Quantitative evaluation of the combined effect of external gamma radiation and internal alpha radiation from 239Pu based on biochemical indices of the organs of the rat immune system

The combined effect of external gamma-radiation (137Cs, 103-26 mC/kg) and incorporated alpha-radiation (239Pu nitrate, 93-9.3 kBq/kg body mass) was estimated by changes in the nucleic acid metabolism and the number of cells in rat thymus, spleen and bone marrow. The data obtained were processed using a model of multiplicate action of the factors which is equivalent, in the case of low effects, to a traditional model of additive effects. The results of the combined action of the two factors may be estimated by the coefficient of the interaction and the coefficient of the enhancement of the effects.