proximity to the fallout area, This study included Rongelap, Uti- rik, and Rongerik again as well as Bikar ard Ailinginae Atolls, The heaviest contamination was found at Rongelap and Rongerik Atolls with an average reading on Rongelap Islarid at the same atoll of 375 mr/hr and an average reading on Eniwetok Island at Rongerik Atoll of 280 mr/nr, Readings from soil samples taken from throughout Rongelap Atoll were as high as 2200 mr/nr and reddings of water samples were high as 400 mz/hr, ~ Important conclusions based on the results of these surveys were drawn, First, it was proved that a large yield surface de- tonation can produce extremely serious radiolegical contamination over a distance of more than 120 miles and significant contamin~ ation for a distance of about 250 miles. The degree of fallout generated from such a high yield detonation nad not been indicated by the MIKE detonation of Operation IVY. Second, the center of the ccntamination pattern for|Sor[appeared to lie somewhat north of Rongezap and Rongerik Atolls and probably not far from a line drawn between Bikini and Bikar Atolls. Third, contamination was greatest on the north side of Rongelap Atoil and decreased by a factor of about eight over the downwind distance of fifty miles between Rongelap and Rongerik Atolls, Finally, it was seen that the standard military field housing being utilized by Task Force personnel on Rongerik provided a significant degree of protection from contamination to personnel inside, There has been earlier discussion of the effect of the afloat 152