If you've ever cursed an oblivious driver who's yammering away on his cell phone (or been such a driver yourself), you know the most obvious health risk these convenient devices pose. But you might also wonder about the whisperings of a connection between cell phones and chronic illnesses, such as cancer. Is this paranoid thinking, or prescient?
Many oncologists and other health experts are asking themselves the same question. Some warn that the devices may indeed increase the odds of developing brain tumors and other health problems, while plenty of experts maintain there's no evidence of risk.
Last September, oncologist Ronald Herberman, director of the University of Pittsburgh Cancer Institute, told the House Subcommittee on Domestic Policy, "I cannot tell this committee that cell phones are definitely dangerous. But I certainly cannot tell you that they are safe."
A close look at the research reveals mixed evidence. "The jury's still out, but I'm worried," says Louis Slesin, Ph.D., editor of Microwave News, an online publication that reports on the effects of electromagnetic radiation. But rather than waiting years for a verdict, it makes sense to arm ourselves with information now. Here's what we know (and don't know) about cell phones and health.
At the root of the concern lies the type of electromagnetic radiation that cell phones emit, known as RF (radio frequency) energy. This frequency is similar to that used in microwave ovens and AM/FM radios yet much lower than that produced by X-ray machines known to increase cancer risk. Still, questions remain about exposure to low-level RF energy, particularly over the long term. Because we typically hold cell phones close to the head, some experts worry about the effects on the brain and nervous system. The majority of studies have not shown a significantly increased risk of brain or other head tumors, says Michael Thun, M.D., emeritus vice president of epidemiology and surveillance research for the American Cancer Society. The FDA and World Health Organization maintain that there isn't enough evidence to definitively link cell phones to health problems.
However, most studies have looked at people who used cell phones for just three to five years. Some studies of long-term use (10 years or more) do suggest increased odds of getting certain tumors. Swedish researchers, for example, found long-term users almost four times more likely to develop a type of tumor called an acoustic neuroma on the side of the head where they usually held the phone. A review of nine studies revealed that long-term users showed a consistent pattern of increased risk for one of the deadliest types of brain cancer, glioma tumors. (Results varied widely among the nine studies, however.)
Risk may also vary by location. According to a study in the February 2008 issue of the American Journal of Epidemiology, long-term, heavy cell-phone users living in rural areas had an increased chance of developing parotid (salivary) gland tumors, while cell-phone users in urban areas did not. A possible reason? The harder a phone works to establish a connection, says Slesin, the more RF it emits.
Tumors aren't the only health concern. Preliminary research suggests the devices may trigger changes in human skin cells, the consequences of which we still don't know. And a 2008 study found that men who frequently used cell phones had decreased semen quality, a factor in infertility.
More studies on cell phones and health are in the works (though few in the United States), including full results from a multicountry initiative called Interphone. In the meantime, "it's perfectly reasonable to be cautious when using a cell phone," says Thun. Here's how to take precautions without sacrificing convenience:
- Limit use. "Cell phones are one of the most successful and useful technologies we have," says Slesin. "But that doesn't mean you need to hold one to your head for hours at a time." Reduce exposure by keeping calls brief and using a landline when possible.
- Hands off. Hands-free devices like headsets and earplugs could reduce health risks by keeping the cell phone away from your head. Keep in mind that Bluetooth earpieces may not mitigate risk, advises Slesin, who says little has been published on the topic.
- Be choosy. When it's time to purchase a new model, look for one with a low specific absorption rate (SAR), the amount of RF absorbed by the head of a cell-phone user. For more information, visit fcc.gov/cgb/sar/.
- Store safely. Avoid carrying your cell phone on your body, such as in a pocket or on a belt. Don't keep it close to your body at night.
- Keep kids safe. The lack of long-term studies on children, and their growing nervous systems, makes cell phones a particular concern for kids.