Normal cell phone use does not cause brain tumors, according to a study involving hundreds of thousands of people that may finally put an end to the matter after more than two decades of speculation and fear.
Researchers have gone further than ever since concerns were first raised in the ’90s, saying cellphones don’t pose a cancer risk for the vast majority of people.
This means that the World Health Organization’s International Agency for Research on Cancer (IARC), which had previously classified cellphone use as “possibly carcinogenic”, has now concluded that the devices are safe for the average user.
It also said there’s no evidence heavy users – those who use the phone to their head for about seven to 10 hours a week or more – are at risk. However, he cannot yet rule this out.
The data comes from a landmark UK study consisting entirely of female participants.
“For normal use I think we have strong convincing evidence that mobile phone use does not cause problems – whilst for the smaller group of people with very heavy use we would offer some precautionary advice. But overall we have the situation pretty much under control,” said lead researcher Joachim Schuez from IARC I.
“This is an important study that builds on previous research. The longer you follow people, the more robust the data becomes. Every new study is a piece of the puzzle.”
dr Schuez does not give the all-clear for heavy mobile use, as the study only examined women, while very heavy users tend to be men. Therefore, the sample size was too small to draw firm conclusions about heavy use.
There is no evidence that heavy users are at risk, but the researchers still advised them to take the precautionary principle and use hands-free phones or headphones whenever possible to minimize their device’s contact with their head.
The researchers used data from the Million Women Study: a huge ongoing research project that has recruited one in four British women born between 1935 and 1950.
About 776,000 respondents completed questionnaires about their cell phone use in 2001, and about half were re-interviewed in 2011. Participants were then followed for an average of 14 years by linking them to their NHS records.
“These results support the growing evidence that cell phone use under normal conditions does not increase the risk of brain cancer,” said Kirstin Pirie of the University of Oxford’s Department of Public Health, who also collaborated on the study.
Because cell phones are held close to the head, the high-frequency waves they emit penetrate several centimeters into the brain, with the temporal and parietal lobes being most exposed. This has raised concerns that mobile users may be at increased risk of developing brain tumors.
Previously, the IARC classified radio frequency waves as “possibly carcinogenic” based on previous concerns and in the absence of much scientific evidence on the subject.
Fears have been reignited more recently by the introduction of 5G technologies.
The evidence from the latest study refutes these theories.
Karis Betts, Health Information Manager at Cancer Research UK said: “There is a persistent myth that cell phones, or the signals they send out, cause cancer. The results of this large study provide further evidence that it is just that – a myth.”
Professor Malcolm Sperrin of Oxford University Hospitals said: “This Oxford study is a welcome addition to the body of knowledge on the risks of mobile phones. There is always a need for more research, especially as phones, wireless, etc. become ubiquitous, but this study should allay many existing concerns.”
dr Michael Jones, Senior Scientist in Genetics and Epidemiology at the Institute of Cancer Research, London, said: “This study supports the accumulating evidence that cell phone use under normal conditions does not increase the risk of brain tumours.”
dr Schuez pointed out that mobile phone technologies are constantly improving, so the newer generations use much less power than before, reducing the risk for frequent users.
The study appears in Journal of the National Cancer Institute.