Long-Term Exposure to Ambient Fine Particulate Matter (PM2.5) and Lung Function in Children, Adolescents, and Young Adults: A Longitudinal Cohort Study

BACKGROUND: The association between long-term exposure to ambient fine particulate matter with aerodynamic diameter <= 2.5 mu m (PM2.5) and lung function in young people remains uncertain, particularly in Asia, where air pollution is generally a serious problem. OBJECTIVES: This study investigated the association between long-term exposure to ambient PM2.5 and lung function in Taiwanese children, adolescents, and young adults. METHODS: This study comprised 24,544 participants 6-24 years of age, with 33,506 medical observations made between 2000 and 2014. We used a spatiotemporal model to estimate PM2.5 concentrations at participants' addresses. Spirometry parameters, i.e., forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and maximum midexpiratory flow (IVEVIEF), were determined. A generalized linear mixed model was used to examine the associations between long-term exposure to ambient PM2.5 and lung function. The odds ratios (ORs) of poor lung function were also calculated after adjusting for a range of covariates. RESULTS: Every 10-mu g/m(3) increase in the 2-y average PM2.5 concentration was associated with decreases of 2.22% [95% confidence interval (CI): -2.60, -1.85], 2.94 (95% CI: -3.36, -2.51), and 2.79% (95% CI: -3.15, -2.41) in the FVC, FEV1, and MMEF, respectively. Furthermore, it was associated with a 20% increase in the prevalence of poor lung function (OR: 1.20; 95% CI: 1.12, 1.29). CONCLUSIONS: Two year ambient PM2.5 concentrations were inversely associated with lung function and positively associated with the prevalence of poor lung function in children, adolescents, and young adults in Taiwan.