The world's leading authority on cancer research has declared the radiofrequency electromagnetic fields emitted by devices such as cellphones are possibly carcinogenic, a major step that is raising new questions about cellphone safety.
The International Agency for Research on Cancer, which is part of the World Health Organization, made the announcement on Tuesday after 31 leading experts from 14 countries met in France to review the existing evidence.
The panel concluded that radiofrequency electromagnetic fields are possibly carcinogenic "based on an increased risk for glioma, a malignant type of brain cancer, associated with wireless phone use." Numerous other substances are considered "possibly carcinogenic," including gasoline, some pesticides and occupational exposure from dry cleaning and firefighting.
Although there are many sources of radiofrequency electromagnetic fields, such as near transmitters, cellphones are the highest source of exposure for most people because they are held directly to the head, allowing the body to absorb radiation.
But the group is also warning consumers not to panic because there is not enough scientific evidence to say that cellphones pose a serious health risk.
"The meeting didn't determine that cellphones cause cancer. It didn't determine that they probably cause cancer," Jack Siemiatycki, Guzzo chair in environment and cancer at the University of Montreal and member of the IARC panel, said in an interview from France. "It determined they possibly cause cancer."
The panel and other leading experts are calling for more research to help determine the nature of the potential risks.
It's an important undertaking, as the popularity of cellphones has skyrocketed over the past decade. Many researchers are particularly worried about the effects of exposure on children, whose brains are still developing and who are more vulnerable to potential health threats than adults are.
"The evidence is mounting, but there's still some uncertainty, which we are addressing through further studies," said Daniel Krewski, director of the McLaughlin Centre for Population Health Risk Assessment at the University of Ottawa.
As fears emerged in recent years about a possible connection between cellphones and cancer, Canada's telecommunications industry has maintained that they are safe.
On Tuesday afternoon, Bernard Lord, president of the Canadian Wireless Telecommunications Association, arrived late from a flight to give a speech at the Canadian Telecom Summit when he found himself faced with media asking for a response to the IARC report.
"None of the studies have been able to conclude that there was a direct link," he said in an interview. "There's more to be learned, and this opens up the opportunity for more research, which we fully support."
Mr. Lord added that product safety standards are set by the government and that cellphone companies "want to make sure that their products are safe."
"I will continue to use my mobile device every day," Mr. Lord said.
Erin Budd, on the other hand, isn't taking chances. The Toronto mother has a cellphone, but uses it only in hands-free mode and makes sure to keep it away from her body at all times.
"Cigarettes, years ago, no one believed it was bad for your health," she said. "It's best to err on the side of caution."
Health Canada says there is no convincing evidence that cellphones are a serious risk to health.
James McNamee, a research scientist with the Consumer and Clinical Radiation Protection Bureau at Health Canada and specialist in electromagnetics, who was also at the meeting, said the department will monitor the situation as new evidence emerges, but that consumers should not be too concerned.
"There could be some risk here and this needs to be watched carefully," he said in a telephone interview from France. "I think this is far from being an alarm-bell situation."
Health Canada advises consumers who are worried about the potential risks to use cellphones in hands-free mode and limit the length of calls. Other experts advise texting instead of calling.