CHAPTER 3 - EFFECTS OF SOIL TYPE AND BUILDING MATERIAL ON THE PORTION OF RADIOACTIVITY DEPOSITED IN LOCAL FALLOUT With the cessation of U.S. atmospheric tests, and in particular, test detonations on or near the surface of the ground, there seems to be little promie of learning just how much difference various types of soil or other materials over which the detonation occurs would make with respect to the amount of radioactivity deposited in local fallout. The recognition, however, that current fallout prediction models probably somewhat overpredict radiation levels, is important. It provides one more reason why, in a nuclear war contingency, people should be urged to take the best available shelter and to improve whatever radiation protection they may have even though some standardized protection factor (say PF 40) cannot be achieved. i oO II