Multiple bronchopulmonary lavages for the removal of 144Ce in fused clay particles from beagle dog lungs.

Abstract

Repeated bronchopulmonary lavage was investigated as a method of removing inhaled cerium-144 fused clay particles from the lungs of beagle dogs. Eight beagle dogs were exposed to a fused clay aerosol containing 144Ce resulting in initial lung burdens ranging from 47 to 71 μCi 144Ce/kg body weight. Three of these dogs received 20 saline lavage treatments, 10 per lung, over an 84-day period. The first 10 lavages Here given within 24 days as an accelerated schedule. A fourth dog, originally scheduled for 20 lavage treatments, received only 11 before its accidental death. The other four dogs that inhaled the radioactive aerosol were not lavaged. Two additional dogs, exposed to an aerosol of fused clay containing stable cerium, also received 20 lung lavages; 10 per lung over an 84-day period. A mean of 52% of the initial lung burden was removed as a result of the 20 lavage treatments of three dogs exposed to the radioactive aerosol. The removal of 144Ce by lavage resulted in the reduction of the cumulative radiation dose to lung to 90 days by 46% and potential infinite dose by 53%. When the results of the accelerated schedule of 10 lavages within 24 days were compared with those from an extended schedule of 10 lavages within 56 days, the average amounts of ILB activity removed were similar, 41.4 and 44%, respectively. At 14 months post-exposure, the three remaining lavaged dogs are alive and under observation. Three of the four dogs that were exposed to the radioactive aerosol but not lavaged died between 7 and 8 months post-exposure. The remaining 144Ce exposed, unlavaged dog is alive at 18 months post-exposure.