Studies on the association between job satisfaction and depression have often been reported. However, no study has examined how job satisfaction impacts depression while considering satisfaction with other aspects of life. In this study, we evaluated the effect of job satisfaction on depression after adjusting for satisfaction with other domains of life.

We used data from the 16th wave of the Korean Welfare Panel Study. A total of 3568 current employees without depression who completed a survey were included. Depression was measured using the abbreviated version of the CES-D scale. Various types of satisfaction, including job satisfaction, were measured using single-item questions and a 5-point Likert scale. The association between job satisfaction and depression after considering satisfaction with other life domains was analyzed using a multiple logistic regression model.

Crude models showed a significant association between job satisfaction and depression in males (odds ratio [OR]: 7.90; 95% confidence interval [CI]: 4.11–15.23) and females (OR: 7.12; 95% CI: 4.40–11.50). When adjusted for sociodemographic factors, health-related factors, and work-related factors, the association remained significant in males (OR: 6.20; 95% CI: 3.10–12.41) and females (OR: 6.28; 95% confidence interval (CI): 3.79–10.40). However, when satisfaction with other life domains was included, the association remained significant only in females (OR: 3.55; 95% CI: 1.93–6.50).

This study shows an association between job satisfaction and depression in Korean employees. However, when satisfaction with other life domains was considered, this association remained significant only in women. Regular screening of job satisfaction should be considered as a means of preventing and managing depression among female employees.

Research on job training and job satisfaction has been conducted from various perspectives. Job training is thought to be associated with job satisfaction, which is known as an important factor for depression among workers. We hypothesized that job training duration could influence depression through potential mediators (job satisfaction, motivation to work, and work engagement).

This study encompassed participants from the sixth Korean Working Conditions Survey (KWCS), conducted between 2020 and 2021. To show the relationships between demographic or occupational characteristics and risk of depression, a χ² test was conducted. The association between job training duration, potential mediators, and risk of depression was analyzed by constructing multiple logistic regression models. The mediating effects of potential mediators on job training duration and risk of depression was evaluated with flexible mediation analysis with weighting-based methods.

The final study population consisted of 25,294 participants. Longer job training duration significantly decreased risk of depression after adjusting for confounders. In the group that received the longest job training duration (≥ 10 days), compared with the group without job training, the odds ratio (OR) for high risk of depression was 0.46 (95% confidence interval [CI], 0.39–0.54). Each three potential mediators showed statistically significant indirect effects and direct effect. Although indirect effects were not strong compared to direct effect, motivation to work had the strongest mediating effect in this study, with an OR of 0.94 (95% CI, 0.92–0.95).

Job training duration was found to have a statistically significant negative association on the risk of depression, and three mediators partially mediating this effect. Although the mechanism was unknown, our findings suggest that job training has a positive influence on workers' mental health. Furthermore, by suggesting the possibility of other pathways existing between job training and depression, we provide directions for future research.

Despite hearing loss being a prevalent chronic condition, estimated to nearly 20% of the global population by the World Health Organization, the specific association with individual lifestyle factors, particularly alcohol consumption, remains unclear. In South Korea, approximately 80% of the population engages in alcohol consumption, with a notably high prevalence among males, indicating a high-risk drinking pattern. Therefore, this study aimed to assess the correlation between alcohol consumption and hearing loss in male workers, as well as to analyze additional variables such as alcohol flushing reaction, with the intention of improving worker health.

The study was conducted from January 2012 to December 2019, targeting 114,114 participants who visited Kangbuk Samsung Hospital Total Healthcare Centers. Data were collected through pure-tone audiometry tests and alcohol-related questionnaire, and statistical analysis was performed using Cox regression analysis. Based on previous studies indicating a potential protective effect of light drinking on hearing loss, this group was designated as the reference. Additionally, stratified analyses were conducted based on the presence of alcohol flushing reaction and different working hours.

The hazard ratio (95% confidence interval) for hearing loss was higher in the heavy drinking group (1.23 [1.11–1.37]) compared to the moderate drinking group (1.09 [0.98–1.20]). Stratified analyses revealed a significantly elevated the hazard ratio of hearing loss in groups with alcohol flushing reaction compared to those without this factor.

Our study demonstrated that moderate or heavy alcohol consumption in male workers can increase the risk of hearing loss, particularly in those with alcohol flushing reaction. These findings underscore the importance of addressing alcohol-related factors concerning hearing health among male workers.

Hearing loss (HL) is linked to an elevated risk of cardiovascular diseases (CVDs). The pathogeneses of HL and CVD commonly involve inflammatory responses. Previous studies investigated elevated levels of inflammatory biomarkers in subjects with HL, however, their findings did not demonstrate statistical significance. In our cross-sectional and longitudinal study, we investigated the correlation between HL and increased high-sensitivity C-reactive protein (hsCRP) levels to determine how HL is associated with CVDs.

We conducted a cross-sectional study with workers aged over 18 years who underwent health check-ups at our institution between 2012 and 2018 (n = 566,507), followed by conducting a longitudinal study of workers aged > 18 who underwent health checkups at least twice at our institution between 2012 and 2018 (n = 173,794). The definition of HL was as an average threshold of ≥ 20 dB in pure-tone air conduction at 0.5, 1.0, and 2.0 kHz in both ears. The incidence of increased hsCRP levels throughout the follow-up period was defined as a level exceeding 3 mg/L. Logistic regression and generalized estimating equations were performed to estimate the risk of increased hsCRP levels according to the occurrence of HL in groups stratified by age.

In the cross-sectional study, the multivariate-adjusted odds ratio (OR) was 1.17 (95% confidence interval [CI]: 1.02–1.34); the OR was 0.99 (95% CI: 0.80–1.22) in those under 40 and 1.28 (1.08–1.53) in those over 40. In the longitudinal study, the multivariable-adjusted OR was 1.05 (95% CI: 0.92–1.19); the OR was 1.10 (95% CI: 0.90–1.35) in those under 40 and 1.20 (1.01–1.43) in those over 40.

This cross-sectional and longitudinal study identified an association between HL and increased hsCRP levels in workers aged over 40 years.

With modernization, air pollution has become increasingly serious, and its effects on health have been revealed. As a result, public interest in environmental pollution has become critical for regulating air pollution. In our study, we aim to evaluate the impact of air pollution levels on public attention to environmental issues and examine whether awareness of the residential environment’s impact on health acts as a mediator in this relationship.

We conducted an analysis on 400 individuals surveyed in the preliminary feasibility study on adverse health effects in the Pohang Industrial Complex, to examine the relationship between particulate matter 2.5 (PM2.5) and attention to environmental issues. Logistic regression analysis was performed, and mediation analysis was used to determine whether awareness of the residential environment’s impact on health mediated the relationship.

The logistic regression analysis results showed that PM2.5 levels were associated with attention to environmental issues (adjusted odds ratio [AOR]: 2.1; 95% confidence interval [CI]: 1.3–3.5; p = 0.003) and awareness of health impacts (AOR: 3.4; 95% CI: 1.6–7.1; p = 0.001). The PM2.5 levels showed 9.9% (95% CI: 5.4–14.0) increase in the prevalence of high attention to environmental issues, of which, only 1.0% (95% CI: 0.2–2.3) were mediated by health impact awareness. In the overall analysis, 10% of the total effect of PM2.5 on attention to environmental issues was mediated by health impact awareness.

According to this study’s results, there was a correlation between air pollution levels and attention to environmental issues. Awareness of the health impacts of air pollution partially mediated the effect of air pollution levels on attention to environmental issues. In future studies, it is recommended to identify other mediators to further understand this structure.

The musculoskeletal disease (MSD) burden is an important health problem among Korean fishers. We aimed to investigate the indicators of the prevalence of MSD and contributions of significant indicators to MSD in Korean fishers.

This cross-section study included 927 fishers (male, 371; female, 556) aged 40 to 79 years who were enrolled from 3 fishery safety and health centers. The outcome variable was one-year prevalence of MSD in 5 body parts (the neck, shoulder, hand, back, and knee). Independent variables were sex, age, educational attainment, household income, job classification, employment xlink:type, hazardous working environment (cold, heat, and noise), ergonomic risk by the 5 body parts, anxiety disorder, depression, hypertension, diabetes, and hyperlipidemia. The adjusted odds ratio of MSDs by the 5 body parts were calculated using multiple logistic regression analysis. We computed the population attributable fraction (PAF) for each indicators of MSDs using binary regression models.

The one-year prevalence of MSD in the neck, shoulder, hand, back, and knee was 7.8%, 17.8%, 7.8%, 27.2%, and 16.2% in males vs. 16.4%, 28.1%, 23.0%, 38.7%, and 30.0% in females, respectively. The ergonomic risk PAF according to the body parts ranged from 22.8%–59.6% in males and 22.8%–50.3% in female. Mental diseases showed a significant PAF for all body parts only among female (PAF 9.1%–21.4%). Cold exposure showed a significant PAF for the neck, shoulder, and hand MSD only among female (25.6%–26.8%). Age was not a significant indicator except for the knee MSD among female.

Ergonomic risk contributed majorly as indicators of MSDs in both sexes of fishers. Mental disease and cold exposure were indicators of MSDs only among female fishers. This information may be important for determining priority risk groups for the prevention of work-related MSD among Korean fishers.

In the manufacturing industry, work-family conflict (WFC) is related to working hour characteristics. Earlier studies on the relationship between working hour characteristics and WFC in the manufacturing industry have been limited to some regions in Korea. No study has addressed the data on a national scale. Thus, this study investigated the impact of weekly working hours, weekend work, and shift work on WFC using national-scale data.

This study was based on the fifth Korean Working Conditions Survey of 5,432 manufacturers. WFC consists of 5 variables; WFC1 “kept worrying about work”; WFC2 “felt too tired after work”; WFC3 “work prevented time for family”; WFC4 “difficult to concentrate on work”; WFC5 “family responsibilities prevented time for work”. As WFC refers to the inter-role conflict between the need for paid work and family work, WFC has been measured in two directions, work to family conflict (WTFC: WFC1, 2, 3) and family to work conflict (FTWC: WFC4, 5). With these WFC variables, we conducted multiple logistic analyses to study how working hours, weekend work, and shift work impact WFC.

Korean manufacturers’ prolonged working hours increased all aspects of WFCs. Odds ratios (ORs) of WFCs based on working hours (reference of under 40 hours) of 41–52, 53–60, over 61 were 1.247, 1.611, 2.279 (WFC1); 1.111, 2.561, 6.442 (WFC2); 1.219, 3.495, 8.327 (WFC3); 1.076, 2.019, 2.656 (WFC4); and 1.166, 1.592, 1.946 (WFC5), respectively. Shift-work in the WFC2 model showed a significantly higher OR of 1.390. Weekend work ‘only on Saturday’ had significant ORs with WFC2 (1.323) and WFC3 (1.552).

An increase in working hours leads to the spending of less time attending to problems between work and family, causing both WTFC and FTWC to increase. As weekends, evenings, and nighttime are considered to be family-friendly to people, working on weekends and shift-work were highly correlated to WTFC.

Although spirometry results can be interpreted differently depending on the reference equation used, there are no established criteria for selecting reference equations as part of the special health examinations for Korean workers. Thus, it is essential to examine the current use of reference equations in Korea, quantify their impact on result interpretation, and propose reference equations suitable for Korean workers, while also considering the environmental conditions of special health examination facilities.

The 213,640 results from the special health examination database were analyzed to identify changes in the ratio of measured values to reference values of lung capacity in Korean workers with changes in age or height, and changes in the agreement of interpretations with the reference equation used. Data from 238 organizations that participated in the 2018–2019 quality control assessment by the Korea Occupational Safety and Health Agency were used to identify the spirometer model and reference equations used in each special health examination facility.

Korean special health examination facilities used six reference equations, and the rate of normal or abnormal ventilatory diagnoses varied with the reference equation used. The prediction curve of the Global Lung Function Initiative 2012-Northeast Asian (GLI2012) equation most resembled that of the normal group, but the spirometry model most commonly used by examination facilities was not compliant with the GLI2012 equation. With a scaling factor of 0.95 applied to the Dr. Choi equation, the agreement with the GLI2012 equation was > 0.81 for men and women.

We propose the GLI2012 equation as reference equation for spirometry in Korean workers. The GLI2012 equation exhibited the most suitable prediction curve against the normal lung function group. For devices that cannot use the GLI2012 equation, we recommend applying a scaling factor of 0.95 to the Dr. Choi equation.

Recently, there has been a call to improve the holistic welfare of dependent contractors (DCs). Thus, our study examined the relationship between DCs and mental health symptoms and how this relationship was modified by age, sex, and income status of workers.

A total of 27,980 workers from the Fifth Korean Working Conditions Survey are included in our study. The participants who reported having depression or anxiety over the last 12 months are defined those who had mental health symptoms. We performed exact matching for age group and sex, followed by conditional logistic regression with survey weights. Finally, stratified analyses by age, sex and income level were conducted.

DCs were found to be at increased risk of depression/anxiety compared to other workers. The odds ratio (OR) is 1.52 (95% confidence interval [CI]: 1.06–2.17). In the stratified analyses, vulnerable groups were middle-aged (OR [95% CI]: 1.68 [1.10–2.54]), female (OR [95% CI]: 1.85 [1.20–2.84]), and low-income (OR [95% CI]: 3.18 [1.77–5.73]) workers.

Our study's results reinforce those of other studies that show that DCs are at greater risk of experiencing mental health issues than other workers and that and this risk is greater for middle-aged, female, and low-income workers. These results suggest that appropriate policy efforts should be made to improve the psychological well-being of DCs.

We conducted this experimental study to estimate a risk of a high-risk group of low back pain (LBP) membership in workers who perform the manual material handling (MMH) tasks in an actual workplace setting.

The subjects include healthy workers who were engaged in 12 MMH tasks at 6 manufacturing companies. We assessed the dynamic motion of trunk or lumbar spine using an industrial lumbar motion monitor (BioDynamics Laboratory of Ohio State University). The subjects were evaluated for the age, gender, years of working and anthropometric measurements (e.g., height, weight, shoulder height, elbow height, iliac height, leg length, trunk length, trunk circumference, iliac width, iliac depth, xiphoid width and xiphoid depth). Moreover, they were also evaluated for a risk of a high-risk group of LBP membership based on lift frequency, average twisting velocity, maximum moment, maximum sagittal flexion and maximum lateral velocity.

The subjects who were engaged in a packaging at a detergent manufacturing company are at the greatest risk of LBP (63.76%). This was followed by packaging at a leather product manufacturing company (57.06%), packaging at a non-metallic casting material manufacturing company (57.03%), manual injection at a non-metallic casting material manufacturing company (52.00%), toggling at a leather product manufacturing company (46.09%), non-metallic casting material manufacturing company (42.88%), rolling at a non-metallic mineral product manufacturing company (42.12%), shooting at a non-metallic casting material manufacturing company (40.99%), vacuum processes at a leather product manufacturing company (35.00%), looping at a general industrial machinery manufacturing company (33.93%), setting at a leather product manufacturing company (30.22%) and packaging at a general metal product manufacturing company (22.02%).

Our approach indicates that there is a risk of a high-risk group of LBP membership in workers who perform the MMH tasks.

Sunlight exposure is a major risk factor for eye disorders. Most outdoor workers cannot avoid sunlight exposure. This study aimed to analyze the relationship between outdoor sunlight exposure and eye disorders in an economically active population.

This study analyzed the 2008–2012 Korea National Health and Nutritional Examination Survey data. Sunlight exposure was categorized as < 5 hours and > 5 hours. We also analyzed the dose-dependent relationship between exposure to sunlight and eye disorders (cataracts, pterygium, and age-related macular degeneration [AMD]) using data from 2010 to 2012 by subdividing the exposure groups into < 2 hours, 2–5 hours, and ≥ 5 hours. Eye disorders were diagnosed by an ophthalmologist. The study participants were stratified by sex, and the results were analyzed using the χ² test and multiple logistic regression analysis.

In the female group, the odds ratio of pterygium in the high-level sunlight exposure group was 1.47 (95% confidence interval [CI]: 1.15–1.89). Regarding AMD, the odds ratios were 1.42 (95% CI: 1.16–1.73), 1.33 (95% CI: 1.03–1.73), and 1.58 (95% CI: 1.15–2.16) in the total, male, and female groups, respectively. Analysis of the dose-response relationship revealed that the odds ratios of pterygium in the high-level sunlight exposure subgroups of the total and female groups were 1.62 (95% CI: 1.25–2.08) and 2.00 (95% CI: 1.39–2.88), respectively.

This study demonstrated a relationship between sunlight exposure and eye disorders in an economically active population. Women were found to be especially vulnerable to pterygium. However, additional prospective studies to clarify the pathophysiology of pterygium are needed.

This study aimed to investigate the association between job stress and suicide ideation/attempts among display manufacturing workers.

Data were collected from 836 workers in a display manufacturing company who participated in health screenings from May 22 to June 16, 2017. The data included general characteristics, night work, job tenure, previous physician-diagnosed chronic diseases, suicidal ideation/suicide attempts, and job stress. We investigated suicidal ideation/suicide attempts that covered the past year by using a self-reported questionnaire. Job stress was measured using the 43-item Korean Occupational Stress Scale. Multiple logistic regression analysis was used to investigate the association between job stress and suicidal ideation/suicide attempts. The mediator effect of depression on suicidal ideation/suicide attempts was tested using a series of logistic regression by applying Baron and Kenny's mediation method.

In the model adjusting for variables (e.g., age, body mass index, smoking, alcohol consumption, regular exercise, shift work, job tenure, chronic disease and depression), physical environment (OR: 3.60, 95% CI: 1.08–12.02), lack of reward (OR: 5.31, 95% CI: 1.54–18.34), and occupation climate (OR: 7.36, 95% CI: 2.28–23.72) were correlated with suicidal ideation/suicide attempts in women. However, all subscales of job stress were not significantly correlated with suicidal ideation/suicide attempts in men. In mediation analysis, job instability and occupational climate were correlated with suicidal ideation/suicide attempts and were mediated by depression in men workers.

In women workers, the experiences of suicidal ideation/suicide attempts were significantly correlated with the physical environment, lack of reward, and occupational climate that were subscales of job stress. In men workers, depression rather than job stress was correlated with experiences of suicidal ideation/suicide attempts.

There have been no health-related studies of pre-employed firefighters without firefighter-specific job-related factors (FSJRF). This study aimed to evaluate the sleep quality of pre-employed firefighters and to examine the relationship between sleep quality and psychosocial factors.

We conducted a self-report questionnaire survey for 602 pre-employed firefighters at 3 Fire Service Academies after brief lecture about sleep. Sleep quality and psychosocial variables such as depression, anxiety, stress and social support were evaluated. The independent 2 sample t-test, χ² test and multiple logistic regression analysis were used to evaluate the effect of the variables on the sleep quality of pre-employed firefighters.

Among a total of 602 people, 347 (57.6%) had good sleep quality and 255 (42.4%) had poor sleep quality. Pittsburgh Sleep Quality Index score of them was 3.29 ± 1.41) and 7.87 ± 2.20), respectively. 24 (4.0%) were evaluated to have insomnia by Insomnia Severity Index. Logistic regression analyses showed that the depression (adjusted odds ratio [aOR]: 5.940, 95% confidence interval [CI]: 3.124–11.292), anxiety (aOR: 4.233, 95% CI: 2.138–8.381), stress (aOR: 2.880, 95% CI: 1.915–4.330) and social support (aOR: 0.959, 95% CI: 0.939–0.980) have a significant effect on sleep quality after adjusted by sex, age, smoking status, drinking status, caffeine intake, past shift working and circadian rhythm type.

Depression, anxiety, stress and social support were associated with sleep quality among pre-employed firefighters. Repeated follow-up studies of pre-employed firefighters are needed to further assess their change of sleep quality and identify the FSJRF that may affect the sleep quality of firefighters.

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.

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.

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).

Indirectly employed blue-collar workers have an increased risk of occupational injury in Korea.

Depression is considered as a risk factor for cardiovascular disease (CVD) and associated with changes in individuals' health status that might influence CVD risk. However, most studies have scrutinized this relationship on a rather narrower and specific study population. By focusing on general population of Korea, we sought to inspect the association of depression with CVD risk and cardiovascular risk factors.

The data from the first year (2016) of the 7th Korea National Health and Nutrition Examination Survey was used. Participants were classified by the Patient Health Questionnaire-9 (PHQ-9) score as such: normal group (PHQ-9 score 0–4), mild depression (MD) group (PHQ-9 score 5–9) and moderate and severe depression (MSD) group (PHQ-9 score 10–27). General linear model was used to analyze differences and the trend of mean CVD risk according to depression level. Adjusted odds ratios (AORs) were calculated by logistic regression to identify the association between depression and cardiovascular risk factors after adjusting for age.

Mean CVD risk of MSD group was higher than that of normal group (p < 0.05). There was a tendency of CVD risk to increase as depression worsened (p < 0.01). Among men, MSD group was associated with current smoking (AOR, 2.97; 95% confidence interval [CI], 1.78–4.97), taking antihypertensive medications (AOR, 2.42; 95% CI, 1.26–4.66), increased fasting blood sugar (> 125 mg/dL; AOR, 2.37; 95% CI, 1.25–4.50) and taking diabetes medications (AOR, 3.08; 95% CI, 1.65–5.72). MD group was associated with current smoking (AOR, 1.60; 95% CI, 1.18–2.17). Among women, MSD group was associated with high body mass index (≥ 25 kg/m²; AOR, 1.61; 95% CI, 1.11–2.32), large waist circumference (≥ 85 cm; AOR, 1.63; 95% CI, 1.12–2.37), current smoking (AOR, 5.11; 95% CI, 3.07–8.52) and taking diabetes medications (AOR, 2.62; 95% CI, 1.68–4.08). MD group was associated with current smoking (AOR, 1.86; 95% CI, 1.18–2.93).

We suggest that depression is associated with increased risk for CVD occurrence in general population of Korea.

This study assessed the association between shift work and high-sensitivity C-reactive protein (hs-CRP) level, a risk factor for cardiovascular disease (CVD), in female workers in electronics manufacturing services (EMS).

Female EMS workers who received special medical examinations for workers in Gyeongnam, Korea between January 2017 and December 2017 were enrolled in this study. Their age, marital status, education level, alcohol consumption, smoking habit, regular exercise, quality of sleep, work stress, and depression were investigated, and blood tests were conducted. The t- and χ² tests were conducted to compare the general and biochemical characteristics between daytime and shift worker groups. Age-adjusted partial correlation analysis was performed to examine the linear relationship between hs-CRP level and other risk factors for CVDs. In addition, the difference in hs-CRP levels according to work schedule was analyzed by ANCOVA after adjusting for variables that could affect the hs-CRP level.

Although the average hs-CRP levels did not differ significantly between daytime and shift workers (0.92 ± 1.87 and 1.07 ± 2.20 mg/dL, respectively), shift workers tended to show a higher hs-CRP level (p = 0.067). After adjusting for variables that can affect the hs-CRP level, the estimated average hs-CRP level was significantly higher in shift workers (1.325 ± 0.156 mg/dL) than that in daytime workers (0.652 ± 0.350 mg/dL) (p = 0.003).

The results of this study identified a relationship between shift work and hs-CRP level increase in women. Because multiple studies have reported associations between increased hs-CRP and CVD, follow-up of hs-CRP may help early detection of CVD in shift workers.

Job stress has been reported as a risk factor of psychological changes, which have been shown to be related to gastrointestinal diseases and symptoms such as functional dyspepsia. However, few studies have assessed the relationship between job stress and functional dyspepsia. Therefore, we investigated the relationship between job stress and functional dyspepsia in South Korea.

This study was conducted between May 23 and July 6, 2016 and included 901 workers in the display manufacturing sector. Subjects completed self-reported questionnaires, regarding Korean Occupational Stress Scale (KOSS), functional dyspepsia, Insomnia Severity Index-K, and health-related behaviors and job characteristics. Subjects were divided into functional dyspepsia-positive and -negative groups based on the Rome III criteria. The KOSS high-risk group was defined as subjects with KOSS score above the 75 percentile of KOSS reference value. Multiple logistic regression analysis was performed to investigate the association between job stress and functional dyspepsia.

In women, the risk of functional dyspepsia was significantly higher in the high-risk groups of the following KOSS subcategories in unadjusted model: job demand (OR 3.282, 95% CI 1.181–9.126), and occupational climate (OR 2.665, 95% CI 1.041–6.823). Even in adjusted model, the risk was significantly higher in the high-risk groups of the following KOSS subcategories: job demand (OR 3.123, 95% CI 1.036–9.416) and occupational climate (OR 3.304, 95% CI 1.198–9.115). In men, the risk of functional dyspepsia was not significant in all KOSS subcategories.

This study showed that job demand and occupational climates were associated with functional dyspepsia in female display manufacturing sector workers. Therefore, both clinical and mental health approaches should be used in the management of functional dyspepsia in women.

It is well known that ergonomic risk factors and back pain are related. However, few studies have examined the relationship between simultaneous exposure to these risk factors and back pain in a Korean population. We aimed to investigate the relationship between simultaneous exposure to ergonomic risk factors and work-related lower back pain (LBP) based on the fourth Korean Working Conditions Survey (KWCS).

The fourth KWCS (2014) was used for this study. Chi-square tests and logistic regression were used to assess relationship between 5 ergonomic risk factors and work-related LBP. We also analyzed the relationship between simultaneous exposure to 2 risk factors and work-related LBP.

All 5 ergonomic risk factors (fatigue-inducing and painful posture; lifting or moving people; dragging, pushing, or moving heavy objects; standing posture; and repetitive hand or arm movements) were significantly correlated with work-related LBP in the severe exposure group (adjusted odd ratios [aOR] 5.09, 95% confidence interval [CI] 4.46–5.83; aOR 1.98, 95% CI 1.62–2.42; aOR 2.09, 95% CI 1.82–2.40; aOR 1.79, 95% CI 1.60–2.01; aOR 2.04, 95% CI 1.82–2.30, respectively). When exposed to 2 risk factors simultaneously, the relationship between exposure and work-related LBP was not greater than exposure to only 1 risk factor in our study (usually exposed to ‘fatigue-inducing or painful posture’ aOR 2.17, 95% CI 2.02–2.34; high exposure to both ‘fatigue-inducing or painful posture’ and ‘dragging, pushing, or moving heavy objects’ aOR 2.00, 95% CI 1.82–2.20).

There was a strong relationship between severe exposure to each ergonomic risk factor and work-related LBP. However, when exposed to 2 ergonomic risk factors simultaneously, the relationship between exposure and work-related LBP was not stronger than when exposed to only 1 risk factor in our study.

Occupational injuries increase burden on society as well as personal health. Low satisfaction with life may not only increases the risk of occupational injuries directly, but also influences other factors that increase the risk of occupational injury. Along with previous studies on the risk of occupational injury, we sought to explore the relationship between satisfaction with life and occupational injury.

The study participants were 6234workers health screened at a university hospital in Incheon. Information on occupational injury and satisfaction with life scale (SWLS) was obtained in a self-report format. Participants were allocated to one of four SWLS groups; the dissatisfied group, the slightly dissatisfied group, the slightly satisfied group, and the satisfied group. The analysis was performed using the chi-square test primarily and by logistic regression adjusted for potential confounders.

In men, the un-adjusted and adjusted odds ratios (ORs) of low satisfaction with life (SWLS< 20) were 1.98(CI1.55–2.53) and 1.81(CI 1.41–2.32), respectively. When the SWLS were divided into four groups, the adjusted ORs of the slightly satisfied (20–25), slightly dissatisfied(15–19), and dissatisfied(≤14) groups were 1.21, 1.72, and 2.70, respectively. That is ORs tended to increase linearly with decreasing SWLS score (p for trend < 0.001). In women, this relation was of borderline significance at best.

When subjects were dichotomized based on SWLS scores, for males, the cured and adjusted RRs of occupational injury in the low satisfaction with life group were1.91 (95% CI: 1.50–2.42) and 1.66 (95% CI: 1.30–2.13), and for females, the adjusted-RR was marginally significant (1.67; 95% CI: 0.93–2.99).

When subjects were divided into four groups by SWLS scores, adjusted RRs tended to increase linearly with decreasing SWLS score for males (slightly satisfied: 1.18, 95% CI: 0.77–1.82; slightly dissatisfied: 1.65, 95% CI: 1.08–2.52; dissatisfied: 2.22, 95% CI: 1.44–3.42; p for trend < 0.001) and for females (slightly satisfied: 1.17, 95% CI: 0.42–3.30; slightly dissatisfied: 1.56, 95% CI: 0.56–4.36; dissatisfied: 2.38, 95% CI: 0.84–6.74; p for trend = 0.040).

This study suggests that the risk of occupational injury was higher in workers not satisfied with life, and indicates attention to satisfaction with life may promote the health of workers.

Polycyclic aromatic hydrocarbons (PAHs) produced by incomplete combustion have negative effects on human health due to their carcinogenicity and teratogenicity. Indoor sources of PAHs include tobacco smoke, heating sources, and cooking. This study evaluated the relationship between human PAH exposure and residence characteristics.

This study was based on the second Korean National Environmental Health Survey (2012–2014). Non-smoking housewives were included in the analyses (n = 1269). The concentrations of urinary PAH metabolites (2-naphthol, 2-hydroxyfluorene, 1-hydroxyphenanthrene, and 1-hydroxypyrene) were adjusted by urine creatinine level. The geometric mean concentrations of urinary PAH metabolites by residential factors were examined. Logistic regression models were used to evaluate associations between residential variables and PAH exposures.

The adjusted geometric mean concentrations of urinary 2-hydroxyfluorene and 1-hydroxyphenanthrene were significantly higher in the group residing within 100 m of a major road (p < 0.05) than in those residing > 100 m from a major road. In logistic regression analyses, the odds ratio (OR) for exceeding the third quartile of urinary 1-hydroxypyrene concentration was significantly higher in the group using coal or wood fuel for residential heating than in the group using gas (OR = 2.745, 95% confidence interval [CI] = 1.295–5.819). The detached house group had a significantly higher OR for 1-hydroxyphenanthrene compared with the apartment group (OR = 1.515, 95% CI = 1.023–2.243).

Our study shows the evidence of associations between some urinary PAH metabolite levels (1-hydroxyphenanthrene and 1-hydroxypyrene) and residence characteristics. Additional studies are needed to clarify these associations.

Exposure to sustained high concentrations of HCFC-123 is known to be hepatotoxic. We report two simultaneous cases of toxic hepatitis related to exposure to 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123), a common refrigerant, at a Korean fire extinguisher manufacturing facility.

Patients A and B were men aged 21 and 22 years, respectively, with no notable medical histories. They had recently started working for a manufacturer of fire extinguishers. During the third week of their employment, they visited the emergency center of a general hospital due to fever, lack of appetite, and general weakness. At the time of their visit, they were suspected as having hepatitis due to elevated aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), and total bilirubin levels and were hospitalized. However, as their condition did not improve, they were moved to a tertiary general hospital. After conservative treatment, one patient improved but the other died from acute hepatic failure. Assessments of the work environment showed that the short-term exposure levels of HCFC-123 for valve assembly processes were as high as 193.4 ppm. A transjugular liver biopsy was performed in patient A; the results indicated drug/toxin-induced liver injury (DILI). Given the lack of a medical history and the occupational exposure to high levels of HCFC-123, a hepatotoxic agent, the toxic hepatitis of the workers was likely related to HCFC-123 exposure.

Work environment assessments have not included this agent. To the best of our knowledge, we are the first to report a case of death related to HCFC-123-induced liver damage. Our findings suggest that exposure standards and limits for HCFC-123 must be developed in Korea; work environments will have to be improved based on such standards.

The olfactory bulb is anatomically exposed and thus can be directly damaged by external stimulation. This can occur as an occupational injury owing to contact with organic solvents or other causes. We present cases of eight patients who sustained occupation-related exposure to potentially toxic substances and later presented with signs and symptoms of anosmia. We examined the occupational and medical characteristics of the patients and evaluated their work-relatedness.

Case 1: A 50-year-old man performed high-frequency heat treatments for approximately 11 years. He experienced decreased senses for olfaction and taste during the later years culminating in the diagnosis of anosmia after 3 years (high work-relatedness). Case 2: A 54-year-old man whose work involved exposure to various organic solvents, such as spray painting and application of paint and thinners for approximately 4 years, was subsequently diagnosed with anosmia based on rhinorrhea, headache, and loss of olfaction (high work-relatedness). Case 3: A 44-year-old-man who performed spray painting for approximately 17 years developed anosmia (high work-relatedness). Case 4: A 44-year-old man was involved in ship engine cleaning once a month, for approximately 7 h per cleaning session; he was diagnosed with anosmia based on loss of olfaction (low work-relatedness). Case 5: A 41-year-old man worked in ship building block construction for approximately 13 years; anosmia diagnosis was based on loss of olfaction (low work-relatedness). Case 6: A 47-year-old woman performed product inspection and labeling at a plant manufacturing automobile parts; anosmia diagnosis was based on decreased olfaction and taste (low work-relatedness). Case 7: A 50-year-old woman performed epoxy coating in a plant manufacturing automobile parts; anosmia diagnosis was based on diminishing olfaction (low work-relatedness). Case 8: A 57-year-old woman performed cleaning of the area where mobile phone parts were manufactured; anosmia diagnosis was based on diminishing olfaction (low work-relatedness).

The study results confirmed work-relatedness when the subject was young, and the duration of exposure was long without any other cause of anosmia. Regarding compensation for occupational diseases, work-relatedness can be recognized as a relative concept.

Workplace health promotion (WHP) strongly requires the employer’s efforts to improve the psychosocial, ergonomic, and physical environments of the workplace. There are many studies discussing the socio-economic advantage of WHP intervention programmes and thus the internal and external factors motivating employers to implement and integrate such programmes. However, the socio-economic impacts of the employer’s multifactorial efforts to improve the work environment need to be adequately assessed.

Data were collected from Swedish company Sandvik Materials Technology (SMT) through a work environment survey in April 2014. Different regression equations were analysed to assess marginal effects of the employer’s efforts on overall labour effectiveness (OLE), informal work impairments (IWI), lost working hours (LWH), and labour productivity loss (LPL) in terms of money.

The employer’s multifactorial efforts resulted in increasing OLE, decreasing IWI and illness-related LWH, and cost savings in terms of decreasing LPL.

Environmental factors at the workplace are the important determinant factor for OLE, and the latter is where socio-economic impacts of the employer’s efforts primarily manifest.

In Korea, Carbon disulfide (CS₂) toxicity was an important social problem from the late 1980s to the early 1990s but there have been few large-scale studies examining the prevalence of diseases after CS₂ exposure discontinuance. So we investigated past working exposure to CS₂ characteristics from surviving ex-workers of a rayon manufacturing plant including cumulative CS₂ exposure index. Furthermore, we studied the prevalence of their chronic diseases recently after many years.

We interviewed 633 ex-workers identified as CS₂ poisoning-related occupational diseases to determine demographic and occupational characteristics and reviewed their medical records. The work environment measurement data from 1992 was used as a reference. Based on the interviews and foreign measurement documents, weights were assigned to the reference concentrations followed by calculation of individual exposure index, the sum of the portion of each time period multiplied by the concentrations of CS₂ during that period.

The cumulative exposure index was 128.2 ppm on average. Workers from the spinning, electrical equipment repair, and motor repair departments were exposed to high concentrations of ≥10 ppm. Workers from the maintenance of the ejector, manufacturing of CS_2, post-process, refining, maintenance and manufacturing of viscose departments were exposed to low concentrations below 10 ppm. The prevalence for hypertension, coronary artery disease, cerebrovascular disease, diabetes, arrhythmia, psychoneurotic disorder, disorders of the nervous system and sensory organ were 69.2%, 13.9%, 24.8%, 24.5%, 1.3%, 65.7%, 72.4% respectively.

We estimated the individual cumulative CS₂ exposure based on interviews and foreign measurement documents, and work environment measurement data. Comparing the work environment measurement data from 1992, these values were similar to them. After identified as CS₂ poisoning, there are subjects over 70 years of average age with disorders of the nervous system and sensory organs, hypertension, psychoneurotic disorder, cerebrovascular disease, diabetes, coronary artery disease, and arrhythmia. Because among ex-workers of the rayon manufacturing plant, only 633 survivors recognized as CS₂ poisoning were studied, the others not identified as CS₂ poisoning should also be investigated in the future.

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.

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.

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.

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.

Sleep disorders and depression/anxiety disorders are long-standing and significant problem for mental health. Also there are already known so many negative health effect of these disorders. But there were few studies to examine the association between activities outside work and forementioned disorders. So this study aimed the association of those things by using the Republic of Korean data.

Data from 32,232 wage workers were used in the 4th Korean Working Condition Survey. General and occupational characteristics, sleep disorders, depression/anxiety disorders and activities outside work are included in questionnaire. To find the relationship between activities outside work and sleep, depression/anxiety disorders, multivariate logistic regression analysis was used after adjusting for general and occupational characteristics.

We observed that volunteer activities increased the odds ratio of both sleep disorders and depression/anxiety disorders(Odds ratio[OR] = 1.35, 95% confidence interval[CI]: 1.03–1.78 and OR = 1.54, 95% CI: 1.29–1.84, respectively). And self-development activities increase the odds ratio of sleep disorders(OR = 1.35, 95% CI: 1.17–1.57). Gardening activities lowered the odds ratio of depression/anxiety disorders(OR = 0.74, 95% CI: 0.59–0.94).

Some of activities outside work were related to sleep disorders and depression/anxiety disorders among Korean wage workers. Our results showed negative health effect of some kinds of activities outside work such as volunteering and self-devlopment compared to other studies that emphasized positive effect of those activities for health.

In 2015, workers dismantling a fluorescent lamp factory in Korea were affected by mercury poisoning from exposure to mercury vapor.

Eighteen out of the 21 workers who participated in the demolition project presented with symptoms of poisoning and, of these, 10 had persistent symptoms even at 18 months after the initial exposure to mercury vapor. Early symptoms of 18 workers included a general skin rash, pruritus, myalgia, sleep disturbance, and cough and sputum production. Following alleviation of these initial symptoms, late symptoms, such as easy fatigue, insomnia, bad dreams, and anxiety disorder, began to manifest in 10 out of 18 patients. Seven workers underwent psychiatric care owing to sleep disturbance, anxiety disorder, and depression, and three workers underwent dermatologic treatment for hyperpigmentation, erythematous skin eruption, and chloracne-like skin lesions. Furthermore, three workers developed a coarse jerky movement, two had swan neck deformity of the fingers, and two received care at an anesthesiology clinic for paresthesia, such as burning sensation, cold sensation, and pain. Two workers underwent urologic treatment for dysfunction of the urologic system and impotence. However, symptomatic treatment did not result in satisfactory relief of these symptoms.

Awareness of the perils of mercury and prevention of mercury exposure are critical for preventing health hazards caused by mercury vapor. Chelation therapy should be performed promptly following mercury poisoning to minimize damage.

Recently, noise coming from the neighborhood via floor wall has become a great social problem. The noise between the floors can be a cause of physical and psychological problems, and the different types of floor impact sound (FIS) may have the different effects on the human’s body and mind. The purpose of this study is to assess the responses of subjective feeling, task performance ability, cortisol and HRV for the various types of floor impact.

Ten men and 5 women were enrolled in our study, and the English listening test was performed under the twelve different types of FIS, which were made by the combinations of bang machine (B), tapping machine (T), impact ball (I) and sound-proof mattress (M). The 15 subjects were exposed to each FIS for about 3 min, and the subjective annoyance, performance ability (English listening test), cortisol level of urine/saliva and heart rate variability (HRV) were examined. The sound pressure level (SPL) and frequency of FIS were analyzed. Repeated-measures ANOVA, paired t-test, Wilcoxon signed rank test were performed for data analysis.

The SPL of tapping machine (T) was reduced with the soundproof mattress (M) by 3.9–7.3 dBA. Impact ball (I) was higher than other FIS in low frequency (31.5–125 Hz) by 10 dBA, and tapping machine (T) was higher than other FIS in high frequency (2–4 k Hz) by 10 dBA. The subjective annoyance is highest in the combination of bang machine and tapping machine (BT), and next in the tapping machine (T). The English listening score was also lowest in the BT, and next in T. The difference of salivary cortisol levels between various types of FIS was significant (p = 0.003). The change of HRV parameters by the change of FIS types was significant in some parameters, which were total power (TP) (p = 0.004), low frequency (LF) (p = 0.002) and high frequency (HF) (p = 0.011).

These results suggest that the human’s subjective and objective responses were different according to FIS types and those combinations.