The evidence is even greater because these studies were very well designed and not only looked at the association directly but also indirectly. For example, if there were a subtle link between brain tumors and cell phone use than one could imagine that only people who used their cell phones very frequently would be at a higher risk. If the studies pooled everyone together, they might miss the link in frequent users. However, the data showed that people who used their cell phone for over an hour a day, or for over five years, were no more likely to have brain tumors than people who used their phones for less than five minutes a day, or for less than six months. Brain tumor location One of the most compelling arguments against the association between brain tumors and cell phone use is based on the location of the tumor.
Most people tend to place the cell phone on the same side of the head when they speak.
Since the RF energy falls off very quickly with increasing distance from the antenna, the dose of energy on the side of the brain where the phone is held is much larger than on the other side of the brain. Several studies in cell phone users with brain tumors have demonstrated that there is no significant correlation between the location of the tumor and the side of preference of the cell phone user. Likewise, tumors in cell phone users are not significantly more frequent in areas of the brain closest to the ear than in other areas of the brain. One study, which did find a tendency for more tumors to appear on the side where the cell phone was used, showed that these tumors were not located in the part of the brain closest to the antenna. The result therefore most likely represented an accidental association.