Characterization of atmospheric PM10 and related chemical species in southern Taiwan during the episode days

The concentrations of atmospheric PM10 on days with episodes of pollution were examined at four different sampling sites (CC, DL, LY, and HK) in southern Taiwan. The related to particulates water-soluble ionic species (Na+, K+, Mg2+, Ca2+, NH4+, Cl−, NO3−, SO42−), carbonaceous species (EC and OC) and metallic species (Zn, Ni, Pb, Fe, Mn, Al, Si, V) were also analyzed. On the episode days of this study, the PM10 mass concentration ranged from 155 to 210 μg m−3, from 150 to 208 μg m−3, from 182 to 249 μg m−3, and from 166 to 228 μg m−3 at CC, DL, LY, and HK, respectively. The results indicate that the dominant water-soluble species were SO42−, NO3−, NH4+, and Cl− at the four sampling sites on these days. Moreover, the high sulfate and nitrate conversion values (SOR and NOR) presented herein suggest that secondary formations from SO2 to SO42− and from NO2 to NO3− are present in significant quantities in the atmosphere of southern Taiwan on episode days. In particular, high SOR and NOR verified that both SO42− and NO3− dominated the increase of atmospheric PM10 concentration in southern Taiwan on episode days.