A-bomb survivors, Atomic Energy Commission--Department of Energy Workers, the population exposed to fallout from atmospheric tests at the Nevada Test Site, etc., have been studied for their potential to provide low-dose risk estimatess for radiogenic cancer. Only some combination of experimental and theoretical work, with epidemiologic studies at higher doses, will provide a reliable guide to such risks. Sources of variation in risk estimates for radiogenic cancer are explored for their significance to research on carcinogenic mechanisms and to give direction to epidemiologic research. Most recently Dr. Beebe joined Dr. Boice in visiting China where plans were made for a collaborative study of thyroid nodules in older women living in high-vs.-low-background areas of south China.
