Polluting student test performance: School-based evidence on the adverse effects of air pollution

This study investigates the relationship between air pollution and children’s performance on standardized tests, focusing on cognitive ability and cognitive effort. Against the backdrop of mounting environmental concerns and policies striving for sustainable cities and inclusive communities, it aims to answer two main questions: (i) to what extent air pollution is negatively associated with children’s performance on tests of cognitive ability and cognitive effort, and (ii) whether socioeconomic status moderates these associations, or in other words, whether poor air quality disproportionately thwarts the development of disadvantaged children. The Study combines individual data from a balanced, school-based sample of 1368 fifth-grade students from a lab-in-the-field study in Madrid and Berlin with data from the Copernicus Atmosphere Monitoring Service on four pollutants (CO, NO2, O3 and PM2.5) over various time intervals. We hypothesize that air pollution reduces performance in both test domains, and that children with low socioeconomic status may be more susceptible to adverse pollution effects, as high SES families may have ways to compensate for the air pollution their children are exposed to at school. Results from hierarchical linear models show significant negative relationships between some cumulative air pollution measures and cognitive ability, with the strongest association observed between cumulative ozone exposure two months prior to the test and cognitive ability. We find little evidence of a relationship between air pollution and cognitive effort. In contrast to our second hypothesis, no heterogeneous effects are found by socioeconomic status.