Long-term exposure to ambient O3 and PM2.5 is associated with reduced cognitive performance in young adults: A retrospective longitudinal repeated measures study in adults aged 18-90 years.

A growing body of evidence indicates that exposure to air pollution affects cognitive performance; however, few studies have assessed this in the context of repeated measures within a large group of individuals or in a population with a large age range. In this study, we evaluated the associations between long-term exposure to fine particulate matter (PM2.5) and ozone (O3) in large cohort of adults aged 18-90 years. The study cohort included 29,091 Lumosity users in the contiguous US who completed 20 repetitions of the Lost in Migration game between 2017 and 2018. Game scores reflect the ability to filter information and avoid distracting information. Long-term air pollution data included ambient PM2.5 and O3 averaged for the 365-day period before each gameplay date. Generalized linear models were used to examine the associations between long-term PM2.5 and O3 and game score percentile. Co-pollutant models were adjusted for meteorology, time trend, age, gender, device, education, local socioeconomic factors, and urbanicity. Results represent the change in attention game score percentile per 1 µg/m3 increase in PM2.5 or 0.01 ppm increase in O3. In the entire cohort, a -0.10 (95% CI: -0.16, -0.04) change in score percentile was associated with PM2.5, while no significant association was observed with O3. Modification of these associations by age was observed for both PM2.5 and O3, with stronger associations observed in younger users. In users aged 18-29, a -0.25 (-0.45, -0.05) change in score percentile was associated with PM2.5, while no associations were observed in other age groups. With O3, there was a -2.92 (-4.63, -1.19) and -2.81 (-4.29, -1.25) change in score percentile for users aged 18-29 and 30-39, respectively. We observed that elevated long-term PM2.5 and O3 were associated with decreased focus scores in young adults, but follow-up research is necessary to further illuminate these associations.