Relationships between ambient fine (PM2.5) and coarse (PM2.5-10) particles and adverse health effects in metropolitan cities, Korea

Abstract

Background: A number of epidemiological studies have been examined the relationships between PM2.5 (less than 2.5 ㎛ in aerodynamic diameter) or PM2.5-10 (less than 10 ㎛ and greater than 2.5 ㎛ in aerodynamic diameter) and adverse health effects.

Objectives: We estimated the effects of PM2.5 or PM2.5-10 on all cause, respiratory, and cardiovascular mortality in Seoul, Busan, and Incheon between 2006 and 2012.

Methods: We compared daily mortality data with air particles data using GAM (Generalized Additive Model) with Poisson distribution. We controlled meteorological variables and dummy variables for the day of week and holidays. We used 2-day moving averages and various single lag to estimate effects of air particles on mortality. Also we compared the results with using Two-pollutant model.

Results: We estimated a 0.34% (95% CI: 0.03, 0.64) increase of excess mortality for all ages and 0.52% (95% CI: 0.09, 0.96) for elderly in all cause mortality, 2.08% (95% CI: 0.74, 3.44) for all ages and 2.24% (95% CI: 0.83, 3.68) for elderly in respiratory mortality, and 0.90% (95% CI: 0.19, 1.62) for all ages in cardiovascular mortality with a 10 ㎍/m3 increase of PM2.5 in Seoul. In case of Busan, a 1.18% (95% CI: 0.64, 1.72) increase of excess mortality for all ages and 1.26% (95% CI: 0.62, 1.91) for elderly in all cause mortality and 2.25% (95% CI: 0.38, 4.15) for all ages and 2.43% (95% CI: 0.51, 4.38) for elderly in respiratory mortality were associated. We also calculated a 0.43% (90% CI: 0.02, 0.95) increase of excess mortality for all ages and 0.66% (95% CI: 0.03, 1.29) for elderly in all cause mortality in Incheon. Busan showed higher associations of PM2.5 on mortality compared to other cities. Generally, PM2.5 was more associated to mortality than PM2.5-10. The results of single lag effects showed similar tendency with lag0-1 results. In case of Two-pollutant model, the reduced value of effects of PM2.5 with PM2.5-10 in Seoul. All cities in this study showed the reduced results of excess mortality in case of PM2.5-10 with PM2.5.

Conclusion: Statistically significant associations between air particles and adverse health effects were observed in this study. Further studies are needed to improve the policy on air quality regulations with more detailed data in various Korean cities.