vehicles’ occupants or that they are safe.
makes it difficult to know which studies are trustworthy.
health. Based upon the research, more than 230 EMF experts have signed the International EMF Scientist Appeal which calls on the World Health Organization to establish stronger guidelines for ELF and radio frequency EMF. Thus, even if EMF measurements comply with the ICNIRP guidelines, occupants of hybrid and electric cars may still be at increased risk for cancer and other health problems.
Given that magnetic
fields have been considered “possibly carcinogenic” in humans by the
International Agency for Research on Cancer of the World Health Organization since
2001, the precautionary principle dictates that we should design consumer
products to minimize consumers’ exposure to ELF EMF. This especially applies to hybrid and electric automobiles as drivers and passengers spend considerable amounts of time in these vehicles, and health risks increase with the duration of exposure.
proposed manufacturing design guidelines that could reduce the magnetic fields in electric vehicles (see
below). All automobile manufacturers should follow these guidelines to ensure their customers’ safety.
research on the health effects of
electromagnetic radiation that is independent of industry to eliminate any potential conflicts of interest. In the U.S., a
major national research and education initiative could be funded with as little as a 5
cents a month fee on mobile phone subscribers.
Following are summaries and links to recent studies and news articles on this topic.
—
and EMI with cardiac implantable electronic devices:
O’Connor M, Horlbeck L, Michel J, Weigand S, Grebmer C, Blazek P, Brkic A,
Semmler V, Haller B, Reents T, Hessling G, Deisenhofer I, Whittaker P, Lienkamp
M, Kolb C. Letter: Electric cars and electromagnetic interference with cardiac implantable electronic devices: A cross-sectional evaluation. Annals of
Internal Medicine. Apr 24, 2018.
Excerpts
Cardiac implantable electronic devices (CIEDs) are considered
standard care for bradycardia, tachycardia, and heart failure. Electromagnetic
interference (EMI) can disrupt normal function … Electric cars represent a
potential source of EMI. However, data are insufficient to determine their
safety or whether their use should be restricted in patients with CIEDs.
Objective: To assess
whether electric cars cause EMI and subsequent CIED dysfunction.
Methods and Findings: We approached
150 consecutive patients with CIEDs seen in our electrophysiology clinic … 40
patients declined to participate, and 2 withdrew consent … Participants were
assigned to 1 of 4 electric cars with the largest European market share…we
excluded hybrid vehicles.
Participants sat in the front seat while cars ran on a roller
test bench … Participants then charged the same car in which they had sat.
Finally, investigators drove the cars on public roads.
Field strength was generally highest during charging (30.1 to
116.5 µT) and increased as the charging current increased. Exposure during
charging was at least an order of magnitude greater than that measured within 5
cm of the CIED in the front seat (2.0 to 3.6 µT). Field strength did not differ
between the front and back seats. Peak field strength measured outside the cars
ranged between the values measured during charging and those measured within
the cars during testing … Field strength measured inside the cars during road
driving was similar to that measured during test bench studies.
We found no
evidence of EMI with CIEDs …The electrocardiographic recorder did observe
EMI, but CIED function and programming were unaffected.
Our sample
was too small to detect rare events … Nevertheless, other evidence supports a lack of EMI
with CIEDs. Magnetic fields are generated in gasoline-powered vehicles if the
vehicles’ steel-belted tires are magnetized (3); average fields of
approximately 20 µT were reported in the back seat of 12 models, and those as
high as 97 µT were reported close to the tires (4). Similar values were
reported in electric trains and trams (5). The lack of anecdotal reports of
CIED malfunction associated with such transportation is consistent with our
findings.
Electric cars
seem safe for patients with CIEDs, and restrictions do not appear to be
required. However, we recommend vigilance to monitor for rare events,
especially those associated with charging and proposed “supercharging”
technology.
—
Lin J, Lu M, Wu T, Yang L, Wu T. Evaluating extremely low frequency magnetic fields in the rear seats of the electric vehicles. Radiat Prot Dosimetry. 2018 Mar 23. doi: 10.1093/rpd/ncy048.
Abstract
In the electric vehicles (EVs), children can sit on a safety seat installed in the rear seats. Owing to their smaller physical dimensions, their heads, generally, are closer to the underfloor electrical systems where the magnetic field (MF) exposure is the greatest. In this study, the magnetic flux density (B) was measured in the rear seats of 10 different EVs, for different driving sessions. We used the measurement results from different heights corresponding to the locations of the heads of an adult and an infant to calculate the induced electric field (E-field) strength using anatomical human models. The results revealed that measured B fields in the rear seats were far below the reference levels by the International Commission on Non-Ionizing Radiation Protection. Although small children may be exposed to higher MF strength, induced E-field strengths were much lower than that of adults due to their particular physical dimensions.
https://www.ncbi.nlm.nih.gov/pubmed/29584925
Excerpts
Small children and infants sitting in a safety seat at the rear part of the vehicle is a common occurrence. Children have smaller physical dimensions and, thus, their heads are generally much closer to the car floor, where the MF strength has been reported to be higher due to tire magnetization and the operation of the underfloor electrical systems (6, 7). The matter of children being potentially subject to greater magnetic field exposure may be relevant as leukemia is the most common type of childhood cancer (8). In particular, Ahlbom et al. (9) and Greenland et al. (10) indicated that the exposure to 50 and 60 Hz MF exceeding 0.3–0.4 μT may result in an increased risk for childhood leukemia although a satisfactory causal relationship has not yet been reliably demonstrated. Also, it was reported that a combination of weak, steady and alternating MF could modify the radical concentration, which had the potential to lead to biologically significant changes (11).
… the B field values measured at location #4 (floor in from of rear seat) were the highest, followed by values from location #3 (rear seat cushion), #2 (child’s head position) and #1 (adult’s head position) (p < 0.012, α = 0.05/3 = 0.017). There was a significant difference between the driving scenarios (F(3, 117) = 3.72, p = 0.013). The acceleration and deceleration scenarios generated higher B fields compared with the stationary and the 40 km/h driving scenarios (p < 0.01, α = 0.05/3 = 0.017) while no difference was identified between acceleration and deceleration (p = 0.16).
… The results demonstrate that the induced E-field strength was lower for the infant model compared with that of the adult in terms of both the head and body as a whole.
The infant was reported to have higher electrical conductivity (29) but there was no database dedicated to the infant. Furthermore, below 1 MHz, the database was hard to be measured and the uncertainty was large (30). Therefore, we would not include the issue in the study.
Although several SCs (spectral components) on higher frequencies have been observed (can spread to 1.24 kHz), the spectral analysis revealed that the SCs concentrated on bands below 1000 Hz. The EVs under test used aluminum alloy wheel rims, which have low magnetic permeability. However, the steel wire in the reinforcing belts of radial tires pick up magnetic fields from the terrestrial MF. When the tires spin, the magnetized steel wire in the reinforcing belts generates ELF MF usually below 20 Hz, that can exceed 2.0 μT at seat level in the passenger compartment (6). The measurement did not identify the ELF MF by different sources because the purpose of the study was to investigate the realistic exposure scenario for the occupants. To note, degaussing the tires or using the fiberglass belted tires can eliminate this effect and provide the MF results solely introduced by the operation of the electrified system.
ICNIRP proposed guidelines to evaluate the compliance of the non-sinusoidal signal exposure(3). The measurements rendered the maximal B field at the level of one-tenth to several μT, far below the reference level of the guidelines (e.g. 200 μT for 20–400 Hz). The similar non-sinusoidal MF signal magnitudes can only account for 6–10% of the reference levels according to the previous reports(32). However, as noted in the Introduction, ‘… 50 and 60 Hz MF exceeding 0.3–0.4 μT may result in an increased risk for childhood leukemia’. Therefore, it is necessary to measure the MF in the EVs to limit the exposure and for the purpose of epidemiological studies.
In this study, we measured ELF MF in the rear seats of ten types of EVs. The measurements were performed for four different driving scenarios. The measurement results were analyzed to determine the worst-case scenario and those values were used for simulations. We made numerical simulations to compare the induced E-field strength due to the physical difference between children and adults using detailed anatomical models. The results support the contention that the MF in the EVs that we tested was far below the reference levels of the ICNIRP guidelines. Furthermore, our findings show that children would not be more highly exposed compared to adults when taking into consideration of their physical differences. However, the measurement results indicated that further studies should be performed to elucidate the concerns on the incidence of the childhood leukemia for infant and child occupants.
—
SangWook Park. Evaluation of Electromagnetic Exposure During 85 kHz Wireless Power Transfer for Electric Vehicles. IEEE Transactions on Magnetics. Volume: PP, Issue: 99. Sep 1, 2017. 10.1109/TMAG.2017.2748498
Abstract
The external fields in the proximity of electric vehicle (EV) wireless power transfer (WPT) systems requiring high power may exceed the limits of international safety guidelines. This study presents dosimetric results of an 85 kHz WPT system for electric vehicles. A WPT system for charging EVs is designed and dosimetry for the system is evaluated for various exposure scenarios: a human body in front of the WPT system without shielding, with shielding, with alignment and misalignment between transmitter and receiver, and with a metal plate on the system for vehicle mimic floor pan. The minimum accessible distances in compliance are investigated for various transmitting powers. The maximum allowable transmitting power are also investigated with the limits of international safety guidelines and the dosimetric results.
—
KHz in electric and gasoline-powered vehicles
Kavet R. Electric and magnetic fields <100 KHz in electric and
gasoline-powered vehicles. Radiat Prot Dosimetry. 2016 Dec;172(4):541-546.
Abstract
Measurements
were conducted to investigate electric and magnetic fields (EMFs) from 120 Hz
to 10 kHz and 1.2 to 100 kHz in 9 electric or hybrid vehicles and 4 gasoline
vehicles, all while being driven. The range of fields in the electric vehicles
enclosed the range observed in the gasoline vehicles. Mean magnetic fields
ranged from nominally 0.6 to 3.5 µT for electric/hybrids depending on the
measurement band compared with nominally 0.4 to 0.6 µT for gasoline vehicles.
Mean values of electric fields ranged from nominally 2 to 3 V m-1 for
electric/hybrid vehicles depending on the band, compared with 0.9 to 3 V m-1 for
gasoline vehicles. In all cases, the fields were well within published exposure
limits for the general population. The measurements were performed with Narda
model EHP-50C/EHP-50D EMF analysers that revealed the presence of spurious
signals in the EHP-50C unit, which were resolved with the EHP-50D model.
—
R. Arribas. Passenger Exposure to Magnetic Fields due to the Batteries
of an Electric Vehicle. IEEE Transactions on Vehicular Technology. 65(6):4564-4571. Jun 2016.
Abstract
In electric vehicles, passengers sit very close to an
electric system of significant power. The high currents achieved in these
vehicles mean that the passengers could be exposed to significant magnetic
fields (MFs). One of the electric devices present in the power train are the
batteries. In this paper, a methodology to evaluate the MF created by these batteries
is presented. First, the MF generated by a single battery is analyzed using
finite-elements simulations. Results are compared with laboratory measurements,
which are taken from a real battery, to validate the model. After this, the MF
created by a complete battery pack is estimated, and results are discussed.
Conclusion
Passengers inside an EV could be exposed to MFs of
considerable strength when compared with conventional vehicles or to other
daily exposures (at home, in the office, in the street, etc.). In this paper,
the MF created by the batteries of a particular electric car is evaluated from
the human health point of view by means of finite-elements simulations,
measurements, and a simple analytical approximation, obtaining an upper bound
for the estimated MF generated by a given battery pack. These results have been
compared with ICNIRP’s recommendations concerning exposure limitation to
low-frequency MFs, finding that the field generated by this particular battery
pack should be below ICNIRP’s field reference levels, and conclusions
concerning the influence of the switching frequency have been drawn. Finally,
some discussion regarding other field sources within the vehicle and different
vehicles designs has been presented. Due to the wide variety of both available
EVs and battery stacks configurations, it is recommended that each vehicle
model should be individually assessed regarding MF exposure.
—
al. Magnetic Field Exposure Assessment in Electric Vehicles. IEEE Transactions
on Electromagnetic Compatibility. 57(1):35-43. Feb 2015.
Abstract
This article
describes a study of magnetic field exposure in electric vehicles (EVs). The
magnetic field inside eight different EVs (including battery, hybrid, plug-in
hybrid, and fuel cell types) with different motor technologies (brushed direct
current, permanent magnet synchronous, and induction) were measured at
frequencies up to 10 MHz. Three vehicles with conventional powertrains were
also investigated for comparison. The measurement protocol and the results of
the measurement campaign are described, and various magnetic field sources are
identified. As the measurements show a complex broadband frequency spectrum, an
exposure calculation was performed using the ICNIRP “weighted peak” approach.
Results for the measured EVs showed that the exposure reached 20% of the ICNIRP
2010 reference levels for general public exposure near to the battery and in
the vicinity of the feet during vehicle start-up, but was less than 2% at head
height for the front passenger position. Maximum exposures of the order of 10%
of the ICNIRP 2010 reference levels were obtained for the cars with
conventional powertrains.
http://ieeexplore.ieee.org/abstract/document/6915707/
—
Hareuveny R, Sudan M, Halgamuge MN, Yaffe Y, Tzabari Y, Namir D, Kheifets L. Characterization of Extremely Low Frequency Magnetic Fields from Diesel, Gasoline and Hybrid Cars under Controlled Conditions. Int J Environ Res Public Health. 2015 Jan 30;12(2):1651-1666.
Abstract
This study characterizes extremely low frequency (ELF) magnetic field (MF) levels in 10 car models.
Extensive measurements were conducted in three diesel, four gasoline, and three hybrid cars, under similar controlled conditions and negligible background fields.
Averaged over all four seats under various driving scenarios the fields were lowest in diesel cars (0.02 μT), higher for gasoline (0.04-0.05 μT) and highest in hybrids (0.06-0.09 μT), but all were in-line with daily exposures from other sources. Hybrid cars had the highest mean and 95th percentile MF levels, and an especially large percentage of measurements above 0.2 μT. These parameters were also higher for moving conditions compared to standing while idling or revving at 2500 RPM and higher still at 80 km/h compared to 40 km/h. Fields in non-hybrid cars were higher at the front seats, while in hybrid cars they were higher at the back seats, particularly the back right seat where 16%-69% of measurements were greater than 0.2 μT.
As our results do not include low frequency fields (below 30 Hz) that might be generated by tire rotation, we suggest that net currents flowing through the cars’ metallic chassis may be a possible source of MF. Larger surveys in standardized and well-described settings should be conducted with different types of vehicles and with spectral analysis of fields including lower frequencies due to magnetization of tires.
Excerpts
Previous work suggests that major sources of MF in cars include the tires and electric currents [4,5]. The level of MF exposure depends on the position within the vehicle (e.g., proximity to the MF sources) and can vary with different operating conditions, as changes to engine load can induce MFs through changes in electric currents. Scientific investigations of the levels of MF in cars are sparse: only one study evaluated fields only in non-hybrid cars [6], two studies of hybrid cars have been carried out [4,7], and few studies have systematically compared exposures in both hybrid and non-hybrid cars [8,9,10,11,12], some based on a very small number of cars
In hybrid cars, the battery is generally located in the rear of the car and the engine is located in the front. Electric current flows between these two points through cables that run underneath the passenger cabin of the car. This cable is located on the left for right-hand driving cars and on the right for left-hand driving cars. Although in principle the system uses direct current (DC), current from the alternator that is not fully rectified as well as changes to the engine load, and therefore the current level, can produce MFs which are most likely in the ELF range. While most non-hybrid cars have batteries that are located in the front, batteries in some of them are located in the rear of the car, with cables running to the front of the car for the electrical appliances on the dashboard. In this study, all gasoline and diesel cars had batteries located in the front of the car.
…the percent of time above 0.2 µT was the most sensitive parameter of the exposure. Overall, the diesel cars measured in this study had the lowest MF readings (geometric mean less than 0.02 μT), while the hybrid cars had the highest MF readings (geometric mean 0.05 μT). Hybrid cars had also the most unstable results, even after excluding outliers beyond the 5th and 95th percentiles. With regard to seat position, after adjusting for the specific car model, gasoline and diesel cars produced higher average MF readings in the front seats, while hybrid cars produced the highest MF readings in the back right seat (presumably due to the location of the battery). Comparing the different operating conditions, the highest average fields were found at 80 km/h, and the differences between operating conditions were most pronounced in the back right seat in hybrid cars. Whether during typical city or highway driving, we found lowest average fields for diesel cars and highest fields for hybrid cars.
Previous works suggest that the magnetization of rotating tires is the primary source of ELF MFs in non-hybrid cars [5,15]. However, the relatively strong fields (on the order of a few μT within the car) originating from the rotating tires are typically at 5–15 Hz frequencies, which are filtered by the EMDEX II meters. ….
Overall, the average MF levels measured in the cars’ seats were in the range of 0.04–0.09 μT (AM) and 0.02–0.05 μT (GM). These fields are well below the ICNIRP [17] guidelines for maximum general public exposure (which range from 200 μT for 40 Hz to 100 μT for 800 Hz), but given the complex environments in the cars, simultaneous exposure to non-sinusoidal fields at multiple frequencies must be carefully taken into account. Nevertheless, exposures in the cars are in the range of every day exposure from other sources. Moreover, given the short amount of time that most adults and children spend in cars (about 30 minutes per day based on a survey of children in Israel (unpublished data), the relative contribution of this source to the ELF exposure of the general public is small. However, these fields are in addition to other exposure sources. Our results might explain trends seen in other daily exposures: slightly higher average fields observed while travelling (GM = 0.096 μT) relative to in bed (GM = 0.052 μT) and home not in bed (GM = 0.080 μT) [1]. Similarly, the survey of children in Israel found higher exposure from transportation (GM = 0.092 µT) compared to mean daily exposures (GM = 0.059 µT). Occupationally, the GM of time-weighted average for motor vehicle drivers is 0.12 μT [18].
Open access paper: http://bit.ly/1u9lUTN
—
vehicles
SINTEF, Jan 6, 2014
the project arrived on the following design guidelines to, if necessary,
minimize the magnetic field in electric vehicles.
- For any DC cable carrying significant amount of current, it should be made in the form of a twisted pair so that the currents in the pair always flow in the opposite directions. This will minimise its EMF emission.
- For three-phase AC cables, three wires should be twisted and made as close as possible so as to minimise its EMF emission.
- All power cables should be positioned as far away as possible from the passenger seat area, and their layout should not form a loop. If cable distance is less than 200mm away from the passenger seats, some forms of shielding should be adopted.
- A thin layer of ferromagnetic shield is recommended as this is cost-effective solution for the reduction of EMF emission as well EMI emission.
- Where possible, power cables should be laid such a way that they are separated from the passenger seat area by a steel sheet, e.g., under a steel metallic chassis, or inside a steel trunk.
- Where possible, the motor should be installed farther away from the passenger seat area, and its rotation axis should not point to the seat region.
- If weight permits, the motor housing should be made of steel, rather than aluminium, as the former has a much better shielding effect.
- If the distance of the motor and passenger seat area is less than 500mm, some forms of shielding should be employed. For example, a steel plate could be placed between the motor and the passenger seat region
- Motor housing should be electrically well connected to the vehicle metallic chassis to minimise any electrical potential.
- Inverter and motor should be mounted as close as possible to each other to minimise the cable length between the two.
- Since batteries are distributed, the currents in the batteries and in the interconnectors may become a significant source for EMF emission, they should be place as far away as possible from the passenger seat areas. If the distance between the battery and passenger seat area is less than 200mm, steel shields should be used to separate the batteries and the seating area.
- The cables connecting battery cells should not form a loop, and where possible, the interconnectors for the positive polarity should be as close as possible to those of the negative polarity.
Jeremy Hsu, IEEE Spectrum, May 5, 2014
Summary
“The study, led by SINTEF, an independent research
organization headquartered in Trondheim, Norway, measured the electromagnetic
radiation—in the lab and during road tests—of seven different electric cars, one hydrogen-powered car, two
gasoline-fueled cars and one diesel-fueled car. Results from all conditions
showed that the exposure was less than 20 percent of the limit recommended by
the International Commission on Non-Ionizing Radiation
Protection (ICNIRP).”
“Measurements taken inside the vehicles—using a test dummy
with sensors located in the head, chest and feet—showed exposure at less than 2
percent of the non-ionizing radiation limit at head-height. The highest electromagnetic field readings—still less than 20
percent of the limit—were found near the floor of the electric cars, close to
the battery. Sensors picked up a burst of radiation that same level, when the
cars were started.”
gasoline-powered vehicles
G, Smith J, Sahl J, Kavet R. ELF magnetic fields in electric and
gasoline-powered vehicles. Bioelectromagnetics. 2013
Feb;34(2):156-61. doi: 10.1002/bem.21730.
Abstract
We conducted
a pilot study to assess magnetic field levels in electric compared to
gasoline-powered vehicles, and established a methodology that would provide
valid data for further assessments. The sample consisted of 14 vehicles, all
manufactured between January 2000 and April 2009; 6 were gasoline-powered
vehicles and 8 were electric vehicles of various types. Of the eight models
available, three were represented by a gasoline-powered vehicle and at least
one electric vehicle, enabling intra-model comparisons. Vehicles were driven
over a 16.3 km test route. Each vehicle was equipped with six EMDEX Lite
broadband meters with a 40-1,000 Hz bandwidth programmed to sample every 4 s.
Standard statistical testing was based on the fact that the autocorrelation statistic
damped quickly with time. For seven electric cars, the geometric mean (GM) of
all measurements (N = 18,318) was 0.095 µT with a geometric standard deviation
(GSD) of 2.66, compared to 0.051 µT (N = 9,301; GSD = 2.11) for four
gasoline-powered cars (P < 0.0001). Using the data from a previous exposure
assessment of residential exposure in eight geographic regions in the United
States as a basis for comparison (N = 218), the broadband magnetic fields in
electric vehicles covered the same range as personal exposure levels recorded
in that study. All fields measured in all vehicles were much less than the
exposure limits published by the International Commission on Non-Ionizing
Radiation Protection (ICNIRP) and the Institute of Electrical and Electronics
Engineers (IEEE). Future studies should include larger sample sizes
representative of a greater cross-section of electric-type vehicles.
—
Consumer Reports News: August 4, 2010
effects of electromagnetic field radiation, known as EMF, for people who drive
in hybrid cars. While all electrical devices, from table lamps to copy
machines, emit EMF radiation, the fear is that hybrid cars, with their big
batteries and powerful electric motors, can subject occupants to unhealthy
doses. The problem is that there is no established threshold standard that says
what an unhealthy dose might be, and no concrete, scientific proof that the
sort of EMF produced by electric motors harms people
conventional non-hybrid small sedan.”
mG (milligauss) in the 2008 Toyota Highlander to 30 mG in the Chevrolet Cobalt.
The hybrids tested at 2-4 mG. Here are some highlights from the tests. EMF
readings were highest in the driver’s foot well and second-highest at the
waist, much lower higher up, where human organs might be more susceptible to
EMF.
personal computers are subject to EMF exposure in the range of 2 to 20 mG,
electric blankets 5 to 30 mG, and a hair dryer 10 to 70 mG, according to an
Australian government compilation. In this country, several states limit EMF
emissions from power lines to 200 mG. However, there are no U.S. standards
specifically governing EMF in cars.”
expose drivers to significantly more EMF than do conventional cars. Consider
this myth, busted.”
—
Tal Bronfer, the truth about cars, March 1, 2010
Summary
“The Australian Radiation Protection and Nuclear Safety
Agency (ARPANSA) recommends a limit of 1,000 mG (milligauss) for a 24 hour
exposure period. While other guidelines pose similar limits, the International
Agency for Research on Cancer (IARC) deemed extended exposure to electromagnetic
fields stronger than 2 mG to be a “possible cause” for cancer. Israel’s
Ministry of Health recommends a maximum of 4 mG.”
“Last year, Israeli automotive website Walla! Cars conducted
a series of tests on the previous generation Toyota Prius, Honda Insight and
Honda Civic Hybrid, and recorded radiation figures of up to 100 mG during
acceleration. Measurements also peaked when the batteries were either full (and
in use) or empty (and being charged from the engine), while normal driving at
constant speeds yielded 14 to 30 mG on the Prius, depending on the area of the
cabin.
The Ministry of Environmental Protection is expected to
publish the results of the study this week. The study will group hybrids sold
in Israel into three different radiation groups, reports Israel’s Calcalist.
It’s expected that the current-gen Prius will be deemed ‘safe’, while the Honda
Insight and Civic Hybrid (as well as the prev-gen Prius) will be listed as
emitting ‘excessive’ radiation.”
—
Jim Motavalli, New York Times, Apr 27, 2008
“… 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.”
“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.”
“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.”