Poudel Deepesh, Avtandilashvili Maia, Klumpp John A, Bertelli Luiz, Tolmachev Sergei Y
Radiation Protection Division, Los Alamos National Laboratory, Los Alamos, NM, United States of America.
U.S. Transuranium and Uranium Registries, Washington State University, Richland, WA, United States of America.
J Radiol Prot. 2021 Nov 18;41(4). doi: 10.1088/1361-6498/abca49.
The U.S. Transuranium and Uranium Registries whole-body tissue donor Case 0407 had an acute intake of 'high-fired' plutonium oxide resulting from a glove-box fire in a fabrication plant at a nuclear defence facility. The respiratory tract of this individual was dissected into five regions (larynx, bronchi, bronchioles, alveolar-interstitial, and thoracic lymph nodes) and analysed for plutonium content. The activities in certain compartments of the respiratory tract were found to be higher than expected from the default models described in publications of the International Commission on Radiological Protection. Because of the extremely slow rate of dissolution of the material inhaled, the presence of bound fraction is incapable of explaining the higher-than-expected retention. A plausible hypothesis-encapsulation of plutonium in scar tissues-is supported by the review of literature. Therefore, scar-tissue compartments corresponding to the larynx, bronchi, bronchioles and alveolar-interstitial regions were added to the existing human respiratory tract model structure. The transfer rates between these compartments were determined using Markov Chain Monte Carlo analysis of data on urinary excretion, lung counts and post-mortem measurements of the liver, skeleton and regional retention in the respiratory tract. Modelling of the data showed that approximately 30% of plutonium activity in the lung was sequestered in scar tissues. The dose consequence of such sequestration is qualitatively compared against that of chemical binding.
美国超铀和铀注册中心的全身组织捐赠者案例0407，因某核防御设施制造工厂的手套箱起火，急性摄入了“高温烧制”的氧化钚。该个体的呼吸道被解剖为五个区域（喉、支气管、细支气管、肺泡间质和胸段淋巴结），并分析了钚含量。发现呼吸道某些隔室中的活度高于国际放射防护委员会出版物中描述的默认模型所预期的活度。由于吸入物质的溶解速度极慢，结合部分的存在无法解释高于预期的滞留情况。文献综述支持了一个合理的假设——钚在瘢痕组织中被包裹。因此，将与喉、支气管、细支气管和肺泡间质区域相对应的瘢痕组织隔室添加到现有的人体呼吸道模型结构中。利用马尔可夫链蒙特卡罗分析尿排泄、肺部计数以及肝脏、骨骼的尸检测量和呼吸道区域滞留的数据，确定了这些隔室之间的转移率。数据建模表明，肺部约30%的钚活度被隔离在瘢痕组织中。将这种隔离的剂量后果与化学结合的剂量后果进行了定性比较。
