d. Blast and displacement. The 15 dogs placed in two communal shelters I400 feetfrom ground zero all survived the detonation and recovered within a few hours. Radiation and thermal effects on the dogs were found to be negligible. Although some degree of local hemorrhage was found in heart valves and lungs, the most severe of these lesions would not have been lethal. Tests with dummies simulating the human body suggested that the tossing about of occupants and objects would have been the greatest hazard in these shelters. e. Biomedical studies. Results of genetic studies using fly populations,plant materials, and a small number of mice will be determined after a amination. longer period of ex- ProjectGABRIEL 12. The Commission has on several occasions examined the general question of how many atomic weapons can be detonated without hazardous long-range and short-range radiation effects upon man, animals, and crops. When the expansion program was considered in 1951 it was tentatively concluded that the proposed stockpile would not danger limit. contain a number of weapons approaching this The Rand Corporation was examine this conclusion more thoroughly. calculated a preliminary sample estimate selected in 1952 to To date Rand has of the range of dis- tribution of radioactive fall-out which would occur from a 1- to 10- kiloton detonation. One important consideration is the relatively large amount of radioactive debris which may be brought down by rain from low-level bomb clouds. In some cases amore serious radiation hazard may be created by weapons of low yield then by those of higher yield, because the radtoactive bomb cloud produced by the latter is carried to higher altitudes 13. After the basic principles been established, the problem will be for one we: than are normally reached by weather disturbances. detonation have to determine possible statistical distributions of rain-out resulting from a number of bombs detonated in patterns which vary in time and - 02 - space. Part VI A