This study investigated indoor air quality (IAQ) in 302 facilities (consisting of 638 monitoring points) across five types of multi-use facilities for the health of vulnerable populations in Seoul. The facility types consisted of the following: ICPs (indoor children’s playgrounds), PCCs (postnatal care centers), ECFs (elderly care facilities), HCFs (health care facilities), and CCCs (child care centers). The investigation was carried out over a 1-year period, from January to December 2024. The objective of this research was to provide a scientific basis for IAQ management by identifying characteristics specific to facility types and potential risk levels for vulnerable populations in Seoul. Five indoor air pollutants (PM10, PM2.5, CO2, HCHO, and TAB) were continuously measured, and their concentration distributions, temporal variability, and multi-pollutant patterns were analyzed using data visualization and statistical methods. Boxplots and ridgeline plots characterized distributions and seasonality by facility type, while star plots and K-means clustering were used to examine multi-pollutant combinations and inter-facility pattern differences. Most measurements were within national IAQ standards. However, HCFs and PCCs exhibited relatively higher mean levels and variability of HCHO and TAB, indicating a greater need to control chemical and microbiological sources. CO2 concentrations approached or temporarily exceeded the national standard, particularly in HCFs, reflecting differences in occupant density, occupancy time, and ventilation management. Kruskal-Wallis and pairwise Wilcoxon rank-sum tests revealed statistically significant differences among facility types, particularly for CO2 and HCHO, consistent with the visualized multi-pollutant profiles. K-means clustering identified three IAQ patterns-multi-pollutant-elevated, activity/ventilation-influenced, and low-pollutionindicating that management needs may vary across facilities despite uniform national standards. These findings provide a methodological basis for IAQ big data analysis, policy making, and supporting future research integrating multi-year, outdoor, building, activity, and health data.

This study examines odor survey results from 2020 and 2024 in the D-City Dyeing Industrial Complex to identify the structural limitations of Korea’s odor control system under the Odor Prevention Act and to assess their administrative implications. Despite significant improvements in both complex and designated odor substances within legal standards, residents’ complaints persisted. This discrepancy suggests that the concentration-based regulatory framework fails to reflect the sensory perception of intermittent odors shaped by meteorological, topographical, and receptor factors. Moreover, the reporting system for odor-emitting facilities is not a legally binding administrative act, limiting local governments’ ability to impose optional measures such as complete process enclosure. These institutional and spatial constraints are transferred to front-line administration, where overburdened officials exhibit street-level bureaucratic behaviors (such as simplified compliance and reactive complaint handling) as adaptive strategies. Drawing on Lipsky’s (1980) theory of street-level bureaucracy, this study interprets such practices as rational responses to structural constraints and proposes policy reforms emphasizing financial support, the adoption of odor-frequency indicators, and the reinforcement of administrative capacity. The findings indicate that effective odor management requires an integrated approach combining institutional reform with strengthened capacity for local implementation.

Odor complaint data collected in Seoul between 2014 and 2021 exhibited significant departures from normality. To address this, a Box-Cox transformation (l = 0.1149) was applied to stabilize variance and improve distributional normality. The transformed data were then evaluated for normality using the Shapiro-Wilk, Kolmogorov- Smirnov, and Anderson-Darling tests, all of which failed to reject the null hypothesis of normality (p > 0.05). However, the corresponding test statistics (0.989, 0.039, and 5.757, respectively) were close to their respective critical thresholds, indicating a substantial improvement in distributional normality. Based on the Box-Cox transformed dataset (l = 0.1149), the inlier range was defined as 4~190 cases/day, while observations of ≤3 cases/day and ≥191 cases/day were classified as low and high outliers, respectively. Within the inlier range, the meteorological variables exerting the strongest influence on IOCE (cases/day) were air (49.5), dew point (48.2), and surface temperature (48.1), whereas precipitation showed the weakest influence (39.7). The highest SROCE interval within the inlier range was associated with mean meteorological conditions of air (27.7±1.0oC), dew point (15.2±1.2oC) and surface temperature (30.4±1.1oC), and precipitation (0.6±1.8 mm). By contrast, the corresponding conditions in the high-outlier range were 19.6±1.2oC, 14.7±1.7oC, 23.1±1.4oC, and 0.3±0.7 mm, respectively. Across both the inlier and high-outlier ranges, the mean variation rate (VMF, %) of meteorological observations within the highest SROCE interval across the 13 meteorological factors was approximately ±11%. However, in the high-outlier range, mean meteorological conditions within complaint-concentrated intervals exhibited noticeable divergence from those observed in the inlier range. This study elucidated the meteorological drivers of IOCE and peak SROCE conditions across both inlier and high-outlier ranges. In addition to facilitating odor occurrence forecasting based on meteorological predictions, these findings provide a scientific basis for managing odor emission sources from specific facilities and regulated areas, extending beyond community level odors in residential areas.

This study examines the relationship between spatiotemporal changes in ecological and natural map (ENM) grades and air pollution levels in the Yeongdong and Yeongseo regions of Gangwon Province, South Korea. In addition, it focuses on how changes in ENM areas associated with urbanization and industrialization relate to regional air quality variations while considering the two regions’ geographic, topographic, meteorological, and climatic characteristics. Using the Taebaek Mountain Range as the geological boundary, the study area was divided into seven districts in the Yeongdong region and 11 districts in the Yeongseo region. Air pollutant concentration data from 2016~2023 were obtained from the urban air quality monitoring network (Air Korea) and analyzed through region-specific time-series analysis. ENM data were collected from the EcoBank platform, which provides time-series information on ENM grades by city or county over the same period. Spatial analysis showed that particulate matter (PM10 and PM2.5) concentrations were highest in Wonju in the Yeongseo region and were generally higher on the western side of the Taebaek Mountain Range, whereas ozone (O3) concentrations were higher in the Yeongdong region. Correlation analysis revealed negative relationships between Grade 1 ENM areas (high ecological value) and PM10, PM2.5, and NO2 concentrations, while positive correlations were observed for Grades 2 and 3. Ozone showed negative correlations across all ENM grades. These findings suggest that degradation of ecologically valuable areas due to land development may be closely associated with changes in regional air pollution levels. Future research should integrate additional environmental spatial datasets, such as the National Environmental Evaluation Map and Land Cover Maps from the Environmental Geographic Information Service (EGIS), to better understand the links between land-use change and air quality dynamics.

Odorous compounds from the operation of wastewater treatment plants (WWTPs) have increasingly become public health concerns and civil complaints. This study identifies priority management stages in WWTPs by quantitatively analyzing the distribution of complex odor and designated odor substances across key processes using a dimensionless tool (the Odor Activity Value, OAV), while providing a statistical basis and operational strategies for efficient odor mitigation in public facilities. Although there was a very poor correlation between designated odorous concentrations and complex odor level (dilution ratio), the application of the OAV yielded much more accurate results with a strong correlation (R2 = 0.7) specifically at high-temperature condition. Odor potential in the wastewater treatment processes fluctuates substantially depending on the specific unit. Statistical analysis using Kruskal–Wallis tests demonstrated that influent and sludge treatment process (return flow and centrate) produce much higher odor intensities compared to the biological reactor and secondary clarifier. Based on PERMANOVA analysis, differences in the profiles of complex odor and the OAVs of designated odorants across 6 treatment stages explained 64.1% of the total variance. Principal Coordinates Analysis (PCoA) showed that sludge treatment processes form a distinct, unique cluster, whereas sewage treatment streams present a more gradual transition of odor profiles. Statistical assessment using the Mann-Whitney U test demonstrated that mean odorants levels did not have considerable shift under high-temperature and low-temperature conditions. However, the sensory perception in higher temperatures enhanced relative to the OAVs. In conclusion, the OAV is an effective dimensionless tool, as it establishes priorities in odor management and control, offering a practical supplementary indicator for addressing civil complaints. These findings provide a robust foundation for optimizing deodorization systems designs and operational efficiency of odor mitigation systems within WWTPs.

Assessing the health impacts of ambient air pollution is essential for evaluating air-quality management policies. Using nationwide data from 2007 to 2023, this study analyzed long-term trends in six major air pollutants (SO2, NO2, O3, CO, PM10, and PM2.5) and examined the responsiveness of two health indicator categories: disease prevalence (asthma, rhinitis, atopy, and stroke) and hospitalization rates for chronic obstructive pulmonary disease (COPD) and asthma. Although concentrations of PM10, PM2.5, SO2, and CO declined substantially during the study period, prevalence indicators showed no corresponding improvements and instead exhibited weak or inconsistent correlations with air pollutants (e.g., PM10-asthma: r = –0.696; PM10-stroke: r = –0.220), reflecting their limited sensitivity to environmental changes. In contrast, hospitalization rates demonstrated strong and consistent associations with air pollution, particularly particulate matter and NO2. Meanwhile, PM2.5 showed the highest correlations with COPD (r = 0.973) and asthma hospitalizations (r = 0.988), and regression analyses indicated steeper slopes for PM2.5 than for PM10. This suggests a greater relative impact of fine particles on acute disease exacerbation. Principal component analysis further confirmed that hospitalization indicators clustered closely with pollutant-related components, whereas prevalence indicators were structurally independent. Overall, hospitalization rates provide a more objective and responsive measure for evaluating the health impacts of air-quality improvements in South Korea, while prevalence indicators are less suitable for assessing environmental policy outcomes.

Odorous emissions from large industrial complexes exhibit significant spatial and temporal variability, which complicates quantitative evaluation and source identification. Odor perception may occur even at low concentrations, and emission characteristics are strongly influenced by industrial processes, meteorological conditions, and local topography. Therefore, odor management strategies based solely on compliance with emission standards have inherent limitations. The Yeosu National Industrial Complex was designated as an odor management area in 2019, and annual surveys of complex odor dilution ratios and specified odor substances have been conducted since then. Despite the accumulation of monitoring data, odor complaints from nearby residential areas have continued. In this study, multi-year (2020-2024) odor monitoring data were integrated with complaint records, and GIS-based mapping and visualization were applied to examine the spatial distribution characteristics of measured odor levels and complaint locations. Map-based visualization facilitated visual comparison of complaint locations and monitoring sites and enabled a comparative assessment between monitoring sites and complaint locations. The results revealed clear spatial heterogeneity among monitoring sites. In particular, the A3 monitoring site recorded the highest annual average dilution ratio, indicating persistent structural characteristics of odor emissions in that area. Although measured odor intensity was relatively higher in summer, complaint frequency peaked in spring and autumn, suggesting that meteorological conditions and human exposure patterns significantly influence perceived odor nuisance. These findings demonstrate that measured odor intensity alone does not fully explain complaint occurrence and highlight the necessity of integrated odor management approaches that incorporate spatial dispersion characteristics, seasonal variability, and community exposure factors. The results can serve as a foundational basis for improving monitoring site placement and establishing spatially differentiated odor management policies.

Odor emissions from sewer systems are a persistent environmental concern in urban areas, particularly in combined sewer systems where septic tanks are widely used. However, the contribution of septic tanks as sources of sewer odor has not been sufficiently quantified. This study investigated the characteristics of hydrogen sulfide (H2S) generation in septic tanks and evaluated its potential influence on sewer odor, as well as the effectiveness of odor mitigation technologies. Field investigations were conducted in combined sewer areas to measure aqueous H2S concentrations in septic tanks. The results showed that H2S concentrations in septic tanks were not significantly affected by septic tank capacity (ANOVA, p > 0.05), suggesting that tank size or user population is not a primary determinant of sulfide generation. In contrast, aqueous H2S exhibited a positive correlation with chemical oxygen demand (COD), indicating that organic matter availability plays an important role in sulfide production through microbial sulfate reduction processes. A significant relationship was observed between aqueous H2S in septic tanks and gaseous H2S measured at catch basins, demonstrating that sulfide derived from septic tanks can transfer to the sewer atmosphere and potentially impact human odor exposure in urban environments. In addition, the performance of odor control technologies applied to septic tanks was evaluated with aeration-based technologies found to significantly reduce H2S concentrations. These findings suggest that septic tanks can serve as important sources of sewer odor highlighting the need for effective management and proper operation of septic tank odor control systems in combined sewer areas.

Vehicle indoor air quality is determined by the complex interaction between interior material emissions (such as VOCs and aldehydes) and road-sourced pollutants. Despite growing public concern, existing frameworks often focus on single pollutants and lack a comprehensive health-impact-based evaluation. This study proposes the Vehicle Indoor Air Quality Index (VIAQI), which integrates acute, chronic, and odor-related exposures from internal sources with the infiltration of ambient air pollutants. The VIAQI adopts a safety-oriented priority (HQacute → SF → OA → HQchronic), reflecting the driver’s cognitive safety. It consists of 10 levels, ranging from Grade 1 (Excellent) to Grade 10 (Hazardous). Under three operating modes (AM, PM-6 hr, and DM), the analysis includes 21 chemical substances, as well as PM2.5 and NO2. Acute risks are assessed using OEHHA’s RELs, chronic risks via US EPA’s RfC, odor effects are quantified using a smell sensitivity index (SF), and outdoor air infiltration is evaluated through a weighted hazard index (OA). After evaluating actual new vehicles, Vehicles A, C, and D are categorized as Grade 3 (Good), while Vehicle B is categorized as Grade 9 (Very Unhealthy) and Vehicle E is categorized as Grade 10 (Hazardous). Notably, Vehicle B is rated Grade 9 due to acute toxicity risks identified through RELs-based assessment, even though it meets all current national regulatory standards. This highlights the existence of health hazards that conventional concentration-based regulations may overlook. As Korea’s first multi-dimensional evaluation system for vehicle air quality, the VIAQI offers a practical tool for manufacturers to implement quality control, set policy, and communicate consumer information, providing a proactive assessment based on real-world driving environments.