By Truman Lewis
ConsumerAffairs.com
October 14, 2009
A new meta-analysis of cell phone cancer studies finds that there is "possible evidence linking mobile phone use to an increased risk of tumors." The researchers, from the University of California, Berkeley, and a consortium of Korean institutions, said more research is needed to arrive at a more definitive conclusion.
The researchers examined 465 articles published in major journals and focused on 23 studies involving 37,916 participants. Their analysis was published in the Journal of Clinical Oncology.
In eight of the studies -- those that were conducted with the most scientific rigor -- cell phone users were shown to have a 10% to 30% increased risk of tumors compared with people who rarely or never used cell phones. The risk was highest among those who had used cellphones for 10 years or more.
In those studies, "blinding" was used, meaning that researchers were not told which people in the study had tumors. Also, the studies were not supported with cell phone industry funding.
Other studies, generally those conducted less rigorously and without the use of blinding, found no effect or even -- surprise -- a protective effect among those who used cell phones.
On the other hand, industry spokesmen were quick to note that most of the subjects in the more rigorous studies were Swedish. Might there be something unique to Sweden that heightens the risk? they asked.
The message?
What's the takeaway message of the meta-analysis?
More studies and, especially, more rigorous studies are needed to pin down whether there is a positive association between cell phone use and tumors, said study coauthor Joel M. Moskowitz, director of the UC Berkeley Center for Family and Community Health.
In an interview with The Los Angeles Times, Moskowitz said the analysis changed the way he views the situation.
"I went into this really dubious that anything was going on," Moskowitz said. "Overall, you find no difference. But when you start teasing the studies apart and doing these subgroup analyses, you do find there is reason to be concerned."
The lead author of the analysis, Dr. Seung-Kwon Myung from the National Cancer Center in Goyang, South Korea, said it is not possible to draw conclusions without larger, more rigorous studies conducted without the influence of the cell phone industry.
"Larger, prospective, cohort studies, independently conducted from the mobile industry, are required to confirm the relationship between mobile phone use and tumor risk," he said.
Senate ponders
A U.S. Senate committee held hearings on the potential cancer risks of cell phones last month but the likelihood of legislation is regarded as slim to non-existent.
With an estimated 270 million Americans using cell phones, National Institutes of Health associate director John Bucher told the senators the nation faces a "potentially significant health problem" but said that studies so far have been inconclusive, partly because of the time element and partly because they rely on users' memories of when and how often they used their wireless devices.
As an interim measure, Bucher suggested regular cell phone users might want to use an ear piece that connects to the phone, rather than holding the phone next to their ear.
Health authorities in Switzerland, Germany, Israel and France have all issued guidelines on cell phone use and have emphasized that the risk may be greater for children, since their brains are smaller and soak up proportionately more radiation than adults' brains. Also, children who start using cell phones at an early age will be exposed to the potentially harmful radiation for many more decades than adults who did not begin using cell phones regularly until they were in their 30s or 40s.
