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Do Cell Phones 'Excite' Your Brain?

Study Shows Increased Electrical Activity on side of Head Where Cell Phone Is Held
By
WebMD Health News
Reviewed by Louise Chang, MD

June 26, 2006 - Talking on a cell phone excites the brain, Italian researchers find -- but they don't yet know whether this is good or bad.

When in use, cell phones emit an electromagnetic field. Different parts of the brain communicate via electrical signals. And people tend to press cell phones to their heads when making calls.

Could this affect their brains?

Yes, find neurologist Paolo Maria Rossini, MD, PhD, research director at Fatebenefratelli Hospital, Rome, and colleagues. Their findings from a small study appear in the August issue of the journal Annals of Neurology.

The researchers say they have "shown definitively" that talking on a cell phone increases electrical activity on the side of the head where the cell phone is held. The effect mostly wears off within an hour, they say.

"We still do not know whether this effect is neutral, or potentially dangerous, or beneficial," Rossini and colleagues report. "But we firmly believe that, starting from this observation, more research is needed both in healthy people and in specific groups of subjects suffering from neurological diseases in which [brain] excitability is affected (for example, epilepsyepilepsy)."

Cell Phone Excitement

Rossini's team studied 15 healthy young men for the impact of cell phone use.

Each man wore a helmet that held a commercially available cell phone about a half inch from his left ear. Two test sessions were held one week apart. In one session the phone was turned on for 45 minutes, in the other it was off.

Before, during, immediately after, and one hour after cell-phone exposure, the researchers used transcranial magnetic stimulation, or TMS, to measure the subjects' brain "excitability." TMS is a device that induces an electric current in the brain.

Rossini's team found that electrical activity was enhanced in the side of the brain near the "on" cell phone, but not on the other side of the brain. And there was no change in brain activity when the cell phone was in the "off" position.

"It could be argued that long-lasting and repeated exposure to electromagnetic fields, linked with intense use of cellular phones in daily life, might be harmful or beneficial in brain-diseased subjects," Rossini and colleagues conclude. "Further studies are needed ... to provide safe rules for the use of this increasingly more widespread device."

Are Cell Phones Safe?

The World Health Organization (WHO) says there have been earlier reports of cell phones affecting brain activity. But WHO concluded these effects "are small and have no apparent health significance."

The FDA says, "Available scientific evidence does not show that any health problems are associated with using wireless phones." But it also notes "there is no proof that wireless phones are absolutely safe."

The American Cancer Society says it's "unlikely" the phones cause cancer.

"CTIA-The Wireless Association" is the trade group representing cell phone companies. "When you look at the overwhelming majority of studies published in scientific journals around the globe, you find that wireless phones do not pose a health risk," Joe Farren, the group's director of public affairs, tells WebMD.

Of course, even a very small risk might affect a sizeable number of people. In 2005, the Wireless Association reports, customers spent 1.5 trillion minutes on their cell phones. That's 2,852 years of use in just that one year. If Shalmaneser III, the ancient king of Assyria, had had that many free minutes, he could have picked up a cell phone instead of sacking Damascus in 842 B.C. -- and still have four years of free minutes left.

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