Air pollution and attention in Polish schoolchildren with and without ADHD

Development and functioning of attention-a key component of human cognition-can be affected by environmental factors. We investigated whether long- and short-term exposure to particulate matter with aerodynamic diameter < 10 μm (PM₁₀) and nitrogen dioxide (NO₂) are related to attention in 10- to 13-year-old children living in Polish towns recruited in the NeuroSmog case-control study.

We investigated associations between air pollution and attention separately in children with attention deficit hyperactivity disorder (ADHD, n = 187), a sensitive, at-risk population with impaired attention and in population-based typically developing children (TD, n = 465). Alerting, orienting, and executive aspects of attention were measured using the attention network test (ANT), while inhibitory control was measured with the continuous performance test (CPT). We assessed long-term exposure to NO₂ and PM₁₀ using novel hybrid land use regression (LUR) models. Short-term exposures to NO₂ and PM₁₀ were assigned to each subject using measurements taken at the air pollution monitoring station nearest to their home address. We tested associations for each exposure-outcome pair using adjusted linear and negative binomial regressions.

We found that long-term exposures to both NO₂ and PM₁₀ were associated with worse visual attention in children with ADHD. Short-term exposure to NO₂ was associated with less efficient executive attention in TD children and more errors in children with ADHD. It was also associated with shorter CPT response times in TD children; however, this effect was accompanied by a trend towards more CPT commission errors, suggestive of more impulsive performance in these subjects. Finally, we found that short-term PM₁₀ exposure was associated with fewer omission errors in CPT in TD children.

Exposure to air pollution, especially short-term exposure to NO₂, may have a negative impact on attention in children. In sensitive populations, this impact might be different than in the general population.