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Brain Cancer Worries? Look Up Your Phone's SAR
CWmike writes "With recent news of a possible link between cell phone radiation and risk of brain cancer, you may have a new-found interest in knowing how much radiation your mobile handset is giving off — or, more importantly, how much your body might be absorbing. The FCC's legal limit for mobile phones is 1.6 Watts of radiofrequency energy per kilogram, using a measure called Specific Absorption Rate (SAR). The Environmental Working Group, which tracks SAR data for more than 1,300 cell phone and smartphone models, notes that several factors besides your handset affect your actual level of exposure. Look up your phone's SAR; or see a full chart of phones." And relax — have a coffee.
Have they bothered thinking about other cancers in all of this? I had testicular cancer last year, and my phone spends a lot more time in my jacket or pants pocket than it does up against my head.
...But coffee is also in the 'may possibly cause cancer' that mobile phones have recently been added to
"IARC conducts numerous reviews and in the past has given the same score to, for example, pickled vegetables and coffee" [http://news.cnet.com/8301-30686_3-20067593-266.html]
The reason is that the frequencies cell phones use are below the spectrum of ultraviolet light. It is near the spectrum of ultraviolet light where the first ionizing radiation occurs, which is required to be able to cause cancer. Ionizing means that the energy level of the individual photons of the transmission have enough energy to disturb the molecular structure of live cells. Microwave "radiation" (which has absolutely nothing to do with nuclear radiation) is far within the level of the non-ionizing radiation spectrum, so there is no possibility of it having the energy required to cause cancer.
Cell phones use frequencies around 800 MHz to around 2 GHz or so. 3 GHz has an energy level of about 12.4 ueV; ultraviolet light where the first ionizing radiation is possible is around 124ev -- that's a 10,000,000:1 difference in energy level. Have a look at the energy level chart on the right hand side of:
http://en.wikipedia.org/wiki/Electromagnetic_spectrum
or even better, see page 3 of FCC OET Bulletin 56, which is a Q&A on Biological Effects and Potential Hazards of Radiofrequency Electromagnetic Fields:
http://www.fcc.gov/Bureaus/Engineering_Technology/Documents/bulletins/oet56/oet56e4.pdf
People are also afraid of the cell base stations, because they don't know how safe they actually are. The transmitters for these typically send 20 - 40 watts -- that's all. This is then sent through directional "sectored" antennas that typically have 120 degrees of horizontal beam width and only 6 to 15 degrees of vertical beam width; so the three-dimensional antenna pattern is like a 120 degree slice of a pancake, yielding gain of about 13 dBi. This focusing is where the "gain" of antennas comes from -- by focusing where the energy is transmitted.
In the U.S., the standard for specifically what frequencies and power levels are considered safe is the IEEE C95.1 standard, which is unfortunately not freely available, however there's a an overview here: http://www.interferencetechnology.com/uploads/media/AG_07.pdf
This standard is incredibly long to read, but boils down to this: the only proven effect of microwave radiation in 60 years of research is the effect of microwave heating. No cancer. Further than that, the standard narrows down to the power levels that are safe for various frequency regions concerning microwave heating.
But if you really want something to "bite your teeth on", have a look at the international ICNIRP guidelines: http://www.icnirp.de/documents/emfgdl.pdf
Now, if you go through the MATH of how close you have to be to the antennas of a cell tower for it to be "unsafe", the result is pretty interesting:
Spec limit for human-absorbed power per IEEE C95-1 at 900 MHz: 50 Watts/m^2
13 dBi gain = gain of 20
EIRP = 20 W transmitted power * gain of 20 = 400 W
400 W / 4*pi*R^2 = 50 W/m^2
R = 0.636 meters
0.636 meters = 2.09 feet
So at 900 MHz and with a typical transmit power of 20 Watts and a sectored antenna with 13 dBi gain, you need to be 2 feet in front of the antenna while it's transmitting for it to be considered unsafe. This means the only way it's unsafe for a human being is if they're not only on the tower, but right in front of the antenna while it's operating at full power.
The cell phones themselves have a limit on how much power they are allowed to transmit. There are different power limits in various countries; in the U.S. the limit is 1.6 W/kg SAR, in Canada I believe the limit is 10 W/kg SAR. SAR stands for "Specific Absorption Rate". What you really want to know is "what SAR power level is unsafe?", and the answer is that in lab t
Stop giving so much weight to this idea that they have concluded that cell phones may cause cancer. It's listed with a ton of other things under the "maybe" level. It's only based on repost that they've read. There was no independent study involved. They read a bunch of reports and based on those, concluded that it falls under the "may cause cancer" classification. As in, they can't state that it does or that it doesn't. Prior to this, they hadn't even gotten around to classifying it. This is a non-news story, except by twats trying to sensationalize it.
FCC says SAR not appropriate to compare.
Link them. I just checked the top Google results and there is a whole ONE paper with a group of 25 men which shows a correlation. There is another which covers most of the US forces in Korea and specifically looked at radar technicians which found no correlation (in fact for several categories they had lower cancer rates). All the others are mixed which screams to me "random cancer cluster" not "non-ionising radiation causes cancer".
The thing you are missing is that early radar equipment used exciters that emitted large amounts of IONISING radiation. The stuff that come out of the antenna was non-ionising, but it wouldn't have been healthy sitting next to the actual transmitter.
And those power levels of orders of magnitudes higher then from a cell phone. So the claim is that not only does non-ionising radiation cause cancer in a way that hasn't been identified in over a century of research, but that repeated small exposures are worse then single large exposures of the same overall magnitude. The opposite of how ionising radiation works.
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CINC, 4th Penguin Legion
IMO the most logical explanation for the correlation between cell phone use and cancer is that the cancers are from the KNOWN carcinogens that leech from plastics. Like the plastic cases that most phones used until the iPhone made metal/glass cases cool. Holding a piece of carcinogen leaking plastic to your head for hours on end for a decade or more seems a much more logical culprit then non-ionising radiation.
P.S. The plastic theory would probably explain why bowel cancer is spiking amongst the young. Young people are eating/drinking from crappy plastic containers at higher rates then ever. If you like carrying water around all the time get a metal or glass flask.
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CINC, 4th Penguin Legion
The reason is that the frequencies cell phones use are below the spectrum of ultraviolet light. It is near the spectrum of ultraviolet light where the first ionizing radiation occurs, which is required to be able to cause cancer. Ionizing means that the energy level of the individual photons of the transmission have enough energy to disturb the molecular structure of live cells. Microwave "radiation" (which has absolutely nothing to do with nuclear radiation) is far within the level of the non-ionizing radiation spectrum, so there is no possibility of it having the energy required to cause cancer.
This is total bullshit. There are a lot of studies show the link between EM radiation at longer wavelengths than the UV causing an increase in cancer rates. I'm not even going to bother providing a references to one of the thousand papers on this subject. Just look at some studies performed in England and Belgian on the incidence of cancer for radar operators in WW2. We are speaking of other magnitudes of energy levels, but it still invalids your opening statement. Maybe you also overlooked non-ionizing biological effects?
No; as I said, the non-ionizing effects are microwave heating... and there aren't any ionizing effects. And I quoted both U.S. and international studies and standards that cover over 60 years of scientific research on the subject.
The only thing you're correct about in your comment is that there are papers as well as books that claim a link between microwaves and cancer; it's a very popular myth, and has been for over a decade. I'm saying it's a myth, and I've told you why I'm personally sure it's a myth, and I've given you some of my research on the subject. ...and you've given me your opinion.
And then... the eyes... Again a falsehood. The eyes are very actively cooled, and that with a very high blood flow, to cool them down from the incoming and concentrated (through the eye optics) radiation. On a very sunny day, where you have over 1 kW/m^2 of irradiance, without a good cooling, they would simply burn/cook.
I wonder how one can present such a thought out post, with calculations and everything, but with such blatantly falls information at the same time.
I never said the eyes weren't actively cooled; I said that they're the most sensitive part of the body because they don't have much blood flow due to only having capillaries in them. They're also the most sensitive because with a sufficient increase in temperature, cataracts will result. On other places on the body, an increase in temperature would mostly cause temporary damage or a burn that would heal later -- but not with the eyes.
now your telling me I can get SARs from a phone. I'm just wondering if it's just me that would find it immensely satisfying to smash their phone with a hammer, sometimes.
My ism, it's full of beliefs.
No need to worry about testicular cancer. Very little power is used when the phone is in standby. Note that the battery charge lasts a long time if you are not talking on the phone. The receiver is working, but the transmitter has a very low transmission rate.
Any transmitted energy from a cell phone in a pants pocket would need to travel through a leg to get to testicles.
Danger -- The Sun is a big electromagnetic radiation transmitter in the sky. Walking from the shade into the sun will heat your body much more than the energy of a cell phone transmitting during a call.
Standing in the sun absorbing high-energy ultraviolet radiation is truly damaging; severe exposure can cause sores and even eventually skin cancer. The photons of ultraviolet light are more than a million times more energetic than cell phone radiation, and the sun emits far, far more energy than a cell phone.
The entire earth receives 1,218,000,000,000,000 Watts from the Sun. The earth receives more total solar energy from the Sun in one hour than is generated and used by humans in an entire year. The average energy received over the entire earth is about 250 Watts per square meter over a 24 hour day, ignoring clouds.
The sun emits energy in the same wavelengths as cell phones. The only difference between the sun's energy and cell phone emissions is that the cell phone energy is at one specific frequency, and the sun emits energy at all frequencies. GSM cell phones use frequency bands at 850, 900, 1800, and 1900 MegaHertz. GSM is the most popular kind of cell phone transmitter design.
But no one has shown any frequency-specific interaction, and the physics is quite clear that there cannot be any. High energy electromagnetic waves definitely can have a strong effect on chemical bonds, but not low energy waves. The energy emitted by cell phones is perhaps 1/10,000 or 1/100,000 of the energy needed.
I haven't yet calculated how much energy is received from the Sun at those frequencies. However, there is no way for the energy from cell phones to be resonant in the body; the wavelength of cell phone radiation is too long. So the cell phone energy just heats the body, as does the Sun's energy. Without resonance, there is insignificant coupling to specific chemical processes.
Instant fame There are many, many very well-educated people in the world who would love to discover a new way that electromagnetic energy interacts with matter. Such a discovery would make any physicist or chemist instantly famous, and would earn him or her a Nobel Prize. The motivation to make such a discovery is enormous for people working in those fields.
The fact that no such discovery of a new kind of interaction has been made indicates at least that it is not easy. Another indication is that apparently no one has even proposed a mechanism for low-energy long-wavelength electromagnetic radiation to have an effect on chemistry.
It's not as though it hasn't occurred to anyone to do research.
People may say that there may be some subtle effect that we have not yet discovered. And there may be. However, those comments often give the impression that they think that the discovery of a new subtle interaction would have a subtle effect on our understanding of the world. That isn't true. In fact, the discovery of a new kind of interaction between electromagnetic radiation and matter would create a revolution in Physics, in areas we think we know well, in areas where our understanding has been stable for many decades. For example, Planck's constant is known with an uncertainty of only 89 parts per billion.
That makes a new discovery seem less likely.
Einstein's discovery of relativity revolutionized our understanding o
The reason is that the frequencies cell phones use are below the spectrum of ultraviolet light. It is near the spectrum of ultraviolet light where the first ionizing radiation occurs, which is required to be able to cause cancer.
99% of all carcinogenic substances do not emit ionizing radiations. On the other hand it is known that microwaves alter the physiology of the brain:
http://www.nature.com/jcbfm/journal/v29/n5/full/jcbfm200914a.html
http://www.nature.com/jcbfm/journal/v26/n7/full/9600279a.html
There are a lot of scientific articles pointing out that low-power microwaves can damage brain cells or alter their physiology. Since that's the primary effect of a ionizing radiation (cancer is a secondary effect of the induced damage), none can exclude that microwaves can cause cancer because "ionizing radiations are required to be able to cause cancer". They're not.