Retention, Excretion and Translocation of 239Pu in Rats Following Inhalation of 239PuO2 Calcined at 1150 and 400°C

Wistar rats inhaled 239PuO2 particles prepared by the calcination of 239Pu hydroxide at 1150 and 400 degrees C. Lung retention, fecal and urinary excretion, and translocation of 239Pu were compared between the two calcination temperatures. The clearance of 239Pu from the lungs was significantly faster in the rats exposed to 239PuO2 calcined at 400 degrees C (low-temperature group) than those exposed to 239PuO2 calcined at 1150 degrees C (high-temperature group). Both the fecal excretion of 239Pu and the ratio of fecal excretion to urinary excretion was greater in the low-temperature group than in high-temperature group. The amounts of 239Pu translocated from the lungs to the other organs were very small. Even in the liver, which accumulated the largest amount of 239Pu except for the lungs, only 0.13-0.20% of the initial lung burden was retained 1 year after inhalation. The amount of 239Pu deposited in the liver was greater in the high-temperature group than in the low-temperature group both at 1 month and 1 year after the inhalation. These findings clearly suggest that the lung retention of 239Pu in rats is significantly affected by the calcination temperature of 239PuO2.