Exposure to mobile telephones carried close to the body
Testing of exposure to waves emitted by mobile telephones was modified in 2016 to take changes in models and uses into account. Since then, manufacturers have been required to assess exposure under realistic conditions of use, i.e. when the telephone is placed very close to the body, at a maximum distance of 5 mm. However, many telephones complying with the earlier regulations, and still in use, generate high levels of exposure when placed close to the body. ANSES was therefore asked to assess the possible health effects associated with these exposure conditions. Following its expert appraisal, ANSES recommends that measures be taken to ensure that users are no longer subject to high levels of exposure when telephones are carried close to the body.
A need to adapt standards to take changes in mobile telephones into account
The SAR, or specific absorption rate, is the indicator used to assess the amount of energy absorbed by the body when exposed to radiofrequency electromagnetic waves. The regulatory SAR limit value in France is set at 2 W/kg, whether the telephone is placed near the head or trunk.
Before telephones can be placed on the market, laboratory measurements are taken to ensure that they comply with this SAR limit value. Until 2016, the regulations stipulated that when taking this SAR measurement, manufacturers could choose the distance between the device and the body, which was between 0 and 25 mm. Most telephones placed on the market were compliant for use at a distance of 15 mm.
However, changes in mobile phone technologies and uses – they are now often carried very close to the trunk, for example in a jacket pocket – led the French Radio Frequency Authority (ANFR) to carry out SAR measurements under more realistic conditions of use. Tests on nearly 300 telephones positioned near the trunk, in contact with the body or at a distance of 5 mm, were carried out between 2012 and 2016. The results show that a large proportion of the telephones tested had SAR values above 2 W/kg, some exceeding 7 W/kg in contact with the body.
Since 2016, a new European directive, known as the "RED", has required the SAR to be measured by positioning the mobile telephone no more than 5 mm from the trunk, corresponding to "foreseeable" conditions of use. However, telephones that comply with the earlier regulations, but have high SAR values when placed close to the body, are still on the market, and many of these telephones are still in use.
Health effects associated with high exposure
In view of the high "trunk SAR" values recorded by the ANFR for many telephones, ANSES was asked to identify any possible biological or health effects specifically related to SAR exposure above 2 W/kg. To do this, ANSES examined recent studies on the possible effects associated with such exposure levels. Publications analysed for previous ANSES expert appraisals on the risks associated with radiofrequencies were also taken into account.
The data available in the literature relate exclusively to experimental studies conducted on animals or cell cultures. In the absence of any human studies, therefore, the methodology for assessing the level of evidence was adapted. The results of the expert appraisal showed, with limited evidence, biological effects on brain activity associated with exposure above 2 W/kg. However, it was not possible to conclude whether or not such trunk exposure was specifically associated with effects on other biological functions.
The Agency also emphasised that, in the context of the SAR measurements carried out for the ANFR, the electromagnetic radiation emissions from mobile telephones corresponded to a "worst case" situation, in which the device was emitting at maximum power throughout the test. In principle, this is not the case under real conditions or use.
Reduce high exposure associated with the use of telephones close to the body
In view of the potentially high levels of exposure when telephones are placed very close to the body and the continuing uncertainty about possible long-term health effects related to the waves emitted by telephones, ANSES recommends that measures be taken to ensure that users are no longer exposed to SARs above 2 W/kg (e.g. through telephone software updates, or telephone recalls).
The Agency also recommends modifying the normative provisions to ensure that measurements to verify "trunk SAR" compliance are carried out with the mobile telephones in contact with the body.