Charles L. Dunham, M.D., Director dune 15, 1956 _ Division of Biology and Medicine Gordon M. Dunning, Health Physicist Division of Biology and Medicine 4001 9) RONGELAP SURVEY DATA I have just made a quick run throngh the final report from HASL on their analysis of the samples from the Rongelap Survey, October 1955. 1. There are four points you may be interested in: | In your memorandum to Dr, Libby in the middle of April, 1956, it was estimated that the coconuts with the highest contamination might be about 1,300 Sunshine Units. 1,200 s.u. The HASL report indicates 2. In the same memorandum it was estimated the highest activity in the vegetable-fruit supply might be 7,700 s.u. The average HASL value (minus the squash and arrowroot data) is about 800 3.u. The arrowroot was reported at 5,500 s.u. There were no data given on Strontium-90 for squash in the final report, but judging from the relative mixed fission product activities, it would be higher than arrowroot. The differences between the estimates and final report may be principally accounted for in the substantially higher percentage of Caicium actually found in the samples compared to the original estimates, 3. The average activity of fish mscle is 77 s.u. lh. Due to the high percentage of Calcium in the soils, the measured S.U. are substantially lower than those estimated by Dr. Libby. highest was 852, the next 86 and the lowest 9.5 s.u. DATE >» Form AEC-318 (Rey. 9-53) 2002014 U.S. GOVERNMENT PRINTING OFFICE 16—--62761-3 The