Radiological investigation, analysis and assessment of pollution from mining operations - health effects

Between 1946 and 1990 about 220,000 tons of uranium were produced in Saxonia and Thuringia by about 400,000 workers of the SAG/SDAG Wismut. Therefore, Eastern Germany became one of the largest producer of uranium of the world at that time. To investigate effects of exposure to radon and other hazardous substances during uranium mining, the German Uranium Miners Study is carried out, one of the largest studies on that topic. For the 'Pathology' sub study, the archives of the Department of the Central Institute of Pathology (ZPI) of the Wismut were opened for scientific investigations and in 1993 transferred to the German Cancer Research Centre Heidelberg. The archives contain material of about 29,000 autopsies. 26,531 autopsy cases of deceased between 1957 and 1990 and older than 15 years at time of death, were suitable for further evaluation. From these, 16,369 men and 1,114 women could be identified as uranium miners. The remaining autopsy cases were of deceased belonging to the ''normal'' population of the mining area, persons not identified as Wismut workers OR coal miners not employed by Wismut. Based on a subgroup of 19,271 men, the effects of exposure to mining pollutants, such as radon, uranium-, arsenium- and quartz containing dusts, on the development of tumour and other diseases were investigated. The analysed exposure groups include 12,926 uranium miners of the SAG/SDAG Wismut (WLM > 0; group 3), 1,987 control cases of not exposed Wismut workers (WLM = 0; group 2), and 4,358 control cases most likely never employed by Wismut (group 1). Mean age at the start of exposure is 33.5 years, mean duration of exposure is 11.8 years and mean age at death is 62.7 years. Mean radon and radon daughter exposure is 725 WLM with a maximum of more than 3,000 WLM. Mean exposure to longlived radionuclides (LRN) is 9.7 kBq (U-238) with a maximum of more than 50 kBq. 5,270 autopsy cases with possible established primary malignant lung tumours were re-examined by three reference pathologists, serving as a basis for further work history evaluation. The data were analysed as case-control study with death from cancer sites of interest as cases and death from cardiovascular diseases as controls using logistic regression under the assumption that the exposure distribution in the reference deaths was the same as in the source population and the assignment to autopsy was independent from radiation exposure level