keep the body covered and, (b) early removal of the body contamination since higher doses are delivered during early times after fallout. The Marshallese were semiclothed, had moist skin, and most of them were out-of-doors during the time of fallout. Sone bathed during” the two-day exposure period before evacuation, but others did not, therefore, there were optimal conditions in general for possible beta damage. The group suffering greatest exposure showed 20% (13 individuals) with deep lesions, 70% (45 individuals) superficial lesions and 10% (6 individuals) no lesions. Likewise, 55% (35 individuals) showed some degree of epilation followed by a regrowth of the hair. However, during this same period of time they received a whole-body gamma dose of 175roentgens —- a value approaching lethality for some of those exposed. These data, together with others, indicate that the external gamma radiation would be the controlling factor for making such decisions as to evacuation, although recognizing that any beta exposure would be an additional body insult. INTERNAL EXPOSURES The principal factor in evaluating long term hazards from ingestion and inhalation is the doses delivered to the bones by isotopes of strontium. This subject will be discussed in detail by others. The principal hazards from intake of relatively large amounts of radioactive fallout for several weeks immediately following a nuclear detonation are doses to the: ; — ts , .