Rabe On Guan oeauces The work of Henriques? suggests thet at the ¢ epth ef 0.07 mm in living poreine akin (maximm thickness of « pidermis) that "1400 ¢ 300 roentgen-equivalent—beta" (delivered over short periods of time seo that they may be ammed te be instantaneous) 1s required te produce recognisable transeridermal injury. The eurve of binlogieal damage rises rather sharply so that af a dose of just wider 2000 rep (at 0.09 an), the epidernis may be expected to exfoliate and in the majerity of eases go on to develop chronie radiation dermatitis persisting for mouths. The preceding discussion suggests that, using the gamma dose rates listed in the eriteria under this ielicy, shieh are based on an estinated 1S roentgen infinity gamma dose, as high as 2,000 reps might be delivered to the basal layer of the epidermis over « period of tine eovered by the lifetine of the radioactive material. There have bean instances where the ealeulated infinity gamma dose in ereas where persomel were present around the Nevada Proving Greunds have reached 12-15 roentgens but there have been no know cases of beta burns {in these areas. The number of persons involved Eatsareas ef highest contamination was relatively small, perhaps a few dozen, end with an observed duration of fallout ef about one hour it is possible that they vere net in a position to receive the full fallout. Likevise, minute areas of the skin may have been so affected yet not detected or reported. In other areas encompassing some 2,000 people the infinity gamma dece was about eight roentgens and no instances of beta injury appeared. 2 gr-sit. Lee HED