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: 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: 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.

Description: Objectives The authors had a unique opportunity to study the early impacts of occupational and recreational exposures on the development of noise-induced hearing loss (NIHL) in a cohort of 392 young workers. The objectives of this study were to estimate strength of associations between occupational and recreational exposures and occurrence of early-stage NIHL and to determine the extent to which relationships between specific noise exposures and early-stage NIHL were mitigated through the use of hearing protection. Methods Participants were young adults who agreed to participate in a follow-up of a randomised controlled trial. While the follow-up study was designed to observe long-term effects (up to 16 years) of a hearing conservation intervention for high school students, it also provided opportunity to study the potential aetiology of NIHL in this worker cohort. Study data were collected via exposure history questionnaires and clinical audiometric examinations. Results Over the 16-year study period, the authors documented changes to hearing acuity that exceeded 15 dB at high frequencies in 42.8% of men and 27.7% of women. Analyses of risk factors for NIHL were limited to men, who comprised 68% of the cohort, and showed that risks increased in association with higher levels of the most common recreational and occupational noise sources, as well as chemical exposures with ototoxic potential. Use of hearing protection and other safety measures, although not universal and sometimes modest, appeared to offer some protection. Conclusions Early-stage NIHL can be detected in young workers by measuring high-frequency changes in hearing acuity. Hearing conservation programmes should focus on a broader range of exposures, whether in occupational or non-occupational settings. Priority exposures include gunshots, chainsaws, power tools, smoking and potentially some chemical exposures.