The World Health Organization and experts working with the International Agency for Research on Cancer said Tuesday they have classified radiofrequency electromagnetic fields as potentially carcinogenic.
Photograph by: Steve Makris, Edmonton Journal
Radiation emitted by cellphones may be carcinogenic to humans, the World Health Organization's cancer research institute ruled Tuesday, in a move that will likely prompt nations to review their mobile-phone regulations.
The International Agency for Research on Cancer said there is enough evidence to warrant the new classification of radio-frequency electromagnetic fields as potentially carcinogenic, based on an increased risk of glioma, a malignant type of brain cancer, associated with wireless phone use.
With estimates of five billion cellphone users worldwide, a working group of 31 scientists, including two Canadians, assessed the evidence of the potential link between health and cellphone use in Lyon, France, at a weeklong session to find that exposure to electromagnetic fields, such as those emitted by wireless communication, could be harmful.
The dramatic findings, which will be published in the IARC Monagraph, are the first to offer more concrete results to one of the most worrisome public-health questions.
The working group of researchers tackled exposure data, hundreds of studies of cancer in humans and the studies of cancer in experimental animals along with a plethora of other data. The investigations looked at the possibility of exposure associated to microwaves, transmission of radio, television and wireless telecommunication and personal exposure from cellphones.
After analyzing results, the researchers classified the electromagnetic fields as "Group B" or "possibly carcinogenic."
This category is used when there is inadequate evidence of carcinogenicity in humans but there is sufficient evidence in animals. Other categories include "carcinogenic," "probably carcinogenic" or "not carcinogenic."
Since 1971, more than 900 agents have been evaluated and 400 have been identified as carcinogenic or potentially carcinogenic to humans.
"The evidence, while still accumulating, is strong enough to support a conclusion . . . the conclusion means that there could be some risk and therefore we need to keep a close watch for a link between cellphones and cancer risk," Dr. Jonathan Samet, a University of Southern California professor who was chairman of the group, said in a statement.
The researchers said that additional research needs to be done to support their findings.
The group did not quantitate the risk but previous studies showed a 40 per cent increased risk for gliomas in the highest category of cellphone users, which was a reported average of 30 minutes per day over a 10-year period.
"Pending the availability of such information, it is important to take pragmatic measures to reduce exposure such as hands-free devices or texting," IARC director Christopher Wild said in a news release.
The conclusions from the weeklong meeting could be used by international officials to implement new safety regulations.
Epidemiology professor Jack Siemiatycki of the University of Montreal and Health Canada's James McNamee, a specialist in electromagnetics, represented Canada at the session.
Tuesday's release comes a year after the agency published results of the largest international study on cellphone use and brain cancers that did little to settle the debate.
Overall, the INTERPHONE study, using data from adults from 13 countries, including Canada, found "no increase of risk" of either glioma or meningioma associated with the use of cellphones, but there were "suggestions of an increase risk of glioma at the highest exposure levels."
Biases in the study, however, prevented a "causal interpretation" that would directly link cellphone radiation to the tumour.
Meningioma is a more common and frequently benign tumour, while glioma is a rarer but deadlier form of cancer.
At the time of the release last May, Canadian researchers who contributed to the massive study delivered conflicting messages about the results.
Siemiatycki called the results "ambiguous" and "perplexing," and said the study's methodological problems meant they group could not say whether there was more evidence of a danger or safety than a decade ago.
The University of Ottawa's Daniel Krewski acknowledged there were different ways to interpret the data, but overall said they were "reassuring."
Meanwhile, the massive study, led by Canadian researcher and former University of Ottawa professor Elisabeth Cardis, said "possible effects of long-term use of mobile phones require further investigation," noting that the majority of subjects "were not heavy users by today's standards."
The study also noted that cancer research involving children's use of cellphone was needed.
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