THYROID NODULES ASA LATE SEQUELA OF RADIOACTIVE FALLOUT* In a Marshall Island Population Exposed in 1954 R. A. Conarp, M.D.,f J. E. Ratu, M.D.,f Pu.D., anp W. W. Sutow, M.D.§ UPTON, LONG ISLAND, NEW YORK NODULES of the thyroid gland have been discovered during the past three years in a number of people of Rongelap Island who had been accidentally exposed to radioactive fallout in 1954. The accident was the result of an unpredicted shift in winds after the experimental detonation of a low their return. During the years after the accident, over 200 Rongelap people or their relatives who had not been exposed to fallout returned to live with the exposed people, and this group has formed an excellent comparison population. deposited on 4 inhabited Marshall Islands to the east. Inhabitants of Rongelap Atoll, about 100 miles away, received the largest amount of fallout. The somatic effects bf this radiation have been well doc- to be sublethal. Aside from widespread anorexia, large thermonuclear device at Bikini in the Marshall Islands, which caused radioactive fallout to be umented in a number of medical reports and are summarized elsewhere.'? ‘This report concerns the recent development of thyroid abnormalities among the 82 people of Ron- gelap Atoll who received the largest exposure to fallout radiation. Sixty-four of these people were on their home island when the detonation occurred. Eighteen others were fishing on the nearby atoll of Ailinginae. They saw the blinding flash of the detonation in the early morning, followed by a white, snow-like fallout throughout that day. The people on Rongelap Island received the largest exposure: 175 rads of whole-body gamma radiation, thousands of rads to the skin (largely beta) from deposit of fallout material on the body and significant amounts of radionuclides absorbed by inhalation and con- SUMMARY OF EARLY FINDINGS The whole-body dose of radiation received proved nausea and a few cases of vomiting and diarrhea, along with irritation of the skin occurring during the first two days, the most notable effect of the exposure was depression of the blood-forming tissues. Although the peripheral leukocyte counts were reduced to about one half to one third of the normal levels and the platelets to about one third to one eighth of the normal values during the first five or six weeks, nei- ther infection nor bleeding clearly related to radia- tion effects (except possibly menorrhagia in a few women) was observed. Recovery of peripheral blood elements was nearly complete by one year but lagged thereafter; the mean levels remained slightly below those of the comparison population through ten years post exposure. However, the survey at eleven years showed levels of peripheral blood elements that appeared to be about the same in the exposed as in the sumption of contaminated food and water. The 18 unexposed people. Radiation lesions (“beta burns”) of the skin and spotty epilation of the head were widespread, begin- were evacuated antecubital fossae and dorsa of the feet. Most of the people on Ailinginae received less than half the exposure of the other Rongelap people. Both groups two days after the accident and lived in a temporary village on a southern island in the Marshall group until 1957, when the radioactive levels had subsided sufficiently on Rongelap to al*From Medical Research Center, Brookhaven National Laboratory. Research supported by the United States Atomic Energy Commussion and the Trust Territory of the Pacific Islands. tSenior scientist, Medical Research Center, Brookhaven National Laboratory, Upton, New York. tDirector of intramural research, Navonal Institute of Arthritis and Metabolic Diseases, National Institutes of Health, Bethesda, Maryland. §Associate pediatrician, Medical Department, University of TexasM.D. Anderson Hospital and Tumor Institute, Houston, Texas. ning about two weeks after exposure. The most com- mon sites for the burns were the head, neck, axilla, lesions were superficial and healed without grossly visible sequelae. However, some of the lesions were deeper and resulted in pigment changes and scarring that have persisted. The hair in all cases regrew in six months and was normal in color and texture. Absorption of radionuclides in the fallout from inhalation and from consumption of contaminated food and water was detected by radiochemical analyses of urine. The highest body burdens occurred during the first two days on the Island before they were evacuated, when they were exposed to an envi- Reprinted from the New England Journal of Medicine 274: 1392-1399 (June 23),