The Unequal Burden of Self-Reported Musculoskeletal Pains Among South Korean and European Employees Based on Age, Gender, and Employment Status

Background@#The objective of this study was to elucidate the relationships musculoskeletal pains with combined vulnerability in terms of age, gender, and employment status @*Methods@#The fifth European Working Conditions Survey (EWCS) in 2010 (43,816 participants aged 15 years and over) analyzed for European employees and the third Korean Working Conditions Survey (KWCS) in 2011 (50,032 participants aged 15 years and older) analyzed for Korean employees. In this study, three well known vulnerable factors to musculoskeletal pains (older age, female gender, and precarious employment status) were combined and defined as combined vulnerability. Associations of musculoskeletal pains with combined vulnerability were assessed with prevalence ratios (PRs) and 95% confidence intervals (CIs) estimated by Poisson regression models with robust estimates of variance. @*Results@#The prevalences of musculoskeletal pains were lower but the absolute and relative differences between combined vulnerabilities were higher among Korean employees compared with the European employees. Furthermore, the increased risk of having musculoskeletal pains according to combined vulnerability was modestly explained by socioeconomic factors and exposure to ergonomic risk factors, especially in Republic of Korea. @*Conclusions@#The results of this study showed that the labor market may be more unfavorable for female and elderly workers in Republic of Korea. Any prevention strategies to ward off musculoskeletal pains, therefore, should be found and implemented to mitigate or buffer against the most vulnerable work population, older, female, and precarious employment status, in Republic of Korea.

The Unequal Burden of Self-Reported Musculoskeletal Pains Among South Korean and European Employees Based on Age, Gender, and Employment Status

Background@#The objective of this study was to elucidate the relationships musculoskeletal pains with combined vulnerability in terms of age, gender, and employment status @*Methods@#The fifth European Working Conditions Survey (EWCS) in 2010 (43,816 participants aged 15 years and over) analyzed for European employees and the third Korean Working Conditions Survey (KWCS) in 2011 (50,032 participants aged 15 years and older) analyzed for Korean employees. In this study, three well known vulnerable factors to musculoskeletal pains (older age, female gender, and precarious employment status) were combined and defined as combined vulnerability. Associations of musculoskeletal pains with combined vulnerability were assessed with prevalence ratios (PRs) and 95% confidence intervals (CIs) estimated by Poisson regression models with robust estimates of variance. @*Results@#The prevalences of musculoskeletal pains were lower but the absolute and relative differences between combined vulnerabilities were higher among Korean employees compared with the European employees. Furthermore, the increased risk of having musculoskeletal pains according to combined vulnerability was modestly explained by socioeconomic factors and exposure to ergonomic risk factors, especially in Republic of Korea. @*Conclusions@#The results of this study showed that the labor market may be more unfavorable for female and elderly workers in Republic of Korea. Any prevention strategies to ward off musculoskeletal pains, therefore, should be found and implemented to mitigate or buffer against the most vulnerable work population, older, female, and precarious employment status, in Republic of Korea.

Relationship between personal care products usage and triclosan exposure: the second Korean National Environmental Health Survey (KoNEHS 2012–2014)

BACKGROUND: We aimed to find the exposure level of triclosan (TCS), a known endocrine disruptor, related to the use of personal care products using a nationally representative data of the general population in Korea. METHODS: This study included data of 6288 adults aged 19 years and older (2692 men, 3596 women), based on the Second Korean National Environmental Health Survey (KoNEHS 2012–2014). The data were divided according to gender. The frequency and proportion of each variable were determined by dividing participants into two groups based on the top 75th percentile concentration of urinary TCS (male: 1.096 μg/g creatinine, female: 1.329 μg/g creatinine). Odds ratios (ORs) were calculated using logistic regression analysis for the high TCS exposure and low TCS exposure groups. RESULTS: Overall, the proportion of participants using personal care products was higher in women than in men. There was a significantly higher proportion of participants in the high TCS exposure group with younger age, higher education and income levels and with more frequent use of fragrance products, hair care products, body cleansers, cosmetics, and antimicrobial agents. In both men and women, ORs tended to increase with increased frequency of use of hair care products, body cleansers, and cosmetics before and after adjustment. CONCLUSIONS: Our findings demonstrate that as the frequency of use of personal care products increases, urine TCS concentration increases. Because TCS is a well-known endocrine disruptor, further studies are needed and explore other health effects with exposure to TCS in general population in Korea. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s40557-019-0283-y) contains supplementary material, which is available to authorized users.

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.

Relationship between dietary factors and bisphenol a exposure: the second Korean National Environmental Health Survey (KoNEHS 2012–2014)

BACKGROUND: This study was aimed at finding out the exposure level of bisphenol A (BPA), a well-known endocrine disruptor, in relation to dietary factors using a data representing the Korean general population. METHODS: This study was performed on 5402 adults aged 19 years and older based on the Second Korean National Environmental Health Survey (KoNEHS 2012–2014). The data analyzed urinary BPA concentration in relation to socio-demographic variables, health behavior-related variables, and dietary factor-related variables. Odds ratio (OR) was calculated through a logistic regression analysis after dividing the participants into high BPA exposure group and low BPA exposure group based on the top 75 percentile concentration. The logistic regression analysis was carried out considering the appropriate sample weight, stratification, and clustering of the second KoNEHS sample design. RESULTS: The group drinking bottled water at home and the group using zip-top bags/plastic bags showed significantly higher urinary BPA concentration in female. OR tends to increase as the intake frequency of frozen food increased and OR of frozen food consumption of more than once a week was 1.48 (95% confidence interval (CI) 1.02–2.24) for male and the group drinking bottled water showed significantly higher OR of 1.45 (95% CI 1.06–2.17) after adjusting the related factors for female. CONCLUSIONS: BPA levels were high in female using bottled water and in male consuming frozen food, and therefore bottled water and frozen food need to be avoided to reduce BPA levels.

The relationship between spontaneous abortion and female workers in the semiconductor industry

BACKGROUND: This study investigated the relationship between job type and the risk for spontaneous abortion to assess the reproductive toxicity of female workers in the semiconductor industry. METHODS: A questionnaire survey was administered to current female workers of two semiconductor manufacturing plants in Korea. We included female workers who became pregnant at least 6 months after the start of their employment with the company. The pregnancy outcomes of 2,242 female workers who experienced 4,037 pregnancies were investigated. Personnel records were used to assign the subjects to one of three groups: fabrication process workers, packaging process workers, and clerical workers. To adjust for within-person correlations between pregnancies, a generalized estimating equation was used. The logistic regression analysis was limited to the first pregnancy after joining the company to satisfy the assumption of independence among pregnancies. Moreover, we stratified the analysis by time period (pregnancy in the years prior to 2008 vs. after 2009) to reflect differences in occupational exposure based on semiconductor production periods. RESULTS: The risk for spontaneous abortion in female semiconductor workers was not significantly higher for fabrication and packaging process workers than for clerical workers. However, when we stratified by time period, the odds ratio for spontaneous abortion was significantly higher for packaging process workers who became pregnant prior to 2008 when compared with clerical workers (odds ratio: 2.21; 95% confidence interval: 1.01–4.81). CONCLUSIONS: When examining the pregnancies of female semiconductor workers that occurred prior to 2008, packaging process workers showed a significantly higher risk for spontaneous abortions than did clerical workers. The two semiconductor production periods in our study (prior to 2008 vs. after 2009) had different automated processes, chemical exposure levels, and working environments. Thus, the conditions prior to 2008 may have increased the risk for spontaneous abortions in packaging process workers in the semiconductor industry. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s40557-017-0204-x) contains supplementary material, which is available to authorized users.

The relationship between night work and involuntary weight change: data from the fifth Korea National Health and Nutrition Examination Survey (KNHANES 2010–2012)

BACKGROUND: Previous studies on the association between shift or night work and weight change have been focused on finding the risk of weight gain caused by shift or night work. In this study, we aimed to reveal the risk of weight gain and weight loss associated with night work by using a nationwide representative data. METHODS: This study was performed on 1605 full-time wage workers between the age of 20 and 69 based on the fifth Korea National Health and Nutrition Examination Survey (KNHANES 2010–2012). The association between night work and involuntary weight change in the previous year was divided into the categories of weight gain and weight loss and studied with modifications in socio-demographic variables, health behavior-related variables, and occupational characteristic variables. RESULTS: The participants working in night work accounted for 10.6 % of total study participants (male; 11.9 %, female 7.4 %). Workers who worked more than 48 hours per week on average accounted for 41.6 % of the total study participants (male; 46.3 %, female 29.1 %). Odds ratio (OR) of weight loss associated with night work in male workers was 0.34 (95 % confidence interval (CI) 0.16–0.76) after controlling for several related factors. OR of weight loss associated with night work in female workers with long working hours was 1.95 (95 % CI 0.47–80.86) and that of weight gain was 2.83 (95 % CI 0.12–69.83) after adjusting associated factors. CONCLUSIONS: In this cross-sectional study with national representative sample, night work may lower the risk of weight loss in male workers and induce weight change (weight loss or weight gain) in female workers with long working hours. Therefore, future studies with cohort study design for night workers are needed to reveal the mechanisms and health effects of weight change associated with night work and establish proper management solutions with health and labor policies for Korean night workers.

The association between long working hours and hearing impairment in noise unexposed workers: data from the 5th Korea National Health and Nutrition Examination Survey (KNHANES 2010–2012)

BACKGROUND: This study is aimed at finding out the relationship between long working hours, one of major job stress elements, and hearing impairment in unexposed workers to occupational and environmental noise. METHODS: This study was performed on 1628 regular, full-time wage workers between the age of 25-64 who indicated in the survey of having no experience of exposure to noise, normal otoscopic findings, and not suffering from diabetes based on the data from the fifth Korea National Health and Nutrition Examination Survey (KNHANES 2010–2012). The average working hours per week was categorized into 40 h and lower group, more than 40 to 48 h group, more than 48 to 60 h group, and more than 60 h group. The groups were defined as suffering from low or high frequencies hearing impairment if the average hearing threshold for 0.5, 1, 2 kHz or 3, 4, 6 kHz in both ears exceeds 25 dB based on the pure tone audiometry. The association between average weekly working hours and hearing impairment was analyzed using logistic regression after gender stratification. RESULTS: The prevalences of low and high frequencies hearing impairment in male workers were 4.3 and 28.6 %, respectively, which were much higher than female’s prevalence of 2.7 and 11.1 %. For male workers, no significant association was found between average weekly working hours and low and high frequencies hearing impairment. For female workers, odds ratios (OR) of low and high frequencies hearing impairment were 4.22 (95 % confidence interval (CI) 1.09–16.27) and 4.49 (95 % CI 1.73–11.67), respectively, after controlling for several related factors, such as, age, Body Mass Index (BMI), socio-economic status, health-related behavioral, and occupational characteristics variables, in the final model in the group working more than 60 h compared to the group working 40 h and lower. In addition, a dose-response relationship was observed that ORs of low and high frequencies hearing impairment were increased according to increasing average weekly working hours. CONCLUSIONS: The association between long working hours and hearing impairment in both low and high frequencies was significant in Korean female workers with a dose-response relationship. Therefore, the law to change the culture of long working hours should be enacted in order to protect the workers’ health and improve the quality of life in Korean workers.

The prevalence and risk factors of allergic rhinitis from a nationwide study of Korean elementary, middle, and high school students

PURPOSE: We investigated the prevalence and risk factors of allergic rhinitis (AR), nationwide in random children and adolescents of Korea. METHODS: A modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire survey was done in 1,820 children from elementary, middle, and high school nationwide in Korea. The subjects were selected by the stratifying sampling method by school grade and five regions. Current AR was defined as having AR symptoms during the last 12 months with a history of physician-diagnosed AR. Skin prick tests for 18 common allergens were performed. RESULTS: The number of males was 945, and that of females was 875. The mean age of the patients was 12.61+/-3.40 years. The prevalence of current AR and atopic current AR were 29.0% and 18.7%, respectively. Risk factors for current AR were male (adjusted odds ratio [aOR], 1.486; 95% confidence interval [CI], 1.189-1.856), family history of paternal AR (aOR, 3.208; 95% CI, 2.460-4.182), family history of maternal AR (aOR, 3.138; 95% CI, 2.446-4.025), antibiotic use in infancy (aOR, 1.547; 95% CI, 1.228-1.949), mold exposure during infancy (aOR, 1.416; 95% CI, 1.103-1.819), mold exposure during the last 12 months (aOR, 1.285; 95% CI, 1.012-1.630), and sensitization on skin prick tests (aOR, 2.596; 95% CI, 2.055-3.279). Risk factors for atopic current AR were the same as those of current AR, whereas breast-milk feeding (aOR, 0.720; 95% CI, 0.530-0.976) was a protective factor. Sensitized allergens as risk factors for current AR were Dermatophagoides pteronyssinus, Dermatophagoides farina, ragweed, mugwort, oak, alder, birch, Japanese hop, cat, and dog. CONCLUSION: The prevalences of current AR and atopic current AR were 29.0% and 18.7%, respectively. Male, sex parental AR, antibiotic use in infancy, mold exposure during the last 12 months, mold exposure during infancy, and atopic sensitization were risk factors for current AR. Breast-milk feeding was a protective factor for atopic current AR. Aeroallergen sensitization was an important risk factor for AR.

Emotional labor and dysmenorrhea in women working in sales and call centers

OBJECTIVES: This study was conducted to investigate the association between emotional labor and dysmenorrhea among women working in sales and call centers in Seoul, South Korea. METHODS: Working women in sales jobs and call centers in Seoul were interviewed face-to-face by well-trained interviewers. In total, 975 participants were analyzed in the final model. Emotional labor was measured using a constructed questionnaire with two components: an emotive effort component with three questions and an emotive dissonance component with five questions. To examine the association between emotional labor and dysmenorrhea, chi-squared tests and logistic regression were applied. RESULTS: The prevalence of dysmenorrhea among sales workers and call center workers were 43.0% and 61.1%, respectively. The adjusted odds ratios (OR) of emotive effort and emotive dissonance for dysmenorrhea in call center workers were 1.88 (95% confidence interval [CI], 1.07-3.28) and 1.72 (95% CI, 1.13-2.63), respectively. The adjusted OR of emotive effort and emotive dissonance for dysmenorrhea in sales workers were 1.71 (95% CI, 0.92-3.16) and 1.15 (95% CI, 0.67-1.98), respectively. CONCLUSIONS: Emotional labor was found to be associated with dysmenorrhea in call center workers. Further studies to investigate other factors, such as management strategies and the relationship between emotional labor and dysmenorrhea, are needed to support interventions to prevent dysmenorrhea that will further promote the quality of health and life of working women.

The Association between Long Working Hours and Self-Rated Health

OBJECTIVES: This study was conducted to determine the number of hours worked per week by full-time wage workers by using the data of the Korean Labor and Income Panel Study (KLIPS), which represents the domestic urban area household, and to determine the association between weekly working hours and the level of self-rated health. METHODS: We used data from the 11th KLIPS conducted in 2008. The subjects of this study were 3,699 full-time wage workers between the ages of 25 and 64 years. The association between weekly working hours and self-rated health was analyzed considering socio-demographic characteristics, work environment, and health-related behaviors. RESULTS: Among the workers, 29.7% worked less than 40 hours per week; 39.7%, more than 40 to 52 hours; 19.7%, more than 52 to 60 hours; and 10.9%, more than 60 hours per week. After controlling for socio-demographic variables, work environment-related variables, and health-related behavior variables, the odds ratio (OR) for poor self-rated health for the group working more than 40 hours and up to 52 hours was calculated to be 1.06 (95% confidence interval (CI), 0.89-1.27) when the group working less than 40 hours per week was considered the reference. The OR for the group working more than 60 hours was 1.42 (95% CI, 1.10-1.83) and that for the group working more than 52 hours and up to 60 hours was 1.07 (95% CI, 0.86-1.33). After stratification by gender and tenure, the OR of the female workers group and that of the group with a tenure of more than 1 year were found to be significantly higher than those of the other groups. CONCLUSIONS: This study showed that workers working more than 60 hours per week have a significantly higher risk of poor self-rated health than workers working less than 40 hours per week. This effect was more obvious for the female workers group and the group with a tenure of more than 1 year. In the future, longitudinal studies may be needed to determine the association between long working hours and various health effects in Korean workers.

The Association between Shift Work and Bone Mineral Density : analysis of 2008-2009 Korean National Health and Nutrition Examination Survey / 대한산업의학회지

OBJECTIVES: The objectives of this study were to explore the association between shift work and the bone mineral density in a representative sample of Korean workers. METHODS: He data from the Fourth Korean National Health and Nutrition Examination Survey (2008-2009) was used. The participants were Korean workers aged 16 to 60 years. Logistic regression analysis was applied to determine the association between shift work and the bone mineral density after controlling for covariates using the SAS version 9.3 package program. RESULTS: The blood vitamin D level in shift workers was significantly lower than that of day workers in both males and females. In male shift workers, shift work was significantly associated with a decreased bone mineral density in the femoral neck (odds ratio(OR) 1.42, 95% confidence interval(CI)=1.05~1.92) and lumbar spine (OR 1.53, 95% CI=1.09~2.15) compared to day workers. After controlling for covariates, this association was still significant. In the case of female shift workers, shift work was significantly related to a decreased bone mineral density in the total femur (OR 2.84, 95% CI=1.69~4.79) and lumbar spine (OR 1.58, 95% CI=1.12~2.24). After controlling for covariates, this risk was not statistically significant. CONCLUSIONS: The blood vitamin D level of shift workers was significantly lower than that of day workers. In male shift workers, shift work can decrease the bone mineral density in the femoral neck and lumbar spine. Prospective studies with information on the shift work intensity and duration and exposuredata to explain mechanisms will be needed.

The Effect of Shift Work on the Level of Self-Rated Health / 대한산업의학회지

OBJECTIVES: The present study was designed to determine the characteristics of shift work and the relationship between shift work and the level of self-rated health using the Korean Labor and Income Panel Study (KLIPS) data, which represents urban households in Korea. METHODS: Using the 9th wave of KLIPS, this study analyzed 2,087 male workers aged 25 to 64 years; participants missing data were excluded from analysis. To determine the impact of shift work on the level of self-rated health, logistic regression analysis was applied that controlled for socio-demographic characteristics, labor environment, and health-related behaviors. RESULTS: Shift workers comprised 13.4% of study subjects overall. The majority(69.2%) of participants were in 2-teams and in 2-shifts. Week 1 shift cycle changes were the highest, 56.3%. The risk of poor self-rated health was not significantly higher among shift workers compared to non-shift workers (OR=1.08, 95% CI=0.79~1.48). When divided by tenure, shift workers with more than 10-years experience (OR=1.79, 95% CI=0.91~3.50) tended to show greater risk than non-shift workers at marginal significance. CONCLUSIONS: In the present study, a significantly higher risk of self-rated poor health among shift workers was not observed. However, shift workers with more than 10-years experience tended to show increased health risk compared to non-shift workers. Further studies are required to determine time-series data and to consider both healthy worker effect and information bias.

The Health Effects of Mercury on the Cardiac Autonomic Activity According to the Heart Rate Variability / 대한산업의학회지

OBJECTIVES: The effect of mercury on the cardiovascular system has recently been reported on, but the mechanisms as well as its nature of this effect still need to be confirmed. In this study, the mercury in the hair of a community population was analyzed in relation to the cardiac autonomic activity. METHODS: A hair sample was obtained from the occiput area and the mercury in the hair was analyzed by using a Direct Mercury Analyzer. We measured the cardiovascular risk factors, including total cholesterol, triglyceride, blood pressure, and the body mass index (BMI). Heart rate variability was assessed for 5 minutes, in the time and frequency domain, by using SA-3000P from the Medi-core(R). company. The association between the mercury in the hair and heart rate variability was assessed after controlling for the other cardiovascular risk factors. RESULTS: The mean age of the 671 total subjects was 36 years. The geometric mean of the hair mercury was 0.90 ppm. The hair mercury level was elevated in males, adults, smokers and drinkers. Hair mercury and age, the systolic and diastolic blood pressure, total cholesterol, triglyceride, LDL cholesterol and BMI were all positively correlated. However, hair mercury and heart rate, HDL cholesterol, standard deviation of the NN intervals (SDNN), total power (TP), low-frequency (LF), high- frequency (HF) were negatively correlated. In the higher mercury group, heart rate, SDNN, LF and HF indices were significantly lower compared with those of the lower mercury group. Heart rate was decreased 2.6 beats/min, Ln (HF) was decreased 0.131 msec2 and HF norm was decreased 2.550 with a 1 ppm increase of Ln (Hg), according to multiple linear regression analysis after controlling for age, gender and other cardiovascular risk factors. CONCLUSION: This cross-sectional study showed that mercury may affect the cardiac autonomic activity through parasympathetic dysfunction.

Case Series for Occupational Skin Disorders in Carbon Fiber Exposed Packing Workers / 대한산업의학회지

OBJECTIVES: We report an outbreak of skin disorder in semiconductor packing workers. Through an evaluation of the degree of work-relatedness in this case, we aim to develop a method to overcome such health problems in the workplace. METHODS: A questionnaire investigating the job characteristics and skin symptoms was administered to 51 packing workers working in a semiconductor production factory and 49 questionnaires returned. The 16 subjects in the exposure group and 12 in the non-exposure group underwent doctor's examination and patch test. Two of 28 subjects were excluded in patch test. We investigated the work environment and carbon fiber level which was the potential causative agent. RESULTS: Forty-five (91.8%) of 49 packing workers complained of itching and stinging. Three of 14(21.4%) in the exposure group and 3 of 11 (27.3%) in the non-exposure group were positive at 48hr reading of patch test for carbon fiber and carbon fiber paper. None was positive at 96hr reading of patch test. Prominent carbon fibers were microscopically observed on the surface of the packing box and the fiber diameter, measured up to 6.0~7.5 micrometer, was likely to induce skin irritation to skin. To avoid worker's direct contact with to carbon fiber, carbon fiber paper box was substituted by a wax coated carbon fiber paper box was substituted for the original carbon fiber paper box, which caused and the workers' symptoms to of workers disappeared. CONCLUSION: The probably cause of this outbreak of skin disorder was mild irritant contact dermatitis for carbon fiber. To prevent outbreaks of such occupational skin disorder like this, workers should avoid direct contact with carbon fiber.