AOR GOS MEDICAL SURVEY OF THE PEOPLE OF RONGELAP AND UTIRIK ISLANDS THIRTEEN, FOURTEEN, AND FIFTEEN YEARS AFTER EXPOSURE TO FALLOUT RADIATION (MARCH 1967, MARCH 1968, AND MARCH 1969) Introduction This report presents in detail the results of medical surveys carried out during the past 3 years (March 1967, 1968, and 1969) on the people of Rongelap and Utirik Atolls who had been exposed to fallout radiation in March 1954. Earlier findings are also reviewed. The last detailed report (BNL 50029)?! covered the surveys of March 1965 and 1966, 11 and 12 years after the accident. In view ofthe seriousness of recent findings regarding development of thyroid abnormalities, continuation of annual medical examinations and publication of detailed reports is considered important. These people had been accidently exposed to fallout radiation following a detonation of a high yield thermonuclear device during experimentsat Bikini in the Pacific Proving Grounds in March 1954. An unpredicted shift in winds caused a deposition of significant amounts of fallout on four inhabited Marshall Islands to the east of Bikini on this island and no skin effects developed. These data are summarized in Table 1. The exposed people were evacuated from these islands by plane and ship about 2 daysafter the accident and taken to Kwajalein Naval Base about 150 miles to the south, where they received extensive examinationsfor the following 3 menths. Duringthis period vigorous efforts were necessary to decontaminate the skin completely. In view of the generally negative findings on the American servicemen, theywere later returned to their duty stations. The Utirik people were also allowed to return to their homeisiand, where radioactive contamination wasslight enough te allow safe habitation. Because Rongelap Atoll was considered to be too highly contaminated, a temporaryvillage was constructed for the Rongelap people (includingthe 18 from Ailingae} on Niajuro Atoll several hundred miles to the south, where they lived for the following 314 years and were examined at yearly intervals by a special medical (see Figure 1) and a!so on 23 Japanese fishermen aboard their fishing vessel, the Lucky Dragon. Of the inhabitants of the island cf Rongelap, 105 nautical miles awayfromthe detonation, 64 received the largest fallout exposure: an estimated dose of 175 rads cf whole-body gammaradiation, contamination of the skin sufficient to result in beta burns, and slight internal absorption of ra- wee RONGERIK > 7 - THOMGELAP = 7-7 dioactive materials throughinhalation and inges- 9 tion. Another 18 Rongeiap people awayon a nearby island (Ailingnac), where less faliout occurred, received only an externai gamma dose of about 69 rads. There were 25 American servicemen on the island of Rongerik further to the east who received about the same amountof radiation as did the Rongelap people on Ailingnae. Lastly, 157 mL 2 SUTIRIK Q.7 Syne .° 2.7 oS © 9 Q 2 ° Marshallese on Utirik Island, about 200 miles Pe & rf EF oa E PY further east, received an estimated 1+ rads of whole-body radiation. The failout was notvisible Figure 1. Map offallout area, Marshall Isiands, March 1, 1954. MAJURO ? N\ es . na - an. 2 a cd