In case of internal contamination with plutonium materials, a treatment with diethylene triamine pentaacetic acid (DTPA) can be administered in order to reduce plutonium body burden and consequently avoid some radiation dose. DTPA intravenous injections or inhalation can start almost immediately after intake, in parallel with urinary and fecal bioassay sampling for dosimetric follow-up. However, urine and feces excretion will be significantly enhanced by the DTPA treatment. As internal dose is calculated from bioassay results, the DTPA effect on excretion has to be taken into account. A common method to correct bioassay data is to divide it by a factor representing the excretion enhancement under DTPA treatment by intravenous injection. Its value may be based on a nominal reference or observed after a break in the treatment. The aim of this study was to estimate the influence of this factor on internal dose by comparing the dose estimated using default or upper and lower values of the enhancement factor for 11 contamination cases. The observed upper and lower values of the enhancement factor were 18.7 and 63.0 for plutonium and 24.9 and 28.8 for americium. For americium, a default factor of 25 is proposed. This work demonstrates that the use of a default DTPA enhancement factor allows the determination of the magnitude of the contamination because dose estimated could vary by a factor of 2 depending on the value of the individual DTPA enhancement factor. In case of significant intake, an individual enhancement factor should be determined to obtain a more reliable dose assessment.

When radiation toxicological monitoring of personnel is carried out following suspected internal contamination with alpha particle emitters, it is imperative that specific techniques be used to detect and measure the actinides present in the biological samples. The technique proposed here makes it possible to measure the activity of the uranium, plutonium, americium and curium isotopes on a single sample, without interference caused by the activity which is produced by the thorium and its descendants. This technique uses both the extracting power of new organic compounds fixed on inert resins, as well as the fixation and elution potential of the various actinides depending on the ionic composition and pH of the solutions used.

RÉSUMÉLa surveillance du personnel exposé aux produits radioactifs repose, selon les radionuclides en cause, sur des dosages qui nécessitent la maîtrise de techniques radiochimiques appliquées aux échantillons biologiques. Toute optimisation des critères techniques ou du facteur temps est extrêmement profitable. Après un rappel des principales techniques habituellement utilisées pour le dosage des actinides et des radioémetteurs bêta, les auteurs présentent les nouveaux composés permettant l'extraction des actinides et du strontium à partir de matrices mises en solution nitrique. Les avantages analytiques sont détaillés : dosage de la totalité des actinides sur un même échantillon, limites de détection améliorées pour l'uranium, gain de temps, spécificité dû dosage du strontium.ABSTRACT According to the radionuclides involved, trie monitoring of personnel exposed to radioactive material implies determination by means of radiochemical techniques applied to biological samples. It is very useful to be able to optimize the technical criteria and the time-factor. A brief review is made of the main techniques used for the determination of actinides and beta emitters. The new compouds making it possible to extract actinides and strontium from substances in a nitric solution are presented. The analytical advantages are described: the determination of trie totality of the actinides on a single sample, improved detection limits for uranium, time-saving, specificity of strontium determination.