Retention, excretion and translocation of Pu-239 in rats following inhalation of (PuO2)-Pu-239 calcined at 1150 and 400 degrees C

Wistar rats inhaled (PuO2)-Pu-239 particles prepared by the calcination of Pu-239 hydroxide at 1150 and 400 degrees C. Lung retention, fecal and urina ry excretion, and translocation of Pu-239 were compared between the two cal cination temperatures. The clearance of Pu-239 from the lungs was significa ntly faster in the rats exposed to (PuO2)-Pu-239 calcined at 400 degrees C (low-temperature group) than those exposed to (PuO2)-Pu-239 calcined at 115 0 degrees C (high-temperature group). Both the fecal excretion of Pu-239 an d the ratio of fecal excretion to urinary excretion was greater in the low- temperature group than in high-temperature group. The amounts of Pu-239 tra nslocated from the lungs to the other organs were very small. Even in the l iver, which accumulated the largest amount of Pu-239 except for the lungs, only 0.13-0.20% of the initial lung burden was retained 1 year after inhala tion. The amount of Pu-239 deposited in the liver was greater in the high-t emperature,group than in the low-temperature group both at 1 month and 1 ye ar after the inhalation. These findings clearly suggest that the lung reten tion of Pu-239 in rats is significantly affected by the calcination tempera ture of (PuO2)-Pu-239.