In addition to accompanying defense and rescue teams, personnel meter readers would be performing detection duties of miscellaneous types following a raid. Some might test the radioactivity of the clothing of patients brought into hospitals. The garments, if found contaminated, might have to be scrubbed until cooled down to a safe limit or else they might be destroyed. Other readers might check for pollution of water-supply systems, milk stations and foodstuffs. If food supplies or the main water system should be found contaminated, radio chemists and other specialists would be called into action to determine the type of “heat” and what to do about it.
That, briefly, is what would be done on an organized community level to prevent widespread panic—for much of the danger of radioactivity is mental—and actual radiation injuries. Whether radiological defense will prove a success depends to a great measure upon each individual within that community, upon each person’s calm knowledge of the true potential of the bomb and its radioactivity, and of the safety steps that can be taken to minimize its dangers.
The radiological hazards of the atomic bomb fall into two classifications and, in order to prevent panic and injury, it is important for everyone to know them. First are the short-lived, “prompt” radiations. These consist of X rays, gamma rays and neutrons that are thrown off at the very second of explosion and last only as long as the detonation itself. Second are the “lingering” radiations. These consist of invisible radioactive fission products—or bomb “ashes”—and just as invisible hot bits of unexploded uranium and plutonium atoms that failed to undergo fission when the weapon was detonated. The lingerers may last for seconds or for years.
Whether a raided community will face much—or any—lingering radiation depends primarily upon the level at which the bomb is exploded. In a mid-air detonation, such as at Hiroshima and Nagasaki, the only serious radiation dangers are the short-lived ones, most of the bomb wastes being swept into the sky by the swiftly rising bomb cloud. A near-surface detonation may result in some lingering contamination, but only rarely will it cover more than a fraction of a square mile. It is in the underwater bombing, where all the radioactive wastes are trapped by the water and mist and scattered spottily over as much as seven or eight square miles, that great danger of lingering radioactivity exists.
The only protection against the bomb’s short-lived, prompt radiations is adequate shielding at the moment of explosion. In the immediate vicinity of ground zero, reasonable safety is afforded by one foot of steel, three feet of concrete and five feet of earth. At 1000 yards, the comparative thicknesses fall roughly to five inches of steel, fifteen inches of concrete and twenty-five inches of earth. A mile from zero, a fraction of an inch of steel and several inches of concrete are all that would be required. It should be recalled here that of all the deaths and injuries at Hiroshima and Nagasaki, only 15 per cent were caused by radiation, and this at a time when whoever was sheltered was sheltered only by accident.
The basement of a building affords not only the most adequate protection against the atomic bomb’s blast and heat but also against its short-lived, prompt radiations; for not only would a person be best sheltered there by surrounding structures but he would also have more radiation barriers—steel, concrete, wood and earth—between him and the bomb. High in a building, there would be few such radiation absorbing materials in the path of the straight-traveling rays and particles. Window glass would let them in readily and even scatter them about.
Because the blast of the atomic bomb is often a spotty thing, a building even close to the point of the explosion might suffer little structural damage, but at the same time, this would not necessarily imply that it would not be riddled with prompt rays and neutrons. These short-lived rays and particles, while having no visible effect upon building materials—no holes, no breakage—might cause artificial, lingering radioactivity in such household items as silverware and prescription drugs, although they would not damage bandages and other common first-aid supplies in the medicine cabinet. The wise person, after a raid, would be wary of the silverware, and throw away the prescription drugs.
Short-lived, prompt radiation that passes through the walls of a house will not, of course, be stopped by the tin or glass of canned or bottled food. Unless the containers were broken by the blast, though, the food probably would still not be dangerously radioactive and could be eaten. A check by a meter reader would be the best precaution, however.
As for water, there is little possibility that the fluid inside household pipes would be dangerously radioactive at the time of attack. The simple precaution here would be to draw some off immediately and keep it in clean, covered receptacles for use during the postraid period. Although the taps might still run after an attack, it would not be wise to use the water from them much later unless told to do so by the authorities. Boiling of water will not remove the radioactive pollution, instead, it will concentrate it.
The operation of mechanical devices—telephones, radios, television sets—is not affected either by prompt or lingering radioactivity, and their usage is part of the over-all plan of radiological defense. The practicability of this was shown beyond doubt by the tests at Bikini. There, by radio, pilotless airplanes were flown straight through the deadly radioactive bomb clouds, and drone boats were sent directly into the target area to pick up water samples. Also, in the underwater test, television receivers on the observation ships portrayed clear pictures of the target fleet, even during the time the area was at its highest radioactive intensity.
And proof of the operation of mechanical devices was brought home to me with special emphasis at Bikini when, walking along the fantail of the U.S.S. Nevada, the central bomb target for the first test, I came upon a delicate chronometer. Although it was one of the most radioactive objects on the ship, it was still ticking away and keeping perfect time. This clock, one of countless exposed test objects, also was further proof to me of the blast’s occasional eccentricities. On one side of it an airplane had been tossed forty feet and wrecked; on the other side there was a huge depression in the deck, like a punched-in pillow. The chronometer, however, was untouched except radioactively.
Therefore, unless power lines were knocked out in a raid, electric lights, radios and telephones should continue to work. As for the family car, radioactivity will not affect its operation. To prevent lingering wastes from entering it, though, the windows should be rolled up, and, if possible, the car should be kept in a closed garage.
While protection against short-lived radiation is a matter of adequate shielding at the moment of the detonation, protection against lingering radioactivity is more than that. Although immediate shielding is important, too, it is also a matter of avoiding contaminated objects and areas after the actual explosion.
In the rarer low-level or underwater bombings—rarer because the atomic bomb is basically an antimatériel weapon and only the midair explosion uses to their full potential the bomb’s forces of blast and heat—there is relatively little that can be done to prevent lingering contamination in the immediate area of an explosion. Even most of the houses in that vicinity would not be free of it; some of the bomb wastes would enter through broken windows, drift down chimneys or seep through cracks. Yet many things can be done to reduce such pollution.
All windows should be kept shut, and broken ones promptly covered with cardboard or blankets. All fireplace flues should be closed. Because wind could blow the hot ashes around or the radioactive wastes could fall out of drifting bomb clouds, householders even in areas outside the stricken one should follow these same precautions.
Also, much pollution could be brought into a house by persons, especially members of defense and rescue squads, carrying the invisible wastes on their clothes and shoes. Therefore shoes and outer garments should be removed and kept outside, later to be scrubbed in disposable tubs. The family washing machine would not be good to use here, as it might become contaminated and make other garments slightly radioactive. It would be safest for anyone connected with any defense or rescue teams to wear overalls and rubbers as well as a hat at his job.
A shower with plenty of soap and water is the best means of cleansing body surfaces of all radioactive materials. At Bikini it seemed as if we were always showering. Even radioactive ships were somewhat cooled down by fire hoses. In taking a shower, a person should pay particular attention to his hair, shampooing it thoroughly, for there is where heat tends to accumulate. It also accumulates under the fingernails. A personal check by a meter reader, even after a shower, would be a sound extra precautionary move.
I never shall forget one particular shower I took. To me, it was like a shot of penicillin. Several days after the Bikini underwater test I was standing on the deck of my base ship, staring out at the fleet in the distance, when a bunkmate held his Geiger counter next to my head. “You’re as hot as a firecracker!” he shouted.
I felt my stomach grow knotted. It was as if I had been condemned to death. I didn’t know which way to turn. Somehow I managed to look at his meter. What I saw confirmed his words: My hair was radioactive slightly above the exposure limit, and it undoubtedly had been so for several days.
Abruptly, but trying to look perfectly calm, I took off for the washroom. I must have stayed under that shower for an hour, scrubbing my hair with soap and water. Then, when I had a reading taken again, I found that my hair was still radioactive but much less so. I was thinking, however, of those days when I had been walking around with a painless though fiery scalp, and I resigned myself to await as calmly as I could the symptoms of radiological sickness, which I was certain soon would appear—falling hair, perhaps nausea, weakness. But days passed and I remained healthy. I didn’t lose a single strand of hair. My appetite improved, if anything.
Which brings me to another point—the wide, healthy gap that looms between detectable and dangerous radioactivity and the gap, too, between injurious and fatal amounts.
Radioactivity is all around us. It is something with which each of us has lived since birth. If I took a Geiger counter in my hand and held it in the peaceful quiet of my home, I probably would get about twelve telltale clicks a minute, mostly because of cosmic radiations from the heavens. These small but readily detectable amounts of radioactivity rarely, if ever, are harmful. Large amounts of radioactivity definitely are, but even then the degree of injury depends upon how much of the body surface is exposed to it.
It is believed from past experience that detectable human injuries rarely result from the absorption of less than one roentgen, that damage does not become apparent until about twenty-five roentgens and that death is not a certainty until the body has soaked up more than 600 roentgens. In terms of distances from ground zero, this means that anyone caught completely unsheltered within 1000 yards of a detonation probably would absorb a fatal amount of radiation. But it also means that the fatality rate would fall off rapidly until, at a little over a mile, although there would be injuries, very few would cause death. Remember, that’s for the completely unsheltered.
But I rarely think of the wide difference between detectable and dangerous amounts of radioactivity in terms of figures. I think of it in terms of that day when my hair was found to be radioactive or that other day when, again at Bikini, I was in my bunk deep in the hold of the ship, and my bunkmate, a curious fellow, casually held his Geiger counter near the outer bulkhead. He turned around quickly, his eyes opened wide. He pulled off his earphones and wiped his lips nervously.
The ship’s hull was radioactive because of fission products of the underwater bomb that were held against its outside surface by barnacles and algae. For days now we had been sleeping with our bunks flush against that hot bulkhead, and no doubt we had soaked up ionizing rays in appreciable quantities.
“What do we do?” my bunkmate asked anxiously.
Instead of answering, all I did was to move my bunk away from the ship’s shell. He did the same. There was little else we could do. Again that wait for symptoms; and again nothing.
Lingering radioactive dusts on the outside of the body are not likely to be highly dangerous. Swallowed, however, they could cause trouble. That is why clean hands and fingernails are important; why cuts should be bandaged as soon as possible; why a person in a contaminated area should not smoke or wipe his sleeve on his face; why, unless checked by a meter reader, unpackaged food should not be eaten; why bottled and canned goods should not be opened until washed thoroughly, or cooking and eating utensils used until scrubbed clean. The person who thinks he has eaten highly radioactive food should lose no time in ridding himself of it.