Fear, but Few Facts, on Hybrid Risk
ALMOST without exception, scientists and policy makers agree that hybrid vehicles are good for the planet. To a small but insistent group of skeptics, however, there is another, more immediate question: Are hybrids healthy for drivers?
There is a legitimate scientific reason for raising the issue. The flow of electrical current to the motor that moves a hybrid vehicle at low speeds (and assists the gasoline engine on the highway) produces magnetic fields, which some studies have associated with serious health matters, including a possible risk of leukemia among children.
With the batteries and power cables in hybrids often placed close to the driver and passengers, some exposure to electromagnetic fields is unavoidable. Moreover, the exposure will be prolonged — unlike, say, using a hair dryer or electric shaver — for drivers who spend hours each day at the wheel.
Some hybrid owners have actually tested their cars for electromagnetic fields using hand-held meters, and a few say they are alarmed by the results.
Their concern is not without merit; agencies including the National Institutes of Health and the National Cancer Institute acknowledge the potential hazards of long-term exposure to a strong electromagnetic field, or E.M.F., and have done studies on the association of cancer risks with living near high-voltage utility lines.
While Americans live with E.M.F.'s all around — produced by everything from cellphones to electric blankets — there is no broad agreement over what level of exposure constitutes a health hazard, and there is no federal standard that sets allowable exposure levels. Government safety tests do not measure the strength of the fields in vehicles — though Honda and Toyota, the dominant hybrid makers, say their internal checks assure that their cars pose no added risk to occupants.
Researchers with expertise in hybrid-car issues say that while there may not be cause for alarm, neither should the potential health effects be ignored.
"It would be a mistake to jump to conclusions about hybrid E.M.F. dangers, as well as a mistake to outright dismiss the concern," said Jim Kliesch, a senior engineer for the clean vehicles program at the Union of Concerned Scientists. "Additional research would improve our understanding of the issue."
Charges that automobiles expose occupants to strong electromagnetic fields were made even before hybrids became popular. In 2002, a Swedish magazine claimed its tests found that three gasoline-powered Volvo models produced high E.M.F. levels. Volvo countered that the magazine had compared the measurements with stringent standards advanced by a Swedish labor organization, not the more widely accepted criteria established by the International Commission on Non-Ionizing Radiation Protection, a group of independent scientific experts based near Munich.
Much of the discussion over high E.M.F. levels has sprung from hybrid drivers making their own readings. Field-strength detectors are widely available; a common model, the TriField meter, costs about $145 online. But experts and automakers contend that it is not simple for a hybrid owner to make reliable, meaningful E.M.F. measurements.
The concern over high E.M.F. levels in hybrids has come not just from worrisome instrument readings, but also from drivers who say that their hybrids make them ill.
Neysa Linzer, 58, of Bulls Head in Staten Island, bought a new Honda Civic Hybrid in 2007 for the 200 miles a week she drove to visit grocery stores in her merchandising job for a supermarket chain. She said that the car reduced her gasoline use, but there were problems — her blood pressure rose and she fell asleep at the wheel three times, narrowly averting accidents.
"I never had a sleepiness problem before," Ms. Linzer said, adding that it was her own conclusion, not a doctor's, that the car was causing the symptoms.
Ms. Linzer asked Honda to provide her with shielding material for protection from the low-frequency fields, but the company declined her request last August, saying that its hybrid cars are "thoroughly evaluated" for E.M.F.'s before going into production. Ms. Linzer's response was to have the car tested by a person she called her wellness consultant, using a TriField meter.
The TriField meter is made by AlphaLab in Salt Lake City. The company's president, Bill Lee, defends its use for automotive testing even though the meter is set up to test alternating current fields, whereas the power moving to and from a hybrid vehicle's battery is direct current. "Generally, an A.C. meter is accurate in detecting large electromagnetic fields or microwaves," he said.
Testing with a TriField meter led Brian Collins of Encinitas, Calif., to sell his 2001 Honda Insight just six months after he bought it — at a loss of $7,000. He said the driver was receiving "dangerously high" E.M.F. levels of up to 135 milligauss at the hip and up to 100 milligauss at the upper torso. These figures contrasted sharply with results from his Volkswagen van, which measured one to two milligauss.
Mr. Collins said he tried to interest Honda in the problem in 2001, but was assured that his car was safe. He purchased shielding made of a nickel-iron alloy, but because of high installation costs decided to sell the car instead.
A spokesman for Honda, Chris Martin, points to the lack of a federally mandated standard for E.M.F.'s in cars. Despite this, he said, Honda takes the matter seriously. "All our tests had results that were well below the commission's standard," Mr. Martin said, referring to the European guidelines. And he cautions about the use of hand-held test equipment. "People have a valid concern, but they're measuring radiation using the wrong devices," he said.
Kent Shadwick, controller of purchasing services for the York Catholic District School Board in York, Ontario, evaluated the Toyota Prius for fleet use. Mr. Shadwick said it was tested at various speeds, and under hard braking and rapid acceleration, using a professional-quality gauss meter.
"The results that we saw were quite concerning," he said. "We saw high levels in the vehicle for both the driver and left rear passenger, which has prompted us to explore shielding options and to consider advocating testing of different makes and models of hybrid vehicles."
In a statement, Toyota said: "The measured electromagnetic fields inside and outside of Toyota hybrid vehicles in the 50 to 60 hertz range are at the same low levels as conventional gasoline vehicles. Therefore there are no additional health risks to drivers, passengers or bystanders."
The statement adds that the measured E.M.F. in a Prius is 1/300th of the European guideline.
The tests conducted by hybrid owners rarely approach the level of thoroughness of those run by automakers.
Donald B. Karner, president of Electric Transportation Applications in Phoenix, who tested E.M.F. levels in battery-electric cars for the Energy Department in the 1990s, said it was hard to evaluate readings without knowing how the testing was done. He also said it was a problem to determine a danger level for low-frequency radiation, in part because dosage is determined not only by proximity to the source, but by duration of exposure. "We're exposed to radio waves from the time we're born, but there's a general belief that there's so little energy in them that they're not dangerous," he said.
Mr. Karner has developed a procedure for testing hybrids, but he said that the cost — about $5,000 a vehicle — had prevented its use.
Lawrence Gust of Ventura, Calif., a consultant with a specialty in E.M.F.'s and electrical sensitivity, was one of the electrical engineers who tested Mr. Collins's Insight in 2001. He agreed that the readings were high but did not want to speculate on whether they were harmful. "There are big blocks of high-amp power being moved around in a hybrid, the equivalent of horsepower," he said. "I get a lot of clients who ask if they should buy hybrid electric cars, and I say the jury is still out."
Health Risks of Hybrid Cars Have Been Misrepresented by the Media
A New York Times article published earlier this year raised questions about the health risks of electromagnetic fields (EMFs) in hybrid or electric vehicles.
EMFs have been linked to serious health matters, including cancer and a potential risk of leukemia among children, so limiting exposure is in your best interest.
However, a safety report by Stan Hartman, an environmental health consultant in Boulder, CO, specializing in electropollution, found that hybrid vehicles are not a problem for your health.
"It's next to impossible to get accurate readings in a moving vehicle. Since there was no lift available to simulate road resistance to the drive train in a constant external EMF atmosphere, the results of this testing are only approximate at best."
|Dr. Mercola's Comments:|
|There's no disputing that hybrid cars are good for the environment. But lately another issue has been raised: Are hybrids healthy for the drivers and passengers? |
It's a legitimate question. I've written extensively on the dangers of electromagnetic fields (EMF) myself, and have previously warned you about the potential dangers these hybrid vehicles might pose.
The flow of electrical current to the motor of a hybrid vehicle produces magnetic fields, which studies have associated with serious health risks, including a heightened risk of leukemia among children.
Additionally, since the batteries and power cables in hybrids are often placed close to the driver and passengers, it's likely that some exposure to electromagnetic fields is unavoidable. And the exposure is a prolonged one as many drivers spend hours each day at the wheel.
So, should you buy a hybrid? Or are you gambling with your health while making an effort to go green?
Electro-Pollution Specialist Weighs in On the Potential Dangers
Stan Hartman is an environmental health consultant in Boulder, CO, specializing in electro-pollution. He believes the article featured in The New York Times contains many misleading statements that may frighten people unnecessarily.
Hartman, who conducted his own EMF safety test of a 2007 Toyota Prius Hybrid, offered the following corrections and explanations to the Times article above:
Hartman's recommendation for Prius owners is to provide some kind of comfortable elevation above the back seats for long trips, and avoid seating children in the back for very long unless they're in a car seat that significantly elevates them above the seat – preferably the center seat, which is already slightly above the side seats and safer from side impacts.
It's also best to avoid hard acceleration. There's a general reverse correlation between fuel economy and magnetic field exposure – the higher the mpg at any moment (which can be constantly displayed on the center touch screen), the lower the magnetic fields.
Additionally, he notes you may also receive less high-frequency exposure if you keep the smart key inserted in the slot on the dash while driving, instead of in your pocket or purse, so the system doesn't have to keep "looking for it." However, he was unable to confirm this during his testing, and it's not certain that the high frequencies around the smart key slot were in fact from the smart key system.
Some May Be More Sensitive Than Others
All of that said, I still believe you need to use your own best judgment and not ignore the issue if you find that you are sensitive or "allergic" to electromagnetic fields – a health concern that is on the rise and gaining more attention.
And some of the concern over high EMF levels in hybrids comes straight from drivers who claim that their hybrids make them ill.
One such case is Neysa Linzer, who concluded that her new Honda Civic Hybrid caused her elevated blood pressure, and that EMFs were the reason for her falling asleep while driving on three occasions.
Naturally, if you've already been diagnosed with Electromagnetic Hypersensitivity Syndrome (EHS), or experience pain or other symptoms while exposed to electrical appliances, computers, wireless internet or cell phones, you will likely need to pay particular attention to potential exposures in your car as well, no matter how low.
For others, however, Hartman's findings may offer some reassurance that choosing a hybrid is still a viable option, although other alternatives that may be far better are showing up on the horizon, such as cars that run on compressed air. No word yet on whether or not they too produce questionable levels of EMF…