I don't smoke, I avoid fats and sugars and I try to stay away from known carcinogens. But nowI worry that my computer may be hazardous to my health.

I've long been concerned about eye strain, back aches and neck pains. Now I'm coping with a sore wrist and the nagging fear that I'm being bombarded with electrical and magnetic radiation.

My radiation concern was fanned by a recent article in MacWorld magazine that suggests that extremely low-frequency (ELF) electromagnetic fields, emanating from computer monitors, might increase the risk of cancer and threaten fetuses of pregnant women.

The article, "The Magnetic-Field Menace," was written by Paul Brodeur, whose book, "Currents of Death," goes into detail about health problems associated with electric and magnetic radiation.

Part of Brodeur's case against cathode ray tubes (CRTs) is circumstantial, but it's definitely worth considering. He cites three studies that show an increased cancer risk for children who live near high-tension electric distribution wires. The incidences of cancer, according to Brodeur, are associated with 60 hertz magnetic fields -- the same frequency emitted by computer displays. Brodeur also cites studies that link CRT use among pregnant women with miscarriages.

Magnetic field strength is measured in units called milligauss (mG). Exposure levels of 2 milligauss to 3 milligauss have been associated with increased incidences of childhood cancer, Brodeur said. Several of the monitors tested by MacWorld exceed that level when measured from a distance of 12 inches or less.

The good news is that ELF radiation drops dramatically as you move away from the source. MacWorld measured ELF from an AppleColor monitor at 22.73 mG at 4 inches from the front, 4.93 mG at 12 inches and only 0.64 mG at 36 inches. The Compaq Video Graphics Color Monitor Model 420 measured 31.13 mG, 6.5 mG and 0.62 mG from those same distances.

ELF radiation, by the way, emanates from all sides of the monitor. The exposure rate, from a given distance, is actually higher from the back and sides than from the front. Those who share offices with other computer users would be wise to sit as far as possible from the back or sides of other people's monitors.

Brodeur's article hasn't prompted me to stop using my computer, but it has caused me to take some precautions. I now position my monitor an arm's length from my body. Unless I'm using both my PC and Mac at the same time, I turn one off.

Concern about radiation hasn't kept me away from the computer, but computer-related hand and wrist pain has recently caused me to take a lot more breaks. Just as many other journalists, I now suffer from what is sometimes referred to as a "repetitive motion disorder." My hands and wrists occasionally hurt even when I'm not using the computer.

My condition is fairly mild but, if I don't take care of it, my chiropractor fears that it could lead to a full-blown case of carpal tunnel syndrome. The carpal tunnel is the space within the wrist that contains tendons and the median nerve that passes impulses to the hand. Repeated stress can cause the tendons to swell, which puts pressure on the nerve. Carpal tunnel syndrome can be crippling and sometimes requires corrective surgery.

I'm temporarily wearing a wrist brace and I recently began using a keyboard wrist rest that prevents me from excessively flexing my hands while typing.

Sometimes the computer takes only part of the blame. Talking on the phone while you type can lead to severe neck strain. An operator-style headset that attaches to just about any phone can alleviate that problem.

You don't need to spend several million dollars to improve the safety of your computing environment. But you do need to know how to set up your work area.

The University of California's Labor Occupational Health Project will send you a free information packet that includes lots of practical recommendations. Write to LOHP, 2521 Channing Way, Berkeley, Calif. 94720.

Companies in need of very detailed information about setting up a workstation can purchase a 90-page book, "American National Standard for Human Factors Engineering of Visual Display Terminal Workstations," for $25 from the Human Factors Society, P.O. Box 1369, Santa Monica, Calif. 90406. Phone: (213) 394-1811.Readers' comments are welcomed, but the author cannot respond individually to letters. Write to Lawrence J. Magid, P.O. Box 620477, Woodside, Calif. 94062, or contact the L. Magid account on the MCI electronic mail system.