Another Reason to be Annoyed by Cell Phones 427
lotussuper7 writes: "This story at newscientist (free, no registration, unlike the NY Times) has some insight into the amount of RF you may be getting from all those cell phones people around you are using. Might be time to buy a cell phone jammer."
Re:I can see it now... (Score:1, Informative)
Well, in actual fact, the opposite happens; there are desgnated areas for those who don't want to use phones ;)
This is really nonsense. (Score:5, Informative)
A microwave cooker uses a very high power magnetron (usually >500W), directed in a narrow, focused beam, into a resonant cavity (the oven itself) from a distance of around 6". Furthermore, the oven uses a specific frequency, much below which RF heating is much weaker, and you need a lot more power (somewhere around 2.45GHz).
Now, a mobile phone uses around 1 or 2 watts *peak*. In normal use, it won't go above 500mW rms, otherwise the batteries would last only a few minutes. Not only that, but the antenna is designed to spread the signal over a wide area.
Mobile phone cell towers are also pretty much safe - although they use a much higher power than phones (15W or so, IIRC) they tend to be stuck up on high poles, well away from people. Inverse Square Law, anyone?
Here in Scotland, we recently had a series of large protests about siting cell towers near schools. The protesters were mainly middle-class mothers, from supposedly posh parts of Glasgow. Damn near all of them had sunbed tans. I'd take my chances with a mobile phone cell tower before I'd risk skin cancer from a sunbed...
Re:don't tell me you're suprised with this news ! (Score:2, Informative)
"We"?
Excessive amounts of water is not good for your health, neither is a) eating too much organic food b) eating too much genetically modified food c) eating "normal" food d)
Microwave oven's output is typically from 600 W upwards. Are you really comparing this to hundreds of milliwatts?
The "risk" of cellular phones has been and is being investigated - large scale and publicly. Check your sources. Unfortunately (or fortunately) for those with radiation phobia, none of the scientific studies have linked cell phones to cancer or other serious health problems.
Microwave radiation has been shown to increase tissue temperature slightly. According to one study it also changes protein production in human cells
Re:hmm (Score:4, Informative)
Microwave is simply an indication for the wavelength of a certain type of RF.
Your normal microwave oven works by emitting an RF signal at 2.45GHz
Jeroen
Idiotic (Score:5, Informative)
Why does everybody still take this stuff seriously? Read the article- all this study does is establish that you get exposed to more RF radiation in a crowded train car than you do in other places. The scary part only comes in when it brings up these "international guidelines" which such exposure may exceed. Who established these guidelines, and how? The article does not say anything beyond the name of the organization, but I note that its name makes it sound like an independent, non-governmental organization- so this could be effectively anybody smart enough to give themselves a clever-sounding name
The idea that RF transmissions will kill you or cause cancer has a long and ugly history of bad science concealed by calculated emotional appeals. It was basically started by a guy whose wife (who used a cell phone a lot) died of brain cancer, from which he concluded that cell phones cause cancer. Most of the "science" that has been done on this issue is basically the same idiotic reasoning dressed up in white lab coats. It is highly likely that the organization setting this 'standard' is in fact one of the lobbying groups associated with the anti-cell-phone movement.
Consider- radio waves are extremely low-energy- far below the threshold necessary to break molecular bonds, which is how genuine cancer-causing radiation works. Thus, if RF waves do cause cancer, the mechanism by which they do this is A. different than for other sorts of radiation, and B. totally unknown.
Plus, as has been pointed out a million times, a 'jammer' is a device which drowns out a signal by emitting a much more powerful signal of its own, not by magically making the other signal go away. If RF waves give you cancer, the jammer will give you cancer faster.
Re:Yeah, that'll help (Score:2, Informative)
Here [computex.com.tw] are some specs and details of such a jamming device.
Electromagnetic radiation - the facts . (Score:2, Informative)
The media would have us believe that radiation is an evil thing that destroys and mutates anything it touches.
So let's just be a little more scientific here shall we, and find out a bit about what EM radiation really is.
Electro-magnetic radiation is a term referring to the radiated field (ie, moving energy) of all types of electro-magnetic waves, from completely benign low-energy stuff like the radio waves your tv and radio receive, to quite nasty stuff such as gamma radiation. The difference is the amount of energy (and hence frequency) involved, and what happens to matter when exposed to those energies.
A large portion of the EM spectrum contains radiation that is of such a low frequency that the most it could do is impart some heat (okay, maybe a lot of heat) into your body. Anyone who has ever stood outside in the sun (yeah I know, I'm talking to a bunch of IT geeks who have probably never gone outside), will have noticed that it feels quite warm. You may not realise you've just experienced what it's like to be exposed to infrared radiation.
Look around, and bask in the knowledge that without the radiation we call visible light hitting the back of your eyes, you wouldn't be able to see a damn thing out there.
Now go back inside, turn on your TV and enjoy the television signals that are propogating through your house and are being converted into a very weak electrical current by the aerial on your TV, which is then hugely amplified so that you can watch a cartoon about mutant ninja turtles who live in a sewer.
When you fall and break your leg, you get carried off to the local hospital, where they radiate your leg with a high-energy radiation commonly called x-rays. When they do this, they cover the parts of your body they don't want to radiate with layers of lead, since lead is a cheap and dense atom and tends to absorb most things that hit it. This provides a shielding affect, which is good, because x-rays *are* dangerous if you are exposed to them for too long.
The reason that x-rays and gamma rays are dangerous, and radio waves and visible light are not, is that high-energy radiation contains sufficient energy to break the bonds within an atom, and can knock off electrons - creating a charged atom (known as an ion).
To say that another (simpler) way, ionising (ionizing for americans) radition is a dangerous thing to play with, since the cells in your body are not designed to operate well when charged. This is not to say that they will 'mutate' and your skin will turn green. More likely is that those cells will die and if you continue to be exposed to the radiation source, your body will be unable to produce new cells fast enough to replace the dead ones. Organs will shut down and stop functioning, and eventually your body will die from specific failures that I don't need to get into here.
Non-ionising radiation does not contain sufficient energy to break nuclear bonds, and thus is pretty safe to be around (The world would be a boring place without visible light).
Having said that, it's not entirely accurate to say that all non-ionising radition is safe - because it can destroy cells by heating them past the point that they can operate at. Anyone who has stayed out on the beach too long will be well aware of the danger of ultraviolet light, which is a non-ionising form of radiation, and thus does not destroy cells at an atomic level, but simply heats them up and burns them.
Fortunately the human body is capable of dealing with this, and the deeper layers of your skin produce a dark compound that is quite good (but not perfect) at absorbing UV radiation. Most people have seen this happening, and call it a sun tan.
This is not *quite* the same as the infra-red radiation that comes from say an oven or heater - that too can burn your skin, but since it has a different level of energy, and thus frequency, the exact manner that damage occurs.
What may surprise many people is that MICROWAVE radiation (1ghz - 100ghz) is also non-ionising. The damage it can cause is thermal, just like UV, radio, tv, infra-red, and ultra-violet radiation.
Microwave ovens work at 2.4ghz by *heating* whatever it is that you put in it. The reason they are shielded is that the makers don't want to cook the people standing outside the oven. If you were stupid enough to stick your hand in a microwave oven and turn it on, your hand would suffer a similar fate to as if you had put it in a fire or over a bunsen burner.
Incidently, 802.11b wireless networking works at around 2.422ghz - the same freqency that your microwave oven works at, but at a much lower power level, which is why you won't even feel a warm spot on your hand if you stuck it in front of the aerial.
GSM cellphones operate at 980Mhz, 1800Mhz, and 1900Mhz, depending on what type of network you are on. Those frequencies are at the end of the 'radio' part of the EM spectrum and the beginning of the 'microwave' part. Bear in mind that the term 'microwave' is simply referring to the size of the wavelength, and covers frequencies in the range 1Ghz to about 100Ghz.
Don't just take my word for it - check for youself. Google knows all, but I'll give you a few starting points:
There's a nice clear diagram showing where the different energies (types of radiation) fit in to the EM spectrum on nasa's site:
http://imagine.gsfc.nasa.gov/docs/science/know_
And there's a good explanation of ionising and non-ionising radiation here:
http://whatis.techtarget.com/definition/0,,sid9
Re:Idiotic (Score:2, Informative)
We know that cell phones (and other radio broadcasting equipment) emit radiation that is harmful to living beings at high power. The current theory is that this radiation at lower powers are not harmful.
But let's look at this. There are many dangers that radiation causes, but the one that concerns most people is cancer. What is the mechanism for radiation causing cancer? An ionizing radiation particle strikes the DNA inside the nucleus of a cell, causing a mutation that causes the cell to go into a state of uncontrolled cell reproduction. It just takes one initial cell to mutate to make a tumor.
Of course for this to happen, the radiation has to strike the DNA in exactly the right place. Your cells contain a lot of error-checking, so it is extremely unlikely for a single photon to make this happen. That is why scientists say you need a high dose of cell phone radiation to get cancer. But cancer has always been a probability game. You can get cancer from swallowing a single molecule of benzene, if it finds its way into the nucleus of a cell and attaches itself to the right place in your DNA. In the same way, a single cell phone call can give you cancer -- it's just not that likely.
Lower power radiation does not mean lower power photons coming from the antenna. It means less photons per second leaving the antenna. They are the same photons - the energy of a photon depends only on its frequency (E=hv, energy = Planck's constant times the frequency.) If a lot of photons of a certain frequency can give you cancer, so can just one.
I am an electrical engineer, but sometimes I think that a hundred years from now, people will look back on what we're doing in these times the same way we look at the coal-burning pollution at the start of the industrial revolution. We're crazy!!
We are bathing ourselves in RF! Not only do we wrap all of our houses in wiring that transmit 60Hz radiation, we broadcast in every known frequency that we can - AM, FM, television, cell phones. (AM is especially bad - so much of the power is wasted in the carrier.) Companies fight over unused parts of the spectrum - they can't wait to send cancer-causing photons into our bodies!!
Using electrons and photons to transmit information (at relatively low levels) is one thing. A century from now they will look back and be surprised that we used electricity - in all its lossy, inefficient, cancer-causing glory - to transmit energy from one place to another. That's just a bad idea. (A lot of people are looking at hydrogen, extracted from water through electrolysis, as a clean way to transport energy)
Of course, as has been mentioned, modern living exposes us to all kinds of health risks. Personally, I will keep driving my benzene-spewing car and using my radiation-emmitting cell phone until the next thing comes along.
yo.
Re:This is really nonsense. (Score:3, Informative)
Re:Idiotic (Score:3, Informative)
It's not just the intensity of the electromagnetic radiation. Cell phones emit non-ionizing radiation. Each photon has much less energy than the UV, X-ray, and gamma ray photons that can cause cancer.
Re:A cultural problem, not a technological problem (Score:3, Informative)
Let me add just a tad more information to this discussion.
As I recall from my E&M class (and I am an electronic engineer) the depth of penetration for an arriving wave is related to the wavelength(actually the energy content of the photon is what we're talking about..) So microwaves just don't penetrate that far in relative to something like 100Meter wave lengths.
Further, alot of the cell phones today are spread spectrum phones - so they spread their energy out - so the Watts/Hz is pretty small.
Lastly - when you consider the inverse square law that applies to radiation of RF, then the guy who has the phone against his head is ALOT more at risk that the guy standing next to him or someone standing down the car 5m away? The additive issues of even a dozen phones isn't likely to be an issue compared to the level you are exposed to with the phone next to you.
I would be REAL suspicious of this guy's work.
cancer at 1.9 GHz, and other myths (Score:4, Informative)
My cell phone (the ubiquitous Nokia 3360) is a TDMA phone that operates in the IS-54 (800 MHz) and IS-136 (1.9 GHz) bands. Now, 1.9 GHz sounds like a big, scary cancer-causing number. So let's see if it really is.
First of all, we need to know how radiation causes cancer. We'll just assume it's electromagnetic radiation, since cell phones definitely do not emit anti-protons, neutrons, muons and other shit like that. There's no way in hell a battery the size of a Triscut can generate reaction energies high enough to produce hadrons or leptons, so we can forget about them. (Well, actually, with a big capacitor you might get a few, but you're already getting showered with cosmic rays, and the pathetic little fart of hadrons you'd get out of a cell phone battery wouldn't count for didly squat.) The cancer-causing mechanism for electromagnetic radiation is fairly simple. In order to be dangerous, a photon (the electromagnetic force carrier particle) needs to carry enough energy to ionize (chemistry parlance for "fuck up") something important. It doesn't really matter how many photons you're slinging around, since it's the frequency that determines the energy of a single quanta.
So, what is our hypothetical candidate cancer-causing quanta going to have to inonize to do the deed? Well, DNA of course. It's going to have to cause a genetic mutation. Because of the way photons interact with matter, they are most likely to be absorbed by electromagnetically contiguous objects of sizes roughly equal to their wavelength. The reasons are deeper than this, but suffice it to say that a photon is "smeared" over an area about the size of its wavelength. Since you can't absorb part of a quanta (that's why they're called quanta, after all), you have to have a thing big enough to soak up a whole particle about the size of the wavelength. In this way, everything is, or is made of, antennae. To cause a mutation, you have to have a photon whose wavelength is about equal to diameter of a DNA molecule. Actually, the ideal length of an antenna is a quarter the wavelength of its intended optimal frequency, so we'll say the wavelength we're looking for is four times the diameter.
So, as I said, my cell phone operates at 1.9 GHz, or 1.9 billion cycles per second. What's the wavelength? Well, wavelength is the period times the speed of light. The period is the the inverse of frequency, so :
3*10^8 / 1.9*10^9 ~= 0.16 M
That's about the length of your hand, give or take a thumb. One quarter of that is about 4 cm - about the length of your thumb, give or take a nail. Now ask yourself this question: How big is your DNA?
If your DNA is built out of atoms the size of rasins, you might have something to worry about. The diameter of the DNA helix is 2 nm and the vertical rise per base pair is 0.34 nm. If you want a photon that will be able to reliably zap DNA, it needs to have a wavelength _smaller_ than 8 nm. The probability that a photon will be absorbed by a given object decreases with respect to the difference between the size of the object and the wavelength of the photon according to the standard deviation. So what's the probability that a given photon spewing out of my cell phone is going to fry some of my DNA? Well, we're a factor of five million away from the optimal wavelength. I'd say it's pretty fucking unlikely.
But wait a second - what's kind of radiation has a wavelength of 8 namometers? Well, we do the opposite to find the frequency :
3*10^8 / 8*10-9 = 3.7*10^16
That's in the ultraviolet range. Surprise, surprise!
So, what can we conclude from this? Well, since a cell phone has a transmission power of less than a watt and a wavelength the size of your thumb, it's not going to do jack shit to your DNA. Nada. Zilch. In other words, THERE IS NO WAY CELL PHONE RADIATION CAN GIVE YOU CANCER!!! I'd be more inclined to beleive that the plastic in the earpiece causes cancer.
You're several orders of magnitude more likely to contract cancer as a result of proximity to a 100 watt incandecant light bulb. It's got a much, much higher output, and its frequency range is thousands of times higher.
So relax, enjoy your wireless technology, and wear your SPF-30.