INTRODUCTION The U.S. nuclear testing programs of the 1 940s and 1950s had significant local environmental impacts on the coral atolls of Bikini and Enewetak in the Marshall Islands. The high levelclose in fallout made these atolls uninhabitable for many years. Fallout from the BRAVO event, which took place at Bikini in 1954, was inadvertently deposited on the nearby Atolls of Rongelap, Rongerik and Utirik. In all, some thirteen atolls in the northern Marshalls were probably affected to a greater or lesser extent by fallout from these nuclear tests. Of these, however, the most significant long-term radiological impact was for the test Atolls, Bikini and Enewetak, and for Rongelap Atoll. In 1957, Rongelap was reoccupied by its original inhabitants who had been evacuated within about two days after BRAVO. During the past several years, definitive plans have been made to repatriate the original inhabitants of Bikini and Enewetak Atolls, and their families. It is hoped that their return can take place soon. In order to identify radiological problems from residual radioactivityin the environment, and to provide a data base for dose predictions applicable to the returning populace, ERDA (and its predecessor, the AEC), has sponsored many radiological surveys in the Marshall Islands. These surveys began during test operations and have been conducted periodically up to present time. the Results of the surveys have been published in numerous reports and scientific journals, References ] through 12 are published reports of AEC/ERDA supported surveys of these atolls. References 13 through 29 are a portion of the published reports on work with collected environmental samples supported by AEC/ERDA. Evaluation of survey results for Bikini Atoll, the consideration of predicted exposures compared with applicable radiation standards, and the acknowledgement of the many benefits to the people if they could return, ™ ~~ TT TF, *] oa “TH! ro ee