A preliminary study in JAMA (JAMA. 2011;305[8]808-814.) has
found that 50-minute cell phone use was associated with
increased brain glucose metabolism, a marker of brain activity,
in the region closest to the phone antenna, but that is not
known to have any clinical significance.     The researchers
found that whole-brain metabolism did not differ between the on
and off conditions. However, there were significant regional
effects. Metabolism in the brain region closest to the antenna
(orbitofrontal cortex and temporal pole) was significantly
higher (approximately 7 percent) for cell phone on than for cell
phone off conditions. "The increases were significantly
correlated with the estimated electromagnetic field amplitudes
both for absolute metabolism and normalized metabolism," the
authors write. "This indicates that the regions expected to have
the greater absorption of RF-EMFs from the cell phone exposure
were the ones that showed the larger increases in glucose
metabolism."  "These results provide evidence