Does Particulate Matter Affect Cognitive Performance?

This study analyzes the effect of test-hour particulate matter (PM10) on the college entrance test performance of 290,000 high school seniors. The data are drawn from Seoul, the capital city of South Korea, where each of the 25 districts has at least one PM10 monitoring station. The study finds that reading test scores decrease when the test-hour PM10 concentration increases. Specifically, when the one-hour average PM10 concentration is ≥75 μg/m3, reading test scores decrease by 0.13 standard deviations relative to when the concentration is lower than 25 μg/m3. The effect size is equivalent to increasing class size by six or seven students. In addition, the one-hour average concentrations measured before and after the reading test have no significant effects on the test scores, meaning that it is unlikely that other factors drive the result.