Spéciation et dosimétrie interne : des espèces chimiques aux modèles dosimétriques

Abstract

RÉSUMÉLes études de spéciation correspondent à la détermination des espèces chimiques d'un élément et à l'analyse de leur distribution dans un échantillon ou un milieu donné. Speciation studies refer to the distribution of species in a particular sample or matrix. These studies are necessary to improve the description, understanding and prediction of trace element kinetics and toxicity. In case of internal contamination with radionuclides, speciation studies could help to improve hoth the biokinetic and dosimetric models for radionuclides. There are different methods to approach the speciation of radionuclide in a biological system, depending on the degree of accnracy needed and the level of uncertainties accepted. Among them, computer modeliing and experimental determination are complementary approaches. This paper describes what is known about speciation of actinides in blood, GI-tract, liver and skeleton and of their consequences in terms of internal dosimeh-y. The conclusion is that such studies provide very valuable data and should be targeted in the future on some specific tissues and biomolecules.' IRSN. hhoraioire de radiotoxicologie expt<iiment?le.

The Chemical Speciation of Uranium in Water Does Not Influence Its Absorption from the Gastrointestinal Tract of Rats

“…This work aimed to assess the influence of initial uranium speciation in water on uranium absorption from the GIT in the context of chronic contamination via drinking water. Ex vivo studies were performed to determine the distribution of uranium in fluids from the GIT and were followed by a computational uranium speciation approach (10) in the electrolytic fraction of these fluids. In both these approaches, the ICRP 30 model of the GIT was considered, i.e., separated compartments such as the mouth and stomach (11).…”