Are cellphones linked to cancer? What experts say about the possible risk

It’s been studied for years only to come back with a mixed bag of results — are cellphones linked to cancer?

The preliminary findings from a U.S. study is warning that radiation from the ubiquitous devices could be tied to cancer, but critics say the research is confusing and causing unnecessary fear.

The study is out of the U.S. National Toxicology Program where scientists experimented on mice and rats, exposing them to radiofrequency radiation coming from cell phones.

The rodents were exposed to the radiation for about nine hours a day from before birth through to about two years of age.

Based on the preliminary results — this is just a sneak peek and the researchers say the rest of the findings won’t be released until 2017 — male rats were most affected.

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Those who had constant and heavy doses of the cellphone radiation ultimately developed brain and heart tumours. For some reason, female rats didn’t.

“Overall we feel that the tumours are likely to be related to the exposures,” Dr. John Bucher, associate director and lead author of the study, said in a telephone briefing last Friday about the findings.

But he concedes, the study was done on mice and rats, all over the body, and at much, much higher levels of exposure than what humans get from cellphones.

“These exposures were done to the whole body of the animals and that, of course, is different than the exposure one would receive from a cellphone which would be held next to a much smaller area of the head,” he explained.

“It may well be that current cellphone use is safe. This is an issue we continue to look at,” he said.

Tweet This Click to share quote on Twitter: "These exposures were done to the whole body of the animals and that, of course, is different than the exposure one would receive from a cellphone which would be held next to a much smaller area of the head," he explained.</p><p>"It may well be that current cellphone use is safe. This is an issue we continue to look at," he said.

But critics weren’t happy with the study’s findings and the media coverage, with some reports suggesting that your cellphone could kill you.

Dr. Aaron Carroll, a pediatrics professor at the Indiana University School of Medicine, said experts can’t “cherry-pick” in science.

He pointed out that it’s odd that male rats were vulnerable to cancers but female rats weren’t. What happens with rodents can’t be extrapolated to apply to humans, too.

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“Given the small number of rats in the study, the many comparisons done, and the low rates of cancer overall, we have to be concerned with the validity of the results,” he warned in a New York Times piece.

Dr. Paul Demers, who directs Cancer Care Ontario’s Occupational Cancer Research Centre, said cellphone radiation is such a new technology, it’s too early to predict what its harms may be.

Right now, it’s unclear if and how radiofrequency radiation tampers with cancer risk. This type of radiation comes from microwaves, radio waves, electromagnetic fields generated from power lines, and even cellphones.

“We don’t have an agreed upon or understood method on how this influences risk of cancer. That’s part of the uncertainty of this,” Demers told Global News.

Tweet This Click to share quote on Twitter: "We don't have an agreed upon or understood method on how this influences risk of cancer. That's part of the uncertainty of this," Demers told Global News.

He’s also a University of Toronto professor who served as chair for the Royal Society of Canada’s own review on radio frequency fields.

For now, he doesn’t think Canadians have anything to worry about.

Rob Nuttall, associate director of health policy at the Canadian Cancer Society, agrees.

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Cellphones have been a major part of Canadians’ daily lives for nearly two decades now. In that time frame, brain cancer rates haven’t increased at all, he suggests.

On its website, the cancer society suggests concerned Canadians can stick to headsets or limit their use of cellphones if they’re worried.

In 2011, the World Health Organization concluded that cellphones are “possibly carcinogenic.” That lumped cellphones in the same category as certain dry-cleaning chemicals and pesticides, for example.

The higher risk groups include “probable” and “known” carcinogens to humans.

Asbestos, diesel engine exhaust, and sun exposure have a much higher effect on cancer risk, for perspective, Demers said.

Read the preliminary findings of the study.

carmen.chai@globalnews.ca
Follow @Carmen_Chai