Protecting schoolchildren from air pollution in Delhi: Evidence from a two-year randomised controlled trial in KV schools
A two-year randomised controlled trial involving approximately 9,000 students in Delhi found that air pollution education increased awareness, encouraged protective behaviours, and improved some health and cognitive outcomes. The educational intervention also generated positive peer spillovers, extending its impact beyond directly treated students. While HEPA air purifiers effectively reduced classroom PM2.5 concentrations, their benefits were partly offset by reduced protective behaviours outside school. The findings support integrating air pollution education into the curriculum and pairing purifier deployment with stronger behavioural messaging to improve student outcomes and inform air quality policy.
Authors
César Antonio Salazar Espinoza
Associate Professor, University of the Bío-BíoKanishka Kacker
Assistant Professor, Economics and Planning Unit, Indian Statistical Institute (Delhi)
Nikita Sangwan
Lecturer, Queen's Business School. Queen's University BelfastMarcela Jaime
Associate Professor, University of Concepcion-
Ruiz-Tagle-Espinoza-Kacker-Sangwan-Jaime-Policy-Brief-April-2026.pdf
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This policy brief summarises findings from a two-year cluster-randomised controlled trial conducted across 180 classes and approximately 9,000 students across Delhi's Kendriya Vidyalaya (KV) schools. It finds that air pollution education increased awareness, encouraged protective behaviours, and improved some health and cognitive outcomes, particularly in the first year.
The educational intervention generated positive peer spillovers, with information spreading beyond directly treated students and increasing awareness across the wider school community.
HEPA air purifiers successfully reduced classroom PM2.5 concentrations, but evidence suggests some students reduced protective behaviours outside school, partially offsetting potential health benefits.
The findings support integrating air pollution education into the school curriculum and pairing purifier deployment with stronger behavioural messaging to improve student health while informing future policy on school operations during severe pollution events.