While researchers debate whether microwaves emitted by cell phones might cause brain cancer, a study published in the Journal of the American Medical Association last February raised an entirely different concern. Lead author Nora Volkow, a psychiatrist at the National Institute on Drug Abuse of the National Institutes of Health, recruited 47 healthy volunteers and used positron emission tomography (PET) scans to measure glucose metabolism in the brain while cell phones were placed over the right or left ear. She found that 50-minute cell phone calls increased metabolism in the regions closest to the phone antenna—specifically, the orbitofrontal cortex and temporal pole, which are involved in sensory integration, language, decision making, and social and emotional processing. Volkow has other studies underway to determine how long the stimulating effects persist.
The next big question is whether the increase in brain metabolism could lead to neurocognitive damage down the road. Volkow does not yet know but says that “true evidence of harm might emerge only after years of extensive use.” Children could be especially vulnerable because their brains are still developing. As for adults, Volkow notes a possible upside: Radio waves akin to cell-phone signals might be therapeutically useful for stimulating the brains of patients suffering from ischemia or stroke.