[See: A Guide to Cancer Prevention.]
Meanwhile, the U.S. Federal Communications Commission is in the midst of reviewing its safety guidelines for radiofrequency exposure. The current guidelines, based on recommendations from federal health and safety groups like the Environmental Protection Agency and Food and Drug Administration, were adopted in 1996.
"The U.S. has among the most conservative standards in the world," says Neil Grace, FCC senior communication adviser. "As part of our routine review of these standards, which we began last year, we will solicit input from multiple stakeholder experts, including federal health agencies and others, to guide our assessment."
Lori Wirth, medical director of the Center for Head and Neck Cancers at Massachusetts General Hospital, calls Hamzany's data "very interesting and intriguing," but adds that it merits a "healthy amount of caution." "We don't know if there is a direct link between markers of oxidative stress in saliva and the risk of cancer," she says. "We do know that oxidative stress can lead to DNA damage, free radical damage of DNA, and that is one potential mechanism of carcinogenesis."
But the more immediate threat from cellphones, she argues, has nothing to do with cancer, and points instead to the more mundane hazards of distracted driving.
"There's very good data that shows that talking on the phone and texting on the cellphone while driving leads to real death on the road, and that's something that we have direct evidence and direct data on," Wirth says. "Honestly, that's where the real harm from cellphones in our society is coming from."