the episodes were further compared. During a 12-year period, 348 large-scale smog episodes occurred in Poland. A total of 307 of these episodes occurred in the winter season, which is characterized by increased emissions from residential heating. The occurrence of episodes significantly (P < 0.05) increased the concentrations of PM10-bound carcinogenic As, Cd, Pb, Ni, and B(a)P. During these events, a significant increase in the overall health risk from those PM10-related compounds was also observed. The highest probability of lung cancer occurrences was found in cities, and the smallest probability was found in the remaining areas outside the cities and agglomerations. The link between PM pollution and cancer risk in Poland is a serious public health threat that needs further investigation. Copyright © 2018 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  11. Concentration and transportation of heavy metals in vegetables and risk assessment of human exposure to bioaccessible heavy metals in soil near a waste-incinerator site, South China.

    Science.gov (United States)

    Li, Ning; Kang, Yuan; Pan, Weijian; Zeng, Lixuan; Zhang, Qiuyun; Luo, Jiwen

    2015-07-15

    There is limited study focusing on the bioaccumulation of heavy metals in vegetables and human exposure to bioaccessible heavy metals in soil. In the present study, heavy metal concentrations (Cr, Ni, Cu, Pb and Cd) were measured in five types of vegetables, soil, root, and settled air particle samples from two sites (at a domestic waste incinerator and at 20km away from the incinerator) in Guangzhou, South China. Heavy metal concentrations in soil were greater than those in aerial parts of vegetables and roots, which indicated that vegetables bioaccumulated low amount of heavy metals from soil. The similar pattern of heavy metal (Cr, Cd) was found in the settled air particle samples and aerial parts of vegetables from two sites, which may suggest that foliar uptake may be an important pathway of heavy metal from the environment to vegetables. The highest levels of heavy metals were found in leaf lettuce (125.52μg/g, dry weight) and bitter lettuce (71.2μg/g) for sites A and B, respectively, followed by bitter lettuce and leaf lettuce for sites A and B, respectively. Swamp morning glory accumulated the lowest amount of heavy metals (81.02μg/g for site A and 53.2μg/g for site B) at both sites. The bioaccessibility of heavy metals in soil ranged from Cr (2%) to Cu (71.78%). Risk assessment showed that Cd and Pb in soil samples resulted in the highest non-cancer risk and Cd would result in unacceptable cancer risk for children and risk. The non-dietary intake of soil was the most important exposure pathway, when the bioaccessibility of heavy metals was taken into account. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Characterization of the analytic performance of an electrochemical point-of-care meter for measuring β-hydroxybutyrate concentration in blood and plasma from periparturient dairy cattle.

    Science.gov (United States)

    Megahed, Ameer A; Hiew, Mark W H; Townsend, Jonathan R; Constable, Peter D

    2017-06-01

    The Precision Xtra electrochemical meter is widely used to measure blood β-hydroxybutyrate concentration (BHBb) in dairy cattle. The meter uses an algorithm optimized for human blood that assumes the HCT in cattle is the same as in people, and that intra-erythrocyte β-hydroxybutyrate (BHBe) and plasma β-hydroxybutyrate (BHBp) concentration are equivalent. The first objective was to characterize the analytic performance of the meter for measuring BHBb and BHBp in dairy cattle. The second objective was to characterize the influence of HCT and sample temperature on BHBp concentration measured by the meter. Blood and plasma samples were obtained from 106 periparturient Holstein cattle and 15 lactating Holstein cows with experimentally induced electrolyte and acid-base imbalances. Meter performance was evaluated using Deming regression and Bland-Altman plots. Multivariable linear regression was used to determine the effect of HCT and sample temperature on BHBb and BHBp concentration, respectively. The meter was linear up to BHB = 3.0 mmol/L as measured by the reference method, equivalent to meter values for BHBb > 4.5 mmol/L and BHBp > 5.2 mmol/L. An increase in HCT resulted in higher BHBb concentration. This result was partially explained by BHBe being much lower than BHBp. Changes in sample temperature caused a linear change in measured BHBp whenever BHBp > 3.0 mmol/L. Meter accuracy was markedly dependent on the BHBe-to-BHBp ratio and consequently the HCT. Therefore, the algorithm used by the meter should be revised when applied to bovine blood for improved accuracy. © 2017 American Society for Veterinary Clinical Pathology.

  13. Chemical Concentrations in Field Mice from Open-Detonation Firing Sites TA-36 Minie and TA-39 Point 6 at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Fresquez, Philip R. [Los Alamos National Laboratory

    2011-01-01

    Field mice (mostly Peromyscus spp.) were collected at two open-detonation (high explosive) firing sites - Minie at Technical Area (TA) 36 and Point 6 at TA-39 - at Los Alamos National Laboratory in August of 2010 and in February of 2011 for chemical analysis. Samples of whole body field mice from both sites were analyzed for target analyte list elements (mostly metals), dioxin/furans, polychlorinated biphenyl congeners, high explosives, and perchlorate. In addition, uranium isotopes were analyzed in a composite sample collected from TA-36 Minie. In general, all constituents, with the exception of lead at TA-39 Point 6, in whole body field mice samples collected from these two open-detonation firing sites were either not detected or they were detected below regional statistical reference levels (99% confidence level), biota dose screening levels, and/or soil ecological chemical screening levels. The amount of lead in field mice tissue collected from TA-39 Point 6 was higher than regional background, and some lead levels in the soil were higher than the ecological screening level for the field mouse; however, these levels are not expected to affect the viability of the populations over the site as a whole.

  14. Tenofovir alafenamide (TAF) does not deplete mitochondrial DNA in human T-cell lines at intracellular concentrations exceeding clinically relevant drug exposures.

    Science.gov (United States)

    Stray, Kirsten M; Park, Yeojin; Babusis, Darius; Callebaut, Christian; Cihlar, Tomas; Ray, Adrian S; Perron, Michel

    2017-04-01

    HIV-infected patients treated with certain nucleoside reverse transcriptase inhibitors (NRTIs) have experienced adverse effects due to drug-related mitochondrial toxicity. Tenofovir alafenamide (TAF) is a novel prodrug of the NRTI tenofovir (TFV) with an improved safety profile compared to tenofovir disoproxil fumarate (TDF). Prior in vitro studies have demonstrated that the parent nucleotide TFV has no significant effects on mtDNA synthesis. This study investigated whether clinically relevant TAF and TDF exposures affect mtDNA content in human lymphocytes. First, activated or resting peripheral blood mononuclear cells (PBMCs), as well as MT-2 and Jurkat T-cell lines, were continuously treated with ddC for 10 days to establish their susceptibility to mtDNA depletion. PBMCs had low sensitivity to NRTI-mediated mtDNA depletion in vitro. In contrast, ddC treatment of rapidly dividing MT-2 and Jurkat cells resulted in a dose-dependent decrease in mtDNA. Therefore, these two T-cell lines were selected for evaluating TAF and TDF treatment effects. MT-2 and Jurkat cells were pulse-treated with TAF or TDF every 24 h for 10 days to mimic pharmacologically relevant drug exposures. Pulse treatment of cells with 3.3 μM TAF or 1.1 μM TDF for 10 days resulted in 2- to 7-fold greater steady-state intracellular TFV-diphosphate (TFV-DP) levels than those observed clinically in TAF- or TDF-treated patients. At these concentrations, no significant TAF- (106.7% and 84.1% of control; p = 0.77 and 0.12 for MT-2 and Jurkat, respectively) or TDF- (100.6% and 91.0% of control; p = 0.91 and 0.37, respectively) associated reduction in mtDNA content was observed compared with untreated control cells. This study demonstrates that, despite delivering higher intracellular levels of TFV-DP than TDF, TAF does not inhibit mtDNA synthesis in vitro at concentrations exceeding the clinically relevant intracellular drug exposures. Thus, TAF has a low potential for mitochondrial toxicity in

  15. Exposure of xenopus laevis tadpoles to cadmium reveals concentration-dependent bimodal effects on growth and monotonic effects on development and thyroid gland activity

    Science.gov (United States)

    Sharma, Bibek; Patino, R.

    2008-01-01

    Xenopus laevis were exposed to 0-855 ??g cadmium (Cd)/l (measured concentrations) in FETAX medium from fertilization to 47 days postfertilization. Measurements included embryonic survival and, at 47 days, tadpole survival, snout-vent length, tail length, total length, hindlimb length, weight, Nieuwkoop-Faber (NF) stage of development, initiation of metamorphic climax (??? NF 58), and thyroid follicle cell height. Embryonic and larval survival were unaffected by Cd. Relative to control tadpoles, reduced tail and total length were observed at 0.1- 8 and at 855 ??g Cd/l; and reduced snout-vent length, hindlimb length, and weight were observed at 0.1-1 and at 855 ??g Cd/l. Mean stage of development and rate of initiation of climax were unaffected by Cd at 0-84 ??g/l; however, none of the tadpoles exposed to 855 ??g Cd/l progressed beyond mid-premetamorphosis (NF 51). Thyroid glands with fully formed follicles were observed in all tadpoles ??? NF 49 examined. Follicle cell height was unaffected by Cd at 0-84 ??g/l but it was reduced at 855 ??g/l; in the latter, cell height was reduced even when compared with NF 49-51 tadpoles pooled from the 0 to 84 ??g Cd/l groups. In conclusion, (1) Cd affected tadpole growth in a bimodal pattern with the first and second inhibitory modes at concentrations below and above 84 ??g Cd/l, respectively; (2) exposure to high Cd concentrations (855 ??g/l) reduced thyroid activity and arrested tadpole development at mid-premetamorphosis; and (3) unlike its effect on growth, Cd inhibited tadpole development and thyroid function in a seemingly monotonic pattern.

  16. Accuracy of a point-of-care ELISA test kit for predicting the presence of protective canine parvovirus and canine distemper virus antibody concentrations in dogs.

    Science.gov (United States)

    Litster, A L; Pressler, B; Volpe, A; Dubovi, E

    2012-08-01

    Canine parvovirus (CPV) and canine distemper virus (CDV) are highly infectious and often fatal diseases with worldwide distributions, and are important population management considerations in animal shelters. A point-of-care ELISA test kit is available to detect serum antibodies to CPV and CDV, and presumptively to predict protective status. The aim of this study was to determine the diagnostic accuracy of the test compared to CPV hemagglutination inhibition titers and CDV serum neutralization titers determined by a reference laboratory, using sera collected from dogs housed at animal shelters. The ELISA test was used under both field and laboratory conditions and duplicate specimens were processed using an extra wash step. The test kit yielded accurate results (CPV: sensitivity 92.3%, specificity 93.5%; CDV: sensitivity 75.7%, specificity 91.8%) under field conditions. CDV sensitivity was improved by performing the test under laboratory conditions and using an optical density (OD) meter (laboratory performed 94.0%; OD 88.1%). Point-of-care ELISA testing for serum CPV and CDV antibody titers was demonstrated to be a useful tool for determining antibody status when making decisions regarding the need for CPV and/or CDV vaccination and also in animal shelters for population management. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Measurements for the determination of acid dew point and SO[sub 3] concentration in the flue gas of utility boilers

    Energy Technology Data Exchange (ETDEWEB)

    Derichs, W.; Menden, W.; Ebel, P.K. (RWE Energie AG, Bergheim (Germany))

    1991-10-01

    Until now, the well-known measuring systems for determining acid dewpoint have been applied primarily to flue gases from oil-fired combustion. Using an acid dewpoint measuring system which has now been available on the market for some time, it is possible to measure the acid dewpoint reliably and continuously in flue gas from coal-fired combustion, with low SO[sub 3] concentrations. This measuring system has also been used for flue gas from which the dust and sulphur have been removed as well as for untreated flue gas of conventional combustion systems with gas, oil, hard coal and brown coal firing and also in fluidized bed combustion systems. 6 refs., 11 figs., 2 tabs.

  18. Cytotoxicity of ZnO NPs towards fresh water algae Scenedesmus obliquus at low exposure concentrations in UV-C, visible and dark conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bhuvaneshwari, M.; Iswarya, V. [Centre for Nanobiotechnology, VIT University, Vellore 632014 (India); Archanaa, S. [Department of Biotechnology, IIT Madras (India); Madhu, G.M. [Department of Chemical Engineering, M.S. Ramaiah Institute of Technology, Bangalore (India); Kumar, G.K. Suraish [Department of Biotechnology, IIT Madras (India); Nagarajan, R. [Department of Chemical Engineering, IIT Madras (India); Chandrasekaran, N. [Centre for Nanobiotechnology, VIT University, Vellore 632014 (India); Mukherjee, Amitava, E-mail: amit.mookerjea@gmail.com [Centre for Nanobiotechnology, VIT University, Vellore 632014 (India)

    2015-05-15

    Highlights: • The cytotoxicity of ZnO NPs with two hydrodynamic sizes towards freshwater algae. • Size dependent toxicity under UV-C, dark and visible light conditions. • Cytotoxicity principally due to ZnO NPs not the released Zn{sup 2+} ions. • The internalization of ZnO NPs leads to membrane damage and ROS production. - Abstract: Continuous increase in the usage of ZnO nanoparticles in commercial products has exacerbated the risk of release of these particles into the aquatic environment with possible harmful effects on the biota. In the current study, cytotoxic effects of two types of ZnO nanoparticles, having different initial effective diameters in filtered and sterilized lake water medium [487.5 ± 2.55 nm for ZnO-1 NPs and 616.2 ± 38.5 nm for ZnO-2 NPs] were evaluated towards a dominant freshwater algal isolate Scenedesmus obliquus in UV-C, visible and dark conditions at three exposure concentrations: 0.25, 0.5 and 1 mg/L. The toxic effects were found to be strongly dependent on the initial hydrodynamic particle size in the medium, the exposure concentrations and the irradiation conditions. The loss in viability, LDH release and ROS generation were significantly enhanced in the case of the smaller sized ZnO-1 NPs than in the case of ZnO-2 NPs under comparable test conditions. The toxicity of both types of ZnO NPs was considerably elevated under UV-C irradiation in comparison to that in dark and visible light conditions, the effects being more enhanced in case of ZnO-1 NPs. The size dependent dissolution of the ZnO NPs in the test medium and possible toxicity due to the released Zn{sup 2+} ions was also noted. The surface adsorption of the nanoparticles was substantiated by scanning electron microscopy. The internalization/uptake of the NPs by the algal cells was confirmed by fluorescence microscopy, transmission electron microscopy, and elemental analyses.

  19. Cytotoxicity of ZnO NPs towards fresh water algae Scenedesmus obliquus at low exposure concentrations in UV-C, visible and dark conditions

    International Nuclear Information System (INIS)

    Bhuvaneshwari, M.; Iswarya, V.; Archanaa, S.; Madhu, G.M.; Kumar, G.K. Suraish; Nagarajan, R.; Chandrasekaran, N.; Mukherjee, Amitava

    2015-01-01

    Highlights: • The cytotoxicity of ZnO NPs with two hydrodynamic sizes towards freshwater algae. • Size dependent toxicity under UV-C, dark and visible light conditions. • Cytotoxicity principally due to ZnO NPs not the released Zn 2+ ions. • The internalization of ZnO NPs leads to membrane damage and ROS production. - Abstract: Continuous increase in the usage of ZnO nanoparticles in commercial products has exacerbated the risk of release of these particles into the aquatic environment with possible harmful effects on the biota. In the current study, cytotoxic effects of two types of ZnO nanoparticles, having different initial effective diameters in filtered and sterilized lake water medium [487.5 ± 2.55 nm for ZnO-1 NPs and 616.2 ± 38.5 nm for ZnO-2 NPs] were evaluated towards a dominant freshwater algal isolate Scenedesmus obliquus in UV-C, visible and dark conditions at three exposure concentrations: 0.25, 0.5 and 1 mg/L. The toxic effects were found to be strongly dependent on the initial hydrodynamic particle size in the medium, the exposure concentrations and the irradiation conditions. The loss in viability, LDH release and ROS generation were significantly enhanced in the case of the smaller sized ZnO-1 NPs than in the case of ZnO-2 NPs under comparable test conditions. The toxicity of both types of ZnO NPs was considerably elevated under UV-C irradiation in comparison to that in dark and visible light conditions, the effects being more enhanced in case of ZnO-1 NPs. The size dependent dissolution of the ZnO NPs in the test medium and possible toxicity due to the released Zn 2+ ions was also noted. The surface adsorption of the nanoparticles was substantiated by scanning electron microscopy. The internalization/uptake of the NPs by the algal cells was confirmed by fluorescence microscopy, transmission electron microscopy, and elemental analyses

  20. IWGT report on quantitative approaches to genotoxicity risk assessment II. Use of point-of-departure (PoD) metrics in defining acceptable exposure limits and assessing human risk.

    Science.gov (United States)

    MacGregor, James T; Frötschl, Roland; White, Paul A; Crump, Kenny S; Eastmond, David A; Fukushima, Shoji; Guérard, Melanie; Hayashi, Makoto; Soeteman-Hernández, Lya G; Johnson, George E; Kasamatsu, Toshio; Levy, Dan D; Morita, Takeshi; Müller, Lutz; Schoeny, Rita; Schuler, Maik J; Thybaud, Véronique

    2015-05-01

    This is the second of two reports from the International Workshops on Genotoxicity Testing (IWGT) Working Group on Quantitative Approaches to Genetic Toxicology Risk Assessment (the QWG). The first report summarized the discussions and recommendations of the QWG related to the need for quantitative dose-response analysis of genetic toxicology data, the existence and appropriate evaluation of threshold responses, and methods to analyze exposure-response relationships and derive points of departure (PoDs) from which acceptable exposure levels could be determined. This report summarizes the QWG discussions and recommendations regarding appropriate approaches to evaluate exposure-related risks of genotoxic damage, including extrapolation below identified PoDs and across test systems and species. Recommendations include the selection of appropriate genetic endpoints and target tissues, uncertainty factors and extrapolation methods to be considered, the importance and use of information on mode of action, toxicokinetics, metabolism, and exposure biomarkers when using quantitative exposure-response data to determine acceptable exposure levels in human populations or to assess the risk associated with known or anticipated exposures. The empirical relationship between genetic damage (mutation and chromosomal aberration) and cancer in animal models was also examined. It was concluded that there is a general correlation between cancer induction and mutagenic and/or clastogenic damage for agents thought to act via a genotoxic mechanism, but that the correlation is limited due to an inadequate number of cases in which mutation and cancer can be compared at a sufficient number of doses in the same target tissues of the same species and strain exposed under directly comparable routes and experimental protocols. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  1. Effect of exposure to sublethal concentrations of sodium cyanide on the carbohydrate metabolism of the Indian Major Carp Labeo rohita (Hamilton, 1822

    Directory of Open Access Journals (Sweden)

    Praveen N. Dube

    2013-07-01

    Full Text Available Experiments were designed to study in-vivo effects of sodium cyanide on biochemical endpoints in the freshwater fish Labeo rohita. Fish were exposed to two sublethal concentrations (0.106 and 0.064mg/L for a period of 15 days. Levels of glycogen, pyruvate, lactate and the enzymatic activities of lactate dehydrogenase (LDH, succinate dehydrogenase (SDH, glucose-6-phosphate dehydrogenase (G6PDH, phosphorylase, alkaline phosphatase (ALP, acid phosphatase (AcP were assessed in different tissues (liver, muscle and gills. Result indicated a steady decrease in glycogen, pyruvate, SDH, ALP and AcP activity with a concomitant increase in the lactate, phosphorylase, LDH and G6PD activity in all selected tissues. The alterations in all the above biochemical parameters were significantly (p<0.05 time and dose dependent. In all the above parameters, liver pointing out the intensity of cyanide intoxication compare to muscle and gills. Study revealed change in the metabolic energy by means of altered metabolic profile of the fish. Further, these observations indicated that even sublethal concentrations of sodium cyanide might not be fully devoid of deleterious influence on metabolism in L. rohita.

  2. Lettuce (Lactuca sativa L.) leaf-proteome profiles after exposure to cylindrospermopsin and a microcystin-LR/cylindrospermopsin mixture: a concentration-dependent response.

    Science.gov (United States)

    Freitas, Marisa; Campos, Alexandre; Azevedo, Joana; Barreiro, Aldo; Planchon, Sébastien; Renaut, Jenny; Vasconcelos, Vitor

    2015-02-01

    The intensification of agricultural productivity is an important challenge worldwide. However, environmental stressors can provide challenges to this intensification. The progressive occurrence of the cyanotoxins cylindrospermopsin (CYN) and microcystin-LR (MC-LR) as a potential consequence of eutrophication and climate change is of increasing concern in the agricultural sector because it has been reported that these cyanotoxins exert harmful effects in crop plants. A proteomic-based approach has been shown to be a suitable tool for the detection and identification of the primary responses of organisms exposed to cyanotoxins. The aim of this study was to compare the leaf-proteome profiles of lettuce plants exposed to environmentally relevant concentrations of CYN and a MC-LR/CYN mixture. Lettuce plants were exposed to 1, 10, and 100 μg/l CYN and a MC-LR/CYN mixture for five days. The proteins of lettuce leaves were separated by two-dimensional electrophoresis (2-DE), and those that were differentially abundant were then identified by matrix-assisted laser desorption/ionization time of flight-mass spectrometry (MALDI-TOF/TOF MS). The biological functions of the proteins that were most represented in both experiments were photosynthesis and carbon metabolism and stress/defense response. Proteins involved in protein synthesis and signal transduction were also highly observed in the MC-LR/CYN experiment. Although distinct protein abundance patterns were observed in both experiments, the effects appear to be concentration-dependent, and the effects of the mixture were clearly stronger than those of CYN alone. The obtained results highlight the putative tolerance of lettuce to CYN at concentrations up to 100 μg/l. Furthermore, the combination of CYN with MC-LR at low concentrations (1 μg/l) stimulated a significant increase in the fresh weight (fr. wt) of lettuce leaves and at the proteomic level resulted in the increase in abundance of a high number of proteins. In

  3. Experimental investigation of the accuracy for absolute quantification of brain creatine concentration using long time echo point resolved spectroscopy sequence with an external standard and linear combination of model spectra

    International Nuclear Information System (INIS)

    Lin Yan; Shen Zhiwei; Xiao Yeyu; Zheng Wenbin; Wu Renhua; Li Hui; Xiao Zhuanwei

    2008-01-01

    Objective: To investigate the accuracy for absolute quantification of brain creatine (Cr) concentration using long time echo (TE) point resolved spectroscopy (PRESS) sequence performed with an extemal standard and postprocessed with the linear combination of model spectra ( LCModel). Methods: Ten swine (3.1 ± 0.6 kg) and an external standard phantom containing detectable compounds of known concentration were investigated in this study by using 1.5 T GE Signa scanner and a standard head coil. The single-voxel proton magnetic resonance spectroscopy ( 1 H-MRS) data were acquired from the two ROIs (2 cm x 2 cm x 2 cm) placed in swine brain and external standard solution using PRESS sequence with TE 135 ms, TR 1500 ms, and 128 scan averages. The in vivo quantification of Cr was accomplished by LCModel. After 1 H-MRS examination, each animal was sacrificed immediately. In vitro Cr concentration was analyzed by high performance liquid chromatography (HPLC). Results: In the 1 H-MRS group, the Cr concentration was (9.37±0.14)mmol/kg. In the HPLC group, the Cr concentration was (8.91± 0.13)mmol/kg. Good agreement was obtained between these two methods (t=9.038, P=0.491). Conclusion: The long echo time PRESS sequence performed with an external standard and processed with LCModel is proven to be an accurate technique to detect the in vivo brain Cr concentration. (authors)

  4. Effects of Short-Term Exposure to Sublethal Concentrations of Silver Nanoparticles on Histopathology and Electron Microscope Ultrastructure of Zebrafish (Danio Rerio Gills

    Directory of Open Access Journals (Sweden)

    Borhan Mansouri

    2015-11-01

    Full Text Available Background: The increasing use of nanomaterials and nanoproducts has increased the possibility of contamination of the environment, which may have adverse effects on different organisms. The aim of this study was to evaluate the effects of silver nanoparticles on histopathology and gill ultrastructure of zebrafish (Danio rerio under laboratory conditions. Methods: Zebrafish were exposed to four concentrations of silver nanoparticles (0.0015, 0.00375, 0.0075, and 0.015 mg/l for a period of 4 days. Gill ultrastructure and histopathological changes were studied using scanning electron microscope and haematoxylin - eosin staining. Results: Exposure to silver nanoparticles significantly (P < 0.001 increased the diameter of gill filaments and secondary lamellae, while silver nanoparticles significantly reduced the length of the secondary gills in zebrafish. Moreover, other changes such as vacuolization, dilated and clubbed tips, hyperplasia, edema, fusion, swelling of mucocytes, hypertrophy, and necrosis were observed. The effects of silver nanoparticles in zebrafish gills were dose dependent. Conclusion: Based on the adverse effects of AgNPs on zebrafish gills, silver nanoparticle solutions can be hazardous pollutants for the environment.

  5. [Studies on markers of exposure and early effect in areas with arsenic pollution: methods and results of the project SEpiAs. Epidemiological studies on population exposed to low-to-moderate arsenic concentration in drinking water].

    Science.gov (United States)

    Bustaffa, Elisa; Bianchi, Fabrizio

    2014-01-01

    Arsenic and its inorganic compounds are classified as human carcinogens. Several epidemiological studies conducted in areas of the world characterized by high arsenic concentration in drinking water, even up to 3,000 μg/l, report associations between arsenic exposure and skin, bladder, lung, liver and kidney cancer as well as cardiovascular diseases, diabetes and reproductive and developmental effects. Since general population is not exposed to these high arsenic concentrations in the last years attention focused on adverse health effects that low-to-moderate arsenic concentrations (0-150 μg/l) in drinking water could induce. The World Health Organization recommends a maximum limit of 10 μg/l for arsenic in drinking water. Almost all epidemiological studies conducted on populations exposed to low-to-moderate arsenic concentrations in drinking water are limited due to problems arising from both individual exposure assessment and low subjects number. The aim of the present review is to collect literature-based evidences regarding adverse health effects associated with exposure to low-to-moderate arsenic concentrations in drinking water (10-150 μg/l) in order to obtain a comprehensive picture of the health outcomes that such exposure can have on general population.

  6. A Point Mutation in the Sensor Histidine Kinase SaeS of Staphylococcus aureus Strain Newman Alters the Response to Biocide Exposure

    NARCIS (Netherlands)

    Schaefer, Daniel; Lam, Thien-Tri; Geiger, Tobias; Mainiero, Markus; Engelmann, Susanne; Hussain, Muzaffar; Bosserhoff, Armin; Frosch, Matthias; Bischoff, Markus; Wolz, Christiane; Reidl, Joachim; Sinha, Bhanu

    2009-01-01

    Staphylococcus aureus reacts to changing environmental conditions such as heat, pH, and chemicals through global regulators such as the sae (S. aureus exoprotein expression) two-component signaling system. Subinhibitory concentrations of some antibiotics were shown to increase virulence factor

  7. Pre-cancerous changes in urothelial endocytic vesicle leakage, fatty acid composition, and As and associated element concentrations after arsenic exposure

    International Nuclear Information System (INIS)

    Grasso, E.J.; Bongiovanni, G.A.; Perez, R.D.; Calderon, R.O.

    2011-01-01

    The urothelium covering the luminal surface of the urinary bladder has developed an efficient permeability barrier that protects it against the back-flow of toxins eliminated in the urine. The subapical endocytic vesicles containing the urinary bladder fluid phase are formed during the micturition cycle by endocytosis processes of the superficial cells. In normal conditions, the permeability barrier of the endocytic vesicles blocks the passage of the fluid phase to the cellular cytoplasm and the fluid is recycled to the bladder lumen. The aim of this work was to investigate the alteration of the endocytic vesicle membrane permeability barrier to toxins such as iAs (inorganic arsenic) administered in drinking water. By using an induced endocytosis model and the fluorescence requenching technique, it is shown that the exposure of rats to ingestion of water containing iAs not only induced pre-cancerous morphological changes, but allowed the differential leakage of an endocytosed fluorescent marker, HPTS, and its quencher, DPX, (hydroxypyrene-1,3,6-trisulfonic acid and p-xylene-bis-pyridinium bromide, respectively) out of the vesicular lumen. The leakage of the cationic DPX was almost complete, while the release of the anionic HPTS molecule was partial and higher in arsenic-treated-rats than in controls. Such membrane alteration would allow the toxins to elude the permeability barrier and to leak out of the endocytic vesicles, thus establishing a 'bypass' to the permeability barrier. The retention of As in the urinary bladder, assessed by synchrotron radiation X-ray fluorescence spectrometry (SR-μXRF), was lower than the kidney accumulation of arsenic previously observed by our group and was accompanied by altered concentrations of K, Ca, Fe, Cu and Zn, all ions related to cellular metabolism. The results support the hypothesis that low amounts of endocytosed As can accumulate in the interior of the urothelial superficial cells and initiate the cytotoxic effects

  8. Homologous stress adaptation, antibiotic resistance, and biofilm forming ability of Salmonella enterica serovar Heidelberg (ATCC8326) on different food-contact surfaces following exposure to sub-lethal chlorine concentrations

    Science.gov (United States)

    Salmonella enterica serovar Heidelberg (American Type Culture Collection; ATCC 8326) was examined for the ability to adapt to the homologous stress of chlorine through exposure to increasing chlorine concentrations (25 ppm daily increments) in tryptic soy broth (TSB). The tested strain exhibited an ...

  9. Dental fluorosis and urinary fluoride concentration as a reflection of fluoride exposure and its impact on IQ level and BMI of children of Laxmisagar, Simlapal Block of Bankura District, W.B., India.

    Science.gov (United States)

    Das, Kousik; Mondal, Naba Kumar

    2016-04-01

    There has been growing public concern about intellectual performance of children at high levels of fluoride exposure. A cross-sectional study was conducted in Simlapal Block of Bankura District, West Bengal, to find out the relationship between fluoride (F) exposure as exposure dose (ED) with dental fluorosis (DF), urinary fluoride concentration (UF), intelligence quotient (IQ) and body mass index (BMI). Fifty groundwater samples were collected from the target area. One hundred forty-nine children belonging to age group 6 to 18 years were considered for this study. Experimental results reveal that mean F(-) concentration of that area is 2.11 mg/L (±SD 1.64). On the basis of F concentration in groundwater and water consumption pattern, ED was calculated to explore the impact of F(-) on DF, UF, IQ, and BMI. Paired t test results suggest that exposure rate of F does not show any significant differences ( severe > mild > very mild > questionable > normal conditions. The highest UF concentration was recorded as 17 mg/L, but the status of DF in the affected children was recorded as moderate. The results also reveal that ED has a positive correlation with DF (r = 0.299, P fluoride toxicity.

  10. In vivo magnetic resonance spectroscopy measurement of gray-matter and white-matter gamma-aminobutyric acid concentration in sensorimotor cortex using a motion-controlled MEGA point-resolved spectroscopy sequence.

    Science.gov (United States)

    Bhattacharyya, Pallab K; Phillips, Micheal D; Stone, Lael A; Lowe, Mark J

    2011-04-01

    Gamma-aminobutyric acid (GABA) is a major inhibitory neurotransmitter in the brain. Understanding the GABA concentration, in vivo, is important to understand normal brain function. Using MEGA point-resolved spectroscopy sequence with interleaved water scans to detect subject motion, GABA level of sensorimotor cortex was measured using a voxel identified from a functional magnetic resonance imaging scan. The GABA level in a 20×20×20-mm(3) voxel consisting of 37%±7% gray matter, 52%±12% white matter and 11%±8% cerebrospinal fluid in the sensorimotor region was measured to be 1.43±0.48 mM. In addition, using linear regression analysis, GABA concentrations within gray and white matter were calculated to be 2.87±0.61 and 0.33±0.11 mM, respectively. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Exposure to point-of-sale displays and changes in susceptibility to smoking: findings from a cohort study of school students.

    Science.gov (United States)

    Bogdanovica, Ilze; Szatkowski, Lisa; McNeill, Ann; Spanopoulos, Dionysis; Britton, John

    2015-04-01

    To investigate the association between frequency of visiting shops and noticing of tobacco point-of-sale (PoS) displays and the development of susceptibility to smoking, or smoking uptake, in secondary school students. Two surveys of a school based cohort study carried out in 2011 and 2012. Nottinghamshire, UK. A total of 2270 children aged 11-16 years from eight schools in Nottinghamshire. We investigated changes in susceptibility to smoking and smoking status in relation to frequency of visiting shops and noticing PoS displays and number of tobacco brands recognized, controlling for a range of potential confounders. Susceptibility to smoking was defined using a set of three questions covering intentions to try smoking, to smoke within the next year and likelihood of smoking if a best friend offered a cigarette. For the analysis we used multinomial logistic regression. Among non-susceptible never smokers, noticing PoS displays more frequently was associated independently with an increased risk of becoming susceptible to smoking [adjusted relative risk ratio (RRR) = 1.74; 99% confidence interval (CI) = 1.13-2.69], but was not associated with smoking uptake. Recognizing a higher number of brands among non-susceptible never smokers doubled the risk of becoming susceptible to smoking and of becoming a smoker, but this did not have a significant effect on transition to smoking among susceptible never smokers. Frequency of noticing tobacco PoS displays was not associated significantly with smoking uptake among those who were susceptible never smokers at baseline. Noticing tobacco point-of-sale displays more often and recognizing a higher number of tobacco brands is associated with an increased risk of becoming susceptible to smoking among adolescents in the United Kingdom, and recognizing a higher number of brands is associated positively with an increased risk of smoking uptake. © 2014 Society for the Study of Addiction.

  12. Effects of cadmium on life-cycle parameters in a multi-generation study with Chironomus riparius following a pre-exposure of populations to two different tributyltin concentrations for several generations.

    Science.gov (United States)

    Vogt, Christian; Hess, Maren; Nowak, Carsten; Diogo, João Barateiro; Oehlmann, Jörg; Oetken, Matthias

    2010-10-01

    So far only a few studies have been performed to assess the effects of dynamic pollutant exposure on life-history parameters of invertebrates. In a previous multi-generation approach with the midge Chironomus riparius we tested if a chronic tributyltin pre-exposure alters the ability of a population to cope with subsequent cadmium stress. In the experiment two separate chironomid populations were exposed via sediments to different TBT-concentrations (4.46 and 8.93 μg Sn/kg dw) for several generations, followed by subsequent cadmium exposure (1.2 mg Cd/kg dw) for three generations. While the TBT-exposure to 4.46 μg Sn/kg dw had only small effects on the development and reproduction of C. riparius the higher TBT-concentration of 8.93 μg Sn/kg dw led to negative effects on life-history traits. Therefore, a higher adverse effect of the higher TBT-concentration and thus a higher susceptibility to other stressors could be assumed. Within, this paper only the results of the second stressor experiment were presented; clear effects of Cd on development and reproduction of C. riparius were determined independent of the pre-exposure scenario. While no differences in Cd-sensitivity were found between the population without pre-exposure to TBT and the population pre-exposed to the low TBT-concentration (4.46 μg Sn/kg dw), the pre-exposure of midges to the higher TBT-concentration (8.93 μg Sn/kg dw) resulted in a significantly higher susceptibility to subsequent Cd-stress. These results document that the exposure history may influence the reaction to altered chemical stress. Our findings are relevant to understand and predict the evolutionary fate of populations in rapidly changing, human-impacted environments. However, the fact that chemical-induced reduced genetic diversity, which is not necessarily linked to genetic adaptation, leads to a reduced fitness under altered stress conditions, is to our knowledge a novel finding.

  13. Tipping Point

    Medline Plus

    Full Text Available ... en español Blog About OnSafety CPSC Stands for Safety The Tipping Point Home > 60 Seconds of Safety (Videos) > The Tipping Point The Tipping Point by ... danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe ...

  14. Fish oil and olive oil supplements attenuate the adverse cardiovascular effects of concentrated ambient air pollution particles exposure in healthy middle-aged adult human volunteers

    Science.gov (United States)

    Exposure to ambient levels of air pollution increases cardiovascular morbidity and mortality. Advanced age is among the factors associated with susceptibility to the adverse effects of air pollution. Dietary fatty acid supplementation has been shown to decrease cardiovascular ris...

  15. Subclinical ketosis in post-partum dairy cows fed a predominantly pasture-based diet: defining cut-points for diagnosis using concentrations of beta-hydroxybutyrate in blood and determining prevalence.

    Science.gov (United States)

    Compton, C W R; Young, L; McDougall, S

    2015-09-01

    Firstly, to define, in dairy cows in the first 5 weeks post-calving fed a predominantly pasture-based diet, cut-points of concentrations of beta-hydroxybutyrate (BHBA) in blood, above which there were associations with purulent vaginal discharge (PVD), reduced pregnancy rates (PR) and decreased milk production, in order to better define subclinical ketosis (SCK) in such cattle; and secondly, to determine the prevalence, incidence and risk factors for SCK. An observational field study was conducted in 565 cows from 15 spring-calving and predominantly pasture-fed dairy herds in two regions of New Zealand during the 2010- 2011 dairy season. Within each herd, a cohort of randomly selected cows (approximately 40 per herd) was blood sampled to determine concentrations of BHBA on six occasions at weekly intervals starting within 5 days of calving. The key outcome variables were the presence/absence of PVD at 5 weeks post-calving, PR after 6 weeks (6-week PR) and after the completion of the breeding season (final PR), and mean daily milk solids production. Two cut-points for defining SCK were identified: firstly concentration of BHBA in blood≥1.2 mmol/L within 5 days post-calving, which was associated with an increased diagnosis of PVD (24 vs. 8%); and secondly concentration of BHBA in blood≥1.2 mmol/L at any stage within 5 weeks post-calving, which was associated with decreased 6-week PR (78 vs. 85%). The mean herd-level incidence of SCK within 5 weeks post-calving was 68 (min 12; max 100)% and large variations existed between herds in peak prevalence of SCK and the interval post-calving at which such peaks occurred. Cows>8 years of age and cows losing body condition were at increased risk of SCK within 5 weeks of calving. Cows with concentration of BHBA in blood≥1.2 mmol/L in early lactation had a higher risk of PVD and lower 6-week PR. Cow and herd-level prevalence of SCK varied widely in early lactation. Subclinical ketosis is common and is significantly

  16. Larval exposure to field-realistic concentrations of clothianidin has no effect on development rate, over-winter survival or adult metabolic rate in a solitary bee, Osmia bicornis.

    Science.gov (United States)

    Nicholls, Elizabeth; Fowler, Robert; Niven, Jeremy E; Gilbert, James D; Goulson, Dave

    2017-01-01

    There is widespread concern regarding the effects of agro-chemical exposure on bee health, of which neonicotinoids, systemic insecticides detected in the pollen and nectar of both crops and wildflowers, have been the most strongly debated. The majority of studies examining the effect of neonicotinoids on bees have focussed on social species, namely honey bees and bumble bees. However, most bee species are solitary, their life histories differing considerably from these social species, and thus it is possible that their susceptibility to pesticides may be quite different. Studies that have included solitary bees have produced mixed results regarding the impact of neonicotinoid exposure on survival and reproductive success. While the majority of studies have focused on the effects of adult exposure, bees are also likely to be exposed as larvae via the consumption of contaminated pollen. Here we examined the effect of exposure of Osmia bicornis larvae to a range of field-realistic concentrations (0-10 ppb) of the neonicotinoid clothianidin, observing no effect on larval development time, overwintering survival or adult weight. Flow-through respirometry was used to test for latent effects of larval exposure on adult physiological function. We observed differences between male and female bees in the propensity to engage in discontinuous gas exchange; however, no effect of larval clothianidin exposure was observed. Our results suggest that previously reported adverse effects of neonicotinoids on O. bicornis are most likely mediated by impacts on adults.

  17. Larval exposure to field-realistic concentrations of clothianidin has no effect on development rate, over-winter survival or adult metabolic rate in a solitary bee, Osmia bicornis

    Directory of Open Access Journals (Sweden)

    Elizabeth Nicholls

    2017-06-01

    Full Text Available There is widespread concern regarding the effects of agro-chemical exposure on bee health, of which neonicotinoids, systemic insecticides detected in the pollen and nectar of both crops and wildflowers, have been the most strongly debated. The majority of studies examining the effect of neonicotinoids on bees have focussed on social species, namely honey bees and bumble bees. However, most bee species are solitary, their life histories differing considerably from these social species, and thus it is possible that their susceptibility to pesticides may be quite different. Studies that have included solitary bees have produced mixed results regarding the impact of neonicotinoid exposure on survival and reproductive success. While the majority of studies have focused on the effects of adult exposure, bees are also likely to be exposed as larvae via the consumption of contaminated pollen. Here we examined the effect of exposure of Osmia bicornis larvae to a range of field-realistic concentrations (0–10 ppb of the neonicotinoid clothianidin, observing no effect on larval development time, overwintering survival or adult weight. Flow-through respirometry was used to test for latent effects of larval exposure on adult physiological function. We observed differences between male and female bees in the propensity to engage in discontinuous gas exchange; however, no effect of larval clothianidin exposure was observed. Our results suggest that previously reported adverse effects of neonicotinoids on O. bicornis are most likely mediated by impacts on adults.

  18. Fixed Points

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 5. Fixed Points - From Russia with Love - A Primer of Fixed Point Theory. A K Vijaykumar. Book Review Volume 5 Issue 5 May 2000 pp 101-102. Fulltext. Click here to view fulltext PDF. Permanent link:

  19. Tipping