3 > canned goods or any materials in impervious, Custproof wrappings. There appears to be no feasible means of saivaging unprotected In surface waters, whereverpossible, of surfaces that either are resistant to such contamination or from which the active material can be readily removed. It has been found, for example, that surfaces coated with certain plastic paints are relatively easily decontaminated. At the present time it appears that well-main- radioactive contaminants will tend to be adsorbed by the suspended and colloidal matter that invariably is pres- ent. In urban water systems, radioactive material that has escaped adsorption in a reservoir itself may tained paint or other sealer is the be picked up by the surface of the distribution system. When, in addition, the purifica- only means of protecting structural material, such as concrete, brick water ones. vented. tection. ; and replaced with new the bomb is used. In a high air burst, such as at Hiroshima and Nagasaki, most of the casualties natural decay of radioactivity, the degree of contamination will decrease with time. In some cities water is taken directly from a river and merely will be from burns and blast effects. There will be a smal] proportion of radiation injuries resulting from chlorinated before being supplied for domestic consumption. If no exposure to the initial nuclear radiations, emitted within the first minute after the burst, but the alternative source of wateris available in case of emergency, consideration should be given to the provision of positive and negative or ex- Personal Injuries Vary filtration, the water might be unfit for consumption for several days. However, because of dilution and columns underwater The types of injuries suffered by personnel in an atomic explosion will vary with the manner in which is not subjected to coagulation or exchange an kept under cover by means of tarpaulins or other movable pro- If a reservoir or river is seriously contaminated, and the water ion against Where these procedures are not possible, vital equipment may be ground, provided surface drainage or contaminated material is pre- ; where moved are generally safe from contamination. So are moderately deep wells, even under contaminated ; woods, plosion is possible. Another possibility is to use coatings that can be easily re- water of soft in new construction near bodies of Welis and Reservoirs sources and radioactive contamination. This should be borne in mind especially tion process includes coagulation, sedimentation and filtration stages, it is expected that very little radioactive material would normally reach the consumer. Underground J The ideal defense against radioactive contamination is the use, food, either in the home, the store, or in the fields. _? wy effect of contamination residual radiations, by the emitted after the first minute, will be negligible. beds (purifying agencies) to be used if the regular supply should be- at come contaminated. Home water softeners might serve the same purpose. In hospi- An explosion at low altitude or ground level would produce somewhat fewer casualties from blast or burns, but a small area would be highly contaminated with tals and on ships sufficient water for emergency purposes could be obtained by distillation. It was found at Bikini, for example, that radioactive material. If proper precautions are taken, the casua!- ities from this residual radiation should be a very small fraction of the total. contaminated water, when distilled, was perfectly safe for drinking. It should be emphasized, how- After a shallow underwater burst, the number of casualties from blast and burns also will be dimin- ever, that mere boiling of water contaminated with radioactivity is of no value. ished. However, some casualties might arise from exposure to ra38 sis and treatment, it is not neces- diation from fission products and, to a lesser extent, material that has escaped fission, spread over sary to distinguish among burns caused by thermal radiation (flashburns), by flame, or by contact an appreciable area by the base- burns, a form of flash-burn caused surge and the fall-out. by dark-clothing materials becom- During the first two months or more the primary danger would be from the gamma rays, in partic- ing hot and burning the skin with which they are in contact. Although there are differences in body surface involved, depth of ular, and the beta particles (electrons) from fission products. Subsequently, the ingestion of plutonium might in exceptional circum- the injury to the skin, and general reactions of the individual to burns of different types, the indicated treatment for burns from an atomic explosion appears to be the stances become a hazard. In the event of serious contamination of this kind, it would be necessary to evacuate the population from the affected areas until they could same as for those encountered in large-scale incendiary raids and in civil disasters. be adequately decontaminated. Injuries by blast are of two kinds, direct and indirect. Direct blast injuries result from the positive pressure phase of the shock Sudden Casualties The unique feature wave acting on the body to cause injury of the lungs, stomach, intes- tines and eardrums, and internal hemorrhage. Such injuries of atomic bomb burns is the great number of casualties produced in a_ brief period, the variety of burns encountered, and the wide range of oc- severity, depending on the distance curred in World War I after largeseale air raids with conventional high explosive bombs. At Hiroshima and Nagasaki, however, the direct blast effect was from the explosion. A great deal was learned during World War II about the treatment of burns, but the subject is still under investigation and has not not a significant primary cause of fatality, because those near enough yet becomestabilized. It is recom- to the explosion to suffer injury in mended, therefore, that until there this manner were burned or crushed to death. A pressure of is more general agreement, the medical men in each community about thirty-five pounds per square employ the treatment for severe inch or more is required to cause direct harm to a human being, The peak pressure of the shock wave from a nominal atomic bomb would burns they have found most effi- cacious, Because of their importance in relation to the effects of an atomic explosion, a comprehensive study attain such values only at distances of 1,000 feet or tess from ground zero, assuming a height of burst of flash burns is being sponsored by the Atomic Energy Commission. at 2,000 feet. The effect of thermal radiation More important than the primary blast injuries in the Japanese bombings were the indirect or sec- on the eyes was surprisingly small. Even those who looked directly at other debris flying about in the blast wave. Persons were injured Nagasaki, from some distance, of course, reported only temporary loss of vision. One patient was so the explosions at Hiroshima and ondary effects from collapsing buildings, and from timber and by flying objects, crushed blinded by the flash that he was unable to distinguish light from dark for two days, but eventually or buried under buildings, and thrown against fixed structures. Glass fragments penetrated up to an inch his recovery was complete. The effects of nuclear radiations, as distinguished from thermal, on living organisms depend not only on the total amount absorbed, but also on the rate of absorption: on whether it is chronic or acute, and beneath the skin, and the light summer clothing worn at the time offered little protection. Unless proper precautions are taken, to be described later, giass is a considerable hazard. For practica! purposes of diagno- on the area of the body exposed. 39g

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