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

Abstract

Wistar rats inhaled ²³⁹PuO₂ particles prepared by the calcination of ²³⁹Pu hydroxide at 1150 and 400° 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° C (low-temperature group) than those exposed to ²³⁹PuO₂ calcined at 1150° 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 of²³⁹PuO₂.