Experience in studying mortality and death causes of the population of 5 Russian regions affected by the Chernobyl NPP accident

The paper presents the investigation results of the mortality causes in the Bryansk, Kaluga, Ryazan, Smolensk and Tula regions affected by the Chernobyl accident during 1991. The defects characteristic for the official statistic of the mortality preventing the accurate estimation of the effect chronic exposure of the population on a person pathology, were detected. It is shown that it is possible to estimate the risk of irradiation only for groups of persons included in the Russian medical-and-dosimetry list, but it covers only separate groups of the population instead of all the population of the contaminated territories