Impact of Reduced Working Hours and Night Work Hours on Metabolic Syndrome: A Quasi-Experimental Study

Objectives@#Epidemiological evidence linking long working hours and shift work to metabolic syndrome remains inadequate. We sought to evaluate the impact of reducing working hours on metabolic syndrome. @*Methods@#We compared the prevalence of metabolic syndrome among male manual workers in a manufacturing company (N = 371) before and after the introduction of policy to reduce daily work hours from 10 to 8 hours. Components of metabolic syndrome were measured in periodic health examinations before the intervention, 6–9 months after, and 1.5–2 years after the intervention. Generalized estimating equation models were used to estimate changes in the prevalence of metabolic syndrome. Analyses were stratified by day work versus shift work. @*Results@#The results showed a significantly decreased prevalence of metabolic syndrome 6–9 months following the intervention in day workers (risk ratio = 0.68, 95% confidence interval 0.52–0.88), but the benefit disappeared after 1.5–2 years. Shift workers showed a decreased prevalence of metabolic syndrome for the whole follow-up duration after the intervention, although the change was not statistically significant. @*Conclusion@#Reducing working hours was associated with short-term improvement in metabolic syndrome in male manual workers.

Association Between Unpredictable Work Schedules and Depressive Symptoms in Korea

Background@#sIrregular and unpredictable work schedules have become more common in most societies. The purpose of this study was to investigate the association between unpredictable work schedules and depressive symptoms in Korea. @*Methods@#Data from 34,486 workers who participated in the Korean Working Condition Survey in 2017 were used. Unpredictable work schedules were measured by questions about the frequency of changes in work schedule and limited advanced notice. Depressive symptoms were assessed by a single item asking if the participants had depressive symptoms over the last 12 months. Multivariable-adjusted logistic regression analysis was used to calculate odds ratios (ORs) for high depressive symptoms. @*Results@#The OR for depressive symptoms was significantly higher in the workers with unpredictable work schedules compared to those with predictable work schedules after controlling for age, sex, education, salary, marital status, occupation, contract period, full-time versus part-time, shift work, weekly working hours, and having a child under the age of 18 years (OR = 2.43, 95% confidence interval 1.93–3.07). @*Conclusion@#Unpredictable work schedules were associated with depressive symptoms controlling for the other dimensions of precarious employment in a representative working population in Korea.

Association Between Unpredictable Work Schedules and Depressive Symptoms in Korea

Background@#sIrregular and unpredictable work schedules have become more common in most societies. The purpose of this study was to investigate the association between unpredictable work schedules and depressive symptoms in Korea. @*Methods@#Data from 34,486 workers who participated in the Korean Working Condition Survey in 2017 were used. Unpredictable work schedules were measured by questions about the frequency of changes in work schedule and limited advanced notice. Depressive symptoms were assessed by a single item asking if the participants had depressive symptoms over the last 12 months. Multivariable-adjusted logistic regression analysis was used to calculate odds ratios (ORs) for high depressive symptoms. @*Results@#The OR for depressive symptoms was significantly higher in the workers with unpredictable work schedules compared to those with predictable work schedules after controlling for age, sex, education, salary, marital status, occupation, contract period, full-time versus part-time, shift work, weekly working hours, and having a child under the age of 18 years (OR = 2.43, 95% confidence interval 1.93–3.07). @*Conclusion@#Unpredictable work schedules were associated with depressive symptoms controlling for the other dimensions of precarious employment in a representative working population in Korea.

Cancer Incidence by Occupation in Korea: Longitudinal Analysis of a Nationwide Cohort

Background@#We performed this study to investigate the inequalities in site-specific cancer incidences among workers across different occupations in Korea. @*Methods@#Subjects included members of the national employment insurance. Incident cancers among 8,744,603 workers were followed from 1995 to 2007. Occupational groups were classified according to the Korean Standard Occupational Classification. Age-standardized incidence rate ratios were calculated. @*Results@#We found that men in service/sales and blue-collar occupations had elevated rates of esophageal, liver, laryngeal, and lung cancer. Among women, service/sales workers had elevated incidences of cervical cancer. Male prostate cancer, female breast, corpus uteri, and ovarian cancers, as well as male and female colorectal, kidney, and thyroid cancer showed lower incidences among workers in lower socioeconomic occupations. @*Conclusions@#Substantial differences in cancer incidences were found depending on occupation reflecting socioeconomic position, in the Korean working population. Cancer prevention policy should focus on addressing these socioeconomic inequalities.

The relationship between night work and breast cancer

BACKGROUND: Since the International Agency for Research on Cancer classified shift work that involves circadian disruption as “probably carcinogenic to humans,” there has been growing concern on the relationship between night work and breast cancer. In Korea, about 10–15% of workers are engaged in night-shift work, and breast cancer is one of the most common cancers in women. The purpose of this study was to review epidemiologic evidence on the relationship between night work and breast cancer. METHODS: We reviewed 21 original articles and 5 meta analyses on relationship between nightwork and breast cancer, and investigated the compensation criteria of Denmark. RESULTS: The association between breast cancer and night work has been reported by numerous epidemiologic studies, including cohort studies, case-control studies, and meta-analysis. However, a dose-response relationship has not clearly emerged among workers exposed to less than 20 years of night work. CONCLUSION: Although there are some limitations to the epidemiological studies so far, further consideration of breast cancer cases in patients with high exposure to night work is needed to assess breast cancer as a work-related disease.

Female non-smokers' environmental tobacco smoking exposure by public transportation mode

BACKGROUND: This study aimed to analyze environmental tobacco smoking exposure in female nonsmokers by public transportation mode using representative data of Koreans. METHODS: Data from the Second Korean National Environmental Health Survey (2012–2014) were analyzed. Urine cotinine was analyzed by public transport behavior, secondhand smoke exposure, socioeconomic factors, and health-related factors. Participants were 1322 adult females; those with the top 75% urine cotinine concentrations were assigned to the high exposure group. A logistic regression analysis was performed considering appropriate weights and stratification according to the sample design of the Second Korean National Environmental Health Survey. RESULTS: The geometric mean of urine cotinine concentrations differed according to public transportation modes: subway (1.66 μg/g creatinine) bus (1.77 μg/g creatinine), and taxi (1.94 μg/g creatinine). The odds ratio [OR] was calculated for the high exposure group. The OR of the taxi (2.39; 95% confidence interval, 1.00–5.69) was statistically significantly higher than the subway value (reference), and marginally significant after adjusted with life style, sociodemographic factors and involuntary smoking frequency (2.42, 95% confidence interval, 0.97–6.04). CONCLUSIONS: The odds ratio of passengers who mainly used taxis was marginally significantly higher than those of passengers who used subways and buses after adjusted with life style and sociodemographic factors. Implementation of supplementary measures and further studies on exposure to environmental tobacco smoking in taxis are warranted.

Phloxine O, a Cosmetic Colorant, Suppresses the Expression of Thymic Stromal Lymphopoietin and Acute Dermatitis Symptoms in Mice

Cosmetics are primarily applied to the skin; therefore, the association of cosmetic dyes with skin diseases or inflammation is a topic of great interest. Thymic stromal lymphopoietin (TSLP) is an interleukin 7-like cytokine that activates dendritic cells to promote Th2 inflammatory immune responses. TSLP is highly expressed in keratinocytes under inflammatory conditions, which suggests that it may play a critical role in the development of skin diseases, such as atopic dermatitis. Therefore, we investigated whether cosmetic dyes influenced the production of TSLP by keratinocytes. Phloxine O, also known as D&C Red No.27, is one of the most common red synthetic pigments and is widely used in colored cosmetics. Our results showed that Phloxine O downregulated phorbol 12-myristate 13-acetate-induced production of TSLP in a murine keratinocyte cell line (PAM212). Phloxine O also suppressed TSLP expression in KCMH-1 cells, which are mouse keratinocytes that constitutively produce high levels of TSLP. To investigate the in vivo effects of Phloxine O, we induced TSLP expression in mouse ear skin by topically applying MC903, a vitamin D3 analogue that is a well-known inducer of atopic dermatitis-like symptoms. Topical application of Phloxine O prevented MC903-induced TSLP production in mouse ear skin, attenuated the acute dermatitis-like symptoms and decreased serum IgE and histamine levels in mice. Suppression of TSLP expression by Phloxine O correlated with reduced expression of OX40 ligand and Th2 cytokines in mouse ear skin. Our results showed that Phloxine O may be beneficial to prevent dermatitis by suppressing the expression of TSLP and Th2 cytokines in skin.

Physical Activity and Blood Lead Concentration in Korea: Study Using the Korea National Health and Nutrition Examination Survey (2008-2013)

Physical activity normally has a positive influence on health, however it can be detrimental in the presence of air pollution. Lead, a heavy metal with established adverse health effects, is a major air pollutant. We evaluated the correlation between blood lead concentration and physical activity using data collected from the Korea National Health and Nutrition Examination Survey. Multivariate logistic regression analysis was performed after dividing participants according to whether they were in the top 25% in the distribution of blood lead concentration (i.e., ≥ 2.76 µg/dL), with physical activity level as an independent variable and adjusting for factors such as age, sex, drinking, smoking, body mass index, region, and occupation. The high physical activity group had greater odds of having a blood lead concentration higher than 2.76 µg/dL (odds ratio 1.29, 95% CI 1.11-1.51) compared to the low physical activity group. Furthermore, blood lead concentration is correlated with increasing physical activity.

Factors associated with suicide ideation among subway drivers in Korea

BACKGROUND: There were several suicide events of subway drivers in Korea. The aim of this study is to explore work-related factors associated with suicide ideation among subway drivers. METHODS: We analyzed data from 980 male subway drivers. A section of the Korean version of the Composite International Diagnostic Interview (K-CIDI 2.1) was administered by trained interviewers to judge whether a driver has suicide ideation and to diagnose psychiatric disorders. A questionnaire was also administered to collect data on sociodemographic characteristics, work environments, occupational stress, person under train (PUT) experience, and work-related problems. Occupational stress was examined by using the Korean Occupational Stress Scale (KOSS). Logistic regression was applied to evaluate the association between work-related factors and suicide ideation among subway drivers. RESULTS: Regarding work-related problems, conflict with passengers and sudden stops due to the emergency bell were significantly associated with suicide ideation. MDD, PTSD, and panic disorder were strongly associated with suicide ideation. In the analysis of occupational stress, insufficient job control (OR 2.34) and lack of reward (OR 2.52) were associated with suicide ideation even after being adjusted for psychiatric disorders and other work-related factors. CONCLUSIONS: Insufficient job control and lack of reward were associated with suicide ideation among subway drivers. Strategies for drivers to have autonomy while working and to achieve effort-reward balance should be implemented. Furthermore, drivers who have experienced negative work-related problems should be managed appropriately.

The effects of individual, occupational, and supportive factors on successful return to work using a structural equation model

OBJECTIVES: We aimed to ascertain the relationship between several factors and successful return to work using a structural equation model. METHODS: We used original data from the Panel Study of Worker's Compensation Insurance, and defined four latent variables as occupational, individual, supportive, and successful return to work. Each latent variable was defined by its observed variables, including age, workplace size, and quality of the medical services. A theoretical model in which all latent variables had a relationship was suggested. After examining the model, we modified some pathways that were not significant or did not fit, and selected a final structural equation model that had the highest goodness of fit. RESULTS: All three latent variables (occupational, individual, and supportive) showed statistically significant relationships with successful return to work. The occupational and supportive factors had relationships with each other, but there was no relationship between individual and the other factors. Nearly all observed variables had significance with their latent variables. The correlation coefficients from the latent variables to successful return to work were statistically significant and the indices for goodness of fit were satisfactory. In particular, four observed variables-handicap level, duration of convalescence, working duration, and support from the company-showed construct validities with high correlation coefficients. CONCLUSIONS: All factors that we examined are related to successful return to work. We should focus on the supportive factor the most because its variables are modifiable to promote a return to work by those injured in their workplace.

Workers' experiences with compensated sick leave due to musculoskeletal disorder: a qualitative study

OBJECTIVES: The most common occupational disease that is compensated by Industrial Accident Compensation Insurance (IACI) in Korea is musculoskeletal disease (MSD). Although complaints about the workers' compensation system have been raised by injured workers with MSD, studies that examine workers' experiences with the Korean system are rare. This paper is a qualitative study designed to examine injured workers' experiences with the workers' compensation system in Korea. The aim of this study is to explore the drawbacks of the workers' compensation system and to suggest ways to improve this system. METHODS: All workers from an automobile parts factory in Anseong, GyeongGi province who were compensated for MSD by IACI from January 2003 to August 2013 were invited to participate. Among these 153 workers, 142 workers completed the study. Semi-structured open-ended interviews and questionnaires were administered by occupational physicians. The responses of 131 workers were analyzed after excluding 11 workers, 7 of whom provided incomplete answers and 4 of whom were compensated by accidental injury. Based on their age, disease, department of employment, and compensation time, 16 of these 131 workers were invited to participate in an individual in-depth interview. In-depth interviews were conducted by one of 3 occupational physicians until the interview contents were saturated. RESULTS: Injured workers with MSD reported that the workers' compensation system was intimidating. These workers suffered more emotional distress than physical illness due to the workers' compensation system. Injured workers reported that they were treated inadequately and remained isolated for most of the recuperation period. The compensation period was terminated without ample guidance or a plan for an appropriate rehabilitation process. CONCLUSIONS: Interventions to alleviate the negative experiences of injured workers, including quality control of the medical care institutions and provisions for mental and psychological care for injured workers, are needed to help injured workers return to work earlier and more healthy.

Development of a Standardized Job Description for Healthcare Managers of Metabolic Syndrome Management Programs in Korean Community Health Centers

PURPOSE: This study aimed to develop a job description for healthcare managers of metabolic syndrome management programs using task analysis. METHODS: Exploratory research was performed by using the Developing a Curriculum method, the Intervention Wheel model, and focus group discussions. Subsequently, we conducted a survey of 215 healthcare workers from 25 community health centers to verify that the job description we created was accurate. RESULTS: We defined the role of healthcare managers. Next, we elucidated the tasks of healthcare managers and performed needs analysis to examine the frequency, importance, and difficulty of each of their duties. Finally, we verified that our job description was accurate. Based on the 8 duties, 30 tasks, and 44 task elements assigned to healthcare managers, we found that the healthcare managers functioned both as team coordinators responsible for providing multidisciplinary health services and nurse specialists providing health promotion services. In terms of importance and difficulty of tasks performed by the healthcare managers, which were measured using a determinant coefficient, the highest-ranked task was planning social marketing (15.4), while the lowest-ranked task was managing human resources (9.9). CONCLUSION: A job description for healthcare managers may provide basic data essential for the development of a job training program for healthcare managers working in community health promotion programs.

Prevalence and Risk Factors of Work-related Low Back Pain Among Operators and Drivers of Transportation Vehicle / 대한산업의학회지

OBJECTIVES: This study is conducted to investigate the prevalence of work-related back pain among Driving and Transport Related Occupations and to identify the risk of mechanical factors and psychosocial factors. METHODS: Subjects were 779 operators and drivers of transportation vehicles selected from respondents from the 1st Korean Working condition survey. The occupation risk factors, including socioeconomic, ergonomic, psychosocial factors, were investigated. We used the multiple logistic regression analysis to determine the relationship between risk factors and low back pain. RESULTS: The prevalence of self-reported work-related low back pain was 27.7%. Adjusting for confounding factors, we determined that whole body vibration(OR 1.64 95% CI: 1.09~2.48), tiring posture(OR 5.18, 95% CI: 3.01~8.93), extended work(OR 1.91, 95% CI: 1.20~3.04), night-time work(OR 2.79, 95% CI: 1.86~4.19), evening work(OR 2.82, 95% CI: 1.78~4.46), shift work(OR 2.35, 95% CI: 1.30~4.26), job dissatisfaction (OR 2.65, 95% CI: 1.76~3.99), and experiencing physical violence at work(OR 5.31, 95% CI: 1.25~22.67) had meaningful relationships with low back pain. CONCLUSIONS: We found that the psychosocial risk factors were the most significant factors among drivers of transportation vehicles in Korea. Therefore, we suggest a health promotion program to relieve Job stress as a solution to prevent and control low back pain among drivers of transportation vehicles in Korea.

Cases Series of Malignant Lymphohematopoietic Disorder in Korean Semiconductor Industry

OBJECTIVES: Seven cases of malignant lymphohematopoietic (LHP) disorder were claimed to have developed from occupational exposure at two plants of a semiconductor company from 2007 to 2010. This study evaluated the possibility of exposure to carcinogenic agents for the cases. METHODS: Clinical courses were reviewed with assessing possible exposure to carcinogenic agents related to LHP cancers. Chemicals used at six major semiconductor companies in Korea were reviewed. Airborne monitoring for chemicals, including benzene, was conducted and the ionizing radiation dose was measured from 2008 to 2010. RESULTS: The latency of seven cases (five leukemiae, a Non-Hodgkin's lymphoma, and an aplastic anemia) ranged from 16 months to 15 years and 5 months. Most chemical measurements were at levels of less than 10% of the Korean Occupational Exposure Limit value. No carcinogens related to LHP cancers were used or detected. Complete-shielded radiation-generating devices were used, but the ionizing radiation doses were 0.20-0.22 uSv/hr (background level: 0.21 microSv/hr). Airborne benzene was detected at 0.31 ppb when the detection limit was lowered as low as possible. Ethylene oxide and formaldehyde were not found in the cases' processes, while these two were determined to be among the 263 chemicals in the list that was used at the six semiconductor companies at levels lower than 0.1%. Exposures occurring before 2002 could not be assessed because of the lack of information. CONCLUSION: Considering the possibility of exposure to carcinogenic agents, we could not find any convincing evidence for occupational exposure in all investigated cases. However, further study is needed because the semiconductor industry is a newly developing one.

Cancer Mortality and Incidence in Korean Semiconductor Workers

OBJECTIVES: The purpose of this study was to evaluate cancer risks in the Korean semiconductor industry. METHODS: A retrospective cohort study was performed in eight semiconductor factories between 1998 and 2008. The number of subjects was 113,443 for mortality and 108,443 for incidence. Standardized mortality ratios (SMR) and standardized incidence ratios (SIR) were calculated. RESULTS: The SMR of leukemia was 0.39 (95% Confidence Interval 0.08-1.14) in males (2 cases) and 1.37 (0.55-2.81) in females (7 cases). The SMR of non-Hodgkin's lymphoma (NHL) was 1.33 (0.43-3.09, 5 cases) in males and 2.5 (0.68-6.40, 4 cases) in females. The SIR of leukemia was 0.69 (0.30-1.37, 8 cases) in males and 1.28 (0.61-2.36, 10 cases) in females. The SIR of NHL in females was 2.31 (1.23-3.95, 13 cases) and that of thyroid cancer in males was 2.11 (1.49-2.89, 38 cases). The excess incidence of NHL was significant in female assembly operators [SIR=3.15 (1.02-7.36, 5 cases)], but not significant in fabrication workers. The SIR of NHL in the group working for 1-5 years was higher than the SIR of NHL for those working for more than five years. The excess incidence of male thyroid cancer was observed in both office and manufacturing workers. CONCLUSION: There was no significant increase of leukemia in the Korean semiconductor industry. However, the incidence of NHL in females and thyroid cancer in males were significantly increased even though there was no definite association between work and those diseases in subgroup analysis according to work duration. This result should be interpreted cautiously, because the majority of the cohort was young and the number of cases was small.

Relationship between Musculoskeletal Symptoms and Non-fatal Occupational Injuries in Construction Workers in Korea / 대한산업의학회지

OBJECTIVES: This study aimed to assess the relationship between musculoskeletal symptoms and non-fatal injuries in construction workers. METHODS: This was a cross-sectional study involving 1,836 male construction workers in petrochemical plants in Korea. For this study, a structured self-reported questionnaire(KOSHA CODE H-30-2003) was used. Musculoskeletal symptoms were defined as symptoms that affect the operation of the musculoskeletal system, for longer than one week or a frequency of more than once per month. To evaluate the association between musculoskeletal symptoms and non-fatal occupatioanl injuries, multiple logistic-regressions were used after adjusting for age, exercise, smoking status, alcohol consumption, work time, work duration, and income. RESULTS: A total of 140 workers were involved in non-fatal injuries cases, representing 7.6% prevalence. After adjusting for confounding variables, the logistic regression analyses indicated the group with musculoskeletal symptoms(OR 1.73 95% CI:1.21~2.47) and intensity criteria of musculoskeletal symptoms as related to 'moderate' criteria(OR 1.82 95% CI:1.18~2.81) or 'severe' criteria(OR 2.57 95% CI:1.43~4.63). This identified group was more likely to experience non-fatal occupational injuries. However, a 'mild' criteria(OR 1.00 95% CI:0.51~1.99) was not associated with non-fatal occupational injuries. CONCLUSIONS: The results indicated a possible association between musculoskeletal symptoms and non-fatal injuries. Hence, strengthening of laws and regulations, effective ergonomic programs and training is necessary to prevent musculoskeletal symptoms.

Occupational Respiratory Cancer in Korea

Malignant mesothelioma and lung cancer are representative examples of occupational cancer. Lung cancer is the leading cause of cancer death, and the incidence of malignant mesothelioma is expected to increase sharply in the near future. Although information about lung carcinogen exposure is limited, it is estimated that the number of workers exposed to carcinogens has declined. The first official case of occupational cancer was malignant mesothelioma caused by asbestos exposure in the asbestos textile industry in 1992. Since then, compensation for occupational respiratory cancer has increased. The majority of compensated lung cancer was due to underlying pneumoconiosis. Other main causative agents of occupational lung cancer included asbestos, hexavalent chromium, and crystalline silica. Related jobs included welders, foundry workers, platers, plumbers, and vehicle maintenance workers. Compensated malignant mesotheliomas were associated with asbestos exposure. Epidemiologic studies conducted in Korea have indicated an elevated risk of lung cancer in pneumoconiosis patients, foundry workers, and asbestos textile workers. Occupational respiratory cancer has increased during the last 10 to 20 yr though carcinogen-exposed population has declined in the same period. More efforts to advance the systems for the investigation, prevention and management of occupational respiratory cancer are needed.

Occupational Burden of Cancer in Korea

OBJECTIVES: The extent of the occupational cancer burden has rarely been estimated in Korea. The aim of this study is to provide an estimation of the population attributable fraction (PAF) of occupational cancer in Korea. METHODS: Nine kinds of Group 1 carcinogens addressed by the International Agency for Research on Cancer (IARC) and 7 kinds of cancer were selected for the target carcinogens and diseases, respectively. The prevalence of carcinogen-exposed workers was estimated and correction factors were applied so that the value would be representative of the total population. Data on relative risk (RR) were taken from IARC reports and were compared with the RRs from the studies on Korean workers. The PAF was estimated according to Levin's formula. RESULTS: The proportion of the general Korean population exposed to carcinogens was 9.7%. The PAF of total cancer was 1.1% for incident cancer cases and 1.7% for cancer deaths. The PAFs of lung cancer and leukemia were 7.0% and 4.%, respectively. With the RRs reported from Korean studies, the PAF for lung cancer and leukemia were 3.7% and 3.4%, respectively. CONCLUSION: The PAF in this study (1.1%) was lower than that reported in previous studies (2-4%) from developed countries. Considering that only 9 of the 29 kinds of Group 1 carcinogens were included in this study, the PAF might be underestimated. However, because the process of industrialization in Korea differs from that which occurred in other developed countries, 1.1% of the PAF might be appropriate for Korea.

Occupational Burden of Cancer in Korea

OBJECTIVES: The extent of the occupational cancer burden has rarely been estimated in Korea. The aim of this study is to provide an estimation of the population attributable fraction (PAF) of occupational cancer in Korea. METHODS: Nine kinds of Group 1 carcinogens addressed by the International Agency for Research on Cancer (IARC) and 7 kinds of cancer were selected for the target carcinogens and diseases, respectively. The prevalence of carcinogen-exposed workers was estimated and correction factors were applied so that the value would be representative of the total population. Data on relative risk (RR) were taken from IARC reports and were compared with the RRs from the studies on Korean workers. The PAF was estimated according to Levin's formula. RESULTS: The proportion of the general Korean population exposed to carcinogens was 9.7%. The PAF of total cancer was 1.1% for incident cancer cases and 1.7% for cancer deaths. The PAFs of lung cancer and leukemia were 7.0% and 4.%, respectively. With the RRs reported from Korean studies, the PAF for lung cancer and leukemia were 3.7% and 3.4%, respectively. CONCLUSION: The PAF in this study (1.1%) was lower than that reported in previous studies (2-4%) from developed countries. Considering that only 9 of the 29 kinds of Group 1 carcinogens were included in this study, the PAF might be underestimated. However, because the process of industrialization in Korea differs from that which occurred in other developed countries, 1.1% of the PAF might be appropriate for Korea.

Hot Tub Lung Due to Mycobacterium Avium Complex in a Public Bath / 대한산업의학회지

BACKGROUND: Hot tub lung is a hypersensitivity pneumonitis caused by nontuberculous mycobacteria (NTM); the primary causative agent is Mycobacterium avium complex (MAC) post contaminated water exposure. Recently, 2 cases of hot tub lung were found in public bath bodyscrubbers working in Korea. However, the disease causing NTM was not identified in these cases. Here, we reported one case, along with clinical diagnostic approach to occupational medicine throughout worksite investigation. CASE: A 53 year-old woman working in the public bath for 13 months' duration developed shortness of breath. She had been cleaning the locker room, several pools and floors every day, and using scrubbers with detergent and warm water. After examination, the patient was diagnosed with hypersensitivity pneumonitis based on high resolution computerized tomography and lung biopsy. Because the Mycobacterium avium was identified in both the patient's sputum and the warm pool, she was diagnosed with hot tub lung due to MAC. CONCLUSION: Hot tub lung due to MAC was confirmed in public bath housekeeper. However, few cases have been reported, even though there are many cases. To prevent damages caused by hot tub lung, general environmental management such as ventilation and cleaning is important for bath operators. Likewise, awareness needs to be increased in workers with potential NTM environmental exposure and in clinicians through education about hot tub lung in order to reduce adverse harm from misdiagnosis and mistreatment of tuberculosis.