EFFECTS OF FALLOUT RADIATION 281 The accident oecurred after the detonation of a large thermonuclear device during experiments at Bikini in the Pacifie Proving Grounds. An unpredicted shift in winds caused deposition of significant amounts of fallout on four nearby inhabited Marshall Islands and on 23 Japanese fisherman aboard their fishing vessel, the Lucky Dragon. 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 whole-body y-radiation, 8-ray lesions of the skin and epilation from con- tamination of the skin, and slight internal absorption of radioactive material. Eighteen Rongelap people away on a nearby island (Alinginae), where less fallout occurred, received about 69 r. [Discussed in earlier reports (10, £2) but not in this report were 28 American servicemen on Rongerik Atoll who received about 70 ¢ and 157 Marshallese on Utirik Atoll who received ubout 14 r.] The people were evacuated to Kwajalein in the Marshall Islands by air and sea about 2 days after the accident. Extensive examinations were carried out during the first 3 months after exposure, and these findings have been reported in detail (72). In viewof the radioactive contamination at their homeisland of Rongelap, the people were subse- quently moved to a village provided for them at Majuro Atoll where further follow-up medical surveys were carried out and reported on at the following periods after exposure: 6 months (5), 1 year (13), 2 years (9), and 3 years (10). Details of the 4-vear findings are being published (17). By June, 1957, the radioactivity levels on Rongelap were considered safe for habitation, and the people were returned to their home island where the present examinations were carried out. The medical team for the four-year survey consisted of 22 doctors and technicians ineluding personnel from Brookhaven National Laboratory, the U. 8. Public Health Service, the Naval Medical Research Institute, the Naval Radiological Defense Laboratory, and Marshallese from the Trust Territory medical group.® Il. EXAMINATIONS A. History axp PuysicaL EXAMINATIONS Histories were taken by a Marshallese practitioner, with particular emphasis on the interval history during the past year. Complete physical examinations carried out on both exposed and comparison populations included examination of the skin, with color photography of selected lesions; ophthalmological studies including slit-lamp observations, visual acuity, and accommodation; growth and development studies in children (less than 20 years of age) including anthropometric studies; eleetrocardiographic records on all subjects over 40 years of age; and X-ray examinations as deemed necessary. oSY Lo Pum oe ® Survey material presented represents findings of the entire team. This paper was not written by all members of the team, and the conclusions presented do not necessarily represent their point of view. Detailed findings of the 4-vear survey are being published (/1).