Particle Pollution and Cognition: Evidence from Sensitive Cognitive Tests in Brazil

This paper analyzes the impact of short-term exposure to fine particulate matter (PM2.5) on the cognitive performance of students who were tested on a range of sensitive tests at a large university in Brazil. To examine whether the effect of PM2.5 varies by cognitive domain, we employ tests measuring simple attention, complex attention, arithmetic processing speed, working memory, and fluid reasoning. Exploiting plausibly exogenous variation in fine particulate matter—which easily penetrates indoor settings—across 54 lab sessions over a 3-year period with 464 students, we find evidence suggesting that exposure to high levels of PM2.5 reduces performance on a fluid reasoning test. By contrast, we do not find evidence to support an effect of PM2.5 on the other cognitive tests, although we are underpowered to detect modest effects on these tests.