Air pollution exposure during pregnancy and childhood, cognitive function, and emotional and behavioral problems in adolescents

Abstract

Background: Exposure to air pollution may impact neurodevelopment during childhood, but current evidence on the association with cognitive function and mental health is inconclusive and primarily focusses on young children. Therefore, we aim to study the association of exposure to air pollution during pregnancy and childhood, with cognitive function and emotional and behavioral problems in adolescents.

Methods: We used data from 5170 participants of a birth cohort in Rotterdam, the Netherlands. Concentrations of fourteen air pollutants at participant's home addresses were estimated during pregnancy and childhood, using land use regression models. We included four cognitive domains (processing speed, working memory, fluid reasoning and verbal intelligence quotient (IQ)) and an estimated full-scale IQ. Internalizing, externalizing, and attention problems were self- and parent-reported. We used linear regression models to assess the association of each air pollutant, with cognitive function and emotional and behavioral problems, adjusting for socioeconomic status and lifestyle characteristics. Then, we performed multipollutant analyses using the Deletion/Substitution/Addition (DSA) algorithm.

Results: Air pollution exposure was not associated with full-scale IQ, working memory, or processing speed. Higher exposure to few air pollutants was associated with higher fluid reasoning and verbal IQ scores (e.g. 0.22 points of fluid reasoning (95%CI 0.00; 0.44) per 1 μg/m³ increase in organic carbon during pregnancy). Higher exposure to some air pollutants was also associated with less internalizing, externalizing, and attention problems (e.g. -0.27 internalizing problems (95% CI -0.52; -0.02) per each 5 ng/m³ increase in copper during pregnancy).

Conclusions: Higher exposure to air pollution during pregnancy and childhood was not associated with lower cognitive function or more emotional and behavioral problems in adolescents. Based on previous literature and biological plausibility, the observed protective associations are probably explained by negative residual confounding, selection bias, or chance and do not represent a causal relationship.

Keywords: Adolescents; Air pollution; Cognitive function; Environmental epidemiology; Mental health; Traffic.