Recent news reports out of Britain are giving credence to the theory that cellular phone use increases the risk of brain cancer. What are the facts?
Think of cellular phones as little radio stations, beaming voice and data to the telephone network via electromagnetic waves called radiofrequency (RF) radiation. Cell phones emit RF radiation with a 800-900 MHz frequency, which is close to the 2,450 MHz frequency used by microwave ovens. The 1,000-watt power of the average microwave oven, however, is significantly greater than a cell phone's 0.6-watt output. Exposure to high levels of RF--many times the amount emitted by cell phones--causes biological damage, but the effects of lower exposure levels are not well established. Since this radiation penetrates the human body, critics theorize that cellular phones could cause physical damage to cells--either through heating or another form of energy release.
Some scientists dispute this hypothesis, arguing that RF energy from cellular phones is significantly weaker than the energy occurring naturally in the body's cells, and would therefore be unable to physically alter them. They also contend that even after long exposure periods, the phones could only cause a fraction of a degree increase in cell temperature--well within the body's normal range. In the absence of another plausible mechanism by which RF radiation could cause damage, they say that cell phones should be presumed safe.
Most RF exposure studies are inconclusive. They either fail to find effects, or have produced statistically insignificant findings. Selecting subjects for ongoing cellular phone studies is a challenge, since the highly exposed population remains relatively small, and many forms of cancer may take years to develop. But one recent British study found that RF may cause brain cells to react as if they were being heated (though no temperature increase was observed), which investigators hypothesized may damage cell function over long periods of time. Another found that cellular phone use was associated with an increased frequency of a certain type of brain tumor (although the overall risk of cancer was not found to increase). Most scientists call for further research and testing. Some cellular phone users are reducing possible risk by using earpiece and microphone headsets that plug into the telephone and make it possible to talk without the phone being held to the head.
Regulatory agencies like the Food and Drug Administration and Federal Communications Commission hedge on the issue, neither guaranteeing cellular phones' safety nor recommending that users stop using them. And the greatest danger posed by cellular phones yet discovered is an increased likelihood of car accidents involving inattentive users.
(Click here to read the FDA's Oct. 20 update on cellular phone safety, and here to view the FCC's RF safety guidelines. In May, Radiation Research magazine published a scientific assessment of the research to date into the cell phone-cancer connection.)