The mankind coexists with a small dosed irradiation during the whole period of its development. So called small or weak doses of irradiation are meant. Since the XX century the natural sources of radiation have been added by the factors of anthropological origin connected with a technical progress in the nuclear industry. In the present paper the authors are trying to outline some details of the formation and influence of the small dosed irradiation. A short review of a modern radioecological contamination map of Ukraine is also proposed.
