This study has been conducted to evaluate the influence of ambient heavy metals to the air quality and to find their sources in Ulsan, Korea. The distribution characteristics of ambient heavy metals with wind direction were investigated by using pollution-rose diagram. Carcinogenic risk for five trace heavy metals (Pb, Cd, Cr, Mn, and Ni), which are classified to carcinogenic material by US EPA, are assessed according to the classification system of USEPA and WHO. According to pollution-rose calculation on pollutants sources, Pb and Cu in Deoksin, which is an adjacent to Onsan industrial complexes, were 0.1058 and 0.3242 µg/m³. These concentration levels are the highest at all sampling sites. From this result we could confirm that it was affected by Onsan industrial complex that is located northeast of Deoksin. And the maximum concentration of Cd, Cr, and Ni were 0.0306, 0.0102, and 0.0146 µg/m³ in Yeocheon respectively. Because Yeocheon is in the Mipo industrial complexes, which have many combustors, incinerators, and manufacturing facilities compared to other regions. In carcinogenic risk assessment, Pb, Ni, and Mn concentration level at six sampling sites were lower than the risk level guideline values (10^-5) of WHO. However, Cr⁶⁺ and Cd concentration in Yeocheon were 60% and 205% higher than the guideline values of WHO. Therefore it is very important that the emission from industrial complexes were carefully managed and controlled to improve air quality in residential area.

Keywordsheavy metals, pollution-rose, carcinogenic, risk assessment, Ulsan