RELATIONSHIP BETWEEN PRENATAL ENVIRONMENTAL EXPOSURES, BIRTH OUTCOMES AND COGNITIVE DEVELOPMENT IN AN URBAN MINORITY COHORT

Abstract

ISEE-192 Introduction: The Columbia Center for Children’s Environmental Health is evaluating effects of environmental exposures during pregnancy on fetal growth and infant neurocognitive development in a cohort of African American and Dominican mothers and infants in NYC. Exposures include polycyclic aromatic hydrocarbons (PAH), environmental tobacco smoke (ETS), and pesticides. Methods: Data sources include personal air monitoring of the mother during pregnancy, detailed questionnaires and laboratory analyses of biomarkers in blood samples collected from the mothers and newborns at delivery. Over 550 pregnant nonsmoking women have been enrolled and their infants are being followed prospectively through school age. Results: High prenatal exposure to PAH as estimated by personal air monitoring is associated with lower birth weight (p=0.003) and smaller head circumference (p<0.01) among African American newborns, after adjusting for potential confounders. Among both African Americans and Dominicans, ETS was associated with decreased head circumference at birth (p=0.04); and there was a significant interaction between prenatal exposure to ETS and PAH-DNA adducts in cord blood such that the combined exposure to high ETS and high adducts had a significant effect on birth weight (p=0.04) and head circumference (p=0.01) after adjusting for potential confounders. ETS exposure and material hardship during pregnancy were significantly inversely associated with infant cognitive development at two years (p<0.05), controlling for confounders, and there was an interaction effect such that infants with both exposures had a 7-point decrement in cognitive scores at 24 months of age. Compared to non-exposed children, those with prenatal ETS exposure were twice as likely to be classified as significantly delayed. Finally, levels of the insecticide chlorpyrifos in umbilical cord blood samples were inversely associated with birth weight and length (p<0.05), controlling for potential confounders. Combined measures of the insecticides chlorpyrifos and diazinon were also inversely associated with birth weight and length (p<0.03). The associations between birth weight/length and cord plasma chlorpyrifos and diazinon were highly significant (p<0.007) among newborns born prior to the 2000–2001 U.S. EPA’s regulatory actions to phase out residential use of these insecticides, but not among newborns born after 1/1/01 (p>0.8). Discussion: These results indicate that interactions between toxicants as well as between toxicants and socioeconomic stressors during pregnancy impair fetal growth and/or child cognitive development in this minority cohort. These results support recent regulatory action to phase out residential uses of chlorpyrifos and diazinon and indicate the need for further measures to reduce ETS and PAH exposures.