Steps May Help Cut Electric and Magnetic Exposure

Can exposure to electric and magnetic fields cause cancer? A number of studies suggest that fields from high-current power lines and some appliances raise the risk, although evidence is ambiguous at this point. While scientists sort it out, some authorities suggest a policy of “prudent avoidance”--or lowering exposures in cheap and easy ways.

Because of the uncertainties, adherents of “prudent avoidance”--including M. Granger Morgan, the Carnegie Mellon University engineering professor who coined the term--counsel against expensive and disruptive lifestyle changes.

So people shouldn’t abandon their residences to move further away from a power line. But home buyers who have small children or are expecting a baby might consider the location of high current lines.

Other safety factors--such as air pollution and traffic levels in the new neighborhood or radon gas levels--might weigh equally or more in the decision on a new home.

Morgan himself practiced prudent avoidance by moving his son’s bed away from the wall where the electric power line enters his house.

Many appliances and power tools produce strong fields, and people may consider using appliances less often, some health authorities say. In most cases, the risk is probably very small because the devices are used only minutes at a time and the fields they produce drop off sharply with distance.

There are exceptions, however. Children who sit with noses pressed against the TV screen may be exposed to elevated fields, and could be safer if made to stay a few feet away.

Electric motors produce strong magnetic fields, and those with motor-driven alarm clocks on their bedside tables may be exposed to fields as they sleep.

It may be wise to move the clock a few feet away or replace it with a digital or windup clock.

Electric blankets directly expose the body to elevated fields.

Blanket users, particularly small children and pregnant women, should consider retiring the blanket or using it only to warm the bed before going to sleep, authorities say.

Responding to consumer fears, all major U.S. electric blanket manufacturers have introduced, or are introducing, blankets that produce reduced magnetic fields.

The new blankets expose users to much lower but still elevated fields.

Computer terminals could be a problem because operators sit close to them for hours at a time.

Users should sit more than two feet from the screen, and at least three feet from neighboring terminals, which typically emit the strongest fields from their sides and backs.

Some manufacturers, including IBM and Digital Equipment, have introduced terminals with reduced magnetic fields.

Others manufacture computer screens that can be installed to block electric fields.

Both the Los Angeles Department of Water and Power and Southern California Edison offer free measurements of electric and magnetic fields in the home or office.

Interested DWP customers may call (213) 482-7376. Edison customers may call the nearest Edison office.