Background

Cellphones emit radio waves, a type of nonionizing radiation that has caused concern that they could be linked to an increased risk of developing cancer.

In 2011, the International Agency for Research on Cancer (IARC), which is part of WHO, classified radio wave exposure as a possible carcinogen to humans. However, according to Ken Karipidis, lead author of the most recent review and health impact assessment assistant director for the Australian Radiation Protection and Nuclear Safety Agency, said that the observational studies IARC relied on for their classification were flawed.

Specifically, IARC relied on case-control studies that compared the responses of those with brain cancer against those without, which Karipidis said can be "somewhat biased." Typically, a person with a brain tumor "wants to know why they've got the brain tumor and tends to overreport their exposure," Karipidis said.

Since IARC's classification, "a lot more studies have come out" on radio waves and they've been "quite extensive," Karipidis said, which prompted WHO's commission of the latest review.

According to Karipidis, people hear the word radiation and assume it's similar to nuclear radiation. "And because we use a mobile phone close to the head when we're making calls, there is a lot of concern," he said.

"Radiation is basically energy that travels from one point to another. There are many different types, for example, ultraviolet radiation from the sun," Karipidis added. "We're always exposed to low-level radio waves in the everyday environment."

Study details

For the systematic review, 11 experts from 10 countries looked at more than 5,000 studies, including 63 observational studies considered to be the most scientifically rigorous. The studies were published between 1994 and 2022, which Karipidis said makes the review "the most comprehensive review to date."

The review specifically focused on cancers of the central nervous system, including brain, meninges, pituitary gland, and ear, as well as salivary gland tumors and brain tumors.

Overall, the review found no association between cellphone use and cancer, including no association between prolonged use (defined as using cellphones for 10 years or more) and cancer, and no association with the amount of cellphone use per day and cancer.

The review also found there was no increased risks of leukemia or brain cancer in children exposed to radio or TV transmitters or cellphone towers, nor was there any association between cellphone towers in general and cancer.

"I'm quite confident with our conclusion," Karipidis said. "And what makes us confident is … even though mobile phone use has skyrocketed, brain tumor rates have remained stable."

Tim Driscoll, a professor at the University of Sydney and chair of the Australian Cancer Council's occupational and environmental cancers committee, said the review's methodology was strong.

"I think people should feel reassured by this study," Driscoll said, adding that "it's worthwhile just remembering that the studies aren't perfect, but the weight of evidence certainly is that mobile phones should be considered safe to use in terms of any concerns about increased risk of cancer." (May, The Guardian, 9/3; Pannett, Washington Post, 9/3; Loughran/Karipidis, The Conversation, 9/3)

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