A necessary adaptation of standards to developments in mobile phones
The SAR, or Specific Absorption Rate, is the indicator used to assess the amount of energy absorbed by the body exposed to radio frequency electromagnetic waves. The regulatory SAR limit value in France is set at 2 W/kg, whether the phone is placed on the head or trunk.
Before they are placed on the market, the compliance of telephones with this SAR limit value is checked by laboratory measurements. Until 2016, the regulations provided that, when carrying out this SAR measurement, manufacturers might choose the separation distance between the device and the body, between 0 and 25 mm. The majority of phones released were compliant for use at a distance of 15mm.
However, the development of technologies and the use of mobile phones, often worn very close to the trunk, such as in a jacket, has led the National Frequency Agency (ANFR) to carry out SAR measurements under conditions more realistic to use. Tests on nearly 300 phones positioned close to the trunk, in contact and 5 mm apart, were thus carried out between 2012 and 2016. The results revealed that a large proportion of the phones tested had SAR values greater than the value of 2 W/kg, some exceeding 7 W/kg on contact.
Since 2016, a new European directive, known as “RED”, requires measuring the SAR by positioning the mobile phone at a maximum of 5 mm from the trunk, corresponding to “foreseeable” conditions of use. However, telephones complying with the previous regulations, but presenting high SAR values when they are placed close to the body, are still placed on the market. Moreover, many of these phones are still in use.
Health effects related to high exposures
Given the high “trunk SAR” values noted by the ANFR for a large number of telephones, ANSES was asked to identify any biological or health effects related specifically to exposure to SARs greater than 2 W/kg. To do this, ANSES examined recent studies on the possible effects associated with such levels of exposure. The publications analyzed in previous ANSES expert appraisals on the risks associated with radio frequencies were also taken into account.
The data available in the literature relate exclusively to experimental studies carried out in animals or in cell cultures. The methodology for assessing the level of evidence was therefore adapted, in the absence of studies in humans. The results of the expert appraisal show, with limited evidence, biological effects on cerebral activity linked to exposures greater than 2 W/kg, but do not make it possible to conclude on the existence or not of effects on other biological functions specifically associated with such trunk exposures.
The Agency also stresses that, within the framework of the SAR measurements carried out for the ANFR, the emissions of electromagnetic radiation from mobile phones correspond to a “worst case” type situation, for which the device emits at maximum power for the entire duration of the test, which does not happen first not in real conditions.
Reduce high exposures associated with the use of phones close to the body
In view of, on the one hand, the potentially high exposures when the telephones are placed very close to the body and, on the other hand, the uncertainties which remain on the possible long-term health effects in connection with the waves emitted by the telephones, the ‘ANSES recommends that measures be taken so that users are no longer exposed to SAR above 2 W/kg (for example through updates of telephone software, recall of telephones).
The Agency also recommends changing the normative provisions so that the conformity verification measurements of the “trunk SAR” of mobile telephones are carried out in contact with the body.
In the meantime, the Agency invites users of these telephones, when they are worn close to the body, to comply with the terms of use, in particular the separation distances mentioned in the instructions for the telephones.