X-RAYS, RADIATION, AND YOU

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MEDICAL SELF-CARE

No matter how careful you are to look after your family's — and your own — well-being, there's simply no way to avoid all of the environmental health hazards (such as air and water pollution) that are present in today's world. The best you can hope to do, then, is to make yourself aware of the sources and effects of such dangers . . . and take appropriate steps to protect yourself and your loved ones against them.

One such environmental hazard is radiation . . . which can, for our purposes, be broken down into two classifications: low-frequency non-ionizing (such as microwaves, radio waves, radar, ultrasound, and visible light) and high-frequency ionizing (such as X-rays, gamma rays, alpha and beta particles, and neutrons). And although the former is likely a health risk, the latter is probably the more dangerous of the two.

You see, high-frequency radiation has the ability to displace electrons from molecules in the body, thereby creating ionized molecules that undergo chemical changes and — ultimately — promote biochemical changes. And, if these transformations take place in the chromosomes, the result may be cancer, while if they occur in the germ cells — which produce ova and sperm — the result may be sterility or birth defects.

HOW RADIATION IS MEASURED

Exposure to ionizing radiation is expressed in rads and rems. . . and small doses are stated in thousandths thereof, or millirads and millirems.

Rad stands for "radiation absorbed dose" and is a measure of energy per gram of body tissue. Rems equal rads multiplied by the relative mutagenic potential — or in other words, the ability to do biological harm to the genes — of the particular kind of radiation involved. For example, each of us receives (on the average) about 84 millirems of background radiation from natural sources each year. A nonfluoroscopic chest X-ray, by comparison, delivers 20 to 60 millirems. A single dose of 600 rems or more produces acute radiation sickness, like that which killed thousands of Japanese in the two weeks following the bombings of Hiroshima and Nagasaki.

It's especially important to remember, though, that the effects of ionizing radiation are cumulative. . . that is, the first X-ray you ever received is still with you today, and its effect is compounded by each subsequent "zap". That's why established standards are stated in terms of allowable levels over a given period of time. The maximum exposure level for nuclear workers, for instance, is currently five rems (5,000 millirems) per year. It's interesting to note that this figure has changed drastically as we've learned more about the actual effects of low-level radiation. In 1900, for instance, ten rems per day was considered permissible exposure . . . whereas these days some experts say that there may be no safe level of exposure.

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