Disposition of Highly Toxic Radioactive Aerosols Inhaled by Beagle Dogs.

摘要

Beagle dogs were exposed to exp 241 Am or exp 244 Cm oxides in an apparatus which permitted separation of expired from inspired air and measurement of these volumes, the aerosol concentrations, and their size distributions. Following exposure, excreta were collected and analyzed for 30 days and for a week prior to sacrifice. Activity in the lungs was estimated from periodic thorax counts, while complete tissue analyses were conducted on groups of 3 dogs sacrificed 10, 30, 90, and 270 days postexposure. Indications from the early thorax counts, excreta, and tissue analyses showed that exp 244 CmO/sub x/ aerosols having AMAD = 0.5 mu m and GSD = 2.1, initial alveolar deposition varied from 40 percent for the low level (10 nCi) to 20 percent for the high level (400 nCi); after early ciliary clearance, as much exp 244 Cm was excreted in the urine as in the feces; at 10 days postexposure, 25 to 35 percent was still in the lung with 45 to 65 percent in other soft tissues and 10 to 30 percent in the skeleton. For exp 241 AmO sub 2 , the size distribution was a function of aerosol concentration, with AMAD = 0.7 mu m and GSD = 2.4 at the low level (1 nCi), increasing to 1.35 mu m and 1.7 at intermediate levels (125 nCi), and 1.45 mu m and 1.7 at the high level (1150 nCi); corresponding mean alveolar depositions were 15, 30, and 35 percent. The exp 241 Am or exp 244 Cm tissue distribution analyses at various times post-exposure showed that both isotopes are readily translocated from the lungs to liver, skeleton, and muscle, exp 244 Cm twice as rapidly as exp 241 Am.