M9.1 EPIDEMIOLOGICAL ESTIMATE OF THE PROPORTION OF FATALITIES RELATED TO OCCUPATIONAL FACTORS IN FINLAND

M. Nurminen, A. Karjalainen.Department of Epidemiology and Biostatistics, Finnish Institute of Occupational Health, Helsinki, Finland

Objective: To estimate the proportion of annual deaths related to occupational factors in Finland, and consider methodological issues and associated uncertainties.

Methods: Statistics on causes of death, numbers of subjects exposed, and risk ratios obtained from epidemiological literature were used to estimate the population attributable fraction and disease burden for causes of death from work related diseases. Sex, age, and disease specific numbers of deaths were provided by Statistics Finland for 1996. Information on the size of the population, broken down by sex, age, occupation, and industry, was acquired from population censuses. A Finnish job exposure matrix supplied data on the prevalence of exposure for specific agents and the level of exposure among exposed workers.

Results: The attributable fraction of work related mortality in the relevant disease and age categories was estimated to be 7% (10% for men and 2% for women), and for all ages the fraction was 4%. For the main cause of death categories, the attributable fractions became 12% for circulatory system diseases, 8% for malignant neoplasms, 4% for respiratory system diseases, 4% for mental disorders, 3% for nervous system diseases, and 3% each for accidents and violence. The following estimates were obtained for specific important diseases: 24% for lung cancer, 17% for ischaemic heart disease, 12% for chronic obstructive pulmonary disease, and 11% for stroke. Based on these fractions, the total number of work related deaths that occurred in Finland in 1996 was calculated to be on the order of 1800 (employed workforce 2.1 million); 86% were men.

Conclusions: High-quality epidemiological studies and national survey data are essential for obtaining reliable estimates of the proportion of deaths attributable to occupational factors. The magnitude of work-related mortality is an insufficiently recognised contributor to the total mortality in Finland, especially from circulatory diseases and other diseases caused by exposure to agents other than asbestos.

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M9.2 QUANTITATIVE ESTIMATES OF WORK RELATED DEATH, DISEASE, AND INJURY IN NEW ZEALAND

A. ’t Mannetje, N. Pearce.Centre for Public Health Research, Massey University, Wellington, New Zealand

Introduction: New Zealand lacks comprehensive statistics on work related injury and illness, and the impact of adverse work conditions on health is therefore unknown. Here we present quantitative estimates of the annual number of deaths from work related disease and injury in New Zealand, as well as the number of incident cases of work related disease and injury.

Methods: Wherever possible, New Zealand specific data were used, but where adequate national data were lacking, a combination of New Zealand data and extrapolations from other countries was used. For work related injury mortality and incidence, we mainly relied on published studies and reports of the New Zealand Accident Compensation Corporation (ACC). For work related disease mortality we mainly used the probable population attributable fractions from overseas studies together with New Zealand mortality data. For work related disease incidence we used both approaches.

Results: We estimate that in New Zealand about 700–1000 deaths occur annually from work related disease and about 100 deaths from work related injury. About 17 000−20 000 new cases of work-related disease occur annually, and about 200 000 work related accidents result in ACC claims.

Conclusions: Despite their imprecision, these conservative estimates indicate the burden of work related death, disease, and injury in New Zealand. The estimates by sex, industry, and disease types provide useful for policy priorities.

M9.3 THE BURDEN OF WORK RELATED DISORDERS IN AUSTRALIA: A JOURNEY INTO THE UNKNOWN

T. Driscoll.School of Public Health, University of Sydney, Australia

The burden of injury and disease arising from occupational exposures is very difficult to estimate. Most of the reasons for this relate to intrinsic exposure–outcome relationships and/or to the available data sources. Work related disorders commonly described as “diseases” are difficult to identify because there is generally a long period between exposure and the development of symptoms, most diseases that can be caused by work can also have non-occupational causes, and there are usually no distinctive features of diseases caused by work compared with the same disease caused by non-work factors. Therefore, it is very difficult to confidently classify an individual case as work related. The only comprehensive attempt to quantify work related disease in Australia, conducted in the mid-1990s, caused much acrimonious debate when the results were released, and the study remains controversial. The connection between a work exposure and a resultant physical injury is usually straightforward to recognise, because the injury typically follows on directly from the exposure. However, the available data sources do not provide comprehensive coverage, so the identification of these injuries is difficult. Workers’ compensation data do not include a sizeable minority of the workforce in Australia, and do not include many of the injuries in the workforce they do cover. Coverage by occupational health and safety agencies is even patchier. The under-recognition of work related disorders that results from these factors, and lack of familiarity of key parties with the relevant epidemiological techniques, almost certainly leads to the under-recognition of the extent of work related ill health, a consequent lack of resources being allocated to their prevention, and a lack of rational debate about work related disease and injury. The involvement of workers’ compensation legal concerns also hampers objective consideration of the issues involved.