Improved Air Quality and Asthma Incidence from School-Age to Young Adulthood: A Population-based Prospective Cohort Study.

Background The benefits of improved air quality on asthma remain understudied. Therefore, our aim was to investigate associations of changes in ambient air pollution with incident asthma from school-age until young adulthood in an area with mostly low air pollution levels. Methods Participants in the BAMSE birth cohort from Stockholm without asthma before the 8-year follow-up were included (N=2371). We estimated the association of change in individual-level air pollutant exposure (particulate matter with diameter ⩽2.5 μm (PM