1.Real-Time Assessment of Black Carbon Peaks Among Workers Exposed to Diesel Engine Exhaust Emissions
Ju-Hyun PARK ; Sangjun CHOI ; Kyung Ehi ZOH ; Seung Won KIM ; Dong-Hee KOH ; Won KIM ; Dong-Uk PARK
Safety and Health at Work 2026;17(1):142-150
Background:
Workers are commonly exposed to diesel engine exhaust (DEE) from diesel-powered engines and vehicles (DEVs), which contain harmful particulates such as black carbon (BC). This study aimed to characterize the peak BC exposures of workers operating or working near DEVs.
Methods:
BC levels were recorded every minute from workers driving or working near DEVs using a portable aethalometer and were categorized by job type and activity. Peak BC levels were characterized using the occupational exposure limits for DEE (measured as elemental carbon) of 10 μg/m 3 and 50 μg/ m3 as cut-off values.
Results:
Forklift operators, garbage collectors, and machine operators showed peak BC exposure levels surpassing 20 μg/m 3 , with average levels above 10 μg/m 3 . Despite their short exposure durations (<1 hour), these peaks contributed significantly (>60%) to the daily average BC exposure. The daily contribution rate of peak exposures above 10 μg/m 3 to the average daily BC exposure often exceeded 50%. The ratio of peak levels above 10 μg/m 3 and 50 μg/m 3 to the arithmetic mean was negatively correlated with exposure duration, the proportion of exposure duration, and the daily contribution of peak levels.
Conclusion
Drivers of diesel-engine vehicles often experienced significant spikes in BC exposure, highlighting the need for real-time monitoring, which is recommended as a best-practice approach to identify and mitigate short-term peak exposures.
2.Roots of the Large-Scale Household Humidifier Disinfectant Poisoning Tragedy: Regulatory and Surveillance Shortcomings in Korea
Dong-Uk PARK ; Kyung Ehi ZOH ; Dae Hwan CHO ; Soyoung PARK ; Jeonghwa HWANG ; Cheong-Hak CHOI ; Dong-Hee KOH ; Yeyong CHOI ; Jinyoung PARK
Journal of Korean Medical Science 2025;40(15):e144-
The multi-decade household humidifier disinfectant poisoning tragedy (HHDT) in South Korea highlights the importance of investigating government failures. This study aims to identify and discuss key failures and shortcomings in the South Korean authorities’ approach to regulating humidifier disinfectants (HDs) and monitoring cases of chemical poisoning. We reviewed both the HD risk prevention measures that the South Korean Ministry of Environment (KME) should have implemented under the Toxic Chemicals Control Act (TCCA) (1991–2013).Polyhexamethylene guanidine phosphate (PHMG), a new chemical, was approved for use as a disinfectant under the TCCA. KME declared PHMG non-hazardous based solely on preproduction documentation provided by the industry. In addition, the Korea Disease Control and Prevention Agency (KDCPA) failed to detect the HHDT that had accumulated each year for more than a decade. KME’s neglect of its responsibilities, coupled with KDCPA’s lack of chemical poisoning surveillance systems, led to the accumulation of widespread HHDT.
3.Roots of the Large-Scale Household Humidifier Disinfectant Poisoning Tragedy: Regulatory and Surveillance Shortcomings in Korea
Dong-Uk PARK ; Kyung Ehi ZOH ; Dae Hwan CHO ; Soyoung PARK ; Jeonghwa HWANG ; Cheong-Hak CHOI ; Dong-Hee KOH ; Yeyong CHOI ; Jinyoung PARK
Journal of Korean Medical Science 2025;40(15):e144-
The multi-decade household humidifier disinfectant poisoning tragedy (HHDT) in South Korea highlights the importance of investigating government failures. This study aims to identify and discuss key failures and shortcomings in the South Korean authorities’ approach to regulating humidifier disinfectants (HDs) and monitoring cases of chemical poisoning. We reviewed both the HD risk prevention measures that the South Korean Ministry of Environment (KME) should have implemented under the Toxic Chemicals Control Act (TCCA) (1991–2013).Polyhexamethylene guanidine phosphate (PHMG), a new chemical, was approved for use as a disinfectant under the TCCA. KME declared PHMG non-hazardous based solely on preproduction documentation provided by the industry. In addition, the Korea Disease Control and Prevention Agency (KDCPA) failed to detect the HHDT that had accumulated each year for more than a decade. KME’s neglect of its responsibilities, coupled with KDCPA’s lack of chemical poisoning surveillance systems, led to the accumulation of widespread HHDT.
4.Roots of the Large-Scale Household Humidifier Disinfectant Poisoning Tragedy: Regulatory and Surveillance Shortcomings in Korea
Dong-Uk PARK ; Kyung Ehi ZOH ; Dae Hwan CHO ; Soyoung PARK ; Jeonghwa HWANG ; Cheong-Hak CHOI ; Dong-Hee KOH ; Yeyong CHOI ; Jinyoung PARK
Journal of Korean Medical Science 2025;40(15):e144-
The multi-decade household humidifier disinfectant poisoning tragedy (HHDT) in South Korea highlights the importance of investigating government failures. This study aims to identify and discuss key failures and shortcomings in the South Korean authorities’ approach to regulating humidifier disinfectants (HDs) and monitoring cases of chemical poisoning. We reviewed both the HD risk prevention measures that the South Korean Ministry of Environment (KME) should have implemented under the Toxic Chemicals Control Act (TCCA) (1991–2013).Polyhexamethylene guanidine phosphate (PHMG), a new chemical, was approved for use as a disinfectant under the TCCA. KME declared PHMG non-hazardous based solely on preproduction documentation provided by the industry. In addition, the Korea Disease Control and Prevention Agency (KDCPA) failed to detect the HHDT that had accumulated each year for more than a decade. KME’s neglect of its responsibilities, coupled with KDCPA’s lack of chemical poisoning surveillance systems, led to the accumulation of widespread HHDT.
5.Roots of the Large-Scale Household Humidifier Disinfectant Poisoning Tragedy: Regulatory and Surveillance Shortcomings in Korea
Dong-Uk PARK ; Kyung Ehi ZOH ; Dae Hwan CHO ; Soyoung PARK ; Jeonghwa HWANG ; Cheong-Hak CHOI ; Dong-Hee KOH ; Yeyong CHOI ; Jinyoung PARK
Journal of Korean Medical Science 2025;40(15):e144-
The multi-decade household humidifier disinfectant poisoning tragedy (HHDT) in South Korea highlights the importance of investigating government failures. This study aims to identify and discuss key failures and shortcomings in the South Korean authorities’ approach to regulating humidifier disinfectants (HDs) and monitoring cases of chemical poisoning. We reviewed both the HD risk prevention measures that the South Korean Ministry of Environment (KME) should have implemented under the Toxic Chemicals Control Act (TCCA) (1991–2013).Polyhexamethylene guanidine phosphate (PHMG), a new chemical, was approved for use as a disinfectant under the TCCA. KME declared PHMG non-hazardous based solely on preproduction documentation provided by the industry. In addition, the Korea Disease Control and Prevention Agency (KDCPA) failed to detect the HHDT that had accumulated each year for more than a decade. KME’s neglect of its responsibilities, coupled with KDCPA’s lack of chemical poisoning surveillance systems, led to the accumulation of widespread HHDT.
6.Management and Collection of Occupational Data for Health (ODH) in National Public Health Statistics: Evaluation and Recommendations for Korea
Dong-Uk PARK ; Kyung Ehi ZOH ; Yun-Keun LEE ; Hoekyeong SEO ; Sangjun CHOI ; Dong-Hee KOH ; Jin-Ha YOON ; Kanwoo YOUN ; Mo-Yeol KANG ; Eun Suk CHOI ; Jungwon KIM ; Yangho KIM ; Domyung PAEK
Safety and Health at Work 2025;16(1):60-68
Background:
The aims of this study are to examine how occupation-related data and information for health (ODH) are collected and managed from census-based surveys and potential occupational illness and injuries (POIS) statistics, and to propose a national strategy for the systematic collection, analysis, and management of ODH by building on the Korean Standard Classification of Occupation (KSCO) and using a job exposure matrix (JEM).
Methods:
The status of the collection and management of ODH registered as national statistics, drawn not only from the census-based general population and workforce, but also from POIS statistics was reviewed and evaluated.
Results:
ODH from the Republic of Korea's Census of Population and Labor Force are collected and classified according to the KSCO. In contrast, national statistics on POIS are not systematically collected for KSCO coding, reflecting the lack of an KSCO and related guidelines on how to collect ODH. Key frameworks for the construction of both an KSCO and a reference JEM for public health surveillance are proposed.
Conclusions
Further research is needed to develop a national system for collecting and managing ODH, which will ultimately contribute to the use of a national KSCO and the construction of JEM for public health surveillance.
7.Occupation classification model based on DistilKoBERT: using the 5th and 6th Korean Working Condition Surveys
Tae-Yeon KIM ; Seong-Uk BAEK ; Myeong-Hun LIM ; Byungyoon YUN ; Domyung PAEK ; Kyung Ehi ZOH ; Kanwoo YOUN ; Yun Keun LEE ; Yangho KIM ; Jungwon KIM ; Eunsuk CHOI ; Mo-Yeol KANG ; YoonHo CHO ; Kyung-Eun LEE ; Juho SIM ; Juyeon OH ; Heejoo PARK ; Jian LEE ; Jong-Uk WON ; Yu-Min LEE ; Jin-Ha YOON
Annals of Occupational and Environmental Medicine 2024;36(1):e19-
Accurate occupation classification is essential in various fields, including policy development and epidemiological studies. This study aims to develop an occupation classification model based on DistilKoBERT. This study used data from the 5th and 6th Korean Working Conditions Surveys conducted in 2017 and 2020, respectively. A total of 99,665 survey participants, who were nationally representative of Korean workers, were included. We used natural language responses regarding their job responsibilities and occupational codes based on the Korean Standard Classification of Occupations (7th version, 3-digit codes). The dataset was randomly split into training and test datasets in a ratio of 7:3. The occupation classification model based on DistilKoBERT was fine-tuned using the training dataset, and the model was evaluated using the test dataset. The accuracy, precision, recall, and F1 score were calculated as evaluation metrics. The final model, which classified 28,996 survey participants in the test dataset into 142 occupational codes, exhibited an accuracy of 84.44%. For the evaluation metrics, the precision, recall, and F1 score of the model, calculated by weighting based on the sample size, were 0.83, 0.84, and 0.83, respectively. The model demonstrated high precision in the classification of service and sales workers yet exhibited low precision in the classification of managers. In addition, it displayed high precision in classifying occupations prominently represented in the training dataset. This study developed an occupation classification system based on DistilKoBERT, which demonstrated reasonable performance. Despite further efforts to enhance the classification accuracy, this automated occupation classification model holds promise for advancing epidemiological studies in the fields of occupational safety and health.
8.Occupation classification model based on DistilKoBERT: using the 5th and 6th Korean Working Condition Surveys
Tae-Yeon KIM ; Seong-Uk BAEK ; Myeong-Hun LIM ; Byungyoon YUN ; Domyung PAEK ; Kyung Ehi ZOH ; Kanwoo YOUN ; Yun Keun LEE ; Yangho KIM ; Jungwon KIM ; Eunsuk CHOI ; Mo-Yeol KANG ; YoonHo CHO ; Kyung-Eun LEE ; Juho SIM ; Juyeon OH ; Heejoo PARK ; Jian LEE ; Jong-Uk WON ; Yu-Min LEE ; Jin-Ha YOON
Annals of Occupational and Environmental Medicine 2024;36(1):e19-
Accurate occupation classification is essential in various fields, including policy development and epidemiological studies. This study aims to develop an occupation classification model based on DistilKoBERT. This study used data from the 5th and 6th Korean Working Conditions Surveys conducted in 2017 and 2020, respectively. A total of 99,665 survey participants, who were nationally representative of Korean workers, were included. We used natural language responses regarding their job responsibilities and occupational codes based on the Korean Standard Classification of Occupations (7th version, 3-digit codes). The dataset was randomly split into training and test datasets in a ratio of 7:3. The occupation classification model based on DistilKoBERT was fine-tuned using the training dataset, and the model was evaluated using the test dataset. The accuracy, precision, recall, and F1 score were calculated as evaluation metrics. The final model, which classified 28,996 survey participants in the test dataset into 142 occupational codes, exhibited an accuracy of 84.44%. For the evaluation metrics, the precision, recall, and F1 score of the model, calculated by weighting based on the sample size, were 0.83, 0.84, and 0.83, respectively. The model demonstrated high precision in the classification of service and sales workers yet exhibited low precision in the classification of managers. In addition, it displayed high precision in classifying occupations prominently represented in the training dataset. This study developed an occupation classification system based on DistilKoBERT, which demonstrated reasonable performance. Despite further efforts to enhance the classification accuracy, this automated occupation classification model holds promise for advancing epidemiological studies in the fields of occupational safety and health.
9.Occupation classification model based on DistilKoBERT: using the 5th and 6th Korean Working Condition Surveys
Tae-Yeon KIM ; Seong-Uk BAEK ; Myeong-Hun LIM ; Byungyoon YUN ; Domyung PAEK ; Kyung Ehi ZOH ; Kanwoo YOUN ; Yun Keun LEE ; Yangho KIM ; Jungwon KIM ; Eunsuk CHOI ; Mo-Yeol KANG ; YoonHo CHO ; Kyung-Eun LEE ; Juho SIM ; Juyeon OH ; Heejoo PARK ; Jian LEE ; Jong-Uk WON ; Yu-Min LEE ; Jin-Ha YOON
Annals of Occupational and Environmental Medicine 2024;36(1):e19-
Accurate occupation classification is essential in various fields, including policy development and epidemiological studies. This study aims to develop an occupation classification model based on DistilKoBERT. This study used data from the 5th and 6th Korean Working Conditions Surveys conducted in 2017 and 2020, respectively. A total of 99,665 survey participants, who were nationally representative of Korean workers, were included. We used natural language responses regarding their job responsibilities and occupational codes based on the Korean Standard Classification of Occupations (7th version, 3-digit codes). The dataset was randomly split into training and test datasets in a ratio of 7:3. The occupation classification model based on DistilKoBERT was fine-tuned using the training dataset, and the model was evaluated using the test dataset. The accuracy, precision, recall, and F1 score were calculated as evaluation metrics. The final model, which classified 28,996 survey participants in the test dataset into 142 occupational codes, exhibited an accuracy of 84.44%. For the evaluation metrics, the precision, recall, and F1 score of the model, calculated by weighting based on the sample size, were 0.83, 0.84, and 0.83, respectively. The model demonstrated high precision in the classification of service and sales workers yet exhibited low precision in the classification of managers. In addition, it displayed high precision in classifying occupations prominently represented in the training dataset. This study developed an occupation classification system based on DistilKoBERT, which demonstrated reasonable performance. Despite further efforts to enhance the classification accuracy, this automated occupation classification model holds promise for advancing epidemiological studies in the fields of occupational safety and health.
10.Lessons From the Household Humidifier Disinfectant Tragedy (HHDT) With Focus on the Chemical Poisoning Surveillance System: Review and Recommendation
Dong-Uk PARK ; Thomas H GASSERT ; Kyung Ehi ZOH ; Dong Young LEE ; Fabrizio SESANA ; Soyoung PARK ; Seong-Yong YOON
Journal of Korean Medical Science 2024;39(21):e178-
Background:
Lessons learned from the Household Humidifier Disinfectant Tragedy (HHDT) in Korea, which poisoned thousands of citizens over a period of years, necessitated an examination of national poison prevention and surveillance systems. The objectives of this study are to identify essential changes needed in chemical poisoning prevention regulations and surveillance systems for effective poison control by comparing recent trends in international poison control center (PCC) operations, and to delineate the critical elements for establishing a state-of-the-art poison control surveillance system in Korea based on recent advances in PCCs with toxicovigilance.
Methods:
A comprehensive review of Korea’s regulatory and surveillance systems for chemical health hazards, with a focus on household products under the HHDT, was conducted. A review of toxicovigilance systems in major countries shows that creating an effective national PCC requires key elements: a centralized database of toxic substances and poisoning cases, mandatory or voluntary reporting of poisoning cases, real-time alerts, collaboration among health organizations, and targeted follow-up of poisoned individuals.
Results:
Significant deficiencies in Korea’s legislation, toxicological data management, and poisoning surveillance systems, explained the inadequate response of the Korean government to the HHDT for nearly 17 years until the end of 2011. Based on a review of PCC toxicovigilance systems in major countries, a national framework with five core components is recommended for establishing a modern comprehensive Korea PCC system with toxicovigilance capacity. The core components include establishment of a centralized database of toxic substances information and clinical poisoning cases, implementation of mandatory or permissive reporting of poisoning cases, real-time alert mechanisms, collaborative systems among health-related organizations, and clinical follow-up of poisoned sub-groups.
Conclusion
A rationale and framework for a state-of-the-art national Korean PCC with toxicovigilance is justified and offered. This proposed system could assist neighboring countries in establishing their own sophisticated, globally integrated PCC networks.

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