True or False: Using a Cell Phone Increases the Risk of a Brain Tumor
Besides being a hazard to safe driving, cell phones have been accused of causing brain tumors. Where does this concern come from? Cellular (cell) phones use radiowaves to carry information between callers. The frequency of these waves ranges from about 850-1900 megahertz (MHz), which is somewhere between the frequencies used by FM radio stations and microwave ovens. The higher the frequencies, the greater the energy carried by the waves.While waves of higher energies can heat living tissues enough to cause damage, the heat generated by cell phones is so small that few scientists believe they can do any damage to human users. Nonetheless, some types of brain tumors have been increasingly diagnosed since the cell phone era began (most notably, acoustic neuroma , which can affect hearing). Still, no studies have conclusively proven a causal relationship between cell phone use and the development of brain tumors. But don’t hang up on the myth just yet–this one doesn’t have an easy answer.
Evidence Against the Claim
Numerous large studies have failed to show a clear connection between cell phone use and overall risk of developing brain cancer
. One study conducted in Sweden compared 233 brain cancer patients diagnosed between 1994-1996 with 466 controls (people who did not have brain cancer). Another study conducted by the American Health Foundation compared 469 brain cancer patients diagnosed between 1994-1998 in New York, Massachusetts, and Rhode Island with 422 controls. And a third study conducted by the US National Cancer Institute compared 782 brain cancer patients diagnosed in Arizona, Pennsylvania, and Massachusetts between 1994-1998 with 799 controls.All of these studies found that patients with brain cancer did not report using cell phones more than those in the control group. These findings were consistent, regardless of what type of brain cancer was present or where in the brain the tumor was located. Ironically, some of the findings indicated a lower risk of brain tumors among cell phone users, reasons for which were not determined. It may have been only a statistical anomaly.Also, most of the studies did not find a link between the side of the head on which the brain tumors occurred and the side of the head on which the cell phone was used. While the findings of the Swedish study were not conclusive on this point, researchers have pointed out that because the patients in the study knew which side their brain tumors were on, it may have biased the accuracy of their reported cell phone use. Two other more recent studies have had similar results. A study conducted in England from 2000-2004 looked at 966 people diagnosed with brain glioma
(a type of brain tumor) and 1716 controls. Researchers did not find evidence that cell phone usage increases the risk of the brain tumors studied. It also found no association with risk of brain tumors based on duration of use, side of use, or amount of cell phone use. These results were similar to those of a Danish study published in the April 12, 2005 issue of Neurology,
the scientific journal of the American Academy of Neurology. This study of 427 people with brain tumors and 822 people without, again demonstrated no increased risk of brain tumors with cell phone use, frequency of use, or number of years of use. The Danish study was somewhat unusual in that in addition to questioning participants about their cell phone habits, it also obtained records from their cell phone companies to document some of the participants’ phone usage, thus increasing the accuracy of the study. Despite this added reassurance, the study’s author pointed out that because a relatively small portion of the Danish population has used cell phones regularly for more than ten years, longer studies are needed to conclusively determine the long-term effects of cell phone use in this group.