Cell Phone Scare: What Do We Really Know About the Health Risks?

Last July, renowned cancer expert Dr. Ronald Herberman sent off a rather alarming note to the 3,000 faculty and staff members at the University of Pittsburgh warning that children should limit their use of cell phones to decrease their risk of cancer. "Although the evidence is still controversial, I am convinced that there are sufficient data to warrant issuing an advisory to share some precautionary advice on cell phone use," wrote Herberman, who heads the University of Pittsburgh Cancer Institute. He also advised adults to choose texting, Bluetooth headsets, or speakerphone options instead of holding a cell phone to the ear.

A few months later, Herberman was standing before the House Subcommittee on Domestic Policy, explaining

why he’d sent up this warning flare. After all, pinning down whether mobile phones -- or the many antenna towers that relay their calls via radiofrequency (RF) signals -- actually cause cancer or other health problems has been a notoriously tricky scientific endeavor. Studies investigating their risks have often been ambiguous and confusing, partly because cell phone technologies are still relatively new, and partly because many cancers take years to develop. Phones’ long-term impact on children, whose brains absorb more RF radiation than those of adults, also remains unclear.

For Herberman, some early study results are troubling enough to warrant caution: "Despite the lack of consistency in outcomes in all the cell phone publications, there are several well-designed studies that suggest that long-term (ten years or more) use of wireless phone devices is associated with a significant increase in risk for glioblastoma (glioma), a very aggressive and fatal brain tumor, and acoustic neuroma, a benign tumor of the auditory nerve that is responsible for our hearing," he testified.

Yet despite worries about their long-term effects, mobile phones are popular because they offer clear-cut short-term health and safety benefits: They can be a lifesaver in emergency situations, and help parents keep tabs on their kids’ whereabouts from a distance. According to the Wireless Association trade group, there are close to 270 million subscribers in the United States -- that’s out of about 300 million Americans.

Cell phone companies have been all too eager to stress their products’ harmlessness. Cell phones emit "non-ionizing radiation," similar to the kind produced by microwave ovens and cordless phones. (X-rays, on the other hand, are a form of ionizing radiation.) These items may heat up when used, but this form of electromagnetic radiation has long been considered unable to change the DNA of an organism -- and DNA breakdown is a possible precursor to cancer.

But cell phones’ explosion in the marketplace, and users’ tendency to wear them close to the body and hold them repeatedly to the same ear, have led scientists to take a second look. The results of international studies have been mixed. Probably the most thorough research so far is the thirteen-country Interphone study overseen by the World Health Organization, which received some funding from the cell phone industry. In some cases, as in the Nordic countries and Britain, cell phone subscribers who used the devices for ten years or more reported higher rates of glioma brain tumors on the side of the head on which they most often used their phones. But scientists relied on people’s recollection of which ear they used for phone conversations and how often they talked on the phone, and human recollection is not always reliable.

On the other end of the spectrum, Germany found no link at all between cell phone use and cancer. Both Israel and Japan, which have large populations of heavy cell phone users, urged more research. The Israeli study suggested there may be an association between heavy mobile phone use and the risk of salivary gland tumors but called for further study. Japanese researchers also said they needed a larger sample size to confirm any link between cell phone use and cancerous tumors.