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 find- ings are also reviewed. The last detailed report (BNL 50029)11 covered the surveys of March 1965 and 1966, 11 and 12 years after the accident. In view of the 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 experiments at 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 noskin effects developed. These data are summarized in Table 1. The exposed people were evacuated from these islands by plane andship 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 months. During this period vigorous efforts were necessary to decontaminate the skin completely. In view of the generally negative findings on the Americanservicemen ey were later returned to their duty stations. i1..c Utirik people were also allowed to return to their homeisland, where radioactive contamination wasslight enough to allow safe habitation. Because Rongelap Atoll was considered to be too highly contaminated, a temporary village was constructed for the Rongelap people (including the 18 from Ailingae) on Majuro Atoll several hundred miles to the south, where they lived for the following 3years and were ex- amined at yearly intervals by a special medical (see Figure 1) and also on 23 Japanese fishermen aboard their fishing vessel, the Lucky Dragon. Of the inhabitants of the island of Rongelap, 105 nautical miles away from the detonation, 64 received the largest fallout exposure: an estimated dose of 175 rads of whole-body gammaradiation, contamination of the skin sufficient to result in beta burns, andslight internal absorption of radioactive materials through inhalation and ingestion. Another 18 Rongelap people away on a nearby island (Ailingnae), where less fallout occurred, received only an external gammadose of about 69 rads. There were 28 American servicemen on the island of Rongerik further to the east whoreceived about the same amountof radiation as did the Rongelap people on Ailingnae. Lastly, 157 Marshallese on Utirik Island, about 200 miles further east, received an estimated 14 rads of whole-body radiation. Thefallout was notvisible . & UTIRIK = 9 <\nnem Qo OQ Figure 1. Mapoffallout area, Marshall Islands, March 1, 1954. Q Q> Qo MAJURO S )