was all due to the fallout with no physical trauma or thermal burns and litele or no psychic trauma. Table I shows the island groups involved. The 64 Marshallese on Rongelap atoll received the heaviest exposure and it is this group that has shown the major radiation effects. Effects in this group along with the 18 Rongelap people who were on Ailingnae island at the time will be presented here. Figure 1 shows a rough map of the fallout pattern involving these islands. All of the island groups were evacuated about 2 days after the accident and taken to a navat base to the south where extensive medical examinations and personnel decontamination were carried out over a 3 month period. At the end of this cime the American service men had shown few effects of theiv exposure to radiation and were returned to their stations. The Ucirik people had shown Little or no effeet of their exposure and were returned to their island. However, Rongelap island was too contaminated and the people lived in a temporary village in a southern atoll of the Marshalls for 3 years. In 1957 4 new village was built at Rongelap by the U.S. Atomic Energy Commissicen. The levels of radiation on the island at this time were considered acceptable and the people returned. Annual examinations by medical specialists from the United States and medical personnel from the Trust Territory of the Pacific Islands have been conducted under the direction of Broothaven National Laboratory. Scme 200 unexposed Rongelap people, away from the istand at the tiine of the accident, have moved back with their exposed relatives and serve as a most satisfactory comparison population. EARLY FINDINGS The penetrating gamma radiation dose of 175 rads resulted in temporary anorexia and nausea in the majority of the people with vomiting and diarrhea in a few, Within a few days after exposure the lymphocyte counts showed significant depression and soon reached levels that were one-nali or below that of the unexposed comparison populations. The neutropail counts became similarly depressed reaching a minimum at about 6 weeks post exposure. Platelet levels dropped to one-cighth to one-third normal levels by 30 days. The exposure proved to be sublethal and there were no infections or frank bleeding that could be related directly to observed hematologic changes. No specific therapy was necessary or given for their depression of blood cells. The deposit of fallout material o:1 the exposed skin surfaces of the people resulted in itching and !}.sur ng sensations during the first 2 days followed by a development . .esions of the skin at about 2 weeks post exposure. These so-called “beta burns" showed a sequence =2-