Fine particulate air pollution and hospital visits for asthma in Beijing, China.

Data on fine particulate matter (PM) in China were first announced in 2013. The primary objective of this study was to evaluate the acute effects of PM on asthma morbidity in Beijing, China. A total of 978,658 asthma hospital visits consisting of 928,607 outpatient visits, 40,063 emergency room visits and 9988 hospital admissions from January 1, 2010, to June 30, 2012, were identified from the Beijing Medical Claim Data for Employees. A generalized additive Poisson model was applied to explore the association between PM and health service use. The mean daily PM concentration was 99.5 μg/m with a range from 7.2 μg/m to 492.8 μg/m. Ambient PM concentration was significantly associated with increased use of asthma-related health services. Every 10 μg/m increase in PM concentration on the same day was significantly associated with a 0.67% (95% CI, 0.53%-0.81%), 0.65% (95% CI, 0.51%-0.80%), and 0.49% (95% CI, 0.35%-0.64%) increase in total hospital visits, outpatient visits and emergency room visits, respectively. The exposure-response association between PM concentration and hospital visits for asthma exacerbations was approximately linear. In conclusion, this study found that short-term elevations in PM concentration may increase the risk of asthma exacerbations. Our findings contribute to the limited scientific literature concerning the acute effects of PM on asthma morbidity outcomes in developing countries.