4081 37 ON ESTIMATED THYROID DOSES & PREDICTED THYROID CANCERS -.,, RCTIVES US DOE ARGi . IN UTAH INFANTS EXPOSED TO FALUOUT I'846 ys ATOMIC ENERGY RG COMMISSION Charles W. Mays -(F Din. Physics Group Leader, Radiobiolp Anatomy Dept., U. of Heapcollection DEL Salt Lake City, Utah ABSTRACT: . |,/%%2 [= “& Brkt QQ ¥S The inadvertent exposure of about reOrRGeUtahsnkants y hyn ee —— * - L to average thyroid doses estimated at 1.3-10 fa . ] aetPinatas(1946 unigue opportunity to establish the effects of low doses of I} irradiation in children. INTRODUCT ION Iodine-131 is produced in nuclear explosions. is contaminated with fresh fallout, If cows eat forage which I??? appears in their milk. If a child drinks this radioactive milk, I’°! concentrates in his thyroid gland and irradiates it. Infants are considered to be the critical members of the population. Dr. Robert C. Pendleton*™ was the first to discover that fallout from the Nevada nuclear tests of 1962 would cause significant contamination from radioactive I??? in Utah) | Following his vigorous urging that steps be taken to reduce the exposure, the Utah State Department of Health recommended: (1) transfer of cows from highly contaminated pasture to stored feed, and (2) diversion of highly contaminated milk from the fresh market ©) protective action set a precedent: This it marked the first official attempt in this country to prevent the intake of fallout-contaminated food. In analyzing the 1962 incident I became fascinated with the implications of exposures from the previous years of testing. Unknown to me at the time, this problem was also being investigated through different approaches by Dr. Harold A. Knapp then with the AEC, and by members of the St. Louis Committee on Nuclear Information. Same conclusion: Working independently, we all came to the significant expoSures were indicated. The problem was complicated enormously by the fact that I??? was not properly recognized as a fallout hazard during the early years of testing (1951, 1952, 1953 & 1955), and, unfortunately, I??? was not measured in milk wv Associate Professor of Genetic and Molecular Biology and Head, Department of Radiological Health, University of Utah. ATTre fn . IT? Serr ~ e 64