July 4, 2011

Doubts Cast On Carcinogenic Effect of Cellphones

The on-again-off-again risk of cell phones causing brain cancer is off again, for now at least, according to a study published July 1 by Environmental Health Perspectives (EHP), a monthly journal of the US National Institute of Environmental Health Sciences (NIEHS).

"In the past 15 years, mobile phone use has evolved from an uncommon activity to one with over 4.6 billion subscriptions worldwide. There is, however, public concern about the possibility that mobile phones might cause cancer, especially brain tumors," study authors Anthony J. Swerdlow, Maria Feychting, Adele C. Green, Leeka Kheifets, and David A. Savitz of the International Commission for Non-Ionizing Radiation Protection (ICNIRP) Standing Committee on Epidemiology wrote.

"Although there remains some uncertainty, the trend in the accumulating evidence is increasingly against the hypothesis that mobile phone use can cause brain tumors in adults," they added.

According to Bloomberg reporter Kristen Hallam, the researchers involved in this most recent report reviewed all existing studies on the possible carcinogenic effects of cellphones on their users, with a special focus on the Interphone study, which Hallam identified as "the largest epidemiological study to date."

That study "was published last year and failed to find a definite link between mobile-phone use and certain types of brain tumors," she said.

Interphone took a look at more than 2,700 patients with a type of brain tumor known as a glioma, as well as a similar number of subjects without said type of tumor, notes BBC News Health Reporter James Gallagher. The authors of that study "concluded that mobile phone users were less likely to get brain tumors, but heavy users had an increased risk," he added.

As Ben Hirschler of Reuters pointed out in an article Friday, this latest study comes approximately two months after the World Health Organization (WHO) International Agency for Research on Cancer (IARC) ruled that cellphone use should be classified as "possibly carcinogenic to humans."

That classification, according to Hallam, would place the tech devices in the same category as diesel fuel, chloroform and working as a firefighter--not to mention coffee, as Gallagher pointed out.

"This is a really difficult issue to research," David Spiegelhalter, a professor of Public Understanding of Risk at the University of Cambridge, told Reuters. "But even given the limitations of the evidence, this report is clear that any risk appears to be so small that it is very hard to detect--even in the masses of people now using mobile phones."

"Although these researchers admit that we can't entirely rule out the idea of a link between mobile phones and brain cancer, they remind us that in most of the research, including their large international study, mobile phone users don't seem to be at increased risk," added Dr. Joanna Owens Cancer Research UK, in an interview with BBC News. "We don't yet have data on very long-term use of mobile phones, or for the effects on cancer risk in children, so it is probably wise to encourage children to limit their mobile phone call time."


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