CUGSZ The Medical Research Center Harvey W. Lyon,* D.D.S., Ph.D., Bethesda, Md., Brookhaven National Laboratory Robert A. Conard,} M.D., Upton, N.Y., Upton, L. L, New York Kenneth F. Glassford,£ Great Lakes, Ill. AOLE26 Long-term intraoral findings in humans after exposure to total-body irradiation from sudden radioactive fallout. I. Five year postdetonation studies Significant quantities of radivactive fall- out precipitated on Rongertk atoll, Rongelap atoll, Ailingnae and Uterik in the Marshall Islands after detonation of a 15 megaton thermonuclear test device at the Bikini Proving Grounds in February 1954, As a result, 239 Marshallese were accidentally exposed to total-body irradiation ranging from 14.to 175 R. Five years later, dental examinations were conducted in conjunction with medical examinations to investigate the morphological effects of the exposure. The initial dental survey reported here showed no significant differences in caries rate or prevalence of periodontal disease in irradiated and non-irradiated groups. However, the degree of periodontal destruction was more extensive in the Rongelapese who received the heaviest exposure to radioactive fallout (175 R). Specific data pertaining to these effects on hard andsoft oral tissues are even less available. Sequelae of locally applied ion- izing radiation to human oraltissues are well known; however, limitations to long- term intraoral observations in total-bodyirradiated patients are determined only by the numberof survivors. Three population groups offer opportunity for further study: inhabitants of Hiroshima and Nagasaki, certain Marshall Island populations and laboratory personnel involved in nuclear criticality reactions. This report describes those intraoral clinical findings obtained in March 1959 by a combined medicodental survey team on groups of Marshallese people five years after exposure to total body irradia- tion from sudden, significant quantities of radioactive fallout. BACKGROUND Initial exposure occurred after detonation of a 15 megaton thermonuclear test Information concerning long-term mor- phological effects from total body irradiation in humans is relatively scant. . device at the Bikini Proving Grounds in February 1954. Because of an unusual shift in winds, varying quantities of fall- out matter were deposited on and in Reprinted from The Journal of the American Dental Association, Volume 68, pages 49/31 to 56/38, January 1964, All expressions of opinion and all statements of supposed facts are published on the authority of the writer over whose signature they appear and are not to be regarded as expressing the views of the American Dental Association unless such statements or opinions have been adopted by the Association. REPOSITORY BNL RECORDS coutection MARSHALL ISLANDS BOX No. MEDICAL DEPT PUBLICATIONS FOLDER -# 526-678 poids

Select target paragraph3