Air pollution and attention in Polish schoolchildren with and without ADHD.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

NeuroSmog: Determining the Impact of Air Pollution on the Developing Brain: Project Protocol.

Exposure to airborne particulate matter (PM) may affect neurodevelopmental outcomes in children. The mechanisms underlying these relationships are not currently known. We aim to assess whether PM affects the developing brains of schoolchildren in Poland, a country characterized by high levels of PM pollution. Children aged from 10 to 13 years (n = 800) are recruited to participate in this case-control study. Cases (children with attention deficit hyperactivity disorder (ADHD)) are being recruited by field psychologists. Population-based controls are being sampled from schools. The study area comprises 18 towns in southern Poland characterized by wide-ranging levels of PM. Comprehensive psychological assessments are conducted to assess cognitive and social functioning. Participants undergo structural, diffusion-weighted, task, and resting-state magnetic resonance imaging (MRI). PM concentrations are estimated using land use regression models, incorporating information from air monitoring networks, dispersion models, and characteristics of roads and other land cover types. The estimated concentrations will be assigned to the prenatal and postnatal residential and preschool/school addresses of the study participants. We will assess whether long-term exposure to PM affects brain function, structure, and connectivity in healthy children and in those diagnosed with ADHD. This study will provide novel, in-depth understanding of the neurodevelopmental effects of PM pollution.