Exposure of the population in Russian Federation as a result of the Chernobyl accident

The paper presents results of ten-years field studies of levels and features of external and internal exposure doses for the population of Bryansk, Tula and Oryol regions of Russia affected by the radioactive contamination after the Chernobyl accident. Consideration is given to radio-ecological processes of migration of 131I, 134Cs, 137Cs, 89Sr and 90Sr in the biosphere, their intake and changes in human body for the residents of the contaminated areas with different soil conditions and extent of radiation protection. A model has been developed to account for external exposure of the public to γ-radiation of radionuclides occurring in the environment. The model has been verified against mass-scale measurements of individual absorbed doses by the thermoluminescence method. The paper also dwells on the models for intake of iodine, cesium and strontium radionuclides in human body which have been verified against mass-scale measurements with whole body counter and 90Sr in the section material. Examples are given showing exposure of residents of Russia in 1986 - 1994 and later. The collective dose from thyroid exposure to incorporated 131I in Russia and expected cancer thyroid morbidity has been assessed.