Mercury and Methylmercury Exposure in the New Jersey Pregnant Population

Methylmercury is a known fetal developmental neurotoxicant. The only significant source of fetal exposure is maternal fish consumption; however, few recent data on exposure of the pregnant population are available. The authors undertook a study of methylmercury exposure in the New Jersey pregnant population to investigate the distribution of exposure and to identify predictors of elevated exposure. Mainly first-trimester pregnant women were recruited through six New Jersey obstetric practices. Hair and blood samples were analyzed for total mercury, and a subset was analyzed for methylmercury. A questionnaire on demographics, life style, and fish-consumption practices was also administered. Although 85-90% of the pregnant population had hair mercury levels that were less than 1.0 μg/gm, 1-2% had levels in a range of possible concern for adverse developmental effects (> 4.0 μg/gm). Regression analysis suggested that blacks and individuals with some college education experienced lower exposures to methylmercury.