How Safe Is Your Cell Phone?

Dariusz Leszczynski, a research professor at Finland's Radiation and Nuclear Safety Authority in Helsinki, has done studies indicating that RF radiation may create a stress reaction in the cells that line blood vessels, leading to a dangerous breach in the blood-brain barrier. "Mobile-phone radiation may be able to indirectly hurt cells, perhaps by interfering with their ability to repair normal DNA damage," he says. "Given the scientific uncertainty, it's premature to say the use of cell phones is safe."

If RF radiation increases the chances of developing brain cancer, it should show up in long-term studies of cell-phone users. But many epidemiological studies have found no clear connection, including a 2007 Danish Cancer Society study of 421,000 cell-phone users, which led many in the media to conclude that mobiles are harmless. To date, "peer-reviewed scientific evidence has overwhelmingly indicated that wireless devices do not pose a risk," says John Walls, a spokesman for CTIA, a global wireless association. (See how to prevent illness at any age.)

There are problems with many of these studies, however. For starters, the Danish one — which reviewed the medical records of people who had signed up for cell phones from 1982 to 1995 — didn't include all the business users, who were among the earliest adopters and most intensive users, because they were not billed directly.

Also, the study looked only at tumors that were diagnosed by 2002 — not long after daily use of cell phones became widespread. Brain cancers can take several decades to develop, so it might be many years before a measurable bump in cancer rates shows up. "The latency period we have is far too short," says Dr. Siegal Sadetzki, a cancer researcher at Israel's Gertner Institute whose epidemiological studies have found some connections between cell-phone use and salivary-gland tumors. "And today, people are using the phone much more heavily." (See TIME's special report "How to Live 100 Years.")

Sadetzki served as Israel's principal investigator in the Interphone study, which was conducted over the past several years by 13 countries, most of them European. The Interphone results initially were to be published in 2006, but the final report has been postponed repeatedly, and the study investigators are reportedly deeply divided. In the U.S., which isn't one of the Interphone countries, the National Toxicology Program is launching studies of the health effects of cell phones. But peer-reviewed results won't be available until at least 2014.

That's a long time to wait for definitive data. The good news is that there are easy ways for those concerned about RF radiation to cut down on exposure. Using your cell phone's speaker or connecting a wired headset — while keeping the handset away from your body — drastically reduces RF exposure. (Bluetooth headsets help too, but they still emit some radiation.) And given the potentially more serious risks for children, who have thinner skulls than adults, parents might want to wait before handing teens their first phone — or at least ensure they use it mostly for texting.

Meanwhile, a start-up, Pong Research, is selling cell-phone cases that significantly reduce radiation exposure by channeling waves away from the head. Says Alfred Wong, Pong's chief scientist and a professor emeritus of physics at UCLA: "I think it's best to avoid as much of the risk as possible until the verdict is in."

That's exactly what Boland and other advocates of warning labels are arguing. It's true that cell-phone use has yet to be linked to cancer risk. "Scientifically speaking, we don't have the proof yet," says Sadetzki. "But as a public-health concern, I'm saying we definitely should adopt precautions."

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