2 It is essential that protection against the external gamma radiation be prepared preattack. A policy depending on improvization in the post- attack period may be very dangerous. ficient time. There probably would be insuf- On the contrary, if indeed the internal emitter problem should turn out to be very serious, there would be time available to take protective action. Obviously, the more we know about ways of reducing this hazard, and the better our plans are for coping with it, the better off we would be if we should have to use them, It is the objective of this paper to discuss problems of fallout contamination in food and water as we view them today in the civil defense context. After outlining certain pertinent background experience that has led to our current understanding of the biological and physiological effects of the more dangerous radionuclides, I will mention our experi- ence in the development of explicit standards and measurement techniques and equipment, and why we now consider such an approach to be unworkable and unnecessary. Then I will touch on the Office of Civil Defense research program, emphasizing our procedures for predicting the contamination levels likely to be associated with various types of nuclear wars, including quantitative estimates of maximum internal doses associated with certain hypothetical wars. Finally, I will men- ron tion the countermeasures that seem to merit consideration.