Effect of Nutrient Potassium on the Uptake of Cæsium-137 and Potassium and on Discrimination Factor

Abstract

PREDICTIONS of the potential hazards from fall-out radioisotopes in man's food chain have often been based on ion-pair relationships^1,2. For example, because of close chemical similarities between strontium and calcium, the transfer of strontium-90 through biological materials has been correlated with calcium. The ratio of strontium-90/calcium of the tissue to the same ratio in the substrate, that is, strontium-90/calcium(tissue)/strontium-90/calcium(substrate), has been termed by Comar the observed ratio³. More recently cæsium-137 hazards have been considered in terms of cæsium-137/potassium ratios. Certain applications of these ratios have been criticized by Kornberg⁴, and the conditions necessary for their valid application in hazard assessment discussed. This report presents results which demonstrate the absence of any consistent relationship between the accumulation of cæsium and potassium in bean plants, and further demonstrates the limited applicability of cæsium-137/potassium ratios in hazard predictions.