Human health risks from methylmercury in fish

Human health risks from methylmercury in fish are evaluated in terms of dose-response relationships for both adult and prenatal human exposures. Specifically, information has become available from three independent epidemiological studies indicating that methylmercury levels in the mother during pregnancy predict the probability of adverse effects in her offspring. The mercury levels in the mother are measured as concentration in head hair which in turn is an excellent predictor of blood concentration. The adverse effects in the offspring take the form of psychomotor retardation. These dose-response relations along with a one-compartment kinetic model for methylmercury accumulation in humans will be used to estimate minimum toxic daily intakes; these are, for nonpregnant adults, 4,300 ng Hg/kg body weight/d and about 600 to 1,100 ng Hg/kg/d for pregnant adults. These values assume continuous exposure until the individual has attained steady state balance with respect to the body burden of methylmercury. This will take up to one year in most cases.