Study on RF and Genetic Damage 112
xeno wrote in to
send us a wired article that talks about RF Genetic Damage.
Its still a bit fuzzy. The scariest part is that the scary
results of this test were actually funded by the
cell phone industry. Interesting...
Re:Get a clue (Score:1)
Heh, that explanes 800MHz RF burns (ouch!). But then 20W in 1 sqaure mm is pretty nasty at any frequency.
Re:Raises another question (Score:1)
Re:hobby project (Score:1)
Anyway, you're overlooking the obvious. Modulate the microwave beam with the control signal. That way you get both your power source and control from the same signal (at the cost of a little power), without worrying about interference.
Re:Just some facts (Score:2)
Is there a moderator in the house?
How many postings are going to erroneously claim that microwave ovens operate at "the resonance frequency of water?" Although it's true that microwaves "vibrate" the water molecules to form the basic mechanism for microwave cooking, this phenomenon has nothing to do with "resonance." A very broad range of RF frequencies will produce heating effects in water due to dielectric losses. And tissue with poor heat dissipation properties-- such as the lens of the eye--is especially vulnerable to damage from such heating. (The testes are also sensitive to such heating--yes, RF can make you sterile, at least temporarily.)
Microwave ovens operate at the frequency they do because it is in an FCC-allocated band for industrial use, harmonically related to many such "junk" bands. The particular band chosen had a wavelength short enough to suit a reasonably small resonant cavity but long enough to penetrate reasonably well through food. If it were an actual resonant frequency for water, most of the energy would be absorbed near the surface of the food--not a good thing.
An aside not directly related to the above: For decades it's been assumed that such heating was the only source of biological damage for EM radiation at energies below the ultraviolet. (Photons at energies of UV and above can break chemical bonds, resulting in direct biological damage.) But consider that lower frequencies--red and near-IR--can have profound effects on certain dye-catalyzed reactions, such as photosynthesis and certain drug treatments, even though they lack the energy to directly affect chemical bonds. It's a pretty big stretch from there to RF, but it's conceivable that other resonance effects may occur at lower frequencies, perhaps by influencing part of a large enzyme molecule whose shape is determined by far weaker forces than "normal" chemical bonds. It seems pretty unlikely, but not so impossible as to dismiss out-of-hand.
Re:A better reason to avoid cell phones... (Score:1)
Go figure.
Don't hate the media, become the media.
Another hazard besides genetic damage! (Score:1)
Once again, the only people that will really benefit are the lawyers.
_______________________________________________
"Feelings" are a wonderful excuse for stupidity
Re:A better reason to avoid cell phones... (Score:1)
So the cell phone only makes it worse.
I don't like to use the phone in the car because I'm too busy driving to pay attention to what they are saying. I do feel that my driving performance probably doesn't suffer much while I'm using my cell phone, but that's only because I'm not really listening. So why bother using it, right? Exactly.
I also get similar distractions from deep conversations. I try to avoid those while driving also, but at least in those cases the other person is right there and can also judge the current traffic situation.
The thing I _really_ don't get is how people can manage to read and drive at the same time. Not only does their driving suffer severely, but how can you enjoy a book that way. Why do two things extremely poorly when you could be attempting to save your life?
Rant over.
Re:1.9GHz, 2.1GHz (Score:1)
Here in
Re:Get a clue, no seriously, get a clue (Score:1)
DNA), the resonant frequency gets much lower, I believe even down to high (100s) KHz. Other molecules are in the infra red region (below visible light), though I think that's the electron band gap stuff, not molecular resonance. In fact, I suspect you're confusing molecular resonance with something else (sub atomic resonance?).
-----------------------------------------------
When you're talking about the resonant frequency of water, what you're really talking about is the vibrational excitation of the H-O bonds. Hate to break it to you, but these occur in the IR (infrared) portion of the spectrum. It makes little sense to talk about the resonance frequency of a single molecule...they do not vibrate like a bulk object, and in any event the frequency depends on the type of bond, not the type of molecule. Electron band gap stuff is applicable to bulk solid materials, not to single molecules. I have no idea what sub-atomic resonance is...how do you plan to induce resonance in the nucleus?
-JB
Re:While microwave is not a worry (hogwash!) (Score:1)
1) Microwaves, as defined by the NTIA, range from about 100 MHz to 300 GHz ( US Frequency Allocation Chart [doc.gov]). Most people think of microwaves as starting at 1 GHz, though (and hardly ever think of 300 GHz). Seriously, though, there's no hard limit in the continuum.
2) Microwave ovens operate at around 2.45 GHz, the resonance of water molecules.
3) The Wired article mentioned neither the carrier frequency nor the energy densities at which the tests were conducted. This kind of vagueness I find unforgivable, because it leads to the sort of vague discussions we're having here on /..
4) I could not find the particular study refered to in the Wired article posted on the WTR website [wtrllc.com], but I did find statements and information about RF radiation and tumor promotion [wtrllc.com]. One in particular from April 30, 1997, refers to a study where rats developed lymphoma at a rate twice the control group. This study was conducted with pulsed RF at 900 MHz, at ``levels similar to those from wireless digital phones.''
5) The field strength just outside a 300 mW AMPS cellular phone (say, right next to your ear) is around 5 to 15 mW/cm^2, depending how close you wedge the phone to your head. But that's just my back-of-the-envelope calculation. See the FCC's OET Bulletin 65 and supplements [fcc.gov] for more on human RF exposure guidlines.
Anyway, there is a big difference between exposing a bird to an RF field and saying there's ``no effect'' dues to heating, and exposing a living thing to RF and asking if there's an increased chance of any kind of long or short-term health effect. As a wireless engineer, I personally have a vested interest in knowing the effects. I sure hope there are none, but what am I going to do if there are? Are the risks of health problems too great to ethically push wireless as a viable consumer technology? Can I still feel morally superior to engineers working on missles and bombs?
As a first step, I'll continue to hold off getting a cell phone. I'll also probably stay away from Bluetooth products as well, since they're right in the microwave oven band and because Bluetooth radios might be clipped onto various parts of my body (BodyLAN). What next? Stop working on 5 GHz WLAN because the components are ``too close'' to humans? What is ``too close''? If wireless is the next new thing, is it the next new thing to kill us, too?
A definitive answer is needed. The effects almost certainly vary with frequency (microwave ovens don't use 900 MHZ for a reason). Once the effects are known, then perhaps we can decide what acceptable risk is.
Re:Some issues... (Score:1)
Well - there's also a condition called hypersensitivity to electricity. People who can actually feel a cell phone tower from a distance, for instance. Except that electrosensitivity isn't regarded as a "real" medical condition in most countries. In Sweden they have special hospital rooms with no electronic equipment or light tubes.
I live in Finland and have a good friend, who lived a couple of years just 250 meters from a big cellular phone tower. Last winter her health just collapsed, and in the end she couldn't stand even daylight. Not to mention any electric devices. Removal of amalgam tooth fillings helped a little, but she still has a way to go back to a normal life.
There are surprisingly many organisations for electrosensitive, check out for example the Swedish site www.feb.se [www.feb.se].
Lessons about absorption spectra (Score:2)
Completely incorrect, I'm afraid, as another poster has pointed out. Several effects cause absorption lines for molecules:
These cause absorption lines in the visible to UV range, as the energy of these photons corresponds to the difference in binding energy of the electrons in the outer shells of the atoms/molecules in question. Deep inner-shell transitions produce X-ray lines, usually seen in emission spectra as opposed to absorption spectra.
A molecule's shape isn't fixed - it can vibrate, as if the atoms were connected by springs. The energy levels of these vibrations are quantized, and the difference in energy levels here generates absorption lines in the IR spectrum. This is what lets you use CO2 to generate infrared in a CO2 laser.
Rotational energy levels
Finally, a molecule's angular momentum is quantized - it can't rotate at any speed it feels like, but must rotate at a speed that is a multiple of a given quantity. This gives you a set of energy levels with differences that generate absorption lines in the microwave spectrum. Chemical-based masers take advantage of this to produce coherent microwave beams using media like ammonia (IIRC). It is this set of absorption bands that the previous poster was referring to.
As far as gamma rays are concerned, they correspond to energy level differences in the _nuclei_ of atoms. The energies involved are almost always far greater than the energy differences even in inner electron shells, which is why the gamma ray portion of the spectrum is higher than the x-ray portion.
As far as microwave absorption doing damage is concerned, I am skeptical because the bond strength in molecules is much greater than the energy of the microwaves. Even if a microwave beam was exactly tuned to one of the absorption bands of - say - DNA, the DNA would dissipate kinetic energy by interaction with the water and other chemicals around it. I doubt that it would come even within orders of magnitude of levels that could cause mechanical breakage.
IMO, further study would be wise before trying to ban all cell phones based on inconclusive studies.
Re:Frequency spectrum (Score:2)
It's inverse square, and for heating at least, it still wouldn't make a difference. One watt (or 0.5 watts) is a miniscule amount of power. It takes 4 joules of energy to heat one gram of water one degree. Your microwaves will be heating up somewhere between a hundred and a thousand grams of water-based tissue over the region in which they are being absorbed (about a fifth of a pound to two pounds, for those not into metric). This gives you a temperature change of at most a few thousanths of a degree per second. Your body has a good cooling system - the circulatory system. This heat will be taken away as quickly as it is generated.
Of more significant concern is the question of strong absorption of microwaves due to rotational and other energy bands in proteins and DNA, but this is unlikely to do much, for reasons that I mentioned in another post. Your DNA molecule would have to vibrate one heck of a lot for the vibrational energy to overcome the energy of the chemical bonds in the DNA. Your DNA molecule is also sitting in a water bath, and water's a lot more viscous on that small a scale. Rotational and vibrational energy will be almost immediately transferred to the surrounding water and dissipated as heat.
I can't prove that there is _no_ danger from cell phones, but IMO it's more likely to come from solvents in the plastic - or talking while driving one-handed - than from EMF.
There is an absorption band. (Score:2)
See my previous post. The absorption bands for rotational energy levels in water are in the microwave range. Microwave operating frequency is subject to legislation, but why do you think that band works so well in the first place?
Water will absorb at other frequencies too, but this just happens to be a fairly good one.
Re:Correlation != Causation (Score:1)
"The number of suckers born each minute doubles every 18 months."
-jafac's law
Re:me = guinea pig (Score:1)
Re:Frequency spectrum (Score:2)
Re:scary thought but couldn't care less about phon (Score:1)
What worries me is all the bad television programming being pumped through my body on a 7x24 basis.
Re:Get a clue (Score:3)
Check out this URL:
http://www.colorado.edu/UCB/AcademicAffairs/ArtsS
It explains it in really small words for the intellectually challanged.
BTW -- this reminds me of a book I read like ten years ago, "The Second Creation" I think, that talked about early particle collider research where the researchers would actually stand between the magnetic coils while they were developing the technology, and the enormous magnetic fields would actually start to "polarize" the water in their brains, and they'd see all sorts of wierd hallucinations.
RF-Cell phoneµwave range (Score:1)
the solution to the cellphone radiation problem... (Score:3)
A Way To Sell Hands Free Kit? (Score:1)
--
Re:hobby project (Score:1)
Hmm. modulation for control sounds like a good idea, but I was hoping to use an off the shelf electric copter minus a battery pack. This way I don't have to change the control systems.
Also, eventually I would like try flying in more than one dimension which would require a pretty good tracking system. I was thinking of a mirror attached to spring & coil to direct the laser/microwaves. But to get the copter's position accurately you would want to do EM pulses and measure the reflection times. My worry is that you will not be able to track it continously and that for short periods of time it would have to rely on an alternate power source as well as communication. I suppose modulation would be ok as long as the microcontrollers held it in a stable state during these periods.
Right now I'm trying to find the best low wattage motor that can give enough torque for lift off and support the weight of a gyro and a small circuit board. It takes a lot more than I originally thought.
Cellphones and GM Food (Score:1)
- both are relatively new industries
- both have had recent scientific studies which cast them in a bad light (various reports have cast doubt on the safety of GM crops which is why they're not being accepted in Europe)
A rather stupid bit of journalism, though - cellphones are sp much more established, and the putative risks so much more avoidable, that the comparison just doesn't bear out.Also, the classic "unfavourable studies don't count" industry is tobacco: despite millions of deaths being directly attributable to this product, the tobacco industry isn't going away any time soon.
--
Re:Correlation != Causation (Score:1)
New Scientist Article (Score:2)
Announcing EMF mailing list (and list web archive) (Score:1)
Send mail to rbeavers@llion.org to apply. Archive of list submissions: aah, gnarl. Couldn't find the link to the excellent searchable archive.
Re:Correlation != Causation (Score:1)
Although I can and have blamed him for disregarding grammar, spelling and capitalization -- these things make a difference in how easy the message is to read, and when wrong, piss people off.
Re:Well, huh... (Score:1)
Re:Frequency spectrum (Score:1)
Most old analog cell phones operate at 800 MHz. Handheld analog cell phones are dangerous because they operate at one watt. That may not sound like much, but absorbed power is proportional to the inverse cube of distance... so your brain is absorbing a decent percentage of that one watt a centimeter or two away.
Most "digital" cell phones (European GSM (Sprint Spectrum or any system that uses those big ol' Ericsson phones with the YES and NO buttons) and PCS) use various bands between 1 and 2 GHz and put out between 100-500 mW (0.1-0.5 watts).
There's an amateur radio band at 1.2 GHz, meant for handheld radios. Traditional ham knowledge (and FCC regulations) say that you should use 100 mW at the very most when operating a handheld transciever because it's right next to your head. The danger isn't so much in the heating effects... if you don't feel your head getting warm, there aren't any worthwhile heating effects. The danger is in the way microwave frequencies are absorbed so well by tissue. On the relatively low "shortwave" frequencies that span the globe (about 3-15 MHz), wavelengths are incredibly long... from about 80 meters to about 20 meters. Very little of that energy can be absorbed by a person less than two meters tall. It's like a cork on a gigantic wave that hasn't broken yet; it just rides the wave.
1.2 GHz has a wavelength of 25 cm. Half of that wavelength (think of the uuper hump of a sine wave) easily fits inside your head. I dunno about you, but I personally don't enjoy microwaving my brain for the convenience of not having to use a pay phone.
Re:There is an absorption band. (Score:1)
Agreed, water is a pretty good absorber of EMR at 2.45GHz, but this isn't due to "resonance" in any conventional sense. The microwaves couple pretty well to water molecules due to the molecules' polar nature (one side is electrically negative relative to the other). They vibrate quite strongly as a result, resulting in heat.
I think people confuse resonance with simple vibrational energy.
Re:There is an absorption band. (Score:2)
This isn't what I was talking about - in _addition_ to this effect, there are absorption bands specifically in this region due to quantization of angular momentum of the water molecule. Whether it should be called "resonance" or not depends on how you choose to explain absorption spectra to the layman. Click on "user info" above to find the post where I go over this in detail.
Raises Questions ... (Score:1)
Newbie questions will come out ... might as well get them out of the way ...
Incremental damage? (Score:1)
Doesn't sound that good, does it. (Score:1)
i am sam i am
Some issues... (Score:3)
The article didn't tell much about HOW they reached those conclusions. The higher incidence of brain tumors for example. This was reported a few years ago, and was deemed non-conclusive, because the sample sets weren't isolated enough to determine that the cell phones were the causative factor. (Ie, if executives are typically using cellphones the most, and they spend most of their time in front of computers, you can't conclusively say one set of factors are the cause vs another). I seem to recall the biggest criticism was that the results then were just statistical results in a set of people who used them a large amount of time, which doesn't prove anything.
The microcell growth I believe is the result, if I recall correctly, of exposure to higher frequency microwaves, at higher power levels. Ditto with the genetic damage.
One other thing to keep in mind is that you undergo a significant amount of genetic damage every day -- and the biochemistry in your cells is designed to correct it when it happens. (basically its not a problem unless you happen to tweak both halves of the DNA strand at precisely the same spot in the squence and happen to hit a gene at the same time... a very rare occurance, otherwise simply walking to your car would cause a fatal skin cancer. (There's actually a medical condition where cells in the skin are unable to properly repair the constant damage from the sun, and sufferers of it -- like half a dozen in the US -- could die even from a few minutes in the sun)
Also keep in mind the prevalance in our environment of dangerous carcinogens, pesticides in the food, the weakening of antibiotics, etc... its a dangerous world we're building for ourselves, so even if a miniscule increase in danger from extended use is proven, in the grand scheme if things it may not really matter. I'm personally not too concerned about it.
That said, I do get off it when my head starts to heat up.
me = guinea pig (Score:2)
[We had the "option" of using a free cellphone + free hours, but in reality it was a requirement. Upon employment, noone *asked* if I wanted the phone, they just gave me the forms to sign and a submission deadline. I'm a sucker for free stuff, so I used it all the time. I suppose I shouldn't have drunk the free Kool-Aid either...]
Re:Frequency spectrum (Score:2)
Re:Incremental damage? (Score:1)
I expect this will lead to changes in cellular technology, like spread-spectrum and code-division multiplexing versus TDMA. If you bother to compute the flux of thermal energy in which DNA exists, it's obvious that the only way that a far smaller flux of RF can damage it is through its greater level of organization: it's coherent. If you go to CDMA or another technology which makes the signal more noise-like, it acquires thermal characteristics all over. Sure, you can decode the signal by subtracting the noise characteristics at the other end, but as far as everything else is concerned it is just a bit more heat.
There's damage just about everywhere... (Score:2)
Beyond the "newbie questions" as cited in an earlier post, there are other points of interest here.
If they're using the Radio Band in the EM (Electro-Magnetic, for you purist coders who missed Physics) Spectrum, that should raise an even more obvious question than "How much RF (Radio Frequency) eneergy is my putting out?" That question being how much are the normal Radio towers affecting us. We've got holes in the Ozone, several dozen carcinogenic artificial products, another several dozen natural carcinogenic products, we've surrounded ourselves in EM Force (what with Power lines, phone lines, TV stations, Satallites, Electronic Devices, Radio towers, Radar Towers, etc...). This is just one more item on top. It's no longer a question of trying to avoid cancer, but more one of what you choose to get it from.
Closer to the topic, if there's damage from Cell Phones, can I get second-hand cell-phone damage if enough people around me are using them, even if I don't? Granted, the effect decreases at a geometric rate (probably something like radius squared), but whereas that used to be an effective argument against that possibility, if there are more users, it could increase low-dose amounts to everyone to some long-term dangerous level.
I know most of this is highly speculative. I don't think any one source is enough of a risk to be noticed... The problem is that it isn't just any one source anymore. It's a combination of hundreds (possibly thousands in cities) of EMF sources bombarding you at any given moment. One won't get you. One hundred probably won't. One thousand probably won't do much for a very long time. But as the number sources increases, maybe some research into the risks of multiple types of EM radiation at once should be done, instead of always trying to see what one individual source does alone.
~Anguirel (lit. Living Star-Iron)
"Veni; Vidi; Vi C++"
Frequency spectrum (Score:3)
Think of it as a problem of resonant frequency. You can subject a fine piece of glass to a very high sound pressure level as long as it's not close to it's resonant frequency. Get it close to resonance though, and it will tear itself apart.
The same is true with RF energy... it will excite molecules, but it will only have a large affect at or near the resonant frequency of the molecule. Because of this, a cell phone should affect a very different set of molecules than a microwave would (microwave ovens are tuned to the resonant frequency of water). This doesn't mean there won't be any overlap of course, but it becomes a question of how much power you're using.
Junk Science (Score:3)
Well, huh... (Score:1)
Seriously, though - I've always hated cell phones, and I've never owned one. They come in great in emergencies, but I cringe every time I see some schmuck driving around like a bat out of hell talking to his best bud on a car phone. It's scary.
Re:Get a clue (Score:1)
correct me if i am wrong... (Score:1)
Re:Get a clue (Score:2)
> You could run a microwave oven at 100 MHz,
> or 10 GHz. There's no "resonance" involved.
> The phenomenon is called "dielectric heating."
But higher frequencies dump their heat closer
to the surface, while lower frequencies penetrate
better, and dump less of their energy into the
dinner per pass as more of it goes clear through.
K band was chosen for microwave ovens because it
could cook stuff up to roast size without leaving
a cold spot in the center, and didn't waste too
much power (and overheat the tube) and cook too
slowly if you only fed it a hotdog.
Re:Correlation != Causation (Score:1)
Re:1.9GHz, 2.1GHz (Score:2)
Re:Raises another question (Score:1)
And does the rise in brain tumours correlate with a rise in right-earlobe cancer or right-hand index finger cancer?
Would cell-phone manufacturers be happy with the prospect of obsoleting all current cellphones and selling all new "special" shielded ones?
Inquiring minds....
Re:Correlation != Causation (Score:1)
-Davester
The biggest killer ... phones, TVs, hair dryers, ? (Score:1)
I can easily imagine that the old hair dryer would win out as being the most lethal of all you mentioned. That is of course disregarding all the fatalities resulting from monitors hurled from high buildings. Hair dryers have quite a nice cord which may be used to trip, tie, strangle and of course they are tragically much fun for young geeks to play with (nice transformers).
Slightly more seriously, as usual I'm about a foot in front of my mongo BIG monitor right now as I usually am for 8+ hours a day. This is definately giving me a bit of a constant cold .... the air is just really dry and I can feel all the electrons being SUCKED from my eyes :) You can get stuff from your doctor for this, take a few drops every day forever, no harm done but a bit of a pain.
Now the thing with mobile phones and monitors is that some of us use either or both ALOT. And while I don't believe the monitor will ever do me serious damage I would be worried if I used a mobile phone a good deal.
However, mmmm, what else do I use alot that could be harmful? Clothes? Hmm, no. Er, ball-point pens? Not really. I have been hit recently by a softball ... but I hardly spend a significant amount of time on that. Ahhhh, _I_ know. I _do_ use a car quite a bit. We can take safety precautions, buckle up, drive safely, ... but most of us accept driving as a reasonable risk for the benefits. It would be nice to likewise compare benefits and dangers of using your mobile. :: phone injuries/usage
I would love to see the comparison of accidents versus usage:
car injuries/usage
(usage is probably %time * people or something)
Can anyone help?
Taking this car vs mobile thing a bit further .... in the beginning, there were horses and then only steam engines. And the horses pretty much beat those steam engines every time so for years transport saftey guidelines consisted of the unwritten "don't get run over" or "don't run into large/sharp things".
They have since developed from their meagre beginnings worldwide into tomes of law, rules of road saftey, safe-cross codes, etc..... Probably the same applies to using "thingies" outputting microwave/high RF energy.
There is a risk there, as for anything. We need a safety code for mobile phone users, as we do for hair-dryers. For now though I would think it more important for mobile phones.
- Phones should log their usage AND power levels and make this available to the user. This would be quite easy to do
... but would the average user understand "WARNING power output increased to indecipherable quantity"? - Educate phone users *shivers* this could be difficult. If entering big sheilded building => phone power increases. If phone strapped next to vital organs => be careful!
- Don't use the phones excessively. I know some people can talk ALL day, but seriously, they would have done something else before the mobile phone.
- If you use a mobile excessively then you need a headset YES you look like a fool jogging down the road looking like some bodyguard gone nuts but not much more of a fool than you do with that thing held against your ear.
Have I forgotten something? Feel free to add.Re:Incremental damage? (Score:1)
As phones strive to use less power this should gradually improve but for now we should keep this survey quiet, suppress it even and wait for natural selection to kill off the more annoying mobile users.
Possible explanation of *why*... (Score:1)
Various people have mentioned that the frequencies and power levels at which cellphones transmit aren't enough to cause direct genetic damage by heating/knocking electrons out of their places. This is true AFAIK.
However, molecules don't just heat up when they absorb radiation--they vibrate and rotate as well. (Chemists and physicists have used microwave-band radiation for a very long time to measure rotational and vibrational modes of various molecules.) Cellphone frequencies and power levels are probably not enough to vibrate DNA/protein molecules (you need infrared to get decent vibration out of even small things) but rotation is a distinct possibility.
Having large and complex molecules rotating at rates other than the normal range might produce problems that are subtle and/or difficult to reproduce. Remember, at room temp, your average water molecule is rotating wildly as it is.
Joe Camel & Joe 'Nads (Score:1)
Come to think of it, I have always hated cell phones for two reasons: 1) people are usually STUPID when they're using cell phones (read: driving or just not paying attention to what is going on around them) and 2) because it has been known for years that they're not good for your head. Unfortunately, I just picked up my first phone last December, and I have used it a total of two hours in the last 6 months (which doesn't really put me at much risk, I suppose). However, sometimes I carry the thing around in my pocket turned on (I almost always leave it on, though VERY few have the number). I wonder if this thing will make me sterile? I know that regardless of use, these devices are constantly "pinging" the radio towers (go to http://www.howstuffworks.com [howstuffworks.com] to read about cell phones and what they do).
Oh well. We'll see a new form of brain tumor in another 15-20 years, I guess.
Contradictory results earlier this year? (Score:1)
Does anyone know of contradictory results presented earlier this year? My wife (BS Biology, 1997) recalled a story (sorry, no ref.) which seemed to state that cellular phones stimulated brain cells (in a seemingly positive way).
Can you refute or verify this?
Re:Ham (Score:1)
Danger compared to smoking? (Score:1)
Shame there's no conclusive information of either available.
Re:New Scientist Article (Score:1)
I still think persons who expose themselves to even comparitively low RF are putting themselves at risk (probably low) of ... something :). What is that something though?
- Faster responses.
- Affecting/damaging cells causing cancer in a few cases.
- Greater knowledge (using RF device to talk to wise people
- Stupidity (using RF device to talk to wise people
... and not understanding) - Escaping danger
... (using RF device to call in the rescue services after getting trapped up a tree in a remote place) - Hot food
..... :)
However, more seriously, I think mobile phones have a much greater capability for damage in other areas. I'm trying to get a bit of perspective here.If someone crashes a car while on a mobile then is it the car manufacturer's fault? The mobile makers fault? The country's fault (for giving driving licence, providing roads, ...)? Or the person's fault? Definately the latter if the person knows all risks involved in what they're doing. However we could blame any of the above or drugs, the bright sun, the cute distracting butt on the sidewalk, ..... and more. So maybe we'd just better default to holding everyone somewhat responsible for themselves.
Mobile phones probably indirectly cause more noise pollution/annoyance than anything else by bringing loud single-sided conversations out everywhere public. While not hugely life threataning in itself (except to those annoying people annoying axe-murderers) it would be probably the effect felt by most people. Would this be a better reason to be worried about mobiles? Depends I suppose.
Something else: Can anyone point us to somewhere on the web where there is information on the growth of plants near power lines or power antennae? This was interesting, plants grew noticably faster.
I am very sorry to inform you... (Score:1)
Correlation != Causation (Score:2)
Could it be that having brain damage makes you more likely to use cellular phones?
Makes sense to me.
Re:I am very sorry to inform you... (Score:1)
BTW, what got him?
1.9GHz, 2.1GHz (Score:1)
Some GSM carriers' PCS offerings also run at 1.9GHz. Most CDMA carriers still operate at 800MHz (I think). However, looking further up the frequency scale, ATT owns licenses to 2.1GHz frequencies for cellular phone usage. They talked publicly about also using 2.1GHz for fixed wireless service about a year ago, but I dunno if it's in use yet.
Just some facts (Score:3)
Re:Get a clue (Score:1)
While microwave is not a worry.. (Score:4)
These studies did not access the potential of DNA breakage, just effects of heat. Because the length of a microwave is so long it would difficult for it effect DNA (which often results in cancerous growth). You should be much more worried about sunlight, which contains a fair amount of energy in ionizing spectrum. If you are then indoors type, sitting in front a monitor exposes you to x-rays which is also a bad spectrum to be exposed to. Even visible light is higher spectrum than microwave. There is no 100% effective way to avoid radiation induced cancer unless you live in a completely dark lead lined tank. Even then....
I'm currently looking into using laser/microwave for power transmission on a hobby project. For some links about this subject area, click on my sig. Anyone who has tried this, please write me.. I need help.
That's an intensity (Score:1)
However, what does this exactly mean? Usually intensity is measured in terms of distance from the source of the power. For instance, the intensity from a speaker is the amount of power output divided by the surface area of the sphere surrounding it at a certain radius.
In this case, does it mean that the bird can not take any more than 50 mW for every square centimeter on *its* body? Or is it that the intensity of the source at the present radius of the bird must be less than 50 mW/cm^2?
How a Microwave really works. (Score:1)
-AC
Junk Legislation (Score:1)
Did you know that there is a 100% fatality percentage among people consuming dihydrogen monoxide? Did you know you were exposed to dihydrogen monoxide every day? Write your Congressmen!!
Re:Correlation != Causation (Score:1)
You've contributed a couple intelligent questions, but some of them could be answered by a little bit of research. Do your homework before you post. I know that everybody occasionally makes mistakes (even I have
I feel much better, thank you very much.
Re:Well, huh... (Score:1)
Re:Raises Questions ... here are some answers? (Score:1)
> 1.What about more modern cellphone technologies like the digital phones from PowerTel (SMS)?
Ultimately, it will come down to the power output level of the transmitter in the phone, the frequency range in which it operates, and possibly the length of continuous exposure.
> 2.There has always been controversy over RF from cellphones and powerlines
You may remember from physics, electromagnetic radiation (RF included) generally follows the inverse square rule for a point source transmission. (Stated in very simple terms, as you move away from the point of transmission, the energy level drops off extremely fast.) Lets say, for example, you have a local radio station with a 50,000 watt FM transmitter located on a mountain top 10 miles (16 kilometers) from your home. At that distance, the RF you receive is only 0.015 milliwatts, or about 0.000015 watts!
The problem with a cellular phone is that the transmitter isn't 10 miles away, its about an inch from your ear and the rest of your brain tissue. Now, the phone does have one good thing going for it, its not a 50,000 watt transmitter like that radio station, current generation phones are more in the range of 0.5 watts. However, at such a close range, you are in the presence of almost the complete 0.5 watts of energy being radiated by the phone. That's about 30 times the energy from that 50,000 watt radio transmitter 10 miles away from you.
So, the same is true of a satellite transmission - sure, you cant get away from it, but the transmitter is miles above the surface of the earth! In fact, the RF levels received from a satellite transmission are much lower than from a local TV or radio station! That is why you need a dish to collect the signal as opposed to a normal antenna for radio or television reception.
Power lines are yet another case - yes, they produce an electromagnetic field but it is not what we generally refer to as RF. For example, FM radio is in the 100kHz range (100,000 cycles per second) - analog cellular phones are in the 0.8 to 1.0GHz range (800,000,000 to 1,000,000,000 cycles per second) - PCS cellular phones are up in the microwave range 1.5 to 2.0GHz (1,500,000,000 to 2,000,000,000 cycles per second.) Power lines, on the other hand, operate at just 60 cycles per second (or possibly 50 cycles per second if you don't happen to live in North America.) This is normally known as VLF (very low frequency) spectrum. This doesn't mean that there is no potential danger. There may be some cause for concern if you live very close to high tension transmission lines (the ones that are generally up on large metal towers and that you can hear buzz and crackle if you stand near.) However, the lower power levels of "ordinary" power lines are probably less a concern. And again, distance counts! If you are really worried about ELF, you might want to think about that electric blanket that is located just inches from your skin as opposed to the power lines across the street from you and 40 feet in the air.
> 3.Is the genetic damage that has been documented significantly more than the theoretical damage from "cosmic ray" radiation or solar radiation (which we are just beginning to document as well)?
Lucky for us, our atmosphere screens out most ultraviolet, x, gamma and cosmic rays. And yes, it is well documented that these very high frequency forms of electromagnetic radiation are damaging to the human body. (A side note, as you might know already, these forms of EM are above visible light, microwaves and other forms of radio waves are below visible light.) Now, as you might know, there is a growing hole in the Earth's ozone layer, which is letting in more and more ultraviolet radiation. I guess if this continues, we will some day be forced to wear sun block or die of skin cancer. Hopefully other layers of the atmosphere responsible for shielding us from higher level radiation (x, gamma, cosmic) do not start to disappear as well or we may end up walking about in lead suites. That doesn't sound to healthy to me.
A better reason to avoid cell phones... (Score:3)
And don't tell me that you happen to drive perfectly fine while you're on the phone. Scientific studies have been conducted (more trustworthy than this one, I might add) that have already linked cell phones to a hefty decrease in driving performance--almost rivalling that of alcohol at times.
I know some counties have already banned the use of cellular phones while driving, and I hope the rest of them follow.
Re:Get a clue (Score:1)
Large industrial dielectric heaters often operate in the tens of kilohertz, as a matter of fact.