An international group of 23 prominent doctors and public health researchers and officials is warning that cell phone use may increase the risk of brain cancer.
One of those who signed, Dr. Ronald Herberman, the head of the University of Pittsburgh Cancer Institute, went so far as to advise his own employees to limit cell phone use.
The actions will likely add to a long-running debate on which there is little consensus among medical authorities.
"The most recent studies, which include subjects with a history of cell phone usage during the last 10 years, show a possible association between certain benign tumors ... and some brain cancers on the side the device is used," the statement reads in part.
The group behind the letter is an ad hoc group of cancer and public health experts concerned about the potential risk from cell phones. None were from Maryland-based institutions. Among those who signed the new letter are Dr. David Carpenter, director of the Institute for Health and the Environment at the University of Albany, and Herberman, director of the University of Pittsburgh Cancer Institute.
"Really at the heart of my concern is that we shouldn't wait for a definitive study to come out, but err on the side of being safe rather than sorry later," Herberman said. In the memo, sent to about 3,000 faculty and staff yesterday, he says children should use cell phones only for emergencies because their brains are still developing.
The key architect of the warning was Devra Lee Davis, head of the department of environmental oncology at the University of Pittsburgh. "The question is do you want to play Russian roulette with your brain," she said. "I don't know that cell phones are dangerous. But I don't know that they are safe." The advisory she and the others signed suggests 10 measures to limit exposure to electromagnetic radiation emitted by the cell phones, such as shortening conversations and keeping the phone away from the head. It also recommends that children not use cell phones except in emergencies.
"It's the first time such a group of public health experts have spoken out for precaution," said Louis Slesin, editor of Microwave News, a Web site that tracks electromagnetic radiation and health.
Scientists remain divided on the issue. A study published this spring in the International Journal of Oncology examined several previous studies, and found that there was an association between long-term cell phone use and some tumors. Several studies have found that people who have brain cancer and were heavy cell phone users tended to have tumors on the side of the head they used their phone.
But other studies have found no link between cell phone use and cancer. A 2008 University of Utah analysis looked at nine studies with thousands of brain tumor patients and concludes, "We found no overall increased risk of brain tumors among cellular phone users. The potential elevated risk of brain tumors after long-term cellular phone use awaits confirmation by future studies." Studies last year in France and Norway concluded the same thing.
Cell phones emit a small amount of electromagnetic radiation. Some researchers argue that chronic exposure to this radiation may raise cancer risk, perhaps by heating brain tissue or damaging DNA. Many researchers worry about children's exposure, because their skulls are thinner and their brains are still developing.
In January, the National Academy of Sciences issued a report calling for more research.