Description: Objectives Occupational exposure to disinfectants is associated with work-related asthma, especially in healthcare workers. However, little is known about the specific products involved. To evaluate disinfectant exposures, we designed job-exposure (JEM) and job-task-exposure (JTEM) matrices, which are thought to be less prone to differential misclassification bias than self-reported exposure. We then compared the three assessment methods: self-reported exposure, JEM and JTEM. Methods Disinfectant use was assessed by an occupational questionnaire in 9073 US female registered nurses without asthma, aged 49–68 years, drawn from the Nurses' Health Study II. A JEM was created based on self-reported frequency of use (1–3, 4–7 days/week) of 7 disinfectants and sprays in 8 nursing jobs. We then created a JTEM combining jobs and disinfection tasks to further reduce misclassification. Exposure was evaluated in 3 classes (low, medium, high) using product-specific cut-offs (eg, 〈30%, 30–49.9%, ≥50%, respectively, for alcohol); the cut-offs were defined from the distribution of self-reported exposure per job/task. Results The most frequently reported disinfectants were alcohol (weekly use: 39%), bleach (22%) and sprays (20%). More nurses were classified as highly exposed by JTEM (alcohol 41%, sprays 41%, bleach 34%) than by JEM (21%, 30%, 26%, respectively). Agreement between JEM and JTEM was fair-to-moderate ( 0.3–0.5) for most disinfectants. JEM and JTEM exposure estimates were heterogeneous in most nursing jobs, except in emergency room and education/administration. Conclusions The JTEM may provide more accurate estimates than the JEM, especially for nursing jobs with heterogeneous tasks. Use of the JTEM is likely to reduce exposure misclassification.

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 Nurses are at increased risk of occupational asthma, an observation that may be related to disinfectants exposure. Whether asthma history influences job type or job changes among nurses is unknown. We investigated this issue in a large cohort of nurses. Methods The Nurses’ Health Study II is a prospective study of US female nurses enrolled in 1989 (ages 24–44 years). Job status and asthma were assessed in biennial (1989–2011) and asthma-specific questionnaires (1998, 2003). Associations between asthma history at baseline (diagnosis before 1989, n=5311) and job type at baseline were evaluated by multinomial logistic regression. The relations of asthma history and severity during follow-up to subsequent job changes were evaluated by Cox models. Results The analytic cohort included 98 048 nurses. Compared with nurses in education/administration (likely low disinfectant exposure jobs), women with asthma history at baseline were less often employed in jobs with likely high disinfectant exposure, such as operating rooms (odds ratio 0.73 (95% CI 0.63 to 0.86)) and emergency room/inpatient units (0.89 (0.82 to 0.97)). During a 22-year follow-up, nurses with a baseline history of asthma were more likely to move to jobs with lower exposure to disinfectants (HR 1.13 (1.07 to 1.18)), especially among those with more severe asthma (HR for mild persistent: 1.13; moderate persistent 1.26; severe persistent: 1.50, compared with intermittent asthma, p trend: 0.004). Conclusions Asthma history was associated with baseline job type and subsequent job changes among nurses. This may partly reflect avoidance of tasks involving disinfectant use, and may introduce bias in cross-sectional studies on disinfectant exposure and asthma in nurses.

Description: Introduction Since 2000 a decline in the incidence of occupational asthma (OA) has been reported in the UK and Europe. We aimed to describe and account for trends in the incidence of OA in the West Midlands, UK using annual notification data from the SHIELD voluntary surveillance scheme over the period 1991–2011. Methods All notifications to the SHIELD database between January 1991 and December 2011 were identified, along with patients’ demographic data, occupations, causative agents and confirmatory tests. Annual notifications were scaled to give an annual count per million workers, giving a measure of incidence, and also standardised against those of bakers’ asthma. Non-parametric analyses were undertaken between annual incidence and time (years) for common causative agents using (1) a negative binomial regression univariate model and (2) a logistic regression model calculating annual reporting ORs. A step-change analysis was used to examine time points at which there were marked reductions in incidence. Results A decrease in annual incidence of OA was observed over the study period (incident rate ratio=0.945; 95% CI 0.933 to 0.957; p〈0.0001), an effect that was lost after standardising for bakers’ asthma. Decreases in incidence were seen for most common causative agents, with only cleaning product-related OA increasing over 21 years. Marked fall in incidence was seen in 2004 for isocyanates, and in 1995 for latex. Most notifications came from a regional specialist occupational lung disease unit, with notifications from other sites falling from 16 cases/million workers/annum in 1995 to 0 in 2004. Conclusions Reporter fatigue and increasing under-recognition of OA are both factors which contribute to the apparent fall in incidence of OA in the West Midlands. There is a future need for interventions that enable health professionals to identify potential cases of OA in the workplace and in healthcare settings.

Description: Background A few studies have investigated exposure–response relationships for sensitisation to wheat, work-related symptoms and wheat allergen exposure. IgG4 is suggested to protect against the development of allergic sensitisation. The main aim of this current study was to explore the nature of exposure–response relationships for a range of clinically relevant endpoints among bakery workers, and to investigate the role of IgG4 in these relationships. Methods A cross-sectional study of 517 supermarket bakery workers in 31 bakeries used a questionnaire, serum-specific IgE and IgG4 to wheat, and methacholine challenge testing. Exposure models were developed previously using job, bakery size, tasks and specific ingredients used. These models were used to predict average personal exposure to wheat allergens. Results The exposure–response relationships for average exposure followed a linear relationship for sensitisation, but a bell-shaped curve for allergic symptoms and probable occupational asthma, increasing up to 10–15 µg/m 3 wheat allergen concentration after which they plateau off and decrease at higher exposure concentrations. This relationship was modified by atopic status. IgG4 levels were strongly exposure related: a clear increase in prevalence of higher IgG4 with increase in wheat allergen exposure was observed among those sensitised and non-sensitised to wheat, with IgG4 even more strongly associated with exposure than IgE to wheat. Conclusions The bell-shaped exposure–response relationship in the current study is consistent with the findings of previous studies. IgG4 showed no protective effect for sensitisation, confirming the findings of previous studies, suggesting that the pattern is probably related to a healthy worker effect.

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: 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: The quality of guidelines is often modest and highly variable. We searched the Medline database for occupational asthma (OA) guidelines meeting our inclusion criteria and undertook a systematic appraisal of them. Six appraisers independently evaluated these guidelines using the AGREE II (Appraisal of Guidelines, Research and Evaluation II) instrument. Standardised scores for each domain and for overall quality were calculated, as well as intraclass correlation coefficients to assess agreement among appraisers. Seven relevant guidelines were identified. Three were based on a systematic review of the evidence. Most guidelines scored high on the domains ‘Scope and purpose’ and ‘Clarity and presentation’, but scores on the other domains were variable. The lowest scores were for ‘Applicability’, suggesting that guideline developers did not pay sufficient attention to practical problems affecting the implementation of their recommendations. We also observed a trend toward improved scores in guidelines published after 2000. Inter-rater agreement was good for most domains, and particularly for ‘Rigour of development’. This domain was most strongly correlated with the overall assessment scores, together with ‘Scope and purpose’ and ‘Editorial independence’. The quality of OA guidelines is variable, both within and across guidelines. There is significant room for improvement, and greater efforts to produce high-quality guidelines are warranted, in order to assist clinical decision-making.