It is a question with hang-ups stretching back 30 years but scientists say they have made a definitive call on whether mobile phones cause brain cancer.
A World Health Organisation review of more than 5000 studies, led by Australian scientists, released an answer on Wednesday, revealing it found no increased risk of several cancers associated with mobile phone use.
Researchers say the findings, to be published in the Environmental International journal, apply regardless of how long people spend on the phone or how many years they use the technology.
The finding comes after widespread concern about the impact of mobile phone radiation and a warning from the International Agency for Research on Cancer in 2011 that classified phone radiation as a possible carcinogen.
Eleven researchers from 10 countries conducted the latest review, commissioned and part-funded by the WHO and led by scientists at the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA).
It probed more than 5000 papers examining the effects of mobile phone radiation between 1994 and 2022, and analysed 63 observational studies on the topic.
Researchers examined whether electromagnetic energy increased incidents of three types of brain cancer, including cases in children, as well as cancer of the pituitary gland, salivary glands, and blood.
ARPANSA health impact assessment assistant director, Associate Professor Ken Karipidis, said concerns about the impact of mobile phone radiation were widespread and persistent, and the comprehensive review had been designed to provide a well-rounded view.
"We've been talking about this issue for the last 30 years," he said.
"There have been many studies in the past that have had contrary conclusions so it's important to combine all the evidence and really let people know what's really going on."
Assoc Prof Karipidis said researchers on the project analysed the 63 most relevant studies for signs of individual cancers and found no higher risks.
"The evidence does not show a link between mobile phone use and brain cancer or other head and neck cancers," he said.
"We also found no association with prolonged use, so if people use their mobile phones for 10 years or more we didn't find an association, and we also found no association with the amount of mobile phone use, either the number of phone calls that people make or the time that people spend on the phone."
University of Auckland cancer epidemiology honorary professor Mark Elwood, who co-authored the study, said its findings were made with "moderate confidence" which was the highest rating in research without access to clinical trials.
The research could not answer questions about unusual mobile phone exposure or rare cancers due to a lack of research, he said, and its findings applied to 3G and 4G networks.
"There are no major studies yet of 5G networks but there are studies of radar, which has similar high frequencies," Prof Elwood said.
"These do not show an increased risk."
ARPANSA research scientist Rohan Mate, who managed the organisation's Talk to a Scientist program, said the finding could encourage and reassure individuals about their safety.
"We're hoping that these results will be another way we can reassure them about their safety (and) hopefully relieve them of some of their anxiety surrounding engaging with technology," he said.
