Dr. Weeks’ Comment: Six years ago, i sponsored a series of public health lectures by leading electrical pollution scientist Dave Stetzer here on Whidbey Island. After the workshops and lectures on electrical pollution, many people sold their hybrid cars. Now almost a decade later, the science is stronger and they are pleased that they took action. What was it again that paves the road to hell? Good (but uninformed) intentions.
Hybrid and Electric Automobiles Should Be Re-Designed to Reduce Electromagnetic Radiation Risks (rev.)
Wed July 2nd 2014
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.
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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.
Cables
- 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.
Motors
- 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.
Batteries
- 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.
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