Growing evidence links prenatal air pollution with early behavioral outcomes, yet U.S. studies remain sparse. We analyzed data from 8370 mother–child dyads from 28 Environmental influences on Child Health Outcomes (ECHO) Cohort sites. Prenatal nitrogen dioxide (NO2), fine particulate (PM2.5), and ozone (O3) levels were estimated using residential addresses. Caregiver-reported Child Behavior Checklist for ages 1.5–5 (CBCL/1.5–5) assessed internalizing and externalizing problems. Covariate-adjusted linear mixed-effects models estimated associations between pollutants and CBCL/1.5–5 T-scores. Child sex, socioeconomic neighborhood conditions, and prenatal depressive symptoms were evaluated as potential modifiers. Each interquartile range increase in pregnancy-average PM2.5 was associated with higher externalizing (βexternalizing = 0.52, 95% confidence intervals: 0.15–0.90) and internalizing (βinternalizing = 0.45, 0.07–0.83) T-scores. Trimester-specific associations were observed: first-trimester PM2.5 was associated with externalizing (βexternalizing = 0.39, 0.08–0.70) and second-trimester PM2.5 with internalizing (βinternalizing = 0.32, 0.01–0.64) T-scores. Third-trimester NO2 was linked to higher behavioral T-scores (βexternalizing = 0.52, 0.03–1.01; βinternalizing = 0.51, 0.00–1.01). Associations for O3 were nonsignificant. Children from the lowest-opportunity neighborhoods exhibited stronger positive associations for NO2. Males and children whose mothers reported lower prenatal depressive symptoms showed stronger inverse associations for O3. Overall, prenatal PM2.5 and NO2 exposures may be associated with modest increases in early behavioral problems, potentially affecting many children given widespread exposure.
Oh et al. (Thu,) studied this question.