EMFs and the potential for injury: real danger or overreaction?

• Author: Liljestrand, Craig T.
• Position: Electromagnetic fields

THERE IS much discussion and concern over the possible health effects associated with an electromagnetic field, known as an EMF. High-voltage power lines, cellular telephones, police radar guns and household electrical appliances are the main focus of the public's attention as potentially harmful sources of EMFs. Others include household wiring, hair dryers, electric blankets, computers, television sets and microwave ovens.

People who believe there are dangers associated with this phenomenon see EMF cases as the next mass tort litigation bonanza, similar to asbestos litigation. They argue that the onset of various cancers to people working in similar occupations or to people living in the same neighborhoods are more than mere coincidence. On the other hand, power and utility companies and manufacturers of electronic devices contend that there is no scientific or medical proof that EMF exposure has adverse health effects on the human population. In fact, they argue that there are numerous scientific studies disproving any potential link. The scientific and medical communities are not certain whether there is a causal relationship.

Most EMF litigation centers on landowners' claims that the value of their property located near high-voltage electrical wires has decreased because of fears that EMFs produced by power lines can cause adverse health effects, such as cancer. Even without conclusive causative medical evidence, the number of personal injury cases is growing. In addition, some people claim that cellular telephones or police radar guns have emitted harmful EMFs, thereby causing them injury. There have been no documented lawsuits to date in which there has been a claim of EMF-related injury from exposure to a household electrical appliance.

In order to begin understanding what EMFs truly are and where this litigation may be headed, it is imperative to monitor both the legal and scientific developments.

WHAT ARE EMFS?

1. General

   Electric and magnetic fields are present wherever there is electric power. Batteries operate on a direct current, whereas the electricity in homes, offices and factories operates on an alternating current.(1) Direct current has raised fewer questions about potential health concerns than alternating current because alternating currents do not move together in the same direction; they "alternate" back and forth. In the United States, this rate is 60 times each second and is known as 60 hertz (Hz) power.(2) Magnetic field strengths are measured in units of Gauss (g) or milligauss (mG).(3) A milligauss is 1/1,000ths of a gauss.

   There are fields associated with 60 Hz power, and these fields create electric charges.(4) Electric fields (resulting from the strength of the charge) and magnetic fields (resulting from the motion of the charge) are produced from these charges,(5) and these two fields are known as an EMF. For instance, an appliance that is plugged into an outlet has an electric field even when it is turned off. To produce a magnetic field, however, the appliance must be plugged into an outlet and turned on so that the electrical current flows.(6) Electric fields may be blocked by earth, trees or buildings, unlike mangetic fields, which penetrate virtually any object.(7)

   Most of the recent scientific research on the possible adverse health effects associated with EMFs has concentrated on magnetic fields.(8) These studies indicate that electric and magnetic field strengths dissipate rapidly the farther away one is from the object producing the EMFs. For instance, when one moves only two feet away from the EMFs being given off from a toaster, oven or iron, the magnetic field strengths virtually disappear altogether.(9) The duration of exposure to household electrical devices is typically much shorter than to power lines. This may explain the lack of litigation to date alleging harmful EMF exposure from those devices.

   As there is no proof that EMFs cause injury, there have been no state or federal standards implemented in the United States governing what levels of EMF exposure pose potential health risks, if any.(10)

   In addition to electrical power, there also are natural sources of EMFs. Unlike power lines or electrical appliances, the Earth's magnetic field, measured at about 500 mG, operates at a constant level. Other natural sources of EMFs include thunderstorms, lightning and even the human body, which makes the heart and nervous system work by producing electrical fields.(11)

2. Various Devices

   Following are the average EMF measurements in mG for common household and office appliances:(12)

   Distance from Source 6 in. 2 ft. 4 ft. Hair dryer 300 - - Dishwasher 20 4 - Microwave oven 200 10 2 Refrigerator 20 1 - Color television 60 2 - Baby monitor 6 - - Coping machine 90 7 1 Fax machine 6 - - PC color monitor 14 2 - Magnetic field strengths depend on the distance away from the electrical power lines, as well as the particular type of power line producing the EMF.(13) Generally, there are two types of power lines--transmission lines and distribution lines. Distribution lines usually are located in neighborhoods, while transmission lines run directly to power plants. Typical exposures to residential distribution lines are usually under 5 mG, but may at times measure as high as 50 mG when the lines are located only a few feet from one's home. The highest measurements of magnetic field strength from electric power lines during peak usage is generally lower than average measurements taken of typical household devices within six inches.(14)

   The unanswered question with regard to power line exposure, however, is whether the much longer duration of EMF exposure to them poses a more serious risk than common household electrical devices?

   The following are EMF measurements in mG of transmission lines during average usage:(15)

   Distance from Source 50 ft. 100 ft. 200 ft. 115 kilovolts (kV) 7 2 .4 230 kilovolts (kV) 10 7 1.8 500 kilovolts (kV) 29 13 3.2 RECENT MEDICAL STUDIES

   Scientists have found that EMFs can produce a variety of biological effects on the human body. For instance, they can produce changes in the levels of specific hormones and other chemicals that the body manufactures, as well as produce changes in the development of individual nerve cells...