Introduction to Low-EMF Cars
Today’s cars expose the driver and passengers to high levels of electromagnetic radiation. This article discusses the basic issues, points out the various sources of the radiation and links to helpful resources.
Keywords: car, truck, vehicle, EMF, electromagnetic, radiation, low EMF, mitigation, electrical sensitivity, dirty electricity
The radiation problem
Cars and trucks contain many sources of radiation that can affect sensitive people riding inside. The symptoms vary with the person. Some become irritable (and perhaps more likely to get “road rage”), some get headaches, joint pain or other aches. In rare cases, people are so sensitive they feel burning sensations in their legs, hands or chest and may not be able to drive a car or even be inside one (Granlund-Lind, 2004; Evans, 2010).
A Swedish survey of 1732 people with electrical sensitivity found that 62% had problems driving or even riding in cars, due to the radiation. The survey took place in 2005, when cars had less electronics than today's models (EI Wellspring, 2019).
This author has met about two dozen people who were so sensitive to car radiation that they were unable, or barely able, to drive themselves. Many are more mildly affected. For a personal account of someone struggling with his car and how he was eventually able to drive a modified car, see the book listed at the end of this article (Evans, 2010).
Sources of radiation
Modern vehicles have a myriad of radiation sources, and more will be added in the future. Older vehicles, from before about 2005, had much fewer sources.
There are three general categories of radiation:
Š extremely low frequency
Š low frequency
Š radio frequency
Some people are sensitive to only certain frequencies, or certain categories of frequencies (as shown by an experiment by Dr. William Rea)(1991).
The radiation level varies dramatically with the model and year of the vehicle, as well as which body-part is measured (Milham, 1999; EI Wellspring, 2002; Halgamuge, 2010).
Instruments can be used to measure all these frequencies, but no instrument can show all of them. A gaussmeter (teslameter) is used to measure the extremely low frequencies. Professional gaussmeters can also measure the low frequencies, but such instruments are costly. A cheaper alternative is to use a simple AM radio. The radio frequencies are measured with an RF meter.
To measure a car, turn on the engine and use one instrument at a time. Move the instrument around everywhere a person would be, including the pedals, the seat, in front of the dashboard and where the head normally is. Try to press on the gas pedal so the engine revs up, which usually increases the radiation level on a gaussmeter.
Some radiation only happens when the car is moving. To measure this, get the help of someone else who slowly drives the car while you measure.
In the following we’ll list the various radiation sources. It is important to be aware of them when trying to lower the radiation or looking for a safer vehicle.
A major source of radiation in a car is the alternator, which generates electricity that charges the battery and powers everything in the car. The alternator produces 12 volt DC electricity in most vehicles (24 volt DC in large trucks). The DC electricity from an alternator is ďdirty,Ē i.e. it has a lot of ďspikesĒ or ďtransientsĒ in the flow of electricity. This makes the wires in the vehicle radiate, which can be very bothersome to sensitive people. Wires that carry a lot of electricity will radiate the most.
The "hot spots" are typically:
Š wire going to battery
Š wiring harness inside or below dash board
Š fuse box area
The radiation increases when the engine goes faster (revs up).
The radiation will be both “extremely low frequency” and “low frequency,” so you may need two instruments to measure it.
Some luxury cars have a backup battery in the trunk with a wire passing under the car, which can be a problem. We have seen this on Mercedes cars.
Headlights and tail lights can on older cars consume hundreds of watts. Newer cars with LED lights consume a lot less. The current feeding the lights will increase the radiation from the wires, fuse box, etc.
In some older cars the current is routed through the high-beam switch, which is located on the dash board or the steering column and close to the driver. They reradiate whenever the lights are on, regardless whether the high beam is used or not.
The fuel tank is always located in the back of the car. Most cars have an electric fuel pump in the tank. The pump motor, and the wire going to the pump, can be a problem. Some older cars have engine-driven fuel pumps that do not radiate.
There is usually an electric fan mounted on the front of the engine radiator. This fan comes on if the engine is overheating on steep mountain roads, or if idling on a hot day. A few cars have transverse mounted engines, which require such a fan to be on all the time. Electric engine fans can generate very powerful EMF; this author has measured 100 milligauss (10 uT) at the driver’s seat from such a fan.
There is usually a small ventilation fan mounted inside the dashboard. It is used when the air conditioning is on, or for ventilation. It is small, but can be a problem since it is so close to the front seat.
Some people with MCS install air cleaners powered from the cigarette outlet. The DC motors in these air cleaners often radiate powerful magnetic fields.
All normal tires have steel belts just below the tread. These steel belts usually become magnetized during manufacturing. When the wheels are turning, this magnetization will create low-frequency radiation (just as it does inside an alternator or a power plant generator).
Scientist Sam Milham measured this effect to expose passengers to 0.2 to 2.0 uT (2 to 20 milligauss) when a car was moving. He found most of the energy to be well below 30 Hz, which most gaussmeters cannot detect. He also determined that the radiation was largely the same regardless of the speed (Milham, 1999). Others have found cases with both higher and lower levels (Halgamuge, 2010; Stankowski, 2006).
Some cars have a magnet inside the transmission, or on every wheel, that generates pulses to measure the speed (see later).
Gasoline engines use spark plugs. Spark plugs ignite the fuel with little electrical sparks many times a second. The first radio transmitters a hundred years ago used the same principle, where they were called “spark gap transmitters.” The spark plugs are powered using an ignition coil, that also radiates.
If you hold an RF meter up against a gasoline engine that is running, it will “light up.” Fortunately, the metal hood and metal firewall will largely protect the people inside the car.
Diesel engines have no spark plugs and no ignition system. The fuel is ignited by compression instead. Older diesel engines operate completely without electricity, though modern engines use electronic controls, fuel injectors, etc.
Modern cars are loaded with electronics of many kinds, that all radiate. There can be more than a hundred microprocessors (tiny computers) throughout the vehicle.
All those electronics need their own voltages, so there are also many voltage converters (DC-DC converters) in a modern car. All of these generate “dirty electricity” as well.
In modern cars the fuel is vaporized using electronic fuel injectors (older cars used carburetors or mechanical fuel injectors).
Radio frequency radiation
Today’s vehicles routinely bathe the driver in radio frequency radiation above 100 uW/m2 and sometimes more than 1000 uW/m2, just from the built-in equipment. In addition, when people use mobile phones or other wireless gadgets inside a car, they will be exposed to much higher levels than if they used them outside the car. This is because the steel plates of the car reflect the radio waves that bounce around inside. And since the mobile phone has trouble reaching the base station, it will ramp up the signal strength, too.
Some cars have a built-in Wi-Fi “hot spot” that radiates whether it is used or not.
There may also be a built-in cellular transmitter for emergencies, such as the OnStar system, or to tell the owner of the car (i.e. rental company or fleet-owning corporation) where the car presently is.
Newer vehicles have ever more safety devices to prevent crashes. These include radars mounted on the front and back (hidden inside bumpers or behind plastic panels) and backup cameras. In the future there will also be V2V (vehicle-to-vehicle) transmitters where each vehicle wirelessly informs other vehicles about its position, speed and direction. These are expected to transmit ten times every second (Bigelow, 2016).
An RF meter is needed to measure all these RF sources, though since they transmit in brief pulses most meters will not be able to give an accurate reading. A work-around is to place the RF meter on a tripod and program it to record the MAX reading over several minutes.
The radar systems operate at frequencies higher than most RF meters can detect.
Older cars have a flexible speedometer cable that goes from the transmission up to the dashboard where it powers a mechanical speedometer and odometer. These are benign.
In the 1980s some manufacturers started to install a magnetic sensor in the transmission that generates electric pulses. The faster the car moves, the more pulses per second. These pulses are carried by electric cable to the dashboard, where electronics convert the pulses to be displayed by the speedometer and odometer.
The cables carrying these pulses radiate low-frequency magnetic radiation that can be measured by a gaussmeter and be a problem if passing near a sensitive person.
Some of the early electronic speedometers (such as used in the Mercedes 300SD) used a mechanical pulse-reader in the speedometer. Newer models use a computer to count the pulses and calculate the vehicle’s speed.
Anti-lock brakes and traction control
Cars with anti-lock brakes (ABS) have magnetic sensors on each wheel to detect when the wheel is not turning (i.e. locked when braking on an icy road). They work very similarly to the electronic speedometer described above and the cables radiate the same way.
Cars with anti-lock brakes usually use the pulses from one of the wheels to measure the speed as well. Cars with traction control use the pulses to detect when a wheel is spinning on an icy road.
With pulsing cables going from all four wheels, it may not be possible for a sensitive person to sit anywhere in such a car, including on the back seat.
The wireless key
All modern cars have a wireless ignition key of sorts. There are two basic types: the RFID key and the smart key.
The RFID key is the most common. It was invented by Ford Motor Company in 1997 and was soon adopted by most other manufacturers. The RFID key has a small chip embedded in the plastic handle. When turning the key in the ignition, a brief radio signal is sent out from the dashboard. The RFID key has a tiny antenna that harvests some of that radiation and uses it to power up the RFID chip, which then sends out a brief radio signal with a serial number. If the serial number is correct, the car will start. (If not correct, the car may still start, but will soon stall.)
This whole sequence takes less than a second, so the radiation exposure is brief and should rarely be a problem.
The technology is similar to those security gates at the exit of some stores to prevent theft.
To check whether a key has RFID, try to wrap the plastic handle in aluminum foil. It will block the wireless communication with the key so the car can’t be started (or it may run briefly).
The smart key system is much worse than the RFID key, as it radiates as long as the car is turned on. The smart key allows the car to be turned on without any key in the ignition at all. The driver just needs to keep the “key” in a pocket or purse. The car is started by pushing a start button on the dashboard; no turning of any key is needed. The system otherwise works like the RFID key, but since the smart key is much further away from the dashboard, the radiation has to be much stronger to power up the little key fob. Also, since the smart key is not in any keyhole, the car will have to keep checking wirelessly that the key is still present. Hence the continuous radiation as long as the engine is on.
We measured such a system in a 2016 Nissan Sentra. The radiation exposure to the head of the driver was about 1800 uW/m2 every ten seconds or so (and around 500 uW/m2 the rest of the time).
The smart key system also allows the doors to be unlocked automatically on some models. When the handle is pulled, an antenna on the side of the car transmits a brief signal to the smart key. The car then unlocks. This part of the system transmits just briefly and should not be a problem to people near the car.
Siemens and Mercedes-Benz developed the smart key system in the late 1990s. Other car manufacturers adopted similar systems later on. It is now commonly used by both American, European and Japanese manufacturers. Each manufacturer has a different name for it, usually including the words “smart,” “keyless” or “intelligent.”
It may be easiest to ask if a car is started by pushing a button, or if a key must be inserted and turned.
The details are kept secret to deter theft, but one source claims the cars transmit at 125 kHz, while the key fob responds at 300 MHz.
Some smart keys have a battery in the fob, while most are fully powered by the radio signal from the car.
The keys that allow you to unlock the car from a distance by pressing a button are not necessarily smart keys. The essential clue is that the car can be started without turning a key.
This system monitors the air pressure in the tires and warns the driver if needed. This is a safety feature, as incorrectly inflated tires can explode, the tread can fall off or it can affect steering and braking.
All cars sold in the United States had to have these systems by 2008. In Europe they became mandatory by 2012. Many manufacturers phased them in before these mandates, especially luxury brands. The Corvette sports car has had it since 1991. It is possible to buy upgrades to older vehicles.
There are three types of systems:
Š direct (wireless with battery)
Š direct (wireless with wireless power)
The indirect systems monitor the speed of each wheel and compare it to the other wheels. Since a change in the tire pressure will affect the circumference of the wheel, the speed of the wheel will change slightly. The speed of each wheel is usually measured by magnetic pulses, which can be a problem. These pulses are also used for anti-lock braking systems (ABS).
The direct systems monitor the air pressure directly in each tire and transmit the information wirelessly to a receiver someplace in the car. Most systems transmit only when the car is moving; a few transmit all the time.
Most direct systems are powered by a tiny battery built into the sensor, which is a part of the air valve. When the battery wears out, the entire sensor will have to be replaced.
A few direct systems use wireless power instead of batteries. Here, a coil (presumably next to each wheel) sends out a pulsing magnetic field that powers the sensor. This is similar to the RFID tags used to deter shoplifting.
Wirelessly powered sensors transmit much more frequently than the battery powered models, since saving electricity is not so important. One source states that these monitors typically transmit 40 times a second.
A car is a metal box and metal reflects EMF, especially radio waves. That means radiation from cellular towers has more difficulty entering the car. That also means that radiation from any transmitter inside the car will be “trapped” inside, and cause much higher radiation levels than if outside the car. It is thus very important to fully turn off mobile phones, tablets and any other wireless device.
Air filters and fans
DC electrical motors powering fans, air filters, etc., radiate low-frequency EMF. That includes the fans built into the dashboard and any air filters. The higher air flow the stronger the magnetic field. 12 volt DC is generally safer than AC electricity, except for the DC motors, which are worse than AC motors.
Wirelessly networked cars
Some vehicles have a built-in wireless network that connects the car with the internet through cellular base stations. It offers wireless Wi-Fi services to the passengers inside the car, while in the future it will also be used to keep track of where the car is, report emergencies, etc. Some industry analysts expect this to be standard on most car models by 2021.
Add-on radio frequency sources
A number of toll roads and bridges in Europe, the United States and elsewhere use an RFID type decal to register when passing the toll gate. The decal has no battery and is inert except when passing through a toll gate. Here it picks up radiation from a powerful transmitter, briefly powers up, sends out its serial number and then goes dormant again. That whole process takes less than a second and is so brief most sensitive people are not affected. This is similar to the anti-theft gates in some stores.
Some states and countries are considering taxes based on which roads are used and at what time of the day. This is called road-pricing. It should help reduce traffic congestion and replace the dwindling fuel taxes (due to electric cars). The problem is that it will likely require the installation of wireless equipment in each vehicle to report where the vehicle is at all times. (This technology also has some obvious privacy issues.)
Electric and hybrid vehicles
Hybrid vehicles are essentially electric vehicles with a gasoline-powered electric generator added on, so they can have a smaller battery. The following apply to both hybrid and full electric vehicles.
The wheels are powered by one or more electric motors. There is usually one electric motor under the hood, but there could be one electric motor mounted directly on two or all wheels.
There are various types of electric motors available. The ones used today are mostly AC motors running at around 12,000 rpm and powered by inverters and DC-DC converters. These systems will emit radiation mostly in the kilohertz range (i.e. not really measurable by a regular gaussmeter).
The motors act as generators when the brakes are applied, to send energy back to the battery instead of wasting it (called regenerative braking).
When the battery is charged (by plugging it in, using the onboard engine or when braking) the current is pulsed to improve charging. This pulsing creates powerful dirty electricity, also in the kilohertz range and thus underreported by a gaussmeter These pulses can backfeed onto the household wiring when charging the car at home. (For more on dirty electricity, see the link at the end of this article.)
The battery is usually placed under the seats or in the trunk, meaning there is no "safer" place to sit anywhere.
The radiation environment in a hybrid or all-electric vehicle is very different from a regular gasoline or diesel vehicle. It is difficult to correctly measure and compare with a regular vehicle.
The author once inspected a Toyota Prius hybrid car and had just a low-cost gaussmeter available. The gaussmeter gave an unremarkable reading when the car was sitting with the engine idling (charging). A brief test drive produced some profound symptoms, unlike any regular car. The author was unable to do any measurements while driving.
Electric and hybrid cars have so many problems that they should simply be avoided by sensitive people.
It will be many years before truly self-driving cars will be available, i.e. cars where no human needs to sit behind the wheel and be ready to take over in special situations. Once that actually happens, a sensitive person might be comfortable sitting on the back seat, further away from the drive train and electronics up front, but that is quite unlikely. The automated cars will employ numerous radiant technologies, including radars and wireless communication with other vehicles. It is also likely that they will use electric motors by then.
Motorcycles expose the driver to higher radiation levels than most cars. The engine is located close to the driver and there is no metal hood or firewall to shield the radio-frequency radiation from the spark plugs. The alternator or magneto is also very close to the driver.
The scooters and mini-motorcycles popular in Europe are built similarly and probably not any better.
Other types of vehicles
There are a number of small gasoline-powered specialty vehicles available. These generally have four wheels and are not enclosed against the weather. They are popular with off-road enthusiasts, golfers and people in retirement communities.
These vehicles typically have the engine mounted under the seats or right behind them. The distance to the driver is very short and there may not be any metal in between to shield the spark plug radiation.
What to do if you don’t tolerate your car
The options to consider are basically:
Š Turn off unneeded devices
Š Find a lower-EMF vehicle
Š Sit elsewhere in vehicle
Š Degauss tires
Š Modify vehicle
Š Use no vehicle
People have done all of the above, depending on their situation. Severely sensitive people may be able to tolerate a not-too-bad vehicle if they sit in the back seat (opposite side of the fuel pump).
Modifying an existing vehicle can provide only limited relief, especially with newer vehicles. Some people simply have to drive vehicles from the 1990s or even the 1980s. Even such older cars may need to be modified.
See the “More information” section below for more information on these options.
It may be possible to make the sensitive person better able to tolerate the car. Many electrically sensitive people are also sensitive to sunlight and noise. Try to experiment driving in the morning before sunrise, but with enough light that headlights are not needed. Also try to wear heavy-duty ear protectors like those used by heavy machinery operators.
Wearing shielded clothing may help with the radio-frequency radiation in newer cars, but not with the lower frequency radiation.
Will the old low-EMF cars be banned?
No government anywhere has ever banned any kind of vehicle before. The oldest cars are still street legal, even those produced without seat belts or any other safety features. They are all grandfathered in. This is likely to continue.
Even though some governments have announced that new non-electrical cars will not be legal to sell by a certain year, the existing cars will continue to be legal. However, some large cities are considering banning non-electric vehicles from their centers to control air pollution.
Cars kill about 30,000 people every year in the United States. The automated cars that can talk to other automated cars wirelessly should dramatically reduce the number of accidents. Cars that do not have the wireless transponders and have a human in control will be much less safe to have on the road. Governments may offer various incentives to get them off the road, just as they have done to get old polluting cars retired (such as the “cash for clunkers” program in the United States). Insurance companies will surely penalize drivers of the old “unsafe” cars by demanding higher insurance rates.
But there are too many people who’ll want to continue to use the old cars. Old cars are much cheaper to buy than newer vehicles, and they are also cheaper to repair, as they do not require a specialized high-tech repair shop. People in rural areas may have no access to ride-sharing so they must have their own vehicles.
Then there are all the car enthusiasts who just love the old cars, especially once the drivers of new cars will no longer be in control of the wheel. Car enthusiasts will surely fight any law limiting their driving pleasures.
Do cars radiate more at higher speeds?
There is not enough data to answer this question. It does not appear that radiation from the tires increases at higher speeds (Milham, 1999), though the wiring does radiate more when the engine turns faster (EI Wellspring, 2002).
We have not seen data on other sources, such as anti-lock brake sensors.
A few countries require all cars to have their headlights on during the day, to improve their visibility. Since headlights use a lot of electricity, that makes it difficult to comply for some sensitive people. In Sweden people with electrical sensitivities are exempt from the always-on law.
In the future, some countries may mandate that all vehicles have a V2V transmitter sending out the car’s position, direction and speed to aid self-driving cars. Insurance companies may exact heavy penalties on drivers without such a transmitter.
People with EHS may get exempted from such a law, but may not avoid the insurance companies’ penalty. If the insurance company allows anyone to opt-out, then a court may not consider the penalty discriminatory.
See www.eiwellspring.org/vehicle.html for articles about mitigating the radiation in a car or finding a lower-EMF vehicle.
For information about dirty electricity and its health effects, go to www.eiwellspring.org/demenu.html.
The book Chemical and Electrical Hypersensitivity: A Sufferer’s Memoir by Jerry Evans (McFarland, 2010) contains a chapter about one person’s battle with his car and how he ultimately succeeded.
Bigelow, Pete. Feds want V2V communication in new cars starting 2021. Car and Driver, December 15, 2016 .
EI Wellspring, 2002. EMF measurements of older cars and trucks, www.eiwellspring.org, 2002.
EI Wellspring, 2019. Survey of people with electrical sensitivities in Sweden, www.eiwellspring.org, 2019. (Summary of Swedish language report.)
Evans, Jerry. Chemical and Electrical Hypersensitivity: a sufferer's memoir, USA: McFarland, 2010.
Granlund-Lind, Rigmor and John Lind. Black on White: voices and witnesses about electro-hypersensitivity, Sweden: Mimers Brunn, 2004.
Halgamuge, Malka et al. Measurement and analysis of electromagnetic fields from trans, trains and hybrid cars, Radiation Protection Dosimetry, 141, 225-268, 2010.
Milham, Samuel et al. Magnetic fields from steel-belted radial tires: implications for epidemiological studies, Bioelectromagnetics 20, 440-445, 1999.
Rea, William et al. Electromagnetic field sensitivity, Journal of Bioelectricity 10 (1 & 2), 241-256, 1991.
Stankowski, S. et al. Low frequency magnetic fields induced by car tire magnetization, Health Physics 90, 148-153, February 2006.