We examined the mortality experience of 3,479 male Dow Canada employees who were employed at Sarnia Division for at least 12 continuous months during the years 1945 through 1983, utilizing the Canadian Mortality Data Base maintained by Statistics Canada, covering 1950-1984. We analyzed cause-specific mortality using male, age and calendar-year-adjusted death rates for Canada and Ontario. Total mortality was significantly below expectation whether the entire follow-up period (240 observed vs. 366.9 expected) or a 15-year latency period (171 observed vs. 290.4 expected) was considered. Statistically significant fewer observed deaths were found for all respiratory cancer, cancer of the bronchus and lung, circulatory disease, ischemic heart disease, cerebrovascular disease, digestive disease, cirrhosis and other liver disease and deaths due to accidents, poisonings and violence. The observation of three deaths due to mesothelioma, a rare cancer often associated with asbestos exposure, was a significant finding as was a statistically significant elevation of observed deaths in the category "other forms of heart disease".
The association between physical workload and low back pain clouded by the "healthy worker" effect: population-based cross-sectional and 5-year prospective questionnaire study.
STUDY DESIGN: A population-based cross-sectional and 5-year prospective questionnaire study. OBJECTIVE: To investigate self-reported physical workload as a risk factor for low back pain. SUMMARY OF BACKGROUND DATA: Both physical and psychosocial workplace factors are considered risk factors for low back pain. However, today no consensus has been reached regarding the exact role of these factors in the genesis of low back pain. METHODS: Questionnaire data were collected at baseline for 1397 (and after 5 years for 1163) men and women aged 31--50 years at baseline. Low back pain ("any low back pain within the past year," "low back pain 30 days in total during the past year") was analyzed in relation to physical workload (sedentary, light physical, and heavy physical work) using logistic regression and controlling for age, gender, and social group. The proportions of workers changing between the workload groups over the 5-year period were analyzed in relation to low back pain status. RESULTS: At baseline no statistically significant differences in low back pain outcomes were found for workers exposed to sedentary, light physical, or heavy physical work. This was true for all age, gender, and social groups. At follow-up there was a statistically significant dose-response association between any low back pain and longstanding low back pain within the past year and increasing physical workload at baseline also after controlling for age, gender, and social group. Subjects with heavy physical workload at baseline changed statistically significantly more often to sedentary work if they experienced low back pain for more than 30 days out of the past year. CONCLUSIONS: Having a sedentary job might have a protective or neutral effect in relation to low back pain, whereas having a heavy physical job constitutes a significant risk factor. Because of migration between exposure groups (the "healthy-worker" effect), longitudinal studies are necessary for investigating the associations between physical workload and low back pain.
AIMS: The Nordic countries have relatively equal employment participation between men and women, but some differences between countries exist in labour market participation. The aim was to examine the association between employment status and health among women and men in Denmark, Finland, Norway, and Sweden, and analyse whether this association is modified by marital status and parental status. METHODS: The data come from nationally representative cross-sectional surveys carried out in Denmark (n = 2,209), Finland (n = 4,604), Norway (n = 1,844) and Sweden (n = 5,360) in 1994-95. Women and men aged 25-49 were included. Employment status was categorized into full-time employed, part-time employed, unemployed, and housewives among women and into employed and unemployed among men. Health was measured by perceived health and limiting longstanding illness. Logistic regression analysis was used, adjusting for age and education. Marital status and parental status were analysed as modifying factors. RESULTS: The non-employed were more likely to report perceived health as below good and limiting longstanding illness than the employed among both women and men. The association between employment status and perceived health remained unchanged when marital status and parental status were adjusted for among all men and Finnish women, but the association was slightly strengthened among Danish and Swedish women, with the housewives becoming more likely to report ill health than employed women. The association between employment status and limiting longstanding illness was slightly strengthened among women, and slightly weakened among Norwegian men when marital and parental status were adjusted for. CONCLUSIONS: Non-employment was associated with poorer health in all countries, although there are differences in the employment patterns between the countries. Among women marital status and parental status showed a modest or no influence on the association between employment status and health. Among men there was no such influence.
The National Institute for Occupational Safety and Health (NIOSH) published a report in 1995 suggesting the possibility of increased incidence of testicular cancer, leukemia, and cancers of the brain, eye, and skin among police officers working with traffic radar. NIOSH recommended epidemiologic study of the issue. This report presents the results of a retrospective cohort cancer incidence study among 22,197 officers employed by 83 Ontario police departments. The standardized incidence ration (SIR) for all tumors sites was 0.9% (95% confidence interval [CI] = 0.83-0.98). There was an increased incidence of testicular cancer (SIR = 1.3, 90% CI = 0.9-1.8) and melanoma skin cancer (SIR = 1.45, 90% CI = 1.1-1.9). These anatomical sites might absorb energy from radar units, but at this time the author has no information about individual exposures to radar emissions, and it is not possible to draw etiologic conclusions. Nested case-control studies are planned to assess individual radar exposures.
A cohort mortality study was undertaken of forestry workers at a public electrical utility who had worked for six months or more during 1950-82 and who were routinely exposed to herbicides including phenoxy acids. A total of 1222 men with 25 274 years at risk experienced 80 deaths. Ascertainment of vital state at the end of follow up was 95.5%. The male population of the province (Ontario) was used as the reference group. Overall, no excess mortality was found in this cohort relative to the reference population. A statistically significant increase in deaths occurred, however, due to suicide (SMR = 210, 95% confidence interval, 95% CI 105-376) for the cohort as a whole. No deaths were seen due to cancers such as soft tissue sarcoma and non-Hodgkin's lymphoma that have been cited by other authors as being associated with exposure to phenoxy acid herbicides. Although the cohort is not large, the absence of deaths due to these cancers is consistent with findings from other studies with sufficient numbers to allow examination of specific risks. The cohort is still young, however, and at the end of follow up most had not reached an age when increased incidence of cancer would normally be expected.
The mortality in a reference population for specific occupations was evaluated by means of occupational studies of different designs. The data originated from a random sample of 19,862 persons from among the total Finnish population. The age standardized mortality for those who had at any time belonged to the active work force in Finland was estimated to be 10% less than the average mortality for the total population. The difference was 20% if the currently active work force was compared with the total population. The standardized mortality ratio was 70% for those who had stayed for less than 10 years within the same occupational category and 80% for those with more than 10 years' work within the same occupational category. The expected mortality varied up to 50% depending on the broad occupational category and on the occupational history when compared with the total mortality in Finland.
STUDY OBJECTIVE: To describe the association between labour market status and death by suicide with focus on admission with a psychiatric disorder. DESIGN: Nested case-control study. Data from routine registers. SETTING: Entire Danish population. PARTICIPANTS: 9011 people aged 25-60 years who committed suicide during 1982-1997 and 180 220 matched controls. MAIN RESULTS: In the general population, not being fully employed is associated with a twofold to threefold increased relative risk of death by suicide, compared with being fully employed. In contrast, fully employed people who have been first admitted to a psychiatric hospital within the past year are at increased suicide risk. Patients who are unemployed, social benefits recipients, disability pensioners, or otherwise marginalised on the labour market have a suicide risk of 0.60 (95% CI: 0.46 to 0.78), 0.41 (0.23 to 0.74), 0.70 (0.45 to 1.08), and 0.86 (0.53 to 1.41), respectively. Although a similar risk decrease is found in women, men, people younger than 30 years, people older than 45 years, and in people who become unemployed, the reversed effect attenuates with time since admission, and little association is seen when a marginal structural model is applied. CONCLUSIONS: Although the results show an increased suicide mortality associated with unemployment and labour market marginalisation in the general population, the results suggest little or an inverse association between unemployment and suicide in people with psychiatric illness. The associations seen suggest the need to consider healthy worker selection effects when studying the causal pathway from unemployment and psychiatric illness to suicide.
This study estimated the effects of changes in unemployment rates of occupation groups on changes in mortality in a period of increasing unemployment.
Census records for all 20- to 64-year-old economically active Finnish men in 1985 were linked to information on unemployment and deaths in 1987 through 1993.
Change in mortality was similar in occupation groups in which unemployment rates increased at a different pace. These relationships were similar for all age groups and for mortality from diseases as well as accidents and violence.
Unemployment does not seem to cause mortality in the short term. Excess mortality rates among unemployed individuals observed in previous studies may have been due in part to selection.
To investigate external-cause mortality among 21 609 Norwegian male military peacekeepers deployed to Lebanon during 1978-1998.
The cohort was followed from the 1st day of deployment through 2013, and mortality during deployment and post discharge was assessed using SMRs calculated from national rates in Norway. Poisson regression was used to see the effect of high-conflict versus low-conflict exposure.
For the total cohort, external-cause mortality was within expected values during deployment (SMR=0.80) and post discharge (SMR=1.05). In the low-conflict exposure group, a lower mortality from all external causes (SMR=0.77), transport accidents (SMR=0.55) and accidental poisoning (SMR=0.53) was seen. The high-conflict exposure group showed an elevated mortality from all external causes (SMR=1.20), transport accidents (SMR=1.51) and suicide (SMR=1.30), but these risks were elevated only during the first 5 years after discharge. This group also showed elevated mortality from all external causes (rate ratio, RR=1.49), and for transport accidents (RR=3.30) when compared with the low-conflict exposure group.
Overall external-cause mortality among our peacekeepers was equal to national rates during deployment and post discharge. High-conflict exposure was associated with elevated mortality from all external causes, transport accidents and suicide during the first 5 years after discharge from service.
