Methylmercury in Populations Eating Large Quantities of Marine Fish

Turner, Mark D.; Marsh, David O.; Smith, J.C.; Inglis, J.B.; Clarkson, Thomas W.; Rubio, Carlos; Chiriboga, J.; Chiriboga, Carlos Collazos

doi:10.1080/00039896.1980.10667521

Cited by 64 publications

(22 citation statements)

References 8 publications

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“…Most studies on MeHg biomarker associations have applied standard regression equations (Akagi, 1998; Bjornberg et al, 2003; Haxton et al, 1979; Phelps et al, 1980; Sherlock et al, 1982; Turner et al, 1980). An important limitation is that this approach includes measurement error only in the dependent variable (Fuller, 1987).…”

Section: Discussionmentioning

confidence: 99%

Effect of hemoglobin adjustment on the precision of mercury concentrations in maternal and cord blood

Kim

Choi²,

et al. 2014

Environmental Research

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The cord-blood mercury concentration is usually considered the best biomarker in regard to developmental methylmercury neurotoxicity. However, the mercury concentration may be affected by the binding of methylmercury to hemoglobin and perhaps also selenium. As cord-blood mercury analyses appear to be less precise than suggested by laboratory quality data, we studied the interrelationships of mercury concentrations with hemoglobin in paired maternal and cord blood samples from a Faroese birth cohort (N = 514) and the Mothers and Children’s Environmental Health study in Korea (n=797). Linear regression and structural equation model (SEM) analyses were used to ascertain interrelationships between the exposure biomarkers and the possible impact of hemoglobin as well as selenium. Both methods showed a significant dependence of the cord-blood concentration on hemoglobin, also after adjustment for other exposure biomarkers. In the SEM, the cord blood measurement was a less imprecise indicator of the latent methylmercury exposure variable than other exposure biomarkers available, and the maternal hair concentration had the largest imprecision. Adjustment of mercury concentrations both in maternal and cord blood for hemoglobin improved their precision, while no significant effect of the selenium concentration in maternal blood was found. Adjustment of blood-mercury concentrations for hemoglobin is therefore recommended.

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Section: Discussionmentioning

confidence: 99%

Effect of hemoglobin adjustment on the precision of mercury concentrations in maternal and cord blood

Kim

Choi²,

et al. 2014

Environmental Research

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“…Methylmercury (MeHg) is a well-recognized environmental contaminant with established health risk to human beings by fish and marine mammal consumption [1]. MeHg can easily cross the blood-brain barriers and cause central nervous system (CNS) damage.…”

Section: Introductionmentioning

confidence: 99%

Riluzole-Triggered GSH Synthesis via Activation of Glutamate Transporters to Antagonize Methylmercury-Induced Oxidative Stress in Rat Cerebral Cortex

Deng

Liu

et al. 2012

Oxidative Medicine and Cellular Longevity

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Objective. This study was to evaluate the effect of riluzole on methylmercury- (MeHg-) induced oxidative stress, through promotion of glutathione (GSH) synthesis by activating of glutamate transporters (GluTs) in rat cerebral cortex. Methods. Eighty rats were randomly assigned to four groups, control group, riluzole alone group, MeHg alone group, and riluzole + MeHg group. The neurotoxicity of MeHg was observed by measuring mercury (Hg) absorption, pathological changes, and cell apoptosis of cortex. Oxidative stress was evaluated via determining reactive oxygen species (ROS), 8-hydroxy-2-deoxyguanosine (8-OHdG), malondialdehyde (MDAs), carbonyl, sulfydryl, and GSH in cortex. Glutamate (Glu) transport was studied by measuring Glu, glutamine (Gln), mRNA, and protein of glutamate/aspartate transporter (GLAST) and glutamate transporter-1 (GLT-1). Result. (1) MeHg induced Hg accumulation, pathological injury, and apoptosis of cortex; (2) MeHg increased ROS, 8-OHdG, MDA, and carbonyl, and inhibited sulfydryl and GSH; (3) MeHg elevated Glu, decreased Gln, and downregulated GLAST and GLT-1 mRNA expression and protein levels; (4) riluzole antagonized MeHg-induced downregulation of GLAST and GLT-1 function and expression, GSH depletion, oxidative stress, pathological injury, and apoptosis obviously. Conclusion. Data indicate that MeHg administration induced oxidative stress in cortex and that riluzole could antagonize this situation through elevation of GSH synthesis by activating of GluTs.

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“…Accumulation of mercury in fish, shellfish, and cetaceans results in increased human exposures to mercury in populations whose diet includes a high intake of aquatic or marine food (Turner et al, 1980). Average hair mercury concentrations in people who do not consume fish are approximately 2 ppm, while in persons ingesting seven fish meals a week, hair mercury concentrations are on the order of 11.6 ppm (WHO, 1990).…”

Section: Introductionmentioning

confidence: 99%

Determination of a site-specific reference dose for methylmercury for fish-eating populations

Shipp¹,

Gentry²,

Lawrence³

et al. 2000

Toxicol Ind Health

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Environmental risk-management decisions in the U.S. involving potential exposures to methylmercury currently use a reference dose (RfD) developed by the U.S. Environmental Protection Agency (USEPA). This RfD is based on retrospective studies of an acute poisoning incident in Iraq in which grain contaminated with a methylmercury fungicide was inadvertently used in the baking of bread. The exposures, which were relatively high but lasted only a few months, were associated with neurological effects in both adults (primarily paresthesia) and infants (late walking, late talking, etc.). It is generally believed that the developing fetus represents a particularly sensitive subpopulation for the neurological effects of methylmercury. The USEPA derived an RfD of 0.1 microg/kg/day based on benchmark dose (BMD) modeling of the combined neurological endpoints reported for children exposed in utero. This RfD included an uncertainty factor of 10 to consider human pharmacokinetic variability and database limitations (lack of data on multigeneration effects or possible long-term sequelae of perinatal exposure). Alcoa signed an Administrative Order of Consent for the conduct of a remedial investigation/feasibility study (RI/FS) at their Point Comfort Operations and the adjacent Lavaca Bay in Texas to address the effects of historical discharges of mercury-containing wastewater. In cooperation with the Texas Natural Resource Conservation Commission and USEPA Region VI, Alcoa conducted a baseline risk assessment to assess potential risk to human health and the environment. As a part of this assessment. Alcoa pursued the development of a site-specific RfD for methylmercury to specifically address the potential human health effects associated with the ingestion of contaminated finfish and shellfish from Lavaca Bay. Application of the published USEPA RfD to this site is problematic; while the study underlying the RfD represented acute exposure to relatively high concentrations of methylmercury, the exposures of concern for the Point Comfort site are from the chronic consumption of relatively low concentrations of methylmercury in fish. Since the publication of the USEPA RfD, several analyses of chronic exposure to methylmercury in fish-eating populations have been reported. The purpose of the analysis reported here was to evaluate the possibility of deriving an RfD for methylmercury, specifically for the case of fish ingestion, on the basis of these new studies. In order to better support the risk-management decisions associated with developing a remediation approach for the site in question, the analysis was designed to provide information on the distribution of acceptable ingestion rates across a population, which could reasonably be expected to be consistent with the results of the epidemiological studies of other fish-eating populations. Based on a review of the available literature on the effects of methylmercury, a study conducted with a population in the Seychelles Islands was selected as the critical study for this analysis. T...

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Methylmercury in Populations Eating Large Quantities of Marine Fish

Cited by 64 publications

References 8 publications

Effect of hemoglobin adjustment on the precision of mercury concentrations in maternal and cord blood

Effect of hemoglobin adjustment on the precision of mercury concentrations in maternal and cord blood

Riluzole-Triggered GSH Synthesis via Activation of Glutamate Transporters to Antagonize Methylmercury-Induced Oxidative Stress in Rat Cerebral Cortex

Determination of a site-specific reference dose for methylmercury for fish-eating populations

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