Transfer of technetium from soil to plants

Experiments on transfer of technetium from soil to edible parts of various agricultural crops were performed using Tc-95m as a tracer. Plants were grown in Andosol (a typical soil in Japan). The transfer factors for edible parts of lettuce, classed with leaf vegetables, were higher than those for other crops (nonleaf vegetables) examined in this study. Relatively low transfer factors were observed in vegetables whose edible parts are fruits or pods. The transfer factors for root vegetables were intermediate. The following average values (based on wet weight) were observed for the edible parts of vegetables: sweet pepper, 0.03; egg plant, 0.01; kidney bean, 0.01; tare, 0.09; yam, 1.0; soybean (based on dry weight), 0.8, cauliflower, 0.1; and lettuce, 7.5.