Human health risks assessment for airborne PM₁₀-bound metals in Seoul, Korea

Seoul, the capital city of South Korea, is the social, political, and economic center of the country. Significant levels of PM₁₀-bound As metalloid and metals have been found in the city, which poses possible adverse health risks to the residents from inhalation exposure. Therefore, this study focuses on the health risk assessment of age-dependent cancer and non-cancer using exposure pathway and human respiratory tract (HRT) mass deposition models. In the case of non-cancer risks, the hazard quotient (HQ) of As via ingestion exposure and the hazard index (HI) was found to be significant (> 1) for the children. The cancer risks through ingestion pathway (CR_ing) were estimated in the order of 10^-4 and 10^-5 for children and adult groups, respectively. The overall CR_ing levels for children were estimated slightly higher than the acceptable level of cancer risk (1 × 10^-4) at all locations throughout the study area. Moreover, the risks of cancer through the inhalation (CR_inh) and incremental lifetime cancer risks (ILCR) due to HRT mass deposition were found to be significant (> 10^-6) and with very small discrepancy in risk levels for both age groups. Furthermore, possible sources of the PM₁₀-bound metalloid (As) and metals were predicted through correlation, principal component, and enrichment factor analysis. The results of source apportionment study indicated the local anthropogenic emission sources (vehicular, biomass/coal/oil combustion, industrial), road dust re-suspension, and trans-boundary sources were responsible for the pollution levels in Seoul, South Korea. The health risks can be minimized by reducing the pollution levels of particulate matter at source.