Radiation Protection Dosimetry Advance Access originally published online on June 6, 2007
Radiation Protection Dosimetry 2007 127(1-4):50-54; doi:10.1093/rpd/ncm250
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Influence of initial lung deposit on pulmonary clearance after plutonium oxide inhalation in rat
CEA/DSV/DRR/SRCA, Laboratory of Radiotoxicology, BP no. 12, 91680 Bruyères le Chatel, France
* Corresponding author: anne.vandermeeren{at}cea.fr
Alveolar macrophages are a key element in the clearance of inhaled particles after phagocytosis, and thus participate actively in lung dose distribution and in the risk of tumour formation. We studied the influence of initial lung deposit (ILD) on lung clearance and distribution of activity from 3 d to 3 months after inhalation of two forms of PuO2 (97% 239Pu and 70% 239Pu) in rats. ILDs ranging from 2.1 to 17 kBq were used. The total activity measured using X-ray spectrometry 3 months post-inhalation, relative to the ILD, showed a similar decrease in all groups, with the remaining activity representing
30% of the ILD. The total activity recovered in bronchoalveolar lavages represented
60% of the total lung activity. This ratio remained stable over time for the lowest ILD tested but decreased for higher ILD. In addition, the percentage of macrophages associated with particles decreased faster with time in rats with the highest ILD. Under our experimental conditions, there were no marked differences in lung clearance between groups. However, the distribution of the activity seems to vary with the time post-exposure between low and high ILD.