Experimentally determined mobility of trace elements in soybean plants

The mobility of Sc-46, Mn-54, Co-58, As-74, Se-75, Rb-83, Sr-85, Y-88, Eu-1 49, Gd-146, Yb-169, Hf-175, Re-183, and Ir-192 in soybean plants after foli ar deposition was determined by a multitracer experiment. The plants were g rown in a controlled area under no-rain conditions for different periods. T hey were exposed to multitracer-absorbed cellulose powder, and the radionuc lide content in the seeds, pods, corpus, tunica, and roots was determined a fter they were harvested. Rubidium showed the highest mobility in the plant among those radionuclides followed by Se and Co which were classified as ' mobile'. Mn, As, Sr, and Re form a second class of 'medium mobility'. The c ontents of Sc-46, Y-88, Eu-149, Gd-146 Yb-169, Hf-175, and Ir-19 were below the detection limit in the seeds; these elements are classified as 'immobi le'. The data obtained in this experiment cannot directly be converted into translocation factors applied in radioecological models, but they allow to check the classification used presently in such a model for elements on wh ich little or no information is available at present. (C) 1999 Published by Elsevier Science B.V. All rights reserved.