calibrated film, or theory, oy a factor of 0.7. That is to say, the relative bio- logical efficiency of nuclear radiation was greater than unity when compared to supervoltage X-ray, These considerations indicate the need for further study of the energy dependence of biological effects caused by ionizing radiations with energies greater than 1,0 Mev. 9, BLAST INJURY On "TTEM" shot, sixteen dogs were placed in 8 foxholes, 6 X 3 X 4 feet deep at distances ranging from 400 to 1,500 yards from ground zero, and pressure gauges were also installed. ‘the occupants, Radiation dosimeters The hole at 400 yards collapsed, burying Live animals were recovered from all others, Severe radiation in- jury was sustained by all animals except those at 1,250 and 1,500 yards, Blast in- jury to the lungs and brain which might have been fatal ultimately was observed in animals placed at 600 and 800 yards. 10, CLINICAL STUDIES a, Clinical studies of the characteristics and the time trend of radiation injury were performed, In the case of swine, such studies consisted of serially killing all of the group exposed to the same supralethal dose of gamma radiation, These animals were killed at intervals of hours and days during the first two weeks after the blast to determine the sequence and the extent of the pathological changes that occurred, In the case of the mice, 2,400 survivors of the dosage mortality study were returned to the Oak Ridge National Laboratory for life time study to obe -gerve the effects of nuclear radiation on longevity, the incidence of cancer and the occurrence of cataracts, b, The clinical studies were successful and excellent Kodachrome photow graphs were obtained of every stage and type of radiation injury. The most signi~ ficant findings (on the basis of gross examination alone since the histological specimens are still being studied} was the early evidence of injury to the intestinal mucaus membrane, This early lesion disappeared after a few hours, but within sever~ al days another rere severe involvement occurred, The gross appearance of these lesions suggested a vascular injury rather than damage to the epithelium alone, This observation is quite valuable and should become the basis for extensive experimental work in the future, Taken as a whole, the gross pathological findings indi-~ cated the essential similarity of radiation injury in man and large animals regardless of whether the source is a nuclear explosion or exposure of the whole body to supervoltage X-ray. Bacteriological studies failed to disclose bactermia except as a terminal finding in dogs and swine. In spite of this finding, it appeared that See Spied Per ATA RosatoDATA RyOMIC FAESEY ACT ~~ 1845