As Bristol experiences 5G mobile phone technology for the first time and conspiracy theories abound, science journalist Andy Extance looks at the technology’s risks and benefits.
Illustration: Louis Wood
‘5G’ technology brings exciting visions of a world where we can enter virtual reality through our mobile phones – but what if that risks our health in everyday reality? Some scientists are worried that the same waves with which fifth generation (5G) mobile networks bring users more data could be more harmful than previous generations.
A team including physicist Dr Paul Ben Ishai from Ariel University, an Israeli institution located in the occupied Palestinian West Bank, has shown that our sweat ducts could help skin absorb some 5G signals. “A lot of people are asking, ‘Shouldn’t we be checking this healthwise?’” Ben Ishai tells the Bristol Cable.
The prospect of 5G has reignited debate around the fuzzy connection between mobile phones and cancer. “Government and industry have brushed aside any health concerns and are simply pushing ahead with 5G as fast as they possibly can because of the amount of money involved,” Ben Ishai says. One YouTube video with nearly a million views even calls the network of 5G towers a ‘kill grid’. That’s clearly taking things too far – but surely claims suggesting possible increased risks demand greater attention.
The need for knowledge is pressing, with UK mobile operator Vodafone’s pre-commercial 5G trials having started in 2018, ahead of a full launch this year. The tests span 40 sites in Bristol, Birmingham, Cardiff, Glasgow, Liverpool and London. Its rival EE intends to launch its full 5G service in 2019, first in London, Cardiff, Edinburgh, Belfast, Birmingham and Manchester, with Bristol in the second wave. Three and O2 similarly plan to bring 5G to their UK networks by the end of 2019.
Like today’s most popular wireless communication systems, 5G transmits information on electromagnetic waves that deliver both benefits and potential harms. They have a lot in common with the waves that appear in a rope when you shake it. 5G technologies differ according to frequency, the number of times wave peaks travel through a certain point in a second. 5G frequencies involve millions of waves per second, for which the measurement is known as megahertz, or billions per second, known as gigahertz.
Scientists have been bitterly divided over whether mobile phones truly raise cancer risks or not
5G has three flavours, operating at low, medium and high frequencies. Low-frequency 5G is least well established, but in the UK it will broadcast at around 700 megahertz, using radio airwaves freed up from digital TV. That origin means that no-one should be any more worried about low-frequency 5G than existing mobile phone technologies. So you might be completely untroubled, a bit suspicious or firmly against – we’ll come back to that shortly.
Medium-frequency 5G operates at 3-6 gigahertz, slightly higher frequency than the existing mobile phone radio wave range, but again the risks should be similar. That’s what UK mobile phone firms are now rolling out, after the country auctioned the right to operate networks around 3.4 gigahertz and from 3.6–4 gigahertz. It means users can get data at 100 megabits per second (Mbps) rates or higher, five times faster than the UK’s average 4G speed.
High-frequency 5G will broadcast at over 24 gigahertz, transferring at least 1000Mbps. The wavelength – the distance between the peaks – of such waves is tens of millimetres, so they’re sometimes called millimetre-waves.
However, millimetre-waves don’t travel as well through buildings, and can be absorbed by plants and rain. One option 5G companies have to overcome this is ‘small cells’. These are basically little phone towers, scattered much more widely. While it’s a potentially expensive strategy, it’s one people are taking seriously. For example CableLabs, the company that determines how cable TV networks will work in the future, told me in 2017 that it intends to support small cells.
Skin in the game
Perhaps if you’re an enthusiast you can handle the idea of lots more boxes firing out a different type of mobile phone signal. If you’re at all nervous, your alarm bells are probably ringing. Whatever group you’re in, you should know that in 2011 the International Agency for Research on Cancer (IARC) classified mobile phone radio waves as a possible cause of cancer. The decision, taken by 31 scientists, was based on a 40% increased risk of a type of brain cancer called glioma. The risk, though, came from long-term use of mobile phone handsets held close to the side of the head, rather than being associated with mobile phone towers in the neighbourhood.
And while that may still sound worrying, the absolute increase in risk is small. One study in Switzerland found that there were around 3.5 gliomas diagnosed per 100,000 people each year. Increasing that by 40% would raise the diagnosis rate to 4.9 gliomas diagnosed per 100,000 people each year.
Those relatively small numbers, along with evidence that IARC admitted was limited, makes it hard to be absolutely certain. And so, in the years since, scientists have been bitterly divided over whether mobile phones truly raise cancer risks or not. The researchers who think they do regularly accuse their opponents of being linked to the ‘industry loyal’ International Commission on Non-Ionizing Radiation Protection (ICNIRP).
In one recent study, Martin Röösli from the Swiss Tropical and Public Health Institute and a team of researchers combined the findings of studies including brain cancer data from 1993-2007. They didn’t see any increase in cancer diagnosis over this time. “If it would be as risky as alcohol or smoking, we would have detected the risk already by now,” Röösli says. “Thus, if there is a risk, it must be small or related to outcomes which are more difficult to measure.”
Cancer Research UK echoes this point. “Overall there’s no convincing evidence that mobile phones, including 5G phones, cause cancer in people,” says spokesperson Fiona Osgun. “But because mobile phones are a relatively recent invention it’s an area we continue to monitor. Despite mobile phone use skyrocketing there hasn’t been a comparable increase in the incidence of brain tumours in the UK in recent decades.”
Yet a team including David O. Carpenter from University at Albany, New York, reached different conclusions after reviewing existing evidence of health risks from electromagnetic waves in 2018. “The evidence shows clearly that excessive exposure increases risk of brain cancer, has effects on nervous system function and in some people results in the syndrome of electro-hypersensitivity,” Carpenter says.
And 5G’s high-frequency, millimetre-wave flavour brings new risks according to Paul Ben Ishai, who has studied the subject in a team led by Yuri Feldman at Hebrew University, Jerusalem. Our sweat ducts are millimetre-scale coils, the perfect size, shape and composition to serve as antennae for millimetre-waves, they realised. Their work includes conducting experiments showing skin can absorb waves in the 75-170 gigahertz ranges. But there is still a ‘tail’ of absorption down to 20 gigahertz, Ben Ishai stresses, meaning the effect is relevant to high-frequency 5G. The Israeli team’s findings support similar earlier results from Queen Mary University of London scientists.
Ben Ishai notes that the high-frequency 5G signals will actually carry less power than existing mobile phone signals. However, he thinks we’ll be exposed to more 5G signals, with small cells ‘potentially in front of almost every block’. In the UK, telecoms giant BT is already calling for open access to lamp posts for just this reason. A lecture hall with 5G wi-fi might have five or six transmitters, Ben Ishai adds. This adds one more factor that should make us concerned: We can decide whether we use a phone, and how we use it. We may not even know if we’re near a small cell.
For now, at least, mobile operators aren’t yet planning to launch high-frequency 5G in Bristol or the UK more broadly. While that might frustrate early adopters itching to get promised data rates, it at least gives the rest of us more time to ask about the health issues it might bring.