Ji-Eun Moon, Ji-Yun Jung, Si-Hyun Park, Jong-Won Kim, Tae-Woo Koo, and Cheol-Min Lee. J Environ Health Sci. 2024;50:428-38. https://doi.org/10.5668/JEHS.2024.50.6.428

Fine particulate matter (PM_2.5; aerodynamic diameter ≤ 2.5 µm) remains a challenging policy for industrialized coastal regions throughout East Asia. In this study, we present a multi-year chemical characterization of PM_2.5 and identify key factors contributing to extreme pollution events in Dangjin, a heavy-industry hub on Korea’s west coast. Between August 2020 and March 2024, 24-h gravimetric filters (up to n = 245; 127–280 valid analyses depending on constituent) were collected twice weekly in winter–spring and weekly in summer–autumn. Meteorological data and 48-h backward HYSPLIT trajectories guided source interpretation. The mean PM_2.5 concentration was 26.22 ± 15.29 µg/m³ (4.74–95.31 µg/m³). The mass was highest in winter (30.83 µg/m³). Secondary inorganic ions constituted 60.3% of the aerosol, with nitrate comprising 29.7%. A nitrate-to-sulfate ratio of 1.94 indicated a stronger influence from mobile NO_x emissions compared to that from coal combustion. The trajectory analysis showed north-easterly transport from Eastern China, followed by local stagnation, which promoted rapid ammonium-nitrate formation. Regional transport contributes to severe PM_2.5 episodes, with their magnitude increased by local NO_x and NH₃ emissions. Our findings suggest that effective mitigation strategies in coastal industrial corridors require coordinated control of long-range transport and domestic measures focused on vehicles and ammonia-rich industries.

Particulate matter with an aerodynamic diameter ≤ 2.5 μ m (PM _2.5 ) is a critical concern in terms of public health and socioeconomic impacts because it can cause various adverse health effects. In particular, patients with allergic diseases are considered a representative vulnerable group and may respond more sensitively to PM _2.5 exposure than the general population. This study used low‐cost air sensor (LCS)–based personal exposure and home indoor and outdoor measurement devices to monitor 81 participants with allergic diseases. Among six classified microenvironments, analysis of time‐activity diaries showed that participants spent the majority of their time in the home. Personal PM _2.5 exposure was highest in the home on both weekdays and weekends (weekdays: 24.83 ± 56.40 μ g/m ³ ; weekends: 25.00 ± 52.75 μ g/m ³ ), showing similar concentrations to those measured by indoor measurement devices in the home environment when study participants were in the home. The indoor to outdoor (I/O) and personal to outdoor (P/O) ratios of PM _2.5 calculated for the home were high (weekdays: 1.61 ± 3.51, 1.54 ± 4.53; weekends: 1.40 ± 2.54, 1.33 ± 3.62), suggesting that study participants were exposed to various indoor PM _2.5 sources. In addition, P/O ratios calculated outdoors (weekdays: 0.97 ± 1.49; weekends: 0.93 ± 1.67) were relatively high compared with those in other microenvironments except the home. Correlation and linear regression analyses showed that home indoor PM _2.5 concentrations had the strongest explanatory power for personal PM _2.5 exposure (26.82%), and outdoor PM _2.5 concentrations explained only a small proportion of the variability in both personal exposure and home indoor PM _2.5 concentrations (0.56% and 0.28%, respectively). This study provides foundational data for developing personal PM _2.5 exposure assessment models and establishing strategies for indoor air quality management.

The composition of air pollutants in industrial complexes differs from that of general urban areas, often containing more hazardous substances that pose significant health risks to both workers and residents nearby. In this study, PM_2.5 and its 29 chemical components (eight ions, two carbon species, and 19 trace elements) were measured and analyzed at five monitoring sites adjacent to the Yeosu and Gwangyang industrial complexes from August 2020 to December 2024. Chemical characterization and source identification were conducted. The average PM_2.5 concentration was 18.63 ± 9.71 μg/m³, with notably higher levels observed during winter and spring. A low correlation (R = 0.56) between elemental carbon (EC) and organic carbon (OC) suggests a dominance of secondary aerosols. The charge balance analysis of [NH₄⁺] with [SO₄²⁻], [NO₃⁻], and [Cl⁻] showed slopes below the 1:1 line, indicating that NH₄⁺ is capable of neutralizing these anions. Positive matrix factorization (PMF) identified eight contributing sources—biomass burning (10.4%), sea salt (11.8%), suspended particles (7.1%), industrial sources (4.6%), Asian dust (5.2%), steel industry (21.8%), secondary nitrate (16.4%), and secondary sulfate (22.7%). These findings provide valuable insights for the development of targeted mitigation strategies and the establishment of effective emission control policies in industrial regions.

Conventional health risk assessments do not adequately reflect short-term exposure characteristics following chemical accidents. We aimed to evaluate the efficacy of existing assessment methods and propose a more suitable risk assessment approach for short-term exposure to hazardous chemicals. We analyzed foundational studies used to derive reference concentration (RfC), reference dose (RfD), and minimal risk level (MRL) values and applied these health guidance values (HGVs) to a hypothetical chemical accident scenario. An analysis of the studies underlying each HGV revealed that, except for the RfC for formaldehyde and the RfD for toluene, all values were derived under research conditions comparable to their respective exposure durations. Given the differing toxicity mechanisms between acute and chronic exposures, MRLs that were aligned with the corresponding exposure durations supported more appropriate risk management decisions. The health risk assessment results showed that RfC/RfD-based hazard quotients (HQs) were consistently higher than MRL-based HQs across all age groups and both substances, indicating that RfC/RfD values tend to yield more conservative risk estimates. For formaldehyde, the use of RfC instead of MRL resulted in an additional 208 tiles (2.08 km²) being classified as areas of potential concern (HQ > 1) relative to the MRL-based evaluation. These findings highlighted that the selection of HGVs can significantly influence the spatial extent of areas of potential concern, potentially altering health risk determinations for large population groups. This study provides a scientific basis for improving exposure and risk assessment frameworks under short-term exposure conditions. It also serves as valuable foundational data for developing effective and rational risk management strategies during actual chemical accidents. To the best of our knowledge, this is the first study to apply MRLs to a short-term chemical accident scenario and directly compare them with traditional reference values.