Early life exposure to organophosphate pesticides, behavioral outcomes, and adaptive skills in adolescents from the CHAMACOS study

Abstract

Background: Epidemiologic studies have linked early life exposure to organophosphate (OP) pesticides with poorer cognitive and behavioral development in school age children. However, few studies have examined whether these associations persist into adolescence.Methods: We investigated associations of early life OP pesticide exposure, assessed by measurement of urinary dialkyl phosphate (DAP) metabolites in pregnant women (samples collected at 13 and 26 weeks’ gestation) and their children (repeated samples collected from birth to 5 years), with maternal-reported behaviors assessed longitudinally at ages 14, 16, and 18 years using the Behavior Assessment System for Children, 2nd edition (BASC-2) in 335 adolescents participating in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) study. We used generalized estimating equation models to assess longitudinal effects and examined differences by sex.Results: Median (IQR) prenatal dimethyl phosphate (DM), diethyl phosphate (DE), and total DAP concentrations were 97.8 (47.0-233.5), 23.9 (11.2-44.4), and 128.2 (72.3-290.1) nmol/g creatinine. We observed that higher prenatal creatinine-adjusted DAP concentrations were associated with more maternal-reported hyperactivity (β per 10-fold increase = 2.0; 95% CI: 0.3, 3.7), aggression (β = 1.5; 95% CI: 0.1, 2.8), and withdrawal (β = 2.6; 95% CI: 0.6, 4.5), and with poorer adaptability (β = -2.4; 95% CI: -4.5, -0.2), activities of daily living (β = -3.3; 95% CI: -5.6, -1.1), and functional communication (β = -3.3; 95% CI: -5.3, -1.3). Associations were similar for prenatal DMs and generally stronger in boys than in girls. We observed null associations for prenatal DE concentrations and childhood OP pesticide metabolites.Conclusion: Our findings indicate that prenatal, but not childhood, OP pesticide exposure may be associated with behavioral problems and adaptive deficits that persist into adolescence. Public health interventions and public policy changes to protect developing brains from avoidable environmental insults, such as OP pesticides, are warranted.