The Effect of Repeated Inhalation on the Distribution of Uranium in Rats

• Published in: Journal of Toxicology and Environmental Health, Part A Vol. 69; no. 17; pp. 1629 - 1649
• Main Authors: Monleau, Marjorie, Blanchardon, Eric, Claraz, Marie, Paquet, François, Chazel, Valérie
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis Group 01-10-2006
• Subjects: Animals; Humans; Inhalation Exposure; Kinetics; Male; Models, Animal; Models, Theoretical; Occupational Exposure; Rats; Rats, Sprague-Dawley; Tissue Distribution; Uranium - pharmacokinetics
• ISSN: 1528-7394; 1087-2620
• DOI: 10.1080/15287390600629882

For the assessment of doses after inhalation of airborne uranium compounds by workers, the International Commission on Radiological Protection (ICRP) developed compartmental models that are used to calculate reference dose coefficients and retention and excretion functions. It is assumed that each acute intake has no effect on the biokinetics of later intakes. Consequently, retention and excretion after multiple or chronic exposure are predicted using the same models as after acute exposure. This assumption was tested here on rats exposed to repeated inhalation of uranium dioxide (UO
2
). First, excretion and organ retention were determined after a single inhalation of UO
2
. The follow-up of incorporated activity was used to design a biokinetic model for uranium inhaled by rats. Second, the biokinetics of uranium were monitored in two experiments of repeated inhalations of uranium dioxide under different intake patterns. For these two experiments, the organs' retention and excretion after repeated UO
2
inhalation were predicted using the biokinetic model and compared to the experimental measurement. Under the two sets of experimental conditions considered, the prediction of the biokinetic model based on acute exposure data was consistent with the biokinetics observed after repeated UO
2
inhalations, with the possible exception of retention in the skeleton.
We wish to thank O. Delissen, B. Dhieux, C. Maubert, A. M. Moreels, and E. Tourlonias for their assistance during the exposure, euthanasia, and dissection. This work was partially supported by COGEMA (DOSINTER program).