The Effects of Nuclear War
Chapter V
EFFECTS ON THE OZONE LAYER
Large nuclear explosions would, among other things, inject a variety of particles into the upper atmosphere. In recent years, considerable attention has focused on the possibility that the injection of a substantial quantity of nitrogen oxide (NOX) into the stratosphere by a large number of high-yield nuclear weapons might cause a depletion or thinning of the ozone layer. Such a depletion might produce changes in the Earth’s climate, and would allow more ultraviolet radiation from the Sun through the atmosphere to the surface of the Earth, where it could produce dangerous burns and a variety of potentially dangerous ecological effects.
As of 1975, a report by the National Academy of Sciences (discussed more fully below) called attention to this danger as a serious one, estimating that a 30 to 70- percent reduction in the ozone column was a possibility.
Table 14. -Long-Term Radiation Effects From Nuclear Attacksa
| A. Air Bursts | ||
|---|---|---|
| Estimaled worldwideb effecls from 1-Mt air burst over a city (OTA Case 1): | ||
| Somatic effects | ||
| Cancer deaths | 200 - 2.000 | |
| Thyroid cancers | about 700 | |
| Thyroid nodules | about 1.000 | |
| Genetic effects | ||
| Abortions due to chromosomal damage | 100 - 1.000 | |
| Other genetic effects | 350 - 3.500 | |
| Estimated worldwideb effects from an attack using 78 air bursts of 1 Mt each (OTA Case 2 attack on the United States) are 78 times as great, that is: | ||
| Somatic effects | ||
| Cancer deaths | 16.000 - 160.000 | |
| Thyroid cancers | about 55,000 | |
| Thyroid nodules | about 78,000 | |
| Genetic effects | ||
| Abortions due to chromosomal damage | 8.000 - 80,000 | |
| Other genetic effects | 27.000 - 270.000 | |
| Estimated totalc effects from an attack using 72 air bursts of 40 kt each (OTA Case 2 attack on U.S.S.R.): | ||
| Somatic effects | ||
| Cancer deaths. | 6,000 - 60,000 | |
| Thyroid cancers | about 50,000 | |
| Thyroid nodules | about 80,000 | |
| Genetic effects | ||
| Abortions due to chromosomal damage | 2.500 - 25,000 | |
| Other genetic effects | 5.000 - 50.000 | |
| B. Limited Surface Bursts | |||
|---|---|---|---|
| Estimated totalc effects of an attack on U.S. oil refineries using surface bursts, with fallout sheltering treated parametrically: | |||
| Somatic effects | PF*=5 | PE*=10 | PF*= 40 |
| Cancer deaths | 2,000,000-5,500,000 | 1,000,000-3,000,000 | 300,000-1,000,000 |
| Thyroid cancers | about 2,000,000 | about 1,000,000 | about 300,000 |
| Thryoid nodules | about 2,500,000 | about 1,500,000 | about 500,000 |
| Genetic effects | |||
| Abortions due to chromosomal damage | 250,000-2,500,000 | 150,000-1,500,000 | 50,000-500,000 |
| Other genetic effects | 900,000-9,000,000 | 500,000-5,000,000 | 150,000-1,500,000 |
| Estimated effects outside the United States from this attack: | |||
| Somatic effects | |||
| Cancer deaths | 8,000 - 80,000 | ||
| Thyroid cancers | about 30,000 | ||
| Thyroid nodules | about 50,000 | ||
| Genetic effects | |||
| Abortions due to chromosomal damage | 4.000 - 40,000 | ||
| Other genetic effects | 13.000 - 130.000 | ||
| C. Counterforce Attacks (Mixed air and surface bursts -Case 3) | |||
|---|---|---|---|
| Estimated totalc effects of an attack on U.S. ICBM silos, using one air burst and one surface burst (each 1 Mt) against 1,054 silos. A case in which bomber and submarine bases are also attacked with air bursts gives similar results. Fallout sheltering is treated parametrically: | |||
| Somatic effects | PF*=5 | PE*=10 | PF*= 40 |
| Cancer deaths | 1,000,000-6,000,000 | 700,000-5,000,000 | 500,000-4,500,000 |
| Thyroid cancers | about 2,000,000 | about 2,000,000 | about 1,500,000 |
| Thyroid nodules | about 3,000,000 | about 3,000,000 | about 2.500,000 |
| Genetic effects | |||
| Abortions due to chromosomal damage | 300,000-3,000,000 | 250,000-2,500,000 | 200,000-2,000,000 |
| Other genetic effects | 900,000-9,000,000 | 750.000-7.500.000 | 650.000-6,500,000 |
| Estimated effects outside the United States from this attack: | |||
| Somatic effects | |||
| Cancer deaths | 400,000 - 3,800,000 | ||
| Thyroid cancers | about 1,400,000 | ||
| Thyroid nodules | about 2.000,000 | ||
| Genetic effects | |||
| Abortions due to chromosomal damage | 170,000 - 1,700,000 | ||
| Other genetic effects | 600,000 - 6,000,000 | ||
| Estimated total effects of an attack on Soviet ICBM silos, using one air burst and one surface burst (each 100 kt) against 1,477 silos. The overwhelming bulk of deaths are from "worldwide" (between 30° and 60° north latitude) fallout, and hence fallout sheltering in the Soviet Union makes little difference: | |||
| Somatic effects | |||
| Cancer deaths | 300,000 - 3,300,000 | ||
| Thyroid cancers | about 2,500,000 | ||
| Thyroid nodules | about 3,600,000 | ||
| Genetic effects | |||
| Abortions due to chromosomal damage | 120,000 - 2.500,000 | ||
| Other genetic effects | 400,000 - 4,000,000 | ||
| D. Comprehensive Attacks (Case 4) | |||
|---|---|---|---|
| Estimated effects inside the United States of an attack on military and economic targets in the United States consisting of 3,325 weapons with a total yield of 6,500 Mt. A mixture of air bursts and surface bursts was assumed, and the ranges include variations in fallout protection available: | |||
| Somatic effects | |||
| Cancer deaths | 1,000,000 - 5,500,000 | ||
| Thyroid cancers | 1,000,000 - 2,000,000 | ||
| Thyroid nodules | 1,500,000 - 2,500,000 | ||
| Genetic effects | |||
| Abortions due to chromosomal damage | 150,000 - 6,000,000 | ||
| Other genetic effects | 400,000 - 9,000,000 | ||
| Estimated effects outside the United States: | |||
| Cancer deaths | 900,000 - 9,000,000 | ||
| Thyroid cancers | about 3,200,000 | ||
| Thyroid nodules | about 4,500,000 | ||
| Genetic effects | |||
| Abortions due to chromosomal damage | 500,000 - 5,000,000 | ||
| Other genetic effects | 1,500,000 - 15,000,000 | ||
| Estimated totalc effects of an attack on military and economic targets in the Soviet Union consisting of 5,660 weapons with a total yield of 1,300 Mt. A mixture of air bursts and surface bursts was assumed, and the ranges include variations in fallout protection: | |||
| Cancer deaths | 1,200,000 - 9,300,000 | ||
| Thyroid cancers | about 5,500,000 | ||
| Thyroid nodules | 7,700,000 - 8.400,000 | ||
| Genetic effects | |||
| Abortions due to chromosomal damage | 320,000 - 8,000,000 | ||
| Other genetic effects | 1,000,000 - 12,500,000 | ||
- * PF = Protection factor.
- a Assumptions and sources are those used for tables 12 and 13.
- b Most worldwide fallout would be in the Northern Hemisphere, and it would be concentrated between 30° and 60° N Latitude.
- c Includes worldwide totals (note b above), but effects are greater in the target country than elsewhere.
Since that time, however, there have been two changes which bear on the question of the degree of risk of ozone depletion:
- Further research into the chemistry of the upper atmosphere has modified the model calculations used in 1975. The results of past nuclear tests do not, however, provide data adequate for the complete validation of any chemistry model. There are also indications that the chemistry concerned is much more complex than was formerly believed. The state of knowledge in early 1979 is roughly this: injections of NO. could deplete the ozone layer if they occur at very high altitudes (80,000 ft [24 km] and upwards), which would result from very high-yield explosions (i.e., substantially more than 1 Mt) in large numbers (1,000 or more), or possibly from high-altitude explosions. Otherwise, ozone depletion is not believed to be likely. However, further changes in the theory of what would happen are Iikely in the future.
- The development of MIRVs has reduced the number-of very high-yield warheads in the arsenals of the superpowers, as they are replaced by multiple weapons of lower yield.
These changes cast doubt on the likelihood of serious ozone depletion as a consequence of nuclear war. However, they by no means demonstrate that ozone depletion is impossible, and even slight depletion could cause an increase in the incidence of skin cancer.
This is an area where research continues, and further changes should not be surprising.