Originally published on the RMG:Clarity blog on June 8, 2011.
What do the likelihood of mobile phones being carcinogenic and a lack of knowledge about the countryside have in common? Well, both have been in the news recently, for example, mobile phones in The Guardian and knowledge of nature in the Daily Mail. More importantly, however, the stories the newspapers are reporting are both from press releases and neither give sufficient information to evaluate the merits of the research.
The World Health Organisation press release from the International Agency for Research on Cancer says that:
From May 24–31 2011, a Working Group of 31 scientists from 14 countries has been meeting at IARC in Lyon, France, to assess the potential carcinogenic hazards from exposure to radiofrequency electromagnetic fields. … The IARC Monograph Working Group discussed the possibility that these exposures might induce long‐term health effects, in particular an increased risk for cancer. … 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.
Leading on from this mobile phones have been categorised as Category 2B on the IARC carcinogen scale. This means that there is ‘limited evidence of carcinogenicity in humans and less than sufficient evidence of carcinogenicity in experimental animals.’ It is this that has been published in one format or another all over the world. However, this says nothing about what the monograph actually says. It does not inform the reader how the conflicting evidence on mobile phone use and cancer has been resolved. The whole point of the press release, and all the media coverage, is that mobile phone radiation is a possible cancer risk. However, nowhere does it say how this may ‘possibly’ happen, nor does it describe the biological mechanism by which the low levels of microwave radiation emitted from mobile phones could cause cancer. At some point the monograph will become available on the IARC website, but I don’t imagine that journalists will revisit their articles in the light of any new information in the full monograph.
Fifteen per cent of adults didn’t know that a dairy cow is female, half weren’t aware that robins live in the UK all year round and one in five didn’t know that acorns come from oak trees. … Additional findings show that a quarter of 18-24 year olds and one in five 25-34 year olds didn’t know that tadpoles become frogs.
The only thing that the press release said about the methodology is in the notes; ‘all stats One Poll Survey, 2,000 adults May 2011’. We are not told the methodology of the survey, was it online, face-to-face, or over the telephone? We are not told whether the people interviewed were from all over the UK, or whether they were from more rural or urban areas, nor are we told how many people between the ages of 18-24 and 25-34 were interviewed. You will get very different results asking about acorns in inner city London and rural Surrey, for example. Only surveying 10 people between the age of 18 and 24 would not give significant results, whilst surveying 200 would.
None of the above is meant to suggest that either the IARC work on mobile phones or the LEAF survey is unreliable, invalid or wrong in any other way. My point is that we do not currently have sufficient information on the methodology and workings of either piece of research to come to a conclusion about its validity. Whenever presented with research findings it is vital to have full details of the methodology used; if this is not available, you should start questioning it yourself.