Temporal and spatial variations of the particle size distribution of PAHs and their dry deposition fluxes in Korea

The atmospheric particle size distributions between 0.1 and 100 μm in diameter and their dry deposition fluxes of polycyclic aromatic hydrocarbons (PAHs) were measured at four sites in the mid-part of Korea to characterize the spatial distribution, the PAHs levels and dry deposition. Samples were collected at Inchon, Seoul, Yangsuri, and Yangpyoung between 21 and 25 February, and between 12 and 16 May 2000. Ambient size distributions were measured with a cascade impactor and a coarse particles rotary impactor. Dry deposition fluxes of particles were measured with dry deposition plates. The total particulate PAHs concentrations are between 22.9 and 410 ng m^-3, with an average of 139 ng m^-3. The total particulate PAHs dry deposition fluxes were between 10 and 24 μg m^-2 day^-1 in winter, and between 4.1 and 8.2 μg m^-2 day^-1 in spring. Both the ambient concentrations and dry deposition fluxes of PAHs in winter are higher than spring mainly due to higher fuel consumption. The ambient concentrations of PAHs in Inchon were the highest followed by Yangpyoung, Yangsuri, and Seoul. The PAHs concentrations and fluxes of Yangsuri and Yangpyoung, rural areas in Korea, are higher than the rural areas in USA. It suggests a serious PAHs pollution level of rural areas in Korea. Based on the PAHs individual compounds' levels and size distributions, it was suggested that Yangpyoung and Yangsuri have local PAHs sources in addition to transport from urban areas.