A French government agency has warned that measures should be taken to reduce everyday exposure to radio signals, even though, it said, there is no definitive proof that such signals have a negative effect on human health.
The French Agency for Environmental and Occupational Health Safety conducted a review of around 3,500 studies and publications.
Around 10 studies indisputably demonstrate that radio signals have an effect on the activity of cells, the agency said, but only one mechanism has so far been identified by which the signals affect cells: the heating effect due to the very high signal levels typically only found close by transmitters.
The agency suggested a number of measures to cut exposure in its report "An updated expert evaluation relating to radio frequencies" published (in French) on Thursday.
Among the measures recommended, it called on authorities to identify the areas of the country subjected to the strongest radio signals, and take efforts to reduce them. However, it also warned city authorities not to introduce local regulations limiting the power of transmitters for mobile phone networks, which might lead to an increase in the number of transmitters, with as-yet unknown consequences.
It also encouraged phone companies and ISPs to supply cordless phones based on the latest low power technologies and to supply DSL routers with multiple Ethernet jacks and an easily accessible physical on/off switch for the Wi-Fi interface.
Consumers should also be given more information about the specific absorption rate (SAR) of all devices emitting radio signals. SAR is a measure of the heating effect of the signals on human tissue, and is already published for most mobile phones, allowing consumers to choose a model with a lower SAR if they are concerned about the effect of radio signals.
The agency recognised that some people undeniably experience pain and other symptoms that those people attribute to their hypersensitivity to radio signals, but said there is no proof that radio signals are indeed the cause of the pain.
French businesses are cashing in on fears about the health effects of radio waves, with health food stores selling all manner of sprays and self-adhesive patches that supposedly protect their wearers from radio signals. However, the agency said, "The effectiveness of these products has not been proven."
Legislators are already taking action to limit the exposure of those they believe most vulnerable to the radio signals. The French Senate last week approved a bill forbidding schoolchildren from using mobile phones in the classroom in primary and middle schools. The bill also requires the approval of the National Assembly before it can become law, but it has not yet been scheduled for debate there.