Sample records for tissue mercury levels

  1. Mercury levels in tissues of Giant otters (Pteronura brasiliensis) from the Rio Negro, Pantanal, Brazil.

    PubMed

    Dias Fonseca, Fabrizio Rafael; Malm, Olaf; Francine Waldemarin, Helen

    2005-07-01

    This research reports the first data on mercury levels found in Giant otters (Pteronura brasiliensis) from South America. Mercury concentrations were analyzed from different organs/tissues of two animals found dead floating on the water of the Rio Negro in the Pantanal, Brazil. The mean mercury concentration ranged from 2.94 to 3.68 microg/g in hair, from 1.52 to 4.3 microg/g in liver, and from 1.11 to 4.59 microg/g in kidney and was 0.17 microg/g in muscle samples. In comparison with other research, there is no evidence of contamination in these animals and mercury concentrations in tissues appeared to be at levels below those associated with toxicity. PMID:15910792

  2. Mercury and selenium levels, and selenium:mercury molar ratios of brain, muscle and other tissues in bluefish (Pomatomus saltatrix) from New Jersey, USA

    PubMed Central

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

    2015-01-01

    A number of contaminants affect fish health, including mercury and selenium, and the selenium: mercury molar ratio. Recently the protective effects of selenium on methylmercury toxicity have been publicized, particularly for consumption of saltwater fish. Yet the relative ameliorating effects of selenium on toxicity within fish have not been examined, nor has the molar ratio in different tissues, (i.e. brain). We examined mercury and selenium levels in brain, kidney, liver, red and white muscle, and skin and scales in bluefish (Pomatomus saltatrix) from New Jersey to determine whether there were toxic levels of either metal, and we computed the selenium: mercury molar ratios by tissues. Total mercury averaged 0.32 ± 0.02 ppm wet weight in edible muscle and 0.09 ± 0.01 ppm in brain. Selenium concentration averaged 0.37 ± 0.03 in muscle and 0.36 ± 0.03 ppm in brain. There were significant differences in levels of mercury, selenium, and selenium: mercury molar ratios, among tissues. Mercury and selenium levels were correlated in kidney and skin/scales. Mercury levels were highest in kidney, intermediate in muscle and liver, and lowest in brain and skin/scales; selenium levels were also highest in kidney, intermediate in liver, and were an order of magnitude lower in the white muscle and brain. Mercury levels in muscle, kidney and skin/scales were positively correlated with fish size (length). Selenium levels in muscle, kidney and liver were positively correlated with fish length, but in brain; selenium levels were negatively correlated with fish length. The selenium: mercury molar ratio was negatively correlated with fish length for white muscle, liver, kidney, and brain, particularly for fish over 50 cm in length, suggesting that older fish experience less protective advantages of selenium against mercury toxicity than smaller fish, and that consumers of bluefish similarly receive less advantage from eating larger fish. PMID:23202378

  3. 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

  4. 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

  5. Wild Boar Tissue Levels of Cadmium, Lead and Mercury in Seven Regions of Continental Croatia

    PubMed Central

    Sedak, Marija; ?oki?, Maja; Šimi?, Branimir

    2010-01-01

    Concentrations of cadmium, mercury and lead were analysed by atomic absorption spectrometry in the kidney and muscle of free-living wild boar (n = 169) from hunting grounds in seven counties of continental Croatia. Mean levels of metals (mg/kg) in muscle and kidney of boars ranged as follows: Cd: 0.005–0.016 and 0.866–4.58, Pb: 0.033–0.15 and 0.036–0.441, Hg: 0.004–0.012 and 0.04–0.152. In all seven regions, concentrations exceeded the permitted values (muscle and kidney mg/kg: cadmium 0.05/1; lead 0.1/0.5; mercury 0.03/0.1) in 13.6% and 71.6% of samples (muscle and kidney, respectively) for cadmium; 13.6% and 8.9% for lead; 19.5% and 2.4% for mercury. There were significant differences among the regions. Vukovar-Srijem and Virovitica-Podravina Counties were highly contaminated with cadmium, Sisak-Moslavina and Virovitica-Podravina Counties with lead and Brod-Posavina County had highest mercury concentrations. These results suggest a detailed investigation of physiological and environmental factors contributing to accumulation of metals in boars. PMID:20405101

  6. Comparison of mercury levels in various tissues of albino and pigmented mice treated with two different brands of mercury skin-lightening creams

    Microsoft Academic Search

    Iman Al-Saleh; Neptune Shinwari; Inaam El-Doush; Grisellhi Billedo; Mona Al-Amodi; Fathia Khogali

    2004-01-01

    The use of mercury containing skin-lightening creams are becoming increasingly popular among dark-skinned women. The long term use of certain brands may cause serious health effects over the years. In the present study, we investigated the dermal absorption of mercury and its accumulation in the tissues of albino and pigmented mice treated with two brands of mercury containing skin-lightening creams

  7. Lead, mercury, cadmium, chromium, and arsenic levels in eggs, feathers, and tissues of Canada geese of the New Jersey Meadowlands

    SciTech Connect

    Tsipoura, Nellie [New Jersey Audubon Society, 11 Hardscrabble Road, Bernardsville, NJ 07924 (United States)] [New Jersey Audubon Society, 11 Hardscrabble Road, Bernardsville, NJ 07924 (United States); Burger, Joanna, E-mail: burger@biology.rutgers.edu [Division of Life Sciences, 604 Allison Road, Piscataway, NJ 08854-8082 (United States) [Division of Life Sciences, 604 Allison Road, Piscataway, NJ 08854-8082 (United States); Environmental and Occupational Health Sciences Institute, Consortium for Risk Evaluation with Stakeholder Participation, Rutgers University, Piscataway, NJ 08854 (United States); Newhouse, Michael [NJ Meadowlands Commission, One DeKorte Park Plaza, Lyndhurst, NJ 07071 (United States)] [NJ Meadowlands Commission, One DeKorte Park Plaza, Lyndhurst, NJ 07071 (United States); Jeitner, Christian [Division of Life Sciences, 604 Allison Road, Piscataway, NJ 08854-8082 (United States) [Division of Life Sciences, 604 Allison Road, Piscataway, NJ 08854-8082 (United States); Environmental and Occupational Health Sciences Institute, Consortium for Risk Evaluation with Stakeholder Participation, Rutgers University, Piscataway, NJ 08854 (United States); Gochfeld, Michael [Environmental and Occupational Health Sciences Institute, Consortium for Risk Evaluation with Stakeholder Participation, Rutgers University, Piscataway, NJ 08854 (United States) [Environmental and Occupational Health Sciences Institute, Consortium for Risk Evaluation with Stakeholder Participation, Rutgers University, Piscataway, NJ 08854 (United States); Environmental and Occupational Medicine. Robert Wood Johnson Medical School, 170 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Mizrahi, David [New Jersey Audubon Society, 11 Hardscrabble Road, Bernardsville, NJ 07924 (United States)] [New Jersey Audubon Society, 11 Hardscrabble Road, Bernardsville, NJ 07924 (United States)

    2011-08-15

    The New Jersey Meadowlands are located within the heavily urbanized New York/New Jersey Harbor Estuary and have been subject to contamination due to effluent and runoff from industry, traffic, and homes along the Hackensack River and nearby waterways. These extensive wetlands, though heavily impacted by development and pollution, support a wide array of bird and other wildlife species. Persistent contaminants may pose threats to birds in these habitats, affecting reproduction, egg hatchability, nestling survival, and neurobehavioral development. Metals of concern in the Meadowlands include arsenic, cadmium, chromium, lead, and mercury. These metals were analyzed in eggs, feathers, muscle, and liver of Canada geese (Branta canadensis) breeding in four wetland sites. We sampled geese collected during control culling (n=26) and collected eggs from goose nests (n=34). Levels of arsenic were below the minimum quantification level (MQL) in most samples, and cadmium and mercury were low in all tissues sampled. Chromium levels were high in feather samples. Mercury levels in eggs of Canada geese, an almost exclusively herbivorous species, were lower (mean {+-}SE 4.29{+-}0.30 {mu}g/g wet weight) than in eggs of omnivorous mallards (Anas platyrhynchos), and insectivorous red-winged blackbirds (Agelaius phoeniceus) and marsh wrens (Cistothorus palustris) from the Meadowlands, consistent with trophic level differences. However, lead levels were higher in the goose eggs (161{+-}36.7 ng/g) than in the other species. Geese also had higher levels of lead in feathers (1910{+-}386 ng/g) than those seen in Meadowlands passerines. By contrast, muscle and liver lead levels were within the range reported in waterfowl elsewhere, possibly a reflection of metal sequestration in eggs and feathers. Elevated lead levels may be the result of sediment ingestion or ingestion of lead shot and sinkers. Finally, lead levels in goose liver (249{+-}44.7 ng/g) and eggs (161{+-}36.7 ng/g) may pose a risk if consumed frequently by humans. Mill Creek, the site with the most documented prior contamination, had significantly elevated cadmium, chromium, mercury, and lead in goose tissues. - Highlights: {yields} The NJ Meadowlands include extensive wetlands in the urban NYC metropolitan area. {yields} We analyzed eggs, feathers, muscle, and liver of Canada geese at 4 Meadowlands sites. {yields} As, Cd, and Hg were low in all tissues sampled, while Cr was high in feathers. {yields} Pb was higher in goose eggs and feathers than in other Meadowlands bird species. {yields} Pb in muscle and liver was lower and within the range seen in waterfowl elsewhere.

  8. Lead, mercury, cadmium, chromium, and arsenic levels in eggs, feathers, and tissues of Canada geese of the New Jersey Meadowlands.

    PubMed

    Tsipoura, Nellie; Burger, Joanna; Newhouse, Michael; Jeitner, Christian; Gochfeld, Michael; Mizrahi, David

    2011-08-01

    The New Jersey Meadowlands are located within the heavily urbanized New York/New Jersey Harbor Estuary and have been subject to contamination due to effluent and runoff from industry, traffic, and homes along the Hackensack River and nearby waterways. These extensive wetlands, though heavily impacted by development and pollution, support a wide array of bird and other wildlife species. Persistent contaminants may pose threats to birds in these habitats, affecting reproduction, egg hatchability, nestling survival, and neurobehavioral development. Metals of concern in the Meadowlands include arsenic, cadmium, chromium, lead, and mercury. These metals were analyzed in eggs, feathers, muscle, and liver of Canada geese (Branta canadensis) breeding in four wetland sites. We sampled geese collected during control culling (n=26) and collected eggs from goose nests (n=34). Levels of arsenic were below the minimum quantification level (MQL) in most samples, and cadmium and mercury were low in all tissues sampled. Chromium levels were high in feather samples. Mercury levels in eggs of Canada geese, an almost exclusively herbivorous species, were lower (mean ±SE 4.29±0.30?g/g wet weight) than in eggs of omnivorous mallards (Anas platyrhynchos), and insectivorous red-winged blackbirds (Agelaius phoeniceus) and marsh wrens (Cistothorus palustris) from the Meadowlands, consistent with trophic level differences. However, lead levels were higher in the goose eggs (161±36.7ng/g) than in the other species. Geese also had higher levels of lead in feathers (1910±386ng/g) than those seen in Meadowlands passerines. By contrast, muscle and liver lead levels were within the range reported in waterfowl elsewhere, possibly a reflection of metal sequestration in eggs and feathers. Elevated lead levels may be the result of sediment ingestion or ingestion of lead shot and sinkers. Finally, lead levels in goose liver (249±44.7ng/g) and eggs (161±36.7ng/g) may pose a risk if consumed frequently by humans. Mill Creek, the site with the most documented prior contamination, had significantly elevated cadmium, chromium, mercury, and lead in goose tissues. PMID:21679937

  9. Immunoassay for mercury in seafood and animal tissues

    SciTech Connect

    Carlson, L.; Holmquist, B.; Ladd, R.; Riddell, M. [BioNebraska, Inc., Lincoln, NE (United States)

    1995-12-01

    Methylmercury accumulates to high levels in the tissues of fish and other animals through biomagnification. Since methylmercury is extremely toxic, it is important to identify fish or animal tissues with mercury levels too high for human consumption. Current methods for the analysis of mercury are expensive and time- consuming, and they must be performed in a laboratory setting. In this study, a rapid and inexpensive mercury-specific immunoassay developed by BioNebraska was used to measure total mercury in tissue following acid digestion and methylmercury decomposition. A good correlation was obtained between the immunoassay and cold vapor atomic absorption spectrophotometry (CVAAS). Use of the mercury immunoassay will facilitate the rapid screening of large numbers of tissue samples.

  10. Effect of selenium on determination of mercury in animal tissues

    Microsoft Academic Search

    A. Naganuma; H. Satoh; R. Yamamoto; T. Suzuki; N. Imura

    1979-01-01

    Selenium in animal tissues was found to influence the reactivity of mercury in the tissues with stannous chloride or with stannous chloride plus cadmium chloride added as reducing agents for the determination of mercury by the method developed by L. Magos and L. Magos and T.W. Clarkson. The recovery of mercury in the tissues of animals to which inorganic mercury

  11. An evaluation of mercury levels in Louisiana fish: Trends and public health issues

    Microsoft Academic Search

    Adrienne Katner; Mei-Hung Sun; Mel Suffet

    2010-01-01

    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

  12. 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

  13. Mercury residues in tissues of dead and surviving birds fed methylmercury

    USGS Publications Warehouse

    Finley, M.T.; Stickel, W.H.; Christensen, R.E.

    1979-01-01

    Concentrations of mercury in passerine birds fed diets containing 40 ppm methylmercury were similar in tissues of birds that died from mercury poisoning and in those that were sacrificed after half the group had died. Residues were higher in tissues of birds that died, but the differences were not statistically significant. Residue levels were highest in livers, followed by kidneys and brains. Levels of mercury were similar in breast muscle, carcass, and whole body. Mercury levels were highest in redwinged blackbirds, lowest in grackles, and intermediate in starlings and cowbirds. Mercury concentrations exceeded 20 ppm in all tissues of all species and were similar to levels reported in wild birds known to have died of mercury poisoning.

  14. 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

  15. Mercury in the muscle tissue of fish from three northern Maine lakes

    SciTech Connect

    Akielaszek, J.J.; Haines, T.A.

    1981-08-01

    We report the levels of mercury in the muscle tissue of brook trout (Salvelinus fontinalis) and lake trout (S. namaycush) from three northern Maine lakes. Mercury levels in fish from two wilderness lakes in the same drainage basin were compared with each other, and in turn with those in fish from a lake in a separate drainage basin. The fish species composition in one of the wilderness lakes, Cliff Lake, is different from that in the other two lakes, enabling us to analyze the effects of trophic structure on mercury concentration in top carnivores. It is unlikely that mercury from agricultural, geological, or local industrial sources occurs in these lakes.

  16. Temporal and spatial trends in freshwater fish tissue mercury concentrations associated with mercury emissions reductions.

    PubMed

    Hutcheson, Michael S; Smith, C Mark; Rose, Jane; Batdorf, Carol; Pancorbo, Oscar; West, Carol Rowan; Strube, Joseph; Francis, Corey

    2014-02-18

    Mercury (Hg) concentrations were monitored from 1999 to 2011 in largemouth bass (LMB) and yellow perch (YP) in 23 lakes in Massachusetts USA during a period of significant local and regional Hg emissions reductions. Average LMB tissue Hg concentration decreases of 44% were seen in 13 of 16 lakes in a regional Hg "hotspot" area. YP in all lakes sampled in this area decreased 43% after the major emissions reductions. Comparative decreases throughout the remainder of the state were 13% and 19% for LMB and YP respectively. Annual tissue mercury concentration rate decreases were 0.029 (LMB) and 0.016 mg Hg/kg/yr (YP) in the hotspot. In lakes around the rest of the state, LMB showed no trend and YP Hg decreased 0.0068 mg Hg/kg/yr. Mercury emissions from major point sources in the hotspot area decreased 98%, and 93% in the rest of the state from the early 1990s to 2008. The significant declines in fish Hg concentrations in many lakes occurred over the second half of a two decade decrease in Hg emissions primarily from municipal solid waste combustors and, secondarily, from other combustion point sources. In addition to the substantial Hg emissions reductions achieved in Massachusetts, further regional, national and global emissions reductions are needed for fish Hg levels to decrease below fish consumption advisory levels. PMID:24494622

  17. 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

  18. Research Article Mercury Concentrations in Tissues of Osprey From the

    E-print Network

    Hopkins, William A.

    , Charleston, SC 29402, USA ABSTRACT Mercury (Hg) contamination is believed to be one of the most significantResearch Article Mercury Concentrations in Tissues of Osprey From the Carolinas, USA WILLIAM A contamination of piscivorous raptors are rare in this region. We analyzed total Hg (THg) concentration

  19. Mercury and fish tissue -- Status of Oregon reservoirs and lakes

    SciTech Connect

    Drake, D.; Stifel, B.; DiDomenico, G.; McCartney, R. [Dept. of Environmental Quality, Portland, OR (United States)

    1995-12-31

    The Oregon Department of Environmental Quality monitors contaminants in fish and sediment. Total mercury was analyzed in fish tissue taken from ten water bodies in 1993 and 1994. Mercury was measured in bass (Micropterus salmoides, M. dolomieui), salmonids (Salmo trutta, Oncorhynchus mykiss, O. clarki) and catfish (Ictalurus punctatus, I. nebulosus) in support of health department consumption advisories. Elevated mercury concentrations above the EPA screening value of 0.6 mg/kg wet were found in fish from watersheds with cinnabar geology or historical mining activity. Established bioaccumulation correlations between mercury and species, age, and length were also observed. Results from East Lake, a popular recreational fishery that had not previously been studied, were found to have fish mercury concentrations approaching 3.0 mg/kg wet. Regulatory and fish management issues will also be presented.

  20. Occupational exposure to mercury. What is a safe level?

    PubMed Central

    Moienafshari, R.; Bar-Oz, B.; Koren, G.

    1999-01-01

    QUESTION: One of my pregnant patients, a dental hygienist, uses mercury in her workplace, but appears to have no symptoms of mercury toxicity. She has heard that mercury might affect her fetus. What should I recommend to her? What is a safe level of mercury in the air for pregnant women? ANSWER: Testing for levels of mercury in whole blood and, preferably, urine is useful for confirming exposure. Currently, mercury vapour concentrations greater than 0.01 mg/m3 are considered unsafe. Also, women of childbearing age should avoid contact with mercury salts in the workplace. PMID:10889853

  1. Total mercury distribution in different tissues of six species of freshwater fish from the Kpong hydroelectric reservoir in Ghana.

    PubMed

    Atta, Alhassan; Voegborlo, Ray Bright; Agorku, Eric Selorm

    2012-05-01

    Total mercury concentrations were determined in seven tissues of 38 fish samples comprising six species from the Kpong hydroelectric reservoir in Ghana by cold vapour atomic absorption spectrometry technique using an automatic mercury analyzer. Mercury concentration in all the tissues ranged from 0.005 to 0.022 ?g/g wet weight. In general, the concentration of mercury in all the tissues were decreasing in the order; liver?>?muscle?>?intestine?>?stomach?>?gonad?>?gill?>?swim bladder. Mercury concentration was generally greater in the tissues of high-trophic-level fish such as Clarotes laticeps, Mormyrops anguilloides and Chrysichthys aurutus whereas low-trophic-level fish such as Oreochromis niloticus recorded low mercury concentration in their tissues. The results obtained for total mercury concentration in the muscle tissues analysed in this study are below the WHO/FAO threshold limit of 0.5 ?g/g. This suggests that the exposure of the general public to Hg through fish consumption can be considered negligible. PMID:21713471

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

    SciTech Connect

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

    1988-01-01

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

  3. A simple {sup 197}Hg RNAA procedure for the determination of mercury in urine, blood, and tissue

    SciTech Connect

    Blotcky, A.J. [VA Medical Center, Omaha, NE (United States); Rack, E.P.; Meade, A.G. [Univ. of Nebraska, Lincoln, NE (United States)] [and others

    1995-12-31

    Mercury has been implicated as a causal agent in such central nervous system diseases as Alzheimer`s and Parkinson`s. Consequently, there has been increased interest in the determination of ultra-trace-level mercury in biological matrices, especially in tissue. While such nonnuclear techniques as cold vapor atomic absorption spectrometry and cold vapor atomic fluorescence spectrometry have been employed routinely for mercury determinations in urine and blood, there is a paucity of nonnuclear techniques for the determination of mercury in the low parts-per-billion range in biological tissue. As pointed out by Fardy and Warner, instrumental and radiochemical neutron activation analysis (INAA and RNAA) require no blank determinations in contrast to nonnuclear analytical techniques employing digestion and/or chemical operations. Therefore, INAA and RNAA become the obvious choices for determination of ultra-trace levels of mercury in tissue. Most separation methods reported in the literature require different and separate methodologies for mercury determinations in urine, blood, or tissue. The purposes of this study are to develop a single methodology for the determination of low levels of mercury in all biological matrices by RNAA and to optimize parameters necessary for an efficacious trace-level determination. Previously, few studies have taken into account the effects of the Szilard-Chalmers reactions of the radioactivatable analyte within a biological matrix. It also would appear that little attention has been given to the optimum postirradiation carrier concentration of the analyte species necessary. This study discusses these various considerations.

  4. Wavelengths, Energy Level Classifications, and Energy Levels for the Spectrum of Neutral Mercury

    E-print Network

    Magee, Joseph W.

    Wavelengths, Energy Level Classifications, and Energy Levels for the Spectrum of Neutral Mercury E of neutral mercury Hg I for both the single isotope 198 Hg and for mercury in its natural isotopic abundance of neutral mercury for both 198 Hg and the natural isotopic mixture. Tabular data for 105 classified lines

  5. Changes in tissue glutathione and mercury concentrations in rats following mercuric chloride injection through the hepatic portal vein

    SciTech Connect

    Chey, Sin Wun; Keong, Wong Ming; Min, Sin Yoke (National Univ. of Singapore (Singapore))

    1989-06-01

    The kidney is known as a primary target organ for mercury deposition. However, it is also known as an important organ for the elimination of the absorbed mercury. Tanaka and her collaborators showed that inorganic mercury when injected through caudal vein is transported to the kidney as mercury-GSH complex. If that is so, liver which contains the highest level of tissue GSH than any other organs in normal animals would appear to be a prime site for the complexion of mercury ions with GSH before they are released and transported to the kidney. In view of this, it is of interest to establish the interrelative changes of the amounts of GSH and mercury in between liver and kidney at the earlier time intervals after a direct injection of a low dosage of mercuric chloride (HgCl{sub 2}) into the hepatic portal vein.

  6. Bioaccumulation of trace mercury in trophic levels of benthic, benthopelagic, pelagic fish species, and sea birds from Arvand River, Iran.

    PubMed

    Hosseini, Mehdi; Nabavi, Seyed Mohammad Bagher; Parsa, Yaghob

    2013-12-01

    In this study, concentration of mercury was determined in the trophic levels of benthic, benthopelagic, pelagic fish species, and river birds from Arvand River, located in the Khuzestan province in the lowlands of southwestern Iran at the head of the Persian Gulf. The order of mercury concentrations in tissues of the fish species was as follows: liver>gill>muscle and in tissues of the kingfisher species was as follows: feather>liver>kidney>muscle. Therefore, liver in fish and feather in kingfisher exhibited higher mercury concentration than the other tissues. There was a positive correlation between mercury concentrations in fish and kingfisher species with 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. The results of this study show that the highest mean mercury level were found in the kingfisher (Anas crecca), followed by benthic (Epinephelus diacanthus), benthopelagic (Chanos chanos), and pelagic fish (Strongylura strongylura). Mean value of mercury in fish species, S. strongylura were (0.61 ?g g(-1) dry weight), C. chanos (0.45 ?g g(-1) dry weight), E. diacanthus (0.87 ?g g(-1) dry weight), and in kingfisher species A. crecca was (2.64 ?g g(-1) dry weight). Significant correlation between mercury concentration in fish and kingfisher may be related to high variability of mercury in the fish. PMID:24174062

  7. 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.

  8. 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

  9. Total mercury and methylmercury levels in commercially important fishes in Japan

    Microsoft Academic Search

    Yumiko Yamashita; Yuji Omura; Emiko Okazaki

    2005-01-01

    The distribution of mercury in the muscle and other tissues was determined in 23 species of fishes and invertebrates. This\\u000a study reveals species-specific patterns of mercury accumulation in the muscle of tuna and alfonsino. Consistently high levels\\u000a of total mercury were found in Beryx splendens (0.78±0.56 ?g\\/g), Atlantic Thunnus thynnus (0.42±0.06 ?g\\/g), Pacific T. thynnus (0.59±0.34 ?g\\/g), Thunnus obesus (0.98±0.34

  10. 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.

  11. Evaluation of mercury in urine as an indicator of exposure to low levels of mercury vapor.

    PubMed Central

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

    2003-01-01

    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 environmental exposures and public health goals (i.e., < 50 microg/m3 down to 1.0 microg/m3). Ten studies reporting paired air and urine mercury data (149 samples total) met criteria for data quality and sufficiency. The log-transformed data set showed a strong correlation between mercury in air and in urine (r = 0.774), although the relationship was best fit by a series of parallel lines with different intercepts for each study R2 = 0.807). Predicted ratios of air to urine mercury levels at 50 microg/m3 air concentration ranged from 1:1 to 1:3, based on the regression line for the studies. Toward the lower end of the data set (i.e., 10 microg/m3), predicted urinary mercury levels encompassed two distinct ranges: values on the order of 20 microg/L and 30-60 microg/L. Extrapolation to 1 microg/m3 resulted in predicted urinary levels of 4-5 and 6-13 microg/L. Higher predicted levels were associated with use of static area air samplers by some studies rather than more accurate personal air samplers. Urinary mercury predictions based primarily on personal air samplers at 1 and 10 microg/m3 are consistent with reported mean (4 microg/L) and upper-bound (20 microg/L) background levels, respectively. Thus, although mercury levels in air and urine are correlated below 50 microg/m3, the impact of airborne mercury levels below 10 microg/m3 is likely to be indistinguishable from background urinary mercury levels. PMID:12676626

  12. Studies of Mercury in High Level Waste Systems

    Microsoft Academic Search

    2004-01-01

    Historically, mercury was added to the nuclear weapons processing as a catalyst for the dissolution of aluminum metal. After neutralization the mercury was disposed to the High Level Waste tanks where its speciation led to mercuric oxides\\/hydroxides in the sludge and a small soluble mercuric ion concentration in the alkaline supernate. This report in its original revision described a three-pronged

  13. STATE FISH SURVEY FINDS MERCURY LEVELS DOWN By Alex Breitler

    E-print Network

    they do not accumulate as much mercury. Salmon also were relatively free of contamination, sinceNews STATE FISH SURVEY FINDS MERCURY LEVELS DOWN By Alex Breitler May 25, 2013 Record Staff Writer downstream you go the more likely fish will be contaminated. For example, the Delta remains a hot spot

  14. 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

  15. 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

  16. 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...

  17. 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

  18. Trace-level mercury removal from surface water

    SciTech Connect

    Klasson, K.T.; Bostick, D.T.

    1998-06-01

    Many sorbents have been developed for the removal of mercury and heavy metals from waters; however, most of the data published thus far do not address the removal of mercury to the target levels represented in this project. The application to which these sorbents are targeted for use is the removal of mercury from microgram-per-liter levels to low nanogram-per-liter levels. Sorbents with thiouronium, thiol, amine, sulfur, and proprietary functional groups were selected for these studies. Mercury was successfully removed from surface water via adsorption onto Ionac SR-4 and Mersorb resins to levels below the target goal of 12 ng/L in batch studies. A thiol-based resin performed the best, indicating that over 200,000 volumes of water could be treated with one volume of resin. The cost of the resin is approximately $0.24 per 1,000 gal of water.

  19. Tissue content of mercury in rats given methylmercuric chloride orally: influence of intestinal flora

    SciTech Connect

    Rowland, I.R.; Davies, M.J.; Evans, J.G.

    1980-05-01

    The effect of intestinal flora on the absorption and disposition of mercury in tissues was investigated using conventional rats, and rats treated with antibiotics to eliminate their gut flora. Antibiotic-treated rats given (/sup 203/Hg) -labeled methylmercuric chloride orally had significantly more mercury in their tissues, especially in kidney, brain, lung, blood, and skeletal muscle, and also excreted less mercury in the feces than conventional rats. Furthermore, in the kidneys of the antibiotic-treated rats, the proportion of mercury present as organic mercury was greater than in the kidneys of the conventional rats. The results support the hypothesis that the metabolism of methylmercuric chloride by the gut flora reduces the tissue content of mercury. When rats were administered 10 mg methylmercuric chloride/Kg.day for 6 days, four or five of those given antibiotics developed neurological symptoms of toxicity, whereas only one of five conventional rats given methylmercuric chloride was affected.

  20. Mercury Exposure Levels in Children with Dental Amalgam Fillings

    PubMed Central

    Miriam Varkey, Indu; Shetty, Rajmohan; Hegde, Amitha

    2014-01-01

    ABSTRACT% Objectives: Mercury combined with other metals to form solid amalgams has long been used in reconstructive dentistry but its use has been controversial since at least the middle of the 19th century. The exposure and body burden of mercury reviews have consistently stated that there is a deficiency of adequate epidemiological studies addressing this issue. Fish and dental amalgam are two major sources of human exposure to organic (MeHg) and inorganic Hg respectively. Materials and methods: A total of 150 subjects aged between 9 and 14 years were divided into two groups of 75 subjects each depending on their diet, i.e. seafood or nonseafood consuming. Each category was subdivided into three groups based on number of restorations. Scalp hair and urine samples were collected at baseline and 3 months later to assess the organic and inorganic levels of mercury respectively by atomic absorption spectrophotometer (AAS). Results: The mean values of urinary mercury (inorganic mercury) in the group of children with restorations were 1.5915 ?g/l as compared to 0.0130 ?g/l in the groups with no amalgam restorations (p < 0.001) (Wilcoxon sign rank test and paired t-test). The hair mercury levels (organic mercury) varied signi-ficantly between the fsh-eating group and nonfsh-eating group, the average values being 1.03 ?g/l and 0.84 ?g/l respectively (p < 0.001) (Mann-Whitney U-test and paired t-test). Conclusion and significance: The notion about the mercury being released from the amalgam restorations as a sole exposure source needs to be put to a rest, as environmental factors collectively overpower the exposure levels from restorations alone. How to cite this article: Varkey IM, Shetty R, Hegde A. Mercury Exposure Levels in Children with Dental Amalgam Fillings. Int J Clin Pediatr Dent 2014;7(3):180-185. PMID:25709298

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

    E-print Network

    Pierce, Graham

    Accumulation of mercury in the tissues of the common octopus Octopus vulgaris (L.) in two August 2004 Abstract Mercury concentrations were measured in tissues of 12 individuals of Octopus, gills, mantle, arms, and gonads). Correlations between mercury concentrations in different tissues were

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

    PubMed Central

    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 distribution, comparing hair mercury levels by studied population and Amazonian river basin, looking for exposure trends. Methods The reviewed papers were selected from scientific databases and online libraries. We included studies with a direct measure of hair mercury concentrations in a sample size larger than 10 people, without considering the objectives, approach of the study or mercury speciation. The results are presented in tables and maps by river basin, displaying hair mercury levels and specifying the studied population and health impact, if any. Results The majority of the studies have been carried out in communities from the central Amazonian regions, particularly on the Tapajós River basin. The results seem quite variable; hair mercury means range from 1.1 to 34.2 ?g/g. Most studies did not show any significant difference in hair mercury levels by gender or age. Overall, authors emphasized fish consumption frequency as the main risk factor of exposure. The most studied adverse health effect is by far the neurological performance, especially motricity. However, it is not possible to conclude on the relation between hair mercury levels and health impact in the Amazonian situation because of the relatively small number of studies. Conclusions Hair mercury levels in the Amazonian regions seem to be very heterogenic, depending on several factors. There is no obvious spatial trend and there are many areas that have never been studied. Taking into account the low mercury levels currently handled as acceptable, the majority of the Amazonian populations can be considered exposed to methylmercury contamination. The situation for many of these traditional communities is very complex because of their high dependence on fish nutrients. It remains difficult to conclude on the Public Health implication of mercury exposure in this context. PMID:20025776

  3. Mercury poisoning dentistry: high-level indoor air mercury contamination at selected dental sites.

    PubMed

    Khwaja, Mahmood A; Abbasi, Maryam Shabbir

    2014-01-01

    Mercury (Hg), also known as quick silver, is an essential constituent of dental amalgam. It is a toxic substance of global concern. Children are more at risk from mercury poisoning which affects their neurological development and brain. In the past, a number of studies at dental sites in many countries have been carried out and reported. The present report briefly describes and discusses our recent investigations carried out at 34 dental sites (teaching institutions, hospitals and private clinics) in Pakistan. It is evident from the data that at many sites the indoor mercury vapor levels exceed far above the permissible limit recommended for safe physical and mental health. At these sites, public in general and the medical, paramedical staff and vulnerable population in particular, are at most serious risk to health resulting from exposure to toxic and hazardous mercury. To minimize such risk, some of the recommendations are, best in-house environmental practices for occupational health and safety, mercury contaminated waste reduction at source, mercury specific legislation and ratification of Minamata convention on mercury by Pakistan and other world governments at the earliest time possible. PMID:24552960

  4. Mercury

    SciTech Connect

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

    1988-01-01

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

  5. Studies of Mercury in High Level Waste Systems

    SciTech Connect

    Wilmarth, W.R.

    2003-09-03

    During nuclear weapons production, nuclear reactor target and fuel rods were processed in F- and H-Canyons. For the target rods, a caustic dissolution of the aluminum cladding was performed prior to nitric acid dissolution of the uranium metal targets in the large canyon dissolvers. To dissolve the aluminum cladding and the U-Al fuel, mercury in the form of soluble mercury (II) nitrate was added as a catalyst to accelerate the dissolution of the aluminum. F-Canyon began to process plutonium-containing residues that were packaged in aluminum cans and thus required the use of mercury as a dissolution catalyst. Following processing to remove uranium and plutonium using the solvent extraction process termed the Plutonium-Uranium Recovery by Extraction (PUREX) process, the acidic waste solutions containing fission products and other radionuclides were neutralized with sodium hydroxide. The mercury used in canyon processing is fractionated between the sludge and supernate that is transferred from the canyons to the tank farm. The sludge component of the waste is currently vitrified in the Defense Waste Processing Facility (DWPF). The vitrified waste canisters are to be sent to the federal repository for High Level Waste. The mercury in the sludge, presumably in an oxide or hydroxide form is reduced to elemental mercury by the chemical additions and high temperatures, steam stripped and collected in the Mercury Collection Tank. The mercury in the dilute supernate is in the form of mercuric ion and is soluble. During evaporation, the mercuric ion is reduced to elemental mercury, vaporizes into the overheads system and is collected as a metallic liquid in the Mercury Removal Tank.

  6. 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.

  7. LEVEL AND EXTENT OF MERCURY CONTAMINATION IN OREGON LOTIC FISH

    EPA Science Inventory

    As part of the U.S. EPA's EMAP Oregon Pilot project, we conducted a probability survey of 154 Oregon streams and rivers to assess the spatial extent of mercury (Hg) contamination in fish tissue across the state. Samples consisted of whole fish analyses of both small (< 120 mm) a...

  8. 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

  9. 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.

  10. Mercury levels in avian feathers from different trophic levels of eight families collected from the northern region of Iran.

    PubMed

    Mashroofeh, Abdulreza; Bakhtiari, Alireza Riyahi; Ghobeishavi, Ahmad; Ahmadpour, Mohsen; Asadi, Asad; Ahmadpour, Mousa; Hosseini, Sayyed Hamid; Eskandari, Tahereh; Burger, Joanna

    2015-05-01

    Mercury levels were determined in feathers from 83 birds belonging to 18 species (eight families), all collected from the northern region of Iran. Mercury levels were evaluated in relation to taxonomic affiliation and feeding strategies. Mercury levels in the feathers were between 0.05?±?0.01 and 1.10?±?0.15 ?g g(-1) dry weight, and there was a significant effect of taxonomic groups (p?mercury levels were found in Accipitridae, and mercury was not detected in the family Upupidae. The pattern for mercury levels was Accipitridae > Pelecanidae > Sternidae > Ardeidae > Anatidae > Rallidae > Phasianidae (p?mercury levels were found among species as a function of feeding method and trophic level. Mercury levels were highest in the carnivorous species and lowest in the herbivorous species. Mercury levels in feathers of birds in this study were generally below the thresholds reported to affect reproduction. PMID:25893758

  11. Mercury levels in sediments and mangrove oysters, Crassostrea rizophorae, from the north coast of Villa Clara, Cuba.

    PubMed

    Olivares-Rieumont, S; Lima, L; Rivero, S; Graham, D W; Alonso-Hernandez, C; Bolaño, Y

    2012-04-01

    Total mercury levels were quantified in sediments and oyster tissues (Crassostrea rizophorae) from the Sagua la Grande River estuary and offshore mangrove keys 19 km downstream of a chlor-alkali plant (CAP) in Villa Clara, Cuba. Relatively elevated total mercury levels were found in sediments from the estuary itself, ranging from 0.507 to 1.81 ?g g(-1) dry weight. However, levels were lower in sediments from the keys farther from the estuary. Oyster mercury levels were always acceptable for human consumption, although levels significantly correlated in sediments and oysters across sampling sites (p < 0.05), which suggests that mercury from the CAP is impacting coastal water quality conditions. PMID:22323046

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

    E-print Network

    Hopkins, William A.

    Tissue mercury concentrations and adrenocortical responses of female big brown bats (Eptesicus fuscus) near a contaminated river Haruka Wada · David E. Yates · David C. Evers · Robert J. Taylor, LLC 2010 Abstract Much of the research on mercury (Hg) in wild vertebrates has focused on piscivores

  13. Does proximity to coal-fired power plants influence fish tissue mercury?

    E-print Network

    of contaminated fish. In this study, we quantified the relative importance of proximity to coal-fired power plantsDoes proximity to coal-fired power plants influence fish tissue mercury? Dana K. Sackett · D. Derek+Business Media, LLC 2010 Abstract Much of the mercury contamination in aquatic biota originates from coal

  14. MERCURY MAPS: A QUANTITATIVE SPATIAL LINK BETWEEN AIR DEPOSITION AND FISH TISSUE

    EPA Science Inventory

    Mercury Maps is a geographic information system (GIS) that relates percent changes in air deposition to percent changes in fish tissue concentration, on a national scale. Mercury Maps documentation derives a simple model, incorporated in the GIS, from recent detailed kinetics-b...

  15. Mercury

    Microsoft Academic Search

    Thomes W. Clarkson

    1989-01-01

    New findings on the environmental fate of Hg indicate that lakes can be contaminated by long distance transport on mercury vapor in the atmosphere and that higher levels of Me Hg in fish are associated with acidification of lakes and with the creation of hydroelectric reservoirs. Considerable progress has been made in the understanding of the disposition and metabolism of

  16. Egg mercury levels decline with the laying sequence in charadriiformes

    SciTech Connect

    Becker, P.H. (Institut fuer Vogelforschung, Wilhelmshaven (Germany))

    1992-05-01

    Whereas pollutants do not differ in concentration among eggs of one clutch in some bird species, in gulls, terns and grebes several organochlorines show intraclutch variation: Concentrations increase with the laying sequence. Heavy metals, however, are not so intensively studied with respect to intraclutch variation. In contrast to lead and cadmium, mercury is accumulated in great quantities in eggs. Variation in mercury levels between the eggs of one clutch were low compared to interclutch variability in the White-tailed Sea Eagle (Haliaeetus albicilla) and the Peregrine (Falco peregrinus). In gulls, however, intraclutch variation was significant and characterized by higher mercury levels in the first than in subsequently laid eggs, which is the opposite to the trend in organochlorine levels. In this paper, the author reports on investigations of intraclutch variation in mercury levels in three Charadriiform-species, Herring Gull, Common Tern and Oystercatcher (Haematopus ostralegus). The results confirm those previously reported in gulls and point to the importance of the egg in reducing the females' mercury burden. 23 refs, 2 tabs.

  17. Risk, mercury levels, and birds: relating adverse laboratory effects to field biomonitoring.

    PubMed

    Burger, J; Gochfeld, M

    1997-11-01

    There is an abundance of field data on levels of mercury in a variety of organisms and there are a number of studies that demonstrate the adverse effects of mercury on laboratory animals, but few studies examine the relationship between the two. Thus it is often difficult to determine the ecological relevance of mercury concentrations found in nature, or to predict the ecosystem consequences of current levels. In this paper we review the levels in tissues that are associated with adverse effects in birds from laboratory studies and compare these with levels found in wild bird populations in the New York Bight to provide a basis for interpreting values in avian populations. We use feathers from fledgling birds which would have been fed on locally obtained food to eliminate the problem of where toxic burdens were acquired by more mobile adult birds. Laboratory studies indicate that in some species mercury levels of 1.5 ppm in eggs and/or 5 to 40 ppm in the feathers of birds are associated with adverse effects, including impaired reproduction. We report egg levels in birds that range as high as 3.8 ppm and feather levels that range as high as 10.3 ppm, although means are much lower. The levels in eggs of some wild birds in the New York Bight are within the range known to lower hatchability, embryo and chick survival, and chick weight, all variables that reduce reproductive success. Species with high egg levels include Forster's tern (Sterna forsteri) and black skimmer (Rynchops niger). Levels in feathers of some young wild birds from the New York Bight are within the range associated with reduced hatchability of eggs, behavioral abnormalities of adults, and infertility. Species with dangerously elevated mercury levels in feathers include great egret (Ardea [=Egretta] alba), snowy egret [Egretta thula), and black skimmers. PMID:9417847

  18. 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...

  19. 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

  20. 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.

  1. 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

  2. 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

  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. 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.

  5. Mercury

    MedlinePLUS

    ... crystals. Mercury also combines with carbon to make organic mercury compounds. The most common one, methylmercury, is produced mainly by microscopic organisms in the water and soil. More mercury in the environment can increase the amounts of methylmercury that these ...

  6. 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.

  7. 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...

  8. 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...

  9. Interrelationships between Fish Tissue Mercury Concentrations and Water Quality for South Dakota Natural Lakes and Impoundments

    Microsoft Academic Search

    James J. Stone; Cindie M. McCutcheon; Larry D. Stetler; Steven R. Chipps

    The purpose of this study was to determine whether water quality parameters commonly associated with primary productivity\\u000a may be used to predict the susceptibility of a specific water body to exceed proposed fish consumption advisory limitation\\u000a of 0.3 mg kg?1. South Dakota currently has nine lakes and impoundments that exceed fish tissue mercury advisory limits of 1.0 mg kg?1 total mercury, far exceeding US

  10. 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, S.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.

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

    PubMed

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

    2002-10-01

    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 delta15N 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. PMID:12389795

  12. Levels of cadmium and mercury in the hair of Atlantic walruses (Odobenus rosmarus rosmarus) from Svalbard, Norway

    SciTech Connect

    Wiig, O. [Univ. of Oslo (Norway). Zoological Museum] [Univ. of Oslo (Norway). Zoological Museum; Renzoni, A. [Univ. degli Studi di Siena (Italy). Dept. di Biologia Ambientale] [Univ. degli Studi di Siena (Italy). Dept. di Biologia Ambientale; Gjertz, I. [Norwegian Polar Inst., Tromsoe (Norway)] [Norwegian Polar Inst., Tromsoe (Norway)

    1999-08-01

    Hair samples of 15 adult male Atlantic walruses (Odobenus rosmarus rosmarus) collected from anesthetized individuals at Svalbard, Norway, were analyzed for cadmium and total mercury. The mean level of cadmium was 0.860 {+-} 0.321 {micro}g/g dry weight and the mean level of mercury was 0.235 {+-} 0.100 {micro}g/g dry weight. Levels of cadmium and mercury in hair of walruses from other areas are not known. Both cadmium and mercury levels in hair of walruses from Svalbard are relatively low compared to the levels found in the hair of other marine mammal species. It has been documented from a number of marine species, including marine mammals such as ringed seals and polar bears, that both cadmium and mercury levels of Svalbard are lower than in other areas. It is uncertain as to what degree levels in hair reflect levels in internal organs in walruses. In rare and highly endangered species or populations tissue samples can be difficult to collect. In walruses, it is possible to collect hair from anesthetized individuals or at the haul-out sites during molt, to monitor heavy metal levels of the population.

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

    PubMed

    Marino, Kady B; Hoover-Miller, Anne; Conlon, Suzanne; Prewitt, Jill; O'Shea, Stephen K

    2011-11-01

    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 392Hgppmdw) than the general population sampled. PMID:21867998

  14. Mercury

    MedlinePLUS

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

  15. Distribution of mercury in the soft tissues of the Blue Tilapia Oreochromis aureus (Steindachner) after acute exposure to mercury (II) chloride

    SciTech Connect

    Allen, P.

    1994-11-01

    Mercury has no known biological functions in the animal body and is described as an ultratrace element. Consequently, there is no well defined regulatory mechanism present in the animal body and it tends to accumulate readily if available in an animal's environment. Sources of mercury include the chloroalkali industry, the manufacture of electrical equipment, paint, fungicides and dentistry. The use of mercury in the gold mining industry has caused extensive pollution in the Amazon Basin. Whether fish take up organic or inorganic mercury, most of it accumulates in the tissues in the organic form. Most cases of mercury poisoning arising from fish consumption are due to methylmercury because mercury entering the aquatic system rapidly becomes methylated. Minamata disease in humans was first reported in 1956 due to consumption of contaminated fish and shellfish from Minamata Bay. Therefore it is important to monitor the mercury content of fish which are caught or farmed for human consumption. Since many commercial animal feeds contain a fish meal component, monitoring is important from the aspect of contamination of farm animals intended for human consumption. Oreochromis aureus (Steindachner) is a species of tilapia often cultured in ponds and also in cages in North and Latin America. Therefore, it is a suitable model to use for studying the effects of mercury exposure on the distribution of mercury in different tissues of fish. Distribution is important, because different cultures consume different fish organs, not just the muscle portion alone. The tissues which have a high content of mercury will be most dangerous from a toxicological viewpoint. Removal of the tissues known to contain the highest concentrations of mercury would reduce the mercury content of fish meal. Since fish are often species-specific in their responses to heavy metals, it is important to study a species which is actually farmed and cultured as a food fish. 20 refs., 2 tabs.

  16. Tissue Levels of Various Sulfonamides in Trout

    Microsoft Academic Search

    S. F. Snieszko; S. B. Friddle

    1951-01-01

    Studies were made on the tissue levels of sulfonamides in trout. The tissue concentrations of sulfamerazine were determined in brook trout given various doses of this drug. It has been found also that there exists a relationship between the rate of feeding, depending on the size of trout, and the tissue concentration of sulfamerazine. The level of sulfamerazine rose much

  17. Mercury levels in fish in the La Grande River area, Northern Quebec

    Microsoft Academic Search

    Eric C. Smith; Fikret Berkes; John A. Spence

    1975-01-01

    High mercury levels in organisms in inland waters have usually been attributed to pollution (e.g. FIMREITE et al. 1971). But there is evidence that high mercury content im rocks in some regions (CAMERON and JONASSON 1972) may be responsible for high mercury levels in organisms. It has been known for some time that fish in the southern James Bay region

  18. 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.

  19. 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...

  20. Risk, Mercury Levels, and Birds: Relating Adverse Laboratory Effects to Field Biomonitoring

    Microsoft Academic Search

    Joanna Burger; Michael Gochfeld

    1997-01-01

    There is an abundance of field data on levels of mercury in a variety of organisms and there are a number of studies that demonstrate the adverse effects of mercury on laboratory animals, but few studies examine the relationship between the two. Thus it is often difficult to determine the ecological relevance of mercury concentrations found in nature, or to

  1. Mercury level in fish caught in Indian River Lagoon higher than it should be?

    E-print Network

    Belogay, Eugene A.

    Mercury level in fish caught in Indian River Lagoon higher than it should be? Harbor Branch at the idea he might ingest too much mercury. "I ain't dead yet," said Justin Baird, who stopped, figured he would gobble it up in two days. Chances are, all the fish contained some mercury. As the poor

  2. 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.

  3. Mercury

    MedlinePLUS

    ... Data and Publications Grants and Funding Science and Technology The Mercury Study Report to Congress About Mercury Basic Information Frequent Questions Human Exposure Health Effects Environmental Effects Protecting Yourself Where You Live Releases and ...

  4. Mercury Concentration in the Tissue of Terrestrial Arthropods from the Central California Coast

    NASA Astrophysics Data System (ADS)

    Ortiz, C.; Weiss-Penzias, P. S.; Flegal, A. R.

    2012-12-01

    The primary goal of this project was to obtain a baseline understanding and investigate the concentration of mercury (Hg) in the tissue of arthropods in coastal California. This region receives significant input of fog which may contain enhanced levels of Hg. Currently there is a lack of data on Hg concentration in the tissue of arthropods (Insecta, Malacostraca, and Arachnida). The sample collection sites were Elkhorn Slough Estuarine Reserve in Moss Landing, and the University of California Santa Cruz (UCSC) campus. Samples collected between February and March, 2012 had total Hg (HgT) concentrations in dry weight that ranged from 27 - 39 ng/g in the Jerusalem cricket (Orthoptera Stenopelmatidae); 80 - 110 ng/g in the camel cricket (Orthoptera Rhaphidophoridae); 21 - 219 ng/g in the ground beetle (Coleoptera Carabidae); 100 - 228 ng/g in the pill bug (Isopoda Armadillidiidae); and 285 - 423 ng/g in the wolf spider (Araneae Lycosidae). Monomethyl mercury (MMHg) concentrations in dry weight were determine to be 4.3 -28.2 ng/g for the ground beetle; 45.5 - 87.8 ng/g for the pill bug, and 252.3 - 293.7 ng/g for the wolf spider. Samples collected in July, 2012 had HgT concentrations in dry weight that ranged from 110 - 168 ng/g in the camel cricket; 337 - 562 ng/g in the ground beetle; 25 - 227 ng/g in the pill bug; and 228 - 501 ng/g in the wolf spider. The preliminary data revealed an 18% increase in the concentration of HgT for wolf spiders, and a 146% increase for ground beetles in the summer when compared to those concentrations measured in the spring. It is hypothesized that coastal fog may be a contributor to this increase of Hg concentration in coastal California arthropods.

  5. 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...

  6. Percent methylmercury and organic mercury in tissues of marine mammals and fish using different experimental and calculation methods

    SciTech Connect

    Wagemann, R.; Trebacz, E.; Hunt, R.; Boila, G. [Dept. of Fisheries and Oceans, Winnipeg, Manitoba (Canada)

    1997-09-01

    Muscle and liver tissues of marine mammals and fish were extracted with methylene chloride-hexane (DCM-hexane) or toluene and the extracts were analyzed for organic mercury by cold vapor atomic absorption spectroscopy (CVAAS) and for methylmercury by gas liquid chromatography with an electron capture detector (GC-ECD). Total mercury in tissues was determined by VCAAS. Methylmercury and organic mercury concentrations in muscle agreed with each other and with total mercury for both marine mammals and fish, indicating that on average 100% of the total mercury in this tissue was in the form of methylmercury. Either total mercury or organic mercury determined by CVAAS was found to be a valid measure of the average methylmercury concentration in muscles of marine mammals and fish. In liver, the CVAAS method produced higher mercury values (15% organic mercury) than the GC-ECD method (6% methylmercury), methylmercury being only 38% of organic mercury. From this, the presence of organic mercury compound(s) other than methylmercury was inferred. The CVAAS method produced a biased estimate of methylmercury in liver; an accurate measure of methylmercury in this tissue was obtained by GC-ECD, either with DCM-hexane or with toluene extraction. The DCM-hexane extract could be directly analyzed by CVAAS for organic mercury while toluene required an additional back-extraction step for such a determination. In calculating the average percentage of methylmercury and organic mercury in a sample, three different calculation methods were used. Only one of them, linear, robust regression analysis produced acceptable results when the variables (MeHg, organic Hg, total Hg) were significantly correlated. The other two methods overestimated the mean percentage under these conditions.

  7. Mercury Levels in Premature and Low Birth Weight Newborns after Receipt of Thimerosal-Containing Vaccines

    PubMed Central

    Pichichero, Michael E.; Gentile, Angela; Giglio, Norberto; Alonso, Margarita Martin; Fernandez Mentaberri, Maria Veronica; Zareba, Grazyna; Clarkson, Thomas; Gotelli, Carlos; Gotelli, Mariano; Yan, Lihan; Treanor, John

    2009-01-01

    Objective We conducted a population-based pharmacokinetic study to assess blood levels and elimination of mercury following vaccination of premature infants born at ? 32 and < 37 weeks of gestation and with birth weight ? 2000 but < 3000 grams. Study design Blood, stool, and urine samples were obtained pre-vaccination and 12 hours to 30 days post-vaccination from 72 premature newborns. Total mercury levels were measured by atomic absorption. Results The mean ± standard deviation (SD) birth weight was 2.4 ±0.3 Kg for the study population. Maximal mean ± SD blood mercury levels was 3.6 ± 2.1 ng/mL occurring at 1 day after vaccination, maximal mean ± SD stool mercury levels were 35.4 ± 38.0 ng/g, occurring on day 5 after vaccination, and urine mercury levels were mostly non-detectable. The blood mercury half-life was calculated to be 6.3 (95% CI:3.85-8.77) days and mercury levels returned to pre-vaccination levels by day 30. Conclusions The blood half-life of intramuscular ethyl mercury from thimerosal in vaccines given to premature infants is substantially shorter than that of oral methyl mercury in adults. Because of the differing pharmacokinetics, exposure guidelines based on oral methyl mercury in adults may not be accurate for children who receive thimerosal-containing vaccines. PMID:19560158

  8. New Jersey mercury regulations

    SciTech Connect

    Elias, D.F.; Corbin, W.E. [RTP Environmental Associates, Inc., Green Brook, NJ (United States)

    1996-12-31

    Mercury, or quicksilver, and its major ore cinnabar (HgS) have been known for thousands of years. Health effects from mercury such as dementia were known as early as the late 19th century ({open_quotes}mad as a hatter{close_quotes}). In the 1960`s and 1970`s, reported levels of mercury in tuna reawakened public awareness of mercury pollution. In the 1970`s, major epidemics of acute mercury poisoning were reported in Japan and Iraq. These incidents highlighted the extreme health risks, such as kidney damage, birth defects, and death, associated with severe mercury poisoning. Fetuses and young children are particularly vulnerable since mercury poisoning can damage growing neural tissues. Recently, the perception of mercury as a dangerous pollutant has been on the rise. Advisories warning the public to avoid or reduce the consumption of freshwater fish caught in specific waterbodies due to mercury contamination have been issued in numerous states. The discovery of mercury in {open_quotes}pristine{close_quotes} lakes in the United States, Canada, and Scandinavia, remote from industry and any known mercury sources, has focused attention on atmospheric emissions of mercury as potential significant sources of mercury.

  9. A comparative study of accumulated total mercury among white muscle, red muscle and liver tissues of common carp and silver carp from the Sanandaj Gheshlagh Reservoir in Iran.

    PubMed

    Khoshnamvand, Mehdi; Kaboodvandpour, Shahram; Ghiasi, Farzad

    2013-01-01

    The Sanandaj Gheshlagh Reservoir (SGR) is a mercury polluted lake that is located in the West of Iran. Common carp (Cyprinus carpio) and silver carp (Hypophthalmichthys molitrix) are the most abundant fishes in the SGR. A total of 48 common and silver carps (24 each) were captured randomly, using 50×6 m gill net (mesh size: 5×5 cm) during July to December 2009. Each month, the levels of accumulated total mercury (T-Hg) in white muscle, red muscle and liver tissues of these fishes were measured using an Advanced Mercury Analyzer (Model; Leco 254 AMA, USA) on the dry weight basis. There were no statistically significant differences between T-Hg concentrations in white muscle, red muscle and liver in common carp in comparison with similar tissues in silver carp (P>0.05). The content of T-Hg in liver tissue of both species was lower than of white and red muscle tissues. Higher levels of accumulated T-Hg were observed during summer. Results showed that T-Hg concentrations in common and silver carps target tissues were strongly dependent on age, length and weight (P<0.05). The results indicated that the levels of accumulated T-Hg in tissues of all samples with weights of over 850 g were greater than those limits established by WHO and FAO (500 ng g(-1)). PMID:23107055

  10. Mercury concentrations in tissues of Colombian slider turtles, Trachemys callirostris, from northern Colombia.

    PubMed

    Zapata, Lina M; Bock, Brian C; Palacio, Jaime A

    2014-05-01

    This study determined the total mercury (THg) concentrations in pectoral muscle, blood and carapace tissue in turtles collected from Magangué and Lorica, Colombia. THg concentrations in ?g/g (wet weight) were 0.39 ± 0.16 in muscle, 0.15 ± 0.08 in carapace and 0.07 ± 0.03 in blood for turtles from the Magdalena River and 0.25 ± 0.18 in muscle, 0.14 ± 0.09 in carapace and 0.06 ± 0.04 in blood for turtles from the Sinú River. Twenty-nine and ten percent of turtle muscle samples from Magangué and Lorica, respectively, exceeded the consumption advisory limit of 0.5 ?g Hg/g for fish. There was a significant correlation between carapace length and THg levels for this specie, depending on the sample site. In addition, a significant correlation was observed in THg concentrations in carapace and muscle. However, significant differences were observed in the THg levels between the two study locations, with turtles caught in the Magdalena River having higher levels of THg. PMID:24458244

  11. Mercury

    NASA Astrophysics Data System (ADS)

    McCoy, T. J.; Nittler, L. R.

    Mercury has always held the distinction of being the terrestrial planet most unlike the others. On 18 March 2011, after three successful flybys of Mercury, the MESSENGER spacecraft entered orbit around Mercury. Essential to the payload of MESSENGER are three instruments designed to measure the geochemistry of the surface - an x-ray spectrometer, a gamma-ray spectrometer, and a neutron spectrometer. Together, the data returned by these three instruments - coupled with insights about planetary structure gained from tracking the spacecraft, spectral data measured in orbit, and a new and complete view of the geology of the surface - have begun to revolutionize the people's understanding of Mercury. In this chapter, the authors first review the pre-MESSENGER views of Mercury, followed by the first results from the MESSENGER mission. The authors then discuss the implications of these first results in constraining the origin of Mercury, followed by looking forward to future work.

  12. 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.

  13. Review: Interpreting Hair Mercury Levels in Individual Patients

    Microsoft Academic Search

    Kern L. Nuttall

    2006-01-01

    Evaluation of mercury exposure in an individual patient ideally includes the presenting history, physical examination, consideration of the differential diagnosis, and mercury analysis of blood and urine specimens. Analysis of mercury in hair specimens may supply useful supplemental information about exposure to organic compounds such as methylmercury, particularly to help reconstruct the pattern of prior exposure. The most appropriate specimen

  14. Effects of low dietary levels of methyl mercury on mallard reproduction

    USGS Publications Warehouse

    Heinz, G.

    1974-01-01

    Mallard ducks were fed a control diet or a diet containing 0.5 ppm or 3 ppm mercury (as methylmercury dicyandiamide). Health of adults and reproductive success were studied. The dietary level of 3 ppm mercury had harmful effects on reproduction, although it did not appear to affect the health of the adults during the 12 months of dosage. Ducks that were fed the diet containing 0.5 ppm mercury reproduced as well as controls, and ducklings from parents fed 0.5 ppm mercury grew faster in the first week of life than did controls....The greatest harm to reproduction associated with the diet containing 3 ppm mercury was an increase in duckling mortality, but reduced egg laying and increased embryonic mortality also occurred....During the peak of egg laying, eggs laid by controls tended to be heavier than eggs laid by ducks fed either level of mercury; however, there seemed to be no eggshell thinning associated with mercury treatment. Levels of mercury reached about 1 ppm in eggs from ducks fed a dietary dosage of 0.5 ppm mercury and between 6 and 9 ppm in the eggs from ducks fed 3 ppm mercury.

  15. Assessment of nonlethal methods for predicting muscle tissue mercury concentrations in coastal marine fishes

    PubMed Central

    Piraino, Maria N.; Taylor, David L.

    2013-01-01

    Caudal fin clips and dorsolateral scales were analyzed in this study as a potential nonlethal approach for predicting muscle tissue mercury (Hg) concentrations in marine fishes. Target fishes were collected from the Narragansett Bay (RI, USA), and included black sea bass Centropristis striata (n = 54, 14–55 cm total length, TL), bluefish Pomatomus saltatrix (n = 113, 31–73 cm TL), striped bass Morone saxatilis (n = 40, 34–102 cm TL), summer flounder Paralichthys dentatus (n = 64, 18–55 cm TL), and tautog Tautoga onitis (n = 102, 27–61 cm TL). For all fish species, Hg concentrations were greatest in muscle tissue (mean muscle Hg = 0.47–1.18 mg/kg dry weight), followed by fin clips (0.03–0.09 mg/kg dry weight) and scales (0.01–0.07 mg/kg dry weight). The coefficient of determination (R2) derived from power regressions of intra-species muscle Hg against fin and scale Hg ranged between 0.35–0.78 (mean R2 = 0.57) and 0.14–0.37 (mean R2 = 0.30), respectively. The inclusion of fish body size interaction effects in the regression models improved the predictive ability of fins (R2 = 0.63–0.80; mean = 0.71) and scales (R2 = 0.33–0.71; mean = 0.53). According to the high level of uncertainty within the regression models (R2 values) and confidence interval widths, scale analysis was deemed an ineffective tool for estimating muscle tissue Hg concentrations in the target species. In contrast, the examination of fin clips as predictors of muscle Hg had value as a cursory screening tool, but this method should not be the foundation for developing human consumption advisories. It is also noteworthy that the efficacy of these nonlethal techniques was highly variable across fishes, and likely depends on species-specific life history characteristics. PMID:23929385

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

    PubMed

    Bond, Alexander L; Diamond, Antony W

    2009-07-01

    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 Machias Seal Island, New Brunswick, Canada - Arctic Tern (Sterna paradisaea), Atlantic Puffin (Fratercula arctica), Common Eider (Somateria mollissima), Common Murre (Uria aalge), Common Tern (Sterna hirundo), Leach's Storm-petrel (Oceanodroma leucorhoa), and Razorbill (Alca torda). We also used stable-isotope ratios of carbon (delta(13)C), and nitrogen (delta(15)N) to evaluate the relationship between carbon source and trophic position and mercury. We found high Hg concentrations across tissue types in Leach's Storm-petrels, and Razorbills, with lower concentrations in other species, the lowest being in Common Eiders. Storm-petrels prey on mesopelagic fish that accumulate mercury, and Razorbills feed on larger, older fish that bioaccumulate heavy metals. Biomagnification of Hg, or the increase in Hg concentration with trophic position as measured by delta(15)N, was significant and greater in albumen than other tissues, whereas in other tissues, delta(15)N explained little of the overall variation in Hg concentration. Hg concentrations in egg components are higher on Machias Seal Island than other sites globally and in the Gulf of Maine region, but only for some species. Further detailed investigations are required to determine the cause of this trend. PMID:19419752

  17. Lead, cadmium and mercury levels in the 2010 Korean diet.

    PubMed

    Kim, Jae Hoon; Lee, Ji Yeon; Seo, Joo Ee; Jeong, Ji Yoon; Jung, Ki Kyung; Yoon, Hae Jung; Park, Kyung Su

    2012-01-01

    This study analysed the level of contamination of harmful heavy metals in 3820 food samples available in Korea in 2010. A total of 119 types of samples were collected, including corns, vegetables, fruits, fishes, mollusks, shellfish, crustaceans, seaweed, bean products, meats and eggs from seven major cities. These samples were analysed using ICP-MS after pre-treatment with a microwave-digestion system. Results of lead, cadmium and mercury analyses were compared with the standard specifications of Korea Food Standards Codex. As a result, high levels of Pb, Cd and Hg were detected in "cockle," "dried-squid" and "shark-meat." Acceptable intake for consumers was checked using provisional tolerable weekly intake values. Such results will be utilised as data on the exposure of human body through foods. In addition, satisfactory results were obtained through purchase and analysis of National Institute of Science and Technology-certified reference materials to obtain reliability on analysis results. PMID:24786406

  18. 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

  19. Mercury in the pelagic food web of Lake Champlain.

    PubMed

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

    2012-04-01

    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 25-75% in summertime dissolved eplimnetic total mercury will likely allow fish tissue mercury concentrations to drop to the target level of 0.3 ?g 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

  20. Concentrations of mercury in tissues of striped dolphins suggest decline of pollution in Mediterranean open waters.

    PubMed

    Borrell, A; Aguilar, A; Tornero, V; Drago, M

    2014-07-01

    The Mediterranean is a semi-enclosed sea subject to high mercury (Hg) pollution from both natural and anthropogenic sources. With the objective of discerning temporal changes in marine Hg pollution in the oceanic waters of the northwestern Mediterranean Sea, we analysed liver and kidney from striped dolphins (Stenella coeruleoalba) collected during 2007-2009 and compared them with previous results from a similar sample from 1990-1993. The effect of body length and sex on tissue Hg concentrations was investigated to ensure an unbiased comparison between the periods. The Hg concentrations did not show significant sex-related differences in any tissue or period but were correlated positively with body length. Using body length as a covariate, Hg concentrations in liver and kidney were higher in 1990-1993 than in 2007-2009. This result suggests that measures to reduce emissions in Western European countries have been effective in reducing mercury pollution in Mediterranean open waters. PMID:24461428

  1. 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.

  2. Strategies for organ level tissue engineering.

    PubMed

    Rustad, Kristine C; Sorkin, Michael; Levi, Benjamin; Longaker, Michael T; Gurtner, Geoffrey C

    2010-01-01

    The field of tissue engineering has made considerable strides since it was first described in the late 1980s. The advent and subsequent boom in stem cell biology, emergence of novel technologies for biomaterial development and further understanding of developmental biology have contributed to this accelerated progress. However, continued efforts to translate tissue-engineering strategies into clinical therapies have been hampered by the problems associated with scaling up laboratory methods to produce large, complex tissues. The significant challenges faced by tissue engineers include the production of an intact vasculature within a tissue-engineered construct and recapitulation of the size and complexity of a whole organ. Here we review the basic components necessary for bioengineering organs-biomaterials, cells and bioactive molecules-and discuss various approaches for augmenting these principles to achieve organ level tissue engineering. Ultimately, the successful translation of tissue-engineered constructs into everyday clinical practice will depend upon the ability of the tissue engineer to "scale up" every aspect of the research and development process. PMID:21197216

  3. Mercury and selenium interaction: A review

    Microsoft Academic Search

    M. L. Cuvin-Aralar; R. W. Furness

    1991-01-01

    This paper reviews studies on mercury and selenium interaction. It includes the effects of selenium on mercury toxicity on the organism, organ\\/tissue, and subcellular levels. The paper also touches on possible mechanisms for the protective action of selenium against mercury toxicity and deals briefly with the synergism between the two elements. 71 references.

  4. Chapter A5. Section 6.4.B. Low-Level Mercury

    USGS Publications Warehouse

    Lewis, Michael Edward; Brigham, Mark E.

    2004-01-01

    Collecting and processing water samples for analysis of mercury at a low (subnanogram per liter) level requires use of ultratrace-level techniques for equipment cleaning, sample collection, and sample processing. Established techniques and associated quality-assurance (QA) procedures for the collection and processing of water samples for trace-element analysis at the part-per-billion level (NFM 3-5) are not adequate for low-level mercury samples. Modifications to the part-per-billion procedures are necessary to minimize contamination of samples at a typical ambient mercury concentration, which commonly is at the subnanogram-per-liter level.

  5. 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...

  6. 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.

  7. Investigation of increased mercury levels in the fisheries of Lower East Fork Poplar Creek (Lefpc), Oak Ridge Reservation, Tennessee

    SciTech Connect

    Byrne-Kelly, D.; Cornish, J.; Hart, A. [MSE Technology Applications, Inc., 200 Technology Way, Butte, MT (United States); Southworth, G. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Sims, L. [Bechtel Jacobs Company, Oak Ridge, TN (United States)

    2007-07-01

    The DOE Western Environmental Technology Office (WETO) is supporting remediation efforts on the U.S. Department of Energy Oak Ridge Reservation in Oak Ridge, Tennessee by performing this study. MSE Technology Applications, Inc. (MSE) has performed a series of literature reviews and bench-scale testing to further evaluate the mercury problem in the Lower East Fork Poplar Creek (LEFPC) at Oak Ridge. The primary problem is that total mercury (HgT) levels in LEFPC water decrease, while HgT levels in sunfish muscle tissue increase, with distance away from the National Security Complex (NSC), despite extensive source control efforts at the facility and within downstream riparian zones. Furthermore, dissolved methylmercury (d-MeHg) levels increase downstream from the NSC, especially during warm weather and/or high flow events. MSE performed four test series that focused on conversion of aqueous phase elemental mercury (Hg deg. A) to methyl mercury (MeHg) by algal-bacterial bio-films (periphyton) present in the stream-bed of LEFPC. Small (mg/L) quantities of un-sulphured molasses and peptone were added to some of the Hinds Creek samples to stimulate initial bacterial growth. Other Hinds Creek samples either were dosed with glutaraldehyde to preclude microbial growth, or were wrapped in aluminum foil to preclude Hg photochemical redox effects. The bench-scale testing for Phase II was completed August 2006. The final reporting and the planning for Phase III testing are in progress. (authors)

  8. Mercury Reduction and Removal from High Level Waste at the Defense Waste Processing Facility - 12511

    SciTech Connect

    Behrouzi, Aria [Savannah River Remediation, LLC (United States); Zamecnik, Jack [Savannah River National Laboratory, Aiken, South Carolina, 29808 (United States)

    2012-07-01

    The Defense Waste Processing Facility processes legacy nuclear waste generated at the Savannah River Site during production of enriched uranium and plutonium required by the Cold War. The nuclear waste is first treated via a complex sequence of controlled chemical reactions and then vitrified into a borosilicate glass form and poured into stainless steel canisters. Converting the nuclear waste into borosilicate glass is a safe, effective way to reduce the volume of the waste and stabilize the radionuclides. One of the constituents in the nuclear waste is mercury, which is present because it served as a catalyst in the dissolution of uranium-aluminum alloy fuel rods. At high temperatures mercury is corrosive to off-gas equipment, this poses a major challenge to the overall vitrification process in separating mercury from the waste stream prior to feeding the high temperature melter. Mercury is currently removed during the chemical process via formic acid reduction followed by steam stripping, which allows elemental mercury to be evaporated with the water vapor generated during boiling. The vapors are then condensed and sent to a hold tank where mercury coalesces and is recovered in the tank's sump via gravity settling. Next, mercury is transferred from the tank sump to a purification cell where it is washed with water and nitric acid and removed from the facility. Throughout the chemical processing cell, compounds of mercury exist in the sludge, condensate, and off-gas; all of which present unique challenges. Mercury removal from sludge waste being fed to the DWPF melter is required to avoid exhausting it to the environment or any negative impacts to the Melter Off-Gas system. The mercury concentration must be reduced to a level of 0.8 wt% or less before being introduced to the melter. Even though this is being successfully accomplished, the material balances accounting for incoming and collected mercury are not equal. In addition, mercury has not been effectively purified and collected in the Mercury Purification Cell (MPC) since 2008. A significant cleaning campaign aims to bring the MPC back up to facility housekeeping standards. Two significant investigations are being undertaken to restore mercury collection. The SMECT mercury pump has been removed from the tank and will be functionally tested. Also, research is being conducted by the Savannah River National Laboratory to determine the effects of antifoam addition on the behavior of mercury. These path forward items will help us better understand what is occurring in the mercury collection system and ultimately lead to an improved DWPF production rate and mercury recovery rate. (authors)

  9. Mercury correlations among six tissues for four waterbird species breeding in San Francisco Bay, California, USA

    USGS Publications Warehouse

    Eagles-Smith, C. A.; Ackerman, J.T.; Adelsbach, T.L.; Takekawa, J.Y.; Miles, A.K.; Keister, R.A.

    2008-01-01

    Despite a large body of research concerning mercury (Hg) in birds, no single tissue has been used consistently to assess Hg exposure, and this has hampered comparisons across studies. We evaluated the relationships of Hg concentrations among tissues in four species of waterbirds (American avocets [Recurvirostra americana], black-necked stilts [Himantopus mexicanus], Caspian terns [Hydroprogne caspia; formerly Sterna caspia], and Forster's terns [Sterna forsteri]) and across three life stages (prebreeding adults, breeding adults, and chicks) in San Francisco Bay, California, USA. Across species and life stages, Hg concentrations (least square mean ?? standard error) were highest in head feathers (6.45 ?? 0.31 ??g/g dry wt) and breast feathers (5.76 ?? 0.28 ??g/g dry wt), followed by kidney (4.54 ?? 0.22 ??g/g dry wt), liver (4.43 ?? 0.21 ??g/g dry wt), blood (3.10 ?? 0.15 ??g/g dry wt), and muscle (1.67 ?? 0.08 ??g/g dry wt). Relative Hg distribution among tissues, however, differed by species and life stage. Mercury concentrations were highly correlated among internal tissues (r 2 ??? 0.89). Conversely, the relationships between Hg in feathers and internal tissues were substantially weaker (r2 ??? 0.42). Regression slopes sometimes differed among species and life stages, indicating that care must be used when predicting Hg concentrations in one tissue based on those in another. However, we found good agreement between predictions made using a general tissue-prediction equation and more specific equations developed for each species and life stage. Finally, our results suggest that blood is an excellent, nonlethal predictor of Hg concentrations in internal tissues but that feathers are relatively poor indicators of Hg concentrations in internal tissues. ?? 2008 SETAC Printed in the USA.

  10. Mercury correlations among six tissues for four waterbird species breeding in San Francisco Bay, California, USA.

    PubMed

    Eagles-Smith, Collin A; Ackerman, Joshua T; Adelsbach, Terrence L; Takekawa, John Y; Miles, A Keith; Keister, Robin A

    2008-10-01

    Despite a large body of research concerning mercury (Hg) in birds, no single tissue has been used consistently to assess Hg exposure, and this has hampered comparisons across studies. We evaluated the relationships of Hg concentrations among tissues in four species of waterbirds (American avocets [Recurvirostra americana], black-necked stilts [Himantopus mexicanus], Caspian terns [Hydroprogne caspia; formerly Sterna caspia], and Forster's terns [Sterna forsteri]) and across three life stages (prebreeding adults, breeding adults, and chicks) in San Francisco Bay, California, USA. Across species and life stages, Hg concentrations (least square mean +/- standard error) were highest in head feathers (6.45 +/- 0.31 microg/g dry wt) and breast feathers (5.76 +/- 0.28 microg/g dry wt), followed by kidney (4.54 +/- 0.22 microg/g dry wt), liver (4.43 +/- 0.21 microg/g dry wt), blood (3.10 +/- 0.15 microg/g dry wt), and muscle (1.67 +/- 0.08 microg/g dry wt). Relative Hg distribution among tissues, however, differed by species and life stage. Mercury concentrations were highly correlated among internal tissues (r2 > or = 0.89). Conversely, the relationships between Hg in feathers and internal tissues were substantially weaker (r2 < or = 0.42). Regression slopes sometimes differed among species and life stages, indicating that care must be used when predicting Hg concentrations in one tissue based on those in another. However, we found good agreement between predictions made using a general tissue-prediction equation and more specific equations developed for each species and life stage. Finally, our results suggest that blood is an excellent, nonlethal predictor of Hg concentrations in internal tissues but that feathers are relatively poor indicators of Hg concentrations in internal tissues. PMID:18444697

  11. Determination of mercury speciation in fish tissue with a direct mercury analyzer.

    PubMed

    Barst, Benjamin D; Hammerschmidt, Chad R; Chumchal, Matthew M; Muir, Derek C G; Smith, James D; Roberts, Aaron P; Rainwater, Thomas R; Drevnick, Paul E

    2013-06-01

    Knowledge of Hg speciation in tissue is valuable for assessing potential toxicological effects in fish. Direct Hg analyzers, which use thermal decomposition and atomic absorption spectrometry, have recently gained popularity for determining organic Hg after procedural solvent extraction from some environmental media, although quantitative recovery from lipid-rich materials, such as fish liver, has been problematic. The authors developed a new method by which organic Hg in fish liver and muscle is estimated by the difference between direct measurements of inorganic Hg in an acid extract and total Hg in whole tissue. The method was validated by analysis of a certified reference material (DOLT-4 dogfish liver) and naturally contaminated fish tissues with comparison to an established Hg speciation method (gas chromatography cold vapor atomic fluorescence spectrometry). Recovery of organic Hg from DOLT-4, estimated by difference, averaged 99?±?5% of the mean certified value for methylmercury. In most liver samples and all muscle samples, estimates of organic Hg from the proposed method were indiscernible from direct speciation measurements of methylmercury (99%?±?6%). Estimation of organic Hg by the difference between total Hg and inorganic Hg was less accurate in liver samples with a high percentage of inorganic Hg (90%). This was because of the increased uncertainty that results from estimating a third value (i.e., organic Hg) by using the difference between two large concentrations (inorganic and total Hg). The proposed method is a useful tool for examining the speciation of Hg in fish muscle and liver, and by extension, potentially other tissues and environmental media. PMID:23417790

  12. Elevated mercury levels in pregnant woman linked to skin cream from Mexico.

    PubMed

    Dickenson, Carrie A; Woodruff, Tracey J; Stotland, Naomi E; Dobraca, Dina; Das, Rupali

    2013-08-01

    Mercury exposure during pregnancy can have serious health effects for a developing fetus including impacting the child's neurologic and cognitive development. Through biomonitoring in a low-income Latina population in California, we identified a patient with high levels of mercury and traced the source to face creams purchased in a pharmacy in Mexico. PMID:23685000

  13. 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

  14. Studies of Mercury in High Level Waste Systems

    Microsoft Academic Search

    Wilmarth

    2003-01-01

    During nuclear weapons production, nuclear reactor target and fuel rods were processed in F- and H-Canyons. For the target rods, a caustic dissolution of the aluminum cladding was performed prior to nitric acid dissolution of the uranium metal targets in the large canyon dissolvers. To dissolve the aluminum cladding and the U-Al fuel, mercury in the form of soluble mercury

  15. 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

  16. Mercury Intoxication: Lack of Correlation Between Symptoms and Levels

    Microsoft Academic Search

    Jyothsna Gattineni; Susan Weiser; Amy M. Becker; Michel Baum

    2007-01-01

    The incidence of mercury intoxication has decreased considerably because of stricter public health regulations. However, it has not been completely eliminated and should be considered in a child with unexplained tachycardia, hypertension, mood changes, weight loss, and acrodynia. Mercury intoxication can be difficult to differentiate from pheochromocytoma and Kawasaki's disease. Here, the authors report the case of an 8-year-old boy

  17. Localizing organomercury uptake and accumulation in zebrafish larvae at the tissue and cellular level

    PubMed Central

    Korbas, Malgorzata; Blechinger, Scott R.; Krone, Patrick H.; Pickering, Ingrid J.; George, Graham N.

    2008-01-01

    Using synchrotron x-ray fluorescence mapping, we have examined the uptake and localization of organic mercury in zebrafish larvae. Strikingly, the greatest accumulation of methyl and ethyl mercury compounds was highly localized in the rapidly dividing lens epithelium, with lower levels going to brain, optic nerve, and various other organs. The data suggest that the reported impairment of visual processes by mercury may arise not only from previously reported neurological effects, but also from direct effects on the ocular tissue. This novel approach is a powerful tool for directly investigating the molecular toxicology of heavy metals, and should be equally applicable to the study of a wide range of elements in developing embryos. PMID:18719123

  18. Localizing Organomercury Uptake And Accumulation in Zebrafish Larvae at the Tissue And Cellular Level

    SciTech Connect

    Korbas, M.; Blechinger, S.R.; Krone, P.H.; Pickering, I.J.; George, G.N.

    2009-05-20

    Using synchrotron x-ray fluorescence mapping, we have examined the uptake and localization of organic mercury in zebrafish larvae. Strikingly, the greatest accumulation of methyl and ethyl mercury compounds was highly localized in the rapidly dividing lens epithelium, with lower levels going to brain, optic nerve, and various other organs. The data suggest that the reported impairment of visual processes by mercury may arise not only from previously reported neurological effects, but also from direct effects on the ocular tissue. This novel approach is a powerful tool for directly investigating the molecular toxicology of heavy metals, and should be equally applicable to the study of a wide range of elements in developing embryos.

  19. Dietary Predictors of Maternal Prenatal Blood Mercury Levels in the ALSPAC Birth Cohort Study

    PubMed Central

    Steer, Colin D.; Hibbeln, Joseph R.; Emmett, Pauline M.; Lowery, Tony; Jones, Robert

    2013-01-01

    Background: Very high levels of prenatal maternal mercury have adverse effects on the developing fetal brain. It has been suggested that all possible sources of mercury should be avoided. However, although seafood is a known source of mercury, little is known about other dietary components that contribute to the overall levels of blood mercury. Objective: Our goal was to quantify the contribution of components of maternal diet to prenatal blood mercury level. Methods: Whole blood samples and information on diet and sociodemographic factors were collected from pregnant women (n = 4,484) enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC). The blood samples were assayed for total mercury using inductively coupled plasma dynamic reaction cell mass spectrometry. Linear regression was used to estimate the relative contributions of 103 dietary variables and 6 sociodemographic characteristics to whole blood total mercury levels (TBM; untransformed and log-transformed) based on R2 values. Results: We estimated that maternal diet accounted for 19.8% of the total variation in ln-TBM, with 44% of diet-associated variability (8.75% of the total variation) associated with seafood consumption (white fish, oily fish, and shellfish). Other dietary components positively associated with TBM included wine and herbal teas, and components with significant negative associations included white bread, meat pies or pasties, and french fries. Conclusions: Although seafood is a source of dietary mercury, seafood appeared to explain a relatively small proportion of the variation in TBM in our UK study population. Our findings require confirmation, but suggest that limiting seafood intake during pregnancy may have a limited impact on prenatal blood mercury levels. Citation: Golding J, Steer CD, Hibbeln JR, Emmett PM, Lowery T, Jones R. 2013. Dietary predictors of maternal prenatal blood mercury levels in the ALSPAC birth cohort study. Environ Health Perspect 121:1214–1218;?http://dx.doi.org/10.1289/ehp.1206115 PMID:23811414

  20. Mercury levels in Great Lakes herring gull eggs, 1972--1992

    SciTech Connect

    Weseloh, D.V.; Koster, M.D.; Ryckman, D.P.; Struger, J. [Canadian Wildlife Service, Burlington, Ontario (Canada). Canada Centre for Inland Waters

    1995-12-31

    Since 1971, the herring gull (Larus argentatus) has been used as a sentinel species for monitoring the levels of persistent contaminants in the Great Lakes ecosystem. In this study, 21 herring gull colonies in the Great Lakes and connecting channels were sampled for years 1972--1976, 1981--1983, 1985 and 1992. For each year, 10 eggs (usually) were collected from each colony site and analyzed for total mercury (ppm, wet weight). Results indicated that eggs from Lake Ontario displayed the highest mercury levels, mean = 0.28 (s.d. = 0.08) to 0.73 (0.23). Lake Erie typically displayed the lowest egg mercury levels, 0.18 (0.08) to 0.24 (0.11). Overall, mercury levels ranged from 0.12 (0.02) in 1985 to 0.88 (0.23) in 1982 for Channel-Shelter Island (Lake Huron) and Pigeon Island (Lake Ontario), respectively. Generally, all colony sites showed peak mercury levels in 1982. A significant decline in egg mercury levels was observed in six colony sites between 1972 and 1992 and in three colony sites between 1981 and 1992. The mean herring gull egg mercury levels observed in the early and mid 1970s and in 1982 for some colony sites were within the range found which potentially reduces hatchability in other fish-eating bird species.

  1. Blood mercury levels among fish consumers residing in areas with high environmental burden.

    PubMed

    Wolkin, Amy; Hunt, Danielle; Martin, Colleen; Caldwell, Kathleen L; McGeehin, Michael A

    2012-03-01

    Mercury is a ubiquitous, persistent toxicant found in the environment. In water, mercury bioaccumulates up the food chain and leads to high concentrations in fish. Consumption of contaminated fish is the major source of exposure to mercury in the US. The objective of this study was to enroll persons living in areas selected by the Environmental Protection Agency (EPA) to have high mercury concentrations and who consume at least 6o z of locally caught fish per week to determine the feasibility of monitoring future trends among a population identified as highly exposed. Blood samples were collected at time of interview and analyzed for mercury. Participants (n=287) were enrolled from North Carolina, Maryland, and South Dakota. Participants reported eating an average of five servings of fish per week. The overall geometric mean for total mercury was 0.75 ?g L(-1), with North Carolina having the highest mean level (2.02 ?g L(-1)). Overall, 42% of the study population had levels greater than the US geometric mean 0.83 ?g L(-1). The number of servings of fish consumed was not found to be associated with blood mercury levels. We were able to identify some persons with elevated mercury concentrations living in areas identified by EPA; however, identifying and monitoring a highly exposed population over time would be challenging. PMID:22153999

  2. Fish consumption and hair mercury levels in women of childbearing age, Martin County, Florida.

    PubMed

    Nair, Anil; Jordan, Melissa; Watkins, Sharon; Washam, Robert; DuClos, Chris; Jones, Serena; Palcic, Jason; Pawlowicz, Marek; Blackmore, Carina

    2014-12-01

    The health effects of mercury in humans are mostly on the developing nervous system. Pregnant women and women who are breastfeeding must be targeted in order to decrease mercury exposure to the populations at highest risk-infants, unborn fetuses, and young children. This purpose of this study is to understand the demographics of fish-consumption patterns among women of childbearing age (including pregnant women) in Martin County, Florida, and to analyze the associations of mercury levels in participants' hair with socio-demographic variables in order to better design prevention messages and campaigns. Mercury concentrations in hair samples of 408 women ages 18-49 were assessed. Data on demographic factors, pregnancy status, fish consumption, and awareness of fish advisories were collected during personal interviews. Data were analyzed using descriptive statistics and multivariate logistic regression. The geometric and arithmetic means of hair mercury concentration were 0.371 and 0.676 µg/g of hair. One-fourth of the respondents had a concentration ?1 µg/g of hair. Consuming a higher number of fish meals per month, consumption of commercially purchased or locally caught fish higher in mercury, White race and income ?$75,000 were positively associated with the likelihood of having higher hair mercury levels. This study confirms the existence of a higher overall mean hair mercury level and a higher percentage of women with ?1 µg/g hair mercury level than those reported at the national level and in other regional studies. This suggests the need for region-specific fish consumption advisories to minimize mercury exposure in humans. PMID:24807406

  3. Relations between total mercury, methylmercury and selenium in five tissues of Sepia officinalis captured in the south Portuguese coast.

    PubMed

    Raimundo, Joana; Pereira, Patrícia; Vale, Carlos; Canário, João; Gaspar, Miguel

    2014-08-01

    Mercury, methylmercury and selenium were determined in digestive gland, branchial hearts, mantle, kidney and gills of Sepia officinalis from two areas of the south Portuguese coast. To the best of our knowledge these are the first data on Hg, MeHg and Se in branchial hearts, kidney and gills of cuttlefish. Digestive gland, branchial hearts and kidney presented higher levels of Hg and Se than mantle and gills. Methylmercury was significantly higher in digestive gland, branchial hearts and mantle. The enhanced levels of Hg in digestive gland and branchial heart reinforce the elevated storage capacity of these two tissues. The percentage of MeHg varied from 6.1% in gills to 92% in mantle. Linear and positive MeHg-Hg relations were obtained for the five tissues, being the better relation and higher slope observed for mantle, followed by branchial hearts, digestive gland, kidney and gills. The Se:Hg molar ratios showed a surplus of Se in all tissues. Calculations based on the equimolarity of Se:Hg point that 95-99% of Se are not linked to Hg (Se free). The negligible quantity of Se associated with Hg suggests that the mechanism of MeHg demethylation was not triggered in none of the tissues, presumably because the threshold for MeHg toxicity was not achieved. PMID:24582035

  4. 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

  5. MERCURY LEVELS IN HAWAIIAN PREDATORY PEI-AGIC FISHES AND THEIR PREY ASA FUNCTION OF DEPTH AND ECOLOGY

    E-print Network

    Luther, Douglas S.

    MERCURY LEVELS IN HAWAIIAN PREDATORY PEI-AGIC FISHES AND THEIR PREY ASA FUNCTION OF DEPTH Gregory F,. P.av:.zza N{argaretA. N.,Icl\\{anus #12;ABSTRACT Mercury is drstributedthroughout the Earth in plants and animals. Inter- and intra-specific variations in mercury levels of predatory pelagic fish have

  6. Increased Mercury Levels in Patients with Celiac Disease following a Gluten-Free Regimen

    PubMed Central

    Elli, Luca; Rossi, Valentina; Conte, Dario; Ronchi, Anna; Tomba, Carolina; Passoni, Manuela; Bardella, Maria Teresa; Roncoroni, Leda; Guzzi, Gianpaolo

    2015-01-01

    Background and Aim. Although mercury is involved in several immunological diseases, nothing is known about its implication in celiac disease. Our aim was to evaluate blood and urinary levels of mercury in celiac patients. Methods. We prospectively enrolled 30 celiac patients (20 treated with normal duodenal mucosa and 10 untreated with duodenal atrophy) and 20 healthy controls from the same geographic area. Blood and urinary mercury concentrations were measured by means of flow injection inductively coupled plasma mass spectrometry. Enrolled patients underwent dental chart for amalgam fillings and completed a food-frequency questionnaire to evaluate diet and fish intake. Results. Mercury blood/urinary levels were 2.4 ± 2.3/1.0 ± 1.4, 10.2 ± 6.7/2.2 ± 3.0 and 3.7 ± 2.7/1.3 ± 1.2 in untreated CD, treated CD, and healthy controls, respectively. Resulting mercury levels were significantly higher in celiac patients following a gluten-free diet. No differences were found regarding fish intake and number of amalgam fillings. No demographic or clinical data were significantly associated with mercury levels in biologic samples. Conclusion. Data demonstrate a fourfold increase of mercury blood levels in celiac patients following a gluten-free diet. Further studies are needed to clarify its role in celiac mechanism. PMID:25802516

  7. Mercury

    NSDL National Science Digital Library

    This NASA (National Aeronautics and Space Administration) planet profile provides data and images of the planet Mercury. These data include planet size, distance from the Sun, rotation and revolution times, temperature, atmospheric composition, density, and albedo. Images of the planet include general surface features such as crater basins, the Caloris Basin, and other images taken by the Mariner 10 spacecraft.

  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. Health effects in the Flemish population in relation to low levels of mercury exposure: from organ to transcriptome level.

    PubMed

    Croes, Kim; De Coster, Sam; De Galan, Sandra; Morrens, Bert; Loots, Ilse; Van de Mieroop, Els; Nelen, Vera; Sioen, Isabelle; Bruckers, Liesbeth; Nawrot, Tim; Colles, Ann; Den Hond, Elly; Schoeters, Greet; van Larebeke, Nicolas; Baeyens, Willy; Gao, Yue

    2014-03-01

    Due to possible health risks, quantification of mercury accumulation in humans was included in the Flemish biomonitoring programmes FLEHS I (2002-2006) and FLEHS II (2007-2011). The general objective of FLEHS I was to assess regional exposure levels in order to link possible differences in these internal exposure levels to different types of local environmental pressure. Therefore, Hg and MMHg (methylmercury) were only measured in pooled blood samples per region and per age class. In FLEHS II, mercury concentrations were measured in hair of each participant. About 200 adolescents and 250 mothers (reference group) and two times 200 adolescents (2 hotspots) were screened. The main objectives of the FLEHS II study were: (1) to determine reference levels of mercury in hair for Flanders; (2) to assess relations between mercury exposure and possible sources like fish consumption; (3) to assess dose-effect relations between mercury exposure and health effect markers. The results showed that mercury concentrations in the Flemish population were rather low compared to other studies. Mercury levels in the Flemish populations were strongly related to the age of the participants and consumption of fish. Significant negative associations were observed between mercury in hair and asthma, having received breast feeding as a newborn, age at menarche in girls, allergy for animals and free testosterone levels. Significant correlations were also observed between mercury in hair and genes JAK2, ARID4A, Hist1HA4L (boys) and HLAdrb5, PIAS2, MANN1B1, GIT and ABCA1 (girls). PMID:23920476

  10. Temporal characterization of mercury accumulation at different trophic levels and implications for metal biomagnification along a coastal food web.

    PubMed

    Cardoso, P G; Pereira, E; Duarte, A C; Azeiteiro, U M

    2014-10-15

    The main goal of this study was to assess temporal mercury variations along an estuarine food web to evaluate the mercury contamination level of the system and the risks that humans are exposed to, due to mercury biomagnification. The highest mercury concentrations in the sediments and primary producers (macrophytes) were observed during winter sampling. Instead, the highest mercury concentrations in the water, suspended particulate matter as well as in the zooplanktonic and suprabenthic communities were observed during summer sampling. Evidences of mercury biomagnification along the food web were corroborated by the positive biomagnification factors, particularly for omnivorous macrobenthic species. Comparing the mercury levels at distinct components with several environmental quality criteria it suggests that sediments, water and edible species (e.g., bivalve Scrobicularia plana and the crustacean Carcinus maenas) presented higher mercury levels than the values accepted by legislation which represent a matter of concern for the environment and human health. PMID:25172612

  11. Mercury levels of small fishes: influence of size and catch area

    Microsoft Academic Search

    Wen Jye Mok; MokManabu Seoka; Yasuyuki Tsukamasa; Ken-ichi Kawasaki; Masashi Ando

    In the present study, we assessed small fishes as potential feed fishes with the lowest mercury levels. The mercury levels\\u000a of four small pelagic fishes and a benthic fish from the Pacific Ocean and the Sea of Japan, i.e., spotted chub mackerel Scomber australasicus, chub mackerel Scomber japonicus, horse mackerel Trachurus trachurus, round scad Decapterus punctatus, and bastard halibut Paralichthys

  12. Mercury in Canadian prairie ducks

    Microsoft Academic Search

    K. Vermeer; F. A. J. Armstrong

    1972-01-01

    Tissues of 190 ducks, shot on the Canadian prairie during the hunting seasons of 1969 and 1970, were analyzed for mercury residues. Residue levels of over 0.5 ppm were found only in breast muscle of common mergansers (Mergus merganser). Livers contained, on the average, 2.9 times as much mercury as breast muscles. Primary feathers contained, on the average, 12 times

  13. Mercury

    NASA Technical Reports Server (NTRS)

    Gault, D. E.; Burns, J. A.; Cassen, P.; Strom, R. G.

    1977-01-01

    Prior to the flight of the Mariner 10 spacecraft, Mercury was the least investigated and most poorly known terrestrial planet (Kuiper 1970, Devine 1972). Observational difficulties caused by its proximity to the Sun as viewed from Earth caused the planet to remain a small, vague disk exhibiting little surface contrast or details, an object for which only three major facts were known: 1. its bulk density is similar to that of Venus and Earth, much greater than that of Mars and the Moon; 2. its surface reflects electromagnetic radiation at all wavelengths in the same manner as the Moon (taking into account differences in their solar distances); and 3. its rotation period is in 2/3 resonance with its orbital period. Images obtained during the flyby by Mariner 10 on 29 March 1974 (and the two subsequent flybys on 21 September 1974 and 16 March 1975) revealed Mercury's surface in detail equivalent to that available for the Moon during the early 1960's from Earth-based telescopic views. Additionally, however, information was obtained on the planet's mass and size, atmospheric composition and density, charged-particle environment, and infrared thermal radiation from the surface, and most significantly of all, the existence of a planetary magnetic field that is probably intrinsic to Mercury was established. In the following, this new information is summarized together with results from theoretical studies and ground-based observations. In the quantum jumps of knowledge that have been characteristic of "space-age" exploration, the previously obscure body of Mercury has suddenly come into sharp focus. It is very likely a differentiated body, probably contains a large Earth-like iron-rich core, and displays a surface remarkably similar to that of the Moon, which suggests a similar evolutionary history.

  14. Low-Cost Options for Moderate Levels of Mercury Control

    SciTech Connect

    Sharon Sjostrom

    2006-03-31

    On March 15, 2005, EPA issued the Clean Air Mercury Rule, requiring phased-in reductions of mercury emissions from electric power generators. ADA-ES, Inc., with support from DOE/NETL and industry partners, is conducting evaluations of EPRI's TOXECON II{trademark} process and of high-temperature reagents and sorbents to determine the capabilities of sorbent/reagent injection, including activated carbon, for mercury control on different coals and air emissions control equipment configurations. DOE/NETL targets for total mercury removal are {ge}55% (lignite), {ge}65% (subbituminous), and {ge}80% (bituminous). Based on work done to date at various scales, meeting the removal targets appears feasible. However, work needs to progress to more thoroughly document and test these promising technologies at full scale. This is the final site report for tests conducted at MidAmerican's Louisa Station, one of three sites evaluated in this DOE/NETL program. The other two sites in the program are MidAmerican's Council Bluff Station and Entergy's Independence Station. MidAmerican's Louisa Station burns Powder River Basin (PRB) coal and employs hot-side electrostatic precipitators with flue gas conditioning for particulate control. This part of the testing program evaluated the effect of reagents used in the existing flue gas conditioning on mercury removal.

  15. Impact of Wildfire on Levels of Mercury in Forested Watershed Systems - Voyageurs National Park, Minnesota

    USGS Publications Warehouse

    Woodruff, Laurel G.; Sandheinrich, Mark B.; Brigham, Mark E.; Cannon, William F.

    2009-01-01

    Atmospheric deposition of mercury to remote lakes in mid-continental and eastern North America has increased approximately threefold since the mid-1800s (Swain and others, 1992; Fitzgerald and others, 1998; Engstrom and others, 2007). As a result, concerns for human and wildlife health related to mercury contamination have become widespread. Despite an apparent recent decline in atmospheric deposition of mercury in many areas of the Upper Midwest (Engstrom and Swain, 1997; Engstrom and others, 2007), lakes in which fish contain levels of mercury deemed unacceptable for human consumption and possibly unacceptable for fish-consuming wildlife are being detected with increasing frequency. In northern Minnesota, Voyageurs National Park (VNP) (fig. 1) protects a series of southern boreal lakes and wetlands situated on bedrock of the Precambrian Canadian Shield. Mercury contamination has become a significant resource issue within VNP as high concentrations of mercury in loons, bald eagle eaglets, grebes, northern pike, and other species of wildlife and fish have been found. The two most mercury-contaminated lakes in Minnesota, measured as methylmercury in northern pike (Esox lucius), are in VNP. Recent multidisciplinary U.S. Geological Survey (USGS) research demonstrated that the bulk of the mercury in lake waters, soils, and fish in VNP results from atmospheric deposition (Wiener and others, 2006). The study by Wiener and others (2006) showed that the spatial distribution of mercury in watershed soils, lake waters, and age-1 yellow perch (Perca flavescens) within the Park was highly variable. The majority of factors correlated for this earlier study suggested that mercury concentrations in lake waters and age-1 yellow perch reflected the influence of ecosystem processes that affected within-lake microbial production and abundance of methylmercury (Wiener and others, 2006), while the distribution of mercury in watershed soils seemed to be partially dependent on forest disturbance, especially the historic forest fire pattern (Woodruff and Cannon, 2002). Forest fire has an essential role in the forest ecosystems of VNP (Heinselman, 1996). Because resource and land managers need to integrate both natural wildfire and prescribed fire in management plans, the potential influence of fire on an element as sensitive to the environment as mercury becomes a critical part of their decisionmaking. A number of recent studies have shown that while fire does have a significant impact on mercury at the landscape level, the observed effects of fire on aquatic environments are highly variable and unpredictable (Caldwell and others, 2000; Garcia and Carrigan, 2000; Kelly and others, 2006; Nelson and others, 2007). Caldwell and others (2000) described an increase in methylmercury in reservoir sediments resulting from mobilization and transport of charred vegetative matter following a fire in New Mexico. Krabbenhoft and Fink (2000) attributed increases in total mercury concentrations in young-of-the-year fish in the Florida Everglades to release of mercury resulting from peat oxidation following fires. A fivefold increase in whole-body mercury accumulation by rainbow trout (Oncorhynchus mykiss) following a fire in Alberta, Canada, apparently resulted from increased nutrient concentrations that enhanced productivity and restructured the food web of a lake within the fire's burn footprint (Kelly and others, 2006). For this study, we determined the short-term effects of forest fire on mercury concentrations in terrestrial and aquatic environments in VNP by comparing and contrasting mercury concentrations in forest soils, lake waters, and age-1 yellow perch for a burned watershed and an adjacent lake, with similar samples from watersheds and lakes with no fire activity (control watersheds and lakes). The concentration of total mercury in whole, 1-year-old yellow perch serves as a good biological indicator for monitoring trends in methylmercury conce

  16. 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.

  17. LEVEL AND EXTENT OF MERCURY CONTAMINATION IN OREGON, USA, LOTIC FISH

    EPA Science Inventory

    Because of growing concern with widespread mercury contamination of fish tissue, we sampled 154 streams and rivers throughout Oregon using a probability design. To maximize the sample size we took samples of small and large fish, where possible, from wadeable streams and boatable...

  18. 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

  19. Optimization of ultrasonic-assisted acid extraction of mercury in muscle tissues of fishes using multivariate strategy.

    PubMed

    Shah, Abdul Q; Kazii, Tasneem G; Arain, Mohammad B; Baig, Jameel A; Afridi, Hassan I; Jamali, Mohammad K; Jalbani, Nusrat; Kandhro, Ghulam A

    2009-01-01

    A simple and rapid ultrasound-assisted extraction procedure was developed for the determination of total mercury (Hg) in muscle tissues of freshwater fish species. A Plackett-Burman experimental design was used as a multivariate strategy for the evaluation of the effects of variables, such as presonication time (without ultrasonic stirring), sonication time, ultrasonic bath temperature, nitric acid concentration, hydrochloric acid concentration, and sample mass of muscle tissues. Some variables showed a significant effect on recovery, and they were further optimized by a 2(3) + star central composite design that involved 16 experiments. The validation was carried out by analysis of certified reference material DORM-2 (dog fish muscles); for comparative purposes, an acid digestion induced by microwave energy was used. Cold vapor atomic absorption spectrometry was used for the determination of total Hg. No significant differences were established between the analytical results and the certified values (paired t-test at P > 0.05). The LOD and LOQ of Hg were 0.133 and 0.445 microg/kg, respectively, which demonstrated the high sensitivity of the proposed procedure for the determination of Hg at trace levels. The Hg concentrations in the muscle tissues of 10 freshwater fish species were found in the range of 35.3-67.8 microg/kg on a dried basis, which were within the permissible limit of the World Health Organization. PMID:19916396

  20. Tuna fish diet influences cat behavior. [Elevated levels of selenium and mercury in commercial tuna fish cat food

    SciTech Connect

    Houpt, K.A.; Essick, L.A.; Shaw, E.B.; Alo, D.K.; Gilmartin, J.E.; Gutenmann, W.H.; Littman, C.B.; Lisk, D.J.

    1988-01-01

    When observed in their home cages, cats fed commercial tuna fish cat food were less active, vocalized less, and spent more time on the floor and more time eating than cats fed commercial beef cat food. There were no differences in response to human handling between the two groups. There were no differences in learning ability on a two-choice point maze or in reversal learning in the same maze between beef- and tuna-fed cats. The behavior of the groups differed in a 15-min open field test only in the number of toys contacted. Cats fed the tuna had elevated tissue levels of mercury and selenium.

  1. 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

  2. Low-Cost Options for Moderate Levels of Mercury Control

    SciTech Connect

    Sharon Sjostrom

    2008-02-09

    This is the final technical report for a three-site project that is part of an overall program funded by the U.S. Department of Energy's National Energy Technology Laboratory (DOE/NETL) and industry partners to obtain the necessary information to assess the feasibility and costs of controlling mercury from coal-fired utility plants. This report summarizes results from tests conducted at MidAmerican's Louisa Generating Station and Entergy's Independence Steam Electric Station (ISES) and sorbent screening at MidAmerican's Council Bluffs Energy Center (CBEC) (subsequently renamed Walter Scott Energy Center (WSEC)). Detailed results for Independence and Louisa are presented in the respective Topical Reports. As no full-scale testing was conducted at CBEC, screening updates were provided in the quarterly updates to DOE. ADA-ES, Inc., with support from DOE/NETL, EPRI, and other industry partners, has conducted evaluations of EPRI's TOXECON II{trademark} process and of high-temperature reagents and sorbents to determine the capabilities of sorbent/reagent injection, including activated carbon, for mercury control on different coals and air emissions control equipment configurations. An overview of each plant configuration is presented: (1) MidAmerican's Louisa Generating Station burns Powder River Basin (PRB) coal in its 700-MW Unit 1 and employs hot-side electrostatic precipitators (ESPs) with flue gas conditioning for particulate control. This part of the testing program evaluated the effect of reagents used in the existing flue gas conditioning on mercury removal. (2) MidAmerican's Council Bluffs Energy Center typically burns PRB coal in its 88-MW Unit 2. It employs a hot-side ESP for particulate control. Solid sorbents were screened for hot-side injection. (3) Entergy's Independence Steam Electric Station typically burns PRB coal in its 880-MW Unit 2. Various sorbent injection tests were conducted on 1/8 to 1/32 of the flue gas stream either within or in front of one of four ESP boxes (SCA = 542 ft{sup 2}/kacfm), specifically ESP B. Initial mercury control evaluations indicated that although significant mercury control could be achieved by using the TOXECON II{trademark} design, the sorbent concentration required was higher than expected, possibly due to poor sorbent distribution. Subsequently, the original injection grid design was modeled and the results revealed that the sorbent distribution pattern was determined by the grid design, fluctuations in flue gas flow rates, and the structure of the ESP box. To improve sorbent distribution, the injection grid and delivery system were redesigned and the effectiveness of the redesigned system was evaluated. This project was funded through the DOE/NETL Innovations for Existing Plants program. It was a Phase II project with the goal of developing mercury control technologies that can achieve 50-70% mercury capture at costs 25-50% less than baseline estimates of $50,000-$70,000/lb of mercury removed. Results from testing at Independence indicate that the DOE goal was successfully achieved. Further improvements in the process are recommended, however. Results from testing at Louisa indicate that the DOE goal was not achievable using the tested high-temperature sorbent. Sorbent screening at Council Bluffs also indicated that traditional solid sorbents may not achieve significant mercury removal in hot-side applications.

  3. 40 CFR Table 5 to Subpart IIIii of... - Required Elements of Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans 5 Table 5 to...Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants Pt. 63, Subpt...Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans Your...

  4. 40 CFR Table 5 to Subpart IIIii of... - Required Elements of Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans 5 Table 5 to...Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants Pt. 63, Subpt...Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans Your...

  5. 40 CFR Table 5 to Subpart IIIii of... - Required Elements of Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans 5 Table 5 to...Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants Pt. 63, Subpt...Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans Your...

  6. 40 CFR Table 5 to Subpart IIIii of... - Required Elements of Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans 5 Table 5 to...Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants Pt. 63, Subpt...Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans Your...

  7. 40 CFR Table 5 to Subpart IIIii of... - Required Elements of Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans 5 Table 5 to...Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants Pt. 63, Subpt...Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans Your...

  8. Potential risks of natural mercury levels to wild predator fish in an Amazon reservoir.

    PubMed

    da Silva, Grazyelle Sebrenski; Filipak Neto, Francisco; Silva de Assis, Helena Cristina; Bastos, Wanderley Rodrigues; de Oliveira Ribeiro, Ciro Alberto

    2012-08-01

    Mercury (Hg) is a toxic metal that bioaccumulates in aquatic organisms and along food chain. Many studies have reported the problem of mercury exposure in aquatic systems from Amazon basin, but very few have focused on the potential risks to wild fish. The present study reports the bioaccumulation of mercury and alterations in target organs of the predator fish Hoplias malabaricus (traíra) from Samuel reservoir, Amazon basin, Northern Brazil. About 18% of fish had mercury levels in muscle exceeding the safe limit for ingestion through food, established by WHO (0.5 ?g Hg g(-1)). Fish were separated in two groups according to mercury bioaccumulation in liver (<0.2 ?g Hg g(-1)-group I and >0.2 ?g Hg g(-1)-group II) for biomarker comparisons. Catalase activity and number of macrophage centers were statistically higher in group II, confirming the potential of Hg to interfere with redox balance and to recruit defense cells to the liver. Conversely, erythrocyte nuclear alterations were less frequent in group II, indicating a more rigorous selection of erythrocytes or hormesis pattern of response. Glutathione S-transferase activity, lipid peroxidation, and histopathological analyses were not statistically different in the liver and gills of both groups. Comparison of lipid peroxidation levels of these fish with others captured in Southern Brazil during another study and the high incidence of morphological alterations in the liver and gills suggest that the bioaccumulation of mercury during continuous exposure is posing potential risks to the species. PMID:21927790

  9. 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 ...

  10. 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...

  11. Low-Cost Options for Moderate Levels of Mercury Control

    Microsoft Academic Search

    Sharon Sjostrom

    2008-01-01

    This is the final technical report for a three-site project that is part of an overall program funded by the U.S. Department of Energy's National Energy Technology Laboratory (DOE\\/NETL) and industry partners to obtain the necessary information to assess the feasibility and costs of controlling mercury from coal-fired utility plants. This report summarizes results from tests conducted at MidAmerican's Louisa

  12. 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.

  13. 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.

  14. Influence of Methylmercury from Tributary Streams on Mercury Levels in Savannah River Asiatic Clams

    SciTech Connect

    Paller, M.H.

    2004-03-01

    Average methylmercury levels in five Savannah River tributary streams sampled 11 times over two years were nearly twice as high as in the Savannah River. Total mercury levels in the tributaries did not differ significantly from the river. All of the tributaries drained extensive wetlands that would be expected to support comparatively high rates of methylation. Mercury concentrations in Asiatic clams (Corbicula fluminea) collected from the discharge plumes of Savannah River tributaries were significantly higher than in Asiatic clams collected from the Savannah River upstream from the tributary mouths . These results indicate that streams draining wetlands into coastal plain rivers can create localized areas of elevated methylmercury with resulting increases in the mercury levels of river biota.

  15. 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

  16. 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.

  17. Pituitary gland levels of mercury, selenium, iron, and zinc in an Alzheimer`s disease study

    SciTech Connect

    Cornett, C.R.; Markesbery, W.R.; Wekstein, D.R.; Ehmann, W.D. [Univ. of Kentucky, Lexington, KY (United States)

    1996-12-31

    Mercury, iron, selenium, and zinc imbalances have been observed in comparisons between Alzheimer`s disease (AD) and control subject brains. Analyses of the pituitary gland have demonstrated that this organ retains relatively high concentrations of trace elements, including mercury, iron, and zinc. Our previous work has shown that the pituitary glands of AD and control subjects are typically higher in these trace elements than brain samples from the same subject. Instrumental neutron activation analysis (INAA) was used to compare the pituitary trace element levels of AD and control subjects. This study also describes the intrasubject relationships of brain trace element levels to those in the pituitary gland of AD and control subjects.

  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.

    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%.

  19. A statistical model and national data set for partioning fish-tissue mercury concentration variation between spatiotemporal and sample characteristic effects

    USGS Publications Warehouse

    Wente, Stephen P.

    2004-01-01

    Many Federal, Tribal, State, and local agencies monitor mercury in fish-tissue samples to identify sites with elevated fish-tissue mercury (fish-mercury) concentrations, track changes in fish-mercury concentrations over time, and produce fish-consumption advisories. Interpretation of such monitoring data commonly is impeded by difficulties in separating the effects of sample characteristics (species, tissues sampled, and sizes of fish) from the effects of spatial and temporal trends on fish-mercury concentrations. Without such a separation, variation in fish-mercury concentrations due to differences in the characteristics of samples collected over time or across space can be misattributed to temporal or spatial trends; and/or actual trends in fish-mercury concentration can be misattributed to differences in sample characteristics. This report describes a statistical model and national data set (31,813 samples) for calibrating the aforementioned statistical model that can separate spatiotemporal and sample characteristic effects in fish-mercury concentration data. This model could be useful for evaluating spatial and temporal trends in fishmercury concentrations and developing fish-consumption advisories. The observed fish-mercury concentration data and model predictions can be accessed, displayed geospatially, and downloaded via the World Wide Web (http://emmma.usgs.gov). This report and the associated web site may assist in the interpretation of large amounts of data from widespread fishmercury monitoring efforts.

  20. Shifts in relative tissue delta15N values in snowy egret nestlings with dietary mercury exposure: a marker for increased protein degradation.

    PubMed

    Shaw-Allen, Patricia L; Romanek, Christopher S; Bryan, A L; Brant, Heather; Jagoe, Charles H

    2005-06-01

    Shifts in tissue nitrogen isotope composition may be a more sensitive general indicator of stress than measurement of high-turnover defensive biomolecules such as metallothionein and glutathione. As a physical resource transmitted along the trophic web, perturbations in protein nitrogen metabolism may also help resolve issues concerning the effects of contaminants on organisms and their consequential hierarchical linkages in ecotoxicology. Snowy egret nestlings (Egretta thula) fed mercury-contaminated diets of constant nitrogen isotope composition exhibited increased relative delta15N values in whole liver (p = 0.0011) and the acid-soluble fraction (ASF) of the liver (p = 0.0005) when compared to nestlings fed a reference diet. When nitrogen isotope data were adjusted for the source term of the diet, liver mercury concentrations corresponded with both whole liver relative 15N enrichment (r2 = 0.79, slope 0.009, p < 0.0001) and relative 15N enrichment in the acid-soluble fraction of the liver (r2 = 0.85, slope 0.026, p < 0.0001). Meanwhile, significant differences were not observed in hepatic levels of the metal-binding peptides metallothionein and glutathione despite a nearly 3-fold difference in liver mercury content. Because increases in tissue delta15N values result from increased rates of protein breakdown relative to synthesis, we propose that the increased relative liver delta15N values reflect a shift in protein metabolism. The relationship between ASF and mercury was significantly stronger (p < 0.0001) than that for whole liver, suggesting that the relationship is driven by an increase in bodily derived amino acids in the acid-soluble, free amino acid pool. PMID:15984804

  1. 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.

  2. Mercury in polar bears from Alaska

    SciTech Connect

    Lentfer, J.W.; Galster, W.A.

    1987-04-01

    Alaskan polar bear (Ursus maritimus) muscle and liver samples collected in 1972 were analyzed for total mercury. Bears north of Alaska had more mercury than bears west of Alaska. The only difference between young and adult animals was in the northern area where adults had more mercury in liver tissue than young animals. Levels were probably not high enough to be a serious threat to bears.

  3. Comparative effect of oral ingestion of methyl mercury on chicks and rats

    Microsoft Academic Search

    J. H. Jr. Soares; D. Miller; H. Lagally; B. R. Stillings; P. Bauersfeld; S. Cuppett

    1973-01-01

    Two experiments with day-old chicks and one experiment with weanling rats were conducted to determine: (1) whether low levels of mercury found in some feedstuffs would result in hazardous accumulations of mercury in their tissues, and (2) the effects of feeding various dietary levels of methyl mercury to chicks and rats. Data show that feeding animal protein (fish meal) containing

  4. Hair mercury levels in relation to fish consumption in a community of the Moroccan Mediterranean coast.

    PubMed

    Elhamri, Hecham; Idrissi, Larbi; Coquery, Marina; Azemard, Sabine; El Abidi, Abdellah; Benlemlih, Mohamed; Saghi, Mohamed; Cubadda, Francesco

    2007-11-01

    Coastal populations with high seafood consumption in the Mediterranean have a significant exposure to dietary methylmercury, and areas where environmental mercury pollution is an issue due to industrial activities are of special concern. The study was undertaken with the aim of assessing methylmercury exposure through fish consumption in a community of north Morocco and characterizing the relevant health risk. Concentrations of total mercury were determined in human hair, a biomarker of methylmercury exposure, and in locally consumed fish by cold vapour atomic absorption spectrophotometry. Based on consumption frequencies reported by the 108 subjects included in the study the weekly intake of methylmercury was estimated and biomarker data were evaluated in relation to the estimated intake and the sociodemographic characteristics of the population. Multiple regression analysis was employed for the interpretation of hair mercury data in relation to fish consumption frequency, gender and the age of individuals. Mercury concentrations in hair ranged from 0.22 to 9.56 microg g(-1) (geometric mean = 1.79 microg g(-1)) and were closely related to fish intake. Fisherman and their families consumed fish three to five times per week and were the most exposed population subgroup. A high proportion of women of child-bearing age (50%) had relatively high levels of mercury in their hair (3.08-7.88 microg g(-1)). PMID:17852400

  5. 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.

  6. [Mercury poisoning].

    PubMed

    Bensefa-Colas, L; Andujar, P; Descatha, A

    2011-07-01

    Mercury is a widespread heavy metal with potential severe impacts on human health. Exposure conditions to mercury and profile of toxicity among humans depend on the chemical forms of the mercury: elemental or metallic mercury, inorganic or organic mercury compounds. This article aims to reviewing and synthesizing the main knowledge of the mercury toxicity and its organic compounds that clinicians should know. Acute inhalation of metallic or inorganic mercury vapours mainly induces pulmonary diseases, whereas chronic inhalation rather induces neurological or renal disorders (encephalopathy and interstitial or glomerular nephritis). Methylmercury poisonings from intoxicated food occurred among some populations resulting in neurological disorders and developmental troubles for children exposed in utero. Treatment using chelating agents is recommended in case of symptomatic acute mercury intoxication; sometimes it improves the clinical effects of chronic mercury poisoning. Although it is currently rare to encounter situations of severe intoxication, efforts remain necessary to decrease the mercury concentration in the environment and to reduce risk on human health due to low level exposure (dental amalgam, fish contamination by organic mercury compounds…). In case of occupational exposure to mercury and its compounds, some disorders could be compensated in France. Clinicians should work with toxicologists for the diagnosis and treatment of mercury intoxication. PMID:20579784

  7. 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

  8. Mercury speciation in fish tissues from a Mediterranean River basin: the Tagus River (central Spain) as a case study.

    PubMed

    Nevado, J J Berzas; Martín-Doimeadios, R C Rodríguez; Bernardo, F J Guzmán; Moreno, M Jiménez; Ropero, M J Patiño; Serrano, A de Marcos

    2011-11-01

    An assessment of mercury (Hg) accumulation in fish from the Tagus River aquatic system (central Spain), which has been influenced by pollution from industrial and urban development, was performed. Total Hg (THg), inorganic Hg (IHg), and monomethylmercury (MMHg) were determined in muscle and liver of different fish species, including Cyprinus carpio, Ameiurus melas, and Chondrostoma miegii, sampled from three locations. Although concentrations of THg and Hg species showed wide variability among the fish species, they were also found to be considerably dependent on location and fish tissue. Relative contents of MMHg to THg in muscle varied from 60 to 88%, whereas those found in liver ranged from 7 to 59%. Mean THg concentrations ranged from 126 to 810 ng/g (dry weight [dw]) in liver and from 159 to 1057 ng/g dw in muscle. Therefore, the mean THg concentration in all fish muscle samples was far lower than the maximum residue level recommended by the European Union for fishery products. Nevertheless, the concentrations of Hg in fish muscle reported in this study were somewhat increased compared with other areas geographically distant from most major anthropogenic Hg sources and, in some cases, even greater than those previously reported elsewhere in more polluted areas. In contrast, Hg contents in liver were lower than those found in Hg-contaminated areas, but they were within the range found in other areas exposed to diffuse sources of pollution by Hg. Thus, this article provides an overview of the concentration and distribution of Hg species in fish muscle and liver tissues samples taken from a freshwater system in the Mediterranean River basin. PMID:21472454

  9. Temporal trend of mercury in polar bears (Ursus maritimus) from4 Svalbard using teeth as a biomonitoring tissue5

    E-print Network

    Paris-Sud XI, Université de

    1 1 2 3 Temporal trend of mercury in polar bears (Ursus maritimus) from4 Svalbard using teeth and carbon stable isotopes in teeth of polar bear29 (Ursus maritimus) from Svalbard as biotracers of temporal exposure, and in total 8731 teeth of polar bears were analysed. Dental Hg levels ranged from 0.6 to 72.3 ng

  10. Hair mercury levels in pregnant women in Mahshahr, Iran: fish consumption as a determinant of exposure.

    PubMed

    Salehi, Zohreh; Esmaili-Sari, Abbas

    2010-09-15

    MeHg is a well-documented neurotoxicant even at low levels of exposure. Developing brain, in particular, is vulnerable to that. Through bioaccumulating to differing degrees in various fish species, it can have serious adverse effects on the development and functioning of the human central nervous system, especially during prenatal exposure. Therefore, the purpose of this study was to investigate mercury concentration in hair samples of pregnant women living in Mahshahr located in Khuzestan province, Iran. It assessed the association between fish consumption and specific characteristics that can influence exposure. From April to June 2008, 149 pregnant women were invited to participate in this study. An interview administered questionnaire was used to collect information about age, body weight, height, fish (fresh, canned and shrimp) consumption, pregnancy stage, residence duration, education level, family income and number of dental amalgam fillings. The obtained results showed that the geometric mean and range for hair total Hg concentration was 3.52 microg/g (0.44-53.56 microg/g). About 5.4% of mothers had hair total Hg levels in excess of 10 microg/g. Maternal hair mercury level was less than threshold level of WHO (5 microg/g). As expected, there was a clear increase in hair Hg with reported fresh marine fish consumption (p=0.04). The highest mean for hair mercury level in a group who consumed fish several times per week, was 4.93 microg/g. Moreover, a significant effect of age and residential time on Hg concentration in the hair of the women was found. Pregnant women in Mahshahr consumed large amounts of fish; consequently, most of their offspring were prenatally exposed to moderately high levels of mercury. The results found suggest that pregnant women should decrease their fish consumption. PMID:20655095

  11. 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.

  12. ORIGINAL PAPER Quantifying mRNA levels across tissue sections

    E-print Network

    Shapiro, Benjamin

    ORIGINAL PAPER Quantifying mRNA levels across tissue sections with 2D-RT-qPCR Michael Armani & Michael A. Tangrea & Benjamin Shapiro & Michael R. Emmert-Buck & Elisabeth Smela Received: 16 March 2011 Abstract Measurement of mRNA levels across tissue sam- ples facilitates an understanding of how genes

  13. 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...

  14. Mercury dynamics in young Common Tern (Sterna hirundo) chicks from a polluted environment.

    PubMed

    Becker, P H; Furness, R W; Henning, D

    1993-03-01

    : We studied mercury concentrations and amounts in tissues of 19 starved young Common Tern chicks (median age 4 days) and in eggs from the same colony. Concentrations and burden were similar between eggs and newly hatched chicks. Mercury concentrations were highest in down, which contained at least 38% of the body mercury. The mercury burden of the whole body and of the tissues as well as the concentration in down increased with age and body mass, indicating the importance of down as an elimination pathway. Conversion ratios between mercury concentrations in tissues and the whole chick body varied according to the contamination level. PMID:24203117

  15. Effects of intensive fishing on the structure of zooplankton communities and mercury levels.

    PubMed

    Masson, Stéphane; Tremblay, Alain

    2003-03-20

    Following the impoundment of hydroelectric reservoirs, a small fraction of the mercury (Hg) in the flooded soils is transformed and released into the ecosystem. This causes an increase in the mercury level in the food chain, particularly in piscivorous fish, and represents a potential risk for human health. In 1998, Hydro-Québec carried out an intensive fishing campaign to examine the feasibility of using intensive fishing as a mitigation tool. The goal of this particular part of the project was to evaluate the impact of intensive fishing on the zooplanktonic communities' structure and mercury levels. Specifically, the effects of intensive fishing on: (1) total biomass and zooplankton size structure (>500, 200-500, 100-200 and 53-100 microm); (2) species composition; and (3) total mercury and methylmercury (MeHg) concentrations in zooplankton of different size fractions were studied. Although important decreases were observed in total zooplankton biomass or its size structure, it cannot be related to the intensive fishing. The results, however, show major changes in the dominance of macrozooplanktonic species in fished lakes as opposed to reference lakes. Similarly, in contrast to the reference lakes, mercury and MeHg concentrations in the four size fractions of the zooplanktonic communities changed from 1998 to 2000 in the fished lakes. The MeHg concentration increased from approximately 20 to 200 ng/gdw from the 53 to 500 microm mesh size fraction, showing a biomagnification in the food chain. The canonical correspondence analysis showed that lakes dominated by Holopedium gibberum presented higher concentrations of Hg and MeHg than lakes dominated by Daphnia spp. PMID:12663198

  16. Effects of Mercury Release from Amalgam Dental Restorations During Cremation on Soil Mercury Levels of Three New Zealand Crematoria

    Microsoft Academic Search

    A. K. Nieschmidt; N. D. Kim

    1997-01-01

    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

  17. Surveying Mercury Levels in Hair, Blood and Urine of under 7-Year Old Children from a Coastal City in China

    PubMed Central

    Chen, Guixia; Chen, Xiaoxin; Yan, Chonghuai; Wu, Xingdong; Zeng, Guozhang

    2014-01-01

    Aim: The average mercury load in children under 7-years old was determined in a populated but not overly industrial coastal area in China. Methods: 395 blood samples, 1072 urine samples, and 581 hair samples were collected from 1076 children, aged 0 to 6 years, from eight representative communities of Xiamen, China. Mercury levels in the samples were surveyed. Results: The 95% upper limits of mercury in blood, urine, and hair for the children were 2.30, 1.50 and 2100.00 ?g/kg, respectively. Levels tended to increase with age. Correlation analyses showed that mercury levels in blood and urine correlated with those in hair (n = 132), r = 0.49, p < 0.0001 and r = 0.20, p = 0.0008; however, blood mercury levels did not correlate with urine levels (n = 284), r = 0.07, p = 0.35. Conclusions: Surveying the average mercury load in children 0 to 6 years, and the 95% upper limit value of mercury in their blood, urine, and hair should help guide risk assessment and health management for children. PMID:25419876

  18. Historical and Other Patterns of Monomethyl and Inorganic Mercury in the Florida Panther ( Puma concolor coryi )

    Microsoft Academic Search

    J. Newman; E. Zillioux; E. Rich; L. Liang; C. Newman

    2004-01-01

    Since the late 1980s, elevated levels of mercury have been reported in the tissues of the Florida panther ( Puma concolor coryi) from the Florida Everglades. The extent, degree, and length of time of mercury contamination in the Florida panther are unknown. The objective of this study was to determine the historical and other patterns of monomethyl and inorganic mercury

  19. 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 0.005ngmL(-1) (0.025nM) 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

  20. 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

  1. Mercury and selenium concentrations in fish, sediments, and water of two northwestern Quebec lakes

    SciTech Connect

    Speyer, M.R.

    1980-03-01

    Research report:In an effort to learn more about mercury in the aquatic ecosystem and about possible ways to moderate the toxicity of mercury accumulated by aquatic organisms, sediment and water samples from Lake Dufault and Lake Duparquet in the Rouyn-Naranda region of Quebec were analyzed. Both mercury and selenium concentrations in muscle tissue of northern pike (Esox lucius) were determined. Significant differences between the mercury and selenium levels in fish from the two lakes were reported. Fish samples from Lake Dufault had low mercury concentrations but elevated levels of selenium. Fish samples from Lake Duparquet, however, had elevated mercury levels and low selenium levels. Elevated mercury levels were present in sediment samples from both lakes. Mercury and selenium levels in water samples from both lakes were at or below analytical detection limits. (15 references, 3 tables)

  2. Cadmium, lead and mercury concentrations in selected red deer (Cervus elaphus L.) tissues from north-eastern Croatia.

    PubMed

    Srebo?an, Emil; Janicki, Zdravko; Crni?, Andreja Prevendar; Tomljanovi?, Kristijan; Sebe?i?, Marinko; Konjevi?, Dean

    2012-01-01

    Concentrations of cadmium, lead and mercury were determined in muscle, liver and kidney tissue from three different age groups of red deer (young animals aged 6 or 7 months, middle-aged animals aged 3 to 5 years, old animals aged over 8 years) from the Baranja region of Croatia. Median cadmium concentrations were low in the muscles of all investigated age groups (0.0002; 0.0009 and 0.0020 ?g/g), higher in the liver (0.0279; 0.0656 and 0.1463 ?g/g) and highest in the kidneys (0.4792; 2.8531 and 6.1657 ?g/g). A positive correlation was established between cadmium concentration and age. In all analyzed tissues the median lead concentration was higher in young (muscle 0.0024; liver 0.0364 and kidney 0.0618 ?g/g), compared to middle-aged animals (muscle 0.0001; liver 0.0184 and kidney 0.0160 ?g/g). In contrast to cadmium, mercury had a negative correlation to age but median concentrations were very low (in muscle: 0.0011; 0.0001 and 0.0006 ?g/g; in liver: 0.0051; 0.0037 and 0.0022 ?g/g and in kidney: 0.0145; 0.0183 and 0.0106 ?g/g) especially compared to cadmium. From the hygienic point of view all the examined tissues are edible since concentrations of the analyzed metals do not exceed values proposed by the official regulations, with the exception of a few kidney samples, which contained cadmium above the recommended value. Furthermore, mercury concentrations are no longer (since 2008) a matter of legislation. PMID:22871008

  3. 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

  4. GOAT ADIPOSE TISSUE MOBILIZATION AND MILK PRODUCTION LEVEL

    E-print Network

    Paris-Sud XI, Université de

    GOAT ADIPOSE TISSUE MOBILIZATION AND MILK PRODUCTION LEVEL D. SAUVANT Y. CHILLIARD, P. BAS P weight that high levels of milk production are closely associated with an intense mobili- zation of body work was conducted to study the relationships which associate milk yield and lipomobilization levels

  5. Mercury levels in fish from the upper peninsula of Michigan (ElS Subregion 2B) in relation to lake acidity

    Microsoft Academic Search

    D. Landers; S. P. Gloss; T. M. Grieb; C. T. Driscoll; C. L. Schofield

    1990-01-01

    The accumulation of mercury by fish and the potential human health effects of eating mercury-contaminated fish have been well documented. However, elevated mercury concentrations in fish from dilute, low-pH lakes have only recently been associated with increased lake acidity. Nevertheless, there now is ample evidence to document that elevated levels of mercury are found in fish from lakes in remote

  6. Prostate tissue metal levels and prostate cancer recurrence in smokers.

    PubMed

    Neslund-Dudas, Christine; Kandegedara, Ashoka; Kryvenko, Oleksandr N; Gupta, Nilesh; Rogers, Craig; Rybicki, Benjamin A; Dou, Q Ping; Mitra, Bharati

    2014-02-01

    Although smoking is not associated with prostate cancer risk overall, smoking is associated with prostate cancer recurrence and mortality. Increased cadmium (Cd) exposure from smoking may play a role in progression of the disease. In this study, inductively coupled plasma mass spectrometry was used to determine Cd, arsenic (As), lead (Pb), and zinc (Zn) levels in formalin-fixed paraffin embedded tumor and tumor-adjacent non-neoplastic tissue of never- and ever-smokers with prostate cancer. In smokers, metal levels were also evaluated with regard to biochemical and distant recurrence of disease. Smokers (N?=?25) had significantly higher Cd (median ppb, p?=?0.03) and lower Zn (p?=?0.002) in non-neoplastic tissue than never-smokers (N?=?21). Metal levels were not significantly different in tumor tissue of smokers and non-smokers. Among smokers, Cd level did not differ by recurrence status. However, the ratio of Cd ppb to Pb ppb was significantly higher in both tumor and adjacent tissue of cases with distant recurrence when compared with cases without distant recurrence (tumor tissue Cd/Pb, 6.36 vs. 1.19, p?=?0.009, adjacent non-neoplastic tissue Cd/Pb, 6.36 vs. 1.02, p?=?0.038). Tissue Zn levels were also higher in smokers with distant recurrence (tumor, p?=?0.039 and adjacent non-neoplastic, p?=?0.028). These initial findings suggest that prostate tissue metal levels may differ in smokers with and without recurrence. If these findings are confirmed in larger studies, additional work will be needed to determine whether variations in metal levels are drivers of disease progression or are simply passengers of the disease process. PMID:24385087

  7. 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.

  8. 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

  9. Strong positive associations between seafood, vegetables, and alcohol with blood mercury and urinary arsenic levels in the Korean adult population.

    PubMed

    Park, Sunmin; Lee, Byung-Kook

    2013-01-01

    Blood mercury and urinary arsenic levels are more than fivefold greater in the Korean population compared with those of the United States. This may be related to the foods people consumed. Therefore, we examined the associations between food categories and mercury and arsenic exposure in the Korean adult population. Data regarding nutritional, biochemical, and health-related parameters were obtained from a cross-sectional study, the 2008-2009 Korean National Health and Nutrition Examination Survey (3,404 men and women age ? 20 years). The log-transformed blood mercury and urinary arsenic levels were regressed against the frequency tertiles of each food group after covariate adjustment for sex, age, residence area, education level, smoking status, and drinking status using food-frequency data. Blood mercury levels in the high consumption groups compared to the low consumption groups were elevated by about 20 percents with salted fish, shellfish, whitefish, bluefish, and alcohol, and by about 9-14 percents with seaweeds, green vegetables, fruits and tea, whereas rice did not affect blood mercury levels. Urinary arsenic levels were markedly increased with consumption of rice, bluefish, salted fish, shellfish, whitefish, and seaweed, whereas they were moderately increased with consumption of grains, green and white vegetables, fruits, coffee, and alcohol. The remaining food categories tended to lower these levels only minimally. In conclusion, the typical Asian diet, which is high in rice, salted fish, shellfish, vegetables, alcoholic beverages, and tea, may be associated with greater blood mercury and urinary arsenic levels. This study suggests that mercury and arsenic contents should be monitored and controlled in soil and water used for agriculture to decrease health risks from heavy-metal contamination. PMID:23011092

  10. 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.

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

    PubMed

    Burger, Joanna; Gochfeld, Michael

    2011-03-15

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

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

    PubMed Central

    Burger, Joanna; Gochfeld, Michael

    2014-01-01

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

  13. Mercury Concentrations in Plant Tissues as Affected by FGDG Application to Soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flue Gas Desulfurization Gypsum (FGDG) is produced by reducing sulfur dioxide emissions from themo-electric coal-fired power plants. The most common practice of FGDG production may trap some of the Mercury (Hg) present in the coal that normally would escape as vapor in the stack gases. Concern for t...

  14. 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...

  15. Environmental Monitoring and Assessment Program Western Pilot Project - Conditions of North Dakota Perennial Streams for Water Chemistry and Mercury in Fish Tissue, 2000-2003

    USGS Publications Warehouse

    Vining, Kevin C.; Lundgren, Robert F.

    2008-01-01

    Sixty-five sampling sites, selected by a statistical design to represent lengths of perennial streams in North Dakota, were chosen to be sampled for water chemistry and mercury in fish tissue to establish unbiased baseline data. From the assessment of all water chemistry constituents, the percentage of stream length considered to be in poor condition was greater in the Rangeland Plains than in the Cultivated Plains. About 30 percent of perennial stream length in North Dakota was considered to be in good condition on the basis of mercury concentrations in fish tissue.

  16. Mercury concentrations in water and hybrid striped bass (Morone saxatilis × M. chrysops) muscle tissue samples collected from the Ohio River, USA.

    PubMed

    Emery, Erich B; Spaeth, John P

    2011-04-01

    We report on long-term aqueous mercury (Hg) measurements collected at fixed locations along the Ohio River, offer insights into patterns of water and fish tissue Hg levels, and calculate site-specific bioaccumulation factors (BAFs) along an extensive longitudinal basis. We examined the relationship between total recoverable Hg concentrations in water and fish samples collected from 12 locations on the mainstem Ohio River. Water samples were collected on a bimonthly basis from each location over a 6-year period preceding the collection of fish tissue samples. This abundance of data enabled us to calculate the long-term average aqueous Hg concentrations and approximate the lifetime aqueous Hg exposure experienced by fish, enabling the calculation of appropriate BAFs. Hybrid striped bass (HSB; Morone saxatilis × M. chrysops) were collected from the Ohio River, composited (three fish), and analyzed for Hg in muscle tissue from each location. Concentrations ranged from 0.2 to 0.4 mg/kg and 41.7% of all samples collected were higher than the US Environmental Protection Agency regulatory threshold of 0.3 mg Hg/kg wet weight. Hg levels generally increased with fish weight, length, and age. However, Hg concentration in the water was the strongest predictor of tissue concentrations. We found that both water and tissue concentrations increased with drainage area, albeit at different rates. This discrepancy in spatial patterns revealed that the bioaccumulation rate of methylmercury might not be consistent throughout the Ohio River mainstem. BAFs calculated at each location supported this finding, as values decreased with increasing drainage area. Our study serves to fill critical, previously identified data gaps and provides decision-makers with the information necessary to develop more appropriate BAF development and risk-management strategies. PMID:20577729

  17. Mercury in seabird feathers: insight on dietary habits and evidence for exposure levels in the western Indian Ocean.

    PubMed

    Kojadinovic, Jessica; Bustamante, Paco; Churlaud, Carine; Cosson, Richard P; Le Corre, Matthieu

    2007-10-01

    Breast feathers were used to estimate mercury levels in six marine birds nesting in the tropical western Indian Ocean, i.e. Sooty Tern (Sterna fuscata), Brown Noddy (Anous stolidus), Lesser Noddy (Anous tenuirostris), Audubon Shearwater (Puffinus lherminieri bailloni), Barau's Petrel (Pterodroma baraui) and the White-tailed Tropicbird (Phaethon lepturus). Juveniles consistently showed lower plumage mercury than adults. The lowest mean level was noted in juvenile Sooty Terns from the Glorioso Archipelago (0.05 microg g(-1)). The highest levels were obtained for adult Barau's Petrels from Reunion Island (0.96 microg g(-1)). An inter-site analysis of Sooty Tern showed higher mercury levels in birds nesting on Juan de Nova Island. Levels were low in comparison with values reported in the plumage of seabirds worldwide. The potential impacts of the size, the type (fish/cephalopod) and the origin (epi-/meso-pelagic) of prey on mercury intake in birds are discussed. Although the diet composition of individuals within a species appeared to be quite variable, combining results on mercury levels with common knowledge of each species allowed additional information on their dietary and foraging habits to be unraveled. PMID:17659323

  18. Catchment Area Composition and Water Chemistry Heavily Affects Mercury Levels in Perch ( Perca Fluviatilis L.) in Circumneutral Lakes

    Microsoft Academic Search

    Lars Sonesten

    2003-01-01

    The environmental impact on the mercury level in perch (Perca fluviatilis L.) is examined using Partial Least Squareregression (PLS) on 48 environmental descriptors assessingland use, various catchment area and lake characteristics,lake water chemistry, and fish stock. The lake specificintercepts of Hg content vs. fish length regressions are usedto describe the Hg level in the fish. The Hg levels in perchfrom

  19. Long-term changes in fish mercury levels in the historically impacted English-Wabigoon River system (Canada).

    PubMed

    Neff, Margaret R; Bhavsar, Satyendra P; Arhonditsis, George B; Fletcher, Rachael; Jackson, Donald A

    2012-09-01

    The English-Wabigoon River system in Northwestern Ontario, Canada, was one of the most heavily mercury-contaminated waterways in the world due to historical discharges in the 1960s from a chlor-alkali plant. This study examines long-term (1970-2010) monitoring data to assess temporal trends in mercury contamination in Walleye, Northern Pike and Lake Whitefish, three species important for sport and subsistence fishing in this region, using dynamic linear modeling and piecewise regression. For all lakes and species, there is a significant decline (36-94%) in mercury concentrations through time; however, there is evidence that this decline is either slowing down or levelling off. Concentrations in the English-Wabigoon fish are elevated, and may still present a potential health risk to humans consuming fish from this system. Various biotic and abiotic factors are examined as possible explanations to slowing rates of decline in mercury concentrations observed in the mid-1980s. PMID:22785387

  20. 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.

  1. 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.

  2. The methylmercury to total mercury ratio in selected marine, freshwater, and terrestrial organisms

    Microsoft Academic Search

    Brenda Lasorsa I; Susan Allen-Gil

    1995-01-01

    Total and methylmercury concentrations were determined in muscle and organ tissue from a wide variety of marine and terrestrial organisms spanning several trophic levels. Sediment and water samples from many of the tissue sampling sites were also analyzed to assess the degree of mercury contamination to which the animals were exposed. The methylmercury to total mercury ratios were examined to

  3. Posidonia oceanica: a biological indicator of past and present mercury contamination in the mediterranean sea

    Microsoft Academic Search

    Christine Pergent-Martini

    1998-01-01

    Concentrations of mercury were measured in various tissues of Posidonia oceanica seagrass at three sites presenting distinct degrees of human activity. The accumulation of mercury differed according to the tissue examined and the level of contamination of the site. Mercury concentrations recorded at Calvi ranged from 10.0ng g?1 dry weight in blades to 30.1ng g?1 in rhizomes, whereas at Marseilles-Cortiou,

  4. Differential Sex, Morphotype and Tissue Accumulation of Mercury in the Crab Carcinus maenas

    Microsoft Academic Search

    Sónia Costa; Ivan Viegas; Eduarda Pereira; Armando C. Duarte; Carlos M. Palmeira; Miguel A. Pardal

    Carcinus maenas is an invasive species of recognised economical and ecological importance in which mercury accumulation could be a pathway\\u000a for bioamplification through food webs. Little information is available about differential accumulation between crab sexes\\u000a and morphotypes. Taking this in mind, a set of different industrial discharge scenarios were investigated in 96-h laboratory\\u000a experiments for assessing the accumulation of inorganic

  5. 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

    2015-03-11

    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

  6. 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

  7. Mercury pollution in fish from South China Sea: levels, species-specific accumulation, and possible sources.

    PubMed

    Liu, Jinling; Xu, Xiangrong; Yu, Shen; Cheng, Hefa; Hong, Yiguo; Feng, Xinbin

    2014-05-01

    Both total mercury (THg) and methylmercury (MeHg) levels in fish collected from South China Sea (SCS) were studied to understand Hg pollution in Chinese tropical marine ecosystems. The average THg concentrations in fish species ranged from 39.6 ?g/kg for rabbitfish (Siganus fuscessens) to 417 ?g/kg for thornfish (Terapon jarbua), while those of MeHg varied from 13 ?g/kg (rabbitfish) to 176 ?g/kg (thornfish). The median values of MeHg/THg ratios in different fish species ranged from 36 to 85%. Significant inter-species differences of THg and MeHg in fish were observed due to feeding habits and fish sizes. Overall, carnivorous fish had higher levels of THg, MeHg and MeHg/THg ratios than omnivorous and herbivorous fish. High Hg levels in fish of the SCS were probably related to Hg input from atmospheric deposition and anthropogenic activities. PMID:24721134

  8. Lead, cadmium, arsenic, mercury and copper levels in Chinese Yunnan Pu'er tea.

    PubMed

    Ning, Pengbo; Gong, Chunmei; Zhang, Yanming; Guo, Kangkang; Bai, Juan

    2011-01-01

    The Yunnan region of China produces a distinctive variety of Pu'er tea, which is consequently labeled as a Chinese geographic indication product. In this study, the safety of Chinese Yunnan Pu'er tea with regard to heavy metal content was evaluated in 30 different brands of Pu'er tea, including 150 commercial samples. Metal levels in the Pu'er tea samples followed the order: copper (12-22 µg/g) > lead (0.26-3.2 µg/g) > arsenic (0.035-0.24 µg/g) > cadmium (0.0059-0.085 µg/g) > mercury (<0.010 µg/g). Mercury was not detected in 17 of the brands of Pu'er tea. Metal-to-metal correlation studies showed that there were no significant correlation between metal pairs. Based on current safety standards, the low levels of metals detected in these Pu'er tea samples mean they are safe for human consumption. PMID:24779659

  9. LOCATIONAL DIFFERENCES IN MERCURY AND SELENIUM LEVELS IN 19 SPECIES OF SALTWATER FISH FROM NEW JERSEY

    PubMed Central

    Burger, Joanna; Jeitner, Christian; Gochfeld, Michael

    2014-01-01

    Individuals who fish, and their families that ingest self-caught fish, make decisions about where to fish, what type of fish to eat, and the quantity of fish to eat. While federal and state agencies often issue consumption advisories for some fish with high mercury (Hg) concentrations, advisories seldom provide the actual metal levels to the general public. There are few data for most saltwater fish, and even less information on variations in Hg levels in fish within a state or geographical region. The objective of this study was to provide Hg concentrations from 19 species of fish caught in different locations in New Jersey to (1) test the hypothesis that mean metal levels vary geographically, (2) provide this information to individuals who fish these coastal waters, and (3) provide a range of values for risk assessors who deal with saltwater fish exposure in the Northeastern United States. Selenium (Se) was also examined because of its purported moderating effect on the toxicity of Hg. Hg levels showed significant geographical variation for 10 of 14 species that were caught in more than one region of New Jersey, but there were significant locational differences for Se in only 5 of the fish. Mercury levels were significantly lower in fish collected from northern New Jersey (except for ling, Molva molva), compared to other regions. As might be expected, locational differences in Hg levels were greatest for fish species with the highest Hg concentrations (shark, Isurus oxyrinchus; tuna, Thunnus thynnus and T. albacares; striped bass, Morone saxatilis; bluefish, Pomatomus saltatrix). Fishers and their families might reduce their risk from Hg exposure not only by selecting fish generally lower in Hg, but by fishing predominantly in some regions over others, further lowering the potential risk. Health professionals might use these data to advise patients on which fish are safest to consume (in terms of Hg exposure) from particular geographical regions. PMID:21598171

  10. MERGANSER- Predicting Mercury Levels in Fish and Loons in New England Lakes

    EPA Science Inventory

    MERGANSER (MERcury Geo-spatial AssesmentS for the New England Region) is an empirical least squares multiple regression model using atmospheric deposition of mercury (Hg) and readily obtainable lake and watershed features to predict fish and common loon Hg (as methyl mercury) in ...

  11. Mercury contamination in human hair and fish from Cambodia: levels, specific accumulation and risk assessment

    Microsoft Academic Search

    Tetsuro Agusa; Takashi Kunito; Hisato Iwata; Touch Seang Tana; Annamalai Subramanian; Shinsuke Tanabe

    2005-01-01

    Mercury (Hg) concentrations in human hair and fish samples from Phnom Penh, Kien Svay, Tomnup Rolork and Batrong, Cambodia, collected in November 1999 and December 2000 were determined to understand the status of contamination, and age- and sex-dependent accumulation in humans and to assess the intake of mercury via fish consumption. Mercury concentrations in human hair ranged from 0.54 to

  12. 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.

  13. Mercury accumulation by lower trophic-level organisms in lentic systems within the Guadalupe River watershed, California

    USGS Publications Warehouse

    Kuwabara, James S.; Topping, Brent R.; Moon, Gerald E.; Husby, Peter; Lincoff, Andrew; Carter, James L.; Croteau, Marie-Noële

    2005-01-01

    The water columns of four reservoirs (Almaden, Calero, Guadalupe and Lexington Reservoirs) and an abandoned quarry pit filled by Alamitos Creek drainage for recreational purposes (Lake Almaden) were sampled on September 14 and 15, 2004 to provide the first measurements of mercury accumulation by phytoplankton and zooplankton in lentic systems (bodies of standing water, as in lakes and reservoirs) within the Guadalupe River watershed, California. Because of widespread interest in ecosystem effects associated with historic mercury mining within and downgradient of the Guadalupe Riverwatershed, transfer of mercury to lower trophic-level organisms was examined. The propensity of mercury to bioaccumulate, particularly in phytoplankton and zooplankton at the base of the food web, motivated this attempt to provide information in support of developing trophic-transfer and solute-transport models for the watershed, and hence in support of subsequent evaluation of load-allocation strategies. Both total mercury and methylmercury were examined in these organisms. During a single sampling event, replicate samples from the reservoir water column were collected and processed for dissolved-total mercury, dissolved-methylmercury, phytoplankton mercury speciation, phytoplankton taxonomy and biomass, zooplankton mercury speciation, and zooplankton taxonomy and biomass. The timing of this sampling event was coordinated with sampling and analysis of fish from these five water bodies, during a period of the year when vertical stratification in the reservoirs generates a primary source of methylmercury to the watershed. Ancillary data, including dissolved organic carbon and trace-metal concentrations as well as vertical profiles of temperature, dissolved oxygen, specific conductance and pH, were gathered to provide a water-quality framework from which to compare the results for mercury. This work, in support of the Guadalupe River Mercury Total Maximum Daily Load (TMDL) Study, provides the first measurements of mercury trophic transfer through planktonic communities in this watershed. It is worth reemphasizing that this data set represents a single ?snap shot? of conditions in water bodies within the Guadalupe River watershed to: (1) fill gaps in trophic transfer information, and (2) provide a scientific basis for future process-based studies with enhanced temporal and spatial coverage. This electronic document was unconventionally formatted to enhance the accessibility of information to a wide range of interest groups.

  14. Influences on Mercury Bioaccumulation Factors for the Savannah River

    SciTech Connect

    Paller, M.H.

    2003-05-06

    Mercury TMDLs (Total Maximum Daily Loads) are a regulatory instrument designed to reduce the amount of mercury entering a water body and ultimately to control the bioaccumulation of mercury in fish. TMDLs are based on a BAF (bioaccumulation factor), which is the ratio of methyl mercury in fish to dissolved methyl mercury in water. Analysis of fish tissue and aqueous methyl mercury samples collected at a number of locations and over several seasons in a 118 km reach of the Savannah River demonstrated that species specific BAFs varied by factors of three to eight. Factors contributing to BAF variability were location, habitat and season related differences in fish muscle tissue mercury levels and seasonal differences in dissolved methyl mercury levels. Overall (all locations, habitats, and seasons) average BAFs were 3.7 x 106 for largemouth bass, 1.4 x 106 for sunfishes, and 2.5 x 106 for white catfish. Inaccurate and imprecise BAFs can result in unnecessary economic impact or insufficient protection of human health. Determination of representative and precise BAFs for mercury in fish from large rivers necessitates collecting large and approximately equal numbers of fish and aqueous methyl mercury samples over a seasonal cycle from the entire area and all habitats to be represented by the TMDL.

  15. Mercury and selenium concentrations in fish, sediments, and water of two northwestern Quebec lakes

    SciTech Connect

    Speyer, M.R.

    1980-03-01

    The results of mercury and selenium analyses conducted on northern pike (Esox lucius) muscle tissue indicate distinct and significant differences between the mercury and selenium levels of fish from two lakes in Quebec. While fish samples from Lake Dufault had very low mercury concentrations, they appeared to have elevated amounts of selenium. Conversely, fish samples originating from Lake Duparquet had elevated mercury concentrations and low selenium levels. In both cases a comparison of means by the Student t test indicated significant (P < 0.01) differences between the mercury and selenium concentrations of fish samples from the two lakes.

  16. Urinary tissue factor levels in patients with bladder andprostate cancer

    Microsoft Academic Search

    B. A Lwaleed; J. L Francis; M Chisholm

    2000-01-01

    Aims Coagulation activation is a recognized complication of cancer in which increased tissue factor (TF) is implicated. TF can be detected in urine (uTF). This study assesses uTF levels in benign and malignant urological disease and correlates the results with conventional markers of tumour progression. Methods Using a simple and reproducible kinetic chromogenic assay, we determined uTF levels in controls

  17. 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

  18. 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.

  19. Can mercury in fish be reduced by water level management? Evaluating the effects of water level fluctuation on mercury accumulation in yellow perch (Perca flavescens).

    PubMed

    Larson, James H; Maki, Ryan P; Knights, Brent C; Gray, Brian R

    2014-10-01

    Mercury (Hg) contamination of fisheries is a major concern for resource managers of many temperate lakes. Anthropogenic Hg contamination is largely derived from atmospheric deposition within a lake's watershed, but its incorporation into the food web is facilitated by bacterial activity in sediments. Temporal variation in Hg content of fish (young-of-year yellow perch) in the regulated lakes of the Rainy-Namakan complex (on the border of the United States and Canada) has been linked to water level (WL) fluctuations, presumably through variation in sediment inundation. As a result, Hg contamination of fish has been linked to international regulations of WL fluctuation. Here we assess the relationship between WL fluctuations and fish Hg content using a 10-year dataset covering six lakes. Within-year WL rise did not appear in strongly supported models of fish Hg, but year-to-year variation in maximum water levels (?maxWL) was positively associated with fish Hg content. This WL effect varied in magnitude among lakes: In Crane Lake, a 1 m increase in ?maxWL from the previous year was associated with a 108 ng increase in fish Hg content (per gram wet weight), while the same WL change in Kabetogama was associated with only a 5 ng increase in fish Hg content. In half the lakes sampled here, effect sizes could not be distinguished from zero. Given the persistent and wide-ranging extent of Hg contamination and the large number of regulated waterways, future research is needed to identify the conditions in which WL fluctuations influence fish Hg content. PMID:25134675

  20. Can mercury in fish be reduced by water level management? Evaluating the effects of water level fluctuation on mercury accumulation in yellow perch (Perca flavescens)

    USGS Publications Warehouse

    Larson, James H.; Maki, Ryan P.; Knights, Brent C.; Gray, Brian R.

    2014-01-01

    Mercury (Hg) contamination of fisheries is a major concern for resource managers of many temperate lakes. Anthropogenic Hg contamination is largely derived from atmospheric deposition within a lake’s watershed, but its incorporation into the food web is facilitated by bacterial activity in sediments. Temporal variation in Hg content of fish (young-of-year yellow perch) in the regulated lakes of the Rainy–Namakan complex (on the border of the United States and Canada) has been linked to water level (WL) fluctuations, presumably through variation in sediment inundation. As a result, Hg contamination of fish has been linked to international regulations of WL fluctuation. Here we assess the relationship between WL fluctuations and fish Hg content using a 10-year dataset covering six lakes. Within-year WL rise did not appear in strongly supported models of fish Hg, but year-to-year variation in maximum water levels (?maxWL) was positively associated with fish Hg content. This WL effect varied in magnitude among lakes: In Crane Lake, a 1 m increase in ?maxWL from the previous year was associated with a 108 ng increase in fish Hg content (per gram wet weight), while the same WL change in Kabetogama was associated with only a 5 ng increase in fish Hg content. In half the lakes sampled here, effect sizes could not be distinguished from zero. Given the persistent and wide-ranging extent of Hg contamination and the large number of regulated waterways, future research is needed to identify the conditions in which WL fluctuations influence fish Hg content.

  1. Heavy metal residues in tissues of marine turtles

    Microsoft Academic Search

    M. M Storelli; G. O Marcotrigiano

    2003-01-01

    Heavy metal concentrations in the tissues of marine turtles are presented. The most frequently monitored elements are mercury, cadmium and lead; and the tissues mainly analysed in nearly all the stranded individuals are muscle, liver and kidney. The highest mercury and cadmium levels were found in liver and kidney respectively; the majority of the lead burden existed in bones and

  2. 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), carcharhinid sharks (Genus...

  3. 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

  4. Seasonal, locational and size variations in mercury and selenium levels in striped bass (Morone saxatilis) from New Jersey.

    PubMed

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

    2012-01-01

    We examined total mercury and selenium levels in muscle of striped bass (Morone saxatilis) collected from 2005 to 2008 from coastal New Jersey. Of primary interest was whether there were differences in mercury and selenium levels as a function of size and location, and whether the legal size limits increased the exposure of bass consumers to mercury. We obtained samples mainly from recreational anglers, but also by seine and trawl. For the entire sample (n=178 individual fish), the mean (±standard error) for total mercury was 0.39±0.02 ?g/g (=0.39 ppm, wet weight basis) with a maximum of 1.3 ?g/g (=1.3 ppm wet weight). Mean selenium level was 0.30±0.01 ?g/g (w/w) with a maximum of 0.9 ?g/g). Angler-caught fish (n=122) were constrained by legal size limits to exceed 61 cm (24 in.) and averaged 72.6±1.3 cm long; total mercury averaged 0.48±0.021 ?g/g and selenium averaged 0.29±0.01 ?g/g. For comparable sizes, angler-caught fish had significantly higher mercury levels (0.3 vs 0.21 ?g/g) than trawled fish. In both the total and angler-only samples, mercury was strongly correlated with length (Kendall tau=0.37; p<0.0001) and weight (0.38; p<0.0001), but was not correlated with condition or with selenium. In the whole sample and all subsamples, total length yielded the highest r(2) (up to 0.42) of any variable for both mercury and selenium concentrations. Trawled fish from Long Branch in August and Sandy Hook in October were the same size (68.9 vs 70.1cm) and had the same mercury concentrations (0.22 vs 0.21 ppm), but different selenium levels (0.11 vs 0.28 ppm). The seined fish (all from Delaware Bay) had the same mercury concentration as the trawled fish from the Atlantic coast despite being smaller. Angler-caught fish from the North (Sandy Hook) were larger but had significantly lower mercury than fish from the South (mainly Cape May). Selenium levels were high in small fish, low in medium-sized fish, and increased again in larger fish, but overall selenium was correlated with length (tau=0.14; p=0.006) and weight (tau=0.27; p<0.0001). Length-squared contributed significantly to selenium models, reflecting the non-linear relationship. Inter-year differences were explained partly by differences in sizes. The selenium:mercury molar ratio was below 1:1 in 20% of the fish and 25% of the angler-caught fish. Frequent consumption of large striped bass can result in exposure above the EPA's reference dose, a problem particularly for fetal development. PMID:22226733

  5. Seasonal, locational and size variations in mercury and selenium levels in striped bass (Morone saxatilis) from New Jersey

    PubMed Central

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

    2014-01-01

    We examined total mercury and selenium levels in muscle of striped bass (Morone saxatilis) collected from 2005 to 2008 from coastal New Jersey. Of primary interest was whether there were differences in mercury and selenium levels as a function of size and location, and whether the legal size limits increased the exposure of bass consumers to mercury. We obtained samples mainly from recreational anglers, but also by seine and trawl. For the entire sample (n = 178 individual fish), the mean (± standard error) for total mercury was 0.39 ± 0.02 ?g/g (= 0.39 ppm, wet weight basis) with a maximum of 1.3 ?g/g (= 1.3 ppm wet weight). Mean selenium level was 0.30 ± 0.01 ?g/g (w/w) with a maximum of 0.9 ?g/g). Angler-caught fish (n = 122) were constrained by legal size limits to exceed 61 cm (24 in.) and averaged 72.6 ± 1.3 cm long; total mercury averaged 0.48 ± 0.021 ?g/g and selenium averaged 0.29 ± 0.01 ?g/g. For comparable sizes, angler-caught fish had significantly higher mercury levels (0.3 vs 0.21 ?g/g) than trawled fish. In both the total and angler-only samples, mercury was strongly correlated with length (Kendall tau = 0.37; p < 0.0001) and weight (0.38; p < 0.0001), but was not correlated with condition or with selenium. In the whole sample and all subsamples, total length yielded the highest r2 (up to 0.42) of any variable for both mercury and selenium concentrations. Trawled fish from Long Branch in August and Sandy Hook in October were the same size (68.9 vs 70.1 cm) and had the same mercury concentrations (0.22 vs 0.21 ppm), but different selenium levels (0.11 vs 0.28 ppm). The seined fish (all from Delaware Bay) had the same mercury concentration as the trawled fish from the Atlantic coast despite being smaller. Angler-caught fish from the North (Sandy Hook) were larger but had significantly lower mercury than fish from the South (mainly Cape May). Selenium levels were high in small fish, low in medium-sized fish, and increased again in larger fish, but overall selenium was correlated with length (tau = 0.14; p = 0.006) and weight (tau = 0.27; p < 0.0001). Length-squared contributed significantly to selenium models, reflecting the non-linear relationship. Inter-year differences were explained partly by differences in sizes. The selenium:mercury molar ratio was below 1:1 in 20% of the fish and 25% of the angler-caught fish. Frequent consumption of large striped bass can result in exposure above the EPA’s reference dose, a problem particularly for fetal development. PMID:22226733

  6. Prostate cancer outcome and tissue levels of metal ions

    USGS Publications Warehouse

    Sarafanov, A.G.; Todorov, T.I.; Centeno, J.A.; MacIas, V.; Gao, W.; Liang, W.-M.; Beam, C.; Gray, Michael A.; Kajdacsy-Balla, A.

    2011-01-01

    BACKGROUND There are several studies examining prostate cancer and exposure to cadmium, iron, selenium, and zinc. Less data are available on the possible influence of these metal ions on prostate cancer outcome. This study measured levels of these ions in prostatectomy samples in order to examine possible associations between metal concentrations and disease outcome. METHODS We obtained formalin fixed paraffin embedded tissue blocks of prostatectomy samples of 40 patients with PSA recurrence, matched 1:1 (for year of surgery, race, age, Gleason grading, and pathology TNM classification) with tissue blocks from 40 patients without recurrence (n = 80). Case-control pairs were compared for the levels of metals in areas adjacent to tumors. Inductively coupled plasma-mass spectrometry (ICP-MS) was used for quantification of Cd, Fe, Zn, and Se. RESULTS Patients with biochemical (PSA) recurrence of disease had 12% lower median iron (95 ??g/g vs. 111 ??g/g; P = 0.04) and 21% lower zinc (279 ??g/g vs. 346 ??g/g; P = 0.04) concentrations in the normal-appearing tissue immediately adjacent to cancer areas. Differences in cadmium (0.489 ??g/g vs. 0.439 ??g/g; 4% higher) and selenium (1.68 ??g/g vs. 1.58 ??g/g; 5% higher) levels were not statistically significant in recurrence cases, when compared to non-recurrences (P = 0.40 and 0.21, respectively). CONCLUSIONS There is an association between low zinc and low iron prostate tissue levels and biochemical recurrence in prostate cancer. Whether these novel findings are a cause or effect of more aggressive tumors, or whether low zinc and iron prostatic levels raise implications for therapy, remains to be investigated. Copyright ?? 2011 Wiley-Liss, Inc.

  7. Differential effects of cobalt and mercury on lipid metabolism in the white adipose tissue of high-fat diet-induced obesity mice

    SciTech Connect

    Kawakami, Takashige, E-mail: tkawakami@ph.bunri-u-ac.jp; Hanao, Norihide; Nishiyama, Kaori; Kadota, Yoshito; Inoue, Masahisa; Sato, Masao; Suzuki, Shinya

    2012-01-01

    Metals and metalloid species are involved in homeostasis in energy systems such as glucose metabolism. Enlarged adipocytes are one of the most important causes of obesity-associated diseases. In this study, we studied the possibility that various metals, namely, CoCl{sub 2}, HgCl{sub 2}, NaAsO{sub 2} and MnCl{sub 2} pose risk to or have beneficial effects on white adipose tissue (WAT). Exposure to the four metals resulted in decreases in WAT weight and the size of enlarged adipocytes in mice fed a high-fat diet (HFD) without changes in liver weight, suggesting that the size and function of adipocytes are sensitive to metals. Repeated administration of CoCl{sub 2} significantly increased serum leptin, adiponectin and high-density lipoprotein (HDL) cholesterol levels and normalized glucose level and adipose cell size in mice fed HFD. In contrast, HgCl{sub 2} treatment significantly decreased serum leptin level with the down-regulation of leptin mRNA expression in WAT and a reduction in adipocyte size. Next, we tried to investigate possible factors that affect adipocyte size. Repeated exposure to HgCl{sub 2} significantly decreased the expression levels of factors upon the regulation of energy such as the PPAR? and PPAR? mRNA expression levels in adipocytes, whereas CoCl{sub 2} had little effect on those genes expressions compared with that in the case of the mice fed HFD with a vehicle. In addition, repeated administration of CoCl{sub 2} enhanced AMPK activation in a dose-dependent manner in the liver, skeletal muscle and WAT; HgCl{sub 2} treatment also enhanced AMPK activation in the liver. Thus, both Co and Hg reduced WAT weight and the size of enlarged adipocytes, possibly mediated by AMKP activation in the mice fed HFD. However, inorganic cobalt may have a preventive role in obesity-related diseases through increased leptin, adiponectin and HDL-cholesterol levels, whereas inorganic mercury may accelerate the development of such diseases. These results may lead to the development of new approaches to establishing the role of metals in adipose tissue of obesity-related diseases. -- Highlights: ? The effects of metals on enlarged white adipose tissue (WAT) were studied. ? As, Hg, Mn and Co ions reduced the size of enlarged adipocytes. ? Co{sup 2+} increased serum leptin and adiponectin levels with AMPK activation in WAT. ? Hg{sup 2+} decreased serum leptin level and leptin mRNA expression in WAT. ? Metal exposure affects the adipocyte size and the function of WAT.

  8. 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

  9. 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...

  10. Recent changes in levels of persistent organochlorines and mercury in eggs of seabirds from the Barents Sea

    Microsoft Academic Search

    R. T. Barrett; J. U. Skaare; G. W. Gabrielsen

    1996-01-01

    Eggs of ten seabird species were collected from six regions in North Norway, Svalbard and NW Russia in 1993, and were analyzed for organochlorines (OCs) and mercury. Significant declines in levels of PCBs, p,p?-DDE, HCB, ?-HCH, ?-HCH and oxychlordane were documented in nearly half the data set since a similar study in 1983 in six of the seabird species breeding

  11. Follow-up of mercury levels in fish, human hair and urine in the Madeira and Tapajós basins, Amazon, Brazil

    Microsoft Academic Search

    O Malm; JRD Guimarães; MB Castro; WR Bastos; JP Viana; FJP Branches; EG Silveira; WC Pfeiffer

    1997-01-01

    Informal economy of gold mining has contaminated some important river basins in Amazon. Follow-up studies on critical compartments showed some areas with high Hg levels in fish as well as in human hair samples. Average Hg in piscivorous fish in the Madeira river itself was 846 ppb (N=284) with a maximum of 3921 ppb. Mercury in fish from non polluted

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

    SciTech Connect

    Ohno, Tomoko [Department of Environmental Health Sciences, Akita University School of Medicine, 1-1-1 Hondo, Akita 010-8543 (Japan); Sakamoto, Mineshi [Department of Epidemiology, National Institute for Minamata Disease, Minamata 867-0008 (Japan); Kurosawa, Tomoko [Department of Environmental Health Sciences, Akita University School of Medicine, 1-1-1 Hondo, Akita 010-8543 (Japan); Dakeishi, Miwako [Department of Environmental Health Sciences, Akita University School of Medicine, 1-1-1 Hondo, Akita 010-8543 (Japan); Iwata, Toyoto [Department of Environmental Health Sciences, Akita University School of Medicine, 1-1-1 Hondo, Akita 010-8543 (Japan); Murata, Katsuyuki [Department of Environmental Health Sciences, Akita University School of Medicine, 1-1-1 Hondo, Akita 010-8543 (Japan)]. E-mail: winestem@med.akita-u.ac.jp

    2007-02-15

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

  13. 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

  14. 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

  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. 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

    Microsoft Academic Search

    Joslin

    2009-01-01

    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,

  18. 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

    Microsoft Academic Search

    J. Devereux Joslin

    1994-01-01

    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,

  19. 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,

  20. Low Level Laser Therapy: laser radiation absorption in biological tissues

    NASA Astrophysics Data System (ADS)

    Di Giacomo, Paola; Orlando, Stefano; Dell'Ariccia, Marco; Brandimarte, Bruno

    2013-07-01

    In this paper we report the results of an experimental study in which we have measured the transmitted laser radiation through dead biological tissues of various animals (chicken, adult and young bovine, pig) in order to evaluate the maximum thickness through which the power density could still produce a reparative cellular effect. In our experiments we have utilized a pulsed laser IRL1 ISO model (based on an infrared diode GaAs, ?=904 nm) produced by BIOMEDICA s.r.l. commonly used in Low Level Laser Therapy. Some of the laser characteristics have been accurately studied and reported in this paper. The transmission results suggest that even with tissue thicknesses of several centimeters the power density is still sufficient to produce a cell reparative effect.

  1. Bioaccumulation of Mercury in Sharks

    E-print Network

    Miami, University of

    Bioaccumulation of Mercury in Sharks Part 1 b After you finish the video and the above questions by humans) sources. 2. How does mercury travel from its source into the tissue of sharks? 3. What are some

  2. 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

  3. DEVELOPMENT AND TEST APPLICATION A SCREENING-LEVEL MERCURY FATE MODEL AND TOOL FOR EVALUATING WILDLIFE EXPOSURE RISK FOR SURFACE WATERS WITH MERCURY-CONTAMINATED SEDIMENTS (SERAFM)

    EPA Science Inventory

    Complex chemical cycling of mercury in aquatic ecosystems means that tracing the linkage between anthropogenic and natural loadings of mercury to watersheds and water bodies and associated concentrations in the environment are difficult to establish without the assistance of nume...

  4. 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

  5. Below a Historic Mercury Mine: Non-linear Patterns of Mercury Bioaccumulation in Aquatic Organisms

    NASA Astrophysics Data System (ADS)

    Haas, J.; Ichikawa, G.; Ode, P.; Salsbery, D.; Abel, J.

    2001-12-01

    Unlike most heavy metals, mercury is capable of bioaccumulating in aquatic food-chains, primarily because it is methylated by bacteria in sediment to the more toxic methylmercury form. Mercury concentrations in a number of riparian systems in California are highly elevated as a result of historic mining activities. These activities included both the mining of cinnabar in the coastal ranges to recover elemental mercury and the use of elemental mercury in the gold fields of the Sierra Nevada Mountains. The most productive mercury mining area was the New Almaden District, now a county park, located in the Guadalupe River drainage of Santa Clara County, where cinnabar was mined and retorted for over 100 years. As a consequence, riparian systems in several subwatersheds of the Guadalupe River drainage are contaminated with total mercury concentrations that exceed state hazardous waste criteria. Mercury concentrations in fish tissue frequently exceed human health guidelines. However, the potential ecological effects of these elevated mercury concentrations have not been thoroughly evaluated. One difficulty is in extrapolating sediment concentrations to fish tissue concentrations without accounting for physical and biological processes that determine bioaccumulation patterns. Many processes, such as methylation and demethylation of mercury by bacteria, assimilation efficiency in invertebrates, and metabolic rates in fish, are nonlinear, a factor that often confounds attempts to evaluate the effects of mercury contamination on aquatic food webs. Sediment, benthic macroinvertebrate, and fish tissue samples were collected in 1998 from the Guadalupe River drainage in Santa Clara County at 13 sites upstream and downstream from the historic mining district. Sediment and macroinvertebrate samples were analyzed for total mercury and methylmercury. Fish samples were analyzed for total mercury as whole bodies, composited by species and size. While linear correlations of sediment, invertebrate, and fish tissue concentrations were obtained, the fits of regression lines were markedly improved by the use of non-linear models such as the Michaelis-Menton model. It was thus possible to extrapolate more precisely from sediment to fish tissue concentrations. The application of such models to evaluating clean up levels and ecological risk of mercury exposure will allow more informed decision making as plans are developed to remediate contaminated watersheds.

  6. Cattle egret ( Bubulcus ibis ) and Little egret ( Egretta garzetta ) as monitors of mercury contamination in Shadegan Wetlands of south-western Iran

    Microsoft Academic Search

    Rasool Zamani-Ahmadmahmoodi; Abbas Esmaili-Sari; Mozhgan Savabieasfahani; Nader Bahramifar

    2010-01-01

    Mercury concentrations in feather, liver, kidney, and muscle tissue of Little egret (n?=?8) and Cattle egret (n?=?3) from Shadegan Wetlands in south-western Iran were examined. Liver of Little egret had significantly higher mercury compared\\u000a to Cattle egret (p?mercury values were consistently larger in Little egret when compared to Cattle egret, but mercury\\u000a levels found in feather, kidney,

  7. Neurobehavioral effects of combined prenatal exposure to low-level mercury vapor and methylmercury.

    PubMed

    Yoshida, Minoru; Suzuki, Megumi; Satoh, Masahiko; Yasutake, Akira; Watanabe, Chiho

    2011-01-01

    We evaluated the effects of prenatal exposure to low-level mercury (Hg(0)) or methylmercury (MeHg) as well as combined exposure (Hg(0) + MeHg exposure) on the neurobehavioral function of mice. The Hg(0) exposure group was exposed to Hg(0) at a mean concentration of 0.030 mg/m(3) for 6 hr/day during gestation period. The MeHg exposure was supplied with food containing 5 ppm of MeHg from gestational day 1 to postnatal day 10. The combined exposure group was exposed to both Hg(0) vapor and MeHg according to above described procedure. After delivery, when their offspring reached the age of 8 weeks, behavioral analysis was performed. Open field (OPF) tests of the offspring showed an increase and decrease in voluntary activity in male and female mice, respectively, in the MeHg exposure group. In addition, the rate of central entries was significantly higher in this group than in the control group. The results of OPF tests in the Hg(0) + MeHg exposure group were similar to those in the MeHg exposure group in both males and females. The results in the Hg(0) exposure group did not significantly differ from those in the control group in males or females. Passive avoidance response (PA) tests revealed no significant differences in avoidance latency in the retention trial between the Hg(0), MeHg, or Hg(0) + MeHg exposure group and the control group in males or females. Morris water maze tests showed a delay in the latency to reach the platform in the MeHg and Hg(0) + MeHg exposure groups compared with the control group in males but no significant differences between the Hg(0), MeHg, or Hg(0) + MeHg exposure group and the control group in females. The results of OPF tests revealed only slight effects of prenatal low-level Hg(0) exposure (0.03 mg/m(3)), close to the no-observable-effect level (NOEL) stated by the WHO (0.025 mg/m(3)), on the subsequent neurobehavioral function. However, prenatal exposure to 5 ppm of MeHg affected exploratory activity in the OPF test, and, in particular, male mice were highly sensitive to MeHg. The MeHg and Hg(0) + MeHg exposure groups showed similar neurobehavioral effects. Concerning the effects of prenatal mercury exposure under the conditions of this study, the effects of MeHg exposure may be more marked than those of Hg(0) exposure. PMID:21297343

  8. Phytoremediation of Ionic and Methyl Mercury Pollution

    SciTech Connect

    Meagher, Richard B.

    2005-06-01

    Phytoremediation is defined as the use of plants to extract, resist, detoxify, and/or sequester toxic environmental pollutants. The long-term goal of the proposed research is to develop and test highly productive, field-adapted plant species that have been engineered for the phytoremediation of mercury. A variety of different genes, which should enable plants to clean mercury polluted sites are being tested as tools for mercury phytoremediation, first in model laboratory plants and then in potential field species. Several of these genes have already been shown to enhance mercury phytoremediation. Mercury pollution is a serious, world-wide problem affecting the health of human and wildlife populations. Environmentally, the most serious mercury threat is the production of methylmercury (CH3Hg+) by native bacteria at mercury contaminated wetland sites. Methylmercury is inherently more toxic than metallic (Hg(0)) or ionic (Hg(II)) mercury, and because methylmercury is prolifically biomagnified up the food chain, it poses the most immediate danger to animal populations. We have successfully engineered two model plants, Arabidopsis and tobacco, to use the bacterial merB gene to convert methylmercury to less toxic ionic mercury and to use the bacterial merA gene to further detoxify ionic mercury to the least toxic form of mercury, metallic mercury. Plants expressing both MerA and MerB proteins detoxify methylmercury in two steps to the metallic form. These plants germinate, grow, and set seed at normal growth rates on levels of methylmercury or ionic mercury that are lethal to normal plants. Our newest efforts involve engineering plants with several additional bacterial and plant genes that allow for higher levels of mercury resistance and mercury hyperaccumulation. The potential for these plants to hyperaccumulate mercury was further advanced by developing constitutive, aboveground, and root-specific gene expression systems. Our current strategy is to engineer plants to control the chemical speciation, electrochemical state, transport, and aboveground binding of mercury in order to manage this toxicant. To advance this mercury phytoremediation strategy, our planned research focuses on the following Specific Aims: (1) to increase the transport of mercury to aboveground tissue; (2) to identify small mercury binding peptides that enhance hyperaccumulation aboveground; (3) to test the ability of multiple genes acting together to enhance resistance and hyperaccumulation; (4) to construct a simple molecular system for creating male/female sterility, allowing engineered grass, shrub, and tree species to be released indefinitely at contaminated sites; (5) to test the ability of transgenic cottonwood and rice plants to detoxify ionic mercury and prevent methylmercury release from contaminated sediment; and (6) to initiate field testing with transgenic cottonwood and rice for the remediation of methylmercury and ionic mercury. The results of these experiments will enable the phytoremediation of methyl- and ionic mercury by a wide spectrum of deep-rooted, fast-growing plants adapted to diverse environments. We have made significant progress on all six of these specific aims as summarized below.

  9. Mercury in hair and blood from residents of Phnom Penh (Cambodia) and possible effect on serum hormone levels.

    PubMed

    Agusa, Tetsuro; Kunito, Takashi; Iwata, Hisato; Monirith, In; Chamnan, Chhoun; Tana, Touch Seang; Subramanian, Annamalai; Tanabe, Shinsuke

    2007-06-01

    High concentration of mercury (Hg) in hair has been reported for Cambodians. To confirm the Hg contamination occurring through intake, Hg concentrations were determined in both hair and blood of residents (n=20) from Phnom Penh, Cambodia. Mercury concentrations in the hair and blood were 0.69-190microg g(-1) dry wt and 5.2-58microg l(-1), respectively, which were lower than those from Hg contaminated or high fish intake regions, but were higher than those from non-contaminated regions. Some female subjects had hair and blood Hg levels exceeding the threshold values for neurotoxic effects. Interestingly, serum estrone and estradiol levels were positively correlated with blood Hg level for both males and females, indicating possible induction of female hormones by Hg exposure in Cambodians. PMID:17292448

  10. Factors influencing blood mercury levels of inhabitants living near fishing areas.

    PubMed

    Lee, Ching-Chang; Chang, Jung-Wei; Huang, Hsin-Yi; Chen, Hsiu-Ling

    2012-05-01

    Methylmercury (MeHg), a well-known neuro-toxicant, is usually emitted by industrial and other man-made activities; it is ingested with seafood and shellfish, and accumulates in the human body. The aim of this study was to compare the differences in blood levels of total mercury (T-Hg) and MeHg in residents of 4 coastal sites and 4 inland sites around Taiwan. Meanwhile, the potential question is warranted to find out the association between dietary intake and MeHg accumulation. We found that coastal residents had significantly higher mean blood T-Hg levels (mean: 16.1 ?g/L, range: 0.9-184.9 ?g/L) than inland residents (mean: 11.8 ?g/L, range: 0.8-146.6 ?g/L). The same was for blood MeHg levels: coastal residents (mean: 16.5 ?g/L, range: 0.9-184.9 ?g/L), inland residents (mean: 11.8 ?g/L, range: 2.1-133.4 ?g/L). These elevated levels were positively associated with seafood and shellfish consumption. However, the nature of their residential area may also be an important factor, because the highest T-Hg and MeHg levels were found in residents of a relatively non-industrialized area. To protect vulnerable population-especially children and pregnant women-it is important to know whether locally caught or raised and consumed fish has any source of Hg and MeHg pollution. PMID:22444062

  11. 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

  12. 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

  13. Establishment of a primary hepatocyte culture from the small Indian mongoose (Herpestes auropunctatus) and distribution of mercury in liver tissue.

    PubMed

    Horai, Sawako; Yanagi, Kumiko; Kaname, Tadashi; Yamamoto, Masatatsu; Watanabe, Izumi; Ogura, Go; Abe, Shintaro; Tanabe, Shinsuke; Furukawa, Tatsuhiko

    2014-11-01

    The present study established a primary hepatocyte culture for the small Indian mongoose (Herpestes auropunctatus). To determine the suitable medium for growing the primary hepatic cells of this species, we compared the condition of cells cultured in three media that are frequently used for mammalian cell culture: Dulbecco's Modified Eagle's Medium, RPMI-1640, and William's E. Of these, William's E medium was best suited for culturing the hepatic cells of this species. Using periodic acid-Schiff staining and ultrastructural observations, we demonstrated the cells collected from mongoose livers were hepatocytes. To evaluate the distribution of mercury (Hg) in the liver tissue, we carried out autometallography staining. Most of the Hg compounds were found in the central region of hepatic lobules. Smooth endoplasmic reticulum, which plays a role inxenobiotic metabolism, lipid/cholesterol metabolism, and the digestion and detoxification of lipophilic substances is grown in this area. This suggested that Hg colocalized with smooth endoplasmic reticulum. The results of the present study could be useful to identify the detoxification systems of wildlife with high Hg content in the body, and to evaluate the susceptibility of wildlife to Hg toxicity. PMID:25142347

  14. Linking Atmospheric Mercury Deposition to Human and Wildlife (Source to Receptor) by Coupling VELMA and WASP with BASS to simulate Fish Tissue Mercury Concentrations

    EPA Science Inventory

    Mercury (Hg) is the toxicant responsible for the majority of fish advisories across the United States, with 1.25 million miles of rivers under advisory due to the exposure risk from ingesting Hg-contaminated fish. The processes governing Hg exposures in lotic ecosystems are not...

  15. Mercury concentrations in the Australian fur seal Arctocephalus pusillus from SE Australian waters

    SciTech Connect

    Bacher, G.J.

    1985-10-01

    Marine carnivores such as seals and sea lions occupy an important position in the upper trophic level of the marine food web and this, together with their longevity, makes these marine mammals useful indicators of mercury accumulation in the marine environment. Little information exists on mercury concentrations in marine mammals from the southern hemisphere. This paper reports total mercury concentrations in the tissues of the Australian Fur Seal Arctocephalus pusillus from southeastern Australian waters.

  16. Determination of mercury in the eggs of common murres (Uria aalge) for the seabird tissue archival and monitoring project

    Microsoft Academic Search

    S. J. Christopher; S. S. Vander Pol; R. S. Pugh; R. D. Day; P. R. Becker

    2002-01-01

    An analytical method using isotope dilution cold vapor inductively coupled plasma mass spectrometry (ID-CV- ICPMS) was developed for the determination of total mercury in the eggs of seabirds. Components including error magnification, verification of method accuracy and assignment of analytical uncertainty are presented in the context of collecting mercury data for single sample aliquots. Forty-one egg samples collected from common

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

    E-print Network

    Paris-Sud XI, Université de

    is transported in the environment by air and water, as well as by biological organisms through the food chain significant. In aqueous environments, inorganic mercury is transformed into organic mercury compounds 213969293. hal-00871108,version1-8Oct2013 Author manuscript, published in "Science of the Total Environment

  18. MERCURY IN THE ENVIRONMENT

    EPA Science Inventory

    Mercury is released from a variety of sources and exhibits a complicated chemistry. According to the Mercury Study Report to Congress, mercury fluxes and budgets in water, soil, and other media have increased by a factor of two to five over pre-industrial levels. The primary expo...

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

    Microsoft Academic Search

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

    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

  20. 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.

  1. Mercury contamination in turtles and implications for human health.

    PubMed

    Green, Aaliyah D; Buhlmann, Kurt A; Hagen, Cris; Romanek, Christopher; Gibbons, J Whitfield

    2010-06-01

    Mercury contamination threatens many ecosystems worldwide. Methylmercury bioaccumulates at each trophic level, and biomagnifies within individuals over time. Long-lived turtles often occupy high trophic positions and are likely to accumulate mercury in contaminated habitats. Millions of turtles worldwide are sold in Asia for human consumption, and consumers may be at risk if turtles contain high levels of mercury. The authors dissected 71 turtles from 14 food trade species and analyzed their tissues (liver, kidneys, muscle, claws, and scutes) for total mercury content. Mercury was generally highest in carnivores, and lowest in herbivores. Liver and scutes had the highest concentrations. The authors compared mercury concentrations with consumption limits developed by the U.S. Environmental Protection Agency and Food and Drug Administration to evaluate mercury in fish tissue. Several samples exceeded the recommended 1,900 parts per billion (ppb) consumption threshold, indicating that consumers who eat certain turtle species frequently may be at risk for mercury-related health problems. PMID:20556939

  2. 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%).

  3. Follow-up of mercury levels in fish, human hair and urine in the Madeira and Tapajós basins, Amazon, Brazil

    Microsoft Academic Search

    O. Malm; J. R. D. Guimarães; M. B. Castro; W. R. Bastos; J. P. Viana; F. J. P. Branches; E. G. Silveira; W. C. Pfeiffer

    1997-01-01

    Informal economy of gold mining has contaminated some important river basins in Amazon. Follow-up studies on critical compartments\\u000a showed some areas with high Hg levels in fish as well as in human hair samples. Average Hg in piscivorous fish in the Madeira\\u000a river itself was 846 ppb (N=284) with a maximum of 3921 ppb. Mercury in fish from non polluted

  4. Relationship between mercury accumulation in young-of-the-year yellow perch and water-level fluctuations

    USGS Publications Warehouse

    Sorensen, J.A.; Kallemeyn, L.W.; Sydor, M.

    2005-01-01

    A three-year (2001 -2003) monitoring effort of 14 northeastern Minnesota lakes was conducted to document relationships between water-level fluctuations and mercury bioaccumulation in young-of-the-year (YOY) yellow perch (Perca flavescens) collected in the fall of each year at fixed locations. Six of those lakes are located within or adjacent to Voyageurs National Park and are influenced by dams on the outlets of Rainy and Namakan lakes. One site on Sand Point Lake coincides with a location that has nine years of previous monitoring suitable for addressing the same issue over a longer time frame. Mean mercury concentrations in YOY yellow perch at each sampling location varied significantly from year to year. For the 12-year monitoring site on Sand Point Lake, values ranged from 38 ng gww-1 in 1998 to 200 ng gww -1 in 2001. For the 14-lake study, annual mean concentrations ranged by nearly a factor of 2, on average, for each lake over the three years of record. One likely factor responsible for these wide variations is that annual water-level fluctuations are strongly correlated with mercury levels in YOY perch for both data sets. ?? 2005 American Chemical Society.

  5. 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

  6. 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.

  7. Plant Uptake of Mercury from Contaminated Soil, Oxford, Alabama

    NASA Astrophysics Data System (ADS)

    Steffy, D. A.; Nichols, A. C.

    2005-12-01

    Mercury contamination in the Oxford, Alabama, area is well documented in soil tests in the Snow Creek watershed. In this investigation, mercury levels in soils as well as local plant species were examined. The objectives of the study were first determining the amount of mercury in the soil and then to determine to what degree this mercury is taken in by plant tissue from specimens at each survey site. Variation in accumulation within the individual plant species (leaves, stems) was also examined. Protocols developed for this study were used to achieve both objectives and also to ascertain if a particular plant species hyper accumulates this toxin at levels that would make it useful in bioremediation of mercury contamination in the area.

  8. Mercury Exposure and Children's Health

    Microsoft Academic Search

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

    2010-01-01

    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

  9. 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.

  10. 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.

  11. Relationship between Blood Mercury Level and Risk of Cardiovascular Diseases: Results from the Fourth Korea National Health and Nutrition Examination Survey (KNHANES IV) 2008–2009

    PubMed Central

    Kim, Young-Nam; Kim, Young A; Yang, Ae-Ri; Lee, Bog-Hieu

    2014-01-01

    Limited epidemiologic data is available regarding the cardiovascular effects of mercury exposure. The purpose of this study was to determine the relationship between mercury exposure from fish consumption and cardiovascular disease in a nationally representative sample of Korean adults using the Fourth Korea National Health and Nutrition Examination Survey (KNHANES IV 2008~2009). Survey logistic regression models accounting for the complex sampling were used to estimate the odds ratios (OR) adjusted for fish consumption frequency, age, education, individual annual income, household annual income, body mass index (BMI), waist circumference (WC), alcohol consumption status, and smoking status. The mean blood mercury level in the population was 5.44 ?g/L. Trends toward increased blood mercury levels were seen for increased education level (P=0.0011), BMI (P<0.0001), WC (P<0.0001), and fish (i.e., anchovy) consumption frequency (P=0.0007). The unadjusted OR for hypertension in the highest blood mercury quartile was 1.450 [95% confidential interval (CI): 1.106~1.901] times higher than that of the lowest quartile. The fish consumption-adjusted OR for hypertension in the highest blood mercury quartile was 1.550 (95% CI: 1.131~2.123) times higher than that of the lowest quartile, and the OR for myocardial infarction or angina in the highest blood mercury quartile was 3.334 (95% CI: 1.338~8.308) times higher than that of the lowest quartile. No associations were observed between blood mercury levels and stroke. These findings suggest that mercury in the blood may be associated with an increased risk of hypertension and myocardial infarction or angina in the general Korean population. PMID:25580399

  12. 13. Mercury speciation in biological matrices

    Microsoft Academic Search

    I. Drabæk; Á. Iverfeldt

    1995-01-01

    In nature, mercury occurs in several forms, e.g.metallic mercury, inorganic mercury and organic mercury compounds. All forms of mercury are considered poisonous, but methyl-mercury is of particular concern since it is extremely toxic and is frequently found in the environment. Through a very effective biomagnification mechanism, methyl-mercury is enriched in food chains which results in high levels in top predators,

  13. Concentrations of 17 elements, including mercury, in the tissues, food and abiotic environment of Arctic shorebirds

    Microsoft Academic Search

    Anna L. Hargreaves; Douglas P. Whiteside; Grant Gilchrist

    2011-01-01

    Exposure to contaminants is one hypothesis proposed to explain the global decline in shorebirds, and is also an increasing concern in the Arctic. We assessed potential contaminants (As, Be, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Se, Tl, V, and Zn) at a shorebird breeding site in Nunavut, Canada. We compared element levels in soil, invertebrates

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

    PubMed

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

    2008-10-01

    Hexamethyldisiloxane (HMDSO) has been identified as a sensitive proton NMR indicator of tissue oxygenation (pO(2)) 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 (1)H echo planar imaging to map T(1) of HMDSO and hence pO(2). PISTOL was used here to obtain maps of pO(2) 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 pO(2) map was obtained in 3(1/2) min, facilitating dynamic measurements of response to oxygen intervention. Altering the inhaled gas to oxygen produced a significant increase in mean pO(2) from 55 Torr to 238 Torr in thigh muscle and a smaller, but significant, increase in mean pO(2) from 17 Torr to 78 Torr in MAT-Lu tumors. Thus, PISTOL enabled mapping of tissue pO(2) at multiple locations and dynamic changes in pO(2) in response to intervention. This new method offers a potentially valuable new tool to image pO(2) in vivo for any healthy or diseased state by (1)H MRI. PMID:18574806

  15. Concentrations of 17 elements, including mercury, in the tissues, food and abiotic environment of Arctic shorebirds.

    PubMed

    Hargreaves, Anna L; Whiteside, Douglas P; Gilchrist, Grant

    2011-09-01

    Exposure to contaminants is one hypothesis proposed to explain the global decline in shorebirds, and is also an increasing concern in the Arctic. We assessed potential contaminants (As, Be, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Se, Tl, V, and Zn) at a shorebird breeding site in Nunavut, Canada. We compared element levels in soil, invertebrates and shorebird blood to assess evidence for bioconcentration and biomagnification within the Arctic-based food chain. We tested whether elements in blood, feathers and eggs of six shorebird species (Pluvialis squatarola, Calidris alpina, C. fuscicollis, Phalaropus fulicarius, Charadrius semipalmatus, and Arenaria interpres) were related to fitness endpoints: adult body condition, blood-parasite load, egg size, eggshell thickness, nest duration, and hatching success. To facilitate comparison to other sites, we summarise the published data on toxic metals in shorebird blood and egg contents. Element concentrations and invertebrate composition differed strongly among habitats, and habitat use and element concentrations differed among shorebird species. Hg, Se, Cd, Cu, and Zn bioconcentrated from soil to invertebrates, and Hg, Se and Fe biomagnified from invertebrates to shorebird blood. As, Ni, Pb, Co and Mn showed significant biodilution from soil to invertebrates to shorebirds. Soil element levels were within Canadian guidelines, and invertebrate Hg levels were below dietary levels suggested for the protection of wildlife. However, maximum Hg in blood and eggs approached levels associated with toxicological effects and Hg-pollution in other bird species. Parental blood-Hg was negatively related to egg volume, although the relationship varied among species. No other elements approached established toxicological thresholds. In conclusion, whereas we found little evidence that exposure to elements at this site is leading to the declines of the species studied, Hg, as found elsewhere in the Canadian Arctic, is of potential concern for breeding bird populations. PMID:21762958

  16. 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...

  17. DIETARY METHYL MERCURY EXPOSURE IN AMERICAN KESTRELS; PILOT STUDY

    EPA Science Inventory

    Anthropogenic mercury emissions have increased atmospheric mercury levels about threefold since the advent of industrial activity. Atmospheric deposition is the primary source of mercury in the environment hence mercury contamination has increased in similar fashion. Methyl mercu...

  18. 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

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

    PubMed

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

    2013-01-01

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

  20. Mercury accumulation and tissue-specific antioxidant efficiency in the wild European sea bass (Dicentrarchus labrax) with emphasis on seasonality.

    PubMed

    Mieiro, C L; Dolbeth, M; Marques, T A; Duarte, A C; Pereira, M E; Pacheco, M

    2014-09-01

    The main goal of this study was to assess both mercury (Hg) accumulation and organs' specific oxidative stress responses of gills, liver and kidney of Dicentrarchus labrax with emphasis on seasonality. Fish were collected in cold and warm periods in three stations: reference, moderated and highly contaminated sites. Our results showed that seasonal factors slightly influenced Hg accumulation between year periods (cold and warm) and strongly affected organs' response basal levels. In contrast, seasonality seemed not to influence oxidative stress responses, since similar response patterns were obtained for both year periods, and moderate degree of antioxidant responses was obtained. Moreover, the oxidative stress profile may be attributed to Hg contamination degree, which showed organ-specific response and accumulation patterns. Hence, gills showed to be able to adapt to Hg contamination, and in opposition, kidney and liver demonstrated some vulnerability to Hg toxicity. The critical Hg concentrations indicated specific threshold limits for each organ. Overall, seasonality should be taken into account in monitoring programmes, helping to characterize the individuals' reference values of response and thus to discriminate between the effects induced by natural causes or by contamination. PMID:24875309

  1. Mercury: Basic Information

    MedlinePLUS

    ... elemental or metallic mercury, inorganic mercury compounds, and organic mercury compounds. Elemental or metallic mercury is a ... elemental or metallic mercury, inorganic mercury compounds, and organic mercury compounds. More information Sources of mercury. Mercury ...

  2. Mercury concentrations in red drum, Sciaenops ocellatus, from estuarine and offshore waters of Florida.

    PubMed

    Adams, Douglas H; Onorato, Gregory V

    2005-03-01

    Dorsal muscle tissue from 712 red drum, Sciaenops ocellatus, from Florida waters were analyzed for total mercury content. Mercury levels detected in these red drum varied but in most study areas were usually lower than regulatory threshold guidelines. Total mercury levels in individual fish from all study areas ranged from 0.020 to 3.6 ppm (wet weight). Total mercury levels detected in red drum from the Florida Keys-Florida Bay area were often higher than those in fish from all other estuarine study areas. Positive relationships between total mercury levels and fish size (length and weight) and fish age were observed in most Florida study areas, indicating that mercury levels tend to increase over time as red drum grow. The majority of large, mature red drum examined contained mercury levels greater than the 0.5-ppm threshold level set by the Florida Department of Health (DOH). Approximately 94% of all adult red drum from offshore waters adjacent to Tampa Bay contained mercury levels greater than or equal to the 0.5-ppm threshold level, and 64% contained levels greater than or equal to the DOH 1.5-ppm "no consumption" level. All fish from this area with mercury levels greater than 1.5 ppm were large individuals (670 mm SL). Eight percent of legal-size red drum from Florida waters contained total mercury levels greater than or equal to the 0.5-ppm threshold level. The majority (52%) of these legal-size fish greater than or equal to 0.5 ppm were from the Florida Keys-Florida Bay area. In the Florida recreational fishery, the current maximum size limit for this species is an effective filter that prevents humans from consuming those red drum with the greatest likelihood of containing high mercury levels. PMID:15757692

  3. Milk transfer and tissue uptake of mercury in suckling offspring after exposure of lactating maternal guinea pigs to inorganic or methylmercury.

    PubMed

    Yoshida, M; Watanabe, C; Satoh, H; Kishimoto, T; Yamamura, Y

    1994-01-01

    Maternal guinea pigs were injected with mercuric chloride (HgCl2; 1 mg Hg/kg body weight) or methylmercury (MeHg; 1 mg Hg/kg) 12 h after parturition, and exposure of the offspring to mercury (Hg) via breast milk were studied on days 3, 5 and 10 postpartum. Milk Hg concentrations were lower than maternal plasma Hg concentrations regardless of the form of Hg given to the dams. Milk Hg was higher in HgCl2-treated dams than in MeHg-treated dams. In MeHg-treated dams, MeHg was separately determined. While the ratio of MeHg to T-Hg decreased in the dams' plasma, it did not in the milk. There was a strong correlation between milk and plasma T-Hg concentrations in HgCl2 treated dams. In the milk of MeHg-treated dams, the plasma MeHg concentrations correlated better than did the plasma T-Hg concentrations. In the offspring, regardless of the chemical forms of Hg given to the dams, the highest Hg concentrations were found in the kidney, followed by the liver and the brain. Brain Hg concentrations were, however, significantly higher in the offspring of MeHg-treated dams than in those of HgCl2-treated dams. In addition, Hg levels in the major organs of the offspring of HgCl2-treated dams peaked on day 5 postpartum, while those of MeHg-treated dams did not show a significant decrease up to day 10 postpartum. These facts indicate that the two chemical forms of Hg were transferred to the offspring via the breast milk and were distributed differently, depending on the chemical form, to the offspring's tissues. PMID:8024464

  4. 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

  5. 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

    Microsoft Academic Search

    J. Devereux Joslin

    1994-01-01

    Concern about mercury pollution from atmospheric deposition has risen markedly in the last decade because of high levels of\\u000a mercury in freshwater fish from relatively pristine waters. Whereas high concentrations have been found principally in Canada,\\u000a the northern United States, and Scandinavia, they have also recently been observed throughout much of Florida. Recent surveys\\u000a of the Tennessee River system, however,

  6. 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...

  7. Cytogenetic damage related to low levels of methyl mercury contamination in the Brazilian Amazon

    Microsoft Academic Search

    MARÚCIA I. M. AMORIM; DONNA MERGLER; MARCELO O. BAHIA; HÉLÈNE DUBEAU; DANIELA MIRANDA; JEAN LEBEL; ROMMEL R. BURBANO; MARC LUCOTTE

    2000-01-01

    The mercury rejected in the water system, from mining operations and lixiviation of soils after deforesta- tion, is considered to be the main contributors to the contamination of the ecosystem in the Amazon Basin. The objectives of the present study were to examine cytogenetic functions in peripheral lymphocytes within a population living on the banks of the Tapajós River with

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

    E-print Network

    Penteriani, Vincenzo

    Superpredation can increase the length of the food chain and potentially lead to mercury (Hg) bioaccu- mulation, but future monitoring is recommended. Keywords Bioaccumulation Á Biomagnification Á Bubo bubo Á Intraguild and are thus more exposed to biomagnification of persistent lipophilic contaminants, including organochlorine

  9. SPATIAL VARIATION AND CORRELATIONS OF MERCURY LEVELS IN THE TERRESTRIAL AND AQUATIC COMPONENTS OF A

    E-print Network

    O'Driscoll, Nelson

    University of Victoria, Department of Earth and Ocean Sciences, Victoria, B.C., Canada V8W 3P6; 4 Environment analyses of existing data) ranged from 0.12­0.72 µg g-1 (wet weight basis) in 24 lakes. Mercury g-1). Lake water pH and dissolved organic carbon (DOC) were the variables most highly correlated

  10. Mercury levels and trends (1993-2009) in bream (Abramis brama L.) and zebra mussels (Dreissena polymorpha) from German surface waters.

    PubMed

    Lepom, Peter; Irmer, Ulrich; Wellmitz, Jörg

    2012-01-01

    Mercury concentrations have been analysed in bream (Abramis brama L.) and zebra mussels (Dreissena polymorpha) collected at 17 freshwater sites in Germany from 1993-2009 and 1994-2009, respectively, within the German Environmental Specimen programme. Mercury concentrations in bream ranged from 21 to 881 ng g(-1) wet weight with lowest concentrations found at the reference site Lake Belau and highest in fish from the river Elbe and its tributaries. Statistical analysis revealed site-specific differences and significant decreasing temporal trends in mercury concentrations at most of the sampling sites. The decrease in mercury levels in bream was most pronounced in fish from the river Elbe and its tributary Mulde, while in fish from the river Saale mercury levels increased. Temporal trends seem to level off in recent years. Mercury concentrations in zebra mussels were much lower than those in bream according to their lower trophic position and varied by one order of magnitude from 4.1 to 42 ng g(-1) wet weight (33-336 ng g(-1) dry weight). For zebra mussels, trend analyses were performed for seven sampling sites at the rivers Saar and Elbe of which three showed significant downward trends. There was a significant correlation of the geometric mean concentrations in bream and zebra mussel over the entire study period at each sampling site (Pearson's correlation coefficient=0.892, p=0.00002). A comparison of the concentrations in bream with the environmental quality standard (EQS) of 20 ng g(-1) wet weight set for mercury in biota by the EU showed that not a single result was in compliance with this limit value, not even those from the reference site. Current mercury levels in bream from German rivers exceed the EQS by a factor 4.5-20. Thus, piscivorous top predators are still at risk of secondary poisoning by mercury exposure via the food chain. It was suggested focusing monitoring of mercury in forage fish (trophic level 3 or 4) for compliance checking with the EQS for biota and considering the age dependency of mercury concentrations in fish in the monitoring strategy. PMID:22071369

  11. Mercury Calculator

    NSDL National Science Digital Library

    2010-09-16

    This interactive calculator produced by Teachers' Domain helps you determine the mercury levels in various types of fish, and enables you to make more informed choices about which fish are safe to eat and which should be avoided or eaten infrequently.

  12. Mercury in various tissues of three mustelid species and other trace metals in liver of European otter from Eastern Finland.

    PubMed

    Lodenius, M; Skarén, U; Hellstedt, P; Tulisalo, E

    2014-01-01

    Mercury concentrations were monitored in European otter (Lutra lutra), European polecat (Mustela putorius) and European pine marten (Martes martes) collected in Eastern Finland during the period 1972-2008. Otters mainly eat fish, which is an important reason to monitor the bioaccumulation of mercury in this predator. In this species, the highest concentrations were found in fur followed by liver and kidney, and the mercury concentrations increased with increasing age and body weight. Males showed in general higher concentrations than females of otters. The food of European polecat consists of small mammals, frogs, birds and insects from both aquatic and terrestrial food chains. The mercury concentrations were lower than in otters without significant differences related to body weight or sex. In European pine martens, the concentrations were rather evenly distributed except for two specimens with high concentrations. Also, concentrations of some other metals (Al, Cd, Cu, Fe, Mn, Ni, Pb and Zn) were analysed from liver samples of otter. Possible adverse effects of mercury on the Finnish populations of these mustelids are discussed. PMID:23974535

  13. 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.

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

    PubMed

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

    2010-05-01

    Mercury is an immunotoxic substance that has been shown to induce autoimmune disease in rodent models, characterized by lymphoproliferation, overproduction of immunoglobulin (IgG and IgE), and high circulating levels of auto-antibodies directed at antigens located in the nucleus (antinuclear auto-antibodies, or ANA) or the nucleolus (antinucleolar auto-antibodies, or ANoA). We have reported elevated levels of ANA and ANoA in human populations exposed to mercury in artisanal gold mining, though other confounding variables that may also modulate ANA/ANoA levels were not well controlled. The goal of this study is to specifically test whether occupational and environmental conditions (other than mercury exposure) that are associated with artisanal gold mining affect the prevalence of markers of autoimmune dysfunction. We measured ANA, ANoA, and cytokine concentrations in serum and compared results from mercury-exposed artisanal gold miners to those from diamond and emerald miners working under similar conditions and with similar socio-economic status and risks of infectious disease. Mercury-exposed gold miners had higher prevalence of detectable ANA and ANoA and higher titers of ANA and ANoA as compared to diamond and emerald miners with no occupational mercury exposure. Also, mercury-exposed gold miners with detectable ANA or ANoA in serum had significantly higher concentrations of pro-inflammatory cytokines IL-1beta, TNF-alpha, and IFN-gamma in serum as compared to the diamond and emerald miners. This study provides further evidence that mercury exposure may lead to autoimmune dysfunction and systemic inflammation in affected populations. PMID:20176347

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

    PubMed Central

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

    2010-01-01

    Mercury is an immunotoxic substance that has been shown to induce autoimmune disease in rodent models, characterized by lymphoproliferation, overproduction of immunoglobulin (IgG and IgE), and high circulating levels of autoantibodies directed at antigens located in the nucleus (anti-nuclear autoantibodies, or ANA) or the nucleolus (anti-nucleolar autoantibodies, or ANoA). We have reported elevated levels of ANA and ANoA in human populations exposed to mercury in artisanal gold mining, though other confounding variables that may also modulate ANA/ANoA levels were not well-controlled. The goal of this study is to specifically test whether occupational and environmental conditions (other than mercury exposure) that are associated with artisanal gold mining affect the prevalence of markers of autoimmune dysfunction. We measured ANA, ANoA, and cytokine concentrations in serum and compared results from mercury-exposed artisanal gold miners to those from diamond and emerald miners working under similar conditions and with similar socioeconomic status and risks of infectious disease. Mercury-exposed gold miners had higher prevalence of detectable ANA and ANoA and higher titers of ANA and ANoA as compared to diamond and emerald miners with no occupational mercury exposure. Also, mercury-exposed gold-miners with detectable ANA or ANoA in serum had significantly higher concentrations of pro-inflammatory cytokines IL-1?, TNF-?, and IFN-? in serum as compared to the diamond and emerald miners. This study provides further evidence that mercury exposure may lead to autoimmune dysfunction and systemic inflammation in affected populations. PMID:20176347

  16. Residue levels of polychlorobiphenyls, ?DDT, and mercury in bird species commonly preyed upon by the peregrine falcon ( Falco peregrinus Tunst.) in Sweden

    Microsoft Academic Search

    Peter Lindberg; Tjelvar Odsjö; Lars Reutergftrdh

    1985-01-01

    The levels of polychlorobiphenyls (PCBs), SDDT, and total mercury were analyzed in samples of common prey species of the peregrine falcon in two falcon territories, one in northern and one in southern Sweden. Resident and herbivorous prey species showed low residue levels, while elevated levels were found in birds feeding on animals in aquatic habitats. According to biomass, waders accounted

  17. Population correlates of circulating mercury levels in Korean adults: the Korea National Health and Nutrition Examination Survey IV

    PubMed Central

    2014-01-01

    Background Prior studies focused on bioaccumulation of mercury (Hg) and on large, long-lived fish species as the major environmental source of Hg, but little is known about consumption of small-sized fish or about non-dietary determinants of circulating Hg levels. The purpose of this study was to evaluate whole blood mercury concentration (WBHg) and its major dietary and non-dietary correlates in Korean adults. Methods We analyzed cross-sectional data from 3,972 (male?=?1,994; female?=?1,978) participants who completed the Korean National Health and Nutrition Examination Survey IV, 2008 to 2009. Relevant factors included diet, geographic location of residence, demographics, and lifestyle. WBHg concentration was measured using cold-vapor atomic absorption spectrometry. Multivariable linear models assessed independent correlates of dietary and non-dietary factors for WBHg levels. Results Median levels of WBHg were 5.1 ?g/L in men and 3.7 ?g/L in women. Higher levels of fish/shellfish intake were associated with higher levels of WBHg. Higher consumption of small-sized fish was linked to higher levels of WBHg. Non-dietary predictors of higher WBHg were being male, greater alcohol consumption, higher income and education, overweight/obesity, increasing age, and living in the southeast region. Conclusions Both dietary and non-dietary factors were associated with WBHg levels in the Korean population. There is significant geographic variation in WBHg levels; residents living in the mid-south have higher WBHg levels. We speculate that uncontrolled geographic characteristics, such as local soil/water content and specific dietary habits are involved. PMID:24884916

  18. 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

  19. Interrelationships between mercury levels in yearling yellow perch, fish condition and water quality

    Microsoft Academic Search

    K. Suns; G. Hitchin

    1990-01-01

    Yearling yellow perch were collected from sixteen Muskoka-Haliburton lakes to determine interrelationships between water quality, Hg residues in fish and fish condition. The lakes studied were Precambrian shield lakes with a pH range of 5.6 to 7.3 and total inflection point alkalinities of 0.4 to 16.0 mg L-1. Mercury residues in yellow perch ranged from 31 to 233 ng g-1

  20. High levels of maternally transferred mercury do not affect reproductive output or embryonic survival of northern watersnakes (Nerodia sipedon).

    PubMed

    Chin, Stephanie Y; Willson, John D; Cristol, Daniel A; Drewett, David V V; Hopkins, William A

    2013-03-01

    Maternal transfer is an important exposure pathway for contaminants because it can directly influence offspring development. Few studies have examined maternal transfer of contaminants, such as mercury (Hg), in snakes, despite their abundance and high trophic position in many ecosystems where Hg is prevalent. The objectives of the present study were to determine if Hg is maternally transferred in northern watersnakes (Nerodia sipedon) and to evaluate the effects of maternal Hg on reproduction. The authors captured gravid female watersnakes (n?=?31) along the South River in Waynesboro, Virginia, USA, where an extensive Hg-contamination gradient exists. The authors measured maternal tissue and litter Hg concentrations and, following birth, assessed (1) reproductive parameters (i.e., litter size and mass, neonate mass); (2) rates of infertility, death during development, stillbirths, malformations, and runts; and (3) the overall viability of offspring. Mercury concentrations in females were strongly and positively correlated with concentrations in litters, suggesting that N. sipedon maternally transfer Hg in proportion to their tissue residues. Maternal transfer resulted in high concentrations (up to 10.10?mg/kg dry wt total Hg) of Hg in offspring. The authors found little evidence of adverse effects of Hg on these measures of reproductive output and embryonic survival, suggesting that N. sipedon may be more tolerant of Hg than other vertebrate species. Given that this is the first study to examine the effects of maternally transferred contaminants in snakes and that the authors did not measure all reproductive endpoints, further research is needed to better understand factors that influence maternal transfer and associated sublethal effects on offspring. PMID:23233365

  1. Phytoremediation of Ionic and Methyl Mercury P

    SciTech Connect

    Meagher, Richard B.

    1999-06-01

    Our long-term goal is to enable highly productive plant species to extract, resist, detoxify, and/or sequester toxic heavy metal pollutants as an environmentally friendly alternative to physical remediation methods. We have focused this phytoremediation research on soil and water-borne ionic and methylmercury. Mercury pollution is a serious world-wide problem affecting the health of human and wild-life populations. Methylmercury, produced by native bacteria at mercury-contaminated wetland sites, is a particularly serious problem due to its extreme toxicity and efficient biomagnification in the food chain. We engineered several plant species (e.g., Arabidopsis, tobacco, canola, yellow poplar, rice) to express the bacterial genes, merB and/or merA, under the control of plant regulatory sequences. These transgenic plants acquired remarkable properties for mercury remediation. (1) Transgenic plants expressing merB (organomercury lyase) extract methylmercury from their growth substrate and degrade it to less toxic ionic mercury. They grow on concentrations of methylmercury that kill normal plants and accumulate low levels of ionic mercury. (2) Transgenic plants expressing merA (mercuric ion reductase) extract and electrochemically reduce toxic, reactive ionic mercury to much less toxic and volatile metallic mercury. This metal transformation is driven by the powerful photosynthetic reducing capacity of higher plants that generates excess NADPH using solar energy. MerA plants grow vigorously on levels of ionic mercury that kill control plants. Plants expressing both merB and merA degrade high levels of methylmercury and volatilize metallic mercury. These properties were shown to be genetically stable for several generations in the two plant species examined. Our work demonstrates that native trees, shrubs, and grasses can be engineered to remediate the most abundant toxic mercury pollutants. Building on these data our working hypothesis for the next grant period is that transgenic plants expressing the bacterial merB and merA genes will (a) remove mercury from polluted soil and water and (b) prevent methylmercury from entering the food chain. Our specific aims center on understanding the mechanisms by which plants process the various forms of mercury and volatilize or transpire mercury vapor. This information will allow us to improve the design of our current phytoremediation strategies. As an alternative to volatilizing mercury, we are using several new genes to construct plants that will hyperaccumulate mercury in above-ground tissues for later harvest. The Department of Energy's Oak Ridge National Laboratory and Brookhaven National Laboratory have sites with significant levels of mercury contamination that could be cleaned by applying the scientific discoveries and new phytoremediation technologies described in this proposal. The knowledge and expertise gained by engineering plants to hyperaccumulate mercury can be applied to the remediation of other heavy metals pollutants (e.g., arsenic, cesium, cadmium, chromium, lead, strontium, technetium, uranium) found at several DOE facilities.

  2. 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...

  3. How do tissues respond to damage at the cellular level? The role of cytokines in irradiated tissues

    NASA Technical Reports Server (NTRS)

    Barcellos-Hoff, M. H.; Chatterjee, A. (Principal Investigator)

    1998-01-01

    The capacity of ionizing radiation to affect tissue function, control tumor growth and elicit pathological sequelae has been attributed in great part to its effects on cellular DNA, which, as the transmitter of genetic information, can both register damage and perpetuate it. Nonetheless, multicellular organisms function as the result of the cooperation of many cell types. What then occurs when individual cells are damaged by ionizing radiation? Is tissue response a sum of cellular effects such as cell death and DNA damage? Or does the tissue respond as a coherent unit to the damage of its parts? In this paper, data in support of the latter model that indicate a role for cytokines, in particular transforming growth factor beta1, as critical components of extracellular signaling pathways that mediate tissue response to radiation will be reviewed. The key to manipulating the consequences of radiation exposure lies in understanding the complex interplay of events initiated at the cellular level, but acting on the tissue.

  4. 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

  5. Temporal trends (1989–2011) in levels of mercury and other heavy metals in feathers of fledgling great egrets nesting in Barnegat Bay, NJ

    SciTech Connect

    Burger, Joanna, E-mail: burger@biology.rutgers.edu [Division of Life Sciences, Rutgers University, 604 Allison Road, Piscataway, New Jersey 08854-8082, USA and also with Environmental and Occupational Health Sciences Institute (EOHSI), Piscataway, New Jersey (United States)] [Division of Life Sciences, Rutgers University, 604 Allison Road, Piscataway, New Jersey 08854-8082, USA and also with Environmental and Occupational Health Sciences Institute (EOHSI), Piscataway, New Jersey (United States)

    2013-04-15

    There is an abundance of data for levels of metals from a range of species, but relatively few long-term time series from the same location. In this paper I examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers from fledgling great egrets (Ardea alba) collected at nesting colonies in Barnegat Bay, New Jersey from 1989 to 2011. The primary objectives were to test the null hypotheses that (1) There were no temporal differences in metal levels in feathers of fledgling great egrets, and (2) Great egrets nesting in different areas of Barnegat Bay (New Jersey) did not differ in metal levels. There were significant yearly variations in levels of all heavy metals in feathers of fledgling great egret, but levels decreased significantly from 1989 to 2011 only for lead (1470 ppb to 54.3 ppb), cadmium (277 ppb to 30.5 ppb), and manganese (only since 1996; 2669 ppb to 329 ppb)). Although mercury levels decreased from 2003–2008 (6430 ppb to 1042 ppb), there was no pattern before 2003, and levels increased after 2008 to 2610 ppb in 2011. Lead, cadmium, chromium, manganese and mercury were higher in feathers from great egrets nesting in the northern part of the bay, and selenium was highest in feathers from mid-bay. The lack of a temporal decline in mercury levels in feathers of great egrets is cause for concern, since the high levels in feathers from some years (means as high as 6430 ppb) are in the range associated with adverse effects (5000 ppb for feathers). -- Highlights: ? Metals were monitored in feathers of great egrets from Barnegat Bay, New Jersey. ? Levels of cadmium and lead decreased significantly from 1989–2011. ? Mercury levels in feathers from great egrets did not decline from 1989–2011. ? Metal levels were generally higher in great egrets and black-crowned night heron feathers than in snowy egrets.

  6. Multiscale mechanobiology: mechanics at the molecular, cellular, and tissue levels

    PubMed Central

    2013-01-01

    Mechanical force is present in all aspects of living systems. It affects the conformation of molecules, the shape of cells, and the morphology of tissues. All of these are crucial in architecture-dependent biological functions. Nanoscience of advanced materials has provided knowledge and techniques that can be used to understand how mechanical force is involved in biological systems, as well as to open new avenues to tailor-made bio-mimetic materials with desirable properties. In this article, we describe models and show examples of how force is involved in molecular functioning, cell shape patterning, and tissue morphology. PMID:23731596

  7. MERCURY LEVELS IN FISH FROM THE UPPER PENINSULA OF MICHIGAN (ELS SUBREGION 2B) IN RELATION TO LAKE ACIDITY

    EPA Science Inventory

    The accumulation of mercury by fish and the potential human health effects of eating mercury-contaminated fish have been well documented. owever, elevated mercury concentrations in fish from dilute, low-pH lakes have only recently been associated with increased lake acidity. ever...

  8. Long-term changes in fish mercury levels in the historically impacted English-Wabigoon River system (Canada)

    E-print Network

    Arhonditsis, George B.

    -Wabigoon River system in Northwestern Ontario, Canada, was one of the most heavily mercury-contaminated waterways-term (1970­2010) monitoring data to assess temporal trends in mercury contamination in Walleye, Northern Pike of the most severely mercury- contaminated waterways in the world.1 Armstrong and Hamil- ton1 reported

  9. Lifespan mercury accumulation pattern in Liza aurata : Evidence from two southern European estuaries

    NASA Astrophysics Data System (ADS)

    Tavares, S.; Oliveira, H.; Coelho, J. P.; Pereira, M. E.; Duarte, A. C.; Pardal, M. A.

    2011-10-01

    Mercury accumulation throughout the lifespan of Liza aurata (Risso, 1810) was analysed in four tissues (muscle, gills, liver and brain) in two southern European coastal ecosystems with distinct mercury contamination. Specimens from four to five age classes were captured in two sampling sites in the Ria de Aveiro (Laranjo bay and Mira), a system historically contaminated by industrial mercury, and in one site in the Mondego estuary, assumed as a mercury-free ecosystem. Mercury concentration in all tissues was found to be significantly higher in the Ria de Aveiro (Laranjo bay) compared to the Mondego, in accordance with the environmental contamination (water, sediments and suspended particulate matter). Significant differences inside the Ria de Aveiro (between the Mira and Laranjo bay) were only detected in the liver. This tissue registered the highest levels of mercury (ranging from 0.11 to 4.2 ?g g -1 ) in all sampling sites, followed by muscle, brain, and gills. In all sampling sites and tissues was denoted a mercury dilution pattern along the lifecycle (except in liver at the Mondego, the reference area where the concentrations are always very low). An exponential trend was found in the metal age variation patterns in Laranjo (the most contaminated area) and a linear trend in the Mira and the Mondego (the least contaminated areas). Organic mercury concentration in muscle generally accounted for over 95% of total mercury concentration, and followed the same accumulation pattern of total mercury. This fish species is of lesser importance in mercury transfer to adjacent coastal areas and although the consumption of fish from Laranjo may present some risk for the humans, this risk decreases with fish age/size.

  10. 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.

  11. LONG-TERM CHANGES IN MERCURY CONCENTRATIONS IN FISH FROM THE MIDDLE SAVANNAH RIVER

    SciTech Connect

    Paller, M; Bill Littrell, B

    2007-01-02

    Total mercury levels were measured in largemouth bass (Micropterus salmoides), ''sunfishes'' (Lepomis spp)., and ''catfish'' (primarily Ameiurus spp.) from 1971 to 2004 in the middle reaches of the Savannah River, which drains the coastal plain of the southeastern U.S. Mercury levels were highest in 1971 but declined over the next ten years due to the mitigation of point sources of industrial pollution. Mercury levels began to increase in the 1980s as a possible consequence of mercury inputs from tributaries and associated wetlands where mercury concentrations were significantly elevated in water and fish. Mercury levels in Savannah River fish decreased sharply in 2001-2003 coincident with a severe drought in the Savannah River basin, but returned to previous levels in 2004 with the resumption of normal precipitation. Regression models showed that mercury levels in Savannah River fish changed significantly over time and were affected by river discharge. Despite temporal changes, there was little overall difference in Savannah River fish tissue mercury levels between 1971 and 2004.

  12. 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.

  13. Mercury hazards from gold mining to humans, plants, and animals

    USGS Publications Warehouse

    Eisler, R.

    2004-01-01

    Mercury contamination of the environment from historical and ongoing mining practices that rely on mercury amalgamation for gold extraction is widespread. Contamination was particularly severe in the immediate vicinity of gold extraction and refining operations; however, mercury--especially in the form of water-soluble methylmercury--may be transported to pristine areas by rainwater, water currents, deforestation, volatilization, and other vectors. Examples of gold mining-associated mercury pollution are shown for Canada, the United States, Africa, China, the Philippines, Siberia, and South America. In parts of Brazil, for example, mercury concentrations in all abiotic materials, plants, and animals--including endangered species of mammals and reptiles--collected near ongoing mercury-amalgamation gold mining sites were far in excess of allowable mercury levels promulgated by regulatory agencies for the protection of human health and natural resources. Although health authorities in Brazil are unable to detect conclusive evidence of human mercury intoxication, the potential exists in the absence of mitigation for epidemic mercury poisoning of the mining population and environs. In the United States, environmental mercury contamination is mostly from historical gold mining practices, and portions of Nevada remain sufficiently mercury-contaminated to pose a hazard to reproduction of carnivorous fishes and fish-eating birds. Concentrations of total mercury lethal to sensitive representative natural resources range from 0.1 to 2.0 ug/L of medium for aquatic organisms; from 2200 to 31,000 ug/kg body weight (acute oral) and 4000 to 40,000 ug/kg (dietary) for birds; and from 100 to 500 ug/kg body weight (daily dose) and 1000 to 5000 ug/kg diet for mammals. Significant adverse sublethal effects were observed among selected aquatic species at water concentrations of 0.03 to 0.1 ug Hg/L. For some birds, adverse effects--mainly on reproduction--have been associated with total mercury concentrations (in ug/kg fresh weight) of 5000 in feather, 900 in egg, and 50 to 100 in diet; and with daily intakes of 640 ug/kg body weight. Sensitive nonhuman mammals showed significant adverse effects of mercury when daily intakes were 250 ug/kg body weight, when dietary levels were 1100 ug/kg, or when tissue concentrations exceeded 1100 ug/kg. Proposed mercury criteria for protection of aquatic life range from 0.012 ug/L for freshwater life to 0.025 ug/L for marine life; for birds, less than 100 ug/kg diet fresh weight; and for small mammals, less than 1100 ug/kg fresh weight diet. All of these proposed criteria provide, at best, minimal protection.

  14. A Toxicokinetic Model for Predicting the Tissue Distribution and Elimination of Organic and Inorganic Mercury Following Exposure to Methyl Mercury in Animals and Humans. II. Application and Validation of the Model in Humans

    Microsoft Academic Search

    Gaétan Carrier; Michèle Bouchard; Robert C. Brunet; Mylène Caza

    2001-01-01

    The objective of this study was to develop a biologically based dynamical model describing the disposition kinetics of methyl mercury and its inorganic mercury metabolites in humans following different methyl mercury exposure scenarios. The model conceptual and functional representation was similar to that used for rats but relevant data on humans served to determine the critical parameters of the kinetic

  15. Mercury Speciation in Fish Tissues from a Mediterranean River Basin: The Tagus River (Central Spain) as a Case Study

    Microsoft Academic Search

    J. J. Berzas Nevado; R. C. Rodríguez Martín-Doimeadios; F. J. Guzmán Bernardo; M. Jiménez Moreno; M. J. Patiño Ropero; A. de Marcos Serrano

    An assessment of mercury (Hg) accumulation in fish from the Tagus River aquatic system (central Spain), which has been influenced\\u000a by pollution from industrial and urban development, was performed. Total Hg (THg), inorganic Hg (IHg), and monomethylmercury\\u000a (MMHg) were determined in muscle and liver of different fish species, including Cyprinus carpio, Ameiurus melas, and Chondrostoma miegii, sampled from three locations.

  16. 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

  17. Hair mercury levels and food consumption in residents from the Pearl River Delta: South China.

    PubMed

    Shao, Dingding; Kang, Yuan; Cheng, Zhang; Wang, Hongsheng; Huang, Minjuan; Wu, Shengchun; Chen, Kunci; Wong, Ming H

    2013-01-15

    The Pearl River Delta (PRD) is located in the Southern part of China and is the main region for fish culture in Guangdong Province. In order to assess the potential health risks associated with dietary consumption of mercury, hair samples from 91 urban, town and fishing village residents, 37 species of fish, cereal, vegetables, and meat samples were collected. The average total mercury (THg) and methylmercury (MeHg) concentrations in hair were 1.08 ± 0.94 and 0.58 ± 0.59 ?g/g, respectively. Daily Hg intake via fish consumption is significantly correlated with THg and MeHg accumulated in human hair (r=0.48, p<0.01; r=0.43, p<0.01). The estimated daily intake of Hg via different food types showed that both fish and cereal consumption were the two main routes of Hg exposure for residents in the sampling areas. Besides food intake, smoking was also an important source for daily THg intake in the smoke group, contributing 11-18% to EDI of THg. PMID:23122114

  18. Relationship between mercury levels in hair and fish consumption in a population living near a hydroelectric tropical dam.

    PubMed

    Marrugo-Negrete, José Luis; Ruiz-Guzmán, Javier Alonso; Díez, Sergi

    2013-02-01

    In the present study, total mercury (T-Hg) concentrations were assessed in human hair samples (n = 76) and fish muscle (n = 33) collected at Urrá dam, upstream Sinú river, northwestern Colombia. Based on interviews with study participants, weekly intakes of total mercury (WIT-Hg) and methylmercury (WIMeHg) by fish consumption were also estimated. T-Hg concentrations in hair samples ranged from 0.40 to 24.56 ?g/g dw. The highest concentrations were recorded in children (CH) (2-15 years old, n = 24) with significant differences (p < 0.05) with respect to women of childbearing age (WCHA) (16-49 years old, n = 29) and the rest of the population (RP) (n = 23), which were not significantly different. The highest T-Hg concentrations in muscle tissue were recorded in the carnivorous fish (0.65-2.25 ?g/g wet weight, ww), with significant differences (p < 0.05) compared to non-carnivorous fish (0.16-0.54 ?g/g ww). WIT-Hg recorded the highest values in CH (2.18-50.41 ?g/kg/week), with significant differences (p < 0.05) with respect to WCHA (2.02-23.54 ?g/kg/week) and RP (1.09-24.71 ?g/kg/week), which were not significantly different. Correlation analysis showed a significant relationship between weekly fish consumption and hair T-Hg in CH (r = 0.37, p < 0.05) and WCHA (r = 0.44, p < 0.05). This association was also observed with the number of days per week with fish consumption in CH (r = 0.37, p < 0.05) and WCHA (r = 0.45, p < 0.05). These results suggest that Hg exposure in people inhabiting the Urrá dam should be carefully monitored, particularly in vulnerable groups such as CH and WCHA. PMID:23242864

  19. Levels and temporal trends (1983-2003) of persistent organic pollutants (POPs) and mercury (Hg) in seabird eggs from Northern Norway.

    PubMed

    Helgason, Lisa B; Barrett, Rob; Lie, Elisabeth; Polder, Anuschka; Skaare, Janneche U; Gabrielsen, Geir W

    2008-09-01

    The main objective of this study was to investigate possible temporal trends of persistent organic pollutants (POPs) and mercury in eggs of herring gulls (Larus argentatus), black-legged kittiwakes (Rissa tridactyla), common guillemots (Uria aalge) and Atlantic puffins (Fratercula arctica) in Northern Norway. Eggs were collected in 1983, 1993 and 2003. Egg concentrations of POPs (PCB congeners IUPAC numbers: CB-28, 74, 66, 101, 99, 110, 149, 118, 153, 105, 141, 138, 187, 128, 156, 157, 180, 170, 194, 206, HCB, alpha-HCH, beta-HCH, gamma-HCH, oxychlordane, trans-chlordane, cis-chlordane, trans-nonachlor, cis-nonachlor, p,p'-DDE, o,p'-DDD, p,p'-DDD, o,p'-DDT and p,p'-DDT) and mercury were quantified. Generally, POP levels decreased between 1983 and 2003 in all species. No significant temporal trend in mercury levels was found between 1983 and 2003. PMID:18262696

  20. 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.

  1. Arsenic, cadmium, chromium, lead, mercury, and selenium levels in blood of four species of turtles from the Amazon in Brazil.

    PubMed

    Burger, Joanna; Jeitner, Christian; Schneider, Larissa; Vogt, Richard; Gochfeld, Michael

    2010-01-01

    Using blood as a method of assessing metal levels in turtles may be useful for populations that are threatened or endangered or are decreasing. In this study the levels of arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg), and selenium (Se) in blood of four species of turtles from the tributaries of the Rio Negro in the Amazon of Brazil were examined. The turtles included the six-tubercled Amazon (river) turtle (Podocnemis sextuberculata), red-headed Amazon (river) turtle (Podocnemis erythrocephala), big-headed Amazon (river) turtle (Peltocephalus dumerilianus), and matamata turtle (Chelus fimbriatus). Blood samples were taken from the vein in the left hind leg of each turtle. There were significant interspecific differences in the sizes of the turtles from the Rio Negro, and in concentrations of Pb, Hg, and Se; the smallest species (red-headed turtles) had the highest levels of Pb in their blood, while Se levels were highest in big-headed turtles and lowest in red-headed turtles. Hg in blood was highest in matamata, intermediate in big-headed, and lowest in the other two turtles. Even though females were significantly larger than males, there were no significant differences in metal levels as a function of gender, and the only relationship of metals to size was for Cd. Variations in metal levels among species suggest that blood may be a useful bioindicator. Metal levels were not high enough to pose a health risk to the turtles or to consumers, such as humans. PMID:19953418

  2. 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

  3. Phytoremediation of mercury-contaminated soils by Jatropha curcas.

    PubMed

    Marrugo-Negrete, José; Durango-Hernández, José; Pinedo-Hernández, José; Olivero-Verbel, Jesús; Díez, Sergi

    2015-05-01

    Jatropha curcas plants species were tested to evaluate their phytoremediation capacity in soils contaminated by different levels of mercury. The experimental treatments consisted of four levels of mercury concentrations in the soil - T0, T1, T5, and T10 (0, 1, 5, and 10?g Hg per g soil, respectively). The total mercury content absorbed by the different plant tissues (roots, stems and leaves) was determined during four months of exposure. The growth behavior, mercury accumulation, translocation (TF) and bioconcentration (BCF) factors were determined. The different tissues in J. curcas can be classified in order of decreasing accumulation Hg as follows: roots>leaves>stems. The highest cumulative absorption of the metal occurred between the second and third month of exposure. Maximum TF was detected during the second month and ranged from 0.79 to 1.04 for the different mercury concentrations. Values of BCF ranged from 0.21 to 1.43. Soils with T1 showed significantly higher BCF (1.43) followed by T10 (1.32) and T5 (0.91), all of them at the fourth month. On the other hand TFs were low (range 0.10-0.26) at the en of the experiment. The maximum reduction of biomass (16.3%) occurred for T10 (10?g Hg g(-1)). In sum, J. curcas species showed high BCFs and low TFs, and their use could be a promising approach to remediating mercury-contaminated soils. PMID:25655698

  4. Student Exposure to Mercury Vapors.

    ERIC Educational Resources Information Center

    Weber, Joyce

    1986-01-01

    Discusses the problem of mercury vapors caused by spills in high school and college laboratories. Describes a study which compared the mercury vapor levels of laboratories in both an older and a newer building. Concludes that the mercurial contamination of chemistry laboratories presents minimal risks to the students. (TW)

  5. MERCURY IN MARINE LIFE DATABASE

    EPA Science Inventory

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

  6. ATMOSPHERIC MERCURY TRANSPORT AND DEPOSITION

    EPA Science Inventory

    The current state of our scientific understanding the mercury cycle tells us that most of the mercury getting into fish comes from atmospheric deposition, but methylation of that mercury in aquatic systems is required for the concentrations in fish to reach harmful levels. We st...

  7. Mercury levels in muscle of six species of turtles eaten by people along the Rio Negro of the Amazon basin.

    PubMed

    Schneider, Larissa; Belger, Lauren; Burger, Joanna; Vogt, Richard C; Ferrara, Camila R

    2010-02-01

    Mercury levels in the Amazon River are generally high, but there are no published studies on Hg levels in turtles from the region. In this study, levels of Hg were examined in the muscle of six species of turtles in the Rio Negro in the Amazon basin of Brazil, including Podocnemis unifilis, Podocnemis expansa, Podocnemis erythrocephala, Podocnemis sextuberculata, Peltocephalus dumerilianus, and Chelus fimbriatus. It is important to analyze Hg levels in chelonians in this region because of the potential health risk to humans and other receptors that eat them, as well as their potential use as bioindicators. The effect of sex, weight, and carapace length on Hg concentrations in turtle muscle was examined to determine if the levels represent a health risk to riverine people. There was a significant interspecific difference in Hg levels but no differences as a function of size or gender. The highest Hg level was found in Chelus fimbriatus (mean = 432 ppb, standard deviation +/- 196 ppb), followed by Peltocephalus dumerilianus (106 +/- 41 ppb), Podocnemis expansa (62 +/- 49 ppb), P. sextuberculata (61 +/- 40 ppb), P. unilifis (35 +/- 17 ppb), and P. erythrocephala (33.1 +/- 17 ppb). Of the species studied, the piscivorous C. fimbriatus had the highest Hg level. Hg levels in turtles were similar to the levels found in fish from the same basin. Levels of Hg in the muscle of C. fimbriatus are sufficiently high to pose a potential risk to humans who consume them. This study represents the first comparative study of Hg levels in muscle of six species of turtles. PMID:19621205

  8. THE CONCENTRATION OF MERCURY, COPPER, NICKEL, SILVER, CADMIUM, AND LEAD IN THE NORTHERN ADRIATIC ANCHOVY, ENGRAULIS ENCRASICHOLUS, AND SARDINE, SARDINA PILCHARDUS

    Microsoft Academic Search

    MALVERN GILMARTIN; NOELIA REVELANTE

    Levels of mercury, copper, nickel, silver, cadmium, and lead were determined in various tissues of the northern Adriatic anchovy, Engraulis encrasicholus, and sardine, Sardina pilchardus. throughout a 7-month fishing season. The highest concentrations of nickel, silver, cadmium, and lead occurred in the skin ar.d gills, with little interspecific differences and no unusually high values. The highest concentrations of mercury and

  9. 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

    2014-12-01

    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

  10. IMPACT OF NOBLE METALS AND MERCURY ON HYDROGEN GENERATION DURING HIGH LEVEL WASTE PRETREATMENT AT THE SAVANNAH RIVER SITE

    SciTech Connect

    Stone, M; Tommy Edwards, T; David Koopman, D

    2009-03-03

    The Defense Waste Processing Facility (DWPF) at the Savannah River Site vitrifies radioactive High Level Waste (HLW) for repository internment. The process consists of three major steps: waste pretreatment, vitrification, and canister decontamination/sealing. HLW consists of insoluble metal hydroxides (primarily iron, aluminum, calcium, magnesium, manganese, and uranium) and soluble sodium salts (carbonate, hydroxide, nitrite, nitrate, and sulfate). The pretreatment process in the Chemical Processing Cell (CPC) consists of two process tanks, the Sludge Receipt and Adjustment Tank (SRAT) and the Slurry Mix Evaporator (SME) as well as a melter feed tank. During SRAT processing, nitric and formic acids are added to the sludge to lower pH, destroy nitrite and carbonate ions, and reduce mercury and manganese. During the SME cycle, glass formers are added, and the batch is concentrated to the final solids target prior to vitrification. During these processes, hydrogen can be produced by catalytic decomposition of excess formic acid. The waste contains silver, palladium, rhodium, ruthenium, and mercury, but silver and palladium have been shown to be insignificant factors in catalytic hydrogen generation during the DWPF process. A full factorial experimental design was developed to ensure that the existence of statistically significant two-way interactions could be determined without confounding of the main effects with the two-way interaction effects. Rh ranged from 0.0026-0.013% and Ru ranged from 0.010-0.050% in the dried sludge solids, while initial Hg ranged from 0.5-2.5 wt%, as shown in Table 1. The nominal matrix design consisted of twelve SRAT cycles. Testing included: a three factor (Rh, Ru, and Hg) study at two levels per factor (eight runs), three duplicate midpoint runs, and one additional replicate run to assess reproducibility away from the midpoint. Midpoint testing was used to identify potential quadratic effects from the three factors. A single sludge simulant was used for all tests and was spiked with the required amount of noble metals immediately prior to performing the test. Acid addition was kept effectively constant except to compensate for variations in the starting mercury concentration. SME cycles were also performed during six of the tests.

  11. 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

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

    PubMed

    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

  13. Subcutaneous injection of metallic mercury

    Microsoft Academic Search

    Y OY Soo; C H Wong; J F Griffith; T YK Chan

    2003-01-01

    Deliberate self-injection of metallic mercury into subcutaneous tissue is uncommon. A 41-year-old lady with a history of schizophrenia was admitted to our hospital after deliberate injection of metallic mercury into her right wrist and antecubital fossa. Physical examination was unremarkable except for the injection marks over right antecubital fossa and wrist. The presence of subcutaneous mercury deposits in her right

  14. 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.

  15. Tissue levels of cadmium and trace elements in patients with myoma and uterine cancer.

    PubMed

    Nasiadek, M; Krawczyk, T; Sapota, A

    2005-12-01

    The aim of this study was to investigate the cadmium (Cd), copper (Cu), zinc (Zn), iron (Fe), magnesium (Mg) and calcium (Ca) concentrations in uterine cancer and uterine myoma. Tissue levels of six elements in 15 uterine cancers and 28 uterine myomas were measured by atomic absorption spectrometry. The samples were collected from women aged 32-79 (uterine myomas, uterine cancer and non-lesion uterine tissues from the same women). The results showed that the tissue Cd concentration was significantly lower in myoma than in non-lesion tissue. In uterine cancer, however, it was statistically significant, but only slightly lower than controls (the non-lesion uterine tissue). In the investigated tissues, the correlation between Cd concentration and age was found, but no effect of menopausal status or smoking habits on Cd level was detected. In uterine cancer tissue, a significant increase in Ca concentration and an insignificant increase in Mg level was observed when compared to normal uterine tissue. In uterine myoma, a significant increase of Mg and Mg/Ca ratio, as well as a decrease in Fe concentration were found. Statistical analysis showed no correlation between smoking habits, age, menopausal status and concentration of Cu, Zn, Fe, Mg and Ca trace metals in myoma or cancer tissue. PMID:16408615

  16. 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN LEVELS IN ADIPOSE TISSUE OF VIETNAM VETERANS

    EPA Science Inventory

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has been detected at levels ranging from 20 to 173 parts per trillion in adipose tissue from three Vietnam veterans who were 'heavily exposed' to Herbicide Orange. Some tissue samples from other Vietnam veterans and from controls also co...

  17. Mercury Quest

    NSDL National Science Digital Library

    In this module, students pretend they have been hired as an environmental consulting firm to deliver testimony for the hearing to develop a mercury pollution reduction plan for the State. In order to accomplish this task their consulting company must: inventory and assess current sources of mercury pollution to the extent feasible, including both (fictitious) Ramford County and regional sources of mercury pollution; review the current science on mercury deposition, transport, and exposure pathways; review the current science on the impacts of mercury pollution on public health and ecosystems; review existing mercury pollution policies in other states and in the US; and review strategies for clean up and reduction of exposure to mercury.

  18. 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

  19. 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

  20. 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.

  1. Mercury accumulation and loss in mallard eggs

    USGS Publications Warehouse

    Heinz, G.H.; Hoffman, D.J.

    2004-01-01

    Female mallards (Anas platyrhynchos) were fed diets containing 5, 10, or 20 ppm mercury as methylmercury chloride. One egg was collected from each bird before the start of the mercury diets and 15 eggs were collected from each bird while it was being fed mercury. The mercury diets were then replaced by uncontaminated diets, and each female was allowed to lay 29 more eggs. Mercury levels in eggs rose to about 7,18, and 35 ppm wet-weight in females fed 5,10, or 20 ppm mercury, respectively. Mercury levels fell to about 0.16,0.80, and 1.7 ppm in the last egg laid by birds that had earlier been fed 5, 10, or 20 ppm mercury, respectively. Higher concentrations of mercury were found in egg albumen than in yolk, and between 95 and 100% of the mercury in the eggs was in the form of methylmercury.

  2. ARSENIC, CADMIUM, CHROMIUM, LEAD, MERCURY, AND SELENIUM LEVELS IN BLOOD OF FOUR SPECIES OF TURTLES FROM THE AMAZON IN BRAZIL

    PubMed Central

    Burger, Joanna; Jeitner, Christian; Schneider, Larissa; Vogt, Richard; Gochfeld, Michael

    2014-01-01

    Using blood as a method of assessing metal levels in turtles may be useful for populations that are threatened or endangered or are decreasing. In this study the levels of arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg), and selenium (Se) in blood of four species of turtles from the tributaries of the Rio Negro in the Amazon of Brazil were examined. The turtles included the six-tubercled Amazon (river) turtle (Podocnemis sextuberculata), red-headed Amazon (river) turtle (Podocnemis erythrocephala), big-headed Amazon (river) turtle (Peltocephalus dumerilianus), and matamata turtle (Chelus fimbriatus). Blood samples were taken from the vein in the left hind leg of each turtle. There were significant interspecific differences in the sizes of the turtles from the Rio Negro, and in concentrations of Pb, Hg, and Se; the smallest species (red-headed turtles) had the highest levels of Pb in their blood, while Se levels were highest in big-headed turtles and lowest in red-headed turtles. Hg in blood was highest in matamata, intermediate in big-headed, and lowest in the other two turtles. Even though females were significantly larger than males, there were no significant differences in metal levels as a function of gender, and the only relationship of metals to size was for Cd. Variations in metal levels among species suggest that blood may be a useful bio-indicator. Metal levels were not high enough to pose a health risk to the turtles or to consumers, such as humans. PMID:19953418

  3. Mercury toxicity in the aquatic oligochaete Sparganophilus pearsei: I. Variation in resistance among populations.

    PubMed

    Vidal, D E; Horne, A J

    2003-08-01

    Mercury contamination has become a problem in many San Francisco Bay Area watersheds due to its elevated presence in sediments and aquatic organisms. The present study used laboratory lethal toxicity (LC50) tests to examine the mercury tolerance of aquatic oligochaete worms, Sparganophilus pearsei, from contaminated and uncontaminated areas. The oligochaetes were collected in the following fresh water reservoirs: Sandy Wool (reference area), San Pablo, Lake Anza, Lake Herman, and Guadalupe. These last four reservoirs were contaminated with levels of mercury that ranged from 1.5 to 2 mg/kg (wet weight). Mercury concentrations in sediment and tissue from Sandy Wool were below detection limits and worms from this site were the least tolerant of mercury in laboratory exposures (LC50 = 0.22 mg/L). Worms from the other, more contaminated, reservoirs contained elevated tissue mercury concentrations and were more tolerant in laboratory tests (LC50 = 1.48-2.19 mg/L). The present study demonstrates that different populations of the aquatic oligochaete S. pearsei have developed different tolerances to mercury depending on their previous history of exposure to mercury contamination. PMID:14565575

  4. Theoretical Bounds for the Influence of Tissue-Level Ductility on the Apparent-Level Strength of Human Trabecular Bone

    PubMed Central

    Nawathe, Shashank; Juillard, Frédéric; Keaveny, Tony M.

    2015-01-01

    The role of tissue-level post-yield behavior on the apparent-level strength of trabecular bone is a potentially important aspect of bone quality. To gain insight into this issue, we compared the apparent-level strength of trabecular bone for the hypothetical cases of fully brittle versus fully ductile failure behavior of the trabecular tissue. Twenty human cadaver trabecular bone specimens (5 mm cube; BV/TV = 6–36%) were scanned with micro-CT to create 3D finite element models (22-micron element size). For each model, apparent-level strength was computed assuming either fully brittle (fracture with no tissue ductility) or fully ductile (yield with no tissue fracture) tissue-level behaviors. We found that the apparent-level ultimate strength for the brittle behavior was only about half the value of the apparent-level 0.2%-offset yield strength for the ductile behavior, and the ratio of these brittle to ductile strengths was almost constant (mean ± SD = 0.56 ± 0.02; n=20; R2 = 0.99 between the two measures). As a result of this small variation, although the ratio of brittle to ductile strengths was positively correlated with the bone volume fraction (R2=0.44, p=0.01) and structure model index (SMI, R2=0.58, p<0.01), these effects were small. Mechanistically, the fully ductile behavior resulted in a much higher apparent-level strength because in this case about 16-fold more tissue was required to fail than for the fully brittle behavior; also, there was more tensile- than compressive-mode of failure at the tissue level for the fully brittle behavior. We conclude that, in theory, the apparent-level strength behavior of human trabecular bone can vary appreciably depending on whether the tissue fails in a fully ductile versus fully brittle manner, and this effect is largely constant despite appreciable variations in bone volume fraction and microarchitecture. PMID:23497799

  5. 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

  6. Reel danger: power plant mercury pollution and the fish we eat

    SciTech Connect

    Figdor, E. [US Public Interest Research Group Education Fund (US PIRG) for Clear the Air, Washington, DC (United States)

    2004-08-15

    This study is based on the first available data from US EPA's ongoing National Study of Chemical Residues in Lake Fish Tissue. From 1999-2001, EPA collected approximately two composite samples of one predator fish species and one bottom-dwelling fish species at 260 lakes, for a total of 520 composite samples, or 2,547 fish. It was found that every fish tested was contaminated with mercury. 55% of the fish tested contained mercury levels that exceed EPA's 'safe' limit for women of childbearing age, and 76% exceeded the safe limit for children under age three. Predator fish, including smallmouth bass, walleye, largemouth bass, lake trout, and Northern pike, had the highest average mercury concentrations. Coal-fired power plants are the single largest source of mercury emissions, contributing 41% of US mercury emissions. They released 90,370 pounds of mercury into the air in 2002, the most recent year for which EPA data are available. In January 2004, the Bush administration issued a proposal for regulating mercury from power plants. In the author's opinion, the EPA's proposal would delay even modest reductions in mercury emissions from power plants until after 2025. In contrast, the Clean Air Act calls for the maximum achievable reductions by 2008. It is recommended that the Bush administration reverse course and require coal-fired power plants to reduce mercury emissions by at least 90% by 2008. 79 refs., 4 figs., 11 tabs., 3 apps.

  7. The Empire Knight: Patterns of mercury contamination in sediment and biota at a marine site

    SciTech Connect

    Hoff, R.Z. [NOAA Hazmat, Seattle, WA (United States)

    1995-12-31

    The Empire Knight, a merchant ship carrying approximately 7.3 metric tons of elemental mercury in its cargo, sank in a storm off the Maine coast in 1 944. Unique attributes of the site include the deep water marine conditions (80 m) and mercury originally in elemental form. Recent evaluations of the site were undertaken to determine environmental risk of the remaining mercury and possible remedial actions. Data collected in 1993 for this risk evaluation included sediment core samples, and a variety of biota samples. Biota were analyzed for total and methylmercury, and the following patterns examined: percent methylmercury, variability between species groups, and spatial patterns related to sediment contamination. Sediment contamination was largely confined to the immediate area near the wreck, with levels decreasing to background within 60 m. Invertebrates within this area had elevated levels of mercury in tissue. Most contamination was in an inorganic form, with percentages of methyl to total mercury below 20%, except for crab and lobster. Most of the residual mercury appears to be largely unavailable to biota, with local invertebrates comprising the main biological receptors. Evidence of bioaccumulation of mercury in higher trophic level organisms was not found, thus mercury did not appear to be a source of contamination beyond the immediate area the wreck.

  8. Mercury accumulation in largemouth bass (Micropterus salmoides) in a Florida Lake

    Microsoft Academic Search

    T. R. Lange; H. E. Royals; L. L. Connor

    1994-01-01

    Rates of mercury accumulation were examined in male and female largemouth bass (Micropterus salmoides) from Lake Tohopekaliga, Florida, to establish methods for fish consumption advisories for the protection of human health. In addition, concentrations were determined in five lower trophic level fish species. Total mercury concentrations in adult largemouth bass muscle tissue ranged from 0.16 to 1.10 µg\\/g (fresh weight)

  9. Tissue Factor and Tissue Factor Pathway Inhibitor as Key Regulators of Global Hemostasis: Measurement of Their Levels in Coagulation Assays

    PubMed Central

    Kasthuri, Raj S.; Glover, Sam L.; Boles, Jeremiah; Mackman, Nigel

    2011-01-01

    The tissue factor (TF)/factor (F)VIIa complex is the primary initiator of coagulation in vivo. Tissue factor pathway inhibitor (TFPI) is the physiological inhibitor of the TF/FVIIa complex. Deficiencies of either TF or TFPI have not been reported in humans, and a complete absence of either of these two proteins in mice is embryonically lethal. To maintain normal hemostasis, levels of TF and TFPI need to be balanced. Increased levels of TF can overwhelm the inhibitory capacity of TFPI, resulting in thrombosis. Decreased levels of TF are associated with bleeding. Global assays of coagulation are defined as tests capable of evaluating all components of the clotting cascade that are present in plasma. In these tests the thrombogenic surface is either provided by platelets or exogenous phospholipids. Clotting assays currently used in clinical practice are not designed to measure endogenous levels of TF and TFPI. Therefore, there is a need to develop sensitive and specific assays for measuring levels of functional TF and TFPI in whole blood and plasma. These assays could be useful in patient management in many scenarios. PMID:20978997

  10. High vacuum mercury retort recovery

    SciTech Connect

    Boyle, J.M. [Bethlehem Apparatus Co., Inc., Hellertown, PA (United States)

    1995-12-31

    Bethlehem Apparatus Company is a worldwide supplier of extremely high purity quadruple distilled mercury. For 40 years, the process of continuous feed vacuum distillation of mercury has been used to achieve the highest levels of purity. In the early 1970`s Bethlehem developed a mercury retort process for the recovery of mercury from manufactured articles. This process is continuously updated with new innovations and is currently a relatively high vacuum system that is capable of handling a wide variety of mercury bearing waste materials.

  11. www.mdpi.com/journal/ijerph The Influence of Fish Length on Tissue Mercury Dynamics: Implications for Natural Resource Management and Human

    E-print Network

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

    2013-01-01

    Abstract: 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

  12. A Toxicokinetic Model for Predicting the Tissue Distribution and Elimination of Organic and Inorganic Mercury Following Exposure to Methyl Mercury in Animals and Humans. I. Development and Validation of the Model Using Experimental Data in Rats

    Microsoft Academic Search

    Gaétan Carrier; Robert C. Brunet; Mylène Caza; Michèle Bouchard

    2001-01-01

    The objective of this study was to develop a biologically based dynamic model for predicting the distribution and elimination of methyl mercury and its metabolite, inorganic mercury, under a variety of exposure scenarios in rats. A model is proposed based on a multicompartment approach; each compartment represents an organ or a group of organs or an excreta. The model translates

  13. Sensitivity of the sea snail Gibbula umbilicalis to mercury exposure--linking endpoints from different biological organization levels.

    PubMed

    Cabecinhas, Adriana S; Novais, Sara C; Santos, Sílvia C; Rodrigues, Andreia C M; Pestana, João L T; Soares, Amadeu M V M; Lemos, Marco F L

    2015-01-01

    Mercury contamination is a common phenomenon in the marine environment and for this reason it is important to develop cost-effective and relevant tools to assess its toxic effects on a number of different species. To evaluate the possible effects of Hg in the sea snail Gibbula umbilicalis, animals were exposed to increasing concentrations of the contaminant in the ionic form for 96 h. After this exposure period, mortality, feeding and flipping behavior, the activity of the biomarkers glutathione S-transferase, superoxide dismutase, catalase, lactate dehydrogenase and cholinesterase, the levels of lipid peroxidation and cellular energy allocation were measured. After 96 h of exposure to the highest Hg concentration (?LC20), there was a significant inhibition of the cholinesterase activity as well as impairment in the flipping behavior and post-exposure feeding of the snails. Cholinesterase inhibition was correlated with the impairment of behavioral responses also caused by exposure to Hg. These endpoints, including the novel flipping test, revealed sensitivity to Hg and might be used as relevant early warning indicators of prospective effects at higher biological organization levels, making these parameters potential tools for environmental risk assessment. The proposed test species showed sensitivity to Hg and proved to be a suitable and resourceful species to be used in ecotoxicological testing to assess effects of other contaminants in marine ecosystems. PMID:25112574

  14. Mercury burdens in Chinese mitten crabs (Eriocheir sinensis) in three tributaries of southern San Francisco Bay, California, USA

    USGS Publications Warehouse

    Hui, C.A.; Rudnick, D.; Williams, E.

    2005-01-01

    Chinese mitten crabs (Eriocheir sinensis), endemic to Asia, were first reported in the San Francisco Bay in 1992. They are now established in nearly all San Francisco Bay tributaries. These crabs accumulate more metals, such as mercury, than crustaceans living in the water column. Because their predators include fish, birds, mammals and humans, their mercury burdens have an exceptional potential to impact the ecosystem and public health. We sought to elucidate the potential threat of mitten crab mercury burdens in three adjacent streams in southern San Francisco Bay, one of which is known to be contaminated with mercury. Mitten crabs had hepatopancreas concentrations of total mercury and methylmercury that did not differ among streams. The maximum burden we measured was below the action level of 1 ppm recommended by the USEPA. Hepatopancreas concentrations of methylmercury declined with increasing crab size, suggesting a mechanism for mercury excretion and that predators might reduce mercury exposure if they select larger crabs. Because mercury may be heterogeneously distributed among tissues, estimation of the impacts of crab mercury burdens on the environment requires more data on the feeding preferences of predators. Hepatopancreas concentrations of mercury decline with crab size, which may have important consequences for bio-magnification in food webs. ?? 2004 Elsevier Ltd. All rights reserved.

  15. Mercury Changes Songs Dire effects of mercury contamination on birds' physiology

    E-print Network

    Irwin, Darren

    Mercury Changes Songs Dire effects of mercury contamination on birds' physiology and behavior make higher blood mercury levels at the contaminated sites compared to the uncontaminated sites (Science 320 up an alarming list of pathologies, and now we can add one more: Mercury in the diet may be poi

  16. Mercury and Chlorinated Pesticides on the Highest Level of the Food Web as Exemplified by Herring from the Southern Baltic and African Penguins from the Zoo.

    PubMed

    Falkowska, Lucyna; Reindl, Andrzej R; Szumi?o, Emilia; Kwa?niak, Justyna; Staniszewska, Marta; Be?dowska, Magdalena; Lewandowska, Anita; Krause, Izabela

    2013-05-01

    Aquatic birds are often used as a health indicator of the marine ecosystem. African penguins living in the zoo make good research material as they form a link between the marine and the terrestrial ecosystem in terms of xenobiotic circulation. Tests were performed on whole herring-the food of the penguins-as well as on bird muscle, liver, brain, eggs, feathers and guano in order to determine total mercury, aldrin, dieldrin, endrin, isodrin, endosulfan isomers, endosulfan sulfate, methoxychlor, dichlorodiphenyltrichloroethane (DDT) and its metabolites. In herring and penguin, the tests did not show the presence of ?-endosulfan, endosulfan sulfate, aldrin and isodrin. It was shown that penguins absorb about 36.8 ?g of organochlorine pesticides and 4.6 ?g of mercury with their food on a daily basis. Xenobiotics accumulate mostly in the liver, from where they are transported to the muscles and the brain, where the highest bioaccumulation factor is reached by endrin and pp'-DDT. Conceivably, the older the penguin, the higher is the concentration level of pesticides in its liver and brain. Molting was found to be the most effective way of eliminating mercury, dieldrin and methoxychlor from the system. Insecticides, such as DDT and its metabolites, were removed most effectively by females through laying of eggs. The standard four eggs laid within a year may have contained up to 20 % of the total amount of pesticides which had been absorbed with food, but no more than 5 % of mercury. PMID:23687395

  17. Inorganic: the other mercury.

    PubMed

    Risher, John F; De Rosa, Christopher T

    2007-11-01

    There is a broad array of mercury species to which humans may be exposed. While exposure to methylmercury through fish consumption is widely recognized, the public is less aware of the sources and potential toxicity of inorganic forms of mercury. Some oral and laboratory thermometers, barometers, small batteries, thermostats, gas pressure regulators, light switches, dental amalgam fillings, cosmetic products, medications, cultural/religious practices, and gold mining all represent potential sources of exposure to inorganic forms of mercury. The route of exposure, the extent of absorption, the pharmacokinetics, and the effects all vary with the specific form of mercury and the magnitude and duration of exposure. If exposure is suspected, a number of tissue analyses can be conducted to confirm exposure or to determine whether an exposure might reasonably be expected to be biologically significant. By contrast with determination of exposure to methylmercury, for which hair and blood are credible indicators, urine is the preferred biological medium for the determination of exposure to inorganic mercury, including elemental mercury, with blood normally being of value only if exposure is ongoing. Although treatments are available to help rid the body of mercury in cases of extreme exposure, prevention of exposure will make such treatments unnecessary. Knowing the sources of mercury and avoiding unnecessary exposure are the prudent ways of preventing mercury intoxication. When exposure occurs, it should be kept in mind that not all unwanted exposures will result in adverse health consequences. In all cases, elimination of the source of exposure should be the first priority of public health officials. PMID:18044248

  18. Predicting mercury in mallard ducklings from mercury in chorioallantoic membranes

    USGS Publications Warehouse

    Heinz, G.H.; Hoffman, D.J.

    2003-01-01

    Methylmercury has been suspected as a cause of impaired reproduction in wild birds, but the confounding effects of other environmental stressors has made it difficult to determine how much mercury in the eggs of these wild species is harmful. Even when a sample egg can be collected from the nest of a wild bird and the mercury concentration in that egg compared to the laboratory-derived thresholds for reproductive impairment, additional information on the mercury levels in other eggs from that nest would be helpful in determining whether harmful levels of mercury were present in the clutch. The measurement of mercury levels in chorioallantoic membranes offers a possible way to estimate how much mercury was in a chick that hatched from an egg, and also in the whole fresh egg itself. While an embryo is developing, wastes are collected in a sac called the chorioallantoic membranes, which often remain inside the eggshell and can be collected for contaminant analysis. We fed methylmercury to captive mallards to generate a broad range of mercury levels in eggs, allowed the eggs to hatch normally, and then compared mercury concentrations in the hatchling versus the chorioallantoic membranes left behind in the eggshell. When the data from eggs laid by mercury- treated females were expressed as common logarithms, a linear equation was created by which the concentration of mercury in a duckling could be predicted from the concentration of mercury in the chorioallantoic membranes from the same egg. Therefore, if it were not possible to collect a sample egg from a clutch of wild bird eggs, the collection of the chorioallantoic membranes could be substituted, and the mercury predicted to be in the chick or whole egg could be compared to the thresholds of mercury that have been shown to cause harm in controlled feeding studies with pheasants, chickens, and mallards.

  19. Human Exposure to Elemental Mercury in a Contaminated Residential Building

    Microsoft Academic Search

    Kenneth C. Orloff; Greg Ulirsch; Lynn Wilder; Arthur Block; Jerald Fagliano; James Pasqualo

    1997-01-01

    Residents of a condominium building in Hoboken, New Jersey, were exposed to mercury contamination in indoor air. Elevated levels of mercury were detected in urine samples provided by the residents, and 69% of the urine mercury levels were 20 ?g\\/l or greater. Urine mercury levels were correlated positively with the duration of residency in the building and with the time

  20. Dietary vitamin E affects ?-TTP mRNA levels in different tissues of the Tan sheep.

    PubMed

    Zuo, Zhao-yun; Luo, Hai-ling; Liu, Kun; Jia, Hui-na; Zhang, Yu-wei; Jiao, Li-juan; Chang, Yan-fei

    2014-05-10

    The ?-tocopherol transfer protein (?-TTP) is a ~32kDa cytosolic protein that plays an important role in the efficient circulation of plasma ?-tocopherol in the body, a factor with great relevance in reproduction. The ?-TTP gene has been studied in a number of tissues; however, its expression and function in some ovine tissues remain unclear. A previous study from our laboratory has demonstrated ?-TTP expression in sheep liver. In the present study we determined whether ?-TTP is expressed in non-liver tissues and investigated the effects of dietary vitamin E on the ?-TTP mRNA levels. Thirty-five male Tan sheep with similar body weight were randomly allocated into five groups and supplemented 0, 20, 100, 200 and 2000IUsheep(-1)day(-1) vitamin E, for four months, respectively. At the end of the study, the animals were slaughtered and tissue samples from the heart, spleen, lung, kidney, longissimus dorsi muscle and gluteus muscle were immediately collected. We found that the ?-TTP gene is expressed in sheep tissues other than the liver. Moreover, dietary vitamin E levels had influenced the expression levels of ?-TTP gene in these tissues in a tissue-specific way. The technique of immunohistochemistry was used to detect ?-TTP in tissues of the heart, spleen, lung, and kidney and we found that ?-TTP was mainly located in the cytoplasm while no ?-TTP immunoreactivity was detected in the cytoplasm of longissimus dorsi and gluteus muscle samples. Importantly, our findings lay the foundation for additional experiments focusing on the absorption and metabolism of vitamin E in tissues other than the liver. PMID:24630963

  1. 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.

  2. Tissue Levels and Optimum Dosage of Vitamin C in Guinea Pigs

    Microsoft Academic Search

    E. Ginter; P. Bobek; D. Vargová

    1979-01-01

    Ascorbic acid mixed with the diet of guinea pigs achieved substantially higher maximum tissue concentrations of ascorbate than when ascorbic acid was administered orally once a day. A 0.5% w\\/w of ascorbic acid in the diet ensured a state close to maximal tissue steady-state levels of ascorbate. In guinea pigs fed a diet with a high content of saturated fatty

  3. Primary Tumor Levels of Human Tissue Kallikreins Affect Surgical Success and Survival in Ovarian Cancer Patients

    Microsoft Academic Search

    Julia Dorn; Manfred Schmitt; Ronald Kates; Barbara Schmalfeldt; Marion Kiechle; Andreas Scorilas; Eleftherios P. Diamandis; Nadia Harbeck

    2007-01-01

    Purpose: Proteolytic factors of the human tissue kallikrein (hK) family and the plasminogen activation system play a key role in tumor progression in various malignancies. We determined antigen levels of urokinase-type plasminogen activator (uPA), its inhibitor PAI-1, and hK5-8, hK10, hK11, and hK13 by ELISA in primary tumor tissue extracts of 142 International Federation of Gynecology and Obstetrics (FIGO) I

  4. SFRSF: Mercury

    NSDL National Science Digital Library

    This South Florida Restoration Science Forum page discusses the problem with mercury in restoring habitats and ecosystems in southern Florida. This study looks at the origin of mercury in the water and atmosphere, and how Everglades restoration will affect mercury risks. Managing water quality and quantity to reduce risks, and understanding the food web to determine entry points and biomagnification are also discussed. Locations where mercury toxicity is above the healthy limit are identified. There are links for more information provided.

  5. 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

  6. 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

  7. Serum Levels of Matrix Metalloproteinases-2 and -9 and Their Tissue Inhibitors in Inflammatory Neuromuscular Disorders

    Microsoft Academic Search

    S. Hurnaus; W. Mueller-Felber; D. Pongratz; B. G. H. Schoser

    2006-01-01

    We monitored serum levels of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) before and during intravenously applied immunoglobulin (IVIG) therapy in 33 patients with chronic immune-mediated neuropathies and myopathies and 15 controls. Baseline MMP-2 and TIMP-2 serum levels were lower and MMP-9 and TIMP-1 serum levels higher in all patients compared to age-matched controls. Eight days after IVIG treatment,

  8. 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.'

  9. Mercury levels in Great Lakes herring gull ( Larus argentatus) eggs, 1972–1992

    Microsoft Academic Search

    M. D. Koster; D. P. Ryckman; D. V. C. Weseloh; J. Struger

    1996-01-01

    Since 1971, the herring gull (Larus argentatus) has been used as a sentinel species for monitoring the levels of persistent contaminants in the Great Lakes ecosystem. In this study, 21 herring gull colonies in the Great Lakes and connecting channels were sampled during 1972–1976, 1981–1983, 1985 and 1992. For each year, 10 eggs (usually) were collected from each colony site

  10. Levels of mercury in scalp hair of fishermen and their families from Camara de Lobos-Madeira (Portugal): A preliminary study

    SciTech Connect

    Gaggi, C.; Zino, F.; Duccini, M.; Renzoni, A. [Universita di Siena (Italy)] [Universita di Siena (Italy)

    1996-12-31

    Mercury is probably one of the most investigated natural and anthropogenic contaminants, especially in aquatic environments. Among the inorganic forms, elemental mercury (HgO) presents a marked tendency to reach the air as vapor, and in terrestrial systems to bioaccumulate in plant biomass, whereas other inorganic compounds (e.g., mercury sulphide) are characterized by low mobility and bioavailability. These last compounds once in water (and especially at the water-sediment interface) can undergo a process of methylation. Methylmercury (MeHg) is readily bioaccumulated by aquatic organisms and leads to a phenomenon of enrichment from lower to higher trophic level. The extensive literature on MeHg and human health shows that the consumption of fish and/or shellfish is the main source of exposure, the contribution from air and water being negligible and mainly related to inorganic forms. A human population consuming large amounts of seafood with high MeHg levels can be considered at risk when consumption exceeds a certain amount. This level has been set by the WHO and other agencies, at 300 {mu}g/week of total mercury (totHg) of which there should be no more than 200 {mu}g as MeHg. The nervous system is the principal target of the effects of MeHg in humans. The most common functions affected are the sensory, visual and auditory functions, together with those of the cerebellum, which is concerned with coordination. As far as prenatal exposure is concerned, the developing central nervous system of humans and animals has been found to be more sensitive to damage from MeHg than the adult nervous system. This preliminary study obtains and examines information about eating habits and general health of a group of fisherman and their families living in a fishing village, at high risk because of the high frequency of seafood in their normal diet. 17 refs., 1 fig., 1 tab.

  11. Effects of brief hypoxia and hyperoxia on tissue element levels in the development chick embryo

    SciTech Connect

    Richards, M.P.; Stock, M.K.; Metcalfe, J. (Dept. of Agriculture, Beltsville, MD (United States) Oregon Health Sciences Univ., Portland (United States))

    1991-03-15

    Brief hypoxia or hyperoxia has been shown to affect growth and metabolism of chick embryos during the later stages of development. The objective of this experiment was to alter the availability of oxygen to chick embryos developing in ovo and to determine the effects on tissue levels of Zn, Cu, Fe and Mn. Hypoxia reduced embryo, heart, brain and liver wts (wet wt), whereas, hyperoxia increased embryo, heart, lung and liver wts compared to normoxic controls. Chorioallantoic membrane (CAM) wt was increased by hypoxia and reduced by hyperoxia. Livers from hyperoxic embryos contained more Zn, Fe and Mn and less Cu than livers from hypoxic or normoxic embryos. Tissue levels of Zn, Cu, Fe and Mn were reduced in brains from hypoxic compared to hyperoxic or normoxic embryos. Hyperoxia increased the concentrations of Zn and Cu in CAM; whereas, hypoxia reduced the levels of Zn and Fe. The amounts of Zn and Cu were increased in hyperoxic compared to normoxic lungs. Hearts from hyperoxic embryos had more Zn, Cu and Mn than hypoxic or normoxic hearts. Hypoxic yolk sac contained more Zn, Cu and Mn than hyperoxic or normoxic yolk sac. Except for yolk sac, the amounts of Zn, Cu, Fe and Mn in tissues from normoxic embryos increased from day 15 to day 18 of incubation in concert with tissue growth. The authors conclude that the availability of O{sub 2} to the developing chick embryo affects tissue trace element levels either through its effects on tissue growth or via effects on the regulation of trace element uptake and assimilation by the tissues.

  12. Got Mercury?

    NASA Technical Reports Server (NTRS)

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

    2009-01-01

    Many of the operational and payload lighting units used in various spacecraft contain elemental mercury. If these devices were damaged on-orbit, elemental mercury could be released into the cabin. Although there are plans to replace operational units with alternate light sources, such as LEDs, that do not contain mercury, mercury-containing lamps efficiently produce high quality illumination and may never be completely replaced on orbit. Therefore, exposure to elemental mercury during spaceflight will remain possible and represents a toxicological hazard. Elemental mercury is a liquid metal that vaporizes slowly at room temperature. However, it may be completely vaporized at the elevated operating temperatures of lamps. Although liquid mercury is not readily absorbed through the skin or digestive tract, mercury vapors are efficiently absorbed through the respiratory tract. Therefore, the amount of mercury in the vapor form must be estimated. For mercury releases from lamps that are not being operated, we utilized a study conducted by the New Jersey Department of Environmental Quality to calculate the amount of mercury vapor expected to form over a 2-week period. For longer missions and for mercury releases occurring when lamps are operating, we conservatively assumed complete volatilization of the available mercury. Because current spacecraft environmental control systems are unable to remove mercury vapors, both short-term and long-term exposures to mercury vapors are possible. Acute exposure to high concentrations of mercury vapors can cause irritation of the respiratory tract and behavioral symptoms, such as irritability and hyperactivity. Chronic exposure can result in damage to the nervous system (tremors, memory loss, insomnia, etc.) and kidneys (proteinurea). Therefore, the JSC Toxicology Group recommends that stringent safety controls and verifications (vibrational testing, etc.) be applied to any hardware that contains elemental mercury that could yield airborne mercury vapor concentrations greater than 0.1 mg/cu m in the total spacecraft atmosphere for exposures lasting 30 days or less or 0.01 mg/cu m mercury vapor for exposures lasting more than 30 days. We also encourage the use of alternative devices that do not contain mercury.

  13. An inverse method for predicting tissue-level mechanics from cellular mechanical input

    PubMed Central

    Kim, Wangdo; Tretheway, Derek C.; Kohles, Sean S.

    2009-01-01

    Extracellular matrix (ECM) provides a dynamic three-dimensional structure which translates mechanical stimuli to cells. This local mechanical stimulation may direct biological function including tissue development. Theories describing the role of mechanical regulators hypothesize the cellular response to variations in the external mechanical forces on the ECM. The exact ECM mechanical stimulation required to generate a specific pattern of localized cellular displacement is still unknown. The cell to tissue inverse problem offers an alternative approach to clarify this relationship. Developed for structural dynamics, the inverse dynamics problem translates measurements of local state variables (at the cell level) into an unknown or desired forcing function (at the tissue or ECM level). This paper describes the use of eigenvalues (resonant frequencies), eigenvectors (mode shapes), and dynamic programming to reduce the mathematical order of a simplified cell–tissue system and estimate the ECM mechanical stimulation required for a specified cellular mechanical environment. Finite element and inverse numerical analyses were performed on a simple two-dimensional model to ascertain the effects of weighting parameters and a reduction of analytical modes leading toward a solution. Simulation results indicate that the reduced number of mechanical modes (from 30 to 14 to 7) can adequately reproduce an unknown force time history on an ECM boundary. A representative comparison between cell to tissue (inverse) and tissue to cell (boundary value) modeling illustrates the multiscale applicability of the inverse model. PMID:19135204

  14. Mercury Contamination of Aquatic Ecosystems

    USGS Publications Warehouse

    Krabbenhoft, David P.; Rickert, David A.

    1995-01-01

    Mercury has been well known as an environmental pollutant for several decades. As early as the 1950's it was established that emissions of mercury to the environment could have serious effects on human health. These early studies demonstrated that fish and other wildlife from various ecosystems commonly attain mercury levels of toxicological concern when directly affected by mercury-containing emissions from human-related activities. Human health concerns arise when fish and wildlife from these ecosystems are consumed by humans. During the past decade, a new trend has emerged with regard to mercury pollution. Investigations initiated in the late 1980's in the northern-tier states of the U.S., Canada, and Nordic countries found that fish, mainly from nutrient-poor lakes and often in very remote areas, commonly have high levels of mercury. More recent fish sampling surveys in other regions of the U.S. have shown widespread mercury contamination in streams, wet-lands, reservoirs, and lakes. To date, 33 states have issued fish consumption advisories because of mercury contamination. These continental to global scale occurrences of mercury contamination cannot be linked to individual emissions of mercury, but instead are due to widespread air pollution. When scientists measure mercury levels in air and surface water, however, the observed levels are extraordinarily low. In fact, scientists have to take extreme precautions to avoid direct contact with water samples or sample containers, to avert sample contamination (Fig 3). Herein lies an apparent discrepancy: Why do fish from some remote areas have elevated mercury concentrations, when contamination levels in the environment are so low?

  15. 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...

  16. Chronic treatment with anesthetic propofol attenuates ?-amyloid protein levels in brain tissues of aged mice.

    PubMed

    Zhang, Yiying; Shao, Haijun; Dong, Yuanlin; Swain, Celeste A; Yu, Buwei; Xia, Weiming; Xie, Zhongcong

    2014-01-01

    Alzheimer's disease (AD) is the most common form of dementia. At the present time, however, AD still lacks effective treatments. Our recent studies showed that chronic treatment with anesthetic propofol attenuated brain caspase-3 activation and improved cognitive function in aged mice. Accumulation of ?-amyloid protein (A?) is a major component of the neuropathogenesis of AD dementia and cognitive impairment. We therefore set out to determine the effects of chronic treatment with propofol on A? levels in brain tissues of aged mice. Propofol (50 mg/kg) was administrated to aged (18 month-old) wild-type mice once a week for 8 weeks. The brain tissues of mice were harvested one day after the final propofol treatment. The harvested brain tissues were then subjected to enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. Here we report that the propofol treatment reduced A? (A?40 and A?42) levels in the brain tissues of the aged mice. Moreover, the propofol treatment decreased the levels of ?-site amyloid precursor protein cleaving enzyme (the enzyme for A? generation), and increased the levels of neprilysin (the enzyme for A? degradation) in the brain tissues of the aged mice. These results suggested that the chronic treatment with propofol might reduce brain A? levels potentially via decreasing brain levels of ?-site amyloid precursor protein cleaving enzyme, thus decreasing A? generation; and via increasing brain neprilysin levels, thus increasing A? degradation. These preliminary findings from our pilot studies have established a system and postulated a new hypothesis for future research. PMID:24725331

  17. Chronic treatment with anesthetic propofol attenuates ?-amyloid protein levels in brain tissues of aged mice

    PubMed Central

    2014-01-01

    Alzheimer’s disease (AD) is the most common form of dementia. At the present time, however, AD still lacks effective treatments. Our recent studies showed that chronic treatment with anesthetic propofol attenuated brain caspase-3 activation and improved cognitive function in aged mice. Accumulation of ?-amyloid protein (A?) is a major component of the neuropathogenesis of AD dementia and cognitive impairment. We therefore set out to determine the effects of chronic treatment with propofol on A? levels in brain tissues of aged mice. Propofol (50 mg/kg) was administrated to aged (18 month-old) wild-type mice once a week for 8 weeks. The brain tissues of mice were harvested one day after the final propofol treatment. The harvested brain tissues were then subjected to enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. Here we report that the propofol treatment reduced A? (A?40 and A?42) levels in the brain tissues of the aged mice. Moreover, the propofol treatment decreased the levels of ?-site amyloid precursor protein cleaving enzyme (the enzyme for A? generation), and increased the levels of neprilysin (the enzyme for A? degradation) in the brain tissues of the aged mice. These results suggested that the chronic treatment with propofol might reduce brain A? levels potentially via decreasing brain levels of ?-site amyloid precursor protein cleaving enzyme, thus decreasing A? generation; and via increasing brain neprilysin levels, thus increasing A? degradation. These preliminary findings from our pilot studies have established a system and postulated a new hypothesis for future research. PMID:24725331

  18. Mercury Exposure and Children’s Health

    PubMed Central

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

    2011-01-01

    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

  19. MERCURY SOURCE IDENTIFICATION AND RISK MANAGEMENT RECOMMENDATIONS FOR FISH TISSUE CONSUMPTION FROM LIVESTOCK PONDS ON THE CHEYENNE RIVER SIOUX TRIBAL LANDS.

    EPA Science Inventory

    In a collaborative 3 year study with the Cheyenne River Sioux Tribe Department of Environmental Protection (CRST DEP), and the Agencies' Environmental Response Team (ERT, Edison N.J.) Region VIII investigated Hg levels in fish tissues from the Cheyenne River and Lake Oahe in nort...

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

    SciTech Connect

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

    2013-04-08

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

  1. 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...

  2. Clinical and prognostic implications of serum and tissue prolactin levels in canine mammary tumours.

    PubMed

    Queiroga, F L; Pérez-Alenza, M D; González Gil, A; Silvan, G; Peña, L; Illera, J C

    2014-10-25

    The biological implications of serum and tissue prolactin levels in canine mammary tumours (CMT) have been previously described although the influence of this hormone on inflammatory mammary carcinomas as well as its value as prognostic indicator remains to be properly clarified. Prolactin determinations were carried out by enzyme immunoassay in tumour tissue and serum of 39 female dogs with spontaneous CMT and in normal mammary gland and serum of 10 controls. Prolactin levels were higher in the case of CMT compared to controls (P<0.05). In malignant CMT, higher levels of tissue prolactin were associated with the occurrence of tumour relapse and/or distant metastasis (P<0.05). Inflammatory mammary carcinomas presented the highest values for tissue prolactin concentrations with concentrations significantly higher than other malignant non-inflammatory mammary carcinoma tumours (P<0.05). The high levels of prolactin found in cases with poor clinical prognoses, including inflammatory mammary carcinoma, open the possibility of being able to better stratify clinical cases in malignant CMT with a view to tailoring treatment appropriately. PMID:25096592

  3. Iron levels change in larval Heliothis virescens tissues following baculovirus infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Inductively-coupled plasma mass spectrometry (ICP-MS) and 59Fe radiotracers were used to investigate changes in levels of iron (Fe) in the tissues of Heliothis virescens following baculovirus infection. Fe concentrations were determined by ICP-MS in hemolymph collected from 4th instar larvae infect...

  4. 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

  5. Daily rhythm of glutathione peroxidase activity, lipid peroxidation and glutathione levels in tissues of pinealectomized rats

    Microsoft Academic Search

    Giyasettin Baydas; M. Ferit Gursu; Seval Yilmaz; Sinan Canpolat; Abdullah Yasar; Gurkan Cikim; Halit Canatan

    2002-01-01

    Melatonin is a component of the antioxidant defense system since it has radical scavenging and antioxidant activities. In the present study, we aimed to investigate the endogenous rhythm of antioxidant enzyme glutathione peroxidase (GSH-Px) activity, oxidized glutathione (GSSG) and lipid peroxidation levels in tissues of pinealectomized rats (PINX). Rats were sacrificed by decapitation at 4 h intervals. GSH-Px activity, GSSG

  6. Cytotoxic drugs efficacy correlates with adipose tissue docosahexaenoic acid level in locally advanced breast carcinoma

    Microsoft Academic Search

    P Bougnoux; E Germain; V Chajès; B Hubert; C Lhuillery; O Le Floch; G Body; G Calais

    1999-01-01

    Experimental studies indicated that long-chain polyunsaturated fatty acids may increase sensitivity of mammary tumours to several cytotoxic drugs. To evaluate this hypothesis in breast cancer, we have prospectively studied the association between levels of fatty acids stored in breast adipose tissue and the response of the tumour to chemotherapy in 56 patients with an initially localized breast carcinoma. Adipose breast

  7. Mortality study of men exposed to elemental mercury

    SciTech Connect

    Cragle, D.L.; Hollis, D.R.; Qualters, J.R.; Tankersley, W.G.; Fry, S.A.

    1984-11-01

    A cohort of 2133 white males who were exposed to elemental mercury vapors between 1953 and 1963 was followed up through the end of 1978. Death certificates were obtained for 371 of the 378 workers who were reported by the Social Security Administration to be deceased. The mortality experience of this group was compared with the age-adjusted mortality experience of the US white male population. Mortality has not been studied previously in assessing the long-term health effects of mercury exposure. Standardized mortality ratios (SMRs) were calculated for a comparable unexposed worker population to determine the mortality patterns among workers at the same plant who were not involved in the mercury process. Statistically significant excesses of deaths from cancer of the lung and cancer of the brain and other CNS tissues were observed among the plant workers who were not involved in the mercury process. An excess of deaths from cancer of the lung was also observed among the mercury workers, although the elevation of this SMR was not statistically significant. Since excesses of lung cancer were evident in both groups of workers, it is unlikely that they are related to the mercury exposure and more probable that they are due to some other factor present in the plant or to some life-style factor prevalent among the plant workers. Exposure to mercury vapors at this plant was not related to any excess of deaths from diseases or cancers of organs determined to be target organs for mercury (liver, lung, brain and CNS, and kidney). No excesses were found when level of exposure and length of exposure were considered.

  8. 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.

  9. Cyclic nucleotide levels in human breast cancer and in rat mammary tissues during tumor development

    Microsoft Academic Search

    Ella Israeli; Batya Raz; Hedwiga Kerner; David Barzilai

    1985-01-01

    The levels of cyclic adenosine 3':5'-monophosphate (cAMP) and cyclic guanosine 3':5'-monophosphate (cGMP) were studied in dimethylbenz(a)anthracene (DMBA)-induced mammary tumors of Sprague-Dawley rats and in human breast cancer. In the rat carcinomas, these levels were significantly lower than in non-malignant tissues when calculated on the basis of DNA content, but higher (cAMP) or equal (cGMP) when calculated on the basis of

  10. Mercury and Your Health

    MedlinePLUS

    ... the Risk of Exposure to Mercury Learn About Mercury What is Mercury? What is Metallic Mercury? Toxicological ... PDF - 3.6MB) En Español (PDF - 1.8MB) Mercury Resources CDC’s Fourth National Report on Human Exposure ...

  11. Blood levels of lead, cadmium, and mercury in the Korean population: Results from the Second Korean National Human Exposure and Bio-monitoring Examination

    SciTech Connect

    Son, Ji-Young [Department of Public Health, Graduate School of Hanyang University, Hanyang University, Seoul (Korea, Republic of)] [Department of Public Health, Graduate School of Hanyang University, Hanyang University, Seoul (Korea, Republic of); Lee, Jinheon [Department of Environmental Education, Kongju National University (Korea, Republic of)] [Department of Environmental Education, Kongju National University (Korea, Republic of); Paek, Domyung [Department of Environmental Health, School of Public Health, Seoul National University, Seoul (Korea, Republic of)] [Department of Environmental Health, School of Public Health, Seoul National University, Seoul (Korea, Republic of); Lee, Jong-Tae, E-mail: jtlee@korea.ac.kr [Department of Environmental Health, College of Health Science, Korea University, San 1 Jeongreung-dong, Seongbuk-gu, Seoul, Korea 136-703 (Korea, Republic of)] [Department of Environmental Health, College of Health Science, Korea University, San 1 Jeongreung-dong, Seongbuk-gu, Seoul, Korea 136-703 (Korea, Republic of)

    2009-08-15

    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 that end, blood metal concentrations were analyzed from a total of 2369 participants who were 18 years of age and older. The geometric mean concentrations and their 95% confidence intervals of metals in blood were found to be lead, 1.72 {mu}g/dL (95% CI, 1.68-1.76); cadmium, 1.02 {mu}g/L (95% CI, 1.00-1.05); and mercury, 3.80 {mu}g/L (95% CI, 3.66-3.93). Regression analyses indicate that the levels of metals in the blood are mainly influenced by gender, age, and the education levels of the participants. Current smoking status is also found to be a significant factor for increasing both lead and cadmium levels. Although our study, as the first nationwide survey of exposure to environmental pollutants in Korea, has value on its own, it should be expanded and extended in order to provide information on environmental exposure pathways and to watch for changes in the level of exposure to environmental pollutants among the population.

  12. Trend of blood lead, mercury, and cadmium levels in Korean population: data analysis of the Korea National Health and Nutrition Examination Survey.

    PubMed

    Seo, Jeong-Wook; Kim, Byoung-Gwon; Kim, Yu-Mi; Kim, Rock-Bum; Chung, Jin-Yong; Lee, Kyoung-Mu; Hong, Young-Seoub

    2015-03-01

    This study was performed to assess the recent trends in lead, mercury, and cadmium levels in the blood among Korean adult population. The geometric means and 95 % confidence intervals (CIs) of blood lead, mercury, and cadmium concentrations were calculated using the data of the subjects from the third (2005, n?=?1997), fourth (2008, n?=?2005; 2009, n?=?1991), and fifth (2010, n?=?1989; 2011, n?=?2014) Korea National Health and Nutrition Examination Survey. Blood lead levels in 2005, 2008, 2009, 2010, and 2011 declined to 2.61 ?g/dL (2.51-2.71), 2.32 ?g/dL (2.27-2.37), 2.29 ?g/dL (2.23-2.35), 2.09 ?g/dL (2.04-2.13), and 1.99 ?g/dL (1.94-2.05), respectively. Blood mercury levels were 4.19 ?g/L (3.99-4.39), 4.73 ?g/L (4.57-4.89), 4.25 ?g/L (4.09-4.41), 3.64 ?g/L (3.49-3.80), and 3.08 ?g/L (2.95-3.22), respectively, which indicated an increase in 2008 compared with those in 2005, and a clear downward trend from 2008 to 2011. Blood cadmium levels were 1.52 ?g/L (1.47-1.57), 0.93 ?g/L (0.89-0.97), 0.94 ?g/L (0.90-0.98), 0.89 ?g/L (0.87-0.92), 0.86 ?g/L (0.83-0.89), respectively, which indicated very high levels in 2005, but a downward trend since 2008. Although the lead, mercury, and cadmium levels in the blood of the Korean adult population are on the decline, they are still relatively high compared with those for the population of the USA, Canada, and Germany. Thus, continuous biological monitoring and measures to reduce these levels are needed in Korea. PMID:25716526

  13. [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

  14. A tissue-level model of the left ventricle for the analysis of regional myocardial function.

    PubMed

    Le Rolle, Virginie; Hernández, Alfredo I; Richard, Pierre-Yves; Donal, Erwan; Carrault, Guy

    2007-01-01

    This paper presents a model-based method for the analysis of regional myocardial strain, based on echocardiography and Tissue Doppler Imaging (TDI). A multi-formalism, tissue-level electromechanical model of the left ventricle is proposed. The parameters of the model are identified in order to reproduce regional strain signal morphologies obtained from a healthy subject and a patient presenting a dilated cardiomyopathy. The parameters identified for the DCM patient allow the localization of the failing myocardial segments and may be useful for a better design of cardiac resynchronization therapy on heart failure patients. PMID:18002171

  15. The Effect of Mercury and PCBs on Organisms from Lower Trophic Levels of a Georgia Salt Marsh

    E-print Network

    Pennings, Steven C.

    , and grass shrimp, at a Superfund site (LCP) contaminated with mercury and polychlorinated biphenyls (PCBs suggested that P. pugio re- production was affected at the LCP site, but we were unable to document clear- River site may not have been a perfect control for the LCP site. Therefore, data from just the LCP site

  16. Ecological factors differentially affect mercury levels in two species of sympatric marine birds of the North Pacific

    E-print Network

    Blvd., Saskatoon, SK, Canada, S7N 3H5 a b s t r a c ta r t i c l e i n f o Article history: Received 22 that might affect mercury burdens in marine predators. Crown Copyright © 2011 Published by Elsevier B.V. All

  17. 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

  18. 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

  19. Landfill impacts on aquatic plant communities and tissue metal levels at Indiana Dunes National Lakeshore

    SciTech Connect

    Stewart, P.M. [National Biological Service, Porter, IN (United States). Lake Michigan Ecological Station; Scribailo, R.W. [Purdue Univ.North Central, Westville, IN (United States). Section of Biology and Chemistry

    1995-12-31

    One important environmental issue facing Northwest Indiana and park management at Indiana Dunes National Lakeshore (INOU) is the contamination of water, sediment and biota by persistent toxic substances. Aquatic plant communities were used to evaluate the water/organismal quality of the Grand Calumet Lagoons and two dunal ponds (pannes) at Gary, Indiana, which are partially located in the Miller Woods Unit of INDU. The lagoon is divided into several areas, the USX Lagoon is located between sections of a large industrial landfill (steel slag and other material). The Marquette Lagoon is located further away from the landfill and tends to be upgradient from the landfill. The West Panne (WP) is located next to the landfill, while the East Panne (EP) is separated from the landfill and the WP by a high dune ridge. Plant populations shift toward fewer submergent aquatics, with a higher abundance of tolerant taxa in the western section of the USX Lagoon. These differences are supported by cluster analysis. Heavy metals in root tissue of Scirpus americanus and other plant species from the pannes were significantly higher than those found in shoots. Shoot tissue metal levels in plants collected from the lagoons were higher than root tissue metal levels. The WP site has the most elevated tissue metal levels for most metals assayed, while the EP site shows similar contaminant levels. The plant distributions observed and tissue metal concentrations measured suggest that INDU`s aquatic plant community has been affected by the industrial landfill and that there exists a hydrological connection between the ponds.

  20. Total and methyl mercury concentrations in seabird feathers and eggs.

    PubMed

    Bond, Alexander L; Diamond, Antony W

    2009-02-01

    Seabirds are used frequently as indicators of mercury contamination in marine ecosystems, but few studies have examined the forms of mercury found in seabird tissues. Here we compare concentrations of total and organic mercury in feathers (n=5) of six sympatric nesting seabirds and in egg components of Leach's storm-petrels from Machias Seal Island, New Brunswick, Canada, during the 2006 breeding season. Essentially all (82-133%) mercury found in seabird feathers and egg components was methyl mercury, with no interspecific differences in percentage methyl mercury. This pattern is consistent with the hypothesis that feather-molt and egg production eliminate toxic methyl mercury, while inorganic forms from demethylation in the liver remain in internal tissues. Additional studies across more species, and comparisons with percentage methyl mercury in internal tissues, are required to validate this theory. PMID:18726541

  1. Ecological effects of mercury in aquatic ecosystems

    SciTech Connect

    Suchanek, T.H.; Richerson, P.J. [Univ. of California, Davis, CA (United States). Division of Environmental Studies

    1994-12-31

    As a result of former mining operations, roughly 100 tons of mercury were released into Clear Lake, California. In 1992 the authors conducted a baseline survey designed to evaluate the levels and potential effects of mercury within this aquatic ecosystem. Both surficial sediments and cores confirm a clear exponential decline in total mercury and methyl mercury as a function of distance from the mine site. The ratio of methyl/total mercury in surficial sediments, however, increases exponentially as a function of distance from the mine. Declines in total mercury in water were not as steep as for sediments. Plankton, oligochaetes and chironomids also exhibited exponential declines in total mercury but not methyl mercury as a function of distance from the mine. Patterns of invertebrate population and community level parameters will be discussed in relation to mercury and other potential pollutants. Fish showed increasing mercury levels with increasing body size and the following species specific differences: carp < silversides < channel catfish < largemouth bass. Some higher than expected levels of methyl mercury were found at sites distant from the mine. An hypothesis to explain these methyl mercury distributions as a function of bioavailability will be presented.

  2. Beyond the Niche: Tissue-Level Coordination of Stem Cell Dynamics

    PubMed Central

    O’Brien, Lucy Erin; Bilder, David

    2014-01-01

    Adult animals rely on populations of stem cells to ensure organ function throughout their lifetime. Stem cells are governed by signals from stem cell niches, and much is known about how single niches promote stemness and direct stem cell behavior. However, most organs contain a multitude of stem cell–niche units, which are often distributed across the entire expanse of the tissue. Beyond the biology of individual stem cell–niche interactions, the next challenge is to uncover the tissue-level processes that orchestrate spatial control of stem-based renewal, repair, and remodeling throughout a whole organ. Here we examine what is known about higher order mechanisms for interniche coordination in epithelial organs, whose simple geometry offers a promising entry point for understanding the regulation of niche number, distribution, and activity. We also consider the potential existence of stem cell territories and how tissue architecture may influence niche coordination. PMID:23937350

  3. Measurement of renal tissue oxygenation with blood oxygen level-dependent MRI and oxygen transit modeling

    PubMed Central

    Morrell, Glen; Rusinek, Henry; Warner, Lizette; Vivier, Pierre-Hugues; Cheung, Alfred K.; Lerman, Lilach O.; Lee, Vivian S.

    2014-01-01

    Blood oxygen level-dependent (BOLD) MRI data of kidney, while indicative of tissue oxygenation level (Po2), is in fact influenced by multiple confounding factors, such as R2, perfusion, oxygen permeability, and hematocrit. We aim to explore the feasibility of extracting tissue Po2 from renal BOLD data. A method of two steps was proposed: first, a Monte Carlo simulation to estimate blood oxygen saturation (SHb) from BOLD signals, and second, an oxygen transit model to convert SHb to tissue Po2. The proposed method was calibrated and validated with 20 pigs (12 before and after furosemide injection) in which BOLD-derived tissue Po2 was compared with microprobe-measured values. The method was then applied to nine healthy human subjects (age: 25.7 ± 3.0 yr) in whom BOLD was performed before and after furosemide. For the 12 pigs before furosemide injection, the proposed model estimated renal tissue Po2 with errors of 2.3 ± 5.2 mmHg (5.8 ± 13.4%) in cortex and ?0.1 ± 4.5 mmHg (1.7 ± 18.1%) in medulla, compared with microprobe measurements. After injection of furosemide, the estimation errors were 6.9 ± 3.9 mmHg (14.2 ± 8.4%) for cortex and 2.6 ± 4.0 mmHg (7.7 ± 11.5%) for medulla. In the human subjects, BOLD-derived medullary Po2 increased from 16.0 ± 4.9 mmHg (SHb: 31 ± 11%) at baseline to 26.2 ± 3.1 mmHg (SHb: 53 ± 6%) at 5 min after furosemide injection, while cortical Po2 did not change significantly at ?58 mmHg (SHb: 92 ± 1%). Our proposed method, validated with a porcine model, appears promising for estimating tissue Po2 from renal BOLD MRI data in human subjects. PMID:24452640

  4. High levels of polychlorinated biphenyls in tissues of Atlantic turtles stranded in the Canary Islands, Spain.

    PubMed

    Orós, J; González-Díaz, O M; Monagas, P

    2009-01-01

    Polychlorinated biphenyls (PCBs 28, 31, 52, 101, 138, 153, 180, and 209) were measured in tissue samples (liver and fat) from 30 loggerhead turtles Caretta caretta, 1 green turtle Chelonia mydas, and 1 leatherback Dermochelys coriacea stranded on the coasts of the Canary Islands, trying to establish a possible relation between PCB concentrations and the lesions and causes of death. Tissues from these turtles contained higher levels of PCBs than those reported in turtles from other geographical regions. Sigma PCB concentrations (1980+/-5320 ng g(-1)wet wt.) in the liver of loggerheads were higher than in the adipose tissue (450+/-1700 ng g(-1)wet wt.). Concentrations of PCB 209 in the liver (1200+/-3120 ng g(-1)wet wt.) of loggerheads and in the liver (530 ng g(-1)wet wt.) and adipose tissue (500 ng g(-1)wet wt.) of the leatherback were remarkable. Frequencies of detection of PCB 209 in the liver (15.5%) and adipose tissue (31%) were also remarkable. Cachexia was detected in 7 turtles (22%) and septicemia was diagnosed in 10 turtles (31%). Statistically, a positive correlation was detected between Sigma PCBs concentration and cachexia. Poor physical condition, cachexia and/or septicaemia could explain the high levels of PCBs and tissue distribution. However, no histological lesions exclusively attributed to the acute effects of PCBs were described. The most prevalent histological lesions were ulcerative and purulent oesophagitis, purulent dermatitis, necrotizing enteritis, and granulomatous pneumonia. The bacteria most frequently isolated were Escherichia coli, Staphylococcus sp., and Aeromonas sp. Although immunosupression as a result of PCBs pollution has been described previously, other factors in this study, such as incidental fishing, nutritional status, and exposition to different micro-organisms, make it difficult to establish a clear association between PCB concentrations and causes of death. PMID:19062067

  5. Bioaccumulation of Mercury in Sharks

    E-print Network

    Miami, University of

    Bioaccumulation of Mercury in Sharks Part 2 a Using a subset of data collected on RJD shark research trips, you will analyze the mercury levels found in the Florida Sharks we catch. Based on your, and hypothesize why that might be. You will also be able to determine whether eating shark is a risk to human

  6. 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.

  7. 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.

  8. Phytoremediation of Ionic and Methyl Mercury Pollution

    SciTech Connect

    Meagher, Richard B.

    2005-06-01

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

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

    SciTech Connect

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

    2013-01-01

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

  10. 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

  11. 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.

  12. The Chemical Nature of Mercury in Human Brain Following Poisoning or Environmental Exposure

    PubMed Central

    2010-01-01

    Methylmercury is among the most potentially toxic species to which human populations are exposed, both at high levels through poisonings and at lower levels through consumption of fish and other seafood. However, the molecular mechanisms of methylmercury toxicity in humans remain poorly understood. We used synchrotron X-ray absorption spectroscopy (XAS) to study mercury chemical forms in human brain tissue. Individuals poisoned with high levels of methylmercury species showed elevated cortical selenium with significant proportions of nanoparticulate mercuric selenide plus some inorganic mercury and methylmercury bound to organic sulfur. Individuals with a lifetime of high fish consumption showed much lower levels of mercuric selenide and methylmercury cysteineate. Mercury exposure did not perturb organic selenium levels. These results elucidate a key detoxification pathway in the central nervous system and provide new insights into the appropriate methods for biological monitoring. PMID:22826746

  13. Concentration of arsenic and mercury in the oyster (Crassostrea iredalei) from Setiu lagoon, Terengganu

    Microsoft Academic Search

    N. Affizah; V. J. Vedamanikam; N. A. M. Shazilli

    2009-01-01

    This study was conducted to determine the concentration of arsenic (As) and mercury (Hg) in the Crassostrea iredalei and examine the correlation between the metal concentration in C. iredalei with sediment and water levels. The mean concentrations of As and Hg in the C. iredalei tissues were significantly different at varying times of sampling. The highest concentration of As in

  14. Mercury Thermometer Replacement Alternatives Thermometer Description Non-Mercury Non-Mercury Non-Mercury

    E-print Network

    Mercury Thermometer Replacement Alternatives Length Thermometer Description Non-Mercury Non-Mercury Non-Mercury Range / Division VWR-Enviro-Safe® Fisherbrand® Brooklyn Thermometer Company Inc. Total/A #12;Mercury Thermometer Replacement Alternatives Length Thermometer Description Non-Mercury Non-Mercury

  15. Effect of metallothionein core promoter region polymorphism on cadmium, zinc and copper levels in autopsy kidney tissues from a Turkish population

    SciTech Connect

    Kayaalti, Zeliha, E-mail: kayaalti@medicine.ankara.edu.t [Ankara University Institute of Forensic Medicine, Institute of Forensic Medicine, Ankara University, Dikimevi, 06590, Ankara (Turkey); Mergen, Goerkem; Soeylemezoglu, Tuelin [Ankara University Institute of Forensic Medicine, Institute of Forensic Medicine, Ankara University, Dikimevi, 06590, Ankara (Turkey)

    2010-06-01

    Metallothioneins (MTs) are metal-binding, low molecular weight proteins and are involved in pathophysiological processes like metabolism of essential metals, metal ion homeostasis and detoxification of heavy metals. Metallothionein expression is induced by various heavy metals especially cadmium, mercury and zinc; MTs suppress toxicity of heavy metals by binding themselves to these metals. The aim of this study was to investigate the association between the - 5 A/G metallothionein 2A (MT2A) single nucleotide polymorphism (SNP) and Cd, Zn and Cu levels in the renal cortex from autopsy cases. MT2A core promoter region - 5 A/G SNP was analyzed by PCR-RFLP method using 114 autopsy kidney tissues and the genotype frequencies of this polymorphism were found as 87.7% homozygote typical (AA), 11.4% heterozygote (AG) and 0.9% homozygote atypical (GG). In order to assess the Cd, Zn and Cu levels in the same autopsy kidney tissues, a dual atomic absorption spectrophotometer system was used and the average levels of Cd, Zn and Cu were measured as 95.54 {+-} 65.58 {mu}g/g, 181.20 {+-} 87.72 {mu}g/g and 17.14 {+-} 16.28 {mu}g/g, respectively. As a result, no statistical association was found between the - 5 A/G SNP in the MT2A gene and the Zn and Cu levels in the renal cortex (p > 0.05), but considerably high accumulation of Cd was monitored for individuals having AG (151.24 {+-} 60.21 {mu}g/g) and GG genotypes (153.09 {mu}g/g) compared with individuals having AA genotype (87.72 {+-} 62.98 {mu}g/g) (p < 0.05). These results show that the core promoter region polymorphism of metallothionein 2A increases the accumulation of Cd in human renal cortex.

  16. The Relation between Plasma Tissue Factor and Oxidized LDL Levels in Acute Coronary Syndromes

    Microsoft Academic Search

    Ebru Emekli-Alturfan; Isik Basar; A. Ata Alturfan; Faruk Ayan; Lale Koldas; Huriye Balci; Nesrin Emekli

    2010-01-01

    Aim: Tissue factor (TF) is a low-molecular-weight glycoprotein responsible for the initiation of the coagulation cascade. The relation between oxidized low-density lipoprotein (Ox-LDL), that has been shown to be involved in atherogenesis, and TF has not been evaluated before in circulating plasma. The aim of this study was to determine plasma levels of TF and Ox-LDL in acute coronary syndrome

  17. Mercury in freshwater fish and clams from the Cerro Prieto geothermal field of Baja California, Mexico

    SciTech Connect

    Gutierrez-Galindo, E.A.; Munoz, G.F.; Flores, A.A.

    1988-08-01

    Several reports have expressed concern about the potential toxicity hazards and environmental contamination of mercury emissions from geothermal fields in Hawaii, New Zealand, Iceland, California and Mexico. Inorganic mercury discharged from the sources may accumulate in the sediments of rivers or lakes and, after microbiological methylation may become concentrated in the edible tissue of fish. This study involves assessment of geothermal mercury pollution arising from Cerro Prieto. For this purpose the fish Tilapia mossambica and the clam Corbicula fluminea were collected from the freshwater courses of the Mexicali Valley. Reports indicated that in 1982, 13 t of T. mossambica were destinated for human consumption. A further aim was to provide base line data and information relevant to the level of mercury contamination for the Mexicali Valley.

  18. FINAL REPORT ON THE AQUATIC MERCURY ASSESSMENT STUDY

    SciTech Connect

    Halverson, N

    2008-09-30

    In February 2000, the United States Environmental Protection Agency (EPA) Region 4 issued a proposed Total Maximum Daily Load (TMDL) for total mercury in the middle and lower Savannah River. The initial TMDL, which would have imposed a 1 ng/l mercury limit for discharges to the middle/lower Savannah River, was revised to 2.8 ng/l in the final TMDL released in February 2001. The TMDL was intended to protect people from the consumption of contaminated fish, which is the major route of mercury exposure to humans. The most bioaccumulative form of mercury is methylmercury, which is produced in aquatic environments by the action of microorganisms on inorganic mercury. Because of the environmental and economic significance of the mercury discharge limits that would have been imposed by the TMDL, the Savannah River Site (SRS) initiated several studies concerning: (1) mercury in SRS discharges, SRS streams and the Savannah River, (2) mercury bioaccumulation factors for Savannah River fish, (3) the use of clams to monitor the influence of mercury from tributary streams on biota in the Savannah River, and (4) mercury in rainwater falling on the SRS. The results of these studies are presented in detail in this report. The first study documented the occurrence, distribution and variation of total and methylmercury at SRS industrial outfalls, principal SRS streams and the Savannah River where it forms the border with the SRS. All of the analyses were performed using the EPA Method 1630/31 ultra low-level and contaminant-free techniques for measuring total and methylmercury. Total mercury at National Pollutant Discharge Elimination System (NPDES) outfalls ranged from 0.31-604 ng/l with a mean of 8.71 ng/l. Mercury-contaminated groundwater was the source for outfalls with significantly elevated mercury concentrations. Total mercury in SRS streams ranged from 0.95-15.7 ng/l. Mean total mercury levels in the streams varied from 2.39 ng/l in Pen Branch to 5.26 ng/l in Tims Branch. Methylmercury ranged from 0.002 ng/l in Upper Three Runs to 2.60 ng/l in Tims Branch. Total mercury in the Savannah River ranged from 0.62 ng/l to 43.9 ng/l, and methylmercury ranged from 0.036 ng/l to 7.54 ng/l. Both total and methylmercury concentrations were consistently high in the river near the mouth of Steel Creek. Total mercury was positively correlated with methylmercury (r = 0.88). Total mercury bound to particulates ranged from 41% to 57% in the river and from 28% to 90% in the streams. Particulate methylmercury varied from 9% to 37% in the river and from 6% to 79% in the streams. Small temporary pools in the Savannah River swamp area near and around Fourmile Branch had the highest concentrations observed in the Savannah River watershed, reaching 1,890 ng/l for total mercury and 34.0 ng/l for methylmercury. The second study developed a mercury bioaccumulation factor (BAF) for the Savannah River near SRS. A BAF is the ratio of the concentration of mercury in fish flesh to the concentration of mercury in the water. BAFs are important in the TMDL process because target concentrations for mercury in water are computed from BAFs. Mercury BAFs are known to differ substantially among fish species, water bodies, and possibly seasons. Knowledge of such variation is needed to determine a BAF that accurately represents average and extreme conditions in the water body under study. Analysis of fish tissue and aqueous methylmercury samples collected at a number of locations and over several seasons in a 110 km (68 mile) reach of the Savannah River demonstrated that BAFs for each species under study varied by factors of three to eight. Influences on BAF variability were location, habitat and season-related differences in fish mercury levels and seasonal differences in methylmercury levels in the water. Overall (all locations, habitats, and seasons) average BAFs were 3.7 x 10{sup 6} for largemouth bass, 1.4 x 10{sup 6} for sunfishes, and 2.5 x 10{sup 6} for white catfish. This study showed that determination of representative BAFs for large rivers requires the collect

  19. Soft Tissue Mobilization and PNF Improve Range of Motion and Minimize Pain Level in Shoulder Impingement

    PubMed Central

    Al Dajah, Salameh Bweir

    2014-01-01

    [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

  20. 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

  1. Mercury Bubbles

    Microsoft Academic Search

    A. T. Hare

    1908-01-01

    I HAVE on several occasions noticed the beautiful bubbles described by Mr. Wright and Sir William Crookes (pp. 8 and 37). On each occasion I was purifying mercury in the following way. I half filled a rather large Woulffe's bottle with mercury and poured on to it weak nitric acid. Then, in order to keep, the whole in a state

  2. Epicardial adipose tissue thickness and NGAL levels in women with polycystic ovary syndrome

    PubMed Central

    2014-01-01

    Background Polycystic ovary syndrome (PCOS) is associated with an increased cardiovascular disease (CVD) risk and early atherosclerosis. Epicardial adipose tissue thickness (EATT) is clinically related to subclinical atherosclerosis. In the present study, considering the major role of neutrophil gelatinase-associated lipocalin (NGAL) which is an acute phase protein rapidly releasing upon inflammation and tissue injury, we aimed to evaluate NGAL levels and EATT in PCOS patients and assess their relationship with cardiometabolic factors. Methods 64 patients with PCOS and 50 age- and body mass index-matched healthy controls were included in the study. We evaluated anthropometric, hormonal and metabolic parameters. EATT was measured by echocardiography above the free wall of the right ventricle. Serum NGAL and high-sensitive C- reactive protein (hsCRP) levels were measured by ELISA. Results Mean EATT was 0,38 +/-0,16 mm in the PCOS group and 0,34 +/-0,36 mm in the control group (p?=?0,144). In the obese PCOS group (n?=?44) EAT was thicker compared to the obese control group (n?=?41) (p?=?0.026). Mean NGAL levels of the patients with PCOS were 101,98 +/-21,53 pg/ml, while mean NGAL levels were 107,40 +/-26,44 pg/ml in the control group (p?=?0,228). We found a significant positive correlation between EATT and age, BMI, waist circumference, fasting insulin, HOMA-IR, triglyceride and hsCRP levels in PCOS group. Conclusions Thickness of the epicardial adipose tissue can be used to follow the risk of CVD development in obese PCOS cases. However serum NGAL levels do not differ in patients with PCOS and control group. PMID:24528623

  3. 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.

  4. 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

  5. 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

  6. Neurobehavioral changes in response to alterations in gene expression profiles in the brains of mice exposed to low and high levels of mercury vapor during postnatal development.

    PubMed

    Yoshida, Minoru; Honda, Akiko; Watanabe, Chiho; Satoh, Masahiko; Yasutake, Akira

    2014-08-01

    This study examined the relationship between neurobehavioral changes and alterations in gene expression profiles in the brains of mice exposed to different levels of Hg(0) during postnatal development. Neonatal mice were repeatedly exposed to mercury vapor (Hg(0)) at a concentration of 0.057 mg/m(3) (low level), which was close to the current threshold value (TLV), and 0.197 mg/m(3) (high level) for 24 hr until the 20(th) day postpartum. Behavioral responses were evaluated based on changes in locomotor activity in the open field test (OPF), learning ability in the passive avoidance response test (PA), and spatial learning ability in the Morris water maze (MM) at 12 weeks of age. No significant differences were observed in the three behavioral measurements between mice exposed to the low level of Hg(0) and control mice. On the other hand, total locomotive activity in mice exposed to the high level of Hg(0) was significantly decreased and central locomotion was reduced in the OPF task. Mercury concentrations were approximately 0.4 ?g/g and 1.9 ?g/g in the brains of mice exposed to the low and high levels of Hg(0), respectively. Genomic analysis revealed that the expression of 2 genes was up-regulated and 18 genes was down-regulated in the low-level exposure group, while the expression of 3 genes was up-regulated and 70 genes was down-regulated in the high-level exposure group. Similar alterations in the expression of seven genes, six down-regulated genes and one up-regulated gene, were observed in both groups. The results indicate that an increase in the number of altered genes in the brain may be involved in the emergence of neurobehavioral effects, which may be associated with the concentration of mercury in the brain. Moreover, some of the commonly altered genes following exposure to both concentrations of Hg(0) with and without neurobehavioral effects may be candidates as sensitive biomarker genes for assessing behavioral effects in the early stages of development. PMID:25056781

  7. Food chain transfer and potential renal toxicity of mercury to small mammals at a contaminated terrestrial field site.

    PubMed

    Talmage, S S; Walton, B T

    1993-12-01

    Mercury concentrations were determined in surface soil and biota at a contaminated terrestrial field site and were used to calculate transfer coefficients of mercury through various compartments of the ecosystem based on trophic relationships. Mercury concentrations in all compartments (soil, vegetation, invertebrates, and small mammals) were higher than mercury concentrations in corresponding samples at local reference sites. Nonetheless, mercury concentrations in biota did not exceed concentrations in the contaminated surface soil, which averaged 269 ?g g(-1). Plant tissue concentrations of mercury were low (0.01 to 2.0 ?g g(-1)) and yielded soil to plant transfer coefficients ranging from 3.7×10(-5) for seeds to 7.0×10(-3) for grass blades. Mercury concentrations in invertebrates ranged from 0.79 for harvestmen (Phalangida) to 15.5 ?g g(-1) for undepurated earthworms (Oligochaeta). Mean food chain transfer coefficients for invertebrates were 0.88 for herbivores/omnivores and 2.35 for carnivores. Mean mercury concentrations in target tissue (kidney) were 1.16±1.16 ?g g(-1) for the white-footed mouse (Peromyscus leucopus), a granivore, and 38.8±24.6 ?g g(-1) for the shorttail shrew (Blarina brevicauda), an insectivore. Transfer coefficients for diet to kidney were 0.75 and 4.40 for P. leucopus and B. brevicauda, respectively. A comparison of kidney mercury residues measured in this study with values from controlled laboratory feeding studies from the literature indicate that B. brevicauda but not P. leucopus may be ingesting mercury at levels that are nephrotoxic. PMID:24201735

  8. Reduced tissue-level stiffness and mineralization in osteoporotic cancellous bone.

    PubMed

    Kim, Grace; Cole, Jacqueline H; Boskey, Adele L; Baker, Shefford P; van der Meulen, Marjolein C H

    2014-08-01

    Osteoporosis alters bone mass and composition ultimately increasing the fragility of primarily cancellous skeletal sites; however, effects of osteoporosis on tissue-level mechanical properties of cancellous bone are unknown. Dual-energy X-ray absorptiometry (DXA) scans are the clinical standard for diagnosing osteoporosis though changes in cancellous bone mass and mineralization are difficult to separate using this method. The goal of this study was to investigate possible difference in tissue-level properties with osteoporosis as defined by donor T scores. Spine segments from Caucasian female cadavers (58-92 years) were used. A T score for each donor was calculated from DXA scans to determine osteoporotic status. Tissue-level composition and mechanical properties of vertebrae adjacent to the scan region were measured using nanoindentation and Raman spectroscopy. Based on T scores, six samples were in the Osteoporotic group (58-74 years) and four samples were in the Not Osteoporotic group (65-92 years). The indentation modulus and mineral to matrix ratio (mineral:matrix) were lower in the Osteoporotic group than the Not Osteoporotic group. Mineral:matrix ratio decreased with age (r (2) = 0.35, p = 0.05), and the indentation modulus increased with areal bone mineral density (r (2) = 0.41, p = 0.04). This study is the first to examine cancellous bone composition and mechanical properties from a fracture prone location with osteoporosis. We found differences in tissue composition and mechanical properties with osteoporosis that could contribute to increased fragility in addition to changes in trabecular architecture and bone volume. PMID:24888692

  9. Phytoremediation of Ionic and Methyl Mercury Pollution

    SciTech Connect

    Meagher, Richard B.

    2004-12-01

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

  10. P36. The prognostic potential of circulating and tissue activin A level in malignant pleural mesothelioma

    PubMed Central

    Dong, Yawen; Hoda, Mir Alireza; Schelch, Karin; Rozsas, Anita; Laszlo, Viktoria; Dome, Balazs; Grusch, Michael; Berger, Walter; Klepetko, Walter; Hegedus, Balazs

    2014-01-01

    Background Malignant pleural mesothelioma (MPM) is an aggressive malignancy characterized by poor outcome and there is a lack of prognostic biomarkers to estimate prognosis. Previously we have shown that suppression of activin A can interfere with MPM tumor growth. In the current study, we compare the circulating and tissue expression level of activin A as a prognostic biomarker in MPM. Methods In a cohort of 53 MPM patients, plasma samples were collected between 2010 and 2014. Controls consisted of age-matched healthy individuals (n=46) and patients with pleuritis or pleural fibrosis (n=16). Circulating activin A was measured by ELISA and correlated to clinicopathological data. Furthermore, activin A expression in the tumor tissue was semiquantitatively measured by immunohistochemistry in 24 patients. Results Plasma activin A level was significantly elevated in MPM patients (n=53, 843±122 pg/mL) when compared to healthy controls (452±144 pg/mL, P=0.0039). Non-malignant pleuritis or pleural fibrosis patients only showed a modest, non-significant increase (625±95 pg/mL, P=0.093). Circulating activin A levels were slightly increased in cases with non-epitheloid morphology (n=16, 1101±183) when compared to epithelioid (n=37, 732±153 pg/mL, P=0.13). MPM patients with below median activin A concentrations had a modestly and non-significantly longer overall survival when compared to the high activin A level patients (469 vs. 271 days, P=0.4751). Interestingly, there was no correlation between circulating and tissue expression level of activin A in 17 patients where both parameters could have been analyzed. Conclusions Our findings suggest that the measurement of circulating activin A may support the diagnosis and prognosis of MPM but additional patient cohorts need to be analyzed to establish the diagnostic and prognostic value of this non-invasive biomarker.

  11. Translocation of mercury and microbial adaptation in a model aquatic system

    SciTech Connect

    Titus, J.A. (Ohio State Univ., Columbus); Parsons, J.E.; Pfister, R.M.

    1980-09-01

    Higher levels of mercury-resistant bacteria have been found in mercury-contaminated sediments than in sediments containing low levels of mercury. The work described in this report was undertaken to investigate the movement of mercury (initially as Hg/sup 0/) through components of an aquarium model aquatic system. Changes in mercury-resistant levels of bacterial populations were followed with increasing sediment mercury load.

  12. 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

  13. Mercury CEM Calibration

    SciTech Connect

    John Schabron; Joseph Rovani; Mark Sanderson

    2008-02-29

    Mercury continuous emissions monitoring systems (CEMS) are being implemented in over 800 coal-fired power plant stacks. The power industry desires to conduct at least a full year of monitoring before the formal monitoring and reporting requirement begins on January 1, 2009. It is important for the industry to have available reliable, turnkey equipment from CEM vendors. Western Research Institute (WRI) is working closely with the Electric Power Research Institute (EPRI), the National Institute of Standards and Technology (NIST), and the Environmental Protection Agency (EPA) to facilitate the development of the experimental criteria for a NIST traceability protocol for dynamic elemental mercury vapor generators. The generators are used to calibrate mercury CEMs at power plant sites. The Clean Air Mercury Rule (CAMR) which was published in the Federal Register on May 18, 2005 requires that calibration be performed with NIST-traceable standards (Federal Register 2007). Traceability procedures will be defined by EPA. An initial draft traceability protocol was issued by EPA in May 2007 for comment. In August 2007, EPA issued an interim traceability protocol for elemental mercury generators (EPA 2007). The protocol is based on the actual analysis of the output of each calibration unit at several concentration levels ranging initially from about 2-40 {micro}g/m{sup 3} elemental mercury, and in the future down to 0.2 {micro}g/m{sup 3}, and this analysis will be directly traceable to analyses by NIST. The document is divided into two separate sections. The first deals with the qualification of generators by the vendors for use in mercury CEM calibration. The second describes the procedure that the vendors must use to certify the generator models that meet the qualification specifications. The NIST traceable certification is performance based, traceable to analysis using isotope dilution inductively coupled plasma/mass spectrometry performed by NIST in Gaithersburg, MD. The outputs of mercury generators are compared to one another using a nesting procedure which allows direct comparison of one generator with another and eliminates analyzer variability effects. The qualification portion of the EPA interim traceability protocol requires the vendors to define generator performance as affected by variables such as pressure, temperature, line voltage, and shipping. WRI is focusing efforts to determine actual generator performance related to the variables defined in the qualification portion of the interim protocol. The protocol will then be further revised by EPA based on what can actually be achieved with the generators. Another focus of the study is to evaluate approaches for field verification of generator performance. Upcoming work includes evaluation of oxidized mercury calibration generators, for which a separate protocol will be prepared by EPA. In addition, the variability of the spectrometers/analyzers under various environmental conditions needs to be defined and understood better. A main objective of the current work is to provide data on the performance and capabilities of elemental mercury generator/calibration systems for the development of realistic NIST traceability protocols for mercury vapor standards for continuous emission CEM calibration. This work is providing a direct contribution to the enablement of continuous emissions monitoring at coal-fired power plants in conformance with the CAMR. EPA Specification 12 states that mercury CEMs must be calibrated with NIST-traceable standards (Federal Register 2005). The initial draft of an elemental mercury generator traceability protocol was circulated by EPA in May 2007 for comment, and an interim protocol was issued in August 2007 (EPA 2007). Initially it was assumed that the calibration and implementation of mercury CEMs would be relatively simple, and implementation would follow the implementation of the Clean Air Interstate Rule (CAIR) SO{sub 2} and NO{sub x} monitoring, and sulfur emissions cap and trade. However, mercury has proven to be significantly more difficult

  14. Comparative study of mercury speciation in commercial fishes of the Brazilian Amazon.

    PubMed

    Rodríguez Martín-Doimeadios, R C; Berzas Nevado, J J; Guzmán Bernardo, F J; Jiménez Moreno, M; Arrifano, G P F; Herculano, A M; do Nascimento, J L M; Crespo-López, M E

    2014-06-01

    Mercury is responsible for serious episodes of environmental pollution throughout the world, especially in the Amazon. This toxicity has led regulatory agencies to focus on fish as the target organism for protecting the health of humans and other sensitive organisms. Unfortunately, in the Amazon area, different sampling strategies and the wide variety of sampling areas and fish species make it extremely difficult to determine relationships across geographic regions or over time to ascertain historical trends. Thus, the aim of this work was to achieve three main objectives: a comparative study of mercury contamination in fish of Itaituba (Tapajós, located downstream of the largest gold-mining region in Amazon) and Belém (an area non-exposed to mercury pollution of anthropogenic origin), perform an analysis of inorganic mercury (IHg) versus monomethylmercury (MeHg) contents, and, finally, compare mercury contamination in Tapajós over time. Five piscivorous species were obtained in Itaituba and Belém. Also, four non-piscivorous species were collected in Itaituba. For the first time, mercury speciation showed that (1) current MeHg levels in piscivorous species in Tapajós are higher than those of the non-exposed area, (2) piscivorous species from Itaituba (dourada, filhote, and sarda) contained mercury levels above the World Health Organization safety limit (~17%) and/or above the US Environmental Protection Agency tissue residue criterion (40%), (3) increased MeHg is usually accompanied by increased IHg, and (4) the mean total mercury concentrations for piscivorous species in Itaituba were within the same range and, associated uncertainties as those previously reported, although a remarkable decreasing trend over time was observed for mean total Hg concentrations in non-piscivorous species from Itaituba. The present study supports the importance of continuous monitoring of both populations in the Amazon Rivers. Our results will better assist the development of preventive strategies and governmental actions to confront the problem of mercury contamination in the Amazon. PMID:24590602

  15. Diamondback terrapins, Malaclemys terrapin, as a sentinel species for monitoring mercury pollution of estuarine systems in South Carolina and Georgia, USA.

    PubMed

    Blanvillain, Gaëlle; Schwenter, Jeffrey A; Day, Rusty D; Point, David; Christopher, Steven J; Roumillat, William A; Owens, David W

    2007-07-01

    Total mercury concentrations were measured in diamondback terrapin blood and scutes collected from four sites in South Carolina, USA, and at a superfund site in Brunswick, Georgia, USA. There was a strong correlation between mercury concentrations in the two terrapin body compartments (Kendall's tau = 0.79, p < 0.001). Mercury concentrations in terrapin scute and blood and in salt marsh periwinkles, Littoraria irrorata, were significantly higher in Brunswick (scute x = 3810.2 ng/g, blood x = 746.2 ng/g) than from all other sites (scute x = 309.5 ng/g, blood x = 43.2 ng/g, p < 0.001). Seasonal fluctuations of total mercury in the blood and scutes of terrapins collected in the Ashley River, South Carolina, were significantly lower in August than in April, June, or October in blood (p < 0.001); however, scute concentrations did not vary seasonally. Overall, we found higher concentrations of mercury in the scutes of females than males (n = 32, p < 0.05). Larger females may preferentially prey on larger food items, like large periwinkles, which had significantly higher mercury levels in their body tissues than smaller periwinkles (p < 0.001). Methylmercury levels in terrapin scutes were measured, revealing that 90% of the total mercury stored in this compartment was in the organic form. A methylmercury biomagnification factor of 173.5 was calculated from snails to terrapin scutes, and we found that mercury levels in scutes were representative of the mercury levels in other compartments of the ecosystem. These findings show that terrapin scutes are good predictors of mercury pollution and that this species could be used as a bioindicator for assessing mercury contamination of estuarine systems. PMID:17665684

  16. Human fibroblast collagenase: glycosylation and tissue-specific levels of enzyme synthesis.

    PubMed

    Wilhelm, S M; Eisen, A Z; Teter, M; Clark, S D; Kronberger, A; Goldberg, G

    1986-06-01

    Human skin fibroblasts secrete collagenase as two proenzyme forms (57 and 52 kDa). The minor (57-kDa) proenzyme form is the result of a partial posttranslational modification of the major (52-kDa) proenzyme through the addition of N-linked complex oligosaccharides. Human endothelial cells as well as fibroblasts from human colon, cornea, gingiva, and lung also secrete collagenase in two forms indistinguishable from those of the skin fibroblast enzyme. In vitro tissue culture studies have shown that the level of constitutive synthesis of this fibroblast-type interstitial collagenase is tissue specific, varies widely, and correlates with the steady-state level of a single collagenase-specific mRNA of 2.5 kilobases. The tumor promoter, phorbol 12-myristate 13-acetate, apparently blocks the control of collagenase synthesis resulting in a similarly high level of collagenase expression (approximately equal to 3-7 micrograms of collagenase per 10(6) cells per 24 hr) in all examined cells. The constitutive level of synthesis of a 28-kDa collagenase inhibitor does not correlate with that of the enzyme. Phorbol 12-myristate 13-acetate stimulates the production of this inhibitor that in turn modulates the activity of collagenase in the conditioned media. As a result, the apparent activity of the enzyme present in the medium does not accurately reflect the rate of its synthesis and secretion. PMID:3012533

  17. 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

  18. Mercury and cadmium uptake from seawater and from food by the Norway lobster Nephrops norvegicus

    SciTech Connect

    Canli, M.; Furness, R.W. [Univ. of Glasgow (United Kingdom). Div. of Environmental and Evolutionary Biology

    1995-05-01

    Norway lobsters, nephrops norvegicus, were fed on a mercury- and cadmium-rich diet for up to 50 d or were exposed to sublethal concentrations of organic mercury, inorganic mercury, or cadmium in seawater for 30 d. Cadmium taken up from seawater accumulated mainly in the hepatopancreas and gill, while it accumulated mainly in the hepatopancreas after feeding. Both organic and inorganic mercury taken up from seawater accumulated mainly in the gill, while highest concentrations were found in the hepatopancreas after the feeding experiment. Accumulation of organic mercury was higher than that of inorganic mercury. Although all treatments resulted in the accumulation of mercury and cadmium from seawater and food, tissue distribution of metals differed significantly among treatments. Distributions of organic and inorganic mercury also varied among tissues after uptake from seawater, with organic mercury being more evenly distributed among tissues than inorganic mercury, the latter being found predominantly in the gill.

  19. 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

  20. Bothrops jararaca Venom Metalloproteinases Are Essential for Coagulopathy and Increase Plasma Tissue Factor Levels during Envenomation

    PubMed Central

    Yamashita, Karine M.; Alves, André F.; Barbaro, Katia C.; Santoro, Marcelo L.

    2014-01-01

    Background/Aims Bleeding tendency, coagulopathy and platelet disorders are recurrent manifestations in snakebites occurring worldwide. We reasoned that by damaging tissues and/or activating cells at the site of the bite and systemically, snake venom toxins might release or decrypt tissue factor (TF), resulting in activation of blood coagulation and aggravation of the bleeding tendency. Thus, we addressed (a) whether TF and protein disulfide isomerase (PDI), an oxireductase involved in TF encryption/decryption, were altered in experimental snake envenomation; (b) the involvement and significance of snake venom metalloproteinases (SVMP) and serine proteinases (SVSP) to hemostatic disturbances. Methods/Principal Findings Crude Bothrops jararaca venom (BjV) was preincubated with Na2-EDTA or AEBSF, which are inhibitors of SVMP and SVSP, respectively, and injected subcutaneously or intravenously into rats to analyze the contribution of local lesion to the development of hemostatic disturbances. Samples of blood, lung and skin were collected and analyzed at 3 and 6 h. Platelet counts were markedly diminished in rats, and neither Na2-EDTA nor AEBSF could effectively abrogate this fall. However, Na2-EDTA markedly reduced plasma fibrinogen consumption and hemorrhage at the site of BjV inoculation. Na2-EDTA also abolished the marked elevation in TF levels in plasma at 3 and 6 h, by both administration routes. Moreover, increased TF activity was also noticed in lung and skin tissue samples at 6 h. However, factor VII levels did not decrease over time. PDI expression in skin was normal at 3 h, and downregulated at 6 h in all groups treated with BjV. Conclusions SVMP induce coagulopathy, hemorrhage and increased TF levels in plasma, but neither SVMP nor SVSP are directly involved in thrombocytopenia. High levels of TF in plasma and TF decryption occur during snake envenomation, like true disseminated intravascular coagulation syndrome, and might be implicated in engendering bleeding manifestations in severely-envenomed patients. PMID:24831016

  1. [Inner- and inter-species differences of mercury concentration in common fishes from the Yellow Sea].

    PubMed

    Zhu, Ai-Jia; Xu, Zhan-Zhou; Liu, Gui-Ze; Deng, Li-Jie; Fang, Hong-Da; Huang, Liang-Min

    2014-02-01

    Mercury concentration in marine fishes and its influencing factors are the key problems in the study of mercury biomagnification in marine ecosystems. In order to understand the inner- and inter-species differences of mercury concentration in fishes from the Yellow Sea, a total of 164 marine wild fishes covering nine different species were collected from the area from August to October, 2012. Mercury (total mercury) concentration in fish muscle tissue was measured by a direct mercury analyzer. Body length and wet weight of each sample were also determined. Moreover, feeding habit and trophic level of different species were examined. Hg concentrations (dry weight) in the muscle tissues of the 164 individuals ranged from 0.025 micro x g(-1) to 0.526 microg x g(-1), with an average of (0.124 +/- 0.096) microg x g(-1). By an inner-species analysis, log10 Hg concentration was significantly correlated to their body length and wet weight. Predator fishes with trophic level > 2.8 were more readily to be contaminated by Hg than the filter feeder with trophic level < 2.8. Furthermore, species with higher increasing rate of weight had lower Hg concentration in the muscle due to growth dilution. The results suggest that length and weight are the main factors affecting the inner- species difference of mercury concentration in common fishes from the Yellow Sea, while dietary preference, trophic level and increasing rate of weight are the main factors affecting the inter-species difference from the Yellow Sea. PMID:24812976

  2. 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...

  3. Total and organic mercury in ten fish species for human consumption from the Mexican Pacific.

    PubMed

    Ruelas-Inzunza, J; Hernández-Osuna, J; Páez-Osuna, F

    2011-06-01

    Total mercury and organic mercury were measured in ten fish species from the Mexican Pacific ocean to have a general view on the ratio of total mercury-organic mercury and potential implications on human health. Highest concentration of total mercury was recorded in muscle tissue of Carcharhinus leucas (0.62 ?g g?¹ wet weight). Organic mercury was more concentrated in Haemulon sexfasciatum (0.4 ?g g?¹ wet weight). Percentages of organic mercury ranged from 33 to 100%. Hazard indices associated to organic mercury and average fish consumption in Mexico ranged from 0.25 in Lutjanus colorado to 1.65 in Haemulon sexfasciatum. PMID:21516459

  4. 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

    . . . . . . . 41 Crassostrea virginica. Linear regressions of Halo!sax 1099 ti sue concentrations versus tissue lipid levels for the ten day depuration period. . . . 43 IiNTRODUCTIOH Due to their sedentary existence, ability to accumulate and release numerous... oil f r 49 days and produced a maximum tissue concentration of 334. 0 ppri total petroleum hydrocarbons . Similar s tudie" with petroleum showed that although both alkanes and aromatics were accumulated in molluscs, the aromatic hydrocarbons...

  5. Organic and total mercury in muscle tissue of five aquatic birds with different feeding habits from the SE Gulf of California, Mexico.

    PubMed

    Ruelas-Inzunza, J; Hernández-Osuna, J; Páez-Osuna, F

    2009-07-01

    We measured organic and total Hg in muscle tissue of five species of aquatic birds from the south-eastern gulf of California region, Mexico. Concentrations of total and organic Hg measured in Pelecanus occidentalis were the highest (2.85 and 2.68 microgg(-1)); lowest values of organic Hg (0.20 microgg(-1)) and total Hg (0.47 microgg(-1)) were detected in Anas discors and Anas clypeata, respectively. Differences of Hg levels were related to feeding habits, being concentrations in birds of piscivorous habits more elevated than corresponding values in non-piscivorous species. PMID:19419748

  6. Resolvin E1 Regulates Inflammation at the Cellular and Tissue Level and Restores Tissue Homeostasis In Vivo1

    Microsoft Academic Search

    Hatice Hasturk; Alpdogan Kantarci; Emilie Goguet-Surmenian; Amanda Blackwood; Chris Andry; Charles N. Serhan; Thomas E. Van Dyke

    Resolvin E1 (RvE1) is a potent proresolving mediator of inflammation derived from omega-3 eicosapentaenoic acid that acts locally to stop leukocyte recruitment and promote resolution. RvE1 displays potent counter-regulatory and tissue-protective actions in vitro and in vivo. Periodontal disease is a local inflammatory disease initiated by bacteria characterized by neutrophil- mediated tissue injury followed by development of a chronic immune

  7. Effects of Intermittent Electrical Stimulation on Superficial Pressure, Tissue Oxygenation, and Discomfort Levels for the Prevention of Deep Tissue Injury

    Microsoft Academic Search

    Leandro R. Solis; Selina Gyawali; Peter Seres; Cara A. Curtis; Su Ling Chong; Richard B. Thompson; Vivian K. Mushahwar

    2011-01-01

    The overall goal of this project is to develop effective methods for the prevention of deep tissue injury (DTI). DTI is a\\u000a severe type of pressure ulcer that originates at deep bone–muscle interfaces as a result of the prolonged compression of tissue.\\u000a It afflicts individuals with reduced mobility and sensation, particularly those with spinal cord injury. We previously proposed\\u000a using

  8. Selenium inhibits the phytotoxicity of mercury in garlic (Allium sativum)

    SciTech Connect

    Zhao, Jiating [CAS Key Laboratory of Nuclear Analytical Techniques, Key Lab for Biomedical Effects of Nanomaterial and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)] [CAS Key Laboratory of Nuclear Analytical Techniques, Key Lab for Biomedical Effects of Nanomaterial and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Gao, Yuxi, E-mail: gaoyx@ihep.ac.cn [CAS Key Laboratory of Nuclear Analytical Techniques, Key Lab for Biomedical Effects of Nanomaterial and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)] [CAS Key Laboratory of Nuclear Analytical Techniques, Key Lab for Biomedical Effects of Nanomaterial and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Li, Yu-Feng; Hu, Yi; Peng, Xiaomin [CAS Key Laboratory of Nuclear Analytical Techniques, Key Lab for Biomedical Effects of Nanomaterial and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)] [CAS Key Laboratory of Nuclear Analytical Techniques, Key Lab for Biomedical Effects of Nanomaterial and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Dong, Yuanxing [Department of Physics, Xinzhou Teachers University, Xinzhou 034000 (China)] [Department of Physics, Xinzhou Teachers University, Xinzhou 034000 (China); Li, Bai; Chen, Chunying [CAS Key Laboratory of Nuclear Analytical Techniques, Key Lab for Biomedical Effects of Nanomaterial and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)] [CAS Key Laboratory of Nuclear Analytical Techniques, Key Lab for Biomedical Effects of Nanomaterial and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Chai, Zhifang, E-mail: chaizf@ihep.ac.cn [CAS Key Laboratory of Nuclear Analytical Techniques, Key Lab for Biomedical Effects of Nanomaterial and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)] [CAS Key Laboratory of Nuclear Analytical Techniques, Key Lab for Biomedical Effects of Nanomaterial and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2013-08-15

    To investigate the influence of selenium on mercury phytotoxicity, the levels of selenium and mercury were analyzed with inductively coupled plasma-mass spectrometry (ICP-MS) in garlic tissues upon exposure to different dosages of inorganic mercury (Hg{sup 2+}) and selenite (SeO{sub 3}{sup 2?}) or selenate (SeO{sub 4}{sup 2?}). The distributions of selenium and mercury were examined with micro-synchrotron radiation X-ray fluorescence (?-SRXRF), and the mercury speciation was investigated with micro-X-ray absorption near edge structure (?-XANES). The results show that Se at higher exposure levels (>1 mg/L of SeO{sub 3}{sup 2?} or SeO{sub 4}{sup 2?}) would significantly inhibit the absorption and transportation of Hg when Hg{sup 2+} levels are higher than 1 mg/L in culture media. SeO{sub 3}{sup 2?} and SeO{sub 4}{sup 2?} were found to be equally effective in reducing Hg accumulation in garlic. The inhibition of Hg uptake by Se correlates well with the influence of Se on Hg phytotoxicity as indicated by the growth inhibition factor. Elemental imaging using ?-SRXRF also shows that Se could inhibit the accumulation and translocation of Hg in garlic. ?-XANES analysis shows that Hg is mainly present in the forms of Hg–S bonding as Hg(GSH){sub 2} and Hg(Met){sub 2}. Se exposure elicited decrease of Hg–S bonding in the form of Hg(GSH){sub 2}, together with Se-mediated alteration of Hg absorption, transportation and accumulation, may account for attenuated Hg phytotoxicity by Se in garlic. -- Highlights: ? Hg phytotoxicity can be mitigated by Se supplement in garlic growth. ? Se can inhibit the accumulation and transportation of Hg in garlic tissues. ? Localization and speciation of Hg in garlic can be modified by Se.

  9. Baboon syndrome induced by mercury - first case report in China.

    PubMed

    Wen, Liping; Yin, Jia; Ma, Dong-Lai; Lanier, Bob

    2007-06-01

    A case of mercury-induced baboon syndrome was reported. A 31-year-old woman presented with itching papules and vesicles in the right axilla, which extended to the left axilla, arms, fossa poplitea, buttocks, and groin. A mercury thermometer was broken 2 days before exanthema. Patch testing to ammoniated mercury, mercury, mercuric chloride, and mercurochrome were positive. Blood and urine mercury level was marginally normal, yet showed a descending trend over time. PMID:17577379

  10. Mercury dynamics in young Common Tern (Sterna hirundo) chicks from a polluted environment

    Microsoft Academic Search

    Peter H. Becker; Robert W. Furness; Diana Henning

    1993-01-01

    We studied mercury concentrations and amounts in tissues of 19 starved young Common Tern chicks (median age 4 days) and in eggs from the same colony. Concentrations and burden were similar between eggs and newly hatched chicks. Mercury concentrations were highest in down, which contained at least 38% of the body mercury. The mercury burden of the whole body and

  11. Volcanic mercury in Pinus canariensis

    NASA Astrophysics Data System (ADS)

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

    2013-08-01

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

  12. Volcanic mercury in Pinus canariensis.

    PubMed

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

    2013-08-01

    Mercury (Hg) is a toxic element that is emitted to the atmosphere by both human activities and natural processes. Volcanic emissions are considered a natural source of mercury in the environment. In some cases, tree ring records taken close to volcanoes and their relation to volcanic activity over time are contradictory. In 1949, the Hoyo Negro volcano (La Palma-Canary Islands) produced significant pyroclastic flows that damaged the nearby stand of Pinus canariensis. Recently, 60 years after the eruption, we assessed mercury concentrations in the stem of a pine which survived volcano formation, located at a distance of 50 m from the crater. We show that Hg content in a wound caused by pyroclastic impacts (22.3 ?g kg(-1)) is an order of magnitude higher than the Hg concentrations measured in the xylem before and after the eruption (2.3 ?g kg(-1)). Thus, mercury emissions originating from the eruption remained only as a mark-in pyroclastic wounds-and can be considered a sporadic and very high mercury input that did not affect the overall Hg input in the xylem. In addition, mercury contents recorded in the phloem (9.5 ?g kg(-1)) and bark (6.0 ?g kg(-1)) suggest that mercury shifts towards non-living tissues of the pine, an aspect that can be related to detoxification in volcanism-adapted species. PMID:23760570

  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. Mercury in the Anthropocene Ocean

    E-print Network

    Lamborg, Carl

    The toxic metal mercury is present only at trace levels in the ocean, but it accumulates in fish at concentrations high enough to pose a threat to human and environmental health. Human activity has dramatically altered the ...

  15. Polychlorinated biphenyl levels in the tissues of exposed and nonexposed humans.

    PubMed Central

    Schecter, A; Stanley, J; Boggess, K; Masuda, Y; Mes, J; Wolff, M; Fürst, P; Fürst, C; Wilson-Yang, K; Chisholm, B

    1994-01-01

    Polychlorinated biphenyls (PCBs) are synthetic chemicals, manufactured in volume from about 1929 to the 1970s. Environmental contamination by PCBs has been documented in various substances, including human tissue. PCBs have been measured in human tissue by a variety of analytical methods. PCB levels have been reported as an approximation of total PCB content expressed in terms of a commercial mixture, by identification and quantification of chromatographic peaks, or by qualitative and quantitative characterization of specific congeners. Until recently, the coplanar mono-ortho- and di-ortho substituted PCBs, which are especially toxic and present in significant concentration in humans from industrial countries, had not been measured in human tissues. Examples of various types of commonly used analyses are presented in general population subjects and in persons who experienced special exposure. In this paper, the usefulness of PCB blood determinations following potential exposure is demonstrated, and their application in health studies is illustrated from a number of case studies. Coplanar PCB, mono-ortho-substituted and di-ortho-substituted PCB levels in human blood are presented and compared with polychlorinated dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) levels in the U.S. population. Dioxin toxic equivalents for the two groups of chemicals are calculated and compared. It is found that mono-ortho-substituted and, to a lesser extent, coplanar PCBs, contribute substantially to dioxin toxic equivalents (TEq) in blood from U.S. adults. Because of substantial PCB contribution to dioxin toxic equivalents, total dioxinlike toxicity can only be determined if dioxins, dibenzofurans, and dioxinlike PCBs are measured.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:8187704

  16. Mercury in fish tissue of Idaho lakes vs. those of the Northeastern United States as it relates to the moderating effects of selenium

    EPA Science Inventory

    The primary methyl-mercury (MeHg) exposure mode to wildlife and humans is through the consumption of aquatic organisms, particulary fish. Selenium has been demonstrated to moderate the toxicity of MeHg in every test animal type examined to date. A molar ratio of Se:Hg >1 appear...

  17. Year-round high arachidonic acid levels in herbivorous rabbit fish Siganus fuscescens tissues.

    PubMed

    Osako, Kazufumi; Saito, Hiroaki; Kuwahara, Koichi; Okamoto, Akira

    2006-05-01

    To identify a stable resource of 20:4 n-6 (arachidonic acid, AA) in marine fish tissues, the lipid profiles of Siganus fuscescens organs (muscle, liver, and other viscera) and stomach contents were examined throughout the year. Crude total lipid (TL) contents in respective organs showed seasonal variations and were high in winter and low in summer. The main FA in TL were 16:0, 18:0, 16:1n-7, 18:1n-9, AA, and 22:6n-3 (DHA). These FA were those generally observed in marine fish lipids, except for comparatively high levels of AA. In TL of muscle and liver, AA showed relatively high values during the period from late May to August (muscle, 4.6-13.1%; liver, 4.5-9.1%), compared with other seasons (muscle, 4.3-9.5%; liver, 3.6-8.4%). The AA levels in TL of other viscera and stomach contents fluctuated (other viscera, 2.0-10.7%; stomach contents, 7.6-26.7%). Regardless of the fishing season, each organ contained a higher level of AA in polar lipids (PL) than in neutral lipids. It was concluded that the fish contain comparatively high levels of AA in their TL throughout the year, and they accumulate AA characteristically in their tissue PL, probably from dietary food sources. Moreover, it was suggested that S. fuscescens has potential utility as a natural marine source of nutritional lipids, because the fish contain comparatively high levels of DHA and AA. PMID:16933792

  18. Comparison of Mercury in Water, Bottom Sediment, and Zooplankton in Two Front Range Reservoirs in Colorado, 2008-09

    USGS Publications Warehouse

    Mast, M. Alisa; Krabbenhoft, David P.

    2010-01-01

    The U.S. Geological Survey, in cooperation with the Colorado Department of Public Health and Environment, conducted a study to investigate environmental factors that may contribute to the bioaccumulation of mercury in two Front Range reservoirs. One of the reservoirs, Brush Hollow Reservoir, currently (2009) has a fish-consumption advisory for mercury in walleye (Stizostedion vitreum), and the other, Pueblo Reservoir, which is nearby, does not. Water, bottom sediment, and zooplankton samples were collected during 2008 and 2009, and a sediment-incubation experiment was conducted in 2009. Total mercury concentrations were low in midlake water samples and were not substantially different between the two reservoirs. The only water samples with detectable methylmercury were collected in shallow areas of Brush Hollow Reservoir during spring. Mercury concentrations in reservoir bottom sediments were similar to those reported for stream sediments from unmined basins across the United States. Despite higher concentrations of fish-tissue mercury in Brush Hollow Reservoir, concentrations of methylmercury in sediment were as much as 3 times higher in Pueblo Reservoir. Mercury concentrations in zooplankton were at the low end of concentrations reported for temperate lakes in the Northeastern United States and were similar between sites, which may reflect the seasonal timing of sampling. Factors affecting bioaccumulation of mercury were assessed, including mercury sources, water quality, and reservoir characteristics. Atmospheric deposition was determined to be the dominant source of mercury; however, due to the proximity of the reservoirs, atmospheric inputs likely are similar in both study areas. Water-quality constituents commonly associated with elevated concentrations of mercury in fish (pH, alkalinity, sulfate, nutrients, and dissolved organic carbon) did not appear to explain differences in fish-tissue mercury concentrations between the reservoirs. Low methylmercury concentrations in hypolimnetic water indicate low potential for increased methylmercury production following the development of anoxic conditions in summer. Based on the limited dataset, water-level fluctuations and shoreline characteristics appear to best explain differences in fish-tissue mercury concentrations between the reservoirs. Due to the shallow depth and the large annual water-level fluctuations at Brush Hollow Reservoir, proportionally larger areas of shoreline at Brush Hollow Reservoir are subjected to annual reflooding compared to Pueblo Reservoir. Moreover, presence of macrophyte beds and regrowth of terrestrial vegetation likely increase the organic content of near-shore sediments in Brush Hollow Reservoir, which may stimulate methylmercury production in littoral areas subject to reflooding. Results of a laboratory incubation experiment were consistent with this hypothesis.

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

    PubMed

    Lech, Teresa

    2014-04-01

    In this work, a case of deliberate self-poisoning is presented. A 14-year-old girl suddenly died during one of the several hospitalizations. Abdominal computer tomography showed a large number of metallic particles in the large intestine. Analysis of blood and internal organs for mercury and other toxic metals carried out by inductively coupled plasma optical emission spectrometry (ICP OES) revealed high concentrations of mercury in kidneys and liver (64,200 and 2470ng/g, respectively), less in stomach (90ng/g), and none in blood. Using cold vapor-atomic absorption spectrometry (CV AAS), high levels of mercury were confirmed in all examined materials, including blood (87ng/g), and additionally in hair. The results of analysis obtained by two techniques revealed that the exposure to mercury was considerable (some time later, it was stated that the mercury originated from thermometers that had been broken over the course of about 1 year, because of Münchausen syndrome). CV AAS is a more sensitive technique, particularly for blood samples (negative results using ICP OES), and tissue samples - with LOQ: 0.63ng/g of Hg (CV AAS) vis-à-vis 70ng/g of Hg (ICP OES). However, ICP OES may be used as a screening technique for autopsy material in acute poisoning by a heavy metal, even one as volatile as mercury. PMID:24630410

  20. Neuropsychological assessment at school-age and prenatal low-level exposure to mercury through fish consumption in an Italian birth cohort living near a contaminated site.

    PubMed

    Deroma, L; Parpinel, M; Tognin, V; Channoufi, L; Tratnik, J; Horvat, M; Valent, F; Barbone, F

    2013-07-01

    The relative effects of prenatal and postnatal low-level mercury exposure and fish intake on child neurodevelopment are still controversial. Limited evidence is available from Mediterranean populations. In this prospective study, we measured the Verbal and Performance IQ in Italian children at school-age who were resident in an area declared as a National contaminated site because of mercury pollution, taking into account the possible beneficial effect of fish consumption and potential confounders. A mother-child cohort made up of 242 children was established at birth in Northeastern Italy in 2001. Their mothers were interviewed approximately 2 months after delivery to determine type, quantity, and origin of fish consumed during pregnancy and about a number of mother, child and family characteristics. Total mercury (THg) and methyl mercury (MeHg) were assessed in maternal hair and breast milk and in the child's hair. When children reached 7-9 years of age, 154 (63.6%) parents gave consent to participate in a follow-up evaluation. On that occasion, a child's hair sample was collected to determine the current concentration of THg, mothers were asked to complete a self-administered questionnaire, and children underwent neuropsychological testing. Verbal IQ, performance IQ and full scale IQ were measured by the Wechsler Intelligence Scale for Children (WISC III) administered by psychologists at school or local health centers. Demographic, socioeconomic and lifestyle information, medical information of the child's family and the child's dietary habits were collected using a questionnaire filled in by mothers. Multivariable linear regression models were used to evaluate the association between prenatal THg exposure through fish consumption of mothers in pregnancy and children's IQ after adjustment for possible confounders such as fish consumption of mothers in pregnancy, child's fish consumption at follow-up, child's birthweight, maternal cigarette smoking during pregnancy, house size and property place of residence during pregnancy and gender. THg in the child's hair at 7 years of age was fairly correlated with THg in maternal hair at delivery (rs=0.35; p<0.0001) and was strongly correlated with child's seafood consumption (rs=0.50, p<0.0001). No differences in maternal THg levels were found when comparing children with low or extremely low or high or extremely high scores vs others, considering separately full scale, verbal, and performance IQs. Children born from mothers with hair THg levels greater than or equal to 2000ng/g had full scale, verbal and performance IQs which were 4-5 points lower than children born from women with lower THg levels, but these differences were not statistically significant. Fresh fish intake of mothers in pregnancy was slightly positively associated with full scale and performance but not so with verbal IQs. Canned fish showed to be negatively associated with all the outcome variables. Unexpectedly, children born to mothers from one town showed IQ scores significantly lower than the other children; however, none of the many variables considered in these analyses could explain this result. The relatively low Hg levels found in the biological samples did not provide evidence of high and extensive Hg exposure in this population. Although THg levels in maternal and child's biological samples are correlated with fish consumption, the effects of THg and fish on neurological outcomes go in opposite directions. These results do not allow to develop recommendations regarding fish consumption in pregnancy but suggest that keeping THg hair levels<2000ng/g might be desirable. PMID:23523155

  1. 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.

  2. Mercury toxicity. Agency for Toxic Substance and Disease Registry

    SciTech Connect

    Not Available

    1992-12-01

    Because mercury has several forms and because it produces subtle effects at chronic low-level exposures, mercury toxicity can be a difficult diagnosis to establish. Elemental mercury vapor accounts for most occupational and many accidental exposures. The main source of organic methyl mercury exposure in the general population is fish consumption. Children are at increased risk of exposure to elemental mercury vapor in the home because it tends to settle to the floor. The chemical and physical forms of mercury determine its absorption, metabolism, distribution and excretion pathways. The central nervous system and kidneys are key targets of mercury toxicity. Chelation therapy has been used successfully in treating patients who have ingested mercury salts or inhaled elemental mercury. There is no antidote for patients poisoned with organic mercury.7 references.

  3. Improved Prediction of Rat Cortical Bone Mechanical Behavior using Composite Beam Theory to Integrate Tissue Level Properties

    PubMed Central

    Kim, Grace; Boskey, Adele L.; Baker, Shefford P.; van der Meulen, Marjolein C. H.

    2012-01-01

    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 modului from microCT attenuation values based on tissue level relationships (Zlin,a and Zlin,b) between mineralization and material properties to predict whole bone mechanical behavior. Zlin,a was determined using the equation of the best fit linear regression between nanoindentation indentation modulus 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 Zlin,b. The predictive capability of the weighted section moduli calculated using a tissue level relationship were compared with average tissue level properties and weighted section moduli calculated using an apparent level relationship (Zexp) 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 Zlin,a, Zlin,b, and Zexp 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

  4. MATERNAL-FETAL TISSUE LEVELS OF SIXTEEN TRACE ELEMENTS IN EIGHT COMMUNITIES

    EPA Science Inventory

    The developing fetus probably represents one of the most vulnerable subgroups of the general population to the toxic effects of trace elements. There have been numerous reports of abortion or fetal malformation due to excessive exposure of the expectant mother to mercury and othe...

  5. Effects of commonly used cooking practices on total mercury concentration in fish and their impact on exposure assessments.

    PubMed

    Morgan, J N; Berry, M R; Graves, R L

    1997-01-01

    The effects of cooking practices commonly used by Native Americans on total mercury concentrations in fish were investigated. A preparation factor relating mercury concentrations in fish as prepared for consumption to mercury concentration data as measured in typical environmental monitoring programs was calculated. Preparation factors are needed to provide risk assessors with a more accurate estimate of the actual amount of mercury ingested through consumption of contaminated fish. Data on fish preparation and consumption practices of two communities of Chippewa residing on the shores of Lake Superior in northern Wisconsin were used to select practices for study. The most commonly consumed species, walleye and lake trout, were selected. Whitefish livers were also selected for study. Commonly used cooking techniques including panfrying, deep-frying, baking, boiling, and smoking were duplicated in the laboratory. Total mercury concentrations were determined in fish portions before and after cooking and in a portion representative of that analyzed in programs to assess water quality (skin-on fillets). Total mercury was determined by microwave digestion-cold vapor atomic absorption spectroscopy. Mercury concentrations (wet weight basis) in panfried, baked, and boiled walleye fillets and deep-fried and baked whitefish livers ranged from 1.1 to 1.5 times higher than in corresponding raw portions. In lake trout, mercury concentrations were 1.5 to 2.0 times higher in cooked portions than in the raw portion. However, total mercury levels were constant before and after cooking, indicating the concentration effect is caused by weight (moisture and fat) loss. The addition of lemon juice to potentially release mercury from its bound state and promote volatilization did not exert any measurable influence on mercury concentrations in cooked walleye. In some cases mercury concentrations were increased with increased cooking times due to further loss of moisture and fat. Preparation factors (defined as the ratio of mercury concentration in cooked fish to the mercury concentration in the environmental portion) ranged from 1.3 to 2.0. Results suggest that consideration be given to the use of preparation factors in risk assessments, exposure assessments, or issuance of fish advisories where mercury concentration in raw fish tissue are used in conjunction with cooked fish meal sizes. PMID:9076613

  6. Pairwise comparisons of ten porcine tissues identify differential transcriptional regulation at the gene, isoform, promoter and transcription start site level

    SciTech Connect

    Farajzadeh, Leila; Hornshøj, Henrik; Momeni, Jamal; Thomsen, Bo; Larsen, Knud; Hedegaard, Jakob; Bendixen, Christian; Madsen, Lone Bruhn, E-mail: LoneB.Madsen@agrsci.dk

    2013-08-23

    Highlights: •Transcriptome sequencing yielded 223 mill porcine RNA-seq reads, and 59,000 transcribed locations. •Establishment of unique transcription profiles for ten porcine tissues including four brain tissues. •Comparison of transcription profiles at gene, isoform, promoter and transcription start site level. •Highlights a high level of regulation of neuro-related genes at both gene, isoform, and TSS level. •Our results emphasize the pig as a valuable animal model with respect to human biological issues. -- Abstract: The transcriptome is the absolute set of transcripts in a tissue or cell at the time of sampling. In this study RNA-Seq is employed to enable the differential analysis of the transcriptome profile for ten porcine tissues in order to evaluate differences between the tissues at the gene and isoform expression level, together with an analysis of variation in transcription start sites, promoter usage, and splicing. Totally, 223 million RNA fragments were sequenced leading to the identification of 59,930 transcribed gene locations and 290,936 transcript variants using Cufflinks with similarity to approximately 13,899 annotated human genes. Pairwise analysis of tissues for differential expression at the gene level showed that the smallest differences were between tissues originating from the porcine brain. Interestingly, the relative level of differential expression at the isoform level did generally not vary between tissue contrasts. Furthermore, analysis of differential promoter usage between tissues, revealed a proportionally higher variation between cerebellum (CBE) versus frontal cortex and cerebellum versus hypothalamus (HYP) than in the remaining comparisons. In addition, the comparison of differential transcription start sites showed that the number of these sites is generally increased in comparisons including hypothalamus in contrast to other pairwise assessments. A comprehensive analysis of one of the tissue contrasts, i.e. cerebellum versus heart for differential variation at the gene, isoform, and transcription start site (TSS), and promoter level showed that several of the genes differed at all four levels. Interestingly, these genes were mainly annotated to the “electron transport chain” and neuronal differentiation, emphasizing that “tissue important” genes are regulated at several levels. Furthermore, our analysis shows that the “across tissue approach” has a promising potential when screening for possible explanations for variations, such as those observed at the gene expression levels.

  7. 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

  8. Levels of heavy metals in tissues of shingi fish (Heteropneustes fossilis) from Buriganga River, Bangladesh.

    PubMed

    Begum, Aleya; Mustafa, Ahmed Ismail; Amin, Md Nurul; Chowdhury, Tasrina Rabia; Quraishi, Shamshad Begum; Banu, Nasrin

    2013-07-01

    Heavy metal pollution was reported in commercially valuable freshwater edible fish in the Buriganga River, Bangladesh. The concentrations of As, Pb, Cd, Cr, Zn, and Cu were investigated in the muscle, gill, stomach, intestine, and liver of Heteropneustes fossilis caught at three stations to assess the degree of fish pollution by heavy metals. Significant differences in concentrations of analyzed elements were observed among different tissues, but not among the stations. The ranges of the measured concentrations (?g/g dry weight) in the tissues of H. fossilis were as follows: arsenic concentration was (0.2-0.4), (0.82-0.90), (3.29-3.99), (2.20-2.80), and (2.41-2.90), that of lead was (1.79-2.20), (4.95-6.55), (10.36-13.38), (5.74-9.70), and (18.20-18.79), that of cadmium was (0.3-0.4), (2.87-4.27), (1.03-1.63), (1.55-4.59), and (2.25-5.50), that of chromium was (1.40-1.70), (3.52-3.72), (2.28-5.29), (2.77-3.79), and (4.25-8.65), that of zinc was (24.47-28.82), (16.82-18.80), (20.22-22.20), (22.86-26.68), and (60.82-67.80), and that of copper was (7.80-8.50), (6.22-6.81), (38.21-44.25), (17.07-21.03), and (43.24-47.30) in the muscle, gill, stomach, intestine, and liver, respectively. This research showed that the liver appeared to be the main heavy metal storage tissue, while the muscle had the lowest levels of analyzed metals. The concentrations of metal in the muscles not exceeded the acceptable levels for a food source for human consumption. PMID:23132754

  9. Quantifying tissue level ischemia: hypoxia response element-luciferase transfection in a rabbit ear model.

    PubMed

    Said, Hakim K; Roy, Nakshatra K; Gurjala, Anandev N; Mustoe, Thomas A

    2009-01-01

    Ischemia is a common underlying factor in a number of pathologic conditions ranging from cardiac dysfunction to delayed wound healing. Previous efforts have shown the resulting hypoxia activates the hypoxia inducible factor, a transcription factor with signaling effects through an intranuclear hypoxia response element (HRE). We hypothesized that ischemic conditions should activate these hypoxic signaling pathways in a measurable manner. We tested our hypothesis using variations of an established rabbit ear ischemic wound model and an HRE-luciferase-reporter gene construct. This plasmid construct was transfected into the ears of young, female New Zealand White rabbits, harvested at day 7 and processed to yield a reactive solution. Luminometry was used to quantify luciferase expression in each solution as a marker for HRE activation in each wound. Quantitative readings of hypoxic signaling as measured by luminescence yielded profound and statistically significant differences between the various ischemic models. Our results suggest that the biologic systems for hypoxic signaling can be used to detect local ischemia. HRE-luciferase transfection is an effective tool for quantifying the degree of tissue hypoxia. The caudal ischemic rabbit ear model showed significantly higher levels of hypoxia. Use of a validated model that produces sufficient tissue levels of hypoxia is recommended for meaningful study of ischemic wound healing. PMID:19614911

  10. Organochlorine levels in adipose tissue of women from a littoral region of Argentina.

    PubMed

    Muñoz-de-Toro, Mónica; Beldoménico, Horacio R; García, Silvia R; Stoker, Cora; De Jesús, Juan J; Beldoménico, Pablo M; Ramos, Jorge G; Luque, Enrique H

    2006-09-01

    Organochlorine compounds (OCCs), such as pesticides and polychlorinated biphenyls (PCBs), are persistent lipophilic chemicals identified as endocrine disruptors, mainly with estrogen-like effects. Northeastern Argentina, near the Paraná River, is characterized by intensive farming and agricultural activities and industrial development, and is therefore prone to high incidences of environmental and dietary exposure to OCCs. Hence, we conducted a study to (1) estimate the organochlorine residues present in mammary fat tissue in a population of women from this littoral region and (2) identify potential sources of exposure to OCCs. Our subjects were 76 women (residing in and around Santa Fe city and not occupationally exposed to organochlorines) who underwent excision biopsy of a breast lesion or had plastic surgery. Both frequency of occurrence and levels of organochlorine residues were high in breast adipose tissue of all the participants. The organochlorine residues most frequently found were p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) in all the subjects analyzed, hexachlorobenzene (HCB) in 86.8%, and beta-hexachlorocyclohexane (beta-HCH) in 75.0%. The incidence of PCB congeners was very low. p,p'-DDE and beta-HCH residues reached the highest levels, 4794 and 1780 ppb, respectively. The diet was a relevant source of exposure, consumption of animal fat and freshwater fish playing a significant role. Bioaccumulation was evidenced by the significant positive association between organochlorine levels and body mass index (p = 0.0003) and the age of the patient (p = 0.0002). The frequency and levels of OCCs found in our study population raise concerns regarding Argentinean exposure to these endocrine disruptors. PMID:16480710

  11. 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

  12. Plasma Tissue Factor Levels and Salivary Tissue Factor Activities of Periodontitis Patients with and without Cardiovascular Disease

    Microsoft Academic Search

    E. Emekli-Alturfan; I. Basar; E. Malali; E. Elemek; S. Oktay; F. Ayan; N. Emekli; U. Noyan

    2011-01-01

    The association between periodontal and cardiovascular disease has received considerable attention. Studies have demonstrated a higher incidence of atherosclerotic complications in patients with periodontal disease. Tissue factor (TF) has been known as a key initiator of the coagulation cascade, and the TF pathway is the primary physiological mechanism of initiation of blood coagulation. Recently, it has been shown that the

  13. Mercury bioaccumulation in organisms from three Puerto Rican estuaries.

    PubMed

    Burger, J; Cooper, K; Saliva, J; Gochfeld, D; Lipsky, D; Gochfeld, M

    1992-09-01

    We analyzed mercury levels in shrimp (Palaemonetes sp.), Blue Crabs (Callinectes sp.), fish (Tarpon Megalops atlantica and Tilapia Tilapia mossambica), lizards (Ameiva exsul), Cattle Egret (Bubulcus ibis) and Moorhen (Gallinula chloropus) in three estuaries in Puerto Rico in 1988. There were no quantifiable concentrations greater than the method detection limit of mercury in shrimp, crabs and lizards from any site. Mercury levels were also below detection limits in Tilapia, except for specimens collected at Frontera Creek, allegedly contaminated with mercury. However, mercury levels ranged from 92-238 ?g/kg (wet weight) in Tarpon, a predaceous fish that feeds on smaller fish. Few of the birds had detectable levels of mercury. Our results indicate relatively low concentrations of mercury in biota collected in all of the three estuaries at most trophic levels, although 10 of 12 Tarpon fillet samples from Frontera had detectable mercury compared to 3 of 12 fillet samples for the other two lagoons. PMID:24226951

  14. Time-course of tissue factor plasma level in patients with acute coronary syndrome.

    PubMed

    Bis, J; Vojácek, J; Dusek, J; Pecka, M; Palicka, V; Stásek, J; Malý, J

    2009-01-01

    Enhanced expression of tissue factor (TF) may result in thrombosis contributing to acute clinical consequences of coronary artery disease. Several studies demonstrated elevated plasma levels of TF in patients with acute coronary syndrome (ACS). The aim of our study was to compare the concentrations of TF in coronary sinus (CS), proximal part of the left coronary artery (LCA) and peripheral vein (PV) of patients with ACS and stable coronary artery disease (SCAD). Time course of the TF plasma levels in PV was followed on day 1 and day 7 after index event of ACS presentation and was compared to day 0 values. No heparin was given prior to the blood sampling. Twenty-nine patients in the ACS group (age 63.6+/-10.8 years, 20 males, 9 females) and 24 patients with SCAD (age 62.3+/-8.1 years, 21 males, 3 females) were examined. TF plasma level was significantly higher in patients with ACS than in those with SCAD (239.0+/-99.3 ng/ml vs. 164.3+/-114.2 ng/ml; p=0.016). There was no difference in TF plasma levels in PV, CS and LCA (239.0+/-99.3 ng/ml vs. 253.7+/-131.5 ng/ml vs. 250.6+/-116.4 ng/ml, respectively). TF plasma levels tended to decrease only non-significantly on the day 7 (224.4+/-109.8 ng/ml). Significant linear correlation between TF and high sensitivity CRP (hs-CRP) levels on day 0 was found. In conclusion, TF plasma levels are elevated in patients with ACS not only locally in CS but also in systematic circulation. Our data support the relationship between TF production and proinflammatory mediators. PMID:19093728

  15. Human impacts on pig frog (Rana grylio) populations in south Florida wetlands: Harvest, water management and mercury contamination

    Microsoft Academic Search

    Cristina A Ugarte

    2004-01-01

    This study investigated how harvest and water management affected the ecology of the Pig Frog, Rana grylio. It also examined how mercury levels in leg muscle tissue vary spatially across the Everglades. Rana grylio is an intermediate link in the Everglades food web. Although common, this inconspicuous species can be affected by three forms of anthropogenic disturbance: harvest, water management

  16. 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

  17. Calculation of the antibiotic level in the lung tissue and bronchial secretion with an oral controlled-release dosage form

    Microsoft Academic Search

    M. Saïdna; E. M. Ouriemchi; J. M. Vergnaud

    1998-01-01

    The drug level-time history in plasma and lung tissue was calculated with an antibiotic orally delivered in either an immediate-release\\u000a or a controlled-release dosage form. The drug profiles were compared with experiment results given in the literature. In the\\u000a same way, the drug level was evaluated in the bronchial secretion in contact with lung tissue. A numerical model, based on

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

    PubMed

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

    2015-02-11

    Artisanal and small-scale gold mining (ASGM) is a major contributor to deforestation and the largest anthropogenic source of atmospheric mercury worldwide. Despite significant information on the direct health impacts of mercury to ASGM miners, the impact of mercury contamination on downstream communities has not been well characterized, particularly in Peru's Madre de Dios region. In this area, ASGM has increased significantly since 2000 and has led to substantial political and social controversy. This research examined the spatial distribution and transport of mercury through the Madre de Dios River with distance from ASGM activity. This study also characterized risks for dietary mercury exposure to local residents who depend on fish from the river. River sediment, suspended solids from the water column, and fish samples were collected in 2013 at 62 sites near 17 communities over a 560 km stretch of the Madre de Dios River and its major tributaries. In areas downstream of known ASGM activity, mercury concentrations in sediment, suspended solids, and fish within the Madre de Dios River were elevated relative to locations upstream of mining. Fish tissue mercury concentrations were observed at levels representing a public health threat, with greater than one-third of carnivorous fish exceeding the international health standard of 0.5 mg kg(-1). This study demonstrates that communities located hundreds of kilometers downstream of ASGM activity, including children and indigenous populations who may not be involved in mining, are at risk of dietary mercury exposure that exceed acceptable body burdens. This report represents the first systematic study of the region to aid policy decision-making related to ASGM activities in Peru. PMID:25573610

  19. 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

  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. Mercury levels assessment in hair of riverside inhabitants of the Tapajós River, Pará State, Amazon, Brazil: Fish consumption as a possible route of exposure.

    PubMed

    Faial, Kleber; Deus, Ricardo; Deus, Simonny; Neves, Ramiro; Jesus, Iracina; Santos, Elisabeth; Alves, Cláudio Nahum; Brasil, Davi

    2015-04-01

    The study present evaluated the levels of mercury (Hg) and methylmercury (MeHg) in hair samples of people from Barreiras community, riverside inhabitants of the Tapajós River (Pará, Brazil), an area impacted by clandestine gold mining, as well as we analyzed the levels of Hg and Se (selenium) in nine fish species (carnivores and non-carnivorous) from the Tapajós River, which stand out as the main species consumed by riverside inhabitants, to evaluate a relationship between frequency of fish consumption and Hg concentration, and also to evaluate possible mechanisms of fish protection (or non-protection) to Hg exposure by Se. Furthermore we analyze the water quality to evaluate the environmental trophic state, fact responsible by creating conditions that can potentiate the effects of toxic mercury. Concentrations of Hg and MeHg were analyzed in hair samples of 141 volunteers in different age band. Of those, 84.40% of samples present values above the threshold for biological tolerance, which is 6.00?gg(-1) of total Hg in hair. Total Hg, in men there was a variation of 2.07-24.93?gg(-1), while for women the variation was 4.84-27.02?gg(-1). Consequently, the level of MeHg in men presented a variation of 1.49-19.57?gg(-1), with an average of 11.68?gg(-1), while with women the variation was from 3.73 to 22.35?gg(-1), with an average of 10.38?gg(-1). In fish species, Hg concentrations in carnivorous species had an average of 0.66?gg(-1), higher than that permitted by current legislation, ranging from 0.30 to 0.98?gg(-1), while the non-carnivorous species have values below the recommended by the legislation averaging 0.09?gg(-1), ranging between 0.02 and 0.44?gg(-1). For Se in fish, show that among carnivores, the contents of Se ranged between 0.18 and 0.54?gg(-1) with a mean of 0.34?gg(-1), while for non-carnivores these values were of the order of 0.16-0.56?gg(-1), with an average of 0.32?gg(-1). In surface water quality variables at the sampling points all showed values in accordance with the range established by current legislation. In this regard, the results provided by this study, while not conclusive, are strong indicators that despite not having been shown the relationship between the concentration of mercury in hair and feeding habits along the Tapajós River basin communities showed that a plausible correlation exists between levels of mercury and selenium in fish. This fact may serve as a subsidy to research human health, because in the Amazon, there is still a lot to examine with regards to the full understanding of the Se cycle. PMID:25467850

  2. 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)

  3. Changes in Metallothionein Level in Rat Hepatic Tissue after Administration of Natural Mouldy Wheat

    PubMed Central

    Vasatkova, Anna; Krizova, Sarka; Adam, Vojtech; Zeman, Ladislav; Kizek, Rene

    2009-01-01

    Mycotoxins are secondary metabolites produced by microfungi that are capable of causing disease and death in humans and other animals. This work was aimed at investigation of influence of mouldy wheat contaminated by pathogenic fungi producing mycotoxins on metallothionein levels in hepatic tissue of rats. The rats were administrating feed mixtures with different contents of vitamins or naturally mouldy wheat for 28 days. It was found that the wheat contained deoxynivalenol (80 ± 5 ?g per kg of mouldy wheat), zearalenone (56 ± 3 ?g/kg), T2-toxin (20 ± 2 ?g/kg) and aflatoxins as a sum of B1, B2, G1 and G2 (3.9 ± 0.2 ?g/kg). Rats were fed diets containing 0, 33, 66 and 100% naturally moulded wheat. Control group 0, 33, 66 and 100% contained vitamins according to Nutrient Requirements of Rats (NRC). Other four groups (control group with vitamins, vit33, vit66 and vit100%) were fed on the same levels of mouldy wheat, also vitamins at levels 100% higher than the previous mixtures. We determined weight, feed conversion and performed dissection to observe pathological processes. Changes between control group and experimental groups exposed to influence of mouldy wheat and experimental groups supplemented by higher concentration of vitamins and mouldy wheat were not observed. Livers were sampled and did not demonstrate significant changes in morphology compared to control either. In the following experiments the levels of metallothionein as a marker of oxidative stress was determined. We observed a quite surprising trend in metallothionein levels in animals supplemented with increased concentration of vitamins. Its level enhanced with increasing content of mouldy wheat. It was possible to determine a statistically significant decline (p<0.05) between control group and groups of animals fed with 33, 66 and 100% mouldy wheat. It is likely that some mycotoxins presented in mouldy wheat are able to block the mechanism of metallothionein synthesis. PMID:19399242

  4. An Assessment of health risk associated with mercury in soil and sediment from East Fork Poplar Creek, Oak Ridge, Tennessee. Final report

    SciTech Connect

    Revis, N.; Holdsworth, G.; Bingham, G.; King, A.; Elmore, J.

    1989-04-01

    This report presents results from a study conducted to determine the toxicity of Mercury in soils sediments samples. Mice were fed via diet, soils and sediment, from various locations along the East Fork Poplar creek. Tissue distribution of pollutants was determined at various intervals. The tissue level relative to toxicity was used to determine the effect of a complex matrix on the gastrointestinal absorption and tissue distribution of the pollutants (other pollutants included cadmium and selenium).

  5. Tissue spectrophotometry and thermographic imaging applied to routine clinical prediction of amputation level viability

    NASA Astrophysics Data System (ADS)

    Hanson, Jon M.; Harrison, David K.; Hawthorn, Ian E.

    2002-06-01

    About 5% of British males over 50 years develop peripheral arterial occlusive disease. Of these about 2% ultimately require lower limb amputation. In 1995 we proposed a new technique using lightguide spectrophotometry to measure the oxygen saturation level of haemoglobin (SO2) in the skin as a method for predicting tissue viability. This technique, in combination with thermographic imaging, was compared with skin blood flow measurements using the I125)4- Iodoantipyrine (IAP) clearance technique. The optical techniques gave a sensitivity and selectivity of 1.0 for the prediction of successful outcome of a below knee amputation compared with a specificity of 93% using the traditional IAP technique at a below knee to above knee amputation ratio (BKA:AKA) of 75%. The present study assesses the routine clinical application of these optical techniques. The study is ongoing, but the data to date comprises 22 patients. 4 patients were recommended for above knee amputation (AKA) and 18 patients for below knee amputation on the basis of thermographic and tissue SO2 measurements. All but one of the predicted BKA amputations healed. The study to date produces evidence of 94% healing rate (specificity) for a BKA:AKA ratio of 82%. This compares favorably with the previous figures given above.

  6. Nonhost versus host resistance to the grapevine downy mildew, Plasmopara viticola, studied at the tissue level.

    PubMed

    Díez-Navajas, A M; Wiedemann-Merdinoglu, S; Greif, C; Merdinoglu, D

    2008-07-01

    Following inoculation of host and nonhost plants with Plasmopara viticola, the grapevine downy mildew, a histological survey was undertaken to identify the stage where its development is contained in nonhosts and in resistant host plants. Three herbaceous nonhost species, Beta vulgaris, Lactuca sativa, and Capsicum annuum, and three grapevine species displaying different level of resistance (Vitis vinifera [susceptible], Vitis riparia [partially resistant] and Muscadinia rotundifolia [totally resistant]) where inoculated by P. viticola using a controlled leaf disk inoculation bioassay. During the early steps of infection, defined as encystment of zoospores on stomata, penetration of the germ tube, and production of the vesicle with the primary hypha, there was no evidence of a clear-cut preference to grapevine tissues that could attest to host specificity. The main difference between host grapevine species and nonhosts was observed during the haustorium formation stage. In nonhost tissues, the infection was stopped by cell wall-associated defense responses before any mature haustorium could appear. Defense responses in resistant grapevines were triggered when haustoria were fully visible and corresponded to hypersensitive responses. These observations illustrate that, for P. viticola, haustorium formation is not only a key stage for the establishment of biotrophy but also for the host specificity and the recognition by grapevine resistance factors. PMID:18943253

  7. Basic Information about Mercury (inorganic) in Drinking Water

    MedlinePLUS

    Mercury (Inorganic) at a Glance Maximum Contaminant Level ( MCL ) = 0.002 milligrams per Liter (mg/L) or ... Health Effects Some people who drink water containing mercury well in excess of the MCL over many ...

  8. Mercury Contamination

    PubMed Central

    Thompson, Marcella R.

    2013-01-01

    IN BRIEF A residential elemental mercury contamination incident in Rhode Island resulted in the evacuation of an entire apartment complex. To develop recommendations for improved response, all response-related documents were examined; personnel involved in the response were interviewed; policies and procedures were reviewed; and environmental monitoring data were compiled from specific phases of the response for analysis of effect. A significant challenge of responding to residential elemental mercury contamination lies in communicating risk to residents affected py a HazMat spill. An ongoing, open and honest dialogue is emphasized where concerns of the public are heard and addressed, particularly when establishing and/or modifying policies and procedures for responding to residential elemental mercury contamination. PMID:23436951

  9. 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

  10. Marine Foraging Birds As Bioindicators of Mercury in the Gulf of Maine

    Microsoft Academic Search

    M. Wing Goodale; David C. Evers; Steven E. Mierzykowski; Alexander L. Bond; Neil M. Burgess; Catherine I. Otorowski; Linda J. Welch; C. Scott Hall; Julie C. Ellis; R. Bradford Allen; Anthony W. Diamond; Stephen W. Kress; Robert J. Taylor

    2008-01-01

    From existing databases, we compiled and evaluated 604 total mercury (Hg) levels in the eggs and blood of 17 species of marine\\u000a foraging birds from 35 Gulf of Maine islands to provide baseline data and to determine the best tissue, age class, and species\\u000a for future biomonitoring. While mean Hg levels in most species did not exceed adverse effects thresholds,

  11. Organochlorines, brominated flame retardants and mercury levels in six seabird species from the Gulf of St. Lawrence (Canada): relationships with feeding ecology, migration and molt.

    PubMed

    Lavoie, Raphael A; Champoux, Louise; Rail, Jean-François; Lean, David R S

    2010-06-01

    Concentrations of organochlorines (OCs), brominated flame retardants (BFRs) and mercury (Hg) were measured in eggs of six seabird species breeding in the Gulf of St. Lawrence, Canada. Stable nitrogen (delta15N) and carbon (delta13C) isotopes were used as ecological tracers to measure trophic level and connectivity with benthos, respectively. Concentrations, patterns as well as ecological tracers varied significantly between species. The sum of polychlorinated biphenyls (SigmaPCBs) was the most important group measured in all seabird species based on concentration followed generally by the sum of chlorinated pesticides (SigmaCPs), the sum of brominated flame retardants (SigmaBFRs) and finally total Hg (THg). SigmaPCBs, SigmaCPs and SigmaBFRs increased with trophic level, whereas THg did not. Only SigmaBFRs increased with a higher connectivity with the benthos. Seabird species resident to the Great Lakes-St. Lawrence ecosystem showed higher Hg and BFR levels than migratory species. Molt patterns were used to explain variations of contaminant levels. PMID:20363539

  12. Tissue polarity points from cells that have higher Frizzled levels towards cells that have lower Frizzled levels

    Microsoft Academic Search

    Paul N. Adler; Randi E. Krasnow; Jingchun Liu

    1997-01-01

    Background: The frizzled (fz) gene of Drosophila encodes the founding member of the large family of receptors for the Wnt family of signaling molecules. It was originally studied in the adult epidermis, where it plays a key role in the generation of tissue polarity. Mutations in components of the fz signal transduction pathway disrupt tissue polarity; on the wing, hairs

  13. Cattle egret (Bubulcus ibis) and Little egret (Egretta garzetta) as monitors of mercury contamination in Shadegan Wetlands of south-western Iran.

    PubMed

    Zamani-Ahmadmahmoodi, Rasool; Esmaili-Sari, Abbas; Savabieasfahani, Mozhgan; Bahramifar, Nader

    2010-07-01

    Mercury concentrations in feather, liver, kidney, and muscle tissue of Little egret (n = 8) and Cattle egret (n = 3) from Shadegan Wetlands in south-western Iran were examined. Liver of Little egret had significantly higher mercury compared to Cattle egret (p < 0.05). In addition, mercury values were consistently larger in Little egret when compared to Cattle egret, but mercury levels found in feather, kidney, and muscle did not differ statistically between the two bird species (p > 0.05). The small Cattle egret sample size, however, makes it difficult to conclude that the same trend would persist had we been able to include more Cattle egrets in this study. An interesting regional comparison between mercury concentrations in the feather of Little egret chicks, from China, Hong Kong, and Pakistan, and adult Little egrets, from Shadegan wetlands, revealed higher mercury in the adult of the species, as one would expect. Conversely, feathers of adult Cattle egrets form Shadegan had less mercury than values reported for young birds of the same species from Aswan in Egypt; but our Cattle egrets had higher or similar mercury concentrations to Cattle egrets from Pakistan, New York, Delaware, Puerto Rico, Hong Kong, and Cairo in Egypt. PMID:19475490

  14. Mercury in Schools

    NSDL National Science Digital Library

    This site explains the importance of mercury as a school and community issue and helps to identify where it is most likely to be found. There is information about online graduate courses for teachers on the environmental and health impacts of mercury; a Powerpoint presentation on mercury in schools; a mercury I.Q. test; and a mercury curriculum. The Taking Action section focuses on pollution prevention, spills and safety, mercury related legislation and school collection programs. There are also links to the U.S. Environmental Protection Agency mercury programs and information on fish consumption advisories, mercury spill inci