Effects of Recent Air Pollution Exposure on Children’s Neurocognitive Functions and the Possible Link with Endothelial Function

Air pollution poses a major health risk, particularly in children, who spend considerable time in school. We monitored air pollution in school environments and investigated its impact on cardiovascular and neurocognitive outcomes. Seven elementary schools in Antwerp, Belgium, including one open-air school, participated in a longitudinal study. Indoor and outdoor particulate matter (PM) and outdoor NO2 concentrations were measured. Endothelial function and attentional outcomes were assessed repeatedly (n = 3) in 138 healthy children (mean age of 10.3 ± 0.5 years, 55.8% male). Mixed effect models were used to investigate the association between PM and NO2 exposure and endothelial and attentional outcomes. This study considered median PM concentrations during the 4 h of the study visits (direct exposure), those during the 24 h (acute exposure) and 1 week preceding the study visits (recent exposure), and monthly NO2 concentrations. Models were adjusted for sex, age, BMI-z, and visit. Increased direct (4 h) indoor PM exposure was associated with reduced microvascular dilatation, while selective and sustained attention improved with direct and recent PM exposure, respectively. No associations were found with NO2. Exclusion of the open-air school slightly altered the findings. Larger longitudinal studies with improved exposure assessment are needed to clarify the effects of PM exposure and the influence of (open-air) school environments on children’s learning and development.