Running heading Effects of Fallout Radiation on Marshallese Background This discussion concerns a brief account of the present health status of the Rongelap people who were exposed to the heaviest dose of radiation from accidental fallout in March 1954 following detonation of an experimental nuclear device at Bikini in the Marshall Islands. An unpredicted shift in winds caused deposition of significant amounts of fallout on four nearby inhabited Marshall Islands and on 23 Japanese fishermen aboard their fishing vessel, the Lucky Dragon. (See Figure 1.) Sixty-four inhabitants of the island of Rongelap, 105 nautical miles away from the detonation, received the largest fallout — an estimated dose of 175 r of whole-body gamma radiation, indeterminate beta ray dose to the skin from contamination of the skin and internal absorption of radioactive fission products. Eighteen Rongelap people away on a nearby island (Ailingnae) whereless fallout occurred received about 69 r with proportionately less contamination of the skin and internal absorption of radionuclides. Dis1 This work is supported by the U.S. Atomic Energy Commission 2 Brookhaven National Laboratory, Upton, N. Y. 4 South Nassau Communities Hospital, Rockville Centre, N.Y. 4 M.D. Anderson Hospital, Houston, Texas 5 National Institutes of Health, Bethesda, Marvland 68 Walter Reed Army Hospital, Washington, D.C. * Memorial Hospital, New York, N. Y. % Atomic Bomb Casualty Commission, Hiroshima, Japan ® Naval Medical Research Institute, Bethesda, Maryland NUCLEAR-MEDIZIN 3E4