weetEach 73 Since this estimate is based on data from acute radiation exposure experiments, the expected number of genetic deaths is too high by a factor of 4-8, because it is well documented that doses of radiation delivered over a long period of time produce less genetic damage than an equal dose delivered acutely. For this reason the contribution to spontaneously occurring genetic deaths expected from mutations which exhibit a small dominant effect in the first generation progeny induced by background radiation (not man-made) would be 0.034-0.068 percent. —