Absorption of technetium by plants in relation to soil type, contamination level and time

Soil availability, plant uptake and soil to plant transfer of 99Tc—A review

“…Further, in much of the temperate zone and the wet tropics, soils are waterlogged periodically. This might help to explain why both laboratory (Mousny and Myttenaere, 1981;Tagami and Uchida, 1998) and field studies (Hoffman et al, 1982;Garten et al, 1984) have found that, even in aerobic soils, the proportion of available 99 Tc is reduced over time. Anaerobic microsites in aerobic soils, often produced within soil aggregates as the water-filled pore space increases, are now recognised to be important in denitrification and the production of ammonium on a global scale (Davidson et al, 2000).…”

Uptake of radionuclides and stable elements from paddy soil to rice: a review

“…Transfer parameters used in such models should be based on equilibrium conditions and TF for a radionuclide should be constant in a soil under an equilibrium condition (depending on soil types). However, the mobilities for some radionuclides in soils change with time, known as the aging effect (Ambe et al, 1999;Krouglov et al, 1997;Mousny and Myttenaere, 1981;Noordijk et al, 1992). In the environment, it is difficult to predict the time required to reach equilibrium conditions for TF after release of radionuclides.…”

Comparison of a radiation counting method and ICP-MS for the determination of99Tc in environmental samples

“…In this form, Tc has a high geochemical mobility 1,2 and availability for plants. 3,4 It is well known that 99Tc is one of the most important elements for dose assessment, because it is produced from the fission of 235U and 239pu with relatively high yield (about 6%) and it has a long half-life (2.1.105 y). The sources of environmental 99Tc are nuclear weapon tests and nuclear industries such as nuclear fuel reprocessing plants, nuclear power plants and waste disposal facilities.…”