IMPACT OF AIR POLLUTION ON RESPIRATORY FUNCTION IN URBAN SCHOOL-AGED CHILDREN

Abstract

Chronic exposure to urban air pollution poses a significant risk to pediatric respiratory health, yet microenvironmental exposure–response relationships remain underexplored. In this cross‐sectional study of 200 schoolchildren (mean age 9.1 ± 1.8 years; 51% male), we quantified ambient PM₂.₅, NO₂, and O₃ at five high‐traffic urban schools over four weeks and assessed lung function via spirometric FEV₁ and FVC z-scores. Mean pollutant concentrations varied markedly by site—PM₂.₅ ranged from 28 to 50 µg/m³, NO₂ from 35 to 55 ppb, and O₃ from 25 to 32 ppb. Multivariable linear regression, adjusted for age, sex, BMI, and passive smoking, revealed that each 1 µg/m³ increase in PM₂.₅ was associated with a 0.012 decrease in FEV₁ z-score (95% CI: –0.015 to –0.009; p < 0.001), while NO₂ and O₃ increases of 1 ppb corresponded to FEV₁ z-score reductions of 0.010 (95% CI: –0.013 to –0.007; p < 0.001) and 0.008 (95% CI: –0.011 to –0.005; p = 0.002), respectively. Similar inverse associations were observed for FVC. Sensitivity analyses across alternative exposure windows and model specifications confirmed the robustness of these findings. These results underscore the vulnerability of developing lungs to pollutant exposures in school environments and highlight the need for targeted mitigation—such as traffic management, green buffers, and stricter emission controls—around schools. Routine lung‐function screening and educational interventions may further protect at-risk children. Future longitudinal studies should evaluate long-term respiratory trajectories and intervention efficacy to inform policy and safeguard urban pediatric populations.