抄録
Technetium-99 is thought to be highly soluble and rarely adsorbed onto soil, however, its mobility under natural environment is not well known because its scarcity and low levels in environmental samples has limited the available data. In this study, we determined 99Tc contents in 27 plant samples collected in three forest sites in 1994 and 1995 around the Chernobyl area to obtain transfer factors (TFs) of Tc in the soil-plant system under environmental conditions. The samples were leaves of raspberry, strawberry and pink plants, black alder, birch, cowberry and oak trees, and ferns. After chemical separation, 99Tc in the sample was measured by ICP-MS. Tc-95m was used as a yield tracer and the total recovery ranged from 0.48 to 0.92 with an average of 0.76. The determined 99Tc concentrations in plants ranged from <0.006 to 6.0 mBq g-1 (dry weight basis). TF values ranged from <0.006 to 0.47, based on the 99Tc contents of the soil organic layers. The highest TF was found in the leaves of raspberry plants. The observed TFs were much lower than the values of 8.1-2600 compiled by IAEA for grass, fodder and leafy vegetables.
