LOS ANGELES — Cellphone users may be at increased risk for two types of rare cancers and should try to reduce their exposure to the energy emitted by the phones, according to a panel of 31 international scientists convened by an agency within the World Health Organization.
Studies so far do not show definitively that cellphone use increases cancer risk, said the authors of the consensus statement issued Tuesday by the WHO. However, “limited” scientific evidence exists, they said, to suggest that the radio frequency energy released by cellphones may increase the risk of two types of cancers: glioma, a type of brain cancer, and acoustic neuroma, a tumor of the nerve that runs from the ear to the brain.
Both types of cancers are rare: In the U.S., about 10,000 to 12,000 people develop a glioma each year and about 3,000 develop acoustic tumors. The elevated risk roughly doubles that risk after a decade of cellphone use, according to some studies. But the number of cellphone users worldwide — about 5 billion — means a potential cancer link should be taken very seriously, said Dr. Jonathan Samet, chairman of the department of preventive medicine at the University of Southern California’s Keck School of Medicine and the chairman of the panel that issued the report.
“What we have here is a warning from a public health point of view,” Samet said. “We have half the world’s population already using cellphones, and people are using them younger and longer. We clearly need to keep track of this.”
Other scientists said that they remained skeptical of the link, which is mired in contradictory science, and that they found the decision by the WHO perplexing.
“I find the conclusions surprising given that there is increasingly strong evidence that cellphone use has no association with brain cancer occurrence,” said David Savitz, a professor in the departments of epidemiology and obstetrics and gynecology at Brown University and a researcher on environmental exposures and health. “With few exceptions, the studies directly addressing the issue indicate the lack of association.”
Cellphones were placed in a “possibly carcinogenic to humans” category by the International Agency for Research on Cancer, which develops scientific cancer-prevention strategies for the WHO. The agency’s four other categories for substances or agents: carcinogenic to humans; probably carcinogenic to humans; not classifiable; and probably not carcinogenic to humans.
Scientists have long debated the potential cancer risk linked to cellphone use, but this statement marks the first time an independent group of scientists has taken anything other than a neutral stand.
“This is a major scientific consensus conference that has basically implicated cellphone radiation with increased tumor risk,” said Joel Moskowitz, director of the Center for Family and Community Health at the University of California at Berkeley’s School of Public Health and a longtime advocate of more research on the potential cellphone-cancer link. “I think they are particularly concerned about cellphones just because of the widespread utilization. It’s not like it’s some esoteric chemical used by industry that they think may be carcinogenic. Everyone is exposed to cellphones.”
Groups representing the wireless industry downplayed the significance of the report, noting that the WHO placed radio frequency electromagnetic fields in the “possibly carcinogenic” category, along with about 266 other agents, including gasoline and occupational exposure to dry cleaning.
Coffee and pickled vegetables are listed as “possibly carcinogenic” also, noted John Walls, vice president for CTIA-The Wireless Association, in a statement issued Tuesday.
“This is not groundbreaking. It is a review of what already existed,” Walls said in an interview. “It’s not the revelation that some would like to make it out to be.” A summary of the panel’s findings will be released online at the WHO website and published in the July 1 issue of the journal Lancet Oncology.
