Effects of Nuclear Weapons TestingAuthor(s): Gordon M. DunningSource: The Scientific Monthly, Vol. 81, No. 6 (Dec., 1955), pp. 265-270. Published by: American Association for the Advancement of Science Stable URL: http://www.jstor.org/stable/22239
[Excerpted] Genetics. There are five relevant points concerning radiation and genetics that may be enumerated.
1) Radiation can cause irreversible inheritable changes (called gene mutations) in the germ cells. Most of these mutations are considered harmful.
2) The number of mutations produced is independent of the rate of radiation exposure; that is, it is the total exposure to a given kind of radiation that is the important factor.
3) Radiations have not produced any kinds of mutations not already known and occurring normally. Thus, the possible effects of irradiation from nuclear detonations rightfully may be compared with those produced by natural causes.
4) If the mutation that occurs is of the "dominant" type, then the effect appears in the first generation. It is believed, however, that by far the largest number of mutations that do occur are of the "recessive" type that may be carried generation after generation without expression until it is matched by a similar mutant gene in the opposite sex-an occurrence of very low probability in a general population such as ours that is out-breeding (owing to taboos against marriage of close relatives). Thus, the presence of a mutant gene very rarely means a "defective" individual in the sense of detectable defects.
5) It has been estimated that natural causes (of which radiation from normal sources accounts for only 10 to 20 percent) (20) may produce on an average two additional mutations among every five individuals. Since we receive mutations from both parents, we may have on an average four "new" mutations in every five individuals, in addition to the very numerous, "old" mutations inherited from earlier generations (21).
An estimate has been made by some that about 80,000 mutations may be present among the populace in the United States living 100 years from now owing to radiation exposure from all nuclear tests to date.