Somewhere along the line, despite lack of any supporting evidence, the notion that mobile phones are somehow connected to brain cancer has recently entered the pop culture lexicon.
A long awaited meta-analysis of mobile phone use and brain cancers, known as the Interphone study, was released yesterday. The net result of the study was that there’s no plausible connection between mobile phone use and cancers- of any sort- but you’d never know that there’s still no evidence for a connection between mobile phones and cancers if you get your information only from mainstream media in Australia. Responsible scientific research, by its nature, never claims something is fully impossible. When scientific research says that a hazard is ‘uncorrelated’ and ‘unlikely,’ it is trying to tell you that it’s something you need not worry about.
Despite the presence of strong radio frequency signals all over the world since the 1920s, the broad use of handheld walkie-talkies since World War Two, the availability of high UHF (800MHz) band mobile phones since about 1980 and the utter ubiquity of handheld mobile phones since the mid 1990s, there’s simply no correlating increase in brain (or other) cancers. While there may be a slight increase in brain cancer diagnoses due to improved detection techniques of late, there’s just no queues around the block of patients at cancer clinics which would correspond with the massive increase in the number of mobile phones which have come into service since the mid-1990s. We’re talking about billions of mobile phones that were not there previously- if mobile phones really could cause brain cancers, there would be corresponding billions of cancers. So, where are the billions of cancers? They don’t appear to exist.
So, what on earth are people afraid of? Is there any reasonable basis for fear of the signals emitted from mobile phones? If you’re going to read no further, the answer is a plain and simple no.
If you’re going to read on, let’s get a few things straight.
Know thy radiation:
‘Radiation’ is a word that scares the crap out of anyone raised in the nuclear age, but not all radiation is harmful. The term ‘radiation’ itself merely describes the emission of something from a single point. A pebble dropped into a pond will cause a radiation of ripples in the water from the point of impact. Candles emit both thermal (heat) and luminous (visible light) radiation- but no sane person has to date tried to implicate pebbles or candles in formation of cancers.
The stuff that should reasonably scare you is known as ionising radiation. Ionising radiation is comprised of electromagnetic signals that are at or higher in frequency than ultraviolet (UV) light. This includes UV emissions, x-rays and gamma rays (and to a lesser degree due to their limited tissue penetrating abilities, alpha and beta radiation), the truly dangerous sort emitted by radionuclear materials like plutonium, uranium, etc. as well as cosmic rays, which are emissions from stars (like our sun), which are nuclear-reaction furnaces.
The reason why ionising radiation is dangerous is because of the extremely high frequency of the emissions and the energy they can impart into electrons orbiting atoms and molecules. Ionising radiation has the ability to knock electrons off the outer shell of atomic particles, which changes their characters. This is a serious problem for DNA molecules exposed to this form of radiation. Knocking electrons off of DNA molecules can cause them to replicate inaccurately (or ‘mutate’), which can reveal as cancers.
Non-ionising radiation, that which is below the frequency of UV, does not have the ability to knock electrons off of atomic particles. All radio signals are far below the frequency of visible light, let alone UV. The only effect of exposure of molecules to non-ionising radiation is induction of thermal energy, such as what happens to water molecules in a microwave oven.
When water is exposed to strong radio frequency (RF) fields at the resonant frequency of a water molecule (2.45GHz), the bonds between the hydrogen and oxygen atoms are repeatedly bent back and forth, inducing thermal energy into the water molecule, in a manner very similar to bending a piece of coathanger wire back and forth. That’s ALL that happens in a microwave oven- there’s no stripping of electrons off the outer shell of the molecules. Thusly, the effect on living, water-containing tissues of exposure to high energy microwave signals is identical to exposure to infrared energy (i.e. standing in front of an open fire)- the tissues simply get warmer. There is no ability of non-ionising radiation to cause DNA mutations and thus no ability to cause cancers.
You’d think the discussion would end there- but no… urban myths, based solely in the lack of understanding of this little snippet of basic physics, leads the underinformed to harbour (or worse, propagate) irrational fears of carcinogenic effects from SOME radio signals, notably mobile phones.
Mobile phone signals vs everything else:
There’s nothing special about mobile phone signals compared to signals emitted from other services transmitted via radio waves, such as television, radar, radio or microwave ovens. The main difference is the way that these signals are modulated. Modulation is the superimposition of information on to a carrier radio wave. The way a signal is modulated does not, in any way, alter the character of the carrier signal. If the carrier signal is non-ionising, it doesn’t matter whether there’s digitised voice, text, video or anything else modulated on to the carrier- the physical characters of a non-ionising carrier wave will not change with the type of modulation.
Mobile phone signals are extremely weak in the general scheme of things. Handheld mobile phones emit about 0.6 watts (6/10 of 1 watt) at 900MHz-2.4GHz, depending upon the scheme the phone is designed to work with. By comparison, a common kitchen microwave oven is capable of emitting around 1000W at 2.45GHz. The acceptable leakage signals from a properly operating microwave oven, at a distance of 1m, are a factor of 10 greater than those emitted from a mobile phone. FM radio broadcast (88-108MHz) transmitters spit out anywhere from 25W to 100,000W. Television broadcast transmitters commonly emit 250,000-1,000,000 watts (or more) in the 45MHz-900MHz region.
So, why is there a pop-culture freakout about mobile phones but not the much, MUCH stronger TV, radio, radar or microwave oven signals? Why are hoax videos claiming to show mobile phones popping corn viewed so many times on YouTube? And yes, the ‘phones popping corn’ video is a hoax! The same visual effect can be demonstrated… with bananas!
Commercial news media want readers who keep coming back for another hit of fear:
The Australian media reaction is muddled, but to some degree predictable. News Ltd outlets, which normally prey on the lack of science education in their reader base, spun the story to give the impression that there WAS some connection found between mobiles and cancer. The ABC, which caters to more educated readers, ran the story fairly accurately, correctly interpreting the study’s ‘inconclusive’ result. Fairfax outlets couldn’t make up their minds. The Age did a bait-and-switch, running a scary headline but then correctly portrayed the result of the study in the body text, sucking in readers but then disappointing those who wanted to see a connection between phones and teh brane canser. The Sydney Morning Herald played upon the misunderstanding of lay readers between ‘study can’t rule out connection‘ and ‘BE VERY AFRAID.’
The conundrum of those who should know better:
However, in my mind, the most reprehensible response to the Interphone study came from neurosurgeon Dr Charlie Teo, who intimated some sort of conspiracy theory about the Interphone study being ‘designed to fail’. Teo has long established form in trying to scare the hell out of people about the dangers of electromagnetic signals, even trying to implicate electric blankets and clocks in carcinogenic effects. Teo also has been caught out parroting long-busted urban myths about hair dyes and cancer. Why Teo does this is a complete mystery- Teo’s purportedly an educated person and should be quite aware of the science of ionising vs. non-ionising radiation and cancers. All I can do is guess about his motivations for his silly comments, which would have to include his desire to be famous, inclusive of his appearances on Channel 7′s ‘Last Chance Surgery’ program and being repeatedly sought by mainstream media for comment on the mobile phone brain cancer issue. It merits mention that the number of actual, qualified neurosurgeons who are willing to make these outlandish claims can be counted on the fingers of one hand, similar to the number of actual, qualified climate scientists who dismiss anthropogenic global warming. There’s always a few nuts even among people who should have a clue.
The event which has disappointed me the most so far, post the release of the Interphone study, is a supposedly skeptical Twitterer I know, who hit me with a very tired ‘argument from authority‘ fallacy, asking me how it was that I know more than Teo about phones and brain cancer. The nut is that Teo’s theories have NO basis in established science- and you don’t have to be a brain surgeon to call Teo out on his deliberate ignorance of basic science any more than you have to be an immunologist to call out vaccination crank Meryl Dorey for her spreading of bullshit about vaccinations, autism and ‘big pharma’ conspiracies. The scientific evidence itself puts the lie to both Dorey and Teo- and you don’t need to be a post-doc to understand the basic science.
I’ll SAVE you, gimme your money!
Worst of all, wherever you find a complex health issue, you’ll find a litany of cranks, quacks and scammers ready to take people’s money to make them feel safer. American alternative-health quack Joe Mercola (who reckons vaccines don’t work and that swine flu is either a hoax, a ‘big pharma’ conspiracy or an outright fraud, depending on the day) will gleefully sell you a ‘Blue Tube‘ headset for your phone to allay your phoney fears. Literally hundreds of scammers will sell you ‘radiation shields’ for your mobile phone. These expensive bits of adhesive-coated tinfoil don’t protect anyone from anything. Since mobile phones raise their power output in response to low signal strength sensed from mobile phone base stations, any shielding between the phone and the outside world actually forces phones to increase their transmitted power output. If there was a hazard from the signals emitted from mobile phones, these ‘shields’ (if they worked, but they don’t) would make the hazard worse, not better! However, since there’s no hazard from mobile phone signals, all these useless ‘shields’ would do if they worked is force the phone to its maximum power output, unnecessarily draining already small phone batteries, reducing the phone’s range and increasing dropouts during calls. Just what you need, eh?
So, when am I gonna get teh phone canser?
Virtually every person you know (that is, anyone born in a developed nation since 1920) has been bathed in strong RF fields since birth, from signal sources much, MUCH stronger than mobile phones. However, brain cancers are vanishingly rare by comparison to the number of people in the developed world, are statistically no higher in people who live near powerful transmitter sites and have not increased commensurate with the utter explosion in numbers of mobile phones. There’s simply nothing to cause reasonable people fear from these devices.
Relax, have a coffee and phone up a friend for a long chat.
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