~99 - ae rn ee 3) 200 persons are supported per Sada 4) that an ingestion of WYAg. of strontium 90 is a threshhold lethal dose per person, i.e. that the mid-lethal integrated dose is Logag - years. m There are 55 grams of strontium 90 per standard (20 kT) bomb. | yt Tesults in 1.5 x 10"Zug - per perso oe vw This “Fig Thereforg§ one concludes that a number x + 5 of standard bombs in the order ci(s>lata aiepersing debris in the same ag manner) would be required to raise the level of toxpcoity dangerously high. Another way of putting this same conclusion is to say that dangerous levels of toxecity will reach only at places where the external radiation has reached degerously high levels. For example, fall out from one of the Greenhouse shots resulted in an integrated exposure of 3r to the personnel attending the tests. 2x 107° per mim. This corresponds to a deposition fraction of For a ykteld of 600 grams of strontium 90 (George shot ? }. Grn?There would result an uptake of 2 x 10°3«+ /ceorge bomb/person per year. > Thus some 5000 detonations made at the same relative position with identical ng meterological conditions would be required. It would take 5000 of such dispersions to raise the fission product density in the g@11, high enough to make the ingestion per year of strontium reach threshhold,level. correspond to a total radiation of around 15000r at this site. This would Thus it appears that dangers from internal and external effects are reached by about the same density of fission products. It is suggested, therefore that the problem of internal poisoning by fission products is part of the Civil Defense, that dangerously high levels of fission poison will be reached only under freak circumstances (such as rainfall from a high density cloud Jand that in all cases one's attention to the presence of toxg@city will be called by the high level of Gamma and Beta radiation. Conclusions and Recommendations The number of standard atomic bombs required to reach lethal levels of debris poisoning is in the order of 10? under expected circumstances. estimation may be 100 too low-- or #310 times too high. It is suggested that high levels of texécity can be discovered through National Civil Defense monitoring. This