ELECTRICAL AND MAGNETIC FIELDS (EMF)

Are electric and magnetic fields a health hazard?

Three decades of research on EMF exposures and human health has not established that a human health hazard exists. Questions remain about whether EMF exposure at home or work is linked to some diseases such as childhood leukemia, adult cancers and miscarriages. While scientific research is continuing, a quick resolution of scientific uncertainties is not expected.
Coordinated international research has resolved many questions about specific diseases. While some health authorities have identified magnetic field exposure as a possible human carcinogen, they acknowledge that additional research will be necessary before a more definitive conclusion can be made.

Electric and magnetic fields

Electric and magnetic fields are created by both natural and man-made forces. A thunderstorm can create very intense electric fields in the millions of volts. When lightning strikes, a magnetic field results from the electrical current flow. Another natural source is the earth and moon's magnetic field. Manmade sources include household or building wiring, electrical appliances and electric power transmission and distribution facilities.

Electric fields

An electric field is sometimes called an electro-static field or static electricity. This occurs wherever a voltage is present, in the same way static can be created by friction between two materials. Electric fields are created around appliances and wires wherever a voltage exists. The signals received by FM radios and TVs are also electric fields.
The strength of an electric field decreases at greater distances from the source.

Magnetic fields

Wherever there is an electric field, there is also a magnetic field. A magnetic field is the attractive force that exists between the poles of permanent magnets and ferrous metals, such as steel and iron. Permanent magnets can be natural or man-made. The earth's magnetic fields measure approximately 500 milliGauss in North America. Magnetic field strength decreases at greater distances from the origin.

How can I protect myself and my children?

Even though the scientific evidence of any health risk from EMF is weak, some people choose to limit their EMF exposures. Simple steps can be taken in the home and at work to minimize exposure. The most effective and least costly way to do this is to avoid coming closer than necessary to electrical appliances and wiring.
Appliances that use large amounts of electrical power in general produce higher levels of EMF. Common household appliances that may produce significant fields are hair dryers, shavers, electric can openers, vacuum cleaners, clock radios, microwave ovens, refrigerators, air conditioning systems, and swimming pool and hot tub equipment.
Sources found at work include copiers, electric motors, fluorescent lights, electric pencil sharpeners, and a variety of industrial machinery.
Electrical circuit breaker panels and meter panels in commercial buildings and homes can also be a significant source of magnetic fields.

Official EMF exposure limits

None have been established. A great deal of animal testing and cell biology research has been conducted, but even extremely high EMF exposure has never produced cancer or any other disease in the laboratory. Scientists, therefore, cannot identify any level of EMF that is harmful in any way. Since no level of exposure has been shown to be hazardous, no government environmental EMF standards have been adopted.


While there are no federal or California established limits for EMF exposure, some non-governmental organizations have issued advisory limits. These limits, however, do not apply to the relatively low levels of EMF found in homes, schools, and offices, or even the EMF exposures being studied in relation to childhood leukemia.
The advisory limits apply only to extreme, short term EMF exposures far higher than those in residential or typical occupational settings. For example, the International Commission on Non-Ionizing Radiation Protection recommends that the general public not be exposed to magnetic field levels above a 24-hour average of 10,000 milliGauss (mG). In contrast, fields inside homes rarely exceed 20 or 30 mG from any source, including household appliances or next to large transmission lines.
A 1993 Study of nearly 1000 homes across America concluded that the average magnetic field level found in the majority of U.S. homes is approximately 1 milligauss (1mG). This level has no connection with any known health effects, but is helpful in comparing EMF readings to a national norm.


What health authorities said about possible health risks from EMF

Several internationally recognized health science agencies and independent research foundations have issued EMF health risk evaluations. Their key conclusions were as follows:

* U.S. National Institute of Environmental Health Sciences (NIEHS) in 1999:
"The scientific evidence suggesting that [EMF] exposures pose any health risk is weak... [EMF] exposures cannot be recognized at this time as entirely safe because of weak scientific evidence that exposures may pose a leukemia hazard.…The NIEHS does not believe that other cancers or non-cancer health outcomes provide sufficient evidence of a risk to currently warrant concern."
* Britain's National Radiological Protection Board (NRPB) in 2001:
"After a wide-ranging and thorough review of scientific research, an independent Advisory Group to the Board of NRPB has concluded that the power frequency electromagnetic fields that exist in the vast majority of homes, are not a cause of cancer in general. However, some epidemiological studies do indicate a possible small risk of childhood leukemia associated with exposure to unusually high levels of power frequency magnetic fields."
* The World Health Organization's International Agency for Research on Cancer (IARC) in 2002.
"… 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 leukaemia. Children who are exposed to residential ELF magnetic fields less than 0.4 microTesla have no increased risk for leukaemia. … In contrast, no consistent evidence was found that childhood exposures to ELF electric or magnetic fields are associated with brain tumors or any other kinds of solid tumors. No consistent evidence was found that residential or occupational exposures of adults to ELF magnetic fields increase risk for any kind of cancer."
 

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