Experimentally determined mobility of trace elements in soybean plants

The mobility of 46Sc, 54Mn, 58Co, 74As, 75Se, 83Rb, 85Sr, 88Y, 149Eu, 146Gd, 169Yb, 175Hf, 183Re, and 192Ir in soybean plants after foliar deposition was determined by a multitracer experiment. The plants were grown in a controlled area under no-rain conditions for different periods. They were exposed to multitracer-absorbed cellulose powder, and the radionuclide content in the seeds, pods, corpus, tunica, and roots was determined after they were harvested. Rubidium showed the highest mobility in the plant among those radionuclides followed by Se and Co which were classified as `mobileʹ. Mn, As, Sr, and Re form a second class of `medium mobilityʹ. The contents of 46Sc, 88Y, 149Eu, 146Gd, 169Yb, 175Hf, and 192Ir were below the detection limit in the seeds; these elements are classified as `immobileʹ. 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 which little or no information is available at present.