A study by the National Institutes of Health found that cell phone radiation can increase brain activity. The researchers found evidence that cell phone radiation does affect the human brain in some way, but they're unsure as to whether this is harmful or not.
This particular study consisted of 47 test subjects who used cell phones for various periods of time. Using PET scans, researchers measured the brain activity of these test subjects when the phone was off, on, muted and held to the ear. What they found was that more than 50 minutes of exposure to an in-use cell phone causes increased brain activity by about 7 percent in areas near the antenna.
Researchers were able to find this by measuring the brain's consumption of glucose instead of measuring cerebral blood flow like other studies have in the past.
"What we showed is glucose metabolism increases in the brain in people who were exposed to a cell phone in the area closest to the antenna," said Volkow.