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:
Increase the distance between yourself and the EMF source
sit at arms 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.
1. 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.
2. 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.
3. Shield yourself. Use shielding devices
on your computer screen and cellular phone. Add shielding
to your household wiring, circuit box, and transformers.
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.
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.
Magnetic fields close to electrical appliances are often much
stronger than those from other sources, including magnetic
fields directly under power lines. Appliance fields decrease
in strength with distance more quickly than do power line fields.