Health & Environmental Research Online (HERO)


Methylmercury


43,975 References Were Found:

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Selenium, arsenic, and mercury in fish inhabiting a fly ash exposure gradient: Interspecific bioaccumulation patterns and elemental associations

Author: Reash, RJ (In Press) Environmental Toxicology and Chemistry. HERO ID: 1015880

[Less] Releases from coal ash impoundments can be a significant source of trace elements to the aquatic environment. . . . [More] Releases from coal ash impoundments can be a significant source of trace elements to the aquatic environment. In the present study, whole body concentrations of arsenic, mercury, and selenium in various fish species inhabiting streams receiving a gradient of fly ash exposure are reported. High exposure sites had elevated water concentrations of arsenic, molybdenum, selenium, and sulfate. Fish were collected during two seasons in 2007. Mercury concentrations in all fish samples were low (range = 0.012-0.99 mg/kg dry wt); highest arsenic concentrations occurred in fish from high exposure sites. Whole body selenium concentrations were low at reference sites but increased as the magnitude of fly exposure increased. For all sites combined, a significant (r2 = 0.60) correlation was observed between the geometric mean of each species' whole body selenium concentration and log-transformed water selenium concentration. A significant inverse relationship was apparent with log-transformed whole body mercury and selenium concentrations (r2 = 0.56 for all species and sites combined), suggesting that high tissue selenium levels antagonistically regulated mercury bioaccumulation. Sunfish (Lepomis sp.) from high and medium-exposure sites had significantly higher selenium body residues, but significantly lower mercury, relative to fish from low exposure and reference sites. Ninety percent of fish from high exposure sites had a surplus of selenium whereas all fish from reference sites had Se/Hg molar ratios < 1.0. These ratios increased as water selenium increased. Where fish have moderate to high exposure to fly ash-influenced water, selenium tissue levels can be expected to be elevated (as well as arsenic, in some cases), but tissue mercury concentrations will likely be low. Environ. Toxicol. Chem. © 2012 SETAC.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Metal interactions in mice under environmental stress

Authors: García-Sevillano, MA; Jara-Biedma, R; González-Fernández, M; García-Barrera, T; Gómez-Ariza, JL (In Press) BioMetals. HERO ID: 1677561

[Less] A metallomic analytical approach based on the use of size exclusion chromatography coupled to ICP-MS . . . [More] A metallomic analytical approach based on the use of size exclusion chromatography coupled to ICP-MS has been used to obtain metal profiles related to overexpression or inhibition of metal-binding biomolecules, which is connected to exposure experiment of laboratory mice Mus musculus to toxic metals, such as Cd, Hg and As. Exposure to Cd induces the formation of Cd-metallothionein in liver that reveals the protective role of this organ; however, exposure to Hg reduces the intensity of the peak associated to Cu-superoxide dismutase (Cu-SOD) while Hg-SOD peak increases, which suggests the competence of Cu and Hg for the active sites of SOD in liver that causes mercury translocation to kidney, in which the concentration of Hg as Hg-metallothionein increases drastically to be excreted by urine. It has been also observed the protective effect of selenium on mercury toxicity in blood plasma, which produces decreasing of the intensity of Se-protein in plasma with Hg exposure and correlative increases of Hg-albumin that transport mercury to kidney for excretion. Finally, arsenic exposure provokes the accumulation of small metabolites of this element, such as dimethylarsenic and monomethylarsenic for excretion. The application of the metallomic approach to liver extracts from free-living mouse Mus spretus shows the overexpression of Cu, Zn and Cd-peaks at 7 kDa (related to metal-metallothionein) in environmental contaminated sites, as well as the increase of peaks related to Cu- and Zn-SOD and Zn-albumin. However, in kidney, can be checked the presence of high concentration of arsenic small metabolites in contaminated areas, similarly to results found in exposure experiments. In addition, the application of a metabolomic approach based on direct infusion mass spectrometry to organ extracts (liver, kidney and serum) from mice (M. musculus) exposed to arsenic reveals important metabolic changes related to antioxidative activity, membrane cell damage, energy metabolism and arsenic elimination. Similar results were obtained from free-living mouse (M. spretus) from areas contaminated with arsenic. The integration of metallomics and metabolomics results provides a more comprehensive evaluation about the biological response in exposure experiments to toxic metals as well as in environmental assessment of contamination.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

(Micro)spectroscopic analyses of particle size dependence on arsenic distribution and speciation in mine wastes

Authors: Kim, CS; Chi, C; Miller, SR; Rosales, RA; Sugihara, ES; Akau, J; Rytuba, JJ; Webb, SM (In Press) Environmental Science and Technology. HERO ID: 1797784

[Less] The chemical speciation and distribution of potentially toxic metal(loid)s in mine wastes is critical . . . [More] The chemical speciation and distribution of potentially toxic metal(loid)s in mine wastes is critical to assessing the risks posed by these wastes and predicting the potential bioavailability of the metal(loid)s present. Of additional potential importance is the role of particle size in the fate, transport, and toxicity of contaminated mining materials. Spectroscopic analyses of size-separated mine tailings and adjacent background samples from the Randsburg Historic Mining District, California were conducted to quantify the speciation and distribution of arsenic (As) as a function of particle size. Micro-X-ray fluorescence (μXRF) mapping of separate size fractions was used to identify multiple populations of particles with different As:Fe ratios, indicating a variety of distinct arsenic-bearing species. Bulk extended X-ray absorption fine structure (EXAFS) spectroscopy identified phases including arseniosiderite, Ca2Fe3(3+)(AsO4)3O3·3H2O, and As(V) sorbed to iron hydroxides (ferrihydrite, goethite), confirming a strong statistical correlation between arsenic and iron observed in both μXRF studies and bulk chemical analyses. Differences in As speciation between the mine tailings and background samples also suggest that weathering of crystalline As-bearing phases in tailings leads to sorption of dissolved arsenic to iron hydroxides in nontailings background material.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

The adverse health consequences of the use of multiple performance-enhancing substances--A deadly cocktail

Authors: Perera, NJ; Steinbeck, KS; Shackel, N (In Press) Journal of Clinical Endocrinology and Metabolism. HERO ID: 2149157

[Less] Context: The harmful consequences of abuse of performance-enhancing substances (PESs), stimulants, and . . . [More] Context: The harmful consequences of abuse of performance-enhancing substances (PESs), stimulants, and masking agents among athletes, recreational weight lifters, and physical trainers are common. However, the adverse health outcomes with severe unexpected and dramatic consequences are unrecognized or under-reported at the expense of short-term glory or body-image effects, especially in elite sports. Objective: We report the case of a recreational weight lifter/physical trainer to help summarize the adverse health consequences and outcomes of polypharmacy among athletes and growing subsets in our population engaged in physical/fitness training. We show that in addition to the risk inherent to “stacking” of PESs, the users are predisposed to harmful consequences, including risk of exposure to toxic contaminants. Design and Setting: A previously healthy man with chronic use of multiple PESs, stimulants, and masking agents presented to a tertiary-care hospital with jaundice and mild hepatitis with rapid progression into liver and multisystem organ failure. This is followed by a brief overview of the specific toxicity (arsenic) and PESs that contributed to the poor outcome in this case. Conclusion: Surreptitiously or self-administered cocktails of potential PESs including anabolic agents, emerging classes of GH-releasing peptides, androgen precursors, stimulants, and masking agents could lead to adverse consequences including early mortality, multisystem pathology, unmask/accelerate malignancy, and expose or predispose users to extreme danger from contaminants. This cautionary case reinforces the need to increase awareness and highlights the challenges that testing agencies, regulators, and clinicians face in the fast-developing licit/illicit trade of these products.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Assessment of heavy metals in water samples and tissues of edible fish species from Awassa and Koka Rift Valley Lakes, Ethiopia

Authors: Dsikowitzky, L; Mengesha, M; Dadebo, E; de Carvalho, CEV; Sindern, S (In Press) Environmental Monitoring and Assessment. HERO ID: 1255505

[Less] The Ethiopian Rift Valley Lakes host populations of edible fish species including Oreochromis niloticus, . . . [More] The Ethiopian Rift Valley Lakes host populations of edible fish species including Oreochromis niloticus, Labeobarbus intermedius and Clarias gariepinus, which are harvested also in other tropical countries. We investigated the occurrence of six heavy metals in tissues of these fish species as well as in the waters of Lake Koka and Lake Awassa. Both lakes are affected by industrial effluents in their catchments, making them ideal study sites. Mercury concentrations were very low in the water samples, but concentrations in the fish samples were relatively high, suggesting a particularly high bioaccumulation tendency as compared with the other investigated metals. Mercury was preferentially accumulated in the fish liver or muscle. It was the only metal with species-specific accumulation with highest levels found in the predatory species L. intermedius. Lower mercury concentrations in O. niloticus could be attributed to the lower trophic level, whereas mercury values in the predatory C. gariepinus were unexpectedly low. This probably relates to the high growth rate of this species resulting in biodilution of mercury. Accumulation of lead, selenium, chromium, arsenic and cadmium did not differ between species, indicating that these elements are not biomagnified in the food chain. Values of cadmium, selenium and arsenic were highest in fish livers, while lead and chromium levels were highest in the gills, which could be related to the uptake pathway. A significant impact of the industrial discharges on the occurrence of metals in the lakes could not be detected, and the respective concentrations in fish do not pose a public health hazard.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Sources and spatial distribution of heavy metals in scleractinian coral tissues and sediments from the Bocas del Toro Archipelago, Panama

Authors: Berry, KLE; Seemann, J; Dellwig, O; Struck, U; Wild, C; Leinfelder, RR (In Press) Environmental Monitoring and Assessment. HERO ID: 1597286

[Less] Marine ecosystems worldwide are threatened by aquatic pollution; however, there is a paucity in data . . . [More] Marine ecosystems worldwide are threatened by aquatic pollution; however, there is a paucity in data from the Caribbean region. As such, five heavy metals (arsenic, cadmium, copper, zinc, mercury) were measured in tissues of the scleractinian corals Porites furcata and Agaricia tenuifolia and in adjacent sediments in the Bocas del Toro Archipelago, Panama. Samples were collected from five reef sites along a gradient of distance from an international shipping port and were analysed using inductively coupled plasma optical emission spectrometry and atomic absorption spectrophotometry for mercury. Copper and zinc were the most abundant metals and ranged from 11 to 63 mg kg(-1) and from 31 to 185 mg kg(-1) in coral tissues, respectively. The highest concentration of each metal was measured in P. furcata tissues, with copper and mercury concentrations significantly higher in P. furcata than in A. tenuifolia at every site. These results suggest that P. furcata has a higher affinity for metal accumulation and storage than A. tenuifolia. With the exception of cadmium, metal concentrations in coral tissues were generally elevated at coral reefs in closer proximity to the port; however, this pattern was not observed in sediments. Hard coral cover was lowest at reefs in closest proximity to the port, suggesting that metal pollution from port-related activities is influencing hard coral abundance at nearby coral reefs.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Metal accumulation in the tissues of grass carps (Ctenopharyngodon idellus) from fresh water around a copper mine in southeast China

Authors: Liu, F; Ni, H-G; Chen, F; Luo, Z-X; Shen, H; Liu, L; Wu, P (In Press) Environmental Monitoring and Assessment. HERO ID: 1021614

[Less] Mining effluents are the main source of metals in the surrounding aquatic environment. The mining district . . . [More] Mining effluents are the main source of metals in the surrounding aquatic environment. The mining district of Purple Mountain has a history of copper mining for more than 30 years, but there is limited investigation of metal bioaccumulation in the aquatic creatures from the Tingjiang river catchment affected by the mining activities. In this study, we collected grass carps (Ctenopharyngodon idellus) from four sites, and analyzed the accumulation of chromium (Cr), nickel (Ni), manganese (Mn), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) in ten tissues (scale, skin, muscle, gill, liver, kidney, fish maw, heart, stomach, and intestine) of the fish samples. Among all tissue samples, the highest concentrations (micrograms per gram wet weight) of Ni (0.263), Cu (69.2), Zn (84.0), As (0.259), Cd (0.640), Hg (0.051), and Pb (0.534) were noted in the liver, gill, and kidney tissues, whereas the highest concentrations of Cr (0.356) and Mn (62.7) were detected in the skin and intestine, respectively. These results gave a better understanding of the variability of metals distribution in different fish tissues. In comparison with the sample sites, metals (especially Mn, Cu, Zn, Ni, and Pb) in liver, gill, kidney, stomach, and intestine showed more inter-site differences than other tissues. The inter-site differences also revealed that site 1 and 2 increased fish uptake of Cu, Zn, Ni, and Pb, which may indicate that the copper mine and urban effluents contributed to high levels of these metals in aquatic environments in site 1 and 2. A potential food safety issue may emerge depending on the mining activities in this region because some metals in a few tissue samples exceeded the guideline values for human consumption of fish.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Mercury and other mining-related contaminants in ospreys along the Upper Clark Fork River, Montana, USA

Authors: Langner, HW; Greene, E; Domenech, R; Staats, MF (In Press) Archives of Environmental Contamination and Toxicology. HERO ID: 1021991

[Less] We investigated links between mining-related contaminants in river sediment and their occurrence in . . . [More] We investigated links between mining-related contaminants in river sediment and their occurrence in nestling ospreys (Pandion haliaetus) in the Clark Fork River Basin, Montana, USA. Blood and feather samples from 111 osprey chicks were collected during 4 years from nests along river sections with greatly different sediment concentrations of arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), zinc (Zn), and mercury (Hg). No significant differences between river sections were found among Zn (3,150 ± 160 μg L(-1)) and Cd (<5 μg L(-1)) concentrations in blood. Cu, Pb, and As concentrations in blood were significantly increased in chicks from the most contaminated river sections (mean values of 298, 8.9, and 100 μg L(-1), respectively). Cu, Zn, and Pb concentrations increased significantly during a year of above-average river runoff combined with high suspended sediment loads in rivers. Total Hg concentrations in blood and feathers were highly correlated and depended on the geographic locations of the nests. The lowest blood concentrations of Hg were observed in the most upstream river section (mean 151 μg L(-1)) where total sediment concentrations were increased (0.80 mg kg(-1)). River sections with intermediate blood concentrations (mean 206 and 303 μg L(-1)) were associated with low to intermediate sediment concentrations (0.058 and 0.46 mg kg(-1)). The highest concentrations of Hg in ospreys (mean 548 μg L(-1)) were observed downstream from a contaminated tributary (1-4 mg kg(-1) in sediment). In river sections with lower Hg concentrations in sediment, there was a negative correlation between blood Hg concentration and chick mass, presumably due to high deposition rates into growing feathers. This relationship was absent in sections of high Hg exposure. Osprey blood and feathers are suitable for monitoring Hg in aquatic ecosystems; however, responses of As, Cd, Cu, Pb, and Zn are more subtle.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Cancer and non-cancer health effects from food contaminant exposures for children and adults in California: A risk assessment

Authors: Vogt, R; Bennett, D; Cassady, D; Frost, J; Ritz, B; Hertz-Picciotto, I (In Press) Environmental Health. HERO ID: 1337520

[Less] ABSTRACT: BACKGROUND: In the absence of current cumulative dietary exposure assessments, this analysis . . . [More] ABSTRACT: BACKGROUND: In the absence of current cumulative dietary exposure assessments, this analysis was conducted to estimate exposure to multiple dietary contaminants for children, who are more vulnerable to toxic exposure than adults. METHODS: We estimated exposure to multiple food contaminants based on dietary data from preschool-age children (2--4 years, n=207), school-age children (5--7 years, n=157), parents of young children (n=446), and older adults (n=149). We compared exposure estimates for eleven toxic compounds (acrylamide, arsenic, lead, mercury, chlorpyrifos, permethrin, endosulfan, dieldrin, chlordane, DDE, and dioxin) based on self-reported food frequency data by age group. To determine if cancer and non-cancer benchmark levels were exceeded, chemical levels in food were derived from publicly available databases including the Total Diet Study. RESULTS: Cancer benchmark levels were exceeded by all children (100%) for arsenic, dieldrin, DDE, and dioxins. Non-cancer benchmarks were exceeded by >95% of preschool-age children for acrylamide and by 10% of preschool-age children for mercury. Preschool-age children had significantly higher estimated intakes of 6 of 11 compounds compared to school-age children (p<0.0001 to p=0.02). Based on self-reported dietary data, the greatest exposure to pesticides from foods included in this analysis were tomatoes, peaches, apples, peppers, grapes, lettuce, broccoli, strawberries, spinach, dairy, pears, green beans, and celery. CONCLUSIONS: Dietary strategies to reduce exposure to toxic compounds for which cancer and non-cancer benchmarks are exceeded by children vary by compound. These strategies include consuming organically produced dairy and selected fruits and vegetables to reduce pesticide intake, consuming less animal foods (meat, dairy, and fish) to reduce intake of persistent organic pollutants and metals, and consuming lower quantities of chips, cereal, crackers, and other processed carbohydrate foods to reduce acrylamide intake.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Review of developmental origins of health and disease publications in environmental epidemiology

Authors: Heindel, JJ; Skalla, LA; Joubert, BR; Dilworth, CH; Gray, KA (In Press) Reproductive Toxicology. HERO ID: 3513932

[Less] The Developmental Origins of Health and Disease (DOHaD) scientific field investigates the influence . . . [More] The Developmental Origins of Health and Disease (DOHaD) scientific field investigates the influence of early life environmental stressors on later life health outcomes. Environmental chemical exposures are a particular focus area within this field. Although the DOHaD hypothesis originated in the 1990s, the data evaluating this hypothesis in environmental epidemiology has not been comprehensively summarized. We conducted a scoping literature review to describe the human evidence for the DOHaD hypothesis and to identify, 1) where there may be reasonable data to draw conclusions, and 2) areas warranting further research. Using PubMed and Web of Science we identified 425 publications through 2014 that met our criteria for evaluating the DOHaD hypothesis in environmental epidemiology. These publications covered 60 different chemicals. The majority of publications focused on neurological/cognitive outcomes, followed by cancer, and respiratory outcomes. We note areas ready for more detailed review, those requiring more data and ideas for future directions.