Studies of infants postnatally exposed to methylmercury

Does Methylmercury Have a Role in Causing Developmental Disabilities in Children?

“…The clinical picture in these children was confirmed as similar to that reported in Japan (8)(9)(10)(12)(13)(14). Mercury levels in maternal hair growing during pregnancy were determined and, for the first time, assessment of associations between the level and timing of exposure and the children's disabilities was possible, thus providing a dose-response relationship (15).…”

“…Its toxicity has been known for centuries (4) and multiple episodes of poisoning in children by both inorganic and organic mercury have been reported (5,6). The organic forms of mercury are particularly neurotoxic (7)(8)(9)(10)(11)(12)(13)(14)(15)(16). Both prenatal and postnatal exposure to MeHg can adversely affect the central nervous system, but it appears to be most neurotoxic prenatally when the brain is developing rapidly.…”

“…A limited number of associations between postnatal exposure and outcomes have been reported. Amin-Zaki et al (9,11,13) Faroe Islands study reported that breastfeeding was associated with enhanced achievement of early developmental milestones (39). However, Grandjean et al (45) reported no associations between postnatal exposure measured at 1 and 7 years and an extensive test battery given at 7 years of age.…”

“…It contains nutrients such as docosahexanoic acid, taurine, and cholesterol that may not be present in infant formulas or cow's milk. However, breast milk can also contain small quantities of organic and inorganic mercury if maternal exposure is high, and it can be an important source of exposure (9,10,13).…”

Effects of breast feeding on neuropsychological development in a community with methylmercury exposure from seafood

“…It has an almost complete absorption from the gut and passes the placental barrier easily (Reynolds and Pitkin, 1975); it can also be transferred to the infant through breast milk (Amin-Zaki et al, 1980). Clinical data from Iraq (Amin-Zaki et al, 1974, 1980 suggest that postnatal exposure via breast milk contributed to or caused several cases of methylmercury intoxication. However, the exact contribution of exposure from milk, as compared to transplacental exposure, is unclear from the published data, partly because some congenital cases of methylmercury poisoning were not diagnosed until 3 months after birth.…”