I examine the impact of prenatal total suspended particulate (TSP) exposure on educational outcomes using county-level variation in the timing and severity of the industrial recession of the early 1980s as a shock to ambient TSPs (similar to Chay and Greenstone 2003b). I then instrument for pollution levels using county-level changes in relative manufacturing employment. A standard deviation decrease in TSPs in a student's year of birth is associated with 2 percent of a standard deviation increase in high school test scores for OLS and 6 percent for IV. I also consider how migration and selection into motherhood relate to my results. (Contains 3 figures, 4 tables, and 20 footnotes.)