A violation of free-radical reactions has been found by the method of free-radical copolymerization in the two groups of Daphnia magna exposed to 100 and 1000 mGy of gamma-rays and their non-exposed first generation progeny. The method is based on a quantitative radiometric registration of the polymerization process that develops in the cells of a multicellular organism in tissue in proportion to the existing number of free radicals. The fact of the increased level of free radicals may be indicative of the hereditary transgenerational effect and the cause of lower survival of Daphnia in both generations. However, the effect of a reduced survival rate does not persist in the second generation, which can be explained by the effect of radiation on the embryos of the first generation after acute irradiation of parents.

A highly sensitive express method has been proposed for assessment of embryotoxicity of the aqueous medium under the conditions of anthropogenic pollution. Amphibian embryos were used as test objects for estimating the level of free radical process during adaptation stress. The method can be used under the field conditions and is proposed as a part of ecological monitoring of natural waters.