C . ; - ~~ the ancunt of radiation received. In other words, the symptoms of the individual or groups of individuals becomes in a sense a personal indicator of ones' own fate, Ex- perience with human radiation injury in Firoshima and Nagasaki (4,5,10,11) with | reactor accidents (3,6,9) and the fallout accident (1,18) to be described later strongly suggest that the best incex of the seriousness of exposure of the individ~ ual is the syaptomatology, in addition to the physical estimate of dose, Radiation injury is complex and subtle, and the manifestations of the injury vary considerably. In a general sense, individuals exposed in the lethal range, (here some, but not all, will die in the first several weeks following exposure) can be divided accoriing to syaptoms and signs, into groups having a different prognosis, Thue they may be divided into three groups in which survival is, res- pectively, improbable, possible, and probatle. It will te apparent that there is no sharp line of dasarcution axcong the groups, The distinguishing features are severity and persistence of vomiting and diarrhea, Group I Survivel Improbeble: if voriting occurs promptly or within a few “ours and continues and is followed in rapid succession by prostration, diarrhea, anorexia and fever the prognosis is grave; death will elmost definitely occur in 100% of the individuals within the first week. There is no known therepy for these people; accordingly in a catastrophe attention should be devoted principslly to others for whom there is some hope or in wiom therapy is clearly indicated. Group II Survival Possible: Vomiting may occur early but will be of relatively short curation followed by a veriod of well being. In this period of well being marked cl.anges sre taking place in the heropoietic tissues. hours and rezain so for aonths, Lymphocytes are profcundly depressed within The neutrophil count 1s depressed to low levels, the decree and time of maximum. depression depending upon the dose. Signs of in fection nay be seen when the total neutrophil count has recened virtually zero DOE ARCHIVES 3S