Thursday, June 02, 2011

The Danger of Cellphones

Extract from Pharyngula:

The World Health Organization had a recent meeting in which the feeble data suggesting a possible link between cell phones was reworked and massaged, and have now come up with a press release in which they announce that maybe possibly cell phones could increase the frequencies of certain kinds of cancers. My doubts are massive. My willingness to accept this conclusion is not helped by arguments like these.

"What microwave radiation does in most simplistic terms is similar to what happens to food in microwaves, essentially cooking the brain," Black said. "So in addition to leading to a development of cancer and tumors, there could be a whole host of other effects like cognitive memory function, since the memory temporal lobes are where we hold our cell phones."

Is anyone out there really chatty? Could you call up my microwave breakfast burrito and yak at it for a while? How long do you think it will take, I'm getting hungry?

That is simply sensationalistic nonsense. No, your cell phone doesn't cook your brain. When was the last time you saw someone with a cell phone burn on their face? "Cooking" has rather more obvious effects than the kinds of subtle, difficult-to-detect, epidemiological results the press release describes. There could be a real effect — you are, after all, holding a small transmitter of electromagnetic radiation right next to your skull — but previous studies have been all over the map and lack any consistency, but generally fall on the side of no observable effect. People have done things like stick cell phones on top of petri dishes of cultured human cells, and nope, the cells don't cook, they live and thrive just fine, and most studies report no change in cellular activity (some have reported a slight increase in activity).

Maybe this one, representing a coalition of many researchers in many countries gathering together to share data, has finally found a smoking gun? I don't know. One problem here is that all we've got is a brief press release, no data, with a promise of a scientific paper to be published in The Lancelet Oncology in a few days. Here, almost nothing is reported: they have a one paragraph conclusion.

The evidence was reviewed critically, and overall evaluated as being limited among users of wireless telephones for glioma and acoustic neuroma, and inadequate to draw conclusions for other types of cancers. The evidence from the occupational and environmental exposures mentioned above was similarly judged inadequate. The Working Group did not quantitate the risk; however, one study of past cell phone use (up to the year 2004), showed a 40% increased risk for gliomas in the highest category of heavy users (reported average: 30 minutes per day over a 10‐year period).

"Limited" and "inadequate" are the strongest words they use to describe their own data. They mention one study with the strongest effect…in other words, they highlight the outlier. That's odd and makes me instantly suspicious.

Also, I recognize those numbers: this is a reworking of the INTERPHONE study from last year, in which the final conclusion was that there was no credible evidence of a cancer risk. What happened? Why has their assessment changed? There is no explanation. That study had methodological problems that an epidemiologist for Nature summarized this way:

"There are standard criteria for assessing whether data from epidemiological studies show causality or not," says Swerdlow. "The results for this study don't get close to passing the standard tests for whether the results show causation."

I'm going to agree with Orac on this one: not very likely. Show me some new evidence, maybe I'll change my mind.

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