Cell phone use does affect brain but health consequences unknown

Last Updated: Wed, Feb 23, 2011 05:30 hrs

A new study has found that increasing use of cell phones is linked to rise in brain glucose metabolism, a marker of brain activity, in the area closest to the phone antenna - however, the clinical significance of this find is not known yet.

"The dramatic worldwide increase in use of cellular telephones has prompted concerns regarding potential harmful effects of exposure to radiofrequency-modulated electromagnetic fields (RF-EMFs). Of particular concern has been the potential carcinogenic effects from the RF-EMF emissions of cell phones," said the article.

"However, epidemiologic studies of the association between cell phone use and prevalence of brain tumors have been inconsistent (some, but not all, studies showed increased risk), and the issue remains unresolved," it said.

Nora D. Volkow of the National Institutes of Health, Bethesda, Md., and colleagues conducted a study amongst 47 participants.

Cell phones were placed on the left and right ears and brain imaging was performed with positron emission tomography (PET) with (18F) fluorodeoxyglucose injection, used to measure brain glucose metabolism twice, once with the right cell phone activated (sound muted) for 50 minutes ("on" condition) and once with both cell phones deactivated ("off" condition).

Results showed that the on/off conditions didn't affect the whole-brain metabolism.

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.

"These results provide evidence that the human brain is sensitive to the effects of RF-EMFs from acute cell phone exposures," the researchers write.

They concluded, "Results of this study provide evidence that acute cell phone exposure affects brain metabolic activity. However, these results provide no information as to their relevance regarding potential carcinogenic effects (or lack of such effects) from chronic cell phone use."

"Further studies are needed to assess if these effects could have potential long-term harmful consequences."

The study appears in the February 23 issue of JAMA. (ANI)