Physical activity attenuates negative effects of short-term exposure to ambient air pollution on cognitive function

[Display omitted] As physical activity benefits brain health whereas air pollution damages it, the cognitive response to these exposures may interact. This study aimed to assess the short-term joint effect of physical activity and air pollution on cognitive function in a panel of healthy young adults. We followed ninety healthy subjects aged around 22 years from September 2020 to June 2021 and measured their personal exposure to fine particulate matter (PM2.5) (μg/m3) and daily accelerometer-based moderate-to-vigorous physical activity (MVPA) (min/day) in 4 one-week-long sessions over the study period. At the end of each measurement session, we assessed executive function using Stroop color-word test and collected resting-state electroencephalogram (EEG) signals. We found short-term PM2.5 exposure damaged executive function (βPM25 = 0.0064, p = 0.039) but physical activity could counterbalance it (βMVPA = −0.0047, p = 0.048), whereby beta-3 wave played as a potential mediating role. MVPA-induced improvement on executive function was larger in polluted air (βMVPA = −0.010, p = 0.035) than that in clean air (βMVPA = −0.003, p = 0.45). To offset the negative effect of air pollution on cognitive function, individuals should do extra 13.6 min MVPA every day for every 10 μg/m3 increase in daily PM2.5. This study implies that physical activity could be used as a preventive approach to compensate the cognitive damages of air pollution.