methylmercury


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di·meth·yl·mer·cu·ry

(dī-meth'il-mĕr'kyū-rē),
A contaminant of seafood products synthesized in sediments from mercury and mercury-containing chemicals dumped in waters supporting marine life. Methylmercury is concentrated in aquatic life forms and can thus be deposited in fish intended for human consumption. Probable cause of Minamata disease, a teratogenic condition characterized by multiple birth defects in Japan. An inorganic reagent.
See also: Minamata disease.
Synonym(s): methylmercury

methylmercury

An inorganic mercury industrial pollutant. It is concentrated up the food chain, is teratogenic, and causes severe CNS defects in children whose mothers consumed methylmercury-contaminated seafood while pregnant.

methylmercury

Dimethyl mercury Toxicology An inorganic mercury industrial pollutant; it is concentrated up the food chain, teratogenic and causes severe CNS defects in children whose mothers consumed MM-contaminated seafood while pregnant. See Mercury, Minamata disease.

methylmercury

, methyl mercury (me-thil-mer'ku-re)
An organic mercury compound produced from inorganic mercury by the addition of a methyl group (CH3) by marine and soil bacteria. This compound is readily taken up by plankton, which are then consumed by marine invertebrates, and subsequently by marine predators, in which it concentrates. Finally, it can enter the human body when people eat fish having high concentrations of the compound, such as salmon or halibut (among others). It can also be absorbed into the body through the skin and respiratory tract. Methylmercury is neurotoxic to humans, esp. children. See: mercury poisoningMinamata disease
References in periodicals archive ?
Much attention has focused on mercury methylation or how methylmercury forms, but few studies to date have examined microbial demethylation, or the breakdown of methylmercury at environmentally relevant conditions, said Baohua Gu, co-author and a team lead in ORNLs Mercury Science Focus Area.
2Max] and neurocognitive outcomes among two groups of higher and lower prenatal exposure to methylmercury.
The results are critical in the prediction of how global climate changes can affect the exposure of methylmercury to ecosystems, and humans," Erik BjAaAaAeA rn, associate professor at UmeAaAaAeAN University, Sweden, and le of the research project, said in (http://www.
Methylmercury formation is promoted by the low oxygen levels established by vegetation decaying in the reservoir behind a dam, where this agent will begin to bioaccumulate--moving up the local food chain in ever higher concentrations from the simplest organisms into plants, then animal predators and finally the human inhabitants.
Silbergeld, "Low level methylmercury exposure affects neuropsychological function in adults," Environmental Health: A Global Access Science Source, vol.
Encouraging as that news was, Smith has not lessened her efforts to investigate, understand and disseminate information about the risks of methylmercury and the ongoing challenges presented by environmental contamination in general.
Methylmercury in fish and seafood is easily absorbed on its journey along the digestive tract.
Implications from the study did support that methylmercury does cross the placenta; however it is still unknown at what level methylmercury would correlate to detrimental fetal effects.
The amounts of methylmercury vary among different fish types and even within species (see chart for examples).
2) Mercury contamination, exposures and risks: A new global picture emerges' (ZMWG); Patterns of global seafood mercury concentrations and their relationship with human health' (BRI); An overview of epidemiological evidence on the effects of methylmercury on brain development and a rationale for a lower definition of tolerable exposure' (ZMWG)
Methylmercury can be taken up by aquatic plants and absorbed by insects, worms and other small creatures that live in the sediments.
Food and Drug Administration and the American Academy of Pediatrics calling for the removal of thimerosal in vaccines sold in the United States was made in haste, based on the inaccurate presumption of identical pharmacokinetics of ethylmercury and methylmercury.