Radioactive Strontium and Caesium in the Edible Parts of Crop Plants after Foliar Contamination

Summary

The degree of contamination of wheat, potato, cabbage and sugar beet has been investigated after the application of ⁸⁹Sr and ¹³⁷Cs in a fine spray at different stages in the growth of the plants. The main experimental treatments were applied over two years to obtain information on seasonal effects. The extent to which ¹³⁷Cs was concentrated in the edible tissues greatly exceeded that of ⁸⁹Sr. Usually the concentration of ⁸⁹Sr or ¹³⁷Cs in each crop varied by less than an order of magnitude irrespective of the state of growth of the crop at the time of contamination and the year in which the experiment was carried out; the ⁸⁹Sr content of wheat grain, however, was considerably lower when the plants were contaminated before the ears emerged. A large part of the radioactivity which was deposited on the leaves was removed rapidly by rain; a further fraction was lost as leaves died. The data obtained have been used to predict the probable degree of contamination of crops growing under normal agricultural conditions.