[Estimation of UV light dose concomitant to ionizing irradiation].

A simple approach to the estimation of UV light dose produced by Cerenkov emission and concomitant irradiation of biological objects with ionizing radiation was suggested. The approach was applied to determine the dependencies of UV light dose (equivalent to 254 nm) accompanied 100 Gy of ionizing radiation on the energy of sparsely ionizing radiation and on the volume of the exposed Escherichia coli cells suspension. It was revealed that the relative excitation contribution to the total lethal effect and the value of the UV dose was greatly increased with an increase in the energy of ionizing radiation and the volume of irradiated suspensions. It is concluded that these observations are in agreement with the supposition that Cerenkov emission is responsible for the production of UV light damage and the phenomenon of photoreacrivation observed after ionizing exposure of bacterial and yeast cells hypersensitive to UV light. A possible synergistic interaction of the damages produced by ionizations and excitations as well as a probable participation of UV component of ionizing radiation in the mechanism of radiation hormesis and adaptive response observed after ionizing radiation exposure is discussed.