How are electronic devices harmful?

Radio interference for the brain

The topic of electrosmog appears again and again in the media at irregular intervals. Once a report boasts the supposed evidence that the electromagnetic fields of modern high-tech devices are harmful to health; Another time an article provides the supposedly unbeatable proof that this is all nonsense and nothing as harmless as a cell phone.

The avalanche-like increase in radiation sources of electromagnetic fields is a cause for concern for many people around the world: Microwave ovens, cell phones and cordless phones, baby monitors, burglar alarms, televisions and computer monitors are part of the basic equipment in households; Radio and television stations, wireless local loops as a direct connection for telephone customers via radio, radio beacons for air traffic control, radio relay and radar systems radiate in public spaces.

Even the sun - the most important natural source - contributes to what is commonly referred to as 'electrosmog': In addition to visible light and the adjacent infrared and ultraviolet spectral components, it also throws high-frequency radiation in the range from 3 to 300 GHz onto the earth however with the very low intensity of less than 10 microwatts per square meter (µW / m2). The "basic concentration" of emissions from household appliances is comparatively in the order of a few dozen µW / m2 and is therefore in the green area according to the current state of knowledge.

However, this actually only applies to the consideration of a single device. The stone of the impetus is the nationwide expansion of mobile communications, which, for reasons of competition, is also taking place in multiple networks with transmission systems from competing operators. Their base stations cover densely populated regions in particular with a fine mesh at distances of down to a hundred meters and transmit in the frequency ranges 905 to 959 MHz (GSM-900, D-Netz) and 1710 to 1880 MHz (DCS-1800, E-Netz). Unlike the extensive coverage of the VHF and television transmitters, whose transmission towers radiate power of up to 500,000 watts in the frequency range 86 to 107 MHz (VHF) and 170 to 600 MHz (VHF, UHF) at a distance of a few tens of kilometers lead to a strong exposure of the population to electromagnetic fields in the immediate vicinity (the field strength decreases inversely proportional to the distance), the mobile radio relies on many small radio cells with weak transmitters. The transmission power of the base stations is between five and 40 watts, that of the cell phones is two watts (GSM-900) or 0.5 W (DCS-1800).

The spectrum of entertainment and communication electronics devices that are suspected of being electro-smog is in the frequency range from 1 MHz to 10 GHz.

And the mobile communications industry is currently doing everything it can to stay on course for growth. In the meantime, the 2.45 GHz radio connection of peripheral devices to computers in the so-called ISM band via Bluetooth is slowly becoming realistic as an alternative to tangled cables. There are also brilliant forecasts for the Wireless Local Loops (WLL) and the Wireless Local Area Networks (WLAN), which are gradually opening up the frequency ranges around 5.2, 17, 19, 26, 48, 40 and 60 GHz for data to be able to transmit to stationary and mobile devices at rates of 25, 155 and 622 Mbit / s.

Radiation density

A study carried out in the USA shows that in larger cities the average background radiation is around 50 µW / m2 is; but around one percent of the population lives in large cities, where they use more than 10,000 µW / m2 is exposed to a power flux density that is more than 200 times stronger - i.e. radiant power per penetrated area unit. But even this value remains far beyond the effects on the human organism that can be proven up to now.

According to the prevailing opinion, only thermal effects on the human organism have been scientifically proven for high-frequency fields. They even use short and microwave therapy for therapeutic treatment; there, the warming of the irradiated areas of the body alleviates rheumatic diseases, inflammations and abscesses.

In order to heat human tissue by one degree Celsius - this temperature increase is considered to be harmless to health because it remains within the range of normal physiological fluctuations - power densities of around 100 million µW / m are required2. The applicable limit values ​​are based exclusively on the thermal effects on biological tissue. In order to limit the warming of the body to a maximum of 0.1 degrees, the 26th Federal Immission Control Ordinance (BImSchVO) sets the maximum permissible average power densities for the GSM-900 network to 4.5 million, for the DCS-1800 network to 10 Million µW / m2 firmly; this corresponds to maximum electric field strengths of 42 and 58 V / m, respectively.

Ionizing and non-ionizing radiation has different effects depending on the frequency range - with the various scientific studies differing greatly in the relevance of possible side effects of electromagnetic fields.

Like most countries, the Federal Republic of Germany is following the recommendations of the International Commission on Radiation Protection for Non-Ionizing Radiation (ICNIRP) [[# lit1 1]], which develops scientifically based guidelines and limit values ​​and, as a non-governmental association, is formally approved by the World Health Organization (WHO ) is recognized.

Limit and threshold values

Since the immission itself does not say anything about the effect on the human organism, it is only an indirect measure of the actual exposure. The decisive factor is how the body absorbs the radiation and processes the energy it has absorbed. These processes are characterized by the specific absorption rate (SAR), the power absorbed per kilogram of body mass. The immission of 100 million µW / m2, which can lead to a temperature increase of one degree Celsius in biological tissue, is based on an SAR of 4 W / kg.

With a safety factor of 10, an SAR value of 0.4 W / kg was defined as the limit value for occupationally exposed persons; For the general population, ICNIRP recommends limiting the SAR to 0.08 W / kg with an additional safety factor of 5. The national radiation protection authorities in most countries use these guidelines as a basis when deriving the frequency-dependent field strength or power density limit values, which are easier to measure in practice than the SAR value.

Limit values, even when derived from complicated formulas, are a political agreement. They define a safety margin to scientifically recognized thresholds. In doing so, as an expert on the subject once aptly put it, they do not necessarily mark the threshold of danger, but rather that of the courtroom: exceeding it does not have to result in direct damage to health; However, it offers those affected legally a means of taking action against the perpetrator.

So far, only the thermal effects of high-frequency fields have been scientifically recognized. Limit values ​​are based on known effects; They do not take into account unsecured knowledge or the risk of not knowing. For suspected hazards - in legal German - the burden of proof is on those affected, not on the disruptor. A reversal of the burden of proof seems hardly conceivable. Otherwise, since background effects cannot be proven, the operators would have to shut down their plants. In this respect, cell phone radiation does not differ from the material immissions of ecotoxic chemicals in water, air and soil: Every setting of limit values ​​is associated with an expected risk and progress remains an ongoing experiment with society.

Measurement actions

In response to the growing public concern, the Austrian Federal Ministry of Science and Transport had exposure measurements of the fields from VHF and television transmitters and cell phone base stations carried out at seven locations last year [[# lit2 2]]. The Austrian standard S 1120 sets limit values ​​between 1 and 10 million µW / m, depending on the frequency2 firmly; the determined maximum power densities of the VHF, VHF and UHF transmitters reached 93 µW / m2; the highest measured power density of a mobile radio system was 856 µW / m2.

In this case it was a company building, on the facade of which there was a GSM-900 antenna; the measured value occurred at 909 MHz. In the same company building, however, the broadband measurement in the entire spectral range from 30 MHz to 1 GHz delivered a six-fold higher value of 5198 µW / m2, which makes up only 0.26 percent of the applicable limit value, but at least shows how much exposure from different sources can add up under certain circumstances.

When evaluating the measurements, the biophysicist Jiri Silny, professor at the Helmholtz Institute for Biomedical Technology at RWTH Aachen University, came to the conclusion that the relevant power flux densities remained a factor of 1000 below the internationally recognized limit values. Allgemeinen In general, these values ​​are clearly undercut, especially in apartments in the immediate vicinity of residential complexes or in rooms that are below the antenna, ’so the conclusion of the study. The typical values ​​for apartments in the vicinity of base stations were 20 µW / m2, a fraction of a thousandth of the applicable limit value. "A health impairment from such weak fields has not yet been shown," it is therefore said.

In the Federal Republic of Germany, the Regulatory Authority for Telecommunications and Post (RegTP) has been carrying out nationwide EMC measurements at regular four-year intervals since 1992. The monitoring is intended to ensure that the construction of new transmitter systems does not overflow and that at some point the maximum permissible personal protection values ​​are exceeded. For this purpose, the field strengths occurring on site are determined at around 1250 measuring locations - mainly in areas of generally accessible streets, squares and facilities as well as schools, kindergartens and hospitals - and compared to the applicable limit values.

Whereas in 1992 the emissions were measured in the frequency range from 10 kHz to 1 GHz, the RegTP extended this range to 10 kHz to 2.9 GHz in the second series of measurements in 1996/97 to also include the newly added mobile communications services, especially the E-networks to be able to capture with. In the current 1999/2000 measurement campaign, the spectrum was expanded again and now includes the low-frequency (1 Hz to 10 MHz) and high-frequency (100 kHz to 300 GHz) fields in two overlapping parts. The evaluation should be completed in the course of this half year and then published on the Internet; Tables with initial results for the individual federal states can already be found there [[# lit3 3]].

The first two series of measurements were based on the limit values ​​of the DIN VDE 0848 Part 2 standard from October 1991. The current series of measurements is based on the ICNIRP guidelines in accordance with the BImSchVO and the EU recommendation 1999/519 / EC from July last year. However, due to the changeover, the new measurement results cannot be compared with the earlier ones and thus no conclusions can be drawn about the development of the immissions over time at a specific measurement point; Statements as to whether an increase or decrease in the field strength level can be identified at individual locations is therefore not possible.

This is not a real loss of information, because even the maximum values ​​now determined in the frequency range from 100 kHz to 300 GHz are still in the per mil range of the maximum permissible value. In Berlin, for example, the highest measured value was 0.6 percent and the lowest 0.01 percent of the limit value; in North Rhine-Westphalia the range was between 0.8 percent and 0.002 percent.


Both the Austrian and the Federal German measurement campaigns, which unanimously show the currently relatively low exposure to the general population, were limited to recording the immissions caused by stationary transmitters. The effect of the cell phones on the cell phone users themselves was not the subject of the investigation.

‘If there is any influence at all, then I would primarily expect it from the cell phones,’ says Silny; ‘The exposure from cell phones is 1000 to 10,000 times greater than that from base stations’. Typical SAR values ​​for cell phones are between 0.2 and 0.4 W / kg. However, the spread is much larger and ranges from 0.02 to 1 W / kg.

The reason for this range is not only to be found in the construction differences of the manufacturers, but is also partly due to the type of measurement and the head and absorption models used. In the worst case, and when the device emits at full power in difficult reception conditions, the fabric of the head can heat up by a few tenths of a degree, an effect that mockers compare to putting on a bobble hat.

But are the thermal effects on which the limit values ​​are currently based really the only ones? The prevailing opinion assumes that non-ionizing radiation is harmless at low intensity and that verifiable effects only occur above a threshold value at a certain minimum field strength. In contrast to X-rays and gamma rays, the high-frequency electromagnetic fields are far too weak to break the bonds that hold the molecules together in the cells and to damage biological tissue - such as the DNA in the cell nucleus - through ionization. This splitting requires at least a radiation energy of a few electron volts (eV); the 1 eV limit is in the ultraviolet part of the spectrum. Of this, the energy of the radiation quanta of cell phone waves - it is 4 µeV at 0.9 GHz and 7 µeV at 1.8 GHz - is about a factor of 10-6 away.

So if there are non-thermal effects and low-level radiation hazards ’of the non-ionizing radiation, they must be based on other interaction mechanisms. The complexity of the medical and physical relationships leaves a wide field for interpretation and speculation. Two papers, for example, caused a sensation in 1992 in which the American biologist Robert Liburdy reported on the influence of electromagnetic fields on calcium ion mobility in cells. Since calcium ions play an important role in cell division and the growth of tumors is in turn related to cell proliferation, they first suspected that non-ionizing radiation could be carcinogenic. That sounded plausible, and the work was recognized accordingly by the specialist colleagues. However, the results could not be reproduced; Rather, inconsistencies suggested that the experimental results had been tampered with. After a lengthy process due to scientific misconduct, the author withdrew both publications last year.

"There are few areas of expertise," says Jiri Silny, "that are so interspersed with theoretical approaches, speculative models of thought, unproven hypotheses or theories, but also with superstitions". Around 25,000 specialist publications on the subject have appeared in the past 30 years. Silny has currently recorded around 3000 in a database with which he wants to ensure more transparency [[# lit4 4]].

The oversupply of information tends to hide how little one really knows. In the emotionally charged debate, most scientists prefer to limit themselves to generating micro-knowledge and shy away from coherent evaluations. In a study on the irradiation of nematodes with 750 MHz microwaves, the results' suggest that the current exposure limit values ​​may need to be checked ', because effects similar to those observed' could also be found in human tissue under the influence of microwaves occur, a possibility that requires further investigation '[[# lit5 5]].

‘Possibly’, Could ’, Indicate’ - Scientists are careful in their choice of words for good reasons. Since it is not possible in biology and medicine to prove zero effects, the guild can only approach the matter with trial and error by hypotheses about suspected or suspected mechanisms of action and then trying to verify them in experimental simulations or epidemiological studies . Meanwhile, the audience in the stands shouts uft Bravo ’or Shift’, depending on which interests or prejudices are being served by the latest investigation. The whole event is already being discredited with the assumption that the researchers are highly selfishly fueling fears and apprehensions and deliberately dramatizing possible dangers and risks in order to show how urgently further research and funding are needed.

But the discussion about-low-level radiation hazards ’cannot be buried that easily. There are indications to be taken seriously of the non-thermal effects of high-frequency, electromagnetic fields of low intensity.For example, the cell biological investigation carried out by researchers from the University of Nottingham and the Canadian University of British Columbia on the roundworms showed that the irradiated worms produced so-called heat shock proteins. These special proteins act as molecular protection to save cell proteins when an organism is attacked by heat or toxic substances.

But in this case there was no warmth involved. The specific absorption rate was only 1000 µW / kg - significantly lower than the 200,000 to 400,000 µW / kg of commercially available cell phones - and the body temperature of the animals in the samples remained the same. In order to achieve the same effect thermally, it would have had to increase by at least three degrees. The fact that the experiments were carried out on roundworms is not necessarily reassuring: the heat-shock reaction is a universal mechanism with which human body cells also release corresponding proteins when they come under stress.

Residual risk?

Epidemiological discrepancies between mobile phone use and the incidence of cancer have not yet been observed. But since tumors take several years to develop, nothing can be deduced from this. In order to find out long-term effects, so-called case-control studies on sick and healthy people not only have to record usage behavior that was around five to ten years ago - that is, it fell into the early phase of the mobile phone boom - but also other cancer-causing factors be able to delimit statistically significant. After all: Even the slight increase in the probability of cancer by one per thousand would mean an additional 500,000 tumor diseases among the currently around half a billion cell phone users worldwide.

The International EMF Project launched by the World Health Organization in 1996 is intended to provide information about such long-term risks [[# lit6 6]]. As part of this project, the Lyon-based International Cancer Research Center (IARC) is currently organizing case-control studies on more than 6,000 subjects in Germany, France, England, the United States and nine other countries. After the conclusion of the survey, which cost around twelve million marks - the first results are expected in three to four years - the question may then be answered whether exposure to low-dose RF fields is associated with an increased risk of cancer.

In addition to the clinical investigations, the WHO project, which will run until 2005, has set itself the goal of coordinating research activities and standardizing the often incomparable measurement methods and evaluation procedures. Around 40 states and a number of international organizations have joined. The specific work is being carried out by the International Commission for Protection against Non-Ionizing Radiation (ICNIRP) and other institutions that work with the WHO on a scientific level. These include the National Radiological Protection Board (England), the Federal Office for Radiation Protection (Germany), the Karolinska Institute (Sweden), the National Institute for Environmental Research (Japan) as well as the Food and Drug Administration, the National Institute of Environmental Health Sciences and the National Institute of Occupational Safety and Health in the USA.

The international EMF project is headed by Michael Repacholi. The Australian went through a change from Paul to Sau-lus. Originally, he himself was convinced of the harmlessness of cell phone emissions - until he carried out his own investigations. With his team at the Royal Adelaide Hospital, he exposed laboratory mice, the model system of biomedical engineers, with a SAR of 0.008 to 4.2 W / kg to the pulsed 900 MHz fields of a GSM cell phone for one hour for 18 months. It turned out that in the irradiated group tumors of the lymph nodes - so-called lymphomas - occurred twice as often as in the non-irradiated control group.

Repacholi had initially submitted the work to the science magazine Science, which refused to publish it on the grounds that such momentous results could cause panic and would first have to be verified by an independent team. Nature and three other relevant journals also rejected the publication until it appeared in Radiation Research in 1997 [[# lit7 7]]. Research groups in Australia and Europe are currently trying to reproduce Repacholi's results; even if the results were to be confirmed, the question of transferability to humans still remains to be clarified. For the time being, cell phone users will have to live with the uncertainty.

Inconvenient experts

The Independent Expert Group on Mobile Phones (IEGMP) in England presented the most comprehensive inventory and assessment of the findings to date on the health risks of mobile telephony in May of this year, where the mobile communications boom is being critically monitored by around 175 local and national citizens' groups. The group of experts, led by Sir William Stewart of the Royal Society, comprised renowned biologists, physicians, epidemiologists, physicists and telecommunications engineers and was convened by the British Ministry of Health last year - a clear affront to the National Radiation Protection Agency (NRPB) and its own scientific advisory board the questions of non-ionizing radiation.

In summary, the British come to the following results in their report ‘Mobile Phones and Health’:

  • In the vicinity of base stations, where exposure remains well below the limit values, there is no general health risk for the population living there.
  • However, there are clear indications that exposure of cell phone users to radiation with intensities below the valid ICNIRP limit values ​​has direct, short-term influences on brain wave activity and the cognitive functions of the brain. "There is an urgent need to find out whether these direct effects on the brain have health consequences, because the exposure limit values ​​then have to be redefined if a threshold value can be specified." It is important to clarify the question of whether the observed effects are a consequence local warming or other, non-thermal mechanisms.
  • The currently available epidemiological and biological evidence does not allow the conclusion that exposure to high-frequency electromagnetic radiation increases the risk of cancer. "However, cell phones have not been in use long enough to allow a comprehensive epidemiological record of their health effects, and at this point in time we cannot rule out the possibility that there is a link between cell phone technology and cancer."
  • Studies on cells and animals do not indicate that cell phone radiation within the framework of the specified limit values ​​has harmful effects on the cardiovascular system, the immune system or reproduction. Even long-term exposure does not seem to affect life expectancy. Even the currently limited epidemiological knowledge does not give cause for concern in this regard.

The experts expect cell phone operators to exclude children as a target group from their marketing activities because they are exposed to a greater risk due to their thinner skull and the still developing nervous system. The mobile phone manufacturers are requested to agree on standardized test procedures for radiation exposure and to indicate the SAR values ​​on the end devices; Based on the model of the consumption values ​​of motor vehicles, the results of such comparative tests should be easily accessible to the public so that consumers can make more informed purchasing decisions.

The IEGMP is particularly critical of politics and the special framework conditions it has created for planning and choosing the location for the base stations, which can also be built in residential areas without a formal approval process: "We consider this to be unacceptable."

Without participation

The practically license-free installation practices in England do not differ from those in the Federal Republic of Germany. As part of the supply contract acquired with the license, the mobile network operators are only required to notify and only need to be able to show a location certificate from the regulatory authority that the operation of the base station complies with the specified limit values. A permit process is not associated with the construction; they only have to negotiate with the property or building owner and agree on the conditions with him.

There is also no publicly accessible cadastre with the locations and emission data of the ‘fixed transmitters’. The IEGMP now requires the legislature to revoke the general operating license and to subject the construction of new and the expansion of existing base stations to the normal application and approval procedures. This is exactly what the special rights for mobile phone operators wanted to avoid, because like the devil they feared holy water the objections of those affected.

You could look forward to them with calm. Because according to the current state of knowledge, as the critical British also state, there is no evidence that exposure to high-frequency electromagnetic radiation below the ICNIRP guide values ​​poses a health risk to the general population. Compared to other risks in everyday life - such as the blood toll of road traffic, which annihilates the population of a small town in Germany year after year and seriously injures the population of a city like Hanover - the risk posed by mobile communication still appears relatively harmless.

It only gets really bad when both of these come together while chatting on your mobile phone on the steering wheel and the increased risk then affects the polluter and uninvolved road users alike. According to studies, it makes no difference whether the phone is made with a handset, ear clip or hands-free system; the danger does not come from the mobile phone waves, but is - the British experts are ‘almost certain’ of this - to be ascribed to the distraction caused by the conversation itself. (jk)


[1] International Commission on Radiation Protection for Non-Ionizing Radiation,

[2] Jiri Silny, Exposure of the general population to high-frequency electromagnetic fields - plausibility of harmlessness to health, September 1999,

[3] Regulatory authority for telecommunications and post,

[4] Helmholtz Institute for Biomedical Technology at RWTH Aachen University, studies on electrosmog,

[5] Nature 417, 405 (2000)

[6] International EMF project of the World Health Organization,

[7] Radiation Research 631, 147 (1997)

[8] Independent Expert Group on Mobile Phones, Mobile Phones and Health,

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Immission limit values ​​of the mobile radio systems

electric field strength42 V / m58 V / m
magnetic field strength0.13 A / m0.157 A / m
medium power density 4.5 W / m210 W / m2

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In contrast to X-rays and gamma rays, the high-frequency electromagnetic fields are not energetic enough to break the binding forces of the molecules in the cells and thus cause ionization. They are therefore also referred to as non-ionizing radiation. It is assumed that it is harmless at low intensities and only causes tissue damage at high intensities. However, it can have different effects on biological systems - cells, plants, animals or humans - which depend on the frequency and intensity.

  • RF fields above 10 GHz are absorbed on the surface of the skin, with only a very small part of the energy penetrating the tissue below. The basic dosimetric variable in this frequency range is the power flux density in W / m2.
  • Fields between 1 MHz and 10 GHz penetrate exposed tissue and heat it up by absorbing energy. The penetration depth depends on the frequency and decreases with increasing frequency: It decreases - good news for the E-Netz participants - from 2.5 cm at 900 MHz to 1 cm at 1800 MHz. The relevant dosimetric variable in this frequency range is the specific absorption rate (SAR) with the unit W / kg.
  • Fields below 1 MHz do not cause any significant warming, but can induce electrical currents and fields in the body. The relevant dosimetric variable in this frequency range is therefore the current density in A / m2. The natural exchange processes in the body lead to "basic currents" in the tissue of the order of 10 mA / m2; induced current densities of over 100 mA / m2 can impair the normal function of the body and lead to unwanted muscle contractions.

In this way, the actual exposure (of people at a certain location) can be related to the more easily measurable immission values ​​(at this location). Since the electric field strength (in V / m) and power flux density (in W / m2) are in a fixed physical relationship to each other and can be converted into each other, it is common to specify the immission limit values ​​in one as well as in the other quantity.

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Conjectures and the all-clear

The British Independent Expert Group on Mobile Phones has summarized some key points of the discussion about the effects of electromagnetic fields from cell phones in its study ‘Mobile Phones and Health’.

Carcinogenicity: The carcinogenic potential of high-frequency electromagnetic fields is controversial. Theoretically, negative influences on the DNA cannot be justified, since the mobile phone radiation is not energetic enough to break molecular bonds in a direct way.

Some studies claim, based on animal experiments, that RF fields can trigger tumors, increase the effects of known carcinogenic substances or accelerate the growth of transplanted tumors. This could be due to the high dose of exposure and thermal effects.

Overall, there is no evidence from in vitro and in vivo experiments that acute or chronic exposure to RF fields increases the frequency of mutations or chromosome changes as long as the temperatures remain in the physiological range.

Calcium transport: Calcium ions signal cells to switch genes on and off and play an important role in cell division. High-frequency fields with intensities well below thermal effects can influence the transport of calcium and other ions through the membranes of nerve cells (neurons). Such effects were only observed under very special conditions (amplitude modulation with 16 Hz), which are irrelevant for mobile radio systems.

Life expectancy: No influence of RF fields on life expectancy has been demonstrated in animal experiments.

Reproduction: Tests on laboratory rats have not provided any evidence that RF fields typical of cellular radio systems damage the fetus or impair fertility.

Cardiovascular system: Animal experiments do not justify any concerns about possible effects on the heart or circulation, as long as the intensity remains in the range typical for mobile radio; observed effects at very high intensities are apparently due to the warming of the body.

Brain wave activities and cognitive functions: Controlled tests with human volunteers indicate that exposure to mobile phone signals below the applicable intensity limit values ​​trigger biological effects that are strong enough to influence behavior. The cause and effect mechanism is unclear. Long-term effects are unknown; the previous investigations have been limited to short-term exposure. Animal experiments showed unspecific, stress-like changes in the brain of laboratory rats under the influence of pulsed RF fields of low intensity.

Memory and ability to learn: ‘There is no consistent experimental evidence that exposure to low-intensity RF fields affects memory and learning behavior in animals. [...] Investigations on human subjects are necessary in order to be able to assess whether the fields of cell phones have any effect on learning ability and memory. "

Eyes: The eye reacts particularly sensitively to the effects of electromagnetic fields because it is difficult to dissipate the heat generated due to the low blood flow; Even minor damage can be irreversible and add up. Eye irritation and clouding of the lens (cataracts ’) have been proven in animal experiments, but this is at significantly higher exposure than is assumed by a cell phone. Tests on primates show that pulsed RF fields can also damage the eye with low intensity. ‘The studies give cause for serious concern about possible impairment of the eye by pulsed RF fields with high peak powers.’

Melatonin balance: Melatonin is a hormone that controls the day-night rhythm in humans and animals; it also protects the genetic information of the cells from damage. In connection with low-frequency fields in the vicinity of high-voltage lines, the melatonin hypothesis asserts an influence on tumor development, which, however, has not been conclusively clarified. There are only a few studies on the influence of high-frequency fields on melatonin production; they did not corroborate the suspicion.

Blood-brain barrier: The blood-brain barrier is a filter that prevents large molecules from entering the cerebral fluid from the bloodstream. The findings on an impairment of the filter effect through RF exposure are inconsistent and contradictory; more recent work has shown no effect.

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Scramble over limit values

Since Italy and Switzerland broke out of the international consensus and, with reference to the precautionary principle, limited the permissible emissions from base stations to significantly lower levels than the recommendations of the International Commission on Radiation Protection for Non-Ionizing Radiation (ICNIRP), the mobile network operators fear that there is now a race for uses the lowest immission standards.

Italy had lowered the limit values ​​to one hundredth of the ICNIRP recommendations in 1998; In Switzerland, since February 1st, electrical field strengths of no more than 4 V / m for GSM-900 antennas and 6 V / m for DCS1800 base stations have been permitted in residential areas as well as in the vicinity of schools and hospitals. The new ordinance on protection from non-ionizing radiation forces operators to reduce the size of the radio cells in densely populated areas and to set up more base stations with lower power. In the case of the Federal Republic, the additional costs are estimated at one billion Swiss francs.

Limit values ​​are the classic arena in which the acceptance or unreasonable expectation of collective risks is debated. In the Federal Republic of Germany, the change from the DIN / VDE standard 0848 to the stricter ICNIRP guidelines was mainly due to years of criticism that the representatives of the relevant industry rather than independent specialists set the tone in the small print of the measurement and evaluation procedures. Whether hormone-like substances in drinking water or pesticide residues in food - the setting of environmental standards is always particularly controversial when it is connected with a legal weighing up of uncertain consequences (the ‘risk of ignorance’) and the concrete, tangible follow-up costs of an immission reduction.

Because of its fundamental importance, the EU Commission therefore presented a recommendation in February that lays down the criteria for applying the precautionary idea. This includes, among other things, proportionality: limit values ​​should ‘not be disproportionate to the desired level of protection and should not aim at a‘ zero risk ’, which can only rarely be achieved’. They should be based on cost / benefit analyzes of action or failure to act and should always be subject to review by new scientific findings.

As a further principle for establishing legal intervention thresholds, the EU Commission calls for 'coherence': 'If the risk cannot be described due to a lack of scientific data and in view of the uncertainties inherent in the assessment, the precautionary measures taken must be different from measures taken in similar areas, in which all necessary scientific data are available, have the same content and have the same scope. '

In plain language: The risk of not knowing has to be measured against known but accepted risks in other areas of life. Such a coherence check has its pitfalls, of course, because where do you look for the reference point of comparison - in motorized private transport (1999: 7749 deaths) or the probability of being struck by a falling branch while walking in the city park?