Zate Oo Homan Exnecures The work ef Henriques! suggests thet at the ¢ epth ef 0.09 m in ~ Living porcine skin (maximum thickness of e pidermis) that *1400 ¢ 300 -—— roentgen-equivalent—beta® (delivered over short periods of time so that they may be emmed to be instantaneous) is required to produce recognis= able transeriderzal injury, The curve of biological damage rises rather sherply so that at a dose of just under 2000 rep (at 0.09 mn), ths epidernis may be expected to exfoliate and in the majority of cases go on to develop chronic radiation dermatitis persisting for months, . oo The preceding discussion suggests thet, using the gamma dose rates —_ listed in the criteria under this Policy, which are based on an estisated 2 | 10 roentgen infinity gamma dose, as high as 2,000 reps might be delivered to the basal layer of the epidermis over a period of tine covered hy the a lifetine of the radioactive material. - There have been instances where the ealouleted infinity gama dose (. in areas where personnel vere present around the Nevada Proving Grounds ™ have reached 12-15 roentgens but there have been no known cases of beta burns in these areas. The nusber ef persons involved in these areas of highest contamination vas relatively ssall, perhaps a few dozen, and with an ¥ observed duration of fallout of about one hour it is possible that they vere not in @ position to receive the full fallout, Likevise, ximte areas of the skin may have been so affected yst not detected or reported. In other areas encompassing some 2,000 people the infinity gama dosevas about eight roentgens and no instances of beta injury appeared. bie 1 grcit. DIEPin