Association of fine particulate matter air pollution and its constituents with lung function: The China Pulmonary Health study.

The associations of long-term exposure to various constituents of fine particulate matter (≤2.5 μm in aerodynamic diameter, PM) air pollution with lung function were not clearly elucidated in developing countries. The aim was to evaluate the associations of long-term exposure to main constituents of PM with lung function in China. This is a nationwide, cross-sectional analysis among 50,991 study participants from the China Pulmonary Health study. Multivariable linear regression models were used to obtain differences of forced expiratory volume in 1 s (FEV), forced vital capacity (FVC), FEV/FVC, peak expiratory flow (PEF), and forced expiratory flow at 25-75% of exhaled FVC (FEF) associated with an interquartile range (IQR) change of PM or its constituents. Residential annual PM levels varied from 26 μg/m to 92 μg/m (average: 53 μg/m). An IQR increase of PM concentrations was associated with lower FEV (19.82 mL, 95% CI: 11.30-28.33), FVC (17.45 mL, 95% CI: 7.16-27.74), PEF (86.64 mL/s, 95% CI: 59.77-113.52), and FEF (31.93 mL/s, 95% CI: 16.64-47.22). Black carbon, organic matter, ammonium, sulfate, and nitrate were negatively associated with most lung function indicators, with organic matter and nitrate showing consistently larger magnitude of associations than PM mass. This large-scale study provides first-hand epidemiological evidence that long-term exposure to ambient PM and some constituents, especially organic matter and nitrate, were associated with lower large- and small- airway function.