Ten years have elapsed since the Chernobyl accident. The gravest technologically generated accident throughout human history has attracted considerable attention from the whole world community. At the same time, the problem of estimating the total damage to life and health of people exposed to radiation remains very complicated. The negative effects of Chernobyl include a spectrum of factors which may reinforce each other. In particular, to date there are no theoretical models or practical recommendations on estimating the contribution of the social, psychological or emotional factors that surround diseases due to radiation accidents. On the other hand, for maximum effective rehabilitation of the affected population, the impartial determination of the contribution by both radiation and non-radiation components is necessary. Therefore, the continuation of long-standing investigations within the framework of the National and Radiation and Epidemiological Registry along with obtaining new scientific data in the field of radiation epidemiology is of great practical importance in limiting the health consequences of the accident.