EMFs: Electromagnetic Fields

Those high-tension power lines in your backyard may be an eyesore, but are they a health hazard?

The U.S. Environmental Protection Agency (EPA), as of November 2004, has not rendered an opinion about this issue. Neither does state law require a home seller to discover and then disclose potential health risks from power lines near a residential property. Nevertheless, homeowners should be informed.

Below is an EPA article about electromagnetic fields (EMFs), with a link to an informative pamphlet from the National Institutes of Health about the possible hazards associated with EMFs.

U.S. Environmental Protection Agency Article on EMFs

Typical residential exposures, not close to operating appliances or household wiring, are about 1 mG. A milligauss (mG) is the unit of magnetic field intensity.

Intensity is considered to be related to the potential for risk. Exposure intensity decreases as distance from power lines increases. If there is a risk, then increased distance from power lines would be expected to reduce risk.

Other factors may contribute to exposure intensity in a residence. A magnetic field exposure measurement is best way to assess the exposure situation. Many power companies provide this service.

So far,EPA has not issued an official statement on the issue of EMF exposure and health risk. However, other credible organizations have evaluated information about exposure and effects and have come to conclusions about risk. The conclusions of two of these assessments follow.

World Health Organization Agency on EMFs

In June , 2001, an expert scientific working group of the International Agency for Research on Cancer (IARC), a World Health Organization agency, concluded that ELF magnetic fields are possibly carcinogenic to humans, based on consistent statistical associations of high level residential magnetic fields with a doubling of risk of childhood leukemia. Analyses of data from a number of well-conducted studies show a fairly consistent statistical association between a doubling of risk of childhood leukemia and power-frequency (50 or 60 Hz) residential extremely-low frequency (ELF) magnetic field strengths above 0.4 microTesla (4 milligauss).

No consistent evidence was found that childhood exposures to ELF electric or magnetic fields are associated with brain tumours or any other kinds of solid tumors. The epidemiological studies included in the IARC evaluation found that children who are exposed to residential (ELF) magnetic fields less than 0.3 to 0.4 microTesla (3 to 4 milligauss) have no increased risk for leukemia. No consistent evidence was found that residential or occupational exposures of adults to ELF magnetic fields increase risk for any kind of cancer.

National Institutes of Health on EMFs

In addition, an assessment of health effects from exposure to ELF electric and magnetic fields (EMFs) by an expert working group, organized by the National Institute of Environmental Health Sciences (NIEHS)/National Institutes of Health, found that that EMFs are possible carcinogens for children exposed to EMFs at home (June 1998) based on epidemiological studies of residential exposure and childhood leukemia.

The NIEHS working group also concluded that the results of in animal, cellular, and mechanistic studies do not confirm or refute the finding of the epidemiological studies. The NIEHS Working Group Report is available on the EMFRAPID Program website.

(Source: U.S. Environmental Protection Agency, at http://www.epa.gov/rpdweb00/sources/emf.htm )