Personal and community-level exposure to air pollution and daily changes in respiratory symptoms and oxygen saturation among adults with COPD

•Air pollution exposure was measured by portable personal and fixed community monitors.•Changes in COPD respiratory symptoms were self-reported by daily electronic surveys.•Community-level O3 and PM2.5 were associated with worsening respiratory symptoms.•Personal exposure to NO2 was associated with lower oxygen saturation.•Personal exposure to PM2.5 was associated with lower odds of worsening symptoms.