Chapter VII — The Radiological Surveys for Residual Radiation A. The Surveys The Atomic Testing Program in the Pacific contaminated the atolis of the Northern Marshali Islands to varying degrees. The greatest contamination on theatolls of Bikini, Rongelap, Ailingnae, Rongerik, and Utirik was from the Bravo detonation in 1954. Atolls just to the southof this group received a small amount of contamination, and there was slight additional contamination from othertests. The effects of the testing program on their atolls have been deeply resented by the Marshallese people and have presented the United States with increasing problems since 1958 when the moratorium against testing in the Pacific was declared. The people who were displaced before and during the testing program have been disappointed in the length of fime ._— away from their homes. This is particularily true of the people from Bikini, who have lived elsewhere for 44 years. These displaced people have exerted considerable pressure on the U.S. authorities to return to their homes; even so, they had some uneasiness aboutresidual radiation on their islands. Unfortunately,in spite of reports, ta thacantrary,thisfeardfrédidtion._ and the suispician:that ihoERSeb played.downthedangers ofresidut!Mout” resulted, in-1986+ istcheevertrationofthe’?=*= Rongelappeepia:whehadteeh’reséettédop . their island for 26¢ears7Osi >. ane 5 rss Numerous radiological surveys of the contaminated atolls were carried out to (a) deter- mine radiological safety for rehabilitation of the ’ displaced islanders, and (b) study the radioecoiogy of the fallout on the islands and surrounding ocean. These surveys were conducted before and continued after the return of the Rongelap and Utirik people; the surveys provided valuable information on the radiological safety for habitation, based on movements of radioactive elements from the soil through the marine and plant food chain to humans. The contaminated environment of these islands provided tracer. quantities of tagged elements, on a scaie impossible to achieve in a planned experiment. These the radiological surveys were conducted by the University of Washington Schoolof Fisheries Laboratory (now the Laboratory of Radiation Biology) (A-41-45, 47), the Naval Radiological Defense Laboratory (A-2, 31), the Safety and Environmental Protection Division at BNL. (A-52, 52, 54), and the University of California Lawrence Livermore Laboratory (A-49, 50). On several occasions, the University of Washington | group accompanied the Medical Team on the surveys. The Japanese have independently carried out oceanographic surveys (B-8). Shortly after the accident we obtained several animals (pigs, chickens, and ducks) from the deserted villages at Rongelap and Utirik; also, some fish and clams were brought back. The animals, although contaminated with radioactivity and malnourished, showed no effects of radiation exposure (A-31). Internally absorbed radioactive materials were found largely in the intestinal tract, with only slight activity in the lungs, suggesting that the most important route of internal radiation absorption was from ingestion of contaminated food and water rather than from inhalationof radioactive material" = 2257" -Nh gic tie. gosape ee “At the ttheoftiePeedi ee,the radidactive¥lenients of.cotitérnwerecesium (Gaia gamingedtitterothhale“lifeof 30., yease),strontiuny (SF. 'abetaex pith tans half-life of28.yeareytaeriael‘ a,a.gamma, emitterwith«Half-life ofoFdays). Smali amounts of other radioactive elements, such as cobalt (*°Co) and iron (**Fe) (A-45), were of much less concern. Low levels of plutonium were noted and will be referred to later. The radioactive iodines were no longer of concern, because they had practically decayed away. The other radioactive elements, cesium and strontium, were found in low amounts mainly in the pandanus, coconuts, breadfruit, and arrowroot plants grown on theislands. Unexpectedly high levels of radioactive cesium and strontium were found in the coconut crab, a great delicacy to the Marshallese (On Rongelap they were temporarily banned from the diet). Examination of the Marshallese people when studies have been an important adjunctto the medical assessmentof radiation exposure to the ' they returned to live on their home islands imposed a unique, added responsibility to the Marshailese. Under the aegis of the AEC/DOE, IOGE TEE 29