The debut of 5G (fifth generation) mobile wireless technologies has revived long-held suspicions that using mobile phones may raise the chance of getting a brain tumor.
Mobile phones send out radiofrequency waves, which can heat and hurt tissues if they are absorbed by them.
The radiofrequency waves emitted by mobile phones penetrate several centimeters into the brain when held close to the head, with the temporal and parietal lobes being the most vulnerable.
The International Agency for Research on Cancer (IARC) has classified radiofrequency waves as “possibly carcinogenic,” raising concerns that mobile phone users may be at an increased risk of developing brain tumors.
However, most of the research that has looked into this subject so far has been retrospective studies in which people report using their phones after being diagnosed with cancer, which means the results could be skewed.
Researchers from Oxford Population Health and the International Agency for Research on Cancer (IARC) published the findings of a large UK prospective study (a study in which participants are enrolled before they develop the disease (s) in question) to look into the link between mobile phone use and the risk of brain tumors today. The findings were published in the National Cancer Institute’s journal.
The researchers examined data from the UK Million Women Study, a long-running study that enrolled one out of every four women born in the United Kingdom between 1935 and 1950.
In 2001, over 776,000 people filled out questionnaires about their mobile phone usage; about half of them were polled again in 2011. The participants were then tracked for an average of 14 years after their NHS records were linked.
Gliomas (a nervous system tumor), acoustic neuromas (a tumor of the nerve linking the brain and inner ear), meningiomas (a tumor of the membrane protecting the brain), and pituitary gland tumors were all studied in relation to the risk of using a mobile phone. The researchers also looked into whether cell phone use was linked to an increased incidence of ocular cancers.
Key findings
- By 2011, almost 75% of women aged between 60 and 64 years used a mobile phone, and just below 50% of those aged between 75 and 79 years
- Over the 14 year follow-up period, 3,268 (0.42%) of the women developed a brain tumor
- There was no significant difference in the risk of developing a brain tumor between those who had never used a mobile phone, and mobile phone users. These included tumors in the temporal and parietal lobes, which are the most exposed parts of the brain
- There was also no difference in the risk of developing glioma, acoustic neuroma, meningioma, pituitary tumors or eye tumors
- There was no increase in the risk of developing any of these types of tumor for those who used a mobile phone daily, spoke for at least 20 minutes a week and/or had used a mobile phone for over 10 years
- The incidence of right-sided and left-sided tumors was similar in mobile phone users, even though mobile phone use tends to be considerably greater on the right than the left side
Using a cell phone in normal situations doesn’t make people more likely to get brain tumors, says co-author Kirstin Pirie of Oxford Population Health’s Cancer Epidemiology Unit.
Although the findings are encouraging, it is unclear whether the dangers linked with mobile phone use differ among individuals who use them much more frequently than the average woman in this group.
In this poll, only 18% of phone users said they talked on their phone for 30 minutes or more per week. Those who talk on their phones for long periods of time might limit their RF exposure by using hands-free kits or loudspeakers.
Although the study did not cover children or teenagers, other researchers have looked at the link between mobile phone use and the incidence of brain tumors in these age groups and found no link.
IARC’s lead investigator, Joachim Schüz, said: “Mobile technologies are constantly improving, and the most current models emit far less output power.
Given the absence of evidence for heavy users, however, recommending mobile phone users to limit needless exposures is a prudent precaution. “
