Associations of Pre- and Postnatal Air Pollution Exposures with Child Cognitive Performance and Behavior: A Multi-cohort Study

Abstract

BACKGROUND AND AIM: Research supports the adverse effect of air pollution exposures on child cognitive performance and behavior, but few studies have utilized spatiotemporally resolved pollution predictions. METHODS: We investigated these associations in 1,894 mother-child dyads from three U.S. pregnancy cohorts (CANDLE, TIDES, GAPPS) in the ECHO-PATHWAYS Consortium. Child cognition was assessed using cohort-specific intelligence scales and quantified as the Full-Scale Intelligence Quotient (IQ). Child behavior was reported using the Child Behavior Checklist and quantified as the total problems raw score. Pre- and postnatal nitrogen dioxide (NO2) and particulate matter ≤2.5μm in aerodynamic diameter (PM2.5) were derived from an advanced spatiotemporal model. We fit multivariate linear regressions, adjusted for sociodemographic, behavioral, and psychological factors, to measure associations per 2-unit increase in pollutant in each window, and examined modification by child sex using interaction models. RESULTS:Mean PM2.5 and NO2 ranged from 8.4-9.1 µg/m3 and 8.4-9.0 ppb, respectively, across pre-and postnatal windows. Average child IQ and total problems raw score at 4-6 years were 102.7 (SD:15.3) and 22.6 (SD:18.3). Children with a higher 3rd trimester NO2 exposure had a lower IQ (β=-0.44, 95%CI: -0.81, -0.07). Each 2-ppb increase of NO2 in the 2nd trimester and averaged over pregnancy was associated with a 0.68 (95%CI: 0.09, 1.27) and a 0.85 (95%CI: 0.09, 1.61) higher total problems raw score, respectively. Prenatal PM2.5 was only associated with a higher total problems score (β=1.94, 95%CI: 0.11, 3.76), while PM2.5 at 2-4 years was associated with both outcomes (IQ: β=-2.30, 95%CI: -4.53, 0.08; Total problems: β=3.00, 95%CI: 0.21, 5.78). Other associations were null. No modification by child sex was suggested. CONCLUSIONS:The findings build on the current literature on air pollution and child neurodevelopment by using more refined exposure assessments across several pre- and postnatal windows in settings with modest air pollution levels. KEYWORDS: nitrogen dioxide, particulate matter, cognitive function, child behavior