Prenatal exposure to methyl mercury among Greenlandic polar Inuits.

During the period 1982 to 1988, 37 paired samples of blood from Inuit women and their newborn children were collected in North Greenland. The samples were analyzed for whole blood content of total mercury (tot-Hg) and for content of methyl mercury (Me-Hg). In maternal blood, 80% of the tot-Hg was found to be methylated in contrast to 98% in cord blood. Concentrations of Me-Hg in maternal and cord blood were significantly correlated, and the mean ratio between fetal and maternal blood Me-Hg was 1.9. Concentrations of Me-Hg in cord blood were closely related to the marine food intake of the mothers. Eighty-four percent of the mothers had blood concentrations of Me-Hg above 0.11 mumol/l (23 micrograms/l), which corresponds to the provisional limit of tolerable intake set by the World Health Organization. This indicates that the majority of the pregnant woman have an unacceptable high intake of methyl mercury.