ACES AT R 1979 Summary (2/28/80) The Brookhaven National Laboratory Marshall Islands Study has been a longitudinal prospective follow-up of 245 Marshall Islanders inadvertently exposed to fallout radiation in 1954. This population is unique in that they received both external gamma and internal gamma and beta radiation from a This report will cover the period from 1 March 1979 mixture of radionuclides. to 1 March 1980, the 26th anniversary of the accident. On 1 March 1954 the second thermonuclear device tested by, the United States was detonated from a tower about 4:00 A.M. on the vatand of Bikini The weapon yielded about 15 megatons, in the Marshall Islands (Fig. 1, map). more than twice its predicted yield, and the fireball rose to well over 100,000 feet where an unexpected windshear carried the fallout over a large elliptical area to the east. The nearest atoll, Rongelap (100 miles east), noted the onset of a heavy particulate fallout within 4-6 hrs. The 64 people of Rongelap (3 in utero) along with a party of 18 Rongelap (one in utero), who were ona trip to the nearby atoll of Ailinginae, were evacuated over a period of 50 to 58 hrs. A U.S. military weather-monitoring team of 28 men was stationed on Rongerik, 135 miles east of Bikini. They were evacuated within 29 to 34 hrs. The next atoll, almost directly east of Bikini, was Utirik at 270 miles. This yroup of 159 Marshallese was evacuated within 55 to 78 hrs. In addition, a Japanese fishing vessel, The Lucky Dragon V,was about 90 miles due east of Bikini with a crew of 23 who received significant radiation (Ref. 1, Appendix 3). The details of the extensive initial work-.p of the irradiated population is presented in the monograph, "Some Effects of Ionizing Radiation on Human Beings", of July 1954 (Ref. 2). Subsequently, Dr. Robert A. Conard assumed the responsibility as principal investigator for the study and retained that position until his retirement from BNL on 1 January 1979. H.S. Pratt assumed the role of Principal Investigator. At that time Dr. This report will discuss only those findings pertinent to the 26th year of observation. The attention of the reader is directed to the 20 year report (Ref. 1) and to the 25th year report (in preparation). OBJECTIVES OF THE STUDY: I. The comprehensive medical follow-up of those Marshallese exposed to the acute effects of fallout on 1 March 1954. II. The early detection and care of any conditions thought to be related III. A comparison of the morbidity/mortality of the acutely-exposed popu- to radiation effects. lation with a "comparison" population selected from an unexposed Rongelap kindred that returned to the island of Rongelap in 1957 with the exposed group. IV. The ancillary provision, whenever possible, for primary care of medical problems unrelated to radiation in cooperation with the Trust Territory, now the Marshall Island Government, medical care system.