Re On March 1, 1954, human beings were accidentally exposed to radiation from fallout, Approximately five hours or longer after the detonation, the fallout commenced, Marshallese and Americans were involved. The exposed individuals consisted of four groups, depending on location: Rongelap 68 Marshallese Ailinginae 14 Rongerik 28 Americans Utirik it 175 r. 78 # 159 Marshallese 69 " 14" (Make a slide) The task force did not have a bio-medical program, and as soon as possible, a medical team and eqhipment was assembled between the Naval Medical Research Institute and the U. S. Naval Radiological Defense Laboratory, and transported to the field commencing studies on the ninth post-exposure day. Interim care and study was provided by the Medical Department, U.S. Naval Station, Kwajalein, to which all exposed people had been evacuated, On Rongelap, and to a lesser extent, on Ailinginae, the fallout was visible and was described as a light snowfall. coral, coated with FP. The material consisted of flakes of CaO, incinerated The material clung to skin, clothes, vegetation and buildings, thus producing a large planar source of gamma radiation and multiple small sources of 8 radiation when in contact with the skin, minate amounts of the material were inhaled and ingested. Indeter- The overall result was the production of relatively uniform whole body irradiation, spotty 6 irradiation of the skin of varying degree, and the internal deposition of some radionuclides. I shall describe the exposure conditions, the general symptomatology and management, and others will amplify on the problems of hematologic changes, cutaneous lesions and internal deposition,