We bring you this article in partnership with Mathieu Vidard's daily science outreach programme on France Inter, "La Tête au carré". Joe Wiart, the author, will be on the programme on April 28, 2017 to discuss his research with Aline Richard, science and technology editor for The Conversation France.
For over ten years now, controlling our exposure to electromagnetic waves and radio frequencies in particular has been the subject of intense debate. A quick look at the scientific reports and publications on the subject shows that what researchers are mainly interested in is the possible impact of mobile phones on our health. At the same time, if we are to believe the press, the public is essentially concerned with cell towers. The fact remains that mobile phones and wireless communication systems in general are used en masse, and have completely transformed how we communicate and work all over the world.
The number of mobile phone users around the globe now exceeds five billion. According to an INSEE survey, the ownership rate for the 18-to-25 age group in France is... 100 percent! It must be said this means of communication is no longer used simply for voice calls; far from it. By 2020, global mobile data traffic is expected to be four times the 2005 volume of Internet traffic. Last year in France, according to the communications regulation authority (ARCEP), more than seven percent of the population only connected to the Internet on a smartphone. And as the use of connected objects soars, this trend looks set to continue.
The fact that the risks associated with radiation from cell phones and from cell towers are perceived differently is partly explicable. The risks are not seen as related and while exposure to electromagnetic radiation from mobiles is considered “voluntary”, it is often thought of as “involuntary” for cell towers. That is why, despite the unchecked enthusiasm for mobiles and connected objects, the deployment of cell towers is still hotly debated, with the controversy usually focused on health impacts.
In practice, national standards that limit exposure to electromagnetic waves are based on the recommendations of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) and scientific knowledge. Many studies have been conducted on the potential effects of electromagnetic radiation on our health. Of course, this research is ongoing, as wireless technologies and their uses are constantly changing. In addition, the radio frequencies used by mobile phones have been classified as “possibly carcinogenic to humans” (group 2B), following the expert assessment organized by the International Agency for Research on Cancer.
Given the large and growing number of young mobile and smartphones users, such vigilance is essential. In France, the National Agency for Food, Environmental and Occupational Safety (ANSES) maintains a close watch through the national environment, health and labor research program (PNREST). To address the public's concerns about cell towers (of which there are more than fifty thousand in France), many municipalities have discussed charters to govern their installation. The Paris City Council signed such a charter in 2003, wanting to set the example for France and the big cities of Europe; the idea was to officially limit exposure to radiation from cell towers through an agreement with the three major operators.
The charter was updated in 2012 and discussed again at the Paris City Council last March. In the same spirit, the Abeille Act proposed to the National Assembly in 2013 and promulgated in February 2015 brings the goal of limiting exposure to electromagnetic fields to the fore. The trouble is that this initiative, like many others, focuses only on cell towers, whereas exposure to electromagnetic waves and radio frequencies has many other sources. By focusing on the towers, we're only dealing with part of the problem. At the very least, we also should be taking into account the exposure from users’ own cell phones or their neighbor’s...
In practice, the electromagnetic radiation from cell towers as a proportion of total exposure is far from preponderant. As several studies have shown, exposure from cell phones is much more significant. Fortunately, rollout of 4G—and later 5G—networks will not only improve data speeds but also help greatly reduce the power emitted by cell phones. A network architecture based on small cells, with small antennas to complement the larger ones, would also limit the radiation emitted. Solutions for low exposure to radio frequencies must be considered at different levels, from radio devices and network architecture to service management and delivery. The partners of the European project LEXNET have been doing just that since 2012, with the goal of halving the public's exposure to the electromagnetic fields of radio frequencies.
In the near future, fifth generation networks will utilize a number of frequency bands and varied architectures dynamically, which should enable them to support rising data rates and the proliferation of connected objects. De facto, it will then be necessary to consider networks and devices as two sides of the same coin, instead of treating them separately. This new paradigm has become an essential focus for researchers, industrialists and public authorities alike. And from this point of view, the latest discussions about installing cell towers and renewing the Paris Council charter are proving symbolic.
Joe Wiart, holder of the C2M Chair at Institut Mines Telecom, Télécom ParisTech – Institut Mines-Télécom, Université Paris-Saclay