American journal of industrial medicine最新文献

Background: Occupational exposure to welding fumes has been suggested as a potential risk factor for bladder cancer, but evidence remains inconclusive. This review aimed to systematically evaluate the association between welding fume exposure and risk of bladder cancer through a meta-analysis of observational studies.

Methods: A comprehensive literature search was conducted in PubMed, Embase, and the Cochrane Library. Eligible studies were identified based on predefined criteria. The pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using a random-effects model. Subgroup analyses were performed based on study design, publication year, geographic region, sex, and exposure assessment methods.

Results: A total of 34 epidemiological studies were included. The pooled analysis revealed a 20% increased risk of bladder cancer among welders (OR = 1.20, 95% CI: 1.11-1.30). This association remained statistically significant in analyses restricted to studies that adjusted for both age and smoking. Subgroup analyses indicated variation by publication period, geographic region, and exposure assessment method. Sensitivity analyses restricted to high-quality studies confirmed the robustness of the findings.

Conclusions: Welding fume exposure is associated with an elevated risk of bladder cancer. These findings suggest the need for improved occupational safety measures, exposure monitoring, and further research to clarify underlying biological mechanisms and dose-response relationships.

In India, some occupational diseases are notifiable under the Mines Act, 1952, and the Factories Act, 1948. Mesothelioma, primarily attributable to asbestos exposure, has been listed specifically as one of the notifiable diseases under the Mines Act, 1952, and is notifiable under the category of occupational cancer in the Factories Act, 1948. The total number of cases of mesothelioma notified to the Directorate General of Mines Safety under the mining safety law was zero from 2004 to 2024. Similarly, under the factory safety law, only one case of occupational cancer was notified in one state, in a country of 28 states and 8 union territories (mesothelioma being listed under occupational cancer and not a separate entry under the factories law). This is in sharp contrast to the medical literature, where a large number of cases have been published by researchers and doctors from Indian hospitals. The absence of notified disease may not automatically mean the absence of disease. Further, a parallel National Cancer Registry Program, which is not only for occupational cancers, but which may overlap with occupational cases, covers only 16% of the country's population. With clear lack of notification of cases and underreporting of occupational mesothelioma, and cancer not being declared as universally notifiable at the national level, disease surveillance in India may need to be invigorated so that easily preventable disease is reduced, load on the already strained healthcare infrastructure is decreased, and overall national medical costs are reduced in the future.

Background: Classified as carcinogenic to humans by the International Agency for Research on Cancer, aluminum production has been transitioning towards lower polycyclic aromatic hydrocarbon-emitting prebake smelters. This study explored the risk of cancer and mortality over 20 years follow-up among a cohort of aluminum prebake smelter workers.

Method: Time-weighted average estimated exposure to the following airborne contaminants was available: total fluoride, sulfur dioxide, asbestos, oil mist, inhalable dust, benzene (a) pyrene (BaP), and benzene soluble fraction (BSF). Data about diagnosed cancers were accessed from the Australian Cancer Database and deaths and cause of deaths from the National Death Index, updating a previous linkage 9 years earlier.

Results: The cohort included 4495 male smelter workers. Mesothelioma was associated with historic asbestos exposure. BaP/BSF exposure were found associated with stomach cancer (10-year lag RR = 2.89 (1.19-6.98) [BaP], 2.88 (1.21-6.87) [BSF]), liver and prostate cancers, and Alzheimer's disease mortality. Oil mist exposure was associated with chronic obstructive pulmonary disease (COPD) mortality. There was no association between any smelter exposure and incidence of either lung or bladder cancer.

Conclusion: In this updated linkage of aluminum prebake smelter workers' data, the association between respiratory cancer and fluoride, inhalable dust and BaP exposure (found in the 2002 linkage analysis) was not confirmed. There was also no increased incidence of bladder cancer. However, compared with the earlier linkage, a stronger association was found for stomach cancer and BaP/BSF exposure. The strong association between mesothelioma and asbestos exposure, found in earlier linkages, remains. Other associations identified will require further investigation.

Background: Mental illness (MI) is prevalent among workers with work-related injury. However, complete mental health includes both MI and positive mental health (PMH). To better understand differences in prevalence, this study compared MI and PMH profiles among injured Ontario workers to a representative sample of the general Ontario working population.

Methods: We studied 1132 Ontario workers with a physical work-related injury from the Ontario Life After Work Injury Study (OLAWIS) and 1652 general workers in compensation-covered industries from the 2012 Mental Health Canadian Community Health Survey (MH-CCHS). MI was self-reported 18 months post-injury as a mood or anxiety disorder diagnosed pre- or post-injury in OLAWIS and defined as a major depressive episode or generalized anxiety disorder in MH-CCHS. PMH was measured in both samples using the Mental Health Continuum Short Form. Latent class analysis in each sample identified MI and PMH profiles, and chi-square tests assessed within- and between-sample differences.

Results: Three MI and PMH classes were identified in the OLAWIS sample, whereas four MI and three PMH classes were identified in the MH-CCHS sample. Compared with general workers, more injured workers belonged to high-burden MI classes (19% vs. 9%) and the languishing PMH class (11% vs. 4%). Injured workers reported lower emotional and psychological well-being but higher belonging than general workers.

Conclusions: Most workers showed low MI and flourishing PMH, but injured workers more often showed high MI and languishing PMH. Targeting aspects of psychological and emotional well-being may help improve overall mental health among injured workers.

Introduction: A growing body of research is focused on the association between employment quality (EQ) and health, yet few studies have explored how transitions between types of EQ impact health in the United States (U.S.). Moreover, unemployed individuals are frequently omitted from EQ studies. The objective of this study was to assess how transitions between different EQ states, including unemployment, are associated with health in the U.S.

Methods: Using U.S. Medical Expenditure Panel Survey data from 2008 to 2022 (n = 71,957; weighted n = 126,312,273), this study identified five unique EQ types for men: 1. Salaried-Intensive; 2. Standard Employment Relationship (SER)-like; 3. Standard but Economically Vulnerable; 4. Precarious; and 5. Unemployed, and four for women: 1. SER-like, Union; 2. SER-like, non-Union; 3. Precarious; and 4. Unemployed. The probability of transitioning between each EQ type was measured using latent transition analysis (LTA). The probability of reporting poor/fair self-rated health (SRH) and self-rated mental health (SRMH) within each EQ transition was measured descriptively and associations of poor/fair SRH or SRMH with each EQ type were measured using generalized estimating equations.

Results: Respondents transitioning to or from low-EQ arrangements (e.g., precarious employment or unemployment) reported poor/fair SRH and SRMH more frequently relative to high-EQ (e.g., SER-like) types. LTA results suggested some respondents cycled between precarious employment and unemployment, potentially compounding the effects of employment instability on health.

Conclusion: Improving employment conditions, particularly for those caught in cycles of precarious employment and unemployment, may be an avenue for improving population health in the U.S.

Background: Since 1997 the Building Trades National Medical Screening Program (BTMed) has offered medical exams to construction workers employed in US nuclear weapons facilities. The process consists of two steps: (1) a detailed work history interview; and (2) a medical exam. Some participants only completed the work history interview, and we compared their mortality experience to those who also completed medical exams.

Methods: We compared the mortality of 3470 work-history-only participants to 23,452 participants who completed both the work history interview and medical exams and, of these, 1720 who additionally participated in lung cancer screening. We used Cox proportional hazard and Poisson regression models to estimate hazard ratios and risk ratios while controlling for potential confounders.

Results: Medical exam participants experienced a reduction in mortality risk of 28% for all causes combined; 27% for all respiratory diseases combined; 37% for chronic obstructive pulmonary disease; 30% for cardiovascular diseases combined; 32% for all cancers combined; 36% for lung cancer; and 53% for colorectal cancer. The more medical exams they undertook the greater the mortality risk reduction (25%, 29%, and 43% for one, two, and three medical exams, respectively), demonstrating a clear trend. BTMed has prevented approximately 2911 premature deaths among our participants through 2021 and added 35,178 years of life, an average of 1.5 years per participant, at a cost of $2757 per year of life saved.

Conclusions: Secondary prevention in occupational high-risk groups is very effective. Continued surveillance beyond retirement age is important to reduce mortality.

Background: A causal association between occupational asbestos exposure and lung disease, including pneumoconiosis and mesothelioma, is well established. Elevated mortality among former asbestos miners is expected. However, large-scale South African studies examining all-cause mortality in this population are lacking. We assessed all-cause mortality among former asbestos miners recorded in the Asbestos and Kgalagadi Relief Trusts' Inyosi database.

Methods: All-cause standard mortality ratios (SMRs) and crude mortality rates (CMRs) were calculated for 11,343 ex-miners. Mortality predictors were modeled using Cox regression analysis, and mortality trends were assessed by examining annual all-cause CMRs and SMRs over the 20-year study period.

Results: The cohort's all-cause mortality exceeded that of the general population by 4% (SMR = 1.04; 95% CI: 1.01-1.07), with excess mortality confined to women (SMR = 1.17; 95% CI: 1.09-1.25). Increasing ILO radiographic profusion category strongly predicted mortality, with adjusted hazard ratios (aHRs) ranging from 1.13 (95% CI: 1.05-1.23) to 2.42 (95% CI: 1.58-3.71). Severely reduced lung function was also associated with increased risk, including forced expiratory volume in 1 s and forced vital capacity z-scores below -3.0 (aHR = 1.60; 95% CI: 1.41-1.81 and aHR = 1.26; 95% CI: 1.12-1.42, respectively). Additional predictors included body mass index less than 18.5 kg/m² (aHR = 1.46; 95% CI: 1.36-1.58) and previous smoking (aHR = 1.43; 95% CI: 1.35-1.53). SMRs declined over time.

Conclusion: Radiological and spirometric indicators were key predictors of mortality. These findings support risk stratification and targeted interventions, particularly early management of respiratory complications and smoking cessation, to reduce mortality. The excess female mortality highlights the occupational hazards of aboveground asbestos activities, gender‑specific work practices, and insufficient control measures in this setting. Although standardized mortality was only modestly elevated, interpretation was limited by incomplete data.

Introduction: Initial stay time (IST), the duration of continuous work before core temperature reaches 38.0°C, has been characterized in young and older adults but not across consecutive work periods or in conjunction with standard work-rest cycles. We examined sex- and age-specific ISTs during moderate-intensity work in very warm conditions and evaluated the effectiveness of prescribed work-rest cycles.

Methods: Thirty young (18-30 years, n = 15 females) and thirty older (50-69 years, n = 15 females) habitually active, non-heat-acclimatized adults completed a 1.5-day simulated work protocol while wearing coveralls ( ~ 1-Clo). On Day 1, participants completed morning (AM1) and afternoon (PM1) work bouts separated by a 1 h lunch recovery in a cooled environment (22°C); on Day 2, a morning bout (AM2) was completed. Work consisted of treadmill walking at ~200 W·m^-2 in 26°C wet-bulb globe temperature until IST, followed by work-rest cycles starting with a 15-min rest and 45 min of work, for up to 240 min or volitional fatigue.

Results: IST was shorter in PM1 than AM1 but did not differ between mornings. Females reached 38.0°C faster than males, with older females showing the shortest IST. Work-rest cycles maintained mean rectal temperature ≤38.3°C in >90% of bouts, with no sex- or age-related differences in cumulative time above 38.0°C. Cardiovascular strain was higher during PM1, while perceptual measures did not reliably track physiological strain.

Conclusion: Continuous work to IST was reduced during afternoon work following morning work but was restored the next morning across sex and age groups. When applied after IST, prescribed work-rest cycles effectively maintained core temperature near safety limits. These findings highlight the need to consider work timing and worker characteristics when planning work in hot environments.

Hypersensitivity pneumonitis (HP) is an immune-mediated interstitial lung disease triggered by repeated inhalation of organic or chemical antigens. Occupational exposures account for approximately 19% of all cases. Early diagnosis, identification of the responsible antigen(s), and immediate avoidance of exposure are crucial to prevent irreversible pulmonary fibrosis. However, HP often remains unrecognized or is misclassified as another respiratory disorder such as asthma, chronic obstructive pulmonary disease (COPD), or idiopathic pulmonary fibrosis. As a result, the causal link between symptoms and workplace exposure is frequently established only in advanced disease stages-or not at all. Such delays may result in chronic respiratory failure, occupational disability, prolonged oxygen therapy, and, in severe cases, lung transplantation. We report four patients in whom HP was ultimately recognized as an occupational disease or recommended for legal recognition in court. At the time of diagnosis, all cases had progressed to advanced, fibrotic HP, rendering both primary and secondary prevention impossible. In each instance, earlier identification of the occupational trigger followed by immediate antigen avoidance could likely have prevented the development of irreversible lung damage. This case series underscores the need for early and comprehensive pulmonary assessment, including detailed occupational history-taking, serologic and radiologic evaluation, and prompt referral to an occupational physician when HP is suspected. Close interdisciplinary collaboration between pulmonologists and occupational medicine specialists is essential to reduce diagnostic latency, prevent progression to end-stage lung disease, and improve clinical and socioeconomic outcomes.