Special effects of low doses and lifespan of irradiated daphnids

Abstract

Specific species-unspecific effects of low-radiation doses were studied. These effects are fundamentally different from stochastic effects. They have a mass character and full appearance at low doses for the species. The characteristic manifestation of the studied type of effect is a steady increase in the probability of cell death. Earlier in the model experiments on the crustacean Daphnia magna it was shown that the studied type of damage at low doses (0.1, 1 and 20 Gy, LD 50/30 = 100 Gy) can develop a dose-independent increased mortality of irradiated daphnids. The present study shows that the studied type of effect can lead to reduced life expectancy of daphnids at a lowest dose of 0.1 Gy. Owing to the fact that the studied effect is observed at organism level, it is assumed that it could affect the life expectancy in mammals (including humans) even at relatively low doses of radiation.