This week, the World Health Organization placed cellphone use into Category 2B: “possibly carcinogenic for humans.”
Also on that list of 266 items: traditional Asian pickled vegetables, coffee (for bladder cancer), carpentry, occupational exposure to dry cleaning and firefighting, magenta dyes, DDT, and engine exhaust.
WHO’s International Agency for Research on Cancer (IARC) announced that it can’t rule out the possibility that heavy cellphone use may increase brain cancer risk. And while the debate has been raging for as long as most of us can remember, IARC’s formal opinion is a new level of consensus and certainly feels influential.
The committee of 31 experts convened during the last week of May to assess potential carcinogenic hazards associated with exposure to ‘radiofrequency electromagnetic fields,’ which includes radio transmitters, microwaves, as well as wireless telephones.
“We found some threads of evidence telling us how cancer might occur,” says IARC chair, Jonathan Samet of the University of Southern California. “But I think there are acknowledged gaps and uncertainties.”
Their concerns emerged largely from the Interphone study, coordinated by IARC using data from 1997 to 2003. It compared reported cellphone use of brain-cancer patients in 13 countries with that of people without cancer.
According to the report published last year, it saw “no increase in risk of glioma or meningioma,” common brain tumors. EXCEPT, however, in those reporting the heaviest use: “There were suggestions” that people who made 30-minute calls every day for 10 years had a 40% higher risk of glioma.
The ‘non-ionizing’ radiation emitted by cellphones is not strong enough to break chemical bonds in DNA molecules – the mechanism by which ionizing radiation causes cancer. There are many studies addressing a possible carcinogenic mechanism, but very little of the published evidence is strong.
The COSMOS survey is currently looking to recruit 250,000 cellphone users across 5 European countries. It’ll monitor the health of participants over the next 20–30 years and compare this to their level of cellphone use.
Samet notes that there are almost 5 billion cellphone subscriptions worldwide, and “we anticipate an ever larger population that is exposed for longer and longer.”
It’s probably more important to note that cellphone technology has developed rapidly since 2003. The 3G devices emit 100-fold less radiation than the GSM generation that dominated during the years that Interphone collected data, according to IARC scientist Robert Baan.
And for another example, the other study that influenced IARC’s opinion – by researchers at Örebro University in Sweden – found that the risk of the brain cancer acoustic neuroma quadrupled in users of analogue cellphones. But these types of phones were phased out in 2000 in the UK and 2008 in the US.
So what to do what to do? IARC’s Kurt Straif says that texting and using hands-free phones “lowers exposure by at least an order of magnitude.” CNN also has a list of tips.
See the complete list of carcinogenic, probably carcinogenic, possibly carcinogenic, not classifiable, and probably not carcinogenic items.
Image by andalusia via morgueFile
