Gestational and early childhood air pollution exposure and neurodevelopmental outcomes in early childhood

Background Exposure to ambient air pollution, including fine particulate matter (PM 2.5 ), nitrogen dioxide (NO 2 ), and elemental carbon, has been associated with worse neurodevelopmental outcomes in children, but research on early childhood outcomes is limited. Objective This study examined the associations between gestational and early childhood exposures to PM 2.5 and NO 2 and child developmental outcomes measured at ages 1, 2, and 3 years. Methods In the Health Outcomes and Measures of the Environment (HOME) Study, a longitudinal pregnancy and birth cohort, we used spatiotemporal models to estimate the concentration of each air pollutant at participants' home addresses during early brain development. Neurodevelopmental outcomes were measured using the Bayley Scales of Infant Development, Second Edition (BSID-II) at ages 1, 2, and 3 years. For 329 children, we examined the associations of air pollution with BSID-II scores using generalized linear models with generalized estimating equations (GEE). Results Gestational and early childhood NO 2 concentrations were positively associated with cognitive development at age 1 year but negatively associated with cognitive development at age 3 years. Similarly, PM 2.5 exposure through age 3 years was negatively associated with cognitive development at age 3 years. Gestational NO 2 concentration was positively associated with motor development at age 1 year but negatively associated with motor development at ages 2 and 3 years. Discussion These results suggest that exposure to traffic-related air pollution during gestation and after birth may impact neurodevelopment in early childhood.