A new study from a "high-quality team" of researchers at the National Institutes of Health has shown that holding a cellphone to your ear for an hour can increase brain activity in the area closest to the antenna, re-opening the debate about cellphone safety.
To be sure, the head researcher of the new study has asked the public to be cautious in interpreting the study's results since it's not known whether this increased brain activity poses any threat to human health. But the finding is still important since it shifts attention away from radiofrequency waves -- believed to be harmless -- to evidence of increased brain glucose metabolism, which was detected using brain scans.
As the New York Times reports, this activity is natural and necessary and happens during normal brain function. "The question is whether repeated artificial stimulation as a result of exposure to electromagnetic radiation might have a detrimental effect.
"Although speculative, one theory about how an artificial increase in brain glucose metabolism could be harmful is that it could potentially lead to the creation of molecules called free radicals, which in excess can damage healthy cells. Or it may be that repeated stimulation by electromagnetic radiation could set off an inflammatory response, which studies suggest is associated with a number of heath problems, including cancer."