"The new studies go a long way toward resolving some of the ambiguities that have prompted doubts about the cancer-ELF link," comments Dr. Slesin. "Most notably, they identify dose response relationships between cancer and ELF exposure."

One of the Swedish studies showed that children with higher exposures to magnetic fields had close to four times the expected rate of leukemia. A Danish study showed five times the risk of lymphoma in children living near high voltage power lines with high magnetic field exposures when compared to children without such exposure.

Other studies are in progress to investigate the link between childhood leukemia and exposure to ELF. One study is being conducted in several major Canadian cities which is examining the ELF exposure of 400 children newly diagnosed with leukemia, and comparing that exposure to that of 400 children of the same age who do not have leukemia. Exposure will be measured using a Canadian designed device worn by the children. The results of this study should be ready in 1995.

Until more is known about the long-term effect of ELF waves on a child's biological rhythms, I recommend that parents limit the amount of computer time and make sure that children are not sitting too close to the computer (see below) and at least ten feet from the TV. Parents should also make sure that children are not being constantly exposed to high magnetic fields near neighbourhood transformers or near the main power source for their house.

What You Can Do

• Make sure YOU and YOUR CHILDREN are at least 28 inches from your computer screen and at least an arm's length or 36 to 40 inches from any other computer terminal. Monitor the total amount of time your children spend in front of a video screen (computer, TV and video games) and make sure they take frequent breaks.

For those who want to sit farther away from their VDT screens but cannot see the screen clearly at a distance, a new combination glare screen magnifier may be the answer. This COMPU-LENZ screen can increase character size three to four times and is available for $204.95 US from: New Concepts, 6710 Embassy Blvd, #204, Port Richey, FL, 43668. 813-845-7544.

• Make sure that you are comfortably seated at your work station while entering data on the computer. This may mean any or all of: an adjustable chair, arm or elbow rest, a copy holder and a small foot rest. The top of the screen should ideally be at eye level.

It is crucial to have a screen that is clear and easy to read with proper lighting and absence of glare. Work stations suitable for typing are completely inappropriate for computers. Windows should be at right angles to the screen, lighting should be assessed and not direct, and all surfaces around the computer should be free of glare.

• Work practices are extremely important. There should be regularly scheduled breaks for ten minutes for every hour of visually demanding work (columns, figures, rapid entry of data) and 15 minutes minimum for every two hours of less demanding work.

During these breaks it is important to leave the computer, stretch, gaze into the distance and drink lots of water. Breaks should never be skipped.

Intensive VDT work should be limited to 50 percent of the work day. Four to five hours of VDT work is what many feel is the most that should be allowed. VDT work should be interspersed with other types of work.

• Pregnant women should be advised of the potential risk and be given the option to work at non-VDT work or use liquid crystal screens (as in the lap top computer) throughout their pregnancy.

In fact, the Canadian Labour Law was amended July 1, 1993, to give pregnant and nursing women the right to ask for other work if they believe the task endangers their children. This law will cover the estimated 700,000 women working at computer terminals in banks, airline offices, telephone companies as well as the federal government.

It is unfair to make pregnant women guinea pigs for our experiments on the effect of ELF or VLF radiation on the fetus.