Cellphone study shows one-hour exposure changes brain activity

By Cecilia Kang

Scientists at the National Institute of Health on Tuesday released a study that showed 50 minutes of cellphone use could alter the activity of the part of the brain closest to a cellphone antenna.

The findings, to be released Wednesday in the Journal of the American Medical Association, comes amid headed debate on the health affects of mobile devices with San Francisco imposing first-ever labeling rules on radiation emissions. Burlingame, Calif. and Oregon are considering similar rules.

The study was led by Nora D. Volkow, director of the National Institute on Drug Abuse, who cautions that it is premature to draw "clinical significance" to the findings. That means it is too early to say the findings mean cellphones could lead to bodily harm, including brain cancer.

"The brain is very important and if you ask what my recommendation is from this study, I'd say I can't overall say this is harmful but we have to study more for long-term effects," Volkow said in an interview.

Specifically her research shows that those people exposed to 50 minutes of cellphone radio frequencies saw an increased brain glucose metabolism in the region closest to the antenna.

"The dramatic increase in use of cellular telephones has generated concern about possible negative effects of radiofrequency signals delivered to the brain," JAMA wrote in background material on the study's release. "However, whether acute cellphone exposure affects the human brain is unclear."

Trade group CTIA-The Wireless Association has fought against local rules that would require labeling of radio-frequency levels at San Francisco retailers. The trade group filed a lawsuit against San Francisco and has sent lobbyists to Maine, California and Oregon to fight similar legilsations.

It has deferred to the Federal Communications Commission and Food and Drug Administrations as the expert agencies to oversee cellphone health. But public-interest groups say the regulatory agencies haven't updated guidelines on cellphone health in more than one decade. And the rapid adoption of cellphones -- 290 million in the U.S. -- call for greater protections, particularly among children who have thinner skulls and ears than adult cellphone users.

Volkow's study was conducted between Jan. 1 and Dec. 31, 2009 and included 47 participants.

The researchers found that metabolism in the brain region closest to the antenna was 7 percent higher when exposed to cellphone use.

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

But they are quick to note: "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."

And the authors encouraged further study.

Louis Slesin, editor of Microwave News, said the study will lead to more questions about the effects low-frequency radiation can have on body tissue. Studies so far have been inconclusive but many researchers have warned about potentially harmful affects on long-term users and youth.

"Whether these short-term changes will lead to health consequences (and what they might be) is far from clear -- though Volkow already has preliminary indications of a long-term effect," Slesin wrote. "Importantly, this new finding upsets the current orthodoxy because

such low-levels EMF effects are thought to be impossible."

Rob Stein at The Checkup also wrote about the study.