Assessing the National Health, Education, and Air Quality Benefits of the United States Environmental Protection Agency’s School Bus Rebate Program: A Randomized Controlled Trial Design

This report, available for downloading below, presents a study led by Sara Adar of the University of Michigan’s School of Public Health. Adar and colleagues conducted a thorough accountability study of a program for replacing old diesel school buses with new, lower-emitting buses across the United States.

The investigators assessed the effects of random location of funding for new school buses to school districts between 2012 and 2017 on student health, educational performance, and community air pollution levels.

Key takeaways:

• Student educational performance and school attendance improved in districts that were selected for funding to replace old buses and improved the most in districts that replaced the oldest (pre-1990) diesel-powered school buses. There was no clear effect on emergency department visits.
• Community-level fine particle air pollution concentrations improved in school districts that had been selected for funding with the largest gains in districts that replaced the oldest buses, although it was not clear to what extent those improvements were driven by the new school buses.
• As electric school buses and other lower-emitting technologies become more widely available, additional benefits from continuing efforts to replace older school buses are expected and should be assessed.

Sara Adar spoke about her research on reducing school bus emissions on our Oct. 17, 2024, episode of “Science on the 7th."