EE a TTRT re ete ee gee ee oF Free segetna 8 fe epntgnenpinmag te gees iit . 31 Dacembor 1946 ° Subj: . . . Pile ee tr yt er ee dee og retin te fee wee eT me PE NTR emerwatemC Redioective Varfoare - owe Prtern ee ae ere ~ Paseo F Four . presents a most ominous complication. Assuming a relatively uniform and widespread doposition of fission products over areas of many square miles, thero will arise varying and wprediotable concentrations of this activity O12 O result of rain or melting snows. It must ba realized that initially a large fraction of the deposited fission products will be on ths surface of the soil, plants, buildings, roads, et oetera, as a thin film of dust. Rain or melting snows will wash a signifioent fraction of these materials away end they will ba accumulated in the run-off water and may be carried cousidsrable distances to anothor location. It is quite logical that a redistributio in a concentrated form would prove most disturbing, part~ feularly from the point of view of, gamna radiation if such removal and . . The possible methods of distribution of fission produots that are of military significance have bosninvestigated only to_averylimited OoeR Oe oe ee es oe se _ redistribution should oocur in a thickly populated area. decree end on an extremely small soales Such methods were developed prin arily at Berkeley for the purposes of studying the behavior of:fission product aerosols following their inhalation by animals. Stable aerosols may be produced by depositing fission products upon a smoke produoing tf eseant, as for example, the zinc hexachloretrane-ammonium perchlorate mix: ture which hss been used for many years for the purpose of obsouration. Such a type of preparation would appear well adapted for producing fission ; product asrosols to subject urban populations ty fission produot poisming | by inhelation. Other possibilities prosent themselves such as dispersal of a fine powder by memsof a bursting oharge, the reduotion of the prin- cipal fission products to a metallio state and their subsequent combustion to form finely divided oxide smokes, the produotion of fine spraya of sol- . utions of fission products, and the dispersion of a fission product mixture || in the form of small particles of the size of the order of 0.1 millimeter in diameter. These are problems about which there are meny individuals better qualified than I to present intelligent suggestions. It should be pointed out that in meny instances, it is to be presumed that where aerosol concentrations of fission products om be created at sufficient levels to produce serious biological damage as a result of inhalatior, there will occur the deposition of such suspensions upon the ground in sufficient quentities that £41 approach, if not exceed the radietion flux, that will result 4n sevef® &xternal gamma ray demaze to individuals so exposed. There are knovm at pressnt vory fev and relatively inadequate measures that can bo employed to oombat the problems srising from radio~ aotive warfare. In the first place, the removal of long-lived fission products, once they have become oither deposited within the lungs or ebsorbed in the body, has been wsuccessful.e Absorption from the digestive tract following oral ingestion om be reduced significently by inoreasing the oaloium content of diet for several weeks before administration of the fission products. The administration of caloiun or strontium at the time of absorption or subsequently, is not of significant value. The administration of strong cathartios at the time of oral ingestion would be of value to reduce the eneee Pte hespares:

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