춘천시 PM2.5의 질량농도 및 이온성분 농도의 특성에 관한 연구

초록

Fine particles (PM2.5) were collected and analyzed from November 2005 through August 2007 in Chuncheon, Korea to investigate the characteristics of PM2.5 and its ionic constituents. The average PM2.5 concentration during the study period was 39 μg/m³, which is almost two times higher than the annual US NAAQS PM2.5 standard of 15 μg/m³. PM2.5 concentrations were higher in spring and winter than in summer and fall. During spring, Asian Dust events dramatically enhanced PM2.5 concentrations, and long-range transport of PM2.5 emitted in industrial area of China often occurred during winter based on trajectory analysis. Contribution of PM2.5 to PM10 concentrations ranged from 72 μg/m³ during Asian Dust events to 457 μg/m³, indicating that a large portion of PM2.5~10 was transported from China during Asian Dust events. Among the major ionic constituents SO₄ ²- showed the highest concentration, followed by NH₄+, NO₃- and NO₂-. Chuncheon appeared to be NH₄+ rich environment, indicating that (NH₄)2SO₄ and NH₄NO₃ were the predominant forms of NO₃- and SO₄²in PM2.5. Haze has frequently occurred in Chuncheon since So-Yang dam was constructed in 1973. Haze events were observed on 23 days during sampling period, and the average PM2.5 concentration was approximately 1.6 times higher during haze events than during non-haze events. This result suggests that haze enhances the secondary aerosol formation because the aerosol spontaneously absorbs water to form a saturated salt solution, deriving a significant increase in the mass of the particle.

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