Annals of Occupational and Environmental Medicine最新文献

Background: Most previous longitudinal studies on lifestyle and gastroesophageal reflux disease (GERD) have focused on physical activity rather than sitting time. The main purpose of this study was to investigate the relationship between prolonged sitting time and the development of erosive esophagitis (EE).

Methods: A self-report questionnaire was used for measuring sitting time in the Kangbuk Samsung Health Study. Sitting time was categorized into four groups: ≤ 6, 7-8, 9-10, and ≥ 11 hours/day. Esophagogastroduodenoscopy (EGD) was performed by experienced endoscopists who were unawared of the aims of this study. Hazard ratios (HRs) and 95% confidence intervals (CIs) for the development of EE were estimated using Cox proportional hazards analyses with ≤ 6 hours/day sitting time as the reference.

Results: There were 6,524 participants included in the study. During a mean follow-up of 3.14 years, 2,048 incident cases developed EE. In age- and sex-adjusted models, the HR in the group sitting ≥ 11 hours per day compared ≤ 6 hours per day was 0.88 (95% CI: 0.76-0.99). After further adjusting for alcohol intake, smoking status, educational level, history of diabetes, and history of dyslipidemia, sitting time was still significantly related to the risk of EE (HR, 0.87; 95% CI: 0.76-0.98). After further adjustment for exercise frequency, this association persisted (HR, 0.86; 95% CI: 0.76-0.98). In subgroup analysis by obesity, the relationship between sitting time and EE was only significant among participants with body mass index < 25 kg/m² (HR, 0.82; 95% CI: 0.71-0.95).

Conclusions: Generally, prolonged sitting time is harmful to health, but with regard to EE, it is difficult to conclude that this is the case.

Background: Little attention has been paid to the relationship between perceived discrimination and self-rated health (SRH) among foreign workers in Korea. Transnational ties with the home country are known to be critical among immigrants, as they allow the maintenance of social networks and support. Nonetheless, as far as we know, no studies have examined the impact of transnational ties on SRH itself and the relationship between perceived discrimination and SRH, which the current study tries to examine.

Methods: Logistic regression analyses were conducted using the 2013 Survey on Living Conditions of Foreign Workers in Korea. Adult foreign workers from different Asian countries (n = 1,370) participated in this study. The dependent variable was good SRH and the independent variable was perceived discrimination. Transnational ties with the home country, as a moderating variable, was categorized into broad (i.e., contacting family members in the home country) vs. narrow types (i.e., visiting the home country).

Results: Foreign workers who perceived discrimination had a lower rate of good SRH than those who did not perceive discrimination. Broad social transnational ties moderated the relationship between perceived discrimination and SRH; narrow social transnational ties did not.

Conclusions: In line with previous studies, an association was found between perceived discrimination and SRH. Broad social transnational ties can be a good source of social support and buffer against the distress of perceived discrimination.

Background: This study aimed to investigate the decline in quality of life (QOL) by examining changes in the employment status of workers who had completed medical treatment after an industrial accident.

Methods: This study utilized the Panel Study of Worker's Compensation Insurance cohort (published in October 2020) containing a sample survey of 3,294 occupationally injured workers who completed medical care in 2017. We divided this population into four groups according to changes in working status. A multivariate logistic regression model was utilized for evaluating QOL decline by adjusting for the basic characteristics and working environment at the time of accident. Subgroup analysis evaluated whether QOL decline differed according to disability grade and industry group.

Results: The QOL decline in the "maintained employment," "employed to unemployed," "remained unemployed," and "unemployed to employed" groups were 15.3%, 28.1%, 20.2%, and 11.9%, respectively. The "maintained employment" group provided a reference. As a result of adjusting for the socioeconomic status and working environment, the odds ratios (ORs) of QOL decline for the "employed to unemployed" group and the "remained unemployed" group were 2.13 (95% confidence interval [CI], 1.51-3.01) and 1.47 (95% CI, 1.13-1.90), respectively. The "unemployed to employed" group had a non-significant OR of 0.76 (95% CI, 0.54-1.07).

Conclusions: This study revealed that continuous unemployment or unstable employment negatively affected industrially injured workers' QOL. Policy researchers and relevant ministries should further develop and improve "return to work" programs that could maintain decent employment avenues within the workers' compensation system.

Background: Antimony is used in catalysts, pesticides, brake systems, pharmaceuticals, and synthetic fire retardants in the plastic, paint, and rubber industries. Accumulation of trivalent antimony compounds in the body can cause cardiotoxic effects and increase the risk of electrocardiogram (ECG) abnormalities and sudden death. Antimony exposure can result in action potential prolongation, causing a cardiac repolarization delay, which appears as QTc prolongation and T-wave abnormalities on the ECG. There are no studies on antimony-associated cardiac toxicity in Korea.

Case presentation: Accordingly, the present study reports cases of ECG abnormalities in workers handling antimony trisulfide at a company located in the Gyeongsangbuk-do region. Nineteen workers employed at an automobile brake lining manufacturer were exposed to antimony trisulfide dust through thermoforming, grinding, and drilling processes. In 2020, the workers were reported to work 12-hour shifts, 5 days a week. The time-weighted average (TWA) of antimony trisulfide exposure measured in workers was 0.0028 mg/m³. Two workers were excluded from the analysis due to pre-existing medical conditions (cardiovascular disease). Of the remaining 17 workers, ECG abnormalities were found in 41% (seven out of 17: four with QTc prolongation and T-wave abnormalities; two with only T-wave abnormalities; and one with only QTc prolongation).

Conclusions: This case report outlines the first few cases in Korea in which potential cardiac toxicity caused by occupational exposure to antimony was identified. However, data regarding cardiac toxicity caused by antimony exposure are still lacking in Korea; thus, additional studies are needed to identify causal relationships.

Background: 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.

Methods: 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.

Results: 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.

Conclusions: 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.

Background: Work is an inseparable element of a person's life, and violence in the workplace has various effects on individual workers and companies. While most studies have focused on specific industries, very few studies have investigated the influence of workplace violence by co-workers. Therefore, this study aimed to evaluate the association between workplace violence and work-related depression/anxiety in various occupations by differentiating the perpetrators of violence as co-workers and clients.

Methods: This study was conducted based on data from the 4th and 5th Korean Working Conditions Surveys (KWCS). The experience of workplace violence was classified in terms of the perpetrator: workplace violence by co-workers and that by clients. Work-related depression and anxiety were assessed using questions about health problems related to depression and anxiety and whether the problems were related to work. Descriptive statistics, χ² tests, and multiple logistic regression analyses were performed using the SPSS 26.0.

Results: After adjusting for sociodemographic characteristics (age, education, income, subjective health status) and occupational characteristics (occupation, weekly working hours, type of employment, size of workplace, and shift work), male workers with experience of workplace violence by co-workers were found to be at a higher risk of work-related depression/anxiety (odds ratio [OR], 11.52; 95% confidence interval [CI], 8.65-15.36). The same was confirmed for female workers (OR, 10.89; 95% CI, 7.90-15.02).

Conclusions: Employees who experienced workplace violence from co-workers were found to be more vulnerable to work-related depression/anxiety. Continuous contact between the victim and the perpetrator may occur, and the possibility of a secondary assault can frighten the victim. Appropriate prevention and intervention measures that focus on the perpetrators of violence are needed.

Background: Gender equality in the workplace remains a challenge. This study aimed to investigate the gender gap of human resources in the field of occupational safety and health (OSH) in Korea.

Methods: Several national statistical data that can confirm the gender distribution of personnel in the OSH sector were reviewed. The gender distribution of industrial technical manpower statistics, professional certificate holders in the OSH field, and the status of the appointment of safety and health managers by industry was analyzed.

Results: The distribution of professionals in the OSH sector in Korea had a large gender gap with a small number of women. In particular, the proportion of women in the safety field was lower than that in the health field. In the younger age group, while the proportion of women is increasing, the gender gap tends to decrease.

Conclusions: Few data are available to understand the gender-related aspects of OSH professions. Nevertheless, our results provide basic information for initiating a discussion on the necessity of establishing gender-sensitive culture and policies in the OSH sector.

Background: Although coronavirus disease 2019 is causing a variety of psychological problems for workers, there are few longitudinal studies on changes in workers' mental health by workplace intervention. This study aimed to evaluate the change in the prevalence of depression and anxiety according to the active involvement of the workplace.

Methods: This study was conducted on 1,978 workers at a workplace who underwent a health screening from January 2019 to August 2020, and classified depression and anxiety disorders using a self-report questionnaire. After the first pandemic, the company stopped health screening, took paid leave and telecommuting, and conducted interventions such as operating its own screening clinic. To see if this workplace intervention affects workers' mental health, we conducted generalized estimating equations to compare odds ratio (OR).

Results: In the pre-intervention group, 384 people (16.86%) had depression, and 507 people (22.26%) had anxiety disorder. Based on the OR before intervention, the OR of depression decreased to 0.76 (0.66-0.87) and the OR of anxiety disorder decreased to 0.73 (0.65-0.82).

Conclusions: As a result of this study, it was confirmed that workplace intervention was related to a decrease in depression and anxiety. This study provides basic data to improve workers' mental health according to workplace intervention, and further research is needed according to workplace intervention in the future.

Background: Repetitive hand use increases the risk of hand osteoarthritis (OA). This study aimed to investigate characteristics of and risk factors for hand OA in Korean women farmers.

Methods: This cross-sectional study included women farmers resident in Jeollanam-do, Korea. The participants were interviewed, and radiographs were taken of both hands. Radiological hand OA was defined based on the Osteoarthritis Research Society International imaging criteria of joint space narrowing or the presence of osteophytes. The participants were divided into age groups of < 60 and ≥ 60 years. Obesity was defined as body mass index of > 25 kg/m². Annual working time was divided into < 2,000, 2,000-2,999, and ≥ 3,000 hours. Agricultural working type was divided into rice farming and field farming. Robust Poisson regression was used to identify factors associated with radiographic hand OA, with adjustment for age, obesity, annual working time, and agricultural classification.

Results: A total of 310 participants with a mean age of 58.1 ± 7.6 years, were enrolled. The prevalence of radiologically confirmed OA was 49.0%, with an OA prevalence of 39.4% the interphalangeal joint in the thumb (IP1). The prevalence of OA was higher in the distal interphalangeal joint than in the proximal interphalangeal, metacarpophalangeal, and carpometacarpal joints. The prevalence of OA varied by age, annual working time, and agriculture type.

Conclusions: Korean women farmers have a high prevalence of OA, particularly in the IP1 joints. OA is associated with age, working hours, and agriculture type.

Background: Long working hours causes several health risks, but little is known about its effects on the liver. This study aimed to examine the correlation between working hours and abnormal liver enzyme levels.

Methods: We used data from the Korea National Health and Nutrition Examination Survey IV-VII. For the final 15,316 study participant, the information on working hours was obtained through questionnaires, and liver enzyme levels, consisting of serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), through blood tests. The relationship between weekly working hours and abnormal levels of liver enzymes was analyzed using multiple logistic regression, and a trend test was also conducted.

Results: In male, working ≥ 61 hours per week was significantly associated with elevated AST and ALT levels compared with working 35-52 hours per week. Even after adjusting for covariates, the odds ratios (ORs) of abnormal AST and ALT increased by 1.51 (95% confidence interval: 1.20-2.05) and 1.25 (1.03-1.52), respectively, and a dose-response relationship was observed. This association was more prominent among the high-risk group, such as those aged > 40 years, obese individuals, worker on non-standard work schedule, pink-collar workers, or temporary worker. No correlation was observed in female.

Conclusions: Long working hours are associated with abnormal liver function test results in male. Strict adherence to statutory working hours is necessary to protect workers' liver health.