The WHO Makes A Bad Call On Mobile Phones And Brain Cancer
Thursday, June 2nd, 2011Yesterday, the World Health Organization caused more than a bit of a stir by declaring that mobile phones are a possible cause of cancer. My own reaction was one of pained disappointment at the news. Whenever any organization makes an announcement like this that is based on dubious medical evidence, especially when filtered through a credulous media to a public that may not be grounded in the basic facts, it causes unnecessary worry that can be a challenge for physicians and scientists to deal with.
Let’s take a closer look at the announcement itself, what it’s based on, and what it means.
Who said it? – The declaration came from the International Agency for Research on Cancer, which is a component of the World Health Organization. This seems to represent the final word from the WHO on the matter, as there is no “higher up” body in the organization that needs to approve or finalize this decision.
What did they say? – The WHO/IARC put out a press release dated May 31, 2011 that classifies radiofrequency electromagnetic fields as being possibly carcinogenic to humans. This was based on the conclusions of a working group of 31 scientists from 14 countries that met to review and discuss the studies involved. The declaration seems to apply to all such energy fields, although the studies they considered were those looking specifically at wireless phone use. They concluded, as one might expect, that more studies are needed in the future, and made the suggestion that people should make use of “hands-free devices or texting”.
What does that mean? – The IARC categorizes agents and exposures into several categories, based on their level of carcinogenic risk. These are:
- Group 1: carcinogenic to humans
- Group 2A: probably carcinogenic to humans
- Group 2B: possibly carcinogenic to humans
- Group 3: not classifiable as to carcinogenicity in humans
- Group 4: probably not carcinogenic to humans
Radiofrequency electromagnetic fields are now classified in group 2B. For the sake of some odd context, other common things classified in group 2B as having possible carcinogenic risk include:
- coffee
- pickled vegetables
- zidovudine (a medication to treat HIV infection)
- metronidazole (a commonly used antibiotic)
- lead
- phenytoin (an older but still frequently used medication for seizures)
- carpentry and dry cleaning (as occupational hazards)
- progestins (a hormone used for many things, including oral contraception)
This is an interesting partial list to me, as it contains exposures that as a physician, I would rarely, if ever, take into consideration when counseling someone about diet or a particular medicine. In the case of the medications above, the associations are just so weak or rare that it doesn’t enter into my decision making process for using them in treatment. That’s why I find the WHO’s suggestion to avoid standard phone use to be strange – based on the level of evidence and classification, this seems to be quite a conservative, if not mostly fear-based, comment.
What do the studies say? – This post contains an excellent summary of the studies involved. Suffice it to say that most do not demonstrate any increased cancer risk with mobile phone use. Those that seem to show some risk are in the minority, most of which come from a single research group, which could indicate a persistent methodologically flaw or bias on their part.
The press release notes that one study found a 40% increase in gliomas (a specific type of brain cancer) in what they called the highest category of heavy mobile phone users, namely those who were on the phone for 30 minutes a day for 10 years. This seems impressive, and is the only hard data point in the press release, which they did not give a citation for. I tracked this down to be from a study last year called INTERPHONE, which overall showed no increased cancer risk; the 40% figure is taken from a subgroup analysis, meaning that statistics were done on a small subset of people in the study, which is technique that significant conclusions should never be drawn from due to statistical vaguery. Presenting this single, cherry-picked piece of data in the press release strikes me as quite disingenuous on the part of it’s author(s).
Is it scientifically plausible? – Apart from the lack of study evidence for increased brain cancer risk, one must consider whether or not it is even scientifically plausible that the radiofrequency electromagnetic waves generated by a mobile phone could cause such a phenomenon. This seems to be a biological impossibility, based on what we know to date. The microwave radiation generated is extremely low in energy, even compared to everyday biological processes, and is unable to cause DNA damage. Any heat energy produced wouldn’t eclipse typical environmental exposures – a period of exposure to warm sunlight, or the typical circadian body temperature variations we experience during the course of a day – and so would have no physiological effect.
What do I think? – “Cancer” consists of a complex spectrum of disorders that are very different from each other, and have different triggers and mechanisms that go beyond mere DNA damage as an instigating factor. It is also possible that mobile phones may have some unelucidated long-term carcinogenic effect on the human brain. All that noted, the idea that radiofrequency electromagnetic waves can cause cancer is biologically implausible, and the vast majority of studies have demonstrated no correlation between phone use and cancer incidence. It is far more likely that natural variance in applying statistics to medical studies, or other non-phone related factors, could be at play in any positive results seen.
Conclusion – The WHO/IARC has promised a more detailed summary of their findings in the July 1 issue of The Lancet Oncology, and that the article in question will be available in a few days online ahead of print. Hopefully this will give a better insight into their interpretation of the data and their thought process. However, unless they reveal some sort of excellent previously unpublished data, which is spectacularly doubtful, I suspect I will remain boggled at their recommendation. It may be that their agenda in this declaration is to spur further study, to sate pressure from special interest groups, or merely a bad choice in an attempt to do the right thing for public health, and I hope to get some hint of that as well.
In any case, we can rest assured that the biggest medical risk from phone use is talking or texting while driving, and not phantom brain tumors – and that’s something we can easily do something about.


Dolores Umbridge (Harry Potter and the Order of the Phoenix) — The Ministry of Magic High Inquisitor who taught Defense Against the Dark Arts in Harry Potter’s fifth year at Hogwarts is vile from head to toe: not only does she abuse her position to impose draconian rules on the students, she is willfully ignorant in regards to the return of He-Who-Must-Not-Be-Named to the point that she submits The Boy Who Lived to some truly cruel and unusual punishments. Umbridge’s only redeeming quality is that her sheer vileness inspires Fred and George Weasley to revolt by means of some truly brilliant pranks. Dolores Umbridge eventually receives her comeuppance, earning a sentence in the wizard prison, Azkaban, which some might consider a fate worse than death.
George Hearst (Deadwood) —
In this episode of The Secret Lair, we’re joined by hacktivist and digital culture commentator
To: All Lair Personnel



Episode 0048: The Great Old Pumpkin