Radiological Hazards Produced by Surface and Sub-Surface Bursts, In planning for radiological defense, the possibility of surface and sub«surface bomb detonations cannot be entirely disregarded, though likelihood of their employment is considered comparatively amall, In a surface burst, the radiol. gical hazards sroduced at the actual time of detonation are grossly comprrable to those of an aerial burst, although the rence of the blast effects may be noticeably lessened, On the other hand, the lingering radiological hazards will usually be of far greater importance than in those instances in which the bomb is exploded in mid-air, Persistent radioactive ground contsminetion may reasonably be expected to be encountered in the target area, It will represent a serious hazard, particularly to personnel whose civil defense duties may recuire entry therein. Downwind - contamination of the air will be =uch the same as that resulting from an aerial burst, In addition, there may be contamination of nearby bodies of water as a result of "fall out", while sprecd of ground contamination through surface drainage and movement of sub-surface waters is also a distinct rossibility. Any distent, downwind hazards attributable to cloud "fall out" will be vorimarily of vsychological significance, as in the case of an aerial burst. Should the tomb be detonated beneath the surface of a body of water, ag was the case in the second Bikini exveriment, the radiological effects will diffcr videly from those =roduced by surface or aerial explosions, eclircumstences, Under these the radiations released at the instant of detonation may Largely be "absorbed" by the -ater and so be vendercd of minor importance, On the other hand, aerial contamination, thouzh zreatl; limited in extent, may be of hich intensity, All nearby land creas and above=surface objects, as well as the water body itself, will doubtless te heavily contaminated with TVER ros ARGH