Electromagnetic
Fields
On A Power Trip
THEA DELEY / Delicious Living Feb02
The alarm clock buzzes next to your head, and after switching the toggle to radio, you crawl out from under your warm, cozy electric blanket and walk to the shower. You dress, blow-dry your hair, and head for the kitchen. While the coffee drips in the coffeemaker, you stand in front of the microwave as you heat your oatmeal, absentmindedly tracking the countdown, thinking about your day ahead. You flip on the TV to watch the news as you eat, then tromp out the door.
Your day has barely started, and you've already been exposed to a significant amount of electromagnetic (EM) radiation. All this and you haven't even stepped in front of your computer monitor, an act that will bombard you with an even higher EM field than most of your morning appliances combined.
While we walk in and out of high electromagnetic fields all day long (using an electric razor, passing in front of a microwave, walking under power lines), it is long-term exposure that appears to pose the greatest threat. People living in urban areas average 3 milligauss-the measurement used to determine the level of an EM field-of constant electromagnetic radiation exposure; those in rural areas, 1 milligauss. Some say these levels are dangerous. Others consider the amounts acceptable risk. Whether they are safe depends on whom you ask.
In the United States, electricity has been common in most homes for about 100 years, but the possible health effects of this low-frequency energy have only been studied for the past 20 years. Some research links EM exposure to cancer, miscarriages, childhood leukemia, brain tumors, infertility, Alzheimer's, learning disabilities, chronic fatigue syndrome, autism, and sudden infant death syndrome, to name a few. But for every study demonstrating a link between EM exposure and illness, there is another study disproving it.
What we do know is that extremely high-frequency energy fields, like X-rays, generate ionizing radiation, which can damage cells and thus cause cancer or genetic mutations. We've found that high frequencies like those found in radio waves and microwaves generate enough nonionizing radiation to cause thermal damage to cells directly exposed. But we're still struggling to understand the impact, if any, of electromagnetic fields in the lower frequencies, like the 60 Hz appliances found in our homes. Until studies show conclusively one way or another, it may be wise to learn what you can do to limit your and your family's electromagnetic exposure.
| Step back
UP TO 60 PERCENT of our electromagnetic exposure at home comes from incorrect electrical wiring and being near electrical appliances. Below, we've grouped these appliances into risk categories-very high to very low-based on the milligauss units at 1 foot. Generally, electromagnetic fields drop to naturally occurring levels within 3 to 4 feet from each appliance. The length of exposure time must also be considered, because it can dramatically alter the overall effect of the magnetic field. Units at 1 foot Units at 3 feet VERY HIGH RISK can opener 7.19-163.02 1.30-6.44 computer monitor 0.20-134.7 0.01-9.37 electric razor* 100 (at 6 inches) 20 (at 1 foot) HIGH RISK desktop light 32.81 1.21 hair dryer 0.1-70 0.1-2.8 microwave oven 0.59-54.33 0.11-4.66 portable fan 0.04-85.64 0.03-3.12 MODERATE RISK drill press 0.21-33.33 0.03-8.35 mixer 0.49-41.21 0.09-3.93 printer 0.74-43.11 0.18-2.45 range 0.60-35.93 0.05-2.83 scanner 2.18-26.91 0.09-3.48 vacuum cleaner 7.06-22.62 0.51-1.28 LOW RISK aquarium pump 0.35-18.21 0.01-1.17 band saw 0.51-14.24 0.05-0.75 clock 0.34-13.18 0.03-0.68 clothes iron 1.66-2.93 0.25-0.37 coffee machine 0.09-7.30 0-0.61 copier 0.05-18.38 0-2.39 dishwasher 4.98-8.91 0.84-1.63 food processor 6.19 0.35 garbage disposal 2.72-7.79 0.19-1.51 portable heater 0.11-19.60 0-1.38 radio 0.43-4.07 0.03-0.98 sewing machine 3.79-7.70 0.35-0.45 tape player 0.13-6.01 0.01-1.66 television 1.80-12.99 0.07-1.11 toaster 0.29-4.63 0.01-0.47 VERY LOW RISK fax machine 0.16 0.03 refrigerator 0.12-2.99 0.01-0.60 VCR 0.19-4.63 0.01-0.41 vending machine 0.46-5.05 0.02-0.59 Source for milligauss amounts: School Exposure Assessment Survey by L. Zaffanella (California Electric and Magnetic Fields Program, November 1997), interim results. * Source for milligauss amounts: Consumer's Guide (Environmental Protection Agency), which reported that electric razors at 6 inches emit an EM reading anywhere from 4 milligauss to 600 milligauss with a median of 100 milligauss, and, at 1 foot, emit up to 100 milligauss with a median of 20 milligauss. |
"There are two kinds of electricity," explains Saul Goldberg, PhD, coauthor of Power Frequency, Magnetic Fields, and Public Health (CRC Press, 1995) and an electrical engineering professor at California Polytechnic State University in San Luis Obispo. "One is called direct current (DC), like a battery. The other is alternating current (AC), like the 60-cycle (or Hertz) power our homes have. When we talk about electromagnetic fields, we mean AC fields." The voltage (or strength) of a charge creates an electric field-which is easily obscured and can barely penetrate the skin-whereas the current (or motion) of the charge creates a magnetic field which can easily penetrate skin, soil, and building materials. If an appliance is plugged in but not turned on, it emits an electric field but not a magnetic one. "You get a magnetic field when there is an electric current involved," says Goldberg.
The farther away you are from an appliance or power line, the less EM exposure you receive. Generally speaking, 3 feet from an appliance is enough for its EM field to drop off to what's considered a naturally occurring or "background" level (see "Step Back," p. 41). Power lines, however, require a greater distance before their EM fields drop to background levels. While underground cables probably emit less radiation because of the way they are wrapped together (which can cancel out each other's fields), most underground cables are buried just 3 feet below the surface. Consequently, if your house is right on top of the lines, so are you. Overhead cables are strung 10 feet above ground, farther away, but with a potentially greater field intensity. And, according to the California Electric and Magnetic Fields Program (CEMFP), you'd need to be 60 to 200 feet from a distribution line and 300 to 1,000 feet from a transmission line for EM fields to drop to background levels.
| Where To Go To Learn
More
Measuring electromagnetic fields at home Do It Yourself Microwave News Ask Public Utility Companies Hire Consultants Agencies dedicated to EM field research California Electric and Magnetic Fields Program Electric and Magnetic Field Research and Public Information
Dissemination Environmental Protection Agency Electromagnetic sensitivity Environmental Health Center in Dallas |
Health-risk controversy
In 1991, following a congressional request, the National Research Council
(NRC) reviewed more than 500 research studies to assess if EM fields adversely
affect health. After three years, its committee concluded that EM exposure does
not appear to pose a risk to humans based on the available evidence. Then in
1996, an NRC committee reviewed 11 epidemiological studies to determine the
relationship between leukemia and children who live near power lines. The
committee concluded that children who live in homes with high magnetic fields
have a 1.5 times greater risk of developing leukemia, but it couldn't explain
why. Later that year, another team of researchers conducted an epidemiological
study in which they found no link between living in homes with high EM fields or
nearby power lines and childhood leukemia (New England Journal of Medicine,
1996, vol. 337, no. 1).
William Rea, MD, founder of the Environmental Health Center in Dallas, has been studying electromagnetic sensitivity for more than 20 years. Symptoms include burning, itching, and tingling of the skin; muscle aches and flu-like symptoms; short-term memory loss; and sometimes tremors and heart irregularities. People who work around computers all the time or who have been exposed to pesticides seem more susceptible, explains Rea. "In our double-blind study, we show that there's no question that electromagnetic sensitivity exists;" he says.
How can it be, then, that some research studies show EM fields are harmful, while others show they're benign? Andrew Marino, PhD, JD, professor at Louisiana State University Medical Center in Shreveport and coauthor of Electric Wilderness (San Francisco Press, 1986), says: "When people are exposed to electromagnetic fields, there are certain consequences that are possible because of the nature of the fields. Whether they materialize or not is hard to say."
He offers this scenario: Five identical lab mice are exposed to the same electromagnetic field for the same amount of time. He finds Mouse 1's weight increases a bit, Mouse 2's decreases a bit, Mouse 3's weight stays the same, Mouse 4's increases dramatically, and Mouse 5's weight decreases dramatically. As in most research studies, the data are averaged, and the bottom-line result looks as if electromagnetic exposure had no impact whatsoever on the five mice. However, the fact that weight altered for the majority of the mice is significant, says Marino. "We now know that electromagnetic fields can affect living systems," he says.
What we don't know, is at what exposure level this happens. Quite simply, it's difficult to determine what's safe, because we don't yet fully understand EM fields.
HOUSE HUNTING
What you need to know
When buying or renting a home or apartment, you may want to first find out
the following:
a Where are the power lines, and how close are they to the building? Are they strung overhead or buried underground? Which type are they-transmission, sub-transmission, overhead distribution, or underground distribution? • Are there any power stations or similar facilities nearby? How old is the electrical wiring? (Older "knob-and-tube" wiring emits higher EM fields.) Does it meet current safety standards? ... Where are sources of high EM fields? Look for appliances, transformers, track lighting, incorrectly wired light-dimmer switches, and the "service drop" where power comes into the building. How close are these EM sources to the rooms where you'll spend most of your time? So, what if you found the perfect home but are struggling to answer these questions? Ask a licensed electrician to determine the type of wiring your house has and its condition. Your local utility company can answer all other questions related to nearby power lines and stations. Source: California Electric and Magnetic Fields Program.
Protect yourself Although research results are inconclusive and contradictory, Goldberg advises to play it safe. "I don't see anything wrong in assuming there's a risk," he says. In fact, many companies and individuals have opted to follow a "no- and low-cost avoidance" strategy. You can too, by implementing the following suggestions.
GET A READING.
Begin by having gaussmeter readings taken in your home and yard. Nearby
power lines may account for 40 percent of the magnetic fields inside our houses,
according to CEMFP The rest of our EM exposure at home comes from incorrect
electrical wiring and being around electrical appliances.
DECORATE STRATEGICALLY.
Goldberg suggests moving electrical appliances away from areas where you
spend a lot of time. For instance, move electric clocks a couple feet away from
your bed, and do not stand close to or in front of appliances-can openers,
microwaves, televisions, portable fans-while they're turned on. If an EM source
can't be moved, rearrange furniture so that you don't spend as much time near
it. Do not place your bed on the other side of a wall where a TV is located if
the television is used while you're sleeping. Goldberg also suggests arranging
furniture so that you don't spend a lot of time next to the wall where the
electrical hook-up box enters your house, since fields tend to be higher there.
TAKE A BREAK. Appliances that generate low EM fields might still pose a risk if
you're exposed to them for a long period of time. For instance, avoid using
electric blankets all night long. You can always use the blanket to heat your
bed before you climb in, then turn off the blanket while you sleep. (Some
experts believe that pregnant women or women trying to become pregnant may want
to unplug electric blankets altogether before climbing into bed.) If you own a
waterbed, turn the heater on to warm up your mattress, then turn it off when you
go to bed. On the other hand, appliances that generate high EM fields but are
used briefly-like an electric razor-pose a risk as well if they're used close to
the body. Consider replacing your razor with a battery-powered or nonelectric
one, or only using your electric razor when it's not plugged in but running on a
charged battery.
SEAL THE NUKES.
Microwave ovens are different from other household appliances since the
frequency they use to cook food is tremendously high, above 500 megaHertz. Do
not stand in front of a microwave oven while it's in use, and have an appliance
repair shop check it yearly to make sure the rubber seal around the door is not
damaged.
PROTECT TYKES.
Since children may be more susceptible to EM fields, there are special
precautions to take for their safety. Set up your yard so that children don't
play in areas where EM fields are highest; keep them away from underground and
aboveground power lines and transformers. Also, encourage kids to play with
battery-operated toys instead of AC ones. And finally, limit or eliminate hair
dryer use on children.
SINCE CHILDREN MAY BE MIRE
SUSCEPTIBLE
to EM fields, there are special precautions
TO TAKE FUR THEIR SAFETY.
WATCH YOUR WORKSTATION.
At the office, replace your computer monitor with a low emission one, and
sit 2 to 3 feet away from it. Also, arrange your space so you don't sit within 3
feet of the sides or back of another monitor-that's where fields are apt to be
the highest. Try to keep the CPU at least 2 to 3 feet away from your body, as
well.
HANG IT UP.
As for cell phones, limit the length of calls and/or use hands-free devices
if possible so the phone isn't held close to your head and body. High radio
frequency is only transmitted during a call.
AVOID THE TOWERS.
A cell phone base station continually transmits signals. Stay back 6 to 15
feet from cellular base stations (3foot antennas mounted on buildings or
towers), and even farther from TV and radio transmission towers. These are
high-frequency fields, an even greater threat than most appliances.
Power down and unplug
Once an appliance is turned off, the EM field disappears and there is no
residual effect. In other words, a room is not left full of EM radiation. The
appliance does continue to generate an electric field, so you may want to err on
the side of caution and unplug.
It's nearly impossible to find a place anywhere on the planet that doesn't play host to some EM fields-radar/radio waves, microwaves, and satellite and cell phone transmissions blanket most of the planet.
In no way, however, do we need to abstain from using electricity to be safe from EM fields. But it can't hurt to use a good old-fashioned manual device-like a can opener whenever possible.
Thea Deley is a freelance writer specializing in alternative health issues. She lives in San Luis Obispo, CA.
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