Weee suctad up tion, clezl. Enenus:s of ‘ 4 ar , an vapvodicted shift in wind direc: redloactively contaminated fallout was deposited on Ronyolap, Allingnus and Utirik atolls. On Rongelep, the fallout was deseribed ag “snow-like" which coated the ground aud vegetation and forned depos dts on the hair anc skin of the peopl:. _Less dense "mist-like" fallout was noted Ailingnze, some 49 on Ailingnae. miles south of Rongelap, wes actually closer to Bikini but it was situated more out of the line of the cloud passzrue. No visibls evidence of fallout was observed on Utirik, 250 miles from Bikini. Fallout comnenced on Rongelap and Ailingnae 4 to 6 hours after the deton= ation of the bomb. the explesion. The radioactive cloud reached Utirik about 22 hours after Evacuation of the contamin ated islands was accomslishad ap- proximately 48 hours after the commencemont of fallout 5, 3 Exposure to radiation involved whole body gemma dose from environment- ally depos ited radioactive fission products, superficial dos es from beta and soft ganna radiation and doses frou internal absorption (through inhalation and ingestion) of radionuclides. The extern al whole body pamna dose has been computed to be 175 rad on Rongelap, 69 rad on Ailingnac and 14 rad on Utirik (Tabie I). Based on culations from radiochemical urine analyses » it has been estimated that the . thyroid gland aceunulated about 11.2 uCi of 131, , 2 lived isotopes, 121, 1337 In ddition, the shorter- ond 135), added considerably to the dese. The most proebeble dose to the thyroid gland of Rongelap Island children “Less . than 4 years of age has been rad>»6, calevlated to be in the range of 700 to 1400 Except for the thyroid gland, the dose from absorbed radioactive material oopears to have been minimal with no discernible biclocies!] effects,7, 5001324