¢ “ , . ..33 is essentially a review of his analysis* , a which has become known as the "Geesaman hypothesis." A The Geesaman Hypothesis Dr. Roy E. Albert and co-workers pe=formed a number of experiments on the induction of cancer in rat skin?4736, Albert's study of radiation-induced carcinoma in rat skin gives some quantitative description of a high-dose carcinogenic situation. A skin area of 24 cm? was exposed to electron radiation with various depths of maximum penetration. The dose response curves are reproduced in Figure l. .In all cases the response at sufficiently high doses (1000- (3000 rem) was large, 1-5 tumors per rat by 80 weeks post exposure. It was noted by Albert that when the dose was normaiized to a skin depth of 0.27 milimeters, the three — -- response curves became continuous _— (See Figure 2). Since this ~. —_ 33/ Geesaman, D.P., UCRL-50387 Addendum, Op. cit. © -—-7~ = 34/ -Albert, R.E., F.J. Burns, and R.D. Heimbach, "The effect of penetration depth of electron radiation on skin tumor formation in the rat," Radiation Res. 30, 1967, pp. 35/ Albert, R.E., F.J. Burns, and R.D. Heimbach, wre 515-524. "Skin camage and tumor formation from grid and sieve patterns of electron and beta radiation in the rat," Radiation Res. 30, 1967, pp. 525- 36/ Albert, R.E., F.J. Burns, and R.D. Heimbach, "The association between chronic radiation damage of the hair follicles and tumor 1967, pp. 590-599, formation in the rat," Radiation Pes. 30, Ml -_ afr sul