Study finds radiation levels in electric cars to be harmless

This is shown by extensive measurements and computer simulations commissioned by the German Federal Office for Radiation Protection (BfS) and the German Federal Ministry for the Environment (BMUV). Regardless of the type of drive, all 14 vehicles analysed fell below the usual threshold, which certifies that they have a harmless level of radiation. For the study, the magnetic fields at the seats of eleven purely electrically powered cars, two hybrid vehicles and one combustion engine from the 2019 to 2021 model years were measured and evaluated in different operating states. The BfS has now published the detailed results under the title “Determination of exposures to electromagnetic fields of electromobility. Results report – Part 1.”

“Comparatively strong magnetic fields were detected in some cases – locally and for a limited time. However, the recommended maximum values for fields induced in the body were complied with in the scenarios investigated, so that according to current scientific knowledge no health-relevant effects are to be expected,” emphasises BfS President Inge Paulini. “The study results are good news for consumers who already drive an electric car or are thinking about switching.”

The study was carried out by a project team consisting of employees from Seibersdorf Labor GmbH, the Research Centre for Electromagnetic Environmental Compatibility at RWTH Aachen University and the ADAC Technology Centre. Vehicle manufacturers were not involved in the study.

A bit of background to the topic: Magnetic fields always occur when electric currents flow. There are therefore many sources of magnetic fields in modern vehicles. These include, for example, air conditioning systems, fans, electric windows and seat heaters. In the case of electric vehicles, a larger and more powerful battery, the high-voltage cabling and the inverter for the drive current as well as the electric drive itself are the main sources. The study analysed all the magnetic fields occurring in the cars and, where possible, assigned them to the respective cause.

According to the study organisers, the measurements and simulations showed that the recommended maximum values for fields generated in the body were adhered to in all recorded scenarios. “However, a differentiated picture emerged in detail: the measured magnetic field values varied significantly between the vehicles analysed, spatially within the individual vehicles and depending on the operating status. For example, the strongest magnetic fields occurred primarily in the foot area in front of the seats, while the magnetic fields in the head and torso area were mostly low,” the project team explains.

Incidentally, there was no clear correlation between the motorisation and the magnetic fields in the interior of the electric vehicles. According to the analysts, the driving style has a greater influence than the power of the motor: “A sporty driving style with strong acceleration and braking briefly produced significantly stronger magnetic fields than a moderate driving style.”

Short-term peak values, “lasting less than one second,” occurred, among other things, when the brake pedal was pressed, when engine components were switched on automatically and – regardless of the drive type – when the vehicles were switched on. The highest single local value was determined when switching on a hybrid vehicle, according to the participants.

“The large differences between the vehicle models show that magnetic fields in electric cars do not have to be excessively strong or even more pronounced than in conventional cars,” emphasised Paulini. “The manufacturers have it in their hands to reduce local peak values and keep average values low with an intelligent vehicle design. For example, the better it is possible to install strong magnetic field sources at a distance from the vehicle occupants, the lower the fields to which the occupants are exposed in the various driving conditions. Such technical possibilities should be considered from the outset when developing vehicles.”

According to the BfS, the study represents the most comprehensive and detailed investigation to date into the occurrence of magnetic fields in electric vehicles. The data collected is based on systematic field strength measurements in vehicles on roller test benches, on a cordoned-off test track and in real road traffic. With an electric scooter, two light motorbikes and an electric motorbike, electric two-wheelers were also included for the first time. As with cars, the strongest magnetic fields occurred in the area of the feet and lower legs. However, the maximum values recommended for health protection were also complied with for two-wheelers in all the scenarios analysed.

According to the BfS, however, there is still a need for action: The background to this is that although the present study was able to reliably record and evaluate even short-term magnetic field peaks lasting less than 0.2 seconds thanks to sophisticated measurement technology, the currently valid measurement regulations disregard such short-term fluctuations. “However, the investigation showed that they occur to a relevant extent. The BfS therefore believes that the measurement standards should be extended accordingly.”

bfs.de (study), nbn-resolving.org, bfs.de (all in German)