Occupational Risk Factors for Stroke: A Comprehensive Review / 대한뇌졸중학회지

For primary prevention, it is important for public health and clinical medicine to identify and characterize modifiable risk factors of stroke. In existing literature, the impact of occupational variables on ischemic and hemorrhagic stroke has been extensively studied. This review summarizes the available data on the significance of occupational variables in stroke. The results of this review suggest that there is sufficient evidence for the relationship between increased risk of stroke and job stress, working in extreme temperatures, long working hours, and/or shift work. The association between long working hours and occupational exposure to noise and chemicals remains inconclusive although several studies have reported this finding. This review will act as a step toward future research and provide information that may serve as a baseline for developing targeted interventions to prevent stroke in the working population.

Increased risk of gastric cancer in workers with occupational dust exposure

Background/Aims@#Workers who are exposed to dust in the workplace tend to show a higher incidence of gastric cancer. Nevertheless, scientific evidence to support an association between dust exposure and the risk of gastric cancer is inadequate. This study aimed to investigate whether or not occupational dust exposure influences the risk of gastric cancer. @*Methods@#We collected the electronic data from the Pneumoconiosis Health Examination (PHE) program, provided by the Ministry of Employment and Labor and the Korea Workers’ Compensation and Welfare Service from 2002 to 2017. The PHE database was linked to the National Health Insurances databases. The age-standardized incidence ratio (SIR) and 95% confidence intervals (CIs) of the risk of gastric cancers were evaluated in workers with occupational dust exposure, and the results were compared to those in the general population. @*Results@#From 2004 to 2015, 1,543 cases of gastric cancer were observed in the male participants, as compared with 1,174 of expected cases, which yielded an SIR of 1.314 (95% CI, 1.249 to 1.380). Under dust exposure, the risk of gastric cancer was increased 23.9% in the male participants (95% CI, 19.9 to 27.5), and the degree of impairment of lung function was inversely related to the risk of gastric cancer. @*Conclusions@#Workers with occupational dust exposure were at higher risk of developing gastric cancer than the general population. Thus, future efforts for the prevention of gastric cancer are necessary for dust exposed workers.

Trends in Obesity Prevalence by Occupation Based on Korean National Health and Nutrition Examination Survey From 1998 to 2015

Background@#It is well known that the prevalence of obesity in Korea is increasing over time, however it is not known how the trends among occupational groups and sex differ in such increasing trends. This study was designed to provide recent trends of obesity among workers in Korea and to identify whether there were differences among occupational groups. @*Methods@#We used data from the Korean National Health and Nutrition Examination Survey, Phases I to VI (1998–2015), to analyze trends in the prevalence of obesity in adult Korean workers. Obesity was defined as a body mass index of 25 kg/m2 or higher. Occupations were classified into 3 groups: (a) nonmanual workers, (b) service/sales workers, and (c) manual workers. @*Results@#During the period of the Korean National Health and Nutrition Examination Survey Phases I to VI, the prevalence of obesity in male workers increased in all occupations (31.1% to 39.5% in manual workers, 32.3% to 38.2% in service/sales workers, and 25.3% to 39.7% in manual workers). However, female workers did not show any particular tendency toward obesity, except for a significant decrease in the prevalence rate in service/sales workers (30.8% to 23.9%, p for trend = 0.0048). @*Conclusion@#The trends of obesity prevalence by sex and occupation were different. For male manual workers, the prevalence rate increased steadily during the data period, while it decreased steadily in female sales/service workers.

Comparison of work environment and occupational injury in direct and indirect employment in Korea and Europe

BACKGROUND: To investigate the risk of injury for indirect employment in Korea, we compared work environment, workplace exposure, and injury risk according to the type of employment contract between Korea and European Union (EU) countries. METHODS: We analyzed data of blue-collar workers from the fourth Korean Working Conditions Survey (2014) and the sixth European Working Conditions Survey (2015) and compared workplace risk factors and preventive factors for occupational injuries. Multiple logistic regression analysis was conducted to identify the relationship between occupational injury and the type of employment contract after adjusting for age and sex. RESULTS: For descriptive characteristics, a relatively older age, lower income, lower proportion of full-time work, greater proportion in small-sized companies, and fewer unionizations were noted in indirect employment in Korea than in direct employment. Workplace exposure was significantly higher in indirect employment in both Korea and Europe. Among safety-related factors, indirect employment in both Korea and Europe lacked the support of company education, coworkers, and supervisors. Indirectly employed blue-collar workers had a significantly higher risk of occupational injury than those directly employed in Korea (odds ratio [OR]: 1.876), whereas there was no significant difference between directly and indirectly employed workers in EU countries (OR: 1.038). CONCLUSIONS: Indirectly employed blue-collar workers have an increased risk of occupational injury in Korea.

Mental disorders among workers in the healthcare industry: 2014 national health insurance data

BACKGROUND: Numerous studies have shown that healthcare professionals are exposed to psychological distress. However, since most of these studies assessed psychological distress using self-reporting questionnaires, the magnitude of the problem is largely unknown. We evaluated the risks of mood disorders, anxiety disorders, sleep disorders, and any psychiatric disorders in workers in healthcare industry using Korea National Health Insurance (NHI) claims data from 2014, which are based on actual diagnoses instead of self-evaluation. METHODS: We used Korea 2014 NHI claims data and classified employees as workers in the healthcare industry, based on companies in the NHI database that were registered with hospitals, clinics, public healthcare, and other medical services. To estimate the standardized prevalence of the selected mental health disorders, we calculated the prevalence of diseases in each age group and sex using the age distribution of the Korea population. To compare the risk of selected mental disorders among workers in the healthcare industry with those in other industries, we considered age, sex, and income quartile characteristics and conducted propensity scored matching. RESULTS: In the matching study, workers in healthcare industry had higher odds ratios for mood disorders (1.13, 95% CI: 1.11–1.15), anxiety disorders (1.15, 95% CI: 1.13–1.17), sleep disorders (2.21, 95% CI: 2.18–2.24), and any psychiatric disorders (1.44, 95% CI: 1.43–1.46) than the reference group did. Among workers in healthcare industry, females had higher prevalence of psychiatric disorders than males, but the odds ratios for psychiatric disorders, compared to the reference group, were higher in male workers in healthcare industry than in females. CONCLUSIONS: The prevalence of mood disorders, anxiety disorders, sleep disorders, and all psychiatric disorders for workers in the healthcare industry was higher than that of other Korean workers. The strikingly high prevalence of sleep disorders could be related to the frequent night-shifts in these professions. The high prevalence of mental health problems among workers in healthcare industry is alarming and requires prompt action to protect the health of the “protectors.”

Establishment and operation of a cooperative program to identify work-related acute myeloid leukemia in a general hospital

BACKGROUND@#The purpose of this report is to introduce the occupational cancer surveillance system, implemented in June 2018, and to share the results of our cooperative program.@*METHODS@#The cooperative program begins when the patient is diagnosed with acute myeloid leukemia (AML). Newly diagnosed AML patients are admitted to the internal medicine hematology department, then attending hematology physician requests a consultation from the occupational and environmental medicine (OEM) department. The OEM doctor next visits the hospitalized patient and interviews them to take their occupational history, and preliminarily evaluates the likelihood that the condition is associated with occupation. If the patient wants to apply for compensation through the Korea Workers' Compensation & Welfare Service, the patient was informed to visits the outpatient clinic of the OEM department and requests a ‘work-relatedness evaluation report’ for use in applying for compensation.@*RESULTS@#Among the 103 patients, who received an OEM departmental work history evaluation, 18 patients were considered to have a work-related incidence and 12 patients were registered in the Industrial Accident Compensation Insurance system.@*CONCLUSIONS@#The present report provides data on a sustainable model for identifying occupational disease in a general hospital setting, while also informing patients about their occupational rights.

Computer use at work is associated with self-reported depressive and anxiety disorder

BACKGROUND: With the development of technology, extensive use of computers in the workplace is prevalent and increases efficiency. However, computer users are facing new harmful working conditions with high workloads and longer hours. This study aimed to investigate the association between computer use at work and self-reported depressive and anxiety disorder (DAD) in a nationally representative sample of South Korean workers. METHODS: This cross-sectional study was based on the third Korean Working Conditions Survey (2011), and 48,850 workers were analyzed. Information about computer use and DAD was obtained from a self-administered questionnaire. We investigated the relation between computer use at work and DAD using logistic regression. RESULTS: The 12-month prevalence of DAD in computer-using workers was 1.46 %. After adjustment for socio-demographic factors, the odds ratio for DAD was higher in workers using computers more than 75 % of their workday (OR 1.69, 95 % CI 1.30−2.20) than in workers using computers less than 50 % of their shift. After stratifying by working hours, computer use for over 75 % of the work time was significantly associated with increased odds of DAD in 20–39, 41–50, 51–60, and over 60 working hours per week. After stratifying by occupation, education, and job status, computer use for more than 75 % of the work time was related with higher odds of DAD in sales and service workers, those with high school and college education, and those who were self-employed and employers. CONCLUSIONS: A high proportion of computer use at work may be associated with depressive and anxiety disorder. This finding suggests the necessity of a work guideline to help the workers suffering from high computer use at work. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40557-016-0146-8) contains supplementary material, which is available to authorized users.

The effect of long working hours on 10-year risk of coronary heart disease and stroke in the Korean population: the Korea National Health and Nutrition Examination Survey (KNHANES), 2007 to 2013

BACKGROUND: Recently, the emergence of long working hours and the associated conditions such as coronary heart disease (CHD) and stroke have gained attention. The aim of this study was to investigate the association between long working hours and the 10-year-risk of CHD and stroke, estimated by Jee’s health risk-appraisal model for ischemic heart disease. METHODS: We analyzed data from Koreans who randomly enrolled in Korean National Health and Nutrition Examination Survey 2008–2012 and finally included 13,799 participants. The participants were classified as per their working hours: 0–30 h/week, 31–39 h/week, 40 h/week, 41–50 h/week, 51–60 h/week, 61–70 h/week, 71–80 h/week, and >80 h/week. The risks for CHD and stroke were determined using Jee’s health risk-appraisal model. Multiple logistic regression was used to analyze the association between working hours and 10-year risk for CHD. RESULTS: The 10-year risks for CHD and stroke were significantly and positively associated with working hours in both men and women. Furthermore, higher risks for CHD and stroke were associated with longer working hours in women. CONCLUSION: Long working hours are significantly associated with the risks of CHD and stroke, estimated by Jee’s health risk-appraisal model. This study suggests the need for proper management of working hours to reduce CHD risk and stroke risk in the Korean population. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40557-016-0149-5) contains supplementary material, which is available to authorized users.

Effect of Long Working Hours on Self-reported Hypertension among Middle-aged and Older Wage Workers

OBJECTIVES: Many studies have reported an association between overwork and hypertension. However, research on the health effects of long working hours has yielded inconclusive results. The objective of this study was to identify an association between overtime work and hypertension in wage workers 45 years and over of age using prospective data. METHODS: Wage workers in Korea aged 45 years and over were selected for inclusion in this study from among 10,254 subjects from the Korean Longitudinal Study of Ageing. Workers with baseline hypertension and those with other major diseases were excluded. In the end, a total of 1,079 subjects were included. A Cox proportional hazards model was used to calculate hazard ratios and adjust for baseline characteristics such as sex, age, education, income, occupation, form of employment, body mass index, alcohol habit, smoking habit, regular exercise, and number of working days per week. Additional models were used to calculate hazard ratios after gender stratification. RESULTS: Among the 1,079 subjects, 85 workers were diagnosed with hypertension during 3974.2 person-months. The average number of working hours per week for all subjects was 47.68. The proportion of overtime workers was 61.0% (cutoff, 40 h per week). Compared with those working 40 h and less per week, the hazard ratio of subjects in the final model, which adjusted for all selected variables, working 41-50 h per week was 2.20 (95% confidence interval [CI], 1.19-4.06), that of subjects working 51-60 h per week was 2.40 (95% CI, 1.07-5.39), and that of subjects working 61 h and over per week was 2.87 (95% CI, 1.33-6.20). In gender stratification models, the hazard ratio of the females tended to be higher than that of the males. CONCLUSION: As the number of working hours per week increased, the hazard ratio for diagnosis of hypertension significantly increased. This result suggests a positive association between overtime work and the risk of hypertension.

Vitamin D status and associated occupational factors in Korean wage workers: data from the 5th Korea national health and nutrition examination survey (KNHANES 2010-2012)

OBJECTIVES: Vitamin D deficiency is increasing worldwide. However, few studies have attempted to examine the vitamin D status of wage workers and the correlation between vitamin D deficiency and working conditions. Hence, we aimed to evaluate the prevalence of vitamin D deficiency and the association between occupational conditions and vitamin D deficiency among Korean wage workers. METHODS: Wage workers aged 20-65 years from the 5th Korea National Health and Nutrition Examination Survey (KNHANES 2010-2012; n = 5409) were included in our analysis. We measured the prevalence of vitamin D deficiency and identified the correlations with the working conditions of these subjects. RESULTS: The prevalence of vitamin D deficiency in male and female subjects was 69.5% and 83.1%, respectively. Among the male subjects, a significant correlation between vitamin D deficiency and working conditions was observed among shift workers, office workers, and permanent workers. No significant correlation with any type of working conditions was observed among female subjects. CONCLUSION: The prevalence of vitamin D deficiency among Korean wage workers was very high and was found to correlate significantly with working conditions, likely because of insufficient exposure to sunlight associated with certain types of work. Wage workers require more frequent outdoor activity and nutrition management to maintain sufficient vitamin D level.

Effects of Volatile Organic Compounds, and Formaldehyde on Heart Rate Variability among Elderly People in Seoul / 대한산업의학회지

OBJECTIVES: The purpose of the present study was to investigate the effects of volatile organic compounds, and formaldehyde on heart rate variability among elderly people who are vulnerable to ambient pollution. METHODS: From May to August of 2009, 57 subjects older than 60 years were recruited in this study. Indoor air pollutants (volatile organic compounds and formaldehyde) were measured by a personal passive sampler. Heart rate variability (HRV) was measured in the sitting position for five minutes and assessed by time-domain and frequency-domain. RESULTS: Multiple linear regression analysis showed significantly less low-frequency (LF) and high-frequency (HF) associated with elevated benzene levels. Exposure to toluene was associated with decreases in the Standard deviation of the NN intervals (SDNN) and LF. SDNN and LF were negatively associated with the increment of ethylbenzene levels. CONCLUSIONS: An adverse effect on cardiovascular function caused by volatile organic compounds was observed among the elderly people of Seoul even though indoor air pollutant levels were lower than the yearly average guideline for indoor air quality in Korea.

Association between Cadmium and Cognitive Function in the Elderly / 대한산업의학회지

OBJECTIVES: We conducted this study to investigate the relationship between the blood concentration of cadmium and cognitive function in elderly Koreans. METHODS: This research is a part of the Korean Elderly Environmental Panel Study (KEEPS). A total of 403 subjects were enrolled and analyzed from August 2008 through August 2010. Demographic information and medical histories were obtained using a questionnaire. Blood concentration of cadmium and Mini-Mental State Examination (MMSE) with Functional Activities Questionnaire (FAQ) were evaluated for each subject. RESULTS: The mean age of subjects was 70.67 (SD 5.18, n=403) and 72% were female. The mean blood cadmium level was 1.22 microg/dl (SD 0.56), mean MMSE score was 25.12 out of 30 and mean FAQ score was 2.03 out of 30. Using linear regression analysis to estimate the relationship between blood cadmium concentration and MMSE and FAQ, we observed a significant association between log transformed values of blood cadmium levels and MMSE (p<0.002) or FAQ (p=0.005) scores. After adjusting for age, sex, level of education, alcohol consumption and smoking habits, the relationship between blood cadmium concentration and MMSE and FAQ scores ramained statistically significant (p=0.033 and 0.029, respectively). CONCLUSIONS: These results suggest that blood cadmium concentration is strongly associated with cognitive function and functional activity in the elderly.