Occupational and Environmental Medicine最新文献

Objectives: To investigate the effect of precarious employment (PE) on the risk of diagnosed chronic musculoskeletal disorders (MSDs) among Swedish workers in occupations with strenuous working conditions.

Methods: This nationwide register-based cohort study included workers registered as living in Sweden in 2005, aged 21-60 at the 2010 baseline. Three samples were included: workers with high biomechanical workload (n=680 841), repetitive work (n=659 422) or low job control (n=703 645). PE was evaluated using the SWE-ROPE (2.0) construct, which includes: contractual insecurity, temporariness, multiple jobs, income and collective bargaining agreement from 2010. Three exposure groups were created: PE, substandard and standard employment (SE). MSD data were obtained from outpatient registers (2011-2020). Cox proportional-hazards models estimated crude and adjusted sex-specific HRs with 95% CIs. Various outcomes were investigated for the different samples.

Results: Among workers with heavy biomechanical workload, results suggest increased risks of back MSDs in PE compared with those in SE. No association was found between PE and tendonitis in repetitive work, but PE was associated with an increased Carpal Tunnel Syndrome risk among men. Among workers with low job control, PE was associated with increased risks of soft tissue disorders among men and fibromyalgia among women.

Conclusions: PE was associated with an increased risk of MSDs among workers with strenuous working conditions, with variations depending on disorder and sex. The findings suggest a differential exposure to biomechanical workload within occupations. Targeted interventions and strengthened workplace safety regulations are needed to protect the musculoskeletal health of workers in PE.

Objective: To conduct meta-analyses of occupational asbestos exposure and oesophageal, stomach and colorectal cancer risk, including a critical exposure assessment approach.

Methods: The search strategy was executed on MEDLINE, Embase, CINAHL, Scopus and Web of Science databases (March 2022, March 2024). Effect estimates (ORs, HRs, standardised incidence ratio and standardised mortality ratio) from eligible cohort and case-control studies were combined in random effects models. Meta-relative risks (mRRs) were calculated by cancer site and exposure characteristics. Investigators with occupational epidemiology and hygiene expertise came to a consensus on the estimates where there was confidence in significant asbestos exposure.

Results: A total of 82 (oesophageal), 153 (stomach) and 144 (colorectal) papers met the inclusion criteria. Elevated mRRs were observed for any occupational asbestos exposure for oesophageal (1.17 (95% CI 1.07 to 1.29)), stomach (1.14 (95% CI 1.05 to 1.23)) and colorectal cancer (1.16 (95% CI 1.08 to 1.24)). There was consistency of mRR estimates and higher mRRs in meta-analyses where there was increased confidence in the categorisation of highly exposed workers, including among the highest exposed workers in exposure-response studies (oesophageal: 1.63 (95% CI 1.29 to 2.06); stomach: 1.28 (95% CI 1.09 to 1.52); colorectal: 1.29 (95% CI 1.09 to 1.53)), among asbestos insulation workers (oesophageal: 1.68 (95% 1.19 to 2.36); stomach: 1.53 (95% 0.93 to 2.51); colorectal: 1.59 (95% 1.14 to 2.23)) and among workers in cohorts with a twofold or greater risk of asbestos-related lung cancer (oesophageal: 1.40 (95% CI 1.14 to 1.71); stomach: 1.33 (95% CI 1.14 to 1.56); colorectal: 1.47 (95% CI 1.34 to 1.61)).

Conclusion: The meta-analyses support a causal link between occupational asbestos exposure and the risk of oesophageal, stomach and colorectal cancer.

Background: Occupational exposure to endotoxin has been associated with reduced lung cancer risk. The mechanisms underlying this association are unclear, though immunological alterations likely play a role. Farmers who perform certain tasks (eg, raising hogs) can be highly exposed to endotoxin. We, therefore, leveraged measurements of circulating immune markers from a prior investigation among male farmers in the Biomarkers of Exposure and Effect in Agriculture study to evaluate associations with newly developed estimates of endotoxin exposure.

Methods: Our investigation included 122 non-smoking farmers from Iowa, oversampling those raising hogs. Serum levels of 60 markers were measured using multiplex bead-based assays and ELISA. Based on an algorithm linking measurement-based task intensity estimates with self-reported task frequency, we estimated cumulative endotoxin exposure in the 30 days up to sample collection. We used multivariable linear regression to estimate geometric mean ratios of immune markers across exposure quartiles.

Results: Higher endotoxin exposure in the last 30 days was associated with increased levels of fibroblast growth factor-2, macrophage inflammatory protein-3 alpha/CCL20 and sIL-4R (P_trend≤0.02) and decreased levels of macrophage-derived chemokine/CCL22 (P_trend=0.02). We also identified novel associations with several additional markers; those with the highest (vs lowest) exposure to endotoxin had decreased levels of TARC/CCL17, sCD27 and IL-1B.

Conclusions: Several circulating immune markers were associated with endotoxin levels in an exposure-response manner. Our findings are consistent with prior work on hog farming and suggest possible biological mechanisms through which endotoxin may confer a reduced risk of lung cancer.

Introduction: Five million US Veterans had possible exposure to open burn pits used for waste disposal through service in Iraq (2003-2011) and Afghanistan (2001-2014). Burn pits generate toxic exposures that may be associated with adverse health outcomes. We examined all-cause and cause-specific mortality in relation to deployment to bases with open burn pits.

Methods: We analysed a cohort of 474 634 Veterans who received some healthcare from the Veterans Health Administration, linked to Department of Defense deployment records to identify assignments to bases with burn pits. In multivariable logistic regression models, we assessed the association between duration of deployment to bases with burn pits and all-cause mortality and cause-specific mortality from the six most common causes among this population of Veterans.

Results: Duration of deployment to bases with burn pits was modestly related to all-cause mortality, with adjusted ORs of 1.07 (95% CI 0.99 to 1.15), 1.08 (95% CI 1.00 to 1.16) and 1.16 (95% CI 1.06 to 1.27) across tertiles, but not associated with mortality due to cancer, heart disease or chronic liver disease/cirrhosis. Positive associations were also found for unintentional injuries, suicide and stroke.

Discussion: These data are suggestive of an association between duration of deployment to bases with burn pits and overall mortality, but not from cancer or heart disease. Unexpected associations with injury and suicide call for a more detailed evaluation. Conclusions are restricted by the broad aggregations of causes of death, a limited number of deaths in this relatively young cohort and the lack of more detailed information on exposure to burn pits.

Objective: The objective of the present study was to develop a method for sampling and detecting an adenovirus-derived gene therapy (GT) vector on isolator worksurfaces.

Methods: We used a quantitative PCR (q-PCR) to detect the viral genome in standard dilutions of pure GT product and extracts of sampled surfaces. We compared three devices for surface sampling (a cotton compress, a cotton swab and a polyester flocked swab) and performed positive control, negative control and induced contamination tests for each.

Results: Our results showed that the GT pure product is detected by the q-PCR assay and is amplified throughout the range of dilutions. The mean difference between the expected and measured number of vector particles in the q-PCR assay was 1.27 log. The numbers of particles in the total extracted volume were 4.66×10⁸ for the polyester swab (7.8% of the initial quantity), 3.82×10⁸ for a cotton compress (6.4%) and 2.88×10⁷ for a cotton swab (4.8%).

Conclusion: These initial results suggest that viral monitoring of worksurfaces is feasible and will help us to validate the GT product supply chain.

Objectives: According to the International Agency for Research on Cancer, styrene is probably carcinogenic for lymphohaematopoietic neoplasms, with insufficient evidence for other cancer sites. We compared mortality and cancer incidence (for the first time) in a UK cohort occupationally exposed to high levels of styrene to that of the general population of England and Wales.

Methods: The follow-up for mortality ran from 1969 to 2022, while the follow-up for cancer incidence ran from 1971 to 2020. Standardised mortality ratios (SMRs) and standardised incidence ratios (SIRs) were calculated for cancer and non-cancer outcomes. Additional analyses compared mortality and cancer incidence with respect to the median age at and time since first exposure.

Results: A total of 1319 males contributed 53 687 person-years of follow-up in the all-cause mortality analysis. Mortality analyses did not indicate any clear increased risks. There was an indication of higher mortality of cancers of the trachea, bronchus or lung (SMR=1.30 (95% CI 0.99 to 1.70)). Mortality from lymphatic and haematopoietic neoplasms was elevated in those first exposed younger than 25 years of age (SMR=2.20 (95% CI 1.12 to 3.92)). The SIR analysis suggested reduced cancer incidence for all malignant neoplasms combined (SIR=0.85 (95% CI 0.76 to 0.96)). The incidence of lymphatic and haematopoietic neoplasms, especially myeloid proliferations and neoplasms, was elevated in those first exposed before 25 years old.

Conclusions: This study provides some limited evidence in support of styrene being a cause of lymphohaematopoietic, particularly myeloid neoplasms and lung cancers. This cohort is contributing to an ongoing international study to help clarify these associations.

Introduction: Previous studies suggest respirable crystalline silica (RCS) is an important driver of resurgent pneumoconiosis among US coal miners. Although greater attention has been focused on dust exposures in underground coal miners, surface miners are also at risk of severe disease. This study explores RCS exposure in this population.

Methods: We analysed 91 950 respirable quartz samples from 4127 US surface coal mines from 1982 to 2023. We calculated the geometric mean of respirable quartz concentration for each mine-year combination. Then, for each calendar year, we averaged the geometric means across all mines. We used generalised estimating equation models with a natural logarithm link function and Poisson distribution to evaluate the marginal effects of mine characteristic variables on the mass concentration of respirable quartz based on individual dust sample results.

Results: Drillers and bulldozer operators had annual mean respirable quartz exposures as high as 0.58 and 0.32 mg/m3, respectively, while other occupations combined had exposure of 0.08 mg/m³. The mean mine-level respirable quartz mass concentrations decreased substantially over time for all three occupation groups. Drillers or bulldozer operators, mine location in Central Appalachia and lack of a mine safety committee were predictive of higher respirable quartz mass concentrations.

Conclusions: These data demonstrate exceptionally high RCS overexposures among certain groups of surface coal miners, particularly drillers and bulldozer operators in the 1980s and 1990s. Despite recent improvement in RCS levels, these data underscore the importance of continued medical surveillance of current and former surface coal miners.

Objective: To assess the role of occupational noise exposure on pregnancy complications in urban Nordic populations.

Methods: A study population covering five metropolitan areas in Denmark, Finland, Norway and Sweden was generated using national birth registries linked with occupational and residential environmental exposures and sociodemographic variables. The data covered all pregnancies during 5-11 year periods in 2004‒2016, resulting in 373 184 pregnancies. Occupational noise exposure was based on a Swedish-developed job-exposure-matrix, containing measured A-weighted annual 8 hour noise levels (L_Aeq8h), and linked with person-specific job-history. Outcomes included diagnosed gestational diabetes, gestational hypertension, mild pre-eclampsia and severe pre-eclampsia. The data were analysed with logistic regression models separately in each country, adjusting for maternal (age, parity, birth year, education and marital status) and residential environmental factors (low neighbourhood income, NO₂ and green and blue space). The results were combined by meta-analysis.

Results: Occupational noise exceeding 80 dB, compared with less than 70 dB, was associated with an increased odds of gestational diabetes in all countries, with a combined OR of 1.26 (95% CI 1.04 to 1.51), and mild pre-eclampsia in all countries except Finland, resulting in a combined OR of 1.22 (95% CI 0.99 to 1.51). Further adjustment by maternal body-mass index attenuated these associations. No association with gestational hypertension or severe pre-eclampsia was found.

Conclusions: Register data from four nationalities show that gestational diabetes and, tentatively, mild pre-eclampsia was increased among pregnant workers working in occupations where noise levels exceed 80 dB L_Aeq8h but not in occupations with lower noise levels.