Systematic review finds mobile phones not linked to brain cancer

A systematic review examining the possible health impacts of exposure to radio waves has found no link between mobile phones and brain cancer.

Commissioned by the World Health Organization, the review is published today in the journal Environment International.

Because mobile phones are commonly held next to the head and transmit radio waves (a form of non-ionising radiation), the idea that they could contribute to brain cancer arose early on.

Concerns about whether mobile phones might cause cancer have persisted for years. Given that mobile phones – and wireless technology more broadly – are embedded in everyday life, it has been crucial for researchers to assess the safety of radio wave exposure from these devices.

Across decades of research, the scientific consensus has stayed firm: there is no relationship between radio waves from mobile phones and brain cancer, nor evidence of wider harm to health.

Radiation as a possible carcinogen

Even with that overall consensus, individual studies have occasionally appeared that hinted at potential risks.

In 2011, the International Agency for Research on Cancer (IARC) categorised radio wave exposure as a possible carcinogen to humans. This label was widely misinterpreted and contributed to heightened public concern.

IARC is part of the World Health Organization. Its decision to list radio waves as a possible carcinogen drew largely on limited findings from human observational research. These studies – also called epidemiological studies – track disease rates in populations and explore how those outcomes might be associated with particular exposures.

Although observational studies are the main approach available for investigating long-term effects in humans, their results can be influenced by bias.

The IARC assessment leaned on earlier observational work in which people with brain cancer over-reported how much they had used a mobile phone. The INTERPHONE study is a well-known example.

This new systematic review of human observational studies draws on a far larger body of data than the evidence base IARC considered in 2011.

It incorporates newer and more wide-ranging studies. As a result, we can be more confident that exposure to radio waves from mobile phones or wireless technologies is not linked to a higher risk of brain cancer.

No association

The review is part of a set of systematic reviews commissioned by the World Health Organization to examine potential health effects that could be associated with exposure to radio waves.

It offers the strongest evidence so far that radio waves from wireless technologies do not pose a hazard to human health.

This is the most extensive review yet in this area. It assessed more than 5,000 studies, and included 63 in the final analysis, published between 1994 and 2022. Most studies were excluded simply because they were not relevant – a common outcome when systematic reviews screen large numbers of search results.

The authors found no association between mobile phone use and brain cancer, or with any other cancer of the head or neck.

No association with cancer was found for people who had used a mobile phone for ten or more years (prolonged use). Frequency of use – whether measured by number of calls or total time spent on the phone – also made no difference.

Crucially, these results are consistent with earlier research. Even though wireless technology use has surged over recent decades, there has been no increase in the incidence of brain cancers.

A good thing

Taken together, the findings are highly reassuring. They indicate that national and international safety limits are protective. Mobile phones emit low-level radio waves below these limits, and there is no evidence that exposure at these levels affects human health.

Even so, ongoing research remains important. Technology is advancing quickly, and with that progress radio waves are being used in new ways and across different frequencies. It is therefore essential that scientific work continues so that exposure to radio waves from these technologies remains safe.

The task now is ensuring this new evidence helps correct the enduring misconceptions and misinformation about mobile phones and brain cancer.

There is still no evidence of any established health effects from exposures related to mobile phones, and that is a good thing.

Sarah Loughran, Director Radiation Research and Advice (ARPANSA), and Adjunct Associate Professor (UOW), University of Wollongong and Ken Karipidis, Assistant Director, Health Impact Assessment, ARPANSA and Adjunct Associate Professor (Practice), School of Public Health and Preventive Medicine, Monash University

This article is republished from The Conversation under a Creative Commons licence. Read the original article.