Epidemiological study of PM2.5 and risk of COPD-related hospital visits in association with particle constituents in Chuncheon, Korea

Background and objective: Aside from smoking, which is already recognized as a strong risk factor for COPD, interest in the impact of particulate matter (PM) on COPD is increasing. This study aimed to investigate the effect of PM, especially with an aerodynamic diameter # 2.5 mu m (PM2.5), and its chemical constituents on the exacerbation of COPD. Methods: Data on hospital visits including admission and outpatient clinic visits for exacerbation of COPD in Chuncheon, Korea, between 2006 and 2012 were extracted from the National Health Insurance Service database. PM2.5 and its chemical constituents were measured on the roof of the four-story Kangwon National University Natural Sciences building once every 3 days. Meteorological data were provided by the Korean Meteorological Administration. Results: During the study period, the mean level of PM2.5 was 35.0 +/- 25.2 mu g/m(3), and the number of daily hospital visits were 6.42 +/- 4.28 and 2.07 +/- 1.93 for males and females, respectively. The number of COPD-related hospital visits increased with increasing PM2.5 after adjusting for meteorological covariates and females tended to be more affected sooner than males. Among the PM2.5 constituents, Al, Si, and elemental carbon were associated with increased hospital visits and there was a difference according to sex. In males, some constituents of PM2.5 were related to an increased risk of a hospital visit, mainly on the first and second days of measurement (Lag1 and Lag2). In contrast, there was no significant increase in the risk of hospital visits due to any of the PM2.5 constituents in females. Conclusion: Concentrations of PM2.5 mass and some of the PM2.5 constituents were associated with increased COPD-related hospital visits in Chuncheon.