previous work indicates that floor scattering may contribute 1/2 to the total dose. When packs were dropped into lead at varying times up to 15 minutes after the exposure was complete the results indicated only a small portion of added dose. The added dose was about 6% of the total given during the true exposure. The results indicated that the additional exposure occurred very early after the assembly was separated as there was no detectable difference between 3 minutes and 15 minutes post exposure in the badge response. d. Animal Calibrations for Teapot, (J, Furchner, W, Schweitzer): A comparison of the effect of radiation alone and radiation preceded by cold stress on the weight changes in the spleens and thymuses of CFl female mice is being made in order to establish the possibility of eliminating expensive heating of exposure containers during Operation Teapot. Themice are placed in cages and exposed to cold in an aluminum test exposure device over night. After exposure to cold, the mice are exposed to X-irradiation. The weight changes in the spleens and thymuses of these mice are compared with relevant weight changes in mice exposed to X-irradiation only. weight are also being compared. Changes in body At present it looks feasible to eliminate heating elements from the exposure:38hniainars during tbe fiehaopeptsons L vs au-bority of tne U.S,E.R.D.A, This is not a definitely established point, he Os Per __ CoKel Ling” e. Toxicity of Hich Costeprrattoat:6 fs bdiam CotassifFT ARSTREED E,Anderson, W, Langham): By (Ara Bek ObY/2§ (SisySture ef person waxing tha changs, and date) To date two groups of 12 mice each have been exposed to the in- halation of a 10% concentration of T. in oxygen. The first group was exposed for 2 hours. Analysis of their urine indicated that they received a total body exposure of about 15,000 rep from the absorption of TO created by auto-oxidation of the tritium-oxygen 2 mixture. All animals died in 3-4 days. 15 wninutes in 10% Tp. ate otp} Die, a \ The second group was exposed for only These animals lived about 8-12 days and analyses of their Be