Large New NIH Study Finds That Cell Phone Use Does Affect Brain Activity

Talking on a Cell Phone

ksteudel via Flickr

Cell phones speed up brain activity, especially in regions of the brain near the phone's antenna during a long phone call, according to researchers from the National Institutes of Health. The meaning and potential health impacts of these changes are unknown, but they show conclusively that cell phone radiation is capable of altering brain activity.

Researchers took brain scans of 47 participants to directly measure how cell phones' electromagnetic radiation affected their brain activity. That's a departure from other studies in the cell phone radiation literature, which have largely consisted of observational studies, and which have been somewhat inconclusive due to biases and errors.

Each participant had a cell phone strapped to both ears and then underwent two 50-minute PET (positron emission tomography) scans, which measure brain activity by monitoring metabolism. In one scan, both cell phones were turned off; in the second, the right cell phone was turned on and played a recorded message, but with the sound muted so there would be no auditory interference.

The PET scans showed a 7 percent increase in activity in the part of the brain closest to the antenna, according to the study, published Wednesday in the Journal of the American Medical Association.

Importantly, the researchers said the increased activity was unlikely to be associated with heat from the phone, because it happened near the antenna instead of where the phone touched the head.

The new study is mum on the meaning of these findings, however — it could be good or bad, as lead author Nora D. Volkow, director of the National Institute on Drug Abuse, told the New York Times.

Previous studies have largely dismissed any ill effects from cell phone radiation, partly because the type of radiation emitted is pretty weak. Cell phones emit non-ionizing radiation, which is weaker than the type of radiation you're exposed to while walking through an airport security scanner, for instance. Non-ionizing radiation does not break chemical bonds or interfere with DNA in the way that ionizing radiation does. As PopSci reported last year, the only universally recognized effect of non-ionizing radiation is minor heating of nearby tissue. The Federal Communications Commission sets limits for cell phone radiation below which that heating does not occur.

This study shows that there are other physiological effects beyond tissue warming, however. Researchers not involved in the work told the Times that the study even suggests different pathways for cancer and other health problems to develop, including the formation of free radicals and tissue swelling.

On the other hand, some studies suggest electromagnetic radiation could be good for you. In one study from 2010, University of South Florida researchers were surprised to find electromagnetic radiation from cell phones actually boosted the memories of young mice, and even reversed Alzheimer's symptoms in old mice. And Volkow said future research may show electromagnetic waves could be used for other therapeutic purposes.

The bottom line is that this study shows non-ionizing radiation from cell phones indeed has an effect on human brain function. Further studies will help explain just what effects mean for our health.