Mobile phones may cause brain cancer in humans, a World Health Organization agency said, citing a review of studies.
Exposure to radiofrequency electromagnetic fields from handsets is greater than that from phone towers and base stations, Robert Baan, the senior scientist in charge of the International Agency for Research on Cancer report on the subject, said on a conference call with reporters. The fields are “possibly” carcinogenic, the same category as diesel fuel, chloroform and working as a firefighter, according to the IARC, based in Lyon, France, which classifies cancer risks.
This is the first time an agency working group has surveyed research on radiofrequency electromagnetic fields to make a definitive classification, the IARC said yesterday. The agency didn’t issue guidelines for cell-phone use and said more study is needed after finding some evidence for an increased risk of glioma, or brain cancer.
“It’s not at the moment clearly established that the use of mobile phones does in fact cause cancer,” said Kurt Straif, head of the IARC Monographs Program, adding that the research points to ways in which risks may be lowered. “For example, the highest exposure is from voice calls. If you use text messaging or headsets, this will lower the exposure.”
Concerns have risen in recent years that cell phones might be harmful to the health of people who use them, according to the WHO agency, which said there are 5 billion wireless subscriptions worldwide. The U.S. Federal Communication Commission has said devices with a specific absorption rate, the amount of radio-frequency energy absorbed by the body, within a set limit are safe.
The IARC considers studies in its reviews that may have flawed data, John Walls, vice president of public affairs for the CTIA wireless industry trade group in Washington, D.C., said in an e-mailed statement yesterday. The classification doesn’t mean mobile phones cause cancer, Walls said.
Nokia Oyj, the largest maker of mobile phones by the number of units sold, said today its products comply with international exposure guidelines and limits set by public health authorities. Apple Inc., the maker of the iPhone, didn’t respond to requests for comment yesterday.
“It is important to note that the IARC has not classified radiofrequency electromagnetic fields as definitely nor even probably carcinogenic to humans,” Espoo, Finland-based Nokia said in an e-mailed statement. The agency has “only concluded that, based on limited evidence, it may be possible that there could be some increased risk for certain cancers.”
The working group of 31 scientists from 14 countries met for seven days last month to study exposure to radiofrequency electromagnetic fields from mobile phones, radar, microwaves and radio, television and wireless signals. By classifying cancer risks, the IARC aims to provide scientific advice to government authorities.
The most recent research considered dated to 2004, and exposure levels from handsets have dropped over time, said Jonathan Samet, a University of Southern California professor and chairman of the working group.
The age of the studies also means the participants had used their phones for no more than 10 to 15 years, leaving open the question of the effect of longer-term exposure. The agency said the evidence was limited, and it may re-evaluate today’s recommendation once more recent research is available.
About a quarter of the more than 900 agents the agency has evaluated were determined to be “possibly carcinogenic.” The IARC lists substances as carcinogenic, probably carcinogenic, possibly carcinogenic, not classifiable and probably not carcinogenic. More than half the substances it has reviewed are listed as not classifiable.
The categorization that mobile phones are possibly carcinogenic to humans is appropriate, said Malcolm Sperrin, director of medical physics and clinical engineering at the Royal Berkshire Hospital in Reading, England.
“The justification for such a risk indicator respects the anecdotal evidence,” Sperrin said in comments distributed by the Science Media Centre in London. “The publication of more data along with a comprehensive justification of any conclusions is eagerly awaited, especially in relation to children.”