Selection of Priority VOC Emission Sources in Seoul by Comparing Source Contributions and Health Risk-Based Contributions

This study conducted age-specific and source-oriented health risk assessments of volatile organic compounds (VOCs) at four measurement sites in Seoul (Gangseo (GS), Gwangjin (GJ), Bukhansan (BHS), and Jongno (JN)). By comparing source-specific concentration contributions with health risk-based contributions, priority sources and compounds were identified. The age-specific health risk assessment showed that, under the central tendency exposure (CTE) scenario, both the total excess cancer risk (TECR) and hazard index (HI) at all measurement sites remained below the recommended guideline values. However, under the reasonable maximum exposure (RME) scenario, TECR exceeded 1 × 10−6 for some adult and elderly groups, indicating the potential for adverse health effects. Compound-specific analysis identified Benzene and Ethylbenzene as the major contributors to TECR, whereas Ethylbenzene, Benzene, and Toluene were the primary contributors to HI. The source-oriented health risk assessment revealed that concentration-based and health risk-based source contributions exhibited different patterns, with manufacturing-related sources ranking among the highest contributors to health risks at all measurement sites. At the GS site, the highest-ranking sources in terms of concentration and health risk contributions were Metal processing product manufacturing and Other product manufacturing, respectively. At the GJ site, Fuel-related emissions ranked highest in concentration contribution, whereas Metal processing products, chemicals and chemical products manufacturing ranked highest in health risk contribution. At the BHS and JN sites, Background hydrocarbons showed the greatest concentration contribution, while Chemicals and chemical products manufacturing, Vehicle exhaust: Acetylene-rich, and Textile product manufacturing were the major contributors. This study demonstrates that VOC management in Seoul should prioritize health risk-based rather than concentration-based approaches.