Bete ey He tee ee 125-14-6535 oe ; - Research Plan A. Introduction: 1. : Objective: , : . _ The primary objective is the determination of the life-time effects of radio— active fallout on the Marshallese wha were accidentally exposed.on Ll March 1954. 2. Background: ae eo, -- - - ‘ This study focuses on the acute and long-term radiation effects on a popu~ ‘ation of Marshall Islanders inadvertently exposed ta fallout. Lo . - The accident occurred on March 1, 1954, when an unexpected shift of winds, following detonation of a thermonuclear device at Bikini, caused radioactive fallout to be deposited on several inhabited islands to the east. Evacuation of the exposed group was accomplished within two days. The estimated whole-body gemma doses to the Marshallese on the three atolls were: Rongelap (64 people), 175 rads; Ailingnae (18 people), 69 rads; and Utirik (158 people), 14 rads~- Acute effects of gamma exposure were noted in the Rongela“D and Ailingnae groups, _ but not in the Utirik group. Another source of exposure in all the island groups was due to internal absorption of radionuclides from inhalation and ingestion of con— ‘ taminated food and water as determined by radiochemical urine analysis. Only the isotopes of iodine, strontium and barium were absorbed to any significant degree. 2 es acute symptoms were noted from this internal absorption and by Six months, urinalyse indicated these isotopes to have been virtually eliminated. Nevertheless, early . exposure to radioiodines resulted in delayed but serious injury to the thyroid glands and hematologic depression for 15 years. The thyroid dose was estimated to be considerably higher in the children due’ to the smaller size of the thyroid glands. In the Rongelap people, the thyroid dose from gamma radiation and radioiodines (principally I131, 132, 133, 135) was estimated to be about 335 rads in adults. 1400 rads. - . In small children, the doses ranged from 760 to. . a Oo Following the initial studies, annual examinations, and more recently, quarterly examinations, of the exposed people, as well as an unexposed comparison Marshallese population, have been: carried out. In the first ten years after the accident, few findings were noted that could be related to radiation exposure. During the second decade, however, serious late | effects developed related primarily to the thyroid gland. In addition, a Rongela man who had been exposed at 1 year of age died of acute myelogenous leukemia ahick was likely related to radiation exposure. Nodules of the thyroid gland began to develop in Rongelap children, and to a lesser extent, in adults, beginning about nine years post exposure. These nodules ave continued to appear over the subsequent fifteen years and virtually all of these have been resected surgically. Cancer was found in seven patients-~ In 28 patients, benisn nodules were found. All seven malignant tumors vere of low grade malignancy. Localized metastasis were noted in Sevecal or wei. cases, re . 1) oul toes vere po disteah mitash:ashe,