Libra Laboratory, University of Valladolid, Spain.
Chemosphere. 2013 Jan;90(2):488-96. doi: 10.1016/j.chemosphere.2012.08.008. Epub 2012 Sep 8.
The study of the vertical distribution of seven radionuclides in soils around a coal fired power plant in a mountain region in the north of Spain has been performed, in order to know if some deposition and migration of these radionuclides has taken place. Thirteen profiles of 30 cm depth have been selected, and every fraction of 5 cm has been analyzed until of a total of 72 soil samples. The activity concentration of (238)U, (226)Ra, (210)Pb, (232)Th, (224)Ra, (40)K and (137)Cs has been measured by gamma-ray spectrometry. The data were analyzed using multivariate statistical techniques, founding the best result when using a simple two-factor model, which can explain the 81.1% of the total variance. Additionally, on the basis of the significant differences found in the concentration of lead in the soil top and deep layers, the evaluation of excess of (210)Pb and the K-parameter was done. A good correlation between the excess of (210)Pb and the concentration of anthropogenic radionuclide (137)Cs in surface soil was found. These results confirm the atmospheric deposition of lead as a decay product of exhaled Rn.
本研究对西班牙北部山区某燃煤电厂周围土壤中的 7 种放射性核素的垂直分布进行了研究，以了解这些放射性核素是否发生了某些沉积和迁移。共选择了 13 个 30 厘米深的剖面，每 5 厘米为一个分层，共分析了 72 个土壤样本。利用伽马能谱法测量了（238）U、（226）Ra、（210）Pb、（232）Th、（224）Ra、（40）K 和（137）Cs 的活度浓度。利用多元统计技术对数据进行了分析，发现使用简单的双因素模型可以得到最佳结果，该模型可以解释总方差的 81.1%。此外，基于土壤表层和深层铅浓度的显著差异，对（210）Pb 过剩和 K 参数进行了评价。发现表层土壤中（210）Pb 过剩与人为放射性核素（137）Cs 浓度之间存在良好的相关性。这些结果证实了铅作为呼出的 Rn 的衰变产物的大气沉积。
