Assessment of Mercury Levels in Mother/Neonate Pairs in Brooklyn

Prenatal mercury exposure can interfere with essential brain development processes, and can cause developmental and language deficits. The most common route of prenatal exposure is through maternal ingestion of contaminated fish, and contaminated products (e.g., skin-lightening creams). This study assessed mercury levels in the urine of pregnant women and in cord blood collected at delivery, and examined sources of exposure in a predominantly Caribbean, urban immigrant population. A questionnaire designed in collaboration with health professionals from the Caribbean community assessed possible environmental exposures to mercury including fish consumption, ritualistic practices, occupational exposures, use of dental amalgams, and use of mercury-containing skin products and household products. Of the 190 participants, 78 provided cord blood samples. The geometric mean (95% CI) for total mercury in cord blood was 2.18 µg/L (1.76-2.69), compared to 0.326 µg/L (0.285-0.372) total blood mercury reported in CDC's Fourth National Report on Human Exposure to Environmental Chemicals in the age group 1-5 years. The 95th percentile levels for our study and CDC's were 9.15 µg/L and 1.80 µg/L, respectively. Predictors of elevated cord blood mercury levels included higher gestational fish consumption and foreign birth of the mother. There were no reports of elemental mercury use in ritualistic practices or use of skin-lightening creams. This study highlights data gaps in the assessment of environmental risk factors related to mercury exposure in urban immigrant communities. Findings may help target interventions with respect to fish consumption habits during pregnancy and appropriate handling and disposal of mercury sources in the home.