Global Asbestos Congress 2004

Use of Exposure Information and Nordic Incidence Data to Predict the Expected Decline in the Mesothelioma Incidence

Sverre Langard
Rikshospitalet University Hospital, Centre for Occupational and Environmental Medicine, Oslo, Norway
[paper submitted—author could not attend]

In Norway and neighbouring countries the use of asbestos for insulation was reduced to a minimum during the second half of the 1970s and the early 1980s. This decline in the use resulted to a great extent from comprehensive information to workers on the untoward effects to health of asbestos exposure. The information to workers was supported by introduction of personal protection when handling asbestos, as well as prohibition of use in the early 1980s.

Depending on the duration of the development time for mesotheliomas, between first exposure to asbestos fibers and occurrence of the tumor, a declined incidence might be expected 20-45 years subsequent to interruption of asbestos exposure.

All the Nordic countries have cancer registers that contain information on all new cancer cases over the past 40-60 years. Hence, the mesothelioma incidence in these registers might be useful for observing the long-term outcome effects from interrupted exposure to asbestos among workers that took place about 25 years ago in Norway and other Nordic countries. About 25 years after interruption of asbestos exposure in Nordic countries, a decline in the incidence of mesothelioma seems to be lacking, and possible explanations for the lack of decline will be discussed. A prediction of the expected decline will be attempted.