-:° 26 = involved, surface doses of 16,000 rad from a P?* plaque induced an average of:1 cancer/animal which is indicative that larger mammals are similarly susceptible to skin cancer after intense radiation insult. Again, these gross obser- vations demonstrate that enhanced tumor incidence does occur after very hich doses. Intense localized radiation of the subcutaneous and intraperitoneal tissue of animals by Pu-239 has also been » 43-45. Shown to cause a high frequency of cancer induction a” Now what are these experiments trying to tell us? oe oe pe ee Certainly a reasonable interpretation of these experimental results (e.g., is: when a critical a hair follicle) architectural unit of a tissue is irradiated at a sufficiently high dosage, the chance of it becoming cancerous is approximately 1073 1074. to This has become known as the “Geesaman hypothesis." B Related Human Experience Since the above experiments relate to cancer induction in animals, it is pertinent to ask whether man is more or less 44/ Sanders, C.L. and T.A. Jackson, "Induction of Mesotheliomas and Sarcomas From ‘Hot Spots' of Pu02 Activity," Health Physics, Vol. 22, No. 6, June 1972, pp. 755-759. 4s/ Lisco, Herman, et al, “Carcinogenic Properties of Radloactive Fission Products and of Plutonium,” Radiology, Vol. 49, No. 3, Sept. 1947, pp. 361-363. . ae : . * EPS wo, a" seh rt ‘ y ee . Iie : mo ‘ : ‘ ‘ ‘ tay Sore . 4 ak : . 7 . * rr oh - - * t worl A : , . “ee ‘3 wee 8 , yt add, ia he “tg . ‘ * _” Rya Ff a wo ‘ ot an soe : * eine ow Me ate: yt: * at . ‘ wre, en ot Leki * eG r Pw. yk. St a eat. + ‘, nh? we ee MEP ee ge ae eae b mo + tcose a . yee Sole oe yo ty , ge me, 4, |