Dr Miriam Stoppard explains how fears over radio waves sparked theories about cellphones causing brain tumors – but examination of data from 776,000 people rules it out
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For years, rumors have swirled about a link between cell phones and brain tumors. Alarmism has been reignited by the recent launch of faster 5G technology.
Since cell phones are held close to the head, the radio frequency waves they emit enter the brain.
And since the International Agency for Research on Cancer (IARC) classifies radio frequency waves as “probably carcinogenic”, there are naturally going to be questions.
So far, most studies that have investigated this question have been retrospective, where people report using a mobile phone after a cancer diagnosis, meaning the results may be biased.
But researchers at Oxford conducted a prospective study – in which participants are enrolled before they develop cancer – to investigate the possible link between mobile phone use and brain tumor risk.
They used data from 776,000 participants in the UK Million Women Study, which includes one in four women born between 1935 and 1950.
They completed questionnaires about their mobile phone use in 2001 and half were surveyed again in 2011 and 2015. Mobile phone use has been examined in relation to the risk of various types of brain tumours: glioma ( a tumor of the nervous system); acoustic neuroma (tumor of the nerve connecting the brain and the inner ear); meningioma (tumor of the membrane surrounding the brain); and pituitary tumors. The researchers also investigated whether mobile phone use was associated with the risk of eye tumours.
Their main conclusions were:
- Almost 75% of women aged 60-64 use a mobile phone, and just under 50% of those aged 75-79.
- 3,268 of the women developed a brain tumour, which accounted for 0.42% of them.
- There were no significant differences in the risk of developing a brain tumor between those who had never used a cell phone and cell phone users.
- There was also no difference in the risk of developing glioma, acoustic neuroma, meningioma, pituitary or eye tumor.
- The incidence of right-sided and left-sided tumors was similar among mobile phone users, although mobile use tends to be significantly higher on the right side than on the left side.
Co-researcher Kirstin Pirie from Oxford Population Health’s Cancer Epidemiology Unit, said: “These results support the growing body of evidence that cellphone use under usual conditions does not increase brain tumor risk.
A niggling question remains. Would talking for long periods of time change the level of risk? I don’t think so because those who use cell phones for long conversations tend to use the speakerphone function or hands-free kits.