Long-term effects of air pollution on hospital admissions and mortality for chronic obstructive pulmonary disease in Beijing, China.

ABSTRACT

OBJECTIVE: We aimed to clarify the association between air pollution and hospital admissions for chronic obstructive pulmonary disease (COPD) and mortality in Beijing, China. METHODS: In this retrospective study, we recruited 510 COPD patients from 1 January 2006 to 31 December 2009. The patient data were obtained from the electronic medical records of Peking University Third Hospital in Beijing. Air pollution and meteorological data were obtained from the Institute of Atmospheric Physics of the Chinese Academy of Sciences. Monthly COPD hospital admissions, mortality and air pollution data were analysed using Poisson regression in generalised additive models adjusted for mean temperature, pressure and relative humidity. RESULTS: There were positive correlations between sulfur dioxide (SO2 ), particulate matter with an aerodynamic diameter ≤ 10 µm (PM10 ) and COPD hospital admissions in the single-pollutant model. An increase of 10 µg/m3 in SO2 and PM10 were associated with an increase of 4.053% (95% CI 1.470-5.179%) and 1.401% (95%CI 0.6656-1.850%) in COPD hospital admissions. In the multiple-pollutant model [SO2 and nitrogen dioxide (NO2 ) combinations], there was only a positive correlation between SO2 and COPD hospital admissions. An increase of 10 µg/m3 in SO2 were associated with an increase of 1.916% (95% CI 1.118-4.286%) in COPD hospital admissions. There was no correlation between three pollutant combinations and COPD hospital admissions. We did not find correlations between air pollution and COPD mortality in either single- or multiple-pollutant models. CONCLUSIONS: SO2 and PM10 may be important factors for the increase in COPD hospital admissions in Beijing, China.