“| INTRODUCTION A radiological survey was conducted from September through November of 1978 to assess the concentrations of persistent manmade radionuclides in the terrestrial and marine environments of 11 atolls and 2 islands in the Northern Marshall Islands. The atolls and islands are shown in Fig. | and include Likiep, Mejit, Ailuk, Utirik, Wotho, Ujelang, Taka, considerable Rongelap, information Rongerik, on the Bikar, Jemo, radiological Ailinginae, and condition of Bikini. Enewetak There is Atoll.! “4 Concentrations of radionuclides on specific islands of Bikini Atoll have also been well documente d.>7!6 However, little radiological information is available for the remainder of the atoll or for other atolls that were considered most likely to have received fallout from nuclear tests conducted at the Pacific Proving Grounds between 1946 and 1958. This survey was essentially designed as a screening survey, which would be used to determine whether or not further detailed sampling effort might be required at any of the atolls. It consisted mainly of an aerial radiological reconnaissance to map the external gamma-ray exposure rates over the islands of each atoll. The logistical support for the entire survey was designed to accommodate this operation. As a secondary phase of the survey, shore parties collected appropriate terrestrial and marine samples to assess the radiological dose from pertinent food chains to those individuals residing on the atolls, who may in the future reside on some of the presently uninhabited atolls, or who collect food from theseatolls. Over 5000 terrestrial and marine samples were collected for radionuclide analysis from 76 different islands. Soils, vegetation, indigenous animals, and cistern water and groundwater were collected from the islands. Reef and pelagic fish, clams, lagoon water, and sediments were obtained from the lagoons. A considerable amount of radionuclide concentration data has been generated from the analyses of these samples. Results from different phases of the program appear in separate reports. In the first report of this series we describe the general operation of the survey, the type and quantity of samples collected, locations sampled, and the methods used to process and analyze the samples. !” The second report summarizes the radionuclide concentrations in cistern water and groundwater sampled at the atolls and the radiological dose assessment from ingestion of water from atoll supplies. !8 The third report summarizes the radionuclide concentrations in fish and the radiological dose assessment for the marine pathway.!? Another report planned describes our analytical quality-control program coordinated by Dr. C. D. Jennings of the Western Oregon State College. In addition, some results are being summarized for publication in international scientific journals.