Science in Christian Perspective
Radioactive debris produced by bomb detonations may be divided into three categories, namely: 1) local, 2) tropospheric, and 3) stratospheric, with the fraction in each category depending upon the bomb size and the conditions of detonation. Local debris is that which quickly falls out near the test site and is of little consequence with regard to the world-wide picture. Tropospheric debris is disseminated into the lower atmosphere (below 40,000 feet) and is washed out by rain within a few months. It thus has time to distribute itself around the world longitudinally with the prevailing winds, but remains somewhat restricted in latitudinal distribution. Stratospheric debris goes into the upper atmosphere and comes down more slowly (mean residence time about 1-3 year.)
Fallout produced at bomb detonation consists of about 189 radio-isotopes representing 37 chemical elements. Fortunately more than two-thirds of these have physical half lives of less than one day. Various other factors reduce the principal hazard to two isotopes, namely strontium-90 and cesium-137. In addition, carbon-14 comes in for some consideration. Carbon-14 is not a fission product but is produced by the action of fission-produced neutrons on nitrogen. The present status of these isotopes in terms of their concentration in the human body is given in Table 1. Also included
From a paper presented at the l3th Annual Convention of the American Scientific Affiliation, Ames, Iowa, August, 1958.
in. this table. is. the 'maximum: permissible concentration (MPC) for each isotope as established by the
International Committee on Radiation Protection for whole
11. Biolo gical Danger to Man
The, hazard from fallout may, be divided into. two categories: :1) somatic hazard, 'i. e., hazard to one's own body and 2) genetic hazard, i.e., that whic h does not affect one's own body but affects his own progeny.
Since strtrontium-90 Is confined to the bones almost exclusively and since it emits only the less penetrating
beta radiation, the isotope does not significantly in crease the radiation to the gonads. Thus it is almost
exclusively a somatic hazard. It is known to produce bone cancer and leukemia in high doses. Cesium-137
and carbon-14 on the other hand are distributed throughout the body and their principal hazard is pre sumed to be genetic. In establishing the hazard from present fallout, the assumption is made that radiation damage is a non-threshold phenomenon which means that there is no safe level below which no damage is done. This is thought to be more likely for genetic damage but is less generally accepted for somatic dam age. It is impossible to demonstrate any damage from the low levels with which we are dealing in present fallout due to a) its very small magnitude, b) the many other variables involved and c) the statistical nature of the results. Therefore damage at high doses is evalu ated and the results extrapolated to these low doses. On the basis of these calculations the present strontium-90 concentration in the skeleton would produce about 1000 leukemias and about 10,000 bone cancers in the entire world population in one generation. By the same sort of reasoning, it is estimated that genetic damage pri marily from cesium-137 would result in 8,000 children being born with gross physical or mental defects in a subsequent generation and would also result in 20,000 stillbirths and childhood deaths plus 40,000 embryon ic and neo-natal deaths in this generation. While these numbers are the result of considerable approximation, it nevertheless appears reasonably certain that people are living today with various ill ef f ects in their bodies as a result of bomb fallout and that furthermore some lives have been shortened from this cause.
To put the problem in perspective, Table 2 summarizes various other radiation effects, including natural background radiation and variations thereof and radiation produced by medical X-rays and fluoroscopies. Although these data do not of course in any sense excuse the indiscriminate dispersion of fallout debris, it does show that other factors which we accept as a part of our daily living are of much more consequence than the fallout. Crow, a geneticist of the University of Wisconsin, concludes that other effects in the nonradiation class such as food additives, smog, etc. are probably a greater hazard than radiation. A. M. Brues of Argonne makes a very interesting calculation in which he uses the sanie criteria for establishing MPC for cigarette smoking as is used for radiation. He concludes that the population MPC for cigarette smoking is 0.24 cigarettes per day or in other words, about one cigarette in four days.
Other hazards of our daily living could be cited, for example, the fact that approximately 40,000 people in the United States lose their lives each year from automotive accidents. Thus in terms of effects produced, automobile riding is much more hazardous than atomic radiation from the present fallout. Furthermore this hazard could be almost completely eliminated if a national speed limit of 25 miles per hour were put into effect with strict enforcement. We apparently feel however that this price of 40,000 deaths per year is a reasonable one to pay in the interest of convenient transportation. However, it is not valid to compare the automobile hazard as well as the other hazards we mentioned to the hazard of fallout since in the former case the individual has some choice in the matter whereas in the latter case, he has no choice. No one on earth can avoid fallout radiation. This brings us to our final point of discussion.III. The Moral Implications of Fallout
The general attitude of our government is that whereas fallout does produce a very small hazard, it is a reasonable price to pay in the interest of maintaining an adequate military defense. If we accept the fact that going to war is under proper circumstances justified, then this position of our government makes sense insofar as our own citizens are concerned, that is to say, that as citizens of the United States we should be willing to accept certain hazards in the interest of maintaining our government and our way of life. At the same time we should insist that our defense officials keep ever before them the philosophy expressed in this phrase from World War II, slightly reworded, " Is this bomb really necessary?" I personally am willing to take ten times the MPC of strontium-90 in my bones if it is necessary. On the other hand, I insist that even 1% of the MPC should not be imposed upon me if it is unnecessary.
The more difficult problem comes however when we consider the effect on other people of the globe. While it is very proper for our government to say we shall demand that each of our citizens accept a small hazard io his life in the interests of our national defense, it is not so clear that our government has the right to this condition upon all people of the world. Is it proper that in the interest of our national defense we cause every child that is born on earth to be born with strontium-90 in his skeleton, which strontium-90 will in some cases (very few to be sure) result in bone cancer, leukemia, or other defects? This is the question which I leave for your consideration and for which I have no answer. However, two possible solutions might be suggested, I ) we might take the view that our government stands for the whole free world. We are seeking the best not only for our own citizens but for the entire world's population and therefore we are justified in having them assume this hazard with us. However, this then is without their choice. 2) We may take the view that after all fallout to date is insignificant and it Is true that other hazards of life are much more irliportant. It is also true that only a minute fraction of the world population is adversely affected. However it is difficult to class something as insignificant where in absolute terms it does result in the premature death of thousands of individuals.
Body Content of Bomb-Produced Isotopes