Abstract
BACKGROUND: Prenatal exposure to organophosphate esters (OPEs) has been linked to neurotoxic effects in children; however, epidemiological evidence remains inconclusive. We investigated associations of prenatal OPE exposure with child behaviors. METHODS: We analyzed data of 2948 mother-child dyads from 12 prospective cohorts of the Environmental influences on Child Health Outcomes (ECHO) Cohort. Nine OPE biomarkers quantified in prenatal maternal urine were modeled based on detection frequency. Child behaviors were assessed using the Child Behavior Checklist for Ages 1½-5. We used linear mixed effects models to examine associations between each OPE biomarker and composite T-scores. We evaluated child sex and social vulnerability as potential effect modifiers. RESULTS: Low bis(butoxyethyl) phosphate exposure, versus non-detect, was associated with higher T-scores for all composite scales (β(internalizing) = 1.06, 95% confidence interval [CI]: 0.14, 1.98; β(externalizing) = 1.06, 95% CI: 0.18, 1.95; β(total) = 1.19, 95% CI: 0.28, 2.11). Low and high bis(1-chloro-2-propyl) phosphate (BCPP) exposure, versus non-detect, were associated with higher T-scores for externalizing problems (β(externalizing) = 1.18, 95% CI: 0.29, 2.07; β(externalizing) = 1.12, 95% CI: 0.21, 2.04). Conversely, detectable dipropyl phosphate (25% detection) was associated with lower externalizing T-scores (β(externalizing) = -0.89, 95% CI: -1.74, -0.04). Associations between high BCPP exposure and higher externalizing and total problem T-scores were stronger among children from highly vulnerable neighborhoods compared to those from less vulnerable neighborhoods (p-interaction < 0.1). Child sex modified associations for bis(1,3-dichloro-2-propyl) phosphate and high BCPP exposure, with males exhibiting greater adverse behaviors for all associations. DISCUSSION: Gestational exposure to several OPEs may be adversely associated with early behavioral development.