Prenatal exposure to air pollution does not increase risk of ADHD symptoms in children
Exposure to air pollution during pregnancy does not appear to increase the risk of attention-deficit/hyperactivity disorder (ADHD) symptoms in children aged 3–10 years, suggests a recent study.
A total of 2,801 children were classified as having ADHD symptoms within the borderline/clinical range and 1,590 within the clinical range.
Prenatal exposure to air pollution did not correlate with higher odds of ADHD symptoms within the borderline/clinical range (eg, adjusted odds ratio [OR], 0.95; 95 percent CI, 0.89–1.01 per 10 µg/m3 increase in nitrogen oxide [NO2]; adjusted OR, 0.98; 0.80–1.19 per 5 µg/m3 increase in particulate matter [PM] 2.5). Similar associations were observed for ADHD within the clinical range.
The authors examined the association between exposure to air pollution during pregnancy and ADHD symptoms in children in a collaborative study of eight European population-based birth/child cohorts, including 29,127 mother–child pairs.
Concentrations of air pollution (NO2 and PM) were measured at the birth address using land-use regression models based on monitoring campaigns conducted between 2008 and 2011. The authors extrapolated concentrations back in time to exact pregnancy periods.
ADHD symptoms were assessed by teachers or parents at 3–10 years of age. Validated cutoffs were used to classify children as having ADHD symptoms either within the borderline/clinical range or within the clinical range.
The authors combined all adjusted area-specific effect estimates using random-effects meta-analysis and multiple imputations, and applied inverse probability weighting methods to correct for loss to follow-up.