[Risk factor asbestos (author's transl)].

In the G.D.R. asbestos is used at a large industrial scale. The material is of interest for oncologists and industrial hygienists due to its fibrogenic and cancerogenic potencies. Both carcinomas of the respiratory organs and the rare malignant mesotheliomas are accepted as occupational diseases due to asbestos. In a retrospective study 915 cases of malignant mesotheliomas covered by the National Cancer Registry over a period of 6 years--all histologically established--were analysed. 36.7% originated from occupational handling of asbestos, 0.8% by non-occupational asbestos contacts. In another 9.1% of the cases asbestos may have been the underlying cause. 33.7% have had no asbestos contact; for 19.7% the data available were insufficient. Among the asbestos-containing materials used packing and insulating materials were prevailing in 47.7%, asbestos-containing talc in 19.6%. In 6.9% of the cases mesothelioma affection was due to wearing fire protective clothing. Different duration of exposure and especially long latency periods demonstrates difficulties interpreting the results concerning the relation between working conditions and illness. Primary (technical) prevention by reduction of asbestos dust emission, limited use of asbestos and lifelong monitoring of asbestos workers are necessary to reduce the tumour risk.