2 September 2026This paper estimates the causal effect of chronic exposure to industrial pollution during middle school on performance in the end-of-middle-school national examination (brevet) and on high-school track choice. We link administrative records for nearly 1.8 million French students from three cohorts (2010-2012) to the universe of industrial facilities reporting emissions of thirteen major pollutants and construct each school cohort’s cumulative exposure over the four years of middle school. We identify its causal effect using a wind-based instrument that exploits within-school, cohort-to-cohort variation in realized wind direction. A one standard deviation (SD) increase in realized downwind exposure lowers brevet scores by 0.069 SD, reduces the brevet pass rate by 1.8 percentage points (pp), and decreases entry into the academic high-school track by 2.5 pp. The effects are driven primarily by emissions from metallurgy and energy plants, especially particulates (PM10), reactive gases, and neurotoxic metals, and are highly concentrated geographically and among disadvantaged students