Doses due to contamination of the Techa river by the Mayak nuclear complex in Russia

Environmental radioactive releases from the “Mayak” military nuclear installation (located in Russia, in southern Urals) have been very high, especially in the early fifties. In particular, releases of Cs-137 and Sr-90 into the Techa river, in the Chelyabinsk region, were extremely high in the years 1950 and 1951. The paper analyses the reasons of those releases, and computes doses to population living in the area. The inhabitants of the village of Metlino, 7 km downstream the release point, are identified as the critical group: the committed dose equivalents for them as so high that, besides a relevant increase of frequency of stochastic radiation effects (leukaemia and other tumors), a new type of disorder (Chronic Radiation Sickness) has been diagnosed in the inhabitants of the area.