ATOMIC RADIATION: The Ts Are Coming

MOST experts agree that all-out atomic war might end civilization. But what about the long-range effects of atomic-age peace? Last year the National Academy of Sciences, financed by the Rockefeller Foundation, undertook to find out. Last week its committees of eminent scientists made their report on what increasing radioactivity can do to humanity. General conclusions: 1) something new, strange and dangerous has come into the world; 2) not enough is known about it; 3) careful precautions should be taken to ward off future disaster.

The committees were not much worried about nuclear-weapons tests. "High-yield" thermonuclear explosions toss radioactive material into the stratosphere, where it hangs for years drifting around the earth. The tests also raise the radio active level of large areas of ocean. But these effects are slight, and will do no appreciable harm unless the tempo of bomb testing is increased many times over. There is nothing, say the scientists, to the popular idea that bomb testing has upset the world's weather.

That is about all the cheerful news in the report. All the committees were worried about the swift growth of the atomic age. Each year more radioisotopes are shipped to laboratories and hospitals; more nuclear reactors go into operation; more "hot" residues are processed and disposed of somehow. Within a few years, the scientists point out, large nuclear power plants will be built in many parts of the world. Many ships will be atomic, many industries will use radioactive equipment. Therefore, many more people will come into contact with radiation.

Ocean & Air. The Committee on Oceanography warned that radioactive wastes foreseeable in the near future will be too potent to discharge into the ocean's surface water, from which they might be carried ashore or enter human bodies in seafood. If the wastes are dumped at sea, they must be carefully sunk in deep spots where bottom water has little circulation. A research program should be started at once, say the scientists, to find the best such places.

The Committee on Meteorology also had worries. Nuclear power plants give off radioactive gases, some of which are difficult to control or get rid of. In the year 2000, the committee figured, the world's atomic power plants will be producing enough krypton 85 to raise appreciably the radioactivity of the middle latitudes of the Northern Hemisphere. Other gases given off at fuel-processing plants, e.g., iodine 131, can do even worse on a local scale. The committee points out that unfavorable weather conditions around a processing plant can concentrate the gases intensely.

Large atomic power plants will contain so much radioactive material that a blow-up would be a major disaster, causing serious damage over thousands of square miles. By 2000, figured the committee, the earth's reactors will contain so much strontium 90 (a cancer-causing radioisotope which deposits in the bones) that the dispersal of 1% of it would seriously contaminate the entire earth.

The Committee on Disposal and Dispersal of Radioactive Wastes pointed out that so far virtually no wastes have been disposed of. The dangerous stuff is stored in tanks of various kinds--which is not permanent disposal. The biggest future sources of radioactivity will be nuclear power plants, and the committee believes that organizations owning such material are legally and morally responsible for it indefinitely. One problem: "The radioactive life of the wastes would probably exceed by several centuries the official life of the organization itself."

The meteorology committee recommended careful international regulations to keep dangerous substances out of the atmosphere. It also suggested meteorological studies to find sites for nuclear installations where prevailing winds will limit the damage done by an accident.

Anemia & Cancer. The Committee on Pathologic Effects related in unpleasant detail what happens when human bodies are exposed to too much radiation. The clinical evidence came from many sources: the victims of Hiroshima and Nagasaki, laboratory workers injured by radiation from high-voltage machines, uranium miners who got lung cancer from breathing radon gas, laboratory animals exposed experimentally to radiation.

It is a disquieting recital: first the early effects (skin burns, vomiting), then intermediate effects (anemia, internal bleeding, ulceration of the intestines); many years later may come leukemia or cancer. Even if no acute effects are detectable, exposure to radiation over a long period of time shortens life considerably. Radiologists die, on the average, five years younger than physicians having no contact with radiation.

Grimmest report by all odds came from the Committee on Genetic Effects. After explaining that little is known about this subject, the committee makes clear that some things are known only too well. It cites the complex mechanism of reproduction, reviewing the manner in which hereditary traits, good and bad, are transmitted by submicroscopic genes in the male and female reproductive cells. These genes can be changed (mutated) by radiation that reaches the gonads (testicles or ovaries). Sometimes the damage is so severe that the individual developing from two cells (with a single damaged gene) is seriously defective or dies before birth. Usually, however, the damaged gene lies latent. The man who is born with it shows only a slight effect, if any, but when he marries a woman with the same damaged gene, their children will show the effect in full, cruel measure. This can happen after 2 or 10 or 100 generations.

Harmful Mutations. The committee points out that humans have always been subjected to radiation from cosmic rays and other natural sources, and the genes that were damaged in this way were causes of defective individuals of the pre-atomic age. The human species, however, evolved under these radiation conditions and had become adjusted to them. It was able to eliminate damaged genetic material at about the same rate as it was formed.

But what will happen, the committee asks, if the radiation dose is raised artificially above the natural level? Defective individuals will increase, of course. Some will die before birth or shortly thereafter. Others will be burdens to themselves, their relatives and to society for many years.

"There is still [another] aspect to consider," says the committee. "A population that is exposed, generation after generation, to an increased amount of radiation will experience a rising death rate and a falling birth rate because of harmful mutations, until a new equilibrium is established between the increased rate of mutation and elimination. If in this process the death rate comes to exceed the birth rate, the population will decline and eventually perish."

How much radiation can be tolerated?

The committee figures that the mutation rate will be doubled by something between 30 and 80 r (roentgens) of radiation to the gonads received between conception and 30 years of age. This means that in each 100 million live births, 4,000,000 (instead of the present 2,000,000) will have serious hereditary defects. About 1% of the defectives will appear in the first generation.

Radiation Budget. To be reasonably though not wholly safe, the committee believes that the average radiation dose for the general population should not rise above 10 r of man-made radiation between conception and 30 years. It recommends that records be kept for each individual, giving the complete history of exposure to radiation. Then a nation can know the prognosis of its posterity.

Of the 10 r allowed to the average individual up to 30 years, about 3 to 4 r, the committee was shocked to discover, is being currently expended on medical ", and dental X rays, which have the same effect as gamma rays from radioactive sources. A dental X ray may give .005 r to the gonads, and general fluoroscopic examinations may give 2 r or more. The committee suggests that doctors and dentists should go easy with X rays. Patients who read the committee's report (especially those who intend to have more children) will surely think twice before they permit prolonged X-ray treatment for any ailment.

The 10 r figure is for the general population, to avoid genetic trouble on a large scale. Individuals can take more without much additional risk to first-generation children, but the committee suggests a top limit of 50 r to age 30 and an additional 50 r to age 40. This is much less than the maximum dose permitted in Atomic Energy Commission laboratories:. 3 r per week or 15.6 r per year. The committee believes that all work involving high radiation exposure should be done, for the good of the race, by people who do not expect to have more children.

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