Long-term personal PM2.5 exposure and lung function alternation: A longitudinal study in Wuhan urban adults

The effect of long-term PM₂.₅ exposure on lung function has not been well established. To investigate the effects of long-term personal PM₂.₅ exposure on lung function decline, obstructive, and restrictive ventilatory disorders. Personal PM₂.₅ concentrations were evaluated using an estimation model. Lung function parameters including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁) and peak expiratory flow (PEF) were measured in 3053 Wuhan participants from the Wuhan-Zhuhai cohort and were repeated every 3 years. Participants were classified into persistently high exposure group, persistently low exposure group and inconsistent exposure group according to the median of PM₂.₅ concentration of each visit. Mixed linear models with subject-specific random intercept were used to assess the association of 3-year change of lung function with personal PM₂.₅ exposure, and generalized linear models were used to assess the association of 6-year change of lung function with personal PM₂.₅ exposure. Cox regression models were applied to assess the associations of PM₂.₅ with obstructive and restrictive ventilatory disorders. The medians of personal PM₂.₅ concentrations at baseline and two follow-ups were 153.18, 209.57 and 83.78 μg/m³, respectively. Compared with participants in the persistently low exposure group, participants in the persistently high exposure group showed a 2.99 % (95 % CI: 0.91, 5.08), a 380.15 mL/s (95 % CI: 32.82, 727.48) and a 5.98 % (95 % CI: 0.84, 11.11) additional decline in FEV₁/FVC, PEF and PEFpred after 6 years, respectively. Stratified analyses showed that age, gender, body mass index, smoking status and drinking status had no significant modification effect on the associations. The associations of PM₂.₅ exposure with obstructive and restrictive ventilatory disorders were not significant, except for a positive association between persistently high PM₂.₅ exposure and restrictive ventilatory disorder among ever drinkers. Long-term high PM₂.₅ exposure was associated with FEV₁/FVC, PEF and PEFpred declines.