Chemical methods to reduce the radioactive contamination of animals and their products in agricultural ecosystems.

After major nuclear accidents the most effective action to reduce activity levels in animal products is to provide uncontaminated feed or feed diluted with uncontaminated material. However, uncontaminated feed may not always be available in such situations. Therefore other effective procedures are needed to reduce activity levels which must be easy to apply, low in cost and have no side effects on animals and their products. Chemical substances administered as feed additive to housed or grazing animals act by influencing gut absorption or increasing the rate of excretion from blood and organs. The main chemical methods used are: (1) dilution of radionuclides by stable isotopes or analogous inactive elements; and (2) natural or artificial binding agents. In this paper a summary and critical review of the different chemical methods described in the literature is given.