Researchers have found that talking on a cell phone for 50 minutes is linked to increased brain activity, but the health risks are still not known.

The study, published today in the Journal of the American Medical Association, found evidence of increased brain activity in the area closest to the antenna. The research, conducted by the National Institutes of Health, is among the first to conclude that the brain appears sensitive to the radiofrequency-modulated electromagnetic fields (RF-EMFs) of cell phones.

While the findings raise questions about the risks of low levels of radiation from mobile phones, researchers cautioned that the results are preliminary and do not explain what the health implications might be. More long-range studies are needed to determine if there is potential for harm, the researchers wrote.

To test the impact of cell phone use on brain activity, researchers recruited 47 men and women. They placed cell phones on their right and left ears and used scans to measure any activity when phones were on and again when phones were off. They found higher activity when the cell phones were on, and in the region closest to the antenna.  

While some medical experts have raised concerns about cell phone safety, studies on the health effects have varied, the paper explains.

Last year, a huge study on whether cell phone use was linked to brain cancer turned up inconclusive. Nevertheless, an emotional debate has been brewing for years about cell phone safety. Just last year, San Francisco passed a law requiring retailers to display how much radiation is emitted from a phone.

What do you make of the debate and the latest findings?

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