Fear, but Few Facts, on Hybrid Risk
By JIM MOTAVALLI, April 27, 2008
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.”
Copyright 2008 The New York Times Company
Saturday, December 13, 2008
Thank you to WEEP for sending this article. It is worth your consideration, and you might wish to read this also.