The Effect of Asian Dust in Estimating the Mortality Effects of Ambient Particles, with Larger Dataset in Seoul, Korea from 1998 to 2015

摘要

Background: Asian Dust (AD) is a natural source of particulate matter (PM) in Korea and increase the concentration of PM remarkably. However, the characteristics of PM from AD differ from that of PM in usual days. Objectives: We investigated the effects of Asian dust in association between PM and mortality in Seoul, Korea, 1998-2015. Methods: We applied time-stratified case-crossover design to estimate the effects of PM10 and PM2.5 on non-accidental, cardiovascular and respiratory mortality. The effect estimates of PM were compared for all days in study period and days without AD events, with stratified analyses by sex and age group. Results: A 10 μg/m3 increase in PM10 and PM2.5 was associated with a 0.15% (95% CI: 0.06, 0.24%) and 0.27% (95% CI: 0.07, 0.47%) increase in risk of non-accidental mortality, respectively, for all days. The associations were enlarged to 0.30% (95% CI: 0.18, 0.42%) and 0.33% (95% CI: 0.10, 0.55%) when AD days were excluded from the analyses. The difference in effect estimates between all days and non-AD days were larger in males and those who aged under 64 years compared to other groups. Conclusion: The change in composition of PM or behavior pattern of population during AD events might result in the different effect of PM during all days and non-AD days. Our study suggest that including AD days in the analyses is likely to underestimate the effect of PM in usual urban environment.