Mobile phones are not linked to brain and head cancer, a comprehensive review of the highest quality available evidence commissioned by the World Health Organization has found.
Led by the Australian Radiation Protection and Nuclear Safety Agency (Arpansa), the systematic review examined more than 5,000 studies from which the most scientifically rigorous were identified and weak studies were excluded.
The final analysis included 63 observational studies in humans published between 1994 and 2022, making it “the most comprehensive review to date”, said the review’s lead author, Associate Prof Ken Karipidis.
“We concluded the evidence does not show a link between cell phones and brain cancer or other head and neck cancers.”
The review published on Wednesday focused on cancers of the central nervous system (including brain, meninges, pituitary gland and ear), salivary gland tumors and brain tumors.
The review found no overall link between mobile phone use and cancer, no link with long-term use (if people use their mobile phones for 10 years or more), and no link with amount of mobile phone use (the number of calls made or time spent on the phone).
“I am quite confident with our conclusion. And what makes us very confident is … even though cell phone use has skyrocketed, brain tumor rates have remained stable,” said Karipidis, Arpansa’s assistant director for health impact assessment.
Cell phones – like anything that uses wireless technology, including laptops, radio and TV broadcasts, and cell towers – emit radio frequency electromagnetic radiation, also known as radio waves.
Karipidis, who is also the vice-chairman of the International Commission on Non-Ionizing Radiation Protection, said people hear the word radiation and assume it is similar to nuclear radiation.
“And because we use a mobile phone close to the head when we make calls, there is a lot of concern,” said Karipidis.
“Radiation is basically energy that moves from one point to another. There are many different types, for example ultraviolet radiation from the sun,” he said.
“We are always exposed to low-level radio waves in the everyday environment.”
Although exposure from cell phones is still low, it has since been much higher than exposure from any other wireless technology source phones are used close to the head, Karipidis said.
The connection between cell phones and cancer arose from early studies where researchers examined differences between a group of people with brain tumors, and a separate group without the cancers by asking both about their exposure history.
The results of this kind of study design tend to be biased because while the group without the tumor provides good information, the group with the tumor tends to overreport their exposure, Karipidis said.
Based on some of these early studies showing that there may be a possible association with brain cancer as a result of using mobile phones against the head for many hours, the WHO’s International Agency for Research on Cancer (IARC) radio frequency fields such as those from mobile phones have been identified as a possible cancer risk.
Karipidis said that although many members of the public became concerned because of the IARC classification, “this classification does not mean that much”.
The IARC has different classifications of cancer riskwith substances that can be classified as a “definite” carcinogen (such as smoke), or ash “probable” or “possible” carcinogens.
By designating radiofrequency electromagnetic fields as a possible carcinogen in 2011, the WHO put them on par with hundreds of other substances for which evidence of harm is uncertain, such as aloe, pickled vegetables and working in a dry cleaner.
However, some high-profile doctors such as Australian neurosurgeon Charlie Teo did at the time raised the profile of the IARC’s decision publicly around cell phones and cancer.
Since that classification, Karipidis said many more cohort studies have been published that don’t rely on people to remember their past exposure, and in 2019 the WHO commissioned a number of systematic reviews to look at the health effects of radio waves.
Karipidis said another The WHO provided a systematic review that looked at male fertility and radio waves found that there was no evidence of a link between phones and a drop in sperm count.
One more The WHO provided a systematic review that looked at female fertility did find an association in some scenarios such as affecting birth weight, “however, that association occurred when exposure to radio waves was well above the safety limit,” Karipidis said.
Tim Driscoll, a professor at the University of Sydney and chairman of the Australian Cancer The council’s occupational and environmental cancer committee said the systematic review’s methodology was strong and the researchers should be considered independent.
“I think people should feel reassured by this study … but it’s worth just remembering that the studies aren’t perfect, but the weight of evidence is definitely that cell phones should be considered safe to use in terms of of any concern about increased risk of cancer,” Driscoll said.
Karipidis and his colleagues are now working on the second part of the study, which will examine cancers less commonly associated with cellphones, including leukemia and non-Hodgkin’s lymphoma.
Karipidis said concerns about the links between cancer and cell phones should be put to rest, but stressed that as technology will continue to develop, it is important to continue research.
