CONFIDENTIAL. (c) Although the proportion of deaths from fallout increases slightly with the cep ee of the attack, the deaths from fallout alone are a very small proportion of the deaths from the attack as a whole. This finding is borne out also in App C of this report. It should be emphasized that. the figures cited here assume no evacuees from urban targets, but are based on the relatively sparse rural and small town populations residing in the area. TABLE 9 Dearus FROM FaLLout aS Funcrion or Arrack Sizz, CEP, anp Season Deaths, thous Bombs CEP 4000 m CEP 8000 m CEP 12,000 m Summer 2 4 7 73 220 262 2 4 7 12 490 470 Winter 78 200 261 72 103 246 76 138 282 22 245 323 Additional from blast and thermal effects, any season 2 4 7 2361 3001 3401 1742 2074 3438 510 1056 1214 FALLOUT AND EVACUATION It is now possible to estimate the numberof additional deaths from fallout that can be expected as a function of 1- or 3-hr evacuation radiating outward from thecity. Figure 27 indicates that for a 4000-m cep attack 12 percent of Washington’s population would be killed by a single weapon whenthe civil defense tactic was 1-hr evacuation, and 9 percent when the tactic was 3-hr evacuation. Figures 30, 32, and 33 show actual Gz for a 4000-m cer summerattack of one, two, and four bombs on the Washington target. Using Fig. 10 as a guide to the new population concentrations created by 1-hr evacuation, it is apparent that approximately 33 percent of the city’s population who were notkilled by blast and thermaleffects would be exposed to a dose of 500 r. Allowing an attenuation factor of 0.5 for shelter equivalent to an automobile or shed-type building, and applying a mortality coefficient of 0.05 for the corrected dose of 250 r, a new estimate of at least 14 percent instead of 12 percent is appropriate when 1-hr evacuation is the civil defense tactic. The disadvantages of evacuation becomestriking when the number of bombsincreases. Figure 33 indicates that for two bombs per target approximately the same percentage of the evacuating population would be exposed to 500 r as for one bomb,resulting in a revised estimate — 51 percent mortalities instead of the 22 percent computed whenfallout was not considered. With four 10-Mt ground bursts, as indicated in Fig. 30, all but perhaps 15 percent of the population of Washington is destroyed by either blast or thermal effects or lethal degrees of radiation. ORO-—R-17 (App B) 45