Cancer mortality in the exposed population of the Techa River area

Radioactive contamination and population exposure resulted from the operation of the Mayak complex, a plutonium-production facility in the Southern Urals. The highest doses were received by residents along the Techa River into which wastes from the complex leaked between 1949 and 1956. A registry was established containing data on 29,528 persons and information on deaths (9426 by 1982; 6439 death certificates) and cancer cases. Six groups differing in exposure levels were set up for the cohort analysis. The range of doses to red bone marrow in these cohorts was from 1.64 to 0.176 Sv. Leukaemia and solid cancer mortality over the 33-year period of exposure was analysed. The age-standardized total cancer mortality rates and their 95% confidence intervals account for 140 (131-150) and 105 (101-109) per 100,000 person-years for the entire exposed and entire control population. The analysis of cancer mortality in different organs has shown increased rates for leukaemia in one exposed group and for cancers of the uterine corpus and cervix in the other exposed group, as compared to the identical control groups.