Sample records for tissue mercury levels

  1. High residue levels and the chemical form of mercury in tissues and organs of seabirds

    SciTech Connect

    Kim, E.Y.; Murakami, Toru; Saeki, Kazutoshi; Tatsukawa, Ryo [Ehime Univ. (Japan). Dept. of Environment Conservation

    1995-12-31

    Total and organic (methyl) mercury in liver, muscle, kidney and feather of 9 species of seabirds were analyzed to determine the levels and their distribution and to clarify the occurrences of high mercury levels and their detoxification process in seabirds. Total mercury levels in liver showed great variations in intra and interspecies, while organic mercury levels were less variable. As compared with species in relatively low mercury levels, the species which accumulated the high concentration of mercury like black-footed albatross exhibited the different distribution of mercury in the body: in total mercury burden, albatross species contained less than 10% in feather and over 50% in liver, while other species contained over 40% in feather and less than 20% in liver. The order of organic mercury concentrations in tissues were as follows: liver > kidney > muscle in seabirds examined, except oldsquaw. The mean percentage of organic mercury in total was 35%, 66%, and 36% in liver, muscle and kidney, respectively, for all the species. The significant negative correlations were found between organic mercury percentage to total mercury and total mercury concentrations in the liver and muscle of black-footed albatross and in the liver of laysan albatross. Furthermore, in liver, muscle, and kidney of all the species, the percentages of organic mercury had a negative trend with an increase of total mercury concentrations. The results suggest that albatross species may be capable for demethylating organic mercury in the tissues (mainly in liver), and for storing the mercury as immobilizable inorganic form in the liver as substitution for delivering organic mercury to other organs. It is noteworthy that the species with high degree of demethylation showed the lower mercury burdens in feather and slow moulting pattern.

  2. Comparison of mercury levels in maternal blood, fetal cord blood, and placental tissues

    SciTech Connect

    Kuhnert, P.M.; Kuhnert, B.R.; Erhard, P.

    1981-01-01

    Previous studies have reported that mercury accumulates in cord blood during pregnancy. This study was carried out to determine where in cord blood the mercury accumulates, i.e., in cord erythrocytes, in cord plasma, or in both, and to determine whether the predominant form of mercury which accumulates is methyl or inorganic mercury. From our data it is clear that methyl mercury accumulates in cord erythrocytes: A total of 30% more methyl mercury was found in fetal erythrocytes than in maternal erythrocytes. Also correlation analysis of the methyl mercury levels in maternal and fetal erythrocytes showed a strong correlation (r = 0.87). In regard to inorganic mercury, the highest concentration was found in the placenta, suggesting a barrier role, but a significant correlation (r = 0.62) was also found between the maternal and fetal plasma levels of inorganic mercury. Moreover, the inorganic mercury concentration per gram of plasma was higher in fetal cord plasma than in maternal plasma. Overall, the relative levels of methyl and inorganic mercury reported here varied considerably in maternal and fetal erythrocytes, plasma, and in the placenta, but all of the levels were low (< 6 ng Hg/gm of tissue) and in agreement with total mercury levels reported by others.

  3. Levels of Cadmium, Lead, Mercury and 137Caesium in Caribou (Rangifer tarandus) Tissues from Northern Québec

    Microsoft Academic Search

    S. ROBILLARD; G. BEAUCHAMP; G. PAILLARD; D. BÉLANGER

    2002-01-01

    Levels of cadmium (Cd), lead (Pb) and total mercury (Hg) were assessed in samples of muscle, kidney, and liver from caribou (Rangifer tarandus; n = 317) harvested in two regions of northern Québec between 1994 and 1996. Levels of 137 caesium (137Cs) were also examined in muscle samples. Log concentration of the three metals varied significantly among tissues and was

  4. Growth response and tissue accumulation trends of herbaceous wetland plant species exposed to elevated aqueous mercury levels.

    PubMed

    Willis, Jonathan M; Gambrell, Robert P; Hester, Mark W

    2010-08-01

    The impacts of elevated aqueous mercury levels (0, 2, and 4 ppm) on the growth status and mercury tissue concentrations of Eleocharis parvula, Saururus cernuus, Juncus effuses, Typha latifolia, and Panicum hemitomon were determined. Both short-term (net CO2 assimilation) and long-term (biomass) indicators of plant growth status suggest that Eleocharis parvula, Saururus cernuus, and Juncus effuses were relatively unimpacted by elevated mercury levels, whereas Typha latifolia and Panicum hemitomon were somewhat impacted at elevated mercury levels. Eleocharis parvula, Panicum hemitomon, and Typha latifolia generally had the greatest overall belowground tissue concentrations of mercury (2 ppm treatment: 7.21, 7.32, and 9.64 ppm respectively; 4 ppm treatment: 16.23, 18.23, and 13.98 ppm, respectively) and aboveground tissue concentrations of mercury (2 ppm treatment: 0.01, 0.04, 0.02; 4 ppm treatment: 0.26; 0.11; 0.17 ppm, respectively). However, the species investigated in this study demonstrated lower levels of mercury accumulation into tissues when compared with similar investigations of other aquatic plants, suggesting that the above species are not optimal for phytoremediation efforts. PMID:21166283

  5. Growth Response and Tissue Accumulation Trends of Herbaceous Wetland Plant Species Exposed to Elevated Aqueous Mercury Levels

    Microsoft Academic Search

    Jonathan M. Willis; Robert P. Gambrell; Mark W. Hester

    2010-01-01

    The impacts of elevated aqueous mercury levels (0, 2, and 4 ppm) on the growth status and mercury tissue concentrations of Eleocharis parvula, Saururus cernuus, Juncus effuses, Typha latifolia, and Panicum hemitomon were determined. Both short-term (net CO2 assimilation) and long-term (biomass) indicators of plant growth status suggest that Eleocharis parvula, Saururus cernuus, and Juncus effuses were relatively unimpacted by

  6. Effects of sublethal levels of DDT, malathion and mercury on tissue proteins of Sarotherodon mossambicus (Peters)

    Microsoft Academic Search

    K Ramalingam

    1982-01-01

    Liver and muscle total proteins declined inSarotherodon mossambicus subjected to sublethal concentrations of ddt, malathion and mercury. The results indicate their role in maintenance of energy\\u000a supply irrespective of the nature of the toxicant. The qualitative variations in serum protein pattern also support the quantitative\\u000a changes in tissues.

  7. Mercury levels in Wisconsin fish and wildlife

    Microsoft Academic Search

    S. J. Kleinert; P. E. Degurse

    1972-01-01

    Mercury determinations were made on 1824 fish fillet samples representing 139 locations covering 52 of Wisconsin's 72 counties and boundary waters of Lake Michigan, Green Bay, Lake Superior, and the Mississippi River. Mercury levels in fish from waters removed from any known source of mercury use averaged .19 ppm and ranged between .01 and .60 ppm mercury. The highest mercury

  8. Mercury baseline levels in Flemish soils (Belgium)

    Microsoft Academic Search

    Filip M. G. Tack; Thomas Vanhaesebroeck; Marc G. Verloo; Kurt Van Rompaey; Eric Van Ranst

    2005-01-01

    It is important to establish contaminant levels that are normally present in soils to provide baseline data for pollution studies. Mercury is a toxic element of concern. This study was aimed at assessing baseline mercury levels in soils in Flanders. In a previous study, mercury contents in soils in Oost-Vlaanderen were found to be significantly above levels reported elsewhere. For

  9. Mercury levels in myliobatid stingrays (Batoidea) from the Gulf of California: tissue distribution and health risk assessment.

    PubMed

    Escobar-Sánchez, O; Ruelas-Inzunza, J; Patrón-Gómez, J C; Corro-Espinosa, D

    2014-03-01

    With the aim of knowing Hg distribution in selected tissues of myliobatid stingrays and assessing health risk to Mexican population, Hg concentration was determined in the muscle and liver of four ray species. Total Hg levels were determined by cold vapor atomic absorption spectrophotometry. With respect to the muscle, devil rays (Mobula spp.) showed lower Hg levels (<0.22 ?g g(-1)) than Rhinoptera steindachneri (0.37?±?0.25 ?g g(-1) wet weight). In the case of the liver, the highest Hg concentration was found in Mobula japanica (0.22?±?0.01 ?g g(-1)). Hg levels in the muscle and liver varied according to the species; in some case, the liver accumulated more Hg than the muscle and the opposite pattern in other cases. R. steindachneri showed a significant difference between both tissues. No significant differences of Hg levels between males and females and between juveniles and adult specimens of R. steindachneri were found. Positive correlation between Hg concentrations and disc width and total weight was not significant for R. steindachneri (Rs??0.05). Batoids showed Hg values below the Mexican (NOM-027-SSA1-1993) limits (1.0 ?g g(-1)) in fishes for human consumption. The species with the highest potential of Hg transfer to human population is R. steindachneri; however, an adult (70 kg) could consume approximately 943 g per week without representing a health risk. Nevertheless, further and continuous monitoring is needed since batoids support an important fishery in Mexican waters, being a food resource and income to coastal communities. PMID:24197561

  10. Mercury levels in common (Actitis hypoleucos) and green (Tringa ochropus) sandpipers from west-central Iran.

    PubMed

    Malekian, Mansoureh; Hosseinpour-Mohamadabadi, Zahra

    2015-05-01

    Mercury concentrations were examined in the liver, kidneys, and tail and breast feathers of common and green sandpipers from Zayanderud Dam in west-central Iran. The aim was to provide indirect information about habitat contamination. Tail feathers of both species had higher mercury levels compared to other tissues. Moreover, tissues of common sandpipers had significantly higher mercury concentrations compared to tissues of green sandpipers. Male specimens of both species had higher values of mercury compared to females. The pattern of larger body size-higher mercury body burden was not completely true in the current study. Smaller and shorter common sandpipers had higher mercury concentrations compared to taller and heavier green sandpipers. At the intraspecific level, body weight was positively correlated with mercury concentrations in tissues of common sandpipers. Based on the data presented here, it appears that these sandpipers, especially common sandpipers, are at potential risk from the toxic effects of mercury. PMID:25851218

  11. Mercury in fish tissue: Association with other measures of lake quality

    SciTech Connect

    Yeardley, R. [DynCorp, Cincinnati, OH (United States); Lazorchak, J. [Environmental Protection Agency, Cincinnati, OH (United States)

    1995-12-31

    This presentation will explore associations between mercury in fish tissue and other measures of lake quality as one method of diagnosing the source or cause of high fish tissue mercury levels. The EMAP-Surface Waters multi-indicator approach helps to make such a diagnosis possible. Correlations between fish tissue mercury data from the 1992 and 1993 EMAP-SW Northeast Pilot studies and corresponding site data from other indicators were found that support specific sources and causes of high mercury levels in fish. Metrics from the stressor indicator (which describe characteristics likely to impact an ecosystem, such as land use) point to a contribution of mercury from atmospheric sources being more important than that from local watershed sources. Lakes with high levels of Hg in fish tissue have less associated local human disturbance: lower population and point source densities and lower percent of total human-disturbed land use in lake watersheds. A positive correlation between runoff and fish mercury levels is also seen, showing the importance of precipitation as at least a contributing factor. Metrics from the water chemistry indicator support correlations seen in other studies between high mercury fish tissue levels and low pH and low acid neutralizing capacity (ANC). Lakes with high mercury fish tissue levels ({>=} 0.2 ppm) were found to have statistically lower water pH and ANC. A correlation was also seen between chemical measures of oligotrophy (lower total-p, total-N, and chlorophyll) and high fish mercury levels, supporting a tissue dilution theory. These as well as other associations are explored.

  12. Mercury

    MedlinePLUS

    ... air, ingesting contaminated water and food, and having dental and medical treatments. Mercury, at high levels, may damage the ... burn mercury-containing fuels. Release of mercury from dental work and medical treatments. Breathing contaminated workplace air or skin contact ...

  13. Mercury accumulation in selected tissues of shrimp Penaeus merguiensis from Musa estuary, Persian Gulf: variations related to sex, size, and season.

    PubMed

    Hosseini, Mehdi; Nabavi, Seyed Mohammad Bagher; Parsa, Yaghoob; Ardashir, Rashid Alijani

    2014-09-01

    The levels of mercury in tissues of Penaeus merguiensis from Musa estuary, northwest of the Persian Gulf, were investigated. This study assessed the relationship between mercury levels in hepatopancrea, gill, and muscle with sex, size, and season. The order of mercury concentrations in tissues of the shrimp P. merguiensis was as follows: hepatopancreas > gill > muscle. There was a positive correlation between mercury concentrations in shrimp species with sex and size of its food items. We expected to see higher mercury levels in tissues of female species because they are larger and can eat larger food items. Also, there was a positive correlation between mercury concentrations in shrimp species with its food source. Therefore, female species feed more on shrimp and plant and are contaminated with high levels of mercury. There was significant difference (p?mercury levels between different seasons; higher mercury levels were found in July (summer season). PMID:24838762

  14. An evaluation of mercury levels in Louisiana fish: trends and public health issues.

    PubMed

    Katner, Adrienne; Sun, Mei-Hung; Suffet, Mel

    2010-11-01

    To characterize statewide fish tissue mercury levels in edible finfish the first comprehensive analysis of Louisiana's fish tissue mercury database was conducted. Analyses were based on fifteen years of fish tissue mercury data collected from 368 waterbodies between 1994 and 2008 (n=14,344). The overall objectives of this study were to establish baseline fish tissue mercury levels; and evaluate species-specific temporal and spatial trends in fish tissue mercury levels. Fish tissue mercury levels ranged from 0.001 ppm (the detection limit) to 5.904 ppm for king mackerel; with an overall geometric mean of 0.218 ppm. Ninety-five percent of samples had mercury levels below the FDA's action level of 1.0 ppm for methylmercury in commercial food. Forty-four percent of all samples had mercury levels above the U.S. EPA's methylmercury fish tissue criterion of 0.3 ppm for sportfish. Species of potential concern include cobia, king mackerel, blackfin tuna, greater amberjack, spotted bass, bowfin, largemouth bass and freshwater drum. There was a significant but small decline in statewide length-adjusted largemouth bass mercury levels between 1994-1999 to 2003-2008 (p<0.05). The highest fish mercury levels were observed in Pearl, Calcasieu, Mermentau, Ouachita, Pontchartrain and Sabine basins. Length-adjusted largemouth bass mercury levels were significantly higher in wetlands and rivers/streams vs. lakes; and in wetlands vs. estuaries (p<0.05). Data were analyzed from a public health perspective to make recommendations for optimizing monitoring and outreach. PMID:20855108

  15. Multi-tissue analyses reveal limited inter-annual and seasonal variation in mercury exposure in an Antarctic penguin community.

    PubMed

    Brasso, Rebecka L; Polito, Michael J; Emslie, Steven D

    2014-10-01

    Inter-annual variation in tissue mercury concentrations in birds can result from annual changes in the bioavailability of mercury or shifts in dietary composition and/or trophic level. We investigated potential annual variability in mercury dynamics in the Antarctic marine food web using Pygoscelis penguins as biomonitors. Eggshell membrane, chick down, and adult feathers were collected from three species of sympatrically breeding Pygoscelis penguins during the austral summers of 2006/2007-2010/2011. To evaluate the hypothesis that mercury concentrations in penguins exhibit significant inter-annual variation and to determine the potential source of such variation (dietary or environmental), we compared tissue mercury concentrations with trophic levels as indicated by ?(15)N values from all species and tissues. Overall, no inter-annual variation in mercury was observed in adult feathers suggesting that mercury exposure, on an annual scale, was consistent for Pygoscelis penguins. However, when examining tissues that reflected more discrete time periods (chick down and eggshell membrane) relative to adult feathers, we found some evidence of inter-annual variation in mercury exposure during penguins' pre-breeding and chick rearing periods. Evidence of inter-annual variation in penguin trophic level was also limited suggesting that foraging ecology and environmental factors related to the bioavailability of mercury may provide more explanatory power for mercury exposure compared to trophic level alone. Even so, the variable strength of relationships observed between trophic level and tissue mercury concentrations across and within Pygoscelis penguin species suggest that caution is required when selecting appropriate species and tissue combinations for environmental biomonitoring studies in Antarctica. PMID:25085270

  16. Using river distance and existing hydrography data can improve the geostatistical estimation of fish tissue mercury at unsampled locations.

    PubMed

    Money, Eric S; Sackett, Dana K; Aday, D Derek; Serre, Marc L

    2011-09-15

    Mercury in fish tissue is a major human health concern. Consumption of mercury-contaminated fish poses risks to the general population, including potentially serious developmental defects and neurological damage in young children. Therefore, it is important to accurately identify areas that have the potential for high levels of bioaccumulated mercury. However, due to time and resource constraints, it is difficult to adequately assess fish tissue mercury on a basin wide scale. We hypothesized that, given the nature of fish movement along streams, an analytical approach that takes into account distance traveled along these streams would improve the estimation accuracy for fish tissue mercury in unsampled streams. Therefore, we used a river-based Bayesian Maximum Entropy framework (river-BME) for modern space/time geostatistics to estimate fish tissue mercury at unsampled locations in the Cape Fear and Lumber Basins in eastern North Carolina. We also compared the space/time geostatistical estimation using river-BME to the more traditional Euclidean-based BME approach, with and without the inclusion of a secondary variable. Results showed that this river-based approach reduced the estimation error of fish tissue mercury by more than 13% and that the median estimate of fish tissue mercury exceeded the EPA action level of 0.3 ppm in more than 90% of river miles for the study domain. PMID:21842901

  17. Mercury levels in soils of the Eastern United States

    Microsoft Academic Search

    G. B. Wiersma; H. Tai

    1974-01-01

    Cropland and noncropland soils were sampled to determine levels of elemental mercury present in the upper three inches of soil. Results showed no difference in mercury levels between cropland and noncropland soils. Levels detected compared closely to levels found in similar studies. Actual mean levels of mercury residues in soils of the eastern United States ranged from 0.05 to 0.10

  18. Mercury concentrations in deer mouse (Peromyscus maniculatus) tissues from Isle Royale National Park

    E-print Network

    Mercury concentrations in deer mouse (Peromyscus maniculatus) tissues from Isle Royale National National Park, a protected area in Lake Superior. Abstract We used deer mice (Peromyscus maniculatus rights reserved. Keywords: Peromyscus; Mercury; Isle Royale; Biomagni®cation; Terrestrial bioaccumulation

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

    PubMed

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

    1997-11-01

    Osprey (Pandion haliaetus) eggs and chick feathers were collected for mercury analysis from nests at four Great Lakes study areas in Ontario (three "naturally formed" lakes in southern Ontario and one reservoir in northern Ontario) and two New Jersey study areas in 1991-1994. Adult osprey feathers were sampled from three Great Lakes study areas in 1991. Feathers sampled from chicks (approximately 28-35 days old) appear to be better indicators of local contaminant conditions since spatial patterns of mercury in known prey, yellow perch (Perca flavescens), also collected in these areas, were more similar to chick feathers than to eggs. Mercury levels were less variable in chick feathers than in eggs. Estimates of biomagnification factors using prey of known size at these areas were also less variable in feathers than in eggs. At naturally formed lakes, no significant correlation in mercury levels between eggs and chick feathers from the same nest was apparent, suggesting that the source of mercury contamination was not the same in these two tissues: mercury levels in eggs reflect mercury acquired on the breeding grounds, wintering grounds, and migratory route; mercury levels in chick feathers reflect local dietary conditions on the breeding grounds. Mercury levels in both osprey eggs and chick feathers were higher at the Ogoki Reservoir than at naturally formed lakes. Adult osprey feathers had higher mercury concentrations than chick feathers. Mercury levels in osprey eggs, chick feathers, and adult feathers did not approach levels associated with toxic reproductive effects. PMID:9419264

  20. Evaluation of Mercury in Urine as an Indicator of Exposure to Low Levels of Mercury Vapor

    Microsoft Academic Search

    Joyce S. Tsuji; Pamela R. D. Williams; Melanie R. Edwards; Krishna P. Allamneni; Michael A. Kelsh; Dennis J. Paustenbach; Patrick J. Sheehan

    2002-01-01

    We conducted a pooled analysis to investigate the relationship between exposure to elemental mercury in air and resulting urinary mercury levels, specifically at lower air levels relevant for envi- ronmental exposures and public health goals (i.e., < 50 µg\\/m3 down to 1.0 µg\\/m3). Ten studies reporting paired air and urine mercury data (149 samples total) met criteria for data quality

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

    SciTech Connect

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

    1986-12-01

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

  2. Total Mercury Concentrations among Fish and Crayfish Inhabiting Different Trophic Levels in Lake Whatcom, Washington

    Microsoft Academic Search

    Karl W. Mueller; David M. Serdar

    2002-01-01

    Tissue samples from six species of fish and one species of crayfish from Lake Whatcom, Washington were analyzed for total mercury content in late spring 2000. Predaceous smallmouth bass (Micropterus dolomieu) displayed the highest levels of mercury (mean ± SE, range = 0.49 ± 0.03, 0.10 ? 1.84 mg\\/kg, n = 95), followed by omnivorous yellow perch (Perca flavescens; 0.20

  3. Feather growth influences blood mercury level of young songbirds.

    PubMed

    Condon, Anne M; Cristol, Daniel A

    2009-02-01

    Dynamics of mercury in feathers and blood of free-living songbirds is poorly understood. Nestling eastern bluebirds (Sialia sialis) living along the mercury-contaminated South River (Virginia, USA) had blood mercury levels an order of magnitude lower than their parents (nestling: 0.09 +/- 0.06 mg/kg [mean +/- standard deviation], n = 156; adult: 1.21 +/- 0.57 mg/kg, n = 86). To test whether this low blood mercury was the result of mercury sequestration in rapidly growing feathers, we repeatedly sampled free-living juveniles throughout the period of feather growth and molt. Mean blood mercury concentrations increased to 0.52 +/- 0.36 mg/kg (n = 44) after the completion of feather growth. Some individuals had reached adult blood mercury levels within three months of leaving the nest, but levels dropped to 0.20 +/- 0.09 mg/kg (n = 11) once the autumn molt had begun. Most studies of mercury contamination in juvenile birds have focused on recently hatched young with thousands of rapidly growing feathers. However, the highest risk period for mercury intoxication in young birds may be during the vulnerable period after fledging, when feathers no longer serve as a buffer against dietary mercury. We found that nestling blood mercury levels were not indicative of the extent of contamination because a large portion of the ingested mercury ended up in feathers. The present study demonstrates unequivocally that in songbirds blood mercury level is influenced strongly by the growth and molt of feathers. PMID:18937528

  4. Mercury exposure in French Guiana: Levels and determinants

    SciTech Connect

    Cordier, S.; Mandereau, L. [Inst. National de Sante et de Recherche Medicale, Villejuif (France); Grasmick, C. [Direction Generale de la Sante, Paris (France); Paquier-Passelaigue, M. [Direction Dept. des Affaires Sanitaires et Sociales, Cayenne (France); Weber, J.P. [Centre de Toxicologie du Quebec (Canada); Jouan, M. [Reseau National de Sante Publique, St. Maurice (France)

    1998-07-01

    Mercury is used widely for gold extraction in French Guiana and throughout the entire Amazon basin. To evaluate contamination among the general population, the authors chose individuals who attended 13 health centers and maternity hospitals dispersed geographically across the territory and served Guiana`s different populations. Five hundred individuals (109 pregnant women, 255 other adults, and 136 children) who received care at one of the centers were selected randomly for this study. Each individual answered a questionnaire and provided a hair sample. The authors determined mercury in hair with atomic absorption spectrometry. The following mean levels of mercury were observed: 1.6 {micro}g/g among pregnant women; 3.4 {micro}g/g among other adults; and 2.5 {micro}g/g among children. Diet factors contributed the most to mercury levels, especially consumption of freshwater fish and livers from game. Other factors, including age, dental amalgams, use of skin-lightening cosmetics, and residence near a gold-mining community, did not contribute significantly to mercury levels. Overall, 12% of the samples contained mercury levels in excess of 10 {micro}g/g, but in some Amerindian communities up to 79% of the children had hair mercury levels that exceeded 10 {micro}g/g. The results of this study indicated that (a) diet played a predominant role in total mercury burden, and (b) in some communities, mercury contamination exceeded safe levels.

  5. Tissue mercury concentrations and adrenocortical responses of female big brown bats (Eptesicus fuscus) near a contaminated

    E-print Network

    Hopkins, William A.

    as the adrenocortical responses of insectivorous big brown bats (Eptesicus fuscus) near the Hg-contaminated South River. Keywords Mercury Á Cortisol Á Fur:blood ratio Á Insectivore Á Eptesicus fuscus Introduction Mercury (HgTissue mercury concentrations and adrenocortical responses of female big brown bats (Eptesicus

  6. Chronic atrophic gastritis in association with hair mercury level.

    PubMed

    Xue, Zeyun; Xue, Huiping; Jiang, Jianlan; Lin, Bing; Zeng, Si; Huang, Xiaoyun; An, Jianfu

    2014-11-01

    The objective of this study was to explore hair mercury level in association with chronic atrophic gastritis, a precancerous stage of gastric cancer (GC), and thus provide a brand new angle of view on the timely intervention of precancerous stage of GC. We recruited 149 healthy volunteers as controls and 152 patients suffering from chronic gastritis as cases. The controls denied upper gastrointestinal discomforts, and the cases were diagnosed as chronic superficial gastritis (n=68) or chronic atrophic gastritis (n=84). We utilized Mercury Automated Analyzer (NIC MA-3000) to detect hair mercury level of both healthy controls and cases of chronic gastritis. The statistic of measurement data was expressed as mean ± standard deviation, which was analyzed using Levene variance equality test and t test. Pearson correlation analysis was employed to determine associated factors affecting hair mercury levels, and multiple stepwise regression analysis was performed to deduce regression equations. Statistical significance is considered if p value is less than 0.05. The overall hair mercury level was 0.908949 ± 0.8844490 ng/g [mean ± standard deviation (SD)] in gastritis cases and 0.460198 ± 0.2712187 ng/g (mean±SD) in healthy controls; the former level was significantly higher than the latter one (p=0.000<0.01). The hair mercury level in chronic atrophic gastritis subgroup was 1.155220 ± 0.9470246 ng/g (mean ± SD) and that in chronic superficial gastritis subgroup was 0.604732 ± 0.6942509 ng/g (mean ± SD); the former level was significantly higher than the latter level (p<0.01). The hair mercury level in chronic superficial gastritis cases was significantly higher than that in healthy controls (p<0.05). The hair mercury level in chronic atrophic gastritis cases was significantly higher than that in healthy controls (p<0.01). Stratified analysis indicated that the hair mercury level in healthy controls with eating seafood was significantly higher than that in healthy controls without eating seafood (p<0.01) and that the hair mercury level in chronic atrophic gastritis cases was significantly higher than that in chronic superficial gastritis cases (p<0.01). Pearson correlation analysis indicated that eating seafood was most correlated with hair mercury level and positively correlated in the healthy controls and that the severity of gastritis was most correlated with hair mercury level and positively correlated in the gastritis cases. Multiple stepwise regression analysis indicated that the regression equation of hair mercury level in controls could be expressed as 0.262 multiplied the value of eating seafood plus 0.434, the model that was statistically significant (p<0.01). Multiple stepwise regression analysis also indicated that the regression equation of hair mercury level in gastritis cases could be expressed as 0.305 multiplied the severity of gastritis, the model that was also statistically significant (p<0.01). The graphs of regression standardized residual for both controls and cases conformed to normal distribution. The main positively correlated factor affecting the hair mercury level is eating seafood in healthy people whereas the predominant positively correlated factor affecting the hair mercury level is the severity of gastritis in chronic gastritis patients. That is to say, the severity of chronic gastritis is positively correlated with the level of hair mercury. The incessantly increased level of hair mercury possibly reflects the development of gastritis from normal stomach to superficial gastritis and to atrophic gastritis. The detection of hair mercury is potentially a means to predict the severity of chronic gastritis and possibly to insinuate the environmental mercury threat to human health in terms of gastritis or even carcinogenesis. PMID:25119602

  7. Background levels of atmospheric mercury in Kagoshima City, and influence of mercury emission from Sakurajima Volcano, Southern Kyushu, Japan

    Microsoft Academic Search

    Takashi Tomiyasu; Ayako Nagano; Hayao Sakamoto; Norinobu Yonehara

    2000-01-01

    Vapor phase mercury concentration was determined daily for 1 year (Jan. 1996–Jan. 1997) in order to present the levels of atmospheric mercury in Kagoshima City and to estimate the influence of mercury emission from Sakurajima Volcano, southern Kyushu, Japan. The atmospheric mercury was collected on a porous gold collector at Kagoshima University and was determined by cold vapor atomic absorption

  8. Lead, mercury, selenium, and other trace elements in tissues of golden eagles from southwestern Montana, USA.

    PubMed

    Harmata, Alan R; Restani, Marco

    2013-01-01

    Lead-based rifle bullets, used in game hunting and recreational shooting, fragment when striking bone and soft tissues. Lead fragments may be ingested by birds scavenging offal piles or nonretrieved carcasses and therefore pose a poisoning risk. We captured and sampled 74 Golden Eagles (Aquila chrysaetos) in southwestern Montana, USA, from 2008 to 2010 to evaluate levels of lead, mercury, selenium, and 13 other trace elements in blood and feathers. Lead was detected in blood of most (97%, n=70) eagles; mean blood level was 0.26 parts per million (ppm). Most eagles (65%) had background levels (<0.2 ppm), 29% had elevated levels (0.2-0.5 ppm), 13% had chronic levels (0.51-1.0 ppm), and 3% had acute levels (>1.0 ppm) in blood. Lead in blood decreased from winter to spring. Resident eagles had higher lead levels than eagles of unknown residency. Mercury was detected in few eagles, whereas selenium was detected in all, but at a low level (0.36 ppm). Other chemical elements in blood were at low or biologically appropriate levels. Lead in feathers (n=29) was correlated with blood lead (P=0.010), as was mercury in blood and feathers (n=48; P=0.003). Concentrations of lead and mercury in feathers were higher in adults than in juveniles and immatures (P<0.016) and both elements tended to increase with age. Selenium in feathers (n=48) appeared stable across plumage classes. Although detection rates of lead in blood of eagles captured in spring increased from 1985-1993 to 2008-2010, mean levels decreased (P<0.023) between periods, as did proportions of eagles exhibiting above background levels (>0.2 ppm; P<0.02). PMID:23307377

  9. Assessment of Mercury in Fish Tissue from Select Lakes of Northeastern Oregon

    EPA Science Inventory

    A fish tissue study was conducted in five northeastern Oregon reservoirs to evaluate mercury concentrations in an area where elevated atmospheric mercury deposition had been predicted by a national EPA model, but where tissue data were sparse. The study targeted resident predator...

  10. Chronic effects of low-level mercury and cadmium to goldfish (Carassius Auratus)

    SciTech Connect

    Westerman, A.G.

    1984-01-01

    During this five and one half year investigation, experiments were performed to determine the effects of nanogram levels of cadmium and mercury on reproductive performance, growth, and tissue residues of goldfish. In addition, embryo-larval bioassays were conducted on these metals to compare the effects of a short-term exposure to a sensitive life-cycle stage (i.e., eggs and larvae) with a sustained exposure to a relatively insensitive life-cycle period (i.e., adult). Reproduction was blocked by the long-term exposure to 0.25 ..mu..g/l mercury and 0.27 ..mu..g/l cadmium. Over the 1972 days, the control fish spawned on eleven occasions, but the experimentals failed to spawn. The metal-induced reproductive impairment continued in the experimentals even after six months in clean water. Growth of the populations exposed to mercury and cadmium was significantly less than that of the control population (P < 0.001). The mercury, cadmium and control populations grew by 229%, 232% and 353%, respectively. Mercury and cadmium continuously accumulated in fish tissues over the entire 1789 days of whole body exposure. Despite exposure to mercury as inorganic metal, organomercury also accumula

  11. Mercury levels in high-end consumers of fish.

    PubMed Central

    Hightower, Jane M; Moore, Dan

    2003-01-01

    Consumption of food containing mercury has been identified as a health risk. The U.S. Environmental Protection Agency (U.S. EPA) and the National Academy of Sciences recommend keeping the whole blood mercury level < 5.0 microg/L or the hair level < 1.0 microg/g. This corresponds to a reference dose (RfD) of 0.1 microg/kg body weight per day. All patients in a 1-year period (n = 720) who came for an office visit in a private internal medicine practice in San Francisco, California, were evaluated for mercury excess using the current RfD. One hundred twenty-three patients were tested (93 females, 30 males). Of these, data were statistically analyzed for 89 subjects. Mercury levels ranged from 2.0 to 89.5 microg/L for the 89 subjects. The mean for 66 women was 15 microg/L [standard deviation (SD) = 15], and for 23 men was 13 microg/L (SD = 5); 89% had levels exceeding the RfD. Subjects consumed 30 different forms or types of fish. Swordfish had the highest correlation with mercury level. Sixty-seven patients with serial blood levels over time after stopping fish showed a decline in mercury levels; reduction was significant (p < 0.0001). A substantial fraction of patients had diets high in fish consumption; of these, a high proportion had blood mercury levels exceeding the maximum level recommended by the U.S. EPA and National Academy of Sciences. The mean level for women in this survey was 10 times that of mercury levels found in a recent population survey by the U.S. Centers for Disease Control and Prevention. Some children were > 40 times the national mean. PMID:12676623

  12. Lead, cadmium, and mercury tissue residues in healthy swine, cattle, dogs, and horses from the midwestern United States

    Microsoft Academic Search

    L. Penumarthy; F. W. Oehme; R. H. Hayes

    1980-01-01

    A survey was conducted in 1975–1976 to determine the background levels of lead, cadmium, and mercury in tissues of healthy swine, cattle, dogs, and horses from the midwestern United States. Blood, muscle, liver, and kidney were assayed from cattle and swine slaughtered at federal meat inspection plants and in dogs and horses obtained from local pounds and sales barns. A

  13. Relations between mercury, methyl-mercury and selenium in tissues of Octopus vulgaris from the Portuguese coast.

    PubMed

    Raimundo, Joana; Vale, Carlos; Canário, João; Branco, Vasco; Moura, Isabel

    2010-06-01

    Mercury, methyl-mercury (MeHg) and selenium were determined in digestive gland and mantle of Octopus vulgaris, from three areas of the Portuguese coast. To our knowledge these are the first data on MeHg in cephalopods. Concentrations were higher in the digestive gland and percentage of MeHg in mantle. Enhanced Hg and MeHg levels were obtained in digestive gland of specimens from Olhão (3.1-7.4 and 2.0-5.0 microg g(-1), respectively). Differences between areas may be partially related to Hg availability. Relationships between concentrations in mantle and digestive gland pointed to proportional increases of Hg and MeHg in tissues of specimens from Matosinhos and Cascais, but relatively constant values in mantle of individuals from Olhão (higher contamination). Se:Hg molar ratio in digestive gland was 32 and 30 in octopus from Matosinhos and Cascais, respectively, and 5.4 from Olhão. The proximity to the unit suggests demethylation as response to elevated MeHg levels in digestive gland. PMID:20363061

  14. Quantification of total mercury in liver and heart tissue of Harbor Seals (Phoca vitulina) from Alaska USA

    SciTech Connect

    Marino, Kady B. [Department of Chemistry, Roger Williams University, Bristol, RI 02809 (United States)] [Department of Chemistry, Roger Williams University, Bristol, RI 02809 (United States); Hoover-Miller, Anne; Conlon, Suzanne; Prewitt, Jill [Alaska SeaLife Center, City of Seward, AK (United States)] [Alaska SeaLife Center, City of Seward, AK (United States); O'Shea, Stephen K., E-mail: soshea@rwu.edu [Department of Chemistry, Roger Williams University, Bristol, RI 02809 (United States)

    2011-11-15

    This study quantified the Hg levels in the liver (n=98) and heart (n=43) tissues of Harbor Seals (Phoca vitulina) (n=102) harvested from Prince William Sound and Kodiak Island Alaska. Mercury tissue dry weight (dw) concentrations in the liver ranged from 1.7 to 393 ppm dw, and in the heart from 0.19 to 4.99 ppm dw. Results of this study indicate liver and heart tissues' Hg ppm dw concentrations significantly increase with age. Male Harbor Seals bioaccumulated Hg in both their liver and heart tissues at a significantly faster rate than females. The liver Hg bioaccumulation rates between the harvest locations Kodiak Island and Prince William Sound were not found to be significantly different. On adsorption Hg is transported throughout the Harbor Seal's body with the partition coefficient higher for the liver than the heart. No significant differences in the bio-distribution (liver:heart Hg ppm dw ratios (n=38)) values were found with respect to either age, sex or geographic harvest location. In this study the age at which Hg liver and heart bioaccumulation levels become significantly distinct in male and female Harbor Seals were identified through a Tukey's analysis. Of notably concern to human health was a male Harbor Seal's liver tissue harvested from Kodiak Island region. Mercury accumulation in this sample tissue was determined through a Q-test to be an outlier, having far higher Hg concentrarion (liver 392 Hg ppm dw) than the general population sampled. - Highlights: Black-Right-Pointing-Pointer Mercury accumulation in the liver and heart of seals exceed food safety guidelines. Black-Right-Pointing-Pointer Accumulation rate is greater in males than females with age. Black-Right-Pointing-Pointer Liver mercury accumulation is greater than in the heart tissues. Black-Right-Pointing-Pointer Mercury determination by USA EPA Method 7473 using thermal decomposition.

  15. Mercury exposure may suppress baseline corticosterone levels in juvenile birds.

    PubMed

    Herring, Garth; Ackerman, Joshua T; Herzog, Mark P

    2012-06-01

    Mercury exposure has been associated with a wide variety of negative reproductive responses in birds, however few studies have examined the potential for chick impairment via the hypothalamic-pituitary-adrenal (HPA) axis. The HPA axis regulates corticosterone levels during periods of stress. We examined the relationship between baseline fecal corticosterone metabolite concentrations and mercury concentrations in down feathers of recently hatched (<3 days) and blood of older (15-37 days) Forster's tern (Sterna forsteri) chicks in San Francisco Bay, California. Baseline fecal corticosterone metabolite concentrations were negatively correlated with mercury concentrations in blood of older chicks (decreasing by 81% across the range of observed mercury concentrations) while accounting for positive correlations between corticosterone concentrations and number of fledgling chicks within the colony and chick age. In recently hatched chicks, baseline fecal corticosterone metabolite concentrations were weakly negatively correlated with mercury concentrations in down feathers (decreasing by 45% across the range of observed mercury concentrations) while accounting for stronger positive correlations between corticosterone concentrations and colony nest abundance and date. These results indicate that chronic mercury exposure may suppress baseline corticosterone concentrations in tern chicks and suggests that a juvenile bird's ability to respond to stress may be reduced via the downregulation of the HPA axis. PMID:22578153

  16. Mercury Exposure May Suppress Baseline Corticosterone Levels in Juvenile Birds.

    USGS Publications Warehouse

    Herring, Garth; Ackerman, Joshua T.; Herzog, Mark P.

    2012-01-01

    Mercury exposure has been associated with a wide variety of negative reproductive responses in birds, however few studies have examined the potential for chick impairment via the hypothalamic-pituitary-adrenal (HPA) axis. The HPA axis regulates corticosterone levels during periods of stress. We examined the relationship between baseline fecal corticosterone metabolite concentrations and mercury concentrations in down feathers of recently hatched (Sterna forsteri) chicks in San Francisco Bay, California. Baseline fecal corticosterone metabolite concentrations were negatively correlated with mercury concentrations in blood of older chicks (decreasing by 81% across the range of observed mercury concentrations) while accounting for positive correlations between corticosterone concentrations and number of fledgling chicks within the colony and chick age. In recently hatched chicks, baseline fecal corticosterone metabolite concentrations were weakly negatively correlated with mercury concentrations in down feathers (decreasing by 45% across the range of observed mercury concentrations) while accounting for stronger positive correlations between corticosterone concentrations and colony nest abundance and date. These results indicate that chronic mercury exposure may suppress baseline corticosterone concentrations in tern chicks and suggests that a juvenile bird's ability to respond to stress may be reduced via the downregulation of the HPA axis.

  17. DETERMINATION OF TOTAL MERCURY IN FISH TISSUES USING PYROLYSIS ATOMIC ABSORPTION SPECTROMETRY WITH GOLD AMALGAMATION

    EPA Science Inventory

    A simple and rapid procedure for measuring total mercury in fish tissues is evaluated and compared with conventional techniques. Using an automated instrument incorporating combustion, preconcentration by amalgamation with gold, and atomic absorption spectrometry (AAS), mill...

  18. Distribution and accumulation of mercury in tissues of captive-reared common loon (Gavia immer) chicks.

    PubMed

    Kenow, Kevin P; Meyer, Michael W; Hines, Randy K; Karasov, William H

    2007-05-01

    We determined the distribution and accumulation of Hg in tissues of common loon (Gavia immer) chicks maintained for up to 15 weeks on either a control diet with no added methylmercury chloride (MeHgCl) or one containing either 0.4 or 1.2 microg Hg (as MeHgCl)/g wet-weight food. Total Hg and MeHg tissue concentrations were strongly positively correlated (r2 > 0.95) with the amount of Hg delivered to individual chicks throughout the course of the experiment. The pattern of differential Hg concentration in internal tissues was consistent within each treatment: Liver > kidney > muscle > carcass > brain. Feather Hg concentrations were consistently higher than those of internal tissues and represented an important route of Hg elimination. Feather mass accounted for 4.3% +/- 0.1% (average +/- standard error) of body mass, yet 27.3% +/- 2.6% of total Hg intake was excreted into feathers. Our calculations indicate that 26.7% +/- 4.9% of ingested Hg was not accounted for and, thus, either was never absorbed or was absorbed and subsequently eliminated in feces. With the additional excretion into feathers, 54% of ingested Hg was excreted. Demethylation was evident in the liver at all treatment levels and in the kidneys of chicks dosed at 1.2 microg Hg/g. Mercury concentrations were strongly positively correlated (r2 > or = 0.95) among internal tissues and with blood Hg concentration. Mercury concentrations of secondary feathers were moderately correlated (r2 = 0.82-0.93) with internal tissues. We supply regression models that may be used to provide perspective and a useful means of interpreting the variety of measures of Hg exposure reported in the literature. PMID:17521154

  19. Distribution and accumulation of mercury in tissues of captive-reared common loon (Gavia immer) chicks

    USGS Publications Warehouse

    Kenow, K.P.; Meyer, M.W.; Hines, R.K.; Karasov, W.H.

    2007-01-01

    We determined the distribution and accumulation of Hg in tissues of common loon (Gavia immer) chicks maintained for up to 15 weeks on either a control diet with no added methylmercury chloride (MeHgCl) or one containing either 0.4 or 1.2 ??g Hg (as MeHgCl)/g wet-weight food. Total Hg and MeHg tissue concentrations were strongly positively correlated (r2 > 0.95) with the amount of Hg delivered to individual chicks throughout the course of the experiment. The pattern of differential Hg concentration in internal tissues was consistent within each treatment: Liver > kidney > muscle > carcass > brain. Feather Hg concentrations were consistently higher than those of internal tissues and represented an important route of Hg elimination. Feather mass accounted for 4.3% ?? 0.1% (average ?? standard error) of body mass, yet 27.3% ?? 2.6% of total Hg intake was excreted into feathers. Our calculations indicate that 26.7% ?? 4.9% of ingested Hg was not accounted for and, thus, either was never absorbed or was absorbed and subsequently eliminated in feces. With the additional excretion into feathers, 54% of ingested Hg was excreted. Demethylation was evident in the liver at all treatment levels and in the kidneys of chicks dosed at 1.2 ??g Hg/g. Mercury concentrations were strongly positively correlated (r2 ??? 0.95) among internal tissues and with blood Hg concentration. Mercury concentrations of secondary feathers were moderately correlated (r2 = 0.82-0.93) with internal tissues. We supply regression models that may be used to provide perspective and a useful means of interpreting the variety of measures of Hg exposure reported in the literature. ?? 2007 SETAC.

  20. Mercury levels in mink (Mustela vison) and river otter (Lontra canadensis) from northeastern North America.

    PubMed

    Yates, David E; Mayack, David T; Munney, Kenneth; Evers, David C; Major, Andrew; Kaur, Taranjit; Taylor, Robert J

    2005-03-01

    Aquatic ecosystems have received mercury released from anthropogenic sources. The northeast region of North America is at especially high risk because of local and regional emission sources, prevailing wind patterns, and certain hydrological and biogeochemical features. Here we examine regional variation in total mercury (Hg) in brain, liver, and fur from otter and mink collected across New York, New England, and Nova Scotia. Gender and age are examined as factors potentially affecting Hg tissue levels. In addition, temporal relationships are analyzed for New York as well as correlative relationships for tissues from Maine. Animals were collected from 1982 to 2003, mostly from licensed trappers. Liver was the only tissue from otter that exhibited significant regional variation (New York versus Maine) in Hg concentration. Mercury concentration was significantly related to age but not to gender for otter. All tissues in mink exhibited significant, but inconsistent, regional variation in total Hg concentration, with the highest mean Hg concentration in liver samples from Massachusetts/Connecticut. Female mink had significantly greater Hg concentrations in liver than males. Total Hg concentration in the liver of both otter and mink from New York decreased significantly with time. Correlations among tissues for Hg concentration were stronger for male and female mink and male otter than female otter from Maine. PMID:15931971

  1. High levels of mercury in biota of a new Prairie irrigation reservoir with a simplified food web in Southern Alberta, Canada

    Microsoft Academic Search

    Lars BrinkmannJoseph; Joseph B. Rasmussen

    2010-01-01

    This study examined mercury levels in northern pike (Esox lucius) from the Twin Valley Reservoir in southern Alberta, 2 years after construction in 2003. The hypothesis was tested that mercury\\u000a concentrations in pike from the reservoir are significantly higher than in pike from the nearby Oldman River. Mercury concentrations\\u000a in muscle tissue (0.37–1.54 ppm) generally exceeded the consumption guideline of 0.5 ppm total

  2. Whole-body imaging of the distribution of mercury released from dental fillings into monkey tissues

    SciTech Connect

    Hahn, L.J.; Kloiber, R.; Leininger, R.W.; Vimy, M.J.; Lorscheider, F.L. (Univ. of Calgary, Alberta (Canada))

    1990-11-01

    The fate of mercury (Hg) released from dental silver amalgam tooth fillings into human mouth air is uncertain. A previous report about sheep revealed uptake routes and distribution of amalgam Hg among body tissues. The present investigation demonstrates the bodily distribution of amalgam Hg in a monkey whose dentition, diet, feeding regimen, and chewing pattern closely resemble those of humans. When amalgam fillings, which normally contain 50% Hg, are made with a tracer of radioactive {sup 203}Hg and then placed into monkey teeth, the isotope appears in high concentration in various organs and tissues within 4 wk. Whole-body images of the monkey revealed that the highest levels of Hg were located in the kidney, gastrointestinal tract, and jaw. The dental profession's advocacy of silver amalgam as a stable tooth restorative material is not supported by these findings.

  3. The Relationship between Adirondack Lake pH and Levels of Mercury in Yellow Perch

    Microsoft Academic Search

    Donald Brown; Alexey Goncharov; Eric Paul; Howard Simonin; David O. Carpenter

    2010-01-01

    Levels of total mercury in yellow perch Perca flavescens from Adirondack lakes were studied in relation to characteristics of the lakes to determine why some lakes had fish with higher concentrations of mercury. Almost all mercury in fish is in the form of methylmercury, which can pose significant health hazards to humans who consume such fish. Fish mercury concentrations and

  4. Accumulation of mercury in the tissues of the common octopus Octopus vulgaris (L.) in two localities on the Portuguese coast

    Microsoft Academic Search

    Sónia Seixas; Paco Bustamante; Graham Pierce

    2005-01-01

    Mercury concentrations were measured in tissues of 12 individuals of Octopus vulgaris, captured by the commercial fishery at two points along the Portuguese coast, Viana do Castelo and Cascais, in spring 2002. Concentrations were determined in six tissues (digestive gland, branchial hearts, gills, mantle, arms, and gonads). Correlations between mercury concentrations in different tissues were examined as were correlations between

  5. Evaluation of an interlaboratory proficiency-testing exercise for total mercury in environmental samples of soils, sediments and fish tissue

    Microsoft Academic Search

    R. Rocha; S RODRIGUES; M OTERO; M VALEGA; C LOPES; P PATO; J COELHO; A LILLEBO; A DUARTE; M PARDAL

    2008-01-01

    A proficiency-testing scheme concerning total mercury determination in soils and sediments (with different levels of contamination) and fish tissue involved 25 European laboratories as participants, who used their regular in-house analytical methods, and reference values were determined from the results obtained. The most precise results were obtained for the fish matrix. The majority of participants obtained satisfactory Z-scores, and laboratories

  6. DISTRIBUTION OF MERCURY IN THE TISSUES OF FIVE SPECIES OF FRESHWATER FISH FROM LAKE MEAD, USA

    EPA Science Inventory

    Total mercury (Hg) concentrations were determined in seven tissues (skeletal muscle, liver, blood, gonad, brain, gill, and heart) of 59 striped bass and four tissues (muscle, liver, blood, and gonad) of 69 largemouth bass, 76 channel catfish, 12 bluegill, and 22 blue tila...

  7. TISSUE MERCURY CONCENTRATIONS AND POTENTIAL NEUROGPATHOLOGICAL CHANGES IN COMMON LOONS (GAVIA IMMER)

    EPA Science Inventory

    Common loons (Gavia immer) in New England are exposed to high levels of mercury through their diet. Mercury bioaccumulates through the food chain as methylmercury, a neurotoxin which has been shown in controlled feeding studies to have detrimental effects on the health and behavi...

  8. Levels of mercury in alligators (Alligator mississippiensis) collected along a transect through the Florida Everglades

    USGS Publications Warehouse

    Rumbold, D.G.; Fink, L.E.; Laine, K.A.; Niemczyk, S.L.; Chandrasekhar, T.; Wankel, Scott D.; Kendall, C.

    2002-01-01

    As part of a multi-agency study of alligator health, 28 American alligators (Alligator mississippiensis) were captured along a transect through the Florida Everglades in 1999. Liver and tail muscle tissues were sampled and analyzed on a wet weight basis for total mercury (THg) using cold-vapor atomic absorption spectrophotometry. All tissues had detectable concentrations of THg that ranged from 0.6 to 17 mg/kg in liver and from 0.1 to 1.8 mg/kg in tail muscle. THg was more concentrated in liver tissue than tail muscle, but levels were highly correlated between tissues. THg concentrations in tissue differed significantly among locations, with animals from Everglades National Park (ENP) having mean concentrations of THg in liver (10.4 mg/kg) and tail muscle (1.2 mg/kg) that were two-fold higher than basin-wide averages (4.9 and 0.64 mg/kg, respectively). The reasons for higher contamination of ENP alligators were unclear and could not be explained by differences in sex, length, weight or animal age. While ??15N values were positively correlated with THg concentrations in tail muscle, spatial patterns in isotopic composition did not explain the elevated THg levels in ENP alligators. Therefore, it appears that ENP alligators were more highly exposed to mercury in their environment than individuals in other areas. Comparisons to a previous survey by Yanochko et al. [Arch Environ Contam Toxicol 32 (1997) 323] suggest that mercury levels have declined in some Everglades alligators since 1994. ?? 2002 Elsevier Science B.V. All rights reserved.

  9. Contaminant levels in fish tissue from San Francisco Bay

    SciTech Connect

    Fairey, R. [California Dept. of Fish and Game, Moss Landing, CA (United States). Moss Landing Marine Labs.; Taberski, K. [San Francisco Bay Regional Water Quality Control Board, Oakland, CA (United States)

    1995-12-31

    Edible fish species were collected from thirteen locations throughout San Francisco Bay, during the spring of 1994, for determination of contaminants levels in muscle tissue. Species collected included white croaker, surfperch, leopard and brown smoothhound sharks, striped bass, white sturgeon and halibut Sixty six composite tissue samples were analyzed for the presence of PAHs, PCBs, pesticides, trace elements and dioxin/furans. The US EPA approach to assessing chemical contaminant data for fish tissue consumption was used for identifying the primary chemicals of concern. Six chemicals or chemical groups were found to exceed screening levels established using the US EPA approach. PCBs (as total Aroclors) exceeded the screening level of 3 ppb in all sixty six tissue samples, with the highest concentrations (638 ppb) found near San Francisco`s industrial areas. Mercury was elevated (> 0.14 ppm) in forty of the sixty-six samples with the highest levels (1.26 ppm) occurring in shark muscle tissues. Concentrations of the organochlorine pesticides dieldrin, total chlordanes and total DDTs exceeded screening levels in a number of samples. Dioxin/furans (as TEQs) were elevated (above 0.15 ppt) in 16 of the 19 samples analyzed. Fish with high lipid content (croaker and surfperch) in their muscle tissue generally exhibited higher contaminant levels while fish with low lipid levels (halibut and shark) exhibited lower organic contaminant levels. Tissue samples taken from North Bay stations most often exhibited high levels of chemical contamination. The California Office of Health Hazard Assessment is currently evaluating the results of this study and has issued an interim Health Advisory concerning the human consumption of fish tissue from San Francisco Bay.

  10. Human hair mercury levels in the Wanshan mercury mining area, Guizhou Province, China.

    PubMed

    Li, Ping; Feng, Xinbin; Qiu, Guangle; Shang, Lihai; Li, Guanghui

    2009-12-01

    The total mercury (T-Hg) and methyl mercury (Me-Hg) concentrations in the hair were measured to evaluate mercury (Hg) exposure for the residents in Da-shui-xi Village (DSX) and Xia-chang-xi Village (XCX) in the Wanshan Hg mining area, Guizhou Province, Southwestern China. The mean concentrations in the hair of DSX residents were 5.5 ± 2.7 ?g/g and 1.9 ± 0.9 ?g/g for T-Hg and Me-Hg, respectively. The concentrations in the hair of XCX residents were 3.3 ± 1.4 ?g/g and 1.2 ± 0.5 ?g/g for T-Hg and Me-Hg, respectively. Hair Me-Hg concentrations were significantly correlated to T-Hg (r = 0.42, P < 0.01) in the two sites; on average, hair Me-Hg concentration accounted for 40 and 44% of T-Hg for DSX and XCX residents, respectively. Age has no obvious correlation with hair Hg and the hair Hg levels showed a significant gender difference, with higher T-Hg and Me-Hg concentrations in the hair from males than females. The rice collected from the two sites showed high levels of T-Hg and Me-Hg concentration. The results indicated a certain Hg exposure for the residents in DSX and XCX in the Wanshan Hg mining area. PMID:19160059

  11. Trophic calculations reveal the mechanism of population-level variation in mercury concentrations between marine ecosystems: case studies of two polar seabirds.

    PubMed

    Brasso, Rebecka L; Polito, Michael J

    2013-10-15

    The incorporation of quantitative trophic level analysis in ecotoxicological studies provides explanatory power to identify the factors, trophic or environmental, driving population-level variation in mercury exposure at large geographic scales. In the Antarctic marine ecosystem, mercury concentrations and stable isotope values in Adélie penguins (Pygoscelis adeliae) were compared between the Antarctic Peninsula and the Ross Sea. Correcting tissue ?(15)N values for baseline ?(15)N values revealed population-level differences in trophic position which contributes to differences in mercury. Data from Thick-billed murres (Uria lomvia) were synthesized from published values from Baffin Bay and Svalbard to demonstrate the utility of baseline ?(15)N values in identifying differences in environmental mercury exposure independent of diet. Here, we demonstrate the importance of calculating population-specific trophic level data to uncover the source of variation in mercury concentrations between geographically distinct populations of marine predators. PMID:23993395

  12. Selenium and mercury interactions wtih emphasis on fish tissue

    EPA Science Inventory

    This review addresses the effects of mercury (Hg) in fish as it relates to the health of the fish themselves as well as potential risks of toxicity in wildlife and humans that consume fish. In particular, it addresses selenium (Se) as a bioindicator of susceptibility to harmful e...

  13. Selenium and Mercury Interactions with Emphasis on Fish Tissue

    Microsoft Academic Search

    Spencer A. Peterson; Nicholas V. C. Ralston; Philip D. Whanger; James E. Oldfield; Wayne D. Mosher

    2009-01-01

    This review addresses the effects of mercury (Hg) in fish as it relates to the health of the fish themselves as well as potential risks of toxicity in wildlife and humans that consume fish. In particular, it addresses selenium (Se) as a bioindicator of susceptibility to harmful effects of Hg exposures and evaluates how Se moderates the toxic effects of

  14. Lead and mercury levels in raccoons from Macon County, Alabama

    SciTech Connect

    Khan, A.T.; Thompson, S.J. [Tuskegee Univ., AL (United States); Mieike, H.W. [Xavier Univ. of Louisiana, New Orleans, LA (United States)

    1995-06-01

    Heavy metal contamination in the environment has become a major concern of the scientific community. The ubiquitous present of heavy metals such as lead, mercury, and cadmium in wildlife animals has been reported. Although the understanding of the full significance of these metals is incomplete, it is known that some species contain concentrations of metals proportional to the levels present in their environments. Thus, wild animals can be used as biological indicators of environmental concentrations of metals. The behavior, omnivorous feeding habits, and adaptability of raccoons (Procyon lotor) qualify this animal as a useful indicator of environmental pollution. The purpose of this paper was to report some preliminary observations on lead and mercury levels in raccoons from Macon County, Alabama, a potential indicator species for wildlife. 19 refs., 3 tabs.

  15. Energy Level Structure of Mercury 192

    Microsoft Academic Search

    B. D. MacDonald; J. L. Wood; E. Zganjar

    1998-01-01

    Gamma-gamma, gamma-electron, and electron-electron coincidence data have been observed in the decay of 192Tl to 192Hg. Sources of 192Tl were produced at the Holifield Heavy Ion Research Facility and separated using the UNISOR isotope separator. We present a detailed level scheme for the 192Hg nucleus and discuss the spin and parities of new levels. Work supported in part by the

  16. Mercury

    NSDL National Science Digital Library

    This lithograph shows mosaic images of Mercury, captured by the Mariner 10 spacecraft. The images are accompanied by a brief description and history, some statistical facts, and a list of significant dates in the exploration of Mercury.

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

    SciTech Connect

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

    1998-02-01

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

  18. POSSIBLE RAMIFICATIONS OF HIGHER MERCURY CONCENTRATIONS IN FILLET TISSUE OF SKINNIER FISH

    EPA Science Inventory

    Mercury concentrations were found to be statistically higher in the fillet tissue of the skinnier individuals of a fish species (striped bass) that was experiencing starvation when collected from Lake Mead, which is located on the Arizona-Nevada border. This is considered a conse...

  19. A PREDICTIVE MODEL OF MERCURY FISH TISSUE CONCENTRATIONS FOR THE SOUTHEAST UNITED STATES

    EPA Science Inventory

    The potential adverse effects of chemical contaminants in fish is an ongoing EPA concern that is directly related to Clean Water Act responsibilities to ensure that waters of the United States are fishable and swimmable. Mercury is a fish tissue contaminant that can bioaccumulat...

  20. Comparison of Indoor Mercury Vapor in Common Areas of Residential Buildings with Outdoor Levels in a Community Where Mercury Is Used for Cultural Purposes

    PubMed Central

    Garetano, Gary; Gochfeld, Michael; Stern, Alan H.

    2006-01-01

    Elemental mercury has been imbued with magical properties for millennia, and various cultures use elemental mercury in a variety of superstitious and cultural practices, raising health concerns for users and residents in buildings where it is used. As a first step in assessing this phenomenon, we compared mercury vapor concentration in common areas of residential buildings versus outdoor air, in two New Jersey cities where mercury is available and is used in cultural practices. We measured mercury using a portable atomic absorption spectrometer capable of quantitative measurement from 2 ng/m3 mercury vapor. We evaluated the interior hallways in 34 multifamily buildings and the vestibule in an additional 33 buildings. Outdoor mercury vapor averaged 5 ng/m3; indoor mercury was significantly higher (mean 25 ng/m3; p < 0.001); 21% of buildings had mean mercury vapor concentration in hallways that exceeded the 95th percentile of outdoor mercury vapor concentration (17 ng/m3), whereas 35% of buildings had a maximum mercury vapor concentration that exceeded the 95th percentile of outdoor mercury concentration. The highest indoor average mercury vapor concentration was 299 ng/m3, and the maximum point concentration was 2,022 ng/m3. In some instances, we were able to locate the source, but we could not specifically attribute the elevated levels of mercury vapor to cultural use or other specific mercury releases. However, these findings provide sufficient evidence of indoor mercury source(s) to warrant further investigation. PMID:16393659

  1. ASSESSING MERCURY LEVELS IN THE WASTEWATER OF AN AGING RESEARCH LABORATORY BUILDING

    PubMed Central

    Ragan, Gregory A.; Gregory Alvord, W.

    2007-01-01

    Increasingly stringent restrictions on mercury concentrations in wastewater discharge may be problematic for aging research laboratory facilities. Relatively high levels of mercury compounds may exist and concentrate deep in the plumbing system and their sediments, resulting in elevated wastewater concentrations. This study was conducted to assess total mercury levels in an aging laboratory building wastewater system. Wastewater outflow, sink trap water, and pipe sediment samples were collected from the building. The Jerome 431™ Mercury Vapor Analyzer was assessed as a tool for screening lab sink trap drains for mercury deposition. Results revealed that the three day average for mercury discharge from this single structure, if not diluted by other waters, would be above the local total release parameters to the wastewater treatment plant. The sink traps did not contain a majority of the mercury; however, the pipe sediment and outflow samples revealed consistently elevated concentrations. PMID:18438463

  2. Methylmercury egg injections: part 1--Tissue distribution of mercury in the avian embryo and hatchling.

    PubMed

    Rutkiewicz, Jennifer; Basu, Niladri

    2013-07-01

    Methylmercury (MeHg) is transferred by female birds into their eggs thus leaving developing embryos exposed to MeHg from the time of fertilization through hatching. Although Hg is a developmental toxicant, little is known about how it distributes among embryonic tissues and subsequently affects neurodevelopment in birds. The main objective of the present study (Part 1 of 2) was to evaluate the distribution of Hg in tissues during different developmental stages in order to better understand potential targets of Hg in the embryo and hatchling. Eight independent, yet related, egg injection studies were conducted. In five studies, white leghorn chicken embryos were air cell injected with methylmercury chloride (MeHgCl; range injected: 0.17-6.4?g/g egg) and Hg concentrations were assessed in seven tissues. We found that soft tissue distribution in embryos and hatchlings was similar to that seen in older birds, with higher total Hg concentrations in liver and kidney than in heart, muscle, and brain (e.g., 5.1, 3.8, 1.9, 2.3, and 1.9?g/g wet weight, respectively, in day 19 embryos after injection with 6.4?g/g MeHgCl). Concentrations were highest in feathers and unabsorbed yolk (e.g., 24.1 and 13.0?g/g in day 19 embryos after injection with 6.4?g/g MeHgCl). Tissue concentrations rose through embryonic days 11, 14, 16, and 19 but generally leveled off at days 1 and 7 post-hatch. We also report on pilot studies that demonstrated that tissue Hg accumulation after MeHgCl injection is similar in chicken and Japanese quail embryos, and that tissue Hg accumulation in chicken embryos after methylmercury cysteine, but not mercury (2) chloride, injection is similar to accumulation after MeHgCl injection. These findings suggest that embryos may accumulate kidney and brain Hg concentrations known to cause renal and neurotoxicity seen in older birds, but that sequestration of Hg into liver and excretion into rapidly growing feathers may offer some protection. This work also demonstrates that air cell injection studies are potentially a useful tool for studies of Hg toxicity in the laboratory. PMID:23669340

  3. Total and methyl mercury levels in wild mammals from the PreCambrian Shield area of south central Ontario, Canada

    SciTech Connect

    Wren, C. (Univ. of Guelph, Ontario); MacCrimmon, H.; Frank, R.; Suda, P.

    1980-07-01

    It has been established that elevated mercury levels in fish occur in areas remote from recognized point sources of mercury contamination. It may be expected, therefore, that mercury levels may also be accumulated through natural processes in wild mammals inhabiting those areas. A process for demethylating organic mercury to less toxic inorganic mercury has been suggested in some marine mammals exposed to high mercury levls. It is possible that similar demethylating process exists in terrestial mammals which are exposed to elevated levels of mercury in their diet. Natural mercury levels in fish have been reported in the PreCambrian Shield of the Muskoka District. The present paper compares total and methyl mercury levels occurring in various organs of wilder beaver, raccoon and otter representing herbivorous, omnivorous and carnivorous life styles, collected from the same general area where substantial mercury levels are known to occur in fish.

  4. Species- and tissue-specific mercury bioaccumulation in five fish species from Laizhou Bay in the Bohai Sea of China

    NASA Astrophysics Data System (ADS)

    Liu, Jinhu; Cao, Liang; Huang, Wei; Dou, Shuozeng

    2013-05-01

    Mercury (Hg) concentrations in the tissues (muscle, stomach, liver, gills, skin, and gonads) of five fish species (mullet Liza ha em atocheil us, flathead fish Platycephalus indicus, sea bass Lateolabrax japonic u s, mackerel Scomberomorus niphonius and silver pomfret Pampus argenteus) collected from Laizhou Bay in the Bohai Sea of China were investigated. The results indicate that Hg bioaccumulation in the five fish was tissue-specific, with the highest levels in the muscle and liver, followed by the stomach and gonads. The lowest levels were found in the gills and skin. Fish at higher trophic levels (flathead fish and sea bass) exhibited higher Hg concentrations than consumers at lower trophic levels. Mercury bioaccumulation tended to be positively correlated with fish length in mullet, silver pomfret, mackerel, and flathead fish, but was negatively correlated with fish length in sea bass. The Hg concentrations in the muscles of all fish species in Laizhou Bay were within the permissible limits of food safety set by national and international criteria. However, the suggesting maximum consumption of sea bass is 263 g per week for human health.

  5. Comparative baseline levels of mercury, Hsp 70 and Hsp 60 in subsistence fish from the Yukon-Kuskokwim delta region of Alaska.

    PubMed

    Duffy, L K; Scofield, E; Rodgers, T; Patton, M; Bowyer, R T

    1999-10-01

    In subsistence fish; northern pike (Esox lucius), burbot (Lota lota), whitefish (Coregonus nelsoni), grayling (Thymallus arcticus) and sheefish (Stenodus lencichthys), we determined the Hsp 60 and Hsp 70 levels in 31 samples from adult fish gills. A dot-blot analysis using antibodies to either Hsp 70 or Hsp 60 showed the average Hsp 70 concentration was 9.1 microg/mg protein, while the average Hsp 60 concentration was 147.4 microg/mg protein. Mercury levels in muscle tissue in these fish averaged 0.382 ppm. Using a subset of samples (n = 24), we determined that the major component in the muscle of Alaskan subsistence fish was methyl mercury. No correlation was observed between Hsp 60 or Hsp 70 expression in gill tissue and mercury concentrations in muscle tissue. Hsp 60 and Hsp 70 protein levels in the gills were correlated. PMID:10622434

  6. Organochlorine and mercury contamination in fish tissues from the River Nestos, Greece.

    PubMed

    Christoforidis, Achilleas; Stamatis, Nikolaos; Schmieder, Klaus; Tsachalidis, Efstathios

    2008-01-01

    Polychlorinated biphenyls (PCBs), hexachlorocyclohexane (HCH) isomers, dichlorodiphenyltrichloroethane (DDT) and its metabolites, other organochlorine pesticides such as hexachlorobenzene (HCB), chlordane compounds (CHLs, including trans-chlordane and cis- and trans-nonachlor) and the heavy metal mercury were quantified in muscle and liver of the European chub (Leuciscus cephalus, Linnaeus, 1758) and in the muscle of the barbel (Barbus cyclolepis, Heckel, 1837) at two sampling sites of the River Nestos, Greece. PCBs in muscle and DDTs in the liver tissues were the predominant organochlorinated contaminants. Among the PCBs, congeners 47 (up to 9.60 ng g(-1) wet wt.), 180 (up to 1.15 ng g(-1) wet wt.) and 190 (up to 1.50 ng g(-1) wet wt.) were the most frequent and abundant. The contamination degree by the sum of PCBs on the fish tissue samples from the River Nestos is lower or similar to PCB levels found in other ecosystems. Among the organochlorine pesticides, essentially only p,p'-DDD, p,p'-DDE and alpha-, beta- and gamma-HCH were found, with the former appearing at mean levels up to 30.71 ng g(-1) wet wt. From a public health standpoint, residue organochlorine pesticide levels from our work are considerably lower than the recommended tolerance limits. Finally, mean values of Hg in chub were significant lower (up to 31.04 ng g(-1) wet wt.) compared to those detected on barbel (up to 169.27 ng g(-1) wet wt.). The concentrations of Hg in fresh water fish from the River Nestos did not exceed WHO and US EPA health guidelines, and were suitable for human consumption. PMID:17688909

  7. Mercury and histopathology of the vulnerable goliath grouper, Epinephelus itajara, in U.S. waters: a multi-tissue approach.

    PubMed

    Adams, Douglas H; Sonne, Christian

    2013-10-01

    Goliath grouper have undergone significant global population declines with potential biological extinction for some subpopulations. Although overfishing and habitat loss are important drivers of these declines, the negative effects of contaminants may also play a role. The life history patterns of goliath grouper may make this species especially prone to exposure to contaminants and may exacerbate bioaccumulation of toxic substances, including mercury, which has documented detrimental health effects. Therefore, we analyzed mercury (in muscle, liver, kidney, gonad, and brain tissue) and the histology of key organs (liver, kidney and gill tissue) in 56 goliath groupers from U.S. waters. Total mercury concentration was greatest in liver tissue, followed by kidney, muscle, gonad, and brain. Maximum mercury concentration ranged from 22.68 ?g/g in liver tissue to 0.89 ?g/g in brain tissue. Mean mercury concentration ranged from 2.87 ?g/g in liver tissue to 0.37 ?g/g in brain tissue with a mean of 0.63 ?g/g in muscle. Mean mercury concentrations observed in goliath grouper from U.S. waters were within the range known to cause direct health effects in fish after long-term exposure. The lesions and histological changes observed in the liver, kidney, and gills of goliath groupers were similar to those found in other fish following laboratory mercury-exposure trials and to those found in mercury-contaminated fish in wild populations carrying similar or even lower concentrations. We suggest that exposure to mercury and other environmental influences such as pathogens and reduced temperatures could be co-factors in the histological effects or anomalies observed in the present study, and resulting stresses may be involved in the observed population declines in the species. PMID:23830062

  8. Mercury in the Pelagic Food Web of Lake Champlain

    PubMed Central

    Chen, Celia; Kamman, Neil; Shanley, James; Chalmers, Ann; Jackson, Brian; Taylor, Vivien; Smeltzer, Eric; Stangel, Pete; Shambaugh, Angela

    2013-01-01

    Lake Champlain continues to experience mercury contamination resulting in public advisories to limit human consumption of top trophic level fish such as walleye. Prior research suggested that mercury levels in biota could be modified by differences in ecosystem productivity as well as mercury loadings. We investigated relationships between mercury in different trophic levels in Lake Champlain. We measured inorganic and methyl mercury in water, seston, and two size fractions of zooplankton from 13 sites representing a range of nutrient loading conditions and productivity. Biomass varied significantly across lake segments in all measured ecosystem compartments in response to significant differences in nutrient levels. Local environmental factors such as alkalinity influenced the partitioning of mercury between water and seston. Mercury incorporation into biota was influenced by the biomass and mercury content of different ecosystem strata. Pelagic fish tissue mercury was a function of fish length and the size of the mercury pool associated with large zooplankton. We used these observations to parameterize a model of mercury transfers in the Lake Champlain food web that accounts for ecosystem productivity effects. Simulations using the mercury trophic transfer model suggest that reductions of 25 to 75% in summertime dissolved eplimnetic total mercury will likely allow fish tissue mercury concentrations to drop to the target level of 0.3 µg g?1 in a 40-cm fish in all lake segments. Changes in nutrient loading and ecosystem productivity in eutrophic segments may delay any response to reduced dissolved mercury and may result in increases in fish tissue mercury. PMID:22193540

  9. Toxic effects of DDT, malathion and mercury on the tissue carbohydrate metabolism of Sarotherodon mossambicus (Peters)

    Microsoft Academic Search

    K Ramalingam

    1988-01-01

    Toxic stress due to DDT, malathion and mercury on the tissue carbohydrate metabolism ofSarotherodon mossambicus revealed the following manifest effects: (i) concentration of free sugars in the liver and muscle increased due to mobilisation\\u000a of it from its bound form, glycogen and (ii) the normal carbohydrate metabolic pathway was altered indicating a switch over\\u000a to anaerobic state involving the conversion

  10. The influence of depth on mercury levels in pelagic fishes and their prey.

    PubMed

    Choy, C Anela; Popp, Brian N; Kaneko, J John; Drazen, Jeffrey C

    2009-08-18

    Mercury distribution in the oceans is controlled by complex biogeochemical cycles, resulting in retention of trace amounts of this metal in plants and animals. Inter- and intra-specific variations in mercury levels of predatory pelagic fish have been previously linked to size, age, trophic position, physical and chemical environmental parameters, and location of capture; however, considerable variation remains unexplained. In this paper, we focus on differences in ecology, depth of occurrence, and total mercury levels in 9 species of commercially important pelagic fish (Thunnus obesus, T. albacares, Katsuwonus pelamis, Xiphias gladius, Lampris guttatus, Coryphaena hippurus, Taractichthys steindachneri, Tetrapturus audax, and Lepidocybium flavobrunneum) and in numerous representatives (fishes, squids, and crustaceans) of their lower trophic level prey sampled from the central North Pacific Ocean. Results indicate that total mercury levels of predatory pelagic fishes and their prey increase with median depth of occurrence in the water column and mimic concentrations of dissolved organic mercury in seawater. Stomach content analysis results from this study and others indicate a greater occurrence of higher-mercury containing deeper-water prey organisms in the diets of the deeper-ranging predators, X. gladius, T. obesus, and L. guttatus. While present in trace amounts, dissolved organic mercury increases with depth in the water column suggesting that the mesopelagic habitat is a major entry point for mercury into marine food webs. These data suggest that a major determinant of mercury levels in oceanic predators is their depth of forage. PMID:19666614

  11. The Quality of Our Nation's Waters Mercury in the Nation's Streams--Levels, Trends, and Implications

    E-print Network

    Torgersen, Christian

    the Earth, its natural and living resources, natural hazards, and the environment, visit httpThe Quality of Our Nation's Waters Mercury in the Nation's Streams--Levels, Trends. Wentz). #12;The Quality of Our Nation's Waters Mercury in the Nation's Streams--Levels, Trends

  12. Ultralow Level Mercury Treatment Using Chemical Reduction and Air Stripping: Scoping Report

    SciTech Connect

    Looney, B.B.

    2000-08-18

    Data collected during the first stage of a Savannah River Technology Center (SRTC) Strategic Research and Development Project confirmed the efficacy of chemical reduction and air stripping/sparging as an ultralow level mercury treatment concept for waters containing Hg(II). The process consists of dosing the water with low levels of stannous chloride to convert the mercury to Hg. This form of mercury can easily be removed from the water by air stripping or sparging. Samples of Savannah River Site (SRS) groundwater containing approximately 130 ng/L of total mercury (as Hg(II)) were used for the study. In undosed samples, sparging removed 0 percent of the initial mercury. In the dosed samples, all of the removals were greater than 94 percent, except in one water type at one dose. This sample, which was saturated with dissolved oxygen, showed a 63 percent reduction in mercury following treatment at the lowest dose. Following dosing at minimally effective levels and sparging, treated water contained less than 10 ng/L total mercury. In general, the data indicate that the reduction of mercury is highly favored and that stannous chloride reagent efficiently targets the Hg(II) contaminant in the presence of competing reactions. Based on the results, the authors estimated that the costs of implementing and operating an ultralow level mercury treatment process based on chemical reduction and stripping/sparging are 10 percent to 20 percent of traditional treatment technologies.

  13. Comparative observations on levels of mercury in scalp hair of humans from different Islands

    Microsoft Academic Search

    Aristeo Renzoni

    1992-01-01

    Following the Minamata events, an extraordinary number of studies concerning mercury toxicity and human health have been undertaken.\\u000a Particular attention has been given to the evaluation of the dose-response relationship, i.e., the body burden at which (evaluated\\u000a through the mercury analyses in blood or hair) the risk of poisoning begins. The results of a comparative study concerning\\u000a levels of mercury

  14. REVIEW OF PUBLISHED LITERATURE FOR MEASUREMENT OF MERCURY AND METHYL MERCURY LEVELS FOR FISH AND FISH-EATING BIRDS IN CARSON RIVER

    EPA Science Inventory

    This project involves conducting a literature search with the goal of identifying "robust" methods for measuring mercury concentrations in biological tissues. Mercury is a significant contaminant of concern in Region 9, due in large part to the extensive mining activities of the...

  15. Determination of mercury in fish tissue using a minianalyzer based on cold vapor atomic absorption spectrometry at the 184.9 nm line.

    PubMed

    Rizea, Maria-Cristina; Bratu, Maria-Cristina; Danet, Andrei Florin; Bratu, Adrian

    2007-09-01

    A sensitive method was proposed and optimized for the determination of total mercury in fish tissue by using wet digestion, followed by cold vapor atomic absorption spectrometry (CVAAS) at the main resonance line of mercury (184.9 nm). The measurements were made using a new type of a non-dispersive mercury minianalyzer. This instrument was initially designed and built for atmospheric mercury-vapor detection. For determining mercury in aqueous samples, the minianalyzer was linked with a mercury/hydride system, Perkin Elmer Model MHS-10. To check the method, the analyzed samples were spiked with a standard solution of mercury. The recoveries of mercury spiked to wet fish tissue were >90% for 0.5 - 0.8 g samples. The results showed a better sensitivity (about 2.5 times higher) when using the mercury absorption line at 184.9 nm compared with the sensitivity obtained by conventional CVAAS at 253.7 nm. PMID:17878589

  16. Mercury

    NASA Astrophysics Data System (ADS)

    Taylor, G. J.; Scott, E. R. D.

    2003-12-01

    Mercury is an important part of the solar system puzzle, yet we know less about it than any other planet, except Pluto. Mercury is the smallest of the terrestrial planets (0.05 Earth masses) and the closest to the Sun. Its relatively high density (5.4 g cm -3) indicates that it has a large metallic core (˜3/4 of the planet's radius) compared to its silicate mantle and crust. The existence of a magnetic field implies that the metallic core is still partly molten. The surface is heavily cratered like the highlands of the Moon, but some areas are smooth and less cratered, possibly like the lunar maria (but not as dark). Its surface composition, as explained in the next section, appears to be low in FeO (only ˜3 wt.%), which implies that either its crust is anorthositic (Jeanloz et al., 1995) or its mantle is similarly low in FeO ( Robinson and Taylor, 2001).The proximity of Mercury to the Sun is particularly important. In one somewhat outmoded view of how the solar system formed, Mercury was assembled in the hottest region close to the Sun so that virtually all of the iron was in the metallic state, rather than oxidized to FeO (e.g., Lewis, 1972, 1974). If correct, Mercury ought to have relatively a low content of FeO. This hypothesis also predicts that Mercury should have high concentrations of refractory elements, such as calcium, aluminum, and thorium, and low concentrations of volatile elements, such as sodium and potassium, compared to the other terrestrial planets.Alternative hypotheses tell a much more nomadic and dramatic story of Mercury's birth. In one alternative view, wandering planetesimals that might have come from as far away as Mars or the inner asteroid belt accreted to form Mercury (Wetherill, 1994). This model predicts higher FeO and volatile elements than does the high-temperature model, and similar compositions among the terrestrial planets. The accretion process might have been accompanied by a monumental impact that stripped away much of the young planet's rocky mantle, accounting for the high density of the planet ( Benz et al., 1988). Most planetary scientists consider such a giant impact as the most likely hypothesis for the origin of the Moon. A giant impact model could explain the high density of Mercury if much of the silicate material failed to reaccrete, but it would not explain the low FeO concentration of the planet. Thus, knowing the composition of Mercury is crucial to testing models of planetary accretion.In this chapter we summarize what we know about the chemical composition of Mercury, with emphasis on assessing the amount of FeO in the bulk planet. FeO is a particularly useful quantity to evaluate the extent to which Mercury is enriched in refractory elements, because its concentration increases with decreasing temperature in a cooling gas of solar composition (e.g., Goettel, 1988). We then examine models for the composition of Mercury and outline tests that future orbital missions to Mercury will be able to make.

  17. Correlations Between Gene Expression and Mercury Levels in Blood of Boys With and Without Autism

    PubMed Central

    Green, Peter G.; Tian, Yingfang; Hertz-Picciotto, Irva; Pessah, Isaac N.; Hansen, Robin; Yang, Xiaowei; Teng, Jennifer; Gregg, Jeffrey P.; Ashwood, Paul; Van de Water, Judy; Sharp, Frank R.

    2009-01-01

    Gene expression in blood was correlated with mercury levels in blood of 2- to 5-year-old boys with autism (AU) compared to age-matched typically developing (TD) control boys. This was done to address the possibility that the two groups might metabolize toxicants, such as mercury, differently. RNA was isolated from blood and gene expression assessed on whole genome Affymetrix Human U133 expression microarrays. Mercury levels were measured using an inductively coupled plasma mass spectrometer. Analysis of covariance (ANCOVA) was performed and partial correlations between gene expression and mercury levels were calculated, after correcting for age and batch effects. To reduce false positives, only genes shared by the ANCOVA models were analyzed. Of the 26 genes that correlated with mercury levels in both AU and TD boys, 11 were significantly different between the groups (P(Diagnosis*Mercury) ? 0.05). The expression of a large number of genes (n = 316) correlated with mercury levels in TD but not in AU boys (P ? 0.05), the most represented biological functions being cell death and cell morphology. Expression of 189 genes correlated with mercury levels in AU but not in TD boys (P ? 0.05), the most represented biological functions being cell morphology, amino acid metabolism, and antigen presentation. These data and those in our companion study on correlation of gene expression and lead levels show that AU and TD children display different correlations between transcript levels and low levels of mercury and lead. These findings might suggest different genetic transcriptional programs associated with mercury in AU compared to TD children. Electronic supplementary material The online version of this article (doi:10.1007/s12640-009-9137-7) contains supplementary material, which is available to authorized users. PMID:19937285

  18. Glutathione enzyme and selenoprotein polymorphisms associate with mercury biomarker levels in Michigan dental professionals

    SciTech Connect

    Goodrich, Jaclyn M.; Wang, Yi [Department of Environmental Health Sciences, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States)] [Department of Environmental Health Sciences, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States); Gillespie, Brenda [Department of Biostatistics, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States)] [Department of Biostatistics, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States); Werner, Robert [Department of Environmental Health Sciences, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States) [Department of Environmental Health Sciences, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States); Department of Physical Medicine and Rehabilitation, University of Michigan, 325 E. Eisenhower Parkway Suite 100, Ann Arbor, MI 48108 (United States); Franzblau, Alfred [Department of Environmental Health Sciences, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States)] [Department of Environmental Health Sciences, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States); Basu, Niladri, E-mail: niladri@umich.edu [Department of Environmental Health Sciences, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States)] [Department of Environmental Health Sciences, University of Michigan School of Public Health, 1415 Washington Heights, Ann Arbor, MI 48109 (United States)

    2011-12-15

    Mercury is a potent toxicant of concern to both the general public and occupationally exposed workers (e.g., dentists). Recent studies suggest that several genes mediating the toxicokinetics of mercury are polymorphic in humans and may influence inter-individual variability in mercury accumulation. This work hypothesizes that polymorphisms in key glutathione synthesizing enzyme, glutathione s-transferase, and selenoprotein genes underlie inter-individual differences in mercury body burden as assessed by analytical mercury measurement in urine and hair, biomarkers of elemental mercury and methylmercury, respectively. Urine and hair samples were collected from a population of dental professionals (n = 515), and total mercury content was measured. Average urine (1.06 {+-} 1.24 ug/L) and hair mercury levels (0.49 {+-} 0.63 ug/g) were similar to national U.S. population averages. Taqman assays were used to genotype DNA from buccal swab samples at 15 polymorphic sites in genes implicated in mercury metabolism. Linear regression modeling assessed the ability of polymorphisms to modify the relationship between mercury biomarker levels and exposure sources (e.g., amalgams, fish consumption). Five polymorphisms were significantly associated with urine mercury levels (GSTT1 deletion), hair mercury levels (GSTP1-105, GSTP1-114, GSS 5 Prime ), or both (SEPP1 3 Prime UTR). Overall, this study suggests that polymorphisms in selenoproteins and glutathione-related genes may influence elimination of mercury in the urine and hair or mercury retention following exposures to elemental mercury (via dental amalgams) and methylmercury (via fish consumption). -- Highlights: Black-Right-Pointing-Pointer We explore the influence of 15 polymorphisms on urine and hair Hg levels. Black-Right-Pointing-Pointer Urine and hair Hg levels in dental professionals were similar to the US population. Black-Right-Pointing-Pointer GSTT1 and SEPP1 polymorphisms associated with urine Hg levels. Black-Right-Pointing-Pointer Accumulation of Hg in hair following exposure from fish was modified by genotype. Black-Right-Pointing-Pointer GSTP1, GSS, and SEPP1 polymorphisms influenced Hg accumulation in hair.

  19. Glutathione S-transferase and metallothionein levels in the freshwater prawn Macrobrachium malcolmsonhi exposed to mercury.

    PubMed

    Yamuna, A; Bhavan, P Saravana; Geraldine, P

    2012-01-01

    Healthy juveniles of M. malcolmsoniiwere exposed to 24.1 microg l(-1) of mercury (96 hr LC50: 145 microg l(-1) Hg) for a period of 21 days. The hepatopancreas and gills of the prawns were sampled on 8th, 15th and 22nd day of exposure. Accumulation and elimination of Hg, activity of glutathione S-transferase (GST), content of glutathione (GSH) and metallothionein (MT) level were studied. Mercury accumulation was found to be higher in the hepatopancreas (88.60 microg g(-1)) and lower in the gills (67.8 microg g(-1)). However, Hg elimination was found to be faster in the gills (62%) and slower in the hepatopancreas (58%). Therefore, the rate of Hg elimination did not match the rate of its uptake. The activity of GST was found to be higher in tissues of test prawns (5.94-9.13 nmol mg(-1) protein min(-1)) on all sampling days when compared with controls (3.454.23 nmol mg(-1) protein min(-1)). Similarly, the content of GSH was found to be higher in tissues of test prawns (0.80-1.43 micromol g(-1) protein) on all sampling days when compared with controls (0.55-1.00 micromol g(-1) protein). These results indicate the formation of glutathione conjugate in test prawns to eliminate Hg. The induction of MT level was also found to be higher in tissues of test prawns (57.50-75.76 nmol g(-1) protein) on all sampling days when compared with control (20.24-45.22 nmol g(-1) protein). This indicates the fact that sequestration of Hg has occurred for its easy elimination. Thus, induction of GST-GSH and MT ensured protection and adaptation of test prawns to thrive in Hg contaminated environment. PMID:23033656

  20. Background levels of atmospheric mercury in Kagoshima City, and influence of mercury emission from Sakurajima Volcano, Southern Kyushu, Japan

    PubMed

    Tomiyasu; Nagano; Sakamoto; Yonehara

    2000-10-01

    Vapor phase mercury concentration was determined daily for 1 year (Jan. 1996-Jan. 1997) in order to present the levels of atmospheric mercury in Kagoshima City and to estimate the influence of mercury emission from Sakurajima Volcano, southern Kyushu, Japan. The atmospheric mercury was collected on a porous gold collector at Kagoshima University and was determined by cold vapor atomic absorption spectrometry; Kagoshima University of Kagoshima City is located approximately 11 km west of Sakurajima Volcano. The mercury concentration obtained was in the range 1.2-52.5 ng m(-3) (mean 10.8 ng m(-3), n = 169). The atmospheric concentration varied from season to season; the concentration was high in summer and lower in winter. A linear relation was obtained by plotting ln[Hg/ng m(-3)] vs. 1/T for the north, south and west winds with correlation coefficients of -0.76, -0.79 and -0.83, respectively, but no such dependency was found for the east wind (r = -0.035). When the wind is blowing from the east, Kagoshima City is on the leeward side of the volcano. The impact of the fumarolic activity of the volcano on ambient air in the city was evident in the disappearance of temperature dependency with the appearance of the east wind. Atmospheric mercury concentration except for the east wind was considered to be background levels of Kagoshima City. As background levels, 8.1 +/- 5.3 ng m(-3), 14.8 +/- 7.9 ng m(-3), 13.9 +/- 11.7 ng m(-3) and 4.4 +/- 1.6 ng m(-3) (mean +/- S.D.) were obtained for spring, summer, autumn and winter, respectively. PMID:11032152

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

    Microsoft Academic Search

    Flavia L Barbieri; Jacques Gardon

    2009-01-01

    BACKGROUND: Mercury is present in the Amazonian aquatic environments from both natural and anthropogenic sources. As a consequence, many riverside populations are exposed to methylmercury, a highly toxic organic form of mercury, because of their intense fish consumption. Many studies have analysed this exposure from different approaches since the early nineties. This review aims to systematize the information in spatial

  2. Evaluation of mercury levels in Pangasius and Cod fillets traded in Sicily (Italy)

    Microsoft Academic Search

    V. Ferrantelli; G. Giangrosso; A. Cicero; C. Naccari; A. Macaluso; F. Galvano; N. D’Orazio; G. E. Arcadipane; F. Naccari

    2012-01-01

    Predator fishes at the top of the aquatic food chain can accumulate large concentrations of metals and their consumption, consequently, makes a significant contribution, in particular, to mercury intake. The aim of this study was to determine mercury levels in fillets of two predatory species: pangasius (Pangasius hypophthalmus) from the Vietnam region of Megong and Chao Pharayai and cod (Gadus

  3. Mercury Levels along the Food Chain and Risk for Exposed Populations

    Microsoft Academic Search

    A. Renzoni; F. Zino; E. Franchi

    1998-01-01

    Mercury was not regarded as a pollutant of primary importance until many deaths due to mercury poisoning occurred in the 1950s. More recently, adverse health effects have been documented at relatively low exposure levels, and monitoring data must now be interpreted in this light. The Mediterranean basin has been studied in great detail over the past 20 years because of

  4. Naringin Levels in Citrus Tissues 1

    PubMed Central

    Jourdan, Pablo S.; McIntosh, Cecilia A.; Mansell, Richard L.

    1985-01-01

    The quantitative distribution of the flavanone-7-neohesperidoside, naringin, in seeds, seedlings, young plants, branches, flowers, and fruit of Citrus paradisi Macfad., cv `Duncan' was analyzed by radioimmunoassay. High levels of naringin were associated with very young tissue and lower levels were found in older tissues. Seed coats of ungerminated seeds and young shoots had high naringin concentrations whereas cotyledons and roots had very low concentrations. Light-grown seedlings contained nearly twice as much naringin as etiolated seedlings and, in young plants and branches, the naringin content was highest in developing leaves and stem tissue. In flowers, the ovary had the highest levels of naringin, accounting for nearly 11% of the fresh weight. There was a net increase in the total naringin content of fruits during growth. However, due to the large increase in fruit size, there was a concomitant decrease in the naringin concentration as the fruit matured. PMID:16664159

  5. Sedentary nestlings of Wood Stork as monitors of mercury contamination in the gold mining region of the Brazilian Pantanal

    Microsoft Academic Search

    Silvia Nassif Del Lama; Cristiano Dosualdo Rocha; Wilson Figueiredo Jardim; Jo-Szu Tsai; Peter Crawford Frederick

    2011-01-01

    Sedentary organisms that are at top trophic levels allow inference about the level of local mercury contamination. We evaluated mercury contamination in feather tissue of nestling Wood Storks (Mycteria americana), sampled in different parts of the Brazilian Pantanal that were variably polluted by mercury releases from gold mining activities. Levels of mercury in feathers sampled in seven breeding colonies were

  6. Hair mercury level of coastal communities in Malaysia: a linkage with fish consumption

    Microsoft Academic Search

    Parvaneh Hajeb; Jinap Selamat; Ahmad Ismail; Fatimah Abu Bakar; Jamilah Bakar; Hanifah Nuryani Lioe

    2008-01-01

    Hair mercury level was assessed in four coastal communities in Malaysia with relation to fish consumption between gender,\\u000a age, and rural and urban area. Mercury level was found at a range of 0.01–21.00 (?g\\/g dry wt). The average mercury levels\\u000a were 13.69, 10.85, 9.94, and 6.78 ?g\\/g dry wt for communities in Kedah, Terengganu, Johor, and Selangor, respectively. The\\u000a same order

  7. Mercury levels in a 21-year-old black-crowned night heron (Nycticorax nycticorax)

    Microsoft Academic Search

    Hoffman

    1976-01-01

    Mercury levels in a 21-year-old black crowned night heron were measured. Concentrations were: breast muscle (0.9 ppm), liver (3.1 ppm), brain (0.5ppm), and primary wing feathers (17.9 ppm). These levels were not substantially different from those found in much younger birds. These data imply that either the kind had been feeding in an area with low levels of mercury contaminations

  8. Ultralow Level Mercury Treatment Using Chemical Reduction and Air Stripping

    SciTech Connect

    Looney, B.B.

    2001-02-23

    The overall objective of this work is to develop a reasonable and cost-effective approach to meet the emerging mercury standards, especially for high volume outfalls with concentrations below the drinking water standard.

  9. Mercury Distribution in Blood, Tissues, and Feathers of Double-Crested Cormorant Nestlings from Arid-Lands Reservoirs in South Central New Mexico

    Microsoft Academic Search

    C. A. Caldwell; M. A. Arnold; W. R. Gould

    1999-01-01

    .   Eggs, blood, liver, muscle, and feathers were analyzed for concentrations of total mercury in double-crested cormorant (Phalacrocorax auritus) nestlings from two reservoirs in south central New Mexico. Total mercury concentrations among eggs, tissues, and feathers\\u000a were not significantly correlated. Concentrations of total mercury averaged 0.40 ?g\\/g in liver and 0.18 ?g\\/g in muscle tissues\\u000a in both populations of nestlings.

  10. Collisionally induced transfer of orientation and alignment between 6s6d levels of mercury

    Microsoft Academic Search

    M. Lukaszewski; D. Lecler

    1978-01-01

    Mercury atoms are stepwise excited to the 6s6d levels by means of a mercury lamp (61S0 to 61P1) and a CW tunable dye laser (61P1 to 61D2 or 63D2). The transfer of coherence (orientation and alignment) between these levels induced in collisions with noble-gas (helium and xenon) atoms is studied in a weak magnetic field by means of the Hanle

  11. Influence of illegal gold mining on mercury levels in fish of North Sulawesi's Minahasa Peninsula, (Indonesia)

    Microsoft Academic Search

    Joice L. Kambey; A. p. Farrell; L. i. Bendell-young

    2001-01-01

    North Sulawesi's Minahasa Peninsula currently is experiencing intense illegal gold mining activity. It has been estimated that 200 t of mercury are used annually in Indonesia in the recovery of gold from the illegal mines. To date no study has assessed the environmental impact of this illegal activity on the nearby aquatic biota. To address this concern, we compared tissue

  12. Mercury and Organochlorines in Black Bream, Acanthopagrus butcheri, from the Gippsland Lakes, Victoria, Australia: Evidence for Temporal Increases in Mercury levels

    Microsoft Academic Search

    G. Fabris; T. Theodoropoulos; A. Sheehan; B. Abbott

    1999-01-01

    Total mercury and organochlorine insecticide (?-HCH, lindane, ?-HCH, heptachlor, ?-HCH, aldrin, heptachlor epoxide, ?- and ?-endosulfan, dieldrin, 4,4?–DDE, endrin, 4,4?-DDD, 4,4?-DDT) concentrations were measured in black bream from 10 widely separated sites within the estuarine Gippsland Lakes, Victoria south-east Australia. Mercury concentrations (mean 0.22 ?g g?1 wet weight) in the axial muscle tissues were below the maximum concentration in fish

  13. Tissue-specific bioaccumulation and oxidative stress responses in juvenile Japanese flounder ( Paralichthys olivaceus) exposed to mercury

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Cao, Liang; Ye, Zhenjiang; Lin, Longshan; Chen, Quanzhen; Dou, Shuozeng

    2012-07-01

    To understand mercury (Hg) toxicity in marine fish, we measured Hg accumulation in juvenile Japanese flounder ( Paralichthys olivaceus) and assessed the effects on growth and antioxidant responses. After Hg exposure (control, 5, 40, and 160 ?g/L Hg) for 28 d, fish growth was significantly reduced. The accumulation of Hg in fish was dose-dependent and tissue-specific, with the maximum accumulation in kidney and liver, followed by gills, bone, and muscle. Different antioxidants responded differently to Hg exposure to cope with the induction of lipid peroxidation (LPO), which was also tissue-specific and dosedependent. As Hg concentration increased, superoxide dismutase (SOD) and catalase (CAT) activities increased significantly, whereas glutathione S -transferase (GST) activity and glutathione (GSH) levels decreased significantly in the gills. SOD and glutathione peroxidase (GPx) activities and the GSH level increased significantly in the liver. SOD activity and GSH levels increased significantly, but CAT activity decreased significantly with an increase in Hg concentration in the kidney. LPO was induced significantly by elevated Hg in the gills and kidney but was least affected in the liver. Therefore, oxidative stress biomarkers in gills were more sensitive than those in the liver and kidney to Hg exposure. Thus, the gills have potential as bioindicators for evaluating Hg toxicity in juvenile flounder.

  14. Mercury levels of Nelson's and saltmarsh sparrows at wintering grounds in Virginia, USA.

    PubMed

    Cristol, Daniel A; Smith, Fletcher M; Varian-Ramos, Claire W; Watts, Bryan D

    2011-11-01

    Nelson's and saltmarsh sparrows (Ammodramus nelsoni and A. caudacutus) have recently been recognized as separate species, and because of their limited distributions and the susceptibility of their wetland habitats to climate change, these two new species are of conservation concern. Both species are known to bioaccumulate mercury at breeding sites in New England, USA where their ranges overlap, with the saltmarsh sparrow reported to have twice the concentration of blood total mercury. In this study we sampled both species on their shared wintering grounds, and documented that mercury exposure is lower than that reported for the breeding range, with saltmarsh sparrow blood mercury 2.6 times higher than in Nelson's sparrow. Feather mercury, which is incorporated on the breeding grounds, confirmed that saltmarsh sparrows had incorporated 2.3 times more mercury than Nelson's sparrows during the previous breeding season. A comparison of stable isotopes of nitrogen and carbon suggests that the higher exposure of saltmarsh sparrows may be not due to feeding at a higher trophic level, as previously hypothesized, but rather could be related to a difference in the carbon source at the base of each species' food chain. This study, along with recently published data from both species on additional breeding and wintering grounds, provides a more complete picture of relative mercury exposure. Saltmarsh sparrows are exposed to mercury levels that warrant concern, with the highest exposure being during the breeding season. Areas set aside for the long-term conservation of this species should be carefully assessed for mercury bioaccumulation. PMID:21698442

  15. Consumption of tomato products is associated with lower blood mercury levels in Inuit preschool children.

    PubMed

    Gagné, Doris; Lauzière, Julie; Blanchet, Rosanne; Vézina, Carole; Vaissière, Emilie; Ayotte, Pierre; Turgeon O'Brien, Huguette

    2013-01-01

    Some evidence suggests that various diet components and nutrients, including vegetables, fruit and food-derived antioxidants, could mitigate contaminant exposure and/or adverse health effects of contaminants. To examine the effect of the consumption of tomato products on blood mercury levels in Inuit preschool children, 155 Inuit children (25.0±9.1months) were recruited from 2006-2008 in Nunavik childcare centers (northern Québec, Canada). Food frequency questionnaires were completed at home and at the childcare center, and total blood mercury concentration was measured by inductively coupled plasma-mass spectrometry. Multivariate regression analysis was performed after multiple imputation. The median blood concentration of mercury was 9.5nmol/L. Age, duration of breastfeeding, annual consumption frequency of seal meat, and monthly consumption frequency of tomato products were significant predictors of blood mercury levels, whereas annual consumption frequencies of beluga muktuk, walrus, Arctic char, and caribou meat were not. Each time a participant consumed tomato products during the month before the interview was associated with a 4.6% lower blood mercury level (p=0.0005). All other significant predictors in the model were positively associated with blood mercury levels. Further studies should explore interactions between consumption of healthy store-bought foods available in Arctic regions and contaminant exposure. PMID:23127601

  16. Modeling radiation effects at the tissue level

    NASA Astrophysics Data System (ADS)

    Müller, M.; Durante, M.; Stöcker, H.; Merz, F.; Bechmann, I.

    2010-10-01

    For the understanding of radiation action in humans, a synergistic approach of experiments and quantitative modeling of working hypotheses is necessary. A large set of experimental data at the single-cell level are available, and biophysical modeling of radiation action has so far mostly concentrated on the first phases of radiation interaction with the biomolecules, and later biochemical stages including DNA breakage, repair, and the formation of chromosomal aberrations. The models can be extended to cell killing and transformation, but so far still using a single-cell (clonal expansion) approach. On the contrary, new experimental evidence points to the microenvironment and the tissue level as a critical radiation target for late effects, and to epigenetic and signaling mechanisms as mediators of radiation damage. This higher structural level is generally ignored in modeling, owing to its complexity and to the lack of experimental data. In this paper we will highlight the requirements for specific experimental approaches targeting the tissue/microenvironment level and the most promising available experimental models.

  17. The relationship between Adirondack lake pH and levels of mercury in yellow perch.

    PubMed

    Brown, Donald; Goncharov, Alexey; Paul, Eric; Simonin, Howard; Carpenter, David O

    2010-12-01

    Levels of total mercury in yellow perch Perca flavescens from Adirondack lakes were studied in relation to characteristics of the lakes to determine why some lakes had fish with higher concentrations of mercury. Almost all mercury in fish is in the form of methylmercury, which can pose significant health hazards to humans who consume such fish. Fish mercury concentrations and water chemistry data were analyzed from eight Adirondack lakes. Four lakes (Halfmoon Lake, Sand Pond, Rock Pond, and Upper Sister Lake) had pH values of less than 5.0. Four other lakes (Lake Adirondack, Kings Flow, Harris Lake, and Lake Kushaqua) had pH values of more than 7.0. The acidic lakes also had high levels of aluminum and low acid-neutralizing capacity relative to the neutral lakes. Yellow perch (n = 100) from the acidic lakes had significantly higher levels of mercury than did those (n = 102) from the neutral lakes (P < 0.001), and the total mercury concentration increased with both length and weight of the fish. We conclude that the pH of the lake water is a major factor in determining the concentration of methylmercury in yellow perch. PMID:21413513

  18. Mercury, Cadmium, and Lead Levels in Human Placenta: A Systematic Review

    PubMed Central

    Esteban-Vasallo, María D.; Aragonés, Nuria; Pollan, Marina; López-Abente, Gonzalo

    2012-01-01

    Background: Placental tissue may furnish information on the exposure of both mother and fetus. Mercury (Hg), cadmium (Cd), and lead (Pb) are toxicants of interest in pregnancy because they are associated with alterations in child development. Objectives: The aim of this study was to summarize the available information regarding total Hg, Cd, and Pb levels in human placenta and possible related factors. Methods: We performed a systematic search of PubMed/MEDLINE, EMBASE, Lilacs, OSH, and Web of Science for original papers on total Hg, Cd, or Pb levels in human placenta that were published in English or Spanish (1976–2011). Data on study design, population characteristics, collection and analysis of placenta specimens, and main results were extracted using a standardized form. Results: We found a total of 79 papers (73 different studies). Hg, Cd, and Pb levels were reported in 24, 46, and 46 studies, respectively. Most studies included small convenience samples of healthy pregnant women. Studies were heterogeneous regarding populations selected, processing of specimens, and presentation of results. Hg concentrations > 50 ng/g were found in China (Shanghai), Japan, and the Faroe Islands. Cd levels ranged from 1.2 ng/g to 53 ng/g and were highest in the United States, Japan, and Eastern Europe. Pb showed the greatest variability, with levels ranging from 1.18 ng/g in China (Shanghai) to 500 ng/g in a polluted area of Poland. Conclusion: The use of the placenta as a biomarker to assess heavy metals exposure is not properly developed because of heterogeneity among the studies. International standardized protocols are needed to enhance comparability and increase the usefulness of this promising tissue in biomonitoring studies. PMID:22591711

  19. Mercury in Freshwater Fish of Northeast North America – A Geographic Perspective Based on Fish Tissue Monitoring Databases

    Microsoft Academic Search

    Neil C Kamman; Neil M. Burgess; Charles T. Driscoll; Howard A. Simonin; Wing Goodale; Janice Linehan; Robert Estabrook; Michael Hutcheson; Andrew Major; Anton M. Scheuhammer; David A. Scruton

    2005-01-01

    As part of an initiative to assemble and synthesize mercury (Hg) data from environmental matrices across northeastern North America, we analyzed a large dataset comprised of 15,305 records of fish tissue Hg data from 24 studies from New York State to Newfoundland. These data were summarized to provide mean Hg concentrations for 40 fish species and associated families. Detailed analyses

  20. MEASUREMENT OF MECURY IN FISH SCALES AS AN ASSESSMENT METHOD FOR PREDICTING MUSCLE TISSUE MERCURY CNOCENTRATIONS IN LARGEMOUTH BASS

    EPA Science Inventory

    The relationship between total mercury (Hg) concentration in fish scales and in tissues of largemouth bass (Micropterus salmoides) from 20 freshwater sites was developed and evaluated to determine whether scale analysis would allow a non lethal and convenient method for predicti...

  1. Assessment of Caudal Fin Clips as a Non-lethal Technique for Predicting Muscle Tissue Mercury Concentrations in Largeouth Bass

    EPA Science Inventory

    The statistical relationship between total mercury (Hg) concentration in clips from the caudal fin and muscle tissue of largemouth bass (Micropterus salmoides) from 26 freshwater sites in Rhode Island, USA was developed and evaluated to determine the utility of fin clip analysis ...

  2. Tissue-to-cellular level deformation coupling in cell

    E-print Network

    Benos, Takis

    Tissue-to-cellular level deformation coupling in cell micro-integrated elastomeric scaffolds John A. pediatrics · Tissue engineering aims to replicate the structure, composition, and mechanical function of native tissue · Lacking knowledge as to how externally applied forces at the tissue level are transmitted

  3. Mercury in freshwater fish of northeast North America--a geographic perspective based on fish tissue monitoring databases.

    PubMed

    Kamman, Neil C; Burgess, Neil M; Driscoll, Charles T; Simonin, Howard A; Goodale, Wing; Linehan, Janice; Estabrook, Robert; Hutcheson, Michael; Major, Andrew; Scheuhammer, Anton M; Scruton, David A

    2005-03-01

    As part of an initiative to assemble and synthesize mercury (Hg) data from environmental matrices across northeastern North America, we analyzed a large dataset comprised of 15,305 records of fish tissue Hg data from 24 studies from New York State to Newfoundland. These data were summarized to provide mean Hg concentrations for 40 fish species and associated families. Detailed analyses were carried out using data for 13 species. Hg in fishes varied by geographic area, waterbody type, and waterbody. The four species with the highest mean Hg concentrations were muskellunge (Esox masquinongy), walleye (Sander vitreus), white perch (Morone americana), and northern pike (Esox luscius). Several species displayed elevated Hg concentrations in reservoirs, relative to lakes and rivers. Normalized deviations from mean tissue levels for yellow perch (Perca flavescens) and brook trout (Salvelinus fontinalis) were mapped, illustrating how Hg concentrations in these species varied across northeastern North America. Certain geographic regions showed generally below or above-average Hg concentrations in fish, while significant heterogeneity was evident across the landscape. The proportion of waterbodies exhibiting exceedances of USEPA's criterion for fish methylmercury ranged from 14% for standard-length brook trout fillets to 42% for standard-length yellow perch fillets. A preliminary correlation analysis showed that fish Hg concentrations were related to waterbody acidity and watershed size. PMID:15931965

  4. Metal tissue levels in Steller sea lion (Eumetopias jubatus) pups.

    PubMed

    Holmes, Amie L; Wise, Sandra S; Goertz, Caroline E C; Dunn, J Lawrence; Gulland, Frances M D; Gelatt, Tom; Beckmen, Kimberlee B; Burek, Kathy; Atkinson, Shannon; Bozza, Mary; Taylor, Robert; Zheng, Tongzhang; Zhang, Yawei; Aboueissa, Abouel-Makarim; Wise, John Pierce

    2008-08-01

    The endangered Western population of the Steller sea lion declined for three decades for uncertain reasons. We present baseline data of metal concentrations in pups as a first step towards investigating the potential threat of developmental exposures to contaminants. Seven metals were investigated: arsenic, cadmium, silver, aluminum, mercury, lead and vanadium. Vanadium was detected in only a single blubber sample. Mercury appears to be the most toxicologically significant metal with concentrations in the liver well above the current action level for mercury in fish. The concentrations of aluminum, arsenic, silver, cadmium and lead were present in one-fourth to two-thirds of all samples and were at either comparable or below concentrations previously reported. Neither gender nor region had a significant effect on metal burdens. Future work should consider metal concentrations in juveniles and adults and toxicological studies need to be performed to begin to assess the toxicity of these metals. PMID:18599091

  5. Achieving very low mercury levels in refinery wastewater by membrane filtration.

    SciTech Connect

    Urgun Demirtas, M.; Benda, P.; Gillenwater, P. S.; Negri, M. C.; Xiong, H.; Snyder, S. W. (Center for Nanoscale Materials); ( ES)

    2012-05-15

    Microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) membranes were evaluated for their ability to achieve the world's most stringent Hg discharge criterion (<1.3 ng/L) in an oil refinery's wastewater. The membrane processes were operated at three different pressures to demonstrate the potential for each membrane technology to achieve the targeted effluent mercury concentrations. The presence of mercury in the particulate form in the refinery wastewater makes the use of MF and UF membrane technologies more attractive in achieving very low mercury levels in the treated wastewater. Both NF and RO were also able to meet the target mercury concentration at lower operating pressures (20.7 bar). However, higher operating pressures ({ge}34.5 bar) had a significant effect on NF and RO flux and fouling rates, as well as on permeate quality. SEM images of the membranes showed that pore blockage and narrowing were the dominant fouling mechanisms for the MF membrane while surface coverage was the dominant fouling mechanism for the other membranes. The correlation between mercury concentration and particle size distribution was also investigated to understand mercury removal mechanisms by membrane filtration. The mean particle diameter decreased with filtration from 1.1 {+-} 0.0 {micro}m to 0.74 {+-} 0.2 {micro}m after UF.

  6. Comparative observations on levels of mercury in scalp hair of humans from different Islands

    NASA Astrophysics Data System (ADS)

    Renzoni, Aristeo

    1992-09-01

    Following the Minamata events, an extraordinary number of studies concerning mercury toxicity and human health have been undertaken. Particular attention has been given to the evaluation of the dose-response relationship, i.e., the body burden at which (evaluated through the mercury analyses in blood or hair) the risk of poisoning begins. The results of a comparative study concerning levels of mercury in the hair of fishermen living in small islands who eat seafood more than four times per week show that in two areas only, and only in a few cases in these areas, the mercury in the hair exceeds the limit at which a possible risk could exist. In fact, the limit of 50 mg/g of total mercury in the hair (indicated as the lower limit above which a possible risk could occur) is surpassed by nine fishermen out of a total of 39 at station 1 and by four fishermen out of a total of 26 at station 3. The average value at station 1 is 36.38 mg/g and that at station 3 is 30.31 mg. Many countries have set legal limits of mercury for seafood, but evidently the system does not offer a true protection for man. Only the provisional tolerable weekly intake (PTWI), as repeatedly suggested by WHO, should be considered the best guideline to prevent possibly harmful consequences.

  7. Mercury concentrations in seabird tissues from Machias Seal Island, New Brunswick, Canada

    Microsoft Academic Search

    Alexander L. Bond; Antony W. Diamond

    2009-01-01

    Mercury is a pervasive environmental contaminant, the anthropogenic portion of which is increasing globally, and in northeastern North America in particular. Seabirds frequently are used as indicators of the marine environment, including mercury contamination. We analysed paired samples for total mercury (Hg) concentrations in feathers and blood from adult and chick, albumen, and lipid-free yolk of seven seabirds breeding on

  8. Ecological characterization of streams, and fish-tissue analysis for mercury and lead at selected locations, Fort Gordon, Georgia, June 1999 to May 2000

    USGS Publications Warehouse

    Gregory, M. Brian; Stamey, Timothy C.; Wellborn, John B.

    2001-01-01

    The U.S. Geological Survey, in cooperation with the Environmental and Natural Resources Management Office of the U.S. Army Signal Center and Fort Gordon, Ga., documented the ecological condition of selected water-bodies on the Fort Gordon military installation from June 1999 to May 2000. This study includes stream-habitat assessments, aquatic invertebrate and fish-community surveys in selected stream reaches, and analyses of mercury and lead concentrations in largemouth bass (Micropterous salmoides) muscle tissue from three impoundments. Assessment surveys indicate lower habitat value scores in some streams draining the more developed areas on Fort Gordon. A small tributary to Butler Creek--which drains parking lots associated with military motor pools and other impervious surfaces--is characterized by moderate levels of bank erosion and excess sediment in the stream channel compared to reference sites. Four other stream reaches are more similar to reference streams in respect to habitat conditions. Invertebrate communities in streams draining these urbanized watersheds are inhabited by 13 to 16 taxa per reach; whereas, 23 and 33 taxa were collected from the two reference stream reaches. Measures of invertebrate abundance, taxa richness, Ephemeroptera, Plecoptera, and Tricoptera Index are lower in streams draining urbanized watersheds. Measures of community similarity also indicate differences between streams draining urbanized areas and reference streams. Streams draining developed areas on Fort Gordon are inhabited by 3 to 10 fish species and included more species regarded as tolerant of degraded water-quality conditions; whereas, the two reference stream reaches support 4 and 10 species, respectively, including one species considered intolerant of degraded water-quality conditions. Mercury was detected in all largemouth bass collected from three impoundments on Fort Gordon. Wet-weight mercury concentrations in fish tissue analyzed from all sites range from 0.08 micrograms per gram to 1.33 micrograms per gram. Median mercury concentrations in fish tissue are 0.83 micrograms per gram at Soil Erosion Lake, 0.72 micrograms per gram at Lower Leitner Lake, and 0.22 micrograms per gram at Gordon Lake. Median mercury concentrations in fish tissue analyzed from Soil Erosion Lake and Lower Leitner Lake are more than two times higher than U.S. Environmental Protection Agency recommendation of 0.3 micrograms per gram for fish consumption. Lead concentrations are below the minimum reporting limit for all specimens analyzed from reservoirs sampled at Fort Gordon.

  9. Electronic Characterization of Defects in Narrow Gap Semiconductors-Comparison of Electronic Energy Levels and Formation Energies in Mercury Cadmium Telluride, Mercury Zinc Telluride, and Mercury Zinc Selenide

    NASA Technical Reports Server (NTRS)

    Patterson, James D.

    1996-01-01

    We have used a Green's function technique to calculate the energy levels and formation energy of deep defects in the narrow gap semiconductors mercury cadmium telluride (MCT), mercury zinc telluride (MZT) and mercury zinc selenide (MZS). The formation energy is calculated from the difference between the total energy with an impurity cluster and the total energy for the perfect crystal. Substitutional (including antisite), interstitial (self and foreign), and vacancy deep defects are considered. Relaxation effects are calculated (with molecular dynamics). By use of a pseudopotential, we generalize the ideal vacancy model so as to be able to consider relaxation for vacancies. Different charge states are considered and the charged state energy shift (as computed by a modified Haldane-Anderson model) can be twice that due to relaxation. Different charged states for vacancies were not calculated to have much effect on the formation energy. For all cases we find deep defects in the energy gap only for cation site s-like orbitals or anion site p-like orbitals, and for the substitutional case only the latter are appreciably effected by relaxation. For most cases for MCT, MZT, MZS, we consider x (the concentration of Cd or Zn) in the range appropriate for a band gap of 0.1 eV. For defect energy levels, the absolute accuracy of our results is limited, but the precision is good, and hence chemical trends are accurately predicted. For the same reason, defect formation energies are more accurately predicted than energy level position. We attempt, in Appendix B, to calculate vacancy formation energies using relatively simple chemical bonding ideas due to Harrison. However, these results are only marginally accurate for estimating vacancy binding energies. Appendix C lists all written reports and publications produced for the grant. We include abstracts and a complete paper that summarizes our work which is not yet available.

  10. [Influence of industrial pollution with mercury on levels of its accumulation in populated area objects and foods].

    PubMed

    Amreeva, K E; Teryokhin, S P; Krashanovskaya, T R

    2015-01-01

    The article deals with results of study covering influence of industrial pollution with mercury on its accumulation level in populated area objects and foods. Mercury content was measured in ambient air, snow, water, bed silt and regional foods of vegetable and animal origin--that is a potential health hazard for Central Kazakhstan population. The data obtained prove that high levels of mercury were detected in all the studied objects. PMID:26036022

  11. Mercury in Morelet's Crocodile Eggs from Northern Belize

    Microsoft Academic Search

    T. R. Rainwater; B. M. Adair; S. G. Platt; T. A. Anderson; G. P. Cobb; S. T. McMurry

    2002-01-01

    Recent studies have examined mercury accumulation in crocodilians. However, though most researchers have focused on tissue\\u000a concentrations, few have examined mercury levels in crocodilian eggs. In July 1995, we analyzed mercury in 31 nonviable Morelet's\\u000a crocodile (Crocodylus moreletii) eggs collected from eight nests across three localities in northern Belize. All eggs were found to contain mercury. Based\\u000a on an individual

  12. Antioxidants and metallothionein levels in mercury-treated mice

    Microsoft Academic Search

    R. Brandão; F. W. Santos; M. Farina; G. Zeni; D. Bohrer; J. B. T. Rocha; C. W. Nogueira

    2006-01-01

    Acute effects of mercury on mouse blood, kidneys, and liver were evaluated. Mice received a single dose of mercuric chloride\\u000a (HgCl2, 4.6 mg\\/kg, subcutaneously) for three consecutive days. We investigated the possible beneficial effects of antioxidant therapy\\u000a (N-acetylcysteine (NAC) and diphenyl diselenide (PhSe)2) compared with the sodium salt of 2,3-dimercapto-1-propanesulfonic acid (DMPS), an effective chelating agent in HgCl2 exposure in

  13. Relating Land Cover Characteristics and Common Loon Mercury Levels Using Geographic Information Systems

    Microsoft Academic Search

    David Kramar; Wing M. Goodale; L. M. Kennedy; L. W. Carstensen; Taranjat Kaur

    2005-01-01

    This effort models the relationship between mercury (Hg) levels in the common loon (Gavia immer) and land cover types as defined by the National Land Cover Database (NLCD). We constructed the model within the framework of a GIS to analyze the spatial relationships between land cover types and blood Hg levels in male common loons. Thiessan polygons were used to

  14. Tissue Bis(2-ethylhexyl)phthalate Levels in Uremic Subjects

    Microsoft Academic Search

    Wenn S. Chen; Julius Kerhay; Karl H. Pearson; Emil P. Paganini; Saturo Nakamoto

    1979-01-01

    A method for the analysis of tissue DEHP levels was developed. Tissue homogenates were extracted with a chloroformrmethanol solution, followed by the addition of 1 g baked alumina to clean up the heavy matrices of the tissues. DEHP levels in tne tissues were determined by gas chromatography. Percent recovery of DEHP from the tissues ranged between 72.2 and 83.3%.An experimentally

  15. Projections of atmospheric mercury levels and their effect on air quality in the United States

    NASA Astrophysics Data System (ADS)

    Lei, H.; Wuebbles, D. J.; Liang, X.-Z.; Tao, Z.; Olsen, S.; Artz, R.; Ren, X.; Cohen, M.

    2014-01-01

    The individual and combined effects of global climate change and emissions changes from 2000 to 2050 on atmospheric mercury levels in the United States are investigated by using the global climate-chemistry model, CAM-Chem, coupled with a mercury chemistry-physics mechanism (CAM-Chem/Hg). Three future pathways from the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) are considered, with the A1FI, A1B and B1 scenarios representing the upper, middle and lower bounds of potential climate warming, respectively. The anthropogenic and biomass burning emissions of mercury are projected from the energy use assumptions in the IPCC SRES report. Natural emissions from both land and ocean sources are projected by using dynamic schemes. TGM concentration increases are greater in the low latitudes than they are in the high latitudes, indicative of a larger meridional gradient than in the present day. In the A1FI scenario, TGM concentrations in 2050 are projected to increase by 2.1-4.0 ng m-3 for the eastern US and 1.4-3.0 ng m-3 for the western US. This spatial difference corresponds to potential increases in wet deposition of 10-14 ?g m-2 for the eastern US and 2-4 ?g m-2 for the western US. The increase in Hg(II) emissions tends to enhance wet deposition and hence increase the risk of higher mercury entering the hydrological cycle and ecosystem. In the B1 scenario, mercury concentrations in 2050 are similar to present level concentrations; this finding indicates that the domestic reduction in mercury emissions is essentially counteracted by the effects of climate warming and emissions increases in other regions. The sensitivity analyses show that changes in anthropogenic emissions contribute 32-53% of projected changes in mercury air concentration, while the independent contribution by climate change and its induced natural emissions change accounts for 47-68%.

  16. Fish faddism causing low-level mercury poisoning in the Caribbean: two case reports

    PubMed Central

    2009-01-01

    Two otherwise healthy middle-aged males presented with persistent abdominal and lower- back pain, progressive weakness, paraesthesias, fatigue and weight loss over 8-12 months. Extensive work-up failed to localize organ pathology. Both men, strongly aware of the nutritional benefits of fish had a diet dedicated of canned and fresh fish. Raised blood mercury levels confirmed clinical suspicion and serial levels declined with symptom resolution after excluding dietary fish. To gain reported health benefits of fish as a healthy food modest consumption is encouraged. Efforts to monitor fish consumption and mercury residues in fish are recommended in Trinidad and Tobago. PMID:20126317

  17. Symptoms of intoxication in dentists associated with exposure to low levels of mercury.

    PubMed

    Neghab, Masoud; Choobineh, Alireza; Hassan Zadeh, Jafar; Ghaderi, Ebrahim

    2011-01-01

    The present study examined the effects of occupational exposure of a group of dentists to low levels of mercury. The study population consisted of 106 dentists and 94 general practitioners (referent group), from private and public clinics in Shiraz city. Subjects were requested to complete a questionnaire on demographic variables, suspicious symptoms of intoxication and work practices. Additionally, atmospheric and urinary concentrations of mercury were measured by Atomic Absorption Spectroscopy technique. The data were analysed by ?(2) test, independent sample t-test and multivariate logistic regression analysis, where applicable. Both groups were similar as far as most demographic and socioeconomic variables, but age and number of personal amalgam fillings, were concerned. Median of atmospheric concentration of mercury was found to be 3.35 ?g/m(3). Likewise, the urinary concentration of mercury in dentists was estimated to be 3.16 ?g/g creatinine. This value was significantly higher than that of the referent group. Similarly, analysis of the data revealed that neuropsychological, muscular, respiratory, cardiovascular and dermal symptoms were more prevalent in dentists. Our findings indicate that occupational exposure of dentists to mercury, even at low levels, is associated with a significant increase in the prevalence of symptoms of intoxication. PMID:21173523

  18. Projections of atmospheric mercury levels and their effect on air quality in the United States

    NASA Astrophysics Data System (ADS)

    Lei, H.; Wuebbles, D. J.; Liang, X.-Z.; Tao, Z.; Olsen, S.; Artz, R.; Ren, X.; Cohen, M.

    2013-08-01

    The individual and combined effects of global climate change and emissions changes from 2000 to 2050 on atmospheric mercury levels in the US are investigated by using the global climate-chemistry model, CAM-chem, coupled with a mercury chemistry-physics mechanism (CAM-Chem/Hg). Three future pathways from the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) are considered, with the A1FI, A1B and B1 scenarios representing the upper, middle and lower bounds of potential climate warming, respectively. The anthropogenic and biomass burning emissions of mercury are projected from the energy use assumptions in the IPCC SRES report. Natural emissions from both land and ocean sources are projected using dynamic schemes. The zonal mean surface total gaseous mercury (TGM) concentrations in the tropics and mid-latitudes of the Southern Hemisphere are projected to increase by 0.5-1.2 ng m-3 in 2050. TGM concentration increases are greater in the low latitudes than they are in the high latitudes, indicative of a larger meridional gradient than in the present day. In the A1FI scenario, TGM concentrations in 2050 are projected to increase by 2.1-4.0 ng m-3 for the eastern US and 1.4-3.0 ng m-3 for the western US. This pattern corresponds to potential increases in wet deposition of 10-14 ?g m-2 for the eastern US and 2-4 ?g m-2 for the western US. The increase in Hg(II) emissions tends to enhance wet deposition and hence increase the risk of higher mercury entering the hydrological cycle and ecosystems. In the B1 scenario, mercury concentrations in 2050 are similar to present level concentrations; this indicates that the domestic reduction in mercury emissions is essentially counteracted by the effects of climate warming and emissions increases in other regions. The sensitivity analyses presented show that anthropogenic emissions changes contribute 32-53% of projected mercury air concentration changes, while the independent contribution by climate change accounts for 47-68%. In summary, global climate change could have a comparable effect on mercury pollution in the US to that caused by global emissions changes.

  19. Visual Functions in 6YearOld Children in Relation to Lead and Mercury Levels

    Microsoft Academic Search

    L Altmann; K Sveinsson; U Krämer; M Weishoff-Houben; M Turfeld; G Winneke; H Wiegand

    1998-01-01

    Within a larger comparative environmental health screening program in East and West Germany we investigated functions of the developing visual system in field experiments in a total of 384 children living in three different areas. Visual functions were assessed neurophysiologically by visual-evoked potentials (VEPs) and psychophysically by measuring the contrast sensitivity (CS). Blood lead concentrations and urinary mercury levels were

  20. A gravimetric approach to providing SI traceability for concentration measurement results of mercury vapor at ambient air levels

    NASA Astrophysics Data System (ADS)

    Ent, Hugo; van Andel, Inge; Heemskerk, Maurice; van Otterloo, Peter; Bavius, Wijnand; Baldan, Annarita; Horvat, Milena; Brown, Richard J. C.; Quétel, Christophe R.

    2014-11-01

    Current measurement and calibration capabilities for mercury vapor in air are maintained at levels of 0.2–40??g?Hg?m?3. In this work, a mercury vapor generator has been developed to establish metrological traceability to the international system of units (SI) for mercury vapor measurement results ?15?ng?Hg?m?3, i.e. closer to realistic ambient air concentrations (1–2?ng?Hg?m?3) [1]. Innovations developed included a modified type of diffusion cell, a new measurement method to weigh the loss in (mercury) mass of these diffusion cells during use (ca. 6–8??g mass difference between successive weighings), and a new housing for the diffusion cells to maximize flow characteristics and to minimize temperature variations and adsorption effects. The newly developed mercury vapor generator system was tested by using diffusion cells generating 0.8 and 16?ng?Hg?min?1. The results also show that the filter system, to produce mercury free air, is working properly. Furthermore, and most importantly, the system is producing a flow with a stable mercury vapor content. Some additional improvements are still required to allow the developed mercury vapor generator to produce SI traceable mercury vapor concentrations, based upon gravimetry, at much lower concentration levels and reduced measurement uncertainties than have been achieved previously. The challenges to be met are especially related to developing more robust diffusion cells and better mass measurement conditions. The developed mercury vapor generator will contribute to more reliable measurement results of mercury vapor at ambient and background air levels, and also to better safety standards and cost reductions in industrial processes, such as the liquefied natural gas field, where aluminum main cryogenic heat exchangers are used which are particularly prone to corrosion caused by mercury.

  1. Tissue mercury concentrations and adrenocortical responses of female big brown bats (Eptesicus fuscus) near a contaminated river.

    PubMed

    Wada, Haruka; Yates, David E; Evers, David C; Taylor, Robert J; Hopkins, William A

    2010-10-01

    Much of the research on mercury (Hg) in wild vertebrates has focused on piscivores and other animals at high trophic levels. However, recent studies indicated that insectivorous terrestrial vertebrates may also be at risk. In the present study, we examined blood and fur Hg concentrations as well as the adrenocortical responses of insectivorous big brown bats (Eptesicus fuscus) near the Hg-contaminated South River, VA and a nearby reference area. Baseline glucocorticoids and adrenocortical responses to handling have been widely used to assess the influence of environmental stressors because plasma glucocorticoids rise in response to various physical, psychological, and physiological challenges. Female bats captured at the contaminated site had 2.6 times higher blood and fur Hg concentrations than those captured at the reference site (blood: 0.11 vs. 0.04 ?g/g wet weight; fur: 28.0 vs. 10.9 ?g/g fresh weight). Fur Hg concentrations at the contaminated site were higher than most wild omnivorous and carnivorous mammals reported in the literature. Although fur and blood Hg concentrations were tightly correlated, fur Hg concentrations averaged 260 times higher than concentrations in blood. This suggests that fur may be an important depuration route for bats, just as it is in other mammals. Despite the high Hg concentrations in bat tissue, we did not observe any site difference in adrenocortical responses. Our results suggest that the bats at the contaminated site were exposed to Hg concentrations below those causing adverse effects on their adrenal axis. PMID:20596767

  2. Evaluation of mercury levels in pangasius and cod fillets traded in Sicily (Italy).

    PubMed

    Ferrantelli, V; Giangrosso, G; Cicero, A; Naccari, C; Macaluso, A; Galvano, F; D'Orazio, N; Arcadipane, G E; Naccari, F

    2012-01-01

    Predator fishes at the top of the aquatic food chain can accumulate large concentrations of metals and their consumption, consequently, makes a significant contribution, in particular, to mercury intake. The aim of this study was to determine mercury levels in fillets of two predatory species: pangasius (Pangasius hypophthalmus) from the Vietnam region of Megong and Chao Pharayai and cod (Gadus morhua) from the Baltic and North Sea, both being commercially important in the Italian market. A comparative analysis of these two imported fish species was carried out as a risk assessment for consumer safety. The results showed the presence of higher mercury levels in pangasius (0.41 ± 0.08 mg kg(-1)) than in cod (0.11 ± 0.004 mg kg(-1)) fillets. These data underline the importance of monitoring on imported fish before marketing, to evaluate better the risk of mercury exposure through fish and seafood consumption, and of selecting safer fishes for consumption by those groups more sensitive to the toxic effects of this metal. PMID:22575000

  3. Mercury and selenium levels in lemon sharks (Negaprion brevirostris) in relation to a harmful red tide event.

    PubMed

    Nam, Dong-Ha; Adams, Douglas H; Reyier, Eric A; Basu, Niladri

    2011-05-01

    Tissue levels of mercury (Hg; total, organic) and selenium (Se) were assessed in juvenile lemon sharks (Negaprion brevirostris) from Florida nearshore waters collected during a harmful algal bloom (HAB, brevetoxin) event and compared with sharks not exposed to HABs. In all sharks studied, total Hg levels in the muscle were generally present in a molar excess over Se (which may protect against Hg toxicity) and mean muscle Hg levels (0.34 microg/g) exceed safe human consumption guidelines. While there was generally no difference in tissue Hg and Se levels following exposure of sharks to HABs, hepatic Hg levels were significantly lower (56% reduction) in the HAB-exposed sharks compared to controls. As Hg and HABs are globally increasing in scope and magnitude, further work is warranted to assess their interactions and biotic impacts within aquatic ecosystems, especially for a species such as the lemon shark that is classified as a near-threatened species by the International Union for the Conservation of Nature. PMID:20625820

  4. Mercury Contamination of Aquatic Ecosystems

    NSDL National Science Digital Library

    D.P. Krabbenhoft

    This United States Geological Survey (USGS) factsheet contains information about US mercury contamination. Issues discussed include how mercury becomes a toxicological problem through bioaccumulation, human effects of mercury toxicity, and levels of atmospheric mercury. Mercury levels in fish are examined to determine how mercury gets into the environment and into the food chain.

  5. Mercury distribution in blood, tissues, and feathers of double-crested cormorant nestlings from arid-lands reservoirs in south central New Mexico.

    PubMed

    Caldwell, C A; Arnold, M A; Gould, W R

    1999-05-01

    Eggs, blood, liver, muscle, and feathers were analyzed for concentrations of total mercury in double-crested cormorant (Phalacrocorax auritus) nestlings from two reservoirs in south central New Mexico. Total mercury concentrations among eggs, tissues, and feathers were not significantly correlated. Concentrations of total mercury averaged 0.40 microg/g in liver and 0.18 microg/g in muscle tissues in both populations of nestlings. There were no significant changes in concentrations of total mercury in whole blood of nestlings collected 7-10 days and 17-22 days posthatch in Caballo Reservoir (0.36 microg/g and 0.39 microg/g, respectively) and in Elephant Butte Reservoir (0.36 microg/g and 0.34 microg/g, respectively). Total mercury concentrations were similar for blood, muscle, and liver in nestlings for both reservoirs. Total mercury concentrations were higher in eggs and tail, primary, and secondary feathers from nestlings at Caballo Reservoir compared to Elephant Butte Reservoir. Although there were no differences in concentrations of total mercury in fishes between the two reservoirs, bioaccumulation and biomagnification was evident in planktivorous and piscivorous fishes. The data demonstrate that feather analysis may not be a good predictor of tissue burden in nestlings from regions of low contamination. PMID:10227865

  6. USE OF THE GEOGRAPHIC INFORMATION SYSTEM TO INVESTIGATE MERCURY LEVELS IN CORRELATION WITH POSTMORTEM FINDINGS OF ASPERGILLUS INDUCED LESIONS IN THE COMMON LOON (GAVIA IMMER) IN THE NORTHEASTERN USA

    EPA Science Inventory

    This study employed the Geographic Information System (GIS) to correlate total mercury levels in liver tissue with post-mortem findings of aspergillosis in common loons (Gavia immer) in the northeast United States of America (USA). Aspergillosis is an opportunistic fungal infecti...

  7. Incorporating uncertainty in watershed management decision-making: A mercury TMDL case study

    USGS Publications Warehouse

    Labiosa, W.; Leckie, J.; Shachter, R.; Freyberg, D.; Rytuba, J.

    2005-01-01

    Water quality impairment due to high mercury fish tissue concentrations and high mercury aqueous concentrations is a widespread problem in several sub-watersheds that are major sources of mercury to the San Francisco Bay. Several mercury Total Maximum Daily Load regulations are currently being developed to address this problem. Decisions about control strategies are being made despite very large uncertainties about current mercury loading behavior, relationships between total mercury loading and methyl mercury formation, and relationships between potential controls and mercury fish tissue levels. To deal with the issues of very large uncertainties, data limitations, knowledge gaps, and very limited State agency resources, this work proposes a decision analytical alternative for mercury TMDL decision support. The proposed probabilistic decision model is Bayesian in nature and is fully compatible with a "learning while doing" adaptive management approach. Strategy evaluation, sensitivity analysis, and information collection prioritization are examples of analyses that can be performed using this approach.

  8. Effects of mercury release from amalgam dental restorations during cremation on soil mercury levels of three New Zealand crematoria

    SciTech Connect

    Nieschmidt, A.K.; Kim, N.D. [Univ. of Waikato, Hamilton (New Zealand)] [Univ. of Waikato, Hamilton (New Zealand)

    1997-05-01

    A vast amount of research has been undertaken in the last 15-20 years on the corrosion reactions occurring in dental amalgam, release of mercury from amalgam restorations, and the toxic effects of this released mercury on the human body. However, one environmental aspect of amalgam dental restorations that has not received a great deal of attention is the release of mercury during cremation. Mercury is liberated during cremation both because dental amalgams are unstable at cremation temperatures (650-700{degrees}C) and because the free mercury metal is highly volatile. In New Zealand, 58% of deaths are followed by cremation and this figure is likely to rise in the future. This increasing use of cremation as the method of corpse disposal, coupled with the fact that each amalgam restoration is approximately 50% mercury, implies that a significant amount of mercury may be emitted into the environment every year. This study examines mercury released from crematoria in New Zealand. 20 refs., 2 figs., 5 tabs.

  9. Ultrasensitive and rapid screening of mercury(II) ions by dual labeling colorimetric method in aqueous samples and applications in mercury-poisoned animal tissues.

    PubMed

    Deng, Yi; Wang, Xin; Xue, Feng; Zheng, Lei; Liu, Jian; Yan, Feng; Xia, Fan; Chen, Wei

    2015-04-01

    Rapid and ultrasensitive detection of trace heavy metal mercury(II) ions (Hg(2+)) are of significant importance due to the induced serious risks for environment and human health. This presented article reports the gold nanoparticle-based dual labeling colorimetric method (Dual-COLO) for ultrasensitive and rapid detection of Hg(2+) using the specific thymine-Hg(2+)-thymine (T-Hg(2+)-T) as recognition system and the dual labeling strategy for signal amplification. Both qualitative and quantitative detections of Hg(2+) are achieved successfully in aqueous samples. More importantly, the achieved detection limit of 0.005 ng mL(-1) (0.025 nM) without any instruments is very competitive to other rapid detection methods even ICP-MS based methods. This Dual-COLO method is also applied directly for real water sample monitoring and, more importantly, applied in analysis of mercury poisoned animal tissues and body fluidic samples, indicating a potentially powerful and promising tool for environmental monitoring and food safety control. PMID:25813233

  10. Mercury levels in muscle of some fish species from the Dique Channel, Colombia

    SciTech Connect

    Olivero, J.; Navas, V.; Perez, A. [Univ. of Cartagena (Colombia)] [and others] [Univ. of Cartagena (Colombia); and others

    1997-06-01

    Gold mining is an activity that has been increasing during the last ten years in Colombia. Most mining activities are carried out using mercury for gold amalgamation. In a recent publication we stated that in the Sur de Bolivar, the main gold mining zone in Colombia, the highest mercury concentration in hair was observed in fishermen. The Magdalena River, the largest and most important river in Colombia, receives all this contamination and carries it to the Atlantic Ocean through two means: The main river course and the Dique Channel. The Dique Channel is surrounded by many marshes, which are a major source of fish for nearly two hundred thousands people in northwestern Colombia. The goal of the present study was to determine, for the first time, the content of mercury in muscle tissue of the four most popular fish species purchased in some towns along the Dique Channel, to establish whether these concentrations fall within the WHO guidelines, and to identify those species which can be consumed with less risk. 11 refs., 1 fig., 2 tabs.

  11. Mercury-resistant bacteria from salt marsh of Tagus Estuary: the influence of plants presence and mercury contamination levels.

    PubMed

    Figueiredo, Neusa L L; Areias, Andreia; Mendes, Ricardo; Canário, João; Duarte, Aida; Carvalho, Cristina

    2014-01-01

    Mercury (Hg) contamination of aquatic systems has been recognized as a global, serious problem affecting both wildlife and humans. High levels of Hg, in particular methylmercury (MeHg), were detected in surface sediments of Tagus Estuary. MeHg is neurotoxic and its concentration in aquatic systems is dependent upon the relative efficiency of reduction, methylation, and demethylation processes, which are mediated predominantly by the microbial community, in particular mercury-resistant (HgR) bacteria. Plants in contaminated ecosystems are known to take up Hg via plant roots. Therefore, the aims of this study were to (1) isolate and characterize HgR bacteria from a salt marsh of Tagus Estuary (Rosário) and (2) determine HgR bacteria levels in the rhizosphere and, consequently, their influence in metal cycling. To accomplish this objective, sediments samples were collected during the spring season in an area colonized by Sacocornia fruticosa and Spartina maritima and compared with sediments without plants. From these samples, 13 aerobic HgR bacteria were isolated and characterized morphologically, biochemically, and genetically, and susceptibility to Hg compounds, Hg(2+), and MeHg was assessed by determination of minimal inhibitory concentration (MIC). Genetically, the mer operon was searched by polymerase chain reaction (PCR) and 16S rRNA sequencing was used for bacterial identification. Results showed that the isolates were capable of growing in the presence of high Hg concentration with MIC values for HgCl2 and MeHgCl in the ranges of 1.7-4.2 ?g/ml and 0.1-0.9 ?g/ml, respectively. The isolates from sediments colonized with Sacocornia fruticosa displayed higher resistance levels compared to ones colonized with Spartina maritima. Bacteria isolates showed different capacity of Hg accumulation but all displayed Hg volatilization capabilities (20-50%). Mer operon was found in two isolates, which genetically confirmed their capability to convert Hg compounds by reducing them to Hg(0). Thus, these results are the first evidence of the relevance of interaction between bacteria and plants in Hg cycling in Tagus Estuary. PMID:25072727

  12. Investigation of mercury levels in soil around a municipal solid waste incinerator in Shenzhen, China

    Microsoft Academic Search

    Jun-Jian Wang; Hong-Wei Zhao; Xiu-Ping Zhong; Si-Fang Kong; Yang-Sheng Liu; Hui Zeng

    Within the management hierarchy of municipal solid waste (MSW), incineration with energy recovery is a desired and viable\\u000a option often used in densely populated and economically developed cities. The gaseous and particulate mercury (Hg) emitted\\u000a from MSW incinerators may accumulate in the soil entering via dry and wet deposition. To investigate the soil Hg level and\\u000a estimate the effects of

  13. Mercury levels in coral reefs along the Caribbean coast of Central America

    Microsoft Academic Search

    Elia M. Garc; APO AA

    Sediment and coral skeleton samples from 23 coral reefs along the Caribbean coast of Costa Rica and Panama (1497 km) were evaluated for total mercury (Hg). High levels of pollution were found in the entire region with averages of 18.9 and 71.3 ppb in coral skeletons and sediments respectively. Significantly higher contamination was found in Panamanian corals (21.4 ppb) while

  14. Zinc, cadmium, mercury and selenium in polar bears (Ursus maritimus) from Central East Greenland

    SciTech Connect

    Dietz, R. [Greenland Environmental Research Institute, Copenhagen (Denmark); Born, E.W. [Greenland Fisheries Research Institute, Copenhagen (Denmark); Agger, C.T. [National Environmental Research Institute, Roskilde (Denmark); Nielsen, C.O. [Ravnsnaesvej, Birkerod (Denmark)

    1995-02-01

    Muscle, liver, and kidney tissues from 38 polar bears (Ursus maritimus) caught in the Scoresby Sound area, Central East Greenland, were analysed for zinc, cadmium, mercury and selenium. In general, cadmium concentrations were low in muscle, liver and kidney tissue. This finding can be explained by low cadmium levels in the blubber of ringed seals. The concentration of mercury in muscle tissue was low, whereas concentrations in liver and kidney tissue were relatively high. Mercury and cadmium were positively correlated with age in liver and kidney. Zinc was positively correlated with in kidney, and selenium was correlated with age in liver. Contrary to other marine mammals, polar bears had higher mercury levels in the kidneys than in the liver. In all three tissues polar bears had significantly lower cadmium levels than ringed seals from the same area. Mercury levels were significantly lower in the muscle tissue of polar bears than in ringed seals, where-as levels in the liver and kidney were significantly higher. The previous geographic trend for cadmium and mercury found in Canadian polar bears could be extended to cover East Greenland as well. Hence cadmium levels were higher in Greenland than in Canada, while the opposite was the case for mercury. Greenland polar bears had higher mercury and cadmium contents in livers and kidneys than polar bears from Svalbard. The mercury levels in muscle and liver tissue from polar bears from East Greenland were twice as high as found in bears from western Alaska, but half the levels found in northern Alaska. Cadmium and zinc were partially correlated in kidney tissue, and this was found for mercury and selenium as well. Cadmium and zinc showed molar ratios close to unity with the highest concentrations occurring in kidney tissue, while the levels of zinc exceeded cadmium in muscle and liver tissue by up to several decades. Mercury and selenium showed molar ratios close to unity in liver and kidneys. 56 refs., 5 figs., 6 tabs.

  15. Monitoring programme on cadmium, lead and mercury in fish and seafood from Valencia, Spain: levels and estimated weekly intake

    Microsoft Academic Search

    V. Yusà; T. Suelves; L. Ruiz-Atienza; M. L. Cervera; V. Benedito; A. Pastor

    2008-01-01

    The study was carried out to determine the current levels of mercury, cadmium, and lead in fish and seafood from the market of Comunitat Valenciana, Spain. Levels of total mercury ranged from 0.02 to 3.15 mg kg w.w. (average = 0.073 mg kg w.w.). Cadmium concentrations ranged from 0.003 to 0.66 mg kg w.w. (average = 0.27 mg kg w.w.)

  16. Tissue Mercury Concentrations in Alligators ( Alligator mississippiensis ) from the Florida Everglades and the Savannah River Site, South Carolina

    Microsoft Academic Search

    G. M. Yanochko; C. H. Jagoe; I. L. Brisbin Jr.

    1997-01-01

    .   Mercury pollution is a serious problem in some areas of\\u000a the southeastern United States. Due to biomagnification, long-lived predators\\u000a should have high Hg concentrations in affected areas. American alligators\\u000a (Alligator mississippiensis) are important predators in many\\u000a southwestern wetlands, but little information is available on Hg\\u000a concentrations in this species. We collected tissues from alligators\\u000a inhabiting two sites in the

  17. Mercury levels in human hair and sex factors

    SciTech Connect

    Shimomura, S.; Kimura, A.; Nakagawa, H.; Takao, M.

    1980-06-01

    Evidence has been presented: (1) that the geometric mean is essential to the statistical analysis of the result of the amount of Hg in hair, and (2) that the individual Hg level in hair must be evaluated by the standard deviation of logarithmic values. The Hg level in hair obtained from 1324 inhabitants on Shikoku Island showed logarithmic-normal distribution curves, with higher values in males than in females. To verify such a sexual difference, hair samples were obtained from male and female children (N = 346), teenagers (N = 300), and adults (N = 354) living in an agricultural area of Tokushima Prefecture on the island. As the result, males were found to have more Hg than females in sexually mature teenagers and adults (P < 0.05 by F test) but not in younger children.

  18. Quantitative and qualitative distribution of mercury in organs from arctic sledgedogs: an atomic absorption spectrophotometric and histochemical study of tissue samples from natural long-termed high dietary organic mercury-exposed dogs from Thule, Greenland.

    PubMed

    Hansen, J C; Danscher, G

    1995-09-01

    Organs from 10 sledgedogs fed methyl mercury-containing organs and meat from predatory marine animals also eaten by humans in the Thule district of Greenland, were examined histochemically for cellular distribution of mercury, and the organ concentrations of mercury were quantified by atomic absorption spectrometry (total Hg). In selected organs the methyl mercuric level was determined by gaschromatography. The highest concentration of total mercury was found in mesenterial lymph nodes followed by liver and kidneys, which indicates that the lymphatic system might play an important role in the regulating transport of mercury to target organs. The concentrations were age-related, and the results suggest that demethylation takes place in all organs except skeletal muscles, but lowest in CNS. The distribution of mercury at cellular and subcellular levels was studied by the autometallographic technique. The atomic absorption spectrometric and autometallographic results were in good agreement. The brain mean concentration in the oldest group was 438 micrograms/kg, a level much lower than what has been reported to cause effects in the human central nervous system. However, if humans over a period of e.g. 50 years eat Arctic marine meat and accumulate mercury in the same way as dogs, the possibility that this may have health implications cannot be entirely excluded. PMID:8884882

  19. Disparities in Children's Blood Lead and Mercury Levels According to Community and Individual Socioeconomic Positions.

    PubMed

    Lim, Sinye; Ha, Mina; Hwang, Seung-Sik; Son, Mia; Kwon, Ho-Jang

    2015-01-01

    We aimed to examine the associations between blood lead and mercury levels and individual and community level socioeconomic positions (SEPs) in school-aged children. A longitudinal cohort study was performed in 33 elementary schools in 10 cities in Korea. Among a total of 6094 children included at baseline, the final study population, 2281 children followed-up biennially, were analyzed. The geometric mean (GM) levels of blood lead were 1.73 ?g/dL (range 0.02-9.26) and 1.56 ?g/dL (range 0.02-6.83) for male and female children, respectively. The blood lead levels were significantly higher in males, children living in rural areas, and those with lower individual SEP. The GM levels of blood mercury were 2.07 ?g/L (range 0.09-12.67) and 2.06 ?g/L (range 0.03-11.74) for males and females, respectively. Increased blood mercury levels were significantly associated with urban areas, higher individual SEP, and more deprived communities. The risk of high blood lead level was significantly higher for the lower individual SEP (odds ratio (OR) 2.18, 95% confidence interval (CI) 1.36-3.50 in the lowest educational attainment of the father), with a significant dose-response relationship observed after adjusting for the community SEP. The association between high blood lead levels and lower individual SEP was much stronger in the more deprived communities (OR 2.88, 95% CI 1.27-6.53) than in the less deprived communities (OR 1.40, 95% CI 0.76-2.59), and showed a significant decreasing trend during the follow-up only in the less deprived communities. The risk of high blood mercury levels was higher in higher individual SEP (OR 0.64, 95% CI 0.40-1.03 in the lowest educational attainment of the father), with a significant dose-response relationship noted. Significant decreasing trends were observed during the follow-up both in the less and more deprived communities. From a public health point-of-view, community level intervention with different approaches for different metals is warranted to protect children from environmental exposure. PMID:26035667

  20. Association between Low-level Mercury Exposure and Neurobehavioral Functions in Korean Adults Living in a Coastal City

    PubMed Central

    Kim, Rock Bum; Kim, Byoung-Gwon; Kim, Yu-Mi; Hong, Young-Seoub; You, Chang-Hun

    2013-01-01

    Objectives The aim of this study was to determine the association between low-level mercury exposure and neurobehavioral functions in adults living in coastal regions of Korea. Methods We selected 172 adults aged 20-65 years living in a city in the coastal region of Korea. A sociodemographic survey was conducted, mercury levels in the blood, urine, and hair were measured, and the associations according to computerized neurobehavioral tests were determined using univariate analysis. After adjustment for associated variables, a multivariate linear regression analysis was performed. Results The geometric mean mercury levels in the blood, urine, and hair were 5.41 µg/L (range, 0.00-15.84 µg/L), 1.17 µg/g-creatinine (range, 0.00-32.86 µg/g-creatinine), and 1.37 mg/kg (range, 0.42-6.56 mg/kg), respectively. Variables that were associated with simple reaction time according to the neurobehavioral test results were age and urine mercury level. Variables associated with choice reaction time were the recent use of Korean traditional medicine and urine mercury level. Variables associated with the right-hand finger tapping speed test were age, gender, smoking behavior, education level, monthly household income, and urine mercury level. Variables associated with the left-hand finger tapping speed test were age, gender, education level, and urine mercury level. After adjustment for associated variables, there was no significant association between urine mercury level and simple reaction time (?=25.96; p=0.47), choice reaction time (?=50.37; p=0.32), or the number of left-hand finger taps (?=-1.54; p=0.21). However, urine mercury level was significantly associated with the number of right-hand finger taps (?=-3.86; p=0.01). Conclusions We found no evidence that low-level mercury exposure in adults is associated with deficits in neurobehavioral functions. A longer follow-up study is required to confirm this conclusion. PMID:24303351

  1. Fish mercury distribution in Massachusetts, USA lakes

    SciTech Connect

    Rose, J.; Hutcheson, M.S.; West, C.R.; Pancorbo, O.; Hulme, K.; Cooperman, A.; DeCesare, G.; Isaac, R.; Screpetis, A.

    1999-07-01

    The sediment, water, and three species of fish from 24 of Massachusetts' (relatively) least-impacted water bodies were sampled to determine the patterns of variation in edible tissue mercury concentrations and the relationships of these patterns to characteristics of the water, sediment, and water bodies (lake, wetland, and watershed areas). Sampling was apportioned among three different ecological subregions and among lakes of differing trophic status. The authors sought to partition the variance to discover if these broadly defined concepts are suitable predictors of mercury levels in fish. Average muscle mercury concentrations were 0.15 mg/kg wet weight in the bottom-feeding brown bullheads (Ameriurus nebulosus); 0.31 mg/kg in the omnivorous yellow perch (Perca flavescens); and 0.39 mg/kg in the predaceous largemouth bass (Micropterus salmoides). Statistically significant differences in fish mercury concentrations between ecological subregions in Massachusetts, USA, existed only in yellow perch. The productivity level of the lakes (as deduced from Carlson's Trophic Status Index) was not a strong predictor of tissue mercury concentrations in any species. pH was a highly (inversely) correlated environmental variable with yellow perch and brown bullhead tissue mercury. Largemouth bass tissue mercury concentrations were most highly correlated with the weight of the fish (+), lake size (+), and source area sizes (+). Properties of individual lakes appear more important for determining fish tissue mercury concentrations than do small-scale ecoregional differences. Species that show major mercury variation with size or trophic level may not be good choices for use in evaluating the importance of environmental variables.

  2. Low-level prenatal mercury exposure in north china: an exploratory study of anthropometric effects.

    PubMed

    Ou, Langbo; Chen, Cen; Chen, Long; Wang, Huanhuan; Yang, Tianjun; Xie, Han; Tong, Yindong; Hu, Dan; Zhang, Wei; Wang, Xuejun

    2015-06-01

    In order to investigate anthropometric effects of mercury (Hg) exposure, we examined the status of human prenatal exposure to Hg species, including total mercury (THg), methylmercury (MeHg) and inorganic mercury (IHg), in North China, as well as their potential effects on fetal and infant growth. Hg concentrations in various bioindicators were measured from 50 Chinese women and newborns in 2011. The participants were followed for 12 months to collect anthropometric information. Linear and two-level regression analyses were performed to determine the associations between Hg levels and body growth. The geometric mean levels of THg in the placenta, cord blood, fetal hair, and maternal blood, hair, and urine were 25.88 ?g/kg dry wt, 2.73 ?g/L, 572.98 ?g/kg, 2.29 ?g/L, 576.54 ?g/kg, and 0.58 ?g/g creatinine, respectively. Nearly 100% of Hg presented as IHg in urine, and the percentage of IHg in other bioindicators was 14.86-48.73%. We observed significantly negative associations between Hg levels in some matrixes and anthropometry of neonates (weight and height) and infants (height) (p < 0.05). THg levels in maternal hair were also negatively associated with infant growth rate of weight during 12 months after delivery (p = 0.017). This study suggests that low-level prenatal Hg exposure could play a role in attenuating fetal and infant growth, and the effects of MeHg and IHg are different. PMID:25936461

  3. Mercury bombardment ion thrusters - Development status, performance levels, and test history

    NASA Technical Reports Server (NTRS)

    Molitor, J. H.

    1974-01-01

    The present work describes the development status, performance levels, and life test history of 5-cm, 8-cm, and 30-cm mercury bombardment ion thrusters and their respective power processors. A 2.6 kW, 30-cm thruster module and its power processor unit are now available that established the performance required by interplanetary and geosynchronous orbit raising missions. An 8-cm thruster with nominal 4.5 mN thrust level capability has demonstrated a high performance over a wide range of thrust and operational life.

  4. Mercury interferes with endogenous antioxidant levels in Yukon River subsistence-fed sled dogs

    NASA Astrophysics Data System (ADS)

    Dunlap, Kriya L.; Reynolds, Arleigh J.; Gerlach, S. Craig; Duffy, Lawrence K.

    2011-10-01

    Before adopting modern corn-and-grain-based western processed diets, circumpolar people had a high fat and protein subsistence diet and exhibited a low incidence of obesity, diabetes and cardiovascular disease. Some health benefits are attributable to a subsistence diet that is rich in omega-3 fatty acids and antioxidants. Pollution, both global and local, is a threat to wild foods, as it introduces contaminants into the food system. Northern indigenous people and their sled dogs are exposed to a variety of contaminants, including mercury, that accumulate in the fish and game that they consume. The sled dogs in Alaskan villages are maintained on the same subsistence foods as their human counterparts, primarily salmon, and therefore they can be used as a food systems model for researching the impact of changes in dietary components. In this study, the antioxidant status and mercury levels were measured for village sled dogs along the Yukon River. A reference kennel, maintained on a nutritionally balanced commercial diet, was also measured for comparison. Total antioxidant status was inversely correlated with the external stressor mercury.

  5. Tissue levels of adiponectin in breast cancer patients

    Microsoft Academic Search

    Mehmet Karaduman; Ahmet Bilici; Ahmet Ozet; Ali Sengul; Ugur Musabak; Melih Alomeroglu

    2007-01-01

    Background  Adiponectin is a new adipocyte-secreted protein and associated with insulin-resistant status, such as type 2 diabetes mellitus\\u000a and obesity. The inverse correlation between serum adiponectin levels and breast cancer risk was recently documented. On the\\u000a other hand, the association of tissue adiponectin levels with breast cancer has not been previously reported. Thus, in the\\u000a present study, the relationship between tissue

  6. Mercury levels of fish in Tucuruí hydroelectric reservoir and in River Mojú in Amazonia, in the state of Pará, Brazil

    Microsoft Academic Search

    Petri Porvari

    1995-01-01

    High mercury (Hg) levels were found in fish of Tucuruí reservoir and River Mojú polluted by mercury due to gold mining activities. The highest Hg concentrations were measured in predatory fish (1.3 ± 0.89 mg\\/kg, N = 121), intermediate values in planktivorous and omnivorous fish (0.32 ± 0.20 mg\\/kg, N = 89) and the lowest values in herbivorous fish (0.11

  7. MERCURY IN FISH TISSUE ACROSS THE WESTERN UNITED STATES: IMPLICATIONS OF SELENIUM INTERACTIONS

    EPA Science Inventory

    We collected 2,707 fish from 626 stream/river sites in 12 western USA states using a probability design to assess the spatial extent of whole fish mercury (Hg) concentrations. In all large (> 120 mm) fish, total Hg concentrations (mean µg·g-1; SD; n) in both piscivores (0.26...

  8. Organochlorine and mercury contamination in fish tissues from the River Nestos, Greece

    Microsoft Academic Search

    Achilleas Christoforidis; Nikolaos Stamatis; Klaus Schmieder; Efstathios Tsachalidis

    2008-01-01

    Polychlorinated biphenyls (PCBs), hexachlorocyclohexane (HCH) isomers, dichlorodiphenyltrichloroethane (DDT) and its metabolites, other organochlorine pesticides such as hexachlorobenzene (HCB), chlordane compounds (CHLs, including trans-chlordane and cis- and trans-nonachlor) and the heavy metal mercury were quantified in muscle and liver of the European chub (Leuciscus cephalus, Linnaeus, 1758) and in the muscle of the barbel (Barbus cyclolepis, Heckel, 1837) at two sampling

  9. Mercury levels in lichens from different host trees around a chlor-alkali plant in New Brunswick, Canada.

    PubMed

    Sensen, Marion; Richardson, David H S

    2002-07-01

    Mercury concentrations were determined in the epiphytic lichen Hypogymnia physodes along five transects starting from a chlor-alkali plant located at Dalhousie, New Brunswick, a landfill site and a nearby electricity generating station. Lichen samples were collected from white birch (Betula papyrifera) and spruce (Picea sp.) or balsam fir (Abies balsamea). Average lichen background mercury values were 0.088+/-0.005 microg/g from white birch and 0.148+/-0.046 microg/g from spruce trees, with a detection limit of 0.05 microg/g. The chlor-alkali plant and a power plant were identified, respectively, as a major source and a minor source of elevated mercury levels in lichens. At 125 m north-west of the New Brunswick Power plant, 0.28 microg/g Hg were found in Hypogymnia physodes from spruce trees, while at 250 m west (downwind) of the chlor-alkali plant, 3.66 microg/g of mercury were determined. High values, 0.98 microg/g in lichens from spruce trees and 0.79 microg/g in lichen samples from white birch were also measured at 125 m south of the chlor-alkali plant and decreased exponentially with distance. The sphere of influence of the chlor-alkali plant with respect to mercury deposition was estimated to extend 2.4-3.4 km from the plant. The mercury concentrations in Hypogymnia physodes collected from white birch were significantly lower than the concentrations in the same lichen from spruce trees in areas with elevated levels of mercury, but not in areas with low mercury levels. The magnitude of this difference dropped with distance from the source. PMID:12109479

  10. Effect of diet on tissue levels of palmitoylethanolamide.

    PubMed

    Hansen, Harald S

    2013-02-01

    Palmitoylethanolamide (PEA) as well as the other N-acylethanolamines (NAEs), e.g. anandamide, oleoylethanolamide, stearoylethanolamide and linoleoylethanolamide, appear to exist in every mammalian cell at low levels, e.g. a few hundred pmol/g tissue for PEA. Their formation can be stimulated by cellular injury and inflammation. In the brain PEA and other NAEs may have neuroprotective functions. PEA levels in tissues seem hardly to be influenced by variation in intake of dietary fatty acids, except in the small intestine where dietary fat results in decreased levels of PEA and other NAEs. In rat small intestine, PEA, oleoylethanolamide and linoleoylethanolamide have anorectic properties. Of other dietary components, only ethanol is known to influence tissue levels of PEA. Thus, an acute intoxicating dose of ethanol will decrease PEA levels in various areas in the brain of rats. The mechanism behind this effect is not known. PMID:23394522

  11. Glutathione peroxidase response in tissues of rats fed diets containing fish protein concentrate prepared from shark flesh of known mercury and selenium contents

    SciTech Connect

    Thrower, S.J. (Commonwealth Scientific and Industrial Research Organization, Hobart, Australia); Andrewartha, K.A.

    1981-01-01

    Studies have been reported using experimental animals and synthetic diets containing selenium and mercury compounds to demonstrate detoxification of mercury by selenium. The mechanism of detoxification remains obscure. Most experiments have involved the use of high levels of both elements and relied on the observation of gross symptoms. The measurement of enzyme systems may be useful in detecting effects of mercury at a lower, subclinical level and in elucidating the biochemistry of mercury/selenium interactions. The activity of the selenoenzyme glutathione peroxidase (GSH-Px) in rats is dependent on dietary selenium and attempts have been made to use this enzyme as an indicator of mercury/selenium interactions. The research described in this paper was designed to investigate the effect of mercury, in the form and amounts which occur naturally in seafood, on the availability of selenium at levels approximating the nutritional requirement. In anticipation of mercury lowering the GSH-Px response a range of selenium concentrations was used, from nutritional deficiency to three times the nutritional requirement.

  12. In Brief: Mountaintop mining under scrutiny; High levels of mercury in U.S. rainfall

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    Proposed new regulations call for mountaintop surface coal mining in U.S. Appalachian states to reduce ``burying'' and other adverse impacts on streams and watersheds. The draft regulations, issued on 29 May by the Army Corps of Engineers, the Environmental Protection Agency, and other agencies, affects a 12-million-acre area encompassing parts of Kentucky, West Virginia, Virginia, and Tennessee.The mercury levels in rainfall in 12 U.S. states far exceeds safe standards established by the Environmental Protection Agency, according to a 29 May report by the National Wildlife Federation, a non-profit environmental group.

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

    Microsoft Academic Search

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

    2007-01-01

    To investigate the relations among total mercury levels in hair, toenail, and urine, together with potential effects of methylmercury intake on renal tubular function, we determined their levels, and urinary N-acetyl-?-d-glucosaminidase activity (NAG) and ?1-microglobulin (AMG) in 59 women free from occupational exposures, and estimated daily mercury intakes from fish and other seafood using a food frequency questionnaire. Mercury levels

  14. Cadmium109 and methyl mercury-203 metabolism, tissue distribution, and secretion into milk of cows

    Microsoft Academic Search

    M. W. Neathery; W. J. Miller; R. P. Gentry; P. E. Stake; D. M. Blackmon

    1974-01-01

    Metabolism of cadmium-109 and methyl mercury-203 was studied in six lactating Jersey cows for 14 days following single tracer oral doses. Most of the cadmium-109 was excreted in feces with only .05% in urine. When the cows were killed 14 to 16 days after dosing, kidney and liver had highest cadmium-109. About .75% of the cadmium-109 was retained in the

  15. A new page on the road book of inorganic mercury in fish body - tissue distribution and elimination following waterborne exposure and post-exposure periods.

    PubMed

    Pereira, Patrícia; Raimundo, Joana; Barata, Marisa; Araújo, Olinda; Pousão-Ferreira, Pedro; Canário, João; Almeida, Armando; Pacheco, Mário

    2015-03-01

    There are several aspects of inorganic mercury (iHg) toxicokinetics in fish that remain undeveloped despite its environmental ubiquity, bioaccumulation capacity and toxicity. Thus, this study presents new information on the uptake, distribution and accumulation of iHg following water contamination by adopting a novel set of body compartments (gills, eye wall, lens, blood, liver, brain and bile) of the white sea bream (Diplodus sargus) over 14 days of exposure. Realistic levels of iHg in water (2 ?g L(-1)) were adopted in order to engender reliable conclusions in the assessment of fish health. A depuration phase of 28 days was also considered with the purpose of clarifying iHg elimination. It was found that iHg was accumulated faster in the gills (within 1 day), which also had the highest accumulated levels among all the target tissues/organs. Moreover, iHg increased gradually with exposure time in all the tissues/organs, except for the lens that showed relatively unaltered levels throughout the experiment. After 14 days of exposure, lower values of Hg were recorded in the brain/eye wall compared to the liver, which is probably related with the presence of blood-organ protection barriers, which limit iHg influx. iHg reached the brain earlier than the eye wall (3 and 7 days, respectively) and, hence, higher accumulated levels were recorded in the former. A depuration period of 28 days did not allow the total elimination of iHg in any of the tissues/organs. Despite this, iHg was substantially eliminated in the gills, blood and liver, whereas the brain and eye wall were not able to eliminate iHg within this timeframe. The brain and eye wall are more "refractory" structures with regard to iHg elimination, and this could represent a risk for wild fish populations. PMID:25677695

  16. High levels of reactive gaseous mercury observed at a high elevation research laboratory in the Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Faïn, X.; Obrist, D.; Hallar, A. G.; McCubbin, I.; Rahn, T.

    2009-07-01

    The chemical cycling and spatiotemporal distribution of mercury in the troposphere is poorly understood. We measured gaseous elemental mercury (GEM), reactive gaseous mercury (RGM) and particulate mercury (HgP) along with CO, ozone, aerosols, and meteorological variables at Storm Peak Laboratory at an elevation of 3200 m a.s.l., in Colorado, from 28 April to 1 July 2008. The mean mercury concentrations were 1.6 ng m-3 (GEM), 20 pg m-3 (RGM) and 9 pg m-3 (HgP). We observed eight events of strongly enhanced atmospheric RGM levels with maximum concentrations up to 135 pg m-3. RGM enhancement events were unrelated to daytime/nighttime patterns and lasted for long time periods of 2 to 6 days. During seven of these events, RGM was inversely correlated to GEM (RGM/GEM regression slope ~ -0.1), but did not exhibit correlations with ozone, carbon monoxide, or aerosol concentrations. Relative humidity was the dominant factor affecting RGM levels with high RGM levels always present whenever relative humidity was below 40 to 50%. We conclude that RGM enhancements observed at Storm Peak Laboratory were not induced by pollution events and were related to oxidation of tropospheric GEM, but the mechanism remain unclear. Based on backtrajectory analysis and a lack of mass balance between RGM and GEM, we propose that in situ production of RGM may have occurred in some distance allowing for scavenging and/or deposition of some RGM prior to reaching the laboratory, and that GEM oxidation is an important tropospheric Hg sink. Our observations provide evidence that the tropospheric pool of mercury is frequently enriched in divalent mercury and that high RGM levels are not limited to the upper troposphere.

  17. Levels of total mercury in predatory fish sold in Canada in 2005

    PubMed Central

    Dabeka, R.W.; McKenzie, A.D.; Forsyth, D.S.

    2011-01-01

    Total mercury was analysed in 188 samples of predatory fish purchased at the retail level in Canada in 2005. The average concentrations (ng g?1, range) were: sea bass 329 (38–1367), red snapper 148 (36–431), orange roughy 543 (279–974), fresh water trout 55 (20–430), grouper 360 (8–1060), black cod 284 (71–651), Arctic char 37 (28–54), king fish 440 (42–923), tilefish 601 (79–1164) and marlin 854 (125–2346). The Canadian standard for maximum total mercury allowed in the edible portions of fish sold at the retail level is 1000 ng g?1 for shark, swordfish, marlin, orange roughy, escolar and both fresh and frozen tuna. The standard is 500 ng g?1 for all other types of fish. In this study, despite the small number of samples of each species, the 1000 ng g–1 maximum was exceeded in five samples of marlin (28%). The 500 ng g?1 maximum was exceeded by six samples of sea bass (20%), four of tilefish (50%), five of grouper (24%), six of king fish (40%) and one of black cod (13%), PMID:21623497

  18. Effects of suspension on tissue levels of glucocorticoid receptors

    NASA Technical Reports Server (NTRS)

    Steffen, J. M.

    1984-01-01

    Differential muscle responses can be simulated by hypokinetic/hypodynamic (H/H) suspension of rats with complete unloading of the hindlimb muscles. Since mechanism(s) underlying these atrophic effects were not clearly elucidated, experiments were initiated to investigate a possible role for glucocorticoids in the physiological and biochemical responses to H/H. The principal objective was to assess the potential for alterations in peripheral responsiveness to glucocorticoids in response to H/H. Studies have initially focused on the determination of tissue levels of glucocorticoid receptors as one index of hormonal sensitivity at the cellular level. Four hindlimb muscles (soleus, gastrocnemius, plantaris and EDL), previously demonstrated to exhibit differential responses to H/H, were investigated. Receptor levels in other glucocorticoid sensitive tissues (heart, liver, and kidney) were determined. Male rats (180-200g) were suspended for 7 or 14 days, sacrificed by cervical dislocation, and the tissues excised.

  19. Total and organic mercury in liver, kidney and muscle of waterbirds from wetlands of the Caspian Sea, Iran.

    PubMed

    Aazami, J; Esmaili-Saria, A; Bahramifar, N; Savabieasfahani, M

    2012-07-01

    We measured and compared total and organic mercury in liver, kidney, and muscle of the Great Cormorant (Phalacrocorax carbo), mallard (Anas platyrhynchos), and coot (Fulica atra) from the Caspian Sea wetlands in Iran. For the Great Cormorant organic mercury in liver, kidney and muscle comprised 82 %, 79 % and 58 % of total mercury. In the mallard same values were 46 %, 54 %, and 64 %. For coot total mercury was: 0.1 ± 0.0, 0.1 ± 0.01, 0.03 ± 0.01 in liver kidney and muscle respectively. We detected no organic mercury. In general older birds that feed on higher trophic levels can accumulate more mercury in their tissues. PMID:22527004

  20. Projecting the Population-level Effects of Mercury on the Common Loon in the Northeast

    NASA Astrophysics Data System (ADS)

    Evers, D. C.; Mitro, M. G.; Gleason, T. R.

    2001-05-01

    The Common Loon (Gavia immer) is a top-level predator in aquatic systems and is at risk to mercury contamination. This risk is of particular concern in the Northeast, the region of North America in which loons have the highest mean body concentration of methylmercury (MeHg). We used matrix population models to project the population-level effects of mercury on loons in four states in the Northeast (New York, Vermont, New Hampshire, and Maine) exhibiting different levels of risk to MeHg. Four categories of risk to MeHg (low, moderate, high, and extra high) were established based on MeHg levels observed in loons and associated effects observed at the individual and population levels in the field (e.g., behavior and reproductive success). We parameterized deterministic matrix population models using survival estimates from a 12-year band-resight data set and productivity estimates from a 25-year data set of nesting loon observations in NH. The juvenile loon survival rate was 0.55 (minimum) and 0.63 (maximum) (ages 1-3), and the adult loon survival rate was 0.95 (ages 4-30). The mean age at first reproduction was 7. The mean fertility was 0.26 fledgelings per individual at low to moderate risk; there were 53% fewer fledged young per individual at high to extra high risk. Productivity was weighted by risk for each state. The portion of the breeding population at high to extra high risk was 10% in NY, 15% in VT, 17% in NH, and 28% in ME. We also constructed a stochastic model in which productivity was randomly selected in each time step from the 25 estimates in the NH data set. Model results indicated a negative population growth rate for some states. There was a decreasing trend in population growth rate as the percentage of the loon population at high to extra high risk increased. The stochastic model showed that the population growth rate varied over a range of about 0.05 from year to year, and this range decreased as the percentage of the loon population at high to extra high risk increased. These results suggest that an increase in risk to mercury that effects a change in reproductive success may have a negative population-level effect on loons.

  1. The Levels of Soluble Nucleotides in Wheat Aleurone Tissue 1

    PubMed Central

    Collins, G. G.; Jenner, C. F.; Paleg, L. G.

    1972-01-01

    The content of soluble nucleotides in aleurone layers isolated from mature wheat (Triticum aestivum var. Olympic) grain was investigated. The most abundant nucleotides were adenosine triphosphate, uridine triphosphate, and uridine diphosphoglucose. Smaller amounts of guanosine triphosphate, cytidine triphosphate, adenosine diphosphate, and nicotinamide adenine dinucleotide were also identified. The levels of some of these nucleotides were increased after incubation of the tissue under certain conditions. Nucleotide levels were measured at intervals during incubation of aleurone layers in water. The changes observed are discussed in relation to a response by the tissue to wounding. PMID:16657969

  2. [Levels of lead, cadmium and mercury in the hair of inhabitants of the Nantes and Grenoble areas].

    PubMed

    Boiteau, H L; Stoklov, M; Remond, D; Buffet, H; Metayer, C; Vincent, F; Corneteau, H; Faure, J

    1983-11-01

    Lead, cadmium and mercury were measured in the air of 398 inhabitants of the Grenoble area and 341 inhabitants of the Nantes area. The hair was washed with hor solution of EDTA, dissolved in nitric acid and analyzed by electrothermal atomic absorption spectrometry. The average concentrations are 6,23 micrograms/g for lead, 0,40 microgram/g for cadmium and 1,06 microgram/g for mercury. There is no difference between found data of the two areas for lead and cadmium. Mercury levels are higher in the Nantes area. Lead content is higher in male hair than in female hair, but the difference is not significant. In the Grenoble area, mercury levels are higher in males than in females; the process is reversed in the Nantes area. We have found no relation between metal levels and age of persons, but lead content is high in the hair of people under ten. Artisans and mechanics have lead content higher than the general people, though exposed people to occupational risks is excluded. We have found to relation between metal in the hair and the size of the town. It seems that the use of tobacco is without influence. Mercury content is related to the eating of fish. It is not increased in the population because of dental amalgams. PMID:6326346

  3. Interspecific and locational differences in metal levels in edible fish tissue from Saudi Arabia.

    PubMed

    Burger, Joanna; Gochfeld, Michael; Batang, Zenon; Alikunhi, Nabeel; Al-Jahdali, Ramzi; Al-Jebreen, Dalal; Aziz, Mohammed A M; Al-Suwailem, Abdulaziz

    2014-10-01

    Metal levels in fish have been extensively studied, but little data currently exists for the Middle East. We examined the levels of metals and metalloids (aluminum, arsenic, copper, manganese, selenium, zinc, and mercury) in the flesh of 13 fish species collected from three fishing sites and a local fish market in Jeddah, Saudi Arabia. We tested the following null hypotheses: (1) there are no interspecific differences in metal levels, (2) there are no differences in metal levels in fishes between market and fishing sites, (3) there are no size-related differences in metal levels, and (4) there are no differences in selenium:mercury molar ratio among different fish species. There were significant interspecific differences in concentrations for all metals. There was an order of magnitude difference in the levels of aluminum, arsenic, mercury, manganese, and selenium, indicating wide variation in potential effects on the fish themselves and on their predators. Fishes from Area II, close to a large commercial port, had the highest levels of arsenic, mercury, and selenium, followed by market fishes. Mercury was positively correlated with body size in 6 of the 13 fish species examined. Mercury was correlated positively with arsenic and selenium, but negatively with aluminum, cobalt, copper, manganese, and zinc. Selenium:mercury molar ratios varied significantly among species, with Carangoides bajad, Cephalopholis argus, Variola louti, and Ephinephelus tauvina having ratios below 10:1. These findings can be used in risk assessments, design of mercury reduction plans, development of fish advisories to protect public health, and future management decision-making. PMID:24997870

  4. Electronic characterization of defects in narrow gap semiconductors: Comparison of electronic energy levels and formation energies in mercury cadmium telluride, mercury zinc telluride, and mercury zinc selenide

    NASA Technical Reports Server (NTRS)

    Patterson, James D.; Li, Wei-Gang

    1995-01-01

    The project has evolved to that of using Green's functions to predict properties of deep defects in narrow gap materials. Deep defects are now defined as originating from short range potentials and are often located near the middle of the energy gap. They are important because they affect the lifetime of charge carriers and hence the switching time of transistors. We are now moving into the arena of predicting formation energies of deep defects. This will also allow us to make predictions about the relative concentrations of the defects that could be expected at a given temperature. The narrow gap materials mercury cadmium telluride (MCT), mercury zinc telluride (MZT), and mercury zinc selenide (MZS) are of interest to NASA because they have commercial value for infrared detecting materials, and because there is a good possibility that they can be grown better in a microgravity environment. The uniform growth of these crystals on earth is difficult because of convection (caused by solute depletion just ahead of the growing interface, and also due to thermal gradients). In general it is very difficult to grow crystals with both radial and axial homogeneity.

  5. Bioaccumulation of mercury in pelagic fishes in NW Gulf of Mexico 

    E-print Network

    Cai, Yan

    2006-08-16

    Total mercury (Hg) levels were determined in the tissues of ten taxa of pelagic fishes, with a special emphasis on apex predators (large vertebrates). Highest Hg levels were observed in blue marlin (Makaira nigricans), ...

  6. Mercury bioacumulation in four tissues of Podocnemis erythrocephala (Podocnemididae: Testudines) as a function of water parameters.

    PubMed

    Schneider, Larissa; Belger, Lauren; Burger, Joanna; Vogt, Richard C

    2009-01-15

    A number of environmental factors influence the dynamics of Hg in aquatic ecosystems, yet few studies have examined these factors for turtles, especially from South America. Red-headed river turtle (Podocnemis erythrocephala) is easy to capture in the black waters of Rio Negro, making it the turtle species that is consumed most often by people of the region. In this study, environmental factors and turtle size were investigated to determine their influence on the Hg concentration in blood, muscle, liver and carapace of the red-headed river turtle. Factors investigated included turtle length, pH, dissolved organic carbon and availability of potential methylation sites (floodplain forests and hydromorphic soils). The study was conducted in the Rio Negro basin, where we collected water and turtle blood, muscle, liver and carapace samples from 12 tributaries for chemical analysis. Through radar imagery and existing soil maps with GIS, the percentage of alluvial floodplains and hydromorphic soils (potential methylation sites) was estimated for each drainage basin at sampling points. The mean Hg concentration in blood of P. erythrocephala was 1.64 ng g(-1) (SD=1.36), muscle 33 ng g(-1) (SD=11), liver 470 ng g(-1) (SD=313) and carapace 68 ng g(-1) (SD=32). Sex or length did not influence the Hg concentration in P. erythrocephala blood, muscle and liver, but Hg increased in carapace tissue when length size increased (ANCOVA p=0.007). In the multiple regression analysis, none of the environmental factors studied had a significant relation with blood, muscle, liver and carapace. P. erythrocephala moves among habitats and in the open and interconnected aquatic systems of the Amazon basin, characterized by high levels of limnological variability, a good bioindicator of Hg concentration needs to be relatively sedentary to represent a specific habitat. However, the levels of Hg in liver were sufficient to pose a potential risk to humans that consume them, suggesting the usefulness of P. erythrocephala as a bioindicator. PMID:19022475

  7. Mercury poisoning in a wild mink

    Microsoft Academic Search

    G. WOBESER; M. SWIFT

    1976-01-01

    Mercury poisoning was diagnosed in a clinically-ill wild mink (Mustela vision) on the basis of clinical signs, histopathologic lesions and tissue mercury concentrations. The probable source of mercury was through ingestion of fish from the nearby South Saskatchewan River which is known to be contaminated with mercury. This is believed to be the first documented case of mercury intoxication of

  8. Pilot Survey of Levels of Polychlorinated Dibenzo-P-Dioxins (PCDDS), Polychlorinated Dibenzofurans (PCDFS), Polychlorinated Biphenyls (PCB) and Mercury in Rural Soils of the U.S.

    EPA Science Inventory

    EPA has released a final report entitled, Pilot Survey of Levels of Polychlorinated Dibenzo-p-dioxins, Polychlorinated Dibenzofurans, Polychlorinated Biphenyls and Mercury in Rural Soils of the United States . The survey measured levels of dioxins, PCBs and mercury in soil ...

  9. Mercury levels in raccoons (Procyon lotor) from the Warta Mouth National Park, northwestern Poland.

    PubMed

    Lanocha, Natalia; Kalisinska, Elzbieta; Kosik-Bogacka, Danuta I; Budis, Halina; Podlasinska, Joanna; Jedrzejewska, Ewa

    2014-06-01

    This is the first report on mercury (Hg) levels in the liver, kidney, skeletal muscle, and brain of raccoon in Europe. It studied Hg concentration in 24 raccoons from the Warta Mouth National Park, northwestern Poland by atomic absorption spectroscopy (AAS). The highest total Hg concentrations in the raccoon were found in the liver (maximum, 18.45 mg/kg dry weight), while the lowest in the brain (maximum, 0.49 mg/kg dw). In adult raccoons, Hg concentrations in the liver, kidney, and brain were higher than in immature individuals (p<0.001), while similar in skeletal muscle in both age groups. Our results are consistent with studies by other authors conducted in North America in areas with similar environmental conditions. PMID:24736978

  10. A Contribution to the Establishment of Reference Values for Total Mercury Levels in Hair and Fish in Amazonia

    Microsoft Academic Search

    E. C. O. Santos; V. M. Câmara; I. M. Jesus; E. S. Brabo; E. C. B. Loureiro; A. F. S. Mascarenhas; K. F. Fayal; G. C. Sá Filho; F. E. S. Sagica; M. O. Lima; H. Higuchi; I. M. Silveira

    2002-01-01

    Studies on mercury levels in the Amazonian Region have typically lacked background or reference parameters. A sectional study on Hg concentration in hair and fish was conducted, together with an assessment of the prevalence of signs and symptoms related to Hg poisoning, in four communities in the Amazon Basin not impacted by gold mining, located either by a river course

  11. Understanding mercury demethylation is the key to decrease the high environmental levels of the neurotoxin methyl-Hg in lakes.

    E-print Network

    Uppsala Universitet

    Understanding mercury demethylation is the key to decrease the high environmental levels of the neurotoxin methyl-Hg in lakes. This year over 130 countries agreed to the UN's Minamata Convention's 100,000 lakes have fish that are unsafe to eat due to Hg, Sweden's early concern and deep involvement

  12. POPULATION-LEVEL RESPONSE OF THE COMMON LOON TO MERCURY IN TWO CANADIAN PROVINCES: A MATRIX MODELING APPROACH

    EPA Science Inventory

    We used data collected from Common Loon Gavia immer populations in two Canadian provinces to demonstrate a matrix population modeling approach for evaluating population-level responses to stressors and to understand how these populations may have responded to mercury contaminatio...

  13. High levels of reactive gaseous mercury observed at a high elevation research laboratory in the Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Faïn, X.; Obrist, D.; Hallar, A. G.; McCubbin, I.; Rahn, T.

    2009-10-01

    The chemical cycling and spatiotemporal distribution of mercury in the troposphere is poorly understood. We measured gaseous elemental mercury (GEM), reactive gaseous mercury (RGM) and particulate mercury (HgP) along with carbon monoxide (CO), ozone (O3), aerosols, and meteorological variables at Storm Peak Laboratory at an elevation of 3200 m a.s.l., in Colorado, from 28 April to 1 July 2008. The mean mercury concentrations were 1.6 ng m-3 (GEM), 20 pg m-3 (RGM) and 9 pg m-3 (HgP). We observed eight events of strongly enhanced atmospheric RGM levels with maximum concentrations up to 137 pg m-3. RGM enhancement events lasted for long time periods of 2 to 6 days showing both enriched level during daytime and nighttime when other tracers (e.g., aerosols) showed different representations of boundary layer air and free tropospheric air. During seven of these events, RGM was inversely correlated to GEM (RGM/GEM regression slope ~-0.1), but did not exhibit correlations with ozone, carbon monoxide, or aerosol concentrations. Relative humidity was the dominant factor affecting RGM levels with high RGM levels always present whenever relative humidity was below 40 to 50%. We conclude that RGM enhancements observed at Storm Peak Laboratory were not induced by pollution events and were related to oxidation of tropospheric GEM. High RGM levels were not limited to upper tropospheric or stratospherically influenced air masses, indicating that entrainment processes and deep vertical mixing of free tropospheric air enriched in RGM may lead to high RGM levels throughout the troposphere and into the boundary layer over the Western United States. Based on backtrajectory analysis and a lack of mass balance between RGM and GEM, atmospheric production of RGM may also have occurred in some distance allowing for scavenging and/or deposition of RGM prior to reaching the laboratory. Our observations provide evidence that the tropospheric pool of mercury is frequently enriched in divalent mercury, that high RGM levels are not limited to upper tropospheric air masses, but that the build-up of high RGM in the troposphere is limited to the presence of dry air.

  14. Influence of mercury accumulation on fish

    SciTech Connect

    Dokholyan, V.K.; Akhmedov, A.M.; Akhmedova, T.P.; Shleyfer, G.S.

    1981-01-01

    Questions of the accumulation and distribution of mercury in the organs and tissues of different species of fish were examined in relation to the influence of mercury on survival, physiological and biochemical indices of the blood and brain. In the sturgeon and the roach, mercury accumulated primarily in the kidneys, liver, spleen and gills. The uneven distribution is evidently due to differentiation and differences in the degree of intensity of the metabolic processes of the cells in the organs and tissues, and the physico-chemical mechanism of the interaction of mercury with the biological structure is also important. There are substantial changes in the composition of the blood as a result of intoxication. In the sturgeon and roach a drop is noted in erythrocytes, hemoglobin and leukocytes and qualitative changes in the red blood cells also occur. Deviations were also noted in the correlation of individual forms of leukocytes. These changes are evidently provoked both by the direct presence of mercury in the blood stream and by its disruption of the functions of the hematopoetic organs. Mercury poisoning leads to disruption of the nitrogen metabolism of the brain of the fish. With the accumulation of mercury in fish to a certain critical level, the metabolic processes are inhibited or altered and the defense functions of the blood are weakened. 17 references, 6 figures, 4 tables.

  15. The Influence of Fish Length on Tissue Mercury Dynamics: Implications for Natural Resource Management and Human Health Risk

    PubMed Central

    Sackett, Dana K.; Cope, W. Gregory; Rice, James A.; Aday, D. Derek

    2013-01-01

    Consumption of fish has well-known human health benefits, though some fish may contain elevated levels of mercury (Hg) that are especially harmful to developing children. Fish length is most often the basis for establishing fishery harvest regulations that determine which fish will ultimately be consumed by humans. It is, therefore, essential to quantify the relationship between fish length and Hg accumulation in regard to harvest regulations for effective fishery and public health policy. We examined this relationship for three sportfish from six lakes across North Carolina, USA. Bluegill (Lepomis macrochirus) had the lowest Hg levels and only the very largest fish in the most contaminated site exceeded the US Environmental Protection Agency (USEPA) Hg screening level. Black crappie (Pomoxis nigromaculatus) had an intermediate level of Hg and larger individuals exceeded the USEPA screening level; however, they tended not to exceed this level before reaching the harvest length limit. Largemouth bass (Micropterus salmoides) exceeded the USEPA screening level at sizes below the fishery length limit in two lakes, leaving only higher risk fish for anglers to harvest and consume. Removing the effects of fish age and trophic position, we found strong positive correlations between Hg and fish length for largemouth bass and black crappie. We suggest public health officials and wildlife managers collaborate to structure fishery regulations and length-based fish consumption advisories that protect consumers from Hg exposure and communicate the relative risk of fish consumption. PMID:23388852

  16. The influence of fish length on tissue mercury dynamics: implications for natural resource management and human health risk.

    PubMed

    Sackett, Dana K; Cope, W Gregory; Rice, James A; Aday, D Derek

    2013-02-01

    Consumption of fish has well-known human health benefits, though some fish may contain elevated levels of mercury (Hg) that are especially harmful to developing children. Fish length is most often the basis for establishing fishery harvest regulations that determine which fish will ultimately be consumed by humans. It is, therefore, essential to quantify the relationship between fish length and Hg accumulation in regard to harvest regulations for effective fishery and public health policy. We examined this relationship for three sportfish from six lakes across North Carolina, USA. Bluegill (Lepomis macrochirus) had the lowest Hg levels and only the very largest fish in the most contaminated site exceeded the US Environmental Protection Agency (USEPA) Hg screening level. Black crappie (Pomoxis nigromaculatus) had an intermediate level of Hg and larger individuals exceeded the USEPA screening level; however, they tended not to exceed this level before reaching the harvest length limit. Largemouth bass (Micropterus salmoides) exceeded the USEPA screening level at sizes below the fishery length limit in two lakes, leaving only higher risk fish for anglers to harvest and consume. Removing the effects of fish age and trophic position, we found strong positive correlations between Hg and fish length for largemouth bass and black crappie. We suggest public health officials and wildlife managers collaborate to structure fishery regulations and length-based fish consumption advisories that protect consumers from Hg exposure and communicate the relative risk of fish consumption. PMID:23388852

  17. Fish Consumption, Low-Level Mercury, Lipids, and Inflammatory Markers in Children

    PubMed Central

    Gump, Brooks B.; MacKenzie, James A.; Dumas, Amy K.; Palmer, Christopher D.; Parsons, Patrick J.; Segu, Zaneer M.; Mechref, Yehia S.; Bendinskas, Kestutis

    2011-01-01

    There is considerable evidence that consuming fish has numerous health benefits, including a reduced risk of cardiovascular disease. However, fish is also the primary source of human exposure to mercury (Hg). In a cross-sectional study of 9–11 year old children (N = 100), we measured fish consumption, blood lipids, total blood Hg, diurnal salivary cortisol (4 samples collected throughout the day), and performed a proteomic analysis of serum proteins using spectral count shotgun proteomics. Children that consumed fish had a significantly more atheroprotective lipid profile but higher levels of blood Hg relative to children that did not consume fish. Although the levels of blood Hg were very low in these children (M = 0.77 ?g/L; all but 1 participant had levels below 3.27 ?g/L), increasing blood Hg was significantly associated with blunted diurnal cortisol levels. Blood Hg was also significantly associated with acute-phase proteins suggesting systemic inflammation, and several of these proteins were found to significantly reduce the association between Hg and diminished cortisol when included in the model. This study of a pediatric population is the first to document an association between blood Hg, systemic inflammation, and endocrine disruption in humans, in a pediatric sample. Without a better understanding of the long-term consequences of an atheroprotective lipid profile relative to blunted diurnal cortisol and systemic inflammation, a determination of the risk-benefit ratio for fish consumption by children is not possible. PMID:22030286

  18. Relating land cover characteristics and common loon mercury levels using geographic information systems.

    PubMed

    Kramar, David; Goodale, Wing M; Kennedy, L M; Carstensen, L W; Kaur, Taranjit

    2005-03-01

    This effort models the relationship between mercury (Hg) levels in the common loon (Gavia immer) and land cover types as defined by the National Land Cover Database (NLCD). We constructed the model within the framework of a GIS to analyze the spatial relationships between land cover types and blood Hg levels in male common loons. Thiessan polygons were used to generate the territory for each loon. We created 150, 300, and 600-m buffers around the Thiessan polygons and modeled the relationships that existed in each distance class. Within the 150-m buffer, three cover types, crop land, shrub land, and wetland were significantly related to blood Hg levels (r2 = 0.552, p < 0.001), which may indicate that the proximity of these cover types influences Hg availability in loon territories. Cropland exhibited a negative relationship with blood Hg levels and may play a role in reducing the amount of available Hg within the study area while wetlands and shrub lands exhibit a positive relationship. The study area consisted of five major lakes and eleven smaller ponds in northwest Maine, and data included a total of 61 male common loon blood Hg samples. PMID:15931970

  19. Low-level mercury in children: associations with sleep duration and cytokines TNF-? and IL-6.

    PubMed

    Gump, Brooks B; Gabrikova, Elena; Bendinskas, Kestutis; Dumas, Amy K; Palmer, Christopher D; Parsons, Patrick J; MacKenzie, James A

    2014-10-01

    There is a sizeable literature suggesting that mercury (Hg) exposure affects cytokine levels in humans. In addition to their signaling role in the immune system, some cytokines are also integrally associated with sleep behavior. In this cross-sectional study of 9-11 year old children (N=100), we measured total blood Hg in whole blood, serum levels of tumor necrosis factor ? (TNF-?) and interleukin 6 (IL-6), and objectively measured sleep and activity using actigraphy. Increasing blood Hg was associated with significantly shorter sleep duration and lower levels of TNF-?. IL-6 was not associated with sleep or blood Hg. This study is the first to document an association between total blood Hg and sleep (albeit a small effect), and the first to consider the associations of total blood Hg with cytokines TNF-? and IL-6 in a pediatric sample. Further research using alternative designs (e.g., time-series) is necessary to determine if there is a causal pathway linking low-level Hg exposure to sleep restriction and reduced cytokines. PMID:25173056

  20. Mercury Levels in Mink ( Mustela vison ) and River Otter ( Lontra canadensis ) from Northeastern North America

    Microsoft Academic Search

    David E. Yates; David T. Mayack; Kenneth Munney; David C. Evers; Andrew Major; Taranjit Kaur; Robert J. Taylor

    2005-01-01

    Aquatic ecosystems have received mercury released from anthropogenic sources. The northeast region of North America is at especially high risk because of local and regional emission sources, prevailing wind patterns, and certain hydrological and biogeochemical features. Here we examine regional variation in total mercury (Hg) in brain, liver, and fur from otter and mink collected across New York, New England,

  1. Reduced Levels of Mercury in First Baby Haircuts of Autistic Children

    Microsoft Academic Search

    Amy S. Holmes; Mark F. Blaxill; Boyd E. Haley

    2003-01-01

    Reported rates of autism have increased sharply in the United States and the United Kingdom. One possible factor underlying these increases is increased exposure to mercury through thimerosal-containing vaccines, but vaccine exposures need to be evaluated in the context of cumulative exposures during gestation and early infancy. Differential rates of postnatal mercury elimination may explain why similar gestational and infant

  2. Naso-jugal groove leveling with fat tissue.

    PubMed

    Loeb, R

    1993-04-01

    One of the causes of a depressed naso-jugal groove is the fixation of the septum orbitale at the level of the inferior-medial portion of the arcus marginalis. To permit the leveling of the groove, it is necessary to liberate the subjacent orbital septum from its fixation to the arcus marginalis. To avoid recurrence of the depression, some fat tissue is properly placed in the undermined space subjacent to the groove. This can be done by free fat grafting or fat pad sliding. PMID:8485948

  3. Relationship between blood mercury levels and components of male song in Nelson's sparrows (Ammodramus nelsoni).

    PubMed

    McKay, Jennifer L; Maher, Christine R

    2012-11-01

    Mercury (Hg) adversely affects the health and behavior of exposed wildlife; however, behavioral effects remain largely unknown. Changes in avian singing behavior may affect a male's fitness because song reveals male quality and thus influences female mate choice and male territory-holding ability. Nelson's sparrows (Ammodramus nelsoni) live exclusively on salt marshes and risk high levels of Hg exposure and bioaccumulation. We recorded songs of male Nelson's sparrows at two locations with different Hg exposure to determine if total blood Hg concentration was related to song characteristics, as previously reported for other species. Males with higher blood Hg levels sang at higher maximum tonal frequency, but blood Hg and site location did not influence low tonal frequency and bout duration, contrary to predictions based on other species. Within the contaminated site, Hg levels were related to bouts per minute and gap duration, such that males at that site sang faster songs. Hg influences hormones and alters brain development, raising questions about specific effects on the brains and singing behavior of male Nelson's sparrows. PMID:22945769

  4. Superpredation increases mercury levels in a generalist top predator, the eagle owl.

    PubMed

    Lourenço, Rui; Tavares, Paula C; del Mar Delgado, Maria; Rabaça, João E; Penteriani, Vincenzo

    2011-06-01

    Superpredation can increase the length of the food chain and potentially lead to mercury (Hg) bioaccumulation in top predators. We analysed the relationship of Hg concentrations in eagle owls Bubo bubo to diet composition and the percentage of mesopredators in the diet. Hg levels were measured in the adult feathers of eagle owls from 33 owl territories in the south-western Iberian Peninsula, and in three trophic levels of their prey: primary consumers, secondary consumers and mesopredators. In addition, we studied 6,181 prey in the eagle owl diet. Hg concentrations increased along the food chain, but the concentrations in eagle owls showed considerable variation. The Hg concentration in eagle owls increased when the percentage of mesopredators in the diet increased and the percentage of primary consumers decreased. Superpredation is often related to food stress, and the associated increase in accumulation of Hg may cause additional negative effects on vertebrate top predators. Hg levels in these eagle owl populations are relatively low, but future monitoring is recommended. PMID:21298339

  5. Properties of mercury and selenium in a high-molecular weight substance in rabbit tissues formed by simultaneous administration.

    PubMed

    Naganuma, A; Imura, N

    1981-09-01

    The properties of mercury and selenium existing in high-molecular weight substance(s) (HMWS) obtained from plasma, stroma-free hemolysate, soluble and insoluble fractions of the liver of rabbits dosed with mercuric chloride and selenite were studied. Analytical procedures--gel filtration, ion exchange chromatography, and sucrose density gradient ultracentrifugation--showed that equimolar amounts of mercury and selenium were present in HMWS in the blood and the liver. Dialysis against mercaptoethanol suggested that selenium and mercury were tightly bound to HMWS in the liver soluble fraction. The formation of the HMWS may contribute to reducing the toxicity of both mercury and selenium. Since mercury and selenium in HMWS in the blood and the liver were present in smaller fragments after trypsin digestion, these HMWS appeared to be protein associated with mercury and selenium. However, after exhaustive digestion with Pronase, mercury and selenium in HMWS were rendered insoluble. The above process appears to take in the body of rabbits after simultaneous administration of mercury and selenium, because the livers excised from these rabbits were found to contain iso-molar and sodium dodecyl sulfate-insoluble selenium and mercury which increased in amount with time. PMID:7291248

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

    PubMed

    Pirard, Catherine; Koppen, Gudrun; De Cremer, Koen; Van Overmeire, Ilse; Govarts, Eva; Dewolf, Marie-Christine; Van De Mieroop, Els; Aerts, Dominique; Biot, Pierre; Casteleyn, Ludwine; Kolossa-Gehring, Marike; Schwedler, Gerda; Angerer, Jürgen; Koch, Holger M; Schindler, Birgit K; Castaño, Argelia; Esteban, Marta; Schoeters, Greet; Den Hond, Elly; Sepai, Ovnair; Exley, Karen; Horvat, Milena; Bloemen, Louis; Knudsen, Lisbeth E; Joas, Reinhard; Joas, Anke; Van Loco, Joris; Charlier, Corinne

    2014-02-15

    A harmonized human biomonitoring pilot study was set up within the frame of the European projects DEMOCOPHES and COPHES. In 17 European countries, biomarkers of some environmental pollutants, including urinary cadmium and hair mercury, were measured in children and their mothers in order to obtain European-wide comparison values on these chemicals. The Belgian participant population consisted in 129 school children (6-11 years) and their mothers (? 45 years) living in urban or rural areas of Belgium. The geometric mean levels for mercury in hair were 0.383 ?g/g and 0.204 ?g/g for respectively mothers and children. Cadmium in mother's and children's urine was detected at a geometric mean concentration of respectively 0.21 and 0.04 ?g/l. For both biomarkers, levels measured in the mothers and their child were correlated. While the urinary cadmium levels increased with age, no trend was found for hair mercury content, except the fact that mothers hold higher levels than children. The hair mercury content increased significantly with the number of dental amalgam fillings, explaining partially the higher levels in the mothers by their higher presence rate of these amalgams compared to children. Fish or seafood consumption was the other main parameter determining the mercury levels in hair. No relationship was found between smoking status and cadmium or mercury levels, but the studied population included very few smokers. Urinary cadmium levels were higher in both mothers and children living in urban areas, while for mercury this difference was only significant for children. Our small population showed urinary cadmium and hair mercury levels lower than the health based guidelines suggested by the WHO or the JECFA (Joint FAO/WHO Expert Committee on Food Additives). Only 1% had cadmium level slightly higher than the German HBM-I value (1 ?g/l for adults), and 9% exceeded the 1 ?g mercury/g hair suggested by the US EPA. PMID:24333995

  7. Organochlorine pesticide levels in female adipose tissue from Puebla, Mexico.

    PubMed

    Waliszewski, Stefan M; Sanchez, K; Caba, M; Saldariaga-Noreña, H; Meza, E; Zepeda, R; Valencia Quintana, R; Infanzon, R

    2012-02-01

    The objective of this study was to determine the levels of organochlorine pesticides HCB, ?-?-?-HCH, pp'DDE, op'DDT and pp'DDT in adipose tissue of females living in Puebla, Mexico. Organochlorine pesticides were analyzed in 75 abdominal adipose tissue samples taken during 2010 by autopsy at the Forensic Services of Puebla. The results were expressed as mg/kg on fat basis. In analyzed samples the following pesticides were detected: p,p'-DDE in 100% of samples at mean 1.464 mg/kg; p,p'-DDT in 96.0.% of samples at mean 0.105 mg/kg; op'DDT in 89.3% of monitored samples at mean 0.025 mg/kg and ?-HCH in 94.7% of the samples at mean 0.108 mg/kg. To show if organochlorine pesticide levels in monitored female's adipose tissues are age dependant, the group was divided in three ages ranges (13-26, 26-57 and 57-96 years). The mean and median levels of all organochlorine pesticides increase significantly (p < 0.05) from the first to second and from the first to third group. At the same time, the increase of mean and medians levels from the second to third group were not statistically significant (p > 0.05). The present results compared to previous ones from 2008 indicates an increase in the concentrations during the 2010 study, but only the differences for pp'DDE and op'DDT were statistically significant. The 2010 group of females was older compared to the 2008 group. The presence of organochlorine pesticide residues is still observed, indicating uniform and permanent exposure to the pesticides by Puebla inhabitants. PMID:22042501

  8. Heavy metal concentrations in feathers of common loons (Gavia immer) in the Northeastern United States and age differences in mercury levels.

    PubMed

    Burger, J; Pokras, M; Chafel, R; Gochfeld, M

    1994-03-01

    Feathers serve as a useful, non-destructive approach for biomonitoring some aspects of environmental quality. Birds can eliminate over 90% of their body burden of mercury by sequestration in growing feathers, and they molt their feathers at least annually. Thus mercury concentrations should not vary in avian feathers as a function of age. We tested the null hypothesis that there are no age differences in the concentrations of mercury, lead, cadmium, selenium, copper, chromium and manganese in the feathers of immature and adult common loons Gavia immer from the Northeastern United States where the species is declining. Adults had significantly higher mean levels of mercury (20245 ppb) than immature loons (9677 ppb), but there were no age-related differences for other elements. Even with the small number of immatures, females had significantly higher levels of mercury than males, although the gender difference was not significant for adults. PMID:24213705

  9. Landscape-level patterns of mercury contamination of fish in North Texas, USA.

    PubMed

    Drenner, Ray W; Chumchal, Matthew M; Wente, Stephen P; McGuire, Mandy; Drenner, S Matthew

    2011-09-01

    Mercury (Hg) is a toxic metal that is found in aquatic food webs and is hazardous to humans. An emerging conceptual model predicts that the areas of the landscape that have the potential to contain food webs with elevated concentrations of Hg are those that receive high amounts of Hg and sulfate deposition and have high coverage of forests and wetlands and low coverage of agriculture. The objective of the present study was to test this conceptual model using concentrations of Hg in largemouth bass (Micropterus salmoides) from 145 reservoirs in four ecoregions of North Texas. The highest level of Hg contamination in fish was in the South Central Plains, the ecoregion that receives the highest levels of Hg and sulfate deposition and contains extensive forest and wetland habitat and little agriculture. The present study has important implications for other areas of the United States, because the South Central Plains extend into parts of Oklahoma, Louisiana, and Arkansas, covering a total area of 152,132 km(2) of the southern United States. PMID:21647946

  10. The processing of simulated high-level radioactive waste sludges containing nitrites and mercury

    SciTech Connect

    Zamecnik, J.R.; Hutson, N.D.; Ritter, J.A.; Carter, J.T.

    1991-01-01

    The reaction of formic acid with simulated alkaline sludge containing mercury and nitrite was studied in an engineering-scale facility. Quantification of offgas production was performed, with the major offgases being CO{sub 2} and NO{sub x}. A small amount of CO was also found. The NO{sub x} was scrubbed in the offgas condenser and formed very acidic solutions of nitrous and nitric acids. These acids dissolved mercury that was stripped from the sludge. However, the overall efficiency of mercury stripping was greater than expected, and the final mercury concentration in the sludge was lower than expected. The NO{sub x} in the offgas also caused large temperature rises in the offgas system due to the exothermic reaction of NO with O{sub 2}. This temperature rise had a detrimental effect on the performance of the Formic Acid Vent Condenser, such that redesign is being contemplated. 6 refs., 6 figs., 3 tabs.

  11. Mercury levels in walleyes from Wisconsin lakes of different water and sediment chemistry characteristics

    SciTech Connect

    Lathrop, R.C.; Noonan, K.C.; Guenther, P.M.; Brasino, T.L.; Rasmussen, P.W.

    1989-01-01

    Forty-three lakes throughout Wisconsin were sampled in 1985-86 to determine the water and sediment chemistry characteristics that were associated with elevated concentrations of mercury in walleyes. Mean mercury concentrations for each of three different length classes of walleyes increased as the parameters lake pH, alkalinity, calcium, conductivity, or chlorophyll-a decreased. Low values for these parameters characterized most lakes in northern Wisconsin. Mean mercury concentrations exceeded the Wisconsin health standard of 0.5 micrograms (ug) Hg/g wet weight of fish for all walleye length classes in lakes with pH values < 6.0, for walleyes > or = to 15.0 inches in lakes with pH 6.0-6.9, and for walleyes > or = 20.0 in. in all lake pH categories. Apparently the older, larger walleyes in hard water as well as soft water lakes can accumulate enough mercury to warrant concern. Sediment mercury concentrations were generally < or = 0.02 ug/g dry weight for all study lakes, but sediment mercury and organic matter were higher in lakes with pH values < 7.0 than in lakes with pH > or = 7.0. Models were developed and tested to predict mercury concentrations in a 17-in. walleye for each lake. The best model derived from the study and tested on an independent dataset used alkalinity and calcium as independent variables. Clearly, walleyes from soft water, poorly buffered, low pH lakes have the highest concentrations of mercury, but the reasons for these higher concentrations require further study. 67 refs., 5 figs., 27 tabs.

  12. Mercury in herons, egrets, and their foods

    Microsoft Academic Search

    R. D. Hoffman; R. D. Curnow

    1979-01-01

    Mercury concentration levels were measured in herons and egrets and their foods collected in the southwestern Lake Erie region. Primary wing feathers, breast muscle, liver, and brain tissues were analyzed from 432 great blue herons (Ardea herodias), 44 black-crowned night herons (Nycticorax nycticorax), and 43 great egrets (Casmerodius albus). Concentrations were higher in island nesting birds than birds collected at

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

    SciTech Connect

    Davis, A.H.

    1981-01-01

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

  14. Removal of mercury from soil with earthworms

    SciTech Connect

    Dorfman, D. [Monmouth Coll., West Long Branch, NJ (United States)

    1994-12-31

    Earthworms can live in soils containing high quantities of mercury, lead, and zinc. The worms (Lumbricus terrestris) concentrate these heavy metals in their tissues. The use of these worms to reduce the quantities of mercury and other heavy metals in soils may be practical. In July, 1993, a preliminary study was made using earthworms and soils with differing amounts of mercury, The quantities were 0.0 grams, 0.5 grams, and 1.0 grams of mercury as mercuric chloride. Earthworms were placed into these soils for two or more weeks, then harvested. The worms were rinsed with deionized water, then dissolved in nitric acid. Each sample was prepared for analysis with the addition of HNO{sub 3}, H{sub 2}SO{sub 4}, potassium permanganate, and hydrozylamine hydrochloride. A Jerome Instrument gold foil analyzer was used to determine levels of mercury after volatilizing the sample with stannous chloride. Worms exposed to contaminated soils remove 50 to 1,400 times as much mercury as do worms in control soils. In a hypothetical case, a site contaminated with one pound of mercury, 1,000 to 45,000 worms would be required to reduce mercury levels to background levels in the soil (about 250 ppb). After harvesting worms in contaminated soil they could be dried (90% of their weight is water), and the mercury regained by chemical processes. Soil conducive to earthworm survival is required. This includes a well aerated loamy soil, proper pH (7.0), and periodic watering and feeding. There are several methods of harvesting worms, including flooding and electricity. Large numbers of worms can be obtained from commercial growers.

  15. Levels of cadmium, mercury, and lead in Magellanic penguins (Spheniscus magellanicus) stranded on the Brazilian coast.

    PubMed

    Vega, Claudia M; Siciliano, Salvatore; Barrocas, Paulo R G; Hacon, Sandra S; Campos, Reinaldo C; do Couto Jacob, Silvana; Ott, Paulo Henrique

    2010-02-01

    Cadmium (Cd), mercury (Hg), and lead (Pb) were determined in samples of liver and breast muscles of first-year Magellanic penguins (Spheniscus magellanicus), from two different areas on the Brazilian coast, 35 on the Rio de Janeiro coast and 12 on the Rio Grande do Sul coast. In both areas, Cd concentrations in muscle samples were <0.025 microg/g. However, the Cd and Hg concentrations found in liver and Hg concentrations found in muscle showed a significant difference between the two regions. The geometric mean of the concentrations was higher in the specimens from Rio de Janeiro (Cd--6.8 microg/g; Hg--liver, 1.6 microg/g, and muscle, 0.4 microg/g wet weight) than in those from Rio Grande do Sul (Cd--2.3 microg/g; Hg--liver, 0.9 microg/g, and muscle, 0.1 microg/g wet weight). The site differences could be related to differences in diet influenced by geographic factors. Brazil's southeastern coast is highly urbanized, and its coastal waters are contaminated by the waste of agricultural and industrial activities. There is a lack of information on the levels of heavy metals in S. magellanicus, however, their wide distribution and top position in the trophic chain make the use of stranded specimens an attractive source of information for monitoring heavy metals in the South Atlantic coast. PMID:19582498

  16. IMPACT OF ELIMINATING MERCURY REMOVAL PRETREATMENT ON THE PERFORMANCE OF A HIGH LEVEL RADIOACTIVE WASTE MELTER OFFGAS SYSTEM

    SciTech Connect

    Zamecnik, J; Alexander Choi, A

    2009-03-17

    The Defense Waste Processing Facility at the Savannah River Site processes high-level radioactive waste from the processing of nuclear materials that contains dissolved and precipitated metals and radionuclides. Vitrification of this waste into borosilicate glass for ultimate disposal at a geologic repository involves chemically modifying the waste to make it compatible with the glass melter system. Pretreatment steps include removal of excess aluminum by dissolution and washing, and processing with formic and nitric acids to: (1) adjust the reduction-oxidation (redox) potential in the glass melter to reduce radionuclide volatility and improve melt rate; (2) adjust feed rheology; and (3) reduce by steam stripping the amount of mercury that must be processed in the melter. Elimination of formic acid pretreatment has been proposed to eliminate the production of hydrogen in the pretreatment systems; alternative reductants would be used to control redox. However, elimination of formic acid would result in significantly more mercury in the melter feed; the current specification is no more than 0.45 wt%, while the maximum expected prior to pretreatment is about 2.5 wt%. An engineering study has been undertaken to estimate the effects of eliminating mercury removal on the melter offgas system performance. A homogeneous gas-phase oxidation model and an aqueous phase model were developed to study the speciation of mercury in the DWPF melter offgas system. The model was calibrated against available experimental data and then applied to DWPF conditions. The gas-phase model predicted the Hg{sub 2}{sup 2-}/Hg{sup 2+} ratio accurately, but some un-oxidized Hg{sup 0} remained. The aqueous model, with the addition of less than 1 mM Cl{sub 2} showed that this remaining Hg{sup 0} would be oxidized such that the final Hg{sub 2}{sup 2+}/Hg{sup 2+} ratios matched the experimental data. The results of applying the model to DWPF show that due to excessive shortage of chloride, only 6% of the mercury fed is expected to be chlorinated, mostly as Hg{sub 2}Cl{sub 2}, while the remaining mercury would exist either as elemental mercury (90%) or HgO (4%).

  17. Attempted suicide by intravenous injection of mercury: a rare cause of cardiac granulomas. A case report.

    PubMed

    Kedziora, A; Duflou, J

    1995-06-01

    We present the autopsy findings of a case of attempted suicide by self-administration of elemental mercury, resulting in mercury embolization to the heart and lungs. The person lived for 5 months afterward and subsequently died as a result of narcotic toxicity combined with loss of blood from an incised radial artery. A collection of metallic mercury droplets imbedded in a fibrous tissue granuloma was found in the apex of the right ventricular chamber, and metallic densities were seen on radiography of heart and lungs. The levels of mercury in various organs are shown, and the toxicology of elemental mercury is briefly discussed. The literature describing similar cases of metallic mercury emboli is reviewed. Owing to the apparent rarity of the phenomenon, many questions regarding the risk of death following intravenous injection of metallic mercury still remain unanswered. PMID:7572878

  18. Mercury levels in surface waters of the Carson River-Lahontan reservoir system, Nevada: Influence of historic mining activities

    Microsoft Academic Search

    J. C. Bonzongo; K. J. Heim; J. J. Warwick; W. B. Lyons

    1996-01-01

    Total mercury (HgT), methylmercury (MeHg), and other operationally defined Hg species were determined on water samples collected from a river-reservoir system impacted by historic mine wastes. Simultaneously, a comprehensive study was undertaken to determine the influence of some major physico-chemical parameters on the fate of Hg within the system. Total Hg levels showed an increase from background concentrations of 4

  19. Regional differences in mercury levels in aquatic ecosystems: A discussion of possible causal factors with implications for the Tennessee river system and the Northern Hemisphere

    NASA Astrophysics Data System (ADS)

    Joslin, J. Devereux

    1994-07-01

    Concern about mercury pollution from atmospheric deposition has risen markedly in the last decade because of high levels of mercury in freshwater fish from relatively pristine waters. Whereas high concentrations have been found principally in Canada, the northern United States, and Scandinavia, they have also recently been observed throughout much of Florida. Recent surveys of the Tennessee River system, however, have found no locations where fish levels exceed EPA guidelines for fish consumption. This paper evaluates a number of factors that may cause certain regions in the northern hemisphere to experience unacceptable fish mercury levels while other regions do not. Relevant regional differences include: (1) Waters of the Tennessee River system are generally nonacidic (pH>6) and well buffered, whereas 16%, 22%, and 40% of the lakes in upper Midwest, Northeast, and Florida, respectively, have acid-neutralizing capacities below 50 µeq/liter. Acidity correlates highly with fish mercury levels in a number of lake surveys, and experimental manipulations of acidity have significantly raised fish mercury levels. (2) The ratio of land area to water surface area in the Tennessee Valley averages about 30, whereas it is 15 in the upper Midwest and 6 in Florida. Low ratios allow mercury in precipitation to be directly deposited to aquatic bodies, without an opportunity for the mercury to be sequestered by terrestrial ecosystems. (3) Stream organic matter concentrations in Florida, the upper Midwest, and Sweden are 2 10 times those in the Tennessee Valley. Mercury binds strongly to organic matter, and organic matter transport in runoff is a major pathway by which mercury enters aquatic ecosystems.

  20. Assessment of total and organic mercury levels in blue sharks (Prionace glauca) from the south and southeastern Brazilian coast.

    PubMed

    de Carvalho, Gabriel Gustinelli Arantes; Degaspari, Iracema Alves Manoel; Branco, Vasco; Canário, João; de Amorim, Alberto Ferreira; Kennedy, Valerie Helen; Ferreira, José Roberto

    2014-06-01

    Mercury occurrence was evaluated in samples of edible muscle tissue of 27 blue sharks (Prionace glauca) caught in the Atlantic Ocean, adjacent to the south and southeastern Brazilian coast, indicating a slight increase in comparison with previous data obtained for the same studied area and being higher than those fish caught at different sites of the Atlantic Ocean. Total Hg concentrations ranged from 0.46 to 2.40 mg kg(-1) with the organic Hg fraction ranging between 0.44 and 2.37 mg kg(-1). A negative correlation between total Hg concentration in muscle tissue and blue shark size was obtained, and 40% of samples analyzed had Hg concentrations higher than 1.0 mg kg(-1) Hg, the maximum concentration permitted in Brazilian predator fish. Data obtained showed that total Hg can be used as a reliable predictor of organic Hg in blue shark muscle because 95 to 98% of the total Hg measured was found to be organic mercury. The wide range of Hg concentrations obtained for our set of samples can be explained by the heterogeneity of sampled population and the large size of the studied area. Given the adverse toxicological effects of Hg on animals and humans, a regular monitoring program of Hg contamination in Brazilian marine ecosystem can be recommended. PMID:24801656

  1. Effects of reservoir drawdown and refill on mercury levels in fish and other biota

    SciTech Connect

    Jagoe, C.H.; Salice, C.; Yabnochko, G.; Grasman, B.T.; Youngblood, T. [Savannah River Ecology Lab., Aiken, SC (United States)

    1995-12-31

    Mercury bioavailability from contaminated sediments is controlled by methylation, related to bacterial activity and degradable organic material. These variables may be affected by large changes in water level and chemistry in a reservoir. At Par Pond, a 1,200 ha impoundment on the USDOE Savannah River Site, South Carolina, potential failure of an earthen dam prompted lowering the reservoir by 3 meters over a two month period in 1991, decreasing water volume about 70%. The reservoir was refilled over a two month period in 1995. Largemouth bass (Micropterus salmoides) were sampled at quarterly intervals before, during and after the drawdown. Length and weight were determined, and liver and muscle analyzed for total Hg. Hg was also measured in top level predators (alligators), forage fish, macrophytes and invertebrates. From Fall 1991 Winter 1994--5, Hg ranged from 0.05 to 2.0 ug/g wet mass in bass muscle, and was strongly related to fish size, based on about 400 fish. Condition factor rose soon after drawdown, then declined as forage populations collapsed. Using fish size as covariate, bass muscle Hg was greater in spring 1992 than all other sampling dates. However, after 3 years of drawdown, there was no overall trend in bass Hg. Forage species differed in Hg, with highest concentrations in brook silversides (0.13 {micro}g Hg/g wet mass in 2 g fish). Alligators contained up to 20 {micro}g Hg/g dry mass in liver. Refill caused inundation of terrestrial plants on exposed sediments, and microbial action associated with the decay of these may enhance Hg methylation. Experiments with caged fish are underway to measure uptake rates.

  2. CORRELATION OF DNA METHYLATION WITH MERCURY CONTAMINATION IN MARINE ORGANISMS: A CASE STUDY OF NOAA MUSSEL WATCH TISSUE SAMPLES

    E-print Network

    Brinkmeyer, Robin; Taylor, Robert; Germ, Kaylyn E.

    2011-08-04

    American oysters (Crassostrea virginica) obtained from the NOAA Mussel Watch program were screened for DNA methylation, a type of epigenetic response to stressors. Oysters were collected from sites in the Gulf of Mexico having high mercury...

  3. CORRELATION OF DNA METHYLATION WITH MERCURY CONTAMINATION IN MARINE ORGANISMS: A CASE STUDY OF NOAA MUSSEL WATCH TISSUE SAMPLES 

    E-print Network

    Brinkmeyer, Robin; Taylor, Robert; Germ, Kaylyn E.

    2011-08-04

    American oysters (Crassostrea virginica) obtained from the NOAA Mussel Watch program were screened for DNA methylation, a type of epigenetic response to stressors. Oysters were collected from sites in the Gulf of Mexico having high mercury...

  4. Analysis of mercury levels in historical bone material from syphilitic subjects--pilot studies (short report).

    PubMed

    Kepa, Ma?gorzata; Koz?owski, Tomasz; Szostek, Krzysztof; Drozd, Alicja; Walas, Stanis?aw; Mrowiec, Halina; Stepa?czak, Beata; G?ab, Henryk; Grupa, Ma?gorzata

    2012-07-01

    The aim of the present work is to study the remains of seven individuals with typical symptoms of tertiary syphilis in terms of mercury content in bones, thereby verifying whether they were subjected to treatment and, if they were, how long their organisms were exposed to toxic mercury fumes. Mercury was used, mainly in the Middle Ages and in the early modern period, as a preventive measure in case of individuals suffering from syphilis, a venereal disease, and also leprosy. Syphilitic patients treated this way should demonstrate increased concentration of mercury in their bones. The skeletons studied in the present work originate from various archaeological sites in southern and north-central Poland. The analyses concerned individuals with diagnosed syphilis as well as healthy individuals who constituted the control group. The analyses were performed by the LA-ICP-MS technique, with the use of laser Nd: YAG, Macro, 266 nm, New Wave, USA, coupled with Spectrometer Elan DRC-e Perkin Elmer, USA. The content analysis of the studied bone material revealed with high probability that the contact method of mercurial treatment was used only in the case of two women from north-central Poland, deceased at the turn of the 15th century at the earliest. PMID:22928357

  5. Disparities in Children’s Blood Lead and Mercury Levels According to Community and Individual Socioeconomic Positions

    PubMed Central

    Lim, Sinye; Ha, Mina; Hwang, Seung-Sik; Son, Mia; Kwon, Ho-Jang

    2015-01-01

    We aimed to examine the associations between blood lead and mercury levels and individual and community level socioeconomic positions (SEPs) in school-aged children. A longitudinal cohort study was performed in 33 elementary schools in 10 cities in Korea. Among a total of 6094 children included at baseline, the final study population, 2281 children followed-up biennially, were analyzed. The geometric mean (GM) levels of blood lead were 1.73 ?g/dL (range 0.02–9.26) and 1.56 ?g/dL (range 0.02–6.83) for male and female children, respectively. The blood lead levels were significantly higher in males, children living in rural areas, and those with lower individual SEP. The GM levels of blood mercury were 2.07 ?g/L (range 0.09–12.67) and 2.06 ?g/L (range 0.03–11.74) for males and females, respectively. Increased blood mercury levels were significantly associated with urban areas, higher individual SEP, and more deprived communities. The risk of high blood lead level was significantly higher for the lower individual SEP (odds ratio (OR) 2.18, 95% confidence interval (CI) 1.36–3.50 in the lowest educational attainment of the father), with a significant dose-response relationship observed after adjusting for the community SEP. The association between high blood lead levels and lower individual SEP was much stronger in the more deprived communities (OR 2.88, 95% CI 1.27–6.53) than in the less deprived communities (OR 1.40, 95% CI 0.76–2.59), and showed a significant decreasing trend during the follow-up only in the less deprived communities. The risk of high blood mercury levels was higher in higher individual SEP (OR 0.64, 95% CI 0.40–1.03 in the lowest educational attainment of the father), with a significant dose-response relationship noted. Significant decreasing trends were observed during the follow-up both in the less and more deprived communities. From a public health point-of-view, community level intervention with different approaches for different metals is warranted to protect children from environmental exposure. PMID:26035667

  6. Correlates between Feeding Ecology and Mercury Levels in Historical and Modern Arctic Foxes (Vulpes lagopus)

    PubMed Central

    Krone, Oliver; Stefanski, Volker; Wibbelt, Gudrun; Unnsteinsdóttir, Ester Rut; Hersteinsson, Páll; Schares, Gereon; Doronina, Lilia; Goltsman, Mikhail; Greenwood, Alex D.

    2013-01-01

    Changes in concentration of pollutants and pathogen distribution can vary among ecotypes (e.g. marine versus terrestrial food resources). This may have important implications for the animals that reside within them. We examined 1) canid pathogen presence in an endangered arctic fox (Vulpes lagopus) population and 2) relative total mercury (THg) level as a function of ecotype (‘coastal’ or ‘inland’) for arctic foxes to test whether the presence of pathogens or heavy metal concentration correlate with population health. The Bering Sea populations on Bering and Mednyi Islands were compared to Icelandic arctic fox populations with respect to inland and coastal ecotypes. Serological and DNA based pathogen screening techniques were used to examine arctic foxes for pathogens. THg was measured by atomic absorption spectrometry from hair samples of historical and modern collected arctic foxes and samples from their prey species (hair and internal organs). Presence of pathogens did not correlate with population decline from Mednyi Island. However, THg concentration correlated strongly with ecotype and was reflected in the THg concentrations detected in available food sources in each ecotype. The highest concentration of THg was found in ecotypes where foxes depended on marine vertebrates for food. Exclusively inland ecotypes had low THg concentrations. The results suggest that absolute exposure to heavy metals may be less important than the feeding ecology and feeding opportunities of top predators such as arctic foxes which may in turn influence population health and stability. A higher risk to wildlife of heavy metal exposure correlates with feeding strategies that rely primarily on a marine based diet. PMID:23671561

  7. Mercury recovering and recycling

    SciTech Connect

    Weyand, T.E.; Rose, M.V.

    1995-11-01

    Efficient, economical treatment of mercury-contaminated soils and industrial wastes requires a treatment process that reduces mercury content to near background levels and recovers the removed mercury in pure recyclable form without producing liquid, solid, or gaseous secondary wastes. Mercury Recovery Services, Inc. has successfully developed and placed commercial operation a medium-temperature thermal desorption process that has into co successfully achieved these goals. The efficacy of the MRS Process to treat mercury-contaminated soils and industrial wastes was first Demonstrated on a pilot scale by means of treating (a) simulated soils containing varying amounts of metallic mercury, mercury oxide, mercury sulfide and mercury chloride, (b) actual natural gas metering site pipeline clay, sandy, and loam soils having total mercury contents in the range of 250 ppm to 15,000 ppm, and (c) waste water treatment sludges from chloralkali production containing up to 20,000 ppm mercury and large significant concentrations of sulfur and chlorine. In every case, the residual total mercury content was reduced to less than 2 ppm after treatment. The performance of MRS` first mobile commercial thermal desorption unit compares very favorably with the previously reported pilot-scale results.

  8. Proton imaging of siloxanes to map tissue oxygenation levels (PISTOL): a tool for quantitative tissue oximetry†

    PubMed Central

    Kodibagkar, Vikram D.; Wang, Xianghui; Pacheco-Torres, Jesús; Gulaka, Praveen; Mason, Ralph P.

    2011-01-01

    Hexamethyldisiloxane (HMDSO) has been identified as a sensitive proton NMR indicator of tissue oxygenation (pO2) based on spectroscopic spin-lattice relaxometry. A rapid MRI approach has now been designed, implemented, and tested. The technique, proton imaging of siloxanes to map tissue oxygenation levels (PISTOL), utilizes frequency-selective excitation of the HMDSO resonance and chemical-shift selective suppression of residual water signal to effectively eliminate water and fat signals and pulse-burst saturation recovery 1H echo planar imaging to map T1 of HMDSO and hence pO2. PISTOL was used here to obtain maps of pO2 in rat thigh muscle and Dunning prostate R3327 MAT-Lu tumor-implanted rats. Measurements were repeated to assess baseline stability and response to breathing of hyperoxic gas. Each pO2 map was obtained in 3½ min, facilitating dynamic measurements of response to oxygen intervention. Altering the inhaled gas to oxygen produced a significant increase in mean pO2 from 55 Torr to 238 Torr in thigh muscle and a smaller, but significant, increase in mean pO2 from 17 Torr to 78 Torr in MAT-Lu tumors. Thus, PISTOL enabled mapping of tissue pO2 at multiple locations and dynamic changes in pO2 in response to intervention. This new method offers a potentially valuable new tool to image pO2 in vivo for any healthy or diseased state by 1H MRI. PMID:18574806

  9. Distribution and residue level of mercury, cadmium and lead in Korean birds

    SciTech Connect

    Lee, Doo Pyo; Honda, Katsuhisa; Tatsukawa, Ryo (Ehime Univ., Matsuyama (Japan)); Won, Pyongoh (Kyung Hee Univ., Seoul (Korea))

    1989-10-01

    In Korea, some bird species have experienced a reduction in numbers since 1960's. This may be due to the destruction of habitats by industrialization, direct or indirect disturbance by people, and increase in the use of toxic contaminants such as organochlorine compounds and heavy metals. In particular, construction of heavy metals. In particular, construction of heavy industrial complexes during the last decade accelerated changes in the environmental quality, which might have influenced the wildlife populations in various ways. However, data on residue levels of contaminants such as organochlorine compounds and toxic metals in Korean birds are very scarce. The present investigation, which examines the tissue distribution of toxic metals (Hg, Cd and Pb) in 16 bird species in Korea, and the residue levels in relation to the feeding habits and habitats, was done in an attempt to learn the general levels of metal pollution in Korean birds.

  10. Chlorinated hydrocarbon and mercury levels in bald eagles (Haliaeetus leucocephalus) found dead in British Columbia, 1988--1993

    SciTech Connect

    Elliott, J.E.; Wilson, L.K. [Canadian Wildlife Service, Delta, British Columbia (Canada); Norstrom, R.J. [Canadian Wildlife Service, Ottawa, Ontario (Canada); Langelier, K.M. [Island Veterinary Hospital, Nanaimo, British Columbia (Canada)

    1994-12-31

    Liver samples from 70 bald eagles found dead or dying in British Columbia between 1988 and 1993 were analyzed for organochlorine and mercury levels. A subset of 11 eagles found around the Strait of Georgia, an area of known pulp mill pollution, in summer (and therefore presumably resident birds) were analyzed for polychlorinated dibenzo-p-dioxins (PCDDS) and polychlorinated dibenzofurans (PCDFs). Levels of DDE and PCBs ranged from less than 1 mg/kg to 190 and 65 mg/kg respectively. Levels of other organochlorines were generally less than 1 mg/kg, with the exception of some chlordane-related compounds which were occasionally over 2 mg/kg. All birds analyzed for PCDDs/PCDFs contained detectable levels of the major 2,378-substituted isomers. Some birds had extremely high levels, one eagle collected near a kraft pulp mill site contained: 400 ng/kg 2378-TCDD, 1400 ng/kg 12378-PnCDD and 4400 ng/kg 123678-HxCDD. All but two eagles had > 1 mg/kg dry wt. of mercury in liver; most contained less than 1 0 mg/kg d.w. but one bird had 130 mg/kg, a level of toxicological concern. All carcasses were autopsied and cause of death determined wherever possible. The relationship between cause of death and sublethal exposure to OCs and Hg is analyzed and discussed.

  11. Studies on activity recovery in some mercury-exposed freshwater fish by using selected weeds

    SciTech Connect

    Shrivastave, S.; Rao, K.S. (Vikram Univ., Ujjain (India))

    1989-06-01

    In spite of worldwide concern about mercury contamination in aquatic environment, relatively little effort has been expended on determining the mechanisms involved in bioaccumulation. It has been found that several species of aquatic plants grow in flowing water of polluted rivers and contain higher mercury levels than the associated water phase. The aquatic weed plants absorb and incorporate the dissolved materials (both inorganic and organic compound) into their own body tissues to rapidly and effectively that they are now considered for use in sewage treatment. The present study evaluated the relative efficiencies of five selected weeds, in mercury toxicity removal suggesting possible methods of mercury removal from contaminated aquatic environments.

  12. A Meta-analysis of Mercury Levels in Lavaca Bay Texas

    E-print Network

    Pillado, Maria C.

    2014-05-07

    Lavaca Bay is a secondary bay to Matagorda Bay on the central Texas Coast. In 1970 Texas Department of Health (TDH) closed parts of Lavaca Bay to the harvesting of oysters due to mercury contamination as a result of contaminated wastewater...

  13. Monitoring of mercury, lead and cadmium levels in seafoods during the years 1993–1995

    Microsoft Academic Search

    Pasquale Gallo; Luigi Serpe

    1998-01-01

    The results of mercury, lead and cadmium analyses in seafoods from Campania and Calabria during the years 1993–1995 are herein reported. We analysed 1795 food samples and carried out 3532 determinations about metal concentrations. The data were evaluated to calculate the frequency of illegal samples in respect to the limits permitted by Italian legislation; moreover, we reported the distribution of

  14. A Meta-analysis of Mercury Levels in Lavaca Bay Texas 

    E-print Network

    Pillado, Maria C.

    2014-05-07

    Lavaca Bay is a secondary bay to Matagorda Bay on the central Texas Coast. In 1970 Texas Department of Health (TDH) closed parts of Lavaca Bay to the harvesting of oysters due to mercury contamination as a result of contaminated wastewater...

  15. Neurodevelopmental Effects of Low-level Prenatal Mercury Exposure From Maternal Fish Consumption in a Mediterranean Cohort: Study Rationale and Design

    PubMed Central

    Valent, Francesca; Horvat, Milena; Sofianou-Katsoulis, Aikaterini; Spiric, Zdravko; Mazej, Darja; Little, D’Anna; Prasouli, Alexia; Mariuz, Marika; Tamburlini, Giorgio; Nakou, Sheena; Barbone, Fabio

    2013-01-01

    Background Mercury is a neurotoxic environmental pollutant. However, the literature on the neurodevelopmental effect of low-level prenatal mercury exposure from maternal fish intake is inconsistent. We assessed the association between prenatal mercury exposure and infant neurodevelopment in coastal areas of 4 Mediterranean countries. Methods This was a prospective cohort study that planned to enroll approximately 1700 mother–infant pairs. Pregnant women and their newborn children were recruited in selected hospitals of the study areas. Biological samples, including maternal hair and cord blood, were collected from mothers and children, and the concentrations of mercury and other elements were measured. Exposures to lifestyle, environmental, and social factors were assessed through questionnaires. The main outcome was child neurodevelopment at 18 months, as measured by the Bayley Scales of Infant and Toddler Development, Third Edition. Conclusions This cohort has a number of strengths. First, mercury concentration was measured in several biological samples, which allows for a better understanding of mercury kinetics and is useful for sensitivity analyses. Therefore, we expect to be able to adjust for the potential confounding effects of lifestyle and social factors and for the effects of other elements that were measured in the biological samples. Finally, this is a multinational study and thus permits assessment of the relation between mercury and child neurodevelopment in different populations. PMID:23269124

  16. Fish mercury levels appear to be increasing lately: a report from 40 years of monitoring in the province of Ontario, Canada.

    PubMed

    Gandhi, Nilima; Tang, Rex W K; Bhavsar, Satyendra P; Arhonditsis, George B

    2014-05-20

    Recent mercury levels and trends reported for North America suggest a mixed (positive/negative) outlook for the environmental mercury problem. Using one of the largest consistent monitoring data sets in the world, here we present long-term and recent mercury trends in Walleye, Northern Pike, and Lake Trout from the Province of Ontario, Canada, which contains about one-third of the world's fresh water and covers a wide geographical area (1.5 and 3 times larger than France and Germany, respectively). Overall, the results indicate that the fish mercury levels either declined (0.01-0.07 ?g/g decade) or remained stable between the 1970s and 2012. The rates of mercury decline were substantially greater (mostly 0.05-0.31 ?g/g decade) during the 1970s/80s possibly in response to reductions in mercury emissions. However, Walleye and Pike levels have generally increased (0.01-0.27 ?g/g decade) in recent years (1995-2012), especially for northern Ontario (effect sizes for differences between the two periods ranged from 0.39 to 1.04). Proportions of Walleye and Pike locations showing a flat or increasing trend increased from 26-44% to 59-73% between the 1970s/80s and 1995-2012. Mercury emissions in North America have declined over the last few decades, and as such it is logical to expect recovery in fish mercury levels; however, other factors such as global emissions, climate change, invasive species, and local geochemistry are likely affecting the response time and magnitude. PMID:24678891

  17. Mercury, cadmium, lead and arsenic levels in three pelagic fish species from the Atlantic Ocean: Intra- and inter-specific variability and human health risks for consumption

    Microsoft Academic Search

    C. Vieira; S. Morais; S. Ramos; C. Delerue-Matos; M. B. P. P. Oliveira

    2011-01-01

    Three commonly consumed and commercially valuable fish species (sardine, chub and horse mackerel) were collected from the Northeast and Eastern Central Atlantic Ocean in Portuguese waters during one year. Mercury, cadmium, lead and arsenic amounts were determined in muscles using graphite furnace and cold vapour atomic absorption spectrometry. Maximum mean levels of mercury (0.1715±0.0857mg\\/kg, ww) and arsenic (1.139±0.350mg\\/kg, ww) were

  18. Alteration of thyroid hormone levels and related gene expression in Chinese rare minnow larvae exposed to mercury chloride.

    PubMed

    Li, Zhi-Hua; Chen, Lu; Wu, Yan-Hua; Li, Ping; Li, Yun-Feng; Ni, Zhao-Hui

    2014-07-01

    Mercury is a prominent environmental contaminant that causes endocrine disorder to human and other organisms. But little is known about the response of the thyroid functions and hypothalamic-pituitary-thyroid (HPT) axis to mercury in teleosts and the few studies that are available have not yielded consistent results. In this study, expression profiles of corticotropin-releasing hormone (crh), thyroid stimulating hormone beta (tsh?), solute carrier family 5 (sodium iodide symporter) member 5 (slc5a5), thyroglobulin (tg), thyroid hormone receptor alpha (tr?) and thyroid hormone receptor beta (tr?) genes were determined in whole-body of Chinese rare minnow (Gobiocypris rarus) larvae after exposure to different levels of Hg(2+) (0, 0.1 and 0.3 mg/l) for 4 days, as well as the thyroid hormones (THs) levels. Moreover, the 96-h lethal concentration of Hg(2+) on rare minnow larvae was determined as 0.32 mg/l. The results showed that crh, tg, tr? and tr? mRNA levels were significantly up-regulated in the larvae, but the gene expression of tsh? and slc5a5 was not significantly changed in our study. Besides, the THs levels increased in the whole-body of fish, especially the thyroxine (T4) level. The above results indicated that Hg(2+) could alter some genes expression in the HPT axis which could be used as the potential biomarkers for evaluating the environmental Hg(2+)-induced stress in fish. PMID:25064382

  19. Mercury and Mink. II. Experimental methyl mercury intoxication.

    PubMed Central

    Wobeser, G; Nielsen, N O; Schiefer, B

    1976-01-01

    Adult female mink were fed rations containing 1.1, 1.8, 4.8, 8.3 and 15.0 ppm mercury as methyl mercury chloride over a 93 day period. Histopathological evidence of injury was present in all groups. Mink fed rations containing 1.8 to 15.0 ppm mercury developed clinical intoxication within the experimental period. The rapidity of onset of clinical intoxication was directly related to the mercury content of the ration. Mercury concentration in tissue of mink which died were similar, despite differences in mercury content of the diets and time of death. The average mercury concentration in the brain of mink which died was 11.9 ppm. The lesions of methyl mercury poisoning are described and criteria for diagnosis are discussed. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. PMID:1000376

  20. Insecticide levels in tissues associated with toxicity: a literature review.

    PubMed

    Mount, M E; Oehme, F W

    1981-02-01

    Extensive residue studies have been done with most of the organochlorine insecticides. The brain is a reliable tissue to determine lethal or exposure residues of the persistent organochlorine insecticides. Fewer studies have been done with organophosphate residues. residues of organophosphate insecticides are useful indicators of poisoning in tissues of exposed animals. Metabolite determination and identification is a necessary consideration since metabolic activation is required for several of the organophosphate insecticides. No studies of tissue residue evaluation of carbamate insecticides are available. PMID:7257167

  1. Quantification of tissue oxygenation levels using diffuse reflectance spectroscopy

    NASA Astrophysics Data System (ADS)

    B. S., Suresh Anand; N., Sujatha

    2011-08-01

    Tumor growth is characterized by increased metabolic activity. The light absorption profile of hemoglobin in dysplastic tissue is different from a normal tissue. Neovascularization is a hallmark of many diseases and can serve as a predictive biomarker for the detection of cancers. Spectroscopic techniques can provide information about the metabolic and morphological changes related to the progression of neoplasia. Diffuse reflectance spectroscopy (DRS) measures the absorption and scattering properties of a biological tissue and this method can provide clinically useful information for the early diagnosis of epithelial precancers. We used tissue simulating phantoms with absorbing and scattering molecules for the determination of total hemoglobin concentration, hemoglobin oxygen saturation and intensity difference between the deoxy and oxy hemoglobin bands. The results show promising approach for the differentiating normal and malignant states of a tissue.

  2. Quantification of tissue oxygenation levels using diffuse reflectance spectroscopy

    NASA Astrophysics Data System (ADS)

    B. S., Suresh Anand; N., Sujatha

    2010-12-01

    Tumor growth is characterized by increased metabolic activity. The light absorption profile of hemoglobin in dysplastic tissue is different from a normal tissue. Neovascularization is a hallmark of many diseases and can serve as a predictive biomarker for the detection of cancers. Spectroscopic techniques can provide information about the metabolic and morphological changes related to the progression of neoplasia. Diffuse reflectance spectroscopy (DRS) measures the absorption and scattering properties of a biological tissue and this method can provide clinically useful information for the early diagnosis of epithelial precancers. We used tissue simulating phantoms with absorbing and scattering molecules for the determination of total hemoglobin concentration, hemoglobin oxygen saturation and intensity difference between the deoxy and oxy hemoglobin bands. The results show promising approach for the differentiating normal and malignant states of a tissue.

  3. Levels of Cadmium, Mercury, and Lead in Magellanic Penguins ( Spheniscus magellanicus ) Stranded on the Brazilian Coast

    Microsoft Academic Search

    Claudia M. Vega; Salvatore Siciliano; Paulo R. G. Barrocas; Sandra S. Hacon; Reinaldo C. Campos; Silvana do Couto Jacob; Paulo Henrique Ott

    2010-01-01

    Cadmium (Cd), mercury (Hg), and lead (Pb) were determined in samples of liver and breast muscles of first-year Magellanic\\u000a penguins (Spheniscus magellanicus), from two different areas on the Brazilian coast, 35 on the Rio de Janeiro coast and 12 on the Rio Grande do Sul coast.\\u000a In both areas, Cd concentrations in muscle samples were <0.025 ?g\\/g. However, the Cd and

  4. Mercury levels of Nelson’s and saltmarsh sparrows at wintering grounds in Virginia, USA

    Microsoft Academic Search

    Daniel A. CristolFletcher; Fletcher M. Smith; Claire W. Varian-Ramos; Bryan D. Watts

    Nelson’s and saltmarsh sparrows (Ammodramus nelsoni and A. caudacutus) have recently been recognized as separate species, and because of their limited distributions and the susceptibility of\\u000a their wetland habitats to climate change, these two new species are of conservation concern. Both species are known to bioaccumulate\\u000a mercury at breeding sites in New England, USA where their ranges overlap, with the

  5. Mecury in Fin Clips and Scales as Assessment Methods for Predicting Muscle Tissue Mercury Concentrations in Red Drum and Snook

    EPA Science Inventory

    Non-lethal techniques for assessing total mercury concentrations in fish are desired because they minimize impacts on fish populations and allow trends in Hg accumulation to be assessed through repeated sampling of individual fish. This study developed relationships of Hg concent...

  6. A dynamic model using monitoring data and watershed characteristics to project fish tissue mercury concentrations in stream systems.

    PubMed

    Chan, Caroline; Heinbokel, John F; Myers, John A; Jacobs, Robert R

    2012-10-01

    A complex interplay of factors determines the degree of bioaccumulation of Hg in fish in any particular basin. Although certain watershed characteristics have been associated with higher or lower bioaccumulation rates, the relationships between these characteristics are poorly understood. To add to this understanding, a dynamic model was built to examine these relationships in stream systems. The model follows Hg from the water column, through microbial conversion and subsequent concentration, through the food web to piscivorous fish. The model was calibrated to 7 basins in Kentucky and further evaluated by comparing output to 7 sites in, or proximal to, the Ohio River Valley, an underrepresented region in the bioaccumulation literature. Water quality and basin characteristics were inputs into the model, with tissue concentrations of Hg of generic trophic level 3, 3.5, and 4 fish the output. Regulatory and monitoring data were used to calibrate and evaluate the model. Mean average prediction error for Kentucky sites was 26%, whereas mean error for evaluation sites was 51%. Variability within natural systems can be substantial and was quantified for fish tissue by analysis of the US Geological Survey National Fish Database. This analysis pointed to the need for more systematic sampling of fish tissue. Analysis of model output indicated that parameters that had the greatest impact on bioaccumulation influenced the system at several points. These parameters included forested and wetlands coverage and nutrient levels. Factors that were less sensitive modified the system at only 1 point and included the unfiltered total Hg input and the portion of the basin that is developed. PMID:22535752

  7. Mercury exposure and children's health.

    PubMed

    Bose-O'Reilly, Stephan; McCarty, Kathleen M; Steckling, Nadine; Lettmeier, Beate

    2010-09-01

    Acute or chronic mercury exposure can cause adverse effects during any period of development. Mercury is a highly toxic element; there is no known safe level of exposure. Ideally, neither children nor adults should have any mercury in their bodies because it provides no physiological benefit. Prenatal and postnatal mercury exposures occur frequently in many different ways. Pediatricians, nurses, and other health care providers should understand the scope of mercury exposures and health problems among children and be prepared to handle mercury exposures in medical practice. Prevention is the key to reducing mercury poisoning. Mercury exists in different chemical forms: elemental (or metallic), inorganic, and organic (methylmercury and ethyl mercury). Mercury exposure can cause acute and chronic intoxication at low levels of exposure. Mercury is neuro-, nephro-, and immunotoxic. The development of the child in utero and early in life is at particular risk. Mercury is ubiquitous and persistent. Mercury is a global pollutant, bio-accumulating, mainly through the aquatic food chain, resulting in a serious health hazard for children. This article provides an extensive review of mercury exposure and children's health. PMID:20816346

  8. Mercury contamination in East Fork Poplar Creek and Bear Creek

    SciTech Connect

    Van Winkle, W.; Counts, R.W.; Dorsey, J.G.; Elwood, J.W.; Lowe, V.W. Jr.; McElhaney, R.; Schlotzhauer, S.D.; Taylor, F.G. Jr.; Turner, R.R.

    1984-02-01

    A one-month study was performed to determine the concentration of mercury in sediment, fish, moss, and pasture grass in the East Fork Poplar Creek (EFPC) and Bear Creek drainages and to determine whether mercury is still being released from the Y-12 Plant. Total mercury concentration in a sediment core from New Hope Pond was 100 ..mu..g/g dry wt at the surface and up to 300 ..mu..g/g dry wt in subsurface sediments, relative to background concentrations of less than 0.3 ..mu..g/g dry wt. There has been an apparent decrease since 1973 in mercury concentration of sediment entering New Hope Pond. Total mercury concentration in muscle tissue of bluegill from EFPC was positively correlated with body weight, as expected. Total mercury concentration averaged 3.5 and 0.2 ..mu..g/g fresh wt for dead and live foliage in pasture grass, respectively, on the flood plain of EFPC. Results for Bear Creek indicate that this drainage is considerably less contaminated with mercury than East Fork Poplar Creek. The concentration in the sediment was 13 ..mu..g/g dry wt near the settling basins at the west end of the Y-12 Plant area, but decreased to background concentrations before the confluence of Bear Creek with EFPC. Total mercury concentration in fish, except for one rock bass, did not exceed the FDA action level. Recommendations are made (1) to limit the quantity of mercury released from the Y-12 Plant area into EFPC, (2) to consider notifying the responsible state agencies and fishermen concerning mercury concentrations found in fish in EFPC, and (3) to measure mercury concentration in hair from cattle grazing on pasture grasses along EFPC. Recommendations concerning further monitoring are also made. 15 references, 3 figures, 8 tables.

  9. JV Task 96 - Phase 2 - Investigating the Importance of the Mercury-Selenium Interaction

    SciTech Connect

    Nicholas Ralston; Laura Raymond

    2008-03-01

    In order to improve the understanding of the mercury issue, it is vital to study mercury's effects on selenium physiology. While mercury present in the environment or food sources may pose health risks, the protective effects of selenium have not been adequately considered in establishing regulatory policy. Numerous studies report that vulnerability to mercury toxicity is inversely proportional to selenium status or level. However, selenium status has not been considered in the development of the reference dosage levels for mercury exposure. Experimental animals fed low-selenium diets are far more vulnerable to mercury toxicity than animals fed normal selenium, and animals fed selenium-rich diets are even more resistant. Selenium-dependent enzymes in brain and endocrine tissues can be impaired by excessive mercury exposure, apparently because mercury has an extremely high binding affinity for selenium. When selenium becomes bound to mercury, it is unable to participate in the metabolic cycling of selenoprotein synthesis. Because of mercury-dependent impairments of selenoprotein synthesis, various antioxidant and regulatory functions in brain biochemistry are compromised. This report details a 2-year multiclient-funded research program designed to examine the interactions between mercury and selenium in animal models. The studies explored the effects of dietary intakes of toxic amounts of methylmercury and the protective effects of the normal dietary range of selenium in counteracting mercury toxicity. This study finds that the amounts of selenium present in ocean fish are sufficient to protect against far larger quantities of methylmercury than those present in typical seafoods. Toxic effects of methylmercury exposure were not directly proportional to mercury concentrations in blood, brain, or any other tissues. Instead, mercury toxicity was proportional to molar ratios of mercury relative to selenium. In order to accurately assess risk associated with methylmercury or mercury exposures, mercury-selenium ratios appear to be far more accurate and effective in identifying risk and protecting human and environmental health. This study also finds that methylmercury toxicity can be effectively treated by dietary selenium, preventing the death and progressive disabilities that otherwise occur in methylmercury-treated subjects. Remarkably, the positive response to selenium therapy was essentially equivalent regardless of whether or not toxic amounts of methylmercury were still administered. The findings of the Physiologically Oriented Integration of Nutrients and Toxins (POINT) models of the effects of mercury and selenium developed in this project are consistent with the hypothesis that mercury toxicity arises because of mercury-dependent inhibition of selenium availability in brain and endocrine tissues. This appears to occur through synergistic effects of mercury-dependent inhibition of selenium transport to these tissues and selective sequestration of the selenium present in the tissues. Compromised transport of selenium to the brain and endocrine tissues would be particularly hazardous to the developing fetus because the rapidly growing tissues of the child have no selenium reserves. Therefore, maternal consumption of foods with high mercury-selenium ratios is hazardous. In summation, methylmercury exposure is unlikely to cause harm in populations that eat selenium-rich diets but may cause harm among populations that consume certain foods that have methylmercury present in excess of selenium.

  10. Metallic mercury recycling. Final report

    SciTech Connect

    Beck, M.A.

    1994-07-01

    Metallic mercury is known to be a hazardous material and is regulated as such. The disposal of mercury, usually by landfill, is expensive and does not remove mercury from the environment. Results from the Metallic Mercury Recycling Project have demonstrated that metallic mercury is a good candidate for reclamation and recycling. Most of the potential contamination of mercury resides in the scum floating on the surface of the mercury. Pinhole filtration was demonstrated to be an inexpensive and easy way of removing residues from mercury. The analysis method is shown to be sufficient for present release practices, and should be sufficient for future release requirements. Data from tests are presented. The consistently higher level of activity of the filter residue versus the bulk mercury is discussed. Recommendations for the recycling procedure are made.

  11. Environmental Geochemistry of Mercury Mines in Alaska

    NSDL National Science Digital Library

    This U.S. Geological Survey fact sheet investigates potential environmental contamination around naturally occurring, mercury-rich mineral deposits in Alaska. Testing of mercury levels in streams and sediments is described, as well as mercury levels in fish downstream from mines and the environmental effects of mercury entering the food chain.

  12. Plasma Levels and Adipose Tissue Messenger Ribonucleic Acid Expression of Retinol-Binding Protein

    E-print Network

    Paris-Sud XI, Université de

    Plasma Levels and Adipose Tissue Messenger Ribonucleic Acid Expression of Retinol-Binding Protein 4 a role in the development of insulin resistance. Objective: We investigated whether RBP4 adipose tissue m. Insulin sensitivity was assessed with the euglycemic hyperinsulinemic clamp. Adipose tissue m

  13. National estimates of blood lead, cadmium, and mercury levels in the Korean general adult population

    Microsoft Academic Search

    Nam-Soo Kim; Byung-Kook Lee

    2011-01-01

    Objectives  To assess the extent of exposure to lead, cadmium, and mercury in the Korean general adult population using a representative\\u000a sample.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  We studied blood concentrations of three heavy metals in a representative sample of 1,997 Koreans as part of the Third Korean\\u000a National Health and Nutrition Examination Survey (KNHANES III) performed in 2005.\\u000a \\u000a \\u000a \\u000a \\u000a Results  The geometric means of the blood lead,

  14. Blood levels of lead, cadmium, and mercury in the Korean population: Results from the Second Korean National Human Exposure and Biomonitoring Examination

    Microsoft Academic Search

    Ji-Young Son; Jinheon Lee; Domyung Paek; Jong-Tae Lee

    2009-01-01

    In Korea, there have been a number of efforts to measure levels of exposure to environmental pollutants among the population. This paper focuses on investigating the distribution of, extent of, and factors influencing the blood levels of lead, cadmium, and mercury in the Korean population, working from data obtained from the Second Korean National Human Exposure and Bio-monitoring Examination. To

  15. Determination of serum and tissue levels of phenazines including clofazimine

    Microsoft Academic Search

    Robert O'Connor; J. F. O'Sullivan; Richard O'Kennedy

    1996-01-01

    A rapid and sensitive HPLC method is described for the analysis of synthetic phenazines, including clofazimine, from a variety of biological samples. Phenazines were extracted from serum, tissue and fat using a mixture of dichloromethane and sodium hydroxide. The drugs were then quantified on a reversed-phase C18 column using a mobile phase consisting of 594 ml of water, 400 ml

  16. Azithromycin levels in plasma and gastric tissue, juice and mucus

    Microsoft Academic Search

    J. D. Harrison; J. A. Jones; D. L. Morris

    1991-01-01

    Azithromycin is the first member of a new class called the azalides. Its distribution in gastric tissues was studied in 27 patients (mean age 66 years) with proven gastric cancer due to be resected. Five groups of patients received a single 500 mg oral dose of azithromycin 24, 48, 72, 96 or 120 h pre-operatively. Samples of blood, gastric juice,

  17. Mercury concentrations in breast feathers of three upper trophic level marine predators from the western Aleutian Islands, Alaska.

    PubMed

    Kaler, Robb S A; Kenney, Leah A; Bond, Alexander L; Eagles-Smith, Collin A

    2014-05-15

    Mercury (Hg) is a toxic element distributed globally through atmospheric transport. Agattu Island, located in the western Aleutian Islands, Alaska, has no history of point-sources of Hg contamination. We provide baseline levels of total mercury (THg) concentrations in breast feathers of three birds that breed on the island. Geometric mean THg concentrations in feathers of fork-tailed storm-petrels (Oceanodroma furcata; 6703 ± 1635, ng/g fresh weight [fw]) were higher than all other species, including snowy owl (Bubo scandiacus; 2105 ± 1631, ng/g fw), a raptor with a diet composed largely of storm-petrels at Agattu Island. There were no significant differences in mean THg concentrations of breast feathers among adult Kittlitz's murrelet (Brachyramphus brevirostris; 1658 ± 1276, ng/g fw) and chicks (1475 ± 671, ng/g fw) and snowy owls. The observed THg concentrations in fork-tailed storm-petrel feathers emphasizes the need for further study of Hg pollution in the western Aleutian Islands. PMID:24656750

  18. Mercury concentrations in breast feathers of three upper trophic level marine predators from the western Aleutian Islands, Alaska

    USGS Publications Warehouse

    Kaler, Robb S.A.; Kenney, Leah A.; Bond, Alexander L.; Eagles-Smith, Collin A.

    2014-01-01

    Mercury (Hg) is a toxic element distributed globally through atmospheric transport. Agattu Island, located in the western Aleutian Islands, Alaska, has no history of point-sources of Hg contamination. We provide baseline levels of total mercury (THg) concentrations in breast feathers of three birds that breed on the island. Geometric mean THg concentrations in feathers of fork-tailed storm-petrels (Oceanodroma furcata; 6703 ± 1635, ng/g fresh weight [fw]) were higher than all other species, including snowy owl (Bubo scandiacus; 2105 ± 1631, ng/g fw), a raptor with a diet composed largely of storm-petrels at Agattu Island. There were no significant differences in mean THg concentrations of breast feathers among adult Kittlitz’s murrelet (Brachyramphus brevirostris; 1658 ± 1276, ng/g fw) and chicks (1475 ± 671, ng/g fw) and snowy owls. The observed THg concentrations in fork-tailed storm-petrel feathers emphasizes the need for further study of Hg pollution in the western Aleutian Islands.

  19. Mercury concentrations in oligohaline wetland vegetation and associated soil biogeochemistry.

    PubMed

    Willis, Jonathan M; Gambrell, Robert P; Hester, Mark W

    2011-10-01

    Concentrations of mercury were determined in above- and below-ground tissues of dominant plant species, as well as soils, in the wetlands of Lake Maurepas, Louisiana. Indicators of wetland soil biogeochemical status, such as soil redox potential, pore-water nutrient concentrations, and pore-water total sulfides, were also determined. Total mercury concentrations in plant tissues were within the typical range for vegetation not exposed to mercury contamination. Similarly, total mercury concentrations in soils were typical of uncontaminated wetlands within this geographic region. Soil methyl mercury levels in this study are slightly lower than those reported in other studies of nearby wetlands. This may reflect the less extensive geographic sampling in this study, or the low water levels in the Lake Maurepas system immediately prior to and during this study, which would have altered soil biogeochemical status. This is corroborated by measurements of soil redox potential and soil pore-water nitrogen and sulfur constituents conducted during this study that suggest minimal sulfate reduction was occurring in surficial soils. This study indicates that the wetlands surrounding Lake Maurepas are typical of many uncontaminated oligohaline wetlands in the southeastern U.S. in regard to mercury concentrations. PMID:21188507

  20. Adipose tissue branched chain amino acid (BCAA) metabolism modulates circulating BCAA levels.

    PubMed

    Herman, Mark A; She, Pengxiang; Peroni, Odile D; Lynch, Christopher J; Kahn, Barbara B

    2010-04-01

    Whereas the role of adipose tissue in glucose and lipid homeostasis is widely recognized, its role in systemic protein and amino acid metabolism is less well-appreciated. In vitro and ex vivo experiments suggest that adipose tissue can metabolize substantial amounts of branched chain amino acids (BCAAs). However, the role of adipose tissue in regulating BCAA metabolism in vivo is controversial. Interest in the contribution of adipose tissue to BCAA metabolism has been renewed with recent observations demonstrating down-regulation of BCAA oxidation enzymes in adipose tissue in obese and insulin-resistant humans. Using gene set enrichment analysis, we observe alterations in adipose-tissue BCAA enzyme expression caused by adipose-selective genetic alterations in the GLUT4 glucose-transporter expression. We show that the rate of adipose tissue BCAA oxidation per mg of tissue from normal mice is higher than in skeletal muscle. In mice overexpressing GLUT4 specifically in adipose tissue, we observe coordinate down-regulation of BCAA metabolizing enzymes selectively in adipose tissue. This decreases BCAA oxidation rates in adipose tissue, but not in muscle, in association with increased circulating BCAA levels. To confirm the capacity of adipose tissue to modulate circulating BCAA levels in vivo, we demonstrate that transplantation of normal adipose tissue into mice that are globally defective in peripheral BCAA metabolism reduces circulating BCAA levels by 30% (fasting)-50% (fed state). These results demonstrate for the first time the capacity of adipose tissue to catabolize circulating BCAAs in vivo and that coordinate regulation of adipose-tissue BCAA enzymes may modulate circulating BCAA levels. PMID:20093359

  1. Adipose Tissue Branched Chain Amino Acid (BCAA) Metabolism Modulates Circulating BCAA Levels*

    PubMed Central

    Herman, Mark A.; She, Pengxiang; Peroni, Odile D.; Lynch, Christopher J.; Kahn, Barbara B.

    2010-01-01

    Whereas the role of adipose tissue in glucose and lipid homeostasis is widely recognized, its role in systemic protein and amino acid metabolism is less well-appreciated. In vitro and ex vivo experiments suggest that adipose tissue can metabolize substantial amounts of branched chain amino acids (BCAAs). However, the role of adipose tissue in regulating BCAA metabolism in vivo is controversial. Interest in the contribution of adipose tissue to BCAA metabolism has been renewed with recent observations demonstrating down-regulation of BCAA oxidation enzymes in adipose tissue in obese and insulin-resistant humans. Using gene set enrichment analysis, we observe alterations in adipose-tissue BCAA enzyme expression caused by adipose-selective genetic alterations in the GLUT4 glucose-transporter expression. We show that the rate of adipose tissue BCAA oxidation per mg of tissue from normal mice is higher than in skeletal muscle. In mice overexpressing GLUT4 specifically in adipose tissue, we observe coordinate down-regulation of BCAA metabolizing enzymes selectively in adipose tissue. This decreases BCAA oxidation rates in adipose tissue, but not in muscle, in association with increased circulating BCAA levels. To confirm the capacity of adipose tissue to modulate circulating BCAA levels in vivo, we demonstrate that transplantation of normal adipose tissue into mice that are globally defective in peripheral BCAA metabolism reduces circulating BCAA levels by 30% (fasting)-50% (fed state). These results demonstrate for the first time the capacity of adipose tissue to catabolize circulating BCAAs in vivo and that coordinate regulation of adipose-tissue BCAA enzymes may modulate circulating BCAA levels. PMID:20093359

  2. A novel tissue model for angiogenesis: evaluation of inhibitors or promoters in tissue level

    NASA Astrophysics Data System (ADS)

    Dai, Bingling; Zhang, Yanmin; Zhan, Yingzhuan; Zhang, Dongdong; Wang, Nan; He, Langchong

    2014-01-01

    A novel tissue model for angiogenesis (TMA) is established for effective evaluation of angiogenesis inhibitors or promoters in vitro. Lung tissues were cultured in fibrinogen ``sandwich'' structure which resembled the formation of neovessels in vivo. The cells and capillary-like structures grew from the lung tissues were identified as endothelial cells and neovessels. Both immunohistochemisty and western blot results indicated that autocrine VEGF bound to the KDR and induced KDR autophosphorylation that could induce the proliferation of endothelial cells and their migration as well as the formation of microvessels on the lung tissue edge. With addition of the TMA, the murine VEGF and cultured medium produced by A549 tumor cells apparently promoted the increase of neovessels. Sorafenib as a tumor angiogenesis inhibitor and Tongxinluo as an angiogenesis promoter were both used to evaluate the TMA performance and they exhibited a good effect on neovessels in the TMA. The model established imitated angiogenesis in vivo and could well serve as an effective method in evaluating the angiogenesis inhibitors or promoters, and could also be practical for screening small molecules that affect blood vessel formation.

  3. Mercury hair levels and factors that influence exposure for residents of Huancavelica, Peru.

    PubMed

    Hagan, Nicole; Robins, Nicholas; Hsu-Kim, Heileen; Halabi, Susan; Espinoza Gonzales, Ruben Dario; Ecos, Enrique; Richter, Daniel; Vandenberg, John

    2015-06-01

    Between 1564 and 1810, nearly 17,000 metric tons of mercury (Hg) vapor was released to the environment during cinnabar refining in the small town of Huancavelica, Peru. The present study characterizes individual exposure to mercury using total and speciated Hg from residential samples, total Hg in hair, and self-reported questionnaire data regarding factors influencing exposure (e.g., frequency of fish consumption, occupation). Total Hg concentrations in hair from 118 participants ranged from 0.10 to 3.6 µg/g, similar to concentrations found in the USA and lower than concentrations in other Hg-exposed populations around the world. Pearson's correlation coefficients for data in this study suggest that there is a positive correlation between concentrations of total Hg in hair and concentrations of total Hg in adobe bricks, dirt floors, and surface dust; however, these correlations are not statistically significant. Results of a one-way analysis of variance (ANOVA) identified that total Hg concentrations in hair were significantly related to gender (p < 0.001), living in a neighborhood where smelters were previously located (p = 0.021), smoking status (p = 0.003), frequency of house cleaning (p = 0.019), and frequency of fish consumption (p = 0.046). These results highlight the need for further studies to better characterize Hg exposure in Huancavelica, particularly as related to residential contamination. A comprehensive analysis of residential Hg contamination and exposure in Huancavelica will guide the development and implementation of mitigation and remediation strategies in the community to reduce potential health risks from residential Hg exposure. PMID:25467206

  4. Mercury content in commercially available finfish in the United States.

    PubMed

    Cladis, Dennis P; Kleiner, Alison C; Santerre, Charles R

    2014-08-01

    Seventy-seven finfish species (300 composites of three fish) were obtained from commercial vendors in six regions of the United States: Great Lakes, mid-Atlantic, New England, northwest, southeast, and southwest. Total mercury in fish muscle tissue ranged from 1 ppb (channel catfish) to 1,425 ppb (king mackerel). Of the top 10 most commonly consumed seafoods in the United States, all finfish species, including salmon species (13 to 62 ppb), Alaskan pollock (11 ppb), tilapia (16 ppb), channel catfish (1 ppb), Atlantic cod (82 ppb), and pangasius (swai) (2 ppb), had low total mercury concentrations. However, two large predatory species, king mackerel and swordfish (1,107 ppb), contained mercury concentrations above the current U.S. Food and Drug Administration action level of 1,000 ppb, indicating that consumers may be unaware that species that are high in mercury are being sold in the marketplace. PMID:25198598

  5. Corticosterone in relation to tissue cadmium, mercury and selenium concentrations and social status of male lesser scaup (Aythya affinis).

    PubMed

    Pollock, Brady; Machin, Karen L

    2009-01-01

    Combined lesser scaup (Aythya affinis) and greater scaup (A. marila) populations have declined steadily from the 1970s. Accompanying the population decline have been two shifts in lesser scaup demographics: a decrease in the proportion of young birds and an increase in male to female ratio. In addition, there are concerns about potential effects of contaminants and trace elements. These metals may influence the stress response and corticosterone secretion. We examined impacts of cadmium, selenium and mercury on the stress response in relation to social status in male lesser scaup near Yellowknife, NWT May to June 2004 and 2005. Kidney cadmium and liver selenium and mercury ranged 0.78-93.6, 2.12-9.64, and 0.56-3.71 microg/g, dry weight, respectively. Results suggest that corticosterone release may be influenced by complex contaminant interactions in relation to body condition and body size. When cadmium was high and birds were in good body condition, there was a negative relationship between liver selenium and corticosterone (R(2) = 0.60, n = 10, P = 0.008) but not in birds with poor body condition (R(2) = 0.07, n = 9, P = 0.50). Unfortunately we were unable to draw any conclusions about metals and social status in relation to corticosterone or glucose and T(4). This study emphasizes the complex nature of biological systems and the importance of considering interactions to characterize effects of metals. PMID:18677562

  6. Microbial methylation of mercury in estuarine sediments

    Microsoft Academic Search

    Compeau

    1985-01-01

    Mercury is a common and potentially hazardous pollutant. Although all forms of the element are toxic, alkylated mercurials are particularly toxic and accumulate in living tissues. Factors affecting the availability of mercury and the microorganisms responsible for methylation are described. The methylation of mercuric ions (Hg\\/sup + +\\/) was investigated in pure culture, in estuarine sediments, and as a function

  7. FABP4 Dynamics in Obesity: Discrepancies in Adipose Tissue and Liver Expression Regarding Circulating Plasma Levels

    PubMed Central

    Ceperuelo-Mallafré, Victoria; Garrido-Sanchez, Lourdes; Miranda, Merce; Clemente-Postigo, Mercedes; Pérez-Pérez, Rafael; Peral, Belen; Cardona, Fernando; Fernández-Real, Jose Manuel; Tinahones, Francisco J.; Vendrell, Joan

    2012-01-01

    Background FABP4 is predominantly expressed in adipose tissue, and its circulating levels are linked with obesity and a poor atherogenic profile. Objective In patients with a wide BMI range, we analyze FABP4 expression in adipose and hepatic tissues in the settings of obesity and insulin resistance. Associations between FABP4 expression in adipose tissue and the FABP4 plasma level as well as the main adipogenic and lipolytic genes expressed in adipose tissue were also analyzed. Methods The expression of several lipogenic, lipolytic, PPAR family and FABP family genes was analyzed by real time PCR. FABP4 protein expression in total adipose tissues and its fractions were determined by western blot. Results In obesity FABP4 expression was down-regulated (at both mRNA and protein levels), with its levels mainly predicted by ATGL and inversely by the HOMA-IR index. The BMI appeared as the only determinant of the FABP4 variation in both adipose tissue depots. FABP4 plasma levels showed a significant progressive increase according to BMI but no association was detected between FABP4 circulating levels and SAT or VAT FABP4 gene expression. The gene expression of FABP1, FABP4 and FABP5 in hepatic tissue was significantly higher in tissue from the obese IR patients compared to the non-IR group. Conclusion The inverse pattern in FABP4 expression between adipose and hepatic tissue observed in morbid obese patients, regarding the IR context, suggests that both tissues may act in a balanced manner. These differences may help us to understand the discrepancies between circulating plasma levels and adipose tissue expression in obesity. PMID:23139800

  8. Metallothionein expression in chloroplasts enhances mercury accumulation and phytoremediation capability.

    PubMed

    Ruiz, Oscar N; Alvarez, Derry; Torres, Cesar; Roman, Laura; Daniell, Henry

    2011-06-01

    Genetic engineering to enhance mercury phytoremediation has been accomplished by expression of the merAB genes that protects the cell by converting Hg[II] into Hg[0] which volatilizes from the cell. A drawback of this approach is that toxic Hg is released back into the environment. A better phytoremediation strategy would be to accumulate mercury inside plants for subsequent retrieval. We report here the development of a transplastomic approach to express the mouse metallothionein gene (mt1) and accumulate mercury in high concentrations within plant cells. Real-time PCR analysis showed that up to 1284 copies of the mt1 gene were found per cell when compared with 1326 copies of the 16S rrn gene, thereby attaining homoplasmy. Past studies in chloroplast transformation used qualitative Southern blots to evaluate indirectly transgene copy number, whereas we used real-time PCR for the first time to establish homoplasmy and estimate transgene copy number and transcript levels. The mt1 transcript levels were very high with 183,000 copies per ng of RNA or 41% the abundance of the 16S rrn transcripts. The transplastomic lines were resistant up to 20 ?m mercury and maintained high chlorophyll content and biomass. Although the transgenic plants accumulated high concentrations of mercury in all tissues, leaves accumulated up to 106 ng, indicating active phytoremediation and translocation of mercury. Such accumulation of mercury in plant tissues facilitates proper disposal or recycling. This study reports, for the first time, the use of metallothioneins in plants for mercury phytoremediation. Chloroplast genetic engineering approach is useful to express metal-scavenging proteins for phytoremediation. PMID:21518240

  9. Methyl Parathion-Induced Changes in Free and Protein-Bound SH Levels in Rat Tissues.

    PubMed

    Yildiz, Deniz; Dalkilic, Semih; Yildiz, Hasan; Oztas, Haydar

    2006-01-01

    The main objective of this study was to investigate the changes in free and protein-bound SH contents in methyl parathion-exposed rat tissues. The free and protein-bound SH levels are usually affected and depleted by oxidative stress-inducing agents. Results would indicate if methyl parathion toxicity partly results from depletion of sulfhydryl content of tissues. Six-week-old male Wistar albino rats were used in this study. Following exposure to methyl parathion for 3 months, the liver, the brain, and the kidney tissues were removed from the rats. The free and protein-bound SH contents were determined in these tissues. In addition, plasma lactate dehydrogenase levels were determined. Our results showed that methyl parathion exposure significantly lowers the free and protein-bound SH levels in rat tissues. However, lactate dehydrogenase activity in the blood plasma did not display any differences compared to the control group. The free SH concentrations in the control rat liver, brain, and kidney tissues were 3.78 +/- 0.1 mumol/100 mg tissue, 1.56 +/- 0.08 mumol/100 mg tissue, and 2.16 +/- 0.08 mumol/100 mg tissue, respectively, whereas the free SH concentrations in rats exposed to methyl parathion were determined as 0.536 +/- 0.1 mumol/100 mg tissue in the liver, 1.06 +/- 0.1 mumol/100 mg tissue in the brain, and 0.108 +/- 0.03 mumol/100 mg tissue in the kidney. The protein-bound SH concentrations in the liver and in the kidney in rats exposed to methyl parathion displayed a significant decrease also. However, the protein-bound SH level in the brain did not change significantly. These results indicate that methyl parathion exposure partially depletes the free and protein-bound SH levels. Thus, it was concluded that methyl parathion toxicity may partly result from oxidative stress. PMID:20021006

  10. Development of an empirical nonlinear model for mercury bioaccumulation in the South and South Fork Shenandoah rivers of Virginia.

    PubMed

    Brent, Robert N; Kain, Donald G

    2011-11-01

    Mercury is a globally distributed pollutant that biomagnifies in aquatic food webs. In the United States, 3781 water bodies fail to meet criteria for safe fish consumption due to mercury bioaccumulation. In the risk assessment and management of these impairments (through the total maximum daily load program), an important step is evaluating the relationship between aqueous mercury and mercury in fish tissue. Often, this relationship is simplified to a bioaccumulation factor (BAF): the ratio of fish tissue mercury to aqueous mercury. This article evaluates the relationship between aqueous mercury and fish tissue mercury across a contamination gradient in the South and South Fork Shenandoah rivers of Virginia. The relationship was found to be nonlinear, with BAFs decreasing as the level of contamination increased. This means that protective water column mercury concentration targets established from site-specific BAFs will be overestimated in contaminated areas and will not be sufficiently protective. To avoid this over-prediction in the South and South Fork Shenandoah rivers, an empirical nonlinear Michaelis-Menten model was used to establish a protective water-quality target. Among other models and variables, the Michaelis-Menten model, relating total mercury in the water column to methylmercury in fish tissue, achieved the best empirical fit (r(2) = 0.9562). The resulting water-quality targets using this model were 3.8 and 3.2 ng/l for the South and South Fork Shenandoah rivers, respectively. These values are 2.1-2.5 times lower than the water-quality target developed using a site-specific BAF. These findings demonstrate the need to consider nonlinear BAF relationships in mercury-contaminated areas. PMID:21448743

  11. Mercury contamination in bank swallows and double-crested cormorants from the Carson River, Nevada

    SciTech Connect

    Kim, R.; Brewer, R.; Peterson, S.C.; Mach, C. [Ecology and Environment, Inc., Buffalo, NY (United States)

    1995-12-31

    An ecological risk assessment was performed in conjunction with a remedial investigation at the Carson River Mercury Site (CRMS) in northwestern Nevada. Large quantities of mercury used in the processing of gold and silver during mining operations in the mid to late 1800s are distributed throughout the Carson River ecosystem. Previous investigations indicated elevated levels of mercury in soil, sediment, water, and the aquatic food chain. Bird exposure to mercury was determined by measuring total mercury and monomethyl mercury in blood and feather samples from 15 unfledged double-crested cormorants (Phalacrocorax auritus), and in blood, feather, and liver samples from 18 juvenile bank swallows (Riparia riparia) at both the CRMS and uncontaminated background locations. Monomethyl mercury accounted for 90 to 98% of the total mercury in the samples. Total mercury concentrations in bird tissues collected at the CRMS were significantly higher than at background locations. Average total mercury concentrations (wet weight) for the swallow blood, liver, and feather samples collected at the CRMS were 2.63, 3.96, and 2.01 mg/kg, respectively; compared with 0.74, 1,03, and 1.84 mg/kg, respectively at the background area. Average total mercury concentrations for cormorant samples collected at the CRMS were 17.07 mg/kg for blood, and 105.1 1 mg/kg for feathers. Cormorant samples collected at the background location had average total mercury concentrations of 0.49 mg/kg for blood and 8.99 mg/kg for feathers. Results are compared with published residue-effects levels to evaluate avian risks.

  12. Phytotoxicity of biosolids and screening of selected plant species with potential for mercury phytoextraction.

    PubMed

    Lomonte, Cristina; Doronila, Augustine I; Gregory, David; Baker, Alan J M; Kolev, Spas D

    2010-01-15

    Mercury contaminated stockpiles of biosolids (3.5-8.4 mg kg(-1) Hg) from Melbourne Water's Western Treatment Plant (MW-WTP) were investigated to evaluate the possibility for their phytoremediation. Nine plant species (Atriplex codonocarpa, Atriplex semibaccata, Austrodanthonia caespitosa, Brassica juncea, Brassica napus, Gypsophila paniculata, Sorghum bicolor, Themeda triandra and Trifolium subterraneum) were screened for phytoextraction potential in Hg-contaminated biosolids from MW-WTP. In addition, the same plant species were germinated and grown in two other substrates (i.e. potting mix and potting mix spiked with mercury(II)). Growth measurements and the mercury uptake for all three substrates were compared. Some plant species grown in potting mix spiked with mercury(II) grew more vigorously than in the other two substrates and showed higher levels of sulphur in their tissues. These results suggested that the mercury stress activated defence mechanisms and it was hypothesised that this was the likely reason for the enhanced production of sulphur compounds in the plant species studied which stimulated their growth. Some species did not grow in biosolids because of the combined effect of high mercury toxicity and high salt content. Atriplex conodocarpa and Australodanthonia caespitose proved to be the most suitable candidates for mercury phytoextraction because of their ability to translocate mercury from roots to the above-ground tissues. PMID:19775810

  13. Tissue levels of (3(-14)C) coumarin in the rat: distribution and excretion.

    PubMed Central

    Piller, N. B.

    1977-01-01

    The benzo-pyrones (including coumarin) are a very effective therapy for mild thermal oedema and cases of acute and chronic lymphoedema. In this preliminary report the distribution of a single injected dose of coumarin was followed in normal tissues of rats for 100 hours. Comparisons are to be made later with drug levels in thermally injured and lymphoedematous tissues. The resluts show 7-4% of the injected dose to remain in the tissues after 100 h. During this time 30-9% was excreted in the faeces and approximately 47% excreted in the urine. At any given time most of the dose was present in the gut, muscular tissues, skin and liver. For the gut tissues this was 33%, for the muscular tissues 28%, for the skin 18% and for the liver 16%. The highest concentrations per gram of tissue were however in the kidney and liver, representing the two organs of metabolism and excretion of the coumarin. PMID:836764

  14. Nasal Associated Lymphoid Tissue of the Syrian Golden Hamster Expresses High Levels of PrPC

    PubMed Central

    Clouse, Melissa D.; Shikiya, Ronald A.; Bartz, Jason C.; Kincaid, Anthony E.

    2015-01-01

    The key event in the pathogenesis of the transmissible spongiform encephalopathies is a template-dependent misfolding event where an infectious isoform of the prion protein (PrPSc) comes into contact with native prion protein (PrPC) and changes its conformation to PrPSc. In many extraneurally inoculated models of prion disease this PrPC misfolding event occurs in lymphoid tissues prior to neuroinvasion. The primary objective of this study was to compare levels of total PrPC in hamster lymphoid tissues involved in the early pathogenesis of prion disease. Lymphoid tissues were collected from golden Syrian hamsters and Western blot analysis was performed to quantify PrPC levels. PrPC immunohistochemistry (IHC) of paraffin embedded tissue sections was performed to identify PrPC distribution in tissues of the lymphoreticular system. Nasal associated lymphoid tissue contained the highest amount of total PrPC followed by Peyer’s patches, mesenteric and submandibular lymph nodes, and spleen. The relative levels of PrPC expression in IHC processed tissue correlated strongly with the Western blot data, with high levels of PrPC corresponding with a higher percentage of PrPC positive B cell follicles. High levels of PrPC in lymphoid tissues closely associated with the nasal cavity could contribute to the relative increased efficiency of the nasal route of entry of prions, compared to other routes of infection. PMID:25642714

  15. LASERS: Pulsed laser based on a resonance—metastable level transition in mercury ion

    NASA Astrophysics Data System (ADS)

    Markova, S. V.; Petrash, G. G.

    1995-09-01

    The method of doubled pulses was used to achieve pulsed lasing due to the 5d106p2P3/2—5d96s2 2D5/2 transition in the mercury ion (? = 398 nm), similar to efficient lasing transitions in copper and gold atoms. Discharge tubes with inner diameters 4 and 8 mm and 30 cm long were used. They were filled with neon or helium as the buffer gases. There was a significant difference between lasing in the narrow and wide tubes. In the wide tube it was possible to observe lasing only when the delay between the pulses was short; the beam was not ring-shaped, contrary to what was found earlier for the narrow tube. Lasing was observed even when the delay between the two pulses was less than 5 ?s, but lasing disappeared when heating of the tube became stronger as the pulse repetition frequency was increased. Possible population and inversion mechanisms were analysed.

  16. Environmental mercury concentrations in cultured low-trophic-level fish using food waste-based diets.

    PubMed

    Cheng, Zhang; Mo, Wing Yin; Man, Yu Bon; Lam, Cheung Lung; Choi, Wai Ming; Nie, Xiang Ping; Liu, Yi Hui; Wong, Ming Hung

    2015-01-01

    In this study, different types of food wastes were used as the major source of protein to replace the fish meal in fish feeds to produce quality fish (polyculture of different freshwater fish). During October 2011-April 2012, the concentrations of Hg in water, suspended particulate matter, and sediment of the three experimental fish ponds located in Sha Tau Kok Organic Farm were monitored, and the results were similar to or lower than those detected in commercial fish ponds around the Pearl River Delta (PRD) region (by comparing data of previous and present studies). Health risk assessments indicated that human consumption of grass carp (Ctenopharyngodon idellus), a herbivore which fed food waste feed pellets would be safer than other fish species: mud carp (Cirrhina molitorella), bighead carp (Hypophthalmichthys nobilis), and largemouth bass (Lepomis macrochirus). Due to the lower species diversity and substantially shorter food chains of the polyculture system consisting of only three fish species, the extent of Hg biomagnification was significantly lower than other polyculture ponds around PRD. Furthermore, the use of food waste instead of fish meal (mainly consisted of contaminated trash fish) further reduced the mercury accumulation in the cultured fish. PMID:25087497

  17. Influence of a chlor-alkali superfund site on mercury bioaccumulation in periphyton and low-trophic level fauna.

    PubMed

    Buckman, Kate L; Marvin-DiPasquale, Mark; Taylor, Vivien F; Chalmers, Ann; Broadley, Hannah J; Agee, Jennifer; Jackson, Brian P; Chen, Celia Y

    2015-07-01

    In Berlin, New Hampshire, USA, the Androscoggin River flows adjacent to a former chlor-alkali facility that is a US Environmental Protection Agency Superfund site and source of mercury (Hg) to the river. The present study was conducted to determine the fate and bioaccumulation of methylmercury (MeHg) to lower trophic-level taxa in the river. Surface sediment directly adjacent to the source showed significantly elevated MeHg (10-40× increase, mean?±?standard deviation [SD]: 20.1?±?24.8 ng g(-1) dry wt) and total mercury (THg; 10-30× increase, mean?±?SD: 2045?±?2669 ng g(-1) dry wt) compared with all other reaches, with sediment THg and MeHg from downstream reaches elevated (3-7× on average) relative to the reference (THg mean?±?SD: 33.5?±?9.33 ng g(-1) dry wt; MeHg mean?±?SD: 0.52?±?0.21?ng g(-1) dry wt). Water column THg concentrations adjacent to the point source for both particulate (0.23?ng L(-1) ) and dissolved (0.76?ng L(-1) ) fractions were 5-fold higher than at the reference sites, and 2-fold to 5-fold higher than downstream. Methylmercury production potential of periphyton material was highest (2-9?ng g(-1) d(-1) dry wt) adjacent to the Superfund site; other reaches were close to or below reporting limits (0. 1?ng g(-1) d(-1) dry wt). Total Hg and MeHg bioaccumulation in fauna was variable across sites and taxa, with no clear spatial patterns downstream of the contamination source. Crayfish, mayflies, and shiners showed a weak positive relationship with porewater MeHg concentration. Environ Toxicol Chem 2015;34:1649-1658. © 2015 SETAC. PMID:25732794

  18. Ammonium thiosulphate enhanced phytoextraction from mercury contaminated soil--results from a greenhouse study.

    PubMed

    Wang, Jianxu; Feng, Xinbin; Anderson, Christopher W N; Qiu, Guangle; Ping, Li; Bao, Zhengduo

    2011-02-15

    According to the 'hard and soft' acid-base principle, mercury is a 'soft metal' and will preferentially form soluble chemical complexes with sulphur-containing ligands. In this work mercury uptake by Chenopodium glaucum L. growing on mercury-contaminated soil was promoted using ammonium thiosulphate. The relative geochemical fractionation of mercury in the soil was subsequently investigated as a function of plant growth with and without thiosulphate amendment. The results indicate that the solubility of mercury is significantly increased through the application of thiosulphate to the soil. Substantially higher mercury levels were found in C. glaucum L. treated with 2 g kg(-1) thiosulphate of soil when compared to the non-treated plants. Compared with initial soil, soluble and exchangeable fractions were increased both in planted and planted treated plants. However, no significant difference was observed between the soils of the planted and planted treated plants. The oxide-bound mercury concentration was significantly decreased for the planted soil (treated and non-treated) at the end of the experiment. Moreover, this fraction was highly correlated with the plant tissue mercury concentration. Taken together, thiosulphate assisted phytoextraction could be used to reduce environmental risk apparent for mercury-contaminated soil through reducing the oxide bound fractions, while managing the bioavailable fractions (compared with no treated plant). PMID:21122988

  19. High acid phosphatase level in the gingival tissues of periodontitis subjects

    PubMed Central

    Pushparani, D. S.

    2015-01-01

    Aim: Periodontitis is one of the major problems slowly progressing and could affect 70% of the global population. The prevalence of periodontitis differs from mild to moderate forms of race and geographic region. The aim of this study is to determine the acid phosphatase (ACP) activity in the gingival tissues of periodontitis subjects. In this study, the activity of ACP in the gingival tissue of subjects with periodontitis was examined. Materials and Methods: A total of 30 subjects were selected for the study and are divided into group I (n = 15, healthy subjects in control) and in group II (n = 15, periodontitis subjects). The gingival tissue from group I and group II subjects were collected after the surgery and the ACP enzyme level was analyzed using ultraviolet spectrophotometer. Assessment of periodontitis was done based on periodontal probing depth (PPD) and clinical attachment level (CAL). The statistical analysis applied was independent sample t-test, P < 0.05 was considered as significant. Results: The results of group II periodontitis subjects showed statistically significant increased gingival tissues ACP level when compared with the control group I subject. The mean levels of CAL and PPD were significantly >4 mm in periodontitis subjects when compared to control. Conclusions: The elevated level of ACP in the gingival tissue and Gram-negative microorganisms found in sub-gingival plaque was greater in periodontitis. Based on these results, gingival tissue ACP level can be considered as an independent risk factor for evaluating the microbial status and periodontal tissue damage. PMID:25767365

  20. The uptake, tissue distribution and depuration of a polychlorinated naphthalene (Halowax 1099) in relation to tissue lipid levels in the American oyster Crassostrea virginica 

    E-print Network

    Rue, William James

    1979-01-01

    THE UPTAKE, TISSUE DISTRIBUTION AND DEPURATION OF A POLYCHLORINATED NAPHTHALENE (HALOWAX 1099) IN RELATION TO TISSUE LIPID LEVELS IN THE AMERICAN OYSTER CRASSOSTREA VIRGINICA A Thesis by WILLIAM JAMES RUE, JR. Submitted to the Graduate... TO TISSUE LIPID LEVELS IN THE AMERICAN OYSTER CRASSOSTREA VIRGINICA A Theseus by WILLIAM JAMES RUE, JR. Approved as to sty1e and content by: (Ch rma of CommI ee) (Head of Department) (Member) Member) May 1979 ABSTRACT The Uptake, . Tissue...

  1. Methods for the Determination of Plasma or Tissue Glutathione Levels

    PubMed Central

    Tipple, Trent E.; Rogers, Lynette K.

    2013-01-01

    We present two different methods for determining levels of glutathione in complex biological samples and plasma. The DTNB/GR enzyme recycling method is sensitive and requires no specialized equipment. The HPLC method is particularly useful for situations in which sample amounts are limited. Detailed instructions for performing each method as well as the advantages and disadvantages of each are discussed in this Chapter. PMID:22669674

  2. Mercury speciation in piscivorous fish from mining-impacted reservoirs

    USGS Publications Warehouse

    Kuwabara, J.S.; Arai, Y.; Topping, B.R.; Pickering, I.J.; George, G.N.

    2007-01-01

    Guadalupe Reservoir (GUA), California, and Lahontan Reservoir (LAH), Nevada, U.S. are both affected either directly or indirectly by the legacy of gold and silver mining in the Sierra Nevada during the nineteenth century. Analysis of total mercury in fish from these lentic systems consistently indicate elevated concentrations (>1 ??g??g-1 wet weight; hereinafter, all concentrations are reported as wet weight unless indicated otherwise) well above the U.S. Environmenal Protection Agency's human consumption advisory level for fish (<0.3 ??g??g-1). Replicate X-ray absorption near edge structure (XANES) analyses on largemouth bass and hybrid striped bass from GUA and LAH were performed to determine predominant chemical species of mercury accumulated by these high-trophic-level piscivores that are exposed to elevated mercury through trophic transfer in mining-impacted lentic systems. Despite distinct differences in mercury source, the proximity of the source, and concentrations of complexing ligands, results of XANES analysis clearly indicated that mercury accumulated in these individual fish from the two reservoirs were dominated by methylmercury cysteine complexes. These findings are consistent with results from commercial fish species inhabiting marine environments which are presumed to include differing mercury sources (e.g., atmospheric, hydrothermal, or benthic). The dominance of methylmercury cysteine complexes in muscle tissues of fish obtained from such contrasting environments and exposure conditions suggests that a generic toxicological model for the consumption of fish could be applicable over a wide range of ecologic settings. ?? 2007 American Chemical Society.

  3. Soft Tissue Discrimination Using Magnetic Resonance Elastography with a New Elastic Level Set Model

    NASA Astrophysics Data System (ADS)

    Li, Bing Nan; Chui, Chee Kong; Ong, Sim Heng; Washio, Toshikatsu; Numano, Tomokazu; Chang, Stephen; Venkatesh, Sudhakar; Kobayashi, Etsuko

    Magnetic resonance elastography (MRE) noninvasively images the propagation of mechanical waves within soft tissues. The elastic properties of soft tissues can then be quantified from MRE wave snapshots. Various algorithms have been proposed to obtain their inversion for soft tissue elasticity. Anomalies are assumed to be discernible in the elasticity map. We propose a new elastic level set model to directly detect and track abnormal soft tissues in MRE wave images. It is derived from the Mumford-Shah functional, and employs partial differential equations for function modeling and smoothing. This level set model can interpret MRE wave images without elasticity reconstruction. The experimental results on synthetic and real MRE wave images confirm its effectiveness for soft tissue discrimination.

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

    Microsoft Academic Search

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

    2010-01-01

    The accumulation of mercury in freshwater aquatic food webs is a widespread health concern. Nearly one-third of US lakes have fish consumption advisories in place due to elevated concentrations of mercury in fish tissue. Mercury, primarily from fossil fuel combustion, is widely deposited across the landscape in the form of ionic mercury. The deposited ionic mercury can be transformed to

  5. Mercury and Selenium in a Mining-Affected Watershed of the Rocky Mountain Northwest

    NASA Astrophysics Data System (ADS)

    Langner, H.

    2011-12-01

    The moderating effect of selenium on mercury toxicity is well established, although mechanisms and environmental implications of this interaction are still a field of intensive research. The Upper Clark Fork River Basin in northwestern Montana offers a suitable field site to test some of the emerging models, as a history of intensive metals mining created sub-watersheds with variable combinations of mercury and selenium sources. To address various levels of the food web, we analyzed a preliminary set of sediments, fish tissues and osprey (Pandion haliaetus) blood samples from various locations throughout the watershed. Sediment mercury concentrations vary between 0.02 and over 10 mg/kg, and selenium in sediments ranges from undetectable to 5 mg/kg in the most contaminated reaches. Mercury levels in fish range from 0.03 to 1.5 mg/kg (wet wt) and are highly dependent on the geographic location, in addition to fish species and size. Mercury concentrations in blood of nestling osprey chicks vary between 97 and 730 ?g/L, with the majority of the variability explained by geographic location. Total mercury concentration in sediment can explain some of the variability in fish and ospreys; however, mercury accumulation in these organisms is also affected by factors such as the environmental methylation potential and possibly the sequestration of mercury in selenium compounds that are not prone to biomagnification in the food web. This hypothesis is supported by the geographic distribution of selenium and mercury levels in osprey blood: Relatively high selenium concentrations (~2000 ?g/L) are associated with the lowest blood mercury levels, despite relatively high mercury levels in the local sediments (~1 mg/kg). In reaches with the lowest selenium concentrations in osprey blood (430 ?g/L), the blood mercury levels are relatively high, despite very low sediment mercury levels. Analysis of this data points toward the role of bioavailable selenium in modifying the fate of mercury in the food web of a large river system in the Rocky Mountain Northwest.

  6. Mercury heavy-metal-induced physiochemical changes and genotoxic alterations in water hyacinths [Eichhornia crassipes (Mart.)].

    PubMed

    Malar, Srinivasan; Sahi, Shivendra Vikram; Favas, Paulo J C; Venkatachalam, Perumal

    2015-03-01

    Mercury heavy metal pollution has become an important environmental problem worldwide. Accumulation of mercury ions by plants may disrupt many cellular functions and block normal growth and development. To assess mercury heavy metal toxicity, we performed an experiment focusing on the responses of Eichhornia crassipes to mercury-induced oxidative stress. E. crassipes seedlings were exposed to varying concentrations of mercury to investigate the level of mercury ions accumulation, changes in growth patterns, antioxidant defense mechanisms, and DNA damage under hydroponics system. Results showed that plant growth rate was significantly inhibited (52 %) at 50 mg/L treatment. Accumulation of mercury ion level were 1.99 mg/g dry weight, 1.74 mg/g dry weight, and 1.39 mg/g dry weight in root, leaf, and petiole tissues, respectively. There was a decreasing trend for chlorophyll a, b, and carotenoids with increasing the concentration of mercury ions. Both the ascorbate peroxidase and malondialdehyde contents showed increased trend in leaves and roots up to 30 mg/L mercury treatment and slightly decreased at the higher concentrations. There was a positive correlation between heavy metal dose and superoxide dismutase, catalase, and peroxidase antioxidative enzyme activities which could be used as biomarkers to monitor pollution in E. crassipes. Due to heavy metal stress, some of the normal DNA bands were disappeared and additional bands were amplified compared to the control in the random amplified polymorphic DNA (RAPD) profile. Random amplified polymorphic DNA results indicated that genomic template stability was significantly affected by mercury heavy metal treatment. We concluded that DNA changes determined by random amplified polymorphic DNA assay evolved a useful molecular marker for detection of genotoxic effects of mercury heavy metal contamination in plant species. PMID:25323404

  7. Pattern of mercury accumulation in different tissues of migratory and resident birds: Western reef heron (Egretta gularis) and Siberian gull (Larus heuglini) in Hara International Wetland-Persian Gulf.

    PubMed

    Majidi, Yousef; Bahramifar, Nader; Ghasempouri, Seyed Mahmoud

    2015-01-01

    The Hara Mangrove Forest of the Persian Gulf is undergoing increasing pollution from industrial, municipal, and petroleum sources; however, little research in ecotoxicology has been carried out in this ecosystem. In the present study, mercury distribution and accumulation were investigated in muscle, liver, kidney, and feather of the resident Western reef heron (n?=?15) and the migratory Siberian gull (n?=?15). We also evaluated the relation between Hg concentrations, sex, and age (juvenile vs. adult). Results showed that the highest concentrations of Hg were recorded in the feather (35?±?0.14-3.0?±?0.27 mg kg(-1) dw) and at 3.7-, 1.6-, and 1.3-fold in muscle, kidney, and liver, respectively. Concentrations of mercury in tissues of migratory birds were two times higher than in resident birds; geographical differences and feeding habits were used to explain these variations. We found a weak relationship between Hg concentrations in feathers and internal tissues (r???0.50); conversely, liver presented strong positive correlations with other soft tissues, especially kidney (p?>?0.05; r?=?0.82). Results showed that sex and age have no significant effects on T-Hg accumulation in these birds (p?>?0.05; r?mercury pollution in this region. PMID:25492705

  8. Hair as an indicator of endogenous tissue levels of brominated flame retardants in mammals.

    PubMed

    D'Havé, Helga; Covaci, Adrian; Scheirs, Jan; Schepens, Paul; Verhagen, Ron; De Coen, Wim

    2005-08-15

    Few data are available on brominated flame retardants (BFRs) in terrestrial mammalian wildlife. Moreover, the use of hair in nondestructive monitoring of BFRs in mammals or humans has not been investigated. In the present study, concentrations of polybrominated diphenyl ethers (PBDEs) and brominated biphenyl 153 (BB 153) were analyzed in tissues of the European hedgehog Erinaceus europaeus. Road kills and carcasses from wildlife rescue centers were used to investigate relationships between concentrations of BFRs in hair and internal tissues, BFR tissue distribution (hair, liver, kidney, muscle, and adipose tissue), and PBDE congener tissue pattern dissimilarities. Liver concentrations of PBDEs and BB 153 were in the ranges 1-1178 and 0-2.5 ng/g of liver wet weight, respectively. PBDEs were predominant in adipose tissue and liver, while accumulation of BB 153 was tissue independent. The less persistent compound BDE 99 was more dominant in hair than in internal tissues. We observed positive relationships between BFR levels in hair and internal tissues for sum PBDEs and BDE 47 (0.37 < r < 0.78). The present study demonstrated that hair is a suitable indicator of PBDE exposure in terrestrial mammals which can be used in nondestructive monitoring schemes. PMID:16173558

  9. Investigation of mercury concentrations in fur of phocid seals using stable isotopes as tracers of trophic levels and geographical regions

    E-print Network

    Paris-Sud XI, Université de

    1 Investigation of mercury concentrations in fur of phocid seals using stable isotopes as tracers seal (Ommatophoca rossii), Weddell seals (Leptonychotes weddellii), crabeater seals (Lobodon carcinophaga), harbour seals (Phoca vitulina), grey seals (Halichoerus grypus), ringed seals (Phoca hispida

  10. Mercury levels in lichens from different host trees around a chlor-alkali plant in New Brunswick, Canada

    Microsoft Academic Search

    Marion Sensen; David H. S Richardson

    2002-01-01

    Mercury concentrations were determined in the epiphytic lichen Hypogymnia physodes along five transects starting from a chlor-alkali plant located at Dalhousie, New Brunswick, a landfill site and a nearby electricity generating station. Lichen samples were collected from white birch (Betula papyrifera) and spruce (Picea sp.) or balsam fir (Abies balsamea). Average lichen background mercury values were 0.088±0.005 ?g\\/g from white

  11. Mercury concentrations of fish, river water, and sediment in the Río Ramis-Lake Titicaca watershed, Peru

    Microsoft Academic Search

    Christopher H. Gammons; Darell G. Slotton; Butch Gerbrandt; Willis Weight; Courtney A. Young; Richard L. McNearny; Eugenio Cámac; Ruben Calderón; Henri Tapia

    2006-01-01

    This study reports the first set of data on the concentration of mercury in muscle tissue of several varieties of fish from Lake Titicaca, including the pejerrey (Basilichthyes bonariensis), the carachi (Orestias), and 2 types of indigenous catfish (Trichomycterus). Approximately 27% of the pejerrey and 75% of the carachi exceeded the US EPA fish tissue-based water quality criterion level of

  12. Phytoremediation of ionic and methyl mercury pollution

    SciTech Connect

    Meagher, R.B.

    1998-06-01

    'The long-term objective of the research is to manipulate single-gene traits into plants, enabling them to process heavy metals and remediate heavy-metal pollution by resistance, sequestration, removal, and management of these contaminants. The authors are focused on mercury pollution as a case study of this plant genetic engineering approach. The working hypothesis behind this proposal was that transgenic plants expressing both the bacterial organo mercury lyase (merB) and the mercuric ion reductase gene (merA) will: (A) remove the mercury from polluted sites and (B) prevent methyl mercury from entering the food chain. The results from the research are so positive that the technology will undoubtedly be applied in the very near future to cleaning large mercury contaminates sites. Many such sites were not remediable previously due to the excessive costs and the negative environmental impact of conventional mechanical-chemical technologies. At the time this grant was awarded 20 months ago, the authors had successfully engineered a small model plant, Arabidopsis thaliana, to use a highly modified bacterial mercuric ion reductase gene, merA9, to detoxify ionic mercury (Hg(II)), reducing it to much less toxic and volatile metallic Hg(0) (Rugh et al., 1996). Seeds from these plants germinate, grow, and set seed at normal growth rates on levels of Hg(II) that are lethal to normal plants. In assays on transgenic seedlings suspended in a solution of Hg(II), 10 ng of Hg(0) was evolved per min per mg wet weight of plant tissue. At that time, the authors had no information on expression of merA in any other plant species, nor had the authors tested merB in any plant. However, the results were so startlingly positive and well received that they clearly presaged a paradigm shift in the field of environmental remediation.'

  13. The effect of selenium on mercury assimilation by freshwater organisms

    E-print Network

    Belzile, Nelson

    The effect of selenium on mercury assimilation by freshwater organisms Nelson Belzile, Yu-Wei Chen mercury in tissues of zooplankton, mayflies (Stenonema femoratum), amphipods (Hyalella azteca), and young

  14. THERMODYNAMIC REACTION CONSTANTS FOR MODELING AQUEOUS ENVIRONMENTAL MERCURY SPECIATION

    EPA Science Inventory

    Unacceptably high fish tissue mercury residues are responsible for the majority of fish consumption advisories issued in 48 states of the United States of America. Mercury also has emerged as a transboundary contaminant of global concern. Although monomethylmercury is generally...

  15. Mercury Accumulation and Biomagnification in Ospreys (Pandion haliaetus) in the James Bay and Hudson Bay Regions of Québec

    PubMed

    DesGranges; Rodrigue; Tardif; Laperle

    1998-08-01

    Mercury exposure was examined in adults and nestlings of ospreys (Pandion haliaetus) from lakes, rivers, and hydroelectric reservoirs in northern Québec between 1989 and 1991 by assessing the amount of mercury transferred from fish to ospreys, which are voracious fish-eaters. The high mercury concentrations detected in adult feathers and tissues (feathers, blood, liver, kidneys, muscles, brain) of nestlings indicate an increase in mercury availability at recently constructed hydroelectric reservoirs (10-12 years for the La Grande-2 Reservoir). With mean total mercury levels of 37.3 mg/kg and 1.9 mg/kg in feathers (dry weight) and in blood (wet weight), respectively, contamination rates were, in both tissues, five times higher for chicks born near the La Grande Reservoirs (western sector) than in those reared in natural habitats. Furthermore, the mean quantity of total mercury in 40-day-old chicks reared near a reservoir was 10.5 mg, compared with to 1.6 mg for those reared in a natural environment. Modeling of mercury transfer from fish to osprey nestlings showed that the mercury level in chicks' blood provides a good estimate of mercury concentrations in ingested food. In addition, the relationship between mercury concentrations in the blood and that in feathers indicates that substantial biomagnification of mercury occurs from the ingested dose to the feathers. The intensity of this biomagnification varies with the age of the chicks and reaches a maximum value as the flight feathers start to form (at 20-25 days of age) declining thereafter until the bird is 45 days old and growth of those feathers is complete. Nevertheless, the mean number of young fledged on reservoirs where mercury exposure is greatest (>40 mg/kg of Hg in chicks' feathers) did not differ (1.6 +/- 0.7) from that observed elsewhere in built-up environments (1.9 +/- 0.7) or in natural habitats (2.0 +/- 0.7) (H = 4.39; p = 0.11). Storage of mercury in growing feathers (86% of all mercury in osprey) prevents accumulation in living tissues, thereby protecting the chick from related toxic effects. However, toxicological problems may arise after fledging. In particular, attention should be paid to postfledging survival before concluding that mercury exposure is insufficiently high in Osprey young reared at reservoirs. PMID:9680526

  16. Stevia, cyclamate and saccharin - natural and artificial sweeteners - exert no effect on sulfane levels in tissues.

    PubMed

    Wilinski, Bogdan; Opoka, Wlodzimierz; Somogyi, Eugeniusz; Piotrowska, Joanna; Wilinski, Jerzy

    2013-01-01

    The interactions among natural and artificial sweeteners and endogenous sulfur metabolism have never been investigated. CBA strain mice were administered orally stevia, cyclamate or saccharin in doses of 5 mg/kg of body weight in water solutions each. The measurements of the free and acid-labile sulfane (H2S) tissue concentrations in brain, heart, liver and kidney were performed with Siegel spectrophotometric modified method. No differences in comparisons between hydrogen sulfide concentrations in the control group and each sweetener group within every tissue type were noted. In conclusion, stevia, cyclamate and saccharine do not change the endogenous sulfur metabolism to the extent of causing sulfane tissue levels alterations. PMID:24858558

  17. Tocotrienol levels in adipose tissue of benign and malignant breast lumps in patients in Malaysia.

    PubMed

    Nesaretnam, Kalanithi; Gomez, Patricia Alison; Selvaduray, Kanga Rani; Razak, Ghazali Abdul

    2007-01-01

    Data on dietary exposure to vitamin E by plasma or adipose tissue concentrations of alpha-tocopherol (alpha-T) in observational studies have failed to provide consistent support for the idea that alpha-T provides women with any protection from breast cancer. In contrast, studies indicate that alpha, gamma, and delta-tocotrienols but not alpha-T have potent anti-proliferative effects in human breast cancer cells. Our aim was to investigate whether there was a difference in tocopherol and tocotrienol concentrations in malignant and benign adipose tissue, in a Malaysian population consuming predominantly a palm oil diet. The study was undertaken using fatty acid levels in breast adipose tissue as a biomarker of qualitative dietary intake of fatty acids. The major fatty acids in breast adipose tissue of patients (benign and malignant) were oleic acid (45-46%), palmitic (28-29%) and linoleic (11-12%). No differences were evident in the fatty acid composition of the two groups. There was a significant difference (p=0.006) in the total tocotrienol levels between malignant (13.7 +/- 6.0 microg/g) and benign (20+/-6.0 microg/g) adipose tissue samples. However, no significant differences were seen in the total tocopherol levels (p=0.42) in the two groups. The study reveals that dietary intake influences adipose tissue fatty acid levels and that adipose tissue is a dynamic reservoir of fat soluble nutrients. The higher adipose tissue concentrations of tocotrienols in benign patients provide support for the idea that tocotrienols may provide protection against breast cancer. PMID:17704032

  18. Method and system for in vivo measurement of bone tissue using a two level energy source

    NASA Technical Reports Server (NTRS)

    Cameron, J. R.; Judy, P. F. (inventors)

    1976-01-01

    Methods and apparatus are provided for radiologically determining the bone mineral content of living human bone tissue independently of the concurrent presence of adipose and other soft tissues. A target section of the body of the subject is irradiated with a beam of penetrative radiations of preselected energy to determine the attenuation of such beam with respect to the intensity of each of two radiations of different predetermined energy levels. The resulting measurements are then employed to determine bone mineral content.

  19. A Screening Level Probabilistic Risk Assessment of Mercury in Florida Everglades Food Webs

    Microsoft Academic Search

    Stephanie E. Duvall; Mace G. Barron

    2000-01-01

    A screening level probabilistic assessment of risks was performed on three species of piscivorous wildlife at the top of Everglades aquatic food webs: the American alligator (Alligator mississippiensis), the great egret (Egretta alba), and the raccoon (Procyon lotor varius). Ranges of dietary exposure concentrations (and probability distribution functions) were derived for two general areas of the Everglades: Shark Slough and

  20. Superpredation increases mercury levels in a generalist top predator, the eagle owl

    E-print Network

    Penteriani, Vincenzo

    effects on vertebrate top predators. Hg levels in these eagle owl populations are relatively low consequences for some raptor species resulting from the bioaccumulation of these chemicals, including low´vora, Portugal P. C. Tavares CVRM-Geo-Systems Centre, Instituto Superior Te´cnico, Av. Rovisco Pais, 1049

  1. Comparison of Blood and Brain Mercury Levels in Infant Monkeys Exposed to Methylmercury or Vaccines Containing Thimerosal

    PubMed Central

    Burbacher, Thomas M.; Shen, Danny D.; Liberato, Noelle; Grant, Kimberly S.; Cernichiari, Elsa; Clarkson, Thomas

    2005-01-01

    Thimerosal is a preservative that has been used in manufacturing vaccines since the 1930s. Reports have indicated that infants can receive ethylmercury (in the form of thimerosal) at or above the U.S. Environmental Protection Agency guidelines for methylmercury exposure, depending on the exact vaccinations, schedule, and size of the infant. In this study we compared the systemic disposition and brain distribution of total and inorganic mercury in infant monkeys after thimerosal exposure with those exposed to MeHg. Monkeys were exposed to MeHg (via oral gavage) or vaccines containing thimerosal (via intramuscular injection) at birth and 1, 2, and 3 weeks of age. Total blood Hg levels were determined 2, 4, and 7 days after each exposure. Total and inorganic brain Hg levels were assessed 2, 4, 7, or 28 days after the last exposure. The initial and terminal half-life of Hg in blood after thimerosal exposure was 2.1 and 8.6 days, respectively, which are significantly shorter than the elimination half-life of Hg after MeHg exposure at 21.5 days. Brain concentrations of total Hg were significantly lower by approximately 3-fold for the thimerosal-exposed monkeys when compared with the MeHg infants, whereas the average brain-to-blood concentration ratio was slightly higher for the thimerosal-exposed monkeys (3.5 ± 0.5 vs. 2.5 ± 0.3). A higher percentage of the total Hg in the brain was in the form of inorganic Hg for the thimerosal-exposed monkeys (34% vs. 7%). The results indicate that MeHg is not a suitable reference for risk assessment from exposure to thimerosal-derived Hg. Knowledge of the toxicokinetics and developmental toxicity of thimerosal is needed to afford a meaningful assessment of the developmental effects of thimerosal-containing vaccines. PMID:16079072

  2. Matrix metalloproteinases (MMPs) in fresh human prostate tumour tissue and organ-cultured prostate tissue: Levels of collagenolytic and gelatinolytic MMPs are low, variable and different in fresh tissue versus organ-cultured tissue

    PubMed Central

    Varani, J; Hattori, Y; Dame, M K; Schmidt, T; Murphy, H S; Johnson, K J; Wojno, K J

    2001-01-01

    Prostate tissue was obtained from 22 radical prostatectomies (performed for clinical management of prostate carcinoma) immediately after surgery. A small piece of tissue was fixed immediately in formalin and used for routine histology while a second piece was frozen in OCT and used for immuno-histochemistry. Another small piece was used for isolation of epithelial and stromal cells. The remainder of the tissue was cut into 2 × 2?mm pieces and incubated in organ culture for 8 days. In organ culture, non-malignant, basal epithelial cells underwent a proliferative response. This was accompanied by de-differentiation of glandular structures and by migration of epithelial cells across the surface of the tissue. Erosion of the basement membrane could also be seen in places, but was not widespread. Invasion of epithelial cells into the adjacent stroma was not evident. Production of matrix metalloproteinases (MMPs) with gelatinolytic activity or collagenolytic activity was assessed in organ culture and compared to expression patterns in fresh tissue. MMP-1 (interstitial collagenase) and MMP-9 (92-kDa gelatinase B) were undetectable or low in fresh tissue specimens. Both enzymes were detected in organ culture and both increased over time. Even after 6 days, however, there was only a low level of gelatin-hydrolytic activity and no measurable collagen-hydrolytic activity. In past studies we used organ cultures of normal skin and malignant skin tumours (basal cell carcinomas) to help elucidate the role of collagenolytic and gelatinolytic MMPs in epithelial cell invasion (Varani et al, 2000). Compared to MMP levels observed in skin, levels of these enzymes in prostate are low. The low level of collagenolytic and gelatinolytic MMPs in fresh prostate tissue and in organ-cultured prostate tissue may help explain why there is little tissue destruction in many primary prostate tumours and why the majority of such tumours remain confined to the prostate for extended periods. © 2001 Cancer Research Campaign http://www.bjcancer.com PMID:11308257

  3. Low mercury levels in marine fish from estuarine and coastal environments in southern China.

    PubMed

    Pan, Ke; Chan, Heidi; Tam, Yin Ki; Wang, Wen-Xiong

    2014-02-01

    This study is the first comprehensive evaluation of total Hg and methylmercury (MeHg) concentrations in wild marine fish from an estuarine and a coastal ecosystem in southern China. A total of 571 fish from 54 different species were examined. Our results showed that the Hg levels were generally low in the fish, and the Hg levels were below 30 ng g(-1) (wet weight) for 82% of the samples, which may be related to the reduced size of the fish and altered food web structure due to overfishing. Decreased coastal wetland coverage and different carbon sources may be responsible for the habitat-specific Hg concentrations. The degree of biomagnification was relatively low in the two systems. PMID:24292441

  4. Software and system level tests of a test flight mercury ion thruster subsystem

    NASA Technical Reports Server (NTRS)

    Robson, R. R.; Low, C. A., Jr.

    1982-01-01

    A U.S. Air Force technology spacecraft flight is scheduled to carry an Ion Auxiliary Propulsion System (IAPS) as part of its experimental payload. This paper presents the results of the successful flight-software qualification and system-level tests which were performed on IAPS. The software tests were performed with an operating engineering model ion thruster and power processing unit, and failure/off-normal recovery modes, operation with and without temperature telemetry from the thruster vaporizers, and with closed-loop control or fixed setpoint operation of the thruster vaporizers. The system-level tests cover a wide range of thermal and operating conditions with the entire system exposed to a simulated space environment.

  5. Naringin Levels in Citrus Tissues : II. Quantitative Distribution of Naringin in Citrus paradisi MacFad.

    PubMed

    Jourdan, P S; McIntosh, C A; Mansell, R L

    1985-04-01

    The quantitative distribution of the flavanone-7-neohesperidoside, naringin, in seeds, seedlings, young plants, branches, flowers, and fruit of Citrus paradisi Macfad., cv ;Duncan' was analyzed by radioimmunoassay. High levels of naringin were associated with very young tissue and lower levels were found in older tissues. Seed coats of ungerminated seeds and young shoots had high naringin concentrations whereas cotyledons and roots had very low concentrations. Light-grown seedlings contained nearly twice as much naringin as etiolated seedlings and, in young plants and branches, the naringin content was highest in developing leaves and stem tissue. In flowers, the ovary had the highest levels of naringin, accounting for nearly 11% of the fresh weight. There was a net increase in the total naringin content of fruits during growth. However, due to the large increase in fruit size, there was a concomitant decrease in the naringin concentration as the fruit matured. PMID:16664159

  6. Levels of PCBs and organochlorine pesticides in human adipose tissue collected in Ehime Prefecture

    SciTech Connect

    Mori, Y.; Kikuta, M.; Okinaga, E.; Okura, T.

    1983-01-01

    Human adipose tissue samples were obtained from National Hospital Shikoku Cancer Center in Matsuyama City, Japan, and analyaed for PCBs and organochlorine Pesticides (HCH, HCB, DDT). The levels of PCBs were almost constant from 1973 to 1976 and tended to decrease gradually from 1976 to 1981, ranging from 5.43 to 3.02 ppm. HCH and DDT levels decreased from 1974 to 1976, and remained fairly constant to 1981. Contaminant levels are related to age, sex, and disease state. (JMT)

  7. [Mercury concentration and its distribution in Nycticorax nycticorax and Chinese Ardeola bacchus fledglings at Huangpu District of Guangzhou City, China].

    PubMed

    Zou, Fasheng; Yang, Qiongfang; Li, Yanhong; Cui, Kunyan

    2005-02-01

    In this study, live fledglings of Nycticorax nycticorax and Ardeola bacchus at the Huangpu District of Guangzhou City were collected, and their primary feather, breast feather, tail feather, liver, chest muscle and egg shell were sampled for mercury determination. The results showed that these two heron species had a very similar distribution pattern of mercury concentration in their tissues and organs, i. e., tail feather > breast and primary feather > liver > chest muscle > egg shell. Ardeola bacchus had higher levels of mercury in all its tissues than Nycticorax nycticorax. There were significant interspecific differences in mercury level for breast feather and primary feather. Because the collection of breast feather is easier and not harmful to birds, it is better to use it rather than primary or tail feather to monitor environmental pollution. The mercury level in breast feather was ten times higher than that in liver, lower than that in tail feather, but not significantly different to that in primary feather. The mercury concentrations in the tissues of Nycticorax nycticorax and Ardeola bacchus from Huangpu District of Guangzhou were similar to those from the suburbs of Chengdu, Sichuan Province, but lower than those from Taihu Lake, Jiangsu Province and higher than those from Hong Kong. PMID:15852945

  8. Endothelial cell protein C receptor-mediated redistribution and tissue-level accumulation of factor VIIa

    PubMed Central

    Clark, C A; Vatsyayan, R; Hedner, U; Esmon, C T; Pendurthi, U R; Rao, L V M

    2012-01-01

    Background Recent studies show that activated factor VII (FVIIa) binds to the endothelial cell protein C receptor (EPCR) on the vascular endothelium; however, the importance of this interaction in hemostasis or pathophysiology is unknown. Objective The aim of the present study was to investigate the role of the FVIIa interaction with EPCR on the endothelium in mediating FVIIa transport from the circulation to extravascular tissues. Methods Wild-type, EPCR-deficient or ECPR-over-expressing mice were injected with human recombinant (r)FVIIa (120 ?g kg?1 body weight) via the tail vein. At varying time intervals after rFVIIa administration, blood and various tissues were collected to measure FVIIa antigen and activity levels. Tissue sections were analyzed by immunohistochemistry for FVIIa and EPCR. Results The data reveal that, after intravenous (i.v.) injection, rFVIIa rapidly disappears from the blood and associates with the endothelium in an EPCR-dependent manner. Immunohistochemical analyses revealed that the association of FVIIa with the endothelium was maximal at 30 min and thereafter progressively declined. The FVIIa association with the endothelium was undetectable at time points exceeding 24 h post-FVIIa administration. The levels of rFVIIa accumulated in tissue correlate with expression levels of EPCR in mice and FVIIa associated with tissues remained functionally active for periods of at least 7 days. Conclusions The observation that an EPCR-dependent association of FVIIa with the endothelium is most pronounced soon after rFVIIa administration and subsequently declines temporally, combined with the retention of functionally active FVIIa in tissue homogenates for extended periods, indicates that FVIIa binding to EPCR on the endothelium facilitates the transport of FVIIa from circulation to extravascular tissues where TF resides. PMID:22950420

  9. A screening level probabilistic risk assessment of mercury in Florida Everglades food webs.

    PubMed

    Duvall, S E; Barron, M G

    2000-11-01

    A screening level probabilistic assessment of risks was performed on three species of piscivorous wildlife at the top of Everglades aquatic food webs: the American alligator (Alligator mississippiensis), the great egret (Egretta alba), and the raccoon (Procyon lotor varius). Ranges of dietary exposure concentrations (and probability distribution functions) were derived for two general areas of the Everglades: Shark Slough and the southcentral Everglades (highly contaminated with Hg), and the northern Everglades (a lower Hg contaminated area in and near Water Conservation Area 1). Ranges of toxicity reference values and probability distribution functions were derived from literature on the toxicity of dietary methyl Hg to birds and mammals. Probability distributions of risk estimates for each receptor were generated using Monte Carlo simulations and indicated that piscivorous wildlife feeding in the south-central region of the Everglades are at high risk from consumption of Hg-contaminated prey. Alligators had 100% exceedences of chronic risk thresholds, and great egrets had 99% exceedences. In the northern Everglades, exceedences of chronic risk thresholds were substantially lower but were still present (6-34% exceedences). Results support previous studies suggesting that top predators of the Everglades may be at risk from Hg contamination and indicate that Hg risks are location-dependent. PMID:11139184

  10. Mercury vapour (Hg(0)): Continuing toxicological uncertainties, and establishing a Canadian reference exposure level.

    PubMed

    Richardson, G Mark; Brecher, Ronald W; Scobie, Hugh; Hamblen, Jane; Samuelian, John; Smith, Cindy

    2009-02-01

    There are four published reference exposure levels (RELs) for Hg(0), ranging from 0.09microg/m(3) to 1microg/m(3). All RELs were derived from the same toxicological database, predominantly of male chloralkali workers. Some key factors are apparent which make the use of that database questionable for REL derivation. Occupational studies of chloralkali workers are not an appropriate basis for a REL for Hg(0). Concomitant exposure to chlorine gas (Cl(2)) diminishes uptake and effects of Hg(0) exposure. There are gender differences in Hg(0) uptake, distribution and excretion, with females at potentially greater risk from Hg(0) exposure than males. Studies of chloralkali workers focused almost exclusively on adult males. Recent investigations of dental professionals (dentists, technicians, assistants) have failed to define a threshold in the dose-response relationship linking Hg(0) with neurobehavioural outcomes, an observation generally ignored in Hg(0) REL development. Finally, there is a growing database on genetic predisposition to health effects associated with Hg(0) exposure. Based on these considerations, we propose a different key study for REL derivation, one that involved male and female dental professionals without concomitant Cl(2) exposure. Adjusting the LOEAL to continuous exposure and applying appropriate UF values, we propose a Canadian REL for Hg(0) of 0.06microg/m(3). PMID:18992295

  11. Biomagnification of mercury and selenium in blue shark Prionace glauca from the Pacific Ocean off Mexico.

    PubMed

    Escobar-Sánchez, Ofelia; Galván-Magaña, Felipe; Rosíles-Martínez, René

    2011-12-01

    The aim of this study was to determine the biomagnification of mercury through the principal prey of the blue shark, Prionace glauca, off the western coast of Baja California Sur, Mexico, as well as the relationship between mercury and selenium in blue sharks. High levels of mercury were found in shark muscle tissues (1.39?±?1.58 ?g/g wet weight); these values are above the allowed 1.0 ?g/g for human consumption. The mercury to selenium molar ratio was 1:0.2. We found a low correlation between mercury bioaccumulation and shark size. Juveniles have lower concentrations of mercury than adults. Regarding the analyzed prey, the main prey of the blue shark, pelagic red crab, Pleuroncodes planipes, bioaccumulated 0.04?±?0.01 ?g/g Hg wet weight, but the prey with higher bioaccumulation was the bullet fish Auxis spp. (0.20?±?0.02 ?g/g wet weight). In terms of volume, the red crab P. planipes can be the prey that provides high levels of mercury to the blue shark. PMID:21465285

  12. Mercury and selenium content of Taiwanese seafood

    Microsoft Academic Search

    G. C. Fang; D. H. Nam; N. Basu

    2011-01-01

    Fish consumption is avid in Taiwan (and other Asian nations), but little is known about the mercury and selenium content in local seafood. This paper reports on total mercury, methylmercury and selenium levels from 14 commonly consumed seafood items obtained from Taichung, Taiwan. Mean total mercury concentrations varied nearly 100-fold across species. Fifty per cent of the marlins sampled and

  13. Cholinesterase and monoamine oxidase activity in relation to mercury levels in the cerebral cortex of wild river otters

    Microsoft Academic Search

    N Basu; A M Scheuhammer; R D Evans; M OBrien; H M Chan

    2007-01-01

    Mercury (Hg) is a global pollutant that is neurotoxic to many mammalian species. The present study was conducted to determine if the bioaccumulation of Hg by wild river otters (Lontra canadensis) could be related to variations in the activities of key neurochemical enzymes. River otters were collected from Ontario and Nova Scotia (Canada) during the trapping seasons, spanning 2002-2004, and

  14. Critical levels of atmospheric pollution: criteria and concepts for operational modelling of mercury in forest and lake ecosystems

    Microsoft Academic Search

    Markus Meili; Kevin Bishop; Lage Bringmark; Kjell Johansson; John Munthe; Harald Sverdrup; Wim de Vries

    2003-01-01

    Mercury (Hg) is regarded as a major environmental concern in many regions, traditionally because of high concentrations in freshwater fish, and now also because of potential toxic effects on soil microflora. The predominant source of Hg in most watersheds is atmospheric deposition, which has increased 2- to >20-fold over the past centuries. A promising approach for supporting current European efforts

  15. Metabolic factors, adipose tissue, and plasminogen activator inhibitor-1 levels in Type 2 diabetes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plasminogen activator inhibitor-1 (PAI-1) production by adipose tissue is increased in obesity, and its circulating levels are high in type 2 diabetes. PAI-1 increases cardiovascular risk by favoring clot stability, interfering with vascular remodeling, or both. We investigated in obese diabetic per...

  16. Circulating 20S Proteasome Levels in Patients with Mixed Connective Tissue Disease and Systemic Lupus Erythematosus?

    PubMed Central

    Majetschak, Matthias; Perez, Magdalena; Sorell, Luis T.; Lam, Janet; Maldonado, Marcos E.; Hoffman, Robert W.

    2008-01-01

    The associations of circulating 20S proteasomes (c20S) with clinical and serologic disease indices in patients with systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD) are unknown. We present the initial report that c20S levels are elevated in MCTD and correlate with clinically relevant changes in disease activity in SLE and MCTD. PMID:18667633

  17. Agent Orange and the Vietnamese: the persistence of elevated dioxin levels in human tissues.

    PubMed Central

    Schecter, A; Dai, L C; Thuy, L T; Quynh, H T; Minh, D Q; Cau, H D; Phiet, P H; Nguyen, N T; Constable, J D; Baughman, R

    1995-01-01

    OBJECTIVES. The largest known dioxin contamination occurred between 1962 and 1970, when 12 million gallons of Agent Orange, a defoliant mixture contaminated with a form of the most toxic dioxin, were sprayed over southern and central Vietnam. Studies were performed to determine if elevated dioxin levels persist in Vietnamese living in the south of Vietnam. METHODS. With gas chromatography and mass spectroscopy, human milk, adipose tissue, and blood from Vietnamese living in sprayed and unsprayed areas were analyzed, some individually and some pooled, for dioxins and the closely related dibenzofurans. RESULTS. One hundred sixty dioxin analyses of tissue from 3243 persons were performed. Elevated 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) levels as high as 1832 ppt were found in milk lipid collected from southern Vietnam in 1970, and levels up to 103 ppt were found in adipose tissue in the 1980s. Pooled blood collected from southern Vietnam in 1991/92 also showed elevated TCDD up to 33 ppt, whereas tissue from northern Vietnam (where Agent Orange was not used) revealed TCDD levels at or below 2.9 ppt. CONCLUSIONS. Although most Agent Orange studies have focused on American veterans, many Vietnamese had greater exposure. Because health consequences of dioxin contamination are more likely to be found in Vietnamese living in Vietnam than in any other populations, Vietnam provides a unique setting for dioxin studies. PMID:7702115

  18. Organochlorine pesticide gradient levels among maternal adipose tissue, maternal blood serum and umbilical blood serum.

    PubMed

    Herrero-Mercado, Margarita; Waliszewski, S M; Caba, M; Martínez-Valenzuela, C; Gómez Arroyo, S; Villalobos Pietrini, R; Cantú Martínez, P C; Hernández-Chalate, F

    2011-03-01

    The objective of the present study was to determine levels and calculate ratios of copartition coefficients among organochlorine pesticides ?-HCH, pp'DDE, op'DDT and pp'DDT in maternal adipose tissue, maternal blood serum and umbilical blood serum of mother-infant pairs from Veracruz, Mexico. Organochlorine pesticides were analyzed in 70 binomials: maternal adipose tissue, maternal serum and umbilical cord serum samples, using gas chromatography with electron capture detection (GC-ECD). The results were expressed as mg/kg on fat basis. p,p'-DDE was the major organochlorine component, detected in every maternal adipose tissue (0.770 mg/kg), maternal serum sample (5.8 mg/kg on fat basis) and umbilical cord blood sample (6.9 mg/kg on fat basis). p,p'-DDT was detected at 0.101 mg/kg, 2.2 mg/kg and 5.9 mg/kg respectively, according to the order given above. ?-HCH was detected at 0.027 mg/kg, 4.2 mg/kg and 28.0 mg/kg respectively. op'DDT was detected only in maternal adipose tissue at 0.011 mg/kg. The copartition coefficients among samples identify significant increases in concentrations from adipose tissue to maternal blood serum and to umbilical blood serum. The increase indicated that maternal adipose tissue released organochlorine pesticides to blood serum and that they are carried over to umbilical cord blood. PMID:21290101

  19. Levels and distribution of organochlorine pollutants in primary dental tissues and bone of lamb.

    PubMed

    Jan, Janja; Urši?, Matjaž; Vrecl, Milka

    2013-11-01

    This study examined the bioconcentration of selected organochlorine pollutants, tetra- and hexa-chlorobiphenyls with planar (PCB-80, PCB-169) and non-planar (PCB-54, PCB-155) structure, and persistent organochlorine pesticides with planar [hexachlorobenzene (HCB)] and non-planar [1,1-bis (4-chlorophenyl)-2,2-dichloroethene (4,4'-DDE)] structure in primary dental tissues (pulp, dentine, and enamel) and mandibular bone of lactationally exposed lambs, and compared it with the organochlorines distribution pattern in permanent dental tissues and bone. Also, the role of pollutants physicochemical properties and tissue specific characteristics in the bioconcentration was assessed. Residual levels of individual pollutants were analyzed by high-resolution gas chromatography with electron-capture detection. Our results showed that transfer of organochlorines to primary hard dental tissues was higher than to permanent hard dental tissues. Metabolically more stable, planar, and toxic organochlorines (e.g. PCB-169 and HCB) predominated in primary hard dental tissues, where they may represent a potential risk for developmental dental defects. PMID:24100271

  20. The effects of various anesthetics on tissue levels of fructose-2,6-bisphosphate in rats.

    PubMed

    Kasten, T; Colliver, J A; Montrey, R D; Dunaway, G A

    1990-07-01

    We report that the short-term use of various anesthetic agents prior to decapitation causes alteration of the levels of fructose-2,6-bisphosphate in kidney, brain, heart, muscle, and liver. These data indicate that even light anesthesia can not be used when levels of this metabolite are to be determined. Also, it appears that the use of any of these anesthetics can profoundly alter glucose utilization in many tissues. PMID:2166868

  1. Tissue culture media supplemented with 10% fetal calf serum contains a castrate level of testosterone

    Microsoft Academic Search

    J. P. Michiel Sedelaar; John T. Isaacs

    2009-01-01

    BACKGROUND: Human prostate cancer cells are routinely maintained in media supplemented with 10% Fetal Calf Serum (FCS) to provide androgen. In the present study, total and free testosterone levels in 10%FCS supplemented tissue culture media were determined and compared to levels in intact and castrated human males. Dextran-coated charcoal stripped FCS (i.e., DC-FCS) is often used instead of FCS to

  2. ELF (extremely-low-frequency) field interactions at the animal, tissue and cellular levels

    SciTech Connect

    Tenforde, T.S.

    1990-10-01

    A description is given of the fundamental physical properties of extremely-low-frequency (ELF) electromagnetic fields, and the mechanisms through which these fields interact with the human body at a macroscopic level. Biological responses to ELF fields at the tissue, cellular and molecular levels are summarized, including new evidence that ELF field exposure produces alterations in gene expression and the cytoplasmic concentrations of specific proteins.

  3. Mercury CEM Calibration

    SciTech Connect

    John F. Schabron; Joseph F. Rovani; Susan S. Sorini

    2007-03-31

    The Clean Air Mercury Rule (CAMR) which was published in the Federal Register on May 18, 2005, requires that calibration of mercury continuous emissions monitors (CEMs) be performed with NIST-traceable standards. Western Research Institute (WRI) is working closely with the Electric Power Research Institute (EPRI), the National Institute of Standards and Technology (NIST), and the Environmental Protection Agency (EPA) to facilitate the development of the experimental criteria for a NIST traceability protocol for dynamic elemental mercury vapor generators. The traceability protocol will be written by EPA. Traceability will be based on the actual analysis of the output of each calibration unit at several concentration levels ranging from about 2-40 ug/m{sup 3}, and this analysis will be directly traceable to analyses by NIST using isotope dilution inductively coupled plasma/mass spectrometry (ID ICP/MS) through a chain of analyses linking the calibration unit in the power plant to the NIST ID ICP/MS. Prior to this project, NIST did not provide a recommended mercury vapor pressure equation or list mercury vapor pressure in its vapor pressure database. The NIST Physical and Chemical Properties Division in Boulder, Colorado was subcontracted under this project to study the issue in detail and to recommend a mercury vapor pressure equation that the vendors of mercury vapor pressure calibration units can use to calculate the elemental mercury vapor concentration in an equilibrium chamber at a particular temperature. As part of this study, a preliminary evaluation of calibration units from five vendors was made. The work was performed by NIST in Gaithersburg, MD and Joe Rovani from WRI who traveled to NIST as a Visiting Scientist.

  4. Elemental mercury exposure among children of thermometer plant workers

    Microsoft Academic Search

    P. J. Hudson; R. L. Vogt; J. Brondum; L. Witherell; G. Myers; D. C. Paschal

    1987-01-01

    Because evidence of mercury exposure was found among workers of a mercury thermometer-manufacturing plant in March 1984, the Vermont Department of Health studied the workers' children for both exposure to mercury and evidence of mercury toxicity. The median urine mercury level of 23 workers' children was 25 micrograms\\/L. This was significantly higher than the level (5 micrograms\\/L) among 39 children

  5. Qualitative and quantitative mass spectrometry imaging of drugs and metabolites in tissue at therapeutic levels.

    PubMed

    Sun, Na; Walch, Axel

    2013-08-01

    Mass spectrometry imaging (MSI) is a rapidly evolving technology that yields qualitative and quantitative distribution maps of small pharmaceutical-active molecules and their metabolites in tissue sections in situ. The simplicity, high sensitivity and ability to provide comprehensive spatial distribution maps of different classes of biomolecules make MSI a valuable tool to complement histopathology for diagnostics and biomarker discovery. In this review, qualitative and quantitative MSI of drugs and metabolites in tissue at therapeutic levels are discussed and the impact of this technique in drug discovery and clinical research is highlighted. PMID:23881163

  6. A case for in vivo mass-independent fractionation of mercury isotopes in fish

    NASA Astrophysics Data System (ADS)

    Das, Reshmi; Salters, Vincent J. M.; Odom, A. Leroy

    2009-11-01

    The recent discovery of mass-independent fractionation of mercury isotopes allows new constraints to be placed on the mercury cycle. Here we report new Hg isotopic analyses of zooplankton and fish from different trophic levels of a freshwater lake (Lake Jackson, Florida) bearing systematic mass-independent fractionation of mercury isotopes. Fish muscle tissues show a progressive enrichment in the odd-mass mercury isotopes having odd atomic mass numbers (199 and 201) with increasing trophic level. Trophic level was determined based on nitrogen isotopic composition as well as fish stomach content. Zooplankton in the lake contain mercury with ?199Hg and ?201Hg values of +0.43 (±0.07)‰ and +0.44 (±0.07)‰, respectively. The ?199Hg values increase by ˜1‰ from ˜+0.4‰ in zooplankton, juvenile bluegill, and several other small fishes to ?199Hg = +1.36‰ for the Florida gar, which is the top predator fish in the lake. Previous observations of odd-mass-number isotope enrichment of mercury have been explained by photoreduction and demethylation of methyl mercury in the water column or as isotope effects related to microbial methylation. However, our data and the data of Jackson et al. (2008) are also consistent with in vivo production of mass-independent fractionation. Considering the alternatives, mass-independent fractionation by metabolic processes is the most straightforward explanation for the mercury isotope data. There are two known mechanisms for mass-independent fractionation of mercury, i.e., the nuclear volume effect and the magnetic isotope effect. While the data are insufficient to serve as proof, the magnitude of the mass-independent effect and the nearly equal enrichment of 199Hg and 201Hg seem most suggestive of a magnetic isotope effect.

  7. Determination of mercury in environmental samples: a constant challenge

    SciTech Connect

    Ferguson, N M

    1980-01-01

    A method for the determination of mercury in environmental samples is described. The laboratory maintenance for low mercury contamination in air and glassware is also described. Sample preparation is discussed. Mercury analysis is performed by cold vapor atomic absorption. This method can measure mercury content at concentration levels ranging from parts-per-trillion to mg/g. (DC)

  8. Leptin Level and Oxidative Stress Contribute to Obesity-Induced Low Testosterone in Murine Testicular Tissue

    PubMed Central

    Zhao, Jian; Zhai, Lingling; Liu, Zheng; Wu, Shuang; Xu, Liping

    2014-01-01

    Objective. This study evaluated the effects of obesity on the function of reproductive organs in male mice and the possible mechanism of male secondary hypogonadism (SH) in obesity. Methods. Ninety-six mice were randomly assigned to three groups: the control group, diet-induced obesity group, and diet-induced obesity resistant group for 8 weeks and 19 weeks. The effects of short- and long-term high-fat diet on the reproductive organs were determined by measuring sperm count and motility, relative testis weight, testosterone level, pathological changes and apoptosis of Leydig cells. Oxidative stress was evaluated by determining malondialdehyde, H2O2, NO levels, and GSH in testis tissues. CAT, SOD, GSH-Px and Nrf2 mRNA were measured by real-time PCR. Results. Short- and long-term high-fat diet decreased sperm count and motility, relative testis weight, testosterone level; decreased CAT, SOD, GSH-Px and Nrf2 mRNA expression; increased MDA, H2O2, NO and leptin levels; inhibited the activity of CAT and GSH-Px enzymes. Pathological injury and apoptosis of Leydig cells were found in testis tissue. Conclusions. Pathological damage of Leydig cells, oxidative stress in testis tissue, and high level of leptin may provide some evidence to clarify the mechanisms of male SH in obesity. PMID:24829619

  9. Infleuce of dietary levels of vitamin E and selenium on tissue and blood parameters in pigs.

    PubMed Central

    Young, L G; Lumsden, J H; Lun, A; Claxton, J; Edmeades, D E

    1976-01-01

    Eighteen barrows approximately three weeks of age were used in a 3 X 3 factorial arrangement to investigate the effect of level of supplemental vitamin E and selenium on tissue and blood parameters. Tissue selenium concentrations increased in a quadratic manner with increased selenium intake with kidney tissue containing considerably greater concentrations than liver, heart or muscle. Supplementation of the diet caused a three-fold increase in serum selenium within the first week with a slight tendency to further increases in subsequent weeks. Serum vitamin E of unsupplemented pigs declined by fifty percent during the experiment, whereas supplemental vitamin E resulted in increased serum vitamin E. There was a considerable viration in percent peroxide hemolysis. Correlation of -0.63 between percent peroxide hemolysis and vitamin E intake and -0.85 between percent peroxide hemolysis and serum vitamin E were observed. PMID:1000383

  10. Mercury contamination study for flight system safety

    NASA Technical Reports Server (NTRS)

    Gorzynski, C. S., Jr.; Maycock, J. N.

    1972-01-01

    The effects and prevention of possible mercury pollution from the failure of solar electric propulsion spacecraft using mercury propellant were studied from tankage loading of post launch trajector injection. During preflight operations and initial flight mode there is little danger of mercury pollution if proper safety precautions are taken. Any spillage on the loading, mating, transportation, or launch pad areas is obvious and can be removed by vacuum cleaning soil and chemical fixing. Mercury spilled on Cape Kennedy ground soil will be chemically complexed and retained by the sandstone subsoil. A cover layer of sand or gravel on spilled mercury which has settled to the bottom of a water body adjacent to the system operation will control and eliminate the formation of toxic organic mercurials. Mercury released into the earth's atmosphere through leakage of a fireball will be diffused to low concentration levels. However, gas phase reactions of mercury with ozone could cause a local ozone depletion and result in serious ecological hazards.

  11. The mammalian testis accumulates lower levels of organochlorine chemicals compared with other tissues.

    PubMed

    Cooke, G M; Newsome, W H; Bondy, G S; Arnold, D L; Tanner, J R; Robertson, P; Whalen, C M; Angers, G; Massé, A

    2001-01-01

    Tissues were obtained from three separate experiments in order to quantify the tissue distribution of organochlorine chemicals that are thought to be potential reproductive toxicants in males: 1) Sprague Dawley rats received 1 microCi of 14C-Aldrin or 14C-Dieldrin (20.6 microCi/micromole) i.p. once a week for three weeks. One week and four weeks after the last injection, tissues were harvested and stored at -80 degrees C. Tissue 14C levels were quantified by scintillation spectrometry. 2) Cis- or trans-nonachlor (0, 0.25, 2.5, 25 mg/kg body weight) were administered daily in corn oil to male rats by gavage for 28 days. Tissues were harvested and frozen at -80 degrees C on the 29th day. Organochlorine residues were extracted and quantified by gas chromatography with electron capture detection. 3) Technical grade toxaphene (0, 0.1, 0.4 or 0.8 mg/kg body weight) was ingested daily by female cynomolgus monkeys of reproductive age for 18 months prior to being mated with control males. Dosing continued during pregnancy and lactation. Their infants received toxaphene via breast milk, and upon weaning, they ingested the same dose as their mothers for 48 to 49 weeks until, at 77 to 80 weeks of age, tissues were harvested and stored at -80 degrees C. Organochlorine residues were extracted and quantified as previously stated. In all three experiments, organochlorine residues in the testis were lower than in most of the other reproductive tract and nonreproductive tract tissues we examined. For example, testicular aldrin and dieldrin levels were <5% the epididymal content; testicular cis- and trans-nonachlor were <25% the epididymal content and, testicular toxaphene levels were <15% of the epididymal content. The reasons for the low degree of accumulation by the testis in comparison with other tissues are unknown. However, the lower testicular content may afford germ cells some protection from the potentially toxic effects of these chemicals. PMID:11390177

  12. Precise optical dosimetry in low-level laser therapy of soft tissues in oral cavity

    NASA Astrophysics Data System (ADS)

    Stoykova, Elena V.; Sabotinov, O.

    2004-06-01

    The new low level laser therapy (LLLT) is widely applied for treatment of diseases of the oral mucosa and parodont. Depending on indication, different optical tips and light-guides are used to create beams with a required shape. However, to the best of our knowledge, the developed irradiation geometries are usually proposed assuming validity of Bouger-Lambert law. This hardly corresponds to the real situation because of the dominating multiple scattering within 600-1200 nm range that destroys correlation between the emitted laser beam and the spatial distribution of the absorbed dose inside the tissue. The aim of this work is to base the dosimetry of the LLLT procedures of periodontal tissues on radiation transfer theory using a flexible Monte-Carlo code. We studied quantitatively the influence of tissue optical parameters (absorption and scattering coefficients, tissue refraction index, anisotropy factor) on decreasing of correlation between the emitted beam and the energy deposition for converging or diverging beams. We evaluated energy deposition for the developed by us LLLT system in a 3-D model of periodontal tissues created using a cross-sectional image of this region with internal structural information on the gingival and the tooth. The laser source is a CW diode laser emitting elliptical beam within 650-675 nm at output power 5-30 mW. To determine the geometry of the irradiating beam we used CCD camera Spiricon LBA 300.

  13. Optimisation of cold vapour atomic absorption spectrometry for determination of high levels of total mercury in activated carbon

    Microsoft Academic Search

    D ARIJA G IBIÈAR; V ESNA J EREB; R ADOJKO J AÆIMOVIÆ; T ATJANA D IZDAREVIÈ; E LISABETH; C. P AIVA; R ICARDO M ELAMED; L UIS G ONZAGA; S. S OBRAL; M ILENA H ORVAT

    The relative efficiency of digestion\\/leaching procedures for the determination of high mercury concen trations in activated carbon obtained from natural gas treatment facilities was investigated. The method is based on acid digestion\\/leaching, reduction by SnCl 2 , gold amalgamation and detection by cold vapour atomic spectrometry. Sample decomposition was c arried out in sealed Pyrex ampoules and closed Teflon vials,

  14. Mercury contamination in human hair and some marine species from Sfax coasts of Tunisia: levels and risk assessment

    Microsoft Academic Search

    Sawssan Mezghani-Chaari; A. Hamza; A. Hamza-Chaffai

    2011-01-01

    The aim of this study was to measure the mercury (Hg) contents of three marine fish and common seafood species (Diplodus annularis, Sarpa salpa and Sepia officinalis) at two sampling sites in the gulf of Gabes, i.e. Sidi Mansour (polluted site) and Kerkennah (control site). These species\\u000a are frequently consumed by the population living at the Sfax coasts of Tunisia,

  15. A Comparison of Mercury Levels in Feathers and Eggs of Osprey ( Pandion haliaetus ) in the North American Great Lakes

    Microsoft Academic Search

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

    1997-01-01

    .   Osprey (Pandion haliaetus) eggs and chick feathers were collected for mercury analysis from nests at four Great Lakes study areas in Ontario (three\\u000a “naturally formed” lakes in southern Ontario and one reservoir in northern Ontario) and two New Jersey study areas in 1991–1994.\\u000a Adult osprey feathers were sampled from three Great Lakes study areas in 1991. Feathers sampled from

  16. Population-modulation study of the filling of mercury ion levels in a He-Hg discharge

    Microsoft Academic Search

    E. L. Latush; M. F. Sem; G. D. Chebotarev

    1984-01-01

    The branching ratios for the lines at 615.0 nm and 794.5 nm and the ratios of the partial chargeexchange cross sections are determined through a comparison of the intensities of spectral lines of the mercury ion in a He-Hg discharge with and without emission at the 615.0-nm line (by the population-modulation method). Absolute values are found for the partial cross

  17. Age-specific profiles of tissue-level composition and mechanical properties in murine cortical bone

    PubMed Central

    Raghavan, Mekhala; Sahar, Nadder D.; Kohn, David H.; Morris, Michael D.

    2012-01-01

    There is growing evidence that bone composition and tissue-level mechanical properties are significant determinants of skeletal integrity. In the current study, Raman spectroscopy and nanoindentation testing were co-localized to analyze tissue-level compositional and mechanical properties in skeletally mature young (4 or 5 months) and old (19 months) murine femora at similar spatial scales. Standard multivariate linear regression analysis revealed age-dependent patterns in the relationships between mechanical and compositional properties at the tissue scale. However, changes in bone material properties with age are often complex and nonlinear, and can be missed with linear regression and correlation-based methods. A retrospective data mining approach was implemented using non-linear multidimensional visualization and classification to identify spectroscopic and nanoindentation metrics that best discriminated bone specimens of different age-classes. The ability to classify the specimens into the correct age group increased by using combinations of Raman and nanoindentation variables (86–96% accuracy) as compared to using individual measures (59–79% accuracy). Metrics that best classified 4 or 5 month and 19 month specimens (2-age classes) were mineral to matrix ratio, crystallinity, modulus and plasticity index. Metrics that best distinguished between 4, 5 and 19 month specimens (3-age classes) were mineral to matrix ratio, crystallinity, modulus, hardness, cross-linking, carbonate to phosphate ratio, creep displacement and creep viscosity. These findings attest to the complexity of mechanisms underlying bone tissue properties and draw attention to the importance of considering non-linear interactions between tissue-level composition and mechanics that may work together to influence material properties with age. The results demonstrate that a few non-linearly combined compositional and mechanical metrics provide better discriminatory information than a single metric or a single technique. PMID:22285889

  18. Correlation between serum testosterone level and concentrations of copper and zinc in hair tissue.

    PubMed

    Chang, Chung Soo; Choi, Jong Bo; Kim, Hae Jin; Park, Sat Byul

    2011-12-01

    Testosterone deficiency is associated with late-onset hypogonadism. Micronutrients including copper (Cu) and zinc (Zn) influence testosterone synthesis. The association between micronutrient concentrations in hair tissue and serum testosterone was studied in Korean men. The subjects were 88 men 40-60 years of age who visited the health promotion center and an outpatient clinic of family medicine at a university hospital from March 2006 to February 2008. Population sociological features of the subjects were acquired by self-administered surveys and interview, height and weight were measured, serum total testosterone was determined in the morning, and Cu and Zn were quantified from hair tissue collected in the morning. Subjects with normal testosterone group had a significantly higher Zn level compared to low testosterone group (P?=?0.003). Significant negative correlations were evident between total testosterone and Cu level (r?=?-0.252, P?=?0.022), and the Cu/Zn ratio (r?=?-0.288, P?=?0.008). Normal testosterone is associated with a higher Zn level. Decreased serum testosterone is significantly associated with a high level of Cu and elevated Cu/Zn ratio in hair tissue. PMID:21671089

  19. Obesity And Laboratory Diets Affects Tissue Malondialdehyde (MDA) Levels In Obese Rats

    NASA Astrophysics Data System (ADS)

    Chowdhury, Parimal; Scott, Joseph; Holley, Andy; Hakkak, Reza

    2010-04-01

    This study was conducted to investigate the interaction of obesity and laboratory diets on tissue malondialdehyde levels in rats. Female Zucker obese and lean rats were maintained on either regular grain-based diet or purified casein diet for two weeks, orally gavaged at day 50 with 65 mg/kg DMBA and sacrificed 24 hrs later. Malondialdehyde (MDA) levels were measured in blood and harvested tissues. Data were recorded as mean ± SEM and analyzed statistically. Results show that the obese group on purified casein diet had reduction of MDA levels in the brain, duodenum, liver, lung and kidney tissues as compared to lean group, p <0.05. Obese group on grain-based diet showed significant increase in MDA levels only in the duodenum, p <0.05. We conclude that dietary intervention differentially affects the oxidative markers in obese rats. It appears that purified casein diets were more effective than grain-based diet in reduction of oxidative stress in obese rats.

  20. Sedentary nestlings of Wood Stork as monitors of mercury contamination in the gold mining region of the Brazilian Pantanal.

    PubMed

    Del Lama, Silvia Nassif; Dosualdo Rocha, Cristiano; Figueiredo Jardim, Wilson; Tsai, Jo-Szu; Frederick, Peter Crawford

    2011-11-01

    Sedentary organisms that are at top trophic levels allow inference about the level of local mercury contamination. We evaluated mercury contamination in feather tissue of nestling Wood Storks (Mycteria americana), sampled in different parts of the Brazilian Pantanal that were variably polluted by mercury releases from gold mining activities. Levels of mercury in feathers sampled in seven breeding colonies were determined by atomic absorption spectroscopy, and the mean value of mercury concentration was 0.557 ?g/g, dry weight (n=124), range 0.024-4.423 ?g/g. From this total sample, 21 feathers that represent 30% of nestlings collected in Porto da Fazenda and Tucum colonies, in the northern region, ranged from 1.0 to 4.43 ?g/g, dry weight (median value=1.87 ?g/g). We found significant differences among regions (H=57.342; p=0<0.05). Results suggest that permanently flooded areas, or along mainstream rivers are more contaminated by mercury than dry areas, regardless of the distance from the gold mining center, which is located in the northern Pantanal. Highest values found in nestlings feathers were similar to those found in feathers of adult birds and in tissues of adult mammals that are less sedentary and were captured in the same region of Pantanal. These findings indicate that mercury released has been biomagnified and it is present in high concentrations in tissues of top consumers. We suggest a program to monitor mercury availability in this ecosystem using sedentary life forms of top predators like Wood Storks or other piscivorous birds. PMID:21851934

  1. Mercury toxicity and the protective role of selenium in eel, Anguilla anguilla.

    PubMed

    Polak-Juszczak, Lucyna; Robak, Stanis?aw

    2015-01-01

    The aim of the study was to determine the impact trace metals, mainly toxic ones, on the condition of eel (Anguilla anguilla) inhabiting four regions of Poland. Metal concentrations in eel muscle tissues were studied as functions of size, region, and season 2011-2012. The levels of metals were also used for risk assessment on consumer health. Copper and zinc occurred at concentrations that could only have positive impacts on eel condition. Low levels of cadmium and lead did not impair the condition of the fish. However, mercury occurred at high levels and increased with fish length and season. The mercury levels in eels were compared with the threshold of toxicity (500-1,200 ?g kg(-1)), which can cause changes in biochemical processes and impair fish reproduction. The concentration of mercury was 1,010 ?g kg(-1) in one specimen of the 120 samples examined, and in 16 specimens, it exceeded 500 ?g kg(-1). The toxic effects of the mercury could have been attenuated by the selenium in the muscles of the eel, especially in the muscles of smaller specimens in which the Se/Hg molar ratio was higher than 1 with a positive correlation between these two elements. In larger specimens measuring in excess of 70 cm, this coefficient was below 1, and the mercury to selenium correlation was negative, which meant that the protective effects of selenium were weaker. The mercury in the muscles of large specimens at levels exceeding 500 ?g kg(-1) could have weakened eel condition and also posed a threat to consumer health. The cadmium and lead in the muscles of the eel did not affect the condition of the fish. Mercury weakened the condition of large eel, A. anguilla. Selenium protected small- and medium-sized eel against the toxic effects of mercury. PMID:25099659

  2. Inorganic and methylmercury levels in plasma are differentially associated with age, gender, and oxidative stress markers in a population exposed to mercury through fish consumption.

    PubMed

    Carneiro, Maria Fernanda Hornos; Grotto, Denise; Barbosa, Fernando

    2014-01-01

    This study aimed to determine the concentrations of plasma methylmercury (Me-Hg) and inorganic mercury (I-Hg) in a population exposed to Me-Hg. In addition, associations between each form of mercury (Hg) and gender, age, plasma selenium (Se), and oxidative stress markers were also investigated. The mean plasma I-Hg level was 5.7 ?g/L while the mean for plasma Me-Hg was 3.6 ?g/L, representing approximately 59 and 41% of the total Hg in blood, respectively. However, several plasma samples contained higher percentages of Me-Hg. Age displayed a direct linkage with plasma I-Hg levels, whereas gender did not correlate with any of the Hg species. In addition, fish intake was only correlated with and a predictor of plasma Me-Hg, suggesting that plasma I-Hg levels originated endogenously through a demethylation reaction that needs to be verified. Further, plasma Me-Hg was markedly correlated with adverse effects to a greater extent than plasma I-Hg and may be considered a valuable, reliable internal dose biomarker for Hg in chronically Me-Hg- exposed individuals. PMID:24555648

  3. Cadmium, zinc, copper, arsenic, selenium and mercury in seabirds from the Barents Sea: levels, inter-specific and geographical differences.

    PubMed

    Savinov, Vladimir M; Gabrielsen, Geir W; Savinova, Tatiana N

    2003-05-01

    Trace elements Cd, Zn, Cu, As, Se and Hg were analysed in muscle and liver of Brünnich's guillemot, Common guillemot, Puffin, Black guillemot, Little auk, Razorbill, Common eider, King eider, Glaucous gull, Herring gull, Black-legged kittiwake, Northern fulmar and Arctic tern collected in 1991-1992 at the main breeding colonies in the Barents Sea. The highest levels of the most toxic elements Cd and Hg were found in birds nesting north of Spitsbergen. Extremely high levels of As were detected in tissues of all seabird species collected at colonies in Chernaya Guba (Novaya Zemlya), where nuclear tests were carried out in the 1960s. In general, levels of all of the trace elements in the Barents Sea seabirds were similar or lower in comparison with those reported for the same seabird species from the other Arctic areas. Data on metallothionein concentrations in different seabird species need to be collected in order to understand the mechanism of bioaccumulation and possible toxic effects of trace elements in Arctic seabirds. PMID:12699923

  4. Dissolved Gaseous Mercury Concentrations and Mercury

    E-print Network

    O'Driscoll, Nelson

    % of total annual mercury inputs to the system, and studies on the Great Lakes (Canada-United States) showDissolved Gaseous Mercury Concentrations and Mercury Volatilization in a Frozen Freshwater Fluvial to examine dissolved gaseous mercury (DGM), mercury volatilization, and sediment interactions in a frozen

  5. Adipose Tissue Levels of Organochlorine Pesticides and Polychlorinated Biphenyls and Risk of Non-Hodgkin's Lymphoma

    Microsoft Academic Search

    Penelope J. E. Quintana; Ralph J. Delfino; Susan Korrick; Argyrios Ziogas; Frederick W. Kutz; Ellen L. Jones; Francine Laden; Eric Garshick

    2004-01-01

    In this nested case-control study we examined the relationship between non-Hodgkin's lymphoma (NHL) and organochlorine pesticide exposure. We used a data set originally collected between 1969 and 1983 in the U.S. Environmental Protection Agency National Human Adipose Tissue Survey. Adipose samples were randomly collected from cadavers and surgical patients, and levels of organochlorine pesticide residues were determined. From the original

  6. Altered Tissue Levels of Vitamin a by Selected Polycyclic Aromatic Hydrocarbons (PAHs)

    Microsoft Academic Search

    Li-Chuan Chen; Isabelle Berberian; Howard P. Glauert; Larry W. Robertson; Ching K. Chow

    1994-01-01

    The purpose of this study was to determine the effects of certain polycyclic aromatic hydrocarbons (PAHs) of known carcinogenic potential on rat tissue levels of retinol and retinyl esters. Male Sprague-Dawley rats fed a vitamin A-adequate diet (1.3 mg of retinyl palmitate\\/kg) for 30 days were intraperitoneally administered three injections of one of the following four PAHs: carcinogenic 3-methylcholanthrene (MC),

  7. DNA adduct level in lung tissue may act as a risk biomarker of lung cancer

    Microsoft Academic Search

    Y.-W Cheng; C.-Y Chen; P Lin; C.-P Chen; K. H Huang; T.-S Lin; M.-H Wu; H Lee

    2000-01-01

    Lung cancer is a leading cause of mortality in Taiwan. We hypothesised that high susceptibility to DNA damage in the target organ acts as a risk biomarker for the development of lung cancer. To verify this hypothesis, the aromatic\\/hydrophobic DNA adduct levels of non-tumorous adjacent lung tissues from 73 primary lung cancer patients and 33 non-cancer controls were evaluated by

  8. Tissue-level segmentation and tracking of cells in growing plant roots

    Microsoft Academic Search

    Vijaya Sethuraman; Andrew French; Darren Wells; Kim Kenobi; Tony Pridmore

    With the spread of systems approaches to biological research, there is increasing demand for methods and tools capable of\\u000a extracting quantitative measurements of biological samples from individual and time-based sequences of microscope images.\\u000a To this end, we have developed a software tool for tissue level segmentation and automatic tracking of a network of cells\\u000a in confocal images of the roots

  9. Tissue levels of lead in experimentally exposed herring gull (Larus argentatus) chicks.

    PubMed

    Burger, J; Gochfeld, M

    1990-01-01

    Two-day-old herring gull (Larus argentatus) chicks were injected with either 0.1 or 0.2 mg lead/g body mass and were sacrificed at 45 d of age. Control birds were injected with sterile water. We examined lead and cadmium levels in blood, kidney, liver, muscle, salt glands, breast feathers, and bone. In control birds lead levels were highest in bone, feathers, salt gland, and kidney, and lowest in blood, muscle, and brain. In experimental birds lead levels were highest in bone, liver, kidney, and feathers, and lowest in blood, muscle, and salt gland. In control birds cadmium levels were highest in the kidney, followed by liver, with blood and brain being the lowest. Lead-exposed birds had increased cadmium deposition in brain. For experimental birds lead levels were correlated for all tissues except the salt gland. Correlations were particularly high for feathers with brain, kidney, liver and bone, suggesting feathers can be used in biomonitoring of natural avian populations. For cadmium there were no significant correlations among tissue levels except for brain and liver. Bioamplification of lead was greatest for liver and blood, and lowest for muscle and salt gland when comparing a lead dose of 0.1 mg/g with controls. PMID:2299695

  10. Soft Tissue Mobilization and PNF Improve Range of Motion and Minimize Pain Level in Shoulder Impingement.

    PubMed

    Al Dajah, Salameh Bweir

    2014-11-01

    [Purpose] The aim of this study was to evaluate the effects of soft tissue mobilization and PNF on pain level, and shoulder ROM in patients with shoulder impingement syndrome. [Subjects and Methods] Thirty patients with painful and limited glenohumeral ROM activities were selected. The subjects were randomly assigned to an experimental group (n=15), which received treatment consisting of soft tissues mobilization and the PNF technique. The control group received an ultrasound treatment. Pain level, glenohumeral external rotation and overhead reach were measured before and after the intervention in groups. [Results] The experimental group showed a significant reduction in pain level in comparison with the control group. The values for Shoulder external rotation showed a significant improvement. The mean value for overhead reach in the experimental group significantly increased. [Conclusion] The combination of soft tissue mobilization for the subscapularis for 7 minutes and 5 repetitions of the contract-relax PNF technique for the shoulder internal rotator muscles followed by 5 repetitions of a PNF facilitated abduction and external rotation diagonal pattern was found to be effective in reducing pain and improving glenohumeral external rotation and overhead reach during a single intervention session. PMID:25435705

  11. Tissue Plasminogen Activator and Plasminogen Activator Inhibitor-1 Levels in Patients with Acute Paraquat Intoxication

    PubMed Central

    Seok, Su-Jin; Kim, Su-Ji; Gil, Hyo-Wook; Yang, Jong-Oh; Lee, Eun-Young

    2011-01-01

    To investigate the effects of reactive oxygen species (ROS) on tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) plasma levels, and their possible implications on clinical outcome, we measured tPA and PAI-1 levels in 101 patients with acute paraquat (PQ) intoxication. The control group consisted of patients who ingested non-PQ pesticides during the same period. tPA and PAI-1 levels were higher in the PQ group than in the controls. PQ levels were significantly correlated with ingested amount, timelag to hospital, tPA level, and hospitalization duration. tPA levels were correlated with PAI-1, fibrin degradation product (FDP), and D-dimer. D-dimer levels were lower in the PQ group than in the controls. Univariate analysis indicated the following significant determinants of death: age, ingested amount, PQ level, timelag to hospital, serum creatinine, lipase, pH, pCO2, HCO3-, WBC, FDP, PAI-1, and tPA. However, multivariate analysis indicated that only PQ level was significant independent factor predicting death. In conclusion, tPA and PAI-1 levels were higher, while D-dimer levels were lower in the PQ group than in the controls, implying that ROS stimulate tPA and PAI-1, but PAI-1 activity overrides tPA activity in this setting. Decreased fibrinolytic activity appears to be one of the clinical characteristics of acute PQ intoxication. PMID:21468253

  12. Mercury and Arsenic in Muscle and Liver of the Golden Cownose Ray, Rhinoptera steindachneri , Evermann and Jenkins, 1891, from the Upper Gulf of California, México

    Microsoft Academic Search

    E. Gutiérrez-Mejía; M. L. Lares; O. Sosa-Nishizaki

    2009-01-01

    Mercury and arsenic levels in muscle and liver of Rhinoptera steindachneri were determined in organisms collected in 2006. Element concentrations in both tissues were directly related to size. Maxima\\u000a mean concentrations of Hg and As (0.41 and 59.9 ?g g?1 dry wt, respectively) were found in adults muscle. Mercury concentrations were significantly different between juveniles\\u000a and adults in muscle and liver. For

  13. A Regulatory Analysis of EPA's Proposed Rule to Reduce Mercury Emissions from Utility Boilers

    Microsoft Academic Search

    Joel Schwartz

    2004-01-01

    EPA's proposed rule for mercury reductions from coal-fired utility boilers is unlikely to provide significant health benefits, both because mercury exposure at current levels is unlikely to be causing harm, and because even in a best case scenario the mercury rule could reduce mercury in fish by no more than a few percent. The claim that reducing mercury in fish

  14. Levels of mercury in muscle and liver of star-spotted dogfish (Mustelus manazo) from the northern region of Japan: a comparison with spiny dogfish (Squalus acanthias).

    PubMed

    Endo, Tetsuya; Hisamichi, Yohsuke; Kimura, Osamu; Ogasawara, Hideki; Ohta, Chiho; Koga, Nobuyuki; Kato, Yoshihisa; Haraguchi, Koichi

    2013-04-01

    We analyzed mercury (Hg) concentrations in muscle and liver samples of star-spotted dogfish (Mustelus manazo) caught off the northern region of Japan and compared them with those of spiny dogfish (Squalus acanthias) caught in the same region. The average body length of male star-spotted dogfish specimens was significantly smaller than that of female specimens, reflecting the slower growth rate of male fish. Hg concentrations in liver and muscle increased with increases in body length and estimated age of both male and female star-spotted dogfish specimens. However, the relationships between Hg concentration in liver or muscle and body length or estimated age of male specimens differed markedly from those of female specimens, reflecting differences in growth rate and cessation of growth on reaching maturity. Marked increases in Hg concentration in liver of male and female star-spotted dogfish specimens were observed slightly later than increases in Hg concentration in muscle of those specimens due to growth cessation. These marked increases in Hg in liver may reflect increases in Hg due to the formation of mercury selenide. Similar results were previously reported in spiny dogfish specimens, except spiny dogfish showed only trace levels of Hg in liver (Endo et al., Chemosphere 77:1333-1337, 2009). The greater lipid content in liver and the larger liver size in spiny dogfish may explain the much lower levels of Hg observed in liver of spiny dogfish compared with those in the star-spotted dogfish. PMID:23271344

  15. Electrochemical determination of mercury: a review.

    PubMed

    Martín-Yerga, Daniel; González-García, María Begoña; Costa-García, Agustín

    2013-11-15

    Mercury is a metal that has been extensively studied, in large part due to its high toxicity. Therefore, mercury levels must be monitored in different sample types using analytical methods. This review summarizes the electrochemical methods that have been used for mercury analysis in a variety of samples. A critical evaluation of the methods and electrode materials employed for mercury analysis is presented according to the following classifications: bare electrodes, chemically modified electrodes and nanostructured electrodes. The advantages and disadvantages of each type of electrode material regarding mercury analysis are also presented. PMID:24148521

  16. Folate and methotrexate polyglutamate tissue levels in rhesus monkeys following chronic low-dose methotrexate.

    PubMed

    Winick, N J; Kamen, B A; Balis, F M; Holcenberg, J; Lester, C M; Poplack, D G

    1987-01-01

    Methotrexate (MTX), a mainstay in the treatment of acute lymphoblastic leukemia, is associated with both hepatic and neurologic toxicity. Like a folate, MTX is metabolized to polyglutamated derivatives (MTXGlun) with long intracellular half-lives. These metabolites may contribute to MTX toxicity through a direct effect on cellular metabolism or indirectly through a perturbation of folate homeostasis. To better define the effects of chronic MTX treatment, tissue levels of MTX, MTXGlun, and folate were measured in three monkeys treated with weekly intramuscular MTX for 1 year. Greater than 80% of the total tissue MTX found was in the form of polyglutamated derivatives. Most of these derivatives were MTXGlu3-5 but Glu6-7 were easily detectable. Total tissue folates were measured in liver, kidney, brain and testis with MTX treated animals having a 90% loss of total folate in brain tissue. This is of special interest since inborn errors of folate metabolism are often associated with severe neurologic abnormalities. PMID:2440550

  17. Serum FGF21 levels are associated with brown adipose tissue activity in humans

    PubMed Central

    Hanssen, Mark J.W.; Broeders, Evie; Samms, Ricardo J.; Vosselman, Maarten J.; van der Lans, Anouk A.J.J.; Cheng, Christine C.; Adams, Andrew C.; van Marken Lichtenbelt, Wouter D.; Schrauwen, Patrick

    2015-01-01

    The obesity pandemic has spurred a need for novel therapies to prevent and treat metabolic complications. The recent rediscovery of brown adipose tissue (BAT) in humans made this tissue a possible therapeutic target, due to its potentially substantial contributions to energy homeostasis. Fibroblast growth factor 21 (FGF21) has been identified as a facilitator of cold-induced thermogenesis in humans. Furthermore, pre-clinical studies revealed that FGF21 administration leads to improvement in the metabolic consequences of obesity, such as dyslipidemia and type 2 diabetes. Here we studied plasma FGF21 levels in two cohorts of human subjects, in whom BAT activity was determined using an individualized cooling protocol by [18F]FDG-PET/CT scan. Importantly, we found that circulating FGF21 levels correlated with BAT activity during acute cold exposure in male subjects. In addition, FGF21 levels were related to the change in core temperature upon acute cold exposure, indicating a role for FGF21 in maintaining normothermia, possibly via activation of BAT. Furthermore, cold acclimation increased BAT activity in parallel with increased FGF21 levels. In conclusion, our results demonstrate that FGF21 levels in humans are related to BAT activity, suggesting that FGF21 may represent a novel mechanism via which BAT activity in humans may be enhanced. PMID:25985218

  18. Cloud-resolving simulations of mercury scavenging and deposition in thunderstorms

    E-print Network

    Nair, U. S; Wu, Y.; Holmes, C. D; Ter Schure, A.; Kallos, G.; Walters, J. T

    2013-01-01

    throughout the United States contain mercury at levels thatMercury De- position Network (MDN) in the Eastern United States.mercury in the troposphere: Model for- mation and results for Florida, the northeastern United States,

  19. An evaluation of elemental mercury vapor exposure to children due to silver-mercury dental amalgam restorations 

    E-print Network

    Taylor, Ronald Dale

    1989-01-01

    was the Bacharach J. W. Mercury Vapor Sniffer, Model MV-2. This instrument measures the concentration of mercury vapor in air. The ultraviolet photometer detector inside the instrument operates on the principle that energy is absorbed by the mercury molecule... of elemental mercury from dental restorations. The mean mercury vapor concentration in the oral cavity of test subjects exceeded the recommended 24-hour ambient air exposure level of 0. 015 mg Hg/m . A regression analysis of the data resulted...

  20. Got Mercury?

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

    Many lamps used in various spacecraft contain elemental mercury, which is efficiently absorbed through the lungs as a vapor. The liquid metal vaporizes slowly at room temperature, but may be completely vaporized when lamps are operating. Because current spacecraft environmental control systems are unable to remove mercury vapors, we considered short-term and long-term exposures. Using an existing study, we estimated mercury vapor releases from lamps that are not in operation during missions lasting less than or equal to 30 days; whereas we conservatively assumed complete vaporization from lamps that are operating or being used during missions lasing more than 30 days. Based on mercury toxicity, the Johnson Space Center's Toxicology Group recommends stringent safety controls and verifications for any hardware containing elemental mercury that could yield airborne mercury vapor concentrations greater than 0.1 mg/m3 in the total spacecraft atmosphere for exposures lasting less than or equal to 30 days, or concentrations greater than 0.01 mg/m3 for exposures lasting more than 30 days.

  1. EVALUATION, ASSESSMENT, AND DETERMINATION OF RISK TO HIGH TROPHIC LEVEL PISCIVORES IN THE MID-ATLANTIC: A SPATIAL, BIOLOGICAL, AND COMPARATIVE CASE STUDY OF MERCURY IN VIRGINIA AND NEW ENGLAND BALD EAGLE (HALIAEETUS LEUCOCEPHALUS) POPULATIONS

    EPA Science Inventory

    I predict that some portion of the Virginia bald eagle population will exhibit levels at or above those considered detrimental to productivity and reproductive success. The analysis of independent variables and their relationship to elevated blood mercury levels will help t...

  2. Determination of in vivo nitric oxide levels in animal tissues using a novel spin trapping technology.

    PubMed

    Vanin, Anatoly F; Timoshin, Alexander A

    2011-01-01

    It has been established that microdialysis ensured by the passage of aqueous solutions of Fe(3+) complexes with N-methyl-D: -glucamine dithiocarbamate (MGDMGD ) through fine dialysis fibers permeable for compounds with molecular weights below 5 kDa. These fibers can be implanted into heart, liver, and kidney tissues, enabling effective binding of Fe(3+)-MGD complexes to nitric oxide generated in interstitial fluids of narcotized rats in vivo. Subsequent treatment of dialyzate samples (60??L) with sodium dithionite favors conversion of newly formed diamagnetic NO-Fe(3+)-MGD complexes into electron paramagnetic resonance-detectable NO-Fe(2+)-MGD complexes. The basal levels of NO determined from the concentrations of the complexes in the respective tissues are similar (1???). The microdialysis data suggest that treatment of rats with a water-soluble analogue of nitroglycerine or a dinitrosyl iron complex with thiosulfate induces a long-lasting (>1 h) increase in the steady-state level of NO in animal tissues. This novel technology can be used for comparative analyses of production rates of NO and reactive oxygen species when using iron-dithiocarbamate complexes and spin traps for reactive oxygen species, respectively. PMID:21161635

  3. Vanadium retention in rat tissues following acute exposures to different dose levels

    SciTech Connect

    Sharma, R.P.; Oberg, S.G.; Parker, R.D.R.

    1980-01-01

    Male Wistar rats were given vanadyl trichloride (/sup 48/VOCl/sub 3/) ip in doses of V ranging from 0.1 to 8 mg/kg and their tissues were collected 1 and 5 d after the injection. V was distributed in the order bone > kidney > liver > spleen > intestines > stomach > muscle > testis > lung > brain. Residues of V in tissues declined rapidly between 24 h and 5 d after administration. The tissue:blood ratios of V were greater than unity for bone, kidney, liver, and spleen and near unity for all other organs except the brain. Brain levels of V were found to be considerably lower than blood in all cases. V residues were linearly related to dose in most organs when the dose was below 2 mg/kg. At 8 mg/kg, however, liver and kidney showed consistently higher amounts than would be expected from the linear relationship at the low doses. Subcellular distribution of V in liver and kidney indicated that it was associated with nuclei, mitochondria, microsomes, and primarily with high-molecular-weight proteins in the soluble fraction of liver. The results suggest that the distribution pattern of V is dependent on exposure level.

  4. Microbial methylation of mercury in estuarine sediments

    SciTech Connect

    Compeau, G.C.

    1985-01-01

    Mercury is a common and potentially hazardous pollutant. Although all forms of the element are toxic, alkylated mercurials are particularly toxic and accumulate in living tissues. Factors affecting the availability of mercury and the microorganisms responsible for methylation are described. The methylation of mercuric ions (Hg/sup + +/) was investigated in pure culture, in estuarine sediments, and as a function of the anionic constituents of seawater. Studies on abiotic methylation of Hg/sup + +/ by methylcobalamin in the presence of sea salts showed that only the sulfide (formed in sulfate reduction) and bicarbonate components interfere with Hg/sup + +/ methylation. Other sea salt anions have no significant influence on the methylation of Hg/sup + +/. Methylation, demethylation, and volatilization of Hg/sup + +/ were studied in estuarine sediments maintained at present values of pH, redox, and salinity. Volatilization of Hg/sup 0/ and CH/sub 3/HgCH/sub 3/ were found to be minimal. Methylation was favored at low redox potential (-220 mW) and low salinity (0.4%) conditions. High salinity (2.5%) decreased methylation at -220 mV, but not at (+110 mV). Demethylation of CH/sub 3/HgCl was favored at +110 mV regardless of the salinity level. Low redox potential under low salinity conditions inhibited demethylation, but high salinity reversed this inhibition. The sulfate-reducing bacteria were identified as the principal Hg/sup + +/ methylating population in anaerobic estuarine sediments.

  5. Histopathology tissue segmentation by combining fuzzy clustering with multiphase vector level sets.

    PubMed

    Bunyak, Filiz; Hafiane, Adel; Palaniappan, Kannappan

    2011-01-01

    High resolution, multispectral, and multimodal imagery of tissue biopsies is an indispensable source of information for diagnosis and prognosis of diseases. Automatic extraction of relevant features from these imagery is a valuable assistance for medical experts. A primary step in computational histology is accurate image segmentation to detect the number and spatial distribution of cell nuclei in the tissue, along with segmenting other structures such as lumen and epithelial regions which together make up a gland structure. This chapter presents an automatic segmentation system for histopathology imaging. Spatial constraint fuzzy C-means provides an unsupervised initialization. An active contour algorithm that combines multispectral edge and region informations through a vector multiphase level set framework and Beltrami color metric tensors refines the segmentation. An improved iterative kernel filtering approach detects individual nuclei centers and decomposes densely clustered nuclei structures. The obtained results show high performances for nuclei detection compared to the human annotation. PMID:21431581

  6. Negative association of acetate with visceral adipose tissue and insulin levels

    PubMed Central

    Layden, Brian T; Yalamanchi, Sudha K; Wolever, Thomas MS; Dunaif, Andrea; Lowe, William L

    2012-01-01

    Background The composition of gut flora has been proposed as a cause of obesity, a major risk factor for type 2 diabetes. The objective of this study was to assess whether serum short chain fatty acids, a major by-product of fermentation in gut flora, are associated with obesity and/or diabetes-related traits (insulin sensitivity and secretion). Methods The association of serum short chain fatty acids levels with measures of obesity was assessed using body mass index, computerized tomography scan, and dual photon X-ray absorptiometry scan. Insulin sensitivity and insulin secretion were both determined from an oral glucose tolerance test and insulin sensitivity was also determined from a hyperinsulinemic euglycemic clamp. Results In this population of young, obese women, acetate was negatively associated with visceral adipose tissue determined by computerized tomography scan and dual photon X-ray absorptiometry scan, but not body mass index. The level of the short chain fatty acids acetate, but not propionate or butyrate, was also negatively associated with fasting serum insulin and 2 hour insulin levels in the oral glucose tolerance test. Conclusions In this population, serum acetate was negatively associated with visceral adipose tissue and insulin levels. Future studies need to verify these findings and expand on these observations in larger cohorts of subjects. PMID:22419881

  7. Accumulation levels and characteristics of some pesticides in human adipose tissue samples from Southeast China.

    PubMed

    Wang, Na; Shi, Lili; Kong, Deyang; Cai, Daoji; Cao, Yanzhong; Liu, Yongming; Pang, Guofang; Yu, Rongbin

    2011-08-01

    This paper presents a comprehensive study of pesticide levels and bio-accumulation characteristics in human adipose tissues among residents of Southeast China. A large number of adipose samples (n=633) were selected for 58 pesticides and were analyzed by high sensitive Gas Chromatography-Tandem Mass Spectrometry (GC-MS/MS). The results showed that POPs pesticides were frequently detected, including 2,4'-DDD, 2,4'-DDE, 2,4'-DDT, 4,4'-DDD, 4,4'-DDE, 4,4'-DDT, ?-HCH, ?-HCH, ?-HCH, ?-HCH, hexachlorobenzene (HCB), and mirex. Other detected pesticide species were dicofol, methamidophos and chlordimeform, which have rarely been reported. Comparing to different countries, the concentrations of total DDT and HCH in these three Chinese southeastern sites were in the middle range, whereas the HCB and mirex were in the lower end. A significant correlation was observed between region as well as age and POPs pesticide levels. Some pesticide residue levels were also found significantly correlated to occupation. However, there was no significant correlation between gender and pesticides. Meanwhile, it is interesting to find that mortality of malignant tumors tends to associate with the pesticides levels in human adipose tissue. More importantly, the measured data presented in this study provide realistic information which is useful for assessing human exposure to pesticides in the general population of Southeast China. PMID:21722941

  8. A tissue-level anisotropic criterion for brain injury based on microstructural axonal deformation.

    PubMed

    Cloots, R J H; van Dommelen, J A W; Geers, M G D

    2012-01-01

    Different length scales from micrometers to several decimeters play an important role in diffuse axonal injury. The kinematics at the head level result in local impairments at the cellular level. Finite element methods can be used for predicting brain injury caused by a mechanical loading of the head. Because of its oriented microstructure, the sensitivity of brain tissue to a mechanical load can be expected to be orientation dependent. However, the criteria for injury that are currently used at the tissue level in finite element head models are isotropic and therefore do not consider this orientation dependence, which might inhibit a reliable assessment of injury. In this study, an anisotropic brain injury criterion is developed that is able to describe the effects of the oriented microstructure based on micromechanical simulations. The effects of both the main axonal direction and of local deviations from this direction are accounted for. With the anisotropic criterion for brain injury, computational head models will be able to account for aspects of diffuse axonal injury at the cellular level and can therefore more reliably predict injury. PMID:22100078

  9. Controlled Systemic Delivery by Polymeric Implants Enhances Tissue and Plasma Curcumin Levels Compared with Oral Administration

    PubMed Central

    Bansal, Shyam S.; Kausar, Hina; Vadhanam, Manicka V.; Ravoori, Srivani; Gupta, Ramesh C.

    2012-01-01

    Curcumin possess potent anti-inflammatory and anti-proliferative activities but with poor biopharmaceutical attributes. To overcome these limitations, curcumin implants were developed and tissue (plasma, brain and liver) curcumin concentrations were measured in female ACI rats for 3 months. Biological efficacy of tissue levels achieved was analyzed by modulation of hepatic cytochromes. Curcumin implants exhibited diffusion-mediated biphasic release pattern with ~2-fold higher in vivo release as compared to in vitro. Plasma curcumin concentration from implants was ~3.3 ng/ml on day 1 which dropped to ~0.2 ng/ml after 3 months whereas only 0.2–0.3 ng/ml concentration was observed from 4–12 days with diet and was undetected subsequently. Almost 10 fold higher curcumin levels were observed in brain on day 1 from implants compared with diet (30.1±7.3 vs 2.7±0.8 ng/g) and were higher even after 90 days (7.7±3.8 vs 2.2±0.8 ng/g). Although, curcumin levels were similar in liver from both the routes (~25–30 ng/g from day 1–4 and ~10–15 ng/g at 90 days), implants were more efficacious in altering hepatic CYP1A1 levels and CYP3A4 activity at ~28 fold lower doses. Curcumin implants provided much higher plasma and tissue concentrations and are a viable alternative for delivery of curcumin to various organs like brain. PMID:22227368

  10. CALORIE RESTRICTION MODIFIES UBIQUINONE AND COQ TRANSCRIPTS LEVELS IN MOUSE TISSUES

    PubMed Central

    Parrado, Cristina; López-Lluch, Guillermo; Rodríguez-Bies, Elisabet; Santa-Cruz, Sara; Navas, Plácido; Ramsey, Jon J.; Villalba, José M.

    2011-01-01

    We studied ubiquinone (Q), Q homologue ratio and steady-state levels of mCOQ transcripts in tissues from mice fed ad libitum or under calorie restriction. Maximum ubiquinone levels on a protein basis were found in kidney and heart, followed by liver, brain and skeletal muscle. Liver and skeletal muscle showed the highest Q9/Q10 ratios with significant inter-individual variability. Heart, kidney, and particularly brain exhibited lower Q9/Q10 ratios and inter-individual variability. In skeletal muscle and heart, the most abundant mCOQ transcript was mCOQ7, followed by mCOQ8, mCOQ2, mPDSS2, mPDSS1 and mCOQ3. In non muscular tissues (liver, kidney and brain) the most abundant mCOQ transcript was mCOQ2, followed by mCOQ7, mCOQ8, mPDSS1, mPDSS2, and mCOQ3. Calorie restriction increased both ubiquinone homologues and mPDSS2 mRNA in skeletal muscle, but mCOQ7 was decreased. In contrast, Q9 and most mCOQ transcripts were decreased in heart. Calorie restriction also modified Q9/Q10 ratio, which was increased in kidney and decreased in heart without alterations of mPDSS1 or mPDSS2 transcripts. We demonstrate for the first time that unique patterns of mCOQ transcripts exist in muscular and non-muscular tissues, and that Q and COQ genes are targets of calorie restriction in a tissue-specific way. PMID:21447381

  11. Snapping turtles (Chelydra serpentina) as monitors for mercury contamination of aquatic environments.

    PubMed

    Golet, W J; Haines, T A

    2001-10-01

    We assessed the distribution of mercury in snapping turtles (Chelydra serpentina) by analyzing front shoulder muscle, back leg muscle, tail muscle, blood, liver, and marginal carapacial scute (shell) of 26 adult turtles from five small lakes. Total mercury concentration in muscle ranged from 50 to 500 ng g(-1) wet weight and was highly correlated among the three tissue locations. There was no relationship between muscle mercury concentration and body size. Mercury concentration in blood was similar to muscle; the correlation with muscle mercury concentration was significant but there was some variability. Mercury concentration in shell was much higher than in muscle or blood, ranging from 500 to 3300 ng g(-1), and was highly correlated with muscle mercury concentration. Liver mercury concentration was similar to shell, but was highly variable and uncorrelated with any other tissue. We conclude that snapping turtles accumulate mercury from their environment and may be useful monitors of mercury contamination. PMID:11683228

  12. Distribution and age-related bioaccumulation of lead (Pb), mercury (Hg), cadmium (Cd), and arsenic (As) in tissues of common carp (Cyprinus carpio) and European catfish (Sylurus glanis) from the Buško Blato reservoir (Bosnia and Herzegovina).

    PubMed

    Has-Schön, Elizabeta; Bogut, Ivan; Vukovi?, Rosemary; Galovi?, Dalida; Bogut, Ante; Horvati?, Janja

    2015-09-01

    The purpose of this study was to quantify the bioaccumulation of Pb, Hg, Cd, and As in tissues of carp (Cyprinus carpio) and catfish (Silurus glanis) from Buško Blato in Bosnia and Herzegovina. Arsenic concentrations were below the Maximal Admissible Concentration (MAC) for Croatia and other countries. Mercury concentrations were below 1mgkg(-1), but in most muscle samples of both species and all catfish liver samples, the values were higher than 0.5mgkg(-1) (higher than the MAC for many countries including Croatia). Lead concentrations were higher than 1mgkg(-1) (the MAC for Croatia) in most muscle samples; all kidney and most catfish liver samples also exceeded 1mgkg(-1). Cadmium concentrations in all tissues, other than the gonads, were higher than 0.1mgkg(-1) (MAC for Croatia), with the highest concentrations found in the kidneys. The only gender difference was found in carp, where a 68.4% higher concentration of As was found in the fry compared to the milt (P<0.05). Concentrations of all of the elements were higher in catfish compared to carp for most tissues. Significant correlations were found between all of the elements in the muscles and the liver of carp. In catfish, the muscles were the only tissue in which multiple correlations were found. Linear positive correlations with age and body mass were demonstrated for the concentrations of all heavy metals for all tissues except the gonads in both fish species. We concluded that significant heavy metal accumulation in carp and a catfish tissues correlates with age and body mass; bioaccumulation is species- and tissue-specific and is different for each element. PMID:25966047

  13. Organochlorine pesticide levels in adipose tissue of pregnant women in Veracruz, Mexico.

    PubMed

    Herrero-Mercado, Margarita; Waliszewski, S M; Valencia-Quintana, R; Caba, M; Hernández-Chalate, F; García-Aguilar, E; Villalba, R

    2010-06-01

    DDT and Lindane (gamma-HCH) which were used until 1999 in Mexico, have provided great benefits in the combat of vectors that spread infection-borne diseases and in agriculture for crop protection. The persistence in the environment and their accumulative properties results in bioconcentration in lipid rich tissues of the human body that reflect the extent of environmental pollution. Human adipose tissue samples were taken during 2009 from abdominal cavities of 69 pregnant women by cesarean surgery and from 34 samples of control donors by autopsy in Veracruz State. The samples were analyzed by gas chromatography with ECD. The results of mean levels (mg/kg on fat basis) were higher in controls compared to pregnant women beta-HCH 0.064 vs 0.027; pp'DDE 1.187 vs. 0.745; op'DDT 0.016 vs. 0.011; pp'DDT 0.117 vs. 0.099 and Sigma-DDT 1.337 vs. 0.854. The pregnant women group was divided according to age: up to 20, 20-30, and more than 30 years, and presented an increase for the more persistent pesticides with age in terms of mean concentrations and a more pronounced higher correlation in medians levels. Pairing Body Mass Index to organochlorine pesticide mean levels revealed no correlation between these factors in pregnant women. PMID:20449723

  14. Comparable Low-Level Mosaicism in Affected and Non Affected Tissue of a Complex CDH Patient

    PubMed Central

    Veenma, Danielle; Beurskens, Niels; Douben, Hannie; Eussen, Bert; Noomen, Petra; Govaerts, Lutgarde; Grijseels, Els; Lequin, Maarten; de Krijger, Ronald; Tibboel, Dick; de Klein, Annelies; Van Opstal, Dian

    2010-01-01

    In this paper we present the detailed clinical and cytogenetic analysis of a prenatally detected complex Congenital Diaphragmatic Hernia (CDH) patient with a mosaic unbalanced translocation (5;12). High-resolution whole genome SNP array confirmed a low-level mosaicism (20%) in uncultured cells, underlining the value of array technology for identification studies. Subsequently, targeted Fluorescence In-Situ Hybridization in postmortem collected tissues demonstrated a similar low-level mosaicism, independently of the affected status of the tissue. Thus, a higher incidence of the genetic aberration in affected organs as lung and diaphragm cannot explain the severe phenotype of this complex CDH patient. Comparison with other described chromosome 5p and 12p anomalies indicated that half of the features presented in our patient (including the diaphragm defect) could be attributed to both chromosomal areas. In contrast, a few features such as the palpebral downslant, the broad nasal bridge, the micrognathia, microcephaly, abnormal dermatoglyphics and IUGR better fitted the 5p associated syndromes only. This study underlines the fact that low-level mosaicism can be associated with severe birth defects including CDH. The contribution of mosaicism to human diseases and specifically to congenital anomalies and spontaneous abortions becomes more and more accepted, although its phenotypic consequences are poorly described phenomena leading to counseling issues. Therefore, thorough follow–up of mosaic aberrations such as presented here is indicated in order to provide genetic counselors a more evidence based prediction of fetal prognosis in the future. PMID:21203572

  15. Effect of low to normal dietary phosphorus levels on zinc metabolism and tissue distribution in calves

    SciTech Connect

    Laflamme, D.P.; Miller, W.J.; Neathery, M.W.; Gentry, R.P.; Blackmon, D.M.; Logner, K.R.; Fielding, A.S.

    1985-08-01

    Sixteen 10-wk-old, phosphorus (P)-depleted Holstein bull calves were fed for 6 wk a control diet containing .08% P or P-supplemented diets containing .14, .20 or .32% P with supplemental P from two sources (CDP and Dynafos). The diets contained .45, .56, .66 and .87% Ca. After 5 wk of the experiment, the calves were dosed orally with WVZn, and daily total fecal collections were initiated. At the end of the experimental period, the calves were killed and tissue samples were taken for total Zn and WVZn analyses. Growth, feed intake and feed efficiency improved with increasing dietary P levels. Level of dietary P and Ca had little or no effect on total Zn content of rib, tibia, liver, heart, kidney, muscle or blood. Likewise, WVZn absorption and content in most tissues were not affected. The results do not preclude the possibility of some minor effects of P levels on Zn metabolism. However, it is apparent that when adequate Zn is fed, any effects are likely to be of little or no practical importance.

  16. Using Fur to Estimate Mercury Concentrations in Mink

    EPA Science Inventory

    Total mercury (Hg) concentrations in fur and muscle tissue from mink (Mustela vison) were compared to determine the utility of fur analysis as a non-lethal and convenient method for predicting mercury concentrations in tissues. Sixty nine wild-trapped mink were collected in Rhode...

  17. [Levels of organochlorine insecticides in Polish women's breast adipose tissue, in years 1997-2001].

    PubMed

    Struci?ski, Pawe?; Ludwicki, Jan K; Góralczyk, Katarzyna; Czaja, Katarzyna; Olszewski, W?odzimierz; Jethon, Józef; Bara?ska, Joanna; Hernik, Agnieszka

    2002-01-01

    Although manufacture and use of chlorinated insecticides was banned or severely restricted in most of countries in the 1970s, the residues of these compounds are still detected in various environmental matrices all over the world. Their highest levels are found in adipose tissue of beings at the top of food chain, including humans. Levels of persistent organochlorine compounds in human specimens are monitored by numerous scientific organizations in various countries, including Poland. The purpose of the study was to survey the current levels of selected organochlorine insecticides (isomers alpha-, beta-, gamma-, delta-HCH, o,p'- and p,p'-DDT, DDE i DDE, oxy-chlordane and heptachlor) in women's breast adipose tissue which can be an indicator of body burden. A total of 67 samples of adipose breast tissue collected between 1997 and 2001 from non-cancer patients, aged from 15 to 74 years have been analyzed. The analytical procedure included extraction, clean-up and analysis by means of GC-ECD with GC-MS confirmation. In all the samples analyzed p,p'-DDE, p,p'-DDT and beta-HCH were present (mean values, expressed as mg/kg of fat: 0.7700, 0.0720, and 0.0635 respectively) with p,p'-DDE, found to be dominant analyte. The levels of the remaining compounds, were usually about or below the method quantification limits (from 0.0025 to 0.0060 mg/kg of fat). The results for DDTs and beta-HCH for the oldest group (above 50 years) were 2.1 to 3.6 times higher than the youngest group (below 39 years). The results obtained in this study are similar to those reported in analogous samples collected from women living in other European countries with similar climate and history or organochlorines usage as well as in the USA. The presence of some organo-chlorine insecticide residues in women's adipose tissue, even those, who were born even 10-15 years after most countries introduced severe restrictions or banned the use of these compounds may be cause for anxiety. That is due to the potential of these compounds to promote toxic effects, including disrupting the human endocrine system. PMID:12621876

  18. Clinical evaluation of tissue plasminogen activator (tPA) levels in patients with liver diseases

    Microsoft Academic Search

    Kazuhiko Okabe; Ikuo Kato; Shunichi Sato; Toshifumi Kashiwabara; Seiichi Furuta; Hiroshi Sato; Kyuichi Tanikawa; Ryukichi Kumashiro; Masaaki Kanayama

    1992-01-01

    Summary  Tissue plasminogen activator (t-PA) levels in plasma or serum were studied in 416 patients with liver diseases: acute hepatitis\\u000a (AH, n=30); fulminant hepatitis (FH, n=36); chronic inactive hepatitis (CIH, n=57); chronic active hepatitis (CAH, n=39);\\u000a compensated liver cirrhosis (cLC, n=78); decompensated liver cirrhosis (dLC, n=84); hepatocellular carcinoma (HCC, n=64);\\u000a advanced hepatocellular carcinoma (aHCC, n=28); and compared with that of a

  19. Accumulation levels and characteristics of some pesticides in human adipose tissue samples from Southeast China

    Microsoft Academic Search

    Na Wang; Lili Shi; Deyang Kong; Daoji Cai; Yanzhong Cao; Yongming Liu; Guofang Pang; Rongbin Yu

    2011-01-01

    This paper presents a comprehensive study of pesticide levels and bio-accumulation characteristics in human adipose tissues among residents of Southeast China. A large number of adipose samples (n=633) were selected for 58 pesticides and were analyzed by high sensitive Gas Chromatography–Tandem Mass Spectrometry (GC–MS\\/MS). The results showed that POPs pesticides were frequently detected, including 2,4?-DDD, 2,4?-DDE, 2,4?-DDT, 4,4?-DDD, 4,4?-DDE, 4,4?-DDT,

  20. Modeling Mercury

    NASA Astrophysics Data System (ADS)

    Burger, M. H.; Killen, R. M.; M, N.; Sarantos, M.; Crider, D. H.; Vervak, R. J.

    2009-04-01

    Mercury has a tenuous exosphere created by the combined effects of solar radiation and micrometeoroid bombardment on the surface and the interaction of the solar wind with Mercury's magnetic field and surface. Observations of this exosphere provide essential data necessary for understanding the composition and evolution of Mercury's surface, as well as the interaction between Mercury's magnetosphere with the solar wind. The sodium component of the exosphere has been well observed from the ground (see review by Killen et al., 2007). These observations have revealed a highly variable and inhomogeneous exosphere with emission often peaking in the polar regions. Radiation acceleration drives exospheric escape producing a sodium tail pointing away from the sun which has been detected up to 1400 Mercury radii from the planet (Potter et al. 2002; Baumgardner et al. 2008). Calcium has also been observed in Mercury's exosphere showing a distribution distinct from sodium, although also variable (Killen et al. 2005). During the first two encounters with Mercury by MESSENGER, observations of the exosphere were made by the UltraViolet and Visible Spectrometer (UVVS) channel of the Mercury Atmospheric and Surface Composition Spectrometer (MASCS). Sodium and calcium emission were detected during both flybys, and magnesium was detected for the first time in Mercury's exosphere during the second flyby. The spatial distributions of these species showed significant, unexpected differences which suggest differences in the mechanisms responsible for releasing them from the surface. We present a Monte-Carlo model of sodium, magnesium, and calcium in Mercury's exosphere. The important source mechanisms for ejecting these species from the surface are sputtering by solar wind ions, photon-stimulated desorption, and micrometeoroid impact vaporization. Thermal desorption on the dayside does not supply enough energy to significantly populate the exosphere, although it does play a role in redistributing volatiles over the surface. In addition, atomic calcium can be produced from the dissociation of Ca-bearing molecules, such as CaO, which can be formed in impact vapors. The primary loss processes are the escape of neutrals ejected with sufficient energy and photoionization. The former process is supplemented by radiation pressure which accelerates neutrals anti-sunward such that escaping neutrals form a tail pointing away from the sun. Because Mercury's heliocentric distance and radial velocity vary during its orbit, both loss processes are functions of Mercury's true anomaly. We also consider the spatial distribution of the surface source. Impact vaporization is roughly isotropic over the surface, although there may be a leading/trailing asymmetry in the impact rate due to Mercury's orbital motion. Sputtering is confined to regions where the solar wind can impact the surface, which is shielded somewhat by the internal magnetic field. The surface regions vulnerable depend on the solar wind conditions. References: Baumgardner et al., GRL, 35, L03201, 2008. Killen, R.M. et al., Space Sci. Rev. 132, 433-509, 2007. Killen, R.M. et al., Icarus, 173, 300-311, 2005. Potter et al., Meteoritics & Planetary Sci., 37, 1165, 2002.

  1. MERCURY CONCENTRATIONS IN FISH-EATING BIRDS FROM THE PINCHI LAKE AREA IN RELATION TO PRODUCTIVITY AND REPRODUCTIVE SUCCESS

    Microsoft Academic Search

    Shari A. Weech; R. P. Bio; Tony M. Scheuhammer

    Bald eagles and red-necked grebes were monitored from 2000 - 2002 on several lakes along the Pinchi fault, an area with a known source of geologic mercury and previous Hg mining (on Pinchi Lake), in an effort to discern whether increased Hg concentrations were affecting reproductive success and productivity. To determine whether or not Hg levels were elevated, fish tissues

  2. Mercury sources and trophic ecology for hawaiian bottomfish.

    PubMed

    Sackett, Dana K; Drazen, Jeffrey C; Choy, C Anela; Popp, Brian; Pitz, Gerald L

    2015-06-01

    In Hawaii, some of the most important commercial and recreational fishes comprise an assemblage of lutjanids and carangids called bottomfish. Despite their importance, we know little about their trophic ecology or where the mercury (Hg) that ultimately resides in their tissue originates. Here we investigated these topics, by analyzing muscle samples for mercury content, nitrogen, carbon, and amino acid specific nitrogen isotope ratios in six species distributed across different depths from the Northwestern Hawaiian Islands (NWHI) and the Main Hawaiian Islands (MHI). Fishes had different sources of nitrogen and carbon, with isotopic values suggesting benthic food sources for shallow nearshore species. High trophic position lutjanids that foraged in deeper water, benthic environments generally had higher Hg levels. Model results also suggested that benthic Hg methylation was an important source of Hg for shallow benthic feeders, while deepwater sources of mercury may be important for those with a diet that derives, at least in part, from the pelagic environment. Further, despite the lack of freshwater sources of Hg in the NWHI, statistical models explaining the variation in tissue Hg in the MHI and NWHI were nearly identical, suggesting freshwater Hg inputs were not a major source of Hg in fish tissue. PMID:25936419

  3. Human Renovascular Disease: Estimating Fractional Tissue Hypoxia to Analyze Blood Oxygen Level–dependent MR

    PubMed Central

    Saad, Ahmed; Crane, John; Glockner, James F.; Herrmann, Sandra M. S.; Friedman, Hannah; Ebrahimi, Behzad; Lerman, Lilach O.

    2013-01-01

    Purpose: To test the hypothesis that fractional kidney hypoxia, measured by using blood oxygen level–dependent (BOLD) magnetic resonance (MR) imaging, correlates with renal blood flow (RBF), tissue perfusion, and glomerular filtration rate (GFR) in patients with atherosclerotic renal artery stenosis (RAS) better than regionally selected region of interest–based methods. Materials and Methods: The study was approved by the institutional review board according to a HIPAA-compliant protocol, with written informed consent. BOLD MR imaging was performed in 40 patients with atherosclerotic RAS (age range, 51–83 years; 22 men, 18 women) and 32 patients with essential hypertension (EH) (age range, 26–85 years; 19 men, 13 women) during sodium intake and renin-angiotensin blockade. Fractional kidney hypoxia (percentage of entire axial image section with R2* above 30 sec?1) and conventional regional estimates of cortical and medullary R2* levels were measured. Stenotic and nonstenotic contralateral kidneys were compared for volume, tissue perfusion, and blood flow measured with multidetector computed tomography. Statistical analysis was performed (paired and nonpaired t tests, linear regression analysis). Results: Stenotic RBF was reduced compared with RBF of contralateral kidneys (225.2 mL/min vs 348 mL/min, P = .0003). Medullary perfusion in atherosclerotic RAS patients was lower than in EH patients (1.07 mL/min per milliliter of tissue vs 1.3 mL/min per milliliter of tissue, P = .009). While observer-selected cortical R2* (18.9 sec?1 [stenosis] vs 18.5 sec?1 [EH], P = .07) did not differ, fractional kidney hypoxia was higher in stenotic kidneys compared with kidneys with EH (17.4% vs 9.6%, P < .0001) and contralateral kidneys (7.2%, P < .0001). Fractional hypoxia correlated inversely with blood flow (r = ?0.34), perfusion (r = ?0.3), and GFR (r = ?0.32). Conclusion: Fractional tissue hypoxia rather than cortical or medullary R2* values used to assess renal BOLD MR imaging demonstrated a direct relationship to chronically reduced blood flow and GFR. © RSNA, 2013 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13122234/-/DC1 PMID:23788716

  4. Measuring mercury in coastal fog water

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2012-04-01

    Mercury, a heavy metal neurotoxin, accumulates in sea life, in some cases reaching levels that make seafood unsafe for humans to eat. How mercury gets into aquatic organisms is debated, but part of the pathway could include mercury carried in precipitation, including rain, snow, and fog. The contribution of mercury in fog water in particular is not well known, especially in foggy coastal areas such as coastal California. To learn more, Weiss-Penzias et al. measured total mercury and monomethyl mercury concentrations in fog water and rainwater samples taken from four locations around Monterey Bay, California, during spring and summer 2011. They found that the mean monomethyl mercury concentrations in their fog water samples were about 34 times higher than the mean concentrations in their rainwater samples. Therefore, the authors believe that fog is an important, previously unrecognized source of mercury to coastal ecosystems. They also explored potential sources of mercury, finding that biotically formed monomethyl mercury from oceanic upwelling may contribute to monomethyl mercury in fog. (Geophysical Research Letters, doi:10.1029/2011GL050324, 2012)

  5. Effects of a Low Level Laser on Periodontal Tissue in Hypofunctional Teeth

    PubMed Central

    Hayashi, Hidetaka; Terao, Akiko; Kunimatsu, Ryo; Kawata, Toshitsugu

    2014-01-01

    Malocclusions, such as an open bite and high canines, are often encountered in orthodontic practice. Teeth without occlusal stimuli are known as hypofunctional teeth, and numerous atrophic changes have been reported in the periodontal tissue, including reductions in blood vessels in the periodontal ligament (PDL), heavy root resorption, and reduced bone mineral density (BMD) in the alveolar bone. Low Level Laser (LLL) has been shown to have a positive effect on bone formation and the vasculature. Although the recovery of hypofunctional teeth remains unclear, LLL is expected to have a positive influence on periodontal tissue in occlusal hypofunction. The aim of the present study was to elucidate the relationship between LLL and periodontal tissue in occlusal hypofunction. Twenty-four male rats aged 5 weeks were randomly divided into control and hypofunctional groups. An anterior metal cap and bite plate were attached to the maxillary and mandibular incisors in the hypofunctional group to simulate occlusal hypofunction in the molars. LLL irradiation was applied to the maxillary first molar through the gingival sulcus in half of the rats. Rats were divided into four groups; control, control+LLL, hypofunctional, and hypofunctional+LLL. Exposure to LLL irradiation was performed for 3 minutes every other day for 2 weeks. Animals were examined by Micro-CT at 5 and 7 weeks and were subsequently sacrificed. Heads were resected and examined histologically and immunohistologically. The hypofunctional group had obvious stricture of the PDL. However, no significant differences were observed in the PDL and alveolar bone between the hypofunctional+LLL and the control groups. In addition, the expression of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF)-positive cells were higher in the hypofunctional + LLL group than in the hypofunctional group. These results indicated that LLL enhanced the production of bFGF and VEGF in the periodontal tissue of hypofunctional teeth. PMID:24927024

  6. Effects of a low level laser on periodontal tissue in hypofunctional teeth.

    PubMed

    Hayashi, Hidetaka; Terao, Akiko; Kunimatsu, Ryo; Kawata, Toshitsugu

    2014-01-01

    Malocclusions, such as an open bite and high canines, are often encountered in orthodontic practice. Teeth without occlusal stimuli are known as hypofunctional teeth, and numerous atrophic changes have been reported in the periodontal tissue, including reductions in blood vessels in the periodontal ligament (PDL), heavy root resorption, and reduced bone mineral density (BMD) in the alveolar bone. Low Level Laser (LLL) has been shown to have a positive effect on bone formation and the vasculature. Although the recovery of hypofunctional teeth remains unclear, LLL is expected to have a positive influence on periodontal tissue in occlusal hypofunction. The aim of the present study was to elucidate the relationship between LLL and periodontal tissue in occlusal hypofunction. Twenty-four male rats aged 5 weeks were randomly divided into control and hypofunctional groups. An anterior metal cap and bite plate were attached to the maxillary and mandibular incisors in the hypofunctional group to simulate occlusal hypofunction in the molars. LLL irradiation was applied to the maxillary first molar through the gingival sulcus in half of the rats. Rats were divided into four groups; control, control+LLL, hypofunctional, and hypofunctional+LLL. Exposure to LLL irradiation was performed for 3 minutes every other day for 2 weeks. Animals were examined by Micro-CT at 5 and 7 weeks and were subsequently sacrificed. Heads were resected and examined histologically and immunohistologically. The hypofunctional group had obvious stricture of the PDL. However, no significant differences were observed in the PDL and alveolar bone between the hypofunctional+LLL and the control groups. In addition, the expression of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF)-positive cells were higher in the hypofunctional + LLL group than in the hypofunctional group. These results indicated that LLL enhanced the production of bFGF and VEGF in the periodontal tissue of hypofunctional teeth. PMID:24927024

  7. Improved prediction of rat cortical bone mechanical behavior using composite beam theory to integrate tissue level properties.

    PubMed

    Kim, Grace; Boskey, Adele L; Baker, Shefford P; van der Meulen, Marjolein C H

    2012-11-15

    Tissue level characteristics of bone can be measured by nanoindentation and microspectroscopy, but are challenging to translate to whole bone mechanical behavior in this hierarchically structured material. The current study calculated weighted section moduli from microCT attenuation values based on tissue level relationships (Z(lin,a) and Z(lin,b)) between mineralization and material properties to predict whole bone mechanical behavior. Z(lin,a) was determined using the equation of the best fit linear regression between indentation modulus from nanoindentation and mineral:matrix ratio from Raman spectroscopy. To better represent the modulus of unmineralized tissue, a second linear regression with the intercept fixed at 0 was used to calculate Z(lin,b). The predictive capability of the weighted section moduli calculated using a tissue level relationship was compared with average tissue level properties and weighted section moduli calculated using an apparent level relationship (Z(exp)) between Young's Modulus and mineralization. A range of bone mineralization was created using vitamin D deficiency in growing rats. After 10 weeks, left femurs were scanned using microCT and tested to failure in 3 point bending. Contralateral limbs were used for co-localized tissue level mechanical properties by nanoindentation and compositional measurements by Raman microspectroscopy. Vitamin D deficiency reduced whole bone stiffness and strength by ?35% and ?30%, respectively, but only reduced tissue mineral density by ?10% compared with Controls. Average tissue level properties did not correlate with whole bone mechanical behavior while Z(lin,a), Z(lin,b), and Z(exp) predicted 54%, 66%, and 80% of the failure moment respectively. This study demonstrated that in a model for varying mineralization, the composite beam model in this paper is an improved method to extrapolate tissue level data to macro-scale mechanical behavior. PMID:23021607

  8. TISSUE CULTURE AND QUANTIFICATION OF INDIVIDUAL-LEVEL RESISTANCE TO ANTHER-SMUT DISEASE IN SILENE VULGARIS

    E-print Network

    Antonovics, Janis

    , Alexander (1989) used vegetative cloning of adult Silene latifolia plants to show large differencesTISSUE CULTURE AND QUANTIFICATION OF INDIVIDUAL-LEVEL RESISTANCE TO ANTHER-SMUT DISEASE IN SILENE is described for cloning individuals of Silene vulgaris plants using the tissue culture of seedling meristems

  9. Effects of intermittent electrical stimulation on superficial pressure, tissue oxygenation, and discomfort levels for the prevention of deep tissue injury.

    PubMed

    Solis, Leandro R; Gyawali, Selina; Seres, Peter; Curtis, Cara A; Chong, Su Ling; Thompson, Richard B; Mushahwar, Vivian K

    2011-02-01

    The overall goal of this project is to develop effective methods for the prevention of deep tissue injury (DTI). DTI is a severe type of pressure ulcer that originates at deep bone-muscle interfaces as a result of the prolonged compression of tissue. It afflicts individuals with reduced mobility and sensation, particularly those with spinal cord injury. We previously proposed using a novel electrical stimulation paradigm called intermittent electrical stimulation (IES) for the prophylactic prevention of DTI. IES-induced contractions mimic the natural repositioning performed by intact individuals, who subconsciously reposition themselves as a result of discomfort due to prolonged sitting. In this study, we investigated the effectiveness of various IES paradigms in reducing pressure around the ischial tuberosities, increasing tissue oxygenation throughout the gluteus muscles, and reducing sitting discomfort in able-bodied volunteers. The results were compared to the effects of voluntary muscle contractions and conventional pressure relief maneuvers (wheelchair push-ups). IES significantly reduced pressure around the tuberosities, produced significant and long-lasting elevations in tissue oxygenation, and significantly reduced discomfort produced by prolonged sitting. IES performed as well or better than both voluntary contractions and chair push-ups. The results suggest that IES may be an effective means for the prevention of DTI. PMID:21072594

  10. Total Mercury in Carnivorous Fish from Brazilian Southeast.

    PubMed

    Ferreira, M S; Marques, A N; Ribeiro, R O R; Conte, C A; Carneiro, C S; Santelli, R E; Freire, A S; São Clemente, S C; Mársico, E T

    2015-07-01

    Total mercury concentrations were determined by atomic absorption spectrometry in muscle tissue of two commercially important species of carnivorous fishes croaker (Micropogonias furnieri) and cutlassfish (Trichiurus lepturus) caught in Itaipu estuary, Rio de Janeiro. In this study, whitemouth croaker presented more mercury than Atlantic cutlassfish. Bioaccumulation differences can be explained by the biological behavior of juveniles whitemouth croaker, that remain in the estuary up to maturity, which makes them good indicators of local environmental impacts (0.110 mg Kg(-1) HgT). It also can be explained by differences in nutritional requirements between the different life stages of two species. The analysis showed the presence of low levels of the metal. However, our results suggest a possible risk to human health, depending on the level of fish consumption. PMID:25666565

  11. Determination of organochlorine pesticide and polychlorinated biphenyl levels in adipose tissue of infertile men.

    PubMed

    Cok, Ismet; Durmaz, Tuba Calik; Durmaz, Emre; Satiroglu, M Hakan; Kabukcu, Cihan

    2010-03-01

    During the recent two decades, a remarkable drop in fertility rates has been noticed almost all over the world. A series of studies have showed that environmental factors had the primary role causing the observed adverse trends in the male reproductive health problems. Especially chlorinated hydrocarbons, for instance polychlorinated biphenyls (PCB) and pesticides, could mimic or antagonize the effects of steroid hormones, like estrogens and androgens and possibly interfering with male reproductive capacity. Organochlorine pesticides (OCPs) (i.e. p.p'-DDT, endosulfan...) and PCBs are widespread used chemicals in agriculture and industry for different purposes all over the world. Although direct evidence is lacking, theoretical considerations and epidemiological evidence implicate these compounds as potential hazards to human and wildlife reproductive health. For this purpose, in this study adipose tissue samples have provided from healthy males which were diagnosed as infertile men living in Ankara, Turkey at least for 5 years. Residual levels of OCPs (alpha-BHC, beta-BHC, gamma-BHC, HCB, Endosulfan I, II, p,p'-DDE, and p,p'-DDT) and seven major persistent PCB congeners (PCB 28, 52, 101, 118, 138, 153, and 180) were measured in 25 infertile men and 21 healthy men's adipose tissue samples by GC-ECD. Levels of OCPs and PCBs in adipose tissue of infertile men compared with those provided from controls. When the concentrations of each of the OCP were compared between the fertile and infertile groups, no statistical significance was obtained. Concentrations of each of the PCB congeners were compared between the fertile and infertile groups, no statistical significance was obtained (p > 0.05), except for 2,2',5,5'-Tetrachlorobiphenyl (PCB 52) (p = 0.032) and 2,2',3,4,4',5,5'-heptachlorobiphenyl (PCB 180) (p = 0.017). PMID:19252989

  12. Methylmercury and total mercury distribution in tissues of gray whales (Eschrichtius robustus) and spinner dolphins (Stenella longirostris) stranded along the lower Gulf of California, Mexico Distribución de metilmercurio y mercurio en tejidos de ballenas grises (Eschrichtius robustus) y delfines tornillo (Stenella longirostris) varados en el bajo Golfo de California, México

    Microsoft Academic Search

    Jorge R. Ruelas-Inzunza; Milena Horvat; Héctor Pérez-Cortés; Federico Páez-Osuna

    2003-01-01

    Four gray whales Eschrichtius robustus and eleven spinner dolphins Stenella longirostris were found stranded along the coasts of the lower Gulf of California, Mexico. Muscle, kidney and liver samples from all the specimens were used for mercury (Hg) analysis. Mean concentrations of total Hg (THg) were significantly different (P < 0.05) in all the tissues of spinner dolphins, resulting in

  13. [Comparative studies of cyclic 11, 12 erythromycin carbonate (davercin) and erythromycin a levels in lung tissue, serum and bronchial secretions].

    PubMed

    Krakówka, P; Kazimierczak, A; Ku?, J; Zagda?ska, J; Schaeffer, A; Bireta, K; Zdziarska, H; Olechnowicz, H; Sawicka, E; Ko?b, P

    1989-01-01

    A comparison of serum, pulmonary tissue and bronchial secretory levels of erythromycin and cyclic--11,12 carbonate of erythromycin (Davercin--Polfa) was carried out in 55 patients with lung cancer. All patients received erythromycin and Davercin 80 hours prior surgery, during which a small fragment of pulmonary tissue was removed for further evaluation. Concentration of both antibiotics was determined microbiologically. Better penetration of Davercin to the pulmonary tissue was found, as well as higher tissue concentration. The study demonstrates the advantage of Davercin over erythromycin in treating bacterial infections of the respiratory system. PMID:2813147

  14. Trends of PCB, hexachlorobenzene, and. beta. -benzene hexachloride levels in the adipose tissue of the U. S. population

    SciTech Connect

    Robinson, P.E.; Remmers, J. (U.S. Environmental Protection Agency, Washington, DC (USA)); Mack, G.A. (Battelle, Columbus, OH (USA)); Levy, R. (U.S. Environmental Protection Agency, Washington, DC (USA)); Mohadjer, L. (Westat, Inc., Rockville, MD (USA))

    1990-12-01

    Results are presented on the levels of selected toxic chemicals in the adipose tissue of the U.S. population. Estimates of baseline levels and time trends are presented for the chemicals {beta}-benzene hexachloride ({beta}-BHC), hexachlorobenzene, and polychlorinated biphenyls (PCBs). The statistical analyses are based on chemical data obtained from analysis of tissue specimens collected from a nationally representative sample of autopsied cadavers and surgical patients by EPA's National Human Adipose Tissue Survey during the period 1970 through 1983. The results show that while nearly the entire U.S. population has detectable levels of these chemicals, the actual concentration levels of {beta}-BHC and PCBs are steadily decreasing and the levels of HCB are remaining fairly constant. Comparisons of levels across demographic subpopulations show that there are some differences in concentration levels across geographic regions, age groups, and race groups.

  15. Determination of sub-nanogram-per-liter levels of mercury in lake water with atmospheric pressure helium microwave induced plasma emission spectrometry

    SciTech Connect

    Nojiri, Y.; Otsuki, A.; Fuwa, K.

    1986-03-01

    A highly sensitive method for the analysis of Hg was developed utilizing atmospheric pressure He microwave induced plasma (He-MIP) emission spectrometry. Mercury vapor was generated from water samples by reduction and purging and was collected with a gold amalgamation trap. The Hg vapor, removed by heating the trap, was introduced into the He-MIP. The atomic emission line of 253.7 nm was used for the determination of Hg. The detection limit, defined as 3 times the standard deviation of the blank operations, was 0.5 pg in 50 mL of water sample, corresponding to 0.01 ng/L. The method was applied to the determination of ultratrace levels of Hg in lake water samples. The inorganic Hg concentration in subsurface water from unpolluted Lake Mashu was found to be 0.3 ng/L. 29 references, 3 figures, 1 table.

  16. Monitoring of organochlorine pesticide residue levels in adipose tissue of Veracruz, Mexico inhabitants.

    PubMed

    Waliszewski, Stefan M; Caba, M; Herrero-Mercado, M; Saldariaga-Noreña, H; Meza, E; Zepeda, R; Martínez-Valenzuela, C; Infanzon, R; Hernández-Chalate, F

    2011-11-01

    The objective of the present study was to monitor the levels of organochlorine pesticides HCB, ?-?-?-HCH, pp'DDE, op'DDT and pp'DDT in 150 adipose tissue samples of Veracruz, Mexico inhabitants. In analyzed samples, the following pesticides were detected: p,p'-DDE in 100% of the samples at mean 1.643 mg/kg; p,p'-DDT in 99.3.% of the samples at mean 0.227 mg/kg; ?-HCH in 97.3% of the samples at mean 0.063 mg/kg; and op'DDT in 93.3% of the samples at mean 0.022 mg/kg. Comparing mean, median and geometric mean concentrations of organochlorine pesticides shows a decrease in values from mean to median and to geometric mean which points out a prevalence of lower concentrations among the total samples and the existence of occasional cases of extreme exposure expressed in range values. The pooled samples divided according to sex, showed only significant differences of pp'DDE median concentrations between sexes. The other organochlorine pesticides indicated no statistical differences between sexes, including the pp'DDE/pp'DDT ratio. The samples grouped according to age, showed that the third tertile was more contaminated for both sexes, indicating age as a positively associated factor with organochlorine pesticide levels in adipose tissue of Veracruz inhabitants. Comparing organochlorine pesticide levels between 2008 and 2010 years, a decreased tendency for ?-HCH, pp'DDE, ?-DDT and pp'DDE/pp'DDT ratio levels was observed. PMID:21681398

  17. Clinical evaluation of tissue plasminogen activator (t-PA) levels in patients with liver diseases.

    PubMed

    Okabe, K; Kato, I; Sato, S; Kashiwabara, T; Furuta, S; Sato, H; Tanikawa, K; Kumashiro, R; Kanayama, M

    1992-02-01

    Tissue plasminogen activator (t-PA) levels in plasma or serum were studied in 416 patients with liver diseases: acute hepatitis (AH, n = 30); fulminant hepatitis (FH, n = 36); chronic inactive hepatitis (CIH, n = 57); chronic active hepatitis (CAH, n = 39); compensated liver cirrhosis (cLC, n = 78); decompensated liver cirrhosis (dLC, n = 84); hepatocellular carcinoma (HCC, n = 64); advanced hepatocellular carcinoma (aHCC, n = 28); and compared with that of a control group (n = 106) of healthy subjects. The t-PA levels showed significant increase in patients with AH, FH, CAH, cLC, dLC and HCC, compared with normal controls. The abnormal rates in t-PA levels (higher than 8.3 ng/ml) for each type of liver diseases were 86.1% in FH, 46.2% in CAH, 50% in cLC, 85.7% in dLC, 67.2% in HCC, and 89.3% in aHCC. t-PA levels tended to be higher in more advanced liver diseases. t-PA levels significantly correlated positively with plasminogen activator inhibitor (PAI-1) in AH, cLC, dLC, HCC and aHCC, and negatively with plasmin alpha 1-plasmin inhibitor complex (PIC), plasminogen (Plg), FDP, AT III and alpha 2-plasmin inhibitor (alpha 2-PI) in dLC, prothrombin time (PT) and fibrinogen (Fbg) in HCC. t-PA levels in patients with FH, CAH and dLC were significantly higher than those in patients with AH, CIH and cLC, respectively. Moreover, the changes of t-PA levels in the clinical courses of various liver diseases revealed that t-PA levels increased sensitively with progression of liver diseases or in advanced liver diseases.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1313384

  18. Trends of PCB, hexachlorobenzene, and beta-benzene hexachloride levels in the adipose tissue of the U.S. population

    Microsoft Academic Search

    P. E. Robinson; G. Mack; J. Remmers; R. Levy; L. Mohadjer

    1990-01-01

    Results are presented on the levels of selected toxic chemicals in the adipose tissue of the U.S. population. Estimates of baseline levels and time trends are presented for the chemicals β-benzene hexachloride (β-BHC), hexachlorobenzene, and polychlorinated biphenyls (PCBs). The statistical analyses are based on chemical data obtained from analysis of tissue specimens collected from a nationally representative sample of autopsied

  19. A Review of Mercury in Seafood

    Microsoft Academic Search

    Rosalee S. Rasmussen; Joyce Nettleton; Michael T. Morrissey

    2005-01-01

    Mercury is a toxic heavy metal released into the environment from both natural and anthropogenic sources. It is of great interest to consumers as to whether it can cause neurological effects at low dose levels. The effects of organic mercury exposure at high levels have been demonstrated in several large-scale poisonings, particularly those in Japan and Iraq in the 1950s,

  20. Linking Myometrial Physiology to Intrauterine Pressure; How Tissue-Level Contractions Create Uterine Contractions of Labor

    PubMed Central

    Young, Roger C.; Barendse, Peter

    2014-01-01

    The mechanisms used to coordinate uterine contractions are not known. We develop a new model based on the proposal that there is a maximum distance to which action potentials can propagate in the uterine wall. This establishes “regions”, where one action potential burst can rapidly recruit all the tissue. Regions are recruited into an organ-level contraction via a stretch-initiated contraction mechanism (myometrial myogenic response). Each uterine contraction begins with a regional contraction, which slightly increases intrauterine pressure. Higher pressure raises tension throughout the uterine wall, which initiates contractions of more regions and further increases pressure. The positive feedback synchronizes regional contractions into an organ-level contraction. Cellular automaton (CA) simulations are performed with Mathematica. Each “cell” is a region that is assigned an action potential threshold. An anatomy sensitivity factor converts intrauterine pressure to regional tension through the Law of Laplace. A regional contraction occurs when regional tension exceeds regional threshold. Other input variables are: starting and minimum pressure, burst and refractory period durations, enhanced contractile activity during an electrical burst, and reduced activity during the refractory period. Complex patterns of pressure development are seen that mimic the contraction patterns observed in laboring women. Emergent behavior is observed, including global synchronization, multiple pace making regions, and system memory of prior conditions. The complex effects of nifedipine and oxytocin exposure are simulated. The force produced can vary as a nonlinear function of the number of regions. The simulation directly links tissue-level physiology to human labor. The concept of a uterine pacemaker is re-evaluated because pace making activity may occur well before expression of a contraction. We propose a new classification system for biological CAs that parallels the 4-class system of Wolfram. However, instead of classifying the rules, biological CAs should classify the set of input values for the rules that describe the relevant biology. PMID:25330227

  1. Linking myometrial physiology to intrauterine pressure; how tissue-level contractions create uterine contractions of labor.

    PubMed

    Young, Roger C; Barendse, Peter

    2014-10-01

    The mechanisms used to coordinate uterine contractions are not known. We develop a new model based on the proposal that there is a maximum distance to which action potentials can propagate in the uterine wall. This establishes "regions", where one action potential burst can rapidly recruit all the tissue. Regions are recruited into an organ-level contraction via a stretch-initiated contraction mechanism (myometrial myogenic response). Each uterine contraction begins with a regional contraction, which slightly increases intrauterine pressure. Higher pressure raises tension throughout the uterine wall, which initiates contractions of more regions and further increases pressure. The positive feedback synchronizes regional contractions into an organ-level contraction. Cellular automaton (CA) simulations are performed with Mathematica. Each "cell" is a region that is assigned an action potential threshold. An anatomy sensitivity factor converts intrauterine pressure to regional tension through the Law of Laplace. A regional contraction occurs when regional tension exceeds regional threshold. Other input variables are: starting and minimum pressure, burst and refractory period durations, enhanced contractile activity during an electrical burst, and reduced activity during the refractory period. Complex patterns of pressure development are seen that mimic the contraction patterns observed in laboring women. Emergent behavior is observed, including global synchronization, multiple pace making regions, and system memory of prior conditions. The complex effects of nifedipine and oxytocin exposure are simulated. The force produced can vary as a nonlinear function of the number of regions. The simulation directly links tissue-level physiology to human labor. The concept of a uterine pacemaker is re-evaluated because pace making activity may occur well before expression of a contraction. We propose a new classification system for biological CAs that parallels the 4-class system of Wolfram. However, instead of classifying the rules, biological CAs should classify the set of input values for the rules that describe the relevant biology. PMID:25330227

  2. A novel method for the determination of mercury and selenium in shark tissue using high-resolution inductively coupled plasma-mass spectrometry

    NASA Astrophysics Data System (ADS)

    Paul, Mitchell C.; Toia, Robert F.; von Nagy-Felsobuki, Ellak I.

    2003-09-01

    A method for measuring Hg and Se in shark tissue by high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) has been developed. Using a matrix of 4% (v/v) aqueous methanol, the spray chamber and transfer tubing memory effects of Hg were significantly reduced. The methanol matrix was able to effectively wash out Hg (10 ppb) and return the signal to blank level in approximately 5 min. This enabled accurate and concomitant measurements of Hg and Se with detection limits (3? blank signal, n=10) of 26 and 4 ppt, respectively. The recoveries of Hg and Se based on the CRM were 88 and 83%, respectively. The concentrations of Hg and Se in the (liver, muscle, kidney) of a hammerhead shark (dry weight) were (2.65±0.85, 7.09±1.32, 4.43±1.36) and (17.3±4.1, 1.28±0.29, 24.1±5.2) mg kg -1 (where the expanded uncertainty uses a k=2 value) respectively. Multi-elemental semi-quantitative analysis of a hammerhead shark liver, muscle and kidney revealed high levels of Cd, Zn and As.

  3. Aquatic Ecosystem Exposure Associated with Atmospheric Mercury Deposition: Importance of Watershed and Water Body Hot Spots and Hot Moments

    EPA Science Inventory

    Atmospheric deposition of divalent mercury (Hg(II)) is often the primary driving force for mercury contamination in fish tissue, resulting in mercury exposure to wildlife and humans. Transport and transformation of the deposited mercury into the environmentally relevant form, met...

  4. Process for removing mercury from aqueous solutions

    DOEpatents

    Googin, J.M.; Napier, J.M.; Makarewicz, M.A.; Meredith, P.F.

    1985-03-04

    A process for removing mercury from water to a level not greater than two parts per billion wherein an anion exchange material that is insoluble in water is contacted first with a sulfide containing compound and second with a compound containing a bivalent metal ion forming an insoluble metal sulfide. To this treated exchange material is contacted water containing mercury. The water containing not more than two parts per billion of mercury is separated from the exchange material.

  5. Detecting tissue deterioration after brain injury: regional blood flow level versus capacity to raise blood flow

    PubMed Central

    Feuerstein, Delphine; Takagaki, Masatoshi; Gramer, Markus; Manning, Andrew; Endepols, Heike; Vollmar, Stefan; Yoshimine, Toshiki; Strong, Antony J; Graf, Rudolf; Backes, Heiko

    2014-01-01

    Regional cerebral blood flow (rCBF) is spatially and temporally adjusted to local energy needs. This coupling involves dilation of vessels both at the site of metabolite exchange and upstream of the activated region. Deficits in upstream blood supply limit the ‘capacity to raise rCBF' in response to functional activation and therefore compromise brain function. We here demonstrate in rats that the ‘capacity to raise rCBF' can be determined from real-time measurements of rCBF using laser speckle imaging during an energy challenge induced by cortical spreading depolarizations (CSDs). Cortical spreading depolarizations (CSDs) occur with high incidence in stroke and various other brain injuries and cause large metabolic changes. Various conditions of cerebral perfusion were induced, either by modifying microvascular tone, or by altering upstream blood supply independently. The increase in rCBF per unit of time in response to CSD was linearly correlated to the upstream blood supply. In an experimental model of stroke, we found that this marker of the capacity to raise rCBF which, in pathologic tissue may be additionally limited by impaired vasoactive signaling, was a better indicator of the functional status of cerebral tissue than local rCBF levels. PMID:24690942

  6. Mercury and methylmercury intake estimation due to seafood products for the Catalonian population (Spain)

    Microsoft Academic Search

    S. Rodellar; M. Fontcuberta; J. F. Arqués; J. Calderon; L. Ribas Barba; L. L. Serra-Majem

    2010-01-01

    This study estimates mercury and methylmercury levels in fish and fishery products commercialized in the city of Barcelona, Spain, from 2001 to 2007. Combining data of mercury levels in food with the consumption data of 2158 people (as the median of two 24-h recall), the total mercury intake of the Catalonian population was calculated. Mercury was detected in 32.8% of

  7. Cholinesterase and monoamine oxidase activity in relation to mercury levels in the cerebral cortex of wild river otters.

    PubMed

    Basu, N; Scheuhammer, A M; Evans, R D; O'Brien, M; Chan, H M

    2007-03-01

    Mercury (Hg) is a global pollutant that is neurotoxic to many mammalian species. The present study was conducted to determine if the bioaccumulation of Hg by wild river otters (Lontra canadensis) could be related to variations in the activities of key neurochemical enzymes. River otters were collected from Ontario and Nova Scotia (Canada) during the trapping seasons, spanning 2002-2004, and their brains were dissected into the cerebral cortex and cerebellum. The activities of cholinesterase (ChE) and monoamine oxidase (MAO) were measured from each sample and correlated with concentrations of brain Hg from the same animal. Significant negative correlations were found between concentrations of brain Hg and ChE (total Hg: r= -0.42; MeHg: r= -0.33) and MAO (total Hg: r= -0.31; MeHg: r= -0.42) activity in the cerebral cortex. The scatterplots relating concentrations of brain Hg and enzyme activity in the cerebral cortex were wedge-shaped, and could be fitted with quantile regression modeling, suggesting that Hg may act as a limiting factor for ChE and MAO activity. No relationships were found in the cerebellum. These data suggest that environmentally relevant concentrations of Hg may influence the activities of ChE and MAO in the cerebral cortex of river otters, and by extension, other fish-eating mammals. PMID:17439924

  8. Detection and Quantification of Unbound Phytochelatin 2 in Plant Extracts of Brassica napus Grown with Different Levels of Mercury1

    PubMed Central

    Iglesia-Turiño, Santiago; Febrero, Anna; Jauregui, Olga; Caldelas, Cristina; Araus, Jose Luis; Bort, Jordi

    2006-01-01

    The mercury (Hg) accumulation mechanism was studied in rape (Brassica napus) plants grown under a Hg concentration gradient (0 ?m–1,000 ?m). Hg mainly accumulated in roots. Therefore, the presence of phytochelatins (PCs) was studied in the roots of the plants. The high stability of the PC-Hg multicomplexes (mPC-nHg) seems to be the main reason for the lack of previous Hg-PC characterization studies. We propose a modification of the method to detect and quantify unbound PC of Hg in plant extracts via high-performance liquid chromatography coupled to electrospray tandem mass spectrometry and inductively coupled plasma mass spectrometry in parallel. We separated the PC from the Hg by adding the chelating agent sodium 2,3-dimercaptopropanesulfonate monohydrate. We only detected the presence of PC after the addition of the chelating agent. Some multicomplexes mPC-nHg could be formed but, due to their large sizes, could not be detected. In this study, only PC2 was observed in plant samples. Hg accumulation was correlated with PC2 concentration (r2 = 0.98). PMID:16920879

  9. Bioconcentration of mercury by mushroom Xerocomus chrysenteron from the spatially distinct locations: levels, possible intake and safety.

    PubMed

    Dry?a?owska, Anna; Falandysz, Jerzy

    2014-09-01

    Concentrations of mercury were determined in specimens of Red Cracking Bolete (Xerocomus chrysenteron) (Bull.) Quél. and overlying soil (0-10cm) collected from 22 spatially distributed sites in Poland during 1996-2013 to assess the potential of this species to bioconcentrate Hg and possible intake by humans. The mean Hg concentrations ranged from 80 to 630 for caps and from 28 to 380ng/g dry matter (dm) for stipes. Decrease in the potential of this mushroom species to bioconcentrate Hg both in caps and stipes was observed when the Hg content in soil substratum increased from 15 to 75-94ng/g dm. A maximum median value for bioconcentration factor (BCF) of Hg determined for caps was 18 for soil with Hg content at 15ng/g dm and decreased to 0.97-3.8 for soils that contained Hg at 37-94ng/g dm. Caps of X. chrysenteron consumed at a volume of 300g daily in a week can yield an exposure amount of Hg at 0.0168-0.1323mg (0.00024 to 0.00189mg/kg body mass); these values are well below the provisionally tolerated weekly intake (PTWI) for inorganic Hg. PMID:24927386

  10. Mercury concentration in 3 species of Gulls, Larus ridibundus, Larus minutus, Larus canus, from south coast of the Caspian Sea, Iran.

    PubMed

    Rajaei, Fateme; Esmaili Sari, Abbas; Bahramifar, Nader; Ghasempouri, Seyed Mahmoud; Savabieasfahani, Mozhgan

    2010-06-01

    In this study, the mercury concentrations of liver, breast feathers and tail feathers in three species of Gull; Black-headed Gull (Larus ridibundus), Common Gull (Larus canus) and Little Gull (Larus minutus) from the South coast of the Caspian Sea in Iran were assayed. Mercury accumulation in liver, breast feathers and tail feathers of species were 1.69-3.16, 2.88-7.18 and 2.09-5.66 mg/kg, respectively. Mercury concentration hierarchy in tissues we tested was as follows: breast feather > tail feather > and liver. We found that despite its small size, Little Gull had highest (3.85-8.05 mg/kg) and Common Gull lowest (1.69-2.88 mg/kg) level of Hg in their bodies. An inverse relationship between body size and Hg levels in these Gulls was detected. Mercury in Little Gull and Black-headed Gull exceeded the 5 ppm threshold for adverse effect. PMID:20424818

  11. Effects of methotrexate and cyclophosphamide on polyamine levels in various tissues of rats.

    PubMed

    Watanabe, S; Sato, S; Nagase, S; Shimosato, K; Ohkuma, S

    1999-01-01

    The effects of methotrexate (MTX) and cyclophosphamide (CYP) on body weight, organ weight, and the concentration of putrescine, spermidine, and spermine in 14 different tissues were measured in rats that had been given these compounds for 5 consecutive days. These three polyamines in both the thymus and spleen of rats treated with MTX and CYP showed a statistically significant decrease. Further, putrescine in the seminal vesicles, kidney, liver, and small intestine of MTX-treated rats, and in the prostate, seminal vesicles, kidney, heart, liver, small intestine, and lung of CYP-treated rats, spermidine in the prostate, seminal vesicles, testis, thymus, spleen, kidney, heart, small intestine, and skeletal muscle of CYP-treated rats, and spermine in the prostate, seminal vesicles, kidney, heart, small intestine, and stomach of CYP-treated rats showed statistically significant decreases. Recognition of the significance of polyamine levels and attention to their response in anti-cancer drug therapy may have clinical implications. PMID:10680975

  12. Levels of Mercury in Scalp Hair of Fishermen and Their Families from Camara de Lobos–Madeira (Portugal): A Preliminary Study

    Microsoft Academic Search

    C. Gaggi; F. Zino; M. Duccini; A. Renzoni

    1996-01-01

    Mercury is probably one of the most investigated natural and anthropogenic contaminants, especially in aquatic environments. It occurs in nature in a wide variety of physical and chemical states and the fate and behavior of the different forms are related mainly to their physico-chemical and partition properties. Among the inorganic forms, elemental mercury (Hg°) presents a marked tendency to reach

  13. Heavy metal concentrations in feathers of common loons ( Gavia immer ) in the Northeastern United States and age differences in mercury levels

    Microsoft Academic Search

    Joanna Burger; Mark Pokras; Rebecca Chafel; Michael Gochfeld

    1994-01-01

    Feathers serve as a useful, non-destructive approach for biomonitoring some aspects of environmental quality. Birds can eliminate over 90% of their body burden of mercury by sequestration in growing feathers, and they molt their feathers at least annually. Thus mercury concentrations should not vary in avian feathers as a function of age. We tested the null hypothesis that there are

  14. Parenteral lipid emulsions in guinea pigs differentially influence plasma and tissue levels of fatty acids, squalene, cholesterol, and phytosterols.

    PubMed

    Harvey, Kevin; Xu, Zhidong; Walker, Candace; Pavlina, Thomas; McGrath, Sheila; Zaloga, Gary; Siddiqui, Rafat

    2014-08-01

    Lipid emulsions are made by mixing vegetable and/or fish oils with egg yolk and contain different types and amounts of fatty acids and sterols. This study assessed the effects of oral diet, soybean oil (SO)-, fish oil (FO)-, a mixture of olive and soybean oil (OOSO)-, and a mixture of fish, olive, coconut, and soybean oil (FOCS)-based emulsions on plasma triacylglycerols and plasma and tissue fatty acid and sterol content following acute and chronic intravenous administration in the guinea pig. Upon acute administration, peak triacylglycerols were highest with SO and lowest with OOSO. Upon chronic administration, the plasma triglyceride levels did not increase in any group over that of the controls. Fatty acid levels varied greatly between organs of animals on the control diets and organs of animals following acute or chronic lipid administration. Squalene levels increased in plasma following acute administration of OOSO, but plasma squalene levels were similar to control in all emulsion groups following chronic administration. Total plasma phytosterol levels were increased in the SO, OOSO, and FOCS groups following both acute and chronic infusions, whereas phytosterols were not increased following FO infusion. Total phytosterol levels were higher in liver, lung, kidney and adipose tissue following SO and OOSO. Levels were not increased in tissues after FO and FOCS infusion. These results indicate that fatty acid and sterol contents vary greatly among organs and that no one tissue reflects the fatty acid or sterol composition of other tissues, suggesting that different organs regulate these compounds differently. PMID:24997615

  15. MERCURY IN TREE RINGS

    EPA Science Inventory

    Contamination caused by release of mercury into the environment is a growing concern. This release occurs due to a variety of anthropogenic activities and natural sources. After release, mercury undergoes complicated chemical transformations. The inorganic forms of mercury releas...

  16. MERCURY STABILITY IN THE ENVIRONMENT

    SciTech Connect

    John H. Pavlish

    1999-07-01

    The 1990 Clean Air Act Amendments (CAAAs) require the U.S. Environmental Protection Agency (EPA) to determine whether the presence of mercury and 188 other trace substances, referred to as air toxics or hazardous air pollutants (HAPs), in the stack emissions from fossil fuel-fired electric utility power plants poses an unacceptable public health risk (1). The EPA's conclusions and recommendations were presented in two reports: Mercury Study Report to Congress and Study of Hazardous Air Pollutant Emissions from Electric Utility Steam Generating Units-Final Report to Congress. The first congressional report addressed both human health and the environmental effects of anthropogenic mercury emissions, while the second report addressed the risk to public health posed by emissions of HAPs from steam electricity-generating units. The National Institute of Environmental Health Sciences is also required by the CAAAs to investigate mercury and determine a safe threshold level of exposure. Recently the National Academy of Sciences has also been commissioned by Congress to complete a report, based the available scientific evidence, regarding safe threshold levels of mercury exposure. Although the EPA reports did not state that mercury controls on coal-fired electric power stations should be required given the current state of the art, they did indicate that EPA views mercury as a potential threat to human health. It is likely that major sources of mercury emissions, including fossil-fired combustion systems, will be controlled at some point. In fact, municipal waste combustion units are already regulated. In anticipation of additional control measures, much research has been done (and continues) regarding the development of control technologies for mercury emitted from stationary sources to the atmosphere. Most approaches taken to date involve sorbent injection technologies or improve upon removal of mercury using existing technologies such as flue gas desulfurization scrubbers, fabric filters, and electrostatic precipitators. Depending on the fly ash chemistry and the form of mercury present in the flue gas, some of these existing technologies can be effective at capturing vapor-phase mercury from the flue gas stream. Although much research has been done on enhancing the removal of mercury from flue gas streams, little research has focused on what happens to the mercury when it is captured and converted and/or transferred to a solid or aqueous solution. The stability (or mobility) of mercury in this final process is critical and leads to the questions, What impact will the increased concentration of mercury have on utilization, disposal, and reuse? and Is the mercury removed from the flue gas really removed from the environment or rereleased at a later point? To help answer these questions, the Energy & Environmental Research Center (EERC) as part of the U.S. Department of Energy (DOE) Base Cooperative Agreement did a series of experiments using thermal desorption and leaching techniques. This report presents the results from these tests.

  17. Mercury contamination in three species of anuran amphibians from the Cache Creek Watershed, California, USA.

    PubMed

    Hothem, Roger L; Jennings, Mark R; Crayon, John J

    2010-04-01

    Fish and wildlife may bioaccumulate mercury (Hg) to levels that adversely affect reproduction, growth, and survival. Sources of Hg within the Cache Creek Watershed in northern California have been identified, and concentrations of Hg in invertebrates and fish have been documented. However, bioaccumulation of Hg by amphibians has not been evaluated. In this study, adult and juvenile American bullfrogs (Lithobates catesbeianus) and foothill yellow-legged frogs (Rana boylii), adult Northern Pacific treefrogs (Pseudacris regilla), and larval bullfrogs were collected and analyzed for total Hg. One or more species of amphibians from 40% of the 35 sites had mean Hg concentrations greater than the US Environmental Protection Agency's tissue residue criterion for fish (0.3 microg/g). Of the bullfrog tissues analyzed, the liver had the highest concentrations of both total Hg and methyl mercury. Total Hg in carcasses of bullfrogs was highly correlated with total Hg in leg muscle, the tissue most often consumed by humans. PMID:19353298

  18. Effect of red and infrared low-level laser therapy in endodontic sealer on subcutaneous tissue

    NASA Astrophysics Data System (ADS)

    Sivieri-Araujo, G.; Berbert, F. L. C. V.; Ramalho, L. T. O.; Rastelli, A. N. S.; Crisci, F. S.; Bonetti-Filho, I.; Tanomaru-Filho, M.

    2011-12-01

    This study evaluated the reactions of connective tissue after the implant of one endodontic sealer (Endofill) that was irradiated with low-level laser therapy (LLLT). Sixty mice were distributed into three Groups ( n = 20): GI—the tubes filled with Endofill were implanted in the animals and were not irradiated with LLLT; GII—the tubes containing Endofill were implanted in the animals and then irradiated with red LLLT (InGaAlP, ? = 685 nm, P = 35 mW, t = 58 s, D = 72 J/cm2, E = 2 J, Ø = 0.60 mm, continuous mode) and GIII—the tubes with Endofill were implanted and irradiated with infrared LLLT (AsGaAl, ? = 830 nm, P = 50 mW, t = 40 s, D = 70 J/cm2, E = 2 J, Ø = 0.60 mm, continuous wave) both are semiconductor diode laser device. The animals were killed after 7 and 30 days. Series sections of 6 ?m thickness were obtained and stained with Hematoxylin-Eosin and Masson Trichrome. The data of the histopathological evaluation were submitted to Kruskal-Wallis and Dunn's tests at 5% significance level. At the 7th day: GI showed the presence of inflammation; GII and GIII reduced inflammation. At 30th day: GI showed low inflammation; GII and GII the absence of inflammation. It was possible show that LLLT reduced the irritating effect promoted by the Endofill, in the period of 7 days ( p > 0.05). The tissue repair occurred in 30 days, regardless of the use of LLLT.

  19. Levels of organochlorine pesticides residues in human adipose tissue, data from Tabasco, Mexico.

    PubMed

    Waliszewski, Stefan M; Caba, M; Rodríguez Díaz, S S; Saldarriaga-Noreña, H; Meza, E; Zepeda, R; Infanzón, R

    2012-11-01

    The objective of this study was to determine the levels of organochlorine pesticides HCB, ?-?-?-HCH, p,p'-DDE, o,p'-DDT and p,p'-DDT in 150 adipose tissue of inhabitants of Tabasco, Mexico. The following pesticides were detected: p,p'-DDE in 100% of samples at mean 1.034 mg/kg; p,p'-DDT in 96.7% at mean 0.116 mg/kg; o,p'-DDT in 78.7% at mean 0.022 mg/kg and ?-HCH in 58.0% at mean 0.049 mg/kg. The pooled sample was divided according to sex of donors (75 female and 75 male). Significantly higher levels of all organochlorine pesticides in females were found. The sample was divided into three age's ranges (15-28, 29-45 and 46-84 years). The mean and median levels of ?-HCH, p,p'-DDE and ?-DDT increase significantly (p < 0.05) from the first to the second and third group. The presence of organochlorine pesticide residues in Tabasco inhabitants is still observed, indicating sources of exposure to the pesticides. PMID:22965333

  20. Identification of Genes with Consistent Methylation Levels across Different Human Tissues

    PubMed Central

    Lu, Tzu-Pin; Chen, Kevin T.; Tsai, Mong-Hsun; Kuo, Kuan-Ting; Hsiao, Chuhsing Kate; Lai, Liang-Chuan; Chuang, Eric Y.

    2014-01-01

    DNA methylation plays an important role in regulating cell growth and disease development. Methylation profiles are examined by bisulfite conversion; however, the lack of markers for bisulfite conversion efficiency and appropriate internal control genes remains a major challenge. To address these issues, we utilized two bioinformatics approaches, coefficients of variances and resampling tests, to identify probes showing stable methylation levels from several independent microarray datasets. Mass spectrometry validated the consistently high methylation levels of the five probes (N4BP2, EGFL8, CTRB1, TSPAN3, and ZNF690) in 13 human tissue types from 24 cell lines. Linear associations between detected methylation levels and methyl concentrations of DNA samples were further demonstrated in three genes (N4BP2, EGFL8, and CTRB1). To summarize, we identified five genes which may serve as internal controls for methylation studies by analyzing large-scale microarray data, and three of them can be used as markers for evaluating the efficiency of bisulfite conversion. PMID:24619003

  1. Low levels of tissue factor pathway inhibitor increase the risk of cerebral venous thrombosis

    PubMed Central

    Javanmard, Shaghayegh Haghjooy; Shahsavarzadeh, Tayebeh; Saadatnia, Mohammad

    2015-01-01

    Background: Decreased concentration of tissue factor pathway inhibitor (TFPI) is a risk factor for development of deep venous thrombosis and coronary heart disease, but there is no evidence for the relationship between TFPI and cerebral venous and sinus thrombosis (CVST). The aim of this study was to determine the level of TFPI in healthy population and in patients with CVST. Materials and Methods: We determined the plasma level of TFPI in 20 patients with CVST (cases) and 31 healthy volunteer subjects (as control group) by enzyme linked immunoassay method. We also examined the association between TFPI and the risk of CVST. Continuous variables were compared between groups using Student's t test, and odds ratio was calculated by multiple logistic regression analysis. Results: The mean TFPI was significantly lower in the CVST group compared with the control group (8.60 ± 4.05 ng/mL; 14.6 ± 8.6 ng/mL; P = 0. 005), respectively. The odds ratio for CVST associated with low (<25th percentile) levels of TFPI was 5.429 (95% CI, 1.487-19.82, P = 0.012). Conclusion: Our investigation demonstrates that reduced TFPI may be one of the risk factors of CVST and associated with increasing the risk of developing CVST. PMID:25625112

  2. Apolipoprotein E genotype affects tissue metallothionein levels: studies in targeted gene replacement mice.

    PubMed

    Graeser, Anne-Christin; Huebbe, Patricia; Storm, Niels; Höppner, Wolfgang; Döring, Frank; Wagner, Anika E; Rimbach, Gerald

    2012-04-01

    The apolipoprotein E (APOE) genotype is an important risk factor for ageing and age-related diseases. The APOE4 genotype (in contrast to APOE3) has been shown to be associated with oxidative stress and chronic inflammation. Metallothioneins (MT) exhibit antioxidant and anti-inflammatory activity, and MT overexpression has been shown to increase lifespan in mice. Interactions between APOE and MT, however, are largely unknown. Hence, we determined the effect of the APOE4 versus APOE3 genotype on MT levels in targeted gene replacement mice. APOE4 versus APOE3 mice exhibited significantly lower hepatic MT1 and MT2 mRNA as well as lower MT protein levels. The decrease in hepatic MT protein levels in APOE4 as compared to APOE3 mice was accompanied by lower nuclear Nrf1, a protein partly controlling MT gene expression. Cell culture experiments using hepatocytes identified allyl-isothiocyanate (AITC) as a potent MT inductor in vitro. Therefore, we supplemented APOE3 and APOE4 mice with AITC. However, AITC (15 mg/kg b.w.) could only partly correct for decreased MT1 and MT2 gene expression in APOE4 mice in vivo. Furthermore, cholesterol significantly decreased both Nrf1 and MT mRNA levels in Huh7 cells indicating that differences in MT gene expression between the two genotypes could be related to differences in hepatic cholesterol concentrations. Overall, present data suggest that the APOE genotype is an important determinant of tissue MT levels in mice and that MT gene expression may be impaired by the APOE4 genotype. PMID:22328270

  3. Red Blood Cell, Serum and Tissue Magnesium Levels in Subjects with Laryngeal Carcinoma

    Microsoft Academic Search

    Z. Szmeja

    1983-01-01

    Red blood cell, serum and tissue Mg concentrations in 100 subjects with aged 34–78, with squamous cell carcinoma of the larynx were determined by atomic absorption spectrophotometry. The concentration of this cation in cancerous tissues was found to be about twice as high as in the unchanged homologous tissues of the host. This was accompanied by a systemic deficiency manifesting

  4. Mercury poisoning in a free-living northern river otter (Lontra canadensis).

    PubMed

    Sleeman, Jonathan M; Cristol, Daniel A; White, Ariel E; Evers, David C; Gerhold, R W; Keel, Michael K

    2010-07-01

    A moribund 5-year-old female northern river otter (Lontra canadensis) was found on the bank of a river known to be extensively contaminated with mercury. It exhibited severe ataxia and scleral injection, made no attempt to flee, and died shortly thereafter of drowning. Tissue mercury levels were among the highest ever reported for a free-living terrestrial mammal: kidney, 353 microg/g; liver, 221 microg/g; muscle, 121 microg/g; brain (three replicates from cerebellum), 142, 151, 151 microg/g (all dry weights); and fur, 183 ug/g (fresh weight). Histopathologic findings including severe, diffuse, chronic glomerulosclerosis and moderate interstitial fibrosis were the presumptive cause of clinical signs and death. This is one of a few reports to document the death of a free-living mammal from presumed mercury poisoning. PMID:20688719

  5. The corticosterone stress response and mercury contamination in free-living tree swallows, Tachycineta bicolor.

    PubMed

    Franceschini, Melinda D; Lane, Oksana P; Evers, David C; Reed, J Michael; Hoskins, Bart; Romero, L Michael

    2009-07-01

    We determined mercury concentrations in tree swallows, Tachycineta bicolor, from Massachusetts and Maine with different levels of contamination. Baseline and stress-induced plasma corticosterone concentrations from adults and nestlings (Massachusetts only) were compared with mercury concentrations. In Massachusetts, adult baseline corticosterone was negatively correlated with blood mercury, but showed a nearly-significant positive correlation with feather mercury. There was a negative relationship between baseline corticosterone and blood mercury in nestlings and between baseline corticosterone and egg mercury. There was no relationship between mercury and stress-induced corticosterone in any of the groups, or with baseline corticosterone in Maine sites where mercury levels were lower. The findings suggest blood and egg mercury may be a better indicator of current condition than feather mercury. Further, mercury contamination may not alter stress-induced corticosterone concentrations in tree swallows but appears to have a significant impact on baseline circulating corticosterone. PMID:19360470

  6. Adipose tissue levels of organochlorine pesticides and polychlorinated biphenyls and risk of non-Hodgkin's lymphoma.

    PubMed

    Quintana, Penelope J E; Delfino, Ralph J; Korrick, Susan; Ziogas, Argyrios; Kutz, Frederick W; Jones, Ellen L; Laden, Francine; Garshick, Eric

    2004-06-01

    In this nested case-control study we examined the relationship between non-Hodgkin's lymphoma (NHL) and organochlorine pesticide exposure. We used a data set originally collected between 1969 and 1983 in the U.S. Environmental Protection Agency National Human Adipose Tissue Survey. Adipose samples were randomly collected from cadavers and surgical patients, and levels of organochlorine pesticide residues were determined. From the original study population, 175 NHL cases were identified and matched to 481 controls; 173 controls were selected from accident victims, and 308 from cases with a diagnosis of myocardial infarction. Cases and controls were mainly from cadavers (> 96%) and were matched on sex, age, region of residence within the United States, and race/ethnicity. Conditional logistic regression showed the organochlorine pesticide residue heptachlor epoxide to be significantly associated with NHL [compared with the lowest quartile: third quartile odds ratio (OR) = 1.82, 95% confidence interval (CI), 1.01-3.28; fourth quartile OR = 3.41, 95% CI, 1.89-6.16]. The highest quartile level of dieldrin was also associated with elevated NHL risk (OR = 2.70; 95% CI, 1.58-4.61), as were higher levels of oxychlordane, p,p'-DDE [p,p'-1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene], and ss-benzene hexachloride (ORs = 1.79, 1.99, and 2.47, respectively). The p-values for trends for these associations were significant. In models containing pairs of pesticides, only heptachlor epoxide and dieldrin remained significantly associated with risk of NHL. Limitations of this study include collection of samples after diagnosis and a lack of information on variables affecting organochlorine levels such as diet, occupation, and body mass index. Given the persistence of pesticides in the environment, these findings are still relevant today. PMID:15175172

  7. Mercury Unveiled

    NASA Astrophysics Data System (ADS)

    Taylor, G. J.

    1997-01-01

    Mercury, the second smallest planet and the closest one to the Sun, may appear to some as a drab, colorless, heavily-cratered world. Not so. New analysis of data returned by the Mariner 10 mission in 1974 and 1975 reveals a surface with lava flows and deposits from explosive volcanic eruptions, variations in composition across its surface and into its crust, and a different chemical composition from the other inner planets. These discoveries were made by Mark Robinson at the United States Geological Survey in Flagstaff, Arizona (he is now at Northwestern University) and Paul Lucey of the University of Hawaii. Using improvements in computer and image-processing technologies, and a better understanding of how light reflects off planetary surfaces than was available in the mid-1970s, Robinson and Lucey manipulated the original data and produced a color image of Mercury that depicts compositional differences across its stark surface

  8. Anthropogenic Mercury Accumulation in Watersheds of the Northern Appalachian Mountains

    NASA Astrophysics Data System (ADS)

    Boyer, E. W.; Drohan, P. J.; Lawler, D.; Grimm, J.; Grant, C.; Eklof, K. J.; Bennett, J.; Naber, M. D.

    2014-12-01

    Atmospheric deposition of mercury (Hg) is a critical environmental stress that affects ecosystems and human health. Mercury emissions to the atmosphere from coal-fired power plants and other sources such as waste incineration can be deposited over large geographic areas to downwind landscapes in precipitation and in dry fallout. The northern Appalachian Mountains are downwind of major atmospheric mercury emissions sources. Some mercury reaches watersheds and streams, where it can accumulate in sediments and biota. Human exposure to mercury occurs primarily through fish consumption, and currently mercury fish eating advisories are in place for many of the streams and lakes in the region. Here, we explored mercury accumulation in forested landscapes - in air, soils, water, and biota. To quantify atmospheric mercury deposition, we measured both wet and dry mercury deposition at 10 forested locations, from which we present variation in mercury deposition and initial assessments of factors affecting the patterns. To quantify mercury accumulation in terrestrial environments, we measured soil mercury concentrations within and surrounding 12 vernal pools spanning various physiographic settings in the region. Given that vernal pools have large inputs of water via precipitation yet do not have any stream discharge outflow, they are likely spots within the forested landscape to accumulate pollutants that enter via wet atmospheric deposition. To quantify mercury accumulation in aquatic environments, we sampled mercury concentrations in streams draining 35 forested watersheds, spanning gradients of atmospheric deposition, climate and geology. Mercury concentrations were measured in stream water under base-flow conditions, in streambed sediments, aquatic mosses, and in fish tissues from brook trout. Results indicate that wet and dry atmospheric deposition is a primary source of mercury that is accumulating in watersheds of the Northern Appalachian Mountains.

  9. The effect of auxin on cytokinin levels and metabolism in transgenic tobacco tissue expressing an ipt gene

    Microsoft Academic Search

    R. Zhang; X. Zhang; J. Wang; D. S. Letham; S. A. McKinney; T. J. V. Higgins

    1995-01-01

    The ipt gene from the T-DNA of Agrobacterium tumefaciens was transferred to tobacco (Nicotiana tabacum L.) in order to study the control which auxin appears to exert over levels of cytokinin generated by expression of this gene. The transgenic tissues contained elevated levels of cytokinins, exhibited cytokinin and auxin autonomy and grew as shooty calli on hormone-free media. Addition of

  10. PSYCHROPHILIC PSEUDOMONAS SP. RESISTANT TO MERCURY FROM PAVLODAR, KAZAKHSTAN

    EPA Science Inventory

    As mercury circulates and deposits globally, the remediation of extensive mercury contamination surrounding a chloralkali plant in Pavlodar, Kazakhstan is critical. High-levels of mercury contamination exist within the confines of the plant, at nearby off-site waste storage and e...

  11. Formation of adherens junctions leads to the emergence of a tissue-level tension in epithelial monolayers

    PubMed Central

    Harris, Andrew R.; Daeden, Alicia; Charras, Guillaume T.

    2014-01-01

    ABSTRACT Adherens junctions and desmosomes integrate the cytoskeletons of adjacent cells into a mechanical syncitium. In doing so, intercellular junctions endow tissues with the strength needed to withstand the mechanical stresses encountered in normal physiology and to coordinate tension during morphogenesis. Though much is known about the biological mechanisms underlying junction formation, little is known about how tissue-scale mechanical properties are established. Here, we use deep atomic force microscopy (AFM) indentation to measure the apparent stiffness of epithelial monolayers reforming from dissociated cells and examine which cellular processes give rise to tissue-scale mechanics. We show that the formation of intercellular junctions coincided with an increase in the apparent stiffness of reforming monolayers that reflected the generation of a tissue-level tension. Tension rapidly increased, reaching a maximum after 150?min, before settling to a lower level over the next 3?h as monolayers established homeostasis. The emergence of tissue tension correlated with the formation of adherens junctions but not desmosomes. As a consequence, inhibition of any of the molecular mechanisms participating in adherens junction initiation, remodelling and maturation significantly impeded the emergence of tissue-level tension in monolayers. PMID:24659804

  12. Mercury in Pleurozium schreberi and Polytrichum commune from areas with various levels of Hg pollution--an accumulation and desorption experiment with microscopic observations.

    PubMed

    Zawadzki, Krzysztof; Soko?owska, Katarzyna; Samecka-Cymerman, Aleksandra; Kolon, Krzysztof; Dubi?ska, Anna; Kempers, Alexander J

    2014-10-01

    Because of its high mobility in ecosystems, mercury is one of the main toxic threats to the environment, and its concentration must be carefully controlled. To fulfill this need, we selected terrestrial mosses with different characteristic life forms: orthotropic and endohydric Polytrichum commune and plagiotropic and ectohydric Pleurozium schreberi. The concentrations of mercury were determined in both species growing together at sites situated approximately 0.75, 1.5, 3 and 6km to the north, south, east and west, respectively of five known mercury polluters. The mercury concentrations reflected the emissions produced by the surrounding industry, reaching values of 0.44mgkg(-1) in P. schreberi and 0.79mgkg(-1) in P. commune in the vicinity of the chlor-alkali industry. To determine how long a load of Hg would remain in the mosses after mercury emitters restricted releases of Hg to the atmosphere, accumulation and desorption experiments were performed. We compared the two moss species collected from clean and moderately and heavily mercury-polluted sites. After eight days of exposure to mercury, P. schreberi accumulated up to 25mgkg(-1) of Hg, and P. commune accumulated up to 31mgkg(-1). Both in the field and in the experiment, P. commune accumulated significantly higher concentrations of Hg than did P. schreberi, most likely because of its surface morphology, which is likely to enhance the capture of metal from the atmosphere. After sixteen days of exposure, mercury changed the structure of the plasma membrane and affected organelles such as the nuclei and chloroplasts, leading to cell disintegration and death. The negative effects of mercury on the functioning of living cells appeared first in the older leaves of P. schreberi. After 64 days growing in the absence of Hg, P. schreberi clearly retained only 10-14% of the initially accumulated Hg, while P. commune retained 10-21%. PMID:25038270

  13. Low-level experimental selenite additions decrease mercury in aquatic food chains and fish muscle but increase selenium in fish gonads.

    PubMed

    Mailman, Mariah; Bodaly, R A; Paterson, Michael J; Thompson, Shirley; Flett, Robert J

    2014-01-01

    We investigated whether low-level addition of selenium (Se) could decrease mercury (Hg) in freshwater fish without imposing Se toxicity. Using a regression design, selenite was added to large mesocosms in a lake to achieve target concentrations ?1.6 ?g/L. (198)Hg (spike Hg) was added to mesocosms to determine changes in Hg bioaccumulation. Adding Se decreased spike total Hg (THg) in fish muscle, ambient THg in fish liver, and bioaccumulation of spike THg in muscle and spike methylmercury (MeHg) in zooplankton and Chironomid larvae relative to controls. Se decreased Hg in the food web but not in water, indicating that the dominant effect of Se on Hg cycling occurs in the food web. Concentrations of Se in gonads of fish were positively correlated with Se concentrations in water but did not exceed reproductive toxicity thresholds after 8 weeks. We conclude that low-level addition of Se decreases MeHg bioaccumulation and increases Se in gonads of fish; however, additions of Se to freshwater systems to decrease Hg in fish should be treated with caution because Se in fish gonads were likely to exceed toxic concentrations if exposed to increased Se for a longer period of time. PMID:23989587

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

    PubMed Central

    Bourdineaud, Jean-Paul; Bellance, Nadège; Bénard, Giovani; Brèthes, Daniel; Fujimura, Masatake; Gonzalez, Patrice; Marighetto, Aline; Maury-Brachet, Régine; Mormède, Cécile; Pédron, Vanessa; Philippin, Jean-Nicolas; Rossignol, Rodrigue; Rostène, William; Sawada, Masumi; Laclau, Muriel

    2008-01-01

    Background In 2005, 84% of Wayana Amerindians living in the upper marshes of the Maroni River in French Guiana presented a hair mercury concentration exceeding the limit set up by the World Health Organization (10 ?g/g). To determine whether this mercurial contamination was harmful, mice have been fed diets prepared by incorporation of mercury-polluted fish from French Guiana. Methods Four diets containing 0, 0.1, 1, and 7.5% fish flesh, representing 0, 5, 62, and 520 ng methylmercury per g, respectively, were given to four groups of mice for a month. The lowest fish regimen led to a mercurial contamination pressure of 1 ng mercury per day per g of body weight, which is precisely that affecting the Wayana Amerindians. Results The expression of several genes was modified with mercury intoxication in liver, kidneys, and hippocampus, even at the lowest tested fish regimen. A net genetic response could be observed for mercury concentrations accumulated within tissues as weak as 0.15 ppm in the liver, 1.4 ppm in the kidneys, and 0.4 ppm in the hippocampus. This last value is in the range of the mercury concentrations found in the brains of chronically exposed patients in the Minamata region or in brains from heavy fish consumers. Mitochondrial respiratory rates showed a 35–40% decrease in respiration for the three contaminated mice groups. In the muscles of mice fed the lightest fish-containing diet, cytochrome c oxidase activity was decreased to 45% of that of the control muscles. When mice behavior was assessed in a cross maze, those fed the lowest and mid-level fish-containing diets developed higher anxiety state behaviors compared to mice fed with control diet. Conclusion We conclude that a vegetarian diet containing as little as 0.1% of mercury-contaminated fish is able to trigger in mice, after only one month of exposure, disorders presenting all the hallmarks of mercurial contamination. PMID:18959803

  15. Increasing substance P levels in serum and synovial tissues from patients with developmental dysplasia of the hip (DDH)

    PubMed Central

    2014-01-01

    Background The tachykininergic neurotransmitters have been proved to be involved in the inflammatory progress and chronic pain in series of disease. The present study was undertaken to evaluate the levels of substance P (SP) and its receptors NK-1 receptor (NK-1R) in both serum and synovial tissues of hip joint from patients with different stages of DDH, and to detect the possible correlation of serum SP levels with pain sensation and dysfunction of the hip joint. Methods SP levels in serum and synovial tissues from patients with DDH and DDH combined with osteoarthritis (DDH&OA) group were compared through immunohistochemistry (IHC), ELISA, and 2-step acetic acid extraction method respectively. Expression of NK-1R in synovial tissues was compared through IHC, quantitive Real-Time PCR (QRT-PCR) and Western-Blot. The severities of pain sensation and the functional activities of hip joint were assessed by Visual analogue scale (VAS) and Harris hip score (HHS). Correlations of serum SP levels with VAS, HHS and erythrocyte sedimentation rate (ESR) were evaluated respectively in these groups. Results Significantly elevated serum SP levels were detected in group of DDH and DDH&OA compared to that in normal group. IHC, QRT-PCR as well as tissue Elisa showed that SP levels in synovial tissue of DDH&OA group is stronger than that in DDH group. Serum SP levels in each group have no gender differences. The enhanced SP levels in synovial tissue mainly came from the segregation of peripheral nerve endings. Serum SP correlated with VAS and HHS in patients with DDH&OA (Male + Female). Serum SP correlated with HHS in patients with DDH (Male). Serum SP levels also correlated with erythrocyte sedimentation rate (ESR) in patients with DDH&OA (Male + Female). Up-regulated expression of NK-1R was also observed in synovial tissue of patients with DDH&OA compared to patients with DDH, through western-blot, IHC, and QRT-PCR. Conclusions These findings indicated that the increasing SP levels in serum and synovial tissues, observed from patients with DDH to patients with DDH&OA, might associate with the loss of function and chronic pain sensation in hip joint. SP along with its receptors NK-1R might be involved in the progression of DDH into DDH&OA. In the future, inhibitors of SP as well as NK-1R may represent a novel pharmacotherapy target for pain relieving, inflammation alleviating and joint degeneration delaying for patients with DDH. PMID:24642234

  16. Mercury in a marine pelagic food chain

    Microsoft Academic Search

    GEORGE A. KNAUER; JOHN H. MARTIN

    1972-01-01

    Phytoplankton, zooplankton, and anchovies collected in Monterey Bay, California, over a 10-month period were analyzed for total mercury. In general, mercury levels were low and no evidence of food chain amplification was observed. Temporal variations of Hg concentrations in phytoplankton were greater than those for zooplankton; however, no seasonal trends were observed for either group. Plankton samples were also collected

  17. Higher Natriuretic Peptide Levels Associate with a Favorable Adipose Tissue Distribution Profile

    PubMed Central

    Neeland, Ian J.; Winders, Benjamin R.; Ayers, Colby R.; Das, Sandeep R.; Chang, Alice Y.; Berry, Jarett D.; Khera, Amit; McGuire, Darren K.; Vega, Gloria L.; de Lemos, James A.; Turer, Aslan T.

    2013-01-01

    Objectives To investigate the association between natriuretic peptides and body fat distribution in a multiethnic cohort. Background Natriuretic peptides stimulate lipolysis, reduce weight gain, and promote adipocyte browning in animal models but data are lacking in humans. Methods 2619 participants without heart failure in the Dallas Heart Study underwent measurements of 1) B-type natriuretic peptide (BNP) and NT-proBNP and 2) body fat distribution by dual energy x-ray absorptiometry and magnetic resonance imaging. Cross-sectional associations of natriuretic peptides with adiposity phenotypes were examined after adjustment for age, sex, race, comorbidities, and body mass index. Results Median BNP and NT-proBNP levels in the study cohort (mean age 44 years, 56% women, 48% African-Americans, 32% obese) were 3.0 and 28.1 pg/mL, respectively. Natriuretic peptide levels above the median were associated with a more favorable body fat profile and less insulin resistance including lower visceral fat, liver fat, and HOMA-IR; and more lower body fat and higher adiponectin (p<0.05 for each). In multivariable analyses, NT-proBNP remained inversely associated with visceral (?= ?0.08, p<0.0001) and liver fat (?= ?0.14, p<0.0001) and positively associated with lower body fat (?= 0.07, p<0.0001) independent of age, sex, race, and obesity-status; findings were similar with BNP. Adjustment for body composition, HOMA-IR, circulating androgens, and adipocytokines did not attenuate the associations. Conclusions Higher natriuretic peptide levels were independently associated with a favorable adiposity profile, characterized by decreased visceral and liver fat and increased lower body fat, suggesting a link between the heart and adipose tissue distribution mediated through natriuretic peptides. PMID:23602771

  18. RECOVERY OF MERCURY FROM CONTAMINATED LIQUID WASTES

    SciTech Connect

    Robin M. Stewart

    1999-09-29

    Mercury was widely used in U.S. Department of Energy (DOE) weapons facilities, resulting in a broad range of mercury-contaminated wastes and wastewaters. Some of the mercury contamination has escaped to the local environment, particularly at the Y-12 Plant in Oak Ridge, Tennessee, where approximately 330 metric tons of mercury were discharged to the environment between 1953 and 1963 (TN & Associates, 1998). Effective removal of mercury contamination from water is a complex and difficult problem. In particular, mercury treatment of natural waters is difficult because of the low regulatory standards. For example, the Environmental Protection Agency has established a national ambient water quality standard of 12 parts-per-trillion (ppt), whereas the standard is 1.8 ppt in the Great Lakes Region. In addition, mercury in the environment is typically present in several different forms, but sorption processes are rarely effective with more than one or two of these forms. To meet the low regulatory discharge limits, an effective sorption process must be able to address all forms of mercury present in the water. One approach is to apply different sorbents in series depending on the mercury speciation and the regulatory discharge limits. ADA Technologies, Inc. has developed four new sorbents to address the variety of mercury species present in industrial discharges and natural waters. Three of these sorbents have been field tested on contaminated creek water at the Y-12 Plant. Two of these sorbents have been successfully demonstrated very high removal efficiencies for soluble mercury species, reducing mercury concentrations at the outlet of a pilot-scale system to less than 12 ppt for as long as six months. The other sorbent tested at the Y-12 Plant targeted colloidal mercury not removed by standard sorption or filtration processes. At the Y-12 Plant, colloidal mercury appears to be associated with iron, so a sorbent that removes mercury-iron complexes in the presence of a magnetic field was evaluated. Field results indicated good removal of this mercury fraction from the Y-12 waters. In addition, this sorbent is easily regenerated by simply removing the magnetic field and flushing the columns with water. The fourth sorbent is still undergoing laboratory development, but results to date indicate exceptionally high mercury sorption capacity. The sorbent is capable of removing all forms of mercury typically present in natural and industrial waters, including Hg{sup 2+}, elemental mercury, methyl mercury, and colloidal mercury. The process possesses very fast kinetics, which allows for higher flow rates and smaller treatment units. These sorbent technologies, used in tandem or individually depending on the treatment needs, can provide DOE sites with a cost-effective method for reducing mercury concentrations to very low levels mandated by the regulatory community. In addition, the technologies do not generate significant amounts of secondary wastes for disposal. Furthermore, the need for improved water treatment technologies is not unique to the DOE. The new, stringent requirements on mercury concentrations impact other government agencies as well as the private sector. Some of the private-sector industries needing improved methods for removing mercury from water include mining, chloralkali production, chemical processing, and medical waste treatment. The next logical step is to deploy one or more of these sorbents at a contaminated DOE site or at a commercial facility needing improved mercury treatment technologies. A full-scale deployment is planned in fiscal year 2000.

  19. A relationship between vitamin B sub 12 , folate, ascorbic acid, and mercury metabolism

    SciTech Connect

    Zorn, N.E.

    1988-01-01

    The effect of megadoses of vitamin B{sub 12}, folate, and vitamin C on the in vivo methylation of mercuric chloride was studied in guinea pigs. The incorporation of high levels of vitamin B{sub 12}, folate, and vitamin C resulted in a decrease in both inorganic mercury and methylmercury concentrations in all tissues except the lungs and heart compared to controls. However, percent methylmercury levels tended to increase with vitamin treatment. The addition of megadoses of vitamin B{sub 12} fed either singularly or in combination with the other vitamins resulted in increased methylmercury concentrations in the liver, spleen, and kidney tissues of the guinea pig. Moreover, percent methylmercury levels increased with B{sub 12} treatment in the liver, heart, and kidney. Incorporation of high levels of folate into the dietary regime also affected the mercury methylation process particularly in the liver, heart, kidney and hair tissues. However, this effect was observed most often in animals fed both B{sub 12} and folate. Vitamin C appears to play a synergistic role with vitamin B{sub 12} and/or folate in the methylation of mercury.

  20. Mercury and other Mining-Related Contaminants in Ospreys along the Upper Clark Fork River, MT

    NASA Astrophysics Data System (ADS)

    Langner, H.; Domenech, R.; Greene, E.; Staats, M. F.

    2010-12-01

    Osprey (Pandion haliaetus) are widely recognized as bio-indicators of the health of aquatic ecosystems. Until the time of fledging, nestlings feed exclusively on fish caught within a few kilometers of the nest. Therefore, tissues of these young birds may reflect the level of contamination of local fish and more generally, the contamination status of the aquatic ecosystem they inhabit. Nests can often be accessed with a boom truck and obtaining small blood samples from the flightless chicks is fairly noninvasive. Ospreys are nesting along the Upper Clark Fork River, Montana, which is heavily contaminated with wastes left from a century of copper and precious metals mining. We have been monitoring the levels of priority pollutants (arsenic, cadmium, lead, copper, zinc, mercury and selenium) in Osprey chicks along a 250 km section of the river for four years. Objectives are to establish current contaminant status, pinpoint pollution hotspots, and assess the success of restoration efforts. Our results suggest that of highest concern may be the bioaccumulation of mercury with blood levels of up to 0.7 mg/L in the growing chicks. These concentrations are expected to increase many fold upon fledging as feather growth stops, which acts as the major sink for mercury. Interestingly, we found mercury levels increased in downstream direction, in contrast to concentrations of other pollutants. Reasons may be the different origin of mercury versus other contaminants and the distribution of wetlands where mercury can be transformed into highly bioavailable methylmercury. Blood levels of selenium are also elevated throughout the Upper Clark Fork River drainage. We discuss the implications for restoration and remediation of the Clark Fork River.

  1. Mercury concentrations in wild mink ( Mustela vison) and river otters ( Lontra canadensis) collected from eastern and Atlantic Canada: Relationship to age and parasitism

    Microsoft Academic Search

    Katherine Klenavic; Louise Champoux; O'Brien Mike; Pierre-Y. Daoust; R. Douglas Evans; Hayla E. Evans

    2008-01-01

    Total mercury (Hg) concentrations were measured in the fur, brain and liver of wild mink (Mustela vison) and river otters (Lontra canadensis) collected from eastern and Atlantic Canada. Total Hg concentrations in fur were strongly correlated with levels in the brain and liver. There was no difference in tissue concentrations between male and female mink; however, female otters had significantly

  2. Dietary selenium reduces retention of methyl mercury in freshwater fish.

    PubMed

    Bjerregaard, Poul; Fjordside, Susanne; Hansen, Maria G; Petrova, Maya B

    2011-11-15

    Adverse effects from organic mercury transported along aquatic food chains are health issues in humans and other top predators. Methyl mercury in organisms at the lower food chain levels is eliminated slowly, and laboratory studies have not clarified the role of selenium in the retention of methyl mercury in fish. Here, we investigated the effects of dietary selenium on the retention of organic and inorganic mercury in freshwater fish. Addition of selenite to the food augmented elimination of methyl mercury (but not inorganic mercury) from goldfish Carassius auratus in a dose dependent manner; selenite caused methyl mercury to be lost from the general body rather than from any specific organ. Seleno-cystine and seleno-methionine (but not selenate) likewise promoted elimination of methyl mercury from goldfish. The threshold for the augmenting effect of selenite on the elimination of methyl mercury in the zebra fish Danio rerio was 0.95 ?g Se g(-1) food; higher concentrations reduced retention of methyl mercury in a dose dependent manner. Selenium concentrations in the food approaching natural background levels increase the elimination of methyl mercury from fish. Thus, selenium levels in a given aquatic food chain may affect mercury contamination along the food chain. PMID:22014184

  3. Mercury concentrations in muscle, brain and bone of Western Alaskan waterfowl.

    PubMed

    Rothschild, Roger F N; Duffy, Lawrence K

    2005-10-15

    Total mercury (THg), which includes both inorganic (Hg(2+)) and methylmercury (MeHg) species, has been reported for seabirds in the North Pacific and Alaska. For the Yup'ik and Aleut people of Alaska, waterfowl are a small but important seasonal component of the diet, but many Alaskan species have not been studied extensively for the presence of mercury. Birds are good subjects for examination of mercury concentrations because they feed at different trophic levels, they can be long-lived, and many are both abundant and widely distributed. In this study, we present the levels of mercury in muscle, brain, and bone tissue of 140 birds taken by subsistence food users across Western Alaska. THg wet weight mean concentrations in the 18 species of waterfowl surveyed ranged from 0.8 to 268.6 ng/g in muscle, from 0.4 to 197.7 ng/g in brain and from 0.7 to 422.9 ng/g in bone. The null hypothesis that there are no interspecific differences in the level of total mercury in the 18 species of Alaska birds surveyed was not supported. We found interspecific differences with the Lesser Scaup (Aythya affinis), and the Black Scoter (Melanitta nigra), having the highest muscle tissue levels of THg. In general, THg mean levels were higher in muscle than in brain with the exceptions of the Bar-tailed Godwit and Northern Shoveler. Bone THg were highest in the Black Scoter. The mean values for THg in the species studied are unlikely to cause adverse reproductive or behavioral effects in the birds. PMID:16076480

  4. The mammalian testis accumulates lower levels of organochlorine chemicals compared with other tissues

    Microsoft Academic Search

    Gerard M Cooke; W. Harvey Newsome; Genevieve S Bondy; Douglas L Arnold; J. Roy Tanner; Patrick Robertson; Carole M Whalen; Georges Angers; André Massé

    2001-01-01

    Tissues were obtained from three separate experiments in order to quantify the tissue distribution of organochlorine chemicals that are thought to be potential reproductive toxicants in males: 1) Sprague Dawley rats received 1 ?Ci of 14C-Aldrin or 14C-Dieldrin (20.6 ?Ci\\/?mole) i.p. once a week for three weeks. One week and four weeks after the last injection, tissues were harvested and

  5. Quantitation of the mRNA levels of Epo and EpoR in various tissues in the ovine fetus

    Microsoft Academic Search

    R. Bruce David; Gaik Bee Lim; Karen M Moritz; Irene Koukoulas; E. Marelyn Wintour

    2002-01-01

    A partial cDNA of the sheep erythropoietin receptor (EpoR) was obtained and used in real-time PCR to quantitate mRNA levels in placenta, liver and kidney throughout development (term=150 days). This was compared with Epo mRNA levels in the same tissues. Both Epo and EpoR mRNA were present in the placenta throughout gestation at low levels from 66 days onwards and

  6. MESSENGER: Exploring Mercury's Magnetosphere

    Microsoft Academic Search

    James A. Slavin; Stamatios M. Krimigis; Mario H. Acuña; Brian J. Anderson; Daniel N. Baker; Patrick L. Koehn; Haje Korth; Stefano Livi; Barry H. Mauk; Sean C. Solomon; Thomas H. Zurbuchen

    2007-01-01

    The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission to Mercury offers our first opportunity to explore this planet's miniature magnetosphere since the brief flybys of Mariner 10. Mercury's magnetosphere is unique in many respects. The magnetosphere of Mercury is among the smallest in the solar system; its magnetic field typically stands off the solar wind only ˜1000 to

  7. New adipokines vaspin and omentin. Circulating levels and gene expression in adipose tissue from morbidly obese women

    PubMed Central

    2011-01-01

    Background Vaspin and omentin are recently described molecules that belong to the adipokine family and seem to be related to metabolic risk factors. The objectives of this study were twofold: to evaluate vaspin and omentin circulating levels and mRNA expression in subcutaneous and visceral adipose tissues in non-diabetic morbidly obese women; and to assess the relationship of vaspin and omentin with anthropometric and metabolic parameters, and other adipo/cytokines. Design We analysed vaspin and omentin circulating levels in 71 women of European descent (40 morbidly obese [BMI ? 40 kg/m2] and 31 lean [BMI ? 25]). We assessed vaspin and omentin gene expression in paired samples of visceral and subcutaneous abdominal adipose tissue from 46 women: 40 morbidly obese and 6 lean. We determined serum vaspin and plasma omentin levels with an Enzyme-Linked Immunosorbent Assay and adipose tissue mRNA expression by real time RT-PCR. Results Serum vaspin levels in the morbidly obese were not significantly different from those in controls. They correlated inversely with levels of lipocalin 2 and interleukin 6. Vaspin mRNA expression was significantly higher in the morbidly obese, in both subcutaneous and visceral adipose tissue. Plasma omentin levels were significantly lower in the morbidly obese and they correlated inversely with glucidic metabolism parameters. Omentin circulating levels, then, correlated inversely with the metabolic syndrome (MS). Omentin expression in visceral adipose tissue was significantly lower in morbidly obese women than in controls. Conclusions The present study indicates that vaspin may have a compensatory role in the underlying inflammation of obesity. Decreased omentin circulating levels have a close association with MS in morbidly obese women. PMID:21526992

  8. Age and albumin D site-binding protein control tissue plasminogen activator levels: neurotoxic impact

    PubMed Central

    Roussel, Benoit D.; Macrez, Richard; Jullienne, Amandine; Agin, Véronique; Maubert, Eric; Dauphinot, Luce; Potier, Marie-Claude; Plawinski, Laurent; Castel, Hervé; Hommet, Yannick; Munuera, Josep; Montaner, Joan; Yepes, Manuel; Vivien, Denis

    2009-01-01

    Recombinant tissue-type plasminogen activator (tPA) is the fibrinolytic drug of choice to treat stroke patients. However, a growing body of evidence indicates that besides its beneficial thrombolytic role, tPA can also have a deleterious effect on the ischaemic brain. Although ageing influences stroke incidence, complications and outcome, age-dependent relationships between endogenous tPA and stroke injuries have not been investigated yet. Here, we report that ageing is associated with a selective lowering of brain tPA expression in the murine brain. Moreover, our results show that albumin D site-binding protein (DBP) as a key age-associated regulator of the neuronal transcription of tPA. Additionally, inhibition of DBP-mediated tPA expression confers in vitro neuroprotection. Accordingly, reduced levels of tPA in old mice are associated with smaller excitotoxic/ischaemic injuries and protection of the permeability of the neurovascular unit during cerebral ischaemia. Likewise, we provide neuroradiological evidence indicating the existence of an inverse relationship between age and the volume of the ischaemic lesion in patients with acute ischaemic stroke. Together, these results indicate that the relationship among DBP, tPA and ageing play an important role in the outcome of cerebral ischaemia. PMID:19574439

  9. Age and albumin D site-binding protein control tissue plasminogen activator levels: neurotoxic impact.

    PubMed

    Roussel, Benoit D; Macrez, Richard; Jullienne, Amandine; Agin, Véronique; Maubert, Eric; Dauphinot, Luce; Potier, Marie-Claude; Plawinski, Laurent; Castel, Hervé; Hommet, Yannick; Munuera, Josep; Montaner, Joan; Yepes, Manuel; Ali, Carine; Vivien, Denis

    2009-08-01

    Recombinant tissue-type plasminogen activator (tPA) is the fibrinolytic drug of choice to treat stroke patients. However, a growing body of evidence indicates that besides its beneficial thrombolytic role, tPA can also have a deleterious effect on the ischaemic brain. Although ageing influences stroke incidence, complications and outcome, age-dependent relationships between endogenous tPA and stroke injuries have not been investigated yet. Here, we report that ageing is associated with a selective lowering of brain tPA expression in the murine brain. Moreover, our results show that albumin D site-binding protein (DBP) as a key age-associated regulator of the neuronal transcription of tPA. Additionally, inhibition of DBP-mediated tPA expression confers in vitro neuroprotection. Accordingly, reduced levels of tPA in old mice are associated with smaller excitotoxic/ischaemic injuries and protection of the permeability of the neurovascular unit during cerebral ischaemia. Likewise, we provide neuroradiological evidence indicating the existence of an inverse relationship between age and the volume of the ischaemic lesion in patients with acute ischaemic stroke. Together, these results indicate that the relationship among DBP, tPA and ageing play an important role in the outcome of cerebral ischaemia. PMID:19574439

  10. Utility of EXAFS in characterization and speciation of mercury-bearing mine wastes

    USGS Publications Warehouse

    Kim, C.S.; Rytuba, J.J.; Brown, Gordon E., Jr.

    1999-01-01

    Extensive mining of large mercury deposits located in the California Coast Range has resulted in mercury contamination of both the local environment and water supplies. The solubility, dispersal, and ultimate fate of mercury are all affected by its chemical speciation, which can be most readily determined in a direct fashion using EXAFS spectroscopy. EXAFS spectra of mine wastes collected from several mercury mines in the California Coast Range with mercury concentrations ranging from 230 to 1060 mg/kg (ppm) have been analyzed using a spectral database of mercury minerals and sorbed mercury complexes. While some calcines have been found to consist almost exclusively of mercuric sulfide, HgS, others contain additional, more soluble mercury phases, indicating a greater potential for the release of mercury into solution. This experimental approach can provide a quantitative measurement of the mercury compounds present and may serve as an indicator of the bioavailability and toxicity levels of mercury mine wastes.

  11. Comparison of organochlorine pesticide levels in human adipose tissue of inhabitants from Veracruz and Puebla, Mexico.

    PubMed

    Waliszewski, Stefan M; Valencia Quintana, R; Corona, C A; Herrero, M; Sánchez, K; Aguirre, H; Aldave, I A; Gomez Arroyo, S; Villalobos Pietrini, R

    2010-01-01

    Since the discovery of insecticide properties of DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) and HCH (hexachlorocyclohexane), they have provided great benefits to humans in sanitary actions to combat the spread of infection-borne disease vectors. Public Health Programs in Mexico used DDT and HCH until 1999 as the insecticides of choice to control disease-transmitting organisms. Because of their persistence and accumulative properties, organochlorine pesticides bioconcentrate in lipids of the human body, reflecting the rate of environmental exposure. Eighty human abdominal adipose tissue samples from Veracruz and 80 samples from Puebla were analyzed and the obtained results were compared among both populations. The results from Veracruz showed higher contamination levels (mg/kg on lipid base) compared to Puebla: beta-HCH, 0.072 vs. 0.029; pp'DDE (Dichlorodiphenyldichloroethylene), 2.364 vs. 0.726; op'DDT, 0.022 vs. 0.025; pp'DDT, 0.192 vs. 0.061; and Sigma-DDT, 2.589 vs. 0.806. The population from Veracruz and from Puebla divided by sex, origin, and cause of death presented no statistical differences. The comparison between sexes (women and men groups) at Veracruz and Puebla indicated significantly higher levels in Veracruz and statistical significant differences. Calculating possible risks (odds ratios, OR), pp'DDE (OR = 5.04) and op'DDT (OR = 2.93) revealed significantly higher risk for the Veracruz population. The study indicated prolonged DDT exposure of Mexicans caused by the past sanitary use and persistence of its residues in soils and air. PMID:19468667

  12. Emergence of tissue sensitivity to Hox protein levels underlies the evolution of an adaptive morphological trait

    PubMed Central

    Refki, Peter Nagui; Armisén, David; Crumière, Antonin Jean Johan; Viala, Séverine; Khila, Abderrahman

    2014-01-01

    Growth control scales morphological attributes and, therefore, provides a critical contribution to the evolution of adaptive traits. Yet, the genetic mechanisms underlying growth in the context of specific ecological adaptations are poorly understood. In water striders, adaptation to locomotion on the water surface is associated with allometric and functional changes in thoracic appendages, such that T2-legs, used as propelling oars, are longer than T3-legs, used as steering rudders. The Hox gene Ubx establishes this derived morphology by elongating T2-legs but shortening T3-legs. Using gene expression assays, RNAi knockdown, and comparative transcriptomics, we demonstrate that the evolution of water surface rowing as a novel means of locomotion is associated with the evolution of a dose-dependent promoting-repressing effect of Ubx on leg growth. In the water strider Limnoporus dissortis, T3-legs express six to seven times higher levels of Ubx compared to T2-legs. Ubx RNAi shortens T2-legs and the severity of this phenotype increases with increased depletion of Ubx protein. Conversely, Ubx RNAi lengthens T3-legs but this phenotype is partially rescued when Ubx protein is further depleted. This dose-dependent effect of Ubx on leg growth is absent in non-rowing relatives that retain the ancestral relative leg length. We also show that the spatial patterns of expression of dpp, wg, hh, egfr, dll, exd, hth, and dac are unchanged in Ubx RNAi treatments. This indicates that the dose-dependent opposite effect of Ubx on T2- and T3-legs operates without any apparent effect on the spatial expression of major leg patterning genes. Our data suggest that scaling of adaptive allometries can evolve through changes in the levels of expression of Hox proteins early during ontogeny, and in the sensitivity of the tissues that express them, without any major effects on pattern formation. PMID:24886828

  13. Development and Example Application of a Pilot Model for the Biogeochemical Cycling of Mercury in Watersheds: SERAFM-NPS

    EPA Science Inventory

    Mercury is a developmental neurotoxicant, ubiquitous in the environment, existing both naturally and through anthropogenic additions, resulting in human and ecological exposure risks primarily via consumption of mercury contaminated fish tissue. To better understand the risk ass...

  14. Mercury and health care

    PubMed Central

    Rustagi, Neeti; Singh, Ritesh

    2010-01-01

    Mercury is toxic heavy metal. It has many characteristic features. Health care organizations have used mercury in many forms since time immemorial. The main uses of mercury are in dental amalgam, sphygmomanometers, and thermometers. The mercury once released into the environment can remain for a longer period. Both acute and chronic poisoning can be caused by it. Half of the mercury found in the atmosphere is human generated and health care contributes the substantial part to it. The world has awakened to the harmful effects of mercury. The World Health Organization and United Nations Environmental Programme (UNEP) have issued guidelines for the countries’ health care sector to become mercury free. UNEP has formed mercury partnerships between governments and other stakeholders as one approach to reducing risks to human health and the environment from the release of mercury and its compounds to the environment. Many hospitals are mercury free now. PMID:21120080

  15. DDT'S, HCH AND HCB LEVELS IN BREAST ADIPOSE TISSUE IN WOMEN WITH BREAST TUMORS

    Microsoft Academic Search

    Stefan M. WALISZEWSKI; Marco T. BERMUDEZ; Carmen S. SILVA; Rosa M. INFANZON; Octavio CARVAJAL; Sandra GOMEZ ARROYO; Rafael VILLALOBOS PIETRINI; Patricia TRUJILLO; Vicente SALDAÑA; Guadalupe MELO; Sergio ESQUIVEL; Felipe CASTRO; Héctor OCAMPO; J. TORRES; Patricia M. HAYWARD

    2005-01-01

    Organochlorine pesticides have been used in Mexico in agriculture, sanitation, malaria programs and livestock to combat ectoparasites. Due to their chemical stability, persis­ tence and lipophility, their residues bioconcentrate in lipid­rich tissues, according to the equilibrium pattern of internal transport and lipid tissue content. The studies on their role as estrogenic or antiandrogenic agents have related these pesticides to breast

  16. Mercury levels in muscle of two fish species and sediments from the Cartagena Bay and the Ciénaga Grande de Santa Marta, Colombia.

    PubMed

    Alonso, D; Pineda, P; Olivero, J; González, H; Campos, N

    2000-07-01

    Mercury (Hg) content in sediments and muscle from two fish species were determined in Cartagena Bay and Ciénaga Grande de Santa Marta, an industrialized bay and an unpolluted estuary in the Caribbean coast of Colombia. Sampling was conducted four times during March-November 1996, including both the dry and rainy seasons. Significant differences in Hg concentration were detected both for fish and sediments between the two waterbodies. Hg values ranged from 94 to 10,293 microg/kg dry weight (dw) in sediments from Cartagena Bay and between 20 and 109 microg/kg dw in Ciénaga Grande de Santa Marta. Highest Hg concentrations were observed for the omnivorous species Eugerres plumieri, and lowest concentrations were found in the detritivorous Mugil incilis. High Hg concentrations in sediments of Cartagena Bay were detected in front of the sewage discharge of an extinct chlor-alkali plant, with decreasing concentrations in stations far from the source. Our results suggest that Hg can be persistent in the sediments of previously exposed ecosystems and that the use of their biological resources should be avoided until decontamination programs guarantee safe levels of the metal in the environment. PMID:15092923

  17. Findings of and treatment for high levels of mercury and lead toxicity in ground zero rescue and recovery workers and lower Manhattan residents.

    PubMed

    Kokayi, Kamau; Altman, Claire Haaga; Callely, Robert W; Harrison, Arlene

    2006-01-01

    In 2005, the Olive Leaf Wholeness Center conducted a demonstration project that provided health assessment, testing, and treatment to 160 uniformed service personnel and residents of Lower Manhattan who were exposed to the air at Ground Zero following September 11, 2001, for extended periods of time. The program, known as Project Olive ReLeaf, found that most individuals had eight or more serious health complaints, including severe respiratory problems, digestive problems, skin rashes, sleeplessness, anxiety, depression, weight gains, elevated blood pressure, lethargy, and recurrent headaches. Heavy metal toxicity was suspected as a causal factor for many of these symptoms. Of those tested for heavy metal toxicity, using a challenge urine test, 85% had excessively high levels of lead and mercury. Chelation treatment using dimercaptuosuccinic acid (DMSA), a Food and Drug Administration (FDA)-approved sulfur compound, was the primary treatment prescribed. After three to four months of treatment, the first cohort of 100 individuals reported significant (greater than 60%) improvement in all symptoms. (This demonstration program was developed based on the results of an earlier pilot in 2003 for 25 emergency service officers of the New York City Police Department.) In addition, adjunctive therapies to assist with the detoxification process and build the immune system were offered. A small grant has been received to conduct follow-up tests on a sample of those treated with DMSA. PMID:16979103

  18. Overview of human exposure to dieldrin residues in the environment and current trends of residue levels in tissue

    SciTech Connect

    Ackerman, L.B.

    1980-09-01

    An overview of available literature indicates that dieldrin residues are still found routinely in soil, air, water, and food, despite the 1974 U.S. Environmental Protection Agency ban on the use of aldrin and dieldrin. Dieldrin residue levels in environmental substrates, which are indicative of aldrin or dieldrin use, have decreased significantly since the mid-1960s, the peak usage years. However, human tissue studies do not show a corresponding decline in dieldrin residue levels. Thirteen studies, conducted between 1963 and 1976, show that average dieldrin levels in human adipose tissue and human milk fat remain between 0.160 ppm and 0.220 ppm. Other studies suggest that an equilibrium exists in the distribution of dieldrin among various tissues in humans, including blood, fat, brain, and liver. This relationship indicates that the concentration of dieldrin in any tissue may be used as an index of total body burden. Thus it appears that the concentration of dieldrin in the human body has reached a constant level at which the amount ingested and absorbed equals the amount metabolized and excreted. The mechanism of the stable concentrations is unknown, as are the possible health effects of chronic, low-level exposure to dieldrin.

  19. Hair mercury concentrations of lactating mothers and breastfed infants in Iran (fish consumption and mercury exposure).

    PubMed

    Okati, Narjes; Sari, Abbas Esmaili; Ghasempouri, Seyed Mahmood

    2012-11-01

    Coastal populations with high seafood consumption in the South Caspian Sea (Iran) have a significant exposure to dietary mercury. This study assesses the biomonitoring of mercury in mothers and breastfed infants in the South Caspian Sea. The mean of mercury concentration in the hair of 93 pairs of mothers and infants was obtained and was 3.55 and 1.89 ?g g(-1), respectively. A statistically significant correlation (R = 0.850, P = 0.000) was seen between mercury concentration in the hair of mothers and infants. The results of this study indicate that hair mercury concentrations exceeded the USEPA reference dose of 1 ?g g(-1) in 82.7 % of mothers and 61.2 % of infants. Also, 31 % of the mothers and 10.7 % of the infants had mercury concentrations more than the WHO "threshold" level (5 ?g g(-1)). The age and fish consumption of mothers were the factors that significantly affected the hair mercury concentration of mothers and infants. Number of dental amalgam fillings of mothers was the factor that only affected mercury in the hair of mothers. According to the results, we can conclude that the main determinant of mercury exposure was the intake of mercury through fish consumption of mothers. PMID:22592844

  20. Removal of mercury from chloralkali electrolysis wastewater by a mercury-resistant Pseudomonas putida strain.

    PubMed

    von Canstein, H; Li, Y; Timmis, K N; Deckwer, W D; Wagner-Döbler, I

    1999-12-01

    A mercury-resistant bacterial strain which is able to reduce ionic mercury to metallic mercury was used to remediate in laboratory columns mercury-containing wastewater produced during electrolytic production of chlorine. Factory effluents from several chloralkali plants in Europe were analyzed, and these effluents contained total mercury concentrations between 1.6 and 7.6 mg/liter and high chloride concentrations (up to 25 g/liter) and had pH values which were either acidic (pH 2.4) or alkaline (pH 13.0). A mercury-resistant bacterial strain, Pseudomonas putida Spi3, was isolated from polluted river sediments. Biofilms of P. putida Spi3 were grown on porous carrier material in laboratory column bioreactors. The bioreactors were continuously fed with sterile synthetic model wastewater or nonsterile, neutralized, aerated chloralkali wastewater. We found that sodium chloride concentrations up to 24 g/liter did not inhibit microbial mercury retention and that mercury concentrations up to 7 mg/liter could be treated with the bacterial biofilm with no loss of activity. When wastewater samples from three different chloralkali plants in Europe were used, levels of mercury retention efficiency between 90 and 98% were obtained. Thus, microbial mercury removal is a potential biological treatment for chloralkali electrolysis wastewater. PMID:10583977

  1. Removal of mercury from chloralkali electrolysis wastewater by a mercury-resistant Pseudomonas putida strain

    SciTech Connect

    Canstein, H. von; Li, Y.; Timmis, K.N.; Deckwer, W.D.; Wagner-Doebler, I.

    1999-12-01

    A mercury-resistant bacterial strain which is able to reduce ionic mercury to metallic mercury was used to remediate in laboratory columns mercury-containing wastewater produced during electrolytic production of chlorine. Factory effluents from several chloralkali plants in Europe were analyzed, and these effluents contained total mercury concentrations between 1.6 and 7.6 mg/liter and high chloride concentrations and had pH values which were either acidic or alkaline. A mercury-resistant bacterial strain, Pseudomonas putida Spi3, was isolated from polluted river sediments. Biofilms of P.putida Spi3 were grown on porous carrier material in laboratory column bioreactors. The bioreactors were continuously fed with sterile synthetic model wastewater or nonsterile, neutralized, aerated chloralkali wastewater. The authors found that sodium chloride concentrations up to 24 g/liter did not inhibit microbial mercury retention and that mercury concentrations up to 7 mg/liter could be treated with the bacterial biofilm with no loss of activity. When wastewater samples from three different chloralkali plants in Europe were used, levels of mercury retention efficiency between 90 and 98% were obtained. Thus, microbial mercury removal is a potential biological treatment for chloralkali electrolysis wastewater.

  2. Mercury in municipal solid wastes and New Jersey mercury prevention and reduction program

    SciTech Connect

    Erdogan, H.; Stevenson, E. [New Jersey Department of Environmental Protection, Trenton, NJ (United States). Division of Science and Research

    1994-12-31

    Mercury is a very toxic heavy metal which accumulates in the brain causing neurological damages involving psychasthenic and vegetative syndrome. At high exposure levels it causes behavioral and personality changes, loss of memory and insomnia. Long-term exposure or exposure during pregnancy to mercury or mercury compounds can permanently damage the kidney and fetus. In addition to potential effects on human health, mercury poisoning can also affect other living organisms. Mercury is different than other heavy metals. It consistently biomagnifies and bioaccumulates within the aquatic food chain. Global sources of mercury release are both natural and anthropogenic. Natural sources include volatilization of gaseous-mercury iron soils ana rocks, volcanic releases, evaporation from the ocean and other water bodies. Anthropogenic sources are fuel and coal combustion, mining, smelting, manufacturing activities, disposal of sludge, pesticides, animal and food waste, and incineration of municipal solid waste. Worldwide combustion of municipal solid waste is the second largest source of atmospheric emission of mercury. In New Jersey, incineration of solid waste is the largest source of atmospheric emission of mercury. The New Jersey Department of Environmental Protection and Energy (NJDEPE) has developed a comprehensive program to control and prevent emission of mercury resulting from combustion municipal solid waste.

  3. The effect of selenium on mercury assimilation by freshwater organisms

    Microsoft Academic Search

    Nelson Belzile; Yu-Wei Chen; John M. Gunn; Jian Tong; Yves Alarie; Tania Delonchamp; Chun-Yan Lang

    2006-01-01

    In this study, we showed that selenium (Se) deposition from metal smelters in Sudbury, Ontario, greatly re- duces the bioassimilation of mercury (Hg) by aquatic biota throughout the food web. Concentrations of total and methyl mercury in tissues of zooplankton, mayflies (Stenonema femoratum), amphipods (Hyalella azteca), and young- of-the-year perch (Perca flavescens) were positively correlated with increasing distance from Sudbury

  4. The tropical African mercury anomaly: lower than expected mercury concentrations in fish and human hair.

    PubMed

    Black, Frank J; Bokhutlo, Thethela; Somoxa, Aaron; Maethamako, Mothusi; Modisaemang, Ontlogetse; Kemosedile, Thebe; Cobb-Adams, Cristina; Mosepele, Ketlhatlogile; Chimbari, Moses

    2011-04-15

    Mercury is a neurotoxin and global pollutant, and wetlands and newly flooded areas are known to be sites of enhanced production of monomethylmercury, the form of mercury that is readily biomagnified in aquatic food chains to potentially toxic levels. The Okavango Delta in Botswana, Southern Africa, is the largest inland delta in the world and a wetland ecosystem that experiences dramatic annual flooding of large tracts of seasonal floodplains. The Delta was, therefore, expected to be home to high mercury levels in fish and to be an area where local subsistence fishing communities would be at substantial risk of mercury toxicity from fish consumption. Total mercury concentrations measured in 27 species of fish from the Okavango Delta averaged (mean±s.d., wet weight) 19±19ng g(-1) in non-piscivorous fish, and 59±53ng g(-1) in piscivorous fish. These mercury concentrations are similar to those reported for fish from lakes in other areas of tropical Africa, demonstrating that not all wetlands are sites of elevated mercury concentrations in biota. Even more intriguing is that concentrations of mercury in fish from across tropical Africa are systematically and substantially lower than those typically reported for fish from freshwater ecosystems elsewhere globally. The reasons for this apparent "African mercury anomaly" are unclear, but this finding poses a unique opportunity to improve our understanding of mercury's biogeochemical cycling in the environment. Mercury concentrations measured in human hair collected in subsistence fishing communities in the Okavango Delta were similarly low (0.21±0.22?g g(-1) dry weight) despite high levels of fish consumption, and reflect the low mercury concentrations in the fish here. PMID:21342703

  5. The relationship of the toxic effects of mercury to exacerbation of the medical condition classified as Alzheimer's disease

    Microsoft Academic Search

    Boyd E. Haley

    2007-01-01

    Mercury(II) or Hg2+, is neurotoxic. When exposed to normal brain tissue homogenates, neurons in culture, Hg2+ (mercury(II) or mercuric mer- cury) is capable of causing many of the same biochemical aberrancies found in Alzheimer's diseased (AD) brain. Also, rats exposed to mercury(0), metallic mercury, vapor show some of these same abnormalities in their brain tissue. Specifically, the rapid inactivation of

  6. Temporal variation of blood and hair mercury levels in pregnancy in relation to fish consumption history in a population living along the St. Lawrence River.

    PubMed

    Morrissette, Joëlle; Takser, Larissa; St-Amour, Genevieve; Smargiassi, Audrey; Lafond, Julie; Mergler, Donna

    2004-07-01

    Fish consumption from the Great Lakes and the St. Lawrence River has been decreasing over the last years due to advisories and increased awareness of the presence of several contaminants. Methylmercury (MeHg), a well-established neurotoxicant even at low levels of exposure, bioaccumulates to differing degrees in various fish species and can have serious adverse effects on the development and functioning of the human central nervous system, especially during prenatal exposure. Most studies on MeHg exposure have focussed on high-level consumers from local fish sources, although mercury (Hg) is also present in fresh, frozen, and canned market fish. Moreover, little information exists on the temporal variation of blood and hair Hg in pregnant women, particularly in populations with low levels of Hg. The aim of the present study was to characterize the temporal variation of Hg during pregnancy and to investigate the relation between fish consumption from various sources prior to and during pregnancy and maternal cord blood and mother's hair Hg levels. We recruited 159 pregnant women from Southwest Quebec through two prenatal clinics of the Quebec Public Health System. All women completed two detailed questionnaires concerning their fish consumption (species and frequency) prior to and during pregnancy. The women also provided blood samples for all three trimesters of pregnancy and hair samples after delivery of up to 9 cm in length. Blood and hair Hg levels were analyzed by cold-vapor atomic-absorption and -fluorescence spectrometry methods, respectively. Results showed that maternal blood and hair Hg levels decreased significantly between the second and third trimesters of pregnancy. However, cord blood Hg was significantly higher than maternal blood at birth. Maternal hair was correlated with Hg blood concentration and was highly predictive of the organic fraction in cord blood. A strong dose relation was observed between the frequency of fish consumption before and during pregnancy and Hg exposure in mothers and newborns. Fish consumption prior to and during pregnancy explained 26% and 20% of cord blood Hg variance, respectively. For this population, detailed multivariate analyses showed that during pregnancy market fish (fresh, canned, and frozen) were more important sources of Hg exposure than were fish from the St. Lawrence River. These results should be taken into account for future advisories and intervention strategies, which should consider Hg levels in different species from all sources in order to maximize the nutritional input from fish and minimize the toxic risk. PMID:15220070

  7. Thymidine Kinase 2 Deficiency-Induced Mitochondrial DNA Depletion Causes Abnormal Development of Adipose Tissues and Adipokine Levels in Mice

    PubMed Central

    Villarroya, Joan; Dorado, Beatriz; Vilà, Maya R.; Garcia-Arumí, Elena; Domingo, Pere; Giralt, Marta; Hirano, Michio; Villarroya, Francesc

    2011-01-01

    Mammal adipose tissues require mitochondrial activity for proper development and differentiation. The components of the mitochondrial respiratory chain/oxidative phosphorylation system (OXPHOS) are encoded by both mitochondrial and nuclear genomes. The maintenance of mitochondrial DNA (mtDNA) is a key element for a functional mitochondrial oxidative activity in mammalian cells. To ascertain the role of mtDNA levels in adipose tissue, we have analyzed the alterations in white (WAT) and brown (BAT) adipose tissues in thymidine kinase 2 (Tk2) H126N knockin mice, a model of TK2 deficiency-induced mtDNA depletion. We observed respectively severe and moderate mtDNA depletion in TK2-deficient BAT and WAT, showing both tissues moderate hypotrophy and reduced fat accumulation. Electron microscopy revealed altered mitochondrial morphology in brown but not in white adipocytes from TK2-deficient mice. Although significant reduction in mtDNA-encoded transcripts was observed both in WAT and BAT, protein levels from distinct OXPHOS complexes were significantly reduced only in TK2-deficient BAT. Accordingly, the activity of cytochrome c oxidase was significantly lowered only in BAT from TK2-deficient mice. The analysis of transcripts encoding up to fourteen components of specific adipose tissue functions revealed that, in both TK2-deficient WAT and BAT, there was a consistent reduction of thermogenesis related gene expression and a severe reduction in leptin mRNA. Reduced levels of resistin mRNA were found in BAT from TK2-deficient mice. Analysis of serum indicated a dramatic reduction in circulating levels of leptin and resistin. In summary, our present study establishes that mtDNA depletion leads to a moderate impairment in mitochondrial respiratory function, especially in BAT, causes substantial alterations in WAT and BAT development, and has a profound impact in the endocrine properties of adipose tissues. PMID:22216345

  8. Effect of Cassia Auriculata Flowers on Blood Sugar Levels, Serum and Tissue Lipids in Streptozotocin Diabetic Rats

    Microsoft Academic Search

    L Pari; M Latha

    2002-01-01

    Aim of the study: The main aim was to demonstrate the effects of Cassia auriculata flowers on blood glucose and lipid levels in experimental diabetic rats. Methodology: Aqueous extract of Cassia auriculata flowers was administered orally and different doses of the extract on blood glucose, haemoglobin, glycosylated haemoglobin, serum and tissue lipids, hexokinase and glucose- 6-phosphatase in streptozotocin-induced diabetic rats

  9. RELATIONSHIPS BETWEEN TISSUE LEVELS OF CARBARYL, A PROTOTYPICAL CARBAMATE PESTICIDE, AND CHOLINESTERASE INHIBITION IN LONG EVANS RATS.

    EPA Science Inventory

    As part of an effort to link pharmacokinetics with biochemical and physiological endpoints, the relationships between cholinesterase (ChE) activity and tissue levels of a prototypical N-methyl carbamate pesticide were examined. In a dose-response study, carbaryl (0, 3, 7.5, 15, 3...

  10. No Influence of Surgical Stress on Postoperative Leptin Gene Expression in Different Adipose Tissues and Soluble Leptin Receptor Plasma Levels

    Microsoft Academic Search

    Ellen Schoof; Anja Stuppy; Frank Harig; Helmut Singer; Roman Carbon; Thomas Horbach; Jürgen Kratzsch; Wolfgang Rascher; Jörg Dötsch

    2003-01-01

    As part of the postsurgical stress response, plasma leptin levels increase in-between 12 h postoperatively. Objective: To study the kinetics of leptin gene expression in different adipose tissues before and after severe surgical trauma in children and adults. Methods: In 22 adults and 23 children with cardiac and 19 adult patients with abdominal surgery, we measured plasma leptin concentrations preoperatively,

  11. Tissue-level failure accumulation in vertebral cancellous bone: a theoretical model.

    PubMed

    Slomka, Noa; Diamant, Idit; Gefen, Amit

    2008-01-01

    Vertebral compression fractures are a potentially severe injury, which is characteristic to osteoporotic elderly. Despite being a significant healthcare problem, the etiology of compression fractures is not fully understood, and there are no biomechanical models in the literature that describe the development of these fractures based on cancellous bone failure accumulation. The objective of this study was therefore to develop a computational model of tissue-level failure accumulation in vertebral cancellous bone, which eventually leads to compression fractures. The model predicts the accumulated percentage of broken trabeculae delta in a vertebral region of interest (ROI) over 60 years, by employing Euler's theory for elastic buckling. The accumulated failure delta is calculated as function of the daily activity characteristics and rate of annual bone loss (RABL) with aging. An RABL of unity represents the normal bone loss attributed to aging per se, whereas RABL>1 is assumed to represent pathological bone metabolism such as osteoporosis. Simulations were conducted for a range of RABLs, to determine the effect of changes in bone metabolism on the accumulation of bone failure. Results showed that bone failure rapidly increased with RABL. Generally, trabecular failure was shown to become more severe for RABL>4. Total failure was exhibited at RABL=7.5 for the central ROI, and at RABL=8.5 for the sub-endplate ROI. We concluded that vertebral compression fractures advance monotonically between the age of 50-55 years and 70 years, and may accelerate thereafter if RABL is high (~8). Additionally, the model identified weight lifting as the action that most dramatically accelerated the destruction of osteoporotic spinal cancellous bone. The present biomechanical model is useful for understanding the etiology of compression fractures, and potentially, depending on further experimental characterization of RABL, for considering the effects of medications that influence bone metabolism on patient prognosis. PMID:18334787

  12. GESTATIONAL MERCURY VAPOR EXPOSURE AND DIET CONTRIBUTE TO MERCURY ACCUMULATION IN NEONATAL RATS.

    EPA Science Inventory

    Exposure of pregnant Long-Evans rats to elemental mercury (Hg0) vapor resulted in a significant accumulation of Hg in tissues of neonates. Because elevated Hg in neonatal tissues may adversely affect growth and development, we were interested in how rapidly Hg was...

  13. The Contribution of Tissue Level Organization to Genomic Stability Following Low Dose/Low Dose Rate Gamma and Proton Irradiation

    SciTech Connect

    Cheryl G. Burrell, Ph.D.

    2012-05-14

    The formation of functional tissue units is necessary in maintaining homeostasis within living systems, with individual cells contributing to these functional units through their three-dimensional organization with integrin and adhesion proteins to form a complex extra-cellular matrix (ECM). This is of particular importance in those tissues susceptible to radiation-induced tumor formation, such as epithelial glands. The assembly of epithelial cells of the thyroid is critical to their normal receipt of, and response to, incoming signals. Traditional tissue culture and live animals present significant challenges to radiation exposure and continuous sampling, however, the production of bioreactor-engineered tissues aims to bridge this gap by improve capabilities in continuous sampling from the same functional tissue, thereby increasing the ability to extrapolate changes induced by radiation to animals and humans in vivo. Our study proposes that the level of tissue organization will affect the induction and persistence of low dose radiation-induced genomic instability. Rat thyroid cells, grown in vitro as 3D tissue analogs in bioreactors and as 2D flask grown cultures were exposed to acute low dose (1, 5, 10 and 200 cGy) gamma rays. To assess immediate (6 hours) and delayed (up to 30 days) responses post-irradiation, various biological endpoints were studied including cytogenetic analyses, apoptosis analysis and cell viability/cytotoxicity analyses. Data assessing caspase 3/7 activity levels show that, this activity varies with time post radiation and that, overall, 3D cultures display more genomic instability (as shown by the lower levels of apoptosis over time) when compared to the 2D cultures. Variation in cell viability levels were only observed at the intermediate and late time points post radiation. Extensive analysis of chromosomal aberrations will give further insight on the whether the level of tissue organization influences genomic instability patterns after low dose radiation exposure. Cells viability/cytotoxicity analysis data are currently being analyzed to determine how these endpoints are affected under our experimental conditions. The results from this study will be translatable to risk assessment for assigning limits to radiation workers, pre-dosing for more effective radiotherapy and the consequences of long duration space flight. The data from this study has been presented a various scientific meetings/workshops and a manuscript, containing the findings, is currently being prepared for publication. Due to unforeseen challenges in collecting the data and standardizing experimental procedures, the second and third aims have not been completed. However, attempts will be made, based on the availability of funds, to continue this project so that these aims can be satisfied.

  14. Changes in endocannabinoid and palmitoylethanolamide levels in eye tissues of patients with diabetic retinopathy and age-related macular degeneration

    Microsoft Academic Search

    I. Matias; J. W. Wang; A. Schiano Moriello; A. Nieves; D. F. Woodward; V. Di Marzo

    2006-01-01

    Cannabinoid receptors and the endocannabinoids (anandamide (N-arachidonoylethanolamine—AEA) and 2-arachidonoylglycerol (2-AG)), as well as the AEA congener, palmitoylethanolamide (PEA), are involved in ocular physiology. We measured endocannabinoid and PEA levels by isotope-dilution liquid chromatography-mass spectrometric analysis in post-mortem eye tissues of patients with diabetic retinopathy (DR) or age-related macular degeneration (AMD). In eyes with DR, significantly enhanced levels of AEA were

  15. mdm2 mRNA level is a prognostic factor in soft tissue sarcoma.

    PubMed Central

    Taubert, H.; Koehler, T.; Meye, A.; Bartel, F.; Lautenschläger, C.; Borchert, S.; Bache, M.; Schmidt, H.; Würl, P.

    2000-01-01

    BACKGROUND: The oncogenic properties of murine double minute-2 (mdm2) protein over-expression, which mostly results from the interaction with the tumor suppressor p53, are well described and their negative impacts on the prognosis of affected patients is well characterized. However, clinical relevance of mdm2 mRNA expression is poorly investigated. MATERIALS AND METHODS: In this study, 65 soft tissue sarcoma (STS) samples were analyzed for mdm2 mRNA expression by a quantitative reverse transcription polymerase chain reaction (RT-PCR) approach using available validated ready-to-use assays based on the TaqMan technology (PE Applied Biosystems, Weiterstadt, Germany). Mdm2 data were correlated to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) expression calculated from the same sample. RESULTS: For patients with a mdm2/GAPDH mRNA ratio below 50 zmol/amol the survival was strikingly reduced in comparison to patients with a ratio of > or =50 (p = 0.0241). Multivariate Cox analysis showed that the difference in prognosis for patients with tumor stage 2 and 3 became even more pronounced between patients with a ratio of <50 zmol/amol and patients with a ratio of > or =50 (p = 0.0041; RR = 5.6). To test if the group with an mdm2 mRNA expression > or =50 is homogenous concerning the prognosis, the group was divided into three subgroups with values of 50 to <100, 100 to <500 and > or =500. The subgroup with values of 100 to <500 showed the best prognosis (p = 0.0164); whereas, the one with values of 50 to <100 showed the worst prognosis in this group and, in between, was the one with values of > or =500. After omitting patients of stage 1 and 4, the subgroup with values of 100 to <500 showed an even more striking best prognosis (p = 0.0015); the other subgroups remained in the same sequence. The risk of tumor-related death over 5 years was most conspicuous in patients with mdm2 mRNA expression <50 than in those with ratios of 100 to <500 displaying a 13.3-fold higher risk. In a comparison between mdm2 mRNA levels and P53 protein expression or p53 mutational status, no relationship was found. CONCLUSIONS: In our study, the mdm2 mRNA level appears to be an independent prognostic factor for STS patients, marking its role in STS genesis and as a potential factor for gene therapeutical approaches. PMID:10803408

  16. Organochlorine Pesticide Levels in Adipose Tissue of Pregnant Women in Veracruz, Mexico

    Microsoft Academic Search

    Margarita Herrero-Mercado; S. M. Waliszewski; R. Valencia-Quintana; M. Caba; F. Hernández-Chalate; E. García-Aguilar; R. Villalba

    2010-01-01

    DDT and Lindane (?-HCH) which were used until 1999 in Mexico, have provided great benefits in the combat of vectors that spread\\u000a infection-borne diseases and in agriculture for crop protection. The persistence in the environment and their accumulative\\u000a properties results in bioconcentration in lipid rich tissues of the human body that reflect the extent of environmental pollution.\\u000a Human adipose tissue

  17. Bird blood as bioindicator for mercury in the environment.

    PubMed

    Kahle, S; Becker, P H

    1999-12-01

    Mercury concentrations were studied in blood, down and feathers of Common Gull (Larus canus L.) to investigate the suitability of bird blood as a matrix for biomonitoring of mercury in the marine environment. Chicks were collected in 1996 on the Elbe river and the Jade Bay. Like the side feathers, blood indicated site differences in mercury contamination. Correlational analyses showed that mercury concentrations in blood are significantly related to levels in side feathers (p < 0.001; Pearson), but not to those in down (p > 0.05; Pearson). Therefore, blood can be considered as a suitable matrix to indicate the current mercury burden in wild birds. PMID:10581697

  18. Quantitative determinations of the steady state transcript levels of hexokinase isozymes and glucose transporter isoforms in normal rat tissues and the malignant tumor cell line AH130

    Microsoft Academic Search

    Yasuo Shinohara; Kenji Yamamoto; Katsuyuki Inoo; Naoshi Yamazaki; Hiroshi Terada

    1998-01-01

    The steady state transcript levels of the four hexokinase (HK) isozymes and four glucose transporter (GLUT) isoforms were determined quantitatively by Northern analysis of RNA samples from rat tissues using synthetic fragments of the RNAs encoding the HK isozymes and GLUT isoforms. Results showed that the levels of HK isozyme transcripts were low in rat tissues, the level of that

  19. Mercury levels in the Carson River and effect of group VI anions on methylmercury production in sediments

    SciTech Connect

    Bonzongo, J.C.; Chen, Y.; Miller, G.C. [Univ. of Nevada, Reno, NV (United States)] [and others

    1995-12-31

    Distribution and speciation of Hg were determined in a fluvial-lacustrine system impacted by Hg-contaminated mine wastes. Levels of total-Hg (THg), introduced into the river by contaminated particles eroded from mine tailings, were found to be controlled by the water flow regimes and varying from background concentrations of {approximately}2 ng L{sup -1} to values in the ppb range in the contaminated section. Concentrations of MeHg were higher in surface waters of both the contaminated river section (>7 ng Hg L{sup -1}) and the reservoir (11 to 4 ng Hg L{sup -1}), than in the seasonally anoxic bottom waters of the reservoir (<1 ng Hg L{sup -1}). The Carson River flows in to the and basin of eastern California and western Nevada, where the rivers are essentially Ca-Na-HCO{sub 3} waters with the terminal lakes being Na-Cl-CO{sub 3} waters. Due to the evapoconcentration of water as it flows downstream in this and environment, levels of naturally occurring oxyanion-forming elements (such as Mo, W, Se,{hor_ellipsis}) known to influence sulfate reduction, are high for noncontaminated freshwaters, exhibiting their highest values in terminal basins. In contrast, MeHg/THg ratios decreased significantly with the increase downstream of oxyanion-forming element concentrations. Experimental results of Hg methylation conducted with sediments showed that combined to alkaline pH (>7.4) and high levels of inorganic Hg, the production of MeHg in the studied aquatic system, mainly by sulfate reducing bacteria, could be negatively affected by some group VI anions, since they could interfere in metabolic processes involving both phosphate and sulfate.

  20. Phytotoxicity and accumulation of mercury in tobacco subjected to different exposure routes

    SciTech Connect

    Suszcynsky, E.M.; Shann, J.R. (Univ. of Cincinnati, OH (United States). Dept. of Biological Sciences)

    1995-01-01

    Experiments were conducted to study the absorption, phytotoxicity, and internal distribution of mercury (Hg) in tobacco plants (Nicotiana miersii) exposed to elemental mercury vapor (Hg[sup 0]) through the shoot or to ionic mercury (Hg[sup 2+]) through the root. Tobacco plants grown hydroponically were exposed to varying Hg[sup 0] treatment concentrations in a specially designed chamber system, examined for visible symptoms of toxicity, and analyzed for Hg content by cold vapor atomic absorption, 1 and 10 d following treatment. In a separate experiment, the roots of hydroponic tobacco plants were exposed to Hg[sup 2+] in the form of a mercury chloride solution and analyzed for growth changes and Hg content. Accumulation, toxicity response, and Hg distribution differed between the two exposure routes, even when internal Hg concentrations in the treated plants were similar. Plants exposed to Hg[sup 0] accumulated Hg in the shoots with no movement to roots. Visible signs of Hg[sup 0] stress were apparent at 1.0 mg/m[sup 3] exposure levels and greater. Root-exposed plants showed accumulation of Hg in the roots with movement to the shoots by day 10. Inhibition of root and shoot growth occurred at treatment levels of 1.0 [mu]g/ml and greater with very limited tissue damage at higher treatment levels.

  1. Metallic mercury recycling. Final report

    Microsoft Academic Search

    Beck

    1994-01-01

    Metallic mercury is known to be a hazardous material and is regulated as such. The disposal of mercury, usually by landfill, is expensive and does not remove mercury from the environment. Results from the Metallic Mercury Recycling Project have demonstrated that metallic mercury is a good candidate for reclamation and recycling. Most of the potential contamination of mercury resides in

  2. OCCURRENCE OF MERCURY-RESISTANT MICROORGANISMS IN MERCURY-CONTAMINATED SOILS AND SEDIMENTS IN PAVLODAR, KAZAKHSTAN

    EPA Science Inventory

    There is extensive mercury contamination of soil surrounding a chloralkali plant in Pavlodar, Kazakhstan that operated from 1970 to 1990. High-level mercury contamination exists within the confines of the plant, at nearby off-site waste storage and evaporation ponds, and in Balky...

  3. OCCURRENCE OF MICROORGANISMS RESISTANT TO MERCURY IN MERCURY CONTAMINATED SOILS AND SEDIMENTS IN PAVLODAR, KAZAKHSTAN

    EPA Science Inventory

    There is extensive mercury contamination of soil surrounding a chloralkali plant in Pavlodar, Kazakhstan that operated from 1970 to 1990. High-level mercury contamination exists within the confines of the plant, at nearby off-site waste storage and evaporation ponds, and in Balky...

  4. Increased Zn/Glutathione Levels and Higher Superoxide Dismutase-1 Activity as Biomarkers of Oxidative Stress in Women with Long-Term Dental Amalgam Fillings: Correlation between Mercury/Aluminium Levels (in Hair) and Antioxidant Systems in Plasma

    PubMed Central

    Cabaña-Muñoz, María Eugenia; Parmigiani-Izquierdo, José María; Bravo-González, Luis Alberto; Kyung, Hee-Moon; Merino, José Joaquín

    2015-01-01

    Background The induction of oxidative stress by Hg can affect antioxidant enzymes. However, epidemiological studies have failed to establish clear association between dental fillings presence and health problems. Objectives To determine whether heavy metals (in hair), antioxidant enzymes (SOD-1) and glutathione levels could be affected by the chronic presence of heavy metals in women who had dental amalgam fillings. Materials and Methods 55 hair samples (42 females with amalgam fillings and 13 female control subjects) were obtained. All subjects (mean age 44 years) who had dental amalgam filling for more than 10 years (average 15 years). Certain metals were quantified by ICP-MS (Mass Spectrophotometry) in hair (?g/g: Al, Hg, Ba, Ag, Sb, As, Be, Bi, Cd, Pb, Pt, Tl, Th, U, Ni, Sn, Ti) and SOD-1 and Glutathione (reduced form) levels in plasma. Data were compared with controls without amalgams, and analyzed to identify any significant relation between metals and the total number of amalgam fillings, comparing those with four or less (n = 27) with those with more than four (n = 15). As no significant differences were detected, the two groups were pooled (Amlgam; n = 42). Findings Hg, Ag, Al and Ba were higher in the amalgam group but without significant differences for most of the heavy metals analyzed. Increased SOD-1 activity and glutathione levels (reduced form) were observed in the amalgam group. Aluminum (Al) correlated with glutathione levels while Hg levels correlated with SOD-1. The observed Al/glutathione and Hg/SOD-1 correlation could be adaptive responses against the chronic presence of mercury. Conclusions Hg, Ag, Al and Ba levels increased in women who had dental amalgam fillings for long periods. Al correlated with glutathione, and Hg with SOD-1. SOD-1 may be a possible biomarker for assessing chronic Hg toxicity. PMID:26076368

  5. Behcet brain tissue identified with increased levels of Si and Al

    NASA Astrophysics Data System (ADS)

    Aranyosiova, Monika; Kopani, Martin; Rychly, Boris; Jakubovsky, Jan; Velic, Dusan

    2008-12-01

    Behcet disease is a multi-system disorder with still uncertain chemical causality. Chemical composition of molecules and elements in a human brain tissue of Behcet diseased patient is of interest. Time-of-flight secondary ion mass spectrometry is used to provide complex composition in Behcet disease and control tissues. Determined organic compounds are represented by fragments of carbohydrates, phospholipids, amino acids, and peptides in both samples without any qualitative differences. Trace heavy elements as Fe, Zn, and Cu are identified in Behcet disease tissue with increased intensities by only an averaged factor of 2.2 in comparison to the control. The significant differences between the control and Behcet disease tissues are in the presence of Si and Al. These two elements have significantly higher intensities by an averaged factor of 10.0 in Behcet disease tissue. The origin of Al and Si occurrence and the chronology of their accumulation are not clear, moreover this observation supports a significance of chemical characterization in an early stage of disease.

  6. PERCEPTION OF MERCURY RISK INFORMATION

    EPA Science Inventory

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

  7. Hg L3 XANES study of mercury methylation in shredded Eichhornia crassipes.

    PubMed

    Rajan, Michael; Darrow, Jeannine; Hua, Michael; Barnett, Brandy; Mendoza, Miguel; Greenfield, Ben K; Andrews, Joy C

    2008-08-01

    Eichhornia crassipes (water hyacinth) is a non-native plant found in abundance in the Sacramento-San Joaquin River Delta (hereafter called Delta). This species has become a problem, clogging waterways and wetlands. Water hyacinth are also known to accumulate mercury. Recent attempts to curb its proliferation have included shredding with specialized boats. The purpose of this research is to better understand the ability of water hyacinth to phytoremediate mercury and to determine the effect of shredding and anoxic conditions on mercury speciation in plant tissue. In the field assessment, total mercury levels in sediment from the Dow Wetlands in the Delta were found to be 0.273 +/- 0.070 ppm Hg, and levels in hyacinth roots and shoots from this site were 1.17 +/- 0.08 ppm and 1.03 +/- 0.52 ppm, respectively, indicating bioaccumulation of mercury. Plant samples collected at this site were also grown in nutrient solution with 1 ppm HgCl2 under (1) aerobic conditions, (2) anaerobic conditions, and (3)with shredded plant material only. The greatest accumulation was found in the roots of whole plants. Plants grown in these conditions were also analyzed at Stanford Synchrotron Radiation Laboratory using Hg L3 X-ray Absorption Near Edge Spectroscopy (XANES), a method to examine speciation that is element-specific and noninvasive. Least-squares fitting of the XANES data to methylated and inorganic mercury(II) model compounds revealed that in plants grown live and aerobically, 5 +/- 3% of the mercury was in the form of methylmercury, in a form similar to methylmercury cysteine. This percentage increased to 16 +/- 4% in live plants grown anaerobically and to 22 +/- 6% in shredded anaerobic plants. We conclude that shredding of the hyacinth plants and, in fact, subjection of plants to anaerobic conditions (e.g., as in normal decay, or in crowded growth conditions) increases mercury methylation. Mechanical removal of the entire plant is significantly more expensive than shredding, but it may be necessary to avoid increased biomagnification of mercury in infested areas. PMID:18754477

  8. Geothermal hazards - Mercury emission

    NASA Technical Reports Server (NTRS)

    Siegel, S. M.; Siegel, B. Z.

    1975-01-01

    Enthusiasm for intensified geothermal exploration may induce many participants to overlook a long-term potential toxicity hazard possibly associated with the tapping of magmatic steam. The association of high atmospheric Hg levels with geothermal activity has been established both in Hawaii and Iceland, and it has been shown that mercury can be introduced into the atmosphere from fumaroles, hot springs, and magmatic sources. These arguments, extended to thallium, selenium, and other hazardous elements, underscore the need for environmental monitoring in conjunction with the delivery of magmatic steam to the surface.

  9. Single cell sequencing reveals low levels of aneuploidy across mammalian tissues

    PubMed Central

    Knouse, Kristin A.; Wu, Jie; Whittaker, Charles A.; Amon, Angelika

    2014-01-01

    Whole-chromosome copy number alterations, also known as aneuploidy, are associated with adverse consequences in most cells and organisms. However, high frequencies of aneuploidy have been reported to occur naturally in the mammalian liver and brain, fueling speculation that aneuploidy provides a selective advantage in these organs. To explore this paradox, we used single cell sequencing to obtain a genome-wide, high-resolution assessment of chromosome copy number alterations in mouse and human tissues. We find that aneuploidy occurs much less frequently in the liver and brain than previously reported and is no more prevalent in these tissues than in skin. Our results highlight the rarity of chromosome copy number alterations across mammalian tissues and argue against a positive role for aneuploidy in organ function. Cancer is therefore the only known example, in mammals, of altering karyotype for functional adaptation. PMID:25197050

  10. Influence of feeding graded levels of canned sardines on the inflammatory markers and tissue fatty acid composition of Wistar rats.

    PubMed

    Rodrigues, Pedro O; Martins, Susana V; Lopes, Paula A; Ramos, Cristina; Miguéis, Samuel; Alfaia, Cristina M; Pinto, Rui M A; Rolo, Eva A; Bispo, Paulo; Batista, Irineu; Bandarra, Narcisa M; Prates, José A M

    2014-08-01

    Canned sardines are a ready-to-use fish product with excellent nutritional properties owing to its high n-3 long-chain PUFA content, mainly EPA (20 : 5n-3) and DHA (22 : 6n-3). The present study aimed to assess the effect of two dosages of canned sardines, recommended for the primary and secondary prevention of human CVD, on the inflammatory marker concentrations and fatty acid composition of erythrocytes and key metabolic tissues (liver, muscle, adipose tissue and brain) in the rat model. Wistar rats were fed a diet containing 11 % (w/w) of canned sardines (low-sardine (LS) diet) and a diet containing 22 % (w/w) of canned sardines (high-sardine (HS) diet) for 10 weeks. Daily food intake, weight gain, and organ and final body weights were not affected by the dietary treatments. The concentrations of total cholesterol, HDL-cholesterol and LDL-cholesterol decreased in both the LS and HS groups, while those of alanine aminotransferase and adiponectin increased. The concentrations of IL-1? increased only with the highest dosage of sardine. The dose-dependent influence of the graded levels of EPA+DHA was tissue specific. Compared with that of other tissues and erythrocytes, the fatty acid composition of the brain was less affected by the canned sardine-supplemented diets. In contrast, the retroperitoneal adipose tissue was highly responsive. The deposition ratios of EPA and DHA indicated that the LS diet was optimal for DHA deposition across the tissues, except in the retroperitoneal adipose tissue. Taken together, our findings indicate that a LS diet positively affects plasma lipid profiles and inflammatory mediators, whereas a HS diet has contradictory effects on IL-1?, which, in turn, is not associated with variations in the concentrations of other pro-inflammatory cytokines. This finding requires further investigation and pathophysiological understanding. PMID:24775714

  11. Mercury concentrations in blood and feathers of prebreeding Forster's terns in relation to space use of San Francisco Bay, California, USA, habitats.

    PubMed

    Ackerman, Joshua T; Eagles-Smith, Collin A; Takekawa, John Y; Bluso, Jill D; Adelsbach, Terrence L

    2008-04-01

    We examined mercury concentrations and space use of prebreeding Forster's terns (Sterna forsteri) in San Francisco Bay, California, USA, to assess factors influencing mercury levels in piscivorous birds. In 2005 and 2006, we collected blood and feathers from 122 Forster's terns and radio-marked and tracked 72 terns to determine locations of dietary mercury uptake. Capture site and capture date were the most important factors explaining variation in blood mercury concentrations (geometric mean +/- standard error: 1.09+/-0.89 microg/g wet wt), followed by sex and year. Accordingly, radiotelemetry data revealed that Forster's terns generally remained near their site of capture and foraged in nearby salt ponds, managed and tidal marshes, and tidal flats. In contrast, capture site and capture date were not important factors explaining variation in feather mercury concentrations, probably because feathers were grown on their wintering grounds several months prior to our sampling. Instead, sex and year were the most important factors explaining mercury concentrations in breast feathers (9.57+/-8.23 microg/g fresh wt), and sex was the most important factor for head feathers (6.94+/-7.04 microg/g fresh wt). Overall, 13 and 22% of prebreeding Forster's terns were estimated to be at high risk for deleterious effects due to mercury concentrations in blood (>3.0 microg/g wet wt) and feathers (>20.0 microg/g fresh wt), respectively. Breeding terns are likely to be even more at risk because blood mercury concentrations more than tripled during the 45-d prebreeding time period. These data illustrate the importance of space use and tissue type in interpreting mercury concentrations in birds. PMID:18333675

  12. Mercury concentrations in blood and feathers of prebreeding Forster's terns in relation to space use of San Francisco Bay, California, USA, habitats

    USGS Publications Warehouse

    Ackerman, J.T.; Eagles-Smith, C. A.; Takekawa, J.Y.; Bluso, J.D.; Adelsbach, T.L.

    2008-01-01

    We examined mercury concentrations and space use of prebreeding Forster's terns (Sterna forsteri) in San Francisco Bay, California, USA, to assess factors influencing mercury levels in piscivorous birds. In 2005 and 2006, we collected blood and feathers from 122 Forster's terns and radio-marked and tracked 72 terns to determine locations of dietary mercury uptake. Capture site and capture date were the most important factors explaining variation in blood mercury concentrations (geometric mean ?? standard error: 1.09 ?? 0.89 ??g/g wet wt), followed by sex and year. Accordingly, radiotelemetry data revealed that Forster's terns generally remained near their site of capture and foraged in nearby salt ponds, managed and tidal marshes, and tidal flats. In contrast, capture site and capture date were not important factors explaining variation in feather mercury concentrations, probably because feathers were grown on their wintering grounds several months prior to our sampling. Instead, sex and year were the most important factors explaining mercury concentrations in breast feathers (9.57 ?? 8.23 ??g/g fresh wt), and sex was the most important factor for head feathers (6.94 ?? 7.04 ??g/g fresh wt). Overall, 13 and 22% of prebreeding Forster's terns were estimated to be at high risk for deleterious effects due to mercury concentrations in blood (>3.0 ??g/g wet wt) and feathers (>20.0 ??g/g fresh wt), respectively. Breeding terns are likely to be even more at risk because blood mercury concentrations more than tripled during the 45-d prebreeding time period. These data illustrate the importance of space use and tissue type in interpreting mercury concentrations in birds. ?? 2008 SETAC.

  13. Elevated Levels of G-Quadruplex Formation in Human Stomach and Liver Cancer Tissues

    PubMed Central

    Biffi, Giulia; Tannahill, David; Miller, Jodi; Howat, William J.; Balasubramanian, Shankar

    2014-01-01

    Four-stranded G-quadruplex DNA secondary structures have recently been visualized in the nuclei of human cultured cells. Here, we show that BG4, a G-quadruplex-specific antibody, can be used to stain DNA G-quadruplex structures in patient-derived tissues using immunohistochemistry. We observe a significantly elevated number of G-quadruplex-positive nuclei in human cancers of the liver and stomach as compared to background non-neoplastic tissue. Our results suggest that G-quadruplex formation can be detected and measured in patient-derived material and that elevated G-quadruplex formation may be a characteristic of some cancers. PMID:25033211

  14. Mercury Continuous Emmission Monitor Calibration

    SciTech Connect

    John Schabron; Eric Kalberer; Ryan Boysen; William Schuster; Joseph Rovani

    2009-03-12

    Mercury continuous emissions monitoring systems (CEMs) are being implemented in over 800 coal-fired power plant stacks throughput the U.S. Western Research Institute (WRI) is working closely with the Electric Power Research Institute (EPRI), the National Institute of Standards and Technology (NIST), and the Environmental Protection Agency (EPA) to facilitate the development of the experimental criteria for a NIST traceability protocol for dynamic elemental mercury vapor calibrators/generators. These devices are used to calibrate mercury CEMs at power plant sites. The Clean Air Mercury Rule (CAMR) which was published in the Federal Register on May 18, 2005 and vacated by a Federal appeals court in early 2008 required that calibration be performed with NIST-traceable standards. Despite the vacature, mercury emissions regulations in the future will require NIST traceable calibration standards, and EPA does not want to interrupt the effort towards developing NIST traceability protocols. The traceability procedures will be defined by EPA. An initial draft traceability protocol was issued by EPA in May 2007 for comment. In August 2007, EPA issued a conceptual interim traceability protocol for elemental mercury calibrators. The protocol is based on the actual analysis of the output of each calibration unit at several concentration levels ranging initially from about 2-40 {micro}g/m{sup 3} elemental mercury, and in the future down to 0.2 {micro}g/m{sup 3}, and this analysis will be directly traceable to analyses by NIST. The EPA traceability protocol document is divided into two separate sections. The first deals with the qualification of calibrator models by the vendors for use in mercury CEM calibration. The second describes the procedure that the vendors must use to certify the calibrators that meet the qualification specifications. The NIST traceable certification is performance based, traceable to analysis using isotope dilution inductively coupled plasma/mass spectrometry (ID/ICP/MS) performed by NIST in Gaithersburg, MD. The outputs of mercury calibrators are compared to one another using a nesting procedure which allows direct comparison of one calibrator with another at specific concentrations and eliminates analyzer variability effects. The qualification portion of the EPA interim traceability protocol requires the vendors to define calibrator performance as affected by variables such as pressure, temperature, line voltage, and shipping. In 2007 WRI developed and conducted a series of simplified qualification experiments to determine actual calibrator performance related to the variables defined in the qualification portion of the interim protocol.

  15. Anthropogenic mercury emissions in China

    NASA Astrophysics Data System (ADS)

    Streets, David G.; Hao, Jiming; Wu, Ye; Jiang, Jingkun; Chan, Melissa; Tian, Hezhong; Feng, Xinbin

    An inventory of mercury emissions from anthropogenic activities in China is compiled for the year 1999 from official statistical data. We estimate that China's emissions were 536 (±236) t of total mercury. This value includes open biomass burning, but does not include natural sources or re-emission of previously deposited mercury. Approximately 45% of the Hg comes from non-ferrous metals smelting, 38% from coal combustion, and 17% from miscellaneous activities, of which battery and fluorescent lamp production and cement production are the largest. Emissions are heaviest in Liaoning and Guangdong Provinces, where extensive smelting occurs, and in Guizhou Province, where there is much small-scale combustion of high-Hg coal without emission control devices. Emissions are gridded at 30×30 min spatial resolution. We estimate that 56% of the Hg in China is released as Hg 0, 32% as Hg 2+, and 12% as Hg p. Particulate mercury emissions are high in China due to heavy burning of coal in residential and small industrial settings without PM controls. Emissions of Hg 2+ from coal-fired power plants are high due to the absence of flue-gas desulfurization units, which tend to dissolve the soluble divalent mercury. Metals smelting operations favor the production of elemental mercury. Much of the Hg is released from small-scale activities in rather remote areas, and therefore the activity levels are quite uncertain. Also, emissions test data for Chinese sources are lacking, causing uncertainties in Hg emission factors and removal efficiencies. Overall, we calculate an uncertainty level of ±44% (95% confidence interval) in the estimate of total emissions. We recommend field testing of coal combustors and smelters in China to improve the accuracy of these estimates.

  16. Mercury exposures and symptoms in smelting workers of artisanal mercury mines in Wuchuan, Guizhou, China.

    PubMed

    Li, Ping; Feng, Xinbin; Qiu, Guangle; Li, Zhonggen; Fu, Xuewu; Sakamoto, Minishi; Liu, Xiaojie; Wang, Dingyong

    2008-05-01

    Mercury exposures to smelting workers of artisanal mercury mines in Wuchuan, Guizhou, China were evaluated by urine and hair mercury survey. The mean urinary mercury (U-Hg), hair total mercury (T-Hg), and hair methyl mercury (Me-Hg) for smelting workers was 1060 microg/g creatinine (microg/g Cr), 69.3 and 2.32 microg/g, respectively. The results were significantly higher than that of control group, which is 1.30 microg/g Cr, 0.78 and 0.65 microg/g, correspondingly. The average urinary beta2-microglobulin (beta2-MG) was 248 microg/g Cr for the exposed group contrasting to 73.5 microg/g Cr for the control group and the data showed a serious adverse effect on renal system for the smelting workers. The workers were exposed to mercury vapor through inhalation, and the exposure route of Me-Hg may be through intake of polluted diet. The results indicate that age, alcohol drinking, and smoking are not crucial factors controlling the urine and hair mercury levels for the exposed and the control group. Clinical symptoms including finger and eyelid tremor, gingivitis, and typical dark-line on gums were observed in six workers. This study indicated that the smelting workers in Wuchuan were seriously exposed to mercury vapor. PMID:17897640

  17. Mercury nano-trap for effective and efficient removal of mercury(II) from aqueous solution

    NASA Astrophysics Data System (ADS)

    Li, Baiyan; Zhang, Yiming; Ma, Dingxuan; Shi, Zhan; Ma, Shengqian

    2014-11-01

    Highly effective and highly efficient decontamination of mercury from aqueous media remains a serious task for public health and ecosystem protection. Here we report that this task can be addressed by creating a mercury ‘nano-trap’ as illustrated by functionalizing a high surface area and robust porous organic polymer with a high density of strong mercury chelating groups. The resultant porous organic polymer-based mercury ‘nano-trap’ exhibits a record-high saturation mercury uptake capacity of over 1,000?mg?g?1, and can effectively reduce the mercury(II) concentration from 10?p.p.m. to the extremely low level of smaller than 0.4?p.p.b. well below the acceptable limits in drinking water standards (2?p.p.b.), and can also efficiently remove >99.9% mercury(II) within a few minutes. Our work therefore presents a new benchmark for mercury adsorbent materials and provides a new perspective for removing mercury(II) and also other heavy metal ions from contaminated water for environmental remediation.

  18. Mercury nano-trap for effective and efficient removal of mercury(II) from aqueous solution.

    PubMed

    Li, Baiyan; Zhang, Yiming; Ma, Dingxuan; Shi, Zhan; Ma, Shengqian

    2014-01-01

    Highly effective and highly efficient decontamination of mercury from aqueous media remains a serious task for public health and ecosystem protection. Here we report that this task can be addressed by creating a mercury 'nano-trap' as illustrated by functionalizing a high surface area and robust porous organic polymer with a high density of strong mercury chelating groups. The resultant porous organic polymer-based mercury 'nano-trap' exhibits a record-high saturation mercury uptake capacity of over 1,000?mg?g(-1), and can effectively reduce the mercury(II) concentration from 10?p.p.m. to the extremely low level of smaller than 0.4?p.p.b. well below the acceptable limits in drinking water standards (2?p.p.b.), and can also efficiently remove >99.9% mercury(II) within a few minutes. Our work therefore presents a new benchmark for mercury adsorbent materials and provides a new perspective for removing mercury(II) and also other heavy metal ions from contaminated water for environmental remediation. PMID:25410491

  19. Mercury in Fish-eating Communities of the Andean Amazon, Napo River Valley, Ecuador

    Microsoft Academic Search

    Jena Webb; Nicolas Mainville; Donna Mergler; Marc Lucotte; Oscar Betancourt; Robert Davidson; Edwin Cueva; Edy Quizhpe

    2004-01-01

    This exploratory study aimed to examine the relationship between fish eating habits, human mercury levels, and mercury levels in fish in three communities of the Napo River Valley, Ecuadorian Andean Amazon, a region without gold mining but with significant deforestation and volcanic soils with naturally high mercury levels. By recognizing the politicoeconomic factors which cause deforestation, the cultural factors which

  20. Wet and Dry Atmospheric Mercury Deposition Accumulates in Watersheds of the Northeastern United States

    NASA Astrophysics Data System (ADS)

    Boyer, E. W.; Grant, C.; Grimm, J.; Drohan, P. J.; Bennett, J.; Lawler, D.

    2013-12-01

    Mercury emissions to the atmosphere from coal-fired power plants and other sources such as waste incineration can be deposited to landscapes in precipitation and in dry fallout. Some mercury reaches watersheds and streams, where it can accumulate in sediments and biota. Human exposure to mercury occurs primarily through fish consumption, and currently mercury fish eating advisories are in place for many of the streams and lakes in the state. Here, we explored mercury in air, soils, water, and biota. To quantify atmospheric mercury deposition, we measured both wet and dry mercury deposition at over 10 locations in Pennsylvania, from which we present variation in mercury deposition and initial assessments of factors affecting the patterns. Further, we simulated mercury deposition at unmonitored locations in Pennsylvania and the northeastern United States over space and time with a high-resolution modeling technique that reflects storm tracks and air flow patterns. To consider mercury accumulation in watersheds, we collected data on soil mercury concentrations in a set of soil samples, and collected baseline data on mercury in streams draining 35 forested watersheds across Pennsylvania, spanning gradients of atmospheric deposition, climate and geology. Mercury concentrations were measured in stream water under base-flow conditions, in streambed sediments, aquatic mosses, and in fish tissues from brook trout. Results indicate that wet and dry atmospheric deposition is a primary source of mercury that is accumulating in watersheds of Pennsylvania and the northeastern United States.

  1. Selenium supplementation modulates zinc levels and antioxidant values in blood and tissues of diabetic rats fed zinc-deficient diet.

    PubMed

    Fatmi, Wided; Kechrid, Zine; Naz?ro?lu, Mustafa; Flores-Arce, Manuel

    2013-05-01

    Diabetes mellitus is associated to a reduction of antioxidant defenses that leads to oxidative stress and complications in diabetic individuals. The present study was undertaken to investigate the effect of selenium on blood biochemical parameters, antioxidant enzyme activities, and tissue zinc levels in alloxan-induced diabetic rats fed a zinc-deficient diet. The rats were divided into two groups; the first group was fed a zinc-sufficient diet, while the second group was fed a zinc-deficient diet. Half of each group was treated orally with 0.5 mg/kg sodium selenite. Tissue and blood samples were taken from all animals after 28 days of treatment. At the end of the experiment, the body weight gain and food intake of the zinc-deficient diabetic animals were lower than that of zinc-adequate diabetic animals. Inadequate dietary zinc intake increased glucose, lipids, triglycerides, urea, and liver lipid peroxidation levels. In contrast, serum protein, reduced glutathione, plasma zinc and tissue levels were decreased. A zinc-deficient diet led also to an increase in serum glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, and liver glutathione-S-transferase and to a decrease in serum alkaline phosphatase activity and glutathione peroxidase. Selenium treatment ameliorated all the values approximately to their normal levels. In conclusion, selenium supplementation presumably acting as an antioxidant led to an improvement of insulin activity, significantly reducing the severity of zinc deficiency in diabetes. PMID:23354544

  2. Chlorinated pesticides levels in human adipose tissue in the district of Pozna?

    Microsoft Academic Search

    G. A. Szymczy?ski; S. M. Waliszewski; M. Tuszewski; P. Pyda

    1986-01-01

    Samples of adipose tissue from the abdominal cavity were taken at random at surgeries on abdominal cavity \\/24 samples\\/ and at necropsy of the deceased \\/29 samples\\/ in the early nineteen eighties. The samples were then analyzed for the presence of chlorinated pesticides by means of gas chromatography with electron capture detection. All the analyzed samples contained beta?BHC, Lindane, HCB,

  3. Vanadium retention in rat tissues following acute exposures to different dose levels

    Microsoft Academic Search

    R. P. Sharma; S. G. Oberg; R. D. R. Parker

    1980-01-01

    Male Wistar rats were given vanadyl trichloride ( VOCl3) ip in doses of V ranging from 0.1 to 8 mg\\/kg and their tissues were collected 1 and 5 d after the injection. V was distributed in the order bone > kidney > liver > spleen > intestines > stomach > muscle > testis > lung > brain. Residues of V

  4. Measurement of tissue cortisol levels in patients with severe burns: a preliminary investigation

    Microsoft Academic Search

    Jeremy Cohen; Renae Deans; Andrew Dalley; Jeff Lipman; Michael S Roberts; Bala Venkatesh

    2009-01-01

    INTRODUCTION: The assessment of adrenal function in critically ill patients is problematic, and there is evidence to suggest that measurement of tissue glucocorticoid activity may be more useful than estimation of plasma cortisol concentrations. Interstitial cortisol concentrations of cortisol represent the available pool of glucocorticoids able to enter the cell and bind to the glucocorticoid receptor. However the concentrations of

  5. Tocotrienol levels in adipose tissue of benign and malignant breast lumps in patients in Malaysia

    Microsoft Academic Search

    Kalanithi Nesaretnam; Patricia Alison Gomez; Kanga Rani

    Data on dietary exposure to vitamin E by plasma or adipose tissue concentrations of ?-tocopherol (?-T) in ob- servational studies have failed to provide consistent support for the idea that ?-T provides women with any pro- tection from breast cancer. In contrast, studies indicate that ?, ?, and ?-tocotrienols but not ?-T have potent anti- proliferative effects in human breast

  6. Mercury Sources to Lake Ozette and Lake Dickey: Highly Contaminated Remote Coastal Lakes, Washington State, USA

    Microsoft Academic Search

    Chad Van Furl; John A. Colman; Michael H. Bothner

    2010-01-01

    Mercury concentrations in largemouth bass and mercury accumulation rates in age-dated sediment cores were examined at Lake\\u000a Ozette and Lake Dickey in Washington State. Goals of the study were to compare concentrations in fish tissues at the two lakes\\u000a with a larger statewide dataset and examine mercury pathways to the lakes. After accounting for fish length, tissue concentrations\\u000a at the

  7. Mercury bioaccumulation in Hayward Marsh, California

    SciTech Connect

    Ohlendorf, H.; Byron, E. [CH2M Hill, Sacramento, CA (United States); Taylor, L.; Cortes, R. [Union Sanitary District, Fremont, CA (United States)

    1995-12-31

    Hayward Marsh was created in 1988 to provide wildlife habitat using treated wastewater from Union Sanitary District, which is located in the San Francisco Bay area. Mercury has been identified as one of the major contaminants of concern for San Francisco Bay sediment and biota. This study was conducted to determine whether mercury bioaccumulation in the Marsh occurred at ecologically significant levels. Sediment, benthic and free-swimming aquatic invertebrates, fish, bird eggs, and muskrat livers were analyzed. Mercury concentrations in the various media were compared to regional background levels and potential adverse effect levels. The findings indicated that mercury concentrations were generally similar to background levels and that there was a low probability of adverse effects to wildlife feeding in the Marsh. An important aspect of the study was inclusion of three bird species, along with their potential food organisms, in the sampling, one of the species had elevated mercury levels in its eggs but those birds probably were exposed outside the Marsh because the two other species and common food-chain organisms did not show elevated mercury levels.

  8. Mercury: Where You Live

    MedlinePLUS

    ... for... Businesses Consumers Health Care Providers Parents Schools Mercury can be found most anywhere. On this page, you will find resources about mercury where you live - your home and community, your ...

  9. Correlation between the serum and tissue levels of oxidative stress markers and the extent of inflammation in acute appendicitis

    PubMed Central

    Dumlu, Ersin Gürkan; Tokaç, Mehmet; Bozkurt, Birkan; Yildirim, Murat Baki; Ergin, Merve; Yalçin, Abdussamed; Kiliç, Mehmet

    2014-01-01

    OBJECTIVES: To determine the serum and tissue levels of markers of impaired oxidative metabolism and correlate these levels with the histopathology and Alvarado score of acute appendicitis patients. METHOD: Sixty-five acute appendicitis patients (mean age, 31.4±12.06 years; male/female, 30/35) and 30 healthy control subjects were studied. The Alvarado score was recorded. Serum samples were obtained before surgery and 12 hours postoperatively to examine the total antioxidant status, total oxidant status, paraoxonase, stimulated paraoxonase, arylesterase, catalase, myeloperoxidase, ceruloplasmin, oxidative stress markers (advanced oxidized protein products and total thiol level) and ischemia-modified albumin. Surgical specimens were also evaluated. RESULTS: The diagnoses were acute appendicitis (n?=?37), perforated appendicitis (n?=?8), phlegmonous appendicitis (n?=?12), perforated+phlegmonous appendicitis (n?=?4), or no appendicitis (n?=?4). The Alvarado score of the acute appendicitis group was significantly lower than that of the perforated+phlegmonous appendicitis group (p?=?0.004). The serum total antioxidant status, total thiol level, advanced oxidized protein products, total oxidant status, catalase, arylesterase, and ischemia-modified albumin levels were significantly different between the acute appendicitis and control groups. There was no correlation between the pathological extent of acute appendicitis and the tissue levels of the markers; additionally, there was no correlation between the tissue and serum levels of any of the parameters. CONCLUSIONS: The imbalance of oxidant/antioxidant systems plays a role in the pathogenesis acute appendicitis. The Alvarado score can successfully predict the presence and extent of acute appendicitis. PMID:25518019

  10. MERCURY CONCENTRATIONS IN SKELETAL MUSCLE OF FISH FROM LAKE MEAD, USA, RELATED TO FISH SIZE, CONDITION, TROPHIC LEVEL, LOCATION, AND CONSUMPTION RISK

    EPA Science Inventory

    In this first large-scale study of mercury (Hg) in Lake Mead, USA, the nation's largest man- made reservoir, total-Hg concentrations were determined in the skeletal muscle of 339 fish collected during the Fall of 1998 and the Spring of 1999. Five species of fish representing ...

  11. Mercury in Nelson's Sparrow Subspecies at Breeding Sites

    PubMed Central

    Winder, Virginia L.; Emslie, Steven D.

    2012-01-01

    Background Mercury is a persistent, biomagnifying contaminant that can cause negative effects on ecosystems. Marshes are often areas of relatively high mercury methylation and bioaccumulation. Nelson's Sparrows (Ammodramus nelsoni) use marsh habitats year-round and have been documented to exhibit tissue mercury concentrations that exceed negative effects thresholds. We sought to further characterize the potential risk of Nelson's Sparrows to mercury exposure by sampling individuals from sites within the range of each of its subspecies. Methodology/Principal Findings From 2009 to 2011, we captured adult Nelson's Sparrows at sites within the breeding range of each subspecies (A. n. nelsoni: Grand Forks and Upham, North Dakota; A. n. alterus: Moosonee, Ontario; and A. n. subvirgatus: Grand Manan Island, New Brunswick) and sampled breast feathers, the first primary feather (P1), and blood for total mercury analysis. Mean blood mercury in nelsoni individuals captured near Grand Forks ranged from 0.84±0.37 to 1.65±1.02 SD ppm among years, between 2.0 and 4.9 times as high as concentrations at the other sites (P<0.01). Breast feather mercury did not vary among sites within a given sampling year (site means ranged from 0.98±0.69 to 2.71±2.93 ppm). Mean P1 mercury in alterus (2.96±1.84 ppm fw) was significantly lower than in any other sampled population (5.25±2.24–6.77±3.51 ppm; P?0.03). Conclusions/Significance Our study further characterized mercury in Nelson's Sparrows near Grand Forks; we documented localized and potentially harmful mercury concentrations, indicating that this area may represent a biological mercury hotspot. This finding warrants further research to determine if wildlife populations of conservation or recreational interest in this area may be experiencing negative effects due to mercury exposure. We present preliminary conclusions about the risk of each sampled population to mercury exposure. PMID:22384194

  12. Bepi-Colombo Mission to Mercury

    NASA Astrophysics Data System (ADS)

    Hayakawa, Hajime; Maejima, Hironori

    2012-07-01

    BepiColombo has been defined as the ESA-JAXA joint mission to Mercury with the aim to understand the process of planetary formation and evolution in the hottest part of the proto-planetary nebula as well as to understand similarities and differences between the magnetospheres of the Mercury and the Earth. The baseline mission consists of two spacecraft: the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (MMO). The two orbiters will be launched together on one Ariane5. JAXA is responsible for development and operation of MMO while ESA is responsible for development and operation of MPO and Mercury Transfer Module (MTM), launch, cruise phase operation, and Mercury orbit insertion. The main objectives of MPO are to study planet Mercury and planetary formation in the inner solar system. For this purpose, MPO is desgined as a 3-axis stabilized spacecraft and will be placed in a 400 km x 1500 km polar orbit. While the main objectives of MMO are to study Mercury's magnetic field and plasma environment around Mercury. For this purpose, MMO is designed as a spin-stabilized spacecraft and will be placed in a same orbital plane as MPO but has a 400 km x 12000 km. The orbital period of MMO and MPO is designed as 4:1 to achieve cross calibration and cooperative observations. System Critical Design Review (CDR) of MMO has been completed in November 2011 and System CDR for whole BepiColombo mission is scheduled in July 2012. Electrical Interface Check (EIC)/ Mechanical Interface Check (MIC) of MMO FM has been completed in January 2012. MMO Mechanical Test Model is transported to ESA/ESTEC to join Mercury Cruise System (MCS) level Mechianical Test which will be held in this year.

  13. Tissue-specific cadmium accumulation and metallothionein-like protein levels during acclimation process in the Chinese crab Eriocheir sinensis

    Microsoft Academic Search

    F. Silvestre; C. Duchêne; G. Trausch; P. Devos

    2005-01-01

    Aquatic organisms chronically exposed to cadmium can increase their resistance to a subsequent elevated exposure. In order to investigate mechanisms involved in acclimation process in the Chinese crab Eriocheir sinensis, we compared Cd level as well as metallothionein-like protein (MTLP) content in different tissues after direct acute exposure (i.e. 500 ?g Cd L?1 for 3 days), and after acute following

  14. Effect of Dietary Copper and Fat on Nutrient Utilization, Digestive Enzyme Activities, and Tissue Mineral Levels in Weanling Pigs1

    Microsoft Academic Search

    X. G. Luo; C. R. Dove

    2010-01-01

    Two 15-d nutrient balance trials were conducted using a total of 32 weanling barrows (averaging 6.8 kg, 26 d). The effect of the addition of 15 or 250 ppm Cu (as CuSO4·5H2O ) to diets containing 0 or 5% added animal fat on nutrient utilization, digestive enzyme activities, and tissue mineral levels in weanling pigs was investigated. In each trial,

  15. Toxicity of oxidized fats II: tissue levels of lipid peroxides in rats fed a thermally oxidized corn oil diet

    Microsoft Academic Search

    B. C Nwanguma; A. C Achebe; L. C Eze

    1999-01-01

    Male Wistar albino rats were fed for 21 days on a diet in which fat (12%) was included either as fresh corn oil, malonaldehyde content=0.11±0.05?g\\/g (control) or thermally oxidized corn oil, malonaldehyde content=0.20±0.03?g\\/g (experimental) and the tissue levels of lipid peroxides in six organs—namely, liver, kidney, brain, heart, lungs and testes—were determined. Of the organs studied, significantly (P<0.1) higher concentrations

  16. The mechanism of the angiotensin-converting enzyme inhibitor quinapril is not related to bradykinin level in heart tissue

    Microsoft Academic Search

    Christiane Barthelemy; Joelle Eurin; Philippe Lechat; Francoise Masson; Micheline Cortines; Nathalie Mougenot; Hayet Soualmia; Alain Carayon

    2002-01-01

    In order to examine the effect of the angiotensin-converting enzyme inhibitor (ACEi) quinapril, we performed a sensitive and specific radioimmunoassay (RIA) to quantify bradykinin, BK-(1–9), in heart and kidney tissues. The BK-(1–9) level was unaffected in the heart of sham and water-deprived rats treated for 2h with quinapril (10mg\\/kg), but was significantly higher in the kidneys in the two groups.

  17. A sensitive method for determining levels of [?]-2,5,-dimethoxy-4-methylamphetamine in the brain tissue

    Microsoft Academic Search

    J. R Eckler; H Greizerstein; R. A Rabin; J. C Winter

    2001-01-01

    Introduction: Indolamine and phenethylamine hallucinogens are drugs of abuse and, as well, mimic some aspects of idiopathic psychosis. To assist in investigating the mechanisms of action of (?)2,5-dimethoxy-4-methylamphetamine ([?]-DOM), a member of the phenethylamine class of serotonergic hallucinogens, a sensitive and precise method for determining its levels in the brain tissue is required. Methods: We now describe a method for

  18. Dental amalgam and mercury

    SciTech Connect

    Mackert, J.R. Jr. (Department of Restorative Dentistry, School of Dentistry, Medical College of Georgia, Augusta (United States))

    1991-08-01

    This paper looks at the issues of the current amalgam controversy: the daily dose of mercury from amalgam, hypersensitivity to mercury, claims of adverse effects from amalgam mercury and alleged overnight 'cures.' In addition, the toxicity and allergenicity of the proposed alternative materials are examined with the same kind of scrutiny applied by the anti-amalgam group to dental amalgam. 100 references.

  19. MERCURY SPECIATION AND CAPTURE

    EPA Science Inventory

    The speciation of mercury has a major impact on its removal in air pollution control equipment. The oxidized forms of mercury, mercuric chloride (HgCl2) in particular, is highly water-soluble and is easier to capture in wet FGD systems than elemental mercury (Hg0), which is not w...

  20. Mercury's sodium exosphere

    Microsoft Academic Search

    F. Leblanc; R. E. Johnson

    2003-01-01

    Mercury's neutral sodium exosphere is simulated using a comprehensive 3D Monte Carlo model following sodium atoms ejected from Mercury's surface by thermal desorption, photon stimulated desorption, micro-meteoroid vaporization and solar wind sputtering. The evolution of the sodium surface density with respect to Mercury's rotation and its motion around the Sun is taken into account by considering enrichment processes due to