镧系元素由土壤向人体转移及其分布

目的 计算14种镧系元素从土壤经膳食向人体的转移系数和在10种器官、组织中的分布。方法 依据我国4个不同膳食类型地区镧系元素膳食摄入量和10种主要器官、组织负荷量研究结果及土壤元素背景值文献资料,采用UNSCEA R陆地转移模式计算土壤、膳食、关键器官或全身三隔室间转移系数,采用LREE HREE作为分异评价指标。结果 镧系元素从土壤向膳食和从膳食向全身的总转移系数分别为0.131 ga^-1/gkg^-1和0.176 g/ga^-1。从膳食向骨骼转移系数比向肝大1个数量级;从土壤向膳食转移中轻稀土组稍有富集,而从膳食向骨骼转移中轻稀土组趋于向骨骼,重稀土组趋于向肝;器官、组织分布以骨骼最高(36.5%),其后依次为肌肉、肺和肝。结论 获得了14种镧系元素从我国土壤经膳食向人体的转移系数、分异状况和在10种器官、组织中分布。本文结果在辐射防护领域为镧系放射性核素内剂量估算、相关卫生标准制定和生物动力学模型及参数的确定提供了直接人体依据,对其他领域广泛研究也有重要意义。

Transfer of Lanthanides From Soil to Human Body and Their Distribution

Objective To calculate the transfer coefficients of 14 lanthanides from soil via diet to human body and their distribution in 10 kinds of organ or tissue.Methods Based on the research Results on dietary intakes and burdens of these lanthanides in 10 kinds of organ or tissue, collected from 4 areas with different dietary types in China, and relevant elementary background values in Chinese soil, their transfer coefficients from soil via diet to critical organ or whole body were calculated by using UNSCEAR terrestrial transfer model.LREE/HREE was used as evaluation index for disagreement.Results The total transfer coefficient of these lanthanides from soil to diet and from diet to whole body accounted for 0.131 ga^-1/gkg^-1 and 0.176 g/ga^-1 respectively.The transfer coefficient from diet to skeleton was one order of magnitude higher than that to liver.The LREE group a little enhanced in transfer from soil to diet.LREE tended to deposit in skeleton and HREE did in liver.The organ and tissue distribution showed that skeleton was the highest (36.5%) and then muscle, lung and liver in decreasing order.Conclusion The transfer coefficients and disagreement of 14 lanthanides from soil via diet to human body and their distribution in 10 kinds of organ or tissue are obtained, the result provides direct human bases for estimating internal doses of lanthanide radionuclides, developing related hygienic standards and biokinetic model as well parameters in radiation protection field and, also are of important significance for research in other extensive fields.