- 26 $ involved, surface doses of 16,000 rad froma p32 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 high doses. Intense localized radiation of the subcutaneous and intraperitoneal tissue of animals by: Pu-239 has also been shown to cause a high frequency of cancer induction43-45, ; Now what are these experiments trying to tell us? Certainly a reasonable interpretation or these experimental results is: when a critical architectural unit of a tissue (e.g., a hair follicle) is irradiated at a sufficiently high dosage, the chance of it becoming cancerous is approximately 1073 to 1074. This has become known as the "Geesaman hypothesis." B Related Human Exverience Since the above experiments: relate to cancer induction | in animals, it is pertinent to ask whether man is more er less 44/ Sanders, C.L. and T.A. Jackson, “Induction of Masotheliomas and Sarcomas From ‘Hot Spots’ of Pu02 Activity," Health Pnvsics, Vol. 22, No. 6, June 1972, pp. 755-759. 45/ Lisco, Herman, et al, “Carcinogenic Properties of Radioactive Fission Products and of Plutonium," Raciolocy, Vol. 49, No. 3, Sept. 1947, pp. 361-363. 3,