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1

Mercury levels and relationships in water, sediment, and fish tissue in the Willamette Basin, Oregon.  

PubMed

In Oregon's Willamette River Basin (the Basin), health advisories currently limit consumption of fish that have accumulated methylmercury (MeHg) to levels posing a significant human health risk. These advisories created the requirement for a mercury total maximum daily load for the Basin, which required a greater understanding of the behavior, distribution, and levels of mercury and MeHg in the Basin. In 2002, the Oregon Department of Environmental Quality initiated a study to measure (using ultraclean techniques) mercury and MeHg levels in water, sediment, and fish samples collected throughout the Basin. Results from the Middle Fork (nominal background) suggested that naturally occurring surface-water concentrations of mercury and MeHg would on an annual average basis be expected in the range of 0.5 to 1.0 and 0.04 to 0.06 ng L(-1), respectively. Concentrations in the Coast Fork (Cottage Grove), which were markedly higher, are likely the result of historical mining discharges. The possibility exists that wetlands alone could contribute the dissolved MeHg levels (approximately 0.04 ng L(-1)) observed in the Main Stem. Mercury levels in sediment were similar, and near background, in the Main Stem, Coast Fork (Row River), and Middle Fork but significantly increased in the Coast Fork (Cottage Grove). Fish tissue mercury levels were typically highest in piscivorous and lowest in invertivorous species but highest in the Coast Fork (Cottage Grove). In the Coast Fork and Cottage Grove Reservoir, discharges from historical mercury mining activities appear to have significantly impacted water, sediment, and fish tissue levels; however these impacts do not appear to extend into the Main Stem. Basinwide mercury data are at present too spottily distributed to determine whether significant mercury point sources exist along the Main Stem. PMID:15750769

Hope, B K; Rubin, J R

2005-04-01

2

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

PubMed

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

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

2011-08-01

3

Organ mercury levels in infants with omphaloceles treated with organic mercurial antiseptic  

Microsoft Academic Search

Samples of fresh and fixed tissues from infants with exomphalos treated by thiomersal application were analysed for mercury content. The results showed that thiomersal can induce blood and organ levels of organic mercury which are well in excess of the minimum toxic level in adults and fetuses. The analysis of fresh and fixed tissues must be carefully controlled against normal

D. G. Fagan; J S Pritchard; T. W. Clarkson; M. R. Greenwood

1977-01-01

4

Effect of selenium on determination of mercury in animal tissues  

Microsoft Academic Search

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

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

1979-01-01

5

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

PubMed

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

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

2014-03-01

6

Mercury residues in tissues of dead and surviving birds fed methylmercury  

USGS Publications Warehouse

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

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

1979-01-01

7

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

2012-09-15

8

Serum mercury level and multiple sclerosis.  

PubMed

Exposure to heavy metals has been associated to a higher incidence of multiple sclerosis. In this work, we present a possible relationship between serum mercury levels and development of multiple sclerosis in Isfahan, the third largest city in Iran. Seventy-four patients affected by multiple sclerosis were retrieved from multiple sclerosis (MS) clinic in Isfahan, Iran. By matching sex and age, 74 healthy volunteers were chosen as control group. Blood samples were collected and serum mercury content was determined. Serum mercury level in MS patients was significantly higher than controls (9.6?±?10.17 vs. 5.7?±?8.6, P?=?0.037). Concerning all MS patients, serum mercury value was significantly higher than the mercury concentration founded in control subjects {odd ratio: 2.39 (CI, 1.96-2.94), P?=?0.00}. Serum mercury level is higher in MS patients with odd ratio equal to 2.39 compared with healthy individuals. It may reveal that high mercury levels in serum might help MS development in susceptible individuals. More studies with larger sample size are needed to confirm this hypothesis. PMID:22068727

Attar, Ahmad Movahedian; Kharkhaneh, Azam; Etemadifar, Masoud; Keyhanian, Kiandokht; Davoudi, Vahid; Saadatnia, Mohammad

2012-05-01

9

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

2010-11-01

10

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

PubMed

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

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

2014-09-01

11

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

12

Uptake and tissue distribution of mercury in some plant species collected from a contaminated area in India: Its ecological implications  

Microsoft Academic Search

A study was made of the pattern of distribution of mercury in the tissues of some plant species collected around a chlor-alkali factory in India. Different plants accumulated different levels of mercury in their tissues. Accumulation in leaves was the highest, followed by the stem and the root and, in some cases, the root and the stem. A significant correlation

B. P. Shaw; A. K. Panigrahi

1986-01-01

13

Tissue distribution of inorganic mercury, methylmercury and cadmium in the Asiatic clam (Corbicula fluminea) in relation to the contamination levels of the water column and sediment.  

PubMed

The comparative experimental study of inorganic mercury (HgII), methylmercury (MeHg) and cadmium (Cd) bioaccumulation in the Asiatic clam Corbicula fluminea was based on a 14 days' exposure to the water column or sediment compartments, as initial contamination sources. For each contaminant and exposure source, a five-point concentration range was set up in order to quantify the relationships between the contamination pressure and bioaccumulation capacity, at the whole soft body level and in five organs: gills, mantle, visceral mass, kidney and foot. Hg and Cd bioaccumulation at the whole organism level was proportional to the metal concentrations in the water column or sediment. For similar exposure conditions, the average ratios between the metal concentrations in the bivalves--[MeHg]/[HgII] and [MeHg]/[Cd]--were close to 10 and 5 for the sediment source and 8 and 15 for the water column source. Metal distribution in the five organs revealed strong specificities, according to the different contamination modalities studied: kidney and gills were clearly associated with Cd exposure, mantle and foot with MeHg exposure and the visceral mass with inorganic Hg exposure. PMID:9415979

Inza, B; Ribeyre, F; Maury-Brachet, R; Boudou, A

1997-12-01

14

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

2011-09-15

15

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

16

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

2012-05-01

17

Tissue distribution of inorganic mercury, methylmercury and cadmium in the Asiatic clam ( Corbicula fluminea) in relation to the contamination levels of the water column and sediment  

Microsoft Academic Search

The comparative experimental study of inorganic mercury (HgII), methylmercury (MeHg) and cadmium (Cd) bioaccumulation in the Asiatic clam Corbicula fluminea was based on a 14 days' exposure to the water column or sediment compartments, as initial contamination sources. For each contaminant and exposure source, a five-point concentration range was set up in order to quantify the relationships between the contamination

B. Inza; F. Ribeyre; R. Maury-Brachet; A. Boudou

1997-01-01

18

Arsenic, antimony, gold, and mercury levels in the soft tissues of intertidal and terrestrial molluscs and trace element composition of their shells.  

PubMed

The concentration levels of As, Au, Hg, and Sb in the fleshy tissues of the giant African land snails (Archachatina Marginata) and periwinkles (Littorina littorea) have been measured by neutron activation analysis (NAA). Post-irradiation separation of 76As, 198Au, 197Hg, and 122Sb as bromides after wet-ashing the samples in a concentrated H2SO4-HBr medium was employed. The concentration ranges of 0.015 approximately 2.48, 0.037 approximately 0.091, 0.018 approximately 0.072, and less than 0.01 approximately 0.25 microgram/g wet weight were determined for As, Au, Hg, and Sb, respectively. The periwinkles showed higher concentrations of As, Au, and Hg than the snails. The concentrations of 16 elements, Al, Br, Ca, Cl, Co, Eu, Fe, K, La, Mn, S, Sc, Si, Sm, Sr, and Zn also have been determined in the calcareous shells of these molluscs. PMID:6867384

Ndiokwere, C L

1983-03-01

19

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

20

Distribution of total and organic mercury in seven tissues of the Pacific blue marlin, Makaira nigricans  

Microsoft Academic Search

Tissue samples from Pacific blue marlin (Makaira nigricans) were collected at a fishing tournament in Kona, Hawaii, in August 1973. Analyses of total and organic (methyl) mercury indicated that the marlin may be biotransforming methyl mercury to inorganic mercury such that about 90 percent of the body burden of mercury is in the inorganic form. Specific analysis of a subsample

C. D. Shultz; D. Crear

1976-01-01

21

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

Microsoft Academic Search

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

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

2002-01-01

22

Autometallographic detection of mercury in testicular tissue of an infertile man exposed to mercury vapor.  

PubMed

A 25-year-old male patient presented with unexplained infertility. Semen analysis showed azoospermia or severe oligoasthenoteratospermia with elevated serum FSH. The history revealed that he had been employed in a chemical factory for 5 years working with chloralkali-electrophoresis. Mercury concentrations in hair, blood, and urine samples were considerably above levels of unexposed controls. Bilateral testicular biopsies revealed marked interstitial lymphatic infiltration. About 33% of the tubules analyzed showed a Sertoli-cell-only (SCO) syndrome and tubular atrophy. Fewer than 4% of tubules showed qualitatively intact spermatogenesis. Autometallographic (AMG) analysis of the biopsy material yielded silver-enhanced mercury grains, primarily in the interstitial Leydig cells. Sections from a control patient not exposed to mercury were devoid of mercury grains. PMID:8274823

Keck, C; Bergmann, M; Ernst, E; Müller, C; Kliesch, S; Nieschlag, E

1993-01-01

23

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

PubMed

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

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

1997-11-01

24

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

PubMed

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

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

2013-12-01

25

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

SciTech Connect

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

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

1986-12-01

26

Are liver and renal lesions in East Greenland polar bears (Ursus maritimus) associated with high mercury levels?  

Microsoft Academic Search

BACKGROUND: In the Arctic, polar bears (Ursus maritimus) bio-accumulate mercury as they prey on polluted ringed seals (Phoca hispida) and bearded seals (Erignathus barbatus). Studies have shown that polar bears from East Greenland are among the most mercury polluted species in the Arctic. It is unknown whether these levels are toxic to liver and kidney tissue. METHODS: We investigated the

Christian Sonne; Rune Dietz; Pall S Leifsson; Gert Asmund; Erik W Born; Maja Kirkegaard

2007-01-01

27

A basin-specific aquatic food web biomagnification model for estimation of mercury target levels.  

PubMed

In the Willamette River Basin (WRB, Oregon, USA), health advisories currently limit consumption of fish that have accumulated methylmercury (MeHg) to levels posing a potential health risk for humans. Under the Clean Water Act, these advisories create the requirement for a total maximum daily load (TMDL) for mercury in the WRB. A TMDL is a calculation of the maximum amount of a pollutant that a body of water can receive and still meet water-quality standards. Because MeHg is known to biomagnify in aquatic food webs, a basin-specific biomagnification factor can be used, given a protective fish tissue criterion, to estimate total mercury concentrations in surface waters required to lower advisory mercury concentrations currently in fish in the WRB. This paper presents an aquatic food web biomagnification model that simulates inorganic mercury (Hg(II)) and MeHg accumulation in fish tissue and estimates WRB-specific biomagnification factors for resident fish species of concern to stakeholders. Probabilistic (two-dimensional Monte Carlo) techniques propagate parameter variability and uncertainty throughout the model, providing decision makers with credible range information and increased flexibility in establishing a specific mercury target level. The model predicts the probability of tissue mercury concentrations in eight fish species within the range of concentrations measured in these species over 20 years of water-quality monitoring. Estimated mean biomagnification factor values range from 1.12 x 10(6) to 7.66 x 10(6) and are within the range of U.S. Environmental Protection Agency national values. Several WRB-specific mercury target levels are generated, which very by their probability of affording human health protection relative to the federal MeHg tissue criterion of 0.30 mg/kg. Establishing a specific numeric target level is, however, a public policy decision, and one that will require further discussions among WRB stakeholders. PMID:14552019

Hope, Bruce

2003-10-01

28

Normal and lethal mercury levels in human beings.  

PubMed

Ethyl mercury in the form of Granosan M was used as a fungicide in dressing grains in Iraq. Disregarding warnings and precautions by the authorities, some villagers used this grain in making their bread. Tissue specimens of poisoned people were analysed for total mercury contents using the flameless atomic absorption spectroscopic technique. The analytical method used is highly sensitive (1 ppb/1% absorbance), and the precision in terms of relative standard deviation (RSD) was about 1.5%. The ranges of mercury content in ppm units in the two cases of poisoning were 8-9 for the kidneys, 6-7 for livers, 3-5 for the cerebella, and about 15 for the blood. The analyses included some other tissues as well. Control values were also present. These were obtained from human beings who died by accident and showed no signs of mercury poisoning. PMID:968912

Hilmy, M I; Rahim, S A; Abbas, A H

1976-01-01

29

Identification and distribution of mercury species in rat tissues following administration of thimerosal or methylmercury.  

PubMed

Methylmercury (Met-Hg) is one the most toxic forms of Hg, with a considerable range of harmful effects on humans. Sodium ethyl mercury thiosalicylate, thimerosal (TM) is an ethylmercury (Et-Hg)-containing preservative that has been used in manufacturing vaccines in many countries. Whereas the behavior of Met-Hg in humans is relatively well known, that of ethylmercury (Et-Hg) is poorly understood. The present study describes the distribution of mercury as (-methyl, -ethyl and inorganic mercury) in rat tissues (brain, heart, kidney and liver) and blood following administration of TM or Met-Hg. Animals received one dose/day of Met-Hg or TM by gavage (0.5 mg Hg/kg). Blood samples were collected after 6, 12, 24, 48, 96 and 120 h of exposure. After 5 days, the animals were killed, and their tissues were collected. Total blood mercury (THg) levels were determined by ICP-MS, and methylmercury (Met-Hg), ethylmercury (Et-Hg) and inorganic mercury (Ino-Hg) levels were determined by speciation analysis with LC-ICP-MS. Mercury remains longer in the blood of rats treated with Met-Hg compared to that of TM-exposed rats. Moreover, after 48 h of the TM treatment, most of the Hg found in blood was inorganic. Of the total mercury found in the brain after TM exposure, 63% was in the form of Ino-Hg, with 13.5% as Et-Hg and 23.7% as Met-Hg. In general, mercury in tissues and blood following TM treatment was predominantly found as Ino-Hg, but a considerable amount of Et-Hg was also found in the liver and brain. Taken together, our data demonstrated that the toxicokinetics of TM is completely different from that of Met-Hg. Thus, Met-Hg is not an appropriate reference for assessing the risk from exposure to TM-derived Hg. It also adds new data for further studies in the evaluation of TM toxicity. PMID:20386881

Rodrigues, Jairo L; Serpeloni, Juliana M; Batista, Bruno L; Souza, Samuel S; Barbosa, Fernando

2010-11-01

30

Mercury Levels in Infants Receiving Routine Immunizations  

MedlinePLUS

... in Infants Receiving Routine Immunizations Study I: Infant Metabolism of Thimerosal versus Methyl Mercury NIAID-supported studies ... Lancet 360:1737-1741 (2002). Study II: Thimerosal Metabolism in Infants Receiving Routine Immunizations NIAID conducted a ...

31

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

32

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

33

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

34

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

35

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

36

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

PubMed

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

Khwaja, Mahmood A; Abbasi, Maryam Shabbir

2014-01-01

37

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...

38

Mercury exposure may suppress baseline corticosterone levels in juvenile birds.  

PubMed

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

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

2012-06-01

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

Summary of: Relationship between mercury levels in blood and urine and complaints of chronic mercury toxicity from amalgam restorations  

Microsoft Academic Search

Aim To determine whether patients complaining of oral and medical symptoms perceived to be associated with chronic mercury toxicity have elevated mercury levels in their blood and urine.Methods The study group in this audit were 56 patients presenting to an oral medicine unit with complaints perceived to be related to chronic mercury toxicity. Their symptoms and co-morbidity were charted and

S. Porter

2010-01-01

42

Relationship between mercury levels in blood and urine and complaints of chronic mercury toxicity from amalgam restorations  

Microsoft Academic Search

Aim To determine whether patients complaining of oral and medical symptoms perceived to be associated with chronic mercury toxicity have elevated mercury levels in their blood and urine.Methods The study group in this audit were 56 patients presenting to an oral medicine unit with complaints perceived to be related to chronic mercury toxicity. Their symptoms and co-morbidity were charted and

J. Eyeson; I. House; Y. H. Yang; K. A. A. S. Warnakulasuriya

2010-01-01

43

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, ...

44

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

SciTech Connect

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

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

2011-11-15

45

Fractional mercury levels in Brazilian gold refiners and miners.  

PubMed

A field study survey of individuals residing in the region of Para, Brazil, was conducted to determine fractional mercury levels in individuals at risk for exposure in the Brazilian Amazon region. Subjects with a history of exposure to mercury either in the gold mining or refining industry, or exposure to these processes through proximity were included. Three groups were identified as either having recent (less than 2 d since last exposure), intermediate (less than 60 d), or remote (greater than 60 d) exposure to mercury vapors. Fractional blood and urinary mercury levels were assessed for these groups. Group I (recent) had the highest geometric mean blood 24.8 (SD 44.1, range 7.6-158.8) micrograms/L and urine 75.6 (SD 213.4, range 6.5-735.9) micrograms/g-cr (microgram mercury per gram of creatinine) mercury; intermediate (group II) geometric mean blood 7.6 (SD 5.5, range 2.2-19.4) micrograms/L and urine levels 23.8 (SD 84.0, range 7.8-297.0) micrograms/g-cr; the lowest levels in remote exposure (group III): geometric mean blood 5.6 (SD 3.3, range 3.1-14.3) micrograms/L and urine 7.0 (SD 9.8, range 3.1 to 32.9) micrograms/g-cr. The fraction of organic was lowest in group I (32.4%), higher in group II (65.7%), and highest in group III (72.2%). While the frequency of symptoms was comparable in the recent and intermediate groups (2.6 mean, SD 2.3, range 0-8, and 3.1 mean, SD 1.9, range 0-7, symptoms per patient), those with remote exposure demonstrated the highest rate of reporting (6.4 mean, SD 4.1, range 0-11, symptoms per patient). There is significant exposure to mercury for those working in or living near the mining and refining industry. Blood and urine levels are a better marker of recent than remote exposure. The fraction of organic mercury increases with time since exposure. Symptoms may be persistent and low levels of blood and urine mercury do not exclude remote or cumulative toxicity. PMID:7837306

Aks, S E; Erickson, T; Branches, F J; Naleway, C; Chou, H N; Levy, P; Hryhorczuk, D

1995-01-01

46

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

47

Total mercury in liver and muscle tissue of two coastal sharks from the northwest of Mexico.  

PubMed

Total mercury (THg) in liver and muscle of three costal sharks from Mexico were evaluated. The highest concentrations of THg in muscle tissue of juveniles were found in Sphyrna lewini (0.82 ± 0.33 mg kg(-1) wet basis). Rhizoprionodon longurio adults had the highest concentrations (0.92 ± 1.03 mg kg(-1)). THg concentrations in liver were low compared to those found in muscle tissue; higher levels were found in liver of juvenile S. lewini (0.250 ± 0.07 mg kg(-1)). Results showed that 35 % of muscle tissue samples are above the precautionary limit (0.50 mg kg(-1) of THg) and a 7 % exceeded the maximum limit for human consumption (1 mg kg(-1)). PMID:22526987

Hurtado-Banda, Rocío; Gomez-Alvarez, Agustín; Márquez-Farías, J Fernando; Cordoba-Figueroa, Marcial; Navarro-García, Gerardo; Medina-Juárez, Luis Angel

2012-06-01

48

Mercury concentrations in muscle tissue from sportfish in Lake Mead, Nevada  

Microsoft Academic Search

The aim of this study was to determine the concentrations of mercury present in commonly consumed fish from Lake Mead and to identify if differences exist between the 4 major basins. To date, no formal study using US Environmental Protection Agency (USEPA) approved methodology has been conducted to quantify the amount of mercury present in fish tissue from Lake Mead.

Joanna Kramer; Shawn L. Gerstenberger

2010-01-01

49

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

EPA Science Inventory

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

50

Mercury  

MedlinePLUS

... has several forms. Metallic mercury is a shiny, silver-white, odorless liquid. If heated, it is a ... products. Metallic mercury is used in glass thermometers, silver dental fillings, and button batteries. Mercury salts may ...

51

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

USGS Publications Warehouse

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

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

2007-01-01

52

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

53

Mercury  

NSDL National Science Digital Library

This site offers information on the planet Mercury. Some topics include: the atmosphere, surface, and interior of Mercury, missions to Mercury, recent discoveries, and myths and culture related to Mercury. There are also numerous pictures and additional websites to find more information.

2005-06-07

54

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

2012-12-01

55

The Comparative Effect of Oral Ingestion of Methyl Mercury on Chicks and Rats.  

National Technical Information Service (NTIS)

Data show that feeding fish protein concentrate animal protein (Fish meal) containing higher than normal levels of mercury did not result in the concentration of mercury in poultry tissues that exceeded FDA guideline levels. After 7 weeks of mercury expos...

J. H. Soares D. Miller H. Lagally B. R. Stillings P. Bauersfeld

1972-01-01

56

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

57

Antioxidants and metallothionein levels in mercury-treated mice.  

PubMed

Acute effects of mercury on mouse blood, kidneys, and liver were evaluated. Mice received a single dose of mercuric chloride (HgCl2, 4.6 mg/kg, subcutaneously) for three consecutive days. We investigated the possible beneficial effects of antioxidant therapy (N-acetylcysteine (NAC) and diphenyl diselenide (PhSe)2) compared with the sodium salt of 2,3-dimercapto-1-propanesulfonic acid (DMPS), an effective chelating agent in HgCl2 exposure in mice. We also verified whether metallothionein (MT) induction might be involved in a possible mechanism of protection against HgCl2 poisoning and whether different treatments would modify MT levels and other toxicological parameters. The results demonstrated that HgCl2 exposure significantly inhibited delta-aminolevulinate dehydratase (delta-ALA-D) activity in liver and only DMPS treatment prevented the inhibitory effect. Mercuric chloride caused an increase in renal non-protein thiol groups (NPSH) and none of the treatments modified renal NPSH levels. Urea concentration was increased after HgCl2 exposure. NAC plus (PhSe)2 was partially effective in protecting against the effects of mercury. DMPS and (PhSe)2 were effective in restoring the increment in urea concentration caused by mercury. Thiobarbituric acid-reactive substances (TBARS), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) activities and ascorbic acid levels were not modified after mercury exposure. Mercuric chloride poisoning caused an increase in hepatic and renal MT levels and antioxidant treatments did not modify this parameter. Our data indicated a lack of therapeutic effect of the antioxidants tested. PMID:16964587

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

2006-11-01

58

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

59

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...

60

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

61

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.

62

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

2013-10-15

63

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

Microsoft Academic Search

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

Joanna Burger; Michael Gochfeld

1997-01-01

64

Selenium and mercury interactions wtih emphasis on fish tissue  

EPA Science Inventory

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

65

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

66

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

67

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

68

Determination of total mercury in biological tissue by isotope dilution ICPMS after UV photochemical vapor generation.  

PubMed

A method is developed for the determination of trace mercury in biological samples using photo chemical vapor generation (PVG) and isotope dilution inductively coupled plasma mass spectrometry (ID ICPMS) detection. Biological tissues were solubilized in formic acid. Subsequently, the sample solutions were exposed to an ultraviolet (UV) source for the reduction of mercury into vapor species prior to ICPMS measurements. The formic acid served not only as a tissue solubilizer in the sample preparation procedure, but also as a photochemical reductant for mercury in the PVG process. The problem arising from the opaque formic acid digested solution was efficiently solved by using ID method. The optimum conditions for sample treatment and PVG were investigated. A limit of detection (LOD) of 0.5 pg g(-1), based on an external calibration, provided 350-fold improvement over that obtained by utilizing conventional pneumatic nebulization sample introduction. Method validation was demonstrated by the determination of total mercury in several biological tissue certified reference materials (CRMs). The results were in good agreement with the certified values. PMID:24209355

Liu, Rui; Xu, Mo; Shi, Zeming; Zhang, Jiayun; Gao, Ying; Yang, Lu

2013-12-15

69

Levels of flurithromycin in female genital tissue.  

PubMed Central

The levels of flurithromycin in gynecological tissue in 20 female patients were studied after preoperative administration. The tissue flurithromycin levels obtained were comparable to those obtained in serum at 3 and 4 h but were frequently higher than those in serum at 6 and 12 h. Flurithromycin reached the highest concentrations in ovary at 4 h and in endometrium at 6 h.

Furneri, P M; Cianci, A; Campo, L; Roccasalva, L S; Tempera, G; Fiore, G; Palumbo, G; Lepore, A M; Nicoletti, G

1995-01-01

70

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

PubMed

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

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

2014-05-01

71

DEVELOPMENT AND VALIDATION OF A METHOD FOR THE DETERMINATION OF MERCURY IN SMALL RAT BRAIN TISSUE SAMPLES BY COLD VAPOR ATOMIC FLUORESCENCE SPECTROMETRY  

Microsoft Academic Search

A rugged, sensitive, semi-automated method for the determination of trace-level mercury in small rat brain tissue samples by cold vapor atomic fluorescence spectrometry (CVAFS) is described. Small tissue aliquots (100 mg) are digested for 6–8 h at an elevated temperature in a mixture of nitric and sulfuric acids. Following digestion, samples are oxidized with potassium bromate\\/bromide at room temperature and treated

Keith E. Levine; Reshan A. Fernando; Glenn T. Ross; Michelle Lang; Daniel L. Morgan; Bradley J. Collins

2002-01-01

72

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

PubMed Central

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

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

2009-01-01

73

Temporal and geographic trends in mercury concentrations in muscle tissue in five species of Hudson River, USA, fish.  

PubMed

We analyzed a New York (USA) state database of mercury concentrations in muscle tissue for five species of fish (striped bass, yellow perch, largemouth bass, smallmouth bass, and carp) over a range of locations in the Hudson River (USA) between 1970 and 2004. We used regression models to discern temporal and geographic change in the fish while controlling for a positive correlation between mercury concentration and body mass. Mercury concentrations significantly increased in fish from New York Harbor waters to the mid-Hudson River. Striped bass and yellow perch showed a shallower increase in mercury concentration with river mile than did carp, largemouth bass, and smallmouth bass. Mercury concentrations declined over the 34-year period. These results imply that a geographically restricted source of mercury may be spread throughout the watershed by toxin-laden dispersing species. The increase of mercury toward the north may relate to a point source in the mid-Hudson River, or it may indicate mercury released from the Adirondack watershed. The decline of mercury over three decades corresponds to a reduction of various inputs in the region. The temporal and geographic pattern of mercury in sediments corresponds to the geographic trend of mercury in fish. PMID:18266478

Levinton, Jeffrey S; Pochron, Sharon T

2008-08-01

74

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

75

Mercury  

MedlinePLUS

... mainly by microscopic organisms in the water and soil. More mercury in the environment can increase the ... from manufacturing plants. It enters the water or soil from natural deposits, disposal of wastes, and volcanic ...

76

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

77

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

NASA Astrophysics Data System (ADS)

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

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

2013-05-01

78

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

79

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

PubMed

Mercury is a pervasive environmental contaminant, the anthropogenic portion of which is increasing globally, and in northeastern North America in particular. Seabirds frequently are used as indicators of the marine environment, including mercury contamination. We analysed paired samples for total mercury (Hg) concentrations in feathers and blood from adult and chick, albumen, and lipid-free yolk of seven seabirds breeding on Machias Seal Island, New Brunswick, Canada - Arctic Tern (Sterna paradisaea), Atlantic Puffin (Fratercula arctica), Common Eider (Somateria mollissima), Common Murre (Uria aalge), Common Tern (Sterna hirundo), Leach's Storm-petrel (Oceanodroma leucorhoa), and Razorbill (Alca torda). We also used stable-isotope ratios of carbon (delta(13)C), and nitrogen (delta(15)N) to evaluate the relationship between carbon source and trophic position and mercury. We found high Hg concentrations across tissue types in Leach's Storm-petrels, and Razorbills, with lower concentrations in other species, the lowest being in Common Eiders. Storm-petrels prey on mesopelagic fish that accumulate mercury, and Razorbills feed on larger, older fish that bioaccumulate heavy metals. Biomagnification of Hg, or the increase in Hg concentration with trophic position as measured by delta(15)N, was significant and greater in albumen than other tissues, whereas in other tissues, delta(15)N explained little of the overall variation in Hg concentration. Hg concentrations in egg components are higher on Machias Seal Island than other sites globally and in the Gulf of Maine region, but only for some species. Further detailed investigations are required to determine the cause of this trend. PMID:19419752

Bond, Alexander L; Diamond, Antony W

2009-07-01

80

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

2012-01-01

81

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

PubMed

Caudal fin clips and dorsolateral scales were analyzed as a potential nonlethal approach for predicting muscle tissue mercury (Hg) concentrations in marine fish. Target fish were collected from the Narragansett Bay (Rhode Island, USA) and included black sea bass Centropristis striata [n = 54, 14-55 cm total length (TL)], bluefish Pomatomus saltatrix (n = 113, 31-73 cm TL), striped bass Morone saxatilis (n = 40, 34-102 cm TL), summer flounder Paralichthys dentatus (n = 64, 18-55 cm TL), and tautog Tautoga onitis (n = 102, 27-61 cm TL). For all fish species, Hg concentrations were greatest in muscle tissue [mean muscle Hg = 0.47-1.18 mg/kg dry weight (dw)] followed by fin clips (0.03-0.09 mg/kg dw) and scales (0.01-0.07 mg/kg dw). The coefficient of determination (R (2)) derived from power regressions of intraspecies muscle Hg against fin and scale Hg ranged between 0.35 and 0.78 (mean R (2) = 0.57) and 0.14-0.37 (mean R (2) = 0.30), respectively. The inclusion of fish body size interaction effects in the regression models improved the predictive ability of fins (R (2) = 0.63-0.80; mean = 0.71) and scales (R (2) = 0.33-0.71; mean = 0.53). According to the high level of uncertainty within the regression models (R (2) values) and confidence interval widths, scale analysis was deemed an ineffective tool for estimating muscle tissue Hg concentrations in the target species. In contrast, the examination of fin clips as predictors of muscle Hg had value as a cursory screening tool; however, this method should not be the foundation for developing human consumption advisories. It is also noteworthy that the efficacy of these nonlethal techniques was highly variable across fishes and likely depends on species-specific life-history characteristics. PMID:23929385

Piraino, Maria N; Taylor, David L

2013-11-01

82

Blood Lead and Mercury Levels in Pregnant Women in the United States, 2003-2008. NCHS Data Brief, No. 52.  

National Technical Information Service (NTIS)

Chemical exposure during pregnancy is potentially harmful to the developing fetus, as the placenta cannot protect against heavy metals such as lead and mercury. Cord blood mercury levels have been associated with childhood cognitive function. High levels ...

J. D. Parker L. Jones P. Mendola

2010-01-01

83

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

PubMed Central

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

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

2009-01-01

84

Correlations between gene expression and mercury levels in blood of boys with and without autism.  

PubMed

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

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

2011-01-01

85

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

SciTech Connect

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

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

2011-12-15

86

Mercury in the pelagic food web of Lake Champlain.  

PubMed

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

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

2012-04-01

87

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...

88

Studies of Mercury in High Level Waste Systems  

Microsoft Academic Search

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

Wilmarth

2003-01-01

89

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

PubMed

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

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

2014-07-01

90

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

PubMed

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

Tomiyasu; Nagano; Sakamoto; Yonehara

2000-10-01

91

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

92

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

93

Atmospheric mercury pollution at an urban site in central Taiwan: mercury emission sources at ground level.  

PubMed

Total gaseous mercury (Hg) (TGM), gaseous oxidized Hg (GOM), and particulate-bound Hg (PBM) concentrations and dry depositions were measured at an urban site in central Taiwan. The concentrations were 6.14±3.91 ng m(-3), 332±153, and 71.1±46.1 pg m(-3), respectively. These results demonstrate high Hg pollution at the ground level in Taiwan. A back trajectory plot shows the sources of the high TGM concentration were in the low atmosphere (<500 m) and approximately 50% of the air masses coming from upper troposphere (>500 m) were associated with low TGM concentrations. This finding implies that Hg is trapped in the low atmosphere and comes from local Hg emission sources. The conditional probability function (CPF) reveals that the plumes of high TGM concentrations come from the south and northwest of the site. The plume from the south comes from two municipal solid waste incinerators (MSWIs). However, no significant Hg point source is located to the northwest of the site; therefore, the plumes from the northwest are hypothesized to be related to the combustion of agricultural waste. Dry deposition fluxes of Hg measured at this site considerably exceeded those measured in North America. Overall, this area is regarded as a highly Hg contaminated area because of local Hg emission sources. PMID:22316589

Huang, Jiaoyan; Liu, Chia-Kuan; Huang, Ci-Song; Fang, Guor-Cheng

2012-04-01

94

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

95

Mercury Levels in Locally Manufactured Mexican Skin-Lightening Creams  

PubMed Central

Mercury is considered one of the most toxic elements for plants and animals. Nevertheless, in the Middle East, Asia and Latin America, whitening creams containing mercury are being manufactured and purchased, despite their obvious health risks. Due to the mass distribution of these products, this can be considered a global public health issue. In Mexico, these products are widely available in pharmacies, beauty aid and health stores. They are used for their skin lightening effects. The aim of this work was to analyze the mercury content in some cosmetic whitening creams using the cold vapor technique coupled with atomic absorption spectrometry (CV-AAS). A total of 16 skin-lightening creams from the local market were investigated. No warning information was noted on the packaging. In 10 of the samples, no mercury was detected. The mercury content in six of the samples varied between 878 and 36,000 ppm, despite the fact that the U.S. Food and Drug Administration (FDA) has determined that the limit for mercury in creams should be less than 1 ppm. Skin creams containing mercury are still available and commonly used in Mexico and many developing countries, and their contents are poorly controlled.

Peregrino, Claudia P.; Moreno, Myriam V.; Miranda, Silvia V.; Rubio, Alma D.; Leal, Luz O.

2011-01-01

96

Unexpectedly high mercury level in pelleted commercial fish feed  

SciTech Connect

An unexpectedly high mercury (Hg) level was found in a pelleted commercial fish feed used to feed fish in laboratory and fish farm settings. Mean total Hg (T-Hg) concentration in the commercial fish pellets was 66 ppb. Mean total selenium (T-Se) concentration in the pellets was 1,120 ppb (ranging from 790 to 1,360 ppb). Total Hg and Se in the whole blood of Sacramento blackfish and in the fish feed were determined by inductively coupled plasma-mass spectrometry (ICP-MS). During a 10-week sampling period T-Hg in blood fluctuated between 35 and 56 ppb. A highly significant, positive correlation was found between T-Hg in the fish blood and in the fish feed through the sampling period. On the other hand, no correlation was found between T-Se in the fish feed and T-Hg or T-Se blood level. Researchers working with fish in Hg studies need to know that fish pellets may contain Hg and to consider the influence of these pellets in their results.

Choi, M.H. [Nalco Chemical Co., Naperville, IL (United States); Cech, J.J. Jr. [Univ. of California, Davis, CA (United States). Dept. of Wildlife, Fish, and Conservation Biology

1998-10-01

97

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

PubMed

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

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

2012-03-01

98

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.

99

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

PubMed

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

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

2013-06-01

100

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

Microsoft Academic Search

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

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

2008-01-01

101

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

USGS Publications Warehouse

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

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

2008-01-01

102

Strategies for organ level tissue engineering  

PubMed Central

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

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

2010-01-01

103

Response of fish tissue mercury in a freshwater lake to local, regional, and global changes in mercury emissions.  

PubMed

A suite of mechanistic atmospheric and mercury (Hg) cycling and bioaccumulation models is applied to simulate atmospheric Hg deposition and Hg concentrations in the water column and in fish in a Hg-impaired freshwater lake located in the northeastern United States that receives its Hg loading primarily through deposition. Two future-year scenarios evaluate the long-term response of fish tissue Hg concentrations to reductions in local and nationwide coal-fired electric-generating utility and other Hg emissions and an increase or decrease in global (non-US) Hg emissions. Results indicate that fish tissue Hg concentrations in this ecosystem could require approximately 3 yr to 8 yr to begin to respond to declines in US emissions and deposition with a fish Hg reduction proportional to deposition reduction requiring over 50 yr. Furthermore, recovery could potentially be partially or completely offset by growth in non-US Hg emissions. Environ Toxicol Chem 2014;33:1238-1247. © 2014 SETAC. PMID:24771700

Vijayaraghavan, Krish; Levin, Leonard; Parker, Lynsey; Yarwood, Greg; Streets, David

2014-06-01

104

Mercury  

NASA Technical Reports Server (NTRS)

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

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

1977-01-01

105

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

106

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

PubMed

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

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

2008-08-26

107

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

PubMed Central

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

2008-01-01

108

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

109

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

PubMed

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

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

2014-08-01

110

Low-Level Mercury Can Enhance Procoagulant Activity of Erythrocytes: A New Contributing Factor for Mercury-Related Thrombotic Disease  

PubMed Central

Background Associations between cardiovascular diseases and mercury have been frequently described, but underlying mechanisms are poorly understood. Objectives We investigate the procoagulant activation of erythrocytes, an important contributor to thrombosis, by low-level mercury to explore the roles of erythrocytes in mercury-related cardiovascular diseases. Methods We used freshly isolated human erythrocytes and ex vivo and in vivo thrombosis models in rats to investigate mercury-induced procoagulant activity. Results Prolonged exposure to low-dose mercuric ion (Hg2+; 0.25–5 ?M for 1–48 hr) induced erythrocyte shape changes from discocytes to echinocytes to spherocytes, accompanied by microvesicle (MV) generation. These MVs and remnant erythrocytes expressed phosphatidylserine (PS), an important mediator of procoagulant activation. Hg2+ inhibited flippase, an enzyme that recovers PS into the inner leaflet of the cell membrane, and activated scramblase, an enzyme that alters lipid asymmetry in the cell membrane. Consistent with these activity changes, Hg2+ increased intracellular calcium and depleted ATP and protein thiol. A thiol supplement reversed Hg2+-induced MV generation and PS exposure and inhibited the increase in calcium ion (Ca2+) and depletion of ATP, indicating that free-thiol depletion was critical to Hg2+-mediated procoagulant activity. The procoagulant activity of Hg2+-treated erythrocytes was demonstrated by increased thrombin generation and endothelial cell adhesion. We further confirmed Hg2+-mediated procoagulant activation of erythrocytes in ex vivo and in vivo rat thrombosis models, where Hg2+ treatment (0.5–2.5 mg/kg) increased PS exposure and thrombus formation significantly. Conclusion This study demonstrated that mercury could provoke procoagulant activity in erythrocytes through protein-thiol depletion–mediated PS exposure and MV generation, ultimately leading to enhanced thrombosis.

Lim, Kyung-Min; Kim, Sujin; Noh, Ji-Yoon; Kim, Keunyoung; Jang, Won-Hee; Bae, Ok-Nam; Chung, Seung-Min; Chung, Jin-Ho

2010-01-01

111

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

USGS Publications Warehouse

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

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

2009-01-01

112

Urinary level of homovanillic acid and mercury in autistic children  

Microsoft Academic Search

Catecholamines and their metabolites affect children's nervous system. Dopamine is an important neurotransmitter in the brain. In the routine analysis for diagnostics of diseases, the dopamine metabolite homovanillic acid (HVA) is determined. Mercury is a neurotoxic agent and can cause different undesirable effects on the brain. In the present work a putative correlation between HVA, the main metabolite of dopamine,

Joanna Ka?u?na-Czapli?ska; Ewa Socha; Monika Michalska; Jacek Rynkowski

2011-01-01

113

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

EPA Science Inventory

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

114

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

115

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

116

Fish mercury levels in lakes—adjusting for Hg and fish-size covariation  

Microsoft Academic Search

Accurate estimates of lake-specific mercury levels are vital in assessing the environmental impact on the mercury content in fish. The intercepts of lake-specific regressions of Hg concentration in fish vs. fish length provide accurate estimates when there is a prominent Hg and fish-size covariation. Commonly used regression methods, such as analysis of covariance (ANCOVA) and various standardization techniques are less

Lars Sonesten

2003-01-01

117

Effects of mercury and selenium on serum transaminase levels of quail, hens and rats  

Microsoft Academic Search

Three studies were conducted in an effort to quantitatively evaluate some of the early effects and nutrient interactions of methyl mercury (CHâ-Hg) in Cotournix quail, Leghorn hens, and Sprague-Dawley rats. Mercury was added to the diets at levels ranging from 0.5 to 32 ppm. In addition, selenium (Se), cystine, and fish protein concentrate were added in various combinations to some

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

1973-01-01

118

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

Microsoft Academic Search

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

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

1999-01-01

119

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

Microsoft Academic Search

As part of a multi-agency study of alligator health, 28 American alligators (Alligator mississippiensis) were captured along a transect through the Florida Everglades in 1999. Liver and tail muscle tissues were sampled and analyzed on a wet weight basis for total mercury (THg) using cold-vapor atomic absorption spectrophotometry. All tissues had detectable concentrations of THg that ranged from 0.6 to

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

2002-01-01

120

Effect of selenium pretreatment in chronic mercury intoxication in rats.  

PubMed

Effect of selenium pretreatment (0.2 mg/kg/day, as sodium selenite), 4 h prior to mercury treatment (0.4 mg/kg/day, as mercuric chloride), administered intraperitoneally, was examined after daily exposure for 20 days' in rats. Liver, kidney and brain tissues were assayed for malondialdehyde (MDA) level, glutathione (GSH) content and mercury concentration. Mercury induced MDA levels, which was also observed in selenium pretreated animals. Significant reduction in GSH levels was observed in mercury alone and selenium pretreated animals. Mercury accumulation was in the order of kidney, liver and brain. Selenium pretreatment resulted in further enhancement in mercury accumulation in liver and kidney. PMID:17639317

Agarwal, R; Behari, J R

2007-09-01

121

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

122

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

NASA Astrophysics Data System (ADS)

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

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

2012-07-01

123

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

124

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

NASA Technical Reports Server (NTRS)

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

Patterson, James D.

1996-01-01

125

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 ...

126

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

127

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

2011-01-01

128

Assessment of mercury and selenium concentrations in captive bottlenose dolphin's (Tursiops truncatus) diet fish, blood, and tissue.  

PubMed

Concentrations of total mercury (Hg) and selenium (Se) were determined in diet fish and whole blood and tissue samples from seven bottlenose dolphins (Tursiops truncatus) housed at the National Aquarium Baltimore (NAB). In addition, concentrations of monomethylmercury (CH(3)Hg(+)) were determined in diet fish and dolphins' tissue samples. The data were compared with the values found in wild populations to better understand how the dietary Hg and Se uptake rates affect the Hg and Se levels in dolphins. The diet fish total Hg concentrations ranged between 14 and 47 ng g(-1) and were markedly lower than for similar fish found in Florida, South Carolina, and other aquaria. CH(3)Hg(+) accounted for 85 to 91% of the total Hg found in diet fish. The diet fish Se concentrations ranged between 270 and 800 ng g(-1), indicating excess molar concentrations of Se over Hg. The Hg concentration range in the blood of NAB dolphins was 27-117 ng g(-1) and the concentrations were about one order of magnitude and several factors lower than the concentrations found in the blood of wild bottlenose dolphins in Florida and in South Carolina, respectively. The total Hg and CH(3)Hg(+) in tissue samples were also significantly lower than the reported values obtained from wild populations of bottlenose dolphins. The differences in the Hg concentrations in the dolphins' blood may be due to the different levels of Hg atmospheric deposition in the area where the dolphins' diet fish were found. The Se concentration range in the blood of NAB dolphins was 221-297 ng g(-1) which was two factors lower than the values found in wild populations. The lower Hg levels, as well as higher Se:Hg molar ratios in the blood of NAB dolphins, suggest that NAB dolphins may be less susceptible to the potential neurotoxicity from the CH(3)Hg(+) in their blood. PMID:22137650

Hong, Yong Seok; Hunter, Sue; Clayton, Leigh A; Rifkin, Erik; Bouwer, Edward J

2012-01-01

129

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

130

Mercury accumulation in and growth rate of rainbow trout, Salmo gairdneri , stocked in an eastern oregon reservoir  

Microsoft Academic Search

Mercury concentrations in lateral muscle tissue from rainbow trout (Salmo gairdneri) stocked in a mercury contaminanted eastern Oregon reservoir increased linearly during the first five months that the fish were in the reservoir, followed by a leveling off period during which the mercury uptake curve became nearly asymptotic after eight months. In addition, the mean mercury concentrations present in three

Glenn R. Phillips; Donald R. Buhler

1980-01-01

131

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

Microsoft Academic Search

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

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

2007-01-01

132

Mercury in Alaskan Eskimo mothers and infants.  

PubMed Central

The potential danger of natural mercury accumulation in the diet of the Eskimo is evaluated through mercury levels determined in cord blood, placenta, maternal blood, hair, and milk of 38 maternal-infant pairs from Anchorage and the Yukon-Kuskokwim Delta. Although mercury levels are not discernably dangerous, trends to larger accumulations in maternal and fetal RBC and placental tissue with proximity to the sea and consumption of seals during pregnancy provide the basis for considering possible indicators of neonatal involvement. Mercury level in RBC from cord blood appeared as the best potential indicator of this involvement, although relationships with the mother's diet and level of mercury in the placenta also appear useful. In this area, average and maximal mercury levels in cord blood are 39 and 78 ng/ml, respectively, far below the acknowledged toxic level in infants of these mothers who eat seals or fish every day during their pregnancy.

Galster, W A

1976-01-01

133

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

134

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

135

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

USGS Publications Warehouse

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

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

2001-01-01

136

[Mercury poisoning].  

PubMed

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

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

2011-07-01

137

An exploratory study of total mercury levels in archaeological caribou hair from northwest Alaska.  

PubMed

Over the past ten years, total mercury (THg) levels have been surveyed in Alaskan wildlife and fish as part of the Arctic Monitoring and Assessment (AMAP). Beyond these studies there is little historical data on THg levels in important subsistence species for people in Alaska. A survey of THg in caribou hair from archaeological deposits would provide data to develop temporal trends for this region of the Arctic. Caribou hair from a Western Thule settlement beneath the Alaska native village of Deering (ca. AD 1150) show variability in hair THg values, with a mean level (86 ng/g) which is in the range that is observed in modern Rangifer sp. (caribou and reindeer). Hair from House 1 had a THg mean level of 99.6 ng/g and hair from House 2 had a THg mean of 64.2 ng/g. This is the earliest reported record of mercury in caribou associated with human subsistence activities in the western North American Arctic, and is a first step toward compilation of a needed database through which to measure and evaluate exposure to mercury by people who rely heavily on caribou as a food source. We hypothesize that similarity in mercury values in archaeological samples of caribou and in contemporary samples would give an additional perspective on human exposure to mercury through caribou harvest and consumption today. Since this hypothesis will be more useful if evaluated at a regional rather than global scale, further studies will be needed at different archaeological sites across Alaska to determine the generality of this observation in relation to geographic scale. PMID:16876850

Gerlach, S Craig; Duffy, Lawrence K; Murray, Maribeth S; Bowers, Peter M; Adams, Rachel; Verbrugge, David A

2006-12-01

138

Influence of methylmercury from tributary streams on mercury levels in Savannah River Asiatic clams  

Microsoft Academic Search

Average methylmercury levels in five Savannah River tributary streams, sampled 11 times over 2 years (0.170 ng\\/l), were nearly twice as high as in the Savannah River (0.085 ng\\/l). Total mercury levels in the tributaries (2.98 ng\\/l) did not differ significantly from the river (2.59 ng\\/l). All of the tributaries drained extensive wetlands that would be expected to support comparatively

M. H Paller; C. H Jagoe; H Bennett; H. A Brant; J. A Bowers

2004-01-01

139

Side-Effects: Mercury Contribution to Body Burden From Dental Amalgam  

Microsoft Academic Search

The purpose of this paper is to examine and report on studies that relate mercury levels in human tissues to the presence of dental amalgams, giving special attention to autopsy studies. Until recently, there have been few published studies examining the relationship between dental amalgams and tissue mercury levels. Improved and highly sensitive tissue analysis techniques have made it possible

J. W. Reinhardt

1992-01-01

140

Mercury vapor pressure of flue gas desulfurization scrubber suspensions: effects of pH level, gypsum, and iron.  

PubMed

Calcium-based scrubbers designed to absorb HCl and SO(2) from flue gases can also remove oxidized mercury. Dissolved mercury halides may have an appreciable partial vapor pressure. Chemical reduction of the dissolved mercury may increase the Hg emission, thereby limiting the coremoval of mercury in the wet scrubbing process. In this paper we evaluate the effects of the pH level, different gypsum qualities, and iron in flue gas desulfurization (FGD) scrubber suspensions. The impact of these parameters on mercury vapor pressure was studied under controlled laboratory conditions in model scrubber suspensions. A major influence is exerted by pH values above 7, considerably amplifying the mercury concentration in the vapor phase above the FGD scrubber suspension. Gypsum also increases the mercury re-emission. Fe(III) decreases and Fe(II) increases the vapor pressure significantly. The consequences of the findings for a reliable coremoval of mercury in FGD scrubbers are discussed. It is shown that there is an increased risk of poor mercury capture in lime-based FGD scrubbers in comparison to limestone FGD scrubbers. PMID:22324514

Schuetze, Jan; Kunth, Daniel; Weissbach, Sven; Koeser, Heinz

2012-03-01

141

Solid phase microextraction capillary gas chromatography combined with furnace atomization plasma emission spectrometry for speciation of mercury in fish tissues  

NASA Astrophysics Data System (ADS)

The use of solid phase microextraction in conjunction with tandem gas chromatography-furnace atomization plasma emission spectrometry (SPME-GC-FAPES) was evaluated for the determination of methylmercury and inorganic mercury in fish tissue. Samples were digested with methanolic potassium hydroxide, derivatized with sodium tetraethylborate and extracted by SPME. After the SPME extraction, species were separated by GC and detected by FAPES. All experimental parameters were optimized for best separation and analytical response. A repeatability precision of typically 2% can be achieved with long-term (3 months) reproducibility precision of 4.3%. Certified Reference Materials DORM-2, DOLT-2 and TORT-2 from the National Research Council of Canada were analyzed to verify the accuracy of this technique. Detection limits of 1.5 ng g -1 for methylmercury and 0.7 ng g -1 for inorganic mercury in biological tissues were obtained.

Grinberg, Patricia; Campos, Reinaldo C.; Mester, Zoltan; Sturgeon, Ralph E.

2003-03-01

142

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

2010-09-15

143

Predicting DNA methylation level across human tissues  

PubMed Central

Differences in methylation across tissues are critical to cell differentiation and are key to understanding the role of epigenetics in complex diseases. In this investigation, we found that locus-specific methylation differences between tissues are highly consistent across individuals. We developed a novel statistical model to predict locus-specific methylation in target tissue based on methylation in surrogate tissue. The method was evaluated in publicly available data and in two studies using the latest IlluminaBeadChips: a childhood asthma study with methylation measured in both peripheral blood leukocytes (PBL) and lymphoblastoid cell lines; and a study of postoperative atrial fibrillation with methylation in PBL, atrium and artery. We found that our method can greatly improve accuracy of cross-tissue prediction at CpG sites that are variable in the target tissue [R2 increases from 0.38 (original R2 between tissues) to 0.89 for PBL-to-artery prediction; from 0.39 to 0.95 for PBL-to-atrium; and from 0.81 to 0.98 for lymphoblastoid cell line-to-PBL based on cross-validation, and confirmed using cross-study prediction]. An extended model with multiple CpGs further improved performance. Our results suggest that large-scale epidemiology studies using easy-to-access surrogate tissues (e.g. blood) could be recalibrated to improve understanding of epigenetics in hard-to-access tissues (e.g. atrium) and might enable non-invasive disease screening using epigenetic profiles.

Ma, Baoshan; Wilker, Elissa H.; Willis-Owen, Saffron A. G.; Byun, Hyang-Min; Wong, Kenny C. C.; Motta, Valeria; Baccarelli, Andrea A.; Schwartz, Joel; Cookson, William O. C. M.; Khabbaz, Kamal; Mittleman, Murray A.; Moffatt, Miriam F.; Liang, Liming

2014-01-01

144

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

2012-04-01

145

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.

146

Bioaccumulation of mercury in muscle tissue of yellowfin tuna, Thunnus albacares, of the eastern Pacific Ocean.  

PubMed

Tuna, like most large pelagic fish, are highly exploited by man, and it is, therefore, important to determine mercury (Hg) levels in these species in order to establish allowable limits for their consumption and/or contamination levels in the environment. In this study, we evaluated Hg accumulation in yellowfin tuna (Thunnus albacares) muscle in two different geographic sites of the eastern Pacific Ocean. There was a positive association between Hg content and tuna size in the equatorial zone (EQZ). Using adjusted sizes, the site of origin was a determinant factor in Hg accumulation. Sex, by contrast, did not affect Hg levels, suggesting that males and females have similar feeding habits. No Hg concentration was over the Hg content thresholds for large marine predators adopted by Mexican norms and by North American authorities (1 ?g g(-1) w.w.). Hg input due to yellowfin tuna consumption represented from 9.84% to 35.87% in Baja California Sur and from 14.78% to 53.87% in EQZ of the provisional tolerable weekly intake adopted by the World Health Organization. The target hazard quotient for Hg was <1 in each group of the population studied, which indicates that consumption of yellowfin tuna is not a threat to human health. PMID:21739161

Ordiano-Flores, Alfredo; Galván-Magańa, Felipe; Rosiles-Martínez, Rene

2011-12-01

147

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

148

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

149

Influence of methylmercury from tributary streams on mercury levels in Savannah River Asiatic clams.  

PubMed

Average methylmercury levels in five Savannah River tributary streams, sampled 11 times over 2 years (0.170 ng/l), were nearly twice as high as in the Savannah River (0.085 ng/l). Total mercury levels in the tributaries (2.98 ng/l) did not differ significantly from the river (2.59 ng/l). 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 (average of 0.044 microg/g wet weight) were significantly (P<0.001) higher than in Asiatic clams collected from the Savannah River upstream from the tributary mouths (average of 0.017 microg/g wet weight). 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. PMID:15144790

Paller, M H; Jagoe, C H; Bennett, H; Brant, H A; Bowers, J A

2004-06-01

150

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...

151

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

PubMed

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 4-6 week) and manure samples were collected from five commercial poultry farms of Hyderabad, Pakistan. The Hg concentrations in feeds, chicken tissues (leg, muscle, liver and heart) and manure samples were determined by CVAAS, prior to microwave assisted acid digestion in closed vessels. For validation, a certified reference material, DORM-2 was used. The limit of detection and quantitation were 0.117 and 0.382 microg/kg, respectively The Hg concentration in different chicken feed were found in the range of 8.57-16.5 microg/kg. The concentration of Hg in chicken tissues were found in the range of 2.54-5.54 microg/kg (liver), 1.27-3.86 microg/kg (muscles) and 2.13-3.27 microg/kg (heart). The bioaccumulation factors (BAF) for Hg in different tissues were found in the range of 0.092-0.269. The obtained data shows the high correlation coefficient between feed and manure, while low r-values were obtained between Hg levels in feed and tissues of broiler chicken of two age groups. PMID:20304027

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

2010-06-01

152

[Mercury and Alzheimer's disease].  

PubMed

Higher mercury concentrations were found in brain regions and blood of some patients with Alzheimer's disease (AD). Low levels of inorganic mercury were able to cause AD- typical nerve cell deteriorations in vitro and in animal experiments. Other metals like zinc, aluminum, copper, cadmium, manganese, iron, and chrome are not able to elicit all of these deteriorations in low levels, yet they aggravate the toxic effects of mercury (Hg). Main human sources for mercury are fish consumption (Methyl-Hg) and dental amalgam (Hg vapour). Regular fish consumption reduces the risk of development of AD. Amalgam consists of approx. 50 % of elementary mercury which is constantly being vaporized and absorbed by the organism. Mercury levels in brain tissues are 2 - 10 fold higher in individuals with dental amalgam. Persons showing a genetically determined subgroup of transportation protein for fats (apolipoprotein E4) have an increased AD risk. Apoliprotein E (APO E) is found in high concentrations in the central nervous system. The increased AD risk through APO E4 might be caused by its reduced ability to bind heavy metals. Latest therapeutic approaches to the treatment of Alzheimer disease embrace pharmaceuticals which remove or bind metals from the brain. Preliminary success has been documented with chelation of synergistic toxic metals (Fe, Al, Zn, Cu) and therefore also Hg. The available data does not answer the question, whether mercury is a relevant risk factor in AD distinctively. In sum, the findings from epidemiological and demographical studies, the frequency of amalgam application in industrialized countries, clinical studies, experimental studies and the dental state of Alzheimer patients in comparison to controls suggest a decisive role for inorganic mercury in the etiology of Alzheimer's disease. Other factors currently discussed as causes (e. g. other metals, inflammations, dietetic factors, vitamin deficiency, oxidative distress, and metabolic impairments) may act as co-factors. PMID:17628833

Mutter, J; Naumann, J; Schneider, R; Walach, H

2007-09-01

153

Remodeling of cellular cytoskeleton drives tissue level morphogenesis  

NASA Astrophysics Data System (ADS)

Mechanical stresses are central to morphogenesis, both as a cause that generates geometric and topological change, and as regulatory signals that couple cells. Live imaging of fluorescently tagged tissues gives us insight into the cellular processes underlying tissue dynamics during morphogenesis. Amongst these is the remodeling of the cytoskeleton and cellular adhesion. Here, following observations from drosophila germ band extension and ventral furrow formation, we a) investigate the mechanical state of the tissue b) perform a quantitative analysis and verification of the cell and tissue level stresses and c) determine how conserved cellular processes are regulated to generate tissue level stresses that drive morphogenesis.

Mani, Madhav; Lecuit, Thomas; Shraiman, Boris

2012-02-01

154

Inorganic mercury exposure, mercury-copper interaction, and DMPS treatment in rats.  

PubMed Central

The aim of this study was to evaluate the efficiency of oral treatment with sodium 2,3-dimercaptopropane-1-sulfonate (DMPS) on reducing mercury deposits in rat kidney after chronic exposure to inorganic mercury. The effect on kidney copper levels was also evaluated. The results showed that after two months of exposure to 50 ppm of mercury (as mercuric chloride) the concentration of mercury in the kidney was 124 micrograms/g wet tissue. At the same time copper concentration rose from 11 to 77 micrograms/g. DMPS treatment caused 2- and almost 4-fold reduction of mercury and copper, respectively. This study demonstrates that chronic exposure to inorganic mercury may alter metabolism of copper and that DMPS is an effective means for reduction of both mercury and copper.

Blanusa, M; Prester, L; Radic, S; Kargacin, B

1994-01-01

155

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

156

Total mercury determination in different tissues of broiler chicken by using cloud point extraction and cold vapor atomic absorption spectrometry.  

PubMed

A cloud point extraction (CPE) method has been developed for the determination of total mercury (Hg) in different tissues of broiler chicken by cold vapor atomic absorption spectrometry (CVAAS). The broiler chicken tissues (leg, breast, liver and heart) were subjected to microwave assisted digestion in a mixture of nitric acid and hydrogen peroxide (2:1 ratio), prior to preconcentration by CPE. Various parameters such as the amount of ammonium O,O-diethyldithiophosphate (DDTP), concentrations of Triton X-114, equilibrium temperature, time and centrifugation have been studied in order to find the best conditions for the determination of mercury. For validation of proposed method a certified reference material, DORM-2 was used. No significant difference p>0.05 was observed between the experimental results and the certified values of CRM (paired t-test). The limit of detection and quantitation obtained under the optimal conditions were 0.117 and 0.382 microg/kg, respectively. The accumulation of Hg in different tissues were found in the order of, liver>muscles>heart. The concentration of Hg in chicken tissues were found in the range of 1.57-2.75, 1.40-2.27, 1.55-4.22, and 1.39-2.61 microg/kg in leg, breast, liver and heart, respectively. PMID:19766690

Shah, A Q; Kazi, T G; Baig, J A; Afridi, H I; Kandhro, G A; Arain, M B; Kolachi, N F; Wadhwa, S K

2010-01-01

157

Elemental Mercury Vapour Toxicity: Treatment and Levels in Plasma and Urine  

Microsoft Academic Search

1 We report two cases of acute mercury vapour intoxication in humans. The mercury vapour was released from smelting alloys (gold-mercury amalgam). The alloy was apparently contaminated with an unknown amount of mercury.2 Within half an hour of the incident, the victims began having moderate headache, nausea, lumbar pain and shortness of breath at rest. The patients were treated with

P. Houeto; P. Sandouk; F. J. Baud; P. Levillain

1994-01-01

158

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

PubMed Central

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

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

2013-01-01

159

Omental and subcutaneous adipose tissue steroid levels in obese men  

Microsoft Academic Search

We examined plasma and fat tissue sex steroid levels in a sample of 28 men aged 24.8–62.2 years (average BMI value of 46.3±12.7kg\\/m2). Abdominal adipose tissue biopsies were obtained during general or obesity surgery. Omental and subcutaneous adipose tissue steroid levels were measured by gas chromatography and chemical ionization mass spectrometry after appropriate extraction procedures. BMI and waist circumference were

Chantal Bélanger; Frédéric-Simon Hould; Stéfane Lebel; Simon Biron; Gaétan Brochu; André Tchernof

2006-01-01

160

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

SciTech Connect

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

Speyer, M.R.

1980-03-01

161

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

162

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

NASA Astrophysics Data System (ADS)

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

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

2011-10-01

163

Mercury in Morelet's crocodile eggs from northern Belize.  

PubMed

Recent studies have examined mercury accumulation in crocodilians. However, though most researchers have focused on tissue concentrations, few have examined mercury levels in crocodilian eggs. In July 1995, we analyzed mercury in 31 nonviable Morelet's crocodile ( Crocodylus moreletii) eggs collected from eight nests across three localities in northern Belize. All eggs were found to contain mercury. Based on an individual egg basis, mean concentration of mercury for all three localities was among the lowest reported for any crocodilian species. When localities were examined separately, mean concentrations for Laguna Seca and Gold Button Lagoon were comparable to those observed in other studies, and the mean for Sapote Lagoon was the lowest ever reported. Based on mean nest concentrations, mercury in eggs from Laguna Seca was approximately two- and tenfold higher than for Gold Button Lagoon and Sapote Lagoon, respectively. Variability in mercury concentrations among localities is likely the result of site-specific differences in mercury input, bioavailabilty, and bioaccumulation. Mercury concentrations were relatively uniform in eggs from the same nest and among nests from the same localities. The presence of mercury in Morelet's crocodile eggs suggests exposure in adult females, developing embryos, and neonates. However, crocodiles in these areas show no overt signs of mercury toxicity, and no indication of population decline is evident. A paucity of data on the effects of mercury on crocodilians precludes meaningful speculation as to the biological significance of tissue and egg concentrations. Controlled laboratory studies and long-term population monitoring are needed to address these questions. PMID:11910460

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

2002-04-01

164

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

PubMed

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

Burger, Joanna; Gochfeld, Michael

2011-03-15

165

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

2013-06-01

166

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

2013-06-01

167

Effects of In-Office and Home Bleaching Gels on the Surface Mercury Levels of Dental Amalgam  

PubMed Central

Objectives: The aim of this study was to evaluate the effect of different in-office and home bleaching gels on the surface mercury levels of dental amalgam. Methods: Sixty disk-shaped amalgam specimens (GS-80, SDI- Australia) were prepared and randomly divided into the following treatment groups: 1. Distilled water (control); 2. 15% home-bleach carbamide peroxide (Opalescence PF, Ultra dent, USA) applied for 6 h/day for 3 weeks; and 3. 35% in-office bleach carbamide peroxide (Opalescence Quick, Ultradent) applied for 30 min/week for 3 weeks. Levels of mercury were measured as weight percentages using an energy dispersive x-ray micro-analyzer detector connected to an electron microscope. Data was analyzed using one-way ANOVA and a post hoc Tukey tests (P<.05). Results: There were no significant differences between the surface mercury levels measured following treatment with the tested home-bleach and in-office bleach products (P=0.71). However, both materials yielded significantly more mercury levels than that of the control group (P<.001). Conclusions: The tested bleaching products significantly elevated the surface mercury levels of amalgam in vitro.

Oskoee, Parnian Alizadeh; Kahnamoui, Mahdi Abed; Oskoee, Siavash Savadi; Zadfattah, Firooz; Pournaghi-Azar, Fatemeh

2010-01-01

168

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

EPA Science Inventory

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

169

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

170

Examination of blood levels of mercurials in practicing dentists using cold-vapor atomic absorption spectrometry  

Microsoft Academic Search

The toxicity of mercury compounds in dentistry has been an issue of increase concern. Relatively few data are available concerning the possible in vivo biotransformation of elemental mercury from dental amalgam into more toxic organic mercurials. The present study was designed to evaluate the existence of this in vivo pathway in dentists who work in a confined environment where metallic

S. B. Chang; C. Siew; S. E. Gruninger

2009-01-01

171

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

PubMed

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

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

2014-05-01

172

Relation between mercury concentration and size in the mako shark  

Microsoft Academic Search

Many countries have set maximum permissible concentrations for mercury in fish which are intended for human consumption, most of these being in the range 0.5-1.0 ~g\\/g mercury in wet tissue (HANCOCK et al. 1977). The relevance of such limits to the South African fishing industry is that mercury concentrations in fish must be lower than the maximum permissible level set

R. J. Watling; T. P. McClurg; R. C. Stanton

1981-01-01

173

Teeth as biomonitors of soft tissue mercury concentrations in beluga, Delphinapterus leucas  

SciTech Connect

This paper reports relationships between bulk Hg concentrations in the tooth cementum and soft tissues of free-living beluga (Delphinapterus leucas). Total Hg levels were determined in slivers of cementum using a solid-sample Hg analyzer, a recent advance in Hg analysis that avoids acid predigestion. Tooth Hg concentrations ranged up to about 350 ng/g dry weight and were significantly correlated with Hg levels in kidneys, liver, muscle, and muktuk (skin) and with the age of the animals. The Hg/Se ratio in liver, the organ with the highest Hg concentrations, may have been an important determinant of tooth Hg. At hepatic Hg/Se molar ratios {ge}0.6, tooth Hg increased steeply, suggesting that Hg in teeth may reflect physiologically available Hg that was not bound in the liver and that was circulating in the bloodstream. This Hg/Se ratio was exceeded in most beluga aged {ge}20 years. The results indicate that teeth can be used as biomonitors to reconstruct temporal and geographic trends in the soft tissue Hg concentrations of beluga, provided that the age structures of the different populations are known.

Outridge, P.M.; Wagemann, R.; McNeely, R.

2000-06-01

174

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

USGS Publications Warehouse

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

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

2005-01-01

175

Effect of diet on tissue levels of palmitoylethanolamide.  

PubMed

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

Hansen, Harald S

2013-02-01

176

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

2010-05-15

177

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

NASA Technical Reports Server (NTRS)

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

Patterson, James D.; Li, Wei-Gang

1995-01-01

178

Identification and distribution of mercury species in rat tissues following administration of thimerosal or methylmercury  

Microsoft Academic Search

Methylmercury (Met-Hg) is one the most toxic forms of Hg, with a considerable range of harmful effects on humans. Sodium ethyl\\u000a mercury thiosalicylate, thimerosal (TM) is an ethylmercury (Et-Hg)-containing preservative that has been used in manufacturing\\u000a vaccines in many countries. Whereas the behavior of Met-Hg in humans is relatively well known, that of ethylmercury (Et-Hg)\\u000a is poorly understood. The present

Jairo L. Rodrigues; Juliana M. Serpeloni; Bruno L. Batista; Samuel S. Souza; Fernando Barbosa Jr

2010-01-01

179

Omental and subcutaneous adipose tissue steroid levels in obese men.  

PubMed

We examined plasma and fat tissue sex steroid levels in a sample of 28 men aged 24.8-62.2 years (average BMI value of 46.3 +/- 12.7 kg/m(2)). Abdominal adipose tissue biopsies were obtained during general or obesity surgery. Omental and subcutaneous adipose tissue steroid levels were measured by gas chromatography and chemical ionization mass spectrometry after appropriate extraction procedures. BMI and waist circumference were negatively correlated with plasma testosterone (r = -0.49 and -0.50, respectively, p < 0.01) and dihydrotestosterone (r = -0.58 and -0.56, respectively, p < 0.01), and positively associated with estrone levels (r = 0.64 and 0.62, respectively, p < 0.001). Regional differences in adipose tissue steroid levels were observed for dihydrotestosterone (p < 0.005), androstenedione (p < 0.0001) and dehydroepiandrosterone levels (p < 0.05), which were all significantly more concentrated in omental versus subcutaneous fat. Positive significant associations were found between circulating level of a steroid and its concentration in omental and subcutaneous adipose tissue, for estrone (r = 0.72 and 0.57, respectively, p < 0.01), testosterone (r = 0.66 and 0.58, respectively, p < 0.01) and dihydrotestosterone (r = 0.58 and 0.45, respectively, p < 0.05). Positive correlations were observed between plasma dehydroepiandrosterone-sulfate and omental (r = 0.56, p < 0.01) as well as subcutaneous adipose tissue dehydroepiandrosterone level (r = 0.38, p = 0.05). Positive significant associations were found between omental adipocyte responsiveness to positive lipolytic stimuli (isoproterenol, dibutyryl cyclic AMP and forskolin) and plasma or omental fat tissue androgen levels. In conclusion, although plasma androgen or estrogen levels are strong correlates of adipose tissue steroid content both in the omental and subcutaneous fat depots, regional differences may be observed. Androgen concentration differences in omental versus subcutaneous adipose tissue suggest a depot-specific impact of these hormones on adipocyte function and metabolism. PMID:16762384

Bélanger, Chantal; Hould, Frédéric-Simon; Lebel, Stéfane; Biron, Simon; Brochu, Gaétan; Tchernof, André

2006-08-01

180

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

SciTech Connect

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

Speyer, M.R.

1980-03-01

181

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

2012-01-01

182

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

EPA Science Inventory

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

183

Energies and widths of atomic core-levels in liquid mercury  

NASA Astrophysics Data System (ADS)

High-resolution measurements of the photoinduced X-ray emission of liquid mercury were performed, using a transmission DuMond-type crystal spectrometer for transitions above 11 keV and a reflection von Hamos-type crystal spectrometer for transitions below 11 keV. The target X-ray fluorescence was produced by irradiating the sample with the Bremsstrahlung from X-ray tubes. The energies and natural linewidths of 6 K-shell, 26 L-shell and 2 M-shell X-ray transitions were determined. Using a least-squares-fit method to solve the two sets of equations derived from the observed transition energies and transition widths the binding energies of the subshells K to M5 and O1 and the level widths of the subshells K to N5 and O1 could also be determined.

Maillard, Y.-P.; Dousse, J.-Cl.; Hoszowska, J.

2010-04-01

184

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

2012-09-01

185

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

2012-07-01

186

The Levels of Soluble Nucleotides in Wheat Aleurone Tissue 1  

PubMed Central

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

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

1972-01-01

187

Tissue levels of leukemia inhibitory factor vary by osteoarthritis grade.  

PubMed

The objective of this study was to observe the expression of leukemia inhibitory factor (LIF) in animals and in different clinical grades of patient osteoarthritic tissues. Thirty-five rabbits were used in a Colombo model of experimental osteoarthritis (OA). Five rabbits each were sacrificed on postoperative days 3, 7, 14, 28, 42, 56, and 84. Immunohistochemistry analysis for LIF expression and distribution in the cartilage and synovium of animals was performed at these times. Sixty-seven samples of human articular tissue were obtained from patients with different grades of OA according to symptoms and radiographic inspection. The mRNA expression of LIF was determined by reverse transcription polymerase chain reaction, and LIF protein was determined by enzyme-linked immunosorbent assay (ELISA). The results showed a slight expression of LIF in normal cartilage tissue but less in synovium tissue; however, the expression of LIF was marked in synovial lining cells and superficial and middle-layer cartilage in animal OA (P<.05). Leukemia inhibitory factor mRNA was expressed at the highest level in moderate degrading subchondral bone, and LIF was expressed at the highest level in seriously degrading articular cartilage tissue. These results were similar to those found with ELISA. This study suggests that LIF in OA articular tissues varies by clinical symptoms and grade. It plays an important role in the pathogenesis of OA. PMID:24810823

Jiang, Yuwen; Xiao, Qiang; Hu, Zhenming; Pu, Bo; Shu, Jun; Yang, Qingqiu; Lao, Hanchang; Hao, Jie

2014-05-01

188

Maternal and umbilical cord blood levels of mercury, lead, cadmium, and essential trace elements in Arctic Canada  

SciTech Connect

Maternal and umbilical cord blood levels of mercury (Hg), lead (Pb), cadmium (Cd), and the trace elements copper (Cu), zinc (Zn), and selenium (Se) are reported for Inuit, Dene/Metis, Caucasian, and Other nonaboriginal participants from Arctic Canada. This is the first human tissue monitoring program covering the entire Northwest Territories and Nunavut for multiple contaminants and establishes a baseline upon which future comparisons can be made. Results for chlorinated organic pesticides and PCBs for these participants have been reported elsewhere. Between May 1994 and June 1999, 523 women volunteered to participate by giving their written informed consent, resulting in the collection of 386 maternal blood samples, 407 cord samples, and 351 cord:maternal paired samples. Geometric mean (GM) maternal total mercury (THg) concentrations ranged from 0.87{mu}g/L (SD=1.95) in the Caucasian group of participants (n=134) to 3.51{mu}g/L (SD=8.30) in the Inuit group (n=146). The GM of the Inuit group was 2.6-fold higher than that of the Dene/Metis group (1.35{mu}g/L, SD=1.60, n=92) and significantly higher than those of all other groups (P<0.0001). Of Inuit women participants, 3% (n=4) were within Health Canada's level of concern range (20-99{mu}g/L) for methylmercury (MeHg) exposure. Of Inuit and Dene/Metis cord samples, 56% (n=95) and 5% (n=4), respectively, exceeded 5.8{mu}g/L MeHg, the revised US Environmental Protection Agency lower benchmark dose. GM maternal Pb was significantly higher in Dene/Metis (30.9{mu}g/L or 3.1{mu}g/dL; SD=29.1{mu}g/L) and Inuit (31.6{mu}g/L, SD=38.3) participants compared with the Caucasian group (20.6{mu}g/L, SD=17.9) (P<0.0001). Half of all participants were smokers. GM blood Cd in moderate smokers (1-8 cigarettes/day) and in heavy smokers (>8 cigarettes/day) was 7.4-fold higher and 12.5-fold higher, respectively, than in nonsmokers. The high percentage of smokers among Inuit (77%) and Dene/Metis (48%) participants highlights the need for ongoing public health action directed at tobacco prevention, reduction, and cessation for women of reproductive age. Pb and THg were detected in more than 95% of all cord blood samples, with GMs of 21 {mu}g/L and 2.7{mu}g/L, respectively, and Cd was detected in 26% of all cord samples, with a GM of 0.08{mu}g/L. Cord:maternal ratios from paired samples ranged from 0.44 to 4.5 for THg, from 0.5 to 10.3 for MeHg, and 0.1 to 9.0 for Pb. On average, levels of THg, MeHg, and Zn were significantly higher in cord blood than in maternal blood (P<0.0001), whereas maternal Cd, Pb, Se, and Cu levels were significantly higher than those in cord blood (P<0.0001). There was no significant relationship between methylmercury and selenium for the range of MeHg exposures in this study. Ongoing monitoring of populations at risk and traditional food species, as well as continued international efforts to reduce anthropogenic sources of mercury, are recommended.

Butler Walker, Jody [J. Butler Walker and Associates, 15 Balsam Crescent, Whitehorse, YT Y1A 4V6 (Canada)]. E-mail: jody@butlerwalker.ca; Houseman, Jan [Formerly Inuvik Regional Human Contaminants Monitoring Program coordinators, Inuvik, NT (Canada); Seddon, Laura [Formerly Mackenzie and Kitikmeot Maternal and Cord Blood Monitoring Program coordinators, Yellowknife, NT (Canada); McMullen, Ed [J. Butler Walker and Associates, Whitehorse, YT (Canada); Tofflemire, Karen [Formerly Inuvik Regional Human Contaminants Monitoring Program coordinators, Inuvik, NT (Canada); Mills, Carole [Formerly Mackenzie and Kitikmeot Maternal and Cord Blood Monitoring Program coordinators, Yellowknife, NT (Canada); Corriveau, Andre [Government of the Northwest Territories (GNWT), Department of Health and Social Services, Yellowknife, NT (Canada); Weber, Jean-Philippe [Laboratoire de Toxicologie, Institut national de sante publique du Quebec, Sainte-Foy, QC (Canada); LeBlanc, Alain [Laboratoire de Toxicologie, Institut national de sante publique du Quebec, Sainte-Foy, QC (Canada); Walker, Mike [Health Canada, Safe Environments Programme, Ottawa, ON (Canada); Donaldson, Shawn G. [Health Canada, Safe Environments Programme, Ottawa, ON (Canada); Van Oostdam, Jay [Health Canada, Safe Environments Programme, Ottawa, ON (Canada)

2006-03-15

189

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...

190

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

Microsoft Academic Search

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

D. Sampaio da Silva; M. Lucotte; S. Paquet; R. Davidson

2009-01-01

191

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

192

Behavior of mercury in bio-systems. II. Depuration of /sup 203/Hg/sup 2 +/ in various trophic levels  

SciTech Connect

Using radiotracer techniques, the depuration rates for methylmercury at three trophic levels in an aquatic ecosystem are examined. Bacteria (decomposers), mosquito larvae (primary consumers), and fish (secondary consumers) were studied. Results indicated that depuration rates for mercury were temperature dependent - the rate of depuration increased with increase in temperature (up to 45/sup 0/C)

Hamdy, M.K.; Prabhu, N.V.

1984-01-01

193

Assessment of Mercury Levels in Soils, Waters, Bottom Sediments and Fishes of Acre State in Brazilian Amazon  

Microsoft Academic Search

Mercury in the aquatic biota and geologic materials in areas without anthropogenic sources has been stimulating the discussion about the possibility of natural Hg occurrence in the Amazon region. In this study the dispersion of Hg in different geologic materials as well as its relationship with high Hg levels, detected in some species of carnivorous fish consumed in the Rio

E. S. Brabo; R. S. Angélica; A. P. Silva; K. R. F. Faial; A. F. S. Mascarenhas; E. C. O. Santos; I. M. Jesus; E. C. B. Loureiro

2003-01-01

194

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

195

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

196

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

EPA Science Inventory

Between 1564 and 1810, nearly 17,000 metric tons of mercury (Hg) vapor were released to the environment during cinnabar refining in the small town of Huancavelica, Peru. The present study characterizes individual exposure to mercury using total and speciated Hg from residential s...

197

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

Microsoft Academic Search

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

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

2005-01-01

198

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

EPA Science Inventory

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

199

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

PubMed

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

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

2011-06-01

200

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

2013-11-01

201

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

SciTech Connect

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

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

2012-01-01

202

Prostate cancer outcome and tissue levels of metal ions  

USGS Publications Warehouse

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

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

2011-01-01

203

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

2013-02-01

204

Towards Prenatal Biomonitoring in North Carolina: Assessing Arsenic, Cadmium, Mercury, and Lead Levels in Pregnant Women  

PubMed Central

Exposure to toxic metals during the prenatal period carries the potential for adverse developmental effects to the fetus, yet such exposure remains largely unmonitored in the United States. The aim of this study was to assess maternal exposure to four toxic metals (arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb)) in a cohort of pregnant women in North Carolina. We analyzed blood samples submitted to the North Carolina Department of Health and Human Services for blood typing to assess toxic metal levels in pregnant women (n?=?211) across six North Carolina counties. Whole blood metal concentrations were measured by inductively coupled plasma mass spectrometry. The association between maternal characteristics, including county of residence, age, and race, and metal exposure was analyzed using multiple linear regression analysis. A large fraction of the blood samples showed detectable levels for each of the four metals. Specifically, As (65.7%), Cd (57.3%), Hg (63.8%), and Pb (100%) were detected in blood samples. Moreover, compared with adult females participating in the Fourth National Report on Human Exposure to Environmental Chemicals and guidelines for pregnant women, some women in the sample population exceeded benchmark levels of Cd, Hg, and Pb. Evidence from this pilot study indicates that pregnant women in North Carolina are exposed to As, Cd, Hg, and Pb and suggests that factors related to maternal county of residence and race may impact maternal exposure levels. As increased levels of one or more of these metals in utero have been associated with detrimental developmental and reproductive outcomes, further study is clearly warranted to establish the impacts to newborns.

Sanders, Alison P.; Flood, Kaye; Chiang, Shu; Herring, Amy H.; Wolf, Leslie; Fry, Rebecca C.

2012-01-01

205

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

206

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

SciTech Connect

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

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

1991-01-01

207

MERCURY IN THE ENVIRONMENT  

EPA Science Inventory

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

208

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

209

Histopathological Changes Induced by Chronic Nonlethal Levels of Elsan, Mercury, and Ammonia in the Small Intestine of Channa punctatus (Bloch)  

Microsoft Academic Search

Histopathological changes in the intestine of Channa punctatus induced by chronic nonlethal levels of Elsan (211 ppb), mercury (16.7 ppb), and ammonia (15.64 ppm) were studied at 7-day intervals for 90 days and the data were presented only for days (7, 28, 63, and 90) when the most conspicuous changes were noted after treatment. In the earlier phases of Elsan

S. Banerjee; S. Bhattacharya

1995-01-01

210

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

Microsoft Academic Search

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

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

1996-01-01

211

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

USGS Publications Warehouse

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

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

2005-01-01

212

The Occurrence of MerR and MerC Gene Sequences Among Mercury Resistant Determinants in River Sediments Containing Elevated Levels of Mercury  

Microsoft Academic Search

Sediments in the River Yare, Norfolk, UK have been contaminated with mercury by the discharge of heavy metal-laden effluents from a local chemical company. In this study probes specific for different genes within commonly occurring gram-negative mercury resistance determinants were used to investigate the occurrence of the mercury resistance transposons Tn21 and Tn501 in bacteria isolated from river-sediments. This work

B. Olson; S. Ford; John Lester

1987-01-01

213

Bioaccumulation of mercury in muscle tissue of fish in the Elbe River (Czech Republic): multispecies monitoring study 1991-1996.  

PubMed

The study monitored mercury (Hg) contamination of fish muscle tissue at 13 geographical sites that can be regarded as crucial points for an ecotoxicological assessment of the Czech Republic section of the Elbe River. The descriptive part of the study was primarily aimed at comparative evaluation of the Hg load during the period 1991-1996. The conclusions were supported by multivariate statistical analyses of the content of Hg in the muscle tissue of 1251 fish belonging to 23 species with four dominant indicator species: Perca fluviatilis (n=163), Abramis brama (n=173), Rutilus rutilus (n=148), and Leuciscus cephalus (n=166). Considering data from 3- to 5-year-old fish, significantly increased contamination was detected in typical predators compared to the other fish species in all sites (P<0.001). On the other hand, omnivorous and planctivorous species were ranked as the least sensitive for Hg pollution. Perch appeared to be the most contaminated species in the sample with muscle Hg concentration in the range of 0.840-1.398 mg Hg kg(-1). Although less contaminated than perch, muscle contamination of bream sensitively separated differently contaminated sites; the highest load ranged from 0.368 to 0.543 mg Hg kg(-1). Time-related comparison of sampling campaigns revealed no significant trend changes, in either sediment samples or fish tissue. Thus, the analyses documented an evidently rather stabilized total Hg pollution in the Elbe River environment. Multivariate multispecies analyses found the age of analyzed individuals and the feeding strategy of a given species as the most important, however mutually interactive, covariates for Hg accumulation in muscle tissue. The analyses revealed decreasing sensitivity of older predator individuals to differentiate highly and moderately contaminated sites. Benthophagous species mostly kept their discrimination capacity toward contaminated sites in all age categories, with the exception of bream that was rather linked to the pattern typical for predator species. The unclear position of omnivorous species, represented namely by roach, corresponded with their weak bioindicator power, mainly in the young age categories. PMID:15883097

Dusek, L; Svobodová, Z; Janousková, D; Vykusová, B; Jarkovský, J; Smíd, R; Pavlis, P

2005-06-01

214

Assessment of Total Mercury Level in Fish Collected from East Calcutta Wetlands and Titagarh Sewage Fed Aquaculture in West Bengal, India  

Microsoft Academic Search

Total mercury levels were quantified in Tilapia mossambicus, Cirrhinus mrigela and Labio rohita, captured from East Calcutta Wetlands and Titagarh sewage fed aquaculture ponds. The bioconcentration factor of collected\\u000a fish was assessed. Total mercury level ranged from 0.073 to 0.94 ?g\\/g in both pre and post monsoon season. T. mossambicus in both season and C. mrigela at pre monsoon, cross

Subarna Bhattacharyya; Punarbasu Chaudhuri; Siddartha Dutta; Subhas Chandra Santra

2010-01-01

215

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

PubMed

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

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

2012-07-01

216

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

217

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

PubMed

Metals and metalloid species are involved in homeostasis in energy systems such as glucose metabolism. Enlarged adipocytes are one of the most important causes of obesity-associated diseases. In this study, we studied the possibility that various metals, namely, CoCl(2), HgCl(2), NaAsO(2) and MnCl(2) pose risk to or have beneficial effects on white adipose tissue (WAT). Exposure to the four metals resulted in decreases in WAT weight and the size of enlarged adipocytes in mice fed a high-fat diet (HFD) without changes in liver weight, suggesting that the size and function of adipocytes are sensitive to metals. Repeated administration of CoCl(2) significantly increased serum leptin, adiponectin and high-density lipoprotein (HDL) cholesterol levels and normalized glucose level and adipose cell size in mice fed HFD. In contrast, HgCl(2) treatment significantly decreased serum leptin level with the down-regulation of leptin mRNA expression in WAT and a reduction in adipocyte size. Next, we tried to investigate possible factors that affect adipocyte size. Repeated exposure to HgCl(2) significantly decreased the expression levels of factors upon the regulation of energy such as the PPAR? and PPAR? mRNA expression levels in adipocytes, whereas CoCl(2) had little effect on those genes expressions compared with that in the case of the mice fed HFD with a vehicle. In addition, repeated administration of CoCl(2) enhanced AMPK activation in a dose-dependent manner in the liver, skeletal muscle and WAT; HgCl(2) treatment also enhanced AMPK activation in the liver. Thus, both Co and Hg reduced WAT weight and the size of enlarged adipocytes, possibly mediated by AMKP activation in the mice fed HFD. However, inorganic cobalt may have a preventive role in obesity-related diseases through increased leptin, adiponectin and HDL-cholesterol levels, whereas inorganic mercury may accelerate the development of such diseases. These results may lead to the development of new approaches to establishing the role of metals in adipose tissue of obesity-related diseases. PMID:22019852

Kawakami, Takashige; Hanao, Norihide; Nishiyama, Kaori; Kadota, Yoshito; Inoue, Masahisa; Sato, Masao; Suzuki, Shinya

2012-01-01

218

Assessment of Total and Organic Mercury Levels in Blue Sharks (Prionace glauca) from the South and Southeastern Brazilian Coast.  

PubMed

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

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

2014-06-01

219

Species- and size-specific variability of mercury concentrations in four commercially important finfish and their prey from the northwest Atlantic.  

PubMed

Total mercury was analyzed as a function of body length, season, and diet in four commercially and recreationally important marine fish, bluefish (Pomatomus saltatrix), goosefish (Lophius americanus), silver hake (Merluccius bilinearis), and summer flounder (Paralichthys dentatus), collected from continental shelf waters of the northwest Atlantic Ocean. Mercury levels in the dorsal muscle tissue of 115 individuals ranged from 0.006 to 1.217 ?g/g (wet weight) and varied significantly among species. The relationship between predator length and mercury concentration was linear for bluefish and summer flounder, while mercury levels increased with size at an exponential rate for silver hake and goosefish. Mercury burdens were the highest overall in bluefish, but increased with size at the greatest rate in silver hake. Seasonal differences were detected for bluefish and goosefish with mercury levels peaking during summer and spring, respectively. Prey mercury burdens and predator foraging habits are discussed as the primary factors influencing mercury accumulation. PMID:21310437

Staudinger, Michelle D

2011-04-01

220

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

2012-01-01

221

Total Blood Mercury Levels and Depression among Adults in the United States: National Health and Nutrition Examination Survey 2005-2008  

PubMed Central

Background Mercury is a neurotoxicant linked with psychiatric symptoms at high levels of exposure. However, it is unclear whether an association is present at the low exposure levels in the US adult population. Materials and Methods Cross-sectional associations of total blood mercury and depression were assessed in 6,911 adults age ?20 in the National Health and Nutrition Examination Survey (NHANES), 2005–2008. The Patient Health Questionnaire-9 was used to assess depression (high likelihood of a depressive spectrum disorder diagnosis; score 5–27). Results Unadjusted survey weighted logistic regression suggested that higher total blood mercury was associated with lower odds of depression (Odds Ratio ?=?0.49, 95% Confidence Interval: 0.36–0.65, comparing the highest and lowest mercury quintiles). This association largely disappeared after adjustment for sociodemographic variables (income-poverty ratio, education, marital status). However, in age-stratified analyses, this inverse relationship remained in older adults (age ?40) even after adjustment for sociodemographic variables. Simulation analyses adjusting for expected confounding effects of fish intake suggested that the inverse relationship among older adults may be plausibly attributed to residual confounding (Odds Ratio ?=?0.75, 95% Confidence Interval: 0.50–1.12, comparing the highest and lowest mercury quintiles). Conclusions Higher total blood mercury was not associated with increased odds of depression. The lower odds of depression in older adults with higher total blood mercury may be due to residual confounding.

Ng, Tsz Hin H.; Mossey, Jana M.; Lee, Brian K.

2013-01-01

222

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

223

Elevated circulating levels of tissue factor in polycystic ovary syndrome.  

PubMed

Women with polycystic ovary syndrome (PCOS) have coagulation disturbances and inflammation, which increases the risk of atherothrombosis. We evaluated the status of circulating tissue factor (TF), the receptor for coagulation factor VII involved in atherothrombosis, in women with PCOS and weight-matched controls. Two-way analysis of variance models were fit to evaluate the effect of PCOS status and weight class on TF and other parameters. The TF levels were significantly higher in lean women with PCOS compared to lean controls. Plasminogen activator inhibitor 1 (PAI-1) levels were significantly higher in obese participants compared to lean participants after controlling for PCOS status. The TF levels directly correlated with percentage of truncal fat and plasma levels of PAI-1, testosterone, androstendione, and dehydroepiandrosterone-sulfate; and inversely correlated with insulin sensitivity index-OGTT(IS(OGTT)). Circulating TF is elevated in PCOS independent of obesity, but both PCOS and obesity contribute to a prothrombotic state. In PCOS, abdominal adiposity and hyperandrogenism may exacerbate the risk of atherothrombosis. PMID:22327820

González, Frank; Kirwan, John P; Rote, Neal S; Minium, Judi

2013-01-01

224

Multiscale Model Predicts Tissue-Level Failure From Collagen Fiber-Level Damage  

PubMed Central

Excessive tissue-level forces communicated to the microstructure and extracellular matrix of soft tissues can lead to damage and failure through poorly understood physical processes that are multiscale in nature. In this work, we propose a multiscale mechanical model for the failure of collagenous soft tissues that incorporates spatial heterogeneity in the microstructure and links the failure of discrete collagen fibers to the material response of the tissue. The model, which is based on experimental failure data derived from different collagen gel geometries, was able to predict the mechanical response and failure of type I collagen gels, and it demonstrated that a fiber-based rule (at the micrometer scale) for discrete failure can strongly shape the macroscale failure response of the gel (at the millimeter scale). The model may be a useful tool in predicting the macroscale failure conditions for soft tissues and engineered tissue analogs. In addition, the multiscale model provides a framework for the study of failure in complex fiber-based mechanical systems in general.

Hadi, Mohammad F.; Sander, Edward A.; Barocas, Victor H.

2013-01-01

225

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

PubMed Central

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

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

2013-01-01

226

Mercury in South Carolina fishes, USA.  

PubMed

The South Carolina Department of Health and Environmental Control has collected, processed, and analyzed fish tissue total mercury (Hg) since 1976. For this study, skin-on-filet data from 1993 to 2007 were examined to determine biotic, spatial and temporal trends in tissue Hg levels for SC fishes. Because of the relatively high number of tissue Hg values below the analytical detection limits interval censored regression and censored least absolute deviations were used to construct several models to characterize trends. Large pelagic, piscivorous fish species, such as bowfin (Amia calva Linnaeus 1766), had higher levels of tissue Hg than smaller omnivorous species. Estuarine species had relatively low levels of tissue Hg compared to freshwater species, while two large open ocean species, king mackerel (Scomberomorus cavalla Cuvier 1829) and swordfish (Xiphias gladius Linnaeus 1758), had higher tissue Hg readings. For a given fish species, length was an important predictor of tissue Hg with larger individuals having higher levels than smaller individuals. The USEPA Level III ecoregion and water body type from where the fishes were collected were important in predicting the levels of tissue Hg. The Middle Atlantic Coastal Plain ecoregion had fishes with the highest levels of tissue Hg, while the Piedmont and Southern Coastal Plain ecoregions had the lowest. For a given ecoregion, large reservoirs and regulated rivers had fish with lower levels of tissue Hg than unregulated rivers. For reservoirs, the size of the impoundment was a significant predictor of tissue mercury with small reservoirs having higher levels of tissue mercury than large reservoirs. Landuse and water chemistry accounted for differences seen in fish of various ecoregions and waterbody types. Sampling locations associated with a high percentage of wetland area had fish with high levels of tissue Hg. Correlation analysis showed a strong positive relationship between tissue Hg levels and water column iron, total organic carbon, ammonia, and total kjedahl nitrogen, and a negative relationship with alkalinity, dissolved oxygen and pH. Results from principle component analysis revealed patterns between waterbody type and water chemistry variables that suggests hydrologic modification can have profound effects on the levels of fish tissue Hg in riverine systems. From 1993 to 2007, fish tissue Hg levels have trended lower. A spike in tissue Hg levels was observed in 2003-2005. The drying and rewetting of the landscape after the 2002 drought is hypothesized to have caused an increase in the methylation efficiencies of the system. PMID:20058074

Glover, James B; Domino, Marisa E; Altman, Kenneth C; Dillman, James W; Castleberry, William S; Eidson, Jeannie P; Mattocks, Micheal

2010-04-01

227

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

228

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

PubMed

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

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

2014-05-20

229

Determination of total mercury in biological tissues by flow injection cold vapour generation atomic absorption spectrometry following tetramethylammonium hydroxide digestion.  

PubMed

A simple, rapid and reliable method was developed for the determination of total mercury in biological samples. Samples were solubilized using tetramethylammonium hydroxide (TMAH). The organically bound mercury was cleaved and converted to inorganic mercury by on-line addition of KMnO4. The decomposed mercury together with inorganic mercury originally present in samples was determined by flow injection cold vapour atomic absorption spectrometry after reduction to elemental mercury vapour using NaBH4. A sample throughput of 100 measurements per hour was achieved after a 30 min dissolution with TMAH. The relative standard deviation for 20 micrograms l-1 Hg was 1.3% (n = 11) and the limit of detection was 0.1 microgram l-1 (3 sigma). The proposed method was validated by the analysis of a suite of certified marine biological reference materials, DORM-2 (dogfish muscle), DOLT-2 (dogfish liver) and TORT-2 (lobster hepatopancreas), with calibration against simple HgII standards. PMID:9764507

Tao, G; Willie, S N; Sturgeon, R E

1998-06-01

230

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

231

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

232

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

2010-05-01

233

On-line speciation of inorganic and methyl mercury in waters and fish tissues using polyaniline micro-column and flow injection-chemical vapour generation-inductively coupled plasma mass spectrometry (FI-CVG-ICPMS)  

Microsoft Academic Search

A simple and efficient method for the determination of ultra-trace amounts of inorganic mercury (iHg) and methylmercury (MeHg) in waters and fish tissues was developed using a micro-column filled with polyaniline (PANI) coupled online to flow injection-chemical vapour generation-inductively coupled plasma mass spectrometry (FI-CVG-ICPMS) system. Preliminary studies indicated that inorganic and methyl mercury species could be separated on PANI column

M. V. Balarama Krishna; K. Chandrasekaran; D. Karunasagar

2010-01-01

234

Plasma mercury levels in Hong Kong residents: in relation to fish consumption.  

PubMed

Mercury exposure is of particular concern since mercury is a neurotoxin and the developing fetus is most sensitive to its adverse effect. Human blood is routinely used as an indicator for the evaluation of human exposure to Hg. To investigate Hg species in human plasma for Hong Kong residents and the relationship between fish consumption and Hg species in plasma, 151 plasma samples were analyzed for Hg species. The mean values of total Hg (THg) and methyl-mercury (MeHg) concentration in plasma were 0.62 and 0.28 ?g/L, respectively. No significant differences were observed between females and males as well as among age groups. Fish consumption rate was significantly positively correlated with MeHg concentrations in plasma, which demonstrated that plasma could be a biomarker for human MeHg exposure. Two methods were used to estimate human MeHg exposure. One was based on fish MeHg content and fish consumption rate (EDI(Fish)), another was employed by converting MeHg concentration in blood to MeHg exposure amount (EDI(Blood)). A significant positive correlation was observed between EDI(Blood) and EDI(Fish), and no significant difference was found between EDI(Blood) and EDI(Fish). These results demonstrated that fish consumption was the major source of MeHg for humans. PMID:23680090

Liang, Peng; Qin, Yan-Yan; Zhang, Chan; Zhang, Jin; Cao, Yucheng; Wu, Sheng-Chun; Wong, Chris K C; Wong, Ming H

2013-10-01

235

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

PubMed Central

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

2014-01-01

236

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

237

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

PubMed

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

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

2014-01-01

238

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

SciTech Connect

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

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

1989-06-01

239

Macroalgae response to a mercury contamination gradient in a temperate coastal lagoon (Ria de Aveiro, Portugal)  

NASA Astrophysics Data System (ADS)

Primary producers represent an important pathway for mercury incorporation in aquatic food webs. With eutrophication processes occurring worldwide, macroalgae may represent a substantial pool of mercury, as a result of its high growth rate and capacity to bind trace metals. The main aim of this work was to evaluate the response of the macroalgae to a human-induced environmental mercury gradient in a temperate coastal lagoon, by assessing the total and organic mercury contamination levels of the dominant species ( Enteromorpha, Fucus and Gracilaria). Total mercury in the plant tissues ranged from 0.02 to 2.1 ?g g -1 dwt. Fucus was the most contaminated algae, followed by Gracilaria and Enteromorpha. As a whole, organic mercury never exceeded 15% of total mercury content, but tended to increase with distance to metal source on all macroalgae indicating complex physiological responses from these primary producers in areas of high and low mercury concentrations. Sessile macroalgae may be important mercury immobilisation agents, while free-floating algae ( Enteromorpha) play an important role in mercury transport from contaminated areas (±10 g ha -1) to other areas of the lagoon and even to coastal waters. Based on the present results the use of macroalgal biomass from contaminated areas for direct or indirect human use (e.g. agricultural, industrial and food purposes) may result in health risks, due to the high bioaccumulation capacity (as high as 10 4 the dissolved mercury concentrations).

Coelho, J. P.; Pereira, M. E.; Duarte, A.; Pardal, M. A.

2005-11-01

240

Effects of environmental levels of cadmium, lead and mercury on human renal function evaluated by structural equation modeling.  

PubMed

A relationship between exposure to heavy metals, including lead and cadmium, and renal dysfunction has long been suggested. However, modeling of the potential additive, or synergistic, impact of metals on renal dysfunction has proven to be challenging. In these studies, we used structural equation modeling (SEM), to investigate the relationship between heavy metal burden (serum and urine levels of lead, cadmium and mercury) and renal function using data from the NHANES database. We were able to generate a model with goodness of fit indices consistent with a well-fitting model. This model demonstrated that lead and cadmium had a negative relationship with renal function, while mercury did not contribute to renal dysfunction. Interestingly, a linear relationship between lead and loss of renal function was observed, while the maximal impact of cadmium occurred at or above serum cadmium levels of 0.8 ?g/L. The interaction of lead and cadmium in loss of renal function was also observed in the model. These data highlight the use of SEM to model interaction between environmental contaminants and pathophysiology, which has important implications in mechanistic and regulatory toxicology. PMID:24769258

Trzeciakowski, Jerome P; Gardiner, Lesley; Parrish, Alan R

2014-07-01

241

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

SciTech Connect

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

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

2013-04-15

242

Hepatic and renal metallothionein induction by an oral equimolar dose of zinc, cadmium or mercury in mice  

Microsoft Academic Search

The hepatic and the renal subcellular distribution of zinc, cadmium or mercury and induction of tissue metallothionein (MT) at 24, 48 and 72 h following an oral equimolar dose (15 ?mol metal\\/kg) of zinc (II) chloride, cadmium (II) chloride or mercury (II) chloride in male albino mice were investigated. There was a moderate increase in hepatic and renal zinc levels

S. K Tandon; S Singh; S Prasad; N Mathur

2001-01-01

243

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

244

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

EPA Science Inventory

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

245

Trace level voltammetric determination of heavy metals and total mercury in tea matrices (Camellia sinensis).  

PubMed

An analytical procedure regarding the voltammetric determination of mercury(II), copper(II), lead(II), cadmium(II) and zinc(II) by square wave anodic stripping voltammetry (SWASV) in matrices involved in food chain is proposed. In particular, tea leaves were analyzed as real samples. The digestion of each matrix was carried out using a concentrated HCl-HNO3-H2SO4 acidic attack mixture; 0.01 mol L(-1) EDTA-Na2+ 0.15 mol L(-1) NaCl + 0.5 mol L(-1) HCl was employed as the supporting electrolyte. The voltammetric measurements were carried out using a conventional three electrode cell, employing, as working electrodes, a gold electrode (GE) and a stationary hanging mercury drop electrode (HMDE). The analytical procedure has been verified on the standard reference materials Spinach Leaves NIST-SRM 1570a, Tomato Leaves NIST-SRM 1573a and Apple Leaves NIST-SRM 1515. For all the elements, the precision as repeatability, expressed as relative standard deviation (sr) was of the order of 3-5%, while the trueness, expressed as relative error (e) was of the order of 3-7%. Once set up on the standard reference materials, the analytical procedure was applied to commercial tea leaves samples. A critical comparison with spectroscopic measurements is also discussed. PMID:24416778

Melucci, Dora; Locatelli, Marcello; Locatelli, Clinio

2013-12-01

246

Monitoring plan for mercury in fish tissue and water from the Boise River, Snake River, and Brownlee Reservoir, Idaho and Oregon  

USGS Publications Warehouse

The methylmercury criterion adopted as a water-quality standard in the State of Idaho is a concentration in fish tissue rather than a concentration in water. A plan for monitoring mercury in fish tissue and water was developed to evaluate whether fish in the Boise River, Idaho, upstream and downstream of wastewater-treatment plant discharges, meet the methylmercury water-quality criterion. Monitoring also will be conducted at sites on the Snake River, upstream and downstream of the confluence with the Boise River, and in Brownlee Reservoir, which lies along the border between Idaho and Oregon. Descriptions of standard procedures for collecting and processing samples and quality assurance steps are included. This monitoring plan is intended to provide a framework for cooperative methylmercury sampling in the lower Boise River basin.

Mebane, Christopher A.; MacCoy, Dorene E.

2013-01-01

247

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.

248

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

USGS Publications Warehouse

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

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

2014-01-01

249

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

PubMed

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

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

2014-05-15

250

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

251

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

252

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

253

Molecular mechanisms triggered by mercury.  

PubMed

Mercury is an ubiquitous environmental toxin that causes a wide range of adverse health effects in humans. Three forms of mercury exist: elemental, inorganic and organic. Each of them has its own profile of toxicity. Exposure to mercury typically occurs by inhalation or ingestion. Mercury can be an indoor air pollutant, however industry emission remains the most important source of inhaled mercury. Furthermore, fresh water and ocean fish may contain large amounts of mercury and dental amalgam can be another important source of inorganic and mercury vapor. The present review discusses the current information on mercury toxicity and the distinct toxicologic profile of the three forms of mercury. The existing therapeutics, new therapeutics development or agents for treating mercury poisoning will also discussed. Since in general low levels of mercurial are tolerable, herein, we also discuss the defensive mechanisms developed by the cell to protect itself against mercury injury. This aspect may be useful to provide a biological protection against toxic effects exerted by mercury or by specific forms of mercury in view of a medicinal purposes. PMID:18077077

Guzzi, GianPaolo; La Porta, Caterina A M

2008-02-01

254

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

255

Cloud point extraction and spectrophotometric determination of mercury species at trace levels in environmental samples.  

PubMed

A new micelle-mediated separation and preconcentration method was developed for ultra-trace quantities of mercury ions prior to spectrophotometric determination. The method is based on cloud point extraction (CPE) of Hg(II) ions with polyethylene glycol tert-octylphenyl ether (Triton X-114) in the presence of chelating agents such as 1-(2-pyridylazo)-2-naphthol (PAN) and 4-(2-thiazolylazo) resorcinol (TAR). Hg(II) ions react with both PAN and TAR in a surfactant solution yielding a hydrophobic complex at pH 9.0 and 8.0, respectively. The phase separation was accomplished by centrifugation for 5 min at 3500 rpm. The calibration graphs obtained from Hg(II)-PAN and Hg(II)-TAR complexes were linear in the concentration ranges of 10-1000 ?g L(-1) and 50-2500 ?g L(-1) with detection limits of 1.65 and 14.5 ?g L(-1), respectively. The relative standard deviations (RSDs) were 1.85% and 2.35% in determinations of 25 and 250 ?g L(-1) Hg(II), respectively. The interference effect of several ions were studied and seen commonly present ions in water samples had no significantly effect on determination of Hg(II). The developed methods were successfully applied to determine mercury concentrations in environmental water samples. The accuracy and validity of the proposed methods were tested by means of five replicate analyses of the certified standard materials such as QC Metal LL3 (VWR, drinking water) and IAEA W-4 (NIST, simulated fresh water). PMID:22265535

Ulusoy, Halil ?brahim; Gürkan, Ramazan; Ulusoy, Songül

2012-01-15

256

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

257

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

2010-02-01

258

Laboratory Protocol for Measuring the Bioaccumulation of Mercury by Earthworms  

NASA Astrophysics Data System (ADS)

Protocol was developed for a series of laboratory tests to determine if Canadian earthworms ( Lumbricus terrestris) can hyperaccumulate mercury from the soil in which they live. Two batches of 300 hundred worms each were measured for mercury uptake by establishing 3 populations (one control and two of known contamination). Populations were sampled every two weeks. Worm lengths were measured as an indicator of worm age and health. Worm tissue was processed by a modified EPA Method 7470 consisting of freeze drying, vacuum extraction, oxidation and acid extraction of the mercury. Each sample needed 2.000 g dry weight of worm tissue required 5 to 6 worms to be homogenized. Mercury concentration in the extraction fluid was measured by a CETAC M-6100 cold vapor mercury analyzer with an ASX-400 Autosampler having a method detection limit of 0.05 ppb. QA/QC activities such as calibration of instrumentation, spike samples, blank samples, reagent control samples, triplicate samples, and standard samples ensure acurate and precise measurements of mercury levels in tissue samples.

Steffy, D.; Nichols, A.; McLaughlin, A.

2007-12-01

259

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 ...

260

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...

261

Changes in brain monoamine levels and monoamine oxidase activity in the catfish, Clarias batrachus, during chronic treatments with mercurials  

SciTech Connect

In mammals, the central nervous system is the primary target for CH{sub 3}Hg poisoning which is clinically known as Minamata disease. Hg is a widely recognized neurotoxin and has been reported to impair brain monoamine neurotransmitter metabolism. Reports on effects of Hg on brain monoamine activity in fishes are scarce. In the present study, therefore, changes in the brain monoamine levels and the degradation enzyme, monoamine oxidase (MAO), are described in the catfish, Clarias batrachus, exposed to sublethal concentrations of mercuric chloride (HgCl{sub 2}-inorganic Hg), methylmercuric chloride (CH{sub 3}HgCl-organic Hg), and a commercial mercurial fungicide formulation, emisan 6 (methoxyethyl Hg-organic Hg) for 45, 90 and 180 d during gonadal recrudescence. These intervals correspond to late preparatory, prespawning and spawning phases, respectively, of the annual reproductive cycle of the catfish.

Kirubagaran, R.; Joy, K.P. (Banaras Hindu Univ., Varanasi (India))

1990-07-01

262

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

NASA Technical Reports Server (NTRS)

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

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

1998-01-01

263

Tissue levels, tissue angiotensin converting enzyme inhibition and antihypertensive effect of the novel antihypertensive agent alacepril in renal hypertensive rats.  

PubMed

Tissue levels, tissue angiotensin I converting enzyme (ACE) inhibition and hypotension were examined 20 min, 1, 5 and 14 h after oral administration of 1-[(S)-3-acetylthio-2-methylpropanoyl]-L-prolyl-L-phenylalanine (alacepril, DU-1219) (37.5 mg (92 mumol)/kg) or 1-[(S)-3-mercapto-2-methylpropanoyl]-L-proline (captopril) (20.0 mg (92 mumol)/kg) in renal hypertensive rats, using 14C-labeled compounds. Alacepril exerted a more gradual and more sustained antihypertensive effect than captopril. The maximal hypotension was observed 1 and 5 h after administration of captopril and alacepril, respectively. After administration of [14C]captopril, serum level reached the maximum at 20 min and then decreased rapidly. After administration of [14C]alacepril, serum level reached the maximum at 1 h and decreased more slowly than after [14C]captopril. Time course patterns of tissue levels were essentially in parallel with those of serum levels. Captopril exerted the maximal reduction of ACE activity in tissues 20 min after oral administration and thereafter, the reduction was diminished with time rapidly. [14C]Alacepril showed gradual reduction (the maximum at 1 h) and recovery of ACE activity relative to captopril. After oral administration of [14C]alacepril, tissue unbound fractions contained captopril and its derived metabolites while serum unbound fraction contained the intermediate metabolite desacetyl-alacepril (DU-1227) as well. Correlations between ACE inhibition and tissue levels and between changes in tissue ACE inhibition and in blood pressure with time after oral administration of the two agents were discussed. Furthermore, the direct comparison of alacepril and captopril was attempted by the difference in blood pressures and in ACE inhibitions induced after oral administration of the agents. PMID:3006710

Nambu, K; Matsumoto, K; Takeyama, K; Hosoki, K; Miyazaki, H; Hashimoto, M

1986-01-01

264

Changes in surface levels of mercury, silver, tin, and copper of dental amalgam treated with carbamide peroxide and hydrogen peroxide in vitro  

Microsoft Academic Search

Objectives. The effect of 10% carbamide peroxide or 10% hydrogen peroxide on the surface levels of mercury, silver, tin, and copper of amalgam fillings was tested in vitro with scanning electron microscopy and energy dispersive spectrometric microanalysis.Study design. Samples of amalgam were treated for 14 and 28 days with either 10% carbamide peroxide or 10% hydrogen peroxide solutions and compared

Ilan Rotstein; Chaim Mor; Joel R Arwaz

1997-01-01

265

Cutaneous mercury granuloma  

PubMed Central

Cutaneous mercury granuloma is rarely encountered. Clinically it may pose difficulty in diagnosis. Here, we report a 23-year-old male presented with erythematous, nodular lesions over the forearm and anterior aspect of chest wall. Metallic mercury in tissue sections appear as dark black, opaque, spherical globules of varying size and number. They are surrounded by granulomatous foreign-body reaction. It is composed of foreign body giant cells and mixed inflammatory infiltrate composed of histiocytes, lymphocytes, plasma cells, and few eosinophils.

Bothale, Kalpana A.; Mahore, Sadhana D.; Pande, Sushil; Dongre, Trupti

2013-01-01

266

Levels and distribution of polybrominated diphenyl ethers in various tissues of birds of prey  

Microsoft Academic Search

In the present study, concentrations and tissue distribution of polybrominated diphenyl ethers (PBDEs; IUPAC # 28, 47, 99, 100, 153, 154, 183, and 209) were examined in brain, adipose tissue, liver, muscle, and serum of birds of prey. Median ?PBDE levels (BDE 28–183) in the tissues of sparrowhawks ranged from 360 to 1900ng\\/g lipid weight (lw), which was in general

Stefan Voorspoels; Adrian Covaci; Peter Lepom; Veerle L. B. Jaspers; Paul Schepens

2006-01-01

267

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

268

Mercury elimination with oral DMPS, DMSA, vitamin C, and glutathione: an observational clinical review.  

PubMed

Tissue mercury levels in humans have increased during the past 50 years to an alarming concentration, with possible deleterious effects that may involve neurological, cardiovascular, and immunological pathology. This article reviews the protocol for the use of oral 2,3-dimercaptopropane-1-sulfonate (DMPS) and oral meso-2, 3-dimercaptosuccinic acid (DMSA) in combination with intravenous glutathione and high-dose vitamin C for treatment of high-level mercury. This protocol yielded an average 69% reduction of urine mercury by provocation analysis. PMID:16708769

Muran, Peter J

2006-01-01

269

Assessment of mercury toxicity by the changes in oxygen consumption and ion levels in the freshwater snail, Pila globosa, and the mussel, Lamellidens marginalis  

SciTech Connect

There are many studies on mercury toxicity in freshwater fishes but very few on freshwater molluscs (Wright 1978) though they serve as bio-indicators of metal pollution. A few reports on marine gastropods and bivalves indicated the importance of these animals in metal toxicity studies. Hence, in the present study, the level of tolerance of the freshwater gastropod Pila globosa and of a freshwater bivalve Lamellidens marginalis mercury at lethal and sublethal levels was determined and compared with the rate of whole animal oxygen consumption and the level of sodium, potassium and calcium ions in the hepatopancreas and the foot of these animals. As the period of exposure is one of the important factors in toxicity studies, the level of tolerance was determined at 120 hours of exposure and the other parameters were analyzed at 1, 3 and 5 days in lethal and at 1, 7 and 15 days in sublethal concentrations.

Sivaramakrishna, B.; Radhakrishnaiah, K.; Suresh, A. (Sri Krishnadevaraya Univ., Andhra Pradesh (India))

1991-06-01

270

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

271

Regulation of tissue oxygen levels in the mammalian lens  

PubMed Central

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 (Q?O2) 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 Q?O2 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 × 10?5 cm2 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 Q?O2 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.

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

2004-01-01

272

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

2012-02-01

273

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

PubMed

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

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

2010-01-15

274

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

SciTech Connect

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

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

2004-08-15

275

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

276

Lipid levels in serum and cancerous tissues of colorectal cancer patients  

PubMed Central

AIM: To investigate the correlations between lipid metabolism disorder and the occurrence and development of colorectal cancer by monitoring the alterations in lipid levels in cancerous tissue and serum in patients with colorectal cancer. METHODS: The levels of total and free cholesterol (TCH and FCH), triglycerides (TG), low density lipoprotein-cholesterol (LDL-C), high density lipoprotein- cholesterol (HDL-C), apolipoprotein A1 (ApoA-1) and ApoB in serum of 206 patients with colorectal cancer, 70 patients with benign colorectal disease and 300 healthy participants, and in the cancerous tissue and paracancerous tissue of 152 patients with colorectal cancer were measured with an Olympus 600 auto-biochemical analyzer. The obtained data were statistically analyzed. RESULTS: Serum FCH level was significantly higher (1.9 ± 0.4 mmol/L vs 1.3 ± 0.3 mmol/L, 1.9 ± 0.4 mmol/L vs 1.2 ± 0.4 mmol/L, P < 0.05), whereas serum levels of TCH, LDL-C, ApoA-I and ApoB were significantly lower in patients with colorectal cancer than in patients with benign colorectal disease and healthy controls. The levels of FCH and TG in cancerous tissue were significantly lower (14.5 ± 9.6 ?mol/g vs 19.3 ± 13.9 ?mol/g, P < 0.05; 16.3 ± 19.8 ?mol/g vs 44.1 ± 38.1 ?mol/g, P < 0.05), whereas HDL-C level was significantly higher (7.9 ± 4.5 ?mol/g vs 5.7 ± 3.9 ?mol/g, P < 0.01) in cancerous tissue than in paracancerous tissue. The levels of TCH and TG in serum and the levels of TCH and HDL-C in cancerous tissue in patients with colorectal cancer were significantly correlated with TNM stage. The levels of TCH and LDL-C in serum were significantly lower, whereas HDL-C level in cancerous tissue was significantly higher in patients with lymph node metastasis than in patients without lymph node metastasis. The levels of TCH, FCH, TG, HDL-C and LDL-C in cancerous tissue were not significantly different from those in paracancerous tissue. The serum levels of FCH and TG were significantly higher, whereas serum HDL-C levels were significantly lower in patients with rectum cancer than in patients with colon cancer. CONCLUSION: The disordered and abnormally altered levels of lipids in cancerous tissue and serum of patients with colorectal cancer may be correlated with the occurrence and development of colorectal cancer.

Zhang, Xin; Zhao, Xian-Wen; Liu, Dong-Bo; Han, Cun-Zhi; Du, Li-Li; Jing, Jie-Xiang; Wang, Yan

2014-01-01

277

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.

278

Predicting mercury in mallard ducklings from mercury in chorioallantoic membranes  

USGS Publications Warehouse

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

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

2003-01-01

279

Early molecular-level changes in rat bladder wall tissue following spinal cord injury  

Microsoft Academic Search

Previously, we demonstrated using a rat model of spinal cord injury (SCI) that bladder wall tissue compliance significantly increased within the first 2 weeks following injury. In order to explore the potential molecular-level mechanisms of this event, the present study quantified molecules pertinent to bladder tissue remodeling and changes in mechanical properties. An initial gene array analysis followed by real-time

Jiro Nagatomi; Fernando DeMiguel; Kazumasa Torimoto; Michael B. Chancellor; Robert H. Getzenberg; Michael S. Sacks

2005-01-01

280

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

EPA Science Inventory

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

281

Predicting bone remodeling around tissue- and bone-level dental implants used in reduced bone width.  

PubMed

The objective of this study was to predict time-dependent bone remodeling around tissue- and bone-level dental implants used in patients with reduced bone width. The remodeling of bone around titanium tissue-level, and titanium and titanium-zirconium alloy bone-level implants was studied under 100 N oblique load for one month by implementing the Stanford theory into three-dimensional finite element models. Maximum principal stress, minimum principal stress, and strain energy density in peri-implant bone and displacement in x- and y- axes of the implant were evaluated. Maximum and minimum principal stresses around tissue-level implant were higher than bone-level implants and both bone-level implants experienced comparable stresses. Total strain energy density in bone around titanium implants slightly decreased during the first two weeks of loading followed by a recovery, and the titanium-zirconium implant showed minor changes in the axial plane. Total strain energy density changes in the loading and contralateral sides were higher in tissue-level implant than other implants in the cortical bone at the horizontal plane. The displacement values of the implants were almost constant over time. Tissue-level implants were associated with higher stresses than bone-level implants. The time-dependent biomechanical outcome of titanium-zirconium alloy bone-level implant was comparable to the titanium implant. PMID:23876712

Eser, Atilim; Tonuk, Ergin; Akca, Kivanc; Dard, Michel M; Cehreli, Murat Cavit

2013-09-01

282

Epicardial adipose tissue adiponectin expression is related to intracoronary adiponectin levels.  

PubMed

The role of adiponectin and epicardial adipose tissue in coronary artery disease (CAD) is a subject of debate. Whether plasma adiponectin concentration in the coronary circulation is locally modulated by the epicardial fat is still unexplored. We evaluated the hypothesis whether intracoronary plasma adiponectin levels are related to adiponectin expression in epicardial adipose tissue in vivo in patients with CAD and without CAD (non-CAD). We examined 12 patients with CAD who required CABG and 10 patients with non-CAD who underwent cardiac surgery for valve replacement. Plasma levels of adiponectin were measured in peripheral vein circulation and in left coronary artery (LCA) during coronary angiography. Epicardial adipose tissue biopsy for adiponectin protein extraction was performed during cardiac surgery in both CAD and non-CAD subjects. Adiponectin protein expression in epicardial adipose tissue was lower in patients with CAD than in those with non-CAD (0.45+/-0.4 vs. 1.1+/-1.0, p<0.05). LCA plasma adiponectin levels significantly correlated with epicardial adipose tissue adiponectin protein expression (r=0.68, p=0.02) in all subjects. Peripheral adiponectin levels and epicardial fat adiponectin protein expression were the best correlates of LCA adiponectin, r (2)=0.49, p<0.01, p<0.05, respectively). Our study showed that intracoronary adiponectin levels reflect systemic adiponectin levels. Epicardial adipose tissue could partially contribute to adiponectin levels in the coronary circulation. PMID:19003726

Iacobellis, G; di Gioia, Cira Rosaria Tiziana; di Gioia, C R Tiziana; Cotesta, D; Petramala, L; Travaglini, C; De Santis, V; Vitale, D; Tritapepe, L; Letizia, C

2009-03-01

283

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

Microsoft Academic Search

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

Stephanie E. Duvall; Mace G. Barron

2000-01-01

284

A femtogram level competitive immunoassay of mercury(ii) based on surface-enhanced Raman spectroscopy.  

PubMed

A femtogram level and specific surface enhanced Raman spectroscopy (SERS) based competitive immunoassay was developed to detect Hg(ii) in aqueous solution for the first time. This novel approach provides an alternative, ultrasensitive and specific analytical method for the detection of Hg(ii). PMID:24986447

Wang, Yuzhen; Chen, Shuai; Wei, Chao; Xu, Minmin; Yao, Jianlin; Li, Yuan; Deng, Anping; Gu, Renao

2014-07-17

285

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

286

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

NASA Astrophysics Data System (ADS)

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

Langner, H.

2011-12-01

287

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

NASA Astrophysics Data System (ADS)

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

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

288

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)] [Universita di Siena (Italy)

1996-12-31

289

Mercury residues in wood ducks and wood duck foods in eastern Tennessee.  

PubMed

Liver, breast muscle and body fat from 50 juvenile and five adult wood ducks (Aix sponsa) collected on the Holston River, Tennessee were analyzed for total mercury content. Black fly larvae (Simulium vittatum) sago pondweed (Potamogeton pectinatus), tapegrass (Vallisneria americanus), water stargrass (Heteranthera dubia), Elodea canadensis, and river bottom sediments were also analyzed to elucidate the distribution of mercury in the wood duck's environment. Liver tissues of juveniles contained the highest mean concentration of mercury (0.42 ppm). Mercury in breast muscle and body fat of juveniles averaged 0.15 and 0.10 ppm, respectively. Residues in corresponding tissues of adults were lower. Of environmental components tested, sediments had the highest mean concentration (0.76 ppm). Black fly larvae and aquatic plants had mean levels below 0.10 ppm. PMID:6887432

Lindsay, R C; Dimmick, R W

1983-04-01

290

Mercury(II) and methyl mercury speciation on Streptococcus pyogenes loaded Dowex Optipore SD2  

Microsoft Academic Search

A solid phase extraction procedure based on speciation of mercury(II) and methyl mercury on Streptococcus pyogenes immobilized on Dowex Optipore SD-2 has been established. Selective and sequential elution with 0.1molL?1 HCl for methyl mercury and 2molL?1 HCl for mercury(II) were performed at pH 8. The determination of mercury levels was performed by cold vapour atomic absorption spectrometry (CVAAS). Optimal analytical

Mustafa Tuzen; Ozgur Dogan Uluozlu; Isa Karaman; Mustafa Soylak

2009-01-01

291

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

292

Phytoremediation of ionic and methyl mercury pollution  

SciTech Connect

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

Meagher, R.B.

1998-06-01

293

Implication of Low Level Inflammation in the Insulin Resistance of Adipose Tissue at Late Pregnancy  

PubMed Central

Insulin resistance is a characteristic of late pregnancy, and adipose tissue is one of the tissues that most actively contributes to the reduced maternal insulin sensitivity. There is evidence that pregnancy is a condition of moderate inflammation, although the physiological role of this low-grade inflammation remains unclear. The present study was designed to validate whether low-grade inflammation plays a role in the development of insulin resistance in adipose tissue during late pregnancy. To this end, we analyzed proinflammatory adipokines and kinases in lumbar adipose tissue of nonpregnant and late pregnant rats at d 18 and 20 of gestation. We found that circulating and tissue levels of adipokines, such as IL-1?, plasminogen activator inhibitor-1, and TNF-?, were increased at late pregnancy, which correlated with insulin resistance. The observed increase in adipokines coincided with an enhanced activation of p38 MAPK in adipose tissue. Treatment of pregnant rats with the p38 MAPK inhibitor SB 202190 increased insulin-stimulated tyrosine phosphorylation of the insulin receptor (IR) and IR substrate-1 in adipose tissue, which was paralleled by a reduction of IR substrate-1 serine phosphorylation and an enhancement of the metabolic actions of insulin. These results indicate that activation of p38 MAPK in adipose tissue contributes to adipose tissue insulin resistance at late pregnancy. Furthermore, the results of the present study support the hypothesis that physiological low-grade inflammation in the maternal organism is relevant to the development of pregnancy-associated insulin resistance.

de Castro, J.; Sevillano, J.; Marciniak, J.; Rodriguez, R.; Gonzalez-Martin, C.; Viana, M.; Eun-suk, O. H.; de Mouzon, S. Hauguel; Herrera, E.

2011-01-01

294

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

PubMed

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

DesGranges; Rodrigue; Tardif; Laperle

1998-08-01

295

THERMODYNAMIC REACTION CONSTANTS FOR MODELING AQUEOUS ENVIRONMENTAL MERCURY SPECIATION  

EPA Science Inventory

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

296

Cutaneous mercury granuloma.  

PubMed

Cutaneous mercury granuloma is rarely encountered. Clinically it may pose difficulty in diagnosis. Here, we report a 23-year-old male presented with erythematous, nodular lesions over the forearm and anterior aspect of chest wall. Metallic mercury in tissue sections appear as dark black, opaque, spherical globules of varying size and number. They are surrounded by granulomatous foreign-body reaction. It is composed of foreign body giant cells and mixed inflammatory infiltrate composed of histiocytes, lymphocytes, plasma cells, and few eosinophils. PMID:24082644

Bothale, Kalpana A; Mahore, Sadhana D; Pande, Sushil; Dongre, Trupti

2013-01-01

297

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

Microsoft Academic Search

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

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

2006-01-01

298

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

NASA Technical Reports Server (NTRS)

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

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

1976-01-01

299

Determination of extracellular methotrexate tissue levels by microdialysis in a rat model  

Microsoft Academic Search

We used a microdialysis technique to determine tissue methotrexate (MTX) levels during steady state in a rodent model. Two\\u000a different approaches were employed to measure the actual extracellular MTX concentrations in muscle, liver, and kidney tissues\\u000a of anesthetized Wistar rats. With the reduced-perfusionrate technique, the flow in the microdialysis perfusate was gradually\\u000a decreased toward zero to permit calculation of zero-flow

Per O. Ekstrřm; Anders Andersen; David J. Warren; Karl E. Giercksky; Lars Slřrdal

1996-01-01

300

Historical and other patterns of monomethyl and inorganic mercury in the Florida panther (Puma concolor coryi).  

PubMed

Since the late 1980s, elevated levels of mercury have been reported in the tissues of the Florida panther (Puma concolor coryi) from the Florida Everglades. The extent, degree, and length of time of mercury contamination in the Florida panther are unknown. The objective of this study was to determine the historical and other patterns of monomethyl and inorganic mercury in the Florida panther by analysis of mercury in panther hair from museum collections. In addition, this study evaluated the effects of preservation of skins on mercury concentrations in hair and the representativeness of museum collections for evaluating historical trends of contamination in the Florida panther. Hair from 42 Florida panther specimens collected from 1896 to 1995 was analyzed for both monomethyl and inorganic mercury. Monomethyl mercury (MMHg) and inorganic mercury (IHg) were found in all specimens. Monomethyl mercury in hair from untanned skins was significantly higher than MMHg in hair from tanned skins. For untanned specimens, the mean MMHg concentration in hair was 1.62 +/- 1.87 mug/g (range 0.11 to 6.68 mug/g, n = 16). Monomethyl mercury accounted for 88% of the total mercury in untanned Florida panther hair. No sexual or geographical differences were found. Although MMHg is generally stable in hair, the tanning process appears to reduce the amount of MMHg in hair. In addition, exogenous IHg contamination of the panther hair was found in museum specimens, especially in older specimens. The implication of these and other factors in interpreting results of museum studies is discussed. The presence of MMHg in panther hair since the 1890s indicates long-term and widespread exposure of the Florida panther to mercury. Levels of MMHg are significantly greater in the 1990s than the 1890s. When combined with field studies of mercury in the Florida panther, considerable individual variability is observed, reflecting short-term changes in exposure of individual panthers to mercury. Although museum specimens showed a significant increase in MMHg over the last 100 years, they did not show the magnitude of increase that field populations of Florida panthers did. A number of Florida panthers appeared to be at risk from mercury over their lifetimes, especially individuals from the early 1990s. PMID:15657808

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

2005-01-01

301

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

PubMed

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

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

2013-01-01

302

Light dosimetry for low-level laser therapy: accounting for differences in tissue and depth  

NASA Astrophysics Data System (ADS)

While Low-level Light Therapy (LLLT) has demonstrated efficacy for certain indications, some aspects of the technology are still controversial. Clinical studies on LLLT range from low quality anecdotal studies to blinded, randomized, control clinical studies. These have used a variety of wavelengths, optical powers and variations in other laser parameters. While these studies show a large range in treatment outcome, comparison of treatment efficacy between these studies with respect to light dose is all but impossible since the light dose characterization in the LLLT field has not been properly defined and is not standardized. Surface irradiance is typically used in the LLLT field as the light dose parameter, ignoring factors such as tissue optical properties, beam divergence, pulsing of the source and tissue thickness to the organ or joint of interest. Drawing on experience with light dosimetry for photodynamic and photothermal therapy, we will provide an overview of light transport and dosimetry in tissue and its implications for LLLT dosimetry. In particular, we suggest that the proper measure of dose is the light fluence rate delivered to the organ or tissue of interest, usually several millimeters below the tissue surface. We have developed a technique that provides an estimate of the subsurface fluence rate based on the diffuse reflectance measured at the tissue surface. Using Monte Carlo simulations and measurements on tissue simulating phantoms, we demonstrate that this technique can be used to predict the subsurface fluence rate to within 30% of the actual value at 3-10 mm below the tissue surface.

Weersink, Robert; White, Roger; Lilge, Lothar

2007-03-01

303

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

PubMed

Chinese mitten crabs (Eriocheir sinensis), endemic to Asia, were first reported in the San Francisco Bay in 1992. They are now established in nearly all San Francisco Bay tributaries. These crabs accumulate more metals, such as mercury, than crustaceans living in the water column. Because their predators include fish, birds, mammals and humans, their mercury burdens have an exceptional potential to impact the ecosystem and public health. We sought to elucidate the potential threat of mitten crab mercury burdens in three adjacent streams in southern San Francisco Bay, one of which is known to be contaminated with mercury. Mitten crabs had hepatopancreas concentrations of total mercury and methylmercury that did not differ among streams. The maximum burden we measured was below the action level of 1 ppm recommended by the USEPA. Hepatopancreas concentrations of methylmercury declined with increasing crab size, suggesting a mechanism for mercury excretion and that predators might reduce mercury exposure if they select larger crabs. Because mercury may be heterogeneously distributed among tissues, estimation of the impacts of crab mercury burdens on the environment requires more data on the feeding preferences of predators. PMID:15519723

Hui, Clifford A; Rudnick, Deborah; Williams, Erin

2005-02-01

304

Mercury vapor determination in hospitals.  

PubMed

The measurements of metallic mercury vapor were carried out in seven local hospitals, where mercury-containing products are widely used, as well as in one residence to check effectiveness of decontamination after mercury spillage. Hopcalite as a solid sorbent was used in active and passive sampling methods, and mercury was analyzed by CV-AAS technique. Good agreement was found between results of mercury measurements using active samplers (pumped hopcalite adsorption tubes) and passive (diffusion) monitors applied in indoor atmosphere. The results indicated the presence of metallic mercury vaporization sources in the assessed hospital rooms but in the majority of cases mercury levels did not exceed 1 microg/m3 i.e. Polish permissible concentration for residence. However, in some of the hospital rooms, elevated concentrations of mercury vapor were found and airborne levels of up to 13.9 microg/m3 were recorded. Higher concentrations of mercury vapor were observed in autumn season when compared to summer. PMID:15931983

Prokopowicz, Adam; Mniszek, Wojciech

2005-05-01

305

Mercury distribution in organs of two species of fish from Amazon region.  

PubMed

Total mercury concentrations were determined in muscle, liver and kidney of Cichlia ocellaris and Colossoma macropomum sampled at Tapajos and Carnapijo Rivers in Amazon ecosystem during the flood period of 2009. In background area the highest levels of mercury were observed in liver of piscivorous (0.3 ± 0.03 ug/g dry wt) and non piscivorous fish (0.20 ± 0.1 ug/g dry wt), but in contaminated area the highest level of mercury in piscivorous fish was detected in liver (0.45 ± 0.27 ug/g dry wt) and in muscle (0.26 ± 0.05 ug/g dry wt) of non piscivorous fish. These results suggested that the presence of anthropogenic source plays a key role in the pattern of mercury distribution in fish tissues. PMID:21874404

Vieira, J L F; Gomes, A L S; Santos, J P N; Lima, T C D; Freitas, J A; Pinheiro, M C N

2011-10-01

306

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

EPA Science Inventory

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

307

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

SciTech Connect

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

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

1991-03-15

308

Mercury CEM Calibration  

SciTech Connect

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

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

2007-03-31

309

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

PubMed

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 microg/kg wet weight were found in liver samples taken from cattle and domestic fowl, respectively. Significantly higher mercury concentrations were found in liver samples collected at mining villages (p<0.05) than those taken from the reference area. While mercury concentrations in liver samples exceeded the acceptable maximum concentrations for humans set in the Netherlands and Poland, the Hg concentrations in muscle were below the limits of most countries. It is recommended that the keeping of freely grazing cattle and domestic fowl in or around artisanal gold mines should be avoided. PMID:19798780

Chibunda, R T; Janssen, C R

2009-11-01

310

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

PubMed Central

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

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

2009-01-01

311

Tissue-specific variation in DNA methylation levels along human chromosome 1  

PubMed Central

Background DNA methylation is a major epigenetic modification important for regulating gene expression and suppressing spurious transcription. Most methods to scan the genome in different tissues for differentially methylated sites have focused on the methylation of CpGs in CpG islands, which are concentrations of CpGs often associated with gene promoters. Results Here, we use a methylation profiling strategy that is predominantly responsive to methylation differences outside of CpG islands. The method compares the yield from two samples of size-selected fragments generated by a methylation-sensitive restriction enzyme. We then profile nine different normal tissues from two human donors relative to spleen using a custom array of genomic clones covering the euchromatic portion of human chromosome 1 and representing 8% of the human genome. We observe gross regional differences in methylation states across chromosome 1 between tissues from the same individual, with the most striking differences detected in the comparison of cerebellum and spleen. Profiles of the same tissue from different donors are strikingly similar, as are the profiles of different lobes of the brain. Comparing our results with published gene expression levels, we find that clones exhibiting extreme ratios reflecting low relative methylation are statistically enriched for genes with high expression ratios, and vice versa, in most pairs of tissues examined. Conclusion The varied patterns of methylation differences detected between tissues by our methylation profiling method reinforce the potential functional significance of regional differences in methylation levels outside of CpG islands.

De Bustos, Cecilia; Ramos, Edward; Young, Janet M; Tran, Robert K; Menzel, Uwe; Langford, Cordelia F; Eichler, Evan E; Hsu, Li; Henikoff, Steve; Dumanski, Jan P; Trask, Barbara J

2009-01-01

312

Mercury Contamination in Costa Rica  

Microsoft Academic Search

Mercury is a potent neurotoxin and a particularly formidable environmental contaminant. Mercury is present in the environment largely as a result of modern industrial emissions as well as ‘legacy-Hg’ from past contamination; however, some areas have high natural background levels also, largely from volcanic and geothermal sources. Recent work suggested that Costa Rica airshed may be highly contaminated with natural

Audrey Fitzgerald Haynes

2012-01-01

313

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.

Meagher, Richard B.

2005-06-01

314

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

SciTech Connect

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

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

2013-01-01

315

N-Palmitoylethanolamine depot injection increased its tissue levels and those of other acylethanolamide lipids  

PubMed Central

N-Palmitoylethanolamine (NAE 16:0) is an endogenous lipid signaling molecule that has limited water solubility, and its action is short-lived due to its rapid metabolism. This poses a problem for use in vivo as oral administration requires a high concentration for significant levels to reach target tissues, and injection of the compound in a dimethyl sulfoxide- or ethanol-based vehicle is usually not desirable during long-term treatment. A depot injection of NAE 16:0 was successfully emulsified in sterile corn oil (10 mg/kg) and administered in young DBA/2 mice in order to elevate baseline levels of NAE 16:0 in target tissues. NAE 16:0 levels were increased in various tissues, particularly in the retina, 24 and 48 hours following injections. Increases ranged between 22% and 215% (above basal levels) in blood serum, heart, brain, and retina and induced an entourage effect by increasing levels of other 18 carbon N-Acylethanolamines (NAEs), which ranged between 31% and 117% above baseline. These results indicate that NAE 16:0 can be used as a depot preparation, avoiding the use of inadequate vehicles, and can provide the basis for designing tissue-specific dosing regimens for therapies involving NAEs and related compounds.

Grillo, Stephanie L; Keereetaweep, Jantana; Grillo, Michael A; Chapman, Kent D; Koulen, Peter

2013-01-01

316

N-Palmitoylethanolamine depot injection increased its tissue levels and those of other acylethanolamide lipids.  

PubMed

N-Palmitoylethanolamine (NAE 16:0) is an endogenous lipid signaling molecule that has limited water solubility, and its action is short-lived due to its rapid metabolism. This poses a problem for use in vivo as oral administration requires a high concentration for significant levels to reach target tissues, and injection of the compound in a dimethyl sulfoxide- or ethanol-based vehicle is usually not desirable during long-term treatment. A depot injection of NAE 16:0 was successfully emulsified in sterile corn oil (10 mg/kg) and administered in young DBA/2 mice in order to elevate baseline levels of NAE 16:0 in target tissues. NAE 16:0 levels were increased in various tissues, particularly in the retina, 24 and 48 hours following injections. Increases ranged between 22% and 215% (above basal levels) in blood serum, heart, brain, and retina and induced an entourage effect by increasing levels of other 18 carbon N-Acylethanolamines (NAEs), which ranged between 31% and 117% above baseline. These results indicate that NAE 16:0 can be used as a depot preparation, avoiding the use of inadequate vehicles, and can provide the basis for designing tissue-specific dosing regimens for therapies involving NAEs and related compounds. PMID:23976843

Grillo, Stephanie L; Keereetaweep, Jantana; Grillo, Michael A; Chapman, Kent D; Koulen, Peter

2013-01-01

317

Levels of oxidized LDL, estrogens, and progesterone in placenta tissues and serum paraoxonase activity in preeclampsia.  

PubMed

In vitro literature studies have suggested that atherosclerotic oxidized low density lipoprotein (OxLDL) inhibits trophoblast invasion. The objective of this study was to determine the levels of OxLDL and to examine the relationship between antioxidative estradiol, estriol, and prooxidative progestin in normal and preeclamptic placental tissues and measure the serum activity of antioxidative paraoxonase (PON1). The study included 30 preeclamptic and 32 normal pregnant women. OxLDL was determined with ELISA, estradiol, unconjugated estriol, and progesterone that were determined with chemiluminescence method in placental tissues. Serum PON1 activity was determined with spectrophotometric method. Levels of OxLDL (P = 0.027), estriol (P < 0.001), estradiol (P = 0.008), and progesterone (P = 0.009) were lower in the placental tissues of preeclamptic group compared to the normal pregnant women. Serum PON1 activity was higher in preeclamptic group (P = 0.040) and preeclamptic group without intrauterine growth restriction (P = 0.008) compared to normal pregnant women. Tissue estriol of preeclamptic group without/with IUGR (P < 0.001, P = 0.002) was lower than the normal group. Results of our study suggest that the events leading to fetoplacental insufficiency lead to a reduction in the levels of estriol limit deposition of OxLDL in placental tissues. The serum PON1 activity is probably important in the inhibition of OxLDL in preeclampsia. PMID:23606795

Aç?kgöz, Serefden; Bayar, Ulkü Ozmen; Can, Murat; Güven, Berrak; Mungan, Görkem; Do?an, Suat; Sümbülo?lu, Vildan

2013-01-01

318

Levels of Oxidized LDL, Estrogens, and Progesterone in Placenta Tissues and Serum Paraoxonase Activity in Preeclampsia  

PubMed Central

In vitro literature studies have suggested that atherosclerotic oxidized low density lipoprotein (OxLDL) inhibits trophoblast invasion. The objective of this study was to determine the levels of OxLDL and to examine the relationship between antioxidative estradiol, estriol, and prooxidative progestin in normal and preeclamptic placental tissues and measure the serum activity of antioxidative paraoxonase (PON1). The study included 30 preeclamptic and 32 normal pregnant women. OxLDL was determined with ELISA, estradiol, unconjugated estriol, and progesterone that were determined with chemiluminescence method in placental tissues. Serum PON1 activity was determined with spectrophotometric method. Levels of OxLDL (P = 0.027), estriol (P < 0.001), estradiol (P = 0.008), and progesterone (P = 0.009) were lower in the placental tissues of preeclamptic group compared to the normal pregnant women. Serum PON1 activity was higher in preeclamptic group (P = 0.040) and preeclamptic group without intrauterine growth restriction (P = 0.008) compared to normal pregnant women. Tissue estriol of preeclamptic group without/with IUGR (P < 0.001, P = 0.002) was lower than the normal group. Results of our study suggest that the events leading to fetoplacental insufficiency lead to a reduction in the levels of estriol limit deposition of OxLDL in placental tissues. The serum PON1 activity is probably important in the inhibition of OxLDL in preeclampsia.

Ac?kgoz, Serefden; Ozmen Bayar, Ulku; Can, Murat; Guven, Berrak; Mungan, Gorkem; Dogan, Suat; Sumbuloglu, Vildan

2013-01-01

319

Relationship Between Localization of Gold Mining Areas and Hair Mercury Levels in People from Bolivar, North of Colombia  

Microsoft Academic Search

Mercury (Hg) is a heavy metal that, once in the environment, is bioaccumulated and biomagnified through food chain impacting\\u000a ecosystems. The aim of this study was to evaluate total Hg (T-Hg) concentrations in individuals along Cauca and Magdalena\\u000a Rivers in Colombia, where most gold mining activities take place. A total of 1,328 hair samples were collected and analyzed\\u000a for T-Hg

Jesús Olivero-Verbel; Karina Caballero-Gallardo; José Negrete-Marrugo

320

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

Microsoft Academic Search

.   Osprey (Pandion haliaetus) eggs and chick feathers were collected for mercury analysis from nests at four Great Lakes study areas in Ontario (three\\u000a “naturally formed” lakes in southern Ontario and one reservoir in northern Ontario) and two New Jersey study areas in 1991–1994.\\u000a Adult osprey feathers were sampled from three Great Lakes study areas in 1991. Feathers sampled from

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

1997-01-01

321

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

Microsoft Academic Search

Recent studies have shown that the complementary analysis of mercury (Hg) concentrations and stable isotopic ratios of nitrogen\\u000a (?15N) and carbon (?13C) can be useful for investigating the trophic influence on the Hg exposure and accumulation in marine top predators. In this\\u000a study, we propose to evaluate the interspecies variability of Hg concentrations in phocids from polar areas and to

Aurore Aubail; Jonas Teilmann; Rune Dietz; Frank Rigét; Tero Harkonen; Olle Karlsson; Aqqalu Rosing-Asvid; Florence Caurant

2011-01-01

322

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

PubMed Central

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

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

2012-01-01

323

Femtomole level photoelectrochemical aptasensing for mercury ions using quercetin-copper(II) complex as the DNA intercalator.  

PubMed

An ultrasensitive and selective photoelectrochemical (PEC) aptasensor for mercury ions was first fabricated based on perylene-3, 4, 9, 10-tetracarboxylic acid/graphene oxide (PTCA/GO) heterojunction using quercetin-copper(II) complex intercalated into the poly(dT)-poly(dA) duplexes. Both the PTCA/GO heterojunction and the quercetin-copper(II) complex are in favor of the sensitivity for the fabricated PEC aptasensor due to band alignment and strong reduction capability, respectively. And they efficiently promote the separation of photoexcited carriers and enhance the photocurrent. The formation of thymine-Hg(2+)-thymine coordination chemistry resulted in the dehybridization of poly(dT)-poly(dA) duplexes and then the intercalator quercetin-copper(II) complex broke away from the surface of the PEC aptasensor. As the concentration of mercury ions increased, the photocurrent gradually decreased. The electrode response for mercury ions detection was in the linear range from 0.01 pmol L(-1) to 1.00 pmol L(-1) with the detection limit of 3.33 fmol L(-1). The label-free PEC aptasensor has excellent performances with ultrasensitivity and good selectivity besides the advantage of economic and facile fabrication. The strategy of quercetin-copper(II) complex as a novel DNA intercalator paves a new way to improve the performances for PEC sensors. PMID:24291750

Li, Hongbo; Xue, Yan; Wang, Wei

2014-04-15

324

Renal and Neurologic Effects of Cadmium, Lead, Mercury, and Arsenic in Children: Evidence of Early Effects and Multiple Interactions at Environmental Exposure Levels  

PubMed Central

Lead, cadmium, mercury, and arsenic are common environmental pollutants in industrialized countries, but their combined impact on children’s health is little known. We studied their effects on two main targets, the renal and dopaminergic systems, in > 800 children during a cross-sectional European survey. Control and exposed children were recruited from those living around historical nonferrous smelters in France, the Czech Republic, and Poland. Children provided blood and urine samples for the determination of the metals and sensitive renal or neurologic biomarkers. Serum concentrations of creatinine, cystatin C, and ?2-microglobulin were negatively correlated with blood lead levels (PbB), suggesting an early renal hyperfiltration that averaged 7% in the upper quartile of PbB levels (> 55 ?g/L; mean, 78.4 ?g/L). The urinary excretion of retinol-binding protein, Clara cell protein, and N-acetyl-?-d-glucosaminidase was associated mainly with cadmium levels in blood or urine and with urinary mercury. All four metals influenced the dopaminergic markers serum prolactin and urinary homovanillic acid, with complex interactions brought to light. Heavy metals polluting the environment can cause subtle effects on children’s renal and dopaminergic systems without clear evidence of a threshold, which reinforces the need to control and regulate potential sources of contamination by heavy metals.

de Burbure, Claire; Buchet, Jean-Pierre; Leroyer, Ariane; Nisse, Catherine; Haguenoer, Jean-Marie; Mutti, Antonio; Smerhovsky, Zdenek; Cikrt, Miroslav; Trzcinka-Ochocka, Malgorzata; Razniewska, Grazyna; Jakubowski, Marek; Bernard, Alfred

2006-01-01

325

Inorganic and methylmercury levels in plasma are differentially associated with age, gender, and oxidative stress markers in a population exposed to mercury through fish consumption.  

PubMed

This study aimed to determine the concentrations of plasma methylmercury (Me-Hg) and inorganic mercury (I-Hg) in a population exposed to Me-Hg. In addition, associations between each form of mercury (Hg) and gender, age, plasma selenium (Se), and oxidative stress markers were also investigated. The mean plasma I-Hg level was 5.7 ?g/L while the mean for plasma Me-Hg was 3.6 ?g/L, representing approximately 59 and 41% of the total Hg in blood, respectively. However, several plasma samples contained higher percentages of Me-Hg. Age displayed a direct linkage with plasma I-Hg levels, whereas gender did not correlate with any of the Hg species. In addition, fish intake was only correlated with and a predictor of plasma Me-Hg, suggesting that plasma I-Hg levels originated endogenously through a demethylation reaction that needs to be verified. Further, plasma Me-Hg was markedly correlated with adverse effects to a greater extent than plasma I-Hg and may be considered a valuable, reliable internal dose biomarker for Hg in chronically Me-Hg- exposed individuals. PMID:24555648

Carneiro, Maria Fernanda Hornos; Grotto, Denise; Barbosa, Fernando

2014-01-01

326

Effects of Magnesium Sulfate on Tissue Lactate and Malondialdehyde Levels after Cerebral Ischemia  

Microsoft Academic Search

In the present study, the effects of magnesium sulfate on tissue lactate and malondialdehyde (MDA) levels after cerebral ischemia in rabbits were studied. The rabbits were divided equally into three groups. Group 1 (n = 8) was the sham-operated control group, in group 2 (n = 8) only cerebral ischemia was induced by clamping bilaterally the common carotid arteries for

H. Bariskaner; M. E. Ustun; A. Ak; A. Yosunkaya; H. B. Ulusoy; M. Gurbilek

2003-01-01

327

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

PubMed Central

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

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

1995-01-01

328

PLASMA KINETICS, EXCRETION IN MILK AND TISSUE LEVELS IN THE COW FOLLOWING IMPLANTATION OF TRENBOLONE ACETATE  

Microsoft Academic Search

SUMMARY The plasma kinetics of biologically stable tritiated trenbolone acetate have been studied in the barren, dry and in the lactating dairy cow following a single intravenous injection and implantation. The excretion of the compound in milk has been investigated. Tissue levels were measured 3 or 5 months following implanta- tion. The ester function is hydrolysed rapidly to yield the

J. Pottier; M. Busigny; J. A. Grandadam

2010-01-01

329

Aldolase A isoenzyme levels in serum and tissues of patients with liver diseases  

SciTech Connect

A radioimmunoassay specific for human aldolase A was used to measure human aldolase A levels in human tissue and serum of patients with various liver diseases. The method was a double-antibody technique using radio-iodinated purified aldolase A, chicken antibody to aldolase A, and rabbit antibody to chicken immunoglobulin G. Normal liver tissue contains only a small amount of aldolase A. In contrast, aldolase A predominates in liver cell carcinoma tissue. Aldolase A levels in the sera of normal subjects were 171 +/- 39 ng/ml (mean +/- 2 SD). In almost all of the nonmalignant liver diseases, the aldolase A levels remained less than 210 ng/ml. The serum aldolase A levels increased remarkable only in fulminant hepatitis. in contrast, 32 of 34 patients with liver cell carcinoma and all of 29 patients with metastatic liver carcinoma showed clearly increased serum aldolase A levels. More patients with primary liver cell carcinoma had increased serum aldolase A levels than elevations of serum alpha-fetoprotein. These results suggest that the determination of aldolase A by radioimmunoassay may be useful to differentiate malignant form nonmalignant liver diseases.

Asaka, M.; Nagase, K.; Miyazaki, T.; Alpert, E.

1983-01-01

330

Elemental mercury exposure among children of thermometer plant workers  

SciTech Connect

Because evidence of mercury exposure was found among workers of a mercury thermometer-manufacturing plant in March 1984, the Vermont Department of Health studied the workers' children for both exposure to mercury and evidence of mercury toxicity. The median urine mercury level of 23 workers' children was 25 micrograms/L. This was significantly higher than the level (5 micrograms/L) among 39 children randomly selected from nonworkers' households in the same community (P less than .001). Mercury-in-air levels measured in workers' homes were higher than those measured in control homes. A significant correlation was found between the urine mercury levels of the workers' children and the urine mercury levels of their working parents. No child had frank mercury toxicity. No evidence of neurologic toxicity among exposed children was discovered by a pediatric neurologist who examined these and unexposed children without knowledge of their exposure status. This is the first report demonstrating mercury exposure in children of mercury workers. Although toxic effects of mercury were not demonstrated at these levels of exposure, children of mercury workers are at risk for mercury exposure and potential mercury toxicity.

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

1987-06-01

331

Cadmium, zinc, copper, arsenic, selenium and mercury in seabirds from the Barents Sea: levels, inter-specific and geographical differences.  

PubMed

Trace elements Cd, Zn, Cu, As, Se and Hg were analysed in muscle and liver of Brünnich's guillemot, Common guillemot, Puffin, Black guillemot, Little auk, Razorbill, Common eider, King eider, Glaucous gull, Herring gull, Black-legged kittiwake, Northern fulmar and Arctic tern collected in 1991-1992 at the main breeding colonies in the Barents Sea. The highest levels of the most toxic elements Cd and Hg were found in birds nesting north of Spitsbergen. Extremely high levels of As were detected in tissues of all seabird species collected at colonies in Chernaya Guba (Novaya Zemlya), where nuclear tests were carried out in the 1960s. In general, levels of all of the trace elements in the Barents Sea seabirds were similar or lower in comparison with those reported for the same seabird species from the other Arctic areas. Data on metallothionein concentrations in different seabird species need to be collected in order to understand the mechanism of bioaccumulation and possible toxic effects of trace elements in Arctic seabirds. PMID:12699923

Savinov, Vladimir M; Gabrielsen, Geir W; Savinova, Tatiana N

2003-05-01

332

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

PubMed

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

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

2013-11-01

333

TISSUE-TO-CELLULAR LEVEL DEFORMATION COUPLING IN CELL-MICROINTEGRATED ELASTOMERIC SCAFFOLDS  

PubMed Central

In engineered tissues we are challenged to reproduce extracellular matrix and cellular deformation coupling that occurs within native tissues, which is a meso-micro scale phenomenon that profoundly affects tissue growth and remodeling. With our ability to electrospin polymer fiber scaffolds while simultaneously electrospraying viable cells, we are provided with a unique platform to investigate cellular deformations within a three dimensional elastomeric fibrous scaffold. Scaffold specimens micro-integrated with vascular smooth muscle cells were subjected to controlled biaxial stretch with 3D cellular deformations and local fiber micro-architecture simultaneously quantified. We demonstrated that the local fiber geometry followed an affine behavior, so that it could be predicted by macro scaffold deformations. However, local cellular deformations depended non-linearly on changes in fiber microarchitecture and ceased at large strains where the scaffold fibers completely straightened. Thus, local scaffold microstructural changes induced by macro-level applied strain dominated cellular deformations, so that monotonic increases in scaffold strain do not necessitate similar levels of cellular deformation. This result has fundamental implications when attempting to elucidate the events of de-novo tissue development and remodeling in engineered tissues, which are thought to depend substantially on cellular deformations.

Stella, John A.; Liao, Jun; Hong, Yi; Merryman, W. David; Wagner, William R.; Sacks, Michael S.

2008-01-01

334

Mercury CEM Calibration  

SciTech Connect

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

John Schabron; Joseph Rovani; Mark Sanderson

2008-02-29

335

Prognostic value of tissue and circulating levels of IMP3 in prostate cancer.  

PubMed

Tissue levels of the oncofetal protein insulin-like growth factor 2 (IGF2) messenger RNA-binding protein 3 (IMP3) have been associated with poor prognosis in multiple human malignancies. However, its circulating levels have not yet been analyzed. Therefore, the aim of this study was to assess the prognostic value of both serum and tissue levels of IMP3 in prostate cancer (PC). IMP3 protein expression was analyzed in 124 PC and 13 benign prostate hyperplasia (BPH) patients using immunohistochemistry. Gene expression levels of IMP3 and its molecular target IGF2 were analyzed in 29 frozen and 26 paraffin-embedded PC tissues using real-time polymerase chain reaction and immunohistochemistry. Serum IMP3 levels were assessed in 94 PC and 20 BPH patients as well as in 20 controls using enzyme-linked immunosorbent assay. IMP3 immunostaining was present in 0% (0/13) of BPHs, 15% (15/101) of clinically localized PCs and 65% (15/23) of palliatively treated metastatic PCs (p?levels were independently associated with poor cancer-specific survival. IMP3 gene and protein expressions were not correlated with those of IGF2. In conclusion, we found enhanced IMP3 levels in tissue and serum samples of PC patients compared to non-PC men. Moreover, IMP3 was associated with metastasis and PC-specific survival. The tumor promoting effect of IMP3 appears to be independent from its regulatory role on IGF2 in PC. PMID:24615121

Szarvas, Tibor; Tschirdewahn, Stephan; Niedworok, Christian; Kramer, Gero; Sevcenco, Sabina; Reis, Henning; Shariat, Shahrokh F; Rübben, Herbert; Vom Dorp, Frank

2014-10-01

336

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.

Meagher, Richard B.

2004-12-01

337

Accumulation levels of organochlorine pesticides in human adipose tissue and blood  

SciTech Connect

Because of their persistence and potential for bioaccumulation, the use of organochlorine pesticides, technical hexachlorocyclohexane (HCH) and pp{prime}-DDT, has been prohibited since 1971 in Japan. Furthermore, chlordane which had been applied for termite control has the potential for bioaccumulation and the use of it has been also prohibited since 1986. These chemicals can enter human body through a food chain or by inhalation of vapors. However, few data on chlordane residue in human adipose tissue are available in Japan. The aims of the present study were to assess the levels of organo-chlorine chemicals in adipose tissue and blood of Japanese and to examine the relationship between them.

Sasaki, Kumiko; Ishizaka, Takashi; Suzuki, Takashi; Takeda, Mitsuharu; Uchiyama, Mitsuru (National Inst. of Hygenic Sciences, Tokyo (Japan))

1991-05-01

338

Chromophore absorbance change quantification in tissue during low-level light therapy  

NASA Astrophysics Data System (ADS)

Low Level Light Therapy (LLLT) has been implicated to stimulate tissue, promoting healing and reducing pain. One of the potential pathways stimulated by LLLT relates to the electron transport chain, where photon quantum energy can induce a change in the biochemical reactions within the cell. The aim of this study is to assess the feasibility to exploit light additionally as a diagnostic tool to determine tissue physiological states, particularly in quantifying the changes in redox states of Cytochrome C as a result of induced LLLT biochemical reactions.

Huynh, Daniel; Chung, Christine; Qian, Li; Lilge, Lothar

2012-02-01

339

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

PubMed Central

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

2010-01-01

340

Mercury Levels in Mole Crabs Hippa cubensis, Emerita brasiliensis, E. portoricensis, and Lepidopa richmondi (Crustacea: Decapoda: Hippidae) from a Sandy Beach at Venezuela  

Microsoft Academic Search

Mercury pollution in Venezuela’s coastal area has been demonstrated for several years, especially at the Golfo Triste region (10° N, 68° W), which was subjected for several years to the discharges of mercury from a chlorine-alkal i plant that used an electrolytic process involving mercury electrodes. From 1987 to 1989 a base line study along the entire coast of Golfo

D. Pérez

1999-01-01

341

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

PubMed Central

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

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

2014-01-01

342

Tissue fluoroacetate residues in prairie dogs dosed with low-level sodium monofluoroacetate.  

PubMed

A total of 83 black-tailed prairie dogs (Cynomys ludovicianus) from South Dakota were subjected to low-level treatment with sodium monofluoroacetate (Compound 1080) in the laboratory (0.01-0.30 mg 1080/kg). The acute oral median lethal dose (LD50) of 1080 administered by oral gavage was established at 0.173 mg/kg. To assay fluoroacetate residues, 8 kinds of tissue from each of 10 prairie dogs dead of low-level 1080 poisoning were analyzed by capillary gas chromatography-mass spectrometry. Of the total of 79 tissues analyzed, 73 contained less than 100 ppb fluoroacetate, and 67 contained less than 50 ppb fluoroacetate. To test the effect of secondary poisoning on non-target species, 8 European ferrets (Mustela furo) were fed ground whole carcasses of prairie dogs dead of low-level 1080 poisoning, with no observable ill effects on the ferrets. PMID:3391967

Hugghins, E J; Casper, H H; Ward, C D

1988-01-01

343

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

SciTech Connect

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

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

1988-08-01

344

Mercury concentration in fillets of Greenland halibut (Reinhardtius hippoglossoides) caught in the Barents Sea in January 2006.  

PubMed

In January 2006 it was reported that Greenland halibut (Reinhardtius hippoglossoides) caught in the Barents Sea contained mercury levels that exceeded the EU's upper limit of 0.5 mg/kg wet weight for this species. To further investigate this finding, the National Institute of Nutrition and Seafood Research (NIFES) in Norway recently undertook a study to quantify the levels of mercury in Greenland halibut caught in the same area of the Barents Sea. A total of 120 Greenland halibut were caught in this area between the 28th and the 30th of January 2006. The fish were immediately frozen and shipped to the laboratory; individual fish were coded, weighed, defrosted, filleted and skinned before their mercury content was determined. Analyses were carried out on 65 individuals of Greenland halibut weighing from 0.81 kg to 7.1 kg, and 40 fish weighing more than 3 kg. The lowest mercury concentration found in muscle tissue (skinless and boneless fillet) was 0.019 mg/kg wet weight, in a fish that weighed 0.81 kg. The highest mercury concentration measured in muscle tissue was 1.1 mg/kg wet weight, from a fish that weighed 4.2 kg. Of the 65 fish analysed, 15 individuals with weight exceeding 3 kg had mercury concentrations in their muscle tissue exceeded the EU's upper limit. PMID:17097134

Julshamn, Kĺre; Grřsvik, Bjřrn Einar; Nedreaas, Kjell; Maage, Amund

2006-12-15

345

End-stage renal disease and low level exposure to lead, cadmium and mercury; a population-based, prospective nested case-referent study in Sweden  

PubMed Central

Background Cadmium (Cd), lead (Pb), and mercury (Hg) cause toxicological renal effects, but the clinical relevance at low-level exposures in general populations is unclear. The objective of this study is to assess the risk of developing end-stage renal disease in relation to Cd, Pb, and Hg exposure. Methods A total of 118 cases who later in life developed end-stage renal disease, and 378 matched (sex, age, area, and time of blood sampling) referents were identified among participants in two population-based prospective cohorts (130,000 individuals). Cd, Pb, and Hg concentrations were determined in prospectively collected samples. Results Erythrocyte lead was associated with an increased risk of developing end-stage renal disease (mean in cases 76 ?g/L; odds ratio (OR) 1.54 for an interquartile range increase, 95% confidence interval (CI) 1.18-2.00), while erythrocyte mercury was negatively associated (2.4 ?g/L; OR 0.75 for an interquartile range increase, CI 0.56-0.99). For erythrocyte cadmium, the OR of developing end-stage renal disease was 1.15 for an interquartile range increase (CI 0.99-1.34; mean Ery-Cd among cases: 1.3 ?g/L). The associations for erythrocyte lead and erythrocyte mercury, but not for erythrocyte cadmium, remained after adjusting for the other two metals, smoking, BMI, diabetes, and hypertension. Gender-specific analyses showed that men carried almost all of the erythrocyte lead and erythrocyte cadmium associated risks. Conclusions Erythrocyte lead is associated with end-stage renal disease but further studies are needed to evaluate causality. Gender-specific analyses suggest potential differences in susceptibility or in exposure biomarker reliability.

2013-01-01

346

Translocation of mercury and microbial adaptation in a model aquatic system  

SciTech Connect

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

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

1980-09-01

347

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

SciTech Connect

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

Harmon, S.M.

2003-05-29

348

Validation of freezing tissues and cells for analysis of DNA strand break levels by comet assay  

PubMed Central

The comet analysis of DNA strand break levels in tissues and cells has become a common method of screening for genotoxicity. The large majority of published studies have used fresh tissues and cells processed immediately after collection. However, we have used frozen tissues and cells for more than 10 years, and we believe that freezing samples improve efficiency of the method. We compared DNA strand break levels measured in fresh and frozen bronchoalveolar cells, and lung and liver tissues from mice exposed to the known mutagen methyl methanesulphonate (0, 25, 75, 112.5mg/kg). We used a high-throughput comet protocol with fully automated scoring of DNA strand break levels. The overall results from fresh and frozen samples were in agreement [R 2 = 0.93 for %DNA in tail (%TDNA) and R 2 = 0.78 for tail length (TL)]. A slightly increased %TDNA was observed in lung and liver tissue from vehicle controls; and TL was slightly reduced in bronchoalveolar lavage cells from the high-dose group. In our comet protocol, a small block of tissue designated for comet analysis is frozen immediately at tissue collection and kept deep frozen until rapidly homogenised and embedded in agarose. To demonstrate the feasibility of long-term freezing of samples, we analysed the day-to-day variation of our internal historical negative and positive comet assay controls collected over a 10-year period (1128 observations, 11 batches of frozen untreated and H2O2-treated A549 lung epithelial cells). The H2O2 treatment explained most of the variation 57–77% and the day-to-day variation was only 2–12%. The presented protocol allows analysis of samples collected over longer time span, at different locations, with reduced variation by reducing number of electrophoreses and is suitable for both toxicological and epidemiological studies. The use of frozen tissues; however, requires great care during preparation before analysis, with handling as a major risk factor.

Jackson, Petra

2013-01-01

349

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

PubMed

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 have been shown for Canada, the U.S., 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 U.S., 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 microg/L of medium for aquatic organisms; from 2,200 to 31,000 microg/kg BW (acute oral) and from 4,000 to 40,000 microg/kg (dietary) for birds; and from 100 to 500 microg/kg BW (daily dose) and from 1,000 to 5,000 microg/kg diet for mammals. Significant adverse sublethal effects were observed among selected aquatic species at water concentrations of 0.03-0.1 microg Hg/L. For some birds, adverse effects, mainly on reproduction, have been associated with total mercury concentrations (microg/kg FW) of 5,000 in feathers, 900 in eggs, and 50-100 in diet, and with daily intakes of 640 microg/kg BW. Sensitive nonhuman mammals showed significant adverse effects of mercury when daily intakes were 250 microg/kg BW, when dietary levels were 1,100 microg/kg, or when tissue concentrations exceeded 1,100 microg/kg. Proposed mercury criteria for protection of aquatic life range from 0.012 microg/L for freshwater life to 0.025 microg/L for marine life; for birds, less than 100 microg/kg diet FW; and for small mammals, less than 1,100 microg/kg FW diet. All these proposed criteria provide, at best, minimal protection. PMID:14738199

Eisler, Ronald

2004-01-01

350

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

PubMed

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

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

2014-03-15

351

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

PubMed

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

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

2009-01-01

352

Obesity And Laboratory Diets Affects Tissue Malondialdehyde (MDA) Levels In Obese Rats  

NASA Astrophysics Data System (ADS)

This study was conducted to investigate the interaction of obesity and laboratory diets on tissue malondialdehyde levels in rats. Female Zucker obese and lean rats were maintained on either regular grain-based diet or purified casein diet for two weeks, orally gavaged at day 50 with 65 mg/kg DMBA and sacrificed 24 hrs later. Malondialdehyde (MDA) levels were measured in blood and harvested tissues. Data were recorded as mean +/- SEM and analyzed statistically. Results show that the obese group on purified casein diet had reduction of MDA levels in the brain, duodenum, liver, lung and kidney tissues as compared to lean group, p <0.05. Obese group on grain-based diet showed significant increase in MDA levels only in the duodenum, p <0.05. We conclude that dietary intervention differentially affects the oxidative markers in obese rats. It appears that purified casein diets were more effective than grain-based diet in reduction of oxidative stress in obese rats.

Chowdhury, Parimal; Scott, Joseph; Holley, Andy; Hakkak, Reza

2010-04-01

353

Elevated Circulating Levels and Tissue Expression of Pentraxin 3 in Uremia: A Reflection of Endothelial Dysfunction  

PubMed Central

Elevated systemic pentraxin 3 (PTX3) levels appear to be a powerful marker of inflammatory status and a superior outcome predictor in patients with chronic kidney disease (CKD). As previous data imply that PTX3 is involved in vascular pathology and that adipose tissue mass may influence circulating PTX3 levels, we aimed to study the importance of adipose tissue expression of PTX3 in the uremic milieu and its relation to endothelial dysfunction parameters. Plasma PTX3 and abdominal subcutaneous adipose tissue (SAT) PTX3 mRNA levels were quantified in 56 stage 5 CKD patients (median age 57 [range 25–75] years, 30 males) and 40 age and gender matched controls (median age 58 [range 20–79] years, 27 males). Associations between PTX3 measures and an extensive panel of clinical parameters, including surrogate markers of endothelial function, were assessed. Functional ex vivo studies on endothelial status and immunohistochemical staining for PTX3 were conducted in resistance subcutaneous arteries isolated from SAT. SAT PTX3 mRNA expression correlated with plasma PTX3 concentrations (rho?=?0.54, p?=?0.0001) and was increased (3.7 [0.4–70.3] vs. 1.2 [0.2–49.3] RQ, p?=?0.02) in CKD patients with cardiovascular disease (CVD), but was not significantly different between patients and controls. The association to CVD was lost after adjustments. SAT PTX3 mRNA levels were independently correlated to asymmetric dimethylarginine and basal resistance artery tone developed after inhibition with nitric oxide synthase and cyclooxygenase (rho?=??0.58, p?=?0.002). Apparent positive PTX3 immunoreactivity was observed in both patient and control arteries. In conclusion, fat PTX3 mRNA levels are associated with measures of endothelial cell function in patients with CKD. PTX3 may be involved in adipose tissue-orchestrated mechanisms that are restricted to the uremic milieu and modify inflammation and vascular complications in CKD patients.

Witasp, Anna; Ryden, Mikael; Carrero, Juan Jesus; Qureshi, Abdul Rashid; Nordfors, Louise; Naslund, Erik; Hammarqvist, Folke; Arefin, Samsul; Kublickiene, Karolina; Stenvinkel, Peter

2013-01-01

354

Mercury banned  

SciTech Connect

This article describes the banning of the use of mercury as a biocide in indoor paints. Mercury will be allowed in outdoor paints but products must be labelled that they contain the metal and must include a warning for outdoor use only. Because mercury can offgas into the environment for several months after a room is painted, exposed individuals may be at risk for kidney disease, neurological impairment, gastrointestinal problems and cardiovascular disorders. Some paint manufacturers feel that the EPA has overreacted to an isolated case in which mercury in paint was found to be responsible for the serious illness of a five-year-old boy. They say that the new mandate will cost the industry an estimated $50 million to mix up-to-code paints, print new labels and test other biocides for efficacy.

Lomuscio, J.

1990-10-01

355

Levels of lead, arsenic, mercury and cadmium in clays for oral use on the Dutch market and estimation of associated risks.  

PubMed

Pregnant women in Africa, Asia and Suriname, and some immigrants in Western societies, traditionally consume clay products known by a variety of names such as mabele, calabash chalk, sikor and pimba. Furthermore, clay is used for health purposes in Western societies. Because certain clays can contain high levels of metals and metalloids, the aim of this study was to determine lead, arsenic, mercury and cadmium in clay products for oral use available on the Dutch market. Traditional clays originating from Africa (n = 10) and Suriname (n = 26), and health clays (n = 27) were sampled from 2004 up to and including 2012. Total metal and metalloid contents were measured by ICP-MS and showed maximum levels of lead, arsenic, mercury and cadmium of 99.7, 45.1, 2.2 and 0.75 mg kg?ą, respectively. In the absence of maximum limits for these type of clays, the potential exposure was estimated from the determined concentration, the estimated daily use level of the clays, and the estimated bioaccessibility of the different metals and arsenic. The intake estimates were compared with existing health-based guidance values. For lead, the use of 34 of the 36 traditional clays and two of the 27 health clays would result in intake levels exceeding the toxicological limit by up to 20-fold. Use of 15 of the 35 traditional clays and 11 of the 27 health clays would result in intake levels exceeding the toxicological limit for inorganic arsenic by up to 19-fold. Although limited bioaccessibility from the clay may limit the exposure and exceedance of the health-based guidance values, it was concluded that lead and arsenic intakes from some clay products could be of concern also because of their use by pregnant women and the potential developmental toxicity. As a result the use of these products, especially by pregnant women, should be discouraged. PMID:23862762

Reeuwijk, N M; Klerx, W N M; Kooijman, M; Hoogenboom, L A P; Rietjens, I M C M; Martena, M J

2013-01-01

356

Age-specific profiles of tissue-level composition and mechanical properties in murine cortical bone  

PubMed Central

There is growing evidence that bone composition and tissue-level mechanical properties are significant determinants of skeletal integrity. In the current study, Raman spectroscopy and nanoindentation testing were co-localized to analyze tissue-level compositional and mechanical properties in skeletally mature young (4 or 5 months) and old (19 months) murine femora at similar spatial scales. Standard multivariate linear regression analysis revealed age-dependent patterns in the relationships between mechanical and compositional properties at the tissue scale. However, changes in bone material properties with age are often complex and nonlinear, and can be missed with linear regression and correlation-based methods. A retrospective data mining approach was implemented using non-linear multidimensional visualization and classification to identify spectroscopic and nanoindentation metrics that best discriminated bone specimens of different age-classes. The ability to classify the specimens into the correct age group increased by using combinations of Raman and nanoindentation variables (86–96% accuracy) as compared to using individual measures (59–79% accuracy). Metrics that best classified 4 or 5 month and 19 month specimens (2-age classes) were mineral to matrix ratio, crystallinity, modulus and plasticity index. Metrics that best distinguished between 4, 5 and 19 month specimens (3-age classes) were mineral to matrix ratio, crystallinity, modulus, hardness, cross-linking, carbonate to phosphate ratio, creep displacement and creep viscosity. These findings attest to the complexity of mechanisms underlying bone tissue properties and draw attention to the importance of considering non-linear interactions between tissue-level composition and mechanics that may work together to influence material properties with age. The results demonstrate that a few non-linearly combined compositional and mechanical metrics provide better discriminatory information than a single metric or a single technique.

Raghavan, Mekhala; Sahar, Nadder D.; Kohn, David H.; Morris, Michael D.

2012-01-01

357

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

PubMed

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

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

2014-06-01

358

Low-level determination of silicon in steels by anodic stripping voltammetry on a hanging mercury drop electrode.  

PubMed

The sensitive differential pulse anodic stripping voltammetry (DPASV) proposed originally by Ishiyama et al. (2001) has been revised and improved to allow the accurate measurement of silicon on a hanging mercury drop electrode (HMDE) instead of a glassy carbon electrode. We assessed the rate of formation of the partially reduced ?-silicododecamolybdate and found that metallic mercury promotes the reaction in the presence of a large concentration of Fe(3+). The scope of the method has been broadened by carrying out the measurements in the presence of a constant amount of Fe(3+). The limit of detection (LOD) of the method described in the present paper is 100 ?g Sig(-1) of steel, with a relative precision ranging from 5% to 12%. It can be further enhanced to 700 ng Sig(-1) of steel provided the weight of the sample, the dilution factors, the duration of the electrolysis and the ballast of iron are adequately revised. The tolerance to several interfering species has been examined, especially regarding Al(3+), Cr(3+) and Cr VI species. The method was validated using four low-alloy ferritic steels certified by the National Institute of Standards and Technology (NIST). Its application to nickel base alloys as well as to less complicated matrixes is straightforward. It has also been successfully applied to the determination of free silicon into silicon carbide nano-powder. PMID:20875585

Rahier, A H; Lunardi, S; Nicolle, F; George, S M

2010-10-15

359

Mercury in traditional Tibetan medicine-panacea or problem?  

Microsoft Academic Search

Symptoms of mercury toxicity, biochemical changes, and blood\\/urine mercury levels were evaluated in a small group of patients. Six patients attending Delek Hospital, Dharamsala, India, taking mercury-containing traditional Tibetan medicine (TTM) (Group I), were compared with three patients taking non-mercury containing TTM (Group II) and healthy volunteers (Group III). Quantitative estimation of mercury ingestion based on chemical analysis was compared

S Sallon; T Namdul; S Dolma; P Dorjee; D Dolma; T Sadutshang; P Ever-Hadani; T Bdolah-Abram; S Apter; S Almog; S Roberts

2006-01-01

360

Human exposure and health effects of inorganic and elemental mercury.  

PubMed

Mercury is a toxic and non-essential metal in the human body. Mercury is ubiquitously distributed in the environment, present in natural products, and exists extensively in items encountered in daily life. There are three forms of mercury, i.e., elemental (or metallic) mercury, inorganic mercury compounds, and organic mercury compounds. This review examines the toxicity of elemental mercury and inorganic mercury compounds. Inorganic mercury compounds are water soluble with a bioavailability of 7% to 15% after ingestion; they are also irritants and cause gastrointestinal symptoms. Upon entering the body, inorganic mercury compounds are accumulated mainly in the kidneys and produce kidney damage. In contrast, human exposure to elemental mercury is mainly by inhalation, followed by rapid absorption and distribution in all major organs. Elemental mercury from ingestion is poorly absorbed with a bioavailability of less than 0.01%. The primary target organs of elemental mercury are the brain and kidney. Elemental mercury is lipid soluble and can cross the blood-brain barrier, while inorganic mercury compounds are not lipid soluble, rendering them unable to cross the blood-brain barrier. Elemental mercury may also enter the brain from the nasal cavity through the olfactory pathway. The blood mercury is a useful biomarker after short-term and high-level exposure, whereas the urine mercury is the ideal biomarker for long-term exposure to both elemental and inorganic mercury, and also as a good indicator of body burden. This review discusses the common sources of mercury exposure, skin lightening products containing mercury and mercury release from dental amalgam filling, two issues that happen in daily life, bear significant public health importance, and yet undergo extensive debate on their safety. PMID:23230464

Park, Jung-Duck; Zheng, Wei

2012-11-01

361

Got Mercury?  

NASA Technical Reports Server (NTRS)

Many lamps used in various spacecraft contain elemental mercury, which is efficiently absorbed through the lungs as a vapor. The liquid metal vaporizes slowly at room temperature, but may be completely vaporized when lamps are operating. Because current spacecraft environmental control systems are unable to remove mercury vapors, we considered short-term and long-term exposures. Using an existing study, we estimated mercury vapor releases from lamps that are not in operation during missions lasting less than or equal to 30 days; whereas we conservatively assumed complete vaporization from lamps that are operating or being used during missions lasing more than 30 days. Based on mercury toxicity, the Johnson Space Center's Toxicology Group recommends stringent safety controls and verifications for any hardware containing elemental mercury that could yield airborne mercury vapor concentrations greater than 0.1 mg/m3 in the total spacecraft atmosphere for exposures lasting less than or equal to 30 days, or concentrations greater than 0.01 mg/m3 for exposures lasting more than 30 days.

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

2010-01-01

362

The effect of muscle actions on the level of connective tissue damage.  

PubMed

The aim of this study was to compare the effect of concentric with eccentric muscle actions on the resulting level of damage to connective tissues by urinary concentration of hydroxyproline. Twenty-one male volunteers were divided into control group (CG), experimental concentric group (ECG), and experimental eccentric group (EEG). The measures of hydroxyproline were performed at three times: pretest, fourth week, and posttest. Biceps curl and chest press exercises also were performed with three sets of 10 repetitions two times per week for both experimental groups. Analysis of variance (ANOVA) showed a significant difference between pretest of the CG and pretest of the ECG (p = 0.002), and between pretest and posttest for the EEG (p = 0.029). Therefore, this study concluded that the level of damage to the connective tissue is greater when exercises involving eccentric muscle actions are performed. The continuity of training, however might reduce this damage. PMID:21988268

Nogueira, Antonio de C; Vale, Rodrigo G S; Gomes, André L M; Dantas, Estélio H M

2011-10-01

363

Combined multi-gene analysis at the RNA and protein levels in single FFPE tissue sections.  

PubMed

Novel approaches of individualized medicine require rapid analyses of comprehensive multi-gene expression patterns both at the RNA and protein levels. Optimally these analyses are achieved with minimal amounts of tissues, which are derived from routine procedures of clinical diagnostics. We demonstrate the parallel analyses of gene expression of six different genes at the RNA and protein levels in two consecutive sections of routinely processed FFPE tissues. This was achieved by combination of multi-epitope-ligand cartography (MELC) and fully automatically magnetic bead-based RNA extraction and subsequent qRT-PCR analysis. Our work provides proof-of-principle that comprehensive analyses of multi-gene expression patterns can be achieved by the combination of these two high content technologies. This may provide new perspectives for the determination of pathogenic gene expression in the framework of individualized medicine. PMID:23583336

Ostalecki, Christian; Konrad, Andreas; Thurau, Elisabeth; Schuler, Gerold; Croner, Roland S; Pommer, Ansgar J; ael Stürzl, Mich

2013-08-01

364

Altered Tissue Levels of Vitamin a by Selected Polycyclic Aromatic Hydrocarbons (PAHs)  

Microsoft Academic Search

The purpose of this study was to determine the effects of certain polycyclic aromatic hydrocarbons (PAHs) of known carcinogenic potential on rat tissue levels of retinol and retinyl esters. Male Sprague-Dawley rats fed a vitamin A-adequate diet (1.3 mg of retinyl palmitate\\/kg) for 30 days were intraperitoneally administered three injections of one of the following four PAHs: carcinogenic 3-methylcholanthrene (MC),

Li-Chuan Chen; Isabelle Berberian; Howard P. Glauert; Larry W. Robertson; Ching K. Chow

1994-01-01

365

Increased levels of GAP43 protein in schizophrenic brain tissues demonstrated by a novel immunodetection method  

Microsoft Academic Search

Studies on the molecular basis of neurological and psychiatric disorders often rely on the precise determination of specific\\u000a proteins in brain tissues. In this study, we have developed a method for measuring the levels of the neural-specific growth-associated\\u000a protein, GAP-43, in human postmortem brain specimens. This rapid and quantitative method is based on immunodetection procedures.\\u000a Briefly, synaptosomal plasma membranes (SPMs)

Angela C. Sower; Edward D. Bird; Nora I. Perrone-Bizzozero

1995-01-01

366

DNA adduct level in lung tissue may act as a risk biomarker of lung cancer  

Microsoft Academic Search

Lung cancer is a leading cause of mortality in Taiwan. We hypothesised that high susceptibility to DNA damage in the target organ acts as a risk biomarker for the development of lung cancer. To verify this hypothesis, the aromatic\\/hydrophobic DNA adduct levels of non-tumorous adjacent lung tissues from 73 primary lung cancer patients and 33 non-cancer controls were evaluated by

Y.-W Cheng; C.-Y Chen; P Lin; C.-P Chen; K. H Huang; T.-S Lin; M.-H Wu; H Lee

2000-01-01

367

Effects of magnesium sulfate on tissue lactate and malondialdehyde levels in experimental head trauma  

Microsoft Academic Search

Objective: To determine the effects of magnesium sulfate (MgSO4) on tissue lactate and malondialdehyde (MDA) levels in rabbit brain after experimental head trauma. Design: Prospective, randomized trial. Subjects: Thirty New Zealand rabbits. Interventions: Group 1 (n=10) was the sham operated group. Group 2 (n=10) (untreated group) and group 3 (n=10) received head trauma with the weight drop method. MgSO4 was

M. E. ÜstÜn; M. Gürbilek; A. Ak; H. Vatansev; A. Duman

2001-01-01

368

Postmitotic tissue selenium and manganese levels in alpha-lipoic acid-supplemented aged rats  

Microsoft Academic Search

Redistribution of selenium and manganese in postmitotic tissues of alpha-lipoic acid-supplemented aged rats has been proposed to contribute to metal-catalyzed protein oxidation. dl-Alpha-lipoic acid (LA) (100mg\\/[kg body wt.day]) was administered intraperitoneally to the Sprague–Dawley rats for 14 days. Serum selenium levels were lowered in the aged rats with LA supplementation compared with those of the rats without LA supplementation. Similarly,

Ufuk Çakatay; Refik Kayali; Ali Riza Kiziler; Birsen Aydemir

2008-01-01

369

Effect of sulfite exposure on zinc, iron, and copper levels in rat liver and kidney tissues  

Microsoft Academic Search

Sulfite is a potentially toxic molecule that might enter the body via ingestion, inhalation, or injection. For cellular detoxification,\\u000a mammalians rely on sulfite oxidase to convert sulfite to sulfate. The purpose of this research was to determine the effect\\u000a of sulfite on zinc, iron, and copper levels in rat liver and kidney tissues. Forty normal and sulfite oxidase-deficient male\\u000a albino

Vural Kucukatay; Sebahat Turgut; Erdogan Kocamaz; Gulten Emmungil; Melek Bor-Kucukatay; Gunfer Turgut; Hakan Akca; Huseyin Bagci

2006-01-01

370

Technical Assistance to the Tennessee Department of Health and Environment. Mercury Exposure Study, Charleston, Tennessee.  

National Technical Information Service (NTIS)

Workers at a chlor-alkali chemical plant were exposed to high levels of elemental mercury during a scheduled maintenance operation and transported mercury into their homes. Concerns about mercury exposure of the families of these workers prompted a health...

1990-01-01

371

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

PubMed

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

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

2013-07-01

372

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

PubMed

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

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

2014-02-01

373

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

SciTech Connect

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

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

2013-08-15

374

Mercury in liver, kidney, feather and muscle of seabirds from major wetlands of the Caspian Sea, Iran.  

PubMed

Concentration of mercury in tissues of the great cormorant (n = 18), mallard (n = 18), and coot (n = 15) of the Caspian Sea were determined. Liver mercury in the great cormorant, mallard, and coot were (5.7 ± 0.91; 0.3 ± 0.02; 0.09 ± 0.02). Kidney levels were (3.6 ± 2.24; 0.26 ± 0.03; 0.08 ± 0.02); feather (8.7 ± 0.8; 1.04 ± 0.16; 0.23 ± 0.15) and muscle were (2.26 ± 2.04; 0.11 ± 0.01; 0.03 ± 0.02) respectively. Mercury Tolerable Daily Intake limit is set at 5 ?g g(-1). But even at levels that are currently considered "tolerable", mercury poisoning can occur in children and young who consume polluted game meat regularly. PMID:21499943

Aazami, J; Esmaili-Sari, A; Bahramifar, N; Ghasempouri, M; Savabieasfahani, M

2011-06-01

375

Mercury toxicity. Agency for Toxic Substance and Disease Registry  

SciTech Connect

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

Not Available

1992-12-01

376

Mercury toxicity. Agency for Toxic Substance and Disease Registry.  

PubMed

Because mercury has several forms and because it produces subtle effects at chronic low-level exposures, mercury toxicity can be a difficult diagnosis to establish. Elemental mercury vapor accounts for most occupational and many accidental exposures. The main source of organic methyl mercury exposure in the general population is fish consumption. Children are at increased risk of exposure to elemental mercury vapor in the home because it tends to settle to the floor. The chemical and physical forms of mercury determine its absorption, metabolism, distribution and excretion pathways. The central nervous system and kidneys are key targets of mercury toxicity. Chelation therapy has been used successfully in treating patients who have ingested mercury salts or inhaled elemental mercury. There is no antidote for patients poisoned with organic mercury. PMID:1456196

1992-12-01

377

TMDLs for Segments Listed for Mercury in Fish Tissue for the Ouachita River Basin, and Bayou Bartholomew, Arkansas and Louisiana to Columbia.  

National Technical Information Service (NTIS)

The Arkansas and Louisiana 1998 Section 303(d) Lists include segments and subsegments in the Ouachita River basin that are impaired due to excess concentrations of mercury in fish. Additional waterbodies in the Ouachita River basin that are not included o...

2002-01-01

378

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

PubMed

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

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

2014-08-01

379

Up-Regulation of Carnitine Transporters Helps Maintain Tissue Carnitine Levels in Carnitine Deficiency Induced by Pivalic Acid  

Microsoft Academic Search

Purpose. Pivalic acid (PVA) forms conjugates with endogenous carnitine and enhances its excretion. The purpose of this study is to determine whether tissue carnitine levels decrease in parallel with plasma levels in carnitine deficiency induced by PVA.

Noriko Okudaira; Masao Fujigaki; Takemi Nakayoshi; Izumi Komiya; Yuichi Sugiyama

2001-01-01

380

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

Microsoft Academic Search

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

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

2011-01-01

381

Effect of doxorubicin on lipid peroxide levels in tissues of mice.  

PubMed

The tissue concentrations of doxorubicin (DOX, 15 mg/kg, ip) and daunorubicin (DAU, 15 mg/kg, ip) in mice were investigated to clarify their relationship to the cardiotoxicity, which is considered to be closely related to the lipid peroxide level in the heart. The largest Cmax of DOX after intraperitoneal injection was obtained in the liver and was equivalent to 1.8 times that in the heart. Elimination of DOX from the heart was not delayed. Nevertheless, the increases of lipid peroxide in the heart found in in vivo and in vitro experiments were considerably higher than those in the liver. Therefore, the cardiotoxicity of DOX can not be explained simply in terms of the relative concentrations of DOX in various tissues. On the other hand, experiments on the tissue concentration of DAU, which shows weaker cardiotoxicity than DOX, and on lipid peroxidation in vitro, suggested that the relative cardiotoxicities of DOX and DAU are directly related to their relative concentrations in the mouse heart. We observed a metabolite of DOX, doxorubicinone, and an unknown metabolite of DAU in various tissues of mouse after drug injection, but these metabolites did not seem to be involved in the cardiotoxicities of DOX and DAU. PMID:3121563

Sazuka, Y; Yoshikawa, K; Tanizawa, H; Takino, Y

1987-11-01

382

In-situ measurements of low-level mercury vapor exposure from dental amalgam with zeeman atomic absorption spectroscopy.  

PubMed

Alongside food, emissions from amalgam fillings are an essential contribution to man's mercury burden. Previous methods for the determination of intraoral mercury vapor (Hg degrees ) release used principally some form of preconcentration of Hg on gold (film or wool), allowing relatively few measurements with unknown precision and sensitivity at selected times. Recently available computer-controlled Hg detectors operating on Zeeman atomic absorption spectroscopy (ZAAS) facilitate the direct real-time measurement of Hg degrees concentrations. It was the aim to adapt this method for a comparative investigation of emission processes from fillings in situ and from amalgam specimens in vitro. In addition to the ZAAS instrument, the apparatus consisted of a pump, magnetic valves, an electronic flow controller and a handle with a disposable mouth piece for aspiration of oral air. A programmable timer integrated the computer-controlled instrument operation and the data collection into a standard sampling protocol. A fast exponential decay of the emission was found after stimulation of amalgam specimens and of fillings in situ (halftimes 8.6 and 10.7 min). Precision was evaluated by a series of measurements on a single patient which indicated a consistently low coefficient of variation between 18% and 25%. After insertion of a few new fillings, sensitivity was high enough to detect a significant increase in emission against the background emission from the majority of old fillings. Zeeman-AAS in connection with a semi-automated sampling protocol and data storage provides precise in-situ measurements of Hg degrees emission from dental amalgam with real-time resolution. This facilitates the detailed exploration of the Hg degrees release kinetics and the applicability to large-scale studies. PMID:20021109

Halbach, Stefan; Welzl, Gerhard

2004-01-01

383

A correlation study of organochlorine levels in serum, breast adipose tissue, and gluteal adipose tissue among breast cancer cases in India.  

PubMed

We used data from a breast cancer pilot study carried out in Kerala, India in 1997, for which organochlorine levels were measured in three biological media, blood serum, breast adipose tissue, and gluteal adipose tissue, of 37 fasting breast cancer cases (pretreatment). Our objective was to investigate the relationships between organochlorine concentrations in different biological media. Gas-liquid chromatography determined serum, breast adipose, and gluteal adipose tissue levels of dichlorodiphenyltricholorethane, dichlorodiphenyldichloroethane, beta-benzene hexachloride, and polychlorinated biphenyl (PCB) congeners, PCB-153 and PCB-180. Correlation plots were made and Spearman correlation coefficients (r) calculated for breast adipose tissue versus serum, gluteal adipose tissue versus serum, and breast adipose versus gluteal adipose tissue. We also examined paired ratios of all summary statistics. There were strong correlations among serum, breast adipose tissue, and gluteal adipose tissue concentrations for most organochlorines analyzed, one exception being gluteal versus serum for PCB-153. The correlations for all other comparisons ranged from r = 0.65 to 0.94. Serum (ng/g) versus adipose ratios approached 1:1 for most of the organochlorine pesticide comparisons and did not vary by summary statistic. To our knowledge, this is the first study to use three different media from fasting subjects and to comprehensively investigate the relationship between organochlorines measured across the three media for both organochlorine pesticides and PCBs. These data indicate that blood serum reflects the present body burden of a range of organochlorines to the same extent as adipose tissue, and they support the view that serum may be collected in lieu of adipose tissue to obtain similar information. However, such measurements are a combination of both recent exposures and past exposures, which have metabolized slowly and may still persist. Therefore, investigators should use caution when assigning a level as lifetime body burden. PMID:15894661

Rusiecki, Jennifer A; Matthews, Aleyama; Sturgeon, Susan; Sinha, Rashmi; Pellizzari, Edo; Zheng, Tongzhang; Baris, Dalsu

2005-05-01

384

Mercury in the Izmir Bay: An assessment of contamination  

NASA Astrophysics Data System (ADS)

The levels of mercury in suspended particulate matter, sediment, plankton and fish were investigated in Izmir Bay (Eastern Aegean). The study aimed to assess the level of mercury in different environmental compartments of the Izmir Bay. Seasonal (dry and wet season) and spatial variations in suspended particulate Hg concentrations showed that pluvial transport is the major pathway to the bay. Suspended particulate matter was the main vehicle for carrying mercury from land based sources to the bay. Gediz River and inactive mining sites (Karaburun) were the most important inputs of mercury to the outer bay. Hg concentrations ranged from 0.70 to 28.7 nmol g - 1 (dry weight) in suspended particulate, from 0.60 to 3.19 nmol g - 1 (dry weight) in plankton, from 0.20 to 3.14 nmol g - 1 (dry weight) in sediment and from 0.05 to 4.54 nmol g - 1 (wet weight) in organisms. Plankton, sediment Hg concentrations and its organic matter contents increased from outer bay to middle-inner bays. Based on the correlation matrix obtained for mercury data, organic matter was the dominant factor controlling Hg distribution in the sediment. There was a correlation between fish length and Hg (muscle tissue) concentrations in Mullus barbatus and Merluccius merluccius. In the other species these were not related to fish length. The maximum permissible mercury limit accepted by WHO for edible parts of marine organisms is 3.5 nmol g - 1 (wet weight); our results indicated that Merlangius merlangus and Pagellus erythrinus exceed this limit.

Kontas, Aynur

2006-06-01

385

Microbial methylation of mercury in estuarine sediments  

SciTech Connect

Mercury is a common and potentially hazardous pollutant. Although all forms of the element are toxic, alkylated mercurials are particularly toxic and accumulate in living tissues. Factors affecting the availability of mercury and the microorganisms responsible for methylation are described. The methylation of mercuric ions (Hg/sup + +/) was investigated in pure culture, in estuarine sediments, and as a function of the anionic constituents of seawater. Studies on abiotic methylation of Hg/sup + +/ by methylcobalamin in the presence of sea salts showed that only the sulfide (formed in sulfate reduction) and bicarbonate components interfere with Hg/sup + +/ methylation. Other sea salt anions have no significant influence on the methylation of Hg/sup + +/. Methylation, demethylation, and volatilization of Hg/sup + +/ were studied in estuarine sediments maintained at present values of pH, redox, and salinity. Volatilization of Hg/sup 0/ and CH/sub 3/HgCH/sub 3/ were found to be minimal. Methylation was favored at low redox potential (-220 mW) and low salinity (0.4%) conditions. High salinity (2.5%) decreased methylation at -220 mV, but not at (+110 mV). Demethylation of CH/sub 3/HgCl was favored at +110 mV regardless of the salinity level. Low redox potential under low salinity conditions inhibited demethylation, but high salinity reversed this inhibition. The sulfate-reducing bacteria were identified as the principal Hg/sup + +/ methylating population in anaerobic estuarine sediments.

Compeau, G.C.

1985-01-01

386

Vitamin levels in lung tissue of rats with bleomycin induced pulmonary fibrosis.  

PubMed

Bleomycin (BLM) is a chemotherapeutic agent against different carcinomas, one dose of which causes dependent pulmonary fibrosis. The present study was taken up in order to measure the reti