The question of whether cell phone use can lead to brain tumors (benign or malignant) has no definitive answer; studies so far have failed to find an association. Cell phones emit electromagnetic radiation close to the head that theoretically can damage DNA and lead to brain tumors. The leading researcher in the field, Henry Lai, Ph.D., of the University of Washington in Seattle, notes that 70 to 80 percent of the energy emitted by a cell phone antenna is absorbed by the head. However, because brain tumors can take 30 to 40 years to develop, we just don't know yet whether, over time, we'll see an increase in brain tumors attributable to cell phones. We do know that the number of cell phones in use in the United States grew from 55 million in 1997 to more than 180 million in 2004.
Dr. Lai has warned against giving cell phones to young children simply because the long-term health effects are unknown. He has voiced concern that the growing brain in children may be more susceptible to radiation than the brains of adults. For the same reasons, the chairman of Britain's National Radiological Protection Board has advised parents not to give cell phones to children under the age of eight. Most of the studies done so far have focused on adults, not children, and most have looked at short term use (cell phones haven't been around long enough or used long enough by a large number of people to assess long-range health effects).
Until we know for sure whether cell phones present any danger (to adults as well as children), it makes sense to take the following precautions:
- Save lengthy phone conversations for conventional phones.
- When in your car, use a cell phone that has a remote antenna outside the vehicle.
- Always use a headset and keep the phone itself away from your body.
- Find out how much radiofrequency energy your cell phone emits. (This measurement is called the Specific Absorption Rate or SAR; you can get the SAR for your cell phone via the FCC at http://www.fcc.gov/oet/rfsafety/sar.html. The SAR permitted in the United States is 1.6 watts per kilogram.
Cell phones have become an indispensable convenience for people around the world, but until we know more about their risks, you may want to follow the advice to use them prudently and not give them to your kids.
Andrew Weil, M.D.