EMF at home: Wi-Fi, 5G, phones and power lines without the panic

A Wi-Fi router in the living room, a phone on the bedside table, a new 5G mast near the estate or a high-voltage line by the garden – electromagnetic fields (EMF) surround us all the time, and many people find them unsettling. Online you will find warnings as well as products that promise to “protect” you. A calm look at the physics and at large studies, however, shows there is no reason to panic, and that the most sensible precautions are cheap or free.

Ionising and non-ionising radiation

The word “radiation” makes us think of X-rays or Chernobyl. But the electromagnetic spectrum is broad. Ionising radiation – X-rays, gamma rays and part of the ultraviolet range – has enough energy to knock electrons out of atoms and damage DNA directly. Non-ionising radiation – the radio waves used by phones, Wi-Fi and 5G, as well as the 50 Hz fields around power lines – does not have that energy, even at high power.

The main well-established biological effect of radiofrequency (RF) fields is tissue heating, much like in a microwave oven. For low-frequency fields, such as those from power lines, it is stimulation of nerves and muscles at very high intensities. Ordinary household exposure is far below both thresholds.

How ICNIRP limits work

The International Commission on Non-Ionizing Radiation Protection (ICNIRP) sets the limits on which the EU Council recommendation and national laws are based. For RF fields the key quantity is SAR – the energy absorbed per kilogram of tissue. The whole-body limit for the public (0.08 W/kg) is fifty times lower than the level linked to harmful heating in experiments. For phones, a limit of 2 W/kg applies to the head and trunk, and manufacturers must state the value.

That includes 5G: fifth-generation networks largely use frequencies similar to 4G, and the higher millimetre-wave bands penetrate only a fraction of a millimetre into the skin. The same limits apply. A Wi-Fi router usually transmits at up to 100 mW, and just a few metres away exposure is many times below the limit.

What IARC 2B means and what large studies show

In 2011 the International Agency for Research on Cancer (IARC) classified RF fields as Group 2B – “possibly carcinogenic”. It sounds alarming, but Group 2B means limited evidence that can be neither ruled out nor confirmed. The same group includes, for example, whole-leaf aloe vera extract and traditionally pickled vegetables. Low-frequency magnetic fields have been in Group 2B since 2002 because of a statistical association between long-term average levels above roughly 0.3–0.4 µT and childhood leukaemia. Causation has not been shown, and only a small fraction of homes have such levels.

Since then, large cohort studies with hundreds of thousands of people have found no increased risk of brain tumours among phone users. Brain tumour rates in populations have not risen in the way a real risk would predict, despite the massive spread of mobile phones. A systematic review commissioned by the World Health Organization and published in 2024 concluded that mobile phone use is not linked to an increased risk of brain cancer. Animal experiments with whole-body exposure far above the limits gave inconsistent results that cannot be transferred directly to people in everyday conditions.

Electromagnetic hypersensitivity

Some people attribute headaches, fatigue or insomnia to Wi-Fi or phone signals. Their symptoms are real and deserve to be taken seriously. In blinded provocation studies, however, people could not tell whether a source was switched on any better than chance, and symptoms appeared mainly when they believed it was on. The WHO therefore recommends looking for the cause of symptoms together with a doctor rather than primarily in the fields.

Cheap precautions that make sense

If you want to reduce your exposure, the most effective tool is distance. Field strength drops quickly with it, so even a few tens of centimetres make a big difference. Most of these steps will also help your sleep and attention.

• Do not keep your phone in bed or under your pillow. Charge it outside the bedroom, or at least on a table a few metres from the bed.
• At night switch on airplane or do-not-disturb mode – less radiation, but above all less light and fewer notifications disturbing your sleep.
• Use the speakerphone or headphones for long calls.
• When the signal is weak (lift, basement, train), postpone the call if you can – the phone then transmits at higher power.
• Place the Wi-Fi router in a hallway or living room, not next to the bed, and switch it off at night with a timer if you wish.
• Encourage children to send messages rather than make long calls with the phone at their ear.

Marketing: stickers, pendants and shielding products

Phone stickers, “harmonising” pendants and bracelets have no proven effect and physically cannot have one. If a sticker really blocked the signal, the phone would raise its power to keep the connection. Shielding canopies, paints and wallpapers do attenuate fields, but they can worsen the signal indoors – and the phone then transmits harder. Such measures make sense only in exceptional cases and based on professional measurements.

Who should be cautious

• People with a pacemaker or defibrillator – do not carry your phone in a breast pocket over the device, and follow the distance recommended by the manufacturer and your doctor.
• People with other implants – such as an insulin pump or cochlear implant – follow the device instructions.
• People troubled by worries about EMF – the symptoms are real; talk to a doctor rather than seeking a solution in expensive products.
• Parents of young children – the same simple measures are enough – distance and keeping phones away from sleep.
• People who sleep with a phone by the pillow – the bigger problem here is disturbed sleep, not radiation.

What to look for when buying

• For a phone: the stated SAR value for head and trunk (up to 2 W/kg in the EU) – you will find it in the manual or the settings.
• For an EMF meter: a stated frequency range, units (V/m, µT) and calibration, not just coloured lights.
• For shielding products: independent measurement before and after, and a check that indoor signal does not get worse.
• A router with a timer or scheduled Wi-Fi switch-off.
• Warning sign: stickers and pendants that “neutralise radiation”, “5G protection” or “frequency harmonisation”.

Conclusion

Electromagnetic fields at home are non-ionising and usually many times below limits that already include a large safety margin. The IARC 2B classification expresses uncertainty, not proven risk, and large studies since 2011 have not confirmed an increased cancer risk. If you want to be cautious, do it cheaply: phone out of bed, airplane mode at night, headphones for long calls and the router outside the bedroom. Do not spend money on stickers and pendants.