I'm getting lots of notes from people about the latest press release from the World Health Organization, saying there is a "possible" link between cell phones and brain cancer. My first reaction was, "Seriously?" This keeps popping up every now and again, but this was the first time I had heard it from a group as big as WHO. The reason for that initial reaction was that I've read about lots of studies showing no link at all between cell phones and health issues (besides quadrupling your odds of a car accident if you drive while using your phone), so my reaction was one of fair skepticism. I'd be surprised if a strong connection had been found. Turns out, it seems, that's the right call. My Discover Magazine co-blogger Ed Yong explains why on the Cancer Research UK website. Basically, the WHO put cell phones into the Group 2B category, meaning they are "possibly carcinogenic to humans". Aiiiieee! Sounds scary... except that word "possibly", it turns out, needs to be understood a little more quantitatively. As Ed shows, the graph showing the results from several tests investigating the links between cell phones and cancer shows that any connection is very weak, and honestly cannot be statistically distinguished from no connection at all. Of course, it's impossible to rule it out, so there's that word "possibly". From looking at the graph, though, I'd put the odds at being very, very low. As Ed says in his post, "It means that there is some evidence linking mobile phones to cancer, but it is too weak to make any strong conclusions." I poked around some news sites (like CNN and MSNBC), and while they aren't over-hyping it, in my opinion they aren't being entirely fair, either. The claims I've seen from people linking cell phones to brain cancer make it seem as if the connection is obvious, but the results from the WHO make it clear that's not the case. There might be a connection, but if there is it's not terribly clear. I'll note the studies only appear to cover a time base of ten years; it's not possible to know what happens after, say 15 or 20 years. Even then, other environmental factors dominate such studies, making teasing out a weak signal very difficult. You may also wish to note what other things are categorized as Group 2B possible carcinogens, including gasoline, pickled vegetables, and (GASP!) coffee. My opinion here is that while a link between cell phones and brain cancer cannot be ruled out, without a strong correlation and a numerical statement about the odds, it seems very unlikely to me that such a connection is something to worry about. I'm far more worried about the dingus in traffic in front of me gabbing to his friend on his phone and causing an accident than I am about me getting brain cancer from my own.
P.S. Speaking of this topic, I'll be at the Dragon*Con in September, attending the Star Party Thursday night to raise money for cancer research. I did this in 2009 -- it's in memory of my old friend Jeff Medkeff, who died of liver cancer a few years ago. I missed it last year, but I'm very much looking forward to it this time. Tip o' the app to Treelobsters for the list of other Group 2B materials.
Related posts: - Repeat after me: cell phones don't cause brain cancer (note the followup in the next link!) - More on cell phones and the lack of harm - xkcd radiates