Biokinetics underlies the basis for assessment of internal exposures. This paper develops a biokinetic method on simultaneous intake of radionuclides from multiple intake scenarios in internal exposures. With numerical techniques that transform the whole biokinetics between the coupled and decoupled representations of the same problem, this method applies to coupled biokinetics with complex structures and has no restrictions of practical importance on the number of intake scenarios, the number of intake parent radionuclides and decay products, and the complexity of decay relationships between parent and progeny nuclides. For illustration, this method is applied to an assumed case of mixed inhalation and ingestion of weapon-grade plutonium material for reference workers that is focused on Pu and Am. Due to coupled biokinetics between the direct intake and ingrowth parts in different intake pathways, the multiple intake results (the contents of lungs, daily excretions, and cumulative contents) display richer behaviors as compared to single intake cases. This method benefits both the prospective and retrospective assessment of internal exposures for complex intake cases in actual applications.

中文翻译：

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多摄入场景中同时摄入放射性核素的生物动力学方法应用于内照射。

生物动力学是内部暴露评估的基础。本文开发了一种生物动力学方法，用于从内照射的多个摄入场景中同时摄入放射性核素。该方法利用数值技术在同一问题的耦合和解耦表示之间转换整个生物动力学，适用于结构复杂的耦合生物动力学，并且对摄入场景的数量、摄入母体放射性核素的数量和衰变没有实际意义的限制产物，以及母体和子代核素之间衰变关系的复杂性。为了便于说明，该方法适用于供参考人员混合吸入和摄入武器级钚材料的假设情况，重点是钚和钚。由于不同摄入途径中直接摄入和向内生长部分之间的生物动力学耦合，多次摄入结果（肺内容物、每日排泄物和累积含量）比单次摄入情况表现出更丰富的行为。该方法有利于实际应用中对复杂摄入案例的内暴露进行前瞻性和回顾性评估。