Journal of Occupational Health最新文献

Objectives: Various factors influence urinary hippuric acid concentrations; however, the role of climatic factors on such concentrations has not been thoroughly investigated.

Methods: This study examined the correlation between urinary hippuric acid concentrations and climatic factors. Data were obtained from health examinations of 2236 employees at a large manufacturing company who used organic solvents over a 3-year period. Each participant underwent a health examination for organic solvent use during both the summer (June to August) and winter (December to February). Urinary hippuric acid concentrations were log-transformed, and a linear mixed-effects model was applied to assess their association with average temperature, relative humidity, and atmospheric pressure recorded in Nagoya City, Japan.

Results: In a multivariate linear mixed-effects model including all meteorological variables, average temperature showed a significant positive association with log-transformed urinary hippuric acid concentrations (estimate = 0.013; 95% CI: 0.007-0.020; P < .001). This corresponds to an estimated 1.3% increase in urinary hippuric acid concentrations per 1°C rise in temperature. In contrast, neither average atmospheric pressure nor relative humidity showed a statistically significant association (P = .981 and P = .817, respectively). Among the confounding variables, smoking was significantly positively associated with concentration (P = .001), whereas alcohol consumption showed a significant negative association (P = .031).

Conclusions: Urinary hippuric acid concentrations exhibited seasonal variation among workers at a large manufacturing company, with elevated levels observed during the summer. These findings underscore the importance of considering climatic factors when interpreting urinary metabolic biomarkers.

Objectives: We used real-time dosimetry for the quantitative evaluation of occupational radiation exposure among zoo veterinarians and animal keepers during x-ray procedures to identify key procedural and contextual determinants of exposure variation.

Methods: This retrospective observational study analyzed 251 radiographic procedures at multiple zoological facilities in Japan. Occupational exposure was measured in real time with a semiconductor dosimeter that recorded the personal dose equivalent, Hp(10), at 1-second intervals. Procedural variables included professional role, manual restraint, sedation or anesthesia, equipment type, tube voltage (kVp), and tube current-time product (mAs). Between-group comparisons were conducted using nonparametric tests, and multiple linear regression was used to identify the independent predictors of occupational exposure.

Results: The overall median Hp(10) per procedure was 0.35 (IQR: 0.15-0.99) μSv. Veterinarians received significantly higher doses than animal keepers (P = .006). Elevated Hp(10) values were associated with procedures involving large-bodied carnivores, performed without manual restraint or sedation. Multivariate analysis identified 5 significant predictors-professional role (β = -.75), manual restraint (β = -.24), tube voltage (β = .43), tube current-time product (β = .11), and large-animal group (β = .34)-explaining 60.4% of the variance (adjusted R2 = 0.604).

Conclusions: Despite the overall low exposure levels, some procedures resulted in Hp(10) values exceeding 10 μSv. A combination of procedural and contextual factors influenced exposure. These findings underscore the importance of comprehensive radiation-protection strategies, including optimized workflows, appropriate use of sedation, and standardized operator protocols, in alignment with international dose-optimization principles.

Objectives: To synthesize ocular and visual effects caused by occupational exposure to video display terminals (VDTs). Additionally, we aimed to identify the occupational and nonoccupational risk and protective factors related to these effects, and to propose a conceptual mapping to manage affected workers.

Methods: The review protocol was registered in PROSPERO and the systematic review was conducted following PRISMA guidelines. A search of MEDLINE, Scopus, and Web of Science was performed to identify studies published between January 2006 and December 2023. Only primary studies were included. Study quality was assessed using a critical appraisal tool based on STROBE statements for cross-sectional studies and the Scottish Intercollegiate Guideline Network checklist for randomized controlled trials and cohort and case-control studies. Low-quality studies were excluded.

Results: Eighty-five articles were included, 50 of high quality. The main ocular and visual effects were computer vision syndrome, dry eye disease, and other isolated signs and symptoms. The main risk factors were the daily hours of VDT exposure, female gender, use of ophthalmic or contact lenses, increasing age, altered lighting conditions, and job seniority. Breaks, adequate workstation design, and ergonomic improvements were the main protective factors. Psychosocial factors and lifestyle behaviors also may influence ocular and visual health at work.

Conclusions: Wide methodological variations were found, making it difficult to compare studies. Nevertheless, an evidence-informed conceptual mapping has been proposed that could be used as a starting point to guide preventive measures in VDT work settings. Further research with appropriate epidemiological designs is needed to establish causal relationships or determine temporal sequences between exposures and outcomes.

Objectives: Biological exposure monitoring is particularly useful for understanding skin absorption of hazardous substances; however, existing measurement methods for aromatic amines show room for improvement, as they focus only on unchanged compounds. This study aimed to determine urinary concentrations of the unchanged compounds and metabolites of 3 aromatic amines (aniline, 2,4-dimethylaniline [m-xylidine], and 2-methylaniline [o-toluidine]) following enzymatic hydrolysis pretreatment, to calculate their proportions, and to assess markers for occupational biological exposure monitoring.

Methods: Urine samples were collected at the end of work shifts on consecutive days from 11 workers at a plant handling aromatic amines. Samples were enzymatically hydrolyzed using glucuronidase and sulfatase. The urinary concentrations of 25 substances were determined using liquid chromatography-tandem mass spectrometry.

Results: After exposure to the 3 aromatic amines, the major urinary excretion types were benzene ring-hydroxylated compounds, ring-hydroxylated and N-acetylated compounds, and side-chain methyl group oxides. The presence of unchanged and N-acetylated compounds was minor. Metabolism and urinary excretion were relatively different between the workers in our study and reported values from animal studies.

Conclusions: Excluding metabolites with low specificity, the sum of unchanged compounds and primary metabolites in urine could be a useful marker for biological exposure monitoring. Regarding aniline exposure, the relevant markers are the sum of aniline, N-acetyl-4-hydroxyaniline, and 2-hydroxyaniline. For 2,4-dimethylaniline exposure, the markers are the sum of 2,4-dimethylaniline, N-acetyl-4-carboxy-2-methylaniline, and 6-hydroxy-2,4-dimethylaniline. For 2-methylaniline exposure, the markers are the sum of 2-methylaniline, N-acetyl-4-hydroxy-2-methylaniline, 4-hydroxy-2-methylaniline, and 6-hydroxy-2-methylaniline. Urine sampling is recommended at the end of work shifts on consecutive working days.

Objectives: To quantify the short-term impact of an unexpected stay-at-home exposure, caused by a shipment suspension, on body mass index (BMI) and cardiometabolic markers among employees with different levels of occupational physical activity.

Methods: Health-check records from 8307 workers at a large Japanese automobile manufacturer were linked to company attendance data covering a shipment suspension (January to April 2024). An interrupted time-series assessed BMI trajectories before, during, and after the halt. Among 614 employees who underwent an additional examination in April 2024, mixed-effects models related the duration of stay-at-home to changes in BMI and blood pressure within low-, medium-, and high-intensity job categories.

Results: Compared with pre-halt trends, medium-intensity and high-intensity workers showed significant level rises in BMI (0.96 kg/m2; 95% CI, 0.56-1.36; and 0.64 kg/m2; 95% CI, 0.24-1.04, respectively) at the onset of the suspension. Mixed-effects analyses showed a positive dose-response between the duration of stay-at-home and BMI gain in high-intensity jobs (0.47 kg/m2 per 20% absent days; 95% CI, 0.37-0.58). Per 20% of scheduled workdays absent, systolic blood pressure was higher in the medium- and high-intensity groups. No significant effects were observed among sedentary workers.

Conclusions: Employees whose daily energy expenditure relies on job-related physical activity are especially susceptible to weight gain and blood pressure elevations during forced work interruptions. Business continuity plans should embed tailored countermeasures-such as structured exercise programs and phased returns to on-site duties-to safeguard metabolic health during future operational disruptions.

Objectives: This study examined the support provided by occupational physicians (OPs) in Japan to employees with Long COVID, a condition that has significantly affected workforce health during the pandemic.

Methods: An exploratory cross-sectional mixed-methods design was employed, consisting of qualitative interviews followed by a questionnaire survey targeting OPs certified by the Japan Society for Occupational Health. The interviews explored actual experiences of supporting workers with Long COVID, and the findings were used to develop the questionnaire. The survey and interview findings were integrated to describe overall occupational health practices.

Results: Twenty OPs reported 30 cases of employees with Long COVID in the interviews. Based on these findings, a questionnaire survey was conducted, yielding 182 valid responses. The integrated results showed that OPs most frequently reported Main OH Responses such as active listening, return-to-work assistance, and lifestyle guidance. Measures such as explaining workers' compensation applications and preparing lists of outpatient clinics were less frequently reported. For Advice for Employers, limitation of overtime, reduction of workload, and telework were commonly reported, whereas demotion and reassignment were rarely reported.

Conclusions: This study clarified how OPs in Japan supported workers with Long COVID through diverse, context-dependent practices. The identified Main OH Responses and Advice for Employers provide a framework for understanding current practices. Developing practical case examples, structured assessment tools, and workplace guidelines, together with further research grounded in real-world practice, will enhance OPs' ability to provide appropriate support and strengthen preparedness for future health crises.

Objectives: The continuity of mental health problems from childhood to adulthood is well acknowledged, as is the impact on work ability. However, knowledge is scarce on individuals who maintain work ability and have no sickness absence (SA), despite mental health problems. The aim was to identify sociodemographic and health-related factors among private and public employees with a history of depression and/or anxiety, and no SA.

Methods: This prospective cohort study included 9039 Swedish twin individuals born in 1975-1986, with and without a history of depression and/or anxiety, and employed in private or public sectors. Survey data from 2005 were used to classify self-rated depression, anxiety, and overall health. Data on SA, education, occupational class, outpatient healthcare use, and prescribed antidepressants were obtained from national registries. Participants were prospectively followed for SA from 2006 to 2020. Logistic regression analyses were applied to calculate odds ratios with 95% confidence intervals.

Results: Approximately 37% of individuals with previous depression and/or anxiety were not on SA during follow-up, compared to 54% of those without such history. Lower use of antidepressants implied higher odds for no SA among both private (OR: 2.09 [1.64-2.66]) and public (OR: 2.38 [1.78-3.19]) employees with previous depression and/or anxiety. Having fewer visits to outpatient healthcare were significantly associated with no SA (ORs: 2.22-3.60). Being a white-collar worker implied higher odds for no SA only among privately employed (OR: 1.39 [1.10-1.76]).

Conclusions: Primarily, health-related factors seemed to play a role in no SA among young employees with previous depression and/or anxiety.

Objective: This study aimed to investigate the association between the coronavirus disease 2019 (COVID-19) pandemic and sickness presenteeism by directly comparing data collected before, during, and after the pandemic.

Methods: We analyzed data from the fifth (conducted before the pandemic: Jul 2017-Nov 2017), sixth (conducted during the pandemic: Oct 2020-Apr 2021), and seventh (conducted after the pandemic: Jul 2023-Nov 2023) Korean Working Conditions Surveys, comprising 114 140 workers. The primary outcome was self-reported sickness presenteeism, defined as attending work despite illness over the past 12 months. Logistic regression models were used to estimate the association between the COVID-19 period and sickness presenteeism after adjusting for demographic characteristics.

Results: The prevalence of sickness presenteeism significantly decreased from 20.9% (before the pandemic) to 17.2% (during the pandemic), and it further decreased to 6.9% (after the pandemic). After adjusting for demographic and workplace characteristics, the odds of sickness presenteeism were significantly lower during the pandemic (odds ratio [OR] 0.84, 95% confidence interval [CI], 0.80-0.87) than before. Furthermore, the odds further decreased after the pandemic (OR 0.35, 95% CI, 0.33-0.37) relative to during the pandemic.

Conclusion: Sickness presenteeism decreased across the COVID-19 pandemic periods in South Korea. This decrease was observed in relation to the implementation of government-mandated sick leave policies for infectious disease control, suggesting an association between policy enforcement and decreasing sickness presenteeism.

Background: Return-to-work (RTW) support has become a growing priority in occupational health. Manual workers-who constitute over half of the global labor force-may face greater RTW barriers due to the physically demanding nature of their jobs. However, few studies have quantitatively compared the perceived RTW barriers between manual and non-manual workers. This study aimed to compare perceived RTW barriers between manual and non-manual workers with chronic conditions to inform the development of tailored support strategies.

Methods: We analyzed 219 employed adults, either actively working or on certified leave, who attended X Hospital consultations between September 2019 and June 2020 to obtain support for balancing work and medical treatment. Perceived RTW barriers were assessed with a validated 10-category yes/no structured checklist (personal: work ability/psychological/health literacy; workplace: structure/system/support; inter-sectoral/social). Logistic regression was performed to compare barriers between manual and non-manual workers.

Results: Manual workers were significantly more likely to report barriers related to psychological impacts (OR = 2.34) and workplace systems (OR = 2.88). Although work ability did not differ significantly by job type, it was the most frequently reported RTW barrier in both groups.

Conclusion: Manual workers' RTW challenges are characterized by psychological and organizational barriers. RTW programs should assess psychological readiness before resumption of duties and provide managerial training to address anxiety and loss of confidence, while implementing job-specific accommodations such as phased tasks, ergonomic adjustments, and light duties in coordination with healthcare providers.

Objectives The cause of chronic kidney disease (CKD) remains uncertain in the majority of affected individuals, and risk of socioeconomic status on CKD progression has recently gained attention. We compared the risk of CKD progression among 18 occupational classifications using an annual health-checkup database. Methods We used the annual health checkup data and health insurance claims data of the Japan Health Insurance Association in Kyoto prefecture between April 2012 and March 2016. The primary outcome for survival analysis was defined as a more than 30% change in the estimated glomerular filtration rate (eGFR) from the first health checkup. We used the Cox proportional-hazards model for time-to-event analyses to estimate the hazard ratio, and 95% CIs for the primary outcome, adjusting for age, sex, eGFR, body mass index, blood pressure, blood sugar, dyslipidemia, uric acid, urinary protein, and existence of kidney diseases at first health checkup. Results We analyzed 239,506 employees, and 1,736 (0.7%) individuals whose eGFR had decreased by 30% or more; the mean follow-up period was 2.8 years. When we compared the risk for "manufacturing," five categories of industries ("information and communications"; "transport and postal services"; "accommodations, eating and drinking services"; "living-related and personal services and amusement service"; "medical, health care and welfare") were associated with a decline in the risk of eGFR after adjusting for the confounding factors and/or mediators. Conclusions We provided evidence that the risk of CKD progression depends on occupational type. Further research is needed to confirm the mechanism and causal relationships involved.