aD 35 alterations were noted in serum chemical tests. pression of about 50%. There was leukocyte de- It was estimated that a feeding level of approx- imately22 pCi per day would have been required to achieve a 25% depression in the neutrophil level at four months of age (L. K. Bustad et al, Hematopoietic Changes in Beagles Fea 7°Sr, reference as above). At Battelle-Northwest Laboratory, Richland, Washington, miniature swine were exposed to strontium-90 feeding levels ranging from 1 to 3100 yCi/day. At ingestion levels of 25 uwCi or less per day for 7 to 10 years, definitive changes were infrequently observed in the formed elements of the blood except for swine showing true leukemia. The cumulative skeletal radiation dose re~ ceived by these animals ranged from 300 to 14,000 rads. At levels greater than 25 uCi/deythere was @ progressive decline in leukocytes and platelets, — and a terminal precipitous drop in red blood cells, noted at 3 to 64 months post-initilation of strontium-90 feeding at average accumulated skeletal radiation doses of 5,000 to 19,000 rads (W. J. Clarke et al, Strontium-90 ‘Induced Neoplasia of Swine, reference as above). . Beagle dogs have been injected intravenously with strontium-90 by scientists at the University of Utah College of Medicine (Dougherty and , Mays,. Bone Cancer Induced by Internally-deposited Emitters in Beagles, Annual Report CO00-119-240, Radiobiology Division of the Department of Anatony, University of Utah, College of Medicine, March 1969). Of twelve dogs that were given a single injection of 32.7 uci/Kg of body weight at an age of 1.4 years, six are still living some 10 years later. died, the average survival time was 9.7 years. Of the six that From this, one can surmise