Occupational and Environmental Medicine最新文献

Objectives: The study investigated the association between occupational biomechanical risk factors and the occurrence of thumb carpometacarpal joint osteoarthritis (CMC1 OA) in construction workers.

Methods: Male construction workers (n=237 525), participating in a Swedish occupational surveillance programme between 1971 and 1993, were followed between 1997 and 2019. CMC1 OA diagnoses were identified through linkage with national medical registries. Job title, smoking status, height, weight and age were collected from the surveillance programme. A job exposure matrix (JEM) was developed with exposure estimates on biomechanical risk factors for each occupational group. Relative risk (RR) of CMC1 OA diagnosis was calculated using a Poisson regression model.

Results: There was an increased risk of CMC1 OA for all biomechanical risk factors (RR range 1.3-1.5). Exposure-response patterns were seen for repetitive wrist flexion and extension (low: RR 1.30 (95% CI 1.07 to 1.59), moderate: 1.32 (95% CI 1.07 to 1.62), high: 1.45 (95% CI 1.19 to 1.75)), wrist extension (low: 1.31 (95% CI 1.09 to 1.59), moderate: 1.41 (95% CI 1.17 to 1.70) and heavy lifting (low: 1.13 (95% CI 0.92 to 1.38), moderate: 1.45 (95% CI 1.18 to 1.77), high: 1.50 (95% CI 1.24 to 1.82). Electricians (1.29 (95% CI 1.03 to 1.89)), concrete workers (1.31 (95% CI 1.02 to 1.67)), plumbers (1.37 (95% CI 1.07 to 1.76)), sheet-metal workers (1.58 (95% CI 1.18 to 2.10)), wood workers (1.66 (95% CI 1.36 to 2.03)), repairers (1.75 (95% CI 1.06 to 2.90)) and glass workers (2.21 (95% CI 1.42 to 3.44) had an increased risk of CMC1 OA compared with the reference group.

Conclusion: Wrist movements and hand loading were associated with CMC1 OA.

Objectives: Although human intestine is sensitive to high ambient temperature, the heat-related morbidity burden remains rarely explored. This study quantified the association between high ambient temperature and non-infectious bowel disease (NBD) hospitalisations in Brazil during 2000-2019-a country experiencing substantial threats both from global warming and NBDs.

Methods: Daily data on weather and NBD hospitalisations were collected from 1816 cities. A time-stratified case-crossover design was used to assess the effect size of ambient temperature during the hot season. Stratified analysis by regions, population subgroups and disease types was performed.

Results: For each 5℃ increase in mean daily temperature, the cumulative OR of NBD hospitalisation over lag 0-3 days was 1.042 (95% CI 1.031 to 1.054) at the national level, reaching the maximum in the northeast and the minimum in the southeast. Assuming a causal relationship, ambient heat exposure explained 12.09% (95% CI 8.69% to 15.09%) of the total hospitalisations. The effect size was the highest in the youth, with no significant gender difference observed. Inflammation-related and function-related NBDs showed significantly higher susceptibility compared with other types of NBDs. The cumulative effect of ambient high temperature attenuated over the 20 years and from early to late hot season, suggesting both long-term and intraseasonal adaptations to heat.

Conclusions: The spatial, temporal and demographic variations in the strength of association should be considered for the development of health preventive strategies towards extreme ambient heat.

Background: Zoonotic transmission of livestock-associated methicillin-resistant Staphylococcus aureus clonal complex 398 (LA-MRSA CC398) from industrial pig farms to farm workers and their household members and secondary transmission to elderly and immunocompromised persons has led to a growing number of serious infections and even death.

Objective: We tested the hypothesis that conventional pig farms confer a higher risk for LA-MRSA CC398 carriage among farm workers and their household members than specific pathogen-free (SPF) farms, which follow a set of stringent rules concerning biosecurity, health control and transportation of pigs between herds.

Methods: We conducted a cross-sectional study of farm workers and their household members from 25 Danish pig farms positive for LA-MRSA CC398. Questionnaires were designed to obtain information about each farm and participant. Nasal samples from pigs and human volunteers were screened for LA-MRSA CC398. Multivariate logistic regression analyses were used to calculate adjusted ORs (aORs) and 95% CIs.

Results: The study included 25 pig farms, 154 farm workers screened at the farm (93 of whom were also screened at home) and 173 household members. The risk of LA-MRSA CC398 carriage among farm workers at the farm (aOR=5.40, 95% CI 1.05 to 27.80) and household members (aOR=8.32; 95% CI 2.81 to 24.63) was significantly higher in conventional pig farms than in SPF farms.

Conclusions: This study shows that strict biosecurity measures reduce the risk of LA-MRSA CC398 carriage among farm workers and their household members and thereby the disease burden in the general population.

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.

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.

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.

Objectives: Environmental lead is a persistent hazard that disproportionately affects children. Keys are known sources of lead exposure in children, but little is known about the specific lead content or frequency of lead in keys. We identified differences in lead concentration and frequency across items with different physical characteristics.

Methods: This study tested a convenience sample of keys and keychain objects using an X-ray Fluorescence (XRF) analyzer.

Results: The mean lead concentration across 362 objects tested was 1722 ppm (SD 3657 ppm; range 95.5-44 400 ppm). Lead was present in the majority (64%) of objects tested. Door keys had the highest concentration of lead (mean 2646 ppm; SD 3701 ppm). Door keys had significantly more lead than both vehicle keys (p<0.0001) and electronic fobs (p=0.0004). Gold-coloured keys contained significantly more lead than silver-coloured keys (p<0.0001). Copied keys were significantly more likely to contain detectable levels of lead compared with original keys (p<0.0001); however, this relationship was not significant when controlling for key type. There was a positive association between key age and lead concentration (p=0.009).

Conclusion: Keys were less likely to contain lead if they were silver-coloured; car keys or electronic fobs; and newer. However, several categories of keys with less lead contained high lead levels, and the majority of items tested (64%) contained more lead than limits on lead in keys that were implemented in Minnesota after data collection (90 ppm). The levels of lead identified highlight the need for public education and potential additional regulatory guidelines for keys.