Takeda A, Tsukada H, Takahashi M, Takaku Y, Hisamatsu S
Department of Radioecology, Institute for Environmental Sciences, Rokkasho, Aomori 039-3212, Japan
Department of Radioecology, Institute for Environmental Sciences, Rokkasho, Aomori 039-3212, Japan Present address: Institute of Environmental Radioactivity, Fukushima University, Fukushima 960-1296, Japan.
Radiat Prot Dosimetry. 2015 Nov;167(1-3):181-6. doi: 10.1093/rpd/ncv240. Epub 2015 May 1.
Information about the chemical form of exogenous iodine in soil is important for predicting the mobility and behaviour of radioiodine in the terrestrial environment. In this study, soil samples collected at various depths in a pine forest in Rokkasho, Japan, were spiked with stable iodine (as iodide or iodate); after incubation of the spiked soils for 1 or 14 d, the chemical forms of iodine were investigated in both the soils and their water extracts. In surface soil and its extracts, inorganic iodine was found to have been transformed to organically bound forms after incubation for 14 d, resulting in a decrease in the amount of water-extractable iodine in the soil. In contrast, in subsurface soil, which had low organic matter content, the predominant chemical form of iodine after incubation did not differ from that in the spiked soil, and the amount of water-extractable iodine did not decrease noticeably.
土壤中外源碘的化学形态信息对于预测陆地环境中放射性碘的迁移性和行为非常重要。在本研究中，采集了日本六所村一片松树林不同深度的土壤样本，并用稳定碘（碘化物或碘酸盐形式）进行加标；加标土壤孵育1天或14天后，对土壤及其水提取物中的碘化学形态进行了研究。在表层土壤及其提取物中，无机碘在孵育14天后被转化为有机结合态，导致土壤中水可提取碘的量减少。相比之下，在有机质含量较低的亚表层土壤中，孵育后碘的主要化学形态与加标土壤中的形态没有差异，水可提取碘的量也没有明显减少。
