X-Ray Excess

Up to 75 million people in the U.S. are exposed each year to diagnostic medical X rays; 50 million have dental X rays; 8,000,000 are fluoroscoped. According to Karl Z. Morgan, health physicist on the 1943 Manhattan Project and now at Oak Ridge National Laboratory, many of the millions are probably being dangerously overexposed to radiation. Before the Senate Commerce Committee last week, Dr. Morgan admitted that statistics on radiation hazards are guesses at best--but he suggested that anywhere from 3,500 to 30,000 U.S. deaths may result each year from the cumulative effects of radiation.

Man-made radiation (now equal to half the total of natural radiation) adds up to 55 mR* annually for every American, said Dr. Morgan, and 90% of this comes from diagnostic X rays. At Oak Ridge, where nuclear physicists are so conscious of radiation hazards that they have done everything conceivable to reduce them, the skin exposure from a chest X ray is 10 mR. This low and relatively safe dose can be matched in any well-equipped, properly run X-ray department and it is achieved by qualified personnel in many of the better hospitals. But, said Dr. Morgan, the equipment and methods vary so widely, especially in doctors' private offices, that the exposures for this one procedure range all the way up to 1,000 mR, with the U.S. average estimated at 200 mR.

When the doctor uses a fluoroscope to see the thoracic organs in motion, the range is from 5 mR to 400 mR.

The most obvious effect of excessive radiation exposure is a superficial burn.

Later, skin cancer may develop at this site, said Dr. Morgan. Hidden from view are internal cancers (especially of the thyroid), which may take many years to develop, and leukemia or "cancer of the blood." If a woman has a pelvic X ray in the first weeks of pregnancy, the fetus may be damaged, to be aborted or stillborn, or the child may eventually develop leukemia. Completely hidden from diagnosis or measurement are genetic effects, which do not appear until a later generation.

Several Lacks. Whatever the current cost in lives and health, X-ray diagnosis is enormously beneficial, Dr. Morgan declared, and undoubtedly saves many tens of thousands of lives annually. The trouble, he emphasized, is not in the available equipment: everything that is needed to reduce the national total of dental X-ray doses to 1% of the current level, and to reduce all diagnostic exposures to 10%, is already perfected and on the market. The fault, said Dr. Morgan, lies in poor techniques, the use of improper (usually old) equipment, the lack of concern by doctors, dentists and technicians for the radiation protection of the patient and their lack of training, and the lack of effective regulation by the states.

"In many cases," said Dr. Morgan, "the exposures are actually given by nurses, secretaries and even by temporary employees such as typists who operate the machines part time. In many of the states, no training or experience is required of the doctor before he uses his X-ray equipment on the patient. The person who exposes our children to X rays must have his automobile inspected periodically and must have a driver's license before he can operate it. Yet the X-ray machine he operates may be obsolete and may fail to meet minimum standards, and he may have little or no training or knowledge in how best to operate it."

To make sure that all X-ray equipment now on the market meets the best current standards, Dr. Morgan endorsed a controversial measure: pre-marketing clearance by some body such as the National Council on Radiation Protection. "By far the most important developments," he insisted, "are very simple and straightforward and can be incorporated with little or no extra cost into the equipment." Above all, he urged regular checks on all equipment in use, by inspectors whose own competence would be certified.

*Thousandths of a rem, a unit of radiation dosage absorbed by tissues.

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