Pollution and Cognition: Evidence from Sensitive Cognitive Tests in Brazil

Poor air quality is a challenging public health problem in many developed and developing nations. While there is a wealth of evidence on the impacts of air pollution on health and productivity, the literature on the link between pollution and cognition is nascent. While changes in health associated with pollution exposure may mediate any impact that exposure to pollution has on cognitive functioning, pollution may also have impacts on cognition that are independent of health. This paper studies the short-term impact of ambient air pollution on the performance of students at the University of São Paolo on a range of highly sensitive cognitive tests. To shed light on the dimension of cognition that may be adversely affected by pollution, we employed several sensitive tests measuring working memory, fluid intelligence, arithmetic processing speed, simple attention, and complex attention. We exploit variation in fine particulate matter (PM2.5)—which easily penetrates indoor settings—across 54 lab sessions over a 3 year period with 470 students. We investigate whether changes in health underlie any effects of PM2.5 on cognitive performance through a complementary analysis of the impact of PM2.5 on measured health (blood pressure, blood oxygen saturation rate, and pulse rate) as well as self-reported respiratory health.