The effect of wildfire smoke exposure on student performance: A nationwide study across two decades (2000–2020) and over 40 million students in Brazil

Abstract

The impact of wildfire smoke exposure on public health has been extensively studied, yet its potential consequences on academic performance remain relatively unexplored, particularly in the context of fire-prone regions, such as Brazil. We conducted a nationwide study of more than 40 million high school students in Brazil who took the National High School Exam (ENEM) between 2000 and 2020. We used mixed-effects regression models with state-specific random intercepts to examine the associations between the wildfire events and academic performance among Brazilian students. We accounted for multiple covariates, including socioeconomic status, spatiotemporal factors, air pollutants, and weather variables. We also explored the effect modification by exam subject (general subjects and essay), school management (private and public schools), location (urban and rural schools), and time period. Our findings suggest that increased wildfire events are associated with lower academic performance in both essay and general subjects. After adjustments for the covariates, the primary analysis results indicate a negative impact of wildfires on essay writing, with an estimated coefficient of −0.09 (95 % CI: −0.13; −0.05) with 100 wildfire records increase. Similarly, an increase of 100 wildfire records per year corresponded to a decrease of 0.10 (95 % CI: 0.06; 0.11) points for general subjects. This effect on academic performance was associated with a reduction of 0.33 % (95 %CI: 0.31 %; 0.34 %) in essay and 0.54 % (95 %CI: 0.52 %; 0.56 %) in general subjects. Our findings highlight the need for further attention to the influence of wildfire smoke exposure on student academic performance, suggesting that even small associations at the individual level could have broader implications for public health and education policies.