Seasonal Variation of Chemical Compositions in PM_1.0 in the Atmosphere of Seoul

In this study, to characterize PM_1.0 concentrations and chemical composition, seasonal PM_1.0 samples were collected using a single channel particulate sampler equipped with PM_1.0 cyclone and quantified the chemical compositions of PM_1.0. The sampling of PM_1.0 was carried out at the Seoul Metropolitan Area Air Pollution Research Center located at Bulgwang in Seoul. The 8 ions (Cl^- NO₃^-, SO₄ ^2-, Na⁺, NH₄ ⁺, K⁺, Ca²⁺, and Mg²⁺), organic carbon (OC), elemental carbon (EC), and 13 elements (As, Cd, Cu, Zn, Pb, Cr, Mn, Fe, Ni, K, V, Se, and Al) were analyzed in the PM_1.0 samples. The annual average of PM_1.0 mass concentration was 18±10 μg/m3 with the highest in winter as 30±9 μg/m³ and the lowest of 12±6 μg/m3 in fall. Among the chemical components of PM_1.0, OC was the most dominating component, and variations of OC and SO₄^2- were not significant, whereas NO₃ ^- and EC showed distinct seasonal variations, highest in winter and lowest in summer. The distributions of precursor gases, oxidation ratio, and meteorological data were used to characterize the difference in PM_1.0 chemical composition between normal and heavy pollution periods. High PM_1.0 concentrations in the spring were associated with increases in precursor gas concentrations, whereas in the winter, transport of PM_1.0 could cause a significant effect on PM_1.0