Characterizing the relationship between air pollution and childhood cognition in the Children's health and air pollution study.

Air pollution has been linked to impaired cognitive outcomes and lower academic performance in children. The Children's Health and Air Pollution Study (CHAPS) is a longitudinal cohort study following children who live in the Fresno metropolitan area of California, where air pollution is notoriously high. In this study, we investigated the relationship between estimated concentrations of three high-priority air pollutants (PM2.5, NO2, and O3) at the home and school and multiple years of standardized test scores from children in the CHAPS cohort. We analyzed data from 97 children between ages 8 to 13 who had reported at least three years of standardized testing between 2015 and 2022. To model the relationship between pollution and testing performance over multiple time points, we ran six mixed effects linear regression models differentiated by pollutant (PM2.5, NO2, and O3), and standardized tests (English Language Arts or math). Math standardized test scores were negatively associated with O3 and PM2.5, but not NO2. A one part per billion (ppb) increase in O3 was associated with a -0.078 (95% CI: -0.145 to -0.010) standard deviation decrease in test scores and a 1 μg per meter cubed (μg/m3) increase in PM2.5 was associated with a -0.074 standard deviation decrease in test score (95% CI: -0.120 to -0.032). There was a weak negative association between English Language Arts and both O3 and PM2.5, however, the confidence intervals for these associations overlapped the null. The association between O3 and math scores was eliminated after adjusting for PM2.5, and may have resulted from collinearity between O3 and PM2.5 rather than a unique association between O3 and math scores. This association between air pollutant exposure at home and school and student standardized test scores emphasizes the possible neurocognitive impact of air pollution on a measure available for nearly all California children.