om o -( ~ \ a 7 purpa, end hypoxia due to enem4a, any one of which may be fatel, Meany detailed - descriptions of the pathogenesis of these phenomena have been published (1-4,12-16). The above picture of radistion syndromes is based on animal experimentation; however, human experience particularly as observed at Hiroshima and Nagasaki and in the Marshallese natives has indicated that man probably corresponds quite closely to the general marmalian response outlined above with the exception of some differences in time cf occurrence. The CNS apparently was not observed by the Japanese at Hiroshina and Nazgesaki. Cne weuld not expect it to have been observed since doses to produce this syndrome were well within the area of almost total destruction, The GIS with deaths in the first week are well documented clinically and patholosically as are deaths from the HS. However in the case of man, desths from infection were most prevalent in the second to fourth weeks (maximum incidence during the third week) and from hemorrhazic phenomena in the third to the sixth weeks (maximum incidence in the fourth week). In the Japanese, after the bembing of Hiroshima and Megercaki, deaths from radiation injuries were occurring as lete as the seventh week, This is in contrast to other animals where deaths from the acute phase are uncomion after the 30th day. PROBABILITY OF SURVIVAL AS RELATED TO SYMPTOMS Predictions of the effects of various doses of gamma radiation are essential to military and civil defense planning. If the absolute sensitivity of man to rediation were known, and if it were practical to determine the dose to groups under catastrophe conditions, a realistic statistical prognosis could be made. Fowever, these predictions cannot be made accurately at the present time, Problexs invclved with estimation of dose received by the individual, present real practical difficulties, It is probable that dose estimates will be evailable from dosinetry devices or-from dose contour lines and the position cof individuals during exposure. The difficulties of relying heavily on the dose estinates for a single individual are apparent. -The exact position of the individual and the degree co skielding DOE ARCHivere