17 locally-deposited fallout and that due to world-wide contributions. Results of a two-sided nuclear exchange can be considered by adding the contribution that weapons detonated on enemy soil would make to the world-wide fallout. Additional mathematical models, also computerized, consider the various paths by which radionuclides could enter the body ultimately to become deposited in the critical organs; or example: the amount of sr?° in the bone, and the amount of I 131 in the thyroid. Such models may start with any war situation one wants to hypothesize and wind up with the body burden of any isotope of interest for people of different ages in the different parts of the country. Through these studies, the expected benefit of various types of countermeasures can be evaluated, as can comparisons between the probable seriousness of external and internal exposure doses. The models used in civil defense studies of food and water contamination and for many other consequences of nuclear attack were developed by Dr. Carl F. Miller, now of Stanford Research Institute, formerly of the Naval Radiological Defense Laboratory and the Office of Civil Defense. The basic descriptive material of Dr. Miller's work may be foundina 2-volume report entitled ''Fallout and Radiological Countermeasures. nl? Ez

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