The suspicion that cell phones may be linked to brain cancer has percolated for years. But the vast majority of scientific studies have shown no association between the two.
The National Cancer Institute has reviewed more than a dozen studies looking for a possible link to brain cancer. Scientists there have found little or no increased risk within the first 10 years of cell phone use.
In addition, from 1987 to 2005 — a period when cell phone usage increased dramatically and phones became more powerful — there was no upturn in the incidence of brain cancers in the United States.
Dimitrios Trichopoulos, a professor of cancer prevention at the Harvard School of Public Health, says that when you combine all the information known so far, there's no cause for alarm.
"It's nothing that would make us very much worried," Trichopoulos says.
British scientists participating in the Mobile Telecommunications and Health Research program also have weighed in. As part of the initiative, Lawrence Challis, emeritus professor of physics at the University of Nottingham, led a panel in England that reviewed 23 studies on cell phone use and health effects.
The panel concluded that radio-frequency radiation from cell phones poses no short-term health risk.
But Challis says that among the few studies that included people who had been using cell phones for more than a decade, there is uncertainty. Some studies identified a very slight increase in the number of brain cancers among cell phone users.
"There are slight hints of something" for people who have used cell phones for more than 10 years," says Challis. "But they are not totally convincing hints. All they are, are suggestions."
It's possible the cancers were due to chance.
People concerned about long-term exposure have several options. They can text message, use headsets or earpieces, or use landlines instead of mobile phones. Some experts also recommend not keeping your cell phone attached to your body.
The British scientists have advised parents to err on the side of caution.
"Children may be more sensitive to exposures," says Challis. That's why the committee discourages the use of cell phones by children.
During a congressional hearing on cell phones and cancer, another expert issued a similar warning. Dr. Ronald Herberman, head of the University of Pittsburgh's Cancer Institute, made headlines in July when he urged his faculty and staff to limit cell phone use. In testimony before a House subcommittee, Herberman said he believes cell phones may pose a larger risk for everyone than the current science sheds light on.
"I cannot tell this committee that cell phones are definitely dangerous," Herberman said. "But I certainly cannot tell you that they're safe."
Herberman urged the panel to work with the cell phone industry and independent researchers. He said everyone needs to work together to produce the best, most accurate, long-term study.