We review the studies of the effects of ionizing radiation on mammalian population dynamics by the methods of mathematical modeling. Most of the attention is given to models that take into account an important aspect of this problem, namely, the relation of radiation mortality to lesion of so-called critical systems. The latter are radiation-sensitive systems performing vital functions. The structure of the models that we review reflects the basic levels where the radiation effects on mammals are formed. The levels are respectively formed by critical systems of an organism, the organism, and the population. This kind of causal model can be used to predict radiobiological effects that are either hard or impossible to test experimentally. It applies primarily to forecasting the impact of a lifelong exposure to weak radiation on the dynamics of population mortality for large mammals, in particular humans. This is a pressing problem because of the need to provide for the radiation safety of large groups of population staying in territories with an increased radiation background and of individuals subjected to chronic irradiation due to their occupation. Employment of the causal models will make it possible to obtain a scientifically justified demographic prognosis and to objectively estimate in this way the real threat of exposure to weak radiation for a man.
