Background: People spend 80~90% of their day indoors, with only 10~20% of their time spent outdoors. Evaluating exposure accurately requires assessments based on an individual's time-activity pattern. Objectives: The purpose of this study is to evaluate the exposure and contribution rates of PM_2.5 by microenvironment, identify related exposure factors, and suggest management measures and priorities. Methods: This study analyzed the time-activity patterns of 3,984 weekday respondents in Seoul using data from the 2014 Time-Use Survey by Statistics Korea. The respondents were clustered, and occupational groups were estimated by conducting a frequency analysis of sociodemographic factors. Location data was collected at 10-minute intervals, followed by exposure scenario construction and active simulations. When calculating the exposure and contribution rates of PM_2.5, the Korean exposure factors handbook was used to account for inhalation rates. Results: Most of the indoor microenvironments where people spend their time are residential. Students spend the most time indoors at 22.7 hours per day, followed by senior citizens at 22.5 hours, office workers at 22.0 hours, and stay-at-home parents at 21.8 hours. Although people spend little time in spaces such as outdoors, in transportation, and other indoor microenvironments, higher PM_2.5 concentrations significantly increase the contribution rates. Among all clusters, even though cluster 10 (office workers) and cluster 2 (night security workers) spend relatively little time in other indoor microenvironments, such as Korean barbecue restaurants and pubs, they were included in the scenarios, resulting in higher exposure concentrations and contribution rates. Conclusions: The analysis of PM_2.5 exposure contribution rates by microenvironment revealed that the highest exposure occurred in the 'other indoor' category, with Korean barbecue restaurants showing the highest concentration levels among them. Based on the PM_2.5 exposure contribution rates in the microenvironments, this study suggests priority locations and population groups for targeted management.

Background: The increase in population density and human activities due to urbanization and industrialization has led to the release of environmental pollutants through various pathways. These include air, water, and soil and result in environmental contamination. Objectives: This study aimed to conduct exposure and risk assessments for five non-carcinogenic and three carcinogenic heavy metals in indoor dust and sought to propose dust exposure limits for children and adults. Methods: The study collected and analyzed indoor dust from 20 households in Myeodo-dong, Yeosu, between June 28 and 30, 2023. The exposure scenario for indoor dust was assessed for children and adults, calculating inhalation, dermal, and ingestion exposures, followed by a risk assessment categorized into non-carcinogenic and carcinogenic substances. Exposure limits for heavy metals in indoor dust were determined by calculating concentrations where the hazard index (HI) for non-carcinogenic substances remains below 1 and the total cancer risk (TCR) for carcinogenic substances stays below 1×10^-6. Results: The highest concentration of heavy metals in indoor dust was found for Zn, with a maximum value of 4912.01 ㎍/g, while Cd had the lowest concentration at 0.001 ㎍/g. There were strong positive correlations observed between Cu-Ni (0.590), Mn-Ni (0.706), Co-Zn (0.601), Co-Pb (0.930), Co-Cr (0.961), Zn-Pb (0.728), Zn-Ni (0.611), Zn-Cr (0.709), and Pb-Cr (0.982) (p<0.01). The assessment revealed no significant health risks for the five non-carcinogenic metals, as the HI remained below 1. However, two of the carcinogenic metals (Cd, Ni) exceeded the recommended exposure limits (TCR>1×10^-6). The exposure limits for carcinogenic substances were found to be relatively lower compared to those for non-carcinogenic substances, and children had lower exposure limits than adults. Conclusions: This study focused on Myeodo-dong in Yeosu, a region vulnerable to environmental pollution, assessing the potential health risks and proposing exposure standards for eight heavy metals found in indoor dust. The results showed no significant health risk for the five non-carcinogenic metals (HI<1), while three of the two carcinogenic metals (Cd, Ni) exceeded safe exposure limits (TCR>1×10^-6).

Background: Municipal solid waste incineration (MSWI) facilities in South Korea are facing challenges in maintaining their efficiency due to aging. Over 50% of these facilities have been in operation for more than 15 years, resulting in a decline in performance and an increase in pollutant emissions, both of which are impacting air quality and public health. Objectives: The objective of this study is to evaluate the optimal major refurbishment cycles for MSWI facilities and assess the appropriate timing for technical diagnostics. The goal is to maintain operational efficiency, minimize pollutant emissions, and ensure compliance with environmental standards. Methods: This study analyzed operational data from 2003 to 2022, focusing on facilities with a capacity of over 30 tons/day. Cost comparisons between major refurbishments and new installations were also performed using 2022 price data. Results: The results showed that, compared to new installations, refurbishments can save approximately 28% in costs while improving performance and reducing emissions. Facilities operating beyond 15 years showed significant declines in efficiency, highlighting the need for timely refurbishment. Conclusions: Refurbishing MSWI facilities every 15 years is both economically and environmentally beneficial. This strategy ensures that the facilities remain efficient and comply with environmental standards while protecting public health.

Background: Polybrominated diphenyl ethers (PBDEs) are used as flame retardants. Wastes burned in solid waste incinerators may contain flame retardants such as PBDEs. Therefore, it is important to study the PBDE exposure of residents in areas around solid waste incinerators. Objectives: This study aimed to analyze the serum PBDE concentration of residents living in an area around a solid waste incinerator and evaluate the factors that could affect PBDE exposure. Methods: The study areas included an exposure area around a solid waste incinerator and a control area (8.6 km away from the exposure area). Participants were 196 women in their 40s, 50s, and 60s, with 98 from each area. The survey investigated participants' age, period of residence, drinking and smoking habits, menopause status, and parity. The medical examination included body mass index (BMI), thyroid stimulating hormone (TSH), and free thyroxine (Free T4). Twenty-two PBDE congeners were analyzed using gas chromatography (Agilent 7890B, Agilent, USA) and mass spectrometry (Xevo TQ-XS, Waters, USA). Mann-Whitney U and Kruskal-Wallis tests were used to compare the significant differences in serum PBDE concentrations by the characteristics of the participants. Multiple regression analysis was performed to evaluate the factors affecting PBDE exposure and the effect of serum PBDE concentration on TSH levels in serum (SAS 9.4). Results: There was a statistically significant difference in serum PBDE concentration by area, age, smoking habits, and menopause status. In the multiple regression analysis result, only the residential area was associated with the serum PBDE concentration. The serum TSH concentration was not associated with serum PBDE concentrations. Conclusions: The serum PBDE concentration of residents in the area around the solid waste incinerator was significantly higher than that of those in the control area. Based on this result it was assessed that the serum PBDE concentration of residents around the solid waste incinerator were affected by the incinerator.

Background: There are many published studies on the association between urinary concentration of 3-hydroxypropylmercapturic acid (3-HPMA), a metabolite of acrolein, and metabolic syndrome. However, inconsistent results have been reported. Additionally, there are currently no studies that have been conducted on Koreans. Objectives: The purpose of this study is to investigate the association between the urinary concentration of 3-HPMA, a metabolite of acrolein, and metabolic syndrome. Methods: We analyzed data from 1,559 Korean adults aged 19 and older who participated in the Korea National Health and Nutrition Examination Survey from 2020 to 2021. The criteria for metabolic syndrome were based on the National Cholesterol Education Program Adult Treatment Panel III, and the concentration of urinary 3-HPMA was divided into quartiles. The least squares means of the components of metabolic syndrome were calculated based on the concentration of 3-HPMA, and logistic regression analysis was performed to provide odds ratios (OR) and 95% confidence intervals (CI). Results: The median concentration of 3-HPMA in the participants' urine was 420.02 (IQR: 690.51~257.30) ㎍/mL, and the prevalence of metabolic syndrome was 37.8%. In the comparison of quartiles, an increase in 3-HPMA concentration was associated with a higher prevalence of components of metabolic syndrome (OR: 3.05, 95% CI: 2.02~4.62). However, after adjusting for all covariates, no significant difference was found between the urinary concentration of 3-HPMA and the components of metabolic syndrome (OR: 1.38, 95% CI: 0.74~2.54). Conclusions: We did not find a significant association between the urinary concentration of 3-HPMA, a metabolite of acrolein, and metabolic syndrome.

Background: Environmental health indicators are regarded as an important tool for assessing and monitoring environmental health policies. Some countries, including the United States and in Europe, have developed and utilized the indicators. Objectives: The main purpose of this study was to develop environmental health indicators in Gyeonggi-do for identifying specific regional environmental problems and environmental vulnerability and enhancing usefulness. Methods: A database of environmental health indicators was established by previous research, with indicators classified based on the DPSEEA (driving forces-pressures-state-exposure-effects-actions) model. The environmental health indicators reflect characteristics of environmental health in Gyeonggi-do for usefulness in linking with policies and reviewed plans for management. Results: The six principal components (outdoor/indoor air quality, climate changes, chemicals, water quality, noise, soil) and eighty-six indicators were extracted from the database of environmental health indicators. In addition, the environmental health indicators for Gyeonggi-do were verified for linkage in policies and reviewed plans for management. Conclusions: The environmental health indicators developed for Gyeonggi-do are a useful tool to identify current environmental health issues in Gyeonggi-do and develop regional policies to prevent environmental exposures and detect new risk factors.