Others who appreciate advance notice of forthcoming shots include archeologists, who, if they failed to allow for fallout, might be off by several centuries in calculating the age of ancient relics on the basis of how much carbon 14—a radioactive isotope that is present in a constant amount in all living things and disintegrates at a known rate after death—they still contain. Uranium prospectors, too, like to be warned ahead of time; back in the days before the far-reaching effects of the tests were understood, more than one prospector was momentarily led to believe that he had at last come upon a bonanza when his Geiger counter set up a wild clicking in response to fallout.
The manner in which a bomb is detonated also strongly affects the intensity of its fallout. If the bomb is exploded at a high altitude—high enough, that is, so that the mass of luminescent gas known as the fireball, from which rises the now all too familiar mushroom, does not touch the earth’s surface—its radioactivity has nothing to condense with except whatever dust it encounters in the air and the vaporized bomb casing. In such instances—and all shots of any consequence within the continental limits of the United States are of this kind—the dust and vapors, swept upward by the blast to an altitude of possibly forty thousand feet, are carried away on the strong winds of that altitude, which, owing to the earth’s rotation, are generally westerly, and may remain aloft for months. By the time the dust particles finally settle, they may well have travelled clear around the globe, becoming so thoroughly scattered and having so thoroughly dissipated their radioactivity in the atmosphere that they are presumed to be harmless. The higher the explosion the better, from the point of view of the eventual effects of its fallout, for the descent of the dust particles is apt to be hastened if they happen into a formation of rain clouds, which they are not likely to encounter until they have drifted down to within twenty thousand feet of the earth.
A surface or near-surface shot—the sort the United States restricts to the Pacific area—is something else again; indeed, radiologically speaking, it is an extremely dangerous proposition. Immediately after such a shot, the bomb’s fireball (the biggest one yet reported measured from three to four miles in diameter) sucks up millions of tons of material from the surface of the earth—rocks, sand, vegetation, water—as it rises, almost with the speed of sound. Moving up through the stem of the mushroom to its head, this hideously contaminated, or “hot,” material also soars up into the stratosphere, where it too is eventually blown away by the wind. But, unlike the radioactive dust of a high-altitude shot, much of this debris is far too heavy to be blown around the world. The winds that beneficently carry the dust of high-altitude shots such great distances blow the fallout from a ground-level shot only far enough away from the testing area to make it a menace. The debris falls rapidly while still intensely radioactive, polluting to a probably lethal degree what the A.E.C. has described as a “comparatively localized” area. Just outside the comparatively localized area, however, lies a much larger one that is definitely jeopardized by the fallout from a ground shot, for during the first few hours after the explosion some of the lighter fragments of debris spread out over thousands of square miles. Given reliable meteorological information, scientists can predict the size and general course of this fallout with a fair amount of accuracy, but, owing to the different weights of the bits and pieces that constitute the mass, and the erratic nature of the winds in the upper regions, they can’t do much more than that. For whatever comfort it might afford people who fear the fallout from surface shots, Dr. Willard F. Libby, a commissioner of the A.E.C., a while ago ventured a guess that in the event of a thermonuclear attack on the United States the enemy would set off “a large fraction” of its bombs high above the earth, since the blast and heat damage of aerial explosions is tactically superior to that of ground blasts. “In other words, the fallout problem might be minimized by the enemy’s attempt to maximize the blast and thermal effects,” Dr. Libby said.
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The fireball of a very large thermonuclear bomb that was set off on March 1st of last year on a coral island in a lagoon at Bikini Atoll touched the surface of the earth. This was the shot that made the world fallout-conscious, and it earned its sorry distinction not only by dangerously contaminating seven thousand square miles of land and sea—an area somewhat larger than Connecticut and Rhode Island together—but by injuring people who were nearly a hundred miles away from the site. The Commission naturally felt deep chagrin at this outcome of the blast, especially since it had gone to great pains to make sure that no lives would be endangered. Weeks before the bomb was detonated, the Commission saw to it that marine and aviation navigational publications printed announcements of the forthcoming test and gave their readers explicit information about the boundaries of a thirty-thousand-square-mile danger zone that had been decided upon. For days prior to the blast, aircraft crisscrossed the zone and the waters adjacent to it to warn away shipping. A meteorological study of the whole region was made, in which special attention was paid to the behavior of winds at all relevant altitudes. “The area for which meteorological data had to be compiled and analyzed was far greater than just that thirty-thousand-square-mile danger zone,” an official of the A.E.C. said later. “In fact, it was greater than that of the United States, and we had only eight or ten observation stations to cover it.” In its report of the shot and of what went wrong with it, the A.E.C. made the mildly consolatory point that without the knowledge derived from the test “we would have been in ignorance of the extent of the effects of radioactive fallout and, therefore…much more vulnerable to the dangers from fallout in the event an enemy should resort to radiological warfare against us.” In addition to the unanticipated lessons it learned about the vagaries of fallout during the March 1st test, the Commission collected some grim testimony as to its potency, expressed in terms of roentgens—one of the units in which radiation is measured. Having previously established that a person exposed to a total accumulation of four hundred and fifty roentgens in the arbitrarily set period of thirty-six hours stands only a 50 percent chance of surviving, the Commission found that during the first thirty-six hours after the March 1st blast, anyone on Bikini, ten miles down-wind from the explosion, would have been exposed to five thousand roentgens, and even if he had had sufficient warning to get to Rongelap Atoll, a hundred miles to the east, the roentgen count against him in at least one section of that tiny island would still have been twenty-three hundred.
The March 1st bomb went off shortly before four in the morning, announcing itself with a blinding flash over a broad expanse of the Pacific. The islet that had served as its platform abruptly disintegrated into pulverized coral, which was swept up into the stratosphere, and it was there that things began to go wrong. As the particles of coral gathered like a pendulous cloud in the sky—this was one time when fallout was all too plainly visible—the wind, which had been counted on to blow them to the northeast, unexpectedly veered a few degrees and began to drive them due east. Natives of the Marshall Islands, Americans participating in the test, and Japanese fishermen—all of them outside the official danger zone, which extended some fifty miles east of Bikini—were now directly in the path of the fallout, which, as it billowed toward them, assumed the shape of a monstrous cigar, two hundred and twenty miles long and up to forty miles wide.
A total of two hundred and thirty-six Marshall Islanders, all residents of the atolls of Rongelap and Utirik, were evacuated as hastily as possible by destroyer to Kwajalein. There only those from Rongelap—seventy-four of them, constituting the island’s total population—were found to have been seriously exposed. (Happily, none had been in the twenty-three-hundred-roentgen section of the atoll.) All the Rongelapians were suffering from radiation burns of the scalp or neck—the most sensitive parts of the body that are usually exposed—and all had ingested, as the nuclear people put it, small amounts of fallout-blighted foods or beverages; the hair of thirty-nine of them had dropped out in patches. Five Navy doctors reported to the c
onvention of the American Medical Association in Atlantic City last month that the children of Rongelap had lost more hair than their elders and that the counts of the children’s white blood cells, which fight infection and which are always affected by serious exposure to radiation, had dropped to lower levels. According to the A.E.C., the islanders’ burns are now healed, hair has grown back on their bald patches, and they all appear to be in good physical shape. They have not yet been taken back to their island, because it is still contaminated, but have been moved to Majuro Atoll, where, the Commission says, they are temporarily occupying “buildings built for them…of a new and improved type, better adapted to the comfort and the needs of the people than the usual type of island houses.” There they have been shown their first Wild West motion pictures, which they think are terrific. There, too, they are being studied by American physicians. Now and then, one of the doctors makes a stab at trying to explain radiation to the Rongelapians, but without much success. As a rule, the attempt quickly turns into a party of some sort. “You start talking to a couple of the islanders, and pretty soon the whole population has gathered around you, smiling and beaming and ready for some kind of fun,” an A.E.C. physician who was assigned to Majuro for a while told me. “They’re an extremely friendly people, which I suppose, considering the circumstances, is just as well.”
The Americans who were threatened by the fallout—thirty-one members of the Army, Navy, and Air Force—were on Rongerik Atoll when the wind shifted. They, too, were evacuated to Kwajalein, where they were examined by American physicians, and from there they were sent on to Tripler General Hospital, in Hawaii, for further examination. None of them was found to have been seriously affected and none has shown any aftereffects.
The Japanese in the path of the fallout were, as the whole world presently came to know, the twenty-three members of the crew of the Lucky Dragon, a hundred-ton trawler engaged in fishing for tuna. On the morning of the big blast, the vessel, which the warning aircraft had somehow missed, was about ninety miles east of Bikini, some forty miles outside the official danger zone, when several members of the crew who happened to be on deck saw a white flash tinged with red far away on the pre-dawn horizon. Seven or eight minutes later, they heard a loud explosion. In about three hours, a fine white dust of radioactive coral particles began to fall on the superstructure of the Lucky Dragon; it was so dense, one of the crew later reported, that it was faintly audible as it landed on the deck. The strange downpour continued until about noon, and by the time it let up, the dust had covered the boat, the men, and their catch like a white sheet; it lay so thick on the deck that the men left footprints when they walked on it. The fishermen had no idea what all this meant, but it was something that they had never experienced before, and plainly something weird, and it made them so uneasy that they hauled in their lines that same day and headed for their home port of Yaizu. As a matter of good seamanship, they washed down their vessel, and this probably saved the lives of a good many of them. The voyage home took thirteen days, during which a number of the men filled bottles with the odd dust to keep as souvenirs, and the whole crew, it was subsequently estimated by Japanese scientists, was exposed to the baleful assault of between two hundred and five hundred roentgens. By the time the Lucky Dragon reached Yaizu, on March 14th, practically every one of the fishermen was ridden with nausea, blisters, lesions, fever, conjunctivitis, abdominal pains, and other symptoms of overexposure to radiation.
Americans who were in Japan in the days that followed the cruise of the Lucky Dragon had some difficult moments in their relations with the people there, but, in retrospect, most of them agree that the Japanese, tragically aware as they already were of the effects of a nuclear explosion, reacted to the incident pretty much the way the citizens of any other country might have. The Japanese were angry, anxious, and voluble. As soon as word of the peculiar condition of the Lucky Dragon’s mariners reached knowledgeable authorities, the fishermen—or at least those who could be rounded up at once—were hustled off to Tokyo and hospitalized. A few days elapsed before the last of the twenty-three was accounted for, in the course of which a couple of them were picked up as they were bicycling through the streets of Yaizu, each with a grossly radioactive dried shark fin from the boat lashed to his back mudguard. Japanese scientists, wearing protective gauze masks and rubber gloves, trooped aboard the Lucky Dragon, where they found some samples of radioactive coral ash still on the bridge and carried off the tuna that had not yet been sold. When they debarked, their masks were radioactive, which gave them good reason to believe that the crew had suffered serious internal injuries.
Back in the laboratory, analysis of various items taken from the trawler, including some tuna that were still waiting for a buyer, revealed the presence of two telltale radioactive elements common to all fallout—radioiodine and radiostrontium, both of which the body can ingest or inhale. Radioiodine tends to single out and damage the cells of the thyroid gland; radiostrontium has a special affinity for the bones and, if enough of it works its way into them, may produce cancer. Word went out to the public-health authorities to confiscate the tuna that had got to the market, but it was discovered that fishmongers in the Osaka Prefecture had already sold parts of them to about a hundred customers. (Fortunately for the customers, the fish were dead at the time of the blast, so only their skin, according to the Japanese scientists, was affected and this had been removed before eating.)
American radiation specialists in Japan offered their fullest cooperation, but their Japanese counterparts, while always personally cordial, indicated that they would prefer to handle the situation themselves. American physicians were not allowed near the fishermen, although they might have been able to make some helpful therapeutic suggestions. But even if there had not been this atmosphere of professional coolness, it is unlikely that the widespread resentment that boiled up in Japan over what had befallen the crew of the Lucky Dragon could have been avoided. And, as time passed, more or less extraneous events seemed to conspire to add heat to the resentment. On March 19th, the A.E.C., in preparing for two more shots on Bikini, announced that the danger zone would be expanded—a step that some Japanese appeared to feel was rather belated. Nor did the shots themselves, which came less than a month after the return of the Lucky Dragon, act as a precisely soothing influence upon the population. At about the same time, a rainstorm over the Atsumi Peninsula blurred the glass panes of several greenhouses with a peculiar substance that a researcher at the Nagoya Technical Research Institute said was dust infused with artificially induced radioactivity, and presently a professor at Kagoshima University asserted that he had found some local vegetables, milk, and drinking water to have been mildly affected by another “radioactive rain.”
In late summer, a thirty-nine-year-old member of the Lucky Dragon’s crew, Aikichi Kuboyama, who was suffering from hepatitis, took a turn for the worse, and his case became a primary national concern. Buddhist priests prayed for his life. Hospital bulletins reporting his condition were more prominently displayed in the press than most news of international importance, and they were broadcast hourly over the radio. Kuboyama died on September 23rd (all his fellow-crewmen have survived and seem to be recovering) and his death took on political implications of the first magnitude. The Japanese Foreign Minister and other dignitaries crowded into the hospital to pay their last respects to the fisherman, and the American Ambassador in Tokyo sent a letter of condolence to the Japanese Foreign Ministry and a check for a million yen (about $2,800) to Kuboyama’s widow “as a token of the deep sympathy felt by the Government and people of the United States.” A Japanese Minister of State called publicly on the United States to show “more sincerity” by increasing the amount of money—a million dollars—that had already been offered to his government as compensation for the injuries to the crew and for the loss to the nation’s fishing industry. (The United States eventually paid two million dollars in reparations.) Japanese labor organizations, newspapers, leading c
itizens, and public opinion in general, impressed by the indiscriminating nature of fallout, called for an end to thermonuclear-bomb tests anywhere, by any country. As the national temper rose, only one incident occurred that somewhat mitigated the wave of anti-American feeling, and this, ironically, was a disaster of greater proportions, even if not of greater significance, than that of the Lucky Dragon—the drowning of more than twelve hundred persons, including about eighty Americans, when a ferryboat capsized in northern Japan just a few days after Kuboyama died. “The Japanese were quite sympathetic,” an A.E.C. man who was in Japan at the time told me. “The accident seemed to clear the atmosphere a little by reminding them that Americans can also die.”
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