Incorporation and distribution of uranium in rats after a contamination on intact or wounded skin

Uranium uptake can occur accidentally by inhalation, ingestion, injection, or absorption through intact or wounded skin. Intact or wounded skin routes of absorption of uranium have received little attention. The aims of our work were (1) to evaluate the influence of the type of wound contamination on the short term distribution and excretion of uranium in rats and (2) to generate data to assess the time available to treat contamination of intact or wounded skin before significant uptake of uranium occurs. Biokinetic data presented in the present paper are based on an in vivo rat model. This study shows that a significant uptake of a uranyl nitrate solution through intact skin can occur within the first 6 h of exposure. Absorption of a uranyl nitrate solution through excoriated skin is significant after only 30 min of exposure. After a 24-h exposure, uranium uptake through intact skin and excoriated skin represents about 0.4% and 38% of the initial deposit of uranium, respectively. Contaminated serious chemical skin burns induced by HNO3 or NaOH are paradoxically less important in terms of uranium uptake risk because 99% of the incorporated uranium remains trapped at the wound site and its incorporation is delayed for at least 6 h after the beginning of contamination. These results confirm that the biokinetics of a given physicochemical form of uranium incorporated after wound contamination depend largely on the physiological evolution of the considered wound. Each type of wound, with its corresponding biokinetics of a uranium species, is a particular case.