title: Field and greenhouse experiments on the fate of technetium in plants and soil.
abstract: The behavior of 95mTc in plants and in a Captina silt loam soil following a single application of the pertechnetate form of the radionuclide to bare soil was compared between field and greenhouse conditions. Over a period of approx. six months, the net uptake of 95mTc by plants from undisturbed, intact soil in the greenhouse was about a factor of 10 greater than that in the field. Sieving the soil through a 2-mm mesh screen before potting and then planting new grass further increased plant uptake of 95mTc by approx. a factor of 20 relative to the field. Uptake by new grass was increased even more by decreasing the pot size. Most of the 95mTc applied to soil in the field or the greenhouse remained in the top 4 cm of the profile. Soon following application to soil, pertechnetate was transformed, or otherwise immobilized, such that extractions with 0.01 M CaCl2 recovered only a portion of the 95mTc present in soil. The extractability of 95mTc from soil using CaCl2 decreased over time as did 95mTc concentrations in vegetation. The pertechnetate applied to soil appeared to be converted over time to a less soluble and therefore less bioavailable form.
mesh_terms: D000821:Animal Feed; D005507:Food Contamination, Radioactive / Q000032:analysis*; D010944:Plants / Q000378:metabolism*; D006109:Poaceae / Q000378:metabolism; D012989:Soil Pollutants / Q000032:analysis*; D012990:Soil Pollutants, Radioactive / Q000032:analysis*; D013667:Technetium / Q000378:metabolism*
chemical_list: D012989:Soil Pollutants; D012990:Soil Pollutants, Radioactive; D013667:Technetium