The Effects of Nuclear War
Chapter 2
GENERAL DESCRIPTION OF EFFECTS
Combined Injuries (Synergism)
So far the discussion of each major effect (blast, nuclear radiation, and thermal radiation) has explained how this effect in isolation causes deaths and injuries to humans. It is customary to calculate the casualties accompanying hypothetical nuclear explosion as follows: for any given range, the effect most likely to kill people is selected and its consequences calculated, while the other effects are ignored.
it is obvious that combined injuries are possible, but there are no generally accepted ways of calculating their probability. What data do exist seem to suggest that calculations of single effects are not too inaccurate for immediate deaths, but that deaths occurring some time after the explosion may well be due to combined causes, and hence are omitted from most calculations. Some of the obvious possibilities are:
- Nuclear Radiation Combined With Thermal Radiation. –Severe burns place considerable stress on the blood system, and often cause anemia. It is clear from experiments with laboratory animals that exposure of a burn victim to more than 100 rems of radiation will impair the blood’s ability to support recovery from the thermal burns. Hence a sublethal radiation dose could make it impossible to recover from a burn that, without the radiation, would not cause death.
- Nuclear Radiation Combined With Mechanical Injuries. –Mechanical injuries, the indirect results of blast, take many forms. Flying glass and wood will cause puncture wounds. Winds may blow people into obstructions, causing broken bones, concussions, and internal injuries. Persons caught in a collapsing building can suffer many similar mechanical injuries. There is evidence that all of these types of injuries are more serious if the person has been exposed to 300 rems, particularly if treatment is delayed. Blood damage will clearly make a victim more susceptible to blood loss and infection. This has been confirmed in laboratory animals in which a borderline lethal radiation dose was followed a week later by a blast overpressure that alone would have produced a low level of prompt lethality. The number of prompt and delayed (from radiation) deaths both increased over what would be expected from the single effect alone.
- Thermal Radiation and Mechanical Injuries. — There is no information available about the effects of this combination, beyond the common sense observation that since each can place a great stress on a healthy body, the combination of injuries that are individually tolerable may subject the body to a total stress that it cannot tolerate. Mechanical injuries should be prevalent at about the distance from a nuclear explosion that produces sublethal burns, so this synergism could be an important one.
In general, synergistic effects are most likely to produce death when each of the injuries alone is quite severe. Because the uncertainties of nuclear effects are compounded when one tries to estimate the likelihood of two or more serious but (individually) nonfatal injuries, there really is no way to estimate the number of victims.
A further dimension of the problem is the possible synergy between injuries and environmental damage. To take one obvious example, poor sanitation (due to the loss of electrical power and water pressure) can clearly compound the effects of any kind of serious injury. Another possibility is that an injury would so immobilize the victim that he would be unable to escape from a fire.