Southern Ural Biophysics Institute, Ozyorsk, Chelabinsk Region, 456780, Russia.
Health Phys. 2010 Oct;99(4):464-70. doi: 10.1097/HP.0b013e3181cb840f.
The purpose of this study was to obtain quantitative data on plutonium microdistribution in different structural elements of human bone tissue for local dose assessment and dosimetric models validation. A sample of the thoracic vertebra was obtained from a former Mayak worker with a rather high plutonium burden. Additional information was obtained on occupational and exposure history, medical history, and measured plutonium content in organs. Plutonium was detected in bone sections from its fission tracks in polycarbonate film using neutron-induced autoradiography. Quantitative analysis of randomly selected microscopic fields on one of the autoradiographs was performed. Data included fission fragment tracks in different bone tissue and surface areas. Quantitative information on plutonium microdistribution in human bone tissue was obtained for the first time. From these data, the quantitative relationships of plutonium decays in bone volume to decays on bone surface in cortical and trabecular fractions were defined as 2.0 and 0.4, correspondingly. The measured quantitative relationship of decays in bone volume to decays on bone surface does not coincide with recommended models for the cortical bone fraction by the International Commission on Radiological Protection. Biokinetic model parameters of extrapulmonary compartments might need to be adjusted after expansion of the data set on quantitative plutonium microdistribution in other bone types in humans as well as other cases with different exposure patterns and types of plutonium.
本研究的目的是获取有关钚在人体骨组织不同结构元素中微分布的定量数据，以进行局部剂量评估和剂量模型验证。从一名曾在马雅克工作的、体内钚负荷相当高的前工作人员身上获取了一块胸椎样本。获取了更多的职业和暴露史、病史以及器官中测量到的钚含量等信息。使用中子诱发自动射线照相术，从聚碳酸酯膜中的裂变轨迹检测到骨片中的钚。对其中一张自动射线照片上随机选择的微观视野进行了定量分析。数据包括不同骨组织和表面积中的裂变碎片轨迹。首次获得了人体骨组织中钚微分布的定量信息。根据这些数据，定义了钚在骨体积中的衰减与皮质骨和小梁骨分数中骨表面的衰减之间的定量关系分别为 2.0 和 0.4。测量得到的骨体积中衰减与骨表面衰减之间的定量关系与国际辐射防护委员会推荐的皮质骨分数模型不一致。可能需要在扩展人体其他骨类型以及其他具有不同暴露模式和钚类型的情况下的定量钚微分布数据集后，调整肺外隔室的生物动力学模型参数。
