Nonostante che nel 2001 WHO tramite IARC ha sentenziato i campi elettromagnetici ad estreme basse frequenze siano possibili cancerogeni, nella progettazione delle auto ibride, dove chiaramente la propulsione è elettrica e quindi una presenza massiccia di batterie e sistemi di ricarica , non si è tenuto conto del campo magnetico che l'autista subisce.
Si propongono delle linee guida nella progettazione di tali auto, ma sono rigettate tirando il ballo i soliti valori (alti) dell'ICNIRP.
Hybrid and Electric Automobiles Should Be Re-Designed to Reduce Electromagnetic Radiation Risks (rev.)
Hybrid and electric cars may be cancer-causing as they emit extremely low frequency (ELF) electromagnetic radiation (EMR) or magnetic fields. Recent studies of the levels of EMR emitted by these automobiles have claimed either that they pose a cancer risk for the vehicles’ occupants or they are safe.
Unfortunately, the little research conducted on this issue has been industry-funded by companies with vested interests on one side of the issue or the other which makes it difficult to know which studies are trustworthy.
Meanwhile, numerous peer-reviewed laboratory studies conducted over several decades have found biologic effects from very limited exposures to ELF EMR. These studies suggest that the EMR guidelines established by the self-appointed, International Commission on Non-Ionizing Radiation Protection (ICNIRP) are inadequate to protect our health. Thus, even if EMR measurements do not exceed the ICNIRP guidelines, occupants of hybrid and electric automobiles may 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 EMR. 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.
In January of this year, SINTEF, the largest independent research organization in Scandinavia, 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.
The public should demand that governments adequately fund high-quality 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 several news articles on this topic.
Design guidelines to reduce the magnetic field in electric vehicles
SINTEF, Jan 6, 2014
Based on the measurements and on extensive simulation work 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.
Magnetic Fields in Electric Cars Won’t Kill You
Jeremy Hsu, IEEE Spectrum, May 5, 2014
“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.”
Mythbuster: EMF levels in hybrids
Consumer Reports News: August 4, 2010
“Some concern has been raised about the possible health 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
“We found the highest EMF levels in the Chevrolet Cobalt, a conventional non-hybrid small sedan.”
[The peak EMF readings at the driver’s feet ranged from 0.5 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.
“To get a sense of scale, though, note that users of 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.”
“In this series of tests, we found no evidence that hybrids expose drivers to significantly more EMF than do conventional cars. Consider this myth, busted.”
Israel Preps World’s First Hybrid Car Radiation Scale
Tal Bronfer, the truth about cars, March 1, 2010
“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.”
Fear, but Few Facts, on Hybrid Risk
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.”