NEECREST SBEST Te eo lay esety ye oe Piles Decembef 31, 1956 ?. A. Sullivan, Envircanental Sciences Branch, DSM RADIOACTIVITY (BETA) IN FISH TISSUES AT RONGCELAP ATOLL Or. Seymour furnished the following data by telephone this morning: “Average gross beta values for Rongelap fish in teres ef micro curies per kilogram of wet tissue are as follows: ARO, % 7 yet . 1. March 1958, Kebelle Island reef fish - auscle .026, whole fish apprexinmately .16. 2. March 1958, Rongelap Island reef fish - muscle .006, whole fish approximstely .010. 3. dAnguet 1958, Rengelap Island reef fish - average naximm value for muscle is .065. 4. Current average valves are as low or lewer than values frou any of the previous collections. _ Leotopic coupesiticn of emmples: a —"— ISHSICN BO . 1. The estimated amount of K-40 in wescle is approximately .003 micro 2. Zinc 65 is the principal gemma emitter in fish auscle. 3. Traces of Cobalt-60 are also present. 4. Only other isotope expected in measurable amounts in fish muscle would be iron 55. 5. Stroatiue-90 has not been found in fish auacle in either the 1956 cc: curfes per kilogran. Maximus value from August 1955 collection is 0.2 wicre curies per kilogran. er 1957 collection. " Dr. Dr. ‘Dr. Dr. Dunhen Wolfe Boss Suoning