Contribution to assessment of malignant tumour risks in ore miners due to radiation exposure

The paper presents the results of a parallel examination of the incidence of malignant tumours in two groups from the same plant with a small difference in the numbers of the examined persons. The mean annual number of the miners (including retired persons) was 463 and there were 453 non-miners. In the time period of 28 years (1954-1981) there were on the whole 127 cases of malignant tumours, 94 in the miners, 33 in non-miners. The incidence of malignant lung tumours in the miners proved to be several times higher than in the non-miners, in agreement with the results by other authors. Moreover, in the miners there was also an increased incidence of malignant tumours of the gastrointestinal tract (stomach, intestine, colon and rectum). The severity of radiation exposure in the previous periods is confirmed by measurements from the years 1969 and 1972 when the concentrations of radioactive substances in the air and water exceeded the maximum permissible concentration two- to six-fold. (author)