Analysis of 129I and 127I in soils of the Chernobyl Exclusion Zone, 29 years after the deposition of 129I.
Analysis of 129I and 127I in soils of the Chernobyl Exclusion Zone, 29 years after the deposition of 129I.
复制标题
129I 沉积 29 年后，切尔诺贝利禁区土壤中 129I 和 127I 的分析。
DOI：
10.1016/j.scitotenv.2019.07.319
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Shaw G
中科院分区：
文献类型：
--
作者：
Shaw G
切尔诺贝利隔离区(CEZ)代表着一个独特的天然实验室，它在1986年的短时间内在一系列土壤和土地利用类型中收到了显著的129I污染。2015年从CEZ高污染地区采集的土壤样本中有129I和127I的数据。稳定碘(127I)的几何平均总浓度为6.7 × 10−7g g−1,129I的总浓度为2.39 × 10−13g g−1，相当于1.56 kg−1。127I的总浓度低于欧洲土壤平均浓度3.94 × 10−6g g−1，而129I的活度浓度显著高于切尔诺贝利前的活度浓度0.094 MBq kg−1。在土壤中引入129I后，127I和129I几乎稳定了30 年。127I和129I主要与碱可提取的土壤有机质有关，这是通过三步连续提取程序建立的。其中127I与土壤总有机质(以烧失量衡量)显著相关，而129I则不相关。土壤有机质萃取物中129I/127I的比值显著低于土壤中较易溶解和吸附的部分，表明土壤腐殖质中的129I与天然127I在土壤中的停留时间为29 。~(129)I在CEZ土壤中的初始物理化学形态尚不清楚，但广泛存在的铀氧化物燃料颗粒不太可能影响~(129)I的环境行为。我们的发现对受污染土壤中129I的长期辐射剂量以及使用天然的、稳定的127I作为129I长期命运的替代具有一定的意义。
The Chernobyl Exclusion Zone (CEZ) represents a unique natural laboratory that received significant129I contamination across a range of soils and land-use types in a short time period in 1986. Data are presented on129I and127I in soil samples collected from highly contaminated areas in the CEZ in 2015. The geometric mean (GM) total concentration of stable iodine (127I) was 6.7 × 10−7g g−1and the (GM) total concentration of129I was 2.39 × 10−13g g−1, equivalent to 1.56 mBq kg−1. GM total127I concentration is below the European average soil concentration of 3.94 × 10−6g g−1, while129I is significantly higher than the pre-Chernobyl activity concentration for129I of 0.094 mBq kg−1. Significant differences were found in the extractability of native, stable127I and129I almost 30 years after the introduction of129I to the soils. Both127I and129I were predominantly associated with alkaline-extractable soil organic matter, established using a three-step sequential extraction procedure. Whereas127I was significantly correlated with gross soil organic matter (measured by loss on ignition), however,129I was not. The ratio of129I/127I was significantly lower in extracts of soil organic matter than in more labile (soluble and adsorbed) fractions, indicating incomplete equilibration of129I with native127I in soil humic substances after 29 years residence time in the CEZ soils. The initial physico-chemical form of129I in the CEZ soils is unknown, but the widespread presence of uranium oxide fuel particles is unlikely to have influenced the environmental behaviour of129I. Our findings have implications for long-term radiation dose from129I in contaminated soils and the use of native, stable127I as a proxy for the long-term fate of129I.