sys rer. ran . ed MY cae Cwta NO NAT ag « ‘ iy wae Gd he oNDLK VOTO BMG LORURE | how t Summary oo the Racwoioica. Status of the Bikini Atoll! Phiiip . Gustafson Fullout Studies Branch Diviston of Biology and Medicine - May 1968 , A number of radiological surveys of Bikini Atoll have been made sinc: iY4o. The most recent survey was conducted in April and May 1967. The “son eriort was dovoted to the measurement of ambient radiation levers usit, noveral types of detectors. The external radiation field was mappedin con- eiderabie detail on Bikini and Eneu Islands, and less thoroughly on the remainder of the atoll. The various radionuclides and their concentrations which gave rise to the observed radiation field were determined from field yomma-ray spectrometry. Representative samples of local plants and animals wousch mepht be caten by the returning natives were collected and have been analyzcd for radioactivity. The results of the 1967 survey provide a basis for making reasonable estimates of the total (external plus internal) radiation exposure which tue Bikinians might receive over the coming years, atoll. if they return to the background radiation on the atoll is. duc almost exclusively to cosmic radiation, and there are only trace amounts of the naturally occurrii radioelements in the area. Except in the immediate vicinily of nuclear a Conations, the composition of the residual gamma-ray radioactivity was vimilar throughout the atoll, consisting of about 70% 137¢s, spy, ‘ye 20%, 90 Cy, and 10% 'o place; Encu was 125. b. the oa ; -placc Variations in intensity were observed from least contaminated, followed by Bikini Island itselt. oo higasSt values in the heavily overgrown interior. web Vad - SAR bake Mame gf . Wanguo Cubbeoy, ay, wae 8, 8, noes — A Jose «radient existed across Bikini, with lowest levels on the beach areas, oan atel "bey i? oo tag ete States. Jd