of planning, marine an samples additional for a program was. included radiological dose to assessment obtain for terrestrial current or and potential inhabitants of the atolls. Therefore the objectives of the Northern Marshall Islands survey and assessment program were as follows. * Obtain aerial photos and aerial radiological maps of the Northern Marshall Islands atolls and islands. * Obtain samples of soil, water, vegetation, food crops, animals, marine life, lagoon water, and lagoon sediments. * Process, analyze, and determine the radionuclide concentration of the collected environmental samples. * Prepare reports describing the estimated doses for alternate living patterns at the atolls and islands. The Lawrence Livermore National Laboratory (LLNL) was responsible for the technical direction of the survey, work, and publishing of results. DOE was responsible interaction with for other subsequent sample processing, analytical The Nevada Operations Office (NVOO) of the program United management States in agencies the planning phases and departments and_ and the government and people of the Marshall Islands. The external gamma aerial survey was conducted from the major support vessel, the U.S.N.S. Wheeling, by EG&G with the support of the naval helicopter group HC-1 Detachment California. 3 from the North Island Naval Air Station, San Diego, TMe EG&G detector and data analysis systems were mounted on one of two helicopters (Sikorski H-3) carried by the Wheeling and grid lines over the islands at each atoll. flown on 46-m A complete report of the external gamma measurement program and the results is available as part of the Northern Marshall Islands survey assessment. The survey was conducted in three legs of about 20-d each. The sequence of atolls and islands visited during each leg is shown in Fig. 1 and listed in Table 1. The first leg of the survey included Rongelap, Rongerik, and Wotho Atolls Ailinginae Atolls. and Jemo and Mejit The second Islands. Taka, Utirik, leg included Likiep, On the concluding Bikar, Ailuk, third and leg we surveyed Ujelang and Bikini Atolls and made a limited stop at Enewetak Atoll. The terrestrial and marine programs were conducted with small boats and the helicopters using the Wheeling as an operation base. The time available for the terrestrial and marine surveys was dictated primarily by the length of