For each new mobile telecommunication standard, existing cell towers are converted or new ones are built. Do such installations pose a risk to our health? Studies to date indicate that this is not the case. And there is a further exciting correlation: in certain situations, 5G might even be potentially capable of reducing radiation exposure.
Radio masts are good neighbours: they don’t make a lot of noise, they perform a useful function – and ideally, they’re not large or conspicuous. Many people are currently acquiring these new neighbours. To bring 5G mobile communications to all parts of the country, existing radio masts are being converted and new ones are being built. Equally, the network of transmission installations is constantly condensed in order to eliminate black spots and improve network coverage. This is causing concern among some citizens because wireless communications use radio-frequency electromagnetic fields (EMFs). The potential impact of such fields on human health has generated a great deal of discussion over the years, and much research has been carried out. Read on for a series of five questions and answers designed to shed some light on the matter.
To date, the frequencies used for the mobile network have been below 2.6 gigahertz. However, the new 5G networks do to some extent require other frequencies to guarantee faster mobile Internet at up to 3.8 gigahertz. These may prospectively be raised to 24.25 to 27.5 gigahertz – in some instances even 60 gigahertz. Hertz is the unit used for measuring frequency. One hertz corresponds to one oscillation per second – so one gigahertz means a billion oscillations per second. The higher the frequency, the smaller the range of the field. Only additional sites can prevent dead spots.
Physicists distinguish between ionising and non-ionising radiation. Radio-frequency electromagnetic fields used for data transmission in mobile networks belong to the category known as non-ionising radiation. Mobile communications cannot cause ionisation in atoms and molecules. In other words, it doesn’t change them. The other category – ionising radiation – carries considerably more energy and is capable of changing matter and breaking chemical bonds.
Rays used in mobile communications only have one proven effect on the human body: they are converted into heat. This happens when the body absorbs a portion of the radiant energy. The oscillating charged molecules found at the frequency of the mobile communications generate the heat. This is known as a thermal effect. How much energy the body absorbs depends on the frequency level and the strength of the electromagnetic field. In principle, the higher the frequency, the less deeply the rays are able to penetrate the human body.
For stationary mobile communications installations – radio masts – clearly defined limits apply, starting from a specific transmitting power. These are based partly on recommendations by the International Commission on Non-Ionizing Radiation Protection (ICNIRP), the German Commission on Radiological Protection (SSK) and the Federal Office for Radiation Protection (BfS). The limits regulate the extent to which people may be exposed to radio-frequency electromagnetic fields without any need to worry about their health being impaired. They are defined in the Federal Immission Control Act and its ordinances and depend on the frequency range used in each respective instance.
The strength of electromagnetic fields drops very rapidly with each successive metre of distance from the mobile communications installation (the inverse square law). As such, people in the vicinity of this type of installation are generally only exposed to a weak electromagnetic field. Radio masts are usually placed on towers, ensuring a substantial distance. Any radiation that does reach people generally adds up to less than one percent of the strength permitted under the legally established limits.
It is not yet possible to predict whether this will change with 5G. It is likely that more small cell installations will be deployed and that they will be located closer to human beings. But the significantly higher frequencies that will be used later – 20 gigahertz and above – have a much smaller range and are easy to shield against. In addition, the technique known as beamforming enables radiation to be emitted in a much more targeted manner. But even if exposure does increase, it will still be far below the limits.
Anyone who actively uses a mobile phone – making calls with it, for example – is exposed to substantially stronger electromagnetic fields than those generated by a nearby mobile communications installation. When a mobile is placed close to the ear, the user’s head is directly subjected to radiation. However, with just a few centimetres’ distance, the effects are already massively reduced. This can easily be achieved by using a headset, for example, or the hands-free function.
Does this mean it is unhealthy to use a mobile for phone calls? This conclusion is premature. A few observational studies associate frequent phone calls on a mobile with an increased risk of brain tumours. This is why the International Agency for Research on Cancer (IARC) has classified use of a mobile for phone calls as possibly carcinogenic. However, the majority of the studies conducted on this topic have been unable to establish any connection between mobile phone calls and cancers. It should also be kept in mind that this classification involves the same risk level as eating red meat or pickled vegetables. Even drinking very hot drinks is classified as riskier/as a higher risk. And please note that this classification applies to mobile radiation from an end device placed against the head or ear, not to cell towers.
For mobile phones too, safety is generally documented by means of the limitation of what is known as the SAR value. This establishes that the energy absorbed by the body must not exceed two watts per kilogram of body tissue in the head and trunk. Any energy absorption below this value is considered harmless.
But anyone who remains concerned and wants to take precautions can still reduce their exposure without resigning their mobile phone use. For longer conversations, the Federal Office for Radiation Protection (BfS) recommends using a headset, thereby keeping your mobile further away from your head. The Federal Office also advises replacing shorter conversations with text messages – this reduces radiation too.
One more point: the better the reception, the lower the radiation exposure from a mobile phone. When reception is bad, mobiles require stronger radio signals in order to reach the nearest mobile communications installation. It therefore follows that positive development of the mobile network is a plus for users. If the transmission mast is nearby, the end device does not need to send such a strong transmitting signal.
A well-developed network is doubly advantageous. Assuming the same level of use, a higher density of radio masts reduces the user’s exposure of radio-frequency electromagnetic fields because the mobile gives off less radiation when transmitting. Either way, both cell towers and mobile devices are subject to legal regulations. Nevertheless, a conscious approach to mobile radiation is both correct and sensible. Research also continues. On the basis of current studies, there are no indications that the expansion of 5G technology goes along with any increased health risk to the general population.
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