Prenatal exposure to ambient fine particulate matter and early childhood neurodevelopment: A population-based birth cohort study

Although previous studies have reported the adverse effect of air pollution exposure during pregnancy on neurodevelopment in children, epidemiological evidence is limited, and the results are inconsistent. This study aimed to explore the association between prenatal ambient fine particulate matter (PM2.5) exposure and early childhood neurodevelopment in a large birth cohort study of 4009 maternal-child pairs. Prenatal daily PM2.5 exposure concentrations at 1 km spatial revolution were estimated using high-performance machine-learning models. Neurodevelopmental outcomes of children at ages 2, 6, 12, and 24 months were assessed using the Ages and Stages Questionnaire (ASQ). Distributed lag nonlinear models were used to identify critical windows of prenatal PM2.5 exposure. General linear mixed models with binomially distributed errors were used to estimate the effect of prenatal PM2.5 exposure on suspected developmental delay (SDD) in five developmental domains based on the longitudinal design. Prenatal PM2.5 exposure was significantly associated with decreased scores for all neurodevelopmental domains of children at ages 2, 6, and 24 months. Each 10-μg/m3 increase in PM2.5 exposure was significantly associated with increased risk of SDD for all subjects (RR: 1.52 95% CI: 1.19, 2.03), specifically, in problem-solving domain for girls (RR: 2.23, 95% CI: 1.22, 4.35). Prenatal PM2.5 exposure in weeks 18 to 34 was significantly associated with both ASQ scores and SDDs. Our study proposed that prenatal PM2.5 exposure affected early childhood neurodevelopment evaluated with the ASQ scale. PM2.5 exposure might increase the risk of SDD for boys and girls, specifically in the problem-solving domain for girls.