"Deltour's team analysed annual incidence rates of two types of brain tumour -- glioma and meningioma -- among adults aged 20 to 79 from Denmark, Finland, Norway, and Sweden from 1974 to 2003. These countries all have good cancer registries that keep a tally of known cancer cases.
...
"It is possible, Deltour's team wrote, that it takes longer than 10 years for tumours caused by mobile phones to turn up, that the tumours are too rare in this group to show a useful trend, or that there are trends but in subgroups too small to be measured in the study.
"It is just as possible that mobile phones do not cause brain tumours, they added.
Would you mind explaining for those of us who are less knowledgeable about physics why you don't believe that there is no known physical mechanism for the supposed phenomena?
(Ignoring the Boltzmann distribution for a moment...)
There are a couple of key things to keep in mind:
1) A photon's energy is proportional to its frequency.
2) It takes a specific amount of energy to induce a potentially carcinogenic effect.
For the rest of this post, I will assume that 1 keV is required to break a DNA backbone bond in one strand. Now, let's say you put your cell phone to your ear and start firing off ~uncountable photons, each of which are in the GHz range.
Billions upon billions of these photons will enter your brain. Imagine - if they were all energetic enough to be ionizing, then you would be experiencing strand breaks all the time while talking on your phone! But in fact, recall our (arbitrary) cutoff of 1 keV required to break a strand. Well, a 1.7 GHz phone is only emitting photons with an energy of around 7 micro eV. Such photons would be billions (10^9) of times too weak to cause a strand break.
Recall also that photonic energy is generally not additive. Think about pebbles being thrown at you. A 1-ounce pebble hitting you in the chest doesn't hurt. 160 1-ounce pebbles hitting you in the chest over the course of a few seconds might be annoying, but it's nothing like having a 10-pound rock thrown at your chest. Likewise, trillions of low-energy particles bombarding your DNA doesn't phase it at all.
Similarly, whereas one photon with 1 keV (again, that number is for sake of argument) might break your DNA, billions of photons with 0.1 keV wouldn't do a thing. This is why it is an odd proposition that low-energy, non-ionizing cell phone radiation should cause cancer.
As an aside, the pebble throwing analogy leads to one other possibility: imagine that all 160 pebbles hit your chest at precisely the same moment (to an accuracy of nanoseconds) at nearly exactly the same place. It would certainly feel as if you had been struck by a 10 pound rock. Likewise, if two photons hit the precise same place at precisely the same time, they will impart equivalent energy of one photon with double their frequency. This is rare, and at any rate the energy of one cell phone photon is so low that two together is still effectively nothing, as well.
Basically, there are some studies that indicate that prolonged exposure to EM radiation has carcinogenic effects. Which is what the article is about. It is not understood, but I can see why many feel worried. People tend not to like being guinea pigs.
It seems, they be the ones demonstrating beyond any doubt that EM radiation is perfectly safe? Which is why more studies are need, especially long term.
None of those experiments have proven reproducible.
Standing under a light bulb exposes you to EM radiation that's orders of magnitude more energetic than anything you will get from any type of radio transmitter.
There is vastly more radiation from sunlight than from using a cellphone. But in any case, I find that since I started wearing a tinfoil hat I'm much less affected by cellphone radiation.
There are multiple environmental cancers that we can acquire, in addition to the numerous other ways that life can get you if things get out of balance. The point is that our adaptive systems to overexposure to sun, such as sunburn and peeling, are well developed. Our adaptive system to avoiding radiation exposure to the ear and brain, not so much.
The article explains the physical mechanism - or at least the area in which it applies:
At the vanguard of a new field of study that came to be known as bioelectromagnetics, he found what appeared to be grave nonthermal effects from microwave frequencies—the part of the spectrum that belongs not just to radar signals and microwave ovens but also, in the past fifteen years, to cell phones. (The only honest way to think of our cell phones is that they are tiny, low-power microwave ovens, without walls, that we hold against the sides of our heads.) Frey tested microwave radiation on frogs and other lab animals, targeting the eyes, the heart, and the brain, and in each case he found troubling results. In one study, he triggered heart arrhythmias. Then, using the right modulations of the frequency, he even stopped frog hearts with microwaves—stopped the hearts dead.
also how modulated microwaves assit in breaching the blood - brain barrier
In a study published in 1975 in the Annals of the New York Academy of Sciences, Frey reported that microwaves pulsed at certain modulations could induce "leakage" in the barrier between the circulatory system and the brain. Breaching the blood-brain barrier is a serious matter: It means the brain's environment, which needs to be extremely stable for nerve cells to function properly, can be perturbed in all kinds of dangerous ways. Frey's method was rather simple: He injected a fluorescent dye into the circulatory system of white rats, then swept the microwave frequencies across their bodies. In a matter of minutes, the dye had leached into the confines of the rats' brains.
Worse - they found that the radiation CAN cause DNA damage.
The potential complications don't end there. In the mid-1990s, a biophysicist at the University of Washington named Henry Lai began to make profound discoveries about the effects of such frequencies not only on the blood-brain barrier but also on the actual structure of rat DNA. Lai found that modulated EM radiation could cause breaks in DNA strands—breaks that could then lead to genetic damage and mutations that would be passed on for generations. What surprised Lai was that the damage was accomplished in a single two-hour exposure.
In essence - even though the energy is not sufficient to ionize it is impacting the function of cells.
It is interesting the approach taken in US vs Europe. Europe is taking more of precautionary approach, they are at least doing more research, they seem more skeptical. In US worrying about cellphone radiation is considered "conspiratorial" for some reason. Are these flak groups sponsored by large wireless telecom carriers?
I observed the same thing in regard to food and additives. FDA seems to need strong irrefutable proof of toxicity before they would ban an additive, Europeans seem to take more of a precautionary approach -- if the additive is thought to be harmful, they will be banned. Is it just me or have others noticed the same?
It shouldn't be surprising if you understand a bit of basic logic. No one can prove a negative, yet this is exactly what the so-called "precautionary principle" demands of us.
I can't prove that cell phone radiation is always harmless to all respects of human health under all conditions, and you can't prove that there's not an invisible teapot in orbit around Neptune. Instead, the burden of proof must lie with the party making the positive assertion.
It would be very obvious by now if handheld radio transceivers caused cancer. The physics say it won't happen, and so does the epidemiology. Case closed for now, worry about something else.
What is lacking is long term studies. That is essentially what the doctor in the article notices.
The same is true for food additives. How many companies do you think conduct 20 year long studies on chemicals that mimic hormones? Pumping rabbits and mice with massive dosages might not be the same as a long term exposure to very small doses.
We're all "long term studies." Where's the brain-cancer epidemic? People who smoke are more likely to get lung cancer, an otherwise rare disease. So if everybody started smoking, we'd see a large spike in lung-cancer cases. However, we have not seen a large spike in brain-cancer cases across all populations who started using cell phones en masse in the 1990s.
So exactly what problem is being addressed here, besides poor high-school physics education?
Does it? That's a very strong statement. We are still very ignorant of the subtle workings of the body.
There have been numerous studies and as I see it the jury is still out. Mobile phones have only really been in common use for a decade; that's less time than it takes for eg. lung cancer to develop. I'm not "worried" as such, but I'm certainly open to new data, and think it's rather too soon to declare absolute victory to one side or the other.
Anyway I wasn't trying to say this study is right or wrong or anything really. I was just commenting on the instantly dismissive attitude of many of the responders to this article. I think such dismissiveness is unwarranted.
I don't know what definition of "photon" you are using but I don't think it is appropriate to describe the effects of microwave radiation, which occurs at very different wavelengths as visible light, which "photon" traditionally refers to.
EM radiation at ~microwave levels has well-known effects, it's true, such as protein denaturing and other localised internal heating. The effect of randomly, and perhaps partially, denaturing proteins over long periods of time in important parts of your body is rather ill-studied, I would have thought.
I'm not sure that's really a general difference in approaches. After Canada banned BPA in baby bottles, people started going crazy about it in the US, and eventually the FDA decided to change its stance. Meanwhile in Europe, nearly all countries concluded no further research was necessary and that BPA was fine.
My European friends that I asked about this claimed that it was because "European governments are much more easily influenced by companies". Not the response I was expecting.
If you read the section on government regulations in the Wikipedia article on BPA, you'll get an interesting perspective on one issue, at least in terms of precautionary principle vs. safe till proven otherwise.
Alright, you actually had me interested. A plausible demonstration of SSB (single strand breakage) or DSB (double strand breakage) after exposure to the type of RF that cell phones emit would be huge. And to his credit, that's exactly what Lai's results indicated (H Lai, NP Singh - Int J Radiat Biol, 1996).
Specifically, Lai found DNA breakage in the brain tissues of rats immediately after a 2hr exposure to a 2450MHz CW (continuous wave) signal, but not immediately after exposure to a 2450MHz PW (pulsed wave) signal. DNA breakage was only found 4hr after exposure to the PW signal ended. Lai didn't provide any temperature information, so we can't know if that was a factor.
Here's my problem: Lai's experiment was reproduced at least once, and found no significant difference in SSBs between the irradiated group and the controls (http://bit.ly/9qr2Hm).
This is on top of numerous other studies that have failed to confirm DNA damage from RF exposure (http://bit.ly/c9H4MR). I'm not saying that RF-induced DNA damage couldn't possibly happen, but the evidence for it seems weak or non-existent at best.
Sure, excessive heat will damage DNA. I would like to see a study that actually induces cancer in a rodent with cell phone radiation at cell phone exposure levels. I suspect, though, that it is not possible.
I know that people get tired of me ruining good "think of the children" debates with this question but here goes anyway:
What if the worst is true? What if one in every 100,000 people who uses a cellphone extensively during a lifetime is killed horribly by it?
Would you stop using yours? If so, why do you still ride in cars? I once saw an activist against the EM fields from power lines smoke 5 cigarettes while pontificating about the illnesses the lines in his yard might cause.
It all comes down to statistics and rationality. It seems humanity has chosen a technological path of growth instead of being content with 40 year lives of subsistence farming. We're gonna need those radio whatsits to get off this rock and preserve the species. Hopefully if there is something to weak EM / cancer thing, we'll evolve immunity to it before we get into space and get into the real radiation. (Or perhaps, advance to the "oops, you've got a DNA error, let me fix that for you" stage.)
Edit: Just to be clear, I'm not advocating head in the sand denialism of any possible ill effects, I'm just advocating rational, proportional responses to the possible danger verses the more common, knee-jerk "it might cause cancer ban them all!" responses.
Microwave radiation is too low energy to cause DNA mutation, so it can't be a direct cause of cancer. Besides, wouldn't we see ear cancer more than brain cancer ?
Non-ionizing radiation does nonetheless affect molecular bonds. It adds energy to them, placing them in more energetic states of vibration, mechanical energy. This is turn influences the chemical reactions they undergo. It could be a catalyst for adverse chemical reactions that lead to pathologies.
(Perhaps in combination with other "man-made" agents; does it perhaps help the odd chlorinated, fluourinate, bromated, or other carcinogen "get a grip" on a a strand of DNA?)
Specific effects depend upon the bonds and the RF frequencies. And affects accumulate in a statistically described fashion; it may take years to for a member of a population to accumulate a significant probability of experiencing an adverse affect.
I haven't had a chemistry class in years (aka I'm no expert). But what I did learn was enough that I don't rule out the possibility of effects induced by non-ionizing radiation. "Non-ionizing" <> no effect whatsoever.
The problem with these stories regarding health risks from tech is that we WANT them to not be true. I read it and say "bah" but in the back of my head it really does worry me.
The problem is elimination of cell phones & wifi would be such an inconvenience in our lifestyles... I mean I rely on both so extensively that even simply cutting back on cell phone use be a huge problem. Heck I work in a building with no less than 17 different wifi networks.
Even if the research is inconvenient on an individual or institutional level I just hope there is more done and more public interest so that at least engineers will focus a little more on developing lifestyle tech that is safer. I mean don't we have enough risks from various environmental pollution already? Wouldn't it make sense to put pressure on changing the things that can be changed? Even if its paranoid would it kill people to care about it a bit more?
34 comments
[ 3.3 ms ] story [ 87.8 ms ] threadhttp://www.smh.com.au/digital-life/mobiles/no-tumour-link-to...
"Deltour's team analysed annual incidence rates of two types of brain tumour -- glioma and meningioma -- among adults aged 20 to 79 from Denmark, Finland, Norway, and Sweden from 1974 to 2003. These countries all have good cancer registries that keep a tally of known cancer cases.
...
"It is possible, Deltour's team wrote, that it takes longer than 10 years for tumours caused by mobile phones to turn up, that the tumours are too rare in this group to show a useful trend, or that there are trends but in subgroups too small to be measured in the study.
"It is just as possible that mobile phones do not cause brain tumours, they added.
As for me and my house, we will follow E = hv.
There are a couple of key things to keep in mind:
1) A photon's energy is proportional to its frequency.
2) It takes a specific amount of energy to induce a potentially carcinogenic effect.
For the rest of this post, I will assume that 1 keV is required to break a DNA backbone bond in one strand. Now, let's say you put your cell phone to your ear and start firing off ~uncountable photons, each of which are in the GHz range.
Billions upon billions of these photons will enter your brain. Imagine - if they were all energetic enough to be ionizing, then you would be experiencing strand breaks all the time while talking on your phone! But in fact, recall our (arbitrary) cutoff of 1 keV required to break a strand. Well, a 1.7 GHz phone is only emitting photons with an energy of around 7 micro eV. Such photons would be billions (10^9) of times too weak to cause a strand break.
Recall also that photonic energy is generally not additive. Think about pebbles being thrown at you. A 1-ounce pebble hitting you in the chest doesn't hurt. 160 1-ounce pebbles hitting you in the chest over the course of a few seconds might be annoying, but it's nothing like having a 10-pound rock thrown at your chest. Likewise, trillions of low-energy particles bombarding your DNA doesn't phase it at all.
Similarly, whereas one photon with 1 keV (again, that number is for sake of argument) might break your DNA, billions of photons with 0.1 keV wouldn't do a thing. This is why it is an odd proposition that low-energy, non-ionizing cell phone radiation should cause cancer.
As an aside, the pebble throwing analogy leads to one other possibility: imagine that all 160 pebbles hit your chest at precisely the same moment (to an accuracy of nanoseconds) at nearly exactly the same place. It would certainly feel as if you had been struck by a 10 pound rock. Likewise, if two photons hit the precise same place at precisely the same time, they will impart equivalent energy of one photon with double their frequency. This is rare, and at any rate the energy of one cell phone photon is so low that two together is still effectively nothing, as well.
http://en.wikipedia.org/wiki/Electromagnetic_radiation_and_h...
Basically, there are some studies that indicate that prolonged exposure to EM radiation has carcinogenic effects. Which is what the article is about. It is not understood, but I can see why many feel worried. People tend not to like being guinea pigs.
It seems, they be the ones demonstrating beyond any doubt that EM radiation is perfectly safe? Which is why more studies are need, especially long term.
Standing under a light bulb exposes you to EM radiation that's orders of magnitude more energetic than anything you will get from any type of radio transmitter.
At the vanguard of a new field of study that came to be known as bioelectromagnetics, he found what appeared to be grave nonthermal effects from microwave frequencies—the part of the spectrum that belongs not just to radar signals and microwave ovens but also, in the past fifteen years, to cell phones. (The only honest way to think of our cell phones is that they are tiny, low-power microwave ovens, without walls, that we hold against the sides of our heads.) Frey tested microwave radiation on frogs and other lab animals, targeting the eyes, the heart, and the brain, and in each case he found troubling results. In one study, he triggered heart arrhythmias. Then, using the right modulations of the frequency, he even stopped frog hearts with microwaves—stopped the hearts dead.
also how modulated microwaves assit in breaching the blood - brain barrier
In a study published in 1975 in the Annals of the New York Academy of Sciences, Frey reported that microwaves pulsed at certain modulations could induce "leakage" in the barrier between the circulatory system and the brain. Breaching the blood-brain barrier is a serious matter: It means the brain's environment, which needs to be extremely stable for nerve cells to function properly, can be perturbed in all kinds of dangerous ways. Frey's method was rather simple: He injected a fluorescent dye into the circulatory system of white rats, then swept the microwave frequencies across their bodies. In a matter of minutes, the dye had leached into the confines of the rats' brains.
The potential complications don't end there. In the mid-1990s, a biophysicist at the University of Washington named Henry Lai began to make profound discoveries about the effects of such frequencies not only on the blood-brain barrier but also on the actual structure of rat DNA. Lai found that modulated EM radiation could cause breaks in DNA strands—breaks that could then lead to genetic damage and mutations that would be passed on for generations. What surprised Lai was that the damage was accomplished in a single two-hour exposure.
In essence - even though the energy is not sufficient to ionize it is impacting the function of cells.
(this is why I posted the article)
I observed the same thing in regard to food and additives. FDA seems to need strong irrefutable proof of toxicity before they would ban an additive, Europeans seem to take more of a precautionary approach -- if the additive is thought to be harmful, they will be banned. Is it just me or have others noticed the same?
Indeed, as demonstrated by the majority of responses to this article. Surprising, at least to me.
I can't prove that cell phone radiation is always harmless to all respects of human health under all conditions, and you can't prove that there's not an invisible teapot in orbit around Neptune. Instead, the burden of proof must lie with the party making the positive assertion.
It would be very obvious by now if handheld radio transceivers caused cancer. The physics say it won't happen, and so does the epidemiology. Case closed for now, worry about something else.
The same is true for food additives. How many companies do you think conduct 20 year long studies on chemicals that mimic hormones? Pumping rabbits and mice with massive dosages might not be the same as a long term exposure to very small doses.
So exactly what problem is being addressed here, besides poor high-school physics education?
Does it? That's a very strong statement. We are still very ignorant of the subtle workings of the body.
There have been numerous studies and as I see it the jury is still out. Mobile phones have only really been in common use for a decade; that's less time than it takes for eg. lung cancer to develop. I'm not "worried" as such, but I'm certainly open to new data, and think it's rather too soon to declare absolute victory to one side or the other.
Anyway I wasn't trying to say this study is right or wrong or anything really. I was just commenting on the instantly dismissive attitude of many of the responders to this article. I think such dismissiveness is unwarranted.
Not at the atomic level, we're not. Photon interactions work the same way in your brain as they do anywhere else.
EM radiation at ~microwave levels has well-known effects, it's true, such as protein denaturing and other localised internal heating. The effect of randomly, and perhaps partially, denaturing proteins over long periods of time in important parts of your body is rather ill-studied, I would have thought.
My European friends that I asked about this claimed that it was because "European governments are much more easily influenced by companies". Not the response I was expecting.
If you read the section on government regulations in the Wikipedia article on BPA, you'll get an interesting perspective on one issue, at least in terms of precautionary principle vs. safe till proven otherwise.
Specifically, Lai found DNA breakage in the brain tissues of rats immediately after a 2hr exposure to a 2450MHz CW (continuous wave) signal, but not immediately after exposure to a 2450MHz PW (pulsed wave) signal. DNA breakage was only found 4hr after exposure to the PW signal ended. Lai didn't provide any temperature information, so we can't know if that was a factor.
Here's my problem: Lai's experiment was reproduced at least once, and found no significant difference in SSBs between the irradiated group and the controls (http://bit.ly/9qr2Hm).
This is on top of numerous other studies that have failed to confirm DNA damage from RF exposure (http://bit.ly/c9H4MR). I'm not saying that RF-induced DNA damage couldn't possibly happen, but the evidence for it seems weak or non-existent at best.
Seriously... if cell phone radiation was harmful, don't you think the trial lawyers would have discovered it by now?
http://news.nationalgeographic.com/news/2010/01/100106-cell-...
Anyway I can't find his research paper.
What if the worst is true? What if one in every 100,000 people who uses a cellphone extensively during a lifetime is killed horribly by it?
Would you stop using yours? If so, why do you still ride in cars? I once saw an activist against the EM fields from power lines smoke 5 cigarettes while pontificating about the illnesses the lines in his yard might cause.
It all comes down to statistics and rationality. It seems humanity has chosen a technological path of growth instead of being content with 40 year lives of subsistence farming. We're gonna need those radio whatsits to get off this rock and preserve the species. Hopefully if there is something to weak EM / cancer thing, we'll evolve immunity to it before we get into space and get into the real radiation. (Or perhaps, advance to the "oops, you've got a DNA error, let me fix that for you" stage.)
Edit: Just to be clear, I'm not advocating head in the sand denialism of any possible ill effects, I'm just advocating rational, proportional responses to the possible danger verses the more common, knee-jerk "it might cause cancer ban them all!" responses.
(Perhaps in combination with other "man-made" agents; does it perhaps help the odd chlorinated, fluourinate, bromated, or other carcinogen "get a grip" on a a strand of DNA?)
Specific effects depend upon the bonds and the RF frequencies. And affects accumulate in a statistically described fashion; it may take years to for a member of a population to accumulate a significant probability of experiencing an adverse affect.
I haven't had a chemistry class in years (aka I'm no expert). But what I did learn was enough that I don't rule out the possibility of effects induced by non-ionizing radiation. "Non-ionizing" <> no effect whatsoever.
The problem is elimination of cell phones & wifi would be such an inconvenience in our lifestyles... I mean I rely on both so extensively that even simply cutting back on cell phone use be a huge problem. Heck I work in a building with no less than 17 different wifi networks.
Even if the research is inconvenient on an individual or institutional level I just hope there is more done and more public interest so that at least engineers will focus a little more on developing lifestyle tech that is safer. I mean don't we have enough risks from various environmental pollution already? Wouldn't it make sense to put pressure on changing the things that can be changed? Even if its paranoid would it kill people to care about it a bit more?
</rant>