Particulate matter (PM) can cause illness, including respiratory diseases, and PM_2.5 compositions are likely to vary according to the emission profiles of industrial complexes. This study analyzed and compared the concentrations and distributions of PM_2.5 and heavy metals in two regions of Republic of Korea: Yeosu·Gwangyang, which houses a massive national industrial complex, and Dangjin, which houses power plants. Further, we conducted a health risk assessment on the residents of the areas near these industrial complexes. Measurements were taken at five different points in each setting over a two-year period from August 2020 to August 2022. We found differences in PM_2.5 concentrations and heavy metal composition ratios across the sites. Specifically, PM_2.5 concentrations exceeded the standard of 1 at all measurement sites, while the specific heavy metals exceeding the standard varied across the sites. Ultimately, we observed regional differences in PM_2.5 composition across measurement sites across and within the two regions and variations in health risks and according health effects due to the absence of PM_2.5 toxicity values, and compared the health risks of two industrial complexes with different characteristics. These findings underscore the importance of considering not only PM_2.5 but also its composition in exposure and health risk assessments.

This study evaluates the chemical components of an aerodynamic diameter less than 2.5 μm (PM_2.5) and its health risks in Seoul, Incheon, and Wonju, South Korea. The results revealed significant regional variations, particularly under the reasonable maximum exposure scenario, with Seoul’s average daily dose (6.4 × 10⁻¹ µg/kg/day) approximately 2 times higher than Incheon (5.8 × 10⁻¹ µg/kg/day) and Wonju (3.2 × 10⁻¹ µg/kg/day) under the central tendency exposure scenario. Furthermore, exposure to the chemical components comprising PM_2.5 can surpass risk thresholds when PM_2.5 concentrations exceed the national standard levels. These findings suggest the potential benefits of preventive measures, such as minimizing outdoor exposure, especially for individuals over 60 years of age, to help reduce health risks. However, further research is needed to confirm the effectiveness of these measures in different regions. The study also highlighted the variation in the health impacts of PM_2.5 concentrations and its chemical components across the different regions. The results suggest that relying solely on PM_2.5 concentrations for health risk assessments may underestimate the risks associated with carcinogenic components such as chromium (Cr, VI). However, under the reasonable maximum exposure (RME) scenario, the excess cancer risk (ECR) for Cr (VI) exceeds the acceptable threshold in all three regions, suggesting a high carcinogenic risk under the RME scenario. For example, the ECR for Cr(VI) in Seoul was calculated as 1.4 × 10⁻⁴, Incheon as 2.0 × 10⁻⁴, and Wonju as 1.2 × 10⁻⁴. Therefore, we emphasize the importance of incorporating both the mass concentration of PM_2.5 and its chemical constituents when conducting health risk assessments to inform region-specific health policies to mitigate health risks, particularly for vulnerable populations.