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.
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:
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Increase the distance between yourself and the EMF source – sit at arm’s length
from your computer terminal.
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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.
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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.
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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.
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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.
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Shield yourself. Use shielding devices on your computer screen and cellular phone.
Add shielding to your household wiring, circuit box, and transformers.
Magnetic fields are not blocked by most materials. Magnetic fields encountered
in homes vary greatly. Magnetic fields rapidly become weaker with distance from
the source.
- Electric fields in the home, on average, range from 0 to 10 volts per meter.
They can be hundreds, thousands, or even millions of times weaker than those encountered
outdoors near power lines.
- Electric fields directly beneath power lines may vary from a few volts per meter
for some overhead distribution lines to several thousands of volts per meter for
extra high voltage power lines.
- Electric fields from power lines rapidly become weaker with distance and can
be greatly reduced by walls and roofs of buildings.