Description: Objective To estimate the rate of work injury over the 24 h clock in Ontario workers over 5 years (2004–2008). Methods A cross-sectional, observational study of work-related injury and illness was conducted for a population of occupationally active adults using two independent data sources (lost-time compensation claims and emergency department encounter records). Hours worked annually by the Ontario labour force by time of day, age, gender and occupation were estimated from population-based surveys. Results There was an approximately 40% higher incidence of emergency department visits for work-related conditions than of lost-time workers’ compensation claims (707 933 emergency department records and 457 141 lost-time claims). For men and women and across all age groups, there was an elevated risk of work-related injury or illness in the evening, night and early morning periods in both administrative data sources. This elevated risk was consistently observed across manual, mixed and non-manual occupational groups. The fraction of lost-time compensation claims that can be attributed to elevated risk of work injury in evening or night work schedules is 12.5% for women and 5.8% for men. Conclusions Despite the high prevalence of employment in non-daytime work schedules in developed economies, the work injury hazards associated with evening and night schedules remain relatively invisible. This study has demonstrated the feasibility of using administrative data sources to enhance capacity to conduct surveillance of work injury risk by time of day. More sophisticated aetiological research is needed to understand the specific mechanisms of hazards associated with non-regular work hours.

Description: Objectives Acute lung function (LF) changes might predict an accelerated decline in LF. In this study, we investigated the association between cross-shift and longitudinal changes in forced expiratory volume in 1 s (FEV 1 ) among woodworkers in a 6-year follow-up study. Methods 817 woodworkers and 136 controls participated with cross-shift changes of FEV 1 at baseline and FEV 1 and forced vital capacity at follow-up. Height and weight were measured and questionnaire information on respiratory symptoms, employment and smoking habits was collected. Wood dust exposure was assessed from 3572 personal dust measurements at baseline and follow-up. Cumulative wood dust exposure was assessed by a study-specific job exposure matrix and exposure time. Results The median (range) of inhalable dust at baseline and cumulative wood dust exposure was 1.0 (0.2–9.8) mg/m 3 and 3.8 (0–7.1) mg year/m 3 , respectively. Mean (SD) for %FEV 1 /workday and FEV 1 /year was 0.2 (6.0)%, and –29.1 (41.8) ml. Linear regression models adjusting for smoking, age, height and weight change showed no association between cross-shift and annual change in FEV 1 among woodworkers or controls. Including different exposure estimates, atopy or cross-shift change dichotomised or as quartiles did not change the results. Conclusions This study among workers exposed to low levels of wood dust does not support an association between acute LF changes and accelerated LF decline.

Description: Objectives Falls are a leading cause of injury at work, and slipping is the predominant cause of falling. Prior research has suggested a modest correlation between objective measures (such as coefficient of friction, COF) and subjective measures of slipperiness (such as worker perceptions) in the workplace. However, the degree of association between subjective measures and the actual risk of slipping at the workplace is unknown. This study examined the association between perception of slipperiness and the risk of slipping. Methods 475 workers from 36 limited-service restaurants participated in a 12-week prospective cohort study. At baseline, demographic information was collected, participants rated floor slipperiness in eight areas of the restaurant, and work environment factors, such as COF, were measured. Restaurant-level and area-level mean perceptions of slipperiness were calculated. Participants then reported their slip experience at work on a weekly basis for the next 12 weeks. The associations between perception of slipperiness and the rate of slipping were assessed. Results Adjusting for age, gender, body mass index, education, primary language, mean COF, use of slip-resistant shoes, and restaurant chain, each 1-point increase in mean restaurant-level perception of slipperiness (4-point scale) was associated with a 2.71 times increase in the rate of slipping (95% CI 1.25 to 5.87). Results were similar for area-level perception within the restaurant (rate ratios (RR) 2.92, 95% CI 2.41 to 3.54). Conclusions Perceptions of slipperiness and the subsequent rate of slipping were strongly associated. These findings suggest that safety professionals, risk managers and employers could use aggregated worker perceptions of slipperiness to identify slipping hazards and, potentially, to assess intervention effectiveness.

Description: Objective Concerns over occupational exposures to blood-borne viruses resulted in increased protective glove use; consequentially latex allergy became a hazard for some occupational groups. Interventions aimed at managing this problem included substitution measures (eg, non-powdered/non-latex gloves), but such changes may not occur simultaneously across occupational sectors. This study evaluated whether the incidence of occupational dermatoses fell after interventions aiming to reduce exposure to ‘latex and rubber glove allergens’ (‘latex’) were introduced, and whether these interventions were more effective for healthcare workers (HCWs), compared with non-HCWs. Methods Incidence rate ratios (IRRs) comparing cases reported to EPIDERM (a UK-wide surveillance scheme) during post versus pre-intervention periods were calculated, both where ‘latex’ was cited and for cases associated with other exposures (‘controls’). Results Among HCWs, cases of contact urticaria and allergic contact dermatitis (ACD) where ‘latex’ was cited showed significant downward trends post-intervention, with IRRs of 0.72, 95% CI; 0.52 to 1.00 and 0.47, 95% CI; 0.35 to 0.64 respectively. For HCWs, this fall in ‘latex’ associated ACD was significantly greater (p=0.02) than for other exposures (‘controls’) IRR=0.85, 95% CI; 0.57 to 1.28, and greater than that among non-HCWs (IRR 0.75, 95% CI; 0.61 to 0.93). Increases over time were seen for irritant contact dermatitis (ICD) reporting for HCWs, both for cases associated with ‘latex’ (IRR 1.47, 95% CI: 1.02 to 2.13) and for other exposures (‘controls’) IRR 1.36, 95% CI 1.06 to 1.76, but not for non-HCWs. Conclusions A reduction in overall ACD, particularly in HCWs, coincided with interventions aimed at managing workplace contact dermatoses associated with ‘latex’ exposure. A coincidental rise in ICD reporting is also important, both for hand care and for infection control strategies.

Description: Diesel exhausts are common both in occupational and non-occupational settings. They are considered as a cause of lung cancer, and International Agency for Research on Cancer (IARC) recently upgraded the evidence from probable to sufficient ( http://www.iarc.fr ). However, the opinions about the health effects are not consistent. A recent review concluded that the published studies lack consistency. 1 A pooled analysis of case-control studies and a study of miners were interpreted as consistent with an increased risk but questioned by others. 2 3 Some of the studies of lung cancer risk from diesel exhaust are evaluating the risk in drivers of vehicles like buses, trains or heavy equipment operators. 1 2 4 The possibility to find an association in epidemiological study depends on the contrast in exposure between groups. We used nitrous dioxide as a marker of diesel exhausts...

Description: Objectives Reliable retrospective exposure assessment continues to be a challenge in most population-based studies. Several methodologies exist for estimating exposures retrospectively, of which case-by-case expert assessment and job-exposure matrices (JEMs) are commonly used. This study evaluated the reliability of exposure estimates for selected carcinogens obtained through three JEMs by comparing the estimates with case-by-case expert assessment within the Netherlands Cohort Study (NLCS). Methods The NLCS includes 58 279 men aged 55–69 years at enrolment in 1986. For a subcohort of these men (n=1630), expert assessment is available for exposure to asbestos, polycyclic aromatic hydrocarbons (PAHs) and welding fumes. Reliability of the different JEMs (DOMJEM (asbestos, PAHs), FINJEM (asbestos, PAHs and welding fumes) and Asbestos JEM (asbestos) was determined by assessing the agreement between these JEMs and the expert assessment. Results Expert assessment revealed the lowest prevalence of exposure for all three exposures (asbestos 9.3%; PAHs 5.3%; welding fumes 11.7%). The DOMJEM showed the highest level of agreement with the expert assessment for asbestos and PAHs (s=0.29 and 0.42, respectively), closely followed by the FINJEM. For welding fumes, concordance between the expert assessment and FINJEM was high (=0.70). The Asbestos JEM showed poor agreement with the expert asbestos assessment (=0.10). Conclusions This study shows case-by-case expert assessment to result in the lowest prevalence of occupational exposure in the NLCS. Furthermore, the DOMJEM and FINJEM proved to be rather similar in agreement when compared with the expert assessment. The Asbestos JEM appeared to be less appropriate for use in the NLCS.

Description: Objectives An earlier investigation raised concern that some cancer cases might be linked to work at a semiconductor manufacturing plant. The aim of this study was to describe an update of the cancer incidence and mortality of these workers and assess whether workplace exposures contributed to any increased risk of selected cancers. Methods Standardised mortality ratios and standardised incidence ratios were calculated for cancer site groups of a priori interest in a cohort previously flagged against the National Health Service Central Register, with follow-up extended to the 2007 for deaths and 2006 for cancer registrations. Cases of female breast cancer, lung and stomach cancer, and male brain cancer, and a random sample of control subjects individually age-matched to the breast cancer cases, were identified from within the cohort dataset and invited to participate via General Practitioners. Exposures were estimated using a job exposure matrix developed from a historical hygiene assessment and assigned to job histories obtained from personal interview of subjects (or proxies). Results Though the findings were uncertain, there were no excesses of mortality or cancer incidence, either overall or for specific cancer sites, suggestive of a workplace effect. Logistic regression analyses comparing 20 cases of breast cancer with 83 matched controls showed no consistent evidence of any relationship with occupational exposures. Assessment of commonalities of workplace exposures among case sets for other cancer types was limited by the small numbers. Conclusions These results do not support earlier concerns about occupational cancer risks among this cohort.

Description: Objectives Professional judgment is necessary to assess occupational exposure in population-based case–control studies; however, the assessments lack transparency and are time-consuming to perform. To improve transparency and efficiency, we systematically applied decision rules to questionnaire responses to assess diesel exhaust exposure in the population-based case–control New England Bladder Cancer Study. Methods 2631 participants reported 14 983 jobs; 2749 jobs were administered questionnaires (‘modules’) with diesel-relevant questions. We applied decision rules to assign exposure metrics based either on the occupational history (OH) responses (OH estimates) or on the module responses (module estimates); we then combined the separate OH and module estimates (OH/module estimates). Each job was also reviewed individually to assign exposure (one-by-one review estimates). We evaluated the agreement between the OH, OH/module and one-by-one review estimates. Results The proportion of exposed jobs was 20–25% for all jobs, depending on approach, and 54–60% for jobs with diesel-relevant modules. The OH/module and one-by-one review estimates had moderately high agreement for all jobs ( w =0.68–0.81) and for jobs with diesel-relevant modules ( w =0.62–0.78) for the probability, intensity and frequency metrics. For exposed subjects, the Spearman correlation statistic was 0.72 between the cumulative OH/module and one-by-one review estimates. Conclusions The agreement seen here may represent an upper level of agreement because the algorithm and one-by-one review estimates were not fully independent. This study shows that applying decision-based rules can reproduce a one-by-one review, increase transparency and efficiency, and provide a mechanism to replicate exposure decisions in other studies.

Description: Objective To investigate the association between serum perfluorooctanoic acid (PFOA) concentration and cardiovascular disease, as measured by homocysteine level and blood pressure in a representative sample of US adults. Methods A cross-sectional study of 2934 adults (≥20 years) who participated in the 2003–2004 and 2005–2006 National Health and Nutrition Examination Survey and had detectable levels of PFOA in their serum. The health effects analysed as potentially associated with PFOA exposure included homocysteine level and blood pressure. Results The geometric mean value (95% CI) of the study participants' serum PFOA concentration was 4.00 μg/l (95% CI 3.86 to 4.13). The homocysteine and systolic blood pressure were shown to increase significantly with an increase in the log-transformed serum PFOA concentration, after adjusting for potential confounding variables. Adjusted ORs comparing participants at the 80th versus the 20th percentiles were 2.62 for hypertension (95% CI 2.09 to 3.14), and a positive association was also evident in models based on quartiles or based on restricted cubic splines. Conclusion These findings suggest that background exposure to PFOA may continue a risk factor for the development of cardiovascular diseases.