HUMAN RADIATION INJURY maximum bleeding was observed in Japanese who were exposed at Hiroshima and Nagasaki. This time trend in the platelet count and the development of hemorrhage is in marked contrast to that seen in laboratory animals whenplatelets reach their lowest level around the 10th to 15th days and hemorrhage occurs shortly thereafter. In this group, individuals with neutrophile counts below 1,000/mm* maybe completely asymptomatic. Likewise, patients with platelet counts of 75,000/mm} or less may show no external signs of bleeding. It is well knownthat all defenses against infection are lowered even by sublethal doses of radiation and thus, patients with severe hematological depression should be kept under close observation and administered appropriate therapy as indicated. 6.6 Relative Hazards of Beta and GammaRadiation From Fallout Comprnep Bera Burns to the skin and whole body gammaradiation injury can be sustained, as in the present experience. However, situations may occur following fallout in which prompt evacuation from the area would limit the whole body dose to minimal levels, but in which delay in decontamination of the skin would permit severe radiation burns. The reverse situation is not only conceivable but oc- curred to a limited extent in the Marshallese and Americans. Those, who were inside, and or completely clothed, received practically no skin burns but received apparently the same degree of whole body radiation. One might also be exposed in the open, decontaminated promptly and then enter a shelter because of delay in exacuation. Under these circumstances, one would receive predominantly whole body radiation injury. Jn the course of the present accident the presence of some open skin burns did not seem to exert a deleterious influence on the spontaneous course of the hematologic depression. However, with more severe degrees of hematologic 103 depression open wounds of any type would present additional potential portals of entry for bacteria. Certainly in the case of thermal burns (23, 24), the chances of recovery are diminished as a result of the combined injury. 6.7 Therapy of Radiation Injury Tue Trearment Or acute radiation injury has been discussed (25). It is essentially that which sound clinical judgment would dictate. Supplies and medications are those indicated for any mass casualty situation, and emphasis shouldlie chiefly on the magnitude of the supply problem. Antibiotics will be required in large amounts to combat the infection that plays a large role in morbidity and mortality among irradiated individuals, and blood, plasma and other intravenous fluids will be required to correct the shock, anemia and fluid imbalance. These agents should be used, as in all clinical conditions, whenclinical and laboratory findings (if laboratory workis possible) indicate their need. Any marked prophylactic value of these agents has not been demonstrated, and considerations of probable short supply in the face of overwhelming demand would militate against their use in the absence of clear clinical indications. There are no drugs specific for radiation injury in man. Considerable progress has been made in developing agents effective in animals if given prior to irradiation. Of great experimental interest in post exposure therapy has been the development of effective therapy by injection of splenic and bone marrow preparations. However, the extreme lability and genetic specificity of these preparations indicates that these agents may never be of practical value. In addition substitution therapy by transfusion of separated platelets and neutrophiles to combat hemorrhage and infection is of experimental interest but at present techniques are not sufficiently developed to warrant consideration of stockpiling. There are no specific drugs for the treatment of beta lesions of the skin. Careful cleanli-