OPS 22: Behavioral effects of chemical exposures, Room 117, Floor 1, August 27, 2019, 4:30 PM - 5:30 PM
Background: Previous epidemiologic studies suggest that phthalates, ubiquitous synthetic chemicals, may adversely impact neurodevelopment. However, data are limited on how prenatal phthalate exposure impacts behavioral outcomes into childhood and adolescence.
Methods: We examined associations between maternal prenatal urinary phthalate metabolite concentrations, measured twice during pregnancy, and performance-based and parent-, teacher-, and self-reported behavioral outcomes from ages 9 through 16 years in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) birth cohort (n=332). We used generalized estimating equation models to assess longitudinal effects and examined differences by sex.
Results: Higher prenatal concentrations of the sum of metabolites of low molecular weight (ΣLMW) phthalates were associated with more self-reported problems for the hyperactivity (β per 2-fold increase in ΣLMW phthalates=0.5; 95% CI: 0.0, 0.9), attention (β=0.8; 95% CI: 0.3, 1.2), depression (β=0.5; 95% CI: 0.0, 1.0), and anxiety (β=0.5; 95% CI: 0.0, 1.0) scales of the Behavior Assessment System for Children, 2nd edition (BASC-2). Similar, albeit weaker, trends were observed for parent-reported results; however, associations with most teacher-reported behaviors were null or in the opposite direction of parent- and self-reported results. ΣLMW phthalates were also associated with greater errors of omission (β per 2-fold increase in ΣLMW phthalates=0.9; 95% CI: 0.0, 1.8) on the Conners’ Continuous Performance Test II (CPT-II). BASC-2 and CPT-II data were examined as age- and sex-standardized T-scores. We observed largely null associations for biomarkers of exposure to di(2-ethylhexyl) and high molecular weight phthalates. We did not observe consistent sex-specific associations.
Conclusion: We observed modest associations between prenatal ΣLMW phthalate biomarkers and internalizing, externalizing, and attention problems in childhood and adolescence. No previous studies have examined the impact of prenatal phthalate exposure on neurodevelopment into adolescence, an important time for manifestations of effects.