Physiology-based modelling in radiation research: The biokinetics of plutonium

For many years, the biokinetics of radioactive substances was calculated on the basis of mathematical criteria only. Biokinetic compartments in most cases did not correspond to anatomically defined distribution areas in an organism but were operational values. However, the quality of the resulting models depends on how accurately their assumptions reflect reality. Ideally, a biokinetic model develops which reproduces reality. In the past few years, this need has resulted increasingly in physiological operational sequences being modelled in realistic anatomical structures of the body along with physicochemical parameters. In this study, an estimate of the biokinetic operational sequence after an incorporation of plutonium is made similar to the pharmacokinetics of a substance showing comparable chemical and physiological behaviours in the body. These behaviours are found for metals, iron and aluminium. Thus, comparison of the biokinetics of plutonium with the pharmacokinetics of aluminium results in some commonalities and some differences. A new model with physiological compartments for plutonium is presented on the basis of the biokinetics of aluminium. (authors)