Image description

An independent consultancy based in UK and operating internationally, providing advice and measurements on public and occupational exposure to electromagnetic fields and  RF radiation.

What IARC said about phone signals, and what it means



IARC is the World Health Organisation's International Agency for Research on Cancer.  Part of IARC's work is to classify agents according to carcinogenicity. The classifications are not actually that straightforword when one looks at the detail, but simplistically they are:


1 Carcinogenic

2A Probably carcinogenic

2B Possibly carcinogenic

3 Not enough information

4  Probably not carcinogenic


IARC has said that phone signals (and also, a decade earlier, power-frequency magnetic fields) are 2B, possibly carcinogenic. So what does that mean?


It's important to understand how the IARC classification is derived. Essentially they look at the weight of evidence for and against risk without explicitly considering plausibility, and that is both a strength and a weakness. As we discuss elsewhere we expect around 20-30% of studies to show an effect even if there is no risk, becuase that's the false positive rate in biomedical reserach. With over 25,000 published studies on this subject, we certainly can't say there is "not enough information" (3), and the presence of those few thousand positive studies prevents us from saying "probably not carcinogenic" (4: in fact IARC has only ever assigned this category to one chemical, which tells you something about the process). Similarly, phone signals are not in IARC's opinion either carcinogenic (1), or probably carcinogenic (2A). The 2B rating reflects that there is some evidence of risk  - but that it's outweighed by the evidence for "no risk".  And that's about as far as it goes.


When expert groups and standards-setters review the science they look also at plausibility, so they consider the weight-of-evidence as IARC did and see that it doesn't suggest a probable risk, and they note that there is no plausible biophysical mechanism for harm. As a result there is absolutely no conflict between those reviews concluding that there is nothing to see, and IARC's 2B rating.