“== Radiological Hacsrds Produced by Aerial Burst. The detonation of an atomic bomb vroduces two generalized types of radiological hazards, In an aerial burst, the first, and by far the most injurious to people, is caused by the intensive gamma r:diation and the vast shower, or "flux", of neutrons released during the splitesecond period of actual detonation, While this particular hazard lasts only a few seconis, its xilling power is incredible, In combination with injuries from other causes, it may be expected to result in death to practically all persons within 1,000 yards of the center of impact, Being an adequate distance from the :oint of detonation is the only practical measure of mass protection from this hazard, although some persons in near-by positions may escape its effects due to "chance shielding", ‘This "accidental™ form of protection may be crovided by terrain, earthen embankments, heavy walls of concrete or similar radiation barriers, The second type of radiol:gical hazard produced by atomic bomb explosions is the lingering, or persistent, hazard attributable to the wesence of radioactive fission products, or “bomb ashes", In an aerial burst, these are of only minor importance, as most of the harmful "waste materials" are swept skyward with the hot gases resulting from the explosion, There they are widely dispersed ty the varying winds at different levels of altitude, The likelihood of serious ground contamination attributable to fission products is emall, even near the center of impact, Aerial contamination may, however, temporarily provide serious hazards to aircraft operating within sone miles downwind of the site of detonation, Then, too, "fall out" from the bomb cloud may produce localized hazards at points far removed from the place of actual attack, The principal effects of the latter would be psychological rather than »hysical, TOS ARCHIVES