1,3-Butadiene has been assessed as a Priority Substance under the Canadian Environmental Protection Act. The general population in Canada is exposed to 1,3-butadiene primarily through ambient air. Inhaled 1,3-butadiene is carcinogenic in both mice and rats, inducing tumors at multiple sites at all concentrations tested in all identified studies. In addition, 1,3-butadiene is genotoxic in both somatic and germ cells of rodents. It also induces adverse effects in the reproductive organs of female mice at relatively low concentrations. The greater sensitivity in mice than in rats to induction of these effects by 1,3-butadiene is likely related to species differences in metabolism to active epoxide metabolites. Exposure to 1,3-butadiene in the occupational environment has been associated with the induction of leukemia; there is also some limited evidence that 1,3-butadiene is genotoxic in exposed workers. Therefore, in view of the weight of evidence of available epidemiological and toxicological data, 1,3-butadiene is considered highly likely to be carcinogenic, and likely to be genotoxic, in humans. Estimates of the potency of butadiene to induce cancer have been derived on the basis of both epidemiological investigation and bioassays in mice and rats. Potencies to induce ovarian effects have been estimated on the basis of studies in mice. Uncertainties have been delineated, and, while there are clear species differences in metabolism, estimates of potency to induce effects are considered justifiably conservative in view of the likely variability in metabolism across the population related to genetic polymorphism for enzymes for the critical metabolic pathway.
Ten cases of angiosarcoma of the liver among vinyl chloride workers from a plant in Shawinigan, Québec, are reported. The author insist mostly on the occupational history of these workers and on the morphologic description of the lesions. A pathogenic hypothesis is submitted.
BACKGROUND: Previous studies of the risk of heart disease after shift work reached different estimates and review authors disagree about the validity of some of the studies. A cross sectional study showed that shift workers had a higher prevalence of nearly every unfavourable work environment factor investigated. Conflicts at work and low decision latitude were more frequent among shift workers, and all-day walking or standing work and part-time jobs were more often found among female shift workers. OBJECTIVES: To estimate the risk of circulatory disease in a prospective follow up of a representative sample of gainfully employed Danes, considering known or suspected confounding factors. METHODS: A cohort of 5517 people who were gainfully employed in 1990 were followed up for all hospital treatments due to circulatory diseases (390-458, ICD-8; I00-I99, ICD-10) from 1991 to 2002 inclusive. A log linear Poisson regression model was applied to control confounding factors and calculate the relative risk for 927 men and women working nights, evenings, or other non-day shifts compared to 4579 day workers. RESULTS: Non-day workers compared to day workers had a relative risk (RR) for all circulatory diseases of 1.31 (95% CI 1.06-1.63). Without control for BMI and smoking, the RR estimate was 1.33 (95% CI 1.07-1.65). For a subgroup of workers with at least three years' seniority, the RR was 1.40 (95% CI 1.09-1.81). The population based aetiological fraction of shift work was estimated to 5%. CONCLUSION: This study adds to a growing body of evidence suggesting that shift work carries an excess risk of circulatory diseases.
The purpose of this study was to describe the rate and distribution of treatment visits provided in an on-site, automotive plant, physiotherapy clinic over a 13-year period.
A retrospective cohort study was conducted using data collected at an on-site physiotherapy clinic (1990-2002, 65,977 visits; n = 2,636 workers).
The average age of workers was 43 +/- 9 years; most remained at work (85%) when treated. Disorders most commonly affected the shoulder, lumbar, and cervical regions; the median number of visits for these was 7, 6, and 5, respectively. Elbow disorders occurred commonly only for work-related complaints and required a median of eight visits. Rate of utilization was higher for women, with 47% of the plant's female workers attending physiotherapy in 1 year. Women had higher rates of cervical spine (12 vs. 22%) and wrist (5 vs. 10%) disorders. The two most common causes of injury reported by workers with an industrial injury were "frank injury arising out of normal employment" (51%) and "gradual onset/no frank injury" (37%). The diagnosis most often reported by the physiotherapist after initial assessment was "strain" which was similar for both industrial (43%) and non-industrial (49%) injuries. The six main departments in this automotive plant account for 93% of all industrial injuries reported. Final Assembly accounted for the largest number and highest rate of injury, although shift variability was noted in utilization rates (13 vs. 26%), despite the same tasks, shift schedules, and demographics. Although there was no control group, the number of visits to discharge was lower than reported in the literature for off-site physical therapy; there was a large reduction in claims (441-275) following introduction of the clinic and reduced duration/costs of lost time were identified by the employer as a rationale to continue and enhance the service over time.
On-site physiotherapy services can provide early, cost-effective management of WRMSD in the automotive sector. Service utilization reflects the influence of gender, job task, and shift-dynamics on rates and location of WRMSD.
OBJECTIVE: To estimate the hazard ratio for disability pension associated with shift work. METHODS: Cohorts of shift and day workers were identified in three waves of the Danish Work Environment Cohort Study and followed up for incidence of disability pension in a national register of social transfer payment. A total of 3980 female and 4025 male employees were included in the cohorts. Information about shift work status, age, smoking habits, body mass index and ergonomic work environment were updated according to responses in subsequent waves of the survey when possible. Respondents reporting shift work were classified as shift workers in the following waves as well. Respondents were followed in the register from the time of first interview and were censored at the time of their 60th birthday, emigration, death or end of follow-up (18 June 2006). The authors used the Cox proportional hazards model to estimate hazard ratios for incidence of disability pension and 95% confidence intervals. RESULTS: The authors observed 253 new disability pensions among women and 173 among men during 56 903 and 57 886 person-years at risk respectively, Among women, shift work predicted disability after adjustment for age, general health and socioeconomic status HR 1.39 (95% CI 1.07 to 1.82). After further adjustment for body mass index, smoking habits, socioeconomic status and ergonomic exposures the association remained statistically significant HR 1.34 (95% CI 1.02 to 1.75). Shift work was not associated with disability among men. CONCLUSION: Shift work might be moderately associated with disability pension among women; however, more powerful studies are needed to establish the possible association.
Sverdlovsk Regional Occupational Center based on the Research Institute has highly qualified staff, incorporates ambulatory department, hospital with modern diagnostic and therapeutic equipment. The Center performs multiple tasks, being an organizational and methodic, diagnostic and occupational examination institution using up-to-date advances in industrial medicine.