Background: While exposure to ambient fine particles <2.5 μm in aerodynamic diameter (PM2.5) has well-established health effects, there is limited quantitative evidence that links specific sources of PM2.5 with those effects. This study was designed to examine the risks of exposure to chemical species and source-specific PM2.5 mass on mortality in Seoul, Korea, a highly populated city.
Methods: We compare daily mortality counts with PM2.5 chemical speciation data collected every 3 days, as well as nine sources of PM2.5 mass resolved by a positive matrix factorization receptor model, from March 2003 through November 2007. A Poisson generalized linear model incorporating natural splines was used to evaluate associations of PM2.5 chemical species and sources with mortality.
Results: PM2.5 mass and several chemical species were associated with mortality. Organic carbon, elemental carbon, and lead were associated with mortality outcomes when using multipollutant models adjusted for other chemical species levels. Source-apportioned PM2.5 derived from mobile sources (ie, gasoline and diesel emissions) and biomass burning was associated with respiratory mortality and cardiovascular mortality, respectively. There were moderate associations of industry and of roadway emissions with cardiovascular mortality.
Conclusions: Local combustion sources may be particularly important contributors to PM2.5, leading to adverse health effects.
From the aEnvironmental Chemistry and Technology Program, University of Wisconsin-Madison, Madison, WI; bWisconsin State Laboratory of Hygiene, University of Wisconsin-Madison, Madison, WI; cHealth Insurance Policy Research Institute, National Health Insurance Service, Seoul, Korea; dDepartment of Environmental Health and Institute of Health and Environment, Graduate School of Public Health, Seoul National University, Seoul, Korea; and eDepartment of Public Health, Graduate School of Public Health, Seoul National University, Seoul, Korea.
This work was supported by the Korea Ministry of Environment (Ecotechnopia 091-071-057, 09001-0032-0) and Global Research Lab (K21004000001-10A0500-00710) from the National Research Foundation of Korea.
The authors report no conflicts of interest.
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Correspondence: Seung-Muk Yi, Department of Environmental health, Graduate School of Public Health, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea. E-mail: firstname.lastname@example.org.