About 50 hours after the "shot", the Navy removed the 64 Rdngelap residents from the Atoll to the medical base at Kwajalein (Sharg & Chapman, 1957; Cronkite et al, 1956) Also, eighteen visiting Rongelapese were removed from Sifo Island, Ailingnae Atoll, and[i57 Utirik people from Utirik Atoll. It was immediately recognizedithat the surveillance and care of these people required far more profess{jonal staff than the base could supply, and a special medical team hufriedly organized for this purpose in the United States, utilizing naval and AEC personnel, reached the base 8 days after the detonation. Consistent with a whole-body dose of 190 rem (over two day two-thirds of the Rongelap group experienced nausea, 10% with v and diarrhea, which cleared within three days or so, and ail s depressed white-blood-cell counts (Cronkite et al, 1956). As the skin dose from physical contact with fallout, about 70% de skin lesions of widely varying severity after a latency period three weeks. Most of these were to heal successfully but a fe significant scarring. result of loped f two to developed The most "significant" part of the initial exposure produ immediate signs or symptoms. A half-dozen thyroid-seeking rad entered the body through fallout-contamination of food and wat the course of the following weeks these iodine and telluriun radionuclides delivered doses that eventually caused thyroid h and the appearance of thyroid tumors. The Bravo test posed new dosimetry problems, only vaguely before. Owing to the gigantic energy-yield at ground level, g quantities of coralloid radioactive material were generated (E and Nagasaki had involved high air-bursts): 142 radionuclides involved whose radiations and rates of decay varied greatly, a eventual effects depended on the weather conditions and the lifi of the exposed population. At the time of evacuation, the exposure rate in Rongelap 1.2 - 2.3 R/hour. The whole-body dose of "175 R in air” repor was approximately correct. The dose estimate for the thyroid however, was much too low because only iodine-131 had been co the calculation. As a result, the appearance of thyroid dise was quite unexpected. ed in 1956 land, idered in e later on An upwards revision of thyroid dose was reported in 1964 lodine-133 and iodine-135 were included. (James, 1964). The 1984 (Lessard et al, 1985; Lessard, 1984a), based on a compre planned attack on the problem (Bond et al, 1978), put the mea whole-body dose at 190 rem. The revised total dose to the th including contributions from all seven important radionuclide greatly increased and varied significantly with age at exposu -~- from 5,200 rem for a one-year old to 1,600 rem at age 14, nd 1,200 rem for the adult male. It was estimated that 95% of the thyr id dose was received during the first three post~exposure weeks, and 100% within three months (Note 4).