How serious is the threat of radiation?
Bombarded by X rays and rays from TV tubes, watch dials, car panels and H-bomb tests, we are constant targets of radioactivity. What is it doing to us—and future generations? Here are some disturbing facts
Within the last decade that most puzzled of all creatures in all history—the twentieth-century human being—has been confronted with a riddle nearly as fundamental as the riddle of the universe: what does atomic energy mean to his race? What does it mean to him as an individual? What—and this part of the riddle may be the hardest of all to guess—what does it mean to his children and their children?
At the polar extremes the answers now seem fairly simple. If w'e go on making bombs and begin dropping them on each other we shall destroy what passes for civilization. If we harness the atom for peaceful use we may build Utopia.
But more and more people have begun to realize that the ultimate answer to the riddle of the atom may not lie at either extreme. It may lie in a no-man’s land of undiscovered mysteries—the area of so-called harmless radiation and so-called beneficial radiation and its effect on health and evolution. More and more authorities have begun to fear that the dangers of radiation lie not only in the ultimate horror of fall-out from a bomb but from the careless use of X rays, luminous paints and industrial and medical isotopes.
The awareness of these still half-hidden dangcrs has emerged so urgently that they became a key issue in the recent U. S. election campaign when Adlai Stevenson called for an end to Hbomb tests. Scientists, as well as politicians, still disagree on the extent of the danger. Dr. Ralph Lapp, one of the best-known atomic physicists in the U. S., says fragments of bomb debris from the Pacific tests are now turning up in the bones of people all over the world and can cause bone cancer. An equally prominent physicist. Dr. Gordon M. Dunning, of the U. S. Atomic Energy Commission, says the point at which the tests will present a real threat to mankind is far off.
We are constantly being bombarded by X-raymachines. fluoroscopes. luminous-dialed watches, clocks and car instrument panels, and television tubes. The newest source of radioactivity—and ultimately the greatest source of danger—is the radioactive isotopes, such as are produced by Atomic Energy of Canada Ltd. at Chalk River, Ont. Radioisotopes arc already being used in a hundred different ways in medicine, research and industry.
Are we already suffering from too much radiation? Has radiation irrevocably damaged our unborn descendants by attacking our genes? Howcan we protect ourselves from too much radiation? These are questions now occupying the attention of many scientists. They are aware that, potentially, radiation is the most serious publichealth problem that has ever confronted mankind. for not only can radiation kill people nowliving. it can maim and injure, through inheritance, millions yet unborn.
In explaining the hazards of radiation, a good starting place would be to introduce the term roentgen, or “r” in abbreviated form. It's the unit used for measuring radiation received by a human being. A simplified yardstick is that it requires 625 roentgens to redden your skin. A massive dose of 500 roentgens at one time over the whole body can kill a person in days or weeks. If a person receives a large dose to his whole body in small installments over many years, it w'on't kill him immediately, but, much later, it may lead to anemia, cancer, sterility or premature death. For radiation doses are cumulative. Every roentgen absorbed by any animal bodystays there and piles up throng'' the years.
But perhaps the most chilling aspect of radiation is that it does genetic damage. Roentgens change human genes so that the descendants of the exposed person may be born defective. And the damage may continue for forty generations. Children of exposed parents may be born with lowered resistance to disease, with mental defects, dwarfism, hemophilia, leukemia or congenital blindness. Some scientists have suggested that in several generations a new race of scarcely human creatures may emerge.
How much radiation is required to do genetic damage? Our most authoritative answers come from two distinguished groups, the U. S. National Academy of Sciences and the British Medical Research Council. By coincidence, both issued long reports on radiation hazards in June 1956. They emphasized that "all radiation is genetically harmful” and that “the only really safe number of roentgens is zero.” However, they set ten roentgens to the reproductive glands as the maximum dose that the average person should receive by his thirtieth birthday. They estimated that if the average dose were to be increased to somewhere between 30 and 80 roentgens, the number of defective children born in the future would double.
In calculating genetically harmful radiation scientists are chiefly interested in the number of roentgens that reach the reproductive glands. In all X-ray examinations at least some radiation will get through to these glands. For instance, in a dental X ray that beams five roentgens to the mouth about 5/1000 roentgens get through. In the examination of the continued on page 115 abdomen of a pregnant woman, the X-ray machine might have a strength of nine roentgens of which a hazardous 1.3 might reach the reproductive glands.
Dangers in disguise . . . Are we risking our lives using radioactive rays to test steel, check teeth, fit shoes? And (below) can we be sure buried atomic waste won’t contaminate the earth?
How much radiation has the average person of thirty accumulated? Nobody knows, but the U. S. National Academy of Sciences estimates that the following number of roentgens has been received from the following sources:
Natural background radiation: Everyone is constantly absorbing background radiation. Some comes from outer space; some from rocks and soils that contain uranium. The dose from this source is estimated at 4.3 roentgens; in high altitudes, it may reach 5.5 roentgens.
X rays: Medical and dental X rays and liuoroscopes are believed to account for three roentgens. A man who has an Xray examination of the hip and femur, for example, receives .7 roentgens in the reproductive glands. Some people get less than three, others a lot more.
Fall-out from testing atomic weapons: Measuring radiation from atomic fall-out is complicated. However, many scientists agree that so far we’ve received from .02 to .5 roentgens from this source, and it’s likely to increase.
Atomic-power plants: The fumes and waste products of nuclear-power plants do not yet constitute a real danger, but within fifty years this continent may be dotted with atomic-energy plants.
Radioactive isotopes: Radioactive iron, iodine, cobalt, gold, phosphorus and many other substances are used in industry, medicine and scientific research. Radioisotopes are now used in more than two hundred Canadian hospitals, research centres and industries. As thflér use spreads—as it undoubtedly will—it will add to the hazard.
Miscellaneous sources: Shoe-fitting fluoroscopes, X-ray machines for hair removal, luminous watches, clocks and car panels and TV picture tubes—all these produce radioactive rays. How many roentgens are received from these sources is unknown.
The growing number of radioactive sources has recently led to many warnings. Paul Martin, the federal minister of health, has described the situation as “a magnificent and terrible challenge.” Martin has established a federal watchdog group known as Radiation Services, headed by Dr. F. D. Sowby. The U. S. National Academy of Sciences has demanded that medical authorities reduce exposure to X rays “to the lowest limit consistent with medical necessity.” The British Medical Research Council says that “the practice in diagnostic radiology should be reviewed; the use of radiology therapy in anything except cancer should be critically examined.” Dr. Edwin Crawford, chairman of the standards, units and protection committee of the Canadian Association of Radiologists, says, "There’s a tendency to use more and more X rays. We often have to say to doctors, ‘Stop! Your patients have had enough.’ ”
The first large-scale warning that radiation menaces health came early in this century from the careless use of radium. Between 1915 and 1930 thousands of people drank “radium water” and received injections of “radium salts” for ailments. In many cases the “cure” proved fatal. Meanwhile, in a watch factory in New Jersey, girls painting radium on watch faces pointed their brushes with their mouths. Most died early, often from cancer.
In the pitchblende-rich mines of Schneeberg and Joachimsthal in Germany at least half the miners died in middle age from a strange disease since identified as lung cancer. It was caused by the radioactive ore in the mines.
In the 1954 A-bomb tests in the Marshall Islands in the Pacific, the fall-out on one island was so heavy that each inhabitant received a whole-body dose of about 175 roentgens. No immediate deaths resulted but many lost their hair, some developed ulcers of the skin and may yet develop cancer.
The U. S. National Academy of Sciences points out that physicians having no contact with radiation live an average of 65.7 years; dermatologists and urologists who have some contact with radiation live, on the average, to 63.3; radiologists only 60.5. Another study, based on obituary notices in the Journal of the American Medical Association, found there were nine times as many deaths from leukemia (cancer of the blood) among radiologists as among other physicians. It has been estimated that the radiologist absorbs as many as a thousand roentgens during his working life. Dr. H. J. Muller, an Indiana University biologist who won a Nobel Prize for his studies on radiation and genetics, has declared flatly, “If a person accumulates six hundred roentgens during his working life, his life is shortened by four to eight years.”
The relationship between over-radiation and leukemia is mentioned in a recent report of the British Medical Research Council. Ankylosing spondylitis is a painful disease that affects the joints of the spine. An effective method of obtaining relief is to irradiate the spine with X rays. Some fourteen thousand patients who had been thus treated between 1935-1954 were studied, and the BMRC concluded: “The incidence of leukemia is ten times greater than it would have been in the absence of radiation.”
Radiation may reduce human fertility and even make people permanently sterile. In men a single dose of five hundred roentgens beamed directly at the testes would probably produce permanent sterility. (A whole-body dose would be fatal.) In a woman nearing the end of her reproductive life, a smaller dose—about three hundred roentgens—would produce the same result. Moderate doses can produce temporary sterility. Dr. Jean Bouchard, vice-president of the Canadian Association of Radiologists, found when he tested one hundred patients receiving radiotherapy for ankylosing spondylitis.
Disturbed by evidence like this, government and health officials have insisted that the use of radioactive products manufactured by Atomic Energy of Canada L.td. be subject to federal regulations. But we appear to be dangerously reckless in handling radiation from X-ray machines. In every province legal control over their sale and use is lax. It’s possible for any layman—no matter how unqualified—to buy X-ray equipment and use it on others.
In several Canadian cities laymen with X-ray machines advertise that they can “painlessly and permanently remove superfluous hair from the face, arms and legs.” They remove the hair as promised but sometimes, several years later, the customer notices that the exposed area of her body becomes dry and itchy. Later
the skin becomes wrinkled, blood vessels split and multiple ulcers appear. These in time may turn into cancer. Dr. Hamilton Baxter, a Montreal plastic surgeon and a professor of surgery at McGill, says, "I’ve treated hundreds of people who had their hair removed by radiology”—by slicing off the damaged skin and resurfacing it with grafted tissue.
How many roentgens does the victim of the hair remover receive? No one can say, but it takes at least seven hundred roentgens concentrated on the hair to remove it permanently. Dr. Allan Small, a Toronto dermatologist, had a patient who had undergone seventy X-ray treatments for hair removal. Her dose could only be counted in the thousands of roentgens. This persuaded him to join forces with a small group of fellow dermatologists and write to Health Minister Martin, demanding that the X-ray hair removers be driven out of business. Martin replied that such matters were a provincial responsibility. I asked health authorities in each of Canada’s ten provinces whether legislation to restrict the use of X-ray machines was being planned. All of them said no.
Another uncontrolled source of radiation is the shoe-fitting fluoroscopes in many shoe and department stores. One Toronto store has five. Many medical authorities have declared that these machines are hazardous. Dr. John MacDonald, radiation physicist at the Toronto General Hospital, says, "They’re harmful to both the people operating them and those using them.”
We’re “X-ray happy”
The International Commission on Radiological Protection, set up by radiologists from all over the world, has recommended minimum safety standards for these machines. It stated that no part of the body should be exposed to more than 78 roentgens a year. The strength of the beam on the fluoroseope should be 12 roentgens a minute, with a knob to adjust it to ten roentgens for women and eight for children. Fittings should be limited to five seconds. Thus, if a person took three fittings for each pair of shoes and visited a store four times a year, lie would be within the maximum permissible limit.
In many Canadian communities these standards of safety are not being met. Some shoe-fitting machines are delivering up to 40 roentgens, instead of 12. Thus a customer could easily use his yearly maximum safe dose in a single purchase. Dr. F. D. Sowby, head of Radiation Services, recently examined twenty shoe-fitting fluoroscopes in Ottawa. "Only one conformed to the ICRP safety standards,” he says. In some stores children were allowed to amuse themselves by playing with the fluoroscopes. “Most of the storekeepers had no idea that the youngsters were playing with dynamite,” says Sowby. Some provinces, like Manitoba, have conducted educational campaigns to protect the public. They are not too cheerful about the results. “One is led to believe,” says Dr. Hugh Malcolmson. of Manitoba’s Bureau of Industrial Hygiene, “that the only way to control this source of radiation is to get rid of the machines.” Federal Health Minister Martin evidently agrees: he recently asked the provinces to ban the shoe-fitting fluoroseope.
The average person will get his largest dose of radiation in a doctor's office or a hospital. Both the public and many in the medical profession seem to have become "X-ray happy.” One of the largest manufacturers of medical and dental X-ray films reports that his sales have doubled in ten years. Hospital radiology departments in recent years have doubled and trebled their capacities. In 1954, 817 Canadian hospitals reported that they had taken five million diagnostic X rays and had given 310.000 radiotherapy treatments.
“Doctors unskilled in radiology are a menace”
Is this tremendous volume of radiology necessary?
According to Dr. Jean Bouchard, vicepresident of the Canadian Association of Radiologists, most of it is—if it's done by a certified radiologist, i.e., a graduate doctor who has had four years’ training in radiology. Many observers disagree. Dr. Sowby, of Radiation Services, says, “Diagnostic examinations are too common. The idea of protecting the patient from exposure hasn't leaked through to enough doctors.” Dr. Charles Leblond, an adviser to the National Cancer Institute of Canada, feels that too many radiologists underestimate radiation hazards.
Bouchard makes the point that the public is partly to blame for the dangerously high popularity of radiology. “They think an X ray will tell you anything and everything, i had a patient the other day who had an X ray taken a year ago. There was .nothing to suggest his condition had changed. I told him this but he begged to have his picture taken anyway.”
Ignorance is the cause of a good deal of the unnecessary radiology performed today. Bouchard points out that practically every doctor has an X-ray machine or a fluoroscope in his office, "but few have had any special training in radiology; what’s more, they haven't made any attempt to get any. Our association is aware of the danger of the untrained radiologist but there’s nothing we can do about it legally. Wc have no jurisdiction.” Dr. C. H. Wilson, of the Industrial Hygiene Division, Ontario Department of Health, examined one patient whose feet were burned by X rays. The patient explained. “The doctor was treating me with X rays for itchy skin.”
Many doctors unskilled in radiology are a danger to themselves as well as to patients. Each year Bouchard is consulted by doctors and dentists who have overexposed themselves to radiation. They usually have radiation dermatitis on their hands. In extreme cases Bouchard has to recommend amputation of fingers or hands.
But much of the outcry against overradiation stems from the fear that we may be endangering the lives of generations yet unborn. Mental and physical characteristics are transmitted from one generation to another by submicroscopic particles called genes. All radiation to the reproductive glands, no matter how small the dose, changes some genes. This is known as gene mutation. These changes are practically always for the worse. The arithmetic of genetics is complicated, but in an attempt to illustrate simply the genetic hazards of radiation the U. S. National Academy of Sciences has prepared the following forecast for the U. S.: at the present rate, for every hundred million future live births, there will he two million infants with hereditary defects. // the average person were to receive 30 to 80 roentgens to the reproductive organs, the number of defectives born would rise to four million. Only ten percent of the defects would appear in the first generation; the remaining 90 percent would be the result of pyramiding in the following thirty-nine generations. (The calculations, for the sake of simplification, assume that the population remains stationary.)
The academy mentions ten roentgens by the age of thirty as the highest per-
missible dose for the average person. Even this modest amount is not without genetic ill effects: it would lead to fifty thousand extra cases of inherited defects in the first generation among the U. S. population.
Recently Dr. Stanley Macht and Dr. Philip S. Lawrence compared the children of four thousand American radiologists with those of four thousand doctors who had little or no contact with radiation. Their conclusions: “Small prolonged doses of radiation produced abnormalities . . . The abnormalities visible in the first generation represent only a small fraction of the damage that may have been inflicted.” Only 80 percent of the radiologists’ children were horn completely normal, compared to 83 percent for the children of the unexposed group. Among the radiologists’ children there were 50 percent more defects of hearing and vision; twice as many imperfections of the lungs, heart, blood vessels and respiratory system. Miscarriages were more numerous.
The Atomic Bomb Casualty Commission, which studied thousands of women who had been pregnant at the time of the A-bomb explosion in Nagasaki, found that radiation resulted in a higher abortion and stillbirth rate.
Geneticists protest violently against beaming X rays directly at the reproductive organs, especially if the patient is a pregnant woman. In one large Canadian city I was told that some doctors almost always ordered radiological examinations of women having a first child. A common procedure is an X ray of the pelvis. The mother can receive 1.3 roentgens to her reproductive glands; her unborn child a massive dose of 2.7 roentgens! This may well shorten the child's life. Researchers at Oxford University have discovered that leukemia is twice as common among children whose mothers had pelvic radiology during pregnancy. Some scientists demand that any X-raying of unborn babies be outlawed.
Next to diagnostic X rays probably the greatest source of exposure is therapeutic radiology. Most people think that radiology is used only in treating cancer. They’re wrong. Dr. Stanley H. Clark, a Los Angeles medical physicist, has estimated that “25 percent of radiotherapy treatments are given for such nonmalignant ailments as arthritis, inflammation, bursitis, skin ailments, certain eye diseases.” Doses are usually heavy. A typical dose for bursitis may be 500 to 800 roentgens in a two-week period. Skin disease may require 300 roentgens. Getting rid of a wart may require up to 1.500 roentgens.
While the abuse of X rays is causing concern, far more is heard about the potential hazards of atomic radiation. The danger lies in three kinds of rays: gamma rays, which are short-lived but can penetrate a foot of steel; alpha and beta rays, much less penetrating but powerful enough to bombard human tissue and destroy it. What makes some radioactive substances emitting beta and alpha rays particularly lethal is the duration of their radioactive power: some remain active for hundreds of years.
Radioisotopes emitting these rays are already doing a thousand useful jobs. Cobalt-60 has become standard treatment for deep radiotherapy in cancer. Iodine131 measures the efficiency with which the thyroid gland is functioning. Radioactive gold helps in certain cancer cases. Phosphorus-32 is used against leukemia. Iron-59 helps in checking the foimation of red blood cells in the bone marrow. In industry isotopes check metal weldings for defects, ferret out leaks in oil pipelines, measure density, viscosity and absorption properties of anything from light-bulb filaments to dyes.
And this is only the beginning. Atomicenergy plants — such as Calder Hall, which has just started operating on the northwest coast of England—will in time supply an important part of the world’s power. Atomic-powered ships, planes and cars will become commonplace. Irradiation will make it possible to store meat, potatoes and cereals for indefinite periods. Drug companies are toying with the idea of sterilizing everything from bandages to hormones by means of the atom. Atomic radiation promises to give manufacturers more durable rubber, better grades of gasoline and stickier adhesive tape. The police too are beginning to show an interest in radioisotopes to track down thieves. In one American city coins and bills in a cash box were painted with a fluid containing radioactive isotopes of silver; if stolen, they could be traced with a Geiger counter.
But as the use of atomic energy is extended so are the risks of contamination by radiation. That is why Radiation Services — a group of fifteen scientists, technicians and clerks, headed by Dr. Sowby — was set up in 1950 as part of the Occupational Health Division of the Canadian Department of National Health and Welfare. Radiation Services advises Atomic Energy of Canada as to who should receive radioisotopes; then it supervises their use. An applicant for radioisotopes is asked: what does he want the material for? Does he have adequate storage facilities? Is he prepared to move or acquire the necessary qualifications? The Ottawa Civic Hospital, for example, had to submit plans to show that the room built to accommodate a Cobalt-60 cancertherapy unit had concrete walls at least three feet thick.
If an applicant is given radioisotopes, Radiation Services informs provincial health authorities who make periodic visits. A double safety check is made by a new kind of specialist employed by Ottawa, known as a radiation surveyor. Ivan Poirier is one. He tours the country, visiting the places where radioisotopes are used, checking safety precautions with an assortment of electronic meters and counters.
To protect the eight hundred people working with radioisotopes, Radiation „Services has inaugurated a “film-monitoring service.” Every worker has a black plastic disk, about the size of a fifty-cent piece pinned to the lapel of his lab coat. Inside each disk is a small piece of film. Every two weeks the films are mailed to Ottawa where analysis reveals how much radiation has been absorbed by every worker. If a worker is running above his quota (.1 roentgens a week) Radiation Services informs his employers and he’s temporarily shifted to another job. The U. S. Academy of Sciences recommends that such workers be selected from the ranks of those “who for age or other reasons are unlikely to have offspring.”
Radiation Services have extended their film-monitoring service to include twentyfive hundred doctors and technicians working with X-ray equipment. According to Sowby, there are an additional seventy-five hundred people in this group who have no idea how many roentgens they are absorbing.
Sowby and his associates have also studied shoe-fitting fluoroscopes and found the majority a peril. Next they will survey X-ray machines in doctors’ offices. “We suspect that many of them are poorly calibrated,” says Sowby. ‘That means that the patient is getting a higher dose than is intended for him.”
Radiation Services also keeps an eye on toys and gadgets containing radium. “We don’t allow luminous toys on the market," says Sowby. “Children may suck them, or even swallow them.” Customs officials are instructed to phone Sowby whenever a product containing radium arrives for clearance. Recently he banned several gross of a luminous gadget intended to light up the key ignition of automobiles.
However the atom remains the main concern of Radiation Services, which has been working with a Committee on the Effects of Low Level Radiation. One of its jobs is to study strontium-90, a fallout product of A-bomb explosions. After an explosion particles of strontium-90 fall on pasturelands, are eaten by cattle, get in milk and are ultimately consumed by humans. It causes bone cancer and leukemia. “What we’re trying to find out,” says committee chairman Dr. E. A. Watkinson, "is how much strontium-90 Canadians are getting in their food.” The committee is collecting samples of dried milk all over the country and measuring the quantity of strontium they contain. (Milk is being used in the fall-out research principally for convenience; other foods
are probably also contaminated.)
How much strontium-90 has already accumulated on the bones of Canadians? Has it approached a dangerous level? To answer these questions, the committee is analyzing amputated limbs collected from all over the country. They’re also carrying on a series of autopsies.
The committee is also planning to measure the natural background radiation in various parts of Canada. Is it going up? Has it reached a dangerous level as the result of A-bomb tests? A series of complicated genetic studies are in the blueprint stage; in these Dr. H. B. Newcombe, head of the biology division of Atomic Energy of Canada, and Gordon Josie, a Dominion Bureau of Statistics biostatistician, are playing leading roles. A number of questions are being raised: is the number of inherited defects among the Canadian people on the increase? To what extent can it be blamed on radiation? To what extent are the children of people working with radiation defective? It’s likely that some of these genetic studies will continue for fifty or a hundred years, or even longer.
Peering into the future, health officials see the growing number of nuclear-power
plants as their main problem. A dozen or more plants may be built in Canada, scores in the U. S. Where should they be built? The possibility of accidents might make it inadvisable to locate an A-plant near populated areas. If a cloud of fission products drifts away from a power plant, perhaps after an explosion, people within an area of several square miles might inhale lethal quantities. In the U. S. the possibility of accidents has prevented many industries from building nuclear plants: they could neither get nor afford enough public-liability insurance. Insurance executives told the U. S. Atomic Energy Commission: “The catastrophic potential, although remote, is more serious than anything now known to industry.”
But the biggest headache — overshadowing all others—will be how to dispose of atomic wastes. The dimensions of the problem have been vividly set forth by Dr. L. P. Hatch, of the Brookhaven National Laboratory on Long Island, N.Y. Today there are about six pounds of radium in use in the world. “By 2000 A.D.,” says Hatch, “the annual waste output of atomic industry will be the equivalent of four hundred thousand tons of radium.”
What are we to do with it all? There are two main methods of disposal: bury the stuff in the ground or dump it into the sea. Nobody apparently has taken seriously the suggestion of Dr. S. F. Singer, of the University of Maryland, that the atomic garbage be shot off into outer space. The cost would probably be a million dollars for every one hundred pounds of waste.
Ground burial is the method of disposal now being used by Atomic Energy of Canada at Chalk River. Care has to be taken that the wastes are placed well above the water table. If they seeped through, the water supply of the area would be contaminated. Periodically holes are drilled in the earth and Geiger counters lowered into them to make sure that the buried wastes aren’t moving toward the water supply.
A. M. Aiken, of Chalk River’s engineering branch, has discussed the possibility of pumping waste products down dry oil wells. “The solution would be sealed in by the rock strata that once held the oil,” he says. An English proposal is to put the waste in metal containers and bury them in abandoned coal mines. English atomic wastes are now being dumped into the Irish Sea; American wastes are being encased in cement and dropped in the Atlantic thirty miles off the coast of New Jersey. Most scientists don’t approve of indiscriminate sea dumping; they fear that the ocean itself might become contaminated. They know that after the 1954 A-bomb tests the surface water near Bikini was a million times more radioactive than normal. Four months later the water fifteen hundred miles away from the test area was three times as radioactive as usual! Later still, small amounts of extra radioactivity were detected thirty-five hundred miles from Bikini.
The U. S. Academy of Sciences points out that the problem of getting rid of wastes is international and that the hazards of radiation are proven and global. Ironically, these hazards are increasing with every new beneficial use found for atomic radiation. This means that atomic radiation, which many have regarded as the promise of a new and better life, could conceivably contaminate the earth and turn us into a race of misshapen weaklings doomed to early extinction. What happens will depend on whether radiation from all sources is handled carefully or carelessly. ★