Cohort Profile: Gachon Regional Occupational Cohort Study (GROCS)

Lee, Wanhyung,Lee, Yongho,Lee, Junhyeong,Kim, Uijin,Han, Eunsun,Ham, Seunghon,Choi, Won-Jun,Kang, Seong-Kyu Occupational Safety and Health Research Institute 2022 Safety and health at work Vol.13 No.1

Background/Aims: The Gachon Regional Occupational Cohort Study (GROCS) is a large-scale longitudinal study of occupational safety and health data (covering Work Environment Monitoring, Workers' Health Surveillance, and Occupational Health Service) conducted by the Gachon University Gil Medical Center (GUGMC) in Incheon, Republic of Korea. We conducted GROCS to identify the health effects of workers' occupational risks, behavior, socioeconomic status, and life style. Methods: The GROCS includes data from Work Environment Monitoring, Workers' Health Surveillance, and Occupational Health Service. The baseline year for all data collection was 2018. Work Environment Monitoring was conducted in 240 companies located in Incheon. General Health Examination and Special Health Examination were performed on 32,725 and 9,504 workers, respectively. Occupational Health Services were provided to 16,883 workers in 171 companies. These data have been collected and operated at an external data management institution and were provided as a retrospective cohort after removing personal identification information. Results: In 2018, the total number of companies was 2,854, among which which 488 special Health Examination, 171 Work Environment Monitoring, and 240 Occupational Health Service. The proportion of companies undergoing Special Health Examination was 17.1%, the proportion of companies undergoing Work Environment Monitoring was 8.4%, and the proportion of Companies undergoing Occupational Health Service was 6.0%. Conclusion: GROCS expects researchers to utilize its useful and reliable resource for occupational health and surveillance with for academic or political purposes to lead to improved workers' health and working environment.

Cancer incidence among male construction workers in Korea: a standardized incidence ratio analysis, 2009-2015

Soonsu Shin(Soonsu Shin),Woo-Ri Lee(Woo-Ri Lee),Jin-Ha Yoon(Jin-Ha Yoon),Wanhyung Lee(Wanhyung Lee) 한국역학회 2023 Epidemiology and Health Vol.45 No.-

OBJECTIVES: Construction workers face an elevated risk for several types of cancer. Nevertheless, there is a lack of large-scale epidemiological studies examining the risk of all cancers in construction workers. This study aimed to investigate the risk of various cancers in male construction workers using the Korean National Health Insurance Service (NHIS) database. METHODS: We used data from the NHIS database from 2009 to 2015. Construction workers were identified using the Korean Standard Industrial Classification code. We calculated the age-standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) for cancer occurrence in male construction workers compared to all male workers. RESULTS: Compared to all male workers, the SIRs for esophageal cancer (SIR, 1.24; 95% CI, 1.07 to 1.42) and malignant neoplasms of the liver and intrahepatic bile ducts (SIR, 1.18; 95% CI, 1.13 to 1.24) were significantly higher in male construction workers. The SIRs for malignant neoplasms of the urinary tract (SIR, 1.19; 95% CI, 1.05 to 1.35) and non-Hodgkin lymphoma (SIR, 1.21; 95% CI, 1.02 to 1.43) were significantly elevated in building construction workers. The SIR for malignant neoplasms of the trachea, bronchus, and lung (SIR, 1.16; 95% CI, 1.03 to 1.29) was significantly higher in heavy and civil engineering workers. CONCLUSIONS: Male construction workers have an increased risk for esophageal cancer, liver cancer, lung cancer, and non- Hodgkin’s cancer. Our results indicate that tailored strategies for cancer prevention should be developed for construction workers.

Factors related to the physician and the employer influencing successful return to work in Korea

Wanhyung Lee,Jin-Ha Yoon,Jaehoon Roh,Yeong-Kwang Kim,Hongdeok Seok,June-Hee Lee,Jong-Uk Won 대한직업환경의학회 2015 대한직업환경의학회지 Vol.27 No.-

Objectives: This study aims to investigate associated factors including the physician and the employer of successful return to work (RTW) in occupationally injured workers. Methods: This study is based on the first panel study of workers’ compensation insurance (PSWCI), published in June 2014. The PSWCI is a sample survey of occupationally injured workers who completed medical care in 2012 (89,921 people). A total of 2000 subjects were sampled based on sex, age, nine metropolitan-based regions, disability ratings, duration of rehabilitation, and whether vocational rehabilitation service was used. We divided the study population into two groups: return to work (RTW) group (job retention, reemployment, unpaid family worker, and self-employment), and non-RTW group (joblessness and economical inactivity). The odds ratios (ORs) and 95 % confidence intervals (CI) related to differences in basic characteristics, part of physician and employer-related factors between those who succeeded to RTW and those who did not were measured using multivariable logistic regression model. Results: The success of RTW is 70.6 % (n = 1412) among participants. The ORs (95 % CI) of the participants belonging to RTW who received periodic recovery assessment from the medical care institution and the physician are 1.51 (1.07–2.13). The ORs (95 % CI) are 1.68 (1.05–2.69) for the RTW group who received work ability assessment and referral for vocational return. When the employer maintains the relationship with the occupationally injured worker, the worker has 1.39 times higher odds (95 % CI: 1.41–2.26) of the RTW group compared to the non-RTW group. Conclusions: The physician and the employer have a significant impact on the RTW.

External Airborne-agent Exposure Increase Risk of Digestive Tract Cancer

Wanhyung Lee,Jihyun Kim,Sung-Shil Lim,Yangwook Kim,Yeon-Soon Ahn,Jin-HaYoon(윤진하) 대한직업환경의학회 2020 대한직업환경의학회 학술대회 논문집 Vol.2020 No.11

Analysis of self-reported mental health problems among the self-employed compared with paid workers in the Republic of Korea

Yongho Lee,Junhyeong Lee,Ui-Jin Kim,Eunseun Han,Seunghon Ham,Won-Jun Choi,Seong-Kyu Kang,Wanhyung Lee 대한직업환경의학회 2022 대한직업환경의학회지 Vol.34 No.-

Background: As self-employed workers are vulnerable to health problems, this study aimed to analyze mental health problems and sleep disturbances among self-employed workers compared with paid workers in Korea. Methods: A total of 34,750 workers (23,938 paid workers and 10,812 self-employed workers) were analyzed from the fifth Korean Working Condition Survey, which included 50,205 households collected by stratified sampling in 2017. To compare mental health problems and sleep disturbance among self-employed workers and paid workers, multivariate logistic regression analyses were performed. Results: The odds ratio in self-employed workers compared with paid workers was 1.25 (95% confidence interval [CI]: 1.09–1.42) for anxiety, 1.11 (95% CI: 1.04–1.17) for overall fatigue, 1.11 (95% CI: 1.04–1.20) for difficulty falling asleep, 1.10 (95% CI: 1.02–1.18) for difficulty maintaining sleep and 1.24 (95% CI: 1.16–1.32) for extreme fatigue after waking up. Conclusions: Self-employed workers in Korea have a higher risk of self-reported mental health problems and sleep disturbances than paid workers. Further studies with a longitudinal design and structured evaluation are required to investigate the causal relationship between health problems and self-employment.

Tuberculosis infection status and risk factors among health workers: an updated systematic review

Sanga Lee,Wanhyung Lee,Seong-Kyu Kang 대한직업환경의학회 2021 대한직업환경의학회지 Vol.33 No.3

Sunlight exposure and eye disorders in an economically active population: data from the KNHANES 2008-2012

Junhyeong Lee,Ui-Jin Kim,Yongho Lee,Eunseun Han,Seunghon Ham,Wanhyung Lee,Won-Jun Choi,Seong-Kyu Kang 대한직업환경의학회 2021 대한직업환경의학회지 Vol.33 No.4

Risk of Leukemia according to industrial classification among Korean workers

Won-Tae Lee(이원태),Wanhyung Lee,Jin-Ha Yoon,Jong-In Lee 대한직업환경의학회 2022 대한직업환경의학회 학술대회 논문집 Vol.2022 No.11

소방 실화재 훈련에서 사용하는 압축목재 가연물에서 발생하는 유해물질 특성

이용호(Yongho Lee),김진희(Jinhee Kim),김의진(Uijin Kim),최원준(Won-Jun Choi),이완형(Wanhyung Lee),강성규(Seong-Kyu Kang),이소연(So Yun Lee),함승헌(Seunghon Ham) 한국환경보건학회 2020 한국환경보건학회지 Vol.46 No.5

Objectives: To identify and investigate through qualitative and quantitative analysis the hazardous substances generated when compressed wood was burned at a live fire-training center. Methods: Four types of compressed wood that are actually used in live fire training were burned in a chamber according to KS F2271. The gaseous material was sampled with a gas detector tube and conventional personal samplers. Results: 1,3-butadiene, benzene, toluene, xylene, formaldehyde, hydrogen chloride, hydrogen cyanide, ammonia, carbon monoxide, and nitric acid were detected. In particular, 1,3-butadiene (497.04-680.44 ppm), benzene (97.79-125.02 ppm), formaldehyde (1.72-13.03 ppm), hydrogen chloride (4.71-15.66 ppm), hydrogen cyanide (3.64-8.57 ppm), and sulfuric acid (3.85-5.01 ppm) exceeded the Korean Occupational Exposure Limit as measured by sampling pump according to the type of compressed wood. Conclusions: We found through the chamber testing that firefighters could be exposed to toxic substances during live fire training. Therefore, firefighter protection is needed and more research is required in the field.

Association Between Flexible Work Arrangement and Sleep Problems Among Paid Workers: Using 6th Korean Working Conditions Survey

Han Eunseun,Lee Yongho,Lee Sanghyuk,Kim Shinhyeong,Ham Seunghon,Lee Wanhyung,Choi Won-Jun,Kang Seong-Kyu 한국산업안전보건공단 산업안전보건연구원 2024 Safety and health at work Vol.15 No.1

Background As social distancing persists and interest in work-life balance grows, more companies are adopting flexible work policies. While there have been studies on sleep disorders associated with different types of work, such as shift work, research exploring the relationship between flexible work schedules and sleep disorders is still limited, particularly among Korean workers. Methods We performed a secondary analysis of the 6th Korean Working Conditions Survey, focusing on 31,243 paid workers out of a total of 50,538 participants. We defined flexible workers as those who set their own working hours. Sleep disorders were divided into three categories: ‘difficulty falling asleep,’ ‘frequent waking during sleep,’ and ‘waking up feeling exhausted and fatigued.’ Using scores derived from three specific symptoms, the Minimal Insomnia Symptoms Scale (MISS) was calculated to assess the prevalence of insomnia. We used chi-square tests to analyze demographic and job-related differences. A multivariate logistic regression analysis was employed to identify any relationship between flexible work schedules and sleep disorders. Results Significant differences were found between flexible and non-flexible workers regarding age, income level, education level, and job type. Flexible workers reported sleep-related symptoms significantly more often. The odds ratio for insomnia was 1.40 (95% CI 1.21–1.61). For males, the odds ratio was 1.68 (1.36–2.08). Conclusion This study establishes a correlation between flexible work schedules and sleep disorders among Korean salaried workers. Potential causes could include changes in circadian rhythm, increased work demands, and extended working hours. To precisely determine causality and associated diseases, further research is required. Background As social distancing persists and interest in work-life balance grows, more companies are adopting flexible work policies. While there have been studies on sleep disorders associated with different types of work, such as shift work, research exploring the relationship between flexible work schedules and sleep disorders is still limited, particularly among Korean workers. Methods We performed a secondary analysis of the 6th Korean Working Conditions Survey, focusing on 31,243 paid workers out of a total of 50,538 participants. We defined flexible workers as those who set their own working hours. Sleep disorders were divided into three categories: ‘difficulty falling asleep,’ ‘frequent waking during sleep,’ and ‘waking up feeling exhausted and fatigued.’ Using scores derived from three specific symptoms, the Minimal Insomnia Symptoms Scale (MISS) was calculated to assess the prevalence of insomnia. We used chi-square tests to analyze demographic and job-related differences. A multivariate logistic regression analysis was employed to identify any relationship between flexible work schedules and sleep disorders. Results Significant differences were found between flexible and non-flexible workers regarding age, income level, education level, and job type. Flexible workers reported sleep-related symptoms significantly more often. The odds ratio for insomnia was 1.40 (95% CI 1.21–1.61). For males, the odds ratio was 1.68 (1.36–2.08). Conclusion This study establishes a correlation between flexible work schedules and sleep disorders among Korean salaried workers. Potential causes could include changes in circadian rhythm, increased work demands, and extended working hours. To precisely determine causality and associated diseases, further research is required.