Short-Term Exposure to Wildfire Smoke and P[M.sub.2.5] and Cognitive Performance in a Brain-Training Game: A Longitudinal Study of U.S. Adults

Background: There is increasing evidence that long-term exposure to fine particulate matter [PM Objectives: We aimed to evaluate the associations between daily and subdaily (hourly) P[M.sub.2.5] and wildfire smoke exposure and cognitive performance in adults. Methods: Scores from 20 plays of an attention-oriented brain-training game were obtained for 10,228 adults in the United States (U.S.). We estimated daily and hourly P[M.sub.2.5] exposure through a data fusion of observations from multiple monitoring networks. Daily smoke exposure in the western U.S. was obtained from satellite-derived estimates of smoke plume density. We used a longitudinal repeated measures design with linear mixed effects models to test for associations between short-term exposure and attention score. Results were also stratified by age, gender, user behavior, and region. Results: Daily and subdaily P[M.sub.2.5] were negatively associated with attention score. A 10 [micro]g/[m.sup.3] increase in P[M.sub.2.5] in the 3 h prior to gameplay was associated with a 21.0 [95% confidence interval (CI): 3.3, 38.7]-point decrease in score. P[M.sub.2.5] exposure over 20 plays accounted for an estimated average 3.7% (95% CI: 0.7%, 6.7%) reduction in final score. Associations were more pronounced in the wildfire-impacted western U.S. Medium and heavy smoke density were also negatively associated with score. Heavy smoke density the day prior to gameplay was associated with a 117.0 (95% CI: 1.7, 232.3)-point decrease in score relative to no smoke. Although differences between subgroups were not statistically significant, associations were most pronounced for younger (18-29 y), older ([greater than or equal to]70 y), habitual, and male users. Discussion: Our results indicate that P[M.sub.2.5] and wildfire smoke were associated with reduced attention in adults within hours and days of exposure, but further research is needed to elucidate these relationships. https://doi.org/10.1289/EHP10498
Introduction Wildfire smoke is a complex mixture of particulate matter (PM) and gases containing many chemical species. (1) Both wildfire smoke and many of its components have been previously associated [...]