ABSTRACT This report is intended as a resource document for the eventual cleanup of Bikini Atoll and contains a summary of the data for the concentrations of 137¢cs, 90sr, 239+240pu, and 24]aAm in vegetation through 1987 and in soil through 1985 for 14 islands at Bikini Atoll. The data for the main residence island, Bikini, and the second most important island, Eneu, are extensive; these islands have been the subject of a continuing research and monitoring program since 1974. Data for radionuclide concentrations in ground water, cistern water, fish and other marine species, and pigs from Bikini and Eneu Islands are presented. Also included are general summaries resuspension and rainfall data from Bikini and Eneu Islands. of our The data for the other 12 islands are much more limited because samples were coilected as part of a screening survey and the islands have not been part of a continuing research and monitoring program. Cesium-137 is the radionuclide that produces most of the estimated dose for returning residents, mostly through uptake by terrestrial foods and secondly by direct external gamma exposure. measures for reducing the !37cs uptake in vegetation are discussed. Remedial INTRODUCTION In the fall of 1978, a radiological survey was made of Bikini Atoll and 11 atolls or islands east and southeast of Bikini. are located in the general These atolls or islands direction of the fallout pattern that originated from the BRAVO test on March 1, 1954 at Bikini Atoll (Fig. 1). This survey, referred to as the Northern Marshall Islands Radiological Survey (NMIRS), was planned to be an aerial radiological reconnaissance to map the external gamma-ray exposure rates over the islands of each atoll. However, an earlier dose assessment of Enewetak Atoll] (US AEC, 1973; Robison et al., 1981c) and a preliminary dose assessment of Bikini Atoll (Robison et al., 1982b) indicated that the most significant potential exposure pathway at the contaminated atolls was the terrestrial food chain. Therefore, we Suggested (in addition to the external gamma aerial survey) that sampling of soil, vegetation, ground water, cistern water, and marine species be included’ as part of the program. 9000308 Thus, the final survey plan incorporated a secondary