Throughout virtually the whole of the 20thcentury, very few questions were raised as to the effects on health of electromagnetic fields (EM), with the exception of waves generated by radioactive material. However, 30 years ago the tone began to change, and questions started to be asked about protection against non-ionising radiation. But what protection should we take when, to date, scientists acknowledge that no consistent and convincing evidence has been found of possible damage to human health, despite the many technologies contributing to the electromagnetic smog that surrounds us? Yet these same scientists also point out that the data available, in terms of in vitro research, epidemiology and exposure readings, are incomplete and insufficient to draw a conclusive verdict.
“Rays”, although potentially dangerous and kept under a close watch, have enabledscinece to make tremendous progress in updating anomalies and diseases. Todaythey are used daily for dignosis, one of the most advanced methods being magnetic resonance imaging.
Transported through conducting cables, electricity is an invisible but very tangible reality: the light comes on, motors start up, the hotplate heats up, the refrigerator cools, the TV screen flickers to life, the telephone rings … and the electric shock creates instant pain in whoever is clumsy enough to touch exposed wires!
At the same time, all these currents – inseparable from the oscillating electric field in which they originate – have a hidden component, one that is external to the conductors themselves and that we cannot feel. This leads to the creation of magnetic fields with the property of inducing, at a distance, the polarisation of the electrical charges present in their near environment.
Since the pioneering times of the late 19th century when this dual reality was demonstrated by physicist Maxwell – the founding father of the theory of electricity – this fundamental conjunction of the electric field, which is necessary for a current to travel, and the magnetic field created when it does travel, has been combined in the unique concept of electromagnetism.
Common and universal spectrum This key concept of electromagnetism relates to the transport of energy, whether in the concrete matter of a conductor or in immaterial space. As well as opening the door to an impressive increase in man’s mastery of electrical applications, this also became one of the most fertile fields for modern physics.
It made it possible to realise that the entire Universe is the site of an incredible variety of modes for the propagation of oscillating electromagnetic waves – waves that can be read in a vast spectrum of frequencies ranging from zero (continuous or unidirectional current) to 1020 hertz.(1)
This common and universal grid of the vibratory phenomena of the atomic or sub-atomic world includes, in the very highest frequencies, cosmic radiation, radioactivity (with gamma rays and X-rays), the characteristics of visible light and the colours of which it is composed, plus the vast zones of infrared and ultraviolet frequencies that lie below and above it in the spectrum.
Within this continuous spectrum, it is at the very bottom of the scale that we find the frequencies of the electrical and electronic applications invented by man. Nevertheless, these have progressively climbed the scale of oscillations for increasingly diverse ends.
On a vast logarithmic frequency scale, the electromagnetic spectrum includes the primordial phenomena of the Universe (cosmic rays, radioactivity, light) as well as the man-made phenomena of electrical civilisation and telecommunications.
The precedent of radioactivity As they propagate, by their very nature electromagnetic waves have an electrical influence on the atoms that compose the objects they encounter, whether inanimate or living. Man became aware of this in the first half of the 20th century when pioneering researchers were fascinated, often to their own detriment, by the properties of radioactivity, unaware of its potentially damaging biological effect. In this area of the electromagnetic spectrum, the power of penetration causes breaks in the atomic bonds, producing ions. At the biological level, this is expressed in major changes to DNA. This group of electromagnetic waves, which is closely monitored, became known as ‘ionising radiation’.
Even though the power of this radiation could prove fatal, it also interested science for the formidable services it could render. During the First World War, Marie Curie devoted all her energies to demonstrating that X-rays could provide an unprecedented way of ‘seeing’ the bone fractures of the men wounded in the trenches. She herself was ultimately a victim of the radiation to which her research had exposed her throughout her life.
In the 1950s, with the development of the nuclear industry and the growing introduction of radioactive applications in medicine and other fields, a whole science of ‘radiological protection’ grew up to study the effects of ionising radiation, to develop the most effective methods of protection and to define the exposure limits – while at the same time exploiting the benefits of this unique form of energy to the maximum. Set up in 1965, the International Society for Radiological Protection (ISRP) began to play a role as a global forum for comparing and disseminating knowledge and updating the safety standards for this very distinctive family of ionising rays.
The last two decades have seen an explosion in the most diverse electromagnetic fields.
Ten years later, scientists at the ISRP began asking the question as to whether concerns about radiological protection should be extended to other areas of the electromagnetic spectrum that were being used increasingly by new technologies – from the very low 50 hertz frequencies of traditional electricity networks to the increasingly broad radio frequencies, and up to the boundaries of the microwaves and infra-red zones. There is in fact a direct link between the wave frequency and the energy transported – and thus the potential impact on matter.
In 1977, in co-operation with the World Health Organisation (WHO) and the United Nations Environment Programme (UNEP), the ISRP set up the first International Committee for Non-Ionising Radiation to study and define the health criteria to be applied in these very extensive fields. In 1992, this Committee broke from the ISRP to become the International Commission for Non-Ionising Radiation Protection (ICNIRP), an independent scientific body charged with worldwide coordination on these issues. This field of research, which had been neglected for too long, thus began to take shape, but on the basis of very limited knowledge.
An all-electric society The protection mission entrusted to this newly created organisation would appear to have been of staggering – and unnecessary – proportions. In our ‘all-electric’ society, it is difficult to imagine concern – and there is no evidence on which to base it – about the countless very-low-frequency electromagnetic fields generated by the many devices we use in our everyday domestic and working lives and the cables that supply them. There is a general consensus that these fields are not in any way harmful as the magnetic induction levels have a limited range and must respect standards that are set at a very low level.
However, the influence of these fields becomes much more extensive and intensive when the currents reach high values, bringing the need for more specific standards. This is the case, for example, for certain very-high-voltage industrial applications or network nerve centres such as power stations, transformation stations and high-voltage power lines. The latter have, in fact, been the subject of debate regarding their possible health effects – effects that recent research would tend to confirm (see box).
Another key field is linked to the development of telecommunications. Here, too, exploitation of the transmission capacities of electromagnetic waves is not new. During the first half of the 20th century, our ability to use these hertz waves, in the range of 300 KHz to 300 GHz, gave rise to radio broadcasting and then to television.
Over the years, these remote ‘wireless’ transmissions continued to develop, using increasingly high so-called ‘radio frequencies’ and giving birth, during World War Two, to radar. Finally, over the past two decades, there has been a veritable explosion in the most diverse electromagnetic signals. With the advent of remote controls, WiFi and BlueTooth, these signals have invaded our space, both in the home and at work. We are being bombarded continually by satellite beams while in shops and airports, for example, we have to pass through a growing number of security points – anti-theft, luggage inspection, etc. – that use pulsed EM beams.
The mobile phone issue However, it is without doubt the mobile phone and its phenomenal success that represents the pinnacle of innovation in this field. A major social phenomenon of our age, it is a means of communication used by all ages – including the very young – and all social categories. As there is nothing exceptional about the intensities and frequencies used, given the electromagnetic environment we already inhabit, initially this new technology did not raise any new questions.
There were, however, two exceptions. The first relates to the transmitting infrastructure that had to be quickly put into place to serve this technology – and increasingly often at the heart of our urban fabric. At first, this was the issue that aroused most of the complaints and concerns. However, to date, the balance of the scientific evidence indicates that there is no general risk to the health due to radiofrequency and microwave exposure (that is the working frequencies of the radio masts) when the exposure is below ICNIRP guidelines. In short, although they add to the already large number of such EM sources in our environment, they do not in themselves constitute a major aggravating factor.
The second question is that of the use of the mobile phone itself. They are devices that are pressed up close to the ear and thus in close proximity to the human brain. This is new and as such raises a new problem for scientists.
In the space of a few years, the exposure to magnetic fields in our everyday lives has increased to the extent that it has become an issue of priority concern. Therefore, a number of European Commission supported research projects have been launched in this field, enquiring in particular into the auditory system, cellular biology and epidemiology (see other articles). In 2004, the EU created the EMF-NET (Electromagnetic Fields Network), a scientific coordination network dedicated to mobile telephony and other technologies with an electromagnetic incidence. EMF-Net aims to harness the various scientific results in this field and to provide an interpretation that is as reliable as it is independent (see box).
(1) A hertz (named after the German physicist who was a contemporary of Maxwell) is equivalent to one wave oscillation per second. On an inverted scale, values are also expressed in wavelengths (such as the ‘microwave’ category) that express the distance the wave travels during an oscillation cycle.
In the very low frequency of 50 hertz – the usual standard for electrical appliances throughout Europe – any EM generation has always been seen as posing no danger to the population. We are used to living under the vast network of high-voltage lines that criss-cross our countries, with ...
Knowledge control tower
Launched in 2004, the mission of the new European EMF-NET (Electromagnetic Fields Network) is to coordinate, evaluate and interpret the growing volume of research results on the potential impact on health of non-ionising magnetic fields, especially in connection with mobile telephone use. Participants ...
GSM (Global System for Mobile communication)
These three initials, which entered the language nearly 20 years ago, are emblematic of a long and sustained success story on the part of the EU. It is a success rooted in a commitment to constructive and close co-operation between technology companies in the telephony and electronics sectors (established ...
In the very low frequency of 50 hertz – the usual standard for electrical appliances throughout Europe – any EM generation has always been seen as posing no danger to the population. We are used to living under the vast network of high-voltage lines that criss-cross our countries, with particular concentrations at the exit of power stations and on the outskirts of major urban areas. Although voices have sometimes been raised to question the presumed innocuousness of the powerful magnetic fields, in the absence of any in-depth studies these concerns have not been acted upon. Over the past decade or so, experts have nevertheless looked at a possible link between leukaemia in children born and living for long periods in close proximity to these high-voltage lines. Incomplete data suggest a possible increase in cases, and it has been acknowledged that if the pattern is confirmed it would indicate ‘more than just chance’.
In June this year, the British Medical Journal published the results of much more in-depth research carried out by a team from Oxford University. They embarked on a vast epidemiological study comparing some 9 700 recorded cases of leukaemia in children aged under 15 in Great Britain with the grid map of very-high-voltage lines and the 22 000 associated pylons. They found a 70% increased risk of leukaemia in children living less than 200 metres from these lines. Cautious of creating alarm, the authors added that, even if a relationship of cause and effect could be deduced from this, it would still represent less than 1% of child leukaemia cases in the country. The nature of the relationship must also be set against the fact that the global study of leukaemia cases generally shows the cause of the disease to be changes in DNA prior to birth or any later environmental factors, such as pronounced exposure to ionising radiation. The increased risk indicated by the British study is therefore only of relative value, if not set against these predominant factors. Nevertheless, in future, it seems that stricter national norms are to be adopted for acceptable distances when siting these high-voltage lines.
Launched in 2004, the mission of the new European EMF-NET (Electromagnetic Fields Network) is to coordinate, evaluate and interpret the growing volume of research results on the potential impact on health of non-ionising magnetic fields, especially in connection with mobile telephone use. Participants include Europe’s best scientific teams working in the Member States or engaged in EU-backed co-operative research.
The initial shortage has given way to a wealth, if not excess, of data. Wherever you turn, magazines, press releases and official health notices are responding to the latest in a steady stream of research results. Generally, the message is one of reassurance. But there are also the occasional less reassuring findings, figures that require further investigation, new fields to be explored and the need to apply the principle of precaution – as for the excessive use of mobile phones by children, for example.
So how can we find out what’s what? The first service rendered concerns the scientific community itself. “The coordination action of EMF-NET is first of all comparable to a kind of research control tower, within which the principal European actors currently involved in these issues can engage in structured dialogue and consultation,” stresses Paolo Ravazzani, coordinator of the network. “We publish a specialised newsletter that reports on this growing volume of information, rooting it in its most solid interdisciplinary bases.”
EMF-NET’s principal ambition is nevertheless interpretation. How to gauge the significance of an announcement coming from a limited group of researchers, or of results showing the absence of effects or, on the contrary, the possibility of their existence? What ‘scientific opinion’ can one deduce from them and what credibility can be lent to them?
"EMF-NET has adopted a joint evaluation mode that the network experts in our technical groups apply to study data and research results. These working groups are charged with providing the European Commission and health authorities with briefing notes and interpretation reports. To respond to precise and urgent requests from policy-makers, we have set up a fast response team able to provide succinct information and comments on the knowledge available on a given subject of topical interest.”
Although the network has no research aim as such, it carries out forward study and scientific and technological monitoring missions in a number of fields – and, of course, on all developments in the emerging technologies. “Attention is far from concentrated solely on the subject of telephony, which is currently very much in the media spotlight. In addition to issues of general protection for the public in all areas of domestic and urban life, we want to place special emphasis on the effects and health risks of a very wide range of professional occupations, whether industrial, medical or in the services sector. Another important element is the perception and communication of risks.”
Contact Paolo Ravazzani, Istituto di Ingegneria Biomedica, Consiglio Nazionale delle Ricerche
To find out more EMF-NET (Effects of the exposure to EMF: from science to public health and safer workplace)
GSM (Global System for Mobile communication)
These three initials, which entered the language nearly 20 years ago, are emblematic of a long and sustained success story on the part of the EU. It is a success rooted in a commitment to constructive and close co-operation between technology companies in the telephony and electronics sectors (established under the EUREKA initiative), the national telecommunications organisations of the European countries and the EU institutions (European Commission, Council and Parliament). All these players made a major contribution to the successful harmonisation that was needed for GSM to be adopted as the standard without encountering the obstacle of international borders. Today the GSM cell phone is used by 1.6 million people worldwide.