Let me be absolutely clear on this: No new studies have been released to spur this decision. The decision was reached by a team of 31 scientists who reviewed the existing scientific literature.
After reviewing the evidence they decided that even though there was no conclusive evidence that cell phones cause cancer, they are going to list it as a possible danger to humans.
They are playing it safe; erring on the side of caution; not counting their chickens before they’re hatched, whatever you want to call it.
[Update (11:57 AM): Here is an excellent explanation on the evidence the WHO used to make its decision, and what their decision actually means.]
This is a touchy subject. While I generally agree with playing it safe, in this case I disagree with the WHO’s decision.
Basically they are saying they need more long-term studies. However, since it is impossible to prove a negative, we will never be able to prove that cell phones don’t cause cancer. You would need an infinite number of studies to do that!
You can’t prove there isn’t a magic teapot floating around the dark side of the moon with a dwarf inside of it that reads romance novels and shoots lightning out of its boobs.
Same deal with cell phones. There is no plausible mechanism by which cell phones can cause cancer since the radiation is non-ionizing. There is also no dramatic increase in cancer rates coinciding with the dramatic increase in cell phone use in recent years.
Critics get around this point by saying that it takes decades for effects to really take hold. On average, yes that is true, but after 10-20 years of regular cell phone use by a large percentage of the population we should still expect to see some signs of adverse health effects.
So I disagree with the WHO. This little announcement is going to cause undo panic and fear.
But the “be afraid of microwaves” crowd has gotten much louder in the last few years, and I suspect this announcement by the WHO is largely due to public pressure rather than scientific evidence.
But who am I, right? I’m just a humble science blogger with a degree is physics who has looked at the scientific evidence and seen that there is no cause for alarm.
So I’m gonna go ahead and say “Don’t panic!”. But I have a sneaking suspicion people are going to anyway…
But when the study has nice, media-friendly buzz-words like “radiation” and “brain activity”, you get a firestorm of media coverage. Even if your study doesn’t say all that much.
The study I am referring to is called “Effects of Cell Phone Radiofrequency Signal Exposure on Brain Glucose Metabolism” which was recently published in the Journal of the American Medical Association.
The study looked at 47 healthy volunteers; a relatively small study. The researchers took these volunteers and gave them all PET scans on their brains. They had also strapped two cellphones on either side of their head. One cell phone was on, and the other was turned off.
During a 50 minute phone call, they compared the two sides of their brain to see if there was any change in glucose uptake.
What did they find?
Whole-brain metabolism did not differ between on and off conditions. In contrast, metabolism in the region closest to the antenna (orbitofrontal cortex and temporal pole) was significantly higher for on than off conditions (35.7 vs 33.3 μmol/100 g per minute; mean difference, 2.4 [95% confidence interval, 0.67-4.2]; P = .004). The increases were significantly correlated with the estimated electromagnetic field amplitudes both for absolute metabolism (R = 0.95,P < .001) and normalized metabolism (R = 0.89; P < .001). [JAMA]
So basically, whole-brain metabolism was the same whether the phone was on or off. However, in regions close to the phone’s antenna, the metabolism was “significantly higher”. It is important to point out that in this context, “significantly” means statistical significance, not a large increase. In fact, the increase was only about 7%.
Brain imaging physicist Dardo Tomasi of Brookhaven National Laboratory, who co-authored the study, said that’s several times less activity than visual brain regions show during an engaging movie. [Wired]
Ok, so now the important question: what does this mean for our health? Nora Volkow, the study’s lead author commented:
Volkow says it is too early to tell whether this is good or bad for the brain. “Much larger fluctuations in brain activity occur naturally,” says Patrick Haggard at University College London. In fact, being able to increase activity might boost the brain’s connectivity, and could even be useful therapeutically, Volkow suggests. [New Scientist]
So although the study was published as a “Preliminary Communication”, and that the study itself concludes:
This finding is of unknown clinical significance. [JAMA] (emphasis mine)
there is still a large number of news outlets which reported on the study. Why?
Well we know why already. That “unknown” word in the above quote carries a lot of baggage.
Cell phones are the new danger to health, of course. Despite there being no conclusive evidence that cell phones even have the ability to cause cancer, and the fact that even with the explosion of cell phone use in recent years, cancer rates have not increased, people are still scared of their cell phone.
This is thanks to poor media coverage, and a few crackpots out there who are determined to prove that technology is going to destroy us all.
And as a result this small, preliminary study with a result that, while interesting, is completely benign, gets extensive media coverage. Not only that, but some news sites give thinly veiled comments suggesting that the results somehow show that cell phones are dangerous, like this one:
The unusual finding, published on Tuesday in the Journal of the American Medical Association, is likely to lead to new calls for stricter regulation of radiation emissions from the ubiquitous phones. The government currently assumes the signals have no effects other than a harmless warming of tissues near where they’re held. [The Globe and Mail]
or this one:
Some studies have linked cell phone exposure to an increased risk of brain cancers, but a large study by the World Health Organization was inconclusive. [MSNBC]
Of course they used the word “inconclusive” in the above quote, when it should really read “it showed no correlation”. Scicurious points out that this is probably because “‘inconclusive’ sounds scarier”.
So nobody panic. This study does not show that cell phones are dangerous. It may show that the electric field from the antenna somehow increases metabolism of glucose, but those findings need to be corroborated by other labs. Let’s wait until their findings are duplicated on a larger scale and a mechanism by which this effect happens can be discovered before we decide what, if any, impact this study should have.
I started this blog to talk about poor science reporting and try to put some good information out there. Usually though, it comes off as complaining.
This has been true a number of cases, and recently because of the Wi-Fi scares going on in Canada.
It is quite clear from a large body of scientific evidence that Wi-Fi is completely safe, and these fears are unwarranted. However, the fears are given credence because of a few crackpot “scientists” and poor media coverage.
It isn’t much, but I wrote an email to the CBC asking them to provide more accurate information in their reporting. Here is the email in its entirety:
I am writing in regards to the CBC’s recent reports regarding Wi-Fi technology in schools.
In recent months, there have been several news items written on the CBC news site regarding the health effects of wireless internet technology. These have mainly consisted of stories from Ontario and Alberta in which a group of parents has approached its local school board and requested that Wi-Fi not be installed in their children’s schools.
While I agree that it is important to report on these issues, I strongly disagree with the lack of background information and tone of the articles themselves. They give the average reader very little sense of the current body of scientific evidence, which overwhelmingly indicates that wireless technology is safe for both adults and children.
The articles fail to show this large disconnect between the mainstream scientific community and the views of a very a small fringe group. Blanket statements such as “Health Canada and the World Health Organization have said Wi-Fi is not dangerous” are simply not adequate to provide readers with an accurate picture. This is of concern to me since it may cause undo panic to parents across the country that are only looking out for the well-being of their children, and may be frightened by the poor representation of the scientific consensus in these articles.
Microwave radiation, at the powers and frequencies used by wireless systems has been thoroughly researched and the evidence is clear that it is quite safe. I respectfully ask that in future news items you provide more information on the research done on Wi-Fi which shows it is safe in order to put the minds of parents at ease.
I decided to write directly to the CBC because I generally respect its reporting and it is my primary source for news. However this issue has troubled me as I’m sure it has troubled many other readers.
Will I get a response? Probably not. Will it make a difference. Ha, probably not. But it is DOING something rather than just complaining, so maybe the skeptic gods (?) will smile down on me and make a difference.