Objectives: To date there has been little observational evidence on the relationship between air lead and blood lead at relatively low workplace air lead concentrations. This study sought to improve upon prior studies methodologically and aimed to examine this relationship in a modern workplace environment.

Methods: Personal measurements of air lead and blood lead concentrations were collected in a modern lead-acid battery manufacturing facility in the United States. A total of 236 workers and their 2221 air-blood lead measurement pairs, collected between 2001 and 2021, were included in the statistical analysis. The association between air lead and blood lead was examined using linear mixed-effects models to account for data correlation. Potential confounders adjusted for included age, sex, job department, time trend, tenure, and seasonality.

Results: The workers were mostly (83%) male and on average 29.75 years of age at the first included measurement. Their air lead concentrations ranged from 1 to 50 (arithmetic mean 16.85) μg/m³; blood lead concentrations ranged from 2 to 35 (arithmetic mean 15.47) μg/dL. After adjusting for potential confounders, a 1 μg/m³ increment in air lead was associated with a 0.025 (95% CI, 0.005-0.045; marginal, semi-partial R² = 0.002) μg/dL higher blood lead.

Conclusions: The relationship between air lead and blood lead at relatively low workplace air lead concentrations over a long employment period may be very weak, but this needs to be further investigated in future observational studies with quantified lead exposures from noninhalation routes and nonoccupational sources.

Objectives: This study reports the development of the Job-Related Uncertainty Stress Scale for Platform Workers (JUSSPW) and examines its reliability and validity.

Methods: The research was conducted in 2 phases. In Study 1, item analysis and exploratory factor analysis were conducted on data from 343 platform riders (males: 321; females: 22; mean (SD) age: 27.03 (6.67) years) in Guangzhou, China. In Study 2, an additional 391 platform riders (males: 328; females: 63; mean (SD) age: 30.36 (4.49) years) were recruited. This phase involved conducting confirmatory factor analysis (CFA) and assessing criterion-related validity by using the Uncertainty Stress Scale (USS-4), Maslach Burnout Inventory (MBI), and Job Satisfaction Inventory (JSI).

Results: The JUSSPW scale comprises 8 items under a unidimensional structure, covering 4 perspectives: work environment, interpersonal relationships, industry-specific characteristics, and personal development prospects; it explained 71.07% of the total variance. CFA results indicated that this 1-factor model provided a good fit (χ²/df = 2.681, Root Mean Square Error of Approximation (RMSEA) = 0.066, Comparative Fit Index (CFI) = 0.987, Incremental Fit Index (IFI) = 0.987, Goodness of Fit Index (GFI) = 0.964, Tucker-Lewis Index (TLI) = 0.982). This scale also demonstrated good convergent (Average Variance Extracted (AVE) = 0.668, Composite Reliability (CR) = 0.941) and criterion validity (area under the curve = 0.935). The total score of JUSSPW was significantly positively correlated with the USS-4 and Maslach Burnout Inventory-Emotional Exhaustion (MBI-EE) scores, and remarkably negatively correlated with the JSI scores. Cronbach α and split-half reliability were .939 and 0.935, respectively.

Conclusions: These results suggest that this scale shows good reliability and validity and can be used as a sound measure to capture platform workers’ job-related uncertainty stress. Limitation and implications are discussed.

Pilonidal sinus is a recognized occupational condition sometimes seen in barbers and pet groomers, and it involves most commonly interdigital spaces. We present a previously unreported case of chronic paronychia with 2 separate digital pilonidal sinuses resulting from multiple embedded hair fragments in the eponychium of a dog groomer, who had been repeatedly treated with antibiotics with no success and ended up having surgical treatment. The objective of this study is to remind readers of this rare but possible occupational disease, particularly among employees working with hair, and to emphasize the importance of preventive measures to prevent its occurrence. Intraoperatively, a crescent of eponychial skin parallel to the proximal nail fold was excised, which incorporated the sinuses. Additionally, the nail plate was removed, and multiple hair fragments were retrieved from the nail folds. At the follow-up, the infection had resolved, and nail growth had resumed. Additional animal hair was found in the nail folds, as the patient continued to work without protective gloves. This case highlights the importance of considering embedded hair as a potential cause for chronic paronychia in individuals with occupations involving hair cutting and grooming. Chronic hand infection poses a risk of infection contaminating clients or patients; for example, a veterinarian should not operate with an infected hand. The costs of sickness absences are considerable for all the stakeholders. The use of protective gloves, hand hygiene, skin care, and thorough removal of loose hair fragments should be emphasized for workers in professions dealing with animal or human hair.

Objectives: Work-related musculoskeletal disorders (WMSDs) are among the most common occupational diseases, affecting various sectors such as agriculture, small-scale industries, handicrafts, construction, and banking. These disorders, caused by overexertion and repetitive motion, lead to work absenteeism, productivity loss, and economic impacts. The aim of the study was to determine the magnitude of musculoskeletal disorders among different occupational workers in India.

Methods: We identified studies reporting the prevalence of WMSDs using the Nordic Musculoskeletal Questionnaire in different databases between 2005 and 2023 through searches on SCOPUS, PubMed Central, and Google Scholar. The required information was then extracted. A random effects model was used to pool estimates of prevalence with 95% CIs. Publication bias was assessed by applying funnel plots.

Results: The 12-month prevalence of WMSDs was reported across several occupational groups, and the meta or the pooled prevalence was estimated as 0.76 (95% CI, 0.70 to 0.82) along with substantial variability in the prevalence estimates between different industries and studies. The meta-prevalence for low back pain was estimated as 0.60 (95% CI, 0.54 to 0.66). The meta-prevalence for neck pain was estimated as 0.40 (95% CI, 0.34 to 0.47) whereas for shoulder pain it was estimated as 0.36 (95% CI, 0.30 to 0.42), respectively. The risk of bias was statistically nonsignificant, and overall publication bias was low as per visual inspections from funnel plots.

Conclusions: WMSDs are prevalent across various Indian industries in significant proportions, particularly in agriculture, health care, and mining, leading to significant productivity loss and economic impact. The variation in prevalence highlights the need for sector-specific interventions. Addressing WMSDs requires comprehensive ergonomic and policy measures. Effective strategies are essential to mitigate these disorders’ widespread impact.

Objectives: Innovative technology at work can lead to stress and has been linked with adverse work and health consequences. This study aimed to examine the association of techno-insecurity and techno-strain with mental well-being in different age and occupational groups.

Methods: We used a nationally representative survey of the working population and restricted our analyses to 2814 employees who reported being engaged with new technology. Techno-insecurity and techno-strain were evaluated by a single question each. Mental health status was assessed by a 5-item scale, and burnout status was assessed by the Copenhagen Burnout Inventory. We used logistic regression analysis to examine the association of techno-insecurity and techno-strain with mental well-being, adjusting for job control, psychological demands, job insecurity, and workplace violence. We further stratified study participants by age and occupational group and examined the association in each group.

Results: One-fifth of the study participants reported having techno-insecurity and techno-strain. Techno-insecurity was associated with a 1.8-fold increased risk of poor mental health and high burnout, whereas techno-strain was associated with a 2.2-fold increased risk of having poor mental health and high burnout. The associations between techno-insecurity or techno-strain and poor mental health were most profound among middle-aged workers. Among all occupational groups, the associations between techno-insecurity or techno-strain and burnout were most profound among manual workers.

Conclusions: Techno-strain and techno-insecurity are emerging occupational mental health threats, particularly among middle-aged and manual workers. To promote mental health, resources provided by the organization are needed to help employees cope and work with technology.

Objectives: To estimate the association between suicide deaths and both occupational skill level and educational attainment in the United States.

Methods: Suicide deaths, employment, education, and demographic data from the 2021 National Center for Health Statistics Multiple Cause of Death Files, for ages 18-64 with a lifetime history of employment, were combined with comparable participants from the 2020-2022 Current Population Survey. Outcomes of interest were associations between suicide death and occupational skill level, assessed as a 5-level variable, and educational attainment. Logistic regression models were used to estimate these associations before and after adjusting for educational attainment, age, and sex, in each racial/ethnic subpopulation.

Results: We found a significant gradient in suicide death across occupational skill levels, with lower-skill occupations associated with higher suicide rates than higher-skill occupations. This gradient was more pronounced among non-Hispanic White (NHW) people and non-Hispanic Black (NHB) people than Hispanic people. However, upon controlling for educational attainment, this association was attenuated, indicating that the initial link was likely confounded by education.

Conclusions: The results suggest that educational attainment is a more robust predictor of suicide risk than occupational skill level. Targeted interventions addressing educational and ethnic disparities within higher-risk occupational groups can mitigate suicide risk.

In 2012, a social issue arose concerning a high incidence of cholangiocarcinoma (bile duct cancer) among printing workers. The cause was prolonged exposure to high concentrations of 1,2-dichloropropane that was included in the ink cleaning agent. Until then, it was not known that this substance could cause cancer in humans. The author was involved in this incident from the beginning. This article describes the course from the start of the investigation to the recognition of cholangiocarcinoma as an occupational disease. Furthermore, the article presents the pathological characteristics of occupational cholangiocarcinoma, as well as epidemiological analysis results.

Objectives: Falls are among the most prevalent workplace accidents, necessitating thorough screening for susceptibility to falls and customization of individualized fall prevention programs. The aim of this study was to develop and validate a high fall risk prediction model using machine learning (ML) and video-based first 3 steps in middle-aged workers.

Methods: Participants to provide training data (n = 190, mean [SD] age = 54.5 [7.7] years, 48.9% male) and validation data (n = 28, age = 52.3 [6.0] years, 53.6% male) were enrolled in this study. Pose estimation was performed using a marker-free deep pose estimation method called MediaPipe Pose. The first 3 steps, including the movements of the arms, legs, trunk, and pelvis, were recorded using an RGB camera, and the gait features were identified. Using these gait features and fall histories, a stratified k-fold cross-validation method was used to ensure balanced training and test data, and the area under the curve (AUC) and 95% CI were calculated.

Results: Of 77 gait features in the first 3 steps, we found 3 gait features in men with an AUC of 0.909 (95% CI, 0.879-0.939) for fall risk, indicating an “excellent” (0.9-1.0) classification, whereas we determined 5 gait features in women with an AUC of 0.670 (95% CI, 0.621-0.719), indicating a “sufficient” (0.6-0.7) classification.

Conclusions: These findings suggest that fall risk prediction can be developed based on ML and the first 3 steps in men; however, the accuracy was only “sufficient” in women. Further development of the formula for women is required to improve its accuracy in the middle-aged working population.

Objectives: Many chemicals have been used for industrial purposes, and some of them are carcinogenic to humans. However, the molecular mechanisms of their carcinogenetic effects have not been well understood. Reactive oxygen species are generated from industrial chemicals and contribute to carcinogenesis. Particles and fibers are accumulated in respiratory systems by inhalation exposure and cause chronic inflammation. Under inflammatory conditions, reactive nitrogen species are generated from inflammatory and epithelial cells. These species cause oxidative and nitrative DNA damage, leading to carcinogenesis. We carried out experiments on DNA damage induced by various industrial chemicals and investigated their molecular mechanisms.

Methods: We examined oxidative DNA damage induced by industrial chemicals using DNA fragments derived from human cancer-relevant genes by polyacrylamide gel electrophoresis. Using immunohistochemistry and immunocytochemistry we also examined the formation of 8-nitroguanine (8-nitroG), a DNA lesion formed under inflammatory conditions, in lung tissues and cultured cells exposed to industrial chemicals.

Results: Benzene and o-toluidine metabolites caused oxidative damage to DNA fragments in the presence of Cu(II). H₂O₂ and Cu(I) were generated during oxidation of these chemicals and involved in DNA damage. 8-NitroG formation was observed in lung tissues of asbestos-exposed mice and humans. Carbon nanomaterials and indium compounds induced 8-nitroG formation in human lung epithelial cells via the release of damage-associated molecular patterns from exposed cells.

Conclusions: Various industrial chemicals are considered to induce carcinogenesis by causing oxidative and nitrative DNA damage. These findings provide an insight into risk assessment of industrial chemicals and prevention of carcinogenesis in workplaces.

Bromopropane was introduced commercially as an alternative to ozone-depleting and global-warming solvents. The identification of 1-bromopropane neurotoxicity in animal experiments was followed by reports of human cases of 1-bromopropane toxicity. In humans, the most common clinical features of 1-bromopropane neurotoxicity are decreased sensation, weakness in extremities, and walking difficulties. Moreover, decreased cognition, abnormal findings on brain magnetic resonance imaging, urinary incontinence, and numbness in the perineal area have also been described in workers exposed to 1-bromopropane. Murine histological studies showed that exposure to 1-bromopropane reduced the density of brain noradrenergic axons. Furthermore, proteome studies demonstrated 1-bromopropane-induced changes in the expression of proteins in the hippocampus of rats, similar to the changes seen in mice exposed to acrylamide, suggesting a common mechanism of electrophile-induced neurotoxicity. In addition to its neurotoxicity, 1-bromopropane also induces male reproductive toxicity in rats, although the targeted areas in the reproductive system differ from those affected by 2-bromopropane. However, exposure to high levels of 1-bromopropane was reported to induce spermatogenic cell degeneration, similar to that caused by 2-bromopropane, suggesting common mechanism(s) underlying 1- and 2-bromopropane-induced male reproductive toxicity. Plural approaches, including human, animal, and mechanistic studies, are useful for identification of 1-bromopropane neurotoxicity. The International Agency for Research on Cancer summarized that 1-bromopropane as well as 2-bromopropane share several key characteristics of carcinogens. Plural approaches can establish evidence-based preventive medicine by modification of the conventional evidence-based medicine (EBM), which has been developed for therapeutic medicine and is represented by the EBM pyramid.

Objectives: The natural fibrous mineral, asbestos, has been useful in industry for many centuries. In the 1960s, epidemiology recognized the association between asbestos exposure and mesothelioma, and in 1987 the International Agency for Research on Cancer designated all kinds of asbestos as Group 1 carcinogens. However, various scientific enigmas remained regarding the molecular mechanisms of asbestos-induced mesothelial carcinogenesis. This review article was undertaken to reveal and summarize recent discoveries to resolve those enigmas.

Methods: We collected recent important findings from our own laboratory and others to explain why mesothelial cells are the target for asbestos-induced carcinogenesis and what are the key molecular mechanisms.

Results: The long incubation period of 30-40 years for mesothelial carcinogenesis after asbestos exposure allows the asbestos fibers to go through the pulmonary parenchyma from the central to peripheral portions and ultimately reach the parietal mesothelium by piercing visceral pleura. Asbestos fibers have affinity for hemoglobin and histones, thus accumulating iron on the surface while traveling through the lung. Mesothelial cells are phagocytic cells, engulfing iron-coated asbestos fibers. Accordingly, homozygous deletion of the p16^INK4a tumor suppressor gene, a signature of excess iron-induced carcinogenesis, is acquired through oxidative DNA damage. Recently, exosome-dependent iron transfer from asbestos-fed macrophages to mesothelial cells was reported. Similar molecular mechanisms are observed with multiwalled carbon nanotubes of ~50-nm diameter.

Conclusions: Physical dimensions, biopersistence, and affinity to iron/histones are essential for fibrous material to be carcinogenic to mesothelial cells. Therefore, local iron reduction may be a strategy to prevent mesothelial carcinogenesis.

With the explosive development of nanotechnology, engineered nanomaterials are currently being used in various industries, including food and medicine. Concern about the health effects of nanomaterials has been raised, and available research indicates that the relative surface area of nanomaterials seems to correlate with the severity of their toxicity. With regard to engineered nanomaterials, the scope of their acute and chronic toxicities and their mechanisms are not fully understood. Studies suggest that exposure to certain nanomaterials can generate reactive oxidant species and enhance permeability of the phagolysosomal membrane, which leads to inflammasome activation, causing oxidative stress and inflammation. Since the latter 2 are implicated in the development of cardiovascular diseases, such as hypertension and atherosclerosis, it can be presumed that exposure to engineered nanomaterials could significantly impact cardiovascular function. In this review, I raise issues that should be considered in the assessment of the effects of engineered nanomaterials on cardiovascular function, and evaluate their cardiovascular toxicity as described in various in vitro and/or in vivo toxicological studies and industrial investigations.

It was previously thought that the particles inhaled by humans and having adverse effects were micron-sized; particles with a particularly high content of crystalline silica were thought to have harmful effects. In recent years, manufactured materials have been further refined to nano-level particles, and it has been reported that these ultrafine particles have different adverse effects, making it necessary to perform occupational health management for chemicals that differ from micron-sized particles. Here we report the adverse effects of carbon nanotubes, welding fumes, and organic substances as examples of nanoparticles.

Objectives: This longitudinal study examined the associations of workplace loneliness with job turnover at 6-month follow-up among Japanese full-time employees.

Methods: This study employed a 6-month prospective design as part of the Employee Cohort Study in Japan. Data from wave 15 (February 2024; baseline, T1) and wave 16 (August 2024; follow-up, T2) were used. Only participants who were employed at baseline and completed the follow-up survey were included in the analysis. Workplace loneliness at T1 was measured using 3 scales: the Loneliness at Work Scale (LAWS), a single-item workplace loneliness scale, and a 3-item scale developed by modifying the short UCLA (University College, Los Angeles) Loneliness Scale for workplace loneliness. Job turnover at T2 was defined based on responses indicating either leaving a job or moving to a different company within the preceding 6 months. Multivariable logistic regression analysis assessed the association between workplace loneliness and job turnover, adjusting for sociodemographic variables.

Results: In total, 706 employees who were employed at baseline were included in the analysis. Observed turnover at follow-up was n = 47 (6.7%). Participants who experienced turnover had significantly higher baseline scores for LAWS and the 3-item scale (P = .044 and P = .012, respectively). In the multivariable logistic regression, all 3 workplace loneliness scales demonstrated similar and significant associations with turnover at follow-up.

Conclusions: Workplace loneliness leads to job turnover. Further research is needed to address the generalization and explore mechanisms of the present findings.

Objectives: Microplastics have been detected in the atmosphere, raising concerns about their impact on the lungs. There have been reports on the effects of surface functional groups in evaluating the physicochemical properties of microplastics, but no reports have evaluated their chronic effects. We performed intratracheal instillation in rats to evaluate the acute and chronic effects on the lungs of microplastics with different surface functional groups.

Methods: Unmodified, NH₂-modified, and COOH-modified polystyrene particles with a particle size of 1 μm were intratracheally instilled into the lungs of rats. Rats were dissected at 3 days, 1 week, 1 month, 3 months, and 6 months after exposure to analyze inflammatory cells and lung injury factors in bronchoalveolar lavage fluid (BALF) and to observe histopathological findings in the lungs.

Results: A significant increase in the number of inflammatory cells in BALF was observed up to 1 week after exposure to the NH₂-based modified polystyrene compared with the negative control group. A significant increase was observed 3 days after exposure, and histopathological findings in the lungs also showed an influx of inflammatory cells into the alveolar space in the acute phase, but not in the chronic phase. In in vitro studies using RAW cell lines, NH₂-based modified polystyrene also induced the highest oxidative stress compared with unmodified and COOH-based modified polystyrene.

Conclusions: These results suggest that these polystyrenes do not have high pulmonary toxicity, although there are differences in toxicity due to differences in surface functional groups only in the acute phase.

Before 2000, very little attention had been paid to the health effects of indium, a rare metal, because there was very little information in the literature on its toxicity. A fatal case of indium-tin oxide (ITO) inhalation occurred in 2001, followed by concerns regarding occupational exposure to indium compounds and their health effects. Epidemiological studies and case reports have established a causal relationship between the inhalation of insoluble indium compounds, mainly ITO, and the development of lung damage. This review focuses on the results of animal studies of ITO and other insoluble indium compounds. Available data indicate that insoluble indium compounds such as ITO, indium arsenide (InAs), indium phosphide (InP), and copper indium gallium diselenide (CIGS) solar cell materials are toxic to the lungs of animals. In addition to lung damage, ITO nanoparticles have been found to cause kidney damage, whereas InAs, InP, and ITO cause testicular damage. Furthermore, there is compelling evidence for the carcinogenic potential of InP in long-term inhalation studies using rats and mice, which was evident in rats exposed to ITO. Based on the results of these animal experiments, the International Agency for Research on Cancer evaluated InP as probably carcinogenic to humans (Group 2A) and ITO as possibly carcinogenic to humans (Group 2 B). Based on the results of animal studies, it should be noted that occupational exposure of humans to insoluble indium compounds not only may cause lung damage, but also lung carcinogenesis and kidney or testicular damage in the future. Greater attention should be directed towards human occupational exposure to insoluble indium compounds.

N,N-Dimethylacetamide (DMAC), which is widely used as an industrial solvent, can be absorbed via the respiratory tract and skin of humans exposed to it. Hepatotoxicity is a main health risk of DMAC exposure in humans, and the relevant cases and epidemiological studies are reviewed herein. No hepatotoxicity was identified in workers exposed to ~3 ppm DMAC, and among workers exposed to >9 ppm DMAC the DMAC exposure was not observed to contribute significantly to liver damage. However, a case of liver damage was identified in which the calculated 8-hour weighted average was 12.8 mg/m³ (3.6 ppm). The skin absorption notation for DMAC is indicated based on human volunteer studies. The evidence regarding DMAC’s potential carcinogenicity in humans is not sufficient, and our literature search identified no report of DMAC as a reproductive toxicant in humans. Further case reports and epidemiological studies are necessary to determine the acceptable DMAC exposure limit for workers and thus protect them from DMAC’s toxicity.

Objectives: Our aim was to report integrative evidence for the health risk assessment of ortho-toluidine (OT) in bladder cancer in a mini-review of the recent studies of humans, experimental animals, and OT skin permeability.

Methods: Bladder cancer cases were identified in workers in Japan who were occupationally exposed in 2014-2017 to aromatic amines, primarily to the human carcinogen OT.

Results: A key epidemiological study of 98 aromatic amine-exposed workers in Japan showed a clear OT exposure-response relationship with a standardized incidence ratio. A rat model experimental study also indicated that OT and acetoaceto-o-toluidine are potent bladder carcinogens. Multiple mechanisms of OT-related bladder cancer have been proposed: metabolic activation to reactive metabolites that bind DNA and proteins, mutagenicity, oxidative DNA damage, chromosomal damage, and cytotoxicity by OT. Recent comprehensive analyses of DNA adducts in rats identified a number of common oxidative DNA adducts, including 8-OHdG, in the rat urothelium and indicated that oxidative stress may play a crucial role in the development of urinary cancer caused by OT. The skin permeability of 6 aromatic amines (o-toluidine, aniline, p-toluidine, o-anisidine, 2,4-dimethylaniline, and o-chloroaniline) was examined with the use of a 3-dimensional (3D) reconstructed human skin model; ~70%-80% of the 6 aromatic amines had permeated through the 3D skin within 8 hours. Genotoxic potency testing in a human urothelial cell line using γ-H2AX, a marker of DNA damage, suggested that OT exhibited strong γ-H2AX generation.

Conclusions: Prolonged dermal exposure to OT along with other genotoxic aromatic amines over many years may contribute to the development of bladder cancer.

Objectives: This study aimed to investigate how many male truck drivers have sleep disorders and what factors are most associated with chronic insomnia symptoms.

Methods: A cross-sectional study of 505 truck drivers in Akita prefecture was conducted using a self-administered questionnaire and health checkup data. We defined insomnia based on the International Classification of Sleep Disorders, third edition, sleep apnea syndrome (SAS) with a simple 4-variable screening tool, and restless legs syndrome (RLS) with RLS/Willis-Ekbom disease diagnostic criteria. Investigated factors included sleep duration, driving characteristics, caffeine types (foods and beverage) and amounts, caffeine intake timing, State-Trait Anxiety Inventory (STAI), individual stress, and other covariates.

Results: The prevalence of suspected SAS was 23.2% (n = 154), and that of RLS was 0.8% (n = 5). After excluding those, chronic insomnia symptoms were present in 36/505 drivers (7.1%). After adjusting for covariates, a logistic model demonstrated that drinking habits [odds ratio (OR), 6.21; 95% CI, 1.07-35.8], caffeine intake before sleep (OR, 2.65; 95% CI, 1.09-6.45), sleep duration on days off (OR, 1.44; 95% CI, 1.01-2.05), and STAI score (OR, 12.8; 95% CI, 2.53-64.2) were significantly associated with chronic insomnia symptoms. STAI was significantly positively correlated with individual stress, such as family worries (r = 0.22), relationships with non-partners (r = 0.28), and health (r = 0.23).

Conclusions: Our study revealed that one-fourth of male truck drivers had sleep disorders that require further medical evaluation. For male truck drivers, lifestyle modification and stress relief may be key to address insomnia.

The novel properties and functions of nanomaterials have naturally alerted toxicologists to the fact that such materials may also have novel effects on the human body and other living organisms. In particular, materials with high stability or biopersistency have been shown to have a tendency to accumulate in the body, leading to chronic toxicity including carcinogenicity. However, in the early stages of toxicity research, the information is often limited to the effects of short-term exposure studies, and findings on chronic effects are very much delayed. In this context, it was exceptional that studies on multi-walled carbon nanotubes (MWCNTs) have started with the verification of their potential to induce mesothelioma. This toxicological endpoint was expected on the basis of existing knowledge of asbestos and asbestos-like fiber particles. This movement has led to the achievement of the original mission of “modern toxicology,” which is “to achieve a win-win situation where both industrial promotion and safety assurance are ensured by communicating and sharing toxicity information to developers and consumers at a stage before mass production and consumption begins, that is, before massive exposure of the general public begins.”

Inaccurate toxicity assessments of asbestos in the 1980s and 1990s allowed its spread to our living environment, which is difficult to decontaminate, and the damage continues to this day. However, the case described here could be an example of realizing the proposition that “nanomaterials, the flagship of high technology, must not repeat the same mistakes.”

Objectives

There has been limited research on demographic and work-related characteristics of general and workplace loneliness. The present descriptive cross-sectional study aimed to determine the demographic and work-related correlates of general and workplace loneliness in a general working population of Japan.

Methods

We recruited 25 000 persons aged 20 years or older and employed by a company, organization, or government agency. We limited the sample to only employees for this analysis. Demographic and work-related characteristics were assessed by a self-report questionnaire. General and workplace loneliness were measured by single-item questions and dichotomized.

Results

A total of 24 021 respondents were subjected for the analysis. Prevalences of general and workplace loneliness were 9.0% and 8.3%, respectively. Those who responded “others” or refused to answer a gender question (possibly gender minority), were middle-aged, not married, with a low household income, working in the manufacturing sector (compared with some service sectors), and reporting long working hours were associated with both general and workplace loneliness. Middle-aged groups and work hours were significantly associated with workplace loneliness after adjusting for general loneliness.

Conclusions

Common demographic and work-related correlates were found for both general and workplace loneliness. Middle age and working long hours may be factors for workplace loneliness, independent of general loneliness, in Japan.

Objectives: The objective of the current study was to elucidate the relationship between blood cadmium (Cd-B) levels and proximal tubular dysfunction using urinary β2-microglobulin (B2M-U) as an indicator among workers in nickel-cadmium battery plants in Japan.

Methods: Medical check-up data from 338 workers exposed to cadmium at 2 plants were collected from 1997 through 2020. Workers with at least 2 check-ups were included, excluding those with other renal dysfunctions. Proximal tubular dysfunction was defined as a B2M-U of 300 μg/g creatinine or higher in 2 or more consecutive check-ups. A multivariable Cox proportional-hazards regression model with time-dependent covariates was performed to analyze the relationship between Cd-B levels and the time to onset of proximal tubular dysfunction, adjusting for age, sex, and smoking history.

Results: Of the 338 workers, 238 met the study eligibility criteria for the analyses. The geometric mean of Cd-B was 1.97 μg/L. The Cox proportional hazards analysis demonstrated that higher time-dependent Cd-B levels were significantly associated with an increased risk of proximal tubular dysfunction, with a hazard ratio of 1.17 (95% CI: 1.06-1.29).

Conclusions: Higher Cd-B levels are associated with an increased risk of proximal tubular dysfunction in workers exposed to cadmium, indicating an increased risk of renal disease under the current industrial health management in Japan. Continuous monitoring and improved management of cadmium exposure are necessary to protect workers’ health even in developed countries such as Japan.

Objectives: This study assessed the impact of the COVID-19 pandemic on the health status of self-employed workers by comparing their status before and during the pandemic, using nationwide data from the Korean Working Conditions Survey.

Methods: The final study included 16 620 and 14 342 self-employed participants in the fifth (2017) and sixth (2020-2021) surveys, respectively. Musculoskeletal symptoms, systemic fatigue, headache, and eye strain, as well as mental health status, such as anxiety, depression, and insomnia, were assessed using a structured questionnaire. Gender, age, education level, and income were adjusted for the multivariable logistic regression analysis to assess pre- and peri-pandemic changes in the health status based on working conditions.

Results: Compared with the pre-pandemic period, all aspects of the health status of self-employed individuals surveyed during the peri-pandemic period showed deterioration. Back pain increased 3.4 times (adjusted odds ratio [OR] 3.44; 95% CI: 3.15-3.75) compared with the pre-pandemic period, followed by anxiety, which increased 2.1 times (adjusted OR 2.13; 95% CI: 1.79-2.54). For single-person businesses, the overall health status showed statistically significant deterioration, highlighting the heightened vulnerability of these groups during this period.

Conclusions: This study confirmed that the physical and mental health status of self-employed individuals significantly deteriorated during the COVID-19 pandemic period compared with the pre-pandemic period. These findings suggest the need for government health protection policies for vulnerable groups, such as self-employed individuals, during future pandemics when social control measures are implemented.

Objectives: Previous research has indicated that shift workers exhibit fewer healthy behaviors than those working regular daytime hours. Although health literacy influences health behaviors, studies comparing health literacy levels between shift and fixed-day workers and investigating whether differences in health behaviors between these 2 groups are mediated by health literacy are lacking.

Methods: This cross-sectional study used a self-administered questionnaire in a large-scale manufacturing company. Overall, 2152 manual workers aged 18-64 years were enrolled in this study (961 and 1191 fixed-day and shift workers, respectively). Logistic regression structural equation models were used for analyzing the mediating role of health literacy in the relationship between shift work and health behaviors.

Results: Shift and fixed-day workers did not show differences in age-adjusted health literacy. Compared with fixed-day workers, the odds ratios of shift workers for leisure time exercise, not currently smoking, having breakfast, brushing their teeth, and eating green and yellow vegetables were 0.85 (95% CI, 0.70-1.02), 0.68 (95% CI, 0.56-0.80), 0.63 (95% CI, 0.52-0.76), 0.79 (95% CI, 0.65-0.95), and 0.58 (95% CI, 0.48-0.70), respectively. Mediation analysis showed that the odds ratios of the direct effects of shift work on favorable habits were almost the same as the total effect.

Conclusions: This study observed that health literacy did not mediate health behavior and shift work. Further research is needed to clarify the causes of these differences.

Objectives: This study aimed to investigate the impact of perceived workplace health support (PWHS) on absenteeism and presenteeism among Japanese workers to determine the significance of health and productivity management in improving labor productivity.

Methods: This prospective cohort study, using data from the Work Systems & Health Internet Research (WSHIR) study, involved 1879 Japanese workers aged 20-69 years. The intensity of PWHS was assessed using self-administered questionnaires. The participants were followed up from October 2021 to October 2022 to evaluate the incidence of absenteeism and presenteeism based on the level of PWHS.

Results: The study findings revealed that higher PWHS significantly correlated with lower presenteeism, indicating better work productivity. Conversely, the relationship between PWHS and absenteeism was less clear, with no consistent trend observed across different levels of PWHS intensity.

Conclusions: Enhanced PWHS was associated with reduced presenteeism among Japanese workers, underscoring the importance of workplace health support for improving employee productivity. This finding emphasizes the need for companies to focus on health promotion activities and recognize the potential of PWHS as a performance indicator in corporate health management.

Objectives: Occupational health studies have identified positive associations between work duration and presenteeism, but there is limited understanding of this relationship in disaster responders. We examined the relationship between the number of work days and presenteeism and the mediating effect of fatigue in disaster responders deployed after the Noto Peninsula earthquake.

Methods: This cross-sectional study examined disaster responders deployed after the Noto Peninsula earthquake (Japan, 2024). Data were collected using the health management version of the app for Japanese Surveillance in Post-extreme Emergencies and Disasters, and included days of work, fatigue score, and presenteeism. Structural equation modeling (SEM) was employed to examine the direct and indirect effects of the number of work days on presenteeism, with fatigue as a potential mediator. Sensitivity analysis was also performed.

Results: We analyzed 4656 disaster responders who were deployed after the Noto Peninsula earthquake. Presenteeism increased with the number of work days, and ranged from 3.4% (1 day) to 16.9% (>7 days). However, fatigue decreased as the number of work days increased. SEM demonstrated a significant direct effect of the number of work days on presenteeism, and that fatigue slightly decreased this effect for work durations of 4 to 7 days and more than 7 days. Sensitivity analyses supported these findings.

Conclusions: Working more days led to increased presenteeism in disaster responders, but fatigue decreased as the number of work days increased. Future longitudinal studies should examine additional factors that may affect presenteeism in disaster responders and other individuals exposed to stressful environments.

Objectives: Teleworking from home was widespread during the 2019 coronavirus disease pandemic. This working practice is expected to maintain popularity among employers and employees. Compared with in-person workers, teleworkers tend to be less physically active and have more musculoskeletal pain. Interventions specific to reducing health risks among teleworkers have not been identified. This study will examine the effects of an occupational lifestyle intervention encompassing 3 components: physical activity promotion, musculoskeletal health, and work environment improvement.

Methods: This cluster randomized trial will have a target sample size of 500 participants. The target population is healthy adults aged 18-64 years who telework at least once per week. Randomization will be conducted on a stratified block basis for clusters of 20 to 100 individuals within the recruited companies. The intervention period will be 12 weeks and comprise individual (online lectures, feedback, and periodic email messages), sociocultural (team building through step competition), physical (poster and tabletop pop-up), and organizational (encouraging message from an executive) strategies. The intervention group will be compared with a wait-list control group. The primary outcome will be the number of steps taken, as assessed by an accelerometer, and the secondary outcomes will be musculoskeletal pain and a telecommuting environment. The study protocol was registered with the University Hospital Medical Information Network Clinical Trials Registry (ID: UMIN000053861) (https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr.cgi?function=brows&action=brows&recptno=R000061478&type=summary&language=J).

Results: Study enrollment began in March 2024, and the intervention will be completed by March 2025.

Conclusions: The results of this study are expected to provide helpful data for promoting healthy teleworking practices.

Objectives: This study measured occupational status from the perspectives of occupational socioeconomic status, employment relationship, and class level, aiming to examine the effect of occupational status on depression among middle-aged and elderly people in China and determine whether being a state functionary plays a moderating role.

Methods: Panel data from the China Family Panel Studies (n = 28 645) were used and the year fixed-effects model was adopted. The 2-way interaction terms “state functionary × occupational status (the International Socioeconomic Index of Occupational Status [ISEI], the Standard International Occupational Prestige Scale [SIOPS], and the Erikson and Goldthorpe class categories [EGP])” were added to examine whether being a state functionary could moderate the relationship between occupational status and depression.

Results: Occupational status was negatively correlated with depression (ISEI: coefficient = −0.03; 95% CI, −0.04 to −0.02; SIOPS: coefficient = −0.01; 95% CI, −0.02 to −0.002; EGP: coefficient = 0.12; 95% CI, 0.08 to 0.15). The 2-way interaction terms “state functionary × occupational status (ISEI/SIOPS/EGP)” were significant among all middle-aged and older participants. The 2-way interaction terms were also significant in the educated and urban subgroups.

Conclusions: Higher occupational status is a protective factor against depression among middle-aged and older Chinese adults. However, being a state functionary can reverse the relationship between occupational status and depression. We found that the higher the occupational status of state functionaries, the more severe their depression. We also found a moderating effect of being a state functionary in the educated and urban subgroups.

Objectives: This systematic scoping review examined the strategies used by different countries and institutions to support the mental health of health care workers (HCWs) during the COVID-19 pandemic, to identify effective practices and the lessons learned in dealing with the associated challenges.

Methods: Of 1330 retrieved articles from PubMed, Scopus, and the Web of Science, 34 articles were ultimately included in the final analysis.

Results: The analysis revealed that mental health consultation services, especially telephone support lines, online interventions, and apps, played a critical role in addressing the psychological burden experienced by HCWs. Group activities and peer support strategies offered personalized support, and educational programs offered crucial information regarding stress management. Improvements in the work environment, such as the addition of dedicated rest areas, enhanced the well-being of HCWs. However, many interventions suffered from low participation and a lack of tailored content, despite their apparent effectiveness.

Conclusions: Many interventions have focused on psychological support and resilience-building for HCWs, but they often overlook systemic issues. Comprehensive mental health support must address these systemic factors, such as adequate staffing, training, and resource allocation. Future strategies should emphasize leadership commitment to tackling root causes and actively involve HCWs in program design to ensure relevance and effectiveness. Educational resources and wellness interventions, although reported as effective, need to be tailored and adapted to specific emergencies. Additionally, research gaps, especially in low-resource settings, highlight the need for further studies to enhance preparedness for future crises.

Objectives: To develop an occupational exposure risk assessment scale for nursing staff during major public health emergencies based on the Likelihood Exposure Consequence (LEC) method. The purpose was to provide managers with a reliable tool for assessing occupational exposure risk faced by nursing staff and to serve as a reference for the formulation of occupational protection standards.

Methods: The item pool of nursing occupational exposure risk factors was screened using the LEC and accident causation theory. This was achieved through a comprehensive literature review, semistructured interviews, and group discussions. The nursing occupational exposure risk assessment scale was developed in conjunction with the Delphi method. The LEC method was used to assess the risk of occupational exposure among nursing staff in hospital clinical fever settings and to determine the level of occupational exposure risk.

Results: Two rounds of expert inquiry were conducted to obtain the results. The recovery rates of the questionnaires deemed effective were 100%. The coefficients pertaining to expert authority were 0.807 and 0.835, and the coefficients associated with expert opinion coordination were 0.785 and 0.808, respectively. In the assessment of nursing occupational exposure risk in fever clinics, 9 risk factors were identified, with a Danger (D) value of ≥70 and risk level of ≥3. These risk factors encompassed personnel, technical, environmental, and management aspects. Considering the prevailing unsafe factors, it is recommended to enhance personnel management training, bolster protection skills, upgrade environmental facilities, improve the supervision system, and implement other appropriate rectification measures.

Conclusions: The scale is both scientifically rigorous and have the ability to present evidence in order to enhance the occupational environment for nursing personnel and guarantee their occupational safety. Additionally, it can function as a policy reference for enhancing the response mechanism of the medical and health systems.

Objectives: This study aimed to establish a method to determine workers’ exposure concentrations to airborne nitrilotriacetic acid (NTA).

Methods: The sampler used an air sampling cassette containing a glass-fiber filter (GFF). After sampling, NTA extracted from the GFF using ultrapure water was derivatized using a boron trifluoride-methanol complex methanol solution and analyzed using a gas chromatograph-mass spectrometer. The developed method was validated for the following parameters: retention efficiency, storage stability, method quantitation limit, and reproducibility.

Results: The retention efficiency for NTA on the GFF was 94%-101%, with the relative SD indicating the overall reproducibility (range 0.9%-2.4%). NTA on the GFF was stable at 4°C for at least 7 days. The method quantitation limit was 4.8 μg per sample.

Conclusions: The developed method will be useful for risk assessments because it can determine workers’ exposure concentrations to NTA ranging from 0.02 to 4 mg/m³ in a 240 L sampling volume; the quantitation limit is 4.8 μg per sample.

Recently, the incidence of pneumoconiosis has decreased due to strict dust control measures and environmental improvements in the workplace. The significance of other occupational diseases has relatively increased. Occupational hypersensitivity pneumonitis (OHP) is mainly caused by allergic reactions to antigens in the workplace. Therefore, the presence of subtle amounts of harmful substances in the environment can increase the risk of developing OHP. Not only organic substances but also inorganic substances can cause OHP. OHP is caused by a specific antibody reaction (type III allergy) or sensitized lymphocytes (type IV allergy) to a specific antigen. Based on the clinical course, OHP is classified into acute and chronic hypersensitivity pneumonitis (HP). Acute HP forms granulomas and is classified as a granulomatous lung disease (nonfibrotic HP), whereas chronic HP rarely forms granulomas and progresses to fibrosis (fibrotic HP). Differentiation between chronic HP and idiopathic or collagen vascular disease-related interstitial pneumonia is challenging. Additionally, the genetic background of each patient influences the onset, leading to diverse onset patterns. Antigens and modes of onset are diverse in the workplace. Therefore, diagnosis is difficult, and many patients may be misdiagnosed. Chronic HP with advanced fibrosis due to delayed antigen identification has a poor prognosis. This study aimed to present an overview of the causative antigens, diagnosis, prevention, and treatment of OHP to provide appropriate and timely medical attention.

Objectives: As digitalization has made knowledge work multilocational, the need for space-efficient, modern-design offices, including activity-based offices, has increased. However, studies of how activity-based offices are related to employee well-being, particularly in hybrid work, are rare. This study investigated whether the perceived activity-based office environment in hybrid work is associated with employee well-being and self-reported work ability.

Methods: We used a cross-sectional survey of 971 employees working in activity-based offices in 5 Finnish organizations in 2022. The workplaces were observed, and the employees responded to a survey of their office environment perceptions, well-being, and work ability. The survey covered burnout risk scores, work engagement, daily recovery, self-reported work ability, insomnia, and pain symptoms. We used the regression analysis general linear model to analyze associations between the environmental perceptions and employee outcomes, adjusting for age, gender, supervisory position, and telework frequency or effort-reward imbalance.

Results: Employees’ daily recovery and self-reported work ability were better when the employees’ office environment perceptions (task privacy, satisfaction with work environment, person-environment fit, workspace support for interaction, ease of workspace switching) were more positive. These associations remained in the adjusted models. Additionally, work engagement increased, and burnout risk scores and insomnia symptoms decreased when workplace conditions were perceived more favorably.

Conclusions: More favorable perceptions of activity-based offices are associated with better employee well-being and self-reported work ability in hybrid work. The perceived office environment seems essential for employee well-being and work ability even when psychosocial aspects (effort-reward imbalance) are taken into account.

Objectives: This study explored the relationship between fear of future workplace violence (FFWV) and burnout, and the moderating effect of psychological resilience on this relationship.

Methods: We recruited 413 pediatricians from 26 specialized and general hospitals in China’s Shandong provinces and Ningxia Hui Autonomous Region from August 2021 to April 2022. Fear of future workplace violence was measured using the Fear of Future Violence at Work Scale. Burnout was assessed using the Maslach Burnout Inventory. Psychological resilience was measured using the 10-item Connor-Davidson Resilience Scale. A multiple linear regression analysis was used to investigate the relationship between FFWV and burnout. The SPSS PROCESS macro was used to examine the moderating effect of psychological resilience on this relationship.

Results: About 85.7% of pediatricians experienced a medium or high level of fear. Fear of future workplace violence was significantly and positively associated with emotional exhaustion, depersonalization, and personal accomplishment (B = 0.23, SE = 0.39, P < .001; B = 0.06, SE = 0.13, P < .001; B = 0.17, SE = 0.03, P < .001, respectively, where B denotes the unstandardized regression coefficient). The interaction effects of FFWV and psychological resilience on emotional exhaustion (B = −0.008; 95% CI, −0.01 to −0.004) and depersonalization (B = −0.003; 95% CI, −0.005 to −0.001) were statistically significant. The protective effect conforms to the “protective-stabilizing” model.

Conclusions: Psychological resilience training may be beneficial for pediatricians in preventing high levels of emotional exhaustion and cynicism resulting from FFWV.

Objectives: Firefighters are frequently exposed to psychologically and physically stressful experiences. This volatile occupational environment is thought to contribute to the risk of firefighter musculoskeletal disorders (MSDs). However, investigations of firefighter MSDs are limited, and to our knowledge, have not been collectively examined. The purpose of this novel systematic review was to systematically identify, critically appraise, and synthesize evidence regarding the relationship between MSDs and personal, physical, and psychosocial factors among career firefighters to guide future study directions.

Methods: Five electronic databases (MEDLINE, CINAHL, SPORTDiscus, APA PsychInfo, PubMed) were searched from inception to December 12, 2024, which yielded 741 results. This review followed PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2020 guidelines and used the AXIS (Assess the Quality of Cross-Sectional Studies) tool.

Results: The final review included 20 cross-sectional studies (AXIS scores 12-18). Of those, 19 examined physical factor(s), and 16 examined psychosocial factor(s). The overall evidence suggests a positive relationship between firefighter MSD reports and body mass index (BMI), occupational stress, and depression. A negative relationship to physical activity engagement was consistently observed.

Conclusions: Body mass index , physical activity, and occupational stress were the most consistently examined factors related to firefighter MSDs. Odds of MSD occurrences were positively related to occupational stress and BMI, and negatively related to physical activity engagement; therefore, future investigations can focus primarily on these factors in relation to MSD risk. The establishment of reliable and culturally appropriate MSD report forms among firefighters is warranted as data collected were heterogeneous and not directly comparable. Finally, this report suggests that prospective examinations of both physical and psychosocial factors related to firefighter MSDs are needed.

Objectives: This study aimed to identify the factors influencing nurses’ posttraumatic growth (PTG) during the early stages of the coronavirus disease 2019 (COVID-19) pandemic.

Methods: A literature search was conducted in February 2023 across databases, including Medline, CINAHL, APA PsycINFO, Web of Science, and Google Scholar, for articles published between January 2020 and February 2023 related to PTG in nurses during the COVID-19 pandemic. Inclusion criteria were English-language articles, original research on nurses’ PTG, and studies conducted after January 2020. Of 1089 identified articles, 142 were screened, and 27 were selected for final analysis. Data extracted from the articles included the author(s) name(s), the study’s geographic location, publication year, study purpose, study design, participants, methods, measurement scales, results, and notes. PTG factors were extracted and grouped into 4 broad categories: COVID-related factors, nursing-related factors, factors in Tedeschi’s PTG conceptual model, and other factors. Smaller categories were then created by inductively categorizing the factors based on similarities and differences.

Results: As factors of nurses’ PTG during the early stage of the COVID-19 pandemic, 16 subcategories were organized under 4 categories. In addition to all factors from Tedeschi’s PTG model, some COVID-related factors (eg, care context, organizational training), and some nursing-related factors (eg, work environment) were shown to be related to PTG. No significant relationships were found between almost all of the other factors, including sociodemographic attributes, and PTG.

Conclusions: Factors found in this study can help identify nurses’ PTG facilitators and guide the development of interventions for future crises.

Objectives: To develop a device to evaluate the permeation resistance of chemical-protective boots continuously in contact with liquid chemicals, and to compare the permeation time of the component material test pieces with the permeation time of the whole boot and thus evaluate its performance.

Methods: The permeation time was calculated for toluene, dichloromethane, and acetone in 4 types of boot, according to Japanese Industrial Standard (JIS) T 8117:2005.

Results: The permeation test for whole boots showed shorter permeation times than those of the component materials, according to JIS T 8117:2005. The permeation time of toluene was more than twice that of boots C and D. The permeation time of dichloromethane was more than twice that of boots A and C and more than 3 times shorter for boot A.

Conclusions: The differences between the whole-boot tests and the material tests were thought to be related to variations in thickness, type of material, difference in adhesion, and penetration from pinwheels. This method enables the determination of the permeation of chemicals and other performance characteristics of the whole boot, which cannot be determined using testing of material specimens alone. By using this device for testing, appropriate boots that are protective against specific chemicals and can prevent chemically induced damage to the feet can be more efficiently selected.

Objectives: Limited empirical data are available regarding the safety of self-employed workers in Japan. This study investigated the associations between working hours, income, and work-related injuries among freelancers.

Methods: A cross-sectional study was conducted using data from an internet survey conducted in 2022. Self-employed individuals who did not work as employees or earn an income from their employment were recruited. Work-related injuries, working hours, and annual income were assessed using self-reported questionnaires. Prevalence ratios (PRs) of injury were estimated using modified Poisson regression models, while controlling for covariates. Additionally, PRs were analyzed for each stratum of working hours and income levels.

Results: In total, 1856 freelancers met the eligibility criteria and were included in the study. Among them, 222 (12.0%) experienced at least 1 work-related injury. A significantly higher risk of injury was observed among those working long hours (≥60 h/wk: PR = 1.65; 95% CI, 1.16-2.34; P = .005) and those in the second-lowest income bracket (¥2 to <¥4 million: PR = 1.43; 95% CI, 1.05-1.94; P = .024). Furthermore, several strata exhibited significantly higher PRs, particularly among workers with high incomes who also worked long hours (≥60 h/wk).

Conclusions: Long working hours, particularly exceeding 60 h/wk, are associated with a significantly higher risk of work-related injuries among freelancers. Additionally, 2 high-risk groups were identified based on the combination of working hours and income levels: those with relatively low incomes, and high-income earners who also worked extended hours.

Objectives: Early detection of neurosensory injury among workers exposed to hand-arm vibration is crucial. The aim of our study was to evaluate the diagnostic test performance of clinical point-of-care testing using a tuning fork and temperature rollers in relation to vibrotactile and thermal quantitative sensory testing.

Methods: We recruited 225 vibration-exposed workers who underwent clinical point-of-care testing using a Rydel Seiffer tuning fork and temperature rollers (25°C and 40°C) applied to the distal phalanges of the index and little fingers bilaterally. Quantitative sensory testing was conducted at the same locations. Sensitivity, specificity, and other measures of diagnostic test performance were calculated.

Results: The study sample consisted of 208 men and 17 women with a median (IQR) age of 38 (26) years, and with a median (IQR) hand-arm vibration exposure duration of 12 (21) years. Using vibrotactile quantitative sensory testing as the reference method, the sensitivity for the Rydel Seiffer tuning fork to detect reduced perception of vibration ranged from 30.0% to 61.1%, depending on the tested finger. The corresponding values for specificity were 91.1% to 94.4%. The sensitivity of temperature roller discrimination in relation to warm detection thresholds ranged from 31.6% to 48.2%, and the specificity from 82.7% to 87.5%. The corresponding sensitivity of temperature roller discrimination in relation to cold detection thresholds ranged from 28.9% to 42.5%, and the specificity from 86.0% to 94.7%.

Conclusions: The sensitivity of clinical point-of-care testing was rather low, indicating that quantitative sensory testing adds value to the diagnostic procedure.

Objectives: This study aimed to clarify the primary preventive effects of physical activity interventions delivered through digital health technology (DHT) on workers’ mental health symptoms, and to examine the conditions of attrition and adherence in these interventions.

Methods: We examined randomized controlled trials (RCTs) that analyzed the effects of physical activity interventions delivered through DHT on workers’ health outcomes. We included RCTs published in English or Japanese since 2010 and excluded studies that targeted specific diseases or secondary and tertiary prevention. We conducted the search on July 25, 2023, using Cochrane CENTRAL, Embase, PsycINFO, PubMed, and Ichushi-Web, and citation searches. We assessed risk of bias using the Cochrane Risk of Bias Tool version 2, and data were integrated using a random-effects model. Attrition rates were averaged, and adherence was qualitatively reviewed.

Results: Eight studies were included in the systematic review, and 5 in the meta-analysis. Pooled effect sizes immediately after intervention were as follows: Cohen d = −0.51 (95% CI, −0.75 to −0.27) for depression and negative affect, and −0.36 (95% CI, −0.60 to −0.05) for perceived stress. The attrition rate was 16.8% and 12.4% for the control and intervention groups, with only 2 studies providing details on adherence.

Conclusions: Physical activity interventions delivered through DHT may moderately improve depression and negative affect, and slightly reduce perceived stress among workers. However, these findings should be interpreted with caution due to the limited number of studies and low evidence certainty. Future studies should explore long-term effects, additional mental health outcomes, and factors affecting adherence.

Objectives: This study examines the cross-sectional association between relatively lower-intensity physical activity (LIPA) during leisure time and presenteeism, accounting for relatively higher-intensity physical activity (HIPA) during leisure time.

Methods: Data were derived from 11 438 workers from 6 worksites of large companies in Japan, which participated in a questionnaire survey conducted between fiscal years 2018 and 2020. Frequency and duration per occasion were assessed for leisure-time physical activities at 3 intensities as determined by shortness of breath. LIPA was defined as activity not causing shortness of breath. The participants were divided into 3 groups according to LIPA volume (none, <60 min/wk, or ≥60 min/wk) and into 2 groups according to HIPA volume (none or engaged). A single question assessed the participants’ presenteeism through self-ratings of their work performance. A multivariable Poisson regression model with a robust variance estimator estimated prevalence ratios (PRs) of presenteeism and their 95% CIs across the categories for both LIPA and HIPA.

Results: The prevalence of presenteeism tended to decrease with increasing amounts of LIPA and HIPA (P for trend <.001). Among those who did not engage in HIPA, a significantly lower prevalence of presenteeism was observed among individuals who engaged in LIPA for ≥60 min/wk compared with those who did not (adjusted PR = 0.74; 95% CI = 0.68-0.81).

Conclusions: This study supports the protective role of LIPA during leisure time that does not cause shortness of breath against presenteeism among workers who do not engage in HIPA during leisure time.

Objectives: To examine the utility of the FIB-3 index as a secondary screening tool for liver fibrosis in workplace-based health checkups, by comparing its concordance and negative predictive values (NPVs) with those of the FIB-4 index.

Methods: This cross-sectional study included 12 622 workers from the Hitachi Cohort Study who underwent workplace-based health checkups between April 2021 and March 2022. FIB-4 was calculated using age, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and platelet count, whereas FIB-3 used the same components except age. To evaluate the utility of FIB-3 in excluding liver fibrosis, NPVs were calculated using FIB-4 thresholds (1.30, 2.01, and 2.67) as references. Concordance between FIB-3 and FIB-4 was examined across different age groups. In addition, multivariate logistic regression analysis was conducted to identify factors associated with false-positive FIB-3 results.

Results: The FIB-3 index demonstrated high NPVs for excluding liver fibrosis, with values of 99.9% at FIB-4 ≥ 1.30 and 98.2% at FIB-4 ≥ 2.67. Strong concordance between FIB-3 and FIB-4 was observed consistently across different age groups. Among participants with elevated ALT (>30 IU/L), FIB-3 consistently ruled out fibrosis, whereas FIB-4 positivity increased with advancing age. Multivariate analysis indicated that higher AST levels and increased alcohol intake were significantly associated with false-positive FIB-3 results.

Conclusions: The FIB-3 index demonstrated stable performance across age groups while maintaining high concordance and NPV relative to FIB-4. These findings suggest that FIB-3 may serve as a practical screening tool in routine workplace-based health checkups, particularly in mitigating age-related overestimation observed with the FIB-4 index.

School refusal is rising globally and has reached an all-time high in Japan. It imposes critical work-family conflict on employed parents, with preliminary surveys linking it to job loss, depression, and anxiety. Despite its public health importance, work-family conflict due to school refusal has scarcely been studied in occupational health. This Opinion reviews existing research on parents of school-refusing children, discusses how occupational health professionals can support this underserved population, and outlines priorities for future research to mitigate the impacts on working-age parents’ health and employment.

Objectives: This study examined the extent to which the severity of andropause symptoms affects daily functioning, specifically in work, housework, outings, social relationships, and leisure activities, among employed Japanese men.

Methods: A cross-sectional internet-based survey was conducted in September 2024. Participants (n = 1054), aged 20-69 years, completed the Aging Males’ Symptoms scale to evaluate symptom severity. Impacts on daily life were assessed using a 4-point scale. Multivariate logistic regression analyses estimated odds ratios (ORs) and 95% CIs.

Results: After adjusting for relevant covariates, moderate and severe symptoms were significantly associated with greater difficulties in daily life. Compared with individuals with very mild symptoms, those with moderate symptoms had higher ORs for severe difficulties in work (OR = 7.2; 95% CI, 2.9-18.0), social relationships (OR = 17.7; 95% CI, 4.0-78.4), and housework (OR = 3.2; 95% CI, 1.2-9.0). Associations were stronger for severe symptoms: work (OR = 21.1; 95% CI, 8.0-55.5), social relationships (OR = 37.2; 95% CI, 7.9-174.3), and housework (OR = 8.5; 95% CI, 2.9-24.4). Severe symptoms were also linked to significant difficulties in outings (OR = 4.7; 95% CI, 1.8-12.4) and leisure (OR = 8.2; 95% CI, 3.0-22.5).

Conclusions: Andropause symptoms significantly affect multiple areas of daily life, particularly work, social engagement, and household tasks. These findings underscore the importance of early recognition and intervention.

Objectives: Use of commercially available mobile health (mHealth) applications in supporting lifestyle improvements has become popular in recent years. However, the effectiveness of advice promoting the use of such applications based on individual behavioral goals in a health guidance setting remains unclear. This study explored how guiding participants of the Specific Health Guidance (SHG) program, a Japanese public health initiative to prevent cardiovascular disease, to use commercially available mHealth applications impacted their application usage, lifestyle habits, and cardiovascular risk factors.

Methods: In this multicenter, randomized, open-label, parallel-group comparison study, 156 individuals with a history of SHG participation and who were engaged in the Motivational Health Guidance program (a type of SHG) in 2021 were assigned to intervention (n = 76) or control (n = 80) groups. Whereas both groups received standard guidance, the intervention group also received recommendations for mHealth applications based on their individual behavioral goals. The participants’ application usage, behavioral changes, and body weight were assessed after 3 months, with health checkup data evaluated after 1 year.

Results: The proportion of mHealth application users after 3 months was significantly higher in the intervention group (68.4%) than in the control group (40.0%). The intervention group also reported a significantly greater weekly frequency of mHealth application usage. Moreover, the intervention group reported a significantly decreased change in triglyceride levels after 1 year compared with the control group.

Conclusions: Recommending commercially available mHealth applications in a health guidance setting significantly increased the number of mHealth application users and their frequency of use.

Background: Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death worldwide, responsible for 3.5 million deaths in 2021. Effective preventive measures are needed. Forest bathing has been reported to have positive effects on the immune system. In addition, the clean air, mild climate, phytoncides, high oxygen concentration, and other elements of forests are expected to have benefits for respiratory diseases such as COPD. Based on the above background, this study used a randomized crossover design to examine the improving effects of forest bathing on inflammatory markers and subjective symptoms related to COPD.

Methods: Thirty male subjects aged 63.1 ± 7.5 years were recruited after obtaining informed consent. These subjects participated in day trips to a Japanese cypress forest park and to a city area of Nagano Prefecture as a control in June 2024. Blood samples were taken in the afternoon of each day before and after the walks. Concentrations of α1-antitrypsin (α1-AT), C-reactive protein (CRP), fibrinogen, and interleukin 6 (IL-6) in blood were measured. Percutaneous oxygen saturation (SpO₂), the profile of mood states (POMS), and questionnaires for subjective fatigue and respiratory symptoms and sleep quality were carried out before and after each trip.

Results: Forest bathing significantly decreased the concentrations of blood CRP, α1-AT, IL-6, and fibrinogen, significantly increased SpO₂, reduced subjective fatigue and respiratory symptoms, improved sleep and the scores of positive feelings, and reduced the scores for negative emotions in POMS.

Conclusions: Forest bathing may improve inflammatory markers, SpO₂, and subjective symptoms related to COPD.

Background: To date, no studies have investigated the relationship between one’s dominant hand and neck/shoulder pain. The aim of this prospective cohort study was to explore the relationship between one’s dominant hand and the severity of neck/shoulder pain. We also examined the relationship between the dominant hand and the onset of neck/shoulder pain at follow-up among workers without neck/shoulder pain at baseline.

Methods: We conducted a prospective cohort study of 9451 workers. The dominant hand was measured by 10 items from the Japanese version of the Flanders Questionnaire at the baseline survey. We assessed neck/shoulder pain using a numeric rating scale. We calculated the unstandardized coefficient (B) using multiple regression analysis and the incidence rate ratio (IRR) for neck/shoulder pain using modified Poisson regression among workers who were free of neck/shoulder pain at baseline.

Results: Among the 9451 respondents for the baseline survey, 6156 responded to the follow-up survey (response rate: 65.1%). Mixed-handed workers reported a higher degree of neck/shoulder pain than right-handed workers (B, 0.33; 95% CI, 0.09-0.58). Among 2481 participants, mixed-handed workers also had a higher IRR for neck/shoulder pain (IRR, 1.27; 95% CI, 1.01-1.61). There was no difference in any of the left-handers compared with the right-handers.

Conclusions: The study found that mixed-handed workers had higher levels of neck/shoulder pain than right-handed workers, and the incidence rate was also higher among mixed-handed workers. Employers should consider these findings when designing work environments, managing tasks, and providing occupational health training to optimize worker comfort and safety.