The development in incidence rates and survival in Denmark, and the rate-ratio in selected municipalities that had industries utilizing asbestos was studied in 1865 cases of malignant mesothelioma identified in the Danish Cancer Registry 1943-1992. For men a steady increase in the incidence to 1.6 per 100,000 personyears in 1992 was found, while the rate for women decreased to 0.28 per 100,000 personyears. Age-specific incidence rates were highest for the older age-groups. An unexplained difference in the distribution of pleural and peritoneal cancers was seen between men and women. The average survival was 6.9 months for men and 7.8 for women and had not changed during the period of observation. The average rate-ratio for the selected municipalities was 1.97 (95% confidence intervals: 1.73-2.24) for men and 1.35 (1.08-1.69) for women. Improvements in working conditions in terms of minimizing asbestos exposure were introduced in 1980. Considering the latency period from exposure to diagnosis of 25-30 years, the impact of this measure on the rate of incidence cannot be expected before the year 2000.
