Description: Background MRI has developed into one of the most important medical diagnostic imaging modalities, but it exposes staff to static magnetic fields (SMF) when present in the vicinity of the MR system, and to radiofrequency and switched gradient electromagnetic fields if they are present during image acquisition. We measured exposure to SMF and motion-induced time-varying magnetic fields (TVMF) in MRI staff in clinical practice in the UK to enable extensive assessment of personal exposure levels and variability, which enables comparison to other countries. Methods 8 MRI facilities across National Health Service sites in England, Wales and Scotland were included, and staff randomly selected during the days when measurements were performed were invited to wear a personal MRI-compatible dosimeter and keep a diary to record all procedures and tasks performed during the measured shift. Results 98 participants, primarily radiographers (71%) but also other healthcare staff, anaesthetists and other medical staff were included, resulting in 149 measurements. Average geometric mean peak SMF and TVMF exposures were 448 mT (range 20–2891) and 1083 mT/s (9–12 355 mT/s), and were highest for radiographers (GM=559 mT and GM=734 mT/s). Time-weighted exposures to SMF and TVMF (GM=16 mT (range 5–64) and GM=14 mT/s (range 9–105)) and exposed-time-weighted exposures to SMF and TVMF (GM=27 mT (range 11–89) and GM=17 mT/s (range 9–124)) were overall relative low—primarily because staff were not in the MRI suite for most of their shifts—and did not differ significantly between occupations. Conclusions These results are comparable to the few data available from the UK but they differ from recent data collected in the Netherlands, indicating that UK staff are exposed for shorter periods but to higher levels. These data indicate that exposure to SMF and TVMF from MRI scanners cannot be extrapolated across countries.

Description: Background The current knowledge on respiratory work disability is based on studies that used crude categories of exposure. This may lead to a loss of power, and does not provide sufficient information to allow targeted workplace interventions and follow-up of patients with respiratory symptoms. Objectives The aim of this study was to identify occupations and specific exposures associated with respiratory work disability. Methods In 2013, a self-administered questionnaire was mailed to a random sample of the general population, aged 16–50, in Telemark County, Norway. We defined respiratory work disability as a positive response to the survey question: ‘Have you ever had to change or leave your job because it affected your breathing?’ Occupational exposures were assessed using an asthma-specific job-exposure matrix, and comparison of risks was made for cases and a median of 50 controls per case. Results 247 workers had changed their work because of respiratory symptoms, accounting for 1.7% of the respondents ever employed. The ‘breath-taking jobs’ were cooks/chefs: adjusted OR 3.6 (95% CI 1.6 to 8.0); welders: 5.2 (2.0 to 14); gardeners: 4.5 (1.3 to 15); sheet metal workers: 5.4 (2.0 to 14); cleaners: 5.0 (2.2 to 11); hairdressers: 6.4 (2.5 to 17); and agricultural labourers: 7.4 (2.5 to 22). Job changes were also associated with a variety of occupational exposures, with some differences between men and women. Conclusions Self-report and job-exposure matrix data showed similar findings. For the occupations and exposures associated with job change, preventive measures should be implemented.

Description: Background The association between lung cancer and occupational exposure to organic solvents is discussed. Since different solvents are often used simultaneously , it is difficult to assess the role of individual substances. Objectives The present study is focused on an in-depth investigation of the potential association between lung cancer risk and occupational exposure to a large group of organic solvents, taking into account the well-known risk factors for lung cancer, tobacco smoking and occupational exposure to asbestos. Methods We analysed data from the Investigation of occupational and environmental causes of respiratory cancers (ICARE) study, a large French population-based case–control study, set up between 2001 and 2007. A total of 2276 male cases and 2780 male controls were interviewed, and long-life occupational history was collected. In order to overcome the analytical difficulties created by multiple correlated exposures, we carried out a novel type of analysis based on Bayesian profile regression. Results After analysis with conventional logistic regression methods, none of the 11 solvents examined were associated with lung cancer risk. Through a profile regression approach, we did not observe any significant association between solvent exposure and lung cancer. However, we identified clusters at high risk that are related to occupations known to be at risk of developing lung cancer, such as painters. Conclusions Organic solvents do not appear to be substantial contributors to the occupational risk of lung cancer for the occupations known to be at risk.

Description: Objectives To conduct a systematic review of changes in lung function in relation to presence of pleural plaques in asbestos-exposed populations. Methods Database searches of PubMed and Web of Science were supplemented by review of papers’ reference lists and journals’ tables of contents. Methodological features (eg, consideration of potential confounding by smoking) of identified articles were reviewed by ≥two reviewers. Meta-analyses of 20 studies estimated a summary effect of the decrements in per cent predicted (%pred) forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV 1 ) associated with presence of pleural plaques. Results Among asbestos-exposed workers, the presence of pleural plaques was associated with statistically significant decrements in FVC (4.09%pred, 95% CI 2.31 to 5.86) and FEV 1 (1.99%pred, 95% CI 0.22 to 3.77). Effects of similar magnitude were seen when stratifying by imaging type (X-ray or high-resolution CT) and when excluding studies with potential methodological limitations. Undetected asbestosis was considered as an unlikely explanation of the observed decrements. Several studies provided evidence of an association between size of pleural plaques and degree of pulmonary decrease, and presence of pleural plaques and increased rate or degree of pulmonary impairment. Conclusions The presence of pleural plaques is associated with a small, but statistically significant mean difference in FVC and FEV 1 in comparison to asbestos-exposed individuals without plaques or other abnormalities. From a public health perspective, small group mean decrements in lung function coupled with an increased rate of decline in lung function of the exposed population may be consequential.

Description: Objectives To estimate the numbers of workers exposed to known and suspected occupational carcinogens in Canada, building on the methods of CARcinogen EXposure (CAREX) projects in the European Union (EU). Methods CAREX Canada consists of estimates of the prevalence and level of exposure to occupational carcinogens. CAREX Canada includes occupational agents evaluated by the International Agency for Research on Cancer as known, probable or possible human carcinogens that were present and feasible to assess in Canadian workplaces. A Canadian Workplace Exposure Database was established to identify the potential for exposure in particular industries and occupations, and to create exposure level estimates among priority agents, where possible. CAREX EU data were reviewed for relevance to the Canadian context and the proportion of workers likely to be exposed by industry and occupation in Canada was assigned using expert assessment and agreement by a minimum of two occupational hygienists. These proportions were used to generate prevalence estimates by linkage with the Census of Population for 2006, and these estimates are available by industry, occupation, sex and province. Results CAREX Canada estimated the number of workers exposed to 44 known, probable and suspected carcinogens. Estimates of levels of exposure were further developed for 18 priority agents. Common exposures included night shift work (1.9 million exposed), solar ultraviolet radiation exposure (1.5 million exposed) and diesel engine exhaust (781 000 exposed). Conclusions A substantial proportion of Canadian workers are exposed to known and suspected carcinogens at work.

Description: Objective The study was designed to investigate whether beryllium exposure was related to illness diagnosed as sarcoidosis. Chronic beryllium disease (CBD) and sarcoidosis are clinically and pathologically indistinguishable, with only the presence of beryllium-specific T-lymphocytes identifying CBD. Testing for such cells is not feasible in community studies of sarcoidosis but a second characteristic of CBD, its much greater incidence in those with a glutamic acid residue at position 69 of the HLA-DPB1 gene (Glu69), provides an alternative approach to answering this question. Methods Cases of sarcoidosis aged 18–60 years diagnosed in Alberta, Canada, from 1999 to 2005 were approached through their specialist physician, together with age-matched and sex-matched referents with other chronic lung disease. Referents were grouped into chronic obstructive pulmonary disease (COPD), asthma and other lung disease. Participants completed a telephone questionnaire, including industry-specific questionnaires. DNA was extracted from mailed-in mouthwash samples and genotyped for Glu69. Duration of employment in types of work with independently documented beryllium exposure was calculated. Results DNA was extracted for 655 cases (270 Glu69 positive) and 1382 referents (561 positive). No increase in sarcoidosis was seen with either Glu69 or beryllium exposure (none, 〈10, ≥10 years) as main effects: longer duration in possible beryllium jobs was related to COPD. In Glu69 positive men with exposure ≥10 years, the trend towards increasing rate of COPD was reversed, and a significant interaction of duration of exposure and Glu69 was detected (OR=4.51 95% CI 1.17 to 17.48). Conclusions The gene–environment interaction supports the hypothesis that some cases diagnosed as sarcoidosis result from occupational beryllium exposure.

Description: Objectives To investigate inter-reader agreement for the detection of pleural and parenchymal abnormalities using CT in a large cross-sectional study comprising information on individual cumulative exposure to asbestos. Methods The project was approved by the hospital ethics committee, and all patients received information on the study and gave their written informed consent. In 5511 CT scans performed in a cohort of retired workers previously exposed to asbestos and volunteering to participate in a multiregional survey programme (Asbestos Related Diseases Cohort, ARDCO), double randomised standardised readings, triple in case of disagreement, were performed by seven trained expert radiologists specialised in thoracic imaging and blind to the initial interpretation. Inter-reader agreement was evaluated by calculating the -weighted coefficient between pairs of expert readers and results of routine practice and final diagnosis after expert reading. Results -Weighted coefficients between trained experts ranged from 0.28 to 0.52 (fair to good), 0.59 to 0.86 (good to excellent) and 0.11 to 0.66 (poor to good) for the diagnosis of asbestosis, pleural plaques and fibrosis of the visceral pleura, respectively. -Weighted coefficients between results of routine practice and final diagnosis after expert reading were 0.13 (poor), 0.53 (moderate) and 0.11 (poor) for the diagnosis of asbestosis, pleural plaques and fibrosis of the visceral pleura, respectively. Conclusions Interpretation of benign asbestos-related thoracic abnormalities requires standardisation of the reading and trained readers, particularly for participants asking for compensation, and with a view to the longitudinal survey of asbestos-exposed workers.

Description: Aims The relation between Dupuytren's contracture and occupational exposure to hand-transmitted vibration (HTV) has frequently been debated. We explored associations in a representative national sample of workers with well-characterised exposure to HTV. Methods We mailed a questionnaire to 21 201 subjects aged 16–64 years, selected at random from the age-sex registers of 34 general practices in Great Britain and to 993 subjects chosen randomly from military pay records, asking about occupational exposure to 39 sources of HTV and about fixed flexion contracture of the little or ring finger. Analysis was restricted to men at work in the previous week. Estimates were made of average daily vibration dose ( A (8) root mean squared velocity (rms)) over that week. Associations with Dupuytren's contracture were estimated by Poisson regression, for lifetime exposure to HTV and for exposures in the past week 〉 A (8) of 2.8 ms –2 rms. Estimates of relative risk (prevalence ratio (PR)) were adjusted for age, smoking status, social class and certain manual activities at work. Results In all 4969 eligible male respondents supplied full information on the study variables. These included 72 men with Dupuytren's contracture, 2287 with occupational exposure to HTV and 409 with A (8)〉2.8 ms –2 in the past week. PRs for occupational exposure to HTV were elevated 1.5-fold. For men with an A (8)〉2.8 ms –2 in the past week, the adjusted PR was 2.85 (95% CI 1.37 to 5.97). Conclusions Our findings suggest that risk of Dupuytren's contracture is more than doubled in men with high levels of weekly exposure to HTV.

Description: Objectives To evaluate respiratory related mortality among underground coal miners after 37 years of follow-up. Methods Underlying cause of death for 9033 underground coal miners from 31 US mines enrolled between 1969 and 1971 was evaluated with life table analysis. Cox proportional hazards models were fitted to evaluate the exposure-response relationships between cumulative exposure to coal mine dust and respirable silica and mortality from pneumoconiosis, chronic obstructive pulmonary disease (COPD) and lung cancer. Results Excess mortality was observed for pneumoconiosis (SMR=79.70, 95% CI 72.1 to 87.67), COPD (SMR=1.11, 95% CI 0.99 to 1.24) and lung cancer (SMR=1.08; 95% CI 1.00 to 1.18). Coal mine dust exposure increased risk for mortality from pneumoconiosis and COPD. Mortality from COPD was significantly elevated among ever smokers and former smokers (HR=1.84, 95% CI 1.05 to 3.22; HR K =1.52, 95% CI 0.98 to 2.34, respectively) but not current smokers (HR=0.99, 95% CI 0.76 to 1.28). Respirable silica was positively associated with mortality from pneumoconiosis (HR=1.33, 95% CI 0.94 to 1.33) and COPD (HR=1.04, 95% CI 0.96 to 1.52) in models controlling for coal mine dust. We saw a significant relationship between coal mine dust exposure and lung cancer mortality (HR=1.70; 95% CI 1.02 to 2.83) but not with respirable silica (HR=1.05; 95% CI 0.90 to 1.23). In the most recent follow-up period (2000–2007) both exposures were positively associated with lung cancer mortality, coal mine dust significantly so. Conclusions Our findings support previous studies showing that exposure to coal mine dust and respirable silica leads to increased mortality from malignant and non-malignant respiratory diseases even in the absence of smoking.

Description: Objectives During the 1950s and 1960s, aluminium dust inhalation was used as a potential prophylaxis against silicosis in underground miners, including in Australia. We investigated the association between aluminium dust inhalation and cardiovascular, cerebrovascular and Alzheimer's diseases in a cohort of Australian male underground gold miners. We additionally looked at pneumoconiosis mortality to estimate the effect of the aluminium therapy. Methods SMRs and 95% CI were calculated to compare mortality of the cohort members with that of the Western Australian male population (1961–2009). Internal comparisons on duration of aluminium dust inhalation were examined using Cox regression. Results Aluminium dust inhalation was reported for 647 out of 1894 underground gold miners. During 42 780 person-years of follow-up, 1577 deaths were observed. An indication of increased mortality of Alzheimer's disease among miners ever exposed to aluminium dust was found (SMR=1.38), although it was not statistically significant (95% CI 0.69 to 2.75). Rates for cardiovascular and cerebrovascular death were above population levels, but were similar for subjects with or without a history of aluminium dust inhalation. HRs suggested an increasing risk of cardiovascular disease with duration of aluminium dust inhalation (HR=1.02, 95% CI 1.00 to 1.04, per year of exposure). No difference in the association between duration of work underground and pneumoconiosis was observed between the groups with or without aluminium dust exposure. Conclusions No protective effect against silicosis was observed from aluminium dust inhalation. Conversely, exposure to aluminium dust may possibly increase the risk of cardiovascular disease and dementia of the Alzheimer's type.