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Objectives Recently, overwork‐related disorders have become a major public health concern in Korea. This study investigated the current trends of working hours, causes of death in the working population, and compensation rates. Methods We reviewed the current trends of working hours, cause of death statistics in the working population, industrial accident compensation insurance (IACI) statistics, issues of compensation and prevention of work‐related cerebro‐cardio vascular diseases (CCVDs), mental disorders, and suicide. Results Although weekly working hours and the proportion of long working days have decreased, workers in small companies with fewer than five employees and those in the service sector continue to work long hours. The age standardized mortality due to CCVD and suicide was highest among those with managerial roles. In total, 589 CCVD cases and 104 mental disorder or suicide cases were compensated as occupational diseases in 2017. Between 2016 and 2017, 61% of 59 compensated suicides were related to overwork, specifically: long working hours, increased responsibility, or increased workload. The Korean government has introduced various policies to reduce working hours and to increase compensation approval rate for overwork‐related CCVDs. Stakeholders have called for the introduction of independent laws to prevent overwork‐related disorders, change organizational culture, and address the blind spots of the IACI Act and Labor Standard Act. Conclusions Prevention and compensation policies have improved working conditions in Korea, but there remains much to be done. This review significantly contributes to the understanding of the overall policies and research to prevent overwork‐related disorders in Korea.

This study assessed the associations between blood levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) and humoral and cellmediated immune response. The subjects included 53 male workers who had worked at industrial waste incinerators for more than one year. The experimental groups were divided into indoor, field, and incinerator workers according to working process. Data on their lifestyles and occupational characteristics were collected using a survey, and blood levels of PCDDs, PCDFs, and PCBs were analyzed to determine their associations with T-lymphocyte subpopulations and immunoglobulin levels. The results showed that total blood dioxins PCB levels were higher in field and incinerator workers (20.46±22.21 and 21.97±18.05 pg toxic equivalence [TEQ]/g fat, respectively) than in indoor workers (7.69± 2.05 pg TEQ/g fat). CD3+, CD4+, CD8+, and CD4+ CD45RO+ cells among T-lymphocyte subpopulations and IgE and IgM levels among immunoglobulins were slightly higher in field and incinerator workers than those in indoor workers, with no statistical significance (p

The purpose of the present study is to investigate the correlations between food intake behavior and job stress level and neuropeptide hormone concentrations. Job strain and food intake behavior were first identified using a self-reported questionnaire, concentrations of neuropeptide hormones (adiponectin, brain derived neurotrophic factor [BDNF], leptin, and ghrelin) were determined, and the correlations were analyzed. In the results, job strain showed significant correlations with adiponectin (odds ratio [OR], 1.220; 95% confidence interval [CI], 1.001~1.498; p < 0.05) and BDNF (OR, 0.793; 95% CI, 0.646~0.974; p < 0.05), and ghrelin exhibited a significant correlation with food intake score (OR, 0.911; 95% CI, 0.842~0.985, p < 0.05). These results suggest that job stress affects food intake regulation by altering the physiological concentrations of neuropeptide hormones as well as emotional status.

Background Korea is one of the highest indium-consuming countries worldwide. The present study aims to determine the relationship between interstitial lung disorders and indium exposure in Korea. Methods In 50 indium workers from seven plants, the effect of serum indium on the lungs was determined using laboratory tests, spirometry, and high-resolution computed tomography (HRCT). Results Higher serum indium and Krebs von den Lungen-6 (KL-6) levels were associated with HRCT-detected interstitial lung changes. Workers with high serum indium levels (≥3 µg/L) had longer exposure durations and a higher prevalence of HRCT-detected interstitial lung changes. KL-6 and surfactant protein-D (SP-D) levels were significantly higher in the highest serum indium quartile than the lowest quartile. Significant dose–effect relationships existed between serum indium levels and KL-6, SP-D levels and the prevalence of HRCT-detected interstitial lung changes. Conclusions Workforce medical surveillance should be established to prevent indium-induced interstitial lung disease in Korea. Am. J. Ind. Med. 58:61–68, 2015. © 2014 Wiley Periodicals, Inc.

Objectives: This paper aims to investigate the influence on stress hormones of job stress resulting from firefighting duties, as well as the degree of such influence. Methods: KOSS-26 and stress hormones such as norepinephrine (NE), epinephrine (EPI), adrenocorticotrophic hormone (ACTH), and cortisol were analyzed for 191 male firefighters from the western area of Incheon, the Incheon Industrial Complex, and Bucheon, Korea. Job stress and stress hormones were compared between a office working group and field-working group. Results: There was no significant difference in EPI and ACTH between the two groups. Change of stress hormones prior to engaging in typical duties, following typical duties, and immediately after field activities was examined. All the EPI, ACTH, and cortisol showed statistically significant changes with time, but not NE in the blood. In the field-working group, the cortisol levels in the blood of the firefighting and rescue groups showed notable differences depending on the time at which the measurements were taken. Conclusion: The differences in stress hormone levels depending on the type of duties of the firefighters were identified. Thus, interventions proper to job requirements is required in order to ease stress.

We have examined the hypothesis that the Gly972Arg variant of the insulin receptor substrate 1 (IRS1) gene is associated with the components contributing to overweight (obesity) and metabolic syndrome. We describe IRS1 genotype frequencies in 274 Korean men. The frequencies of Gly972Gly (G/G) and Gly972Arg (G/A variant) of the IRS1 gene were 88.3% and 11.7%, respectively, and the differences in frequencies between the overweight (BMI≥25 kg/m2) group and non‐overweight (BMI

Objectives The purpose of this study was to evaluate the exposure to arsenic in preventive maintenance (PM) engineers in a semiconductor industry by detecting speciated inorganic arsenic metabolites in the urine. Methods The exposed group included 8 PM engineers from the clean process area and 13 PM engineers from the ion implantation process area; the non-exposed group consisted of 14 office workers from another company who were not occupationally exposed to arsenic. A spot urine specimen was collected from each participant for the detection and measurement of speciated inorganic arsenic metabolites. Metabolites were separated by high performance liquid chromatography-inductively coupled plasma spectrometry-mass spectrometry. Results Urinary arsenic metabolite concentrations were 1.73 g/L, 0.76 g/L, 3.45 g/L, 43.65 g/L, and 51.32 g/L for trivalent arsenic (As3+), pentavalent arsenic (As5+), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), and total inorganic arsenic metabolites (As3+ + As5+ + MMA + DMA), respectively, in clean process PM engineers. In ion implantation process PM engineers, the concentrations were 1.74 g/L, 0.39 g/L, 3.08 g/L, 23.17 g/L, 28.92 g/L for As3+, As5+, MMA, DMA, and total inorganic arsenic metabolites, respectively. Levels of urinary As3+, As5+, MMA, and total inorganic arsenic metabolites in clean process PM engineers were significantly higher than that in the non-exposed group. Urinary As3+ and As5+ levels in ion implantation process PM engineers were significantly higher than that in non-exposed group. Conclusion Levels of urinary arsenic metabolites in PM engineers from the clean process and ion implantation process areas were higher than that in office workers. For a complete assessment of arsenic exposure in the semiconductor industry, further studies are needed.

To investigate the effects of short-term exposure of beryllium on the human immune system, the proportion of T-lymphocytes such as CD3+, CD4+, CD8+, CD95, and NK cells, andthe proportion of B cells and TNFα level in peripheral blood and immunoglobulins in the serum of 43 exposed workers and 34 healthy control subjects were studied. External exposure to beryllium was measured by atomic absorption spectrometer as recommended by the NIOSH analytical method 7300. T lymphocyte subpopulation analysis was carried out with flow cytometer. The working duration of exposed workers was less than 3 months and the mean ambient beryllium level was 3.4 μg/m(3), 112.3 μg/m(3), and 2.3 μg/m(3) in molding (furnace), deforming (grinding), and sorting processes, respectively (cited from Kim et al., 2008). However, ambient beryllium level after process change was non-detectable (0.1 μg/m(3)). The number of T lymphocytes and the amount of immunoglobulins in the beryllium-exposed workers and control subjects were not significantly different, except for the total number of lymphocytes and CD95 (APO1/FAS). The total number of lymphocytes was higher in the beryllium-exposed individuals than in the healthy control subjects. Multiple logistic regression analysis showed lymphocytes to be affected by beryllium exposure (odd ratio = 7.293; p0.001). These results show that short-term exposure to beryllium does not induce immune dysfunction but is probably associated with lymphocytes proliferation.

The purpose of this study was to understand the mechanism of cardiovascular disease (CVD) caused by exposure to hazardous chemicals. We investigated changes in the symptoms of metabolic syndrome, which is strongly related to CVD, and in levels of other CVD risk factors, with a special emphasis on the roles of catecholamines and oxidative stress. The results revealed that neither body mass index (BMI) nor waist and hip circumferences were associated with exposure to hazardous chemicals. Among metabolic syndrome criteria, only HDL-cholesterol level increased on exposure to hazardous chemicals. Levels of epinephrine (EP) and norepinephrine (NEP) were not influenced by exposure to hazardous chemicals; however, the total antioxidative capacity (TAC) reduced because of increased oxidative stress. Both hazardous chemical exposure level and metabolite excretion were related to EP, NEP, and the oxidative stress index (OSI). Logistic regression analysis with these factors as independent variables and metabolic syndrome criteria as dependent variables revealed that EP was associated with blood pressure, and NEP with metabolic syndrome in the chemicalexposed group. In conclusion, the results suggest that reactive oxygen species generated and oxidative stress due to exposure to hazardous chemicals act as mediators and cause changes in the physiological levels of EP and NEP to increase blood pressure. This ultimately leads to the development of CVD through increase in cholesterol, triglyceride, and blood glucose levels by lipid peroxidation.

Objectives: This study was designed to investigate whether long-term, low-level exposure to monocyclic aromatic hydrocarbons (MAHs) induced insulin resistance. Methods: The subjects were 110 male workers who were occupationally exposed to styrene, toluene, and xylene. One hundred and ten age-matched male workers who had never been occupationally exposed to organic solvents were selected as a control group. Cytokines, which have played a key role in the pathogenesis of insulin resistance, and oxidative stress indices were measured. Assessment of exposure to MAHs was performed by measuring their ambient levels and their urinary metabolites in exposed workers, and the resulting parameters between the exposed group and non-exposed control groups were compared. Results: There was no significant difference in general characteristics and anthropometric parameters between the two groups; however, total cholesterol, fasting glucose, fasting insulin, and homeostasis model assessment of insulin resistance levels were significantly higher in the exposed group. Phenylglyoxylic acid levels showed significant association with tumor necrosis factor-α, total oxidative status, and oxidative stress index via multiple linear regression analysis. Further, there was a negative correlation between methylhippuric acid levels and total anti-oxidative capacity, and there was a significant relationship between MAHs ex posure and fasting glucose levels, as found by multiple logistic regression analysis (odds ratio = 3.95, 95% confidence interval = 1.074-14.530). Conclusion: This study indicated that MAHs increase fasting glucose level and insulin resistance. Furthermore, these results suggested that absorbing the organic solvent itself and active metabolic intermediates can increase oxidative stress and cytokine levels, resulting in the changes in glucose metabolism and the induction of insulin resistance.

Objectives The present study was designed to determine whether there is a relationship between indium compound exposure and interstitial lung damage in workers employed at indium tin oxide manufacturing and reclaiming factories in Korea. Methods In 2012, we conducted a study for the prevention of indium induced lung damage in Korea and identified 78 workers who had serum indium or Krebs von den Lungen-6 (KL-6) levels that were higher than the reference values set in Japan (3 μg/L and 500 U/mL, respectively). Thirty-four of the 78 workers underwent chest high-resolution computed tomography (HRCT), and their data were used for statistical analysis. Results Geometric means (geometric standard deviations) for serum indium, KL-6, and surfactant protein D (SP-D) were 10.9 (6.65) μg/L, 859.0 (1.85) U/mL, and 179.27 (1.81) ng/mL, respectively. HRCT showed intralobular interstitial thickening in 9 workers. A dose–response trend was statistically significant for blood KL-6 levels. All workers who had indium levels ≥50 μg/L had KL-6 levels that exceeded the reference values. However, dose–response trends for blood SP-D levels, KL-6 levels, SP-D levels, and interstitial changes on the HRCT scans were not significantly different. Conclusions Our findings suggest that interstitial lung changes could be present in workers with indium exposure. Further studies are required and health risk information regarding indium exposure should be communicated to workers and employers in industries where indium compounds are used to prevent indium induced lung damage in Korea.

─ The Relationship between Job Stress and Musculoskeletal Symptoms in Migrant Workers Min Heui Jo 1) , Kyoo Sang Kim 1) , Sun Wung Lee 2) , Tae Gyun Kim 1) , Hyang Woo Ryu 1) , Mi Young Lee 1) , Yong Lim Won 1) Occupational Safety and Health Research Institute, Korea Occupational Safety and Health Agency 1) Ahnsan Medical Consumer’s Cooperation 2) Objective: To investigate the musculoskeletal symptoms of migrant workers. We focused on the rela-tionship between job stress and musculoskeletal symptoms. Method: A questionnaire was administered to 502 migrant workers who visited NGO migrant workercenters located in Gyung-gi province. A structured, self-reported questionnaire was administered to par-ticipants in order to capture the following information: sociodemographics, health factors including pastmedical history, work related characteristics, job stress, and musculoskeletal symptoms. The job stressquestionnaires were used according to KOSS-26 and musculoskeletal symptoms were measured usingKOSHA Code H-30-2003. We used multiple logistic regression analysis to assess the relationshipbetween risk factors which included job stress, and musculoskeletal symptoms.