Residential PM2.5 Exposure and Spirometric Lung Function Deficit in School-Age Children: A 5-Year Prospective Cohort Study in California

This study investigates longitudinal association between residential fine particulate matter (PM2.5) exposure and spirometric lung function trajectory in school-age children over 5 years within the context of environmental epidemiology and pediatric pulmonology, an area of growing scientific importance given its implications for pediatric air quality standard development, asthma school intervention targeting, and housing equity policy for air quality. Using annual spirometry (FEV1, FVC, FEV1/FVC) over 5 years combined with residential address-linked EPA monitoring and land-use regression model PM2.5 assignment, we examine PM2.5-induced pulmonary inflammation and oxidative stress suppressing alveolar development and accelerating lung function growth trajectory deficit in developing airways in 2,184 children from 64 elementary schools in 8 California air basin zones followed from 2017-2022 with annual spirometry drawn from school-based spirometry clinics with residential PM2.5 assigned from nearest EPA monitoring station augmented by land-use regression. Results indicate that each 10 ug/m3 increase in annual mean PM2.5 is associated with a 3.2% lower FEV1 % predicted at 5-year follow-up, with effects twice as large in children with prevalent asthma (adjusted beta -6.4%, 95% CI -9.2 to -3.6) (p < 0.001), with 3.2% lower FEV1 per 10 ug/m3 PM2.5 increase; 6.4% in children with asthma as the primary quantitative benchmark. Concordance between primary and confirmatory measurement approaches exceeded 93%, validating the analytical framework. These findings contribute empirically to environmental epidemiology and pediatric pulmonology and carry actionable implications for the design of programs and policies targeting pediatric air quality standard development, asthma school intervention targeting, and housing equity policy for air quality.