Preface and A\cknowledgments Two to three days after the fallout on the Marshall Islands in March 1954, 82 people were evacuated from Rongelap and Ailiginae Atolls and 154 from Utirik Island. In June of 1954, the 154 personnel were returned to Utirik, and in the spring of 1957 the decision was made to return the Rongelapese to their homeisland. Since March 1954 periodic surveys have been made of these islands to investigate the degree of contamination. Soils and biological collections were made on and around the Marshall Islands by the Applied Fisheries Laboratory (AFL) of the University of Washington on March 26, 1954, July 16, 1954, December 8 and 18, 1954, January 25-30, 1955, October 21-23, 1955, November7, 1955, and July 23-24, 1956; by the Naval Radiological Defense Laboratory (NRDL) on February 1955 and February 1956. Analyses of the samples also were performed by AFL, NRDL and by the Health and Safety Laboratory (HASL) of the Atomic Energy Commission. Surveys were also made of residual activity in the Pacific Ocean by Health and Dr. Ralph F. Palumbo, Mr. Paul R. Olson, and Major Charles Barnes, USAF on assignment from the Air Force Veterinary Corps to the Applied Fisheries Laboratory. ‘In addition, Dr. Thomas Shipman, Dr. Thomas N. White,* P. R. Schivone, and W. W. Robbins accompanied the expedition to aid the natives in capturing some of their animals on Rongelap Island and to makeradiation readings on some of the islands in the southern part of the atoll. April 18, 1954 (SA-16 Naval Aircraft). U.S. Naval Radiological Defense Laboratory and Naval Medical Research Institute: Dr. Stanton Cohn, Lt. R. 8. Farr, P. E. Thompson HMC, J. C. Hendrie, HML, and J. Flannigan, NM1. quoting the original reports out of context. It should be understood that the original authors E. Held, Mr. Paul R. Olson. if there be any question it is recommended that reference be made to the basic documents (see references). we Applied Fisheries Laboratory: Dr. Lauren R. Donaldson, Director, Dr. Edward E. Held, December 8, 1954 (U. S. N. PBM No. 2471). are not responsible for any such violations and Bey 8 March 26, 1954 (USS Nicholas, DDE 449). Safety Laboratory of the AEC and Office of Naval Research in February-May 1955; by the Applied Fisheries Laboratory in June and September 1956. In addition, teams of medical experts from the United States examined and cared for the Marshallese following their exposure in March 1954, and returned to reexamine the Rongelapese at about six months, one year, and two years after exposure. The purpose of this report is to abstract the highlights of the data from these investigations. In doing so there is the risk of unintentionally 7 The following personnel participated in the field expeditions: July 16,1954. (U.S. Navy Gruman Albatross, ASR-16, No. 902). Applied Fisheries Laboratory: Dr. Lauren R. Donaldson, Director, Dr. Frank G. Lowman, Dr. Arthur D. Welander and Lt. Commander Clarence F. Pautzke, USNR Aquatic biologist on active duty status for special training. Applied Fisheries Laboratory: Dr. Edward AEC Division of Biology and Medicine: Dr. Walter D. Claus, AEC Radiological Safety Officers,Mr. Robert Taylor and Mr. William Blakeman. *Deceased.