Healthy Home Basics - Electrical Wiring

55. What are electromagnetic fields?

Electromagnetic fields, or EMFs for short, are invisible areas of energy. There are actually many different kinds. EMFs can be found around gamma rays, X-rays, ultraviolet light, visible light, infrared radiation, and radio waves. However, the kind most people are concerned about are the EMFs surrounding electrical wiring and appliances.

Anything that uses electricity will be surrounded with electromagnetic fields, of which there are two types—magnetic fields and electric fields. Just plugging something in will cause it have an electric field around it, but it must be operating (current must be flowing) to have a magnetic field.

Most researchers believe that electric fields are relatively benign, and that health effects are more likely to be related to magnetic fields. Magnetic fields are measured in units called milliGauss (mG), but there aren’t any well-established guidelines as to how much is too much. Still, it’s believed by most researchers that you should stay away from long-term exposures above 3 mG.

56. Can electrical appliances and the wiring inside my walls make me sick?

In most cases, probably not—but there are certainly situations where you should be concerned. The most common health effect researchers are looking into is cancer, but the evidence is often conflicting. In electrical occupations (electricians, linemen, etc.), some forms of cancer are seen more often than in workers who aren’t routinely around high-strength fields. And, some studies have found leukemia more often in people who live near high-voltage power lines.

There are three factors that determine how harmful an EMF exposure is: the strength of the field, your distance from the field, and your exposure time. Being near a high-strength field for many hours at a time is believed to be more serious than being near a high-strength field for a few minutes, or a low-strength field for an extended period of time.

To know for sure how strong a field is, you must measure it with a special device called a Gaussmeter. Gaussmeters are available from several mail-order or Internet-based companies. Fields vary considerably from one appliance to another, and they fluctuate at different times of the day. For example on a hot summer day, when everyone is using their air conditioner, there will stronger fields under outdoor power lines than on a cool fall evening when less electricity is being used.

You can often measure magnetic fields in the hundreds of mG very close to small electrical appliances (shavers, hair dryers, hand mixers, etc.). However, you don’t use these devices for hours on end, and the fields are often fairly weak a foot or so away. This is an important point to keep in mind—all electromagnetic fields g...