Uranium behaviour in the baboon after the deposition of a ceramic form of uranium dioxide and uranium octoxide in the lungs : implications for human exposure

U 0 2 and U 3 0 8 were inhaled by baboons in amounts such that the mass concentrat ions in the lungs were between about 3 and 20, and 1 and 7.4 t imes respectively those calculated in human lungs after exposure to 1 ALI of the compounds . The results show that 1 year later : 1) the initial lung deposits of uranium retained in the chest are greater for U 0 2 than for U 3 0 8 ; 2) the ratios of the amounts of uranium retained in the lymph nodes vs those in the lungs, expressed both in terms of concentrat ion and mass, are greater for U 0 2 than for U 3 0 8 ; 3) for both U 0 2 and U 3 0 8 , the amounts of uranium retained in the lymph nodes, expressed as a percentage of that in the chest, do not appear to be affected to a great extent by the initial lung deposits ; 4) after inhalation of U 0 2 and U 3 0 8 in different amounts, the trend in the mass concentrations of uranium in the var ious t issues assayed were lymph nodes > lungs » skull > femoraclavicles > lumbar vertebra thoracic cage > sternum > kidneys > liver ; 5) the measurement of urine concentrat ions of some enzymes may be a useful index for assessing substantial overexposures to U 0 2 and U 3 0 8 , however, so far, external chest monitor ing and urinary assays of uranium should remain the procedures of choice. * Commissariat à l'énergie atomique, Institut de protection et de sûreté nucléaire, BP 6, 92265 Fontenay-aux-Roses Cedex, France. ** Commissariat à l'énergie atomique, Direction des sciences du vivant, BP 12, 91680 Bruyères-le-Chatel, France. *** National radiological protection board, Chilton, Didcot, Oxon, OX11 ORQ, UK. RADIOPROTECTION VOL. 27 0033-8451/1992/11/$ 5.00/© Les Editions de Physique 263 Article published by EDP Sciences and available at http://www.radioprotection.org or http://dx.doi.org/10.1051/radiopro/1992010