Science & Technology
IS YOUR HAIR DRYER OUT TO GET YOU?
Except for the padlocked driveway gate, the year-old house on East New Lenox Road looks much the same as others in the quiet Berkshires town of Lenox, Mass. But inside, the main furnishings are appliances, and the walls are open to expose wiring and pipes. The idea is to measure the electromagnetic fields (EMFs) generated in an average residence, and the results of this experiment ultimately could affect every home in America.
For 22 years, a growing body of evidence--hinting at a link between the (EMFs) surrounding electrical currents and health problems such as cancer--has focused on power lines and substations. More recently, public scrutiny has widened to other sources of exposure, such as video display terminals. Now, there's a third concern: households.
NEW STANDARDS. This worry hasn't yet galvanized appliance makers. The Association of Home Appliance Manufacturers in Chicago says its 150-odd members likely won't redesign their products until the health risk is definite. And it may be years before such data are conclusive.
Still, homeowners are blocking new power lines, and a few states have set EMF standards for existing ones. And momentum is building to rewire all manner of products. Jack Adams, a researcher in Carnegie Mellon University's engineering and public policy department, explains why: "It's conceivable that a short exposure from something like a hair dryer could give the same effect as many hours of exposure to neighborhood distribution lines."
The term EMF refers both to electric fields, which are produced by voltage, and to magnetic fields, which develop as currents flow. Human skin can block electric fields. Magnetic forces, however, are hard to shield and -- in theory -- could produce changes inside cells. The Lenox house, hub of the Electric Power Research Institute's $700,000-a-year Magnetic Field Research Facility, won't resolve the health debate. But it should shed light on household exposure to EMFs. To see how this can be minimized, EPRI constantly changes the arrangement of wiring and power sources--reflecting actual conditions encountered in an ongoing nationwide survey of 1,000 homes. The researchers have found that EMF exposures can vary by a factor of 100,000, depending on the design of a house and where a person stands.
Besides looking at appliances and phone lines, researchers have fed both underground and overhead power lines into the house, to see how each affects EMF fields. Because electrical service panels are often grounded to water lines to avoid shock and fire, even water-pipe layouts can influence EMF exposure. If the power in one house is shut off, current can still flow through its pipes from other houses on the same water system. Out back of the EPRI house, power lines feed into "other homes"--18 gray panel boxes that are grounded to water lines. "We have our own private subdivision here," says Gary B. Johnson, a General Electric Co. research engineer. He manages the EMF experiment for EPRI, which is funded by electric utilities.
Johnson warns homeowners not to disconnect grounds. But some fixes may only require what the Carnegie Mellon team calls prudent avoidance--things like moving nondigital electric clocks, a large EMF source, away from bedsides. Others have gone a step further--to prudent circuit design. Power Management International Inc., a startup in Chappaqua, N. Y., is developing solid-state power control devices for appliances and other equipment that, as a byproduct, don't give off EMFs. Co-founder Theodore R. Conant says these also are cheaper and more reliable than conventional components. Brandeis University senior scientist Daniel Perlman has patented a low-EMF design for heating elements in appliances such as irons and hair dryers. The trick is dividing currents into parallel circuits that run in opposite directions--so their magnetic fields cancel out. "It's an embarrassingly simple concept," he says.
Simpler than the EMF issue itself. "I'm interested, but I'm waiting for conclusive information," says Don Cunningham, engineering vice-president for Emerson Electric Co.'s E. L. Wiegand Div., which makes heating elements for electric ranges. That view is common--but less so as time goes by. VDT makers such as Qume Corp. and Sigma Design Inc. are touting "low-rad" terminals. And by 1992, says Louis Slesin, editor of Microwave News, "all computer terminals will be low EMF."
PRESSURE. Sunbeam Corp.'s electric-blanket unit also has acted. Responding to consumer fears, the Northern Electric Div. has spent millions to change blanket wiring so EMF fields largely cancel out. That has cut emissions to 1/80th of what they were before, says engineering consultant Lee Roszyk, who adds that Sunbeam remains "convinced there was no real danger with the product."
Even if he's right, pressure could build on appliance makers. Fieldcrest Cannon Inc. was also redesigning its electric blankets before it dropped out of that business for other reasons. Michael M. Dineen, the division vice-president who oversaw the work, doesn't think the issue is going to die. He compares EMF concerns to those that led to warnings on cigarette packs and products with saccharine. So one day, even appliances may bear the label: "This item may be hazardous to your health."Robert Buderi in Lenox, Mass.