So it looks as though we are all going to die. Again. This time it’s our mobile phones that are going to kill us. And who says so? Well, exactly. As in, the WHO says so. In a news story that has captured the imagination of cancer obsessives around the world, no less an authority that the UN’s own health agency have stated that radiofrequency electromagnetic fields — namely, those generated by mobile phones — are “possibly carcinogenic”. Unsurprisingly, given that in over 50 countries there are now actually more mobile phones than people, the global media have gone into something of a tizzy. The story has proven controversial as well as shocking. For one thing, a number of commentators have pointed out that the WHO’s conclusions are strikingly inconsistent with several previous large-scale research studies that have looked for risks associated with mobile phones. So if an authority like the WHO formulates a new position on such an issue, we would be forgiven for assuming that their methods are breathtakingly sophisticated and their evidence both clear and convincing. Well, guess what…
Actually, to be fair, it is quite difficult to comment on the scientific merit of the WHO’s position because, contrary to what you might think from the assorted media coverage, the actual research has not yet been released. Instead, the storm of media coverage has surrounded the pre-publication press release issued by the WHO (the actual report concerned won’t be published for another month, in the journal Lancet Oncology). So all the media have had to go on thus far is the description of the research presented in the press release, which basically comes down to the following sentence:
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.
One thing to note straight away is that the proposed cancer-link concerns only “glioma and acoustic neuroma” cancers, and explicitly excludes other types. But what of the methodology? Well, here’s how the press release puts it:
The IARC Monograph Working Group discussed and evaluated the available literature…
And that’s it. All we are looking at here are the conclusions of a working group who busied themselves by reading the available literature, which was in the public domain anyway. There is no reference to the use of meta-analysis or systematic reviewing to draw aggregated statistical inferences from the combined dataset represented by the research literature as a whole. What we have here are impressions.
If anything, the working group — established under the auspices of the WHO’s International Agency for Research on Cancer, or IARC — seem to have gone out of their away to avoid statistical conclusions. They explicitly state that they “did not quantitate the risk” of mobile phone radiation. However, despite this, in the very same sentence they refer to the quantified outcome of “one study”, which put the “increased risk” of cancer at “40%”. This statement is particularly vague, not least because it fails to mention the absolute risk of gliomas, which stands at a mere 0.007%. This means that the “increased risk” refers to a jump to just 0.010%. Another way of putting this is that only 3 people per every 100,000 will get phone-related cancer, compared with 7 people who will get cancer whether or not they use a phone. In other words, the risk described is totally minuscule. You literally have more of a chance of being shot to death (that is, if you live in the US).
(And by the way, if it is true that the IARC working group “did not quantitate the risk”, then how do they know that the “40%” finding is worth highlighting? It could be hugely misleading. Without their own attempt at quantification, the group have no basis to pick out that particular study from all the others.)
A different way of looking at the risk context relates to the WHO’s conclusion that mobile phones are only “possibly” carcinogenic. What could “possibly” mean here? Well, other things that the WHO feel are “possibly carcinogenic” include such frightening entities as bracken fern, condensed coconut oil, and talcum powder. They also include obscure organic compounds such as acetaldehyde, which occurs naturally in fruit and bread, and naphthalene, which is used to make moth balls.
Perhaps more revealing is the stuff the WHO classify as “probably carcinogenic”, such as the emissions from frying. Yes — if you are in the habit of frying your food, the emissions you generate at high temperatures are classified as more likely to cause cancer than using a mobile phone. Cisplatin is also in the “probably carcinogenic” category. This is the chemical compound cis-PtCl2(NH3)2, formerly known as Peyrone’s salt. Nowadays it is used as a drug. What for? To, ahem, treat cancer.
The WHO classifications also include cancer risks associated with different professions. For example, if you work as a hairdresser, your risk of cancer is sufficient to place you in the “probably carcinogenic” category (i.e., along with emissions from frying). If you work as a carpenter, then you are in the “possibly carcinogenic” category (i.e., along with talcum powder and, of course, using a mobile phone). So, really, when the WHO uses terms like “possibly” (or “probably”), they need to be interpreted very carefully indeed.
Much of the media coverage over the past few days — a lot of it presumably posted by journalists or scrutinized by readers using mobile phones — has created a stir that is way out of kilter with the underlying story. For one thing, the coverage has largely failed to convey the fact that it relates not to a research study presenting new empirical evidence, but rather to a press release describing impressions formed by a group of people who read the old studies. In addition, the media reports have generally failed to note that the proposed cancer-risk is actually minuscule and restricted to a small subset of possible cancers. Moreover, the coverage has tended not to describe the plethora of previous, more systematic, studies that have failed to find any link between mobile phone use and cancer. And it has generally ignored the fact that what is being spoken of as the danger posed by mobile phones is actually barely equivalent to that posed by talcum powder — and less than that posed by being a hairdresser.
Warnings that in order to avoid cancer we should now send texts rather that talk on phones seem risibly disproportionate. In fact, instead of being the “next big public health crisis”, this news story is simply not much to phone home about.