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.

This study compares CO₂ emissions from municipal (M-W) and industrial (I-W) waste incineration facilities in Korea using emission factor-based methods (Tier 1, 2, 3) and Continuous Emission Monitoring method (Tier 4). The objective of this study is to quantify the greenhouse gas (GHG) reduction effect associated with methodological improvements and to evaluate method-specific uncertainties, ultimately aiming to propose reliable emission reduction strategies. Results indicated significant reductions in fossil-derived CO₂ emissions using Tier 4. In the industrial facility (I-W), emissions were lowest with Tier 4 (304 ± 15 tons), a 30.1% decrease compared to Tier 1 (435 tons). Similarly, in the municipal facility (M-W), Tier 4 emissions (224 ± 9 tons) represented a 22.0% reduction from Tier 1 (287 tons). Uncertainty analysis revealed that Tier 4 provided substantially greater precision (uncertainty 4.02% ~ 4.91%) compared to Tier 1 (up to 348%), primarily due to uncertainties in emission factors and waste composition assessments. In the short term, it is necessary to reduce the high uncertainty associated with emission factor-based methods by developing Korea-specific fossil carbon fraction (FCF) emission factors based on appropriate biomass content analysis methods. In the long term, applying Continuous Emission Monitoring method (Tier 4) is recommended as the most effective approach for accurately and reliably managing and reporting GHG emissions from waste incineration facilities.