CHAPTER 5 DETECTION OF FALLOUT BY THE PHYSICAL SENSES The DCPA is concerned about advice to be given to people living in isolated or thinly populated areas who do not have the help of radiation measuring instruments to guide their actions in cases of possible fallout following nuclear attack. It is quite important that these people have as much time as possible to bring stock into barns and supply them with water and feed, to protect equipment from the elements, and to gather water and supplies for themselves and their families. There is evidence that much if not all heavy fallout observed during atmospheric nuclear tests was visible as individual particles falling and striking objects, or as deposits accumulated on the surfaces of various objects. »2 “Similar particulate fallout from volcanoes in similar quantities has been visible.?? For persons exposed to the particulate fallout from volcanoes,,. the forehead and nose are the most sensitive detectors of falling particles. At a stage of rapid accumulation of particles or under windy conditions, the presence of the airborne particles may be detected by irritation of the eyes or a gritty sensation on the lips and between the teeth. Us ly at that stage of deposition the forehead will feel like sandpaper to & touch of the hand. The gritty sensation will also be felt on the hand$* and on bared arms. In rain, volcanic fallout has been observed on an automobile windshield behind the sweep of the wiper. The DCPA might issue guidance to isolatedindividuals along these, lines: "If you are within one or two hundred miles of an explosion, you will know the country has been under attack by seeing flashes and, even if clouds intervene, by hearing shock waves, and you can confirm what has happened by listening to the radio. You will want to protect yourself and your family from fallout by going to the basement or to your storm celler, if you have one; however, fallout travels with the wind and will not arrive right away. Indeed, it may be several hours (or never) before fallout reaches you, and you probably will have time to protect your stock and equipment, and bring supplfes into your own shelter. Probably you do not have a radiation-measuring instrument (if you do you can work outside until the instrument reads 0.5 R/hr), but heavy fallout can still be detected by one of these several clues: lL. Seeing fallout particles, fine, soil-colored, some fused, bouncing upon or hitting a solid object, particularly visible on shining surfaces such as the hood or top of a car or truck. A white board or piece of white paper on a flat surface may serve as a visual detecting device. 19