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1

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

PubMed

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

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

2010-08-01

2

Tissue levels of mercury determined in a deceased worker after occupational exposure  

Microsoft Academic Search

Objectives: To examine mercury (Hg) and selenium (Se) levels in autopsy samples from a thermometer worker who had been exposed over a\\u000a long period to, and monitored for, mercury vapor. Case report: Hg and Se levels were determined using radiochemical neutron activation analysis in a worker who had commited suicide 4 weeks\\u000a after the end of 14 years of exposure

L. Barregĺrd; G. Sällsten; N. Conradi

1999-01-01

3

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

SciTech Connect

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.

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

4

Metallothioneins failed to reflect mercury external levels of exposure and bioaccumulation in marine fish--considerations on tissue and species specific responses.  

PubMed

The suitability of metallothioneins (MT) in fish as biomarker of exposure to mercury has been questioned. Therefore, this study aimed at investigating the relationship between external levels of exposure, mercury accumulation and MT content, assessing species and tissue specificities. Two ecologically different fish species--Dicentrarchus labrax and Liza aurata--were surveyed in an estuary historically affected by mercury discharges. Total mercury (T-Hg) and MT content were determined in gills, blood, liver, kidney, muscle and brain. All tissues reflected differences in T-Hg accumulation in both species, although D. labrax accumulated higher levels. Regarding MT, D. labrax revealed a depletion in brain MT content and an incapacity to induce MT synthesis in all the other tissues, whereas L. aurata showed the ability to increase MT in liver and muscle. Tissue-specificities were exhibited in the MT inducing potential and in the susceptibility to MT decrease. L. aurata results presented muscle as the most responsive tissue. None of the investigated tissues displayed significant correlations between T-Hg and MT levels. Overall, the applicability of MT content in fish tissues as biomarker of exposure to mercury was uncertain, reporting limitations in reflecting the metal exposure levels and the subsequent accumulation extent. PMID:21680008

Mieiro, C L; Bervoets, L; Joosen, S; Blust, R; Duarte, A C; Pereira, M E; Pacheco, M

2011-06-15

5

Mercury levels in fishes from some Missouri lakes with and without known mercury pollution  

Microsoft Academic Search

Mercurial fungicides used in golf greens can lead to elevated mercury levels in fish from lakes receiving greens drainage. The largemouth bass is the most sensitive indicator with levels ranging from 1-7 mg mercury\\/g of wet tissue in fish taken from lakes that receive drainage from treated greens. Many lakes with no known source of mercury contamination produce bass that

S. R. Koirtyohann; R. Meers; L. K. Graham

1974-01-01

6

Methylmercury and total mercury in tissues of arctic marine mammals  

Microsoft Academic Search

Concentrations of methylmercury, total mercury and selenium in marine mammal tissues were determined in liver, muscle, skin (muktuk) and blubber of belugas, ringed seals and narwhal, using atomic absorption and capillary gas chromatography with ECD detection. Mean MeHg levels in the types of tissues analysed, except blubber, generally exceeded the Canadian Federal Consumption Guideline for mercury in fish (0.5 ?g\\/g

R Wagemann; E Trebacz; G Boila; W. L Lockhart

1998-01-01

7

Mercury concentrations in tissues of Florida bald eagles  

SciTech Connect

We collected 48 blood and 61 feather samples from nestling bald eagles at 42 nests and adult feather samples from 20 nests in north and central Florida during 1991-93. We obtained 32 liver, 10 feather, and 5 blood samples from 33 eagle carcasses recovered in Florida during 1987-93. For nestlings, mercury concentrations in blood (GM = 0.16 ppm wet wt) and feather (GM = 3.23 ppm) samples were correlated (r = 0.69, P = 0.0001). Although nestlings had lower mercury concentrations in feathers than did adults (GM = 6.03 ppm), the feather mercury levels in nestlings and adults from the same nest were correlated (r = 0.63, P < 0.02). Mercury concentrations in blood of captive adult eagles (GM = 0.23 ppm) was similar to Florida nestlings but some Florida nestlings had blood mercury concentrations up to 0.61 ppm, more than twice as high as captive adults. Feather mercury concentrations in both nestlings and adults exceeded those in captive eagles, but concentrations in all tissues were similar to, or lower than, those in bald eagles from other wild populations. Although mercury concentrations in Florida eagles are below those that cause mortality, they are in the range of concentrations that can cause behavioral changes or reduce reproduction. We recommend periodic monitoring of mercury in Florida bald eagles for early detection of mercury increases before negative effects on reproduction occur. 26 refs., 5 figs., 2 tabs.

Wood, P.B.; Wood, J.M. [Wes Virginia Univ., Morgantown, WV (United States); White, J.H. [Florida Game and Fresh Water Fish Commission, Eustis, FL (United States)] [and others

1996-01-01

8

Mercury baseline levels in Flemish soils (Belgium)  

Microsoft Academic Search

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

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

2005-01-01

9

Mercury speciation analysis in terrestrial animal tissues.  

PubMed

No previous analytical procedures are available and validated for mercury speciation analysis in terrestrial animal tissues. This analysis is a difficult task both because the expected concentrations are low, since important accumulation process are not likely to occur, and also because there are not commercially available certified reference material. Thus, an analytical methodology has been developed and validated for mercury speciation for the specific case of terrestrial animal tissues. The proposed method is based on the quantitative extraction of the species by closed-vessel microwave assisted heating with an alkaline reagent, followed by ethylation. The ethylated derivatives were then submitted to head-space solid phase microextraction with a 100 ?m polidimethylsiloxane-coated fiber, and desorbed onto a gas chromatograph coupled to atomic fluorescence detection via pyrolysis unit (HS-SPME-GC-pyro-AFS). Procedural detection limits were 31.8 ng g(-1) and 52.5 ng g(-1) for CH(3)Hg(+) and Hg(2+), respectively, for liver and 35.3 ng g(-1) and 58.1 ng g(-1) for CH(3)Hg(+) and Hg(2+), respectively, for kidney. These limits of detection are 5.5 and 6 times better than the obtained without solid phase microextraction for CH(3)Hg(+) and Hg(2+), respectively. The methodology was found linear up to 120 ?g L(-1) and reproducible from one day to the following. It was validated with certified reference materials NCS ZC 71001 (beef liver) and BCR No 186 (pig kidney) for total mercury, calculated as the sum of species, and with spiked red deer liver and kidney for speciation. Finally, it was applied to the analysis of samples of red deer liver, red deer kidney and wild boar kidney coming from the Almadén's mercury mining area (Ciudad Real, Spain), the longest and largest producer of mercury in the world until its closure in 2002. PMID:22967634

Berzas Nevado, J J; Rodríguez Martín-Doimeadios, R C; Guzmán Bernardo, F J; Rodríguez Farińas, N; Patińo Ropero, M J

2012-07-24

10

Induction by mercury compounds of metallothioneins in mouse tissues: inorganic mercury accumulation is not a dominant factor for metallothionein induction in the liver.  

PubMed

Among the naturally occurring three mercury species, metallic mercury (Hg(0)), inorganic mercury (Hg(II)) and methylmercury (MeHg), Hg(II) is well documented to induce metallothionein (MT) in tissues of injected animals. Although Hg(0) and MeHg are considered to be inert in terms of directly inducing MT, MT can be induced by them after in vivo conversion to Hg(II) in an animal body. In the present study we examined accumulations of inorganic mercury and MT inductions in mouse tissues (brain, liver and kidney) up to 72 hr after treatment by one of three mercury compounds of sub-lethal doses. Exposure to mercury compounds caused significant mercury accumulations in mouse tissues examined, except for the Hg(II)-treated mouse brain. Although MeHg caused the highest total mercury accumulation in all tissues among mercury compounds, the rates of inorganic mercury were less than 10% through the experimental period. MT inductions that depended on the inorganic mercury accumulation were observed in kidney and brain. However, MT induction in the liver could not be accounted for by the inorganic mercury accumulation, but by plasma IL6 levels, marked elevation of which was observed in Hg(II) or MeHg-treated mouse. The present study demonstrated that MT was induced in mouse tissues after each of three mercury compounds, Hg(0), Hg(II) and MeHg, but the induction processes were different among tissues. The induction would occur directly through accumulation of inorganic mercury in brain and kidney, whereas the hepatic MT might be induced secondarily through mercury-induced elevation in the plasma cytokines, rather than through mercury accumulation in the tissue. PMID:21628964

Yasutake, Akira; Nakamura, Masaaki

2011-06-01

11

Effect of lead on tissue deposition of mercury in mice  

SciTech Connect

Lead and mercury are two common toxic industrial pollutants found in our living environment. The inorganic forms of these heavy metals enter food chains and end up in our food and drinks. However, little is known about the interaction of lead with mercurial compounds in animal tissue. Therefore, the authors examined the deposition of inorganic mercury in mice when lead and the inorganic mercury were both orally co-administered or administered separately.

Sin, Y.M.; Wong, M.K.; Low, L.K.

1985-03-01

12

A small dose of ethanol increases the exhalation of mercury in low-level-exposed humans.  

PubMed

Inorganic mercury is mainly eliminated by urinary and fecal excretion, but it is also eliminated by exhalation and sweat. There are only a few reports on exhalation of mercury in humans. In volunteers with short-term mercury exposure, an increased exhalation of mercury was found after alcohol intake. The aim of this study was to determine mercury in end-exhaled air and the influence of ethanol on mercury exhalation in subjects with long-term mercury exposure from diet, amalgam fillings, or the work environment. Fourteen subjects, with different grades of mercury exposure, were given 0.2 g ethanol/kg body weight. Measurements of mercury in end-exhaled air were performed before and after alcohol intake. Mercury in end-exhaled air could be detected in all subjects. In 10 individuals without amalgam fillings the mercury concentration was 3 to 12 pg/L. A marked increase, in general about fivefold, in mercury concentrations in end-exhaled air was seen in all subjects 30 min after intake of alcohol, regardless of the level of mercury exposure. Higher ethanol doses resulted in higher mercury levels in end-exhaled air and longer time periods before a return to background levels. An increase was seen even after an ethanol dose of only 0.1 g ethanol/kg body weight (about 0.08 L wine). The decrease in exhaled mercury at higher alcohol doses followed approximately zero-order kinetics and probably reflects the elimination of ethanol in tissues. In conclusion, low levels of mercury can be detected in end-exhaled air also in individuals without amalgam fillings. About a fivefold increase was seen 30 min after alcohol intake, and the relative increase seemed to be independent of the body burden of mercury. Exhalation of mercury represents only a small percentage of the total elimination of mercury. PMID:10872631

Sällsten, G; Kreku, S; Unosson, H

2000-05-26

13

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

PubMed

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

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

2010-09-19

14

Mercury and Selenium in Fish from the Savannah River: Species, Trophic Level, and Locational Differences  

Microsoft Academic Search

Levels of contaminants in fish are of considerable interest because of potential effects on the fish themselves, as well as on other organisms that consume them. In this article we compare the mercury levels in muscle tissue of 11 fish species from the Savannah River, as well as selenium levels because of its known protective effect against mercury toxicity. We

Joanna Burger; Karen F. Gaines; C. Shane Boring; Warren L. Stephens; Joel Snodgrass; Michael Gochfeld

2001-01-01

15

Mercury pollution and macrophage centres in pike ( Esox lucius ) tissues  

Microsoft Academic Search

From June 1993 to October 1994, studies have been carried out on the effects of mercury in the Oder River and pike tissue\\u000a contamination (muscle, kidney, liver). The mean mercury contents in the sediment range from 0.03 to 1.1 mg\\/kg dry weight.\\u000a In the pike muscle, between 0.22 and 0.85 mg\\/kg, on a wet weight basis, were found. The measured

Thomas Meinelt; Ralf Kriiger; Michael Pietrock; Reiner Osten; Christian Steinberg

1997-01-01

16

Mercury and selenium in fish from the Savannah river: species, trophic level, and locational differences.  

PubMed

Levels of contaminants in fish are of considerable interest because of potential effects on the fish themselves, as well as on other organisms that consume them. In this article we compare the mercury levels in muscle tissue of 11 fish species from the Savannah River, as well as selenium levels because of its known protective effect against mercury toxicity. We sampled fish from three stretches of the river: upstream, along, and downstream the Department of Energy's Savannah River Site, a former nuclear material production facility. We test the null hypothesis that there were no differences in mercury and selenium levels in fish tissue as a function of species, trophic level, and location along the river. There were significant interspecific differences in mercury levels, with bowfin (Amia calva) having the highest levels, followed by largemouth bass (Micropterus salmoides) and pickerel (Esox niger). Sunfish (Lepomis spp.) had the lowest levels of mercury. As expected, these differences generally reflected trophic levels. There were few significant locational differences in mercury levels, and existing differences were not great, presumably reflecting local movements of fish between the sites examined. Selenium and mercury concentrations were positively correlated only for bass, perch (Perca flavescens), and red-breasted sunfish (Lepomis auritus). Mercury levels were positively correlated with body mass of the fish for all species except American eel (Anguilla rostrata) and bluegill sunfish (L. macrochirus). The mercury and selenium levels in fish tissue from the Savannah River are similar to or lower than those reported in many other studies, and in most cases pose little risk to the fish themselves or to other aquatic consumers, although levels in bowfin and bass are sufficiently high to pose a potential threat to high-level consumers. PMID:11683594

Burger, J; Gaines, K F; Boring, C S; Stephens, W L; Snodgrass, J; Gochfeld, M

2001-10-01

17

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

PubMed

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

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

2011-08-29

18

Mercury levels in freshwater fish of the state of South Carolina.  

PubMed

Samples of fish from freshwater sources of rivers, lakes and ponds all over the state of South Carolina were collected during the Summer of 1974 and 1975. The fish collected were Bass, Bluegill, Redbreast, Catfish, Shad, Carp, Crappie, Mudfish and Pike. Samples were analyzed using the flameless atomic absorption procedure outlined by Hatch and Ott, and Uthe et al as modified for use with Perkin-Elmer, Coleman MAS-50 mercury analyzer. Triplicate samples of fish tissue were analyzed by wet digestion method. The mean mercury levels in ppb were determined for baseline mercury levels. A significant finding of this report is that those species for which fish of widely differing weights were analyzed, larger fish had higher mercury levels. Mercury levels exceeding the U.S. Food and Drug Administration guideline of 500 ppb for fish tissues have been found in the Mudfish from Edisto River and Pike fish from Lake Murray. Higher levels of mercury occurred in the highly vascularized blood tissues of liver and kidney than in muscle. Carnivorous and bottom-feeding fishes are the most reliable indicators of mercury pollution. PMID:836979

Koli, A K; Williams, W R; McClary, E B; Wright, E L; Burrell, T M

1977-01-01

19

Release of mercury from dental amalgam fillings in pregnant rats and distribution of mercury in maternal and fetal tissues  

Microsoft Academic Search

Mercury vapor released from a single amalgam restoration in pregnant rats and mercury concentrations in maternal and fetal rat tissues were studied. Dental treatment was given on day 2 of pregnancy. Mercury concentration in air sample drawn from the metabolism chamber with the rat was measured serially for 24 h on days 2, 8 and 15 of pregnancy. An average

Yoshifumi Takahashi; Shozo Tsuruta; Jiro Hasegawa; Yoichiro Kameyama; Minoru Yoshida

2001-01-01

20

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

PubMed

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

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

2011-06-29

21

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

SciTech Connect

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.

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

1988-01-01

22

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

PubMed

We used deer mice (Peromyscus maniculatus) to investigate variation in mercury exposure across the terrestrial ecosystem of Isle Royale National Park (Michigan, USA). Although previous work suggested that mercury (Hg) levels may be higher inside the Sargent Lake watershed of Isle Royale than outside the watershed, Hg concentrations in livers were higher outside the Sargent Lake watershed (100.13 ng Hg/g dry tissue) than inside the watershed (35.50 ng Hg/g dry tissue; P = 0.06). Mercury levels in kidneys did not differ significantly (P = 0.57) between samples collected outside (443.23 ng Hg/g dry tissue) and inside (360.62 ng Hg/g dry tissue) the Sargent Lake watershed. Mean Hg concentrations in the livers of mice at some sites in Isle Royale are not significantly lower (P = 0.62) than Hg concentrations considered by some government agencies to be unhealthy for human consumption. Although Hg concentrations in mouse tissues were not remarkably high (compared to heavily polluted sites), concern is warranted because: (1) Isle Royale National park is a protected area in a remote location; (2) any exposure in deer mice represents a path for biomagnification in the terrestrial food web; and (3) the source of this mercury remains unidentified. PMID:11443999

Vucetich, L M; Vucetich, J A; Cleckner, L B; Gorski, P R; Peterson, R O

2001-01-01

23

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

SciTech Connect

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.

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

24

Cinnabar is different from mercuric chloride in mercury absorption and influence on the brain serotonin level.  

PubMed

The toxicity of cinnabar, a naturally occurring mercury sulphide (HgS), has long been referred to soluble mercury chloride (HgCl2 ). To investigate whether the speciation of mercury plays a role in its disposition and toxicity, we hereby investigated and compared cinnabar with soluble HgCl2 and pure insoluble HgS in mice on mercury absorption, tissue distribution and in relation to the biological effects. The male C57BL/6J mice were treated by oral administration of various doses of cinnabar, with 0.01 g/kg of HgCl2 for comparison, or the same dose of cinnabar or pure HgS (0.1 g/kg), once a day for 10 consecutive days. The total mercury contents in serum and tissue (brain, kidney, liver) were measured by atomic fluorescence spectrometer (AFS). The biological effects investigated involved monoamine neurotransmitters (serotonin, 5-HT) in brain as an indicator of therapeutic function, and serum alanine transaminase (ALT) as a marker of hepatic damage, blood urea nitrogen (BUN) and serum creatinine as markers for renal function. The mercury absorption of cinnabar or HgS was much less than that of HgCl2 . The mercury levels in brains of the cinnabar group were only slightly changed and kept in a steady-state with the dose elevated. Cinnabar or HgS suppressed brain 5-HT levels. HgCl2 could not cause any changes in brain 5-HT although the mercury level increased considerably. The results revealed that cinnabar or HgS is markedly different from HgCl2 in mercury absorption, tissue distribution and influence on brain 5-HT levels, which suggests that the pharmacological and/or toxicological effects of cinnabar undertake other pathways from mercuric ions. PMID:23302034

Wang, Qi; Yang, Xiaoda; Zhang, Baoxu; Yang, Xiuwei; Wang, Kui

2013-02-07

25

Mercury exposure in French Guiana: Levels and determinants  

SciTech Connect

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.

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

26

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

PubMed Central

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.

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

27

Factors affecting the accumulation and removal of mercury from tissues of the American oyster Crassostrea virginica  

Microsoft Academic Search

Adult oysters, Crassostrea virginica (Gmelin) were held in seawater containing 10 or 100 ppb mercury in the form of mercuric acetate for 45 days. Mercury concentration in tissues was determined by analysis of individually homogenized oyster meats using wet digestion and flameless absorption spectrophotometry. After 45 days, average mercury tissue concentration was 91,600 and 12,100 ppb in the 100 and

P. A. Cunningham; M. R. Tripp

1975-01-01

28

Total mercury and methylmercury levels in commercially important fishes in Japan  

Microsoft Academic Search

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

Yumiko Yamashita; Yuji Omura; Emiko Okazaki

2005-01-01

29

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

PubMed

Mucosal biopsies from 48 patients with and 9 without amalgam tattoos were analysed with respect to their mercury content, distribution of mercury in the tissue, and histological tissue reactions. The distribution of mercury was assessed by autometallography (AMG), a silver amplification technique. The mercury content was determined by energy dispersive X-ray fluorescence (EDXRF), a multielemental analysis. Mercury was observed in connective tissue where it was confined to fibroblasts and macrophages, in vessel walls and in structures with the histological character of nerve fibres. A correlation was found between the histopathological tissue reaction, the type of mercury deposition, the intensity of the AMG reaction, and the mercury content. Mercury was also found in patients with amalgam dental fillings but without amalgam tattoos. PMID:9527359

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

1998-02-01

30

Mercury levels in high-end consumers of fish.  

PubMed Central

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.

Hightower, Jane M; Moore, Dan

2003-01-01

31

Mercury levels in high-end consumers of fish.  

PubMed

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

Hightower, Jane M; Moore, Dan

2003-04-01

32

Mercury Bioconcentration Factors in American Alligators ( Alligator mississippiensis) in the Florida Everglades  

Microsoft Academic Search

Alligators inhabiting the Florida Everglades contain elevated levels of mercury within their tissues due to accumulation of mercury in the sediments. The objective of this study was to determine the mercury bioconcentration factors (BCFs) in the alligators based on mercury concentrations in the alligator tissues and mercury levels in the water column. Data from studies on mercury concentrations in the

Bernine Khan; Berrin Tansel

2000-01-01

33

Trace-level mercury removal from surface water  

SciTech Connect

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.

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

1998-06-01

34

Mercury pollution in the Tapajos River basin, Amazon: mercury level of head hair and health effects.  

PubMed

There is increasing concern about the potential neurotoxic effects of exposure to methylmercury for the 6 million people living in the Amazon, even in regions situated far away from the gold mines (garimpos), considered to be the major source of mercury pollution. In November 1998, a spot investigation on mercury contamination was conducted in three fishing villages (Barreiras, Rainha, and Sao Luiz do Tapajos) on the Tapajos River, an effluent of the Amazon, situated several hundred kilometers downstream from the gold-mining areas. A total of 132 fishermen and their families volunteered for the current study. As was anticipated, the total mercury levels in the head hair collected from the fishing villages were relatively high (14.1-20.8 ppm on the average) and the number of subjects with a high total mercury level over 10 ppm (the least upper bound of a normal value) was 103 (78.0%) in total, along with various symptoms, thereby suggesting wide mercury contamination in the Tapajos River basin. Moreover, in view of the absence of other diseases (e.g., alcoholism or malaria), a high intake of fish containing a methylmercury level, and high hair mercury levels in addition to the various symptoms such as sensory disturbance (especially glove-and-stocking type, which is characteristic of Minamata disease), tremor, failure in two-point discrimination, and slight balancing failure, several subjects examined were diagnosed with mild Minamata disease. The findings obtained suggest, thus, that the mercury pollution in the Amazon should be crucially observed for head hair mercury level and health in a much broader region. PMID:11686639

Harada, M; Nakanishi, J; Yasoda, E; Pinheiro, M C; Oikawa, T; de Assis Guimarâes, G; da Silva Cardoso, B; Kizaki, T; Ohno, H

2001-10-01

35

Hair Mercury Levels of Residents in China, Indonesia, and Japan  

Microsoft Academic Search

The authors used gold-amalgamation cold-vapor atomic absorption spectrometry and ECD-gas chromatography to analyze total mercury and methylmercury levels in hair samples obtained from 362 residents in Harbin, China; Medan, Indonesia; and Tokushima, Japan. In this study, the authors initially questioned whether mercury levels in hair differed among different study areas, and if there were differences, they questioned the contributing factors.

Qiuyang Feng; Yasuo Suzuki; Akinori Hisashige

1998-01-01

36

Mercury  

SciTech Connect

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.

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

1988-01-01

37

Studies of Mercury in High Level Waste Systems  

SciTech Connect

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.

Wilmarth, W.R.

2003-09-03

38

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

PubMed

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

Harmata, Alan R; Restani, Marco

2013-01-01

39

Mercury Exposure May Suppress Baseline Corticosterone Levels in Juvenile Birds.  

USGS Publications Warehouse

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.

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

2012-01-01

40

Increased blood mercury levels in patients with Alzheimer's disease  

Microsoft Academic Search

Summary.   Alzheimer's disease (AD) is a common neurodegenerative disorder that leads to dementia and death. In addition to several\\u000a genetic parameters, various environmental factors may influence the risk of getting AD. In order to test whether blood levels\\u000a of the heavy metal mercury are increased in AD, we measured blood mercury concentrations in AD patients (n = 33), and compared

C. Hock; G. Drasch; S. Golombowski; F. Müller-Spahn; B. Willershausen-Zönnchen; P. Schwarz; U. Hock; J. H. Growdon; R. M. Nitsch

1998-01-01

41

Determination of Total Mercury in Fish Tissues using Combustion Atomic Absorption Spectrometry with Gold Amalgamation  

Microsoft Academic Search

A simple and rapid procedure for measuring total mercury in fishtissues is evaluated and compared with conventional techniques.Using an automated instrument incorporating combustion, preconcentration by amalgamation with gold, and atomic absorptionspectrometry (AAS), milligram quantities of wet fish tissue wereanalyzed directly for mercury (i.e., without acid digestion). Seven tissue types (skeletal muscle, liver, blood, gonad, brain, gill, and heart) from five

James V. Cizdziel; Thomas A. Hinners; Edward M. Heithmar

2002-01-01

42

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...

43

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...

44

Mercury levels and liver pathology in feral fish living in the vicinity of a mercury cell chlor-alkali factory  

Microsoft Academic Search

Twenty-three barbels (Barbus graellsii), 30 bleaks (Alburnus alburnus) and 4 sediment samples were collected from four areas of the Cinca River (NE Spain), upstream and downstream of a mercury cell chlor-alkali plant. Mercury concentration in sediments downstream of the plant was about 25 times higher than the concentration upstream. Mercury levels in the muscle and liver of barbels downstream of

Demetrio Raldúa; Sergi Díez; Josep M. Bayona; Damiŕ Barceló

2007-01-01

45

Mercury  

MedlinePLUS

... of the lungs Medication to remove mercury and heavy metals from the body INORGANIC MERCURY For inorganic mercury ... McGraw Hill; 2008:chap 365. Baum CR. Mercury: Heavy metals and inorganic agents. In: Shannon MW, Borron SW, ...

46

Mercury  

Microsoft Academic Search

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

Thomes W. Clarkson

1989-01-01

47

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

Microsoft Academic Search

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

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

1980-01-01

48

Size and biomagnification: How Habitat selection explains beluga mercury levels.  

PubMed

Mercury (Hg) levels in the Beaufort Sea beluga (Delphinapterus leucas) population increased during the 1990s; levels have since declined but remain higher than the 1980s. The diet of this beluga population is not well-known, thus it is difficult to assess dietary Hg sources. During the summer, the Beaufort Sea belugas segregate by length, sex, and reproductive status corresponding to habitat use that may result in feeding differences and ultimately Hg uptake. To test this hypothesis, we examine beluga dietary variation using fatty acid profiles and determine which biological variables best predict diet Relationships between biological variables and fatty acids were further evaluated with stable isotopes and Hg concentrations in liver and muscle. Hg concentrations in muscle were better related to liver delta15N than muscle delta15N. Stable isotopes and fatty acids are compared in their ability to describe dietary Hg processes in beluga. Fatty acids provided support for influences of whale behavior on dietary Hg uptake, whereas stable isotopes inferred tissue Hg metabolic rates. Here, we show beluga length drives diet variability leading to differences in Hg uptake and biomagnification processes dominate beluga Hg levels over Hg bioaccumulation over time. PMID:18589955

Loseto, L L; Stern, G A; Ferguson, S H

2008-06-01

49

Distribution of mercury in rainbow trout tissues at embryo-larval and juvenile stages.  

PubMed

The aims of the study were to determine total mercury concentrations in "rainbow trout Oncorhynchus mykiss (Walbaum)" at their embryo-larval and juvenile stages and to assess mercury concentration dynamics in individual tissues. Samples of rainbow trout were collected at two-month intervals over a period of 18 months (one stock production cycle) at the Velká Losenice trout farm. Feedstuff samples were collected at the same time and analyzed for mercury concentrations. Tissue mercury concentrations were determined in muscle, liver, and kidneys. Analyses were performed using the AMA 254 atomic absorption spectrophotometer. The lowest mercury concentration was found in 14-day-old embryos (hard roe), and the highest concentrations in muscle tissue, liver, and kidneys at the end of monitoring, that is, in rainbow trout aged 18 months. The amount of mercury in feedstuffs showed an increasing trend and ranged between 0.0126 and 0.0859 mg kg(-1). A significant effect (P < 0.001) of mercury intake on mercury concentrations in muscle tissue, liver, and kidneys was demonstrated. Muscle mercury concentrations in 18-month-old market-ready rainbow trout of 0.128 ± 0.048 mg kg(-1) met the criteria for fish meat hygiene. PMID:22645443

Kenšová, Renáta; Kružíková, Kamila; Havránek, Jan; Haruštiaková, Danka; Svobodová, Zde?ka

2012-05-02

50

Mercury vapour levels in dental practices and body mercury levels of dentists and controls  

Microsoft Academic Search

Aim A study of 180 dentists in the West of Scotland was conducted to determine their exposure to mercury during the course of their work and the effects on their health and cognitive function.Design Data were obtained from questionnaires distributed to dentists and by visiting their surgeries to take measurements of environmental mercury.Methods Dentists were asked to complete a questionnaire

K A Ritchie; W H Gilmour; E B Macdonald; I M Dale; R M Hamilton; D A McGowan; V Binnie; D Collington; R Hammersley; F J T Burke

2004-01-01

51

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

PubMed

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

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

2012-02-10

52

TOTAL MERCURY BIOACCUMULATION IN TISSUES OF CARNIVOROUS FISH (Micropogonias furnieri and Cynoscion acoupa) AND OYSTERS (Crassostrea brasiliana) FROM SEPETIBA BAY, BRAZIL  

Microsoft Academic Search

Total mercury (Hg) levels were determined by cold vapor atomic absorption spectrophotometry (CVAAS) in tissues of two species of carnivorous fishes and in soft tissue of oysters caught in Sepetiba Bay, Brazil. Hg was distributed unevenly in the organs and tissues of the fish; the mean Hg content was highest in the kidneys (0.048 ?g\\/g wet weight) and lowest in

Carla da Silva Carneiro; Eliane Teixeira Mársico; Roberta de Oliveira Resende Ribeiro; Edgar Francisco Oliveira de Jesus

2012-01-01

53

The association between amalgam dental surfaces and urinary mercury levels in a sample of Albertans, a prevalence study  

PubMed Central

Objective The objective of this study was to quantify the relationship between number of dental amalgam surfaces and urinary mercury levels. Methods This study uses participant data from a large philanthropic chronic disease prevention program in Calgary, Alberta, Canada. Urine samples were analysed for mercury levels (measured in ?g/g-creatinine). T-tests were used to determine if differences in urine mercury were statistically significant between persons with no dental amalgam surfaces and one or more dental amalgam surfaces. Linear regression was used to estimate the change in urinary mercury per amalgam surface. Results Urinary mercury levels were statistically significantly higher in participants with amalgam surfaces, with an average difference of 0.55 ?g/g-creatinine. Per amalgam surface, we estimated an expected increase of 0.04 ?g/g-creatinine. Measured urinary mercury levels were also statistically significantly higher in participants with dental amalgam surfaces following the oral administration of 2,3-dimercaptopropane-l-sulfonate (DMPS) and meso-2,3-dimercaptosuccinic acid (DMSA) which are used to mobilize mercury from the blood and tissues. Discussion Our estimates indicate that an individual with seven or more dental amalgam surfaces has 30% to 50% higher urinary mercury levels than an individual without amalgams. This is consistent with past literature that has identified seven amalgam surfaces as an unsafe level of exposure to mercury vapor. Our analysis suggests that continued use of silver amalgam dental fillings for restorative dentistry is a non-negligible, unnecessary source of mercury exposure considering the availability of composite resin alternatives.

2013-01-01

54

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

PubMed

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

Burger, J; Gochfeld, M

1997-11-01

55

The release, tissue distribution and excretion of mercury from experimental amalgam tattoos.  

PubMed Central

Following the subcutaneous implantation of powdered dental amalgam in guinea pigs, there was an initial extrusion of material from the healing implantation wounds. Longer-term release of mercury from the lesions was demonstrated by linear regression analysis of the mercury contents of implant sites removed after time periods of up to 2 years. Raised mercury levels were detected in the blood, bile, kidneys, liver, spleen and lungs of implanted animals; by far the highest concentrations were found in the renal cortex. Mercury was excreted with the urine and, to a lesser extent, the faeces. The pattern of mercury redistribution resembled that seen following chronic exposure to mercuric compounds.

Cox, S. W.; Eley, B. M.

1986-01-01

56

The association between cadmium, lead and mercury blood levels and reproductive hormones among healthy, premenopausal women  

PubMed Central

BACKGROUND Cadmium, lead and mercury have been identified in human follicular fluid and ovarian tissue, and have been associated with adverse reproductive outcomes in epidemiologic studies; however, few studies have examined the relationship between blood metal levels and reproductive hormones. METHODS Among 252 premenopausal women aged 18–44 years, we examined the association between blood metal levels (cadmium, lead and mercury), cycle length, and reproductive hormones [FSH, LH, estradiol (E2) and progesterone] measured at clinically relevant time points in the menstrual cycle. The association between metal levels (continuous) and hormone levels was assessed using linear regression with hormone levels (natural) log transformed and the results interpreted as the percentage difference in hormone level per unit increase in metal level. RESULTS Median (interquartile range) cadmium, lead and mercury levels were 0.30 µg/l (0.19, 0.43), 0.87 µg/dl (0.68, 1.20) and 1.10 µg/l (0.58, 2.10), respectively. Each 1 µg/l increase in cadmium levels was associated with a 21% [95% confidence interval (CI): ?2.9, 49.9] increase in early follicular phase E2 levels after adjusting for age, race/ethnicity, lead and mercury. This association decreased when restricted to never smokers (10%; 95% CI: ?19.5, 51.3). Cadmium was also associated with a non-significant 9% (95% CI: ?0.2, 19.9), or 2.7 day, increase in cycle length among never smokers. No associations were observed between lead or mercury and the outcomes in adjusted analyses. CONCLUSIONS Further evaluation of the association between cadmium, E2 and cycle length is warranted, taking into consideration cigarette smoke and its multiple components.

Jackson, L.W.; Howards, P.P.; Wactawski-Wende, J.; Schisterman, E.F.

2011-01-01

57

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

Microsoft Academic Search

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

Lars BrinkmannJoseph; Joseph B. Rasmussen

2010-01-01

58

Current hair mercury levels in Japanese: survey in five districts.  

PubMed

To understand the current Japanese hair mercury levels, we planned a survey of hair mercury among the general populations of different regions in Japan. The present paper, as the first report of the survey, summarized the results obtained in five districts, Minamata, Kumamoto, Tottori, Wakayama and Chiba. Hair samples were collected at beauty salons, barbershops and primary schools in each district with questionnaires on age, sex, amount and species of fish usually consumed, hair-dyed and artificial hair waving "permanent wave." The total mercury levels of 3686 hair samples collected were analyzed by an oxygen combustion-gold amalgamation method. The geometric mean of the total mercury concentration was significantly higher in males than in females, i.e., 2.55 microg/g and 1.43 microg/g, respectively. The sex difference was also observed on hair samples without artificial waving, i.e., 2.64 microg/g and 1.64 microg/g, respectively. The geometric mean in each district varied from 2.23 to 4.79 microg/g for males and from 1.23 to 2.50 microg/g for females. The average hair mercury levels were highest in Chiba among the five districts both in males and females. A multiple regression analysis revealed a significant correlation of the mercury level with age, sex, amount of daily fish consumption, tuna and bonito as usually consumed fish, artificial waving and Chiba as a residential area. In the laboratory experiment, we found that the treatment of hair samples with a lotion for artificial waving caused a 30%-reduction in the mercury content. Furthermore, longitudinal hair analysis showed a marked difference in the concentration between the hair root and the tip of the hair taken from artificially waved females; higher values were observed at the hair root. These results suggested that artificial waving significantly removes hair mercury and that hair analysis at the hair root should be necessary to estimate an accurate methylmercury exposure for waved persons. PMID:12703660

Yasutake, Akira; Matsumoto, Miyuki; Yamaguchi, Masako; Hachiya, Noriyuki

2003-03-01

59

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

PubMed Central

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

Goodrich, Jaclyn M.; Wang, Yi; Gillespie, Brenda; Werner, Robert; Franzblau, Alfred; Basu, Niladri

2012-01-01

60

Mercury accumulation profiles and their modification by interaction with cadmium and lead in the soft tissues of the Cichlid Oreochromis aureus during chronic exposure  

SciTech Connect

Mercury, cadmium and lead have no well known biological functions in the animal body and are described as ultratrace elements. Their toxicity is due in part to competition with essential metals for binding sites and interference with sulfhydryl groups, essential for the normal functioning of enzymes and structural proteins. Cadmium blocks sulfhydryl groups in enzymes and competes for sites with zinc and calcium. To a lesser extent, lead may replace calcium in structures and react with sulfhydryl groups, while mercury has a high affinity for sulfhydryl groups and is lipid soluble in its methylated form. The chloroalkali industry is a major source of mercury pollution. When fish take up mercury, whether organic or inorganic, most of it accumulates in tissues in the organic form. Minamata disease in humans was first reported in 1956. The form of mercury responsible was found to be methylmercury, which being lipid soluble is much more toxic than inorganic mercury. It is important to monitor and assess the mercury content of fish which are caught, or farmed, for human consumption. Since many commercial animal feeds contain a fishmeal component, there is a risk of contamination of farm animals intended for human consumption. Since Oreochromis aureus (Steindachner) is cultured in North and Latin America, and other regions, it is a suitable model to use for studying the distribution of mercury in different tissues of food fish. Tilapias have been used effectively an constituents of pig food either directly or through fish silage or fishmeal. Laboratory studies of heavy metal pollution often overlook the effects of exposure to more than one heavy metal at the same time and often heavy metals occur in combination. In Jakarta Bay, high levels of cadmium were found together with mercury. The present study Investigates the effects of exposure to combinations of mercury with cadmium or lead on tissue accumulation of mercury. 19 refs., 3 tabs.

Allen, P.

1994-11-01

61

Mercury levels in pristine and gold mining impacted aquatic ecosystems of Suriname, South America.  

PubMed

Mercury levels in sediment and predatory fish were measured for 53 localities in Suriname. The average mercury level in bottom sediment surpassed the Canadian standard for sediment in most localities, except the coastal plains. Of the predatory fish, 41 % had a mercury level above the European Union standard for human consumption of 0.5 ?g g(-1). Highest mercury levels were found in fish from the Brokopondo Reservoir and from the Upper Coppename River. High levels of mercury in fish in pristine areas are explained by atmospheric transportation of mercury with the northeastern trade winds followed by wet deposition. Contrary to gold mining areas, where mercury is bound to drifting sediments, in "pristine" areas the mercury is freely available for bio-accumulation and uptake. Impacts on piscivorous reptiles, birds, and mammals are unknown, but likely to be negative. PMID:22669686

Ouboter, Paul E; Landburg, Gwendolyn A; Quik, Jan H M; Mol, Jan H A; van der Lugt, Frank

2012-06-06

62

Mercury and selenium content and chemical form in human and animal tissue.  

PubMed

The content, chemical form, and distribution of mercury and selenium were determined for selected samples of human and animal tissue by gas chromatography. Methylmercury averaged 38.7% of the total mercury content in homogenized human brain. For human heart, spleen, liver, kidney and placenta, methylmercury comprised 40.2%, 57.0%, 39.6%, 6.0% and 57.1% respectively, of the total mercury content. Similar results were obtained for the heart and liver of a whitetail deer. Methylmercury represented 9.1%, 62.9% and 24.1% of the total mercury content in seal liver, seal meat and deer meat, respectively. For all samples, a significant portion of the total selenium content, averaging 27%, was present as selenate (Se VI). Tissue selenium content did not correlate with the corresponding mercury content. In brain, heart and placenta, and in seal liver and meat, 53% to 80% of the total mercury content was water-extractable. For human kidney, liver and spleen, and deer meat, only 15% to 45% of the total mercury was extractable. On a percentage basis, inorganic mercury was more extractable than methylmercury, except for human kidney and liver, and deer meat. For all samples, except kidney, liver and deer meat, 55% to 76% of the total selenium content was water-extractable, Se VI being more extractable on a percentage basis than selenite (Se IV) and selenide (Se-II). PMID:7242026

Cappon, C J; Smith, J C

63

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

SciTech Connect

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.

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

1990-11-01

64

Factors influencing total mercury levels among Lebanese dentists.  

PubMed

The aim of the current study is to examine the various factors, which contribute to high levels of mercury (Hg) in the hair of Lebanese dentists. The survey, which was carried out on ninety-nine dentists in the greater Beirut area, included a structured questionnaire designed to provide information about the parameters that influenced their occupational exposure to Hg. These included: precautionary measures, dental fillings, work habits and lifestyle of the tested dentists. The study showed that two of the four investigated precautionary measures had a significant effect on Hg level. The results revealed that, at the 95% confidence levels, Hg concentration in hair was significantly lower among the dentists who always used gloves and masks. Multiple regression analysis showed that the use of masks (P = 0.055) had significant effects on mercury accumulation in hair. In addition, dentists who saw more than eight patients per day had marginally higher mercury levels in their hair than those who did not. Since it was shown that precautionary measures could limit exposure to Hg concentration, then the use of protective measures needs to be emphasized. PMID:12389787

Harakeh, Steve; Sabra, Nada; Kassak, Kassem; Doughan, Bassel

2002-10-01

65

Hair mercury levels versus freshwater fish consumption in household members of Swedish angling societies  

Microsoft Academic Search

Hair mercury levels were determined in 143 individuals from households of members in angling societies in an area of Sweden with many lakes that have freshwater fish with relatively high mercury levels. Thus, the individuals had a potentially high intake of methyl mercury. The mean mercury concentration of pike and perch was approximately 0.7mg\\/g. One-third of the subjects consumed these

Cecilia Johnsson; Gerd Sallsten; Andrejs Schutz; Anna Sjors; Lars Barregarda

66

Hair mercury levels versus freshwater fish consumption in household members of Swedish angling societies  

Microsoft Academic Search

Hair mercury levels were determined in 143 individuals from households of members in angling societies in an area of Sweden with many lakes that have freshwater fish with relatively high mercury levels. Thus, the individuals had a potentially high intake of methyl mercury. The mean mercury concentration of pike and perch was approximately 0.7?g\\/g. One-third of the subjects consumed these

Cecilia Johnsson; Gerd Sällsten; Andrejs Schütz; Anna Sjörs; Lars Barregĺrd

2004-01-01

67

Effect of sublethal dose of mercury toxicity on liver cells and tissue of yellowfin seabream.  

PubMed

The aim of the present study was to provide baseline data on the prevalence of histopathological liver lesions in Acanthopagrus latus under experimental mercury exposure. Experimental study was at seawater recirculatory tanks. Mercury concentrations were determined using a standard cold vapour atomic absorption. Histopathological analyses were done in tissue processor and the slides were stained with haematoxylin and counterstained with eosin. There were many liver lesions including enlarged and lateral nuclei, nuclear degeneration and vacuolation; oncotic, apoptic, focal, massive, centrilobular and periportal necrosis; atrophy, lipidosis, hydropic and cloudy swelling, oval cell proliferation; bile stagnation, dilation of sinusoid, intracellular oedema and dark granules in both field and laboratory conditions. In conclusion the present investigation indicated that mercury is a toxic substance in yellowfin seabream and the sublethal concentrations of mercury may cause several changes in the histological indices of the studied fish, and we can use these changes as biomarkers of mercury detection. PMID:21949090

Safahieh, Alireza; Hedayati, Aliakbar; Savari, Ahmad; Movahedinia, Abdolali

2011-09-23

68

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

SciTech Connect

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.

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

1999-08-01

69

Mercury levels in the Cree population of James Bay, Quebec, from 1988 to 1993/94  

PubMed Central

BACKGROUND: High levels of mercury in the Cree population of James Bay, Que., have been a cause of concern for several years. This study examines changes in mercury levels within the Cree population between 1988 and 1993/94 and identifies potential determinants of high mercury levels. METHODS: Data on mercury levels among the Cree were obtained through a surveillance program undertaken by the Cree Board of Health and Social Services of James Bay. In 1988 and again in 1993/94 surveys were carried out in all 9 Cree communities of northern Quebec. Hair samples were obtained and analysed for mercury content. Analyses were carried out to determine the proportion of people who had mercury levels in excess of established norms. Changes in mercury levels between 1988 and 1993/94 and determinants of high levels were estimated by means of regression methods. RESULTS: The proportion of the Cree population with mercury levels in excess of 15.0 mg/kg declined from 14.2% in 1988 to 2.7% in 1993/94. Wide variations in mercury levels were observed between communities: 0.6% and 8.3% of the Eastmain and Whapmagoostui communities respectively had mercury levels of 15.0 mg/kg or greater in 1993/94. Logistic regression analyses showed that significantly higher levels of mercury were independently associated with male sex, increasing age and trapper status. There was a correlation between the mercury level of the head of the household and that of the spouse. INTERPRETATION: Mercury levels in the Cree of James Bay have decreased in the recent past. Nevertheless, this decrease in mercury levels may not be permanent and does not necessarily imply that the issue is definitively resolved.

Dumont, C; Girard, M; Bellavance, F; Noel, F

1998-01-01

70

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...

71

Mercury  

MedlinePLUS

... Releases and Spills Fish Consumption Advisories Consumer Products Mercury News December 2012. EPA Finalizes Clean Air Standards ... if one is requested. Learn more Ban on Mercury Exports will begin January 1, 2013 By federal ...

72

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.

73

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

SciTech Connect

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.

Allen, P.

1994-11-01

74

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

Microsoft Academic Search

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

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

75

[Effect of dietary intoxication by mercury salts on cysteine proteinase activity in rat tissues].  

PubMed

The experiments on dietary intoxication of rats by HgI2 or Hg(NO3)2 show that the activities of lysosomal proteinase cathepsin B and cytosolic Ca(2+)-activated proteinases (calpains I and II) in the liver and kidney depend on the mercury salt solubility and the exposure duration. Mercury iodide and nitrate contribute more to inhibiting cathepsin B and calpains activities in the above tissues, respectively. PMID:12647538

Bondareva, L A; Nemova, N N; Kia?viaria?nen, E I; Krupnova, M Iu; Ostashkova, V V

76

Glutathione level after long-term occupational elemental mercury exposure  

SciTech Connect

Many in vitro and in vivo studies have elucidated the interaction of inorganic mercury (Hg) and glutathione. However, human studies are limited. In this study, we investigated the potential effects of remote long-term intermittent occupational elemental Hg vapour (Hg{sup o}) exposure on erythrocyte glutathione levels and some antioxidative enzyme activities in ex-mercury miners in the period after exposure. The study included 49 ex-mercury miners divided into subgroups of 28 still active, Hg{sup o}-not-exposed miners and 21 elderly retired miners, and 41 controls, age-matched to the miners subgroup. The control workers were taken from 'mercury-free works'. Reduced glutathione (GSH) and oxidized disulphide glutathione (GSSG) concentrations in haemolysed erythrocytes were determined by capillary electrophoresis, while total glutathione (total GSH) and the GSH/GSSG ratio were calculated from the determined values. Catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) activities in erythrocytes were measured using commercially available reagent kits, while urine Hg (U-Hg) concentrations were determined by cold vapour atomic absorption (CVAAS). No correlation of present U-Hg levels, GSH, GSSG, and antioxidative enzymes with remote occupational biological exposure indices were found. The mean CAT activity in miners and retired miners was significantly higher (p<0.05) than in the controls. No differences in mean GPx activity among the three groups were found, whereas the mean GR activity was significantly higher (p<0.05) in miners than in retired miners. The mean concentrations of GSH (mmol/g Hb) in miners (13.03{+-}3.71) were significantly higher (p<0.05) than in the control group (11.68{+-}2.66). No differences in mean total GSH, GSSG levels, and GSH/GSSG ratio between miners and controls were found. A positive correlation between GSSG and present U-Hg excretion (r=0.41, p=0.001) in the whole group of ex-mercury miners was observed. The significantly lower GSH level (p<0.05) determined in the group of retired miners (9.64{+-}1.45) seems to be age-related (r=-0.39, p=0.001). Thus, the moderate but significantly increased GSH level, GR and CAT activity in erythrocytes in the subgroup of miners observed in the period after exposure to Hg{sup o} could be an inductive and additive response to maintain the balance between GSH and antioxidative enzymes in interaction with the Hg body burden accumulated during remote occupational exposure, which does not represent a severely increased oxidative stress.

Kobal, Alfred Bogomir [University Medical Centre Ljubljana, Institute of Clinical Chemistry and Biochemistry, Njegoseva 4, SI-1525 Ljubljana (Slovenia)], E-mail: abkobal@volja.net; Prezelj, Marija [University Medical Centre Ljubljana, Institute of Clinical Chemistry and Biochemistry, Njegoseva 4, SI-1525 Ljubljana (Slovenia); Horvat, Milena [Department of Environmental Sciences, Jozef Stefan Institute, Ljubljana (Slovenia); Krsnik, Mladen [University Medical Centre Ljubljana, Institute of Clinical Chemistry and Biochemistry, Njegoseva 4, SI-1525 Ljubljana (Slovenia); Gibicar, Darija [Department of Environmental Sciences, Jozef Stefan Institute, Ljubljana (Slovenia); Osredkar, Josko [University Medical Centre Ljubljana, Institute of Clinical Chemistry and Biochemistry, Njegoseva 4, SI-1525 Ljubljana (Slovenia)

2008-05-15

77

Mercury  

Microsoft Academic Search

Mercury may provide answers to questions regarding the formation and evolution of our Solar System. This article reviews what\\u000a is known about Mercury from the Mariner 10 flybys of 1974 and 1975 and from thirty years of ground-based telescopic observations\\u000a with ever improving instrumentation. Many new discoveries, such as possible water ice at Mercury’s polar regions, make the\\u000a anticipation of

Robert G. Strom; Ann L. Sprague

78

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

PubMed

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

Brasso, Rebecka L; Polito, Michael J

2013-08-30

79

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...

80

Total Mercury in Muscle Tissue of Five Shark Species from Brazilian Offshore Waters: Effects of Feeding Habit, Sex, and Length  

Microsoft Academic Search

This study was carried out to assess mercury levels in fish from Brazilian offshore waters. Generally sharks have relatively high mercury levels which are also affected by diet, age (associated with length), and sex. Total mercury levels were determined in five shark species with different habits (Carcharhinus signatus, Mustelus canis, Mustelus norrisi, Squalus megalops, and Squalus mitsukurii) which were collected

Alexandra Penedo de Pinho; Jean Remy Davée Guimarăes; Agnaldo S. Martins; P. A. S. Costa; G. Olavo; Jean Valentin

2002-01-01

81

Human hair mercury levels in Tucuruí area, State of Pará, Brazil  

Microsoft Academic Search

The environmental mercury contamination at the Tucuruí water reservoir was studied by measuring the amount of mercury in human hair samples collected from fishermen and their families. Samples were also collected from the Parakană Indian reservation in the vicinity to give information about the background levels in the area. The mercury concentrations in hair samples ranged from 0.9 to 240

Tuija Leino; Martin Lodenius

1995-01-01

82

Hair mercury levels, fish consumption, and cognitive development in preschool children from Granada, Spain  

Microsoft Academic Search

The main source of human exposure to mercury is the consumption of fish contaminated with methylmercury, which may adversely affect early neurodevelopment. This study assessed mercury levels in hair of preschoolers in Spain, where fish consumption is elevated, with the aim of investigating the influence of their fish intake and other factors on mercury exposure, and evaluating their association with

Carmen Freire; Rosa Ramos; Maria-Jose Lopez-Espinosa; Sergi Díez; Jesús Vioque; Ferrán Ballester; Mariana-Fátima Fernández

2010-01-01

83

Total mercury distribution in different tissues of frigate tuna (Auxis thazard thazard) from the Atlantic Coastal Waters of Ghana, Gulf of Guinea.  

PubMed

Total mercury concentrations in different tissues of frigate tuna fish (Auxis thazard thazard) was determined by the cold vapour atomic absorption spectrometry technique using an automatic mercury analyzer. A mixture of HNO3, HClO4 and H(2)SO(4) was used for complete oxidation of organic tissue. The concentration of mercury obtained was in the order Gills < Stomach < Gonads < Intestine < Heart < Duodenum < Liver < Muscle. The concentration of total mercury detected in the edible muscle tissue of the tuna fish tested ranged from 0.044 to 0.201 microg g(-1) (mean = 0.108 microg g(-1)) wet weight. These levels are all within the maximum allowed/recommended level in fish (0.5 mug g(-1) wet weight) set by the Food and Agriculture Organisation/World Health Organisation (FAO/WHO) and are therefore unlikely to constitute any significant mercury exposure to the general population because of consumption of tuna fish. The results of the study suggest a relatively clean marine environment that has not been significantly impacted by mercury contamination probably due to minimal industrial activity in the region. PMID:17286183

Voegborlo, R B; Adimado, A A; Ephraim, J H

2007-02-08

84

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

SciTech Connect

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

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

1998-02-01

85

Certification of three mussel tissue standard reference materials (SRM) for methylmercury and total mercury content  

Microsoft Academic Search

SRM 1974a, Organics in Mussel Tissue (Mytilus edulis); SRM 2974, Organics in Mussel Tissue (freeze-dried); and SRM 2976, Mussel Tissue (trace elements and methylmercury) have\\u000a been recently certified for methylmercury and total mercury content. Three independent analytical procedures were used to\\u000a determine the certified methylmercury concentrations. Four independent procedures combined with data from two intercomparison\\u000a exercises were used to determine

Mary Kate Donais; Rajananda Saraswati; Elizabeth Mackey; Rabia Demiralp; Barbara Porter; Mark Vangel; Mark Levenson; Vesna Mandic; Sabine Azemard; Milena Horvat; Karl May; Hendrik Emons; Stephen Wise

1997-01-01

86

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

PubMed Central

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

Ragan, Gregory A.; Gregory Alvord, W.

2007-01-01

87

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

Microsoft Academic Search

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\\u000a exposed to HABs. In all sharks studied, total Hg levels in the muscle were generally present in a molar excess over Se (which\\u000a may

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

2011-01-01

88

Methylmercury exposure during lactation: Milk concentration and tissue uptake of mercury in the neonatal rat  

SciTech Connect

In recent years toxicological interest in mercury has predominantly been focused on the effects of prenatal exposure to methylmercury on the physical and mental development of children. Thus, there has been a general concern to limit the exposure of pregnant women to methylmercury. Much less attention has been paid to postnatal exposure to mercury. However, there is also a possibility of elevated mercury exposure in the newborn due to exposure via breast milk. There is a lack of data from both humans and animals on lactational transfer of many metals. However, metabolic evidence suggests that during the neonatal period the infant is sensitive to effects of these compounds. Thus, the gastrointestinal absorption and the retention of metals is higher during this period than adult life. In the present study the dose-dependent transfer of mercury into milk was studied in lactating rats treated with methyl-mercury. The uptake of mercury in tissues and blood was followed in the offspring exposed via milk.

Sundberg, J.; Oskarsson, A.; Albanus, L. (National Food Administration, Uppsala (Sweden))

1991-02-01

89

The Effect of Fish Consumption on Blood Mercury Levels of Pregnant Women  

PubMed Central

In the present study, we examined the relationship between average fish consumption, as well as the type of fish consumed and levels of mercury in the blood of pregnant women. We also performed follow-up studies to determine if blood mercury levels were decreased after counseling and prenatal education. To examine these potential relationships, pregnant women were divided into two groups: a study group was educated to restrict fish intake, whereas a control group did not receive any prenatal education regarding fish consumption. We measured blood mercury level and performed follow-up studies during the third trimester to examine any differences between the two groups. Out of the 63 pregnant women who participated in our study, we performed follow-up studies with 19 pregnant women from the study group and 12 pregnant women from control group. The average initial blood mercury level of both groups was 2.94 µg/L, with a range of 0.14 to 10.75 µg/L. Blood mercury level in the group who ate fish more than four times per month was significantly higher than that of the group who did not consume fish (p = 0.02). In follow-up studies, blood mercury levels were decreased in the study group but slightly increased in the control group (p = 0.014). The maternal blood mercury level in late pregnancy was positively correlated with mercury levels of cord blood (r = 0.58, p = 0.047), which was almost twice the level found in maternal blood. Pregnant women who consume a large amount of fish may have high blood mercury levels. Further, cord blood mercury levels were much higher than that of maternal blood. Because the level of fish intake appears to influence blood mercury level, preconceptual education might be necessary in order decrease fish consumption.

Kim, Euy Hyuk; Kwon, Ja Young; Kim, Sang Wun; Park, Yong Won

2006-01-01

90

Mercury levels in dental students and faculty measured by neutron activation analysis.  

PubMed

Samples of head hair, fingernails, and toenails were taken from 61 dental students and faculty members. The mercury levels were analyzed using a simple neutron activation analysis technique which proved to be easily applicable to large numbers. Significant results were found for the head hair and fingernail groups. There may be a correlation between the higher mercury levels and increased pressure of work, which might result in decreased standards of mercury hygiene. PMID:6928964

Sinclair, P M; Turner, P R; Johns, R B

1980-05-01

91

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

Microsoft Academic Search

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.

LESZEK J. HAHN; REINHARD KLOIBER; RONALD W. LEININGER; M. J. Vimy; FRITZ L. LORSCHEIDER

1990-01-01

92

Effects of low dietary levels of methyl mercury on mallard reproduction  

USGS Publications Warehouse

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.

Heinz, G.

1974-01-01

93

[Mercury in muscle tissue of flounder Platychthis flesus from two sites in the Gulf of Gdansk].  

PubMed

Total mercury concentration was determined in the muscle tissue of flounder collected under Stegna (ca. 1 mile east of the Vistula River outlet) and under Gdynia (ca. 12 miles northwest of the Vistula River Outlet) sampling sites in the Gulf of Gda?sk in 1992 and 1993. The method of measurement was cold-vapour atomic absorption spectrometry (CV-AAS) after wet digestion of the samples with concentrated nitric acid. The arithmetic means of mercury concentration in muscle tissue of flounder collected under Stegna were 46 +/- 24 in 1992 and 57 +/- 47 in 1993, while for those under Gdynia 20 +/- 19 and 26 +/- 18, micrograms/kg on a wet weight basis, respectively. Mercury concentrations in muscle tissue of flounder collected under Stegna were positively correlated with the body length and body weight of fish (0.05 < p < 0.001), while in the case of specimens collected under Gdynia no such relationships were found. These observations seem to imply that Vistula River is an important source and pathway of mercury entrance into the Gulf of Gda?sk. PMID:8533029

Falandysz, J; Piotrowska, M

1995-01-01

94

Fish mercury levels in relation to characteristics of hydroelectric reservoirs in Newfoundland, Canada  

Microsoft Academic Search

Mercury levels in fish have been demonstrated to increase after impoundment with augmented levels of mercury predicted to decline as the reservoir ages. Previous research in Newfoundland predicted return rates in the order of 10 to 12 years for landlocked Atlantic salmon or ouananiche (Salmo salar) and 7 years for brook trout (Salvelinus fontinalis). In order to test the validity

K. J. French; M. R. Anderson; D. A. Scruton; L. J. Ledrew

1998-01-01

95

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

SciTech Connect

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.

Looney, B.B.

2000-08-18

96

Mercury pollution in the Tapajos River basin, Amazon Mercury level of head hair and health effects  

Microsoft Academic Search

There is increasing concern about the potential neurotoxic effects of exposure to methylmercury for the 6 million people living in the Amazon, even in regions situated far away from the gold mines (garimpos), considered to be the major source of mercury pollution. In November 1998, a spot investigation on mercury contamination was conducted in three fishing villages (Barreiras, Rainha, and

Masazumi Haradaa; Maria da Conceicao; N. Pinheiroc; Hideki Ohnod

97

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

Microsoft Academic Search

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

Aristeo Renzoni

1992-01-01

98

A Prospective Clinical Study on Blood Mercury Levels Following Endodontic Root-end Surgery with Amalgam  

PubMed Central

Introduction The purpose of this clinical study was to compare the blood mercury levels before and after endodontic surgery using amalgam as a root-end filling material. Materials and Methods Fourteen patients requiring periradicular surgery participated in this prospective clinical study. A zinc-free amalgam was employed as root-end filling material. Blood samples were collected at three intervals: immediately before, immediately after and one week postoperatively. Mercury content of the blood was determined using gold amalgamation cold-vapor atomic absorption spectrometry. Obtained data were analyzed using analysis of variance for repeated measures and paired t-test. Results The mean (SD) of blood mercury levels was 2.20 (0.24) ng/mL immediately before surgery, 2.24 (0.28) ng/mL immediately after surgery and 2.44 (0.17) ng/mL one week after the periradicular surgery. The blood mercury level one week post-operative was significantly higher than both blood mercury levels immediately before (P<0.001) and immediately after (P=0.005) the surgery. Conclusion Placement of an amalgam retroseal during endodontic surgery can increase blood mercury levels after one week. The mercury levels however, are still lower than the toxic mercury levels. We suggest using more suitable and biocompatible root-end filling materials.

Saatchi, Masoud; Shadmehr, Elham; Talebi, Seyed Morteza; Nazeri, Mohsen

2013-01-01

99

Effect of teeth amalgam on mercury levels in the colostrums human milk in Lenjan.  

PubMed

Human milk is usually the only source of food for infants during the first 4 to 5 months of their life. Maternal environmental mercury exposure is directly related to fish consumption or amalgam filling. In this research, 38 human milk samples were collected from mothers of Lenjan area who were not occupationally exposed with mercury. Mercury concentration in human milk was determined by AMA254 Mercury Analyzer. A level of mercury was examined in relation to somatometric, demographic and dental amalgam parameters. Obtained results showed that only dental amalgam significantly increased the mercury level in human milk (p?< 0.001). The mean mercury concentrations in milk of mothers without teeth fillings (n?= 13), with one to three teeth fillings (n?= 10), and four to eight teeth fillings (n?= 15) were 2.87, 5.47, and 13.33 ?g/l, respectively. The result of this study also showed a positive correlation of mercury milk levels with the number of teeth fillings of the mother (p?< 0.05, r?= 0.755). The estimated weekly intake of mercury of a breastfed infant in this study was, in some cases, higher than provisional tolerance weekly intake recommended by FAO/WHO, which pose a threat to their health. PMID:21494835

Norouzi, Elaheh; Bahramifar, Nader; Ghasempouri, Seyed Mahmoud

2011-04-15

100

Sequential analysis of hair mercury levels in relation to fish diet of an Amazonian population, Brazil.  

PubMed

Several studies in the Amazonian Basin have shown that riverine populations are exposed to methylmercury through fish consumption. It has been suggested that seasonal variations in hair mercury observed through sequential analyses may be related to the changes in fish species ingested by the local communities. The aim of the present study was to investigate the relationship between fish-eating practices and seasonal variation in mercury exposure. A group of 36 women from a village located on the banks of the Tapajós River, a major tributary of the Amazon, comprised the present study population. An interview-administered questionnaire was used to gather information on socio-demographic characteristics, fish-eating practices and other relevant information. The women also provided hair samples of at least 24 cm in length for mercury analysis. Hair total and inorganic mercury concentration was measured using a cold vapor atomic absorption analytical method. Trigonometric regression analysis was done to assess the seasonal variation of total mercury levels. Variations in inorganic mercury were examined by repeated measures analysis of variance, and analysis of contrast variable with a polynomial transformation. The results showed that hair mercury levels varied with the season. Higher levels were observed in months corresponding to the dry season, with lower levels in the rainy season. Herbivorous fish predominated the diet for 47.2% of the women during the dry season, but this rose to 72.2% during the rainy season. Those who reported eating fish daily had higher mercury levels in hair compared to those who only ate fish a few times per week. Retrospective mercury analyses, evaluated by the quantity of mercury present in each centimeter of hair, indicate that mean mercury level of the population decreased over the 2 years prior to the study. The percentage of inorganic mercury over the total mercury in hair increased towards the extremities of the hair strand. Higher percentages of inorganic mercury were found for the group who ate more fish (on a daily consumption basis). These results support the assumption that there are seasonal variations in methylmercury exposure and also a relationship between type of fish species consumed and the resulting hair mercury levels. PMID:11346043

Dolbec, J; Mergler, D; Larribe, F; Roulet, M; Lebel, J; Lucotte, M

2001-04-23

101

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

PubMed

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

Rutkiewicz, Jennifer; Basu, Niladri

2013-05-10

102

Identification of the double acceptor levels of the mercury vacancies in HgCdTe  

NASA Astrophysics Data System (ADS)

Photoluminescence and temperature-dependent Hall measurements of nonintentionally doped HgCdTe epilayers were compared. These films were grown by liquid phase epitaxy and postannealed under different conditions as follows: a p-type annealing was used to control the mercury vacancy concentration and a n-type annealing under saturated Hg atmosphere was used to fill the mercury vacancies. The comparison of the photoluminescence measurements with Hall effect measurements allows us to identify the two acceptor energy levels of the mercury vacancy and to evidence its ``negative-U'' property corresponding to a stabilization of the ionized state V- of the mercury vacancy compared to its neutral state V0.

Gemain, F.; Robin, I. C.; de Vita, M.; Brochen, S.; Lusson, A.

2011-03-01

103

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

USGS Publications Warehouse

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.

Lewis, Michael Edward; Brigham, Mark E.

2004-01-01

104

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

Microsoft Academic Search

The total mercury (T-Hg) and methyl mercury (Me-Hg) concentrations in the hair were measured to evaluate mercury (Hg) exposure\\u000a for the residents in Da-shui-xi Village (DSX) and Xia-chang-xi Village (XCX) in the Wanshan Hg mining area, Guizhou Province,\\u000a Southwestern China. The mean concentrations in the hair of DSX residents were 5.5 ± 2.7 ?g\\/g and 1.9 ± 0.9 ?g\\/g for T-Hg and\\u000a Me-Hg, respectively. The concentrations

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

2009-01-01

105

Hair mercury levels in Amazonian populations: spatial distribution and trends  

Microsoft Academic Search

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

Flavia L Barbieri; Jacques Gardon

2009-01-01

106

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

PubMed

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

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

2007-08-03

107

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...

108

Determination and assessment of total mercury levels in local, frozen and canned fish in Lebanon.  

PubMed

Fish is an important constituent of the Lebanese diet. However, very little attention in our area is given to bring awareness regarding the effect of the toxicity of mercury (Hg) mainly through fish consumption. This study aimed to report analytical data on total mercury levels in several fish species for the first time in thirty years and to also made individuals aware of the presence and danger from exposure to mercury through fish consumption. Fish samples were selected from local Lebanese markets and fisheries and included 94 samples of which were fresh, frozen, processed, and canned fish. All values were reported as microgram of mercury per gram of fish based on wet weight. The level of mercury ranged from 0.0190 to 0.5700 microg/g in fresh samples, 0.0059 to 0.0665 microg/g in frozen samples, and 0.0305 to 0.1190 microg/g in canned samples. The data clearly showed that higher levels of mercury were detected in local fresh fish as opposed to other types thus placing consumers at higher risk from mercury exposure. Moreover, the data revealed that Mallifa (yellowstripe barracuda/Sphyraena chrysotaenia), Sargous (white seabream/Diplodus sargus), Ghobbos (bogue/Boops boops), and shrimp (Penaeus sp.) were among the types containing the highest amounts of mercury. On the other hand, processed fish such as fish fillet, fish burger, small shrimp and crab are found to contain lower levels of mercury and are associated with lower exposure risks to mercury. Lebanese population should therefore, be aware to consume limited amounts of fresh local fish to minimize exposure to mercury. PMID:22432295

Obeid, Pierre J; El-Khoury, Bilal; Burger, Joanne; Aouad, Samer; Younis, Mira; Aoun, Amal; El-Nakat, John Hanna

2011-01-01

109

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

PubMed

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

Adams, Douglas H; Sonne, Christian

2013-07-02

110

Mercury Levels along the Food Chain and Risk for Exposed Populations  

Microsoft Academic Search

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

A. Renzoni; F. Zino; E. Franchi

1998-01-01

111

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

Microsoft Academic Search

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

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

2012-01-01

112

Effects of low dietary levels of methyl mercury on mallard reproduction  

Microsoft Academic Search

Summary 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

Gary Heinz

1974-01-01

113

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

PubMed

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

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

2013-05-16

114

Effects of Mercury and Selenium on Serum Transaminase Levels of Quail, Hens and Rats.  

National Technical Information Service (NTIS)

Three studies were conducted in an effort to quantitatively evaluate some of the early effects and nutrient interactions of methyl mercury (CH3-HG) in Cotournix quail, Leghorn hens, and Sprague-Dawley rats. Mercury was added to the diets at levels ranging...

S. O. Welsh J. H. Soares B. R. Stilling H. Lagally

1973-01-01

115

Investigation of Increased Mercury Levels in the Fisheries of Lower East Fork Poplar Creek (LEFPC), Oak Ridge Reservation, Tennessee  

SciTech Connect

The DOE Western Environmental Technology Office (WETO) is supporting Oak Ridge's remediation efforts 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. 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 dissolved and colloidal forms of elemental mercury (Hg deg.A) to methyl mercury (MeHg) by algal-bacterial bio-films (periphyton) present in the stream-bed of LEFPC; MeHg production by these bio-films under anoxic versus oxic conditions was the critical measurement taken. The bench-scale testing for Phase I was completed November 2005. The final reporting and the planning for Phase II testing are in progress. (authors)

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

2006-07-01

116

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

SciTech Connect

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)

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

117

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

PubMed

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

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

2013-06-26

118

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

PubMed Central

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

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

2013-01-01

119

Mercury and selenium interaction: A review  

SciTech Connect

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.

Cuvin-Aralar, M.L.; Furness, R.W. (Binangonan Freshwater Station, Southeast Asian Fisheries Development, Center Aquaculture Department, Rizal (Philippines))

1991-06-01

120

Mercury and selenium interaction: A review  

Microsoft Academic Search

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.

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

1991-01-01

121

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

PubMed

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

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

2012-01-01

122

Mercury Levels in an Urban Pregnant Population in Durham County, North Carolina  

PubMed Central

The adverse effects of prenatal mercury exposure, most commonly resulting from maternal fish consumption, have been detected at very low exposure levels. The omega-3 fatty acids found in fish, however, have been shown to support fetal brain and vision development. Using data from a prospective, cohort study of pregnant women from an inland area in the US South, we sought to understand the fish consumption habits and associated mercury levels across subpopulations. Over 30% of women had at least 1 ?g/L of mercury in their blood, and about 2% had blood mercury levels above the level of concern during pregnancy (?3.5 ?g/L). Mercury levels were higher among Asian/Pacific Islander, older, higher educated, and married women. Fish consumption from any source was reported by 2/3 of the women in our study, with older women more likely to consume fish. Despite eating more fish meals per week, lower income, lower educated women had lower blood mercury levels than higher income, higher educated women. This suggests the different demographic groups consume different types of fish. Encouraging increased fish consumption while minimizing mercury exposure requires careful crafting of a complex health message.

Miranda, Marie Lynn; Edwards, Sharon; Maxson, Pamela J.

2011-01-01

123

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.

124

Ultralow Level Mercury Treatment Using Chemical Reduction and Air Stripping  

SciTech Connect

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.

Looney, B.B.

2001-02-23

125

Relation of blood cadmium, lead, and mercury levels to biomarkers of lipid peroxidation in premenopausal women.  

PubMed

Exposures to cadmium, lead, and mercury are associated with adverse health effects, including cardiovascular disease, which may be promoted by lipid peroxidation. The authors examined cadmium, lead, and mercury in relation to plasma levels of F(2)-8? isoprostanes (isoprostane), 9-hydroperoxy-10,12-octadecadienoic acid (9-HODE), 13-hydroxy-9,11-octadecadienoic acid (13-HODE), and thiobarbituric acid reactive substances (TBARS) in 252 women from western New York State (2005-2007). Healthy premenopausal women were followed for ?2 menstrual cycles, with biomarkers of lipid peroxidation being assessed ?8 times per cycle. Metals were measured at baseline in whole blood. Linear mixed models were used to estimate the association between cadmium, lead, and mercury and lipid peroxidation biomarkers. Median cadmium, lead, and mercury levels were 0.30 ?g/L, 0.86 ?g/dL, and 1.10 ?g/L, respectively. Blood cadmium, lead, and mercury were not associated with increases in isoprostane, TBARS, 9-HODE, or 13-HODE levels. Isoprostane levels decreased 6.80% (95% confidence interval: -10.40, -3.20) per 1% increase in mercury. However, after adjustment for a simulated strong confounding factor, such as precisely measured fish consumption, the observed association was attenuated, suggesting that this unexpected association could be attributable to unmeasured confounding. In this population of healthy premenopausal women with low exposure levels, cadmium, lead, and mercury were not associated with elevated lipid peroxidation biomarkers. PMID:22302120

Pollack, Anna Z; Schisterman, Enrique F; Goldman, Lynn R; Mumford, Sunni L; Perkins, Neil J; Bloom, Michael S; Rudra, Carole B; Browne, Richard W; Wactawski-Wende, Jean

2012-02-02

126

Relation of Blood Cadmium, Lead, and Mercury Levels to Biomarkers of Lipid Peroxidation in Premenopausal Women  

PubMed Central

Exposures to cadmium, lead, and mercury are associated with adverse health effects, including cardiovascular disease, which may be promoted by lipid peroxidation. The authors examined cadmium, lead, and mercury in relation to plasma levels of F2-8? isoprostanes (isoprostane), 9-hydroperoxy-10,12-octadecadienoic acid (9-HODE), 13-hydroxy-9,11-octadecadienoic acid (13-HODE), and thiobarbituric acid reactive substances (TBARS) in 252 women from western New York State (2005–2007). Healthy premenopausal women were followed for ?2 menstrual cycles, with biomarkers of lipid peroxidation being assessed ?8 times per cycle. Metals were measured at baseline in whole blood. Linear mixed models were used to estimate the association between cadmium, lead, and mercury and lipid peroxidation biomarkers. Median cadmium, lead, and mercury levels were 0.30 ?g/L, 0.86 ?g/dL, and 1.10 ?g/L, respectively. Blood cadmium, lead, and mercury were not associated with increases in isoprostane, TBARS, 9-HODE, or 13-HODE levels. Isoprostane levels decreased 6.80% (95% confidence interval: ?10.40, ?3.20) per 1% increase in mercury. However, after adjustment for a simulated strong confounding factor, such as precisely measured fish consumption, the observed association was attenuated, suggesting that this unexpected association could be attributable to unmeasured confounding. In this population of healthy premenopausal women with low exposure levels, cadmium, lead, and mercury were not associated with elevated lipid peroxidation biomarkers.

Pollack, Anna Z.; Schisterman, Enrique F.; Goldman, Lynn R.; Mumford, Sunni L.; Perkins, Neil J.; Bloom, Michael S.; Rudra, Carole B.; Browne, Richard W.; Wactawski-Wende, Jean

2012-01-01

127

Levels of selenium in relation to levels of mercury in fish from Mjoesa, a freshwater lake in southeastern Norway  

SciTech Connect

In addition to its role as a micro nutrient, selenium exerts an antagonistic effect in mercury poisoning. The levels of selenium in fish from water systems contaminated with mercury are therefore of great interest. This is especially so in Norway, a country known as a low-selenium area. The present paper reports levels of selenium and their relationship to mercury accumulation in the flesh of fish from Mjoesa. For comparison, fish from five lakes in the surrounding area were also included in the investigation.

Froeslie, A.; Norheim, G.; Sandlund, O.T.

1985-04-01

128

Methylmercury levels and bioaccumulation in the aquatic food web of a highly mercury-contaminated reservoir.  

PubMed

The low Ebro River basin (NE Spain) represents a particular case of chronic and long-term mercury pollution due to the presence of an industrial waste (up to 436 ?g/g of Hg) coming from a chlor-alkali plant Albeit high total mercury (THg) levels have been previously described in several aquatic species from the surveyed area, methylmercury (MeHg) values in fish individuals have never been reported. Accordingly, in order to investigate bioaccumulation patterns at different levels of the aquatic food web of such polluted area, crayfish and various fish species, were analysed for THg and MeHg content. At the hot spot, THg mean values of crayfish muscle tissue and hepatopancreas were 10 and 15 times, respectively, greater than the local background level. Higher mean THg concentrations were detected in piscivorous (THg=0.848 ± 0.476 ?g/g wet weight (ww); MeHg=0.672 ± 0.364 ?g/g ww) than in non-piscivorous fish (THg=0.305 ± 0.163 ?g/g ww; MeHg=0.278 ± 0.239 ?g/g ww). Although these results indicated that THg in fish increased significantly with increasing trophic position, the percentage of the methylated form of Hg was not strongly influenced by differences in relative trophic position. This is an important finding, since the fraction of THg as MeHg in the top fish predator was unexpectedly lower than for other species of the aquatic food chain. Moreover, mean THg concentrations in piscivorous fish exceed the maximum level recommended for human consumption. From our findings, it is clear that for this specific polluted system, speciation becomes almost mandatory when risk assessment is based on MeHg, since single measurements of THg are inadequate and could lead to an over- or under-estimation of contamination levels. PMID:21658770

Carrasco, Luis; Benejam, Lluís; Benito, Josep; Bayona, Josep M; Díez, Sergi

2011-06-11

129

Fish consumption patterns and mercury exposure levels among women of childbearing age in Duval County, Florida.  

PubMed

Consumption of fish containing methylmercury can pose serious health concerns including neurotoxic effects in adults and toxicity to the fetuses of mothers exposed during pregnancy. In the study described in this article, the authors examined fish consumption patterns and measured hair mercury levels of women of childbearing age in a coastal county in Florida. Women from the community participated in a risk factor assessment survey (N = 703). Hair samples (n = 698) were collected and analyzed for mercury. The authors identified 74.8% below detection limit; 25.2% had detectable limits of mercury, while 7% exceeded 1 pg/g. Hair mercury levels increased with fish consumption and age. Race, income, and education levels were also associated with increased hair mercury levels. Women of Asian/Pacific Islander origin had the highest levels. Although reported fish consumption exceeded the recommendations for women of childbearing age, the study population had lower mercury levels than other comparative studies in Florida and at national levels. PMID:23397644

Traynor, Sharleen; Kearney, Greg; Olson, David; Hilliard, Aaron; Palcic, Jason; Pawlowicz, Marek

130

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

Microsoft Academic Search

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

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

131

Low-Cost Options for Moderate Levels of Mercury Control  

SciTech Connect

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.

Sharon Sjostrom

2006-03-31

132

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

SciTech Connect

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.

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

2009-05-20

133

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 false Required Elements of Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans...Emission Standards for Hazardous Air Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants Pt. 63, Subpt....

2010-07-01

134

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 false Required Elements of Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans...Emission Standards for Hazardous Air Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants Pt. 63, Subpt....

2013-07-01

135

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

...2009-07-01 false Required Elements of Floor-Level Mercury Vapor Measurement and Cell Room Monitoring Plans...Emission Standards for Hazardous Air Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants Pt. 63, Subpt....

2009-07-01

136

Naringin Levels in Citrus Tissues 1  

PubMed Central

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

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

1985-01-01

137

Head Hair Total Mercury and Methylmercury Levels in Some Ghanaian Individuals for the Estimation of Their Exposure to Mercury: Preliminary Studies  

Microsoft Academic Search

The extent of human exposure to mercury in some individuals in Ghana was evaluated by analysing samples of human head hair\\u000a for total mercury and methylmercury. The average level of total mercury was 0.843 ?g g?1 (in range of 0.119–4.140, n = 123) and that of methylmercury was 0.787 ?g g?1 (in range of 0.208–1.847, n = 42). Mercury was present in the hair samples almost completely in

Ray B. Voegborlo; Akito Matsuyama; Anthony A. Adimado; Hirokatsu Akagi

2010-01-01

138

Mercury and Methylmercury Concentrations in Muscle Tissue of Fish Caught in Major Rivers of the Czech Republic  

Microsoft Academic Search

Kružíková K., T. Randák, R. Kenšová, H. Kroupová, D. Leontovy?ová, Z. Svobodová: Mercury and Methylmercury Concentrations in Muscle Tissue of Fish Caught in Major Rivers of the Czech Republic. Acta Vet Brno 2008, 77: 637-643. The aim of the study was to evaluate mercury contamination at twelve outlet sites of rivers in the Czech Republic (Labe, Oh?e, Vltava, Berounka, Sázava,

K. Kružíková; T. Randák; R. Kenšová; H. Kroupová; D. Leontovy?ová; Z. Svobodová

2008-01-01

139

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

PubMed Central

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

Kasraei, Sh.; Mortazavi, H.; Vahedi, M.; Bakianian Vaziri, P.; Assary, MJ.

2010-01-01

140

Mercury levels in hair from people eating large quantities of Swedish freshwater fish.  

PubMed

Mercury concentrations in hair were related to fish-eating habits in a group of 50 people reported to have a high consumption of freshwater fish. Mercury levels in hair ranged from 0.3 to 10.8 mg/kg with a mean +/- SD of 3.2 +/- 2.3 mg/kg. The average mercury level in hair from men was significantly higher than that in hair from women (3.8 +/- 2.6 mg/kg versus 2.4 +/- 1.8 mg/kg. Seven individuals (14%) had levels above 6 mg/kg. In people with equal fish consumption, significantly higher mercury levels were found in the hair of those eating fish from lakes Mälaren and Vättern than in those eating fish from Lake Hjälmaren. It has been reported that fish from the latter lake contains approximately 0.2 mg/kg mercury, whereas fish from the other two lakes contains approximately 0.4 mg/kg. The mean mercury level in hair was higher in the group eating freshwater fish more than three times a week (greater than or equal to 500 g fish flesh/week) than in the group eating less, although the difference was of borderline significance. Within couples (n = 16) eating equal numbers of fish meals per week, the men had significantly higher levels (mean 3.7 mg/kg) than the women (mean 2.5 mg/kg). The results from the present study show that people with a high consumption of Swedish freshwater fish have elevated levels of mercury in their hair, when compared with previously reported levels in the hair of Swedish pregnant women. PMID:2394276

Oskarsson, A; Ohlin, B; Ohlander, E M; Albanus, L

141

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

Microsoft Academic Search

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

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

2001-01-01

142

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

PubMed

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

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

2010-12-01

143

Low-Cost Options for Moderate Levels of Mercury Control  

SciTech Connect

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.

Sharon Sjostrom

2008-02-09

144

Relation between Cord Blood Mercury Levels and Early Child Development in a World Trade Center Cohort  

PubMed Central

Objective This study was designed to determine whether prenatal mercury exposure, including potential releases from the World Trade Center (WTC) disaster, adversely affects fetal growth and child development. Methods We determined maternal and umbilical cord blood total mercury of nonsmoking women who delivered at term in lower Manhattan after 11 September 2001, and measured birth outcomes and child development. Results Levels of total mercury in cord and maternal blood were not significantly higher for women who resided or worked within 1 or 2 miles of the WTC in the month after 11 September, compared with women who lived and worked farther away. Average cord mercury levels were more than twice maternal levels, and both were elevated in women who reported eating fish/seafood during pregnancy. Regression analyses showed no significant association between (ln) cord or maternal blood total mercury and birth outcomes. Log cord mercury was inversely associated with the Bayley Scales of Infant Development psychomotor score [Psychomotor Development Index (PDI)] at 36 months (b = –4.2, p = 0.007) and with Performance (b = –3.4, p = 0.023), Verbal (b = –2.9, p = 0.023), and Full IQ scores (b = –3.8, p = 0.002) on the Wechsler Preschool and Primary Scale of Intelligence, Revised (WPPSI-R), at 48 months, after controlling for fish/seafood consumption and other confounders. Fish/seafood consumption during pregnancy was significantly associated with a 5.6- to 9.9-point increase in 36-month PDI, and 48-month Verbal and Full IQ scores. Conclusions Blood mercury was not significantly raised in women living or working close to the WTC site in the weeks after 11 September 2001. Higher cord blood mercury was associated with reductions in developmental scores at 36 and 48 months, after adjusting for the positive effects of fish/seafood consumption during pregnancy.

Lederman, Sally Ann; Jones, Robert L.; Caldwell, Kathleen L.; Rauh, Virginia; Sheets, Stephen E.; Tang, Deliang; Viswanathan, Sheila; Becker, Mark; Stein, Janet L.; Wang, Richard Y.; Perera, Frederica P.

2008-01-01

145

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

PubMed

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

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

2011-09-17

146

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

SciTech Connect

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.

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

147

Inverse relationships between selenium and mercury in tissues of young walleye (Stizosedion vitreum) from Canadian boreal lakes.  

PubMed

The concentrations of total mercury (Hg), methylmercury (MeHg) and total selenium (Se) were determined in muscle, liver and brain tissues of young-of-the-year walleye (Stizosedion vitreum) specimens collected from 8 boreal lakes that are located within 107km around the Sudbury smelters in Ontario, Canada. Dry weight basis concentrations of Hg were highest in muscle and lowest in brain (p<0.05), those of MeHg were higher in muscle than in liver and brain but there was no significant difference between liver and brain (p<0.05). The highest Se concentrations were found in liver and the lowest in brain (p<0.05). Considering the biomass of the studied tissues, muscle was the part of the body where most of Hg, MeHg and Se were accumulated. In fish muscle, the percentage of MeHg over Hg was the highest and this percentage was the lowest in liver. The concentrations of Hg, MeHg and Se in the studied tissues were closely related to the concentrations of total dissolved Se in lake waters which vary with the distance of the lakes from the smelters. Thresholds of Se concentrations in tissues were revealed (6.2, 12.0 and 3.5mgkg(-1) dry wt., for muscle, liver and brain, respectively), above which a significant reduction of MeHg concentrations was observed in all studied tissues compared to lower Se levels in the same tissues. Based on the collected information and data analysis, possible mechanisms for the biological processes behind the observed inverse relationships between Se and Hg in fish tissues are discussed. PMID:20006995

Yang, Dan-Yi; Ye, Xu; Chen, Yu-Wei; Belzile, Nelson

2009-12-16

148

Total Mercury Distribution in Different Tissues of Frigate Tuna ( Auxis thazard thazard ) from the Atlantic Coastal Waters of Ghana, Gulf of Guinea  

Microsoft Academic Search

Total mercury concentrations in different tissues of frigate tuna fish (Auxis thazard thazard) was determined by the cold vapour atomic absorption spectrometry technique using an automatic mercury analyzer. A mixture\\u000a of HNO3, HClO4 and H2SO4 was used for complete oxidation of organic tissue. The concentration of mercury obtained was in the order Gills < Stomach\\u000a < Gonads < Intestine <

R. B. Voegborlo; A. A. Adimado; J. H. Ephraim

2007-01-01

149

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

PubMed Central

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

Esteban-Vasallo, Maria D.; Aragones, Nuria; Pollan, Marina; Lopez-Abente, Gonzalo

2012-01-01

150

Analysis of total mercury in human tissues prepared by microwave decomposition using a hydride generator system coupled to an atomic absorption spectrometer  

Microsoft Academic Search

A fast and efficient procedure has been developed for the analysis of total mercury in human tissues and blood using a hydride vapor generator system coupled to an atomic absorption spectrometer (HVG–AA). Tissue and blood samples were digested in a pressurized microwave decomposition system and the digest diluted prior to formation of free mercury vapor and analysis by atomic absorption.

Xenophon Cominos; Sotiris Athanaselis; Artemis Dona; Antonios Koutselinis

2001-01-01

151

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

NASA Astrophysics Data System (ADS)

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.

Renzoni, Aristeo

1992-09-01

152

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

SciTech Connect

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.

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

2012-05-15

153

Relationship between the prenatal exposure to low-level of mercury and the size of a newborn’s cerebellum  

Microsoft Academic Search

Exposure to methylmercury at any stage of central nervous system development could induce alterations and result in severe congenital abnormalities. Total mercury level in maternal hair during pregnancy correlates well with blood levels of methylmercury and with total mercury levels in fetal brain.A prospective study has been conducted and a total of 137 childbearing women living at the coastal region

I. Bilic Cace; A. Milardovic; I. Prpic; R. Krajina; O. Petrovic; P. Vukelic; Z. Spiric; M. Horvat; D. Mazej; J. Snoj

2011-01-01

154

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

SciTech Connect

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.

Paller, M.H.

2004-03-01

155

High Hair and Urinary Mercury Levels of Fish Eaters in the Nonpolluted Environment of Papua New Guinea  

Microsoft Academic Search

Hair and mercury concentrations of 134 fish-eating subjects in the Lake Murray area and 13 non-fish-eating subjects in the upper-Strickland area, Papua New Guinea, were studied. Hair mercury levels among the subjects in the Lake Murray area (mean = 21.9 ?g\\/g, range = 3.7–71.9 ?g\\/g) and urinary mercury levels (mean = 7.6 ?g\\/g creatinine, range = 1.4–25.6 ?g\\/g creatinine) were

Taku Abe; Ryutaro Ohtsuka; Tetsuro Hongo; Tsuguyoshi Suzuki; Chiharu Tohyama; Atsuhiro Nakano; Hirokatsu Akagi; Tomoya Akimichi

1995-01-01

156

Environmental contamination and risk assessment of mercury from a historic mercury mine located in southwestern China.  

PubMed

A field survey of mercury pollution in environmental media and human hair samples obtained from residents living in the area surrounding the Chatian mercury mine (CMM) of southwestern China was conducted to evaluate the health risks of mercury to local residents. The results showed that mine waste, and tailings in particular, contained high levels of mercury and that the maximum mercury concentration was 88.50 ?g g(-1). Elevated mercury levels were also found in local surface water, paddy soil, and paddy grain, which may cause severe health problems. The mercury concentration of hair samples from the inhabitants of the CMM exceeded 1.0 ?g g(-1), which is the limit recommended by the US EPA. Mercury concentrations in paddy soil were positively correlated with mercury concentrations in paddy roots, stalks, and paddy grains, which suggested that paddy soil was the major source of mercury in paddy plant tissue. The average daily dose (ADD) of mercury for local adults and preschool children via oral exposure reached 0.241 and 0.624 ?g kg(-1) body weight per day, respectively, which is approaching or exceeds the provisional tolerable daily intake. Among the three oral exposure routes, the greatest contributor to the ADD of mercury was the ingestion of rice grain. Open-stacked mine tailings have resulted in heavy mercury contamination in the surrounding soil, and the depth of appreciable soil mercury concentrations exceeded 100 cm. PMID:22722913

Li, Yonghua

2012-06-22

157

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

PubMed Central

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

2009-01-01

158

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

SciTech Connect

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.

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

1996-12-31

159

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

PubMed

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

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

2010-12-16

160

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...

161

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 ...

162

Is low-level environmental mercury exposure of concern to human health?  

PubMed

Mercury has long been recognised as toxic, principally in relation to its effects on humans following acute or prolonged high-level occupational exposures and, in the latter half of the last century, from a number of environmental incidents. Recognised target organs are the kidneys, central nervous system and thyroid glands. Recently concern has grown about the potential risks to the human population from current background environmental levels, leading bodies such as the World Health Organisation to call for the reduction or, wherever possible, elimination of the use of mercury. This review considers the strength of the epidemiological evidence on the effects of prolonged low-level exposure to the various forms of mercury. The limited research base suggests that several of the potential targets of long-term environmental exposure to mercury are similar to those occurring from occupational exposure including the renal, cardiovascular and immune systems. However, the evidence also suggests that, particularly in the case of organic mercury compounds, the most sensitive endpoint is central nervous system toxicity, especially in relation to exposure during the in utero period and childhood. It also appears that those human populations which have traditionally consumed diets high in seafoods are at greatest risk. While the extent of risk to the general population that may arise from existing environmental exposure levels appears limited, this conclusion is based on an incomplete dataset and therefore the general consensus view that exposure to mercury in its various forms should be minimised where practical, appears to be justified. A number of potential areas of further research are suggested as being pre-requisite to the development of a more rigorous risk assessment. PMID:19850321

Holmes, P; James, K A F; Levy, L S

2009-10-21

163

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

Microsoft Academic Search

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

Alexander L. Bond; Antony W. Diamond

2009-01-01

164

Trace level analysis of mercury using urease in combination with an ammonia gas sensitive semiconductor structure  

SciTech Connect

A method for the determination of mercury(II)ions at trace levels is described. The method is based on the profound inhibitory effect of mercury on the enzyme urease. The activity of the enzyme was determined by the rate of ammonia produced from urea as followed by an ammonia gas sensitive iridium thin metal film-oxide-semiconductor (IrTMOS) structure. Two systems were investigated. For the initial urease activity studies, a simple microcell was used. Also a test plate, containing dry reagent strips with all necessary chemicals was developed, making the analytical procedure very simple to perform. The test volume applied was 2 ..mu..l and the sensitivity to standard of mercury(II) ions is at least 0.005..mu..M (1.0 ng/ml). One sample could be analyzed in less than 8 minutes. Furthermore, the kinetics of sensor response versus enzyme activity is discussed.

Winquist, F.; Lundstroem, I.; Danielsson, B.

1988-10-01

165

PROLONGATION OF HUMAN NEUTROPHIL SURVIVAL BY LOW-LEVEL MERCURY VIA INHIBITION OF SPONTANEOUS APOPTOSIS  

Microsoft Academic Search

Low levels of organic and inorganic mercury compounds have been reported previously to induce cell death by apoptosis in human peripheral blood mononuclear cells (MNC), but little is known about their potential effects on the viability and death of polymorphonuclear neutrophils (PMN). In contrast to MNC, PMN are known to undergo readily spontaneous apoptosis both in vivo and in vitro.

Eliane Moisan; Sylvie Arbour; Nhi Nguyen; Marie-Josée Hébert; Denis Girard; Jacques Bernier; Michel Fournier; Edouard Kouassi

2002-01-01

166

Impact of Consumption of Freshwater Fish on Mercury Levels in Hair, Blood, Urine, and Alveolar Air  

Microsoft Academic Search

Human exposure to methylmercury occurs mainly via consumption of fish. The aim of the study was to investigate the influence of freshwater fish consumption on mercury levels in hair, blood, urine, and end-exhaled air. Twenty subjects without dental amalgam fillings were recruited from sport-fishing societies. They ranged in age from 61 to 87 yr. Six individuals ate freshwater fish at

Cecilia Johnsson; Andrejs Schütz; Gerd Sällsten

2005-01-01

167

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

Microsoft Academic Search

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

Zohreh Salehi; Abbas Esmaili-Sari

2010-01-01

168

Factors Affecting Mercury and Selenium Levels in New Jersey Flatfish: Low Risk to Human Consumers  

Microsoft Academic Search

Some fish contain high levels of mercury (Hg), which could pose a risk to fish eaters themselves or their children. In making decisions about fish consumption, people must decide whether to eat fish, how much to eat, what species to eat, and what size fish to eat, as well as suitable (or unsuitable) locations, among other factors. Yet to make

Joanna Burger; Christian Jeitner; Mark Donio; Sheila Shukla; Michael Gochfeld

2009-01-01

169

Locational Differences in Mercury and Selenium Levels in 19 Species of Saltwater Fish from New Jersey  

Microsoft Academic Search

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

Joanna Burger; Christian Jeitner; Michael Gochfeld

2011-01-01

170

Mercury levels and potential risk from subsistence foods from the Aleutians.  

PubMed

Considerable attention has been devoted to contaminants (mainly PCBs and mercury) in subsistence foods (particularly fish) from various parts of the world. However, relatively little attention has been devoted to examining mercury levels in a full range of subsistence foods from a particular region. While managers and scientists compute risk based on site-specific data on contaminant levels and consumption rates, a first step in making risk decisions by subsistence peoples is knowledge about the relative levels of mercury in the foods they eat. This study examined levels of mercury in subsistence foods (edible components) from several islands in the western Aleutians of Alaska, including algae (4 species), invertebrates (9 species), fish (15 species) and birds (5 species). Samples were gathered by both subsistence hunters/fishers and by scientists using the same equipment. Another objective was to determine if there were differences in mercury levels in subsistence foods gathered from different Aleutian islands. We tested the null hypotheses that there were no interspecific and interisland differences in mercury levels. Because of variation in distribution and the nature of subsistence hunting and fishing, not all organisms were collected from each of the islands. There were significant and important differences in mercury levels among species, but the locational differences were rather small. There was an order of magnitude difference between algae/some invertebrates and fish/birds. Even within fish, there were significant differences. The highest mean mercury levels were in flathead sole (Hippoglossoides elassodon, 0.277 ppm), yellow irish lord (Hemilepidotus jardani, 0.281 ppm), great sculpin (Myoxocephalus polyacanthocephalus, 0.366 ppm), glaucous-winged gull (Larus glaucescens, 0.329 ppm) and its eggs (0.364 ppm), and pigeon guillemot (Cepphus columba, 0.494 ppm). Mercury levels increased with increasing weight of the organisms for limpets (Tectura scutum), and for 11 of the 15 fish species examined. Nine of the 15 fish species had some samples over the 0.3 ppm level, and 7 of 15 fish had some samples over 0.5 ppm. For birds, 95% of the pigeon guillemot muscle samples were above the 0.3 ppm, and 43% were above 0.5 ppm. While health professionals may argue about the risk and benefits of eating fish, and of eating alternative protein sources, the public should be provided with enough information for them to make informed decisions. This is particularly true for subsistence people who consume large quantities of self-caught foods, particularly for sensitive sub-populations, such as pregnant women. We argue that rather than giving people blanket statements about the health benefits or risks from eating fish, information on mean and maximum mercury levels should also be provided on a wide range of subsistence foods, allowing informed decisions, especially by those most at risk. PMID:17590413

Burger, Joanna; Gochfeld, Michael; Jeitner, Christian; Burke, Sean; Stamm, Tim; Snigaroff, Ronald; Snigaroff, Dan; Patrick, Robert; Weston, Jim

2007-06-27

171

Mercury in Morelet's Crocodile Eggs from Northern Belize  

Microsoft Academic Search

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

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

2002-01-01

172

Potential side effects of dental amalgam restorations. (II). No relation between mercury levels in the body and mental disorders.  

PubMed

A group of 50 consecutive patients, referred for self-reported complaints which they related to dental amalgam restorations, was compared with control patients matched by age, sex and postal zip code. All patients were subjected to a psychiatric examination and a set of rating scales and questionnaires, and the symptoms were related to the mercury levels in blood, urine and hair. A psychiatric diagnosis was established in 70% of the patients in the index group versus 14% in the control group. The prevailing symptoms were anxiety, asthenia and depression. Mercury levels in blood, urine and hair were similar among index cases and controls, and were far below critical levels of mercury intoxication. There was no correlation between mercury levels and the severity of the reported symptoms. Therefore, mercury was not a likely cause of the complaints. Instead, the reported symptoms were part of a broad spectrum of mental disorders. PMID:9249191

Bratel, J; Haraldson, T; Ottosson, J O

1997-06-01

173

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

USGS Publications Warehouse

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.

Wente, Stephen P.

2004-01-01

174

Fish consumption patterns and blood mercury levels in Wisconsin Chippewa Indians.  

PubMed

Methylmercury is a known neurotoxin at high blood levels (> 400 micrograms/l) and is thought to cause neurologic symptoms at substantially lower levels in susceptible adults and infants. Given that levels of methylmercury in fish in northern Wisconsin lakes can be high (> 1 ppm, FDA standard) and Chippewa Indians take large amounts of fish from these lakes, the extent of their exposure to methylmercury was investigated. Using tribal-maintained registries, 465 Chippewa adults living on reservation were selected randomly and were invited to participate; 175 (38%) participated in the study. In an effort to characterize nonrespondents, 75 nonrespondents were selected randomly and were followed up aggressively. An additional 152 volunteers who were selected nonrandomly also participated in the study. Subjects completed a questionnaire about fish consumption patterns and had blood drawn for mercury determination. Sixty-four persons (20%) had blood mercury levels in excess of 5 micrograms/l (i.e., upper limit of normal in nonexposed populations); the highest level found was 33 micrograms/l. Fish consumption was higher in males and the unemployed. Blood mercury levels were highly associated with recent walleye consumption (p = .001). Methylmercury levels in some Wisconsin Chippewa were found to be elevated, but were below the levels associated with adverse health effects. We recommend a continuation of efforts to limit exposures in this high-risk population. PMID:8117148

Peterson, D E; Kanarek, M S; Kuykendall, M A; Diedrich, J M; Anderson, H A; Remington, P L; Sheffy, T B

175

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

PubMed

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

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

2005-06-01

176

Mercury in polar bears from Alaska  

SciTech Connect

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.

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

1987-04-01

177

Mercury levels in plasma and urine after removal of all amalgam restorations: The effect of using rubber dams  

Microsoft Academic Search

ObjectiveThe aim of the present study was to determine whether removal of all amalgam restorations might significantly affect mercury levels in plasma and urine and whether the use of rubber dams might reduce patient exposure to mercury during amalgam removal.

Anders Berglund; Margareta Molin

1997-01-01

178

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

PubMed

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

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

2012-05-11

179

Mercury and docosahexaenoic acid levels in maternal and cord blood in relation to segmental maternal hair mercury concentrations at parturition.  

PubMed

Fish is a major source of harmful methylmercury (MeHg) and beneficial docosahexaenoic acid (DHA) in the developing brain. In this study, we investigated the correlations among maternal and umbilical cord (cord) MeHg and DHA levels at parturition, and mercury (Hg) concentration in 1-cm incremental segments hair samples which grew during gestation representing monthly MeHg exposure levels throughout the period. Whole blood Hg and plasma DHA levels were measured in blood sample pairs collected from 54 mothers at early gestation and parturition, and in cord blood. Maternal hair samples were collected at parturition, and Hg concentrations were measured in 1-cm incremental segments. Hg level in mothers at parturition was slightly lower than that at early gestation and the level in cord blood were approximately 1.9 times higher than that in mothers at parturition. On the other hand, DHA level in mothers at parturition was approximately 2.3 and 1.6 times higher than those in mothers at early gestation and in cord plasma, respectively. These results indicate that kinetics of these chemicals in mothers during gestation and placental transfer are completely different. However, Hg and DHA levels had significant positive correlation in fetal circulation. The cord blood Hg showed the strongest correlation with maternal hair Hg in the first 1-cm segment from the scalp at parturition (r=0.87), indicating that fetal MeHg level reflects maternal MeHg burden at late gestation. In contrast, maternal and cord plasma DHA concentrations at parturition showed the highest correlation coefficients with Hg in the fifth (r=0.43) and fourth (r=0.38) 1-cm hair segments, suggesting that maternal and fetal DHA levels reflects maternal fish intake during mid-gestation. PMID:22425897

Sakamoto, Mineshi; Chan, Hing Man; Domingo, José L; Kawakami, Shoichi; Murata, Katsuyuki

2012-03-15

180

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

PubMed

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

Salehi, Zohreh; Esmaili-Sari, Abbas

2010-07-22

181

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

Microsoft Academic Search

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

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

1979-01-01

182

The absorption, blood levels, and excretion of mercury after a single dose of mercury vapor in humans.  

PubMed

Nine healthy volunteers without amalgam fillings were exposed to 400 micrograms/m3 mercury vapor (Hg0) for 15 min, corresponding to 5.5 nmol Hg0/kg body wt (median range: 4.4-7.2). Frequent sampling of blood, urine, and exhaled air was performed for 30 days after exposure. The median retention of Hg0 was 69% of the inhaled dose. During the first 3 days after exposure 7.5-12% of the absorbed dose was lost by exhalation, with the median half time of Hg0 in expired breath being 2.0 days. In blood and plasma, a rapid absorption phase of Hg was seen, followed by a biexponential decline of the curves in both media. A substantial interindividual variation was observed in the area under the concentration-time curves of Hg in blood and plasma. In plasma the median half time of the second phase was 10 days. About 1.0% of the absorbed Hg was excreted via urine during the first 3 days after exposure, whereas the estimated amount excreted during 30 days ranged from 8 to 40%. In order to evaluate the chronic exposure to mercury from dental amalgam in the general population, the daily Hg dose from the fillings were estimated based on the plasma Hg levels found in subjects with amalgam fillings and on the plasma Hg clearance obtained in the present study. The daily Hg dose was estimated to 5-9 micrograms/day in subjects with an ordinary number of amalgam fillings. PMID:9630463

Sandborgh-Englund, G; Elinder, C G; Johanson, G; Lind, B; Skare, I; Ekstrand, J

1998-05-01

183

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

Microsoft Academic Search

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

A. K. Nieschmidt; N. D. Kim

1997-01-01

184

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

SciTech Connect

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

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

1997-05-01

185

Mercury Contamination of Aquatic Ecosystems  

NSDL National Science Digital Library

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.

Krabbenhoft, D. P.; Rickert, D. A.

186

Impact of consumption of freshwater fish on mercury levels in hair, blood, urine, and alveolar air.  

PubMed

Human exposure to methylmercury occurs mainly via consumption of fish. The aim of the study was to investigate the influence of freshwater fish consumption on mercury levels in hair, blood, urine, and end-exhaled air. Twenty subjects without dental amalgam fillings were recruited from sport-fishing societies. They ranged in age from 61 to 87 yr. Six individuals ate freshwater fish at least once a week and were categorized as high consumers. Eight individuals were classified as medium consumers and ate freshwater fish at least once a month but less than once a week. Six individuals were categorized as low consumers and had not eaten freshwater fish in the past 3 mo. Among the high consumers, median concentrations of mercury were 8.6 microg/L in blood, 2.4 microg/g in hair, 10 pg/L in end-exhaled air, and 1.1 microg/g creatinine in urine. The relationship between freshwater fish consumption and mercury was significant in all biological media. The high-consumption group had much higher mercury levels in blood (9-fold), hair (7-fold), alveolar air (3-fold), and urine (15-fold) than the low-consumption group. The latter finding may be explained by demethylation of methylmercury in the body. The ratio between mercury concentration in blood and hair was 1:270. This implies that the typical blood-hair ratio of 1:250, specified by the World Health Organization (WHO) in 1990, is valid also for exposure to low amounts of methylmercury. PMID:15762551

Johnsson, Cecilia; Schütz, Andrejs; Sällsten, Gerd

2005-01-22

187

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

PubMed

The aim of this study was to measure the mercury (Hg) contents of three marine fish and common seafood species (Diplodus annularis, Sarpa salpa and Sepia officinalis) at two sampling sites in the gulf of Gabes, i.e. Sidi Mansour (polluted site) and Kerkennah (control site). These species are frequently consumed by the population living at the Sfax coasts of Tunisia, particularly by the families of fisherman. Additionally, the hair mercury levels of 55 volunteers (28 women, 27 men) were analysed and the daily total mercury intake through the fish and seafood diet was estimated. The key findings were: (1) the mercury contents of the examined fish and seafood species frequently exceeded the regulatory guideline value of 0.5 mg/kg, (2) no site-specific differences in hair mercury contents were found, (3) fish and seafood consumption is probably the major contributor of mercury exposure in this population, (4) the daily mercury intake through frequent consumption of D. annularis exceeds the US EPA reference dose. Further studies are necessary to evaluate the health risks associated with such high mercury exposure levels in order to allow optimal counseling and therapy of the concerned population and to avoid future impairment of human health, particularly children's health. PMID:21136288

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

2010-12-07

188

Mercury burden and health impairment in dental auxilaries. Final report  

SciTech Connect

An effort was made to develop a safe and effective x-ray fluorescence system for monitoring mercury and other elements in human tissues in-situ, to determine mercury levels in 207 dental auxiliaries exposed to dental amalgam on the job, to evaluate mercury in matching nonexposed populations and in 298 dentists using mercury amalgam, and to evaluate deficiencies in central and peripheral nervous systems resulting from the mercury exposure. Mercury levels were below 20 micrograms/gram in 60% of the dentists and 90% of the dental auxiliaries. Dentists with the higher mercury concentrations in their heads or wrists had considerably longer median motor distal latencies and median F-wave latency. Five of them demonstrated abnormalities consistent with carpal tunnel syndrome; seven had polyneuropathies defined as reduced motor or sensory conduction velocities of response amplitudes in two or more nerves. Neuropsychological tests indicated both groups of dental workers were adversely affected by mercury exposure.

Shapiro, I.M.; Bloch, P.; Ship, I.I.; Spitz, L.; Summer, A.

1988-01-01

189

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

SciTech Connect

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

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

1997-06-01

190

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

PubMed

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

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

2010-07-02

191

Mercury speciation in brain tissue of polar bears (Ursus maritimus) from the Canadian Arctic.  

PubMed

Methylmercury (MeHg) is a neurotoxicant that has been found at elevated concentrations in the Arctic ecosystem. Little is known about its internal dose in wildlife such as polar bears. We measured concentrations of mercury (Hg) in three different brain regions (cerebellum, frontal lobe and brain stem) of 24 polar bears collected from the Nunavik, Canada between 2000 and 2003. Speciation of Hg was measured by High Performance Liquid Chromatography coupled to Inductively Coupled Plasma Mass Spectroscopy (HPLC-ICP-MS). Concentrations of mean total Hg in brain tissue were up to 625 times lower (0.28 ± 0.07 mg kg(-1) dry weight (dw) in frontal lobe, 0.23 ± 0.07 mg kg(-1) dw in cerebellum and 0.12 ± 0.0 3mg kg(-1) dw in brain stem) than the mean total Hg concentration previously reported in polar bear liver collected from Eastern Baffin Island. Methylmercury (MeHg) accounted for 100% of the Hg found in all three brain regions analyzed. These results suggest that polar bear might reduce the toxic effects of Hg by limiting the uptake into the brain and/or decrease the rate of demethylation so that Hg can be excreted from the brain more easily. The toxicokinetics and the blood-brain-barrier mechanisms of polar bears are still unknown and further research is required. PMID:22406289

Krey, Anke; Kwan, Michael; Chan, Hing Man

2012-03-08

192

Transport of Inorganic Mercury and Methylmercury in Target Tissues and Organs  

Microsoft Academic Search

Owing to the prevalence of mercury in the environment, the risk of human exposure to this toxic metal continues to increase. Following exposure to mercury, this metal accumulates in numerous organs, including brain, intestine, kidneys, liver, and placenta. Although a number of mechanisms for the transport of mercuric ions into target organs were proposed in recent years, these mechanisms have

Christy C. Bridges; Rudolfs K. Zalups

2010-01-01

193

Occupational health Blood mercury levels of dental students and dentists at a dental school  

Microsoft Academic Search

Objective To determine the blood mercury levels in dental students and clinical teaching staff in a dental school using amalgam as a restorative material.Setting A dental school in Ege University, Turkey surveyed during one academic year.Subjects and methods Cross-sectional study of groups of dental students (n=92) in years I to V, clinical teachers in restorative dentistry (n=16) and controls (n=14).

H Tezel; F Ozata; C Erakin; A Kayali; O S Ertas

2001-01-01

194

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

Microsoft Academic Search

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

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

195

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

Microsoft Academic Search

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

Elia M. Garc; APO AA

196

Blood Levels of Lead, Cadmium, and Mercury in Residents of Tehran  

Microsoft Academic Search

Monitoring of toxic trace elements for human blood has been of interest to researchers in the fields of environmental chemistry\\u000a and medical science. The amount of blood toxic elements can reflect the disease state of the person or the environment where\\u000a that person resides or works. Chronic, low-level exposure to toxic metals such as lead (Pb), cadmium (Cd), and mercury

Leila Farzin; Mojtaba Amiri; Hadi Shams; Mohammad Amin Ahmadi Faghih; Mohammad Esmail Moassesi

2008-01-01

197

Modeling cardiac electrical activity at the cell and tissue levels.  

PubMed

Significant tissue structures exist in cardiac ventricular tissue, which are of supracellular dimension. It is hypothesized that these tissue structures contribute to the discontinuous spread of electrical activation, may contribute to arrhythmogenesis, and also provide a substrate for effective cardioversion. However, the influences of these mesoscale tissue structures in intact ventricular tissue are difficult to understand solely on the basis of experimental measurement. Current measurement technology is able to record at both the macroscale tissue level and the microscale cellular or subcellular level, but to date it has not been possible to obtain large volume, direct measurements at the mesoscales. To bridge this scale gap in experimental measurements, we use tissue-specific structure and mathematical modeling. Our models, which can incorporate ion channel models at the cell level into the reaction-diffusion equations at the tissue level, have enabled us to consider key hypotheses regarding discontinuous activation. PMID:17132793

Austin, Travis M; Hooks, Darren A; Hunter, Peter J; Nickerson, David P; Pullan, Andrew J; Sands, Gregory B; Smaill, Bruce H; Trew, Mark L

2006-10-01

198

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...

199

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

Microsoft Academic Search

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

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

2008-01-01

200

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

PubMed

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

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

2011-04-07

201

Mercury and mink. I. The use of mercury contaminated fish as a food for ranch mink.  

PubMed Central

Adult female and juvenile ranch mink were fed rations containing 50 and 75% of fish containing 0.44 ppm total mercury over a 145 day period. There was no clinical or pathological evidence of intoxication in these animals and mercury concentrations in tissue appeared to be at a level below that associated with toxicity.

Wobeser, G; Nielsen, N O; Schiefer

1976-01-01

202

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

USGS Publications Warehouse

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

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

2005-01-01

203

Levels of Total Mercury in Marine Organisms from Adriatic Sea, Italy  

Microsoft Academic Search

The presence of total mercury in fish, crustacean and cephalopod from Adriatic Sea, was investigated. The highest concentrations\\u000a were observed in decreasing order in: Norway lobster (0.97 ± 0.24 mg\\/kg; mean ± SE), European hake (0.59 ± 0.14 mg\\/kg), red\\u000a mullet (0.48 ± 0.09 mg\\/kg), blue whiting (0.38 ± 0.09 mg\\/kg), Atlantic mackerel (0.36 ± 0.08 mg\\/kg) and European flying squid\\u000a (0.25 ± 0.03 mg\\/kg). A significant difference (p < 0.01) was found between the levels of total mercury in Norway lobster

Monia Perugini; Pierina Visciano; Maurizio Manera; Annalisa Zaccaroni; Vincenzo Olivieri; Michele Amorena

2009-01-01

204

[Mercury levels in fish consumed by the Sai Cinza indigenous community, Munduruku Reservation, Jacareacanga County, State of Pará, Brazil].  

PubMed

This study evaluated fish consumption and mercury levels in fish consumed by an indigenous community in the State of Pará. Eighty fish samples were collected (barbado, surubim, traíra, tucunaré, piranha, aruană, caratinga, aracu, mandiá, jandiá, and pacu). Mercury analysis was performed using a Mercury Analyzer HG-3500. Average mercury concentration in carnivorous species was 0.293 (g/g (SD=0.104), while in non-carnivorous species it was 0.112 (g/g (SD=0. 036). Brazilian legislation establishes a maximum permissible limit of 0.5 (g/g for fish consumption. No significant correlation was found between fish length or weight and mercury concentration. Types of fish most frequently consumed by the community were tucunaré, pacu, jaraqui, traíra, aracu, matrinchă, and caratinga. Carnivorous species, especially tucunaré and traíra, amongst the most frequently eaten, had higher mercury levels than non-carnivorous species. Frequency of consumption is crucial to assess the risk of mercury contamination in communities who lack alternative food sources. PMID:10409785

Brabo, E D; Santos, E D; Jesus, I M; Mascarenhas, A F; Faial, K F

205

Dental silver tooth fillings: A source of mercury exposure revealed by whole-body image scan and tissue analysis  

SciTech Connect

Mercury (Hg) vapor is released from dental silver tooth fillings into human mouth air after chewing, but its possible uptake routes and distribution among body tissues are unknown. This investigation demonstrates that when radioactive 203Hg is mixed with dental Hg/silver fillings (amalgam) and placed in teeth of adult sheep, the isotope will appear in various organs and tissues within 29 days. Evidence of Hg uptake, as determined by whole-body scanning and measurement of isotope in specific tissues, revealed three uptake sites: lung, gastrointestinal, and jaw tissue absorption. Once absorbed, high concentrations of dental amalgam Hg rapidly localize in kidneys and liver. Results are discussed in view of potential health consequences from long-term exposure to Hg from this dental material.

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

1989-12-01

206

Naringin Levels in Citrus Tissues 1  

PubMed Central

The preparation of a tritiated radiotracer that was used in the radioimmunoassay of naringin (naringenin-7-O-?-rhamnosyl- (1-2)-?-d-glucopyranoside) and which was synthesized by reduction of the carbonyl group of the flavanone is reported. The resulting assay has a detection limit of 0.5 picomole per 0.1 milliliter, is specific for the 7-neohesperidoside substitution on flavanones, and can measure naringin in crude extracts of plant tissues. This radioimmunoassay is compared with three other naringin immunoassays which use antibodies raised against two different haptens and different tracers labeled with 125I or 3H. The applicability of the methods to the quantification of naringin and other flavanone neohesperidosides in citrus tissue is discussed.

Jourdan, Pablo S.; Weiler, Elmar W.; Mansell, Richard L.

1985-01-01

207

Determination of Ultratrace Levels of Mercury in SRM 2781 Domestic Sludge by Combustion RNAA  

SciTech Connect

The domestic sludge SRM 2781 was collected from Denver, Colorado, sewage disposal district 1 (DMSDD) in the early 1990s. The DMSDD calls this material 'domestic' because only light industry is present in this district. The term 'domestic' differs from an 'industrial' label by the amount of heavy industry present in the area. The determination of mercury and other toxic elements in these sludges is important to monitor the sources and pathways of environmental exposure to these materials. Analytical results for the determination of total mercury in SRM 2781, domestic sludge, by radiochemical neutron activation analysis (RNAA) are listed in Table I. These analyses were made to measure the total mercury for use in the certification process of this reference material. The control sample data agreed well with the certified values and confirm the methods, procedures, and corrections used. This RNAA combustion procedure is effective in producing high-quality analytical data at the microgram/kilogram concentration level in both the organic and inorganic matrices of these samples. The procedure has both high sensitivity and freedom from significant reagent blanks when properly performed.

Bruce R. Norman; Donald A. Becker; Richard T. Lostritto

2000-11-12

208

Measurement of Mercury Levels in Concentrated Over-the-Counter Fish Oil Preparations Is Fish Oil Healthier Than Fish?  

Microsoft Academic Search

c Context.—Fish consumption has been associated with a decreased risk of coronary artery disease. Recent studies have illustrated that the high mercury content in cold-wa- ter fish may negate the cardiovascular benefits of fish meals. Fish oils have similar antiatherogenic properties to fish, and similar studies should be performed to determine the level of mercury in fish oils. Objective.—To determine

Stacy E. Foran; James G. Flood; Kent B. Lewandrowski

209

Hair mercury levels in an urban population from southern Italy: Fish consumption as a determinant of exposure  

Microsoft Academic Search

Mercury levels in hair of a general population, 237 adults aged between 35–45, in Naples, Italy, were assessed. The subjects were asked to fill in a questionnaire about age, gender, body weight, height, body mass index (BMI), fish consumption, number, surface and area of dental amalgam fillings. Total mercury (THg) concentrations in human hair ranged from 0.221 to 3.402 ?g\\/g and

Sergi Díez; Paolo Montuori; Adele Pagano; Pasquale Sarnacchiaro; Josep M. Bayona; Maria Triassi

2008-01-01

210

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

Microsoft Academic Search

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

Petri Porvari

1995-01-01

211

Comparison of total mercury levels in relation to diet and molt for nine species of marine birds  

Microsoft Academic Search

Total mercury (Hg) concentrations were analyzed for tissues of nine species of marine birds from the Quoddy region, New Brunswick, Canada, including cormorants (Phalacrocorax auritus), eiders (Somateria mollissima), guillemots (Cepphus grylle), phalaropes (Phalaropus lobatus), gulls (Larus argentatus, L. Philadelphia), terns (Sterna hirundo, S. paradisaea) and kittiwakes (Rissa tridactyla). There was a progressive decrease in Hg concentration from the innermost to

Birgit M. Braune

1987-01-01

212

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

Microsoft Academic Search

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

Joice L. Kambey; A. P. Farrell; L. I. Bendell-Young

213

Distribution of mercury in the environment at Almaden, Spain  

SciTech Connect

An ecological survey of the concentration and distribution of mercury in terrestrial and aquatic systems near the mercury mine at Almaden, Spain, was initiated in 1974. Field studies were completed in 1977, and chemical analyses were completed in 1979. Sample collection at Almaden followed a trophic-level approach in which certain compartments were sampled at a given instant in time (fall 1974, fall 1975, spring 1976, fall 1976, spring 1977). Mean total mercury concentration in terrestrial plants (8 taxa combined) ranged from >100 ..mu..g/g within 0.5 km of the mine to 1 ..mu..g/g 20 km distant from the mine. Different plant species had different affinities for mercury, but moss species usually had higher total mercury concentration than vascular plants. Woody plants were lower in mercury concentration than forbs. Total mercury concentration in muscle, brain, kidney, and liver tissue from mice was highest at a station near the stream receiving liquid effluent from the mine (mean total mercury at this station ranging from 0.18 ..mu..g/g in muscle to 4.74 ..mu..g/g in kidney). Approximately 15 to 30% of total mercury in mouse tissue was in the methylated form. Total mercury concentration in muscle tissue from house sparrows varied inversely with distance from the mine, with highest concentrations exceeding 0.1 ..mu..g/g. Approximately 1 to 4% of total mercury in sparrow muscle was in the methylated form.

Hildebrand, S.G.; Huckabee, J.W.; Diaz, F.S.; Janzen, S.A.; Solomon, J.A.; Kumar, K.D.

1980-10-01

214

Correlations between mercury concentrations in umbilical cord tissue and other biomarkers of fetal exposure to methylmercury in the Japanese population.  

PubMed

Methylmercury (MeHg) is one of the most risky substances to affect humans through fish consumption, and the fetus is known to be in the most susceptible group. Our objective in this study is to examine the relationships of total mercury (THg) and MeHg concentrations between umbilical cord tissue and other tissues as biomarkers of fetal exposure to MeHg in the Japanese population. In total, 116 paired samples were collected in three Japanese districts, the Tsushima Islands, Fukuoka City, and Katsushika ward of metropolitan Tokyo. THg was measured for hair and THg and MeHg were measured in cord tissues, maternal blood, and cord blood. The relationships among tissues in Hg concentrations were similar among districts. Therefore, we analyzed the relationships using all the samples. More than 90% of Hg in cord tissue, cord blood, and maternal blood was MeHg. THg and MeHg in cord blood was about two times higher than in maternal blood. A strong correlation was found between THg and MeHg in cord tissue. The cord tissue THg and MeHg showed a strong correlation with cord blood Hg, which is recognized as the best biomarker for fetal exposure to MeHg. The findings of this study indicate the significance of cord tissue THg and MeHg as biomarkers for fetal exposure to MeHg at parturition. PMID:16650842

Sakamoto, Mineshi; Kaneoka, Tsuyoshi; Murata, Katsuyuki; Nakai, Kunihiko; Satoh, Hiroshi; Akagi, Hirokatsu

2006-05-02

215

Effect of lifestyles on the blood mercury level in Korean adults.  

PubMed

Mercury (Hg) is widely distributed in the environment and oral exposure is a main route in the general population. In this study, we estimated the dietary intake of Hg and its relationship with blood Hg levels in Korean adults. The study subjects were recruited from three different districts (rural: 189, coastal: 208 and urban: 184). We used a general questionnaire to collect information about demographic factors, lifestyles and diet. Dietary habits were studied using the 24-h recall method. The estimation of Hg intake was performed using the database of Hg contents in 128 Korean foods based on the previous studies. Blood Hg was analyzed using Direct Mercury Analyzer with the gold-amalgam method. Daily intake of Hg by diet was estimated at 13.57 ?g (0.22 ?g/kg body weight). The geometric mean Hg concentration in whole blood was 3.92 ?g/L. Blood Hg level and Hg intake by diet was higher in coastal areas than in urban or rural areas, respectively. Blood Hg level correlated with the intake of Hg consumed from diet. Seafood was highly responsible and account for 75.6% of total dietary Hg intake. In this study, blood Hg concentrations were found to be significantly affected by sex, age, individual lifestyles and especially the amount of seafood intake, which might play an important role in determining blood Hg levels in Korean adults. PMID:23155199

Kim, N-Y; Ahn, S-J; Ryu, D-Y; Choi, B-S; Kim, H; Yu, I-J; Park, J-D

2012-11-15

216

Sub-clinical neurobehavioral abnormalities associated with low level of mercury exposure through fish consumption.  

PubMed

In order to assess early neurotoxic effects associated with relatively low levels of mercury absorbed through fish eating, two groups of 22 adult male subjects, habitual consumers of tuna fish, and 22 controls were examined using a cross-sectional field study. The assessment included neurobehavioral tests of vigilance and psychomotor function, hand tremor measurements and serum prolactin assessment. Mercury in urine (U-Hg) and serum prolactin (sPRL) were measured in all exposed subjects and controls, whereas measurements of the organic component of mercury in blood (O-Hg) were available for only 10 exposed and six controls. U-Hg was significant higher among exposed subjects (median 6.5 microg/g of creatinine, range 1.8-21.5) than controls (median 1.5 microg/g of creatinine, range 0.5-5.3). The median values of O-Hg were 41.5 microg/l among the tuna fish eaters and 2.6 microg/l in the control group. Both U-Hg and O-Hg were significantly correlated with the quantity of fish consumed per week. Significant differences in sPRL were found between exposed (12.6 ng/ml) and controls (9.1 ng/ml). Individual sPRL were significantly correlated with both U-Hg and O-Hg levels. The neurobehavioral performance of subjects who consumed tuna fish regularly was significantly worse on color word reaction time, digit symbol reaction time and finger tapping speed (FT). After considering the education level and other covariates, the multiple stepwise regression analysis indicated that O-Hg concentration was most significantly associated with individual performance on these tests, accounting for about 65% of the variance in test scores. PMID:12900074

Carta, Plinio; Flore, Costantino; Alinovi, Rossella; Ibba, Antonio; Tocco, Maria Giuseppina; Aru, Gabriella; Carta, Roberta; Girei, Emanuela; Mutti, Antonio; Lucchini, Roberto; Randaccio, Francesco Sanna

2003-08-01

217

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

SciTech Connect

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

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

1995-02-01

218

Optical and Electrical Studies of the Double Acceptor Levels of the Mercury Vacancies in HgCdTe  

NASA Astrophysics Data System (ADS)

Correlations between photoluminescence and temperature-dependent Hall measurements were carried out on unintentionally doped HgCdTe epilayers with cadmium composition of 32.7%. These films were grown by liquid-phase epitaxy and post-annealed under different conditions as follows: a p-type annealing was used to control the mercury vacancy concentration, and an n-type annealing under saturated mercury atmosphere was used to fill the mercury vacancies. Comparison of the results obtained by these two characterization techniques allowed us to identify the two acceptor energy levels of the mercury vacancy. Moreover, the "U-negativity" of the vacancy was evidenced: the ionized state V- is stabilized under the neutral state V0 by the dominance of the Jahn-Teller effect over Coulombic repulsion. Finally, three epilayers with different cadmium compositions were also characterized to complete this study.

Gemain, F.; Robin, I. C.; Brochen, S.; De Vita, M.; Gravrand, O.; Lusson, A.

2012-10-01

219

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

PubMed

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

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

2007-07-19

220

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

NASA Astrophysics Data System (ADS)

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

Showstack, Randy

221

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

Microsoft Academic Search

The recent discovery of mass-independent fractionation of mercury isotopes allows new constraints to be placed on the mercury cycle. Here we report new Hg isotopic analyses of zooplankton and fish from different trophic levels of a freshwater lake (Lake Jackson, Florida) bearing systematic mass-independent fractionation of mercury isotopes. Fish muscle tissues show a progressive enrichment in the odd-mass mercury isotopes

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

2009-01-01

222

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

Microsoft Academic Search

Much of the research on mercury (Hg) in wild vertebrates has focused on piscivores and other animals at high trophic levels.\\u000a However, recent studies indicated that insectivorous terrestrial vertebrates may also be at risk. In the present study, we\\u000a examined blood and fur Hg concentrations as well as the adrenocortical responses of insectivorous big brown bats (Eptesicus fuscus) near the

Haruka WadaDavid; David E. Yates; David C. Evers; Robert J. Taylor; William A. Hopkins

2010-01-01

223

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

Microsoft Academic Search

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

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

2007-01-01

224

Exon-level expression profiling of ocular tissues.  

PubMed

The normal gene expression profiles of the tissues in the eye are a valuable resource for considering genes likely to be involved with disease processes. We profiled gene expression in ten ocular tissues from human donor eyes using Affymetrix Human Exon 1.0 ST arrays. Ten different tissues were obtained from six different individuals and RNA was pooled. The tissues included: retina, optic nerve head (ONH), optic nerve (ON), ciliary body (CB), trabecular meshwork (TM), sclera, lens, cornea, choroid/retinal pigment epithelium (RPE) and iris. Expression values were compared with publically available Expressed Sequence Tag (EST) and RNA-sequencing resources. Known tissue-specific genes were examined and they demonstrated correspondence of expression with the representative ocular tissues. The estimated gene and exon level abundances are available online at the Ocular Tissue Database. PMID:23500522

Wagner, Alex H; Anand, V Nikhil; Wang, Wan-Heng; Chatterton, Jon E; Sun, Duo; Shepard, Allan R; Jacobson, Nasreen; Pang, Iok-Hou; Deluca, Adam P; Casavant, Thomas L; Scheetz, Todd E; Mullins, Robert F; Braun, Terry A; Clark, Abbot F

2013-03-14

225

Mercury concentration in fish from Piracicaba River (Minas Gerais, Brazil)  

Microsoft Academic Search

Mercury emissions from some upstream gold mining areas and recent findings of high natural Hg levels in sediments motivated\\u000a studies on the Hg cycle in the Minas Gerais state. The study presents the total mercury amount found in Geophagus brasiliensis’ muscular tissue (wet weight) and sediments from Piracicaba River. Mercury was analyzed using acid digestion followed by\\u000a determination of total

I. A. Arantes; M. T. C. Pinto; P. A. Mangabeira; M. F. Grenier-Loustalot; M. A. R. V. Veado; A. H. Oliveira

2009-01-01

226

Evaluation of Nonlethal Methods for the Analysis of Mercury in Fish Tissue  

Microsoft Academic Search

Thousands of fish are sacrificed each year to determine potential human exposure to mercury (Hg) from fish consumption. In this paper, we use lake whitefish Coregonus clupeaformis and northern pike Esox lucius to demonstrate that accurate and reliable measures of fish muscle Hg concentrations can be determined from small samples (<100 mg) harvested with biopsy tools. Reliability of results primarily

R. F. Baker; P. J. Blanchfield; M. J. Paterson; R. J. Flett; L. Wesson

2004-01-01

227

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...

228

Mercury residues in free-grazing cattle and domestic fowl form the artisanal gold mining area of Geita district, Tanzania  

Microsoft Academic Search

Environmental contamination with mercury from artisanal gold mines in Tanzania has been widely reported. People living around mining villages keep domestic animals which are allowed to feed freely in mercury-contaminated areas. This study investigated Hg accumulation in the liver and muscle tissue of cattle and domestic fowl reared in mining villages. Total mercury levels up to 436 and 820 µg\\/kg

R. T. Chibunda; C. R. Janssen

2009-01-01

229

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

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.

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

1981-01-01

230

Determination of total mercury in chicken feed, its translocation to different tissues of chicken and their manure using cold vapour atomic absorption spectrometer  

Microsoft Academic Search

In this study, the contents of total mercury (Hg) present in poultry feed, tissues of broiler chicken and manure were assessed. For this purpose, chicken feeds (five brands), different tissues of broiler chicken of two age groups (1–3 and 4–6week) and manure samples were collected from five commercial poultry farms of Hyderabad, Pakistan. The Hg concentrations in feeds, chicken tissues

A. Q. Shah; T. G. Kazi; J. A. Baig; H. I. Afridi; G. A. Kandhro; S. Khan; N. F. Kolachi; S. K. Wadhwa

2010-01-01

231

Tissue specific expression and serum levels of human tissue factor in patients with urological cancer.  

PubMed

Human tissue factor (TF) is involved in tumor angiogenesis and metastasis. However, little is known about the distribution of TF in urological cancer. In this study we investigated the TF expression in tumor tissue and autologous non-malignant tissue as well as in serum of patients with renal cell carcinoma (RCC), bladder cancer, and prostate cancer (PCa). To study the distribution of TF in tumor tissue and in the surrounding non-malignant tissue, we measured TF protein by ELISA in tissue specimens obtained intraoperatively from 18 RCC, seven bladder cancer and six PCa patients. Differences in TF expression were found between tumor tissue and nonmalignant tissue for the three tumor types at the protein level (in the order RCC < bladder cancer < PCa). In all but one of the 18 RCC patients (94 %) higher TF protein level was observed in non-malignant tissue as compared to the tumor tissue. In addition, the relative TF mRNA expression analyzed by a quantitative RT-PCR assay in the same RCC tissue sample pairs was higher in 78% of non-malignant tissues in comparison to the tumor tissue specimens. Moreover, using enzyme linked immunosorbent assay the TF protein content was measured in serum samples of 66 patients with bladder cancer, 75 RCC patients and 157 PCa patients, and was compared with the TF serum level of 92 healthy volunteers. Whereas no differences were detected between normal volunteers and patients with PCa or RCC, patients with bladder cancer showed a significantly increased level of serum TF (P=0.0076). However, no causal association between TF levels in serum and TF content in tissue extracts for all three tumor types of urological tumors was found. Our results suggest that TF in non-malignant renal tissues was expressed at a higher level compared to the supposed de novo TF expression in RCC tissue specimens. This indicates a tumor-associated induction of TF expression in the TF-negative RCC progenitor cells. The increased serum TF levels are alike the reported higher urinary TF levels found in bladder cancer patients. The potential clinical relevance of this finding should be further elucidated. PMID:12691825

Förster, Yvonne; Meye, Axel; Albrecht, Sybille; Kotzsch, Matthias; Füssel, Susanne; Wirth, Manfred P; Schwenzer, Bernd

2003-04-10

232

Scalp hair and saliva as biomarkers in determination of mercury levels in Iranian women: amalgam as a determinant of exposure.  

PubMed

The aim of this study was to determine the relationship between mercury concentrations in saliva and hair in women with amalgam fillings and its relation with age and number of amalgam fillings. Eighty-two hair and saliva samples were collected randomly from Iranian women who have the same fish consumption pattern and free from occupational exposures. The mean+/-SD age of these women was 29.37+/-8.12 (ranged from 20 to 56). The determination of Hg level in hair samples was carried out by the LECO, AMA 254, Advanced Mercury Analyzer according to ASTM, standard No. D-6722. Mercury concentration in saliva samples was analyzed by PERKIN-ELMER 3030 Cold Vapor Atomic Absorption Spectrophotometer. The mean+/-SD mercury level in the women was 1.28+/-1.38 microg/g in hair and 4.14+/-4.08 microg/l in saliva; and there were positive correlation among them. A significant correlation was also observed between Hg level of saliva (Spearman's rho=0.93, P<0.001) and hair (Spearman's rho=0.92, P<0.001) with number of amalgam fillings. According to the results, we can conclude that amalgam fillings may be an effective source for high Hg concentration in hair and releasing the mercury to the saliva samples. PMID:20034733

Fakour, H; Esmaili-Sari, A; Zayeri, F

2009-12-04

233

Tissue levels of adiponectin in breast cancer patients  

Microsoft Academic Search

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

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

2007-01-01

234

A study of mercury in the hair of dentists and dental?related professionals in 1985 and subcohort comparison of 1972 and 1985 mercury hair levels  

Microsoft Academic Search

Dentists may be exposed to mercury used in dental restorations. An epidemiologic study was conducted in central New York in 1985 comparing the concentration of mercury in the hair of 85 dentists to that of 23 dental?related health professionals (mainly orthodontists and oral surgeons) who do not use mercury. Mercury in the hair of dentists was nominally higher (2.98 ±

Janet M. Scarlett; Walter H. Gutenmann; Donald J. Lisk

1988-01-01

235

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

PubMed

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

Emery, Erich B; Spaeth, John P

2010-06-25

236

Influences on Mercury Bioaccumulation Factors for the Savannah River  

SciTech Connect

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.

Paller, M.H.

2003-05-06

237

Effect of ?-tocopherol tissue levels on beef quality.  

PubMed

To evaluate meat quality of beef with different ?-tocopherol tissue levels, 55 feedlot steers were fed a barley-based finisher diet with four vitamin E supplementation levels (0, 350, 700 and 1400 IU DL-?-tocopheryl acetate/animal per day) for 120 days. Although the increase in oxidation levels overtime was much smaller (P < 0.001) in the high-medium and high groups, ?-tocopherol tissue levels did not affect (P > 0.05) pH, proximate analysis, drip and cooking losses, and shear force of steaks. No effect of ?-tocopherol tissue levels was found in retail evaluation of steaks after a short ageing time of 6 days, but with 21 days of ageing, a delay in formation of metmyoglobin (P = 0.008) was observed in steaks with higher tissue levels of ?-tocopherol. Similar results were found for ground beef (25% fat) prepared from 6-day aged meat. Thus, higher ?-tocopherol tissue levels protect ground beef and long-aged steaks from discolouration and lipid oxidation. PMID:22440478

Nassu, R T; Dugan, M E R; Juárez, M; Basarab, J A; Baron, V S; Aalhus, J L

2011-12-01

238

An Investigation of Modifying Effects of Metallothionein Single-Nucleotide Polymorphisms on the Association between Mercury Exposure and Biomarker Levels  

PubMed Central

Background: Recent studies have suggested that several genes that mediate mercury metabolism are polymorphic in humans. Objective: We hypothesized that single-nucleotide polymorphisms (SNPs) in metallothionein (MT) genes may underlie interindividual differences in mercury biomarker levels. We studied the potential modifying effects of MT SNPs on mercury exposure–biomarker relationships. Methods: We measured total mercury in urine and hair samples of 515 dental professionals. We also surveyed occupational and personal exposures to dental amalgam and dietary fish consumption, from which daily methylmercury (MeHg) intake was estimated. Log-transformed urine and hair levels were modeled in multivariable linear regression separately against respective exposure surrogates, and the effect modification of 13 MT SNPs on exposure was investigated. Results: The mean mercury levels in urine (1.06 ?g/L) and hair (0.51 ?g/g) were not significantly different from the U.S. general population (0.95 ?g/L and 0.47 ?g/g, respectively). The mean estimated daily MeHg intake was 0.084 ?g/kg/day (range, 0–0.98 ?g/kg/day), with 25% of study population intakes exceeding the current U.S. Environmental Protection Agency reference dose of 0.1 ?g/kg/day. Multivariate regression analysis showed that subjects with the MT1M (rs2270837) AA genotype (n = 10) or the MT2A (rs10636) CC genotype (n = 42) had lower urinary mercury levels than did those with the MT1M or MT2A GG genotype (n = 329 and 251, respectively) after controlling for exposure and potential confounders. After controlling for MeHg intake, subjects with MT1A (rs8052394) GA and GG genotypes (n = 24) or the MT1M (rs9936741) TT genotype (n = 459) had lower hair mercury levels than did subjects with MT1A AA (n = 113) or MT1M TC and CC genotypes (n = 15), respectively. Conclusion: Our findings suggest that some MT genetic polymorphisms may influence mercury biomarker concentrations at levels of exposure relevant to the general population.

Wang, Yi; Goodrich, Jaclyn M.; Gillespie, Brenda; Werner, Robert; Basu, Niladri

2012-01-01

239

Prenatal low-level mercury exposure and neonatal anthropometry in rural northern China.  

PubMed

Mercury (Hg) is a ubiquitous heavy metal that can negatively affect human health; however, few studies have examined the impact of prenatal low-level Hg exposure on fetal growth. We investigated prenatal exposure levels of Hg and the relationship between Hg levels and neonatal anthropometrics, including birth weight, length, and head circumference. A total of 258 mother-infant pairs were recruited from a rural community located on the southern coastal area of Laizhou Bay of the Bohai Sea in northern China between September 2010 and December 2011. We measured maternal and cord whole blood Hg levels and examined their association with neonatal anthropometrics. The geometric means (GMs) of Hg in maternal and cord whole blood were 0.84?gL(-1) and 1.46?gL(-1), respectively. The Hg exposure levels in our study population were much lower than those reported in previous domestic studies. No significant associations were found between maternal or cord blood Hg levels and birth weight, length, and head circumference. However, our results should be interpreted with caution given the high toxicity of Hg and its persistence in the body. Studies focusing on long-term adverse outcomes are needed to further examine the cumulative effects of low-level Hg exposure. PMID:23411084

Ding, Guodong; Cui, Chang; Chen, Limei; Gao, Yu; Zhou, Yijun; Shi, Rong; Tian, Ying

2013-02-11

240

Dietary intake, levels in food and estimated intake of lead, cadmium, and mercury.  

PubMed

Since 1980, systematic efforts have been made by the Joint UNEP/FAO/WHO Food Contamination Monitoring Programme to collect information on dietary intake of various contaminants, exemplified by lead, cadmium and mercury. In 1980-88, average adult intakes of lead varied from 1 to 63 micrograms/kg bw/week, approaching or exceeding the Provisional Tolerate Weekly Intake (PTWI) of 25 micrograms/kg bw in four countries providing data. Major sources in food and drinking water differed from country to country. A downward trend was observed consequent on reduction in use of lead-soldered cans and of lead in petrol. Few countries provided data on intakes by infants and children (more vulnerable groups) but the mean exceeded the PTWI in three countries, heavily influenced by levels in water and lowest in infants consuming only breast milk. Average adult intakes of cadmium were, with one exception, below the PTWI of 7 micrograms/kg bw; intakes by children were higher on a body weight basis but still within the PTWI in countries supplying data. Highest levels occurred in offal (mean 320 micrograms/kg) and shellfish (200 micrograms/kg) but, because of amounts consumed, reduction of concentrations in cereals, roots and tubers would be most effective. Important sources of contamination included phosphate fertilizer sewage sludge, plated/galvanized equipment, enamels and glazes. For mercury, average intakes were below the PTWI (300 micrograms/person; 200 micrograms/person or 3.3 micrograms/kg bw as methylmercury) for adults and for breast-fed infants. Contributions from fish varied from 20 to 85%; in some countries because of different dietary habits, cereals or meat may contribute similar amounts. Because of inadequate data on food other than fish, intake estimates are biassed and sometimes based solely on typical levels in fish. PMID:8504867

Galal-Gorchev, H

241

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

PubMed

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

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

2012-01-09

242

Mercury, arsenic and selenium exposure levels in relation to fish consumption in the Mediterranean area.  

PubMed

In order to assess mercury (Hg), selenium (Se) and arsenic (As) exposure in the Mediterranean area, total mercury (THg), monomethylmercury (MeHg), Se and As levels were measured in umbilical cord blood and breast milk from Italian (n=900), Slovenian (n=584), Croatian (n=234) and Greek (n=484) women. THg, MeHg, As, and Se levels were also determined in blood samples of the same mothers from Italy and Croatia. In addition, THg and MeHg were determined in the same women's hair from all the countries involved in this study and As and Se levels were determined in the mother's urine samples from Italy, Croatia and Greece. Besides recording the consumption of other food items, the frequencies of fish consumption were assessed by detailed food frequency questionnaires, since fish represents an important source of Hg, Se and As in humans. The highest levels of THg and As were found in cord blood (Med((THg))=5.8 ng/g; Med((As))=3.3 ng/g) and breast milk (Med((THg))=0.6 ng/g; Med((As))=0.8 ng/g) from Greek women, while the highest Se levels were found in cord blood (Med=113 ng/g) from Italy. Significant linear correlations were found between Hg, Se and As in blood, cord blood and breast milk. In addition, significant relations were found between the frequencies of total fish consumption and biomarkers of As, MeHg and Se exposure, with the strongest Spearman rank coefficients between frequencies of total fish consumption and THg levels in cord blood (r(s)=0.442, p<0.001) or THg levels in hair (r(s)=0.421, p<0.001), and between frequencies of total fish consumption and As levels in cord blood (r(s)=0.350, p<0.001). The differences in Hg and As exposure between countries were probably due to different amounts of fish consumption and the consumption of different species of fish of different origin, while the highest Se levels in women from Italy were probably the consequence of the more frequent consumption of different non specific food items. Moreover, fish consumption, the possible common source of As, Hg and Se intake, could explain the correlations between the elements determined in cord blood, mother's blood or breast milk. PMID:22999706

Miklav?i?, Ana; Casetta, Anica; Snoj Tratnik, Janja; Mazej, Darja; Krsnik, Mladen; Mariuz, Marika; Sofianou, Katia; Spiri?, Zdravko; Barbone, Fabio; Horvat, Milena

2012-09-21

243

Using native epiphytic ferns to estimate the atmospheric mercury levels in a small-scale gold mining area of West Java, Indonesia.  

PubMed

Mercury pollution is caused by artisanal and small-scale gold mining (ASGM) operations along the Cikaniki River (West Java, Indonesia). The atmosphere is one of the primary media through which mercury can disperse. In this study, atmospheric mercury levels are estimated using the native epiphytic fern Asplenium nidus complex (A. nidus) as a biomonitor; these estimates shed light on the atmospheric dispersion of mercury released during mining. Samples were collected from 8 sites along the Cikaniki Basin during September-November, 2008 and September-November, 2009. The A. nidus fronds that were attached to tree trunks 1-3m above the ground were collected and measured for total mercury concentration using cold vapor atomic absorption spectrometry (CVAAS) after acid-digestion. The atmospheric mercury was collected using porous gold collectors, and the concentrations were determined using double-amalgam CVAAS. The highest atmospheric mercury concentration, 1.8 × 10(3) ± 1.6 × 10(3) ngm(-3), was observed at the mining hot spot, and the lowest concentration of mercury, 5.6 ± 2.0 ngm(-3), was observed at the remote site from the Cikaniki River in 2009. The mercury concentrations in A. nidus were higher at the mining village (5.4 × 10(3) ± 1.6 × 10(3) ngg(-1)) than at the remote site (70 ± 30 ngg(-1)). The distribution of mercury in A. nidus was similar to that in the atmosphere; a significant correlation was observed between the mercury concentrations in the air and in A. nidus (r=0.895, P<0.001, n=14). The mercury levels in the atmosphere can be estimated from the mercury concentration in A. nidus using a regression equation: log (Hg(A.nidu)/ngg(-1))=0.740 log (Hg(Air)/ngm (-3)) - 1.324. PMID:22595529

Kono, Yuriko; Rahajoe, Joeni S; Hidayati, Nuril; Kodamatani, Hitoshi; Tomiyasu, Takashi

2012-05-15

244

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

PubMed

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

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

2012-04-22

245

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

Microsoft Academic Search

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

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

1997-01-01

246

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...

247

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

PubMed

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 alpha1-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 microg/g in hair, 0.59+/-0.32 microg/g in toenail, and 0.86+/-0.66 microg/g creatinine in urine; and, there were positive correlations among them (P<0.001). The daily mercury intake of 9.15+/-7.84 microg/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 microg/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 (microg/g)]=2.44x[toenail mercury (microg/g)]. PMID:16890218

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

2006-08-04

248

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

SciTech Connect

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)].

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

249

Acute effects of mercuric chloride on intracellular GSH levels and mercury distribution in the fish Oreochromic aureus  

SciTech Connect

In recent years there has been much interest in the effects of trace metals on intracellular levels of reduced glutathione (GSH). Most of the research has been performed on rats. As GSH is ubiquitous in living organisms it is of interest to establish a relationship between mercury intoxication and intracellular GSH levels in fish; especially as fish living in rivers and coastal areas are often expose to mercury as an aquatic pollutant. The role of GSH in fish trace metal toxicity has not been thoroughly investigated. The distribution of total glutathione (oxidized + reduced) in selected black sea bass organs seems to follow the established pattern for mammalian organs. Thus, it would appear that teleostian and mammalian glutathione metabolism may have many similarities. There are few reports concerning the effects of mercury during the first few hours of exposure. The aim of this investigation is to establish any changes in organ GSH and mercury levels following just 2 h exposure to mercuric chloride (HgCl/sub 2/).

Allen, P.; Min, S.Y.; Keong, W.M.

1988-02-01

250

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

PubMed

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

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

2005-03-01

251

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

PubMed Central

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.

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

252

MERCURY LEVELS IN NORTHERN PIKE, ESOX LUCIUS, RELATIVE TO WATER CHEMISTRY IN NORTHERN MINNEOSTA LAKES  

Microsoft Academic Search

Previous studies on lakes in northern Minnesota revealed elevated fish mercury concentrations. These results prompted fish consumption advisories on several lakes. As a followup to that work, fish fillet samples were collected for mercury analysis from 98 lakes in northern Minnesota from 1981 through 1983. Northern pike (Esox lucius) was picked as an indicator species because of its distribution throughout

Steven A. Heiskary; Daniel D. Helwig

1986-01-01

253

Determination of trace levels of mercury in water samples based on room temperature phosphorescence energy transfer  

Microsoft Academic Search

A novel method has been developed for the sensitive determination of mercury in aqueous media by room temperature phosphorescence (RTP). The measurement principle is based on the energy transfer (ET) from a phosphor molecule (acting as a donor) to a Hg-sensitive dye (acceptor). To our acknowledgment this is the first RTP method for mercury measurement developed so far. ?-Bromonaphthalene (BrN)

Blanca San Vicente de la Riva; José M. Costa-Fernández; Wei Jun Jin; Rosario Pereiro; Alfredo Sanz-Medel

2002-01-01

254

Research SummaryA study of the mercury levels in Scottish dentists  

Microsoft Academic Search

Aim A study of 180 dentists in the West of Scotland was conducted to determine their exposure to mercury during the course of their work and the effects on their health and cognitive function.Design Data were obtained from questionnaires distributed to dentists and by visiting their surgeries to take measurements of environmental mercury.Methods Dentists were asked to complete a questionnaire

D Brown

2004-01-01

255

Fish consumption, advisory awareness, and hair mercury levels among women of childbearing age  

Microsoft Academic Search

The Wisconsin Division of Public Health and the State of Maine Bureau of Health collaborated on a 12 state mercury awareness project. The primary goals of this initiative were to evaluate mercury sport fishing advisory awareness among women of childbearing age and assess the methylmercury exposure among this subpopulation. The project, which was conducted between December 1998 and December 1999,

Lynda Knobeloch; Henry A. Anderson; Pamela Imm; Debi Peters; Andrew Smith

2005-01-01

256

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

PubMed

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

McKay, Jennifer L; Maher, Christine R

2012-09-04

257

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

PubMed

Mercury levels measured in 302 hair samples of 4 year-old children from Menorca (western Mediterranean Sea) are reported. Their concentrations, arithmetic mean 1.4 ?g/g, ranging between 0.040 ?g/g and 10 ?g/g, were higher than in other children inland populations but lower than in previously studied island cohorts, e.g. Faroe, Madeira and Seychelles. 20% of the samples were above the WHO recommended values. Higher concentrations in females than males were observed. Frequent consumption of fish and other seafood were significantly related to the observed mercury concentrations. Oily fish was the main source of this pollutant but shellfish and squid consumption were also associated with high mercury concentrations. Maternal smoking, occupational status or previous siblings were also found to significantly influence the levels of this pollutant. McCarthy Scales of Children's Abilities used to assess children's motor and cognitive abilities did not show association with mercury concentrations at 4 years of age. PMID:23959058

Garí, Mercč; Grimalt, Joan O; Torrent, Maties; Sunyer, Jordi

2013-08-16

258

Maternal fish intake during pregnancy, blood mercury levels, and child cognition at age 3 years in a US cohort.  

PubMed

The balance of contaminant risk and nutritional benefit from maternal prenatal fish consumption for child cognitive development is not known. Using data from a prospective cohort study of 341 mother-child pairs in Massachusetts enrolled in 1999-2002, the authors studied associations of maternal second-trimester fish intake and erythrocyte mercury levels with children's scores on the Peabody Picture Vocabulary Test (PPVT) and Wide Range Assessment of Visual Motor Abilities (WRAVMA) at age 3 years. Mean maternal total fish intake was 1.5 (standard deviation, 1.4) servings/week, and 40 (12%) mothers consumed >2 servings/week. Mean maternal mercury level was 3.8 (standard deviation, 3.8) ng/g. After adjustment using multivariable linear regression, higher fish intake was associated with better child cognitive test performance, and higher mercury levels with poorer test scores. Associations strengthened with inclusion of both fish and mercury: effect estimates for fish intake of >2 servings/week versus never were 2.2 (95% confidence interval (CI): -2.6, 7.0) for the PPVT and 6.4 (95% CI: 2.0, 10.8) for the WRAVMA; for mercury in the top decile, they were -4.5 (95% CI: -8.5, -0.4) for the PPVT and -4.6 (95% CI: -8.3, -0.9) for the WRAVMA. Fish consumption of < or =2 servings/week was not associated with a benefit. Dietary recommendations for pregnant women should incorporate the nutritional benefits as well as the risks of fish intake. PMID:18353804

Oken, Emily; Radesky, Jenny S; Wright, Robert O; Bellinger, David C; Amarasiriwardena, Chitra J; Kleinman, Ken P; Hu, Howard; Gillman, Matthew W

2008-03-18

259

Environmental levels of cadmium, lead and mercury in brown hares and their relation to blood metabolic parameters.  

PubMed

The purpose of this study was to examine concentrations of selected heavy metals in the liver and kidney of brown hares (Lepus europaeus). In addition, correlations between heavy metals and biochemical parameters in blood plasma were determined. The average concentrations of heavy metals (mmol/L) +/- SD were as follows: liver: Pb 0.221 +/- 0.189, Cd 0.160 +/- 0.140, Hg 0.021 +/- 0.030, kidney: Pb 0.115 +/- 0.125, Cd 1.570 +/- 1.103, Hg 0.030 +/- 0.053. The average concentrations of biochemical parameters in the blood plasma were as follows: Ca 3.16 mmol/L, P 2.19 mmol/L, Mg 1.40 mmol/L, Na 148.71 mmol/L, K 8.12 mmol/L, glucose 6.56 mmol/L, total proteins 56.49 g/L, urea 5.00 mmol/L, total lipids 1.40 g/L, bilirubin 3.97 micro mol/L, cholesterol 1.53 mmol/L, aspartate aminotransferase (AST) 6.06 micro kat/L and alanine aminotransferase (ALT) 1.94 micro kat/L. Average levels of hormones (ng/mL) were as follows: testosterone 2.94, androstendiol 0.13, estradiol 501.59, progesterone 6.63, oxytocin 328.60. Tissue analysis showed an accumulation of lead, cadmium and mercury in the liver and kidney of brown hares. There were no significant correlations between levels of heavy metals in liver, kidney, and biochemical parameters. PMID:18393073

Kolesarova, Adriana; Slamecka, Jaroslav; Jurcik, Rastislav; Tataruch, Frieda; Lukac, Norbert; Kovacik, Jaroslav; Capcarova, Marcela; Valent, Miroslav; Massanyi, Peter

2008-05-01

260

Relationship between RBC Mercury Levels and Serum n3 Polyunsaturated Fatty Acid Concentrations among Japanese Men and Women  

PubMed Central

Aims. To evaluate potential health risk and benefits of fish consumption, the association of fish consumption with total mercury levels in red blood cells (RBCs) and serum eicosapentaenoic acid (EPA) concentrations was examined. Subjects and Methods. Study subjects were 269 Japanese (98 men and 171 women) living in a remote island of Kagoshima, and their blood was drawn in 1994. Results. Total mercury levels were related to weekly fish consumption among women (P = 0.035) but not among men (P = 0.643). However, serum EPA levels were not related to fish consumption in both women and men. In contrast, EPA levels in the high-density ipoprotein (HDL) fraction of the sera were significantly related to fish consumption (P values for men and women were 0.014 and 0.073, resp.). Interestingly, mercury levels were related to serum EPA levels and EPA in the HDL fraction of the sera (P = 0.001) among women (P = 0.005) but not among men. Sex differences in fish species consumed may be an explanation for the observed sex difference. Conclusion. Those findings suggest that the health benefit of fish consumption can be maximized by the careful selection of fish species consumed.

Tsuji, Mayumi; Ando, Tetsuo; Kitano, Takao; Wakamiya, Junji; Koriyama, Chihaya; Akiba, Suminori

2012-01-01

261

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

PubMed

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

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

2011-07-05

262

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

PubMed

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

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

2012-03-22

263

Phytoremediation of Ionic and Methyl Mercury Pollution  

SciTech Connect

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.

Meagher, Richard B.

2005-06-01

264

Tissue-specific response of metallothionein and superoxide dismutase in the clam Mactra veneriformis under sublethal mercury exposure.  

PubMed

To identify the relationship between mercury (Hg) and stress responses in the clam Mactra veneriformis, metallothionein (MT) and superoxide dismutase (SOD) mRNA expression in the digestive gland, gill, and mantle as well as MT protein content and SOD activity in the digestive gland were examined under sublethal Hg exposure at doses of 10, 20, and 40 ?g/L for 21 days. The ranking of the tissues in decreasing order of their basal MvMT and MvSOD mRNA expression is as follows: digestive gland > mantle > gill > adductor muscle > foot and digestive gland > mantle > gill > foot > adductor muscle, respectively. Hg exposure significantly elevated MvMT and MvSOD mRNA transcripts in the digestive gland, gill, and mantle in a tissue-specific way. In the digestive gland, a dose-dependent increase of MvMT and MvSOD mRNA expression, stimulation of MT protein, and alteration of SOD activity were observed under Hg stress. MT protein responded later than MT mRNA to Hg exposure and no clear relationship was found between them, indicating the occurrence of posttranscriptional events. All of the results suggest that MT and SOD cooperate in resisting Hg toxicity and maintaining cellular metabolic homeostasis in M. veneriformis. MT and SOD mRNA expressions have great potential as biomarkers of Hg pollution in the aquatic environment for the studied species. PMID:22678552

Fang, Yan; Yang, Hongsheng; Liu, Baozhong

2012-06-08

265

Mercury levels in road dust and household TSP/PM?.? related to concentrations in hair in Guangzhou, China.  

PubMed

Road dust, household total suspended particulate matters (TSP) and PM?.? were collected in urban area of Guangzhou, south of China, to investigate the concentrations of total mercury (THg) and methyl mercury (MeHg). The household PM?.? concentrations varied between 16.2 and 623 ?g/mł. The average PM?.? level (174 ?g/mł) from all of the locations exceeded 24-h concentration from WHO air quality guideline The average concentrations of THg and MeHg were: 235 ?g/kg and 0.392 ?g/kg in road dust, 600 ?g/kg and 1.49 ?g/kg in TSP; 1006 ?g/kg (104 pg/mł) and 1.40 ?g/kg (0.134 pg/mł) in PM?.?. Risk assessment showed that the Hazardous quotients (HQs) of exposure to Hg and MeHg via road dust and TSP were less than 1, indicating that no adverse risk was manifested. Ingestion of dust was found to constitute a relatively minor pathway of Guangzhou residents' exposure to Hg. Furthermore, human hair samples from 88 Guangzhou citizens were also analyzed to investigate the mercury accumulation in human body in Guangzhou. The average concentrations of THg and MeHg in human hair samples were 869±831 ?g/kg and 104±108 ?g/kg respectively. However, no significant correlations of the mercury species were noted between human hair and road dust, TSP and PM?.?. PMID:22579217

Huang, Minjuan; Wang, Wei; Leung, Homan; Chan, Chuen Yu; Liu, Wing Keung; Wong, Ming Hung; Cheung, Kwai Chung

2012-05-10

266

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

PubMed Central

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.

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

2013-01-01

267

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

PubMed

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

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

2013-02-06

268

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

NASA Astrophysics Data System (ADS)

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.

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

2001-12-01

269

Hydrolysis of carbohydrates in roach ( Rutilus rutilus (L.)) at different levels of mercury accumulation  

Microsoft Academic Search

It has been shown that chronic exposure to dietary mercury results in the intensive accumulation of this metal in roach yearlings.\\u000a The concentrations of accumulated mercury in their organisms were proportional to the amount of metal added to water of experimental\\u000a tanks. Increased Hg content in the organisms (0.05–0.16 mg\\/kg) of developing juvenile roaches decreases the activity of digestive\\u000a carbohydrases

I. L. Golovanova; V. T. Komov; V. A. Gremyatchikh

2008-01-01

270

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

SciTech Connect

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.

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

1989-01-01

271

Chronic low-level mercury exposure, BDNF polymorphism, and associations with cognitive and motor function  

Microsoft Academic Search

Potential cognitive and motor effects from exposure to elemental mercury (Hg0) were examined in the presence and absence of a polymorphism (Val66Met) in brain-derived neurotrophic factor (BDNF). A group of 194 male dentists (DDs) and 233 female dental assistants (DAs) were occupationally exposed to mercury and had no history of kidney or nervous system disorders. Acute exposure was measured using

Diana Echeverria; James S. Woods; Nicholas J. Heyer; Dianne S. Rohlman; Federico M. Farin; Alvah C. Bittner; Tingting Li; Claire Garabedian

2005-01-01

272

Food consumption and adipose tissue DDT levels in Mexican women.  

PubMed

This article analyzes food consumption in relation to levels of DDE (the principal metabolite of DDT) in the adipose tissue of 207 Mexican women residing in States with high and low exposure to DDT. Data on the women's dietary habits and childbearing history were obtained from a personal interview. Adipose tissue DDE levels were measured by gas-liquid chromatography and compared by analysis of variance (ANOVA) and multiple linear regression. Adipose tissue DDE levels increased significantly with age (p = 0.005) and residence in coastal areas (p = 0.002) and non-significantly with the consumption of onion, cauliflower, prickly pear, squash blossoms, sweet corn, broad beans, chili pepper sauce, ham, and fish. Even so, during breastfeeding there was a non-significant reduction in these levels. The findings suggest that certain foods serve as vehicles for DDE residues and confirm that breastfeeding is a mechanism for the elimination of this insecticide, which accumulates over the years in the human body. PMID:11923886

Galván-Portillo, Marcia; Jiménez-Gutiérrez, Carlos; Torres-Sánchez, Luisa; López-Carrillo, Lizbeth

273

Inter- and intraclutch variation in egg mercury levels in marine bird species from the Canadian Arctic.  

PubMed

Mercury (Hg) is a toxic metal that has been of increasing concern in the Canadian Arctic. We measured total Hg in eggs of three marine birds (Arctic terns Sterna paradisaea, common eiders Somateria mollissima borealis, long-tailed ducks Clangula hyemalis) that breed in the Canadian Arctic, to compare Hg laying order effects from the same clutch and to examine Hg among species. Early-laid eggs of all three species had 24-48% higher Hg concentrations than late laid eggs. Arctic terns had approximately twice the concentration of Hg in their eggs as the two duck species, and Hg in eider eggs from the High Arctic was higher than Hg in eggs from the Low Arctic. Higher Hg in tern eggs was consistent with this species occupying a higher trophic position in marine food webs, as indicated by stable nitrogen isotope (delta(15)N) values. The egg-laying sequence may need to be considered for Hg biomonitoring studies where small samples sizes are planned, and early eggs may be preferable for such studies since early eggs may be more representative of potential maximum levels of Hg in the marine food webs. PMID:19962722

Akearok, Jason A; Hebert, Craig E; Braune, Birgit M; Mallory, Mark L

2009-12-04

274

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

Microsoft Academic Search

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,

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

2010-01-01

275

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

SciTech Connect

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%).

Zamecnik, J; Alexander Choi, A

2009-03-17

276

Temporal trend of mercury in polar bears (Ursus maritimus) from Svalbard using teeth as a biomonitoring tissue.  

PubMed

We examined the use of mercury (Hg) and nitrogen and carbon stable isotopes in teeth of polar bear (Ursus maritimus) from Svalbard as biotracers of temporal changes in Hg pollution exposure between 1964 and 2003. Teeth were regarded as a good matrix of the Hg exposure, and in total 87 teeth of polar bears were analysed. Dental Hg levels ranged from 0.6 to 72.3 ng g(-1) dry weight and increased with age during the first 10 years of life. A decreasing time trend in Hg concentrations was observed over the recent four decades while no temporal changes were found in the stable isotope ratios of nitrogen (?(15)N) and carbon (?(13)C). This suggests that the decrease of Hg concentrations over time was more likely due to a lower environmental Hg exposure in this region rather than a shift in the feeding habits of Svalbard polar bears. PMID:22113146

Aubail, Aurore; Dietz, Rune; Rigét, Frank; Sonne, Christian; Wiig, Řystein; Caurant, Florence

2011-11-24

277

Nematode and mercury content in freshwater fish belonging to different trophic levels.  

PubMed

Fish are a protein source for many people in Colombia. However, environmental pollution of some aquatic ecosystems may pose health risks to humans. The aim of this study was to assess the levels of total mercury (T-Hg) in muscle and their relationship with nematode infections in fish from Dique Channel, a freshwater ecosystem located Northern Colombia. Eight hundred ninety fish specimens belonging to 13 different species were collected. T-Hg concentration was measured using atomic absorption spectroscopy, previous electrothermal atomization. Nematodes were identified as Contracaecum sp. Species such as Hoplias malabaricus and Sorubim cuspicaudus presented the highest values for Hg and parasite infection (0.09?±?0.01, 0.12?±?0.02 ?g/g; prevalence 100, 100 %, respectively), whereas the lowest were detected in Prochilodus magdalenae (0.02?±?0.002 ?g/g; 0 %). Pooled data revealed a high correlation between trophic level and parasite abundance (??=?0.771; P?=?0.002) as well as with T-Hg (??=?0.786; P?level of the fish species, similarly to what occurs with Hg. Moreover, the co-occurrence of these two stressors involves different types of interactions with morphometric variables that are species-specific. These observations open new doors to the understanding of the interaction between chemical pollutants and organisms. PMID:23494159

Olivero-Verbel, Jesus; Caballero-Gallardo, Karina

2013-03-14

278

Levels of chlordane, oxychlordane, and nonachlor in human adipose tissues  

SciTech Connect

Chlordane was used as a termiticide for more than twenty years in Japan. Chlordane is stable in the environment such as sediment and its bioaccumulation in some species of bacteria, freshwater invertebrates, and marine fish is large. Many researches were done to elucidate the levels of chlordane and/or its metabolite oxychlordane in human adipose tissues. A comprehensive review concerning chlordane was recently provided by USEPA. On the other hand, Japan authorities banned the use of chlordane in September 1986. In the last paper, the authors reported that both water and sediment of the rivers around Saga city were slightly contaminated with chlordane. In the present study, they investigated the levels of chlordane, oxychlordane and nonachlor in human adipose tissues.

Hirai, Yukio; Tomokuni, Katsumaro (Saga Medical School (Japan))

1991-08-01

279

Clean conditions for the determination of ultra-low levels of mercury in ice and snow samples  

Microsoft Academic Search

Laboratory facilities and methods are presented for the determination of ultra-low levels of mercury (Hg) in ice and snow\\u000a samples originating from polar ice caps or temperate regions. Special emphasis will be given to the presentation of the clean\\u000a laboratory and the cleaning procedures. The laboratory is pressurized with air filtered through high efficiency particle filters.\\u000a This first filtration is

C. P. Ferrari; A. L. Moreau; C. F. Boutron

2000-01-01

280

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

Microsoft Academic Search

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

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

1997-01-01

281

Maternal Fish Intake During Pregnancy, Blood Mercury Levels, and Child Cognition at Age 3 Years in a US Cohort  

Microsoft Academic Search

The balance of contaminant risk and nutritional benefit from maternal prenatal fish consumption for child cog- nitive development is not known. Using data from a prospective cohort study of 341 mother-child pairs in Massa- chusetts enrolled in 1999-2002, the authors studied associations of maternal second-trimester fish intake and erythrocyte mercury levels with children's scores on the Peabody Picture Vocabulary Test

Emily Oken; Jenny S. Radesky; Robert O. Wright; David C. Bellinger; Chitra J. Amarasiriwardena; Ken P. Kleinman; Howard Hu; Matthew W. Gillman

2008-01-01

282

Prognostic significance of Dicer cellular levels in soft tissue sarcomas.  

PubMed

In the present study we assessed the expression and distribution of endoribonuclease Dicer in soft tissue tumors and correlated its cellular levels with clinicopathological parameters, including clinical outcome. Dicer was expressed in the tested cell line as well as in the majority of the sarcomas examined. Staining intensity was significantly higher in sarcomas compared with benign neoplasms and in high-grade compared with low-grade tumors. Elevated Dicer immunoreactivity was strongly associated with poor outcome and Dicer cellular levels were an independent negative prognostic factor. PMID:22149178

Papachristou, Dionysios J; Rao, Uma N M; Korpetinou, Angeliki; Giannopoulou, Efstathia; Sklirou, Emilia; Kontogeorgakos, Vasileios; Kalofonos, Haralabos P

2011-12-13

283

Mercury Exposure and Children's Health  

Microsoft Academic Search

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

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

2010-01-01

284

Biomagnification of Mercury and Selenium in Blue Shark Prionace glauca from the Pacific Ocean off Mexico  

Microsoft Academic Search

The aim of this study was to determine the biomagnification of mercury through the principal prey of the blue shark, Prionace glauca, off the western coast of Baja California Sur, Mexico, as well as the relationship between mercury and selenium in blue sharks.\\u000a High levels of mercury were found in shark muscle tissues (1.39?±?1.58 ?g\\/g wet weight); these values are above

Ofelia Escobar-Sánchez; Felipe Galván-Magańa; René Rosíles-Martínez

285

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

SciTech Connect

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.

Bacher, G.J.

1985-10-01

286

Mercury contamination in turtles and implications for human health.  

PubMed

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

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

2010-06-01

287

A possible approach for setting a mercury risk-based action level based on tribal fish ingestion rates.  

PubMed

Risks from mercury and other contaminants in fish for a large Columbia River dataset are evaluated in this paper for a range of consumption rates. Extensive ethnohistorical, nutritional, recent ethnographic surveys, and other documentation was reviewed to confirm previous determinations that the traditional subsistence fish consumption rate is 500 pounds per capita annually, or 620 g per day (gpd). Lower comtemporary consumption rates for other population subsets are also discussed. The causes of the current suppression of fish consumption are discussed and the cultural, educational, social, and trade and economic impacts of the loss of fish are considered. Action levels for mercury for riverine Tribes in the Columbia Basin are suggested at 0.1 ppm or less based on the combined risk from mercury plus other contaminants, the higher fish consumption rates, the existing cultural deficit due to loss of salmon and other stressors, the health benefits of fish, and the cultural and economic importance of fish. The goal of fish advisories is to reduce fish consumption even further, which shifts the burden of avoiding risk to the very people who already bear the burdens of contaminant exposure, socio-economic impacts and cultural loss. However, because Tribal communities often do not have the choice of giving up more food, income, religion, culture, and heritage in order to avoid contamination, they are forced into choosing between culture and health. Many tribal members choose to incur chemical risk rather than giving up their culture and religion. We believe that lowering the action level for mercury is part of the federal fiduciary responsibility to American Indian Tribes. PMID:17631290

Harper, Barbara L; Harris, Stuart G

2007-07-13

288

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

Microsoft Academic Search

The endangered Western population of the Steller sea lion declined for three decades for uncertain reasons. We present baseline data of metal concentrations in pups as a first step towards investigating the potential threat of developmental exposures to contaminants. Seven metals were investigated: arsenic, cadmium, silver, aluminum, mercury, lead and vanadium. Vanadium was detected in only a single blubber sample.

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

2008-01-01

289

Evaluation of species-specific dissimilarities in two marine fish species: mercury accumulation as a function of metal levels in consumed prey.  

PubMed

The aim of this research was to compare mercury (Hg) accumulation (total and organic) and tissue distribution in two marine fish species with contrasting feeding tactics. Thus, juvenile specimens of European sea bass and Golden grey mullet were surveyed in an estuary historically affected by Hg discharges. Total Hg was preferentially accumulated in intestine, muscle, and liver, whereas gills and brain presented the lowest Hg levels observed in both species. Significant differences between species were only verified for muscle, with D. labrax's levels being greater than L. aurata's. Muscle accounted for >87% of the Hg relative tissue burden, whereas liver did not exceed 11%. Organic Hg accumulation occurred mainly in liver and muscle, with D. labrax evidencing significantly greater loads. Moreover, organic Hg in consumed prey items was also significantly greater in D. labrax. Accumulation of organic Hg in liver, intestine, and muscle seemed to vary as a function of the consumed prey items contamination, suggesting fish feeding strategies as the dominant factor determining metal accumulation. For both fish species, a stable ratio was observed between Hg increments from the reference to the contaminated site, possibly indicating that the organic Hg content of diet may regulate the internal levels of this contaminant. Thus, this ratio might prove to be a useful contamination predictor tool in early life stages of fish. PMID:22189708

Mieiro, C L; Coelho, J P; Pacheco, M; Duarte, A C; Pereira, M E

2011-12-22

290

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

PubMed

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

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

2013-05-06

291

A dose-dependent relationship between mercury exposure from dental amalgams and urinary mercury levels: a further assessment of the Casa Pia Children's Dental Amalgam Trial.  

PubMed

Dental amalgams are a commonly used dental restorative material, and amalgams are about 50% mercury (Hg). In our study, urinary Hg levels was examined in children of age 8-18 years, with and without dental amalgam fillings, from a completed clinical trial (parent study) that was designed to evaluate the potential health consequences of prolonged exposure to Hg from dental amalgam fillings. Our study was designed to determine whether there was a significant dose-dependent correlation between increasing Hg exposure from dental amalgams and urinary Hg levels. Hg exposure depends on the size and number of teeth with dental amalgams. Overall, consistent with the results observed in the parent study, there was a statistically significant dose-dependent correlation between cumulative exposure to Hg from dental amalgams and urinary Hg levels, after covariate adjustment. Further, it was observed that urinary Hg levels increased by 18% to 52% among 8 to 18 year old individuals, respectively, with an average exposure to amalgams, in comparison to study subjects with no exposure to amalgams. The results of our study suggest that dental amalgams contribute to ongoing Hg exposure in a dose-dependent fashion. PMID:21803780

Geier, D A; Carmody, T; Kern, J K; King, P G; Geier, Mark R

2011-07-29

292

Effects of coadministered sodium selenite on short-term distribution on methyl mercury in the rat  

SciTech Connect

Adult male Sprague-Dawley rats received iv injections of 1 ..mu..mole of methyl mercury/kg alone or coadministered with 5 ..mu..mole of sodium selenite/kg. Tissue concentrations of methyl mercury were determined at 5, 20, and 60 min after treatment. Selenite treatment produced a significant increase in cerebral methyl mercury concentrations and a significant decrease in kidney methyl mercury concentrations at all time points. The concentration of methyl mercury in liver was significantly increased by selenite coadministration at 5 and 20 min but at 60 min after injection the concentration was not significantly different from that found in rats receiving methyl mercury alone. Selenite treatment also significantly lowered blood methyl mercury concentrations at all time points. This decrease was associated with a significant decrease in the concentration of methyl mercury in erythrocytes at 5, 20, and 60 min. Plasma methyl mercury levels at 5 min postinjection were slightly higher in selenite-treated rats but were significantly lower in treated animals at 20 and 60 min. Treatment of rats with selenite did not specifically alter the extent of methyl mercury binding to glutathione in the 108,000 g supernatant of cerebrum of in erythrocyte hemolysates. In rats receiving either methyl mercury alone or with selenite, low-molecular-weight methyl mercury complexes could not be detected in plasma 5 min after iv injection.

Thomas, D.J.; Smith, J.C.

1984-08-01

293

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

SciTech Connect

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.

Davis, A.H.

1981-01-01

294

Total and Organic Mercury in Marine Fish.  

National Technical Information Service (NTIS)

A study to determine total and organic mercury levels in the muscle tissue of certain pelagic and inshore fish of Hawaii which are used for human consumption is reported. In all species, except the Pacific Blue Marlin, there was close correlation between ...

J. B. Rivers J. E. Pearson C. D. Shultz

1972-01-01

295

Inter and intraclutch variation in egg mercury levels in marine bird species from the Canadian Arctic  

Microsoft Academic Search

Mercury (Hg) is a toxic metal that has been of increasing concern in the Canadian Arctic. We measured total Hg in eggs of three marine birds (Arctic terns Sterna paradisaea, common eiders Somateria mollissima borealis, long-tailed ducks Clangula hyemalis) that breed in the Canadian Arctic, to compare Hg laying order effects from the same clutch and to examine Hg among

Jason A. Akearok; Craig E. Hebert; Birgit M. Braune; Mark L. Mallory

2010-01-01

296

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

Microsoft Academic Search

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

Pasquale Gallo; Luigi Serpe

1998-01-01

297

Sequential analysis of hair mercury levels in relation to fish diet of an Amazonian population, Brazil  

Microsoft Academic Search

Several studies in the Amazonian Basin have shown that riverine populations are exposed to methylmercury through fish consumption. It has been suggested that seasonal variations in hair mercury observed through sequential analyses may be related to the changes in fish species ingested by the local communities. The aim of the present study was to investigate the relationship between fish-eating practices

Julie Dolbec; Donna Mergler; Fabrice Larribe; Marc Roulet; Jean Lebel; Marc Lucotte

2001-01-01

298

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

Microsoft Academic Search

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

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

2007-01-01

299

Chemical form and distribution of mercury and selenium in eggs from chickens fed mercury-contaminated grain  

SciTech Connect

Interactions between dietary mercury and selenium have been observed in chickens whereby significant amounts of both elements are deposited in the eggs. Dietary transfer into eggs is influenced by the level and chemical form of both elements in the diet. We have previously examined the chemical form and distribution of mercury and selenium in the edible muscle of marine and freshwater fish and in human tissue. Information is reported here on (1) the level of specific mercury and selenium chemical forms in egg white and egg yolk, and (2) the distribution of these forms in specific protein fractions of these egg components.

Cappon, C.J.; Smith, J.C.

1981-04-01

300

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

SciTech Connect

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

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

1989-10-01

301

Spatial Variation and Correlations of Mercury Levels in the Terrestrial and Aquatic Components of a Wetland Dominated Ecosystem: Kejimkujik Park, Nova Scotia, Canada  

Microsoft Academic Search

This study investigates the ranges and spatial variation ofmercury in various media in the wetland ecosystems ofKejimkujik Park, Nova Scotia. Mercury concentrations infive-year-old yellow perch (age based on regression analysesof existing data) ranged from 0.12–0.72 µgg-1(wet weight basis) in 24 lakes. Mercury concentrations inred maple ranged from 5 to 41 ng g-1 and levels inwhite pine ranged from 5 to

A. N. Rencz; N. J. O'Driscoll; G. E. M. Hall; T. Peron; K. Telmer; N. M. Burgess

2003-01-01

302

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

PubMed

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

Lepom, Peter; Irmer, Ulrich; Wellmitz, Jörg

2011-11-08

303

Mercury Calculator  

NSDL National Science Digital Library

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.

Foundation, Wgbh E.

2010-12-23

304

Dental amalgam mercury exposure in rats  

Microsoft Academic Search

The aim of this study was to measure the distribution of mercury, in tissues of rats exposed to amalgam over a two months period. Possible interaction of mercury with copper and zinc in organs was also evaluated. Rats were either exposed to mercury from 4 dental amalgams, or fed the diet containing powdered amalgam during two months. Mercury was measured

Nada Galic; Goranka Prpic-Mehi?ic; Ljerka Prester; Maja Blanuša; Žarka Krnic; Željko Feren?ic

1999-01-01

305

Mercury speciation in the Mediterranean Sea  

NASA Astrophysics Data System (ADS)

An interesting feature of mercury biogeochemistry in the Mediterranean is that several fish species from the Mediterranean show higher concentrations of Hg in their tissues than same fish species in the Atlantic ocean. although the concentrations of mercury in the open waters of both oceans are similar. It has been suggested that the higher mercury levels noted in many larger pelagic fish species in the Mediterranean are not related to anthropogenic inputs, but rather are due to the higher than average natural environmental levels of this metal originating from the Mediterranean mercury anomaly. Although elevated Hg levels have been noted in environmental matrices from the Mediterranean regions adjacent to known mercury anomalies, the data do not clearly indicate that the effects of these anomalies have been transmitted to open waters or to lower trophic level species living in these waters. In the present contribution data obtained during three oceanographic cruises carried out in the framework of the MERCYMS project (An integrate approach to assess mercury cycling in the Mediterranean basin) funded by EU in the period between 2000 and 2003 will be presented. Measurements included total mercury measurements and its speciation (reactive Hg, total Hg and monomethylmercury (MMHg) in filtered and non-filtered sea water samples, dissolved gaseous mercury (DGM) and dimethylmercury (DMHg) in open and coastal waters of the Mediterranean Sea. Radon, as a tracer gas of tectonic activity was also measured in depth profiles. The results presented clearly show that hg species distribution in surface and deep oceanic waters is affected by several dynamic processes such as photochemical transformation at the surface, phytoplankton biomass stratification in the photic zone, development of an oxygen depletion zone at intermediate depths and diffusion from deeper layers due to biological and/or tectonic activities.

Horvat, M.; Kotnik, J.; Ogrinc, N.; Fajon, V.; Logar, M.; Gibicar, D.; Vaupotic, J.; Pirrone, N.

2004-12-01

306

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

PubMed

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

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

2011-07-16

307

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

PubMed

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

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

2010-02-21

308

Hair mercury levels in an urban population from southern Italy: fish consumption as a determinant of exposure.  

PubMed

Mercury levels in hair of a general population, 237 adults aged between 35-45, in Naples, Italy, were assessed. The subjects were asked to fill in a questionnaire about age, gender, body weight, height, body mass index (BMI), fish consumption, number, surface and area of dental amalgam fillings. Total mercury (THg) concentrations in human hair ranged from 0.221 to 3.402 microg/g and the mean value for the subjects under study was 0.638 microg/g. Study participants were divided into three groups in accordance with fish consumption and dental amalgam: ANF (amalgam and no fish); NAF (no amalgam but with fish) and AAF (amalgam and fish). Significant differences in THg were found in the three groups (p<0.05). A multiple linear regression analysis showed a weak but significant correlation of THg content in hair with respect to gender and age, but almost no association was found between THg and dental fillings. Conversely, a strong correlation was obtained between THg and fish consumption regardless of the group evaluated. Finally, mercury levels in hair exceeded the levels corresponding to the EPA reference dose (RfD) of 0.1 microg Hg/kg body weight per day (1 microg Hg/g hair) in 6% of the population (4% men and 2% women). However, the THg limits in our subjects were not exceeded according to the WHO guidelines, which use a benchmark dose of 0.23 microg Hg/kg bw/day (14 microg Hg/g maternal hair). PMID:17904222

Díez, Sergi; Montuori, Paolo; Pagano, Adele; Sarnacchiaro, Pasquale; Bayona, Josep M; Triassi, Maria

2007-09-27

309

Effect of lead, zinc, mercury, and copper with and without estrogen on serum vitellogenin level in Magur fish (Clarias batrachus L.).  

PubMed

Injection(s) of lead, zinc, and mercuric acetate decreased the serum vitellogenin content in Magur fish, while cupric acetate failed to cause any change in the vitellogenin level. Estrogen injections on 7th, 8th and 9th d increased the serum vitellogenin level in normal and copper salt treated fish, but were totally ineffective in altering the reduced vitellogenin content in lead, zinc, and mercury salts treated fish. Vitellogenin level almost restored to normal level at 6 week in lead, zinc, and mercury treated fish, and estrogen injections on 37th, 38th, and 39th d enhanced the serum vitellogenin content in all groups. PMID:2099309

Panigrahi, A; Dasmahapatra, A K; Medda, A K

1990-01-01

310

Longitudinally guided level sets for consistent tissue segmentation of neonates.  

PubMed

Quantification of brain development as well as disease-induced pathologies in neonates often requires precise delineation of white matter, grey matter and cerebrospinal fluid. Unlike adults, tissue segmentation in neonates is significantly more challenging due to the inherently lower tissue contrast. Most existing methods take a voxel-based approach and are limited to working with images from a single time-point, even though longitudinal scans are available. We take a different approach by taking advantage of the fact that the pattern of the major sulci and gyri are already present in the neonates and generally preserved but fine-tuned during brain development. That is, the segmentation of late-time-point image can be used to guide the segmentation of neonatal image. Accordingly, we propose a novel longitudinally guided level-sets method for consistent neonatal image segmentation by combining local intensity information, atlas spatial prior, cortical thickness constraint, and longitudinal information into a variational framework. The minimization of the proposed energy functional is strictly derived from a variational principle. Validation performed on both simulated and in vivo neonatal brain images shows promising results. PMID:22140029

Wang, Li; Shi, Feng; Yap, Pew-Thian; Lin, Weili; Gilmore, John H; Shen, Dinggang

2011-12-03

311

Reduced tissue thyroid hormone levels in fatal illness.  

PubMed

Patients with severe nonthyroidal illnesses (NTIs) frequently have decreased serum concentrations of triiodothyronine (T3) and less often of thyroxine (T4) without clear evidence of hypothyroidism. To determine whether T3 and T4 levels are also reduced in the tissues, we analyzed autopsy samples from 12 patients dying of NTI and 10 previously healthy individuals dying suddenly from trauma. Mean serum T3, T4, and free T4 index values were lower by 79%, 71%, and 49%, respectively, in the NTI group than in controls, but serum thyrotropin (TSH) values did not differ significantly. Mean T3 concentrations in cerebral cortex, hypothalamus, pituitary, liver, kidney, and lung were lower in the NTI group than in controls by 43% to 76%, but mean values in heart and skeletal muscle did not differ significantly between the groups. The mean liver T4 concentration was 66% lower in the NTI group, but mean T4 concentrations in the cerebral cortex were similar in the two groups. These results indicate that many tissues may be deficient in thyroid hormones in patients with fatal NTI, although the severity of the reduction in thyroid hormone concentrations may vary from one organ to another. PMID:8412761

Arem, R; Wiener, G J; Kaplan, S G; Kim, H S; Reichlin, S; Kaplan, M M

1993-09-01

312

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

Microsoft Academic Search

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

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

313

Temporal Trends in Beluga, Narwhal and Walrus Mercury Levels: Links to Climate Change  

Microsoft Academic Search

\\u000a The exposure of Arctic marine mammals to contaminants may change via ecological dynamics in response to climate change. For\\u000a example, changes to the structure of the food web or shifts in regional foraging could affect dietary exposure. We examined\\u000a the temporal variation of total mercury (THg) concentrations in Hudson Bay beluga (Delphinapterus leucas) and Foxe Basin walrus (Odobenus rosmarus rosmarus)

A. Gaden; G. A. Stern

314

An investigation of modifying effects of single nucleotide polymorphisms in metabolism-related genes on the relationship between peripheral nerve function and mercury levels in urine and hair.  

PubMed

Mercury (Hg) is a potent neurotoxicant. We hypothesized that single nucleotide polymorphisms (SNPs) in genes coding glutathione-related proteins, selenoproteins and metallothioneins may modify the relationship of mercury biomarkers with changes in peripheral nerve function. Dental professionals (n=515) were recruited in 2009 and 2010. Sensory nerve function (onset latency, peak latency and amplitude) of the median, ulnar and sural nerves was recorded. Samples of urine, hair and DNA were collected. Covariates related to demographics, nerve function and elemental and methyl-mercury exposure were also collected. Subjects included 244 dentists (47.4%) and 269 non-dentists (52.2%; mostly dental hygienists and dental assistants). The mean mercury levels in urine (1.06 ?g/L) and hair (0.51 ?g/g) were not significantly different from the US general population (0.95 ?g/L and 0.47 ?g/g, respectively). In multivariate linear models predicting nerve function adjusting for covariates, only 3 out of a total of 504 models showed stable and statistically significant interaction of SNPs with mercury biomarkers. Overall, given the possibility of false positives, the results suggested little evidence of effect modification of the SNPs on the relationship between mercury biomarkers with peripheral nerve function at exposure levels that are relevant to the general US population. PMID:22236634

Wang, Yi; Goodrich, Jaclyn M; Werner, Robert; Gillespie, Brenda; Basu, Niladri; Franzblau, Alfred

2012-01-10

315

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

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

Peter Lindberg; Tjelvar Odsjö; Lars Reutergftrdh

1985-01-01

316

Development of a cavity ringdown laser absorption spectrometer for detection of trace levels of mercury.  

PubMed

A potential new laser-based air pollution measurement technique, capable of measuring ultralow concentrations of urban air toxins in the field and in real time, is examined. Cavity ringdown laser absorption spectroscopy (CRLAS) holds promise as an air pollution monitor because it is a highly sensitive species detection technique that uses either pulsed or continuous tunable laser sources. The sensitivity results from an extremely long absorption path length and the fact that the quantity measured, the cavity decay time, is unaffected by fluctuations in the laser source. In laboratory experiments, we reach detection limits for mercury of the order of 0.50 parts per trillion. We developed a CRLAS system in our laboratory and measured Hg with the system, investigating issues such as background interference. We report experimental results for mercury detection limits, the dynamic range of the sensor, detection of Hg in an absorbing background of ozone and SO(2), and detection of a mercury-containing compound (HgCl(2) in this case). PMID:18345163

Spuler, S; Linne, M; Sappey, A; Snyder, S

2000-05-20

317

Mercury and Mink. II. Experimental methyl mercury intoxication.  

PubMed Central

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

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

1976-01-01

318

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

PubMed

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

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

2013-03-01

319

Influences on Mercury Bioaccumulation Factors for the Savannah River  

Microsoft Academic Search

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

M. H. Paller; J. A. Bowers; J. W. Littrell; A. V. Guanlao

2004-01-01

320

Influences on Mercury Bioaccumulation Factors for the Savannah River  

Microsoft Academic Search

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

Paller

2003-01-01

321

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

PubMed Central

Hexamethyldisiloxane (HMDSO) has been identified as a sensitive proton NMR indicator of tissue oxygenation (pO2) based on spectroscopic spin-lattice relaxometry. A rapid MRI approach has now been designed, implemented, and tested. The technique, proton imaging of siloxanes to map tissue oxygenation levels (PISTOL), utilizes frequency-selective excitation of the HMDSO resonance and chemical-shift selective suppression of residual water signal to effectively eliminate water and fat signals and pulse-burst saturation recovery 1H echo planar imaging to map T1 of HMDSO and hence pO2. PISTOL was used here to obtain maps of pO2 in rat thigh muscle and Dunning prostate R3327 MAT-Lu tumor-implanted rats. Measurements were repeated to assess baseline stability and response to breathing of hyperoxic gas. Each pO2 map was obtained in 3˝ min, facilitating dynamic measurements of response to oxygen intervention. Altering the inhaled gas to oxygen produced a significant increase in mean pO2 from 55 Torr to 238 Torr in thigh muscle and a smaller, but significant, increase in mean pO2 from 17 Torr to 78 Torr in MAT-Lu tumors. Thus, PISTOL enabled mapping of tissue pO2 at multiple locations and dynamic changes in pO2 in response to intervention. This new method offers a potentially valuable new tool to image pO2 in vivo for any healthy or diseased state by 1H MRI.

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

2011-01-01

322

Determination of the level of DNA modification with cisplatin by catalytic hydrogen evolution at mercury-based electrodes.  

PubMed

Electrochemical methods proved useful as simple and inexpensive tools for the analysis of natural as well as chemically modified nucleic acids. In particular, covalently attached metal-containing groups usually render the DNA well-pronounced electrochemical activity related to redox processes of the metal moieties, which can in some cases be coupled to catalytic hydrogen evolution at mercury or some types of amalgam electrodes. In this paper we used voltammetry at the mercury-based electrodes for the monitoring of DNA modification with cis-diamminedichloroplatinum (cisplatin), a representative of metallodrugs used in the treatment of various types of cancer or being developed for such purpose. In cyclic voltammetry at the mercury electrode, the cisplatin-modified DNA yielded catalytic currents the intensity of which reflected DNA modification extent. In square-wave voltammetry, during anodic polarization after prereduction of the cisplatinated DNA, a well-developed, symmetrical signal (peak P) was obtained. Intensity of the peak P linearly responded to the extent of DNA modification at levels relevant for biochemical studies (rb = 0.01-0.10, where rb is the number of platinum atoms bound per DNA nucleotide). We demonstrate a correlation between the peak P intensity and a loss of sequence-specific DNA binding by tumor suppressor protein p53, as well as blockage of DNA digestion by a restriction endonuclease Msp I (both caused by the DNA cisplatination). Application of the electrochemical technique in studies of DNA reactivity with various anticancer platinum compounds, as well as for an easy determination of the extent of DNA platination in studies of its biochemical effects, is discussed. PMID:20187631

Horáková, Petra; Tesnohlídková, Lucie; Havran, Ludek; Vidláková, Pavlína; Pivonková, Hana; Fojta, Miroslav

2010-04-01

323

Mercury Exposure and Children's Health  

PubMed Central

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.

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

2011-01-01

324

Use of preserved museum fish to evaluate historical and current mercury contamination in fish from two rivers in Oklahoma, USA.  

PubMed

We examined the effects of a commonly used preservation technique on mercury concentration in fish tissue. After fixing fish muscle tissue in formalin followed by preservation in isopropanol, we found that mercury concentration in fish muscle tissue increased by 18%, reaching an asymptote after 40 days. We used formalin-isopropanol-preserved longear sunfish (Lepomis megalotis) from the Sam Noble Oklahoma Museum of Natural History to examine historical changes and predict current mercury concentrations in fish from two rivers in southeastern Oklahoma. Glover River was free-flowing, while Mountain Fork River was impounded in 1970 and a coldwater trout fishery was established upstream from the collection site in 1989. Mercury concentrations in longear sunfish from Glover River showed no historical changes from 1963 to 2001. Mercury concentrations in longear sunfish from Mountain Fork River showed no change from 1925 to 1993 but declined significantly from 1993 to 2003. We also compared mercury concentrations of the most recently collected longear sunfish in the museum to mercury concentrations of unpreserved fish collected from the rivers in 2006. Concentrations of mercury in museum fish were not significantly different from mercury concentrations in unpreserved fish we collected from the rivers. Our study indicates that preserved museum fish specimens can be used to evaluate historical changes and predict current levels of mercury contamination in fish. PMID:19377911

Hill, J Jaron; Chumchal, Matthew M; Drenner, Ray W; Pinder, John E; Drenner, S Matthew

2009-04-18

325

Mercury in seafood: mechanisms of accumulation and consequences for consumer health.  

PubMed

Mercury is a largely uncontrollable heavy metal contaminant in that it is globally ubiquitous, and environmentally persistent. The element has the potential for global mobilization following liberation from environmental stores, which can occur as a consequence of either anthropogenic activities or natural processes. Furthermore, organic forms like methylmercury accumulate in biological tissues with an exceptionally long biological half-life, facilitating the magnification of this toxin along trophic food chains. Bioaccumulation is particularly evident in aquatic environments, in which long-lived piscivorous fishes and marine mammals are reported with a mercury burden one-million times that of the surrounding water body, typically attaining mercury burdens exceeding 1 microg g(-1). Mercury levels in other seafood, however, are typically reported in the range of 0.1 to 0.2 microg g(-1) and usually less then 0.5 microg g(-1). The primary source of human exposure to environmental mercury is through seafood consumption. The dangers associated with the consumption of large amounts of methylmercury accumulated in seafood are well recognized from past poisoning incidents, in which fish with mercury burdens in the range of 9 to 24 microg g(-1) were consumed. Nevertheless, the toxicological consequence of chronic low-level mercury exposure from habitual seafood consumption is an area of contention. This review discusses the mechanisms of mercury accumulation and distribution in fish tissues and the toxicological consequences of mercury exposure from seafood consumption with regard to international safety guidelines. PMID:17894202

Balshaw, S; Edwards, J; Daughtry, B; Ross, K

326

Second-Kind Collisions Between Electrons and Mercury Atoms in the 6 triplet P(0) and 6 triplet P(2) Metastable Levels.  

National Technical Information Service (NTIS)

The differential cross sections for inelastic second-kind collisions were measured for 2.4-eV electrons scattered from the 6 triplet P(0) and 6 triplet P92) metastable levels of mercury. Separation of the scattering from the two levels was achieved. The e...

K. F. Higginbotham

1972-01-01

327

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.

328

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

PubMed

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

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

2012-09-02

329

Mercury contamination in East Fork Poplar Creek and Bear Creek  

SciTech Connect

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

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

1984-02-01

330

Emergence of delayed behavioral effects in offspring mice exposed to low levels of mercury vapor during the lactation period.  

PubMed

This study examined the emergence of delayed behavioral effects in offspring mice exposed to low levels of mercury vapor (Hg(0)) during the lactation period. Female offspring of mice were repeatedly exposed to Hg(0) at 0.057 mg/m(3), similar to the current threshold value (TLV), for 24 hr until the 20(th) day postpartum. The behavioral effects were evaluated with locomotor activity in the open field (OPF), learning activity in the passive avoidance response (PA) and spatial learning ability in the Morris water maze (MM) at the ages of 3 and 15 months. Hg(0)-exposed mice did not differ from controls in the three behavioral measurements at 3 months of age, and no neurobehavioral effects were observed. On the other hand, the mice exhibited significantly more central locomotion in the OPF task when tested at 15 months of age, but no abnormality in other behavioral performance. Immediately after postnatal exposure, the brain mercury concentration of offspring was about 150 times that of the control, in which the concentrations were approximately 0.4 µg/g. The results indicate that mice exposed to Hg(0) at concentrations around TLV during the developing period resulted in the emergence of delayed behavioral effects at a later stage in life. PMID:23358134

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

2013-02-01

331

Total mercury content found in edible tissues of top predator fish from the Gulf of California, Mexico  

Microsoft Academic Search

Fish at the top of the food chain bioaccumulate and biomagnify toxic metals including mercury (Hg), at a higher rate than nonpredatory fish. However, although some top predator fish species are important in the human diet, the risks for consumers in Mexico are difficult to evaluate due to the scarce baseline information available. In the present article, data on the

Jaqueline García-Hernández; Lázaro Cadena-Cárdenas; Miguel Betancourt-Lozano; Luz Maria García-De-La-Parra; Leticia García-Rico; Fernando Márquez-Farías

2007-01-01

332

Tissue specific expression and serum levels of human tissue factor in patients with urological cancer  

Microsoft Academic Search

Human tissue factor (TF) is involved in tumor angiogenesis and metastasis. However, little is known about the distribution of TF in urological cancer. In this study we investigated the TF expression in tumor tissue and autologous non-malignant tissue as well as in serum of patients with renal cell carcinoma (RCC), bladder cancer, and prostate cancer (PCa). To study the distribution

Yvonne Förster; Axel Meye; Sybille Albrecht; Matthias Kotzsch; Susanne Füssel; Manfred P Wirth; Bernd Schwenzer

2003-01-01

333

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

USGS Publications Warehouse

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.

Eisler, R.

2004-01-01

334

Tritium level in Japanese diet and human tissue  

Microsoft Academic Search

Tritium concentrations are reported for diet and human tissue samples collected in the Akita district of northern Japan. Sixteen separate food group samples and a total diet sample were collected for Akita City during April and May 1987. Six samples of heart and nine samples of kidney tissue were collected from 10 decreased individuals in Akita Prefecture from January to

S. Hisamatsu; T. Ohmura; Y. Takizawa; T. Katsumata; Y. Inoue; M. Itoh; K. Ueno; M. Sakanoue

1992-01-01

335

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

PubMed

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

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

2012-12-15

336

Mercury in Indiana watersheds: retrospective for 2001-2006  

USGS Publications Warehouse

Information about total mercury and methylmercury concentrations in water samples and mercury concentrations in fish-tissue samples was summarized for 26 watersheds in Indiana that drain most of the land area of the State. Mercury levels were interpreted with information on streamflow, atmospheric mercury deposition, mercury emissions to the atmosphere, mercury in wastewater, and landscape characteristics. Unfiltered total mercury concentrations in 411 water samples from streams in the 26 watersheds had a median of 2.32 nanograms per liter (ng/L) and a maximum of 28.2 ng/L. When these concentrations were compared to Indiana water-quality criteria for mercury, 5.4 percent exceeded the 12-ng/L chronic-aquatic criterion, 59 percent exceeded the 1.8-ng/L Great Lakes human-health criterion, and 72.5 percent exceeded the 1.3-ng/L Great Lakes wildlife criterion. Mercury concentrations in water were related to streamflow, and the highest mercury concentrations were associated with the highest streamflows. On average, 67 percent of total mercury in streams was in a particulate form, and particulate mercury concentrations were significantly lower downstream from dams than at monitoring stations not affected by dams. Methylmercury is the organic fraction of total mercury and is the form of mercury that accumulates and magnifies in food chains. It is made from inorganic mercury by natural processes under specific conditions. Unfiltered methylmercury concentrations in 411 water samples had a median of 0.10 ng/L and a maximum of 0.66 ng/L. Methylmercury was a median 3.7 percent and maximum 64.8 percent of the total mercury in 252 samples for which methylmercury was reported. The percentages of methylmercury in water samples were significantly higher downstream from dams than at other monitoring stations. Nearly all of the total mercury detected in fish tissue was assumed to be methylmercury. Fish-tissue samples from the 26 watersheds had wet-weight mercury concentrations that exceeded the 0.3 milligram per kilogram (mg/kg) U.S. Environmental Protection Agency (USEPA) methylmercury criterion in 12.4 percent of the 1,731 samples. The median wet-weight concentration in the fish-tissue samples was 0.13 mg/kg, and the maximum was 1.07 mg/kg. A coarse-scale analysis of all fish-tissue data in each watershed and a fine-scale analysis of data within 5 kilometers (km) of the downstream end of each watershed showed similar results overall. Mercury concentrations in fish-tissue samples were highest in the White River watershed in southern Indiana and the Fall Creek watershed in central Indiana. In fish-tissue samples within 5 km of the downstream end of a watershed, the USEPA methylmercury criterion was exceeded by 45 percent of mercury concentrations from the White River watershed and 40 percent of the mercury concentration from the Fall Creek watershed. A clear relation between mercury concentrations in fish-tissue samples and methylmercury concentrations in water was not observed in the data from watersheds in Indiana. Average annual atmospheric mercury wet-deposition rates were mapped with data at 156 locations in Indiana and four surrounding states for 2001-2006. These maps revealed an area in southeastern Indiana with high mercury wet-deposition rates-from 15 to 19 micrograms per square meter per year (ug/m2/yr). Annual atmospheric mercury dry-deposition rates were estimated with an inferential method by using concentrations of mercury species in air samples at three locations in Indiana. Mercury dry deposition-rates were 5.6 to 13.6 ug/m2/yr and were 0.49 to 1.4 times mercury wet-deposition rates. Total mercury concentrations were detected in 96 percent of 402 samples of wastewater effluent from 50 publicly owned treatment works in the watersheds; the median concentration was 3.0 ng/L, and the maximum was 88 ng/L. When these concentrations were compared to Indiana water-quality criteria for mercury, 12 percent exceeded the 12-n

Risch, Martin R.; Baker, Nancy T.; Fowler, Kathleen K.; Egler, Amanda L.; Lampe, David C.

2010-01-01

337

Total mercury concentrations in an industrialized catchment, the Thur River basin (north-eastern France): geochemical background level and contamination factors.  

PubMed

River bottom sediments and soils were collected from the industrialized Thur River basin (north-eastern France) to assess mercury contamination. The regional geochemical background level of total mercury was evaluated to calculate mercury contamination factors (Fc) in soils and river bottom sediments. Our estimate of the mean background mercury levels in river sediments and soils, not affected by human activities, was 232 ng x g(-1) (range: 27-406 ng x g(-1)). Sediments contaminated by the effluent from a chlor-alkali plant yielded the highest contamination factors (Fc=1784). Contamination factors of surficial soils within 1 km of the industrial site range from 6.3 to 43.6. This contamination is attributed to diffuse atmospheric deposition from this local plant. However, even upstream from this industrial area elevated contamination factors were recorded for river bottom sediments (Fc=3.2 to 26.4) and for one alluvial soil profile (Fc=10). This is possibly due to past pollution resulting from waste water discharges. Mercury contamination in the different horizons of alluvial soils is not correlated with soil organic carbon content, but may be the result of occasional accidental pollution arising from the introduction of contaminated suspended particulate matter by the Thur River during periods of flooding. PMID:12738301

Rémy, S; Prudent, P; Hissler, C; Probst, J L; Krempp, G

2003-07-01

338

Multiple spiking species-specific isotope dilution analysis by molecular mass spectrometry: simultaneous determination of inorganic mercury and methylmercury in fish tissues.  

PubMed

This work demonstrates, for the first time, the applicability of multiple spiking isotope dilution analysis to molecular mass spectrometry exemplified by the speciation analysis of mercury using GC(EI)MS instrumentation. A double spike isotope dilution approach using isotopically enriched mercury isotopes has been applied for the determination of inorganic mercury Hg(II) and methylmercury (MeHg) in fish reference materials. The method is based on the application of isotope pattern deconvolution for the simultaneous determination of degradation-corrected concentrations of methylmercury and inorganic mercury. Mass isotopomer distributions are employed instead of isotope ratios to calculate the corrected concentrations of the Hg species as well as the extent of species degradation reactions. The isotope pattern deconvolution equations developed here allow the calculation of the different molar fractions directly from the GC(EI)MS mass isotopomer distribution pattern and take into account possible impurities present in the spike solutions employed. The procedure has been successfully validated with the analysis of two different certified reference materials (BCR-464 and DOLT-4) and with the comparison of the results obtained by GC(ICP)MS. For the tuna fish matrix (BCR-464), no interconversion reactions were observed at the optimized conditions of open focused microwave extraction at 70 degrees C during 8 min. However, significant demethylation was found under the same conditions in the case of the certified dogfish liver DOLT-4. Methylation and demethylation factors were confirmed by GC(ICP)MS. Transformation reactions have been found to depend on the sample matrix and on the derivatization reagent employed. Thus, it is not possible to recommend optimum extraction conditions suitable for all types of matrices demonstrating the need to apply multiple spiking methodologies for the determination of MeHg and Hg(II) in biological samples. Double spike isotope dilution analysis methodologies using widespread GC(EI)MS instrumentation are proposed here for the routine analysis of inorganic mercury and methylmercury in fish samples. The estimated method detection limits were below 10 ng g(-1) for both mercury species. Precision was evaluated for the concentrations present in the certified reference materials (CRMs) which vary from 0.1 to 5 microg g(-1), achieving values of coefficients of variation ranging from 7% to 2%. The concentrations obtained in both CRMs analyzed were in excellent agreement with the certified values, demonstrating the accuracy of the method at these concentration levels. PMID:20192179

Castillo, Angel; Rodríguez-González, Pablo; Centineo, Giuseppe; Roig-Navarro, Antoni Francesc; García Alonso, J Ignacio

2010-04-01

339

Immunology of mercury.  

PubMed

The heavy metal mercury is ubiquitously distributed in the environment resulting in permanent low-level exposure in human populations. Mercury can be encountered in three main chemical forms (elemental, inorganic, and organic) which can affect the immune system in different ways. In this review, we describe the effects of these various forms of mercury exposure on immune cells in humans and animals. In genetically susceptible mice or rats, subtoxic doses of mercury induce the production of highly specific autoantibodies as well as a generalized activation of the immune system. We review studies performed in this model and discuss their implications for the role of environmental chemicals in human autoimmunity. PMID:19076354

Vas, Jaya; Monestier, Marc

2008-11-01

340

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

PubMed

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

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

2010-01-01

341

Mercury concentration in fish from Piracicaba River (Minas Gerais, Brazil).  

PubMed

Mercury emissions from some upstream gold mining areas and recent findings of high natural Hg levels in sediments motivated studies on the Hg cycle in the Minas Gerais state. The study presents the total mercury amount found in Geophagus brasiliensis' muscular tissue (wet weight) and sediments from Piracicaba River. Mercury was analyzed using acid digestion followed by determination of total mercury by cold vapour atomic absorption spectrophotometry. This study was also complemented with the analysis of the limnological parameters (water temperature, conductivity, total dissolved solids, suspended particles, pH, dissolved oxygen, maximum depth, photic index and total carbon). The mercury concentration in sediments samples was higher than the mercury concentration in muscular tissue of fish. The lowest Hg level measured in fish was 0.0147 microg g( - 1), while the highest was 0.101 microg g( - 1). In the sediment samples, the lowest and highest levels were 0.02 microg g( - 1) and 0.16 microg g( - 1), respectively. The Hg concentrations in fish and sediment were both under the maximum limit permitted by the World Health Organization. PMID:18683058

Arantes, I A; Pinto, M T C; Mangabeira, P A; Grenier-Loustalot, M F; Veado, M A R V; Oliveira, A H

2008-08-06

342

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

SciTech Connect

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.

Paller, M; Bill Littrell, B

2007-01-02

343

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

SciTech Connect

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.

Nicholas Ralston; Laura Raymond

2008-03-01

344

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 ...

345

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...

346

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

PubMed

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

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

2009-07-21

347

Levels of mercury and organohalogen compounds in Pacific bluefin tuna (Thunnus orientalis) cultured in different regions of Japan.  

PubMed

Contamination levels of total mercury (T-Hg), p,p'-DDE, and polychlorinated biphenyls (PCBs) in akami (leaner meat) and toro (fatty meat) samples from Pacific bluefin tuna cultured in the southern (four locations) and central (three locations) regions of Japan were analyzed. The contamination level of T-Hg in the akami and toro samples from the southern region tended to decrease with an increase in latitude, whereas those of p,p'-DDE and PCBs tended to increase. These spatial trends in contaminants were similar to those reported previously in wild tuna caught off the coast of Japan (Hisamichi et al., in Environ Sci Technol 44:5971-5978, 2010). However, the contamination level of T-Hg in akami and toro samples from one location in the central region was the highest among all seven locations, whereas the contamination level of p,p'-DDE was lower than that from any location studied in the southern region. Thus, contamination levels of T-Hg, p,p'-DDE, and PCBs in the cultured tuna may reflect contamination levels not only in the marine environment but also in prey fish used as bait. PMID:21766244

Hisamichi, Yohsuke; Haraguchi, Koichi; Endo, Tetsuya

2011-07-16

348

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

SciTech Connect

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.

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

2009-03-03

349

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

Microsoft Academic Search

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.

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

350

Uptake of mercury by the hair of methylmercury-treated newborn mice  

SciTech Connect

Human hair has unique advantages in monitoring environmental exposures to methyl-mercury. Using newborn Balb/c mice as a model system, the incorporation of methylmercury into the hair was studied and compared with methylmercury distributions in other tissues. Newborn mice were given intraperitoneal injections of {sup 203}Hg-labeled methylmercury at designated times according to hair growth stages of the mouse. Animals were sacrificed 2 days after dosing. Distribution of mercury in pelt and other tissues was measured. The level of mercury in pelt was found to correlate with hair growth. The amount of mercury in pelt peaked when hair growth was most rapid and the total amount of mercury in pelt was significantly higher than that in other tissues, constituting 40% of the whole body burden. However, when the hair ceased growing, the amount of mercury in pelt dramatically dropped to 4% of whole body burden and mercury concentrations in other tissues except brain were elevated. Autoradiographic studies with tritium-labeled methylmercury demonstrated that methylmercury concentrated in hair follicles in the skin. Within hair follicles and hairs, methylmercury accumulated in regions that are rich in high-sulfur proteins. The uptake of inorganic mercury (administered as HgCl{sub 2}) by pelt was also compared with that of methylmercury. The amount of inorganic mercury found in pelt was less than one-half that of methylmercury in animals with growing hair. Cessation of hair growth did not decrease the inorganic mercury level in pelt to the same extent as in the case of methylmercury.

Shi, Chenyang; Lane, A.T.; Clarkson, T.W. (Univ. of Rochester, NY (USA))

1990-04-01

351

Tissue-specificity of prostate specific antigens: comparative analysis of transcript levels in prostate and non-prostatic tissues.  

PubMed

Activation of immune defense mechanisms against tumor antigens appears to be a promising therapeutic option for advanced prostate cancer (PCa). Specific immunotherapy critically depends on target antigens that are selectively expressed in the tumorous and optional in the normal prostate tissue in sufficient amounts. Although several prostate antigens have been described and some have already been used in clinical trials, a detailed comparative evaluation of their tissue-specificity and expression levels is still lacking. We determined the transcript levels of eight prostate targets (PSA, PAP, PSCA, PSGR, Prostein, PSMA, AIbZIP, trp-p8) in 16 different tissues by quantitative PCR and calculated a tissue-specificity index (TSI) for each molecule. Besides a preferential expression in prostate for all targets, striking differences in the expression levels and TSI were revealed which may be important for the selection of appropriate antigens for immunotherapy of PCa. PMID:16046056

Cunha, Ana C; Weigle, Bernd; Kiessling, Andrea; Bachmann, Michael; Rieber, E Peter

2005-07-19

352

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.

353

A stationary cold-vapor technique for the determination of submicrogram amounts of mercury in biological tissues by flameless atomic absorption spectrophotometry.  

PubMed

A procedure is provided for the determination of mercury in animal tissue using a single unit stationary cold-vapor generator utilizing atomic absorption spectrophotometry. The entire reduction-absorption cell is fitted to the burner mount on the instrument. Sample digests are introduced into the sample compartment along with reductant, and background corrected absorbance is measured after three minutes of sample-reductant mixing. The method is sensitive to 2 ng Hg (0.50 ng/mL Hg at 0.0044 absorbance units), which corresponds to 25 ng Hg per gram wet tissue using the prescribed digestion procedure. Reproducibility and accuracy are comparable to conventional cold-vapor techniques and the fact that relatively small sample aliquots (4.0 mL) are used for analysis provides for multideterminations of Hg in a single tissue digest; this is not ordinarily possible using conventional cold-vapor methods. A total of 15 digested tissue sample can be analyzed per hour. The method is proposed as an alterative to presently used cold-vapor Hg techniques. PMID:7242023

Bourcier, D R; Sharma, R P

354

Profiling transcript levels for steroidogenic enzymes in fetal tissues  

Microsoft Academic Search

Cytochrome P450 (CYP) and hydroxysteroid dehydrogenase enzymes are involved in the conversion of cholesterol to steroid hormones. These enzymes are primarily expressed in the placenta, adrenal and gonads. Interestingly, some of these enzyme activities have been demonstrated in non-endocrine tissues, where they may be involved in important paracrine and autocrine actions. This is particularly the case in the human fetus

Vincenzo Pezzi; J. M Mathis; William E Rainey; Bruce R Carr

2003-01-01

355

Azithromycin levels in plasma and gastric tissue, juice and mucus  

Microsoft Academic Search

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

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

1991-01-01

356

Uremic hyperstannum: elevated tissue tin levels associated with uremia  

Microsoft Academic Search

Previous work has shown that the concentration of the essential trace element tin is elevated in several tissues of dialyzed uremic patients. Analysis of 80 postmortem liver samples from controls and nondialyzed uremic and dialyzed uremic patients now shows that nondialyzed uremic patients also have abnormally high tin concentrations, averaging about three times that of controls. It is concluded that

L. L. Nunnelley; W. R. Smythe; A. C. Alfrey; L. S. Ibels

1978-01-01

357

Metallothionein biosynthesis as a detoxification mechanism in mercury exposure in fish, spotted scat (Scatophagus argus).  

PubMed

It is of crucial importance to study on the biomarkers types to assess the specification of the pollutants and health status of marine ecosystems in environmental evaluation projects. In this respect, total metallothionein biosynthesis and mercury bioaccumulation in the liver and gills under acute mercury exposure were investigated in fish, Scat (Scatophagus argus). Spotted scat was exposed to different mercury concentrations (0, 10, 20, 30) for 24, 48, 72 h. Total MT levels were determined by enzyme-linked immunosorbent assay (ELISA) method. Mercury contents were determined through cold vapor atomic absorption spectrometry (CVAAS). Induction of MT during exposure was tissue specific, displaying different response pattern in gills and liver. Mercury accumulated in liver much higher than in gills and the latter also showed lower MT level (P<0.05). MT biosynthesis in liver showed a significant (P<0.05) increase after exposure to different mercury concentration with increase in exposure time, whereas total MT content did not significantly (P>0.05) change in gills except for 72 h exposure at 30 ?g l(-1). Nonetheless, the relationship between MT biosynthesis and Mercury bioaccumulation in both tissues was significant (P<0.05). The results suggest that this form of MT in S. argus was Hg inducible and could be extended as a biomarker of mercury pollution in marine ecosystems. PMID:20499274

Sinaie, Mahmood; Bastami, Kazem Darvish; Ghorbanpour, Masoud; Najafzadeh, Hossein; Shekari, Majid; Haghparast, Sara

2010-05-25

358

A contribution to the establishment of reference values for total mercury levels in hair and fish in amazonia.  

PubMed

Studies on mercury levels in the Amazonian Region have typically lacked background or reference parameters. A sectional study on Hg concentration in hair and fish was conducted, together with an assessment of the prevalence of signs and symptoms related to Hg poisoning, in four communities in the Amazon Basin not impacted by gold mining, located either by a river course (Santana do Ituqui and Caxiuană) or by a lake (Aldeia do Lago Grande and Vila do Tabatinga). Mercury determinations in hair and fish were made by flameless atomic absorption spectrophotometry. Mean total Hg in hair was 4.33 microg/g (0.40-11.60 microg/g) in 321 individuals from Santana do Ituqui, 3.98 microg/g (0.40-11.76 microg/g) for 316 persons in Aldeia do Lago Grande, 5.46 microg/g (0.37-49.85 microg/g) for 504 individuals from Vila do Tabatinga and 8.58 microg/g (0.61-45.59 microg/g) for 203 inhabitants from Caxiuană. Fish consumption was very high in all those communities but no signs or symptoms associated with Hg poisoning were found. Mean Hg concentration in fish varied from 0.006 to 2.529 microg/g for carnivores and from 0.008 to 0.871 microg/g for noncarnivores. These values suggest that further studies including a larger number of communities would eventually lead to values of "normal" Hg concentration in the Amazonian Region quite above the limits suggested by the World Health Organization. PMID:12359185

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

2002-09-01

359

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

PubMed

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 (1,470 ppb to 54.3 ppb), cadmium (277 ppb to 30.5 ppb), and manganese (only since 1996; 2,669 ppb to 329 ppb)). Although mercury levels decreased from 2003-2008 (6,430 ppb to 1,042 ppb), there was no pattern before 2003, and levels increased after 2008 to 2,610 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 6,430 ppb) are in the range associated with adverse effects (5,000 ppb for feathers). PMID:23434313

Burger, Joanna

2013-02-20

360

Simultaneous measurement of tissue oxygen level-dependent (TOLD) and blood oxygenation level-dependent (BOLD) effects in abdominal tissue oxygenation level studies.  

PubMed

PURPOSE: To assess oxygenation in abdominal organs with magnetic resonance imaging (MRI), a novel approach is presented to simultaneously measure both T1 - and T2*-maps serially during a single dynamic MRI scan in response to an oxygen challenge. MATERIALS AND METHODS: The proposed acquisition scheme consists of a multishot multiecho gradient echo planar imaging sequence (ms-GEPI) interleaved with a multishot inversion recovery echo planar imaging (ms-IR-EPI) sequence. Respiratory motion compensation was accomplished with standard belt triggering and by acquiring all image data at the same phase of expiration. This respiratory-triggered, free-breathing, interleaved tissue oxygenation level-dependent (TOLD) and blood oxygenation level-dependent (BOLD) acquisition technique was validated on phantoms and seven healthy volunteers in response to an oxygen challenge. RESULTS: Measurements of relaxation times both in vitro and in vivo were in good agreement with those obtained using conventional pulse sequences and reported in the literature. The interleaved sequence was able to measure oxygen-induced relaxation time changes in human abdominal organs. CONCLUSION: The free-breathing respiratory-triggered interleaved T1 and T2* sequence successfully provided relaxation time maps of abdominal organs in a dynamic scan without the need for image registration. The simultaneous monitoring of tissue and blood oxygenation improves time efficiency and should enhance studies comparing dynamic T1 and T2* data within the abdomen. J. Magn. Reson. Imaging 2012;. © 2012 Wiley Periodicals, Inc. PMID:23749420

Ding, Yao; Mason, Ralph P; McColl, Roderick W; Yuan, Qing; Hallac, Rami R; Sims, Robert D; Weatherall, Paul T

2013-06-01

361

The Hair-Organ Relationship in Mercury Concentration in Contemporary Japanese  

Microsoft Academic Search

The hair-organ relationship of mercury concentration was investigated in 46 autopsy samples in Tokyo, Japan. Hair mercury levels were highly significantly correlated with organ Hg levels in the cerebrum, cerebellum, heart, spleen, liver, kidney cortex, and kidney medulla, when the total mercury or methyl mercury value in the organ was compared with the hair total mercury or organic mercury, respectively.

Tsuguyoshi Suzuki; Tetsuro Hongo; Jun Yoshinaga; Hideki Imai; Minato Nakazawa; Naoto Matsuo; Hirokatsu Akagi

1993-01-01

362

The Movement of Aquatic Mercury Through Terrestrial Food Webs  

Microsoft Academic Search

Mercury has contaminated rivers worldwide, with health consequences for aquatic organisms and humans who consume them. Researchers have focused on aquatic birds as sentinels for mercury. However, trophic transfer between adjacent ecosystems could lead to the export of aquatic mercury to terrestrial habitats. Along a mercury-contaminated river in Virginia, United States, terrestrial birds had significantly elevated mercury levels, similar to

Daniel A. Cristol; Rebecka L. Brasso; Anne M. Condon; Rachel E. Fovargue; Scott L. Friedman; Kelly K. Hallinger; Adrian P. Monroe; Ariel E. White

2008-01-01

363

Expression of tissue levels of matrix metalloproteinases and tissue inhibitors of metalloproteinases in renal cell carcinoma  

PubMed Central

Background Matrix metalloproteinases (MMPs) are one of the major classes of proteolytic enzymes involved in tumor invasion and metastasis and are inhibited by naturally occurring tissue inhibitors of metalloproteinases (TIMPs). {AU Query: Please verify that corrections made to previous sentence did not alter intended meaning}. In this study, we examined the expression of MMP-2, MMP-9, membrane-type 1 (MT1)-MMP, TIMP-1, and TIMP-2 in renal tissue samples of renal cell cancer and examined the correlation between their expression and clinicopathological parameters. Methods Renal tissue samples from 76 patients with renal cell carcinoma were available for this study. To determine the expression of MMP-2, MMP-9, MT1-MMP, TIMP-1, and TIMP-2, semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was carried out on tumor and normal tissues. Results Mean MMP-2, MMP-9, MT1-MMP, TIMP-1, and TIMP-2 mRNA expression in the renal cell carcinomas was significantly higher than in the normal renal tissue (P <0.05). The RT-PCR data of MMP-2, MMP-9, MT1-MMP, TIMP-1, and TIMP-2 did not show any significant correlation with tumor type or pathologic grade of renal cell carcinoma. MMP-2, MMP-9 and MT1-MMP mRNA expression increased significantly with the TNM stage of the tumor. Conclusions Mean MMP-2, MMP-9, MT1-MMP, TIMP-1, and TIMP-2 mRNA expression in the renal cell carcinomas was significantly higher than in the normal renal tissue.

2013-01-01

364

Metallothionein expression in chloroplasts enhances mercury accumulation and phytoremediation capability.  

PubMed

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

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

2011-04-24

365

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

PubMed

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

Pollock, Brady; Machin, Karen L

2008-08-02

366

Clean conditions for the determination of ultra-low levels of mercury in ice and snow samples.  

PubMed

Laboratory facilities and methods are presented for the determination of ultra-low levels of mercury (Hg) in ice and snow samples originating from polar ice caps or temperate regions. Special emphasis will be given to the presentation of the clean laboratory and the cleaning procedures. The laboratory is pressurized with air filtered through high efficiency particle filters. This first filtration is not enough to get rid of contamination by Hg in air. Experiments are conducted in a clean bench, especially built for Hg analysis, equipped with both particle filter and activated charcoal filter. It allows to obtain very low levels of atmospheric Hg contamination. Ultrapure water is produced for cleaning all the plastic containers that will be used for ice and snow samples and also for the dilution of the standards. Hg content in laboratory water is about 0.08+/-0.02 pg/g. A Teflon system has been developed for the determination of Hg in ice and snow samples based on Hg(II) reduction to Hg(0) with a SnCl2/HNO3 solution followed by the measurement of gaseous Hg(0) with a Hg analyzer GARDIS 1A+ based on the Cold Vapor Atomic Absorption Spectroscopy method. Blank determination is discussed. PMID:11220334

Ferrari, C P; Moreau, A L; Boutron, C F

2000-03-01

367

Mercury, lead and cadmium levels in the urine of 170 Spanish adults: a pilot human biomonitoring study.  

PubMed

Human biomonitoring is a well-recognized tool for estimating the exposure of human populations to environmental pollutants. However, information regarding biomarker concentrations of many environmental chemicals in the general population is limited for many countries. The Spanish Environment Ministry has recently funded a human biomonitoring study on the Spanish general population. This study aims to determine reference levels for several biomarkers, especially heavy metals, persistent organic pollutants (POPs) and cotinine, in urine, whole blood, serum and hair, and will involve 2000 volunteers throughout Spain. Samples were taken during 2009-2010 and analyses are currently underway. The results presented herein were obtained in a pilot study carried out in the Madrid region. The study group comprised 170 volunteers, of which 79% were female and 21% male (age: 23-66 years). All participants were asked to complete a questionnaire regarding diet and living habits and provides a morning urine sample. The geometric means for total mercury (Hg), lead (Pb) and cadmium (Cd) were 1.23, 1.11 and 0.25 ?g/g creatinine, respectively. Levels of Pb and Hg were higher than those reported for the general population in the USA and Germany, whereas Cd was in the same range (CDC, 2009; Becker et al., 2003). The values reported here are similar to those reported in other Spanish studies. PMID:21968334

Castańo, Argelia; Sánchez-Rodríguez, Jinny E; Cańas, Ana; Esteban, Marta; Navarro, Carmen; Rodríguez-García, Ana C; Arribas, Misericordia; Díaz, Gema; Jiménez-Guerrero, José A

2011-10-02

368

Levels of gingival tissue platelet activating factor after conventional and regenerative periodontal surgery  

Microsoft Academic Search

The hypothesis, a relationship between gingival tissue platelet activating factor (PAF) levels and healing after periodontal\\u000a surgery, was tested by measuring PAF levels in gingival tissues collected from sites that had undergone flap surgery and guided\\u000a tissue regeneration (GTR) or flap surgery alone. Using a split-mouth design, 20 intrabony defects were randomly assigned to\\u000a treatment with flap surgery and GTR

Gonca Cayir Keles; Burcu Ozkan Cetinkaya; Bulent Ayas; Ibrahim Isildak; Emine Diraman; Hulya Koprulu; Gokhan Acikgoz

2007-01-01

369

Auto-aggressive metallic mercury injection around the knee joint: a case report  

PubMed Central

Background Accidental or intentional subcutaneous and/or intramuscular injection of metallic mercury is an uncommon form of poisoning. Although it does not carry the same risk as mercury vapour inhalation, it may cause destructive early and late reactions. Case Presentation Herein we present the case of a 29-year-old male patient who developed an obsessive-compulsive disorder causing auto-aggressive behaviour with injection of elemental mercury and several other foreign bodies into the soft tissues around the left knee about 15 years before initial presentation. For clinical examination X-rays and a CT-scan of the affected area were performed. Furthermore, blood was taken to determine the mercury concentration in the blood, which showed a concentration 17-fold higher than recommended. As a consequence, the mercury depots and several foreign bodies were resected marginally. Conclusion Blood levels of mercury will decrease rapidly following surgery, especially in combination with chelating therapy. In case of subcutaneous and intramuscular injection of metallic mercury we recommend marginal or wide excision of all contaminated tissue to prevent migration of mercury and chronic inflammation. Nevertheless, prolonged clinical and biochemical monitoring should be performed for several years to screen for chronic intoxication.

2011-01-01

370

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

PubMed

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

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

2010-11-03

371

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

PubMed Central

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

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

2010-01-01

372

ELF field interactions at the animal, tissue and cellular levels.  

National Technical Information Service (NTIS)

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...

T. S. Tenforde

1990-01-01

373

Mercury bioaccumulation and the population dynamics of Mesopodopsis slabberi (Crustacea: Mysidacea) along a mercury contamination gradient.  

PubMed

The mercury bioaccumulation and population dynamics of the mysid Mesopodopsis slabberi was assessed along a mercury gradient in Ria de Aveiro (Portugal). M. slabberi is one of the most important mysid species in European temperate coastal shallow waters playing a key ecological role. Nevertheless, no references were found concerning the possible consequences of the Hg on the trophodynamics of these coastal ecosystems. M. slabberi showed a clear bioaccumulation along the Hg gradient and through life, with mature females reaching the highest concentrations. In terms of population structure, higher densities and biomasses of M. slabberi were assessed in the most contaminated areas contrarily to the least polluted areas. Despite the mercury accumulation in its tissues no strong negative effects on the structure and population dynamics of the species were observed. However, mysids might be important in the transfer of metals from the sediments and zooplankton to higher trophic levels such as fishes, most of them with commercial interest. PMID:23982276

D'Ambrosio, M; Marques, S C; Azeiteiro, U M; Pardal, M A; Pereira, E; Duarte, A C; Cardoso, P G

2013-08-28

374

Regulation of tissue oxygen levels in the mammalian lens.  

PubMed

Opacification of the lens nucleus is a major cause of blindness and is thought to result from oxidation of key cellular components. Thus, long-term preservation of lens clarity may depend on the maintenance of hypoxia in the lens nucleus. We mapped the distribution of dissolved oxygen within isolated bovine lenses and also measured the rate of oxygen consumption (QO2) by lenses, or parts thereof. To assess the contribution of mitochondrial metabolism to the lens oxygen budget, we tested the effect of mitochondrial inhibitors on (QO2) and partial pressure of oxygen (PO2). The distribution of mitochondria was mapped in living lenses by 2-photon microscopy. We found that a steep gradient of PO2 was maintained within the tissue, leading to PO2 < 2 mmHg in the core. Mitochondrial respiration accounted for approximately 90% of the oxygen consumed by the lens; however, PO2 gradients extended beyond the boundaries of the mitochondria-containing cell layer, indicating the presence of non-mitochondrial oxygen consumers. Time constants for oxygen consumption in various regions of the lens and an effective oxygen diffusion coefficient were calculated from a diffusion-consumption model. Typical values were 3 x 10(-5) cm(2) s(-1) for the effective diffusion coefficient and a 5 min time constant for oxygen consumption. Surprisingly, the calculated time constants did not differ between differentiating fibres (DF) that contained mitochondria and mature fibres (MF) that did not. Based on these parameters, DF cells were responsible for approximately 88% of lens oxygen consumption. A modest reduction in tissue temperature resulted in a marked decrease in (QO2) and the subsequent flooding of the lens core with oxygen. This phenomenon may be of clinical relevance because cold, oxygen-rich solutions are often infused into the eye during intraocular surgery. Such procedures are associated with a strikingly high incidence of postsurgical nuclear cataract. PMID:15272034

McNulty, Richard; Wang, Huan; Mathias, Richard T; Ortwerth, Beryl J; Truscott, Roger J W; Bassnett, Steven

2004-07-22

375

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

PubMed

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

Brent, Robert N; Kain, Donald G

2011-03-30

376

Tissue distribution of metals in striped dolphins ( Stenella coeruleoalba) from the Apulian coasts, Southern Italy  

Microsoft Academic Search

Tissue distributions of metals (mercury, lead, cadmium, zinc, copper, iron, manganese) were determined in six specimens of striped dolphins (Stenella coeruleoalba, Meyen) stranded on the Apulian coasts (Southern Italy) between February and June 1987. Methyl mercury and selenium were also determined in the liver samples. The liver accumulated the highest concentrations of metals, except for cadmium and chromium. Metal levels

N Cardellicchio; S Giandomenico; P Ragone; A Di Leo

2000-01-01

377

Effect of castration monotherapy on the levels of adrenal androgens in cancerous prostatic tissues.  

PubMed

The mechanism accounting for the development of castration-resistant prostate cancer (CRPC) remains unclear. Studies in CRPC tissues suggest that, after androgen deprivation therapy (ADT), the adrenal androgens may be an important source of testosterone (T) and 5-alpha dihydrotestosterone (DHT) in CRPC tissues. To clarify the role of adrenal androgens in the prostatic tissues (prostatic tissue adrenal androgens) during ADT, we developed a high sensitive and specific quantification method for the levels of androgens in prostatic tissue using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Human prostatic tissues were purified using mixed-mode reversed-phase, strong anion exchange Oasis cartridges (Oasis MAX). Analysis of steroids was performed using LC-MS/MS after picolinic acid derivatization. The validation tests showed that our method of quantitative analysis was precise and sensitive enough for the quantification of dehydroepiandrosterone (DHEA), androstenedione, androstenediol, T, and DHT in the prostatic tissue. The levels of adrenal androgens in prostate cancer tissues after ADT were similar to those in untreated PCa. Especially, DHEA was the most existing androgen precursor in PCa tissues after ADT. The levels of DHEA were high in PCa tissues, irrespective of ADT. We assumed that DHEA played a significant role in the synthesis of T and DHT in PCa tissues after ADT. PMID:21147140

Arai, Seiji; Miyashiro, Yoshimichi; Shibata, Yasuhiro; Tomaru, Yukio; Kobayashi, Mikio; Honma, Seijiro; Suzuki, Kazuhiro

2010-12-13

378

Inorganic: the other mercury.  

PubMed

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

Risher, John F; De Rosa, Christopher T

2007-11-01

379

Volatilization of Mercury By Bacteria  

PubMed Central

Volatilization of mercury has been observed from various biological media (tissue homogenates, infusion broth, plasma, urine) containing mercuric chloride. That micro-organisms were responsible was indicated by the finding that the rates of volatilization were highly variable, that a latent period often preceded volatilization, that toluene inhibited the process, and that the capacity to volatilize mercury could be transferred from one biological medium to another. Two species of bacteria when isolated and cultured from these homogenates were able to volatilize mercury. Two other bacteria, one of which was isolated from the local water supply, were also highly active. The volatile mercury was identified as mercury vapour. The importance of these findings in relation to the storage of urine samples prior to mercury analysis is discussed.

Magos, L.; Tuffery, A. A.; Clarkson, T. W.

1964-01-01

380

Influence of ecological factors and of land use on mercury levels in fish in the Tapajós River basin, Amazon.  

PubMed

Mercury (Hg) contamination of riparian communities and of environmental compartments of the Amazon can be directly related to the occupation of the territory. The objective of this study was to identify the characteristics of aquatic environments that are associated with high levels of Hg in ichthyofauna. Our research aimed at determining the influence of variables related to fish ecology, types of aquatic environment, fishing activities by local riparian populations, and watershed use on the levels of contamination of ichthyofauna. Six sites were sampled during two distinct periods of the hydrological cycle: at the beginning of descending waters and during low waters. We focused on ten dominant fish species representing four trophic levels: Curimata inornata, Geophagus proximus, Schizodon vittatum, Leporinus fasciatus, Anostomoides laticeps, Hemiodus unimaculatus, Caenotropus labyrinthicus, Hoplias malabaricus, Plagioscion squamosissimus, Acestrorhynchus falcirostris. The study sites, which included lotic and lentic habitats, are exploited year-round by local riparian communities. Spatial variations in Hg contamination in ichthyofauna were determined by factorial analysis of variance taking into account fish diets, seasons, and sampling sites. Multiple regressions were used to check the influence of ecological and anthropogenic variables and variables related to watershed uses, on Hg levels in key species representing the four trophic groups. Each variable was checked independently. Next, multiple regressions were used to verify the concomitant influence of selected variables. Independently of the study site and the phase of the hydrologic cycle, fish Hg contamination followed the trend piscivores>omnivores>herbivores>detritivores. In all the aquatic study sites, Hg levels measured in predatory species were often higher than the 500 ng/g fresh weight threshold. Mean Hg levels in key species were significantly higher during descending waters in lotic environments, and during low waters in lentic environments. Data from this study demonstrated that simple models based on watershed use and on easily obtained variables such as the suspended particulate matter (SPM) load and SPM Hg concentrations, number of inhabitants, habitat types, and the stage in the hydrological cycle enable very good prediction of Hg levels in fish. Our cartographical data clearly showed that the watershed site with the highest aquatic vegetation cover (6% of the open water body) and with the lowest forest cover (62% of the land) corresponded to the highest Hg concentrations in fish. Conversely, the watershed site with 94% forest cover and 1% aquatic vegetation corresponded to the lowest levels Hg concentrations in fish. These results suggest that land uses of watersheds play a key role in the level of Hg contamination of local ichthyofauna. PMID:19356749

Sampaio da Silva, D; Lucotte, M; Paquet, S; Davidson, R

2009-04-08

381

Methods for the Determination of Plasma or Tissue Glutathione Levels  

PubMed Central

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

Tipple, Trent E.; Rogers, Lynette K.

2013-01-01

382

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.

383

Relationship between localization of gold mining areas and hair mercury levels in people from Bolivar, north of Colombia.  

PubMed

Mercury (Hg) is a heavy metal that, once in the environment, is bioaccumulated and biomagnified through food chain impacting ecosystems. The aim of this study was to evaluate total Hg (T-Hg) concentrations in individuals along Cauca and Magdalena Rivers in Colombia, where most gold mining activities take place. A total of 1,328 hair samples were collected and analyzed for T-Hg using atomic absorption spectroscopy. T-Hg concentrations ranged from 0.01 to 20.14 ?g/g. Greatest levels were detected in La Raya (5.27?±?0.32 ?g/g), Achi (2.44?±?0.22 ?g/g), and Montecristo (2.20?±?0.20 ?g/g), places that are located near gold mines. Concentrations decreased with the distance from main mining areas. Only 0.75% of the individuals had T-Hg levels above 10 ?g/g. Men had significantly higher T-Hg levels than women, and correlation analysis revealed moderately weak but significant relationships between T-Hg and weight (R?=?0.111, P?

Olivero-Verbel, Jesús; Caballero-Gallardo, Karina; Marrugo Negrete, Jose; Negrete-Marrugo, José

2011-04-08

384

Prostatic Phyto-Oestrogen Tissue Levels in Different Austrian Regions  

Microsoft Academic Search

Introduction: A number of studies suggest that the low incidence of prostate cancer as well as benign prostatic enlargement in Asia depends on the extended consumption of phyto-oestrogens in these parts of the world. In most Asian men, phyto-oestrogen levels are multiple higher compared to Austrian (European) men. The aim of our study was to evaluate, according to the East-West

Clemens Brössner; Karin Petritsch; Klaus Fink; Marco Auprich; Anton Ponholzer; Stefan Madersbacher; Herman Adlercreutz; Peter Petritsch

2006-01-01

385

Comments on the article "the toxicology of mercury and its chemical compounds" by Clarkson and Magos (2006).  

PubMed

Clarkson and Magos (2006) provide their perspectives on the toxicology of mercury vapor and dental amalgam. As scientists who are involved in preparing a German federal guideline regarding dental amalgam, we welcome additional scientific data on this issue. However, Clarkson and Magos do not present all the relevant studies in their review. The additional data provided here show that: (a) Dental amalgam is the main source of human total mercury body burden, because individuals with amalgam have 2-12 times more mercury in their body tissues compared to individuals without amalgam; (b) there is not necessarily a correlation between mercury levels in blood, urine, or hair and in body tissues, and none of the parameters correlate with severity of symptoms; (c) the half-life of mercury deposits in brain and bone tissues could last from several years to decades, and thus mercury accumulates over time of exposure; (d) mercury, in particular mercury vapor, is known to be the most toxic nonradioactive element, and is toxic even in very low doses, and (e) some studies which conclude that amalgam fillings are safe for human beings have important methodogical flaws. Therefore, they have no value for assessing the safety of amalgam. PMID:17661216

Mutter, Joachim; Naumann, Johannes; Guethlin, Corina

2007-01-01

386

Increased striatal dopamine synthesis is associated with decreased tissue levels of tyrosine.  

PubMed

Tyrosine levels do not generally affect indices of dopamine (DA) synthesis or efflux under basal conditions, but can do so when DA synthesis is increased. One possibility is that a high rate of DA synthesis depletes the normally adequate pool of endogenous tyrosine. To study this, we administered drugs known to preferentially increase striatal DA synthesis and examined DOPA levels in striatal microdialysate during perfusion with NSD-1015. In additional groups, we also measured DA, tyrosine and large neutral amino acids in striatal microdialysate, as well as in tissue from striatum and medial prefrontal cortex (MPFC). gamma-butyrolactone (GBL) (750 mg/kg i.p.) increased DOPA levels in striatal microdialysate, increased tissue DA levels in the MPFC and striatum, but lowered tissue tyrosine levels only in striatum. In striatal microdialysate, GBL markedly lowered DA levels; tyrosine levels were only marginally lower. Haloperidol (HAL) (1.0 mg/kg s.c.)+/-amfonelic acid (AFA) (5 mg/kg i.p.) increased striatal DOPA accumulation, increased striatal DA efflux, lowered striatal tissue tyrosine levels, but did not affect microdialysate tyrosine levels. There were no consistent changes in levels of other large neutral amino acids. We conclude that increased tyrosine hydroxylation can significantly deplete the endogenous pool of tyrosine. Under such conditions, near normal extracellular tyrosine levels are maintained despite lower tissue levels. The data are consistent with a net transfer of tyrosine from non-DAergic cells to DA terminals in support of DA synthesis. PMID:16934236

Bongiovanni, Rodolfo; Young, Damon; Newbould, Erica; Jaskiw, George E

2006-08-24

387

Metal Levels in Raccoon Tissues: Differences On and Off the Department of Energy's Savannah River Site in South Carolina  

Microsoft Academic Search

Levels of arsenic, cadmium, chromium, copper, lead, manganese, selenium, and strontium88 were examined in heart, kidney, muscle, spleen and liver of raccoons (Procyon lotor) from four areas on the Department of Energy's Savannah River Site (SRS), including near a former reactor cooling reservoir and a coal ash basin, and from public hunting areas within 15 km of the site. Mercury

J. Burger; K. F. Gaines; C. G. Lord; I. L. Brisbin; S. Shukla; M. Gochfeld

2002-01-01

388

Levels of prenatal mercury exposure and their relationships to neonatal anthropometry in Wujiang City, China.  

PubMed

We determined the levels of prenatal Hg exposure in Wujiang City, located in the southeast of Taihu Lake in China's Jiangsu Province, and analyze the relationship between prenatal exposure to Hg and neonatal anthropometry, including birth weight, body length, and head circumference. From June 2009 to July 2010, a total of 213 mother-infant pairs were enrolled. The geometric means of Hg levels in maternal hair, fetal hair, placentas, and cord blood were 496.76 ?g/kg, 233.94 ?g/kg, 3.58 ?g/kg, and 1.54 ?g/L, respectively. The Hg levels detected in our study were significantly lower than those reported by previous studies. In addition, no significant correlations were found between Hg levels in maternal hair, fetal hair, placenta, or cord blood and neonatal anthropometrics. Together, our findings may be important for understanding the effects of prenatal exposure to Hg on newborns' development and have implications concerning the recommended dose for Hg. PMID:23920315

Guo, Bao-Qiang; Cai, Shi-Zhong; Guo, Jun-Liang; Xu, Jian; Wu, Wei; Li, Hui; Zhou, Xin; Kim, Dae-Seon; Yan, Chong-Huai; Lü, Hong-Dao

2013-08-03

389

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

Microsoft Academic Search

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

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

1996-01-01

390

A new densitometric procedure to measure protein levels in tissue slices used in quantitative autoradiography.  

PubMed

A new quantitative staining technique for the assay of protein in tissue sections using the dye Coomassie brilliant blue G 250 is discussed. This densitometric procedure uses commercially available hardware and software employed in the quantitation of receptor autoradiographs. Rather than assuming a homogeneous distribution of protein in the tissue section, regional levels of protein are measured in the same tissue slice used to produce the autoradiograph. Additionally, the process of staining tissue with Coomassie blue for protein is reversible; the tissue can be destained after the measurement of protein is complete and then restained with a standard histological stain such as Cresyl violet. This technique is a more reliable method for normalizing receptor densities by tissue protein levels and allows for a more accurate comparison between QAR and membrane binding techniques. PMID:2838130

Miller, J A; Curella, P; Zahniser, N R

1988-04-26

391

Seasonal mercury levels in phytoplankton and their relationship with algal biomass in two dystrophic shield lakes  

SciTech Connect

This study focused on the seasonal dynamics of total Hg in the phytoplankton (living and dead) of two dystrophic shield lakes (Mouse and Ranger). Phytoplankton samples were taken from metalimnetic and hypolimnetic depths in the euphotic zone and were collected and analyzed using ultraclean techniques. In both lakes, phytoplankton Hg (PHYTO-Hg) levels (pg/L) in the metalimnion did not significantly change among dates over the season, although Ranger Lake exhibited significant differences between Hg values measured at the beginning and end of the season. In contrast, PHYTO-Hg significantly increased in the hypolimnia of both lakes by the end of the season. Combined influences of external Hg inputs, remineralization, phytoplankton sedimentation, and increased methylmercury production in the hypolimnia over the season may have contributed to these trends. A highly significant positive relationship existed between PHYTO-Hg levels and whole-water Hg levels, and the mean bioconcentration factor for Hg between the water column and phytoplankton was significantly higher in the hypolimnion compared to the metalimnion for both lakes. In most cases, parameters associated with algal biomass had significant positive correlations with PHYTO-Hg levels. Weight-specific PHYTO-Hg (pg/mg dry weight) varied significantly over the season, and there were interlake differences with respect to season trends. On the basis of these results, the authors recommend that the future sampling regimes include collection of phytoplankton at different limnetic depths through the season to account for spatial and temporal variations. Weight specific Hg levels in phytoplankton could not be explained well by the parameters tested, and the only significant regressions were with parameters reflecting algal biomass. This study provides in situ evidence of Hg accumulation in lake phytoplankton as a function of algal biomass on a seasonal basis and stresses the need to confirm these trends in other lake systems.

Kirkwood, A.E.; Chow-Fraser, P. [McMaster Univ., Hamilton, Ontario (Canada). Dept. of Biology; Mierle, G. [Ontario Ministry of the Environment and Energy, Dorset, Ontario (Canada). Dorset Research Center

1999-03-01

392

Food web analysis reveals effects of pH on mercury bioaccumulation at multiple trophic levels in streams.  

PubMed

Biomagnification processes and the factors that govern them, including those for mercury (Hg), are poorly understood in streams. Total and methyl Hg concentrations and relative trophic position (using ?(15)N) were analyzed in biofilm and invertebrates from 21 streams in New Brunswick, Canada to assess food web biomagnification leading to the common minnow blacknose dace (Rhinichthys atratulus), a species known to have Hg concentrations that are higher in low pH waters. Biomagnification slopes within stream food webs measured using Hg vs. ?(15)N or corresponding trophic levels (TL) differed depending on the chemical species analyzed, with total Hg exhibiting increases of 1.3-2.5 per TL (mean slope of total Hg vs. ?(15)N=0.14±0.06 S.D., range=0.06-0.20) and methyl Hg showing a more pronounced increase of 2.8 to 6.0 per TL (mean slope of methyl Hg vs. ?(15)N=0.30±0.08 S.D., range=0.22-0.39). While Hg biomagnification slopes through the entire food web (Trophic Magnification Factors, TMFs) were not influenced by water chemistry (pH), dietary concentrations of methyl Hg strongly influenced biomagnification factors (BMFs) for consumer-diet pairs within the food web at lower trophic levels, and BMFs between dace and predatory invertebrates were significantly higher in low pH waters. These analyses, coupled with observations of higher Hg in primary producers in streams with low pH, suggest that pH influences both baseline concentrations and biomagnification of Hg in these systems. Because higher Hg concentrations in the diets of primary consumers and predatory insects in lower pH waters led to lower BMFs, these feeding groups showed insignificant relationships between Hg and pH; thus, altered BMFs associated with dietary concentrations can dampen the effects of environmental conditions on Hg concentrations. PMID:23454309

Jardine, Timothy D; Kidd, Karen A; O' Driscoll, Nelson

2013-02-08

393

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

SciTech Connect

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.

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

1996-12-31

394

The evaporation of a drop of mercury  

NASA Astrophysics Data System (ADS)

The evaporative rates of two drops of mercury at room temperature are determined experimentally and theoretically. The resulting mercury vapor levels are estimated and measured, compared with the OSHA permissible exposure limit, and found to be small by comparison.

Winter, Thomas G.

2003-08-01

395

The fate of coal mercury during combustion  

Microsoft Academic Search

The fate of the mercury content of four UK coals has been investigated using a 1 MWth Combustion Test Facility (CTF). The results demonstrate that the mercury retention in dust is related to the carbon content of the dust, with increasing retention as carbon levels increase. Conversely, as carbon levels decrease, vapour phase mercury emissions increase. The measurements also showed

W. H Gibb; F Clarke; A. K Mehta

2000-01-01