Annals of Occupational and Environmental Medicine最新文献

Background: Shift work has been shown to increase the risk of cardiovascular disease (CVD) based on several evidences. The classic risk factors of CVD include age, hypertension, smoking, obesity and diabetes. Recently, the serum homocysteine level has been reported to be a valuable indicator of CVD risk. This study aimed to determine the variation in serum homocysteine level as a cardiovascular risk indicator among female workers according to shift work.

Methods: The data of regular health examination of workers at an electronic manufacturing services company in Yeongnam region, South Korea in 2019 were examined in this study. The investigation was based on a cross-sectional study conducted on 697 female workers (199 day workers and 498 shift workers). The sociodemographic and biochemical characteristics were compared between day workers and shift workers. Through a logistic regression analysis, the odds ratio (OR) of the increased serum homocysteine level in relation to shift work was determined.

Results: Compared to female day workers, female shift workers showed significantly higher level of serum homocysteine (8.85 ± 2.16 vs. 9.42 ± 2.04 μmol/mL; p = 0.001). The OR of day workers against shift workers was 1.81 (95% confidence interval [CI]: 1.25-2.63). With the adjustment of variables that may influence the level of serum homocysteine, the adjusted OR was 1.68 (95% CI: 1.09-2.60).

Conclusions: The serum homocysteine level was significantly higher in shift workers than in day workers. It is thus likely to be a useful predictor of CVD in shift workers.

Background: Exposure to heavy metals is a public health concern worldwide. Previous studies on the association between heavy metal exposure and neurobehavioral functions in children have focused on single exposures and clinical manifestations. However, the present study evaluated the effects of heavy metal complex exposure on subclinical neurobehavioral function using a Korean Computerized Neurobehavior Test (KCNT).

Methods: Urinary mercury, lead, cadmium analyses as well as symbol digit substitution (SDS) and choice reaction time (CRT) tests of the KCNT were conducted in children aged between 10 and 12 years. Reaction time and urinary heavy metal levels were analyzed using partial correlation, linear regression, Bayesian kernel machine regression (BKMR), the weighted quantile sum (WQS) regression and quantile G-computation analysis.

Results: Participants of 203 SDS tests and 198 CRT tests were analyzed, excluding poor cooperation and inappropriate urine sample. Partial correlation analysis revealed no association between neurobehavioral function and exposure to individual heavy metals. The result of multiple linear regression shows significant positive association between urinary lead, mercury, and CRT. BMKR, WQS regression and quantile G-computation analysis showed a statistically significant positive association between complex urinary heavy metal concentrations, especially lead and mercury, and reaction time.

Conclusions: Assuming complex exposures, urinary heavy metal concentrations showed a statistically significant positive association with CRT. These results suggest that heavy metal complex exposure during childhood should be evaluated and managed strictly.

Background: Studies on the association between occupational stress and depression have been frequently reported. However, the cross-sectional designs of studies limited insight into causal associations. In this study, we investigated the longitudinal association between occupational stress and new-onset depression among employees in a single manufacturing plant.

Methods: The annual health checkup data of employees at a manufacturing plant in Korea were collected. A total of 1,837 male employees without depression who completed a health checkup during two consecutive years were included. Occupational stress was measured using a short form of the Korea Occupational Stress Scale (KOSS-SF), and depression was assessed using a Patient Health Questionnaire-2. The association between occupational stress change over the two years and newly developed depression was investigated using two logistic regression models.

Results: Across all sub-factors of KOSS-SF, employees who reported increased occupational stress had a higher risk of new-onset depression. Newly developed depression was significantly associated with job demand (odds ratio [OR]: 4.34; 95% confidence interval [CI]: 2.37-7.96), job insecurity (OR: 3.21; 95% CI: 1.89-5.48), occupational climate (OR: 3.18; 95% CI: 1.91-5.31), lack of reward (OR: 2.28; 95% CI: 1.26-4.12), interpersonal conflict (OR: 2.14; 95% CI: 1.18-3.86), insufficient job control (OR: 1.93; 95% CI: 1.05-3.56), and the organizational system (OR: 1.84; 95% CI: 1.01-3.36).

Conclusions: For every sub-factor of the KOSS-SF, occupational stress increase and persistent high stress were associated with the risk of developing new-onset depression. Among the seven sub-factors, job demand had the most significant effect. Our results show that occupational stress should be managed to promote employee mental healthcare.

Background: Indoor air pollution can cause and exacerbate asthma. We report a previously undescribed case of occupational asthma related to indoor air pollution in a worker at an indoor air gun shooting range and highlight the potential risk of developing occupational asthma in this environment.

Case presentation: A 31-year-old man presented with dyspnea, cough, and sputum and was diagnosed with asthma complicated by pneumonia. Objective evidence of asthma was obtained by performing a methacholine bronchial provocation test. It was suspected that the patient had occupational asthma, which began one month after changing jobs to work within the indoor air gun shooting range. The highest peak expiratory flow (PEF) diurnal variability on working days was 15%, but the highest variation was 24%, with 4 days out of 4 weeks having a variation of over 20% related to workplace exposure. Conversely, the diurnal variability on the rest days was 7%, and no day showed a variation exceeding 20%. The difference in the average PEF between working and rest days was 52 L/min. PEF deterioration during working days and improvement on rest days were noted.

Conclusions: The results obtained from the in-depth analysis of the PEF were adequate to diagnose the patient with occupational asthma. Exposure to indoor air pollution and lead and the patient's atopy and allergic rhinitis may have contributed to the development of occupational asthma.

Background: Studies on the relationship between organic solvent exposure and chronic kidney disease (CKD) have presented inconsistent results. Definition of CKD has changed in 2012, and other cohort studies have been newly published. Therefore, this study aimed to newly confirm the relationship between organic solvent exposure and CKD through an updated meta-analysis including additional studies.

Methods: This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The search was conducted on January 2, 2023 using Embase and MEDLINE databases. Case-control and cohort studies on the relationship between organic solvent exposure and CKD were included. Two authors independently reviewed full-text.

Results: Of 5,109 studies identified, a total of 19 studies (control studies: 14 and cohort studies: 5) were finally included in our meta-analysis. The pooled risk of CKD in the organic solvent exposed group was 2.44 (1.72-3.47). The risk of a low-level exposure group was 1.07 (0.77-1.49). The total risk of a high-level exposure group was 2.44 (1.19-5.00). The risk of glomerulonephritis was 2.69 (1.18-6.11). The risk was 1.46 (1.29-1.64) for worsening of renal function. The pooled risk was 2.41 (1.57-3.70) in case-control studies and 2.51 (1.34-4.70) in cohort studies. The risk of subgroup classified as 'good' by the Newcastle Ottawa scale score was 1.93 (1.43-2.61).

Conclusions: This study confirmed that the risk of CKD was significantly increased in workers exposed to mixed organic solvents. Further research is needed to determine the exact mechanisms and thresholds. Surveillance for kidney damage in the group exposed to high levels of organic solvents should be conducted.

Trial registration: PROSPERO Identifier: CRD42022306521.

Background: This study was conducted to examine the relationship between chronotype and depressive symptoms to provide grounded knowledge in establishing nurses' health promotion strategies.

Methods: The subjects of this study were 493 newly hired nurses working in 2 general hospitals within the university from September 2018 to September 2020. Sociodemographic and work-related characteristics were collected from a medical examination database and a self-reported questionnaire. These included sex, age, marital status, living situation, education level, alcohol consumption, physical activity, prior work experience before 3 months, workplace, and departments. To analyze the associations between the chronotype and depressive symptoms, multiple logistic regression analyses were performed to calculate odds ratios (ORs).

Results: Among participants, 9.1% had depressive symptoms and 16.4% had insomnia. The subjects are divided into morningness (30.2%), intermediate (48.7%), and eveningness (21.1%). The multiple logistic regression analysis controlling for age, living status, education level, alcohol consumption, physical activity, workplace, prior work experience before 3 months, and insomnia, revealed that the OR of depressive symptoms in the eveningness group was 3.71 (95% confidence interval [CI]: 1.50-9.18) compared to the morningness group, and the R² value was 0.151. It also can be confirmed that insomnia symptoms have a statistically significant effect on depressive symptoms (OR: 2.16, 95% CI: 1.03-4.52).

Conclusions: Our findings suggest that evening-type nurses are more likely to have depression than morning-type nurses. We should consider interventions in a high-risk group such as the evening type nurses to reduce depressive symptoms in nurses.

Background: This study aimed to investigate the characteristics of work-related musculoskeletal disorders (WRMSDs) in occupational disease claims and identify patterns of WRMSDs for each body part by industry and occupation.

Methods: This study analyzed the raw data of occupational disease claims for musculoskeletal disorders deliberated by the Occupational Disease Decision Committee of the Korea Workers' Compensation & Welfare Service in 2020. The data was classified into 6 body parts with the highest numbers of occupational disease cases by using the complete enumeration data on principal diagnoses and 4 types of subdiagnoses in the raw data. The characteristics and approval rates of WRMSDs by body part, industry and occupation were examined and summarized.

Results: A total of 13,015 occupational disease cases for WRMSDs were classified, and lumbar spinal (back) diseases accounted for the largest proportion of claimed diseases, followed by shoulder, elbow, wrist, knee, and neck diseases in a descending order. The occupations with the highest and second highest numbers of occupational disease cases by body part were found to be automobile assemblers and production-related elementary workers for the neck, school meal service workers and cooks for the back, construction frame mold carpenters and school meal service workers for the shoulder, elementary workers in mining and food service workers for the elbow, food service workers and automobile parts assemblers for the wrist, and ship welders and school meal service workers for the knee.

Conclusions: This study examined the characteristics and approval status of WRMSDs by body part and occupation. Based on the study results, management strategies for the prevention of WRMSDs should be established regarding occupations with a high risk of WRMSDs for each body part.

Background: Although working hours have decreased in Korea, they are still high compared to that of other countries. In Korea, cardiovascular and cerebrovascular diseases (CCVDs) related to overwork in Korea continually occur, and the social burden from overwork is estimated to be high. This study investigated the amendment of regulations affecting the approval rate of occupational CCVDs.

Methods: The change in approval rate of occupational CCVDs and related regulations were investigated using the Act and public notice on the standards for recognition of occupational CCVDs and the yearbooks of the Ministry of Employment and Labor. The CCVD mortality was estimated using data on the number of deaths according to the cause of death, the number of employed people, and resident registration population aged 15-64 years. The cumulative mortality of CCVDs was estimated using the Kaplan-Meier method.

Results: Since the establishment of the standards for recognition in Korea in 1982, the scope of occupational diseases has been expanded to include intracerebral hemorrhage, subarachnoid hemorrhage, cerebral infarction, myocardial infarction, and aortic dissection. In 2013, the concept of working hours was introduced in chronic overwork. The approval rate of occupational CCVDs was 44.7% in 2006, which decreased to 12.9% in 2011. After the improvement of related regulations, the approval rate increased to 41.3% in 2018. From 2000 to 2017, the CCVD mortality of both the unemployed and employed tended to decrease, and their cumulative CCVD mortalities were 549.3 and 319.7 per 100,000 people, respectively.

Conclusions: CCVDs are recognized as occupational diseases in Korea. The amendments to the standards for recognition, the introduction of the Occupational Disease Adjudication Committee, the principle of presumption, and the reduction of working hours have changed the approval rate of occupational CCVDs. A strategic approach is needed to further reduce the incidence of CCVDs.