伤口摄入超铀核素的内照射剂量估算

目的 比较NCRP伤口生物动力学模型和ICRP 78号报告推荐的注入模式下伤口摄入超铀核素所致内照射剂量的差异，了解器官剂量的分布特性。方法 以²⁴¹Am（M类，颗粒态）为例计算了上述两种不同模型模式下工作人员伤口摄入单位活度后所致人体各组织器官当量剂量和待积有效剂量，及其在部分器官（肝、骨等）和部分生物样品（尿、粪等）中的滞留/排泄分数曲线。结果 工作人员经由伤口摄入单位活度²⁴¹Am所致待积有效剂量的两种模型计算结果相差约为18.5%；器官当量剂量由高到低依次为骨表面，肝和红骨髓；伤口摄入单位活度²⁴¹Am后全身滞留分数较高，不易排出，在骨和肝中的滞留分数随时间推移而显著升高，而在尿、粪中的排泄分数则较低且变化较小。结论 利用现有的两种模型估算超铀核素伤口污染所致的内照射剂量尚有较大的差异，值得继续深入开展研究。

The internal dose evaluation for transuranic nuclide-contaminated wounds

Objective To compare the internal doses for transuranic nuclide-contaminated wounds by using ICRP wound biokinetic model and injection model recommended by ICRP 78 publication, and acquaint with the distribution of organ doses.Methods As an example, the effective dose and the distribution of organ equivalent doses caused by unit activity of ²⁴¹Am (M class, Particle) were calculated by above two models, and the intake retention/excretion fraction curves in some organs (liver, bone, etc.) and some biological samples (urine, feces, etc.) were also studied.Results The deviation of effective doses estimated by the above two models was about 18.5%. The organ equivalent doses caused by ²⁴¹Am (M class, Particle) through wound were in the order of bone surface, liver and red bone marrow. The intake retention fraction for the whole body was high, and it was hard to be excreted. The intake retention fraction in bone and liver increased significantly with time, while the excretion fraction in urine and feces were low and hardly changed.Conclusion The deviation of internal doses for transuranic nuclides-contaminated wounds estimated by using the two present models is relatively large, further studies are still needed.