The Cognitive Performance Effects of PM2.5 and Wildfire Smoke Exposure in the United States
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There is increasing evidence that exposure to air pollution adversely impacts cognitive health. While PM2.5 and wildfire smoke are pollutants of growing concern, there is limited evidence to date if short-term exposure impacts cognitive function. We aimed to evaluate the relationship between daily and sub-daily PM2.5 and smoke exposure and changes in cognitive performance in adults. Cognitive performance data was obtained for 1,809 Lumosity users, age 18+, who completed 20 plays of a brain-training game targeted to improve attention in the western United States during 2017-2018. We considered two measures of daily and sub-daily air pollution exposure: (1) daily and hourly PM2.5 concentration estimates, obtained from a Bayesian Maximum Entropy data fusion of observations from FRM/FEM and PurpleAir monitors, and (2) smoke density, obtained from NOAA’s Hazard Mapping System Smoke Product. We used a longitudinal repeated measures study design with a linear mixed effects model to quantify the relationships between measures of short-term exposure and cognitive performance, overall and by age group and gender. All measures of daily and sub-daily PM2.5 exposure were significantly negatively associated with Lumosity performance. A 10 μg/m3 increase in daily average PM2.5 the day of gameplay was associated with 44.28 (95% CI: -84.27, -4.28) point decrease in Lumosity score. The elderly (70+) were most significantly affected and there were no observed differences by gender. Heavy smoke density at lag 1 and 1 week prior were significantly negatively associated with Lumosity performance. Heavy smoke density the day prior to gameplay was associated with a 119.30 (95% CI: -212.24, -26.36) point decrease in score relative to no smoke. The youngest age group (18-29) and men were most affected. Overall, our results indicate that short-term exposure to PM2.5 and wildfire smoke adversely impact attention in adults. More research is needed to investigate these relationships. This abstract does not reflect EPA policy.