I. Introductory remarks, This report concerns the present status of the 82 Marshallese people from Rongelap Atoll, 4 years after the sccideital exposure of this population to significant amounts of fallout radiation. The accident oc=- curred following the detonation of a large thermonuclear device during experiments at Bikini in the Pacific Proving Grounds. An unpredicted shift in winds caused deposition of significant amounts of fallout on 4 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, recaived the largest fallout; viz. an estimated dose of 175 r whole-body gamma radiation, beta lesions of the skin and epilation from contamination of the skin and slight internal absorption of radioactive material, Also 18 Rongelap people away on a nearby island (Ailingnae), where less fallout occurred, received only about 69 r. (Discussed in earlier reports but not in this report were 28 American servicemen on Rongerik Atoll who received about 70 r and 157 Marshallese on Utirik Atoll who received about 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.(m) In view of the radioactive contamination at their home island of Rongelap, the people were subsequently moved to a village provided for them at Majuro Atoll where further followeup medical surveys were carried out and reported on at the following periods after exposure: and 3 years.(D} 6 months, (5) 1 year, (3) 2 years,(9) Details of the 4 year findings are being published. (i) By june, 1957 the radioactivity levels on Rongelap were considered safe o-l-