Short-term effects of ambient fine particulate matter pollution on hospital visits for chronic obstructive pulmonary disease in Beijing, China

Background: Little is known about the effect of ambient fine particulate matter (PM2.5) on chronic obstructive pulmonary disease (COPD) in China. The objective of this study was to explore the short-term effects of PM2.5 on outpatient and inpatient visits for COPD in Beijing, China. Methods: A total of 3,503,313 outpatient visits and 126,982 inpatient visits for COPD between January 1, 2010, and June 30, 2012, were identified from the Beijing Medical Claim Data for Employees. A generalized additive Poisson model was applied to estimate the percentage change with 95% confidence interval (CI) in hospital visits for COPD in relation to an interquartile range (IQR) (90.8 mu g/m(3)) increase in PM2.5 concentrations. Results: Short-term exposure to PM2.5 was significantly associated with increased use of COPD-related health services. There were clear exposure-response associations of PM2.5 with COPD outpatient and inpatient visits. An IQR increase in the concurrent day PM2.5 concentrations was significantly associated with a 2.38% (95% CI, 2.22%-2. 53%) and 6.03% (95% CI, 5.19%-6.87%) increase in daily outpatient visits and inpatient visits, respectively. Elderly people were more sensitive to the adverse effects. The estimated risk was higher during the warm season compared to the cool season. Conclusions: Short-term exposure to PM2.5 was associated with increased risk of hospital visits for COPD. Our findings contributed to the limited evidence concerning the effects of ambient PM2.5 on COPD morbidity in developing countries.