Can the electric and magnetic fields (EMF) to which people are routinely exposed cause health effects? What are sources of EMFs, and when are EMFs dangerous?
EMF (or ElectroMagnetic Field) is a broad term which includes electric fields generated by charged particles in motion, and radiated fields such as TV, radio, hair dryer, and microwaves. Electric fields are measured in units of volts per meter or V/m. Magnetic fields are measured in milli-Gauss or mG. The field is always strongest near the source and diminishes as you move away from the source. These energies have the ability to influence particles at great distances. For example, the radiation from a radio tower influences the atoms within a distant radio antenna, allowing it to pick up the signal. Despite the many wonderful conveniences of electrical technology, the effects of EMF on biological tissue remains the most controversial aspect of the EMF issue, with virtually all scientists agreeing that more research is necessary to determine safe or dangerous levels.
Research since the mid-1970s has provided extensive information on biological responses to power-frequency electric and magnetic fields. The Electric and Magnetic Fields (EMF) Research and Public Information Dissemination (RAPID) Program was charged with the goal of determining if electric and magnetic fields associated with the generation, transmission, and use of electrical energy pose a risk to human health. The fact that 20 years of research have not answered that question is clear evidence that health effects of EMF are not obvious and that risk relationships, if risk is identified, are not simple. Because epidemiologic studies have raised concerns regarding the connection between certain serious human health effects and exposure to electric and magnetic fields, the program adopts the hypothesis that exposure to electric or magnetic fields under some conditions may lead to unacceptable risk to human health. The focus of the program is not only to test, as far as possible within the statutory time limits, that hypothesis for those serious health effects already identified, but to identify as far as possible the special conditions that lead to elevated risk and to recommend measures to manage risk. Details of many of the research projects are available on the web. You can select the projects of interest and then access information about the investigator or the research abstract.
Electromagnetic hypersensitivity (ES) is a physiological disorder characterized by symptoms directly brought on by exposure to electromagnetic fields. It produces neurological and allergic-type symptoms. Symptoms may include, but are not limited to, headache, eye irritation, dizziness, nausea, skin rash, facial swelling, weakness, fatigue, pain in joints and/or muscles, buzzing/ringing in ears, skin numbness, abdominal pressure and pain, breathing difficulty, and irregular heartbeat. Those affected persons may experience an abrupt onset of symptoms following exposure to a new EMF such as fields associated with a new computer or with new fluorescent lights, or a new home or work environment. Onset of ES has also reported following chemical exposure.
A concerted effort to provide scientifically valid research on which to base decisions about EMF exposures is under way, and results are expected in the next several years. Meanwhile, some authorities recommend taking simple precautionary steps, such as the following:
- Increase the distance between yourself and the EMF source – sit at arm’s length from your computer terminal.
- Avoid unnecessary proximity to high EMF sources – don’t let children play directly under power lines or on top of power transformers for underground lines.
- Reduce time spent in the field – turn off your computer monitor and other electrical appliances when you aren’t using them.
The Office of Technology Assessment of the Congress of the United States recommends a policy of “prudent avoidance” with respect to EMF. Prudent avoidance means to measure fields, determine the sources, and act to reduce exposure.
- Detect EMFs in your home and work environment. It is good to know where the sources of EMF are in your everyday world and how strong these sources are. Is there wiring in the wall behind your bed that you don’t even know about? Is the vaporizer emitting strong fields in the baby’s room? How much EMF are you and your family getting from the power lines in the street? Even hair dryers emit EMFs. Home inspectors often have meters to measure EMFs, or they can be purchased and shared with friends.
- Diminish your exposure to the EMFs you find. Determine how far you must stay away from the EMF emitters in your home and work environment to achieve less than 2.5 mG of exposure—the microwave oven, the alarm clock, the computer, and so on. Rearrange your furniture (especially the beds, desks, and couches where you spend the most time) away from heaters, wiring, fluorescent lights, electric doorbells, and other EMF “hot spots.” Where practical, replace electric appliances with non-electric devices. Where practical, replace electric appliances with non-electric devices. Have an electrician correct faulty high EMF wiring and help you eliminate dangerous stray ground currents. Consult a qualified EMF engineer if necessary. Contact National Electromagnetic Field Testing Association at 1-847-475-3696 for consultants in your area.
- Shield yourself. Use shielding devices on your computer screen and cellular phone. Add shielding to your household wiring, circuit box, and transformers
A review by a committee of the National Research Council examined more than 500 studies spanning 17 years of research. The committee said there is no conclusive evidence that residential exposure to electromagnetic fields plays a role in the development of cancer, reproductive and developmental abnormalities, or learning and behavioral problems. They also reported that in laboratory studies, no evidence has been found that the EMF levels common in homes can alter the functions of cells or damage DNA.
For a more detailed report from the National Research Council Committee, one can read Possible Health Effects of Exposure to Residential Electric and Magnetic Fields.
- “EMFs and Electric Blankets: There’s Less Reason to Worry,” Consumer Reports, January 1997.
- National Institute of Environmental Health Sciences (NIEHS). http://www.niehs.nih.gov/emfrapid/html/overview.htm.
- Department of Energy.
- National Academy Press. http://www.nap.edu/catalog/5155.html.
Developed by Janie L. Harris, M.Ed., CRS, former Extension Housing and Environment Specialist, Texas A&M AgriLife Extension Service, Texas A&M System. 2000.
Last updated: July 3, 2015