抄録
Tellurium (Te) isotopes were released into the environment with radioactive cesium (Cs) and radioactive iodine as a result of the accident at the Fukushima Daiichi Nuclear Power Plant. Te-127m and Te-129m, with half-lives of 109 and 33.6 days, may have moved from soil to foodstuffs and been ingested by local residents. Data on the transfer of Te to plants through roots are essential to estimate the contribution of radioactive Te to the internal radiation dose to the public in the early stages of the accident. However, little is known about soil retention and transfer from soil to plant of Te in the environment. In the present study, the transfer factors from soils to radish and komatsuna were determined for stable Te and Cs. These two kinds of plants were cultured in four kinds of soils adjusted to 1 mg Te or Cs /dry-soil-kg. After 2 weeks-2 months of cultivation, Te and Cs in plants were measured by ICP-MS. The experimental data showed that exchangeable cation retarded the transfer of Cs, and anionic adsorbent of the soils decreased the transfer of Te. The transfer factors of Te were 8.6 × 10-3-3.2 × 10-2 from soil to leaves of radish, 1.2 × 10-2-3.0 × 10-2 to roots of radish, and 1.4 × 10-2-5.1 × 10-2 to leaves of komatsuna. Those of Cs are 2.3 × 10-2-7.6 × 10-1, 1.1 × 10-2-2.7 × 10-1 and 6.7 × 10-3-3.9 × 10-1, respectively.
