The concentrations of PAHs in PM10 fine particles were determined at two sites, which were Jongno, one of the
urban core sites of Seoul, and Yongin, a downwind site of Seoul. The average concentration of PAHs in PM10 was
19.92?8.49 ng m-3 with the range of 1.28~81.22 ng m-3 at Jongno site of Seoul from August 2006 to August
2007, and 14.06?.96 ng m-3 with the range of 1.66~31.84 ng m-3 at Yongin site from September to November
of 2006. In the results of monthly comparison, the concentration of PAHs in August was the lowest level of 3.23 ng
m-3, but the highest level of 46.24 ng m-3 in January. The seasonal comparison showed the concentration in winter
was higher by the factor of 11.9 than in summer. The concentrations of PAHs during a warm period (November~March) increased as 5.1 times higher than those during a cold period (April~October). The concentrations of PAHs
were assumed to be largely attributed to the consumption of fossil fuels, temperature, mixing height, and photochemical
reactions in Seoul metropolitan area.