How Bad Can Wi-fi Be? 434
An anonymous reader writes "Sunday night in the UK, the BBC broadcast an alarmist Panorama news programme that suggested wireless networking might be damaging our health. Their evidence? Well, they admitted there wasn't any, but they made liberal use of the word 'radiation', along with scary graphics of pulsating wifi base stations. They rounded-up a handful of worried scientists, but ignored the majority of those who believe wifi is perfectly harmless. Some quotes from the BBC News website companion piece: 'The radiation Wi-Fi emits is similar to that from mobile phone masts ... children's skulls are thinner and still forming and tests have shown they absorb more radiation than adults'. What's the science here? Can skulls really 'absorb' EM radiation? The wifi signal is in the same part of the EM spectrum as cellphones but it's not 'similar' to mobile phone masts, is it? Isn't a phone mast several hundred/thousand times stronger? Wasn't safety considered when they drew up the 802.11 specs?"
Re:Eek! (Score:4, Interesting)
Re:WiFi is microwaves (Score:4, Interesting)
I'm not a physicist, so really: is there an advantage to this frequency? Why not 1.2GHz.. or 3.6GHz, etc.? Why something so close to the frequency range of microwave ovens?
If this is a really dumb question, I already ask for forgiveness.
Leukaemia (Score:5, Interesting)
My neighbours all have wireless, cordless and mobiles so I eventually turned all mine back on. Two years on and no-one else in the house, including my 2 other boys, have cancer.
Who knows what caused it. Live life to the full, make the kids smile and if low power wireless gadgets worry you, please get out more.
Re:Eek! (Score:5, Interesting)
They did however mention that Sweden recognises electro-sensitivity as an official disability so there is perhaps some credibility in the whole idea, how much is still questionable of course.
Re:WiFi is microwaves (Score:3, Interesting)
The Jury is Still Out (Score:2, Interesting)
http://iol.unh.edu/ [unh.edu]
Keep in mind this was an environment where we literally had hundreds of uncertified and untested wireless devices all around us. My job was going to be to read through the draft 802.11 standard, and write perl scripts that tested conformance to the standard. Well, the very first day the first thing they did was hand me a study that basically laid out that it would take at least a decade before any real conclusions could be drawn about the hazards (or non hazards) of wifi and human health. It mentioned that there was a correlation between ocular cancer and the radiation from television, and that it took something like 25 years before this was discovered.
Do I find it scary that we put so much into our environment and expose ourselves to so much that we don't understand? Yes. My big problem is that wifi uses the airwaves, so even someone who does not want anything to do with Wifi is having the air that surrounds them used by wifi. I'm a libertarian, and I consider the commons (earth, oceans, space, air, nature basically) to be something that each of us has equal rights to. I see this as the tragedy of the commons (read the book if you're unfamiliar). I would at least like to be able to tax those that use my air for purposes that I don't approve of, or have some kind of options. Right now, the FCC just decides using a decision making process that I find repugnant.
I see the potential health problem of wifi to be a symptom of a much greater problem.
2.4GHz is the garbage pit of the spectrum (Score:2, Interesting)
There is good news on the horizon.... 802.16 WiMax technology using other segments of the RF spectrum in the near future will begin to put things right WRT wireless data networking. Now if only the FCC would give us the 960MHz - 1060MHz one hundred MHz slice of the lower segment of what's now allocated to ancient, legacy aviation radio/navigation, that would be an ideal spectrum for wireless data transmission. All the old analog radar systems used by the national aerospace system (1080MHz) need to go away anyway and be replaced by modern ADS-B digital systems where every aircraft in the sky has an GPS system on board that transmits its precise location, altitude, airspeed, and directional vectors. Such a system could make mid-air collisions a thing of the past too.
between 800MHz-1GHz is really good though (Score:3, Interesting)
Microwave ovens are higher than that because of the loss of frequency as the waves penetrate the material, so they gradually get better at heating as the wave passes through whatever you're cooking. In this way, it will cook the middle instead of just burning the outside.
So look at it like this: If that old 900 MHz telephone didn't give you a surface burn (and it would have, had it been powerful enough) there's no reason to worry about a 2.4GHz source such as wifi, they don't operate on a vastly increased power output.
Re:Zen clocks (Score:2, Interesting)
I just had an idea. We should get together and make a liquid "Wifi screen" that is *cough* PROVEN, to reduce wifi radio signal from entering your brain. Sell it as a gel or hairspray. Hell, even sell glasses that are Wifi resistant.
Yeah, it would be a scam... and it would probably cause cancer.... BUT, people would probably buy it just as much as dick enlargement cream.
Re:WiFi is microwaves (Score:2, Interesting)
That doesn't happen [abc.net.au]. You're right about heat dissipation, though.
RF radiation is nothing like nuclear radiation
Except, you know...the nuclear radiation that is RF radiation...which is all of it.
the critical difference is that nuclear radiation is ionizing, that is to say that it can not only vibrate molecules a bit, but it has enough energy to alter them.
What about UV? That causes mutations too. Does that have as much energy as gamma (the answer: not if the amplitude is the same)? This is just crap. Any kind of radiation can have three effects on cells:
1) It gets absorbed and dissipated before coming into contact with living cells
2) It gets absorbed by cells and damages them
3) It gets abosrbed by cells and destroys them
The more energy, the more likely to get #3. However, there are agents in the skin to absorb most of the energy in most of the RF spectrum. Any part of the spectrum can cause mutations if you can get it to do step #2 and not step #3. There are other mutagens besides just the radiation in nuclear stuff though - there's the emission of particles that also do serious damage.
I worked at a company that built RF power amplifiers for cell towers (30-45W average power output), and many of my coworkers had been working with microwave RF amps since the very first cell system Motorola deployed.
Your story aside, that much power could easily burn someone to cinders if they happened to be sitting on the focal point of a microwave dish. They don't actually get 45W of microwave energy hitting them ever, so it's not a problem.
Re:Eek! (Score:3, Interesting)
since i was a child, i noticed that i can say when certain electrodomestics were working: tv, video, refrigerator,etc...
i maked some experiments long time ago( that scared my parents as hell
i asked my father to switch on and off a tv (with no sound) and i tell from outside the house if is working or not. The result was that i can tell from 20 tests, in 20 of them i can tell if it was on or off ( my father randomly choose a state with a coin toss and tell me to say if it was on or off).
i tested covering my ears with cotton or something absorbent, but only decreased the sensitivity, so i deduced the detection system was sound based ( i was like 16 years old (like 10 years ago), so may me my deduction was incorrect).
The same happen to me when i was exposed to certain frequencies....may be are harmonics (i tried 100kH sounds and i can hear some of the nearby frequencies, but i cant hear some lower...)
is interesting to see that other people experiment the same
Re:What crap. (Score:5, Interesting)
Actually, in the late 1890's and early 1900's people who worked in the field of XRays often died from over exposure of radiation. They simply didn't know what they heck they were working with. Thomas Edison was so horrified of what happened to his worker Clarence Dally [wikipedia.org] due to radiation poisoning that he abandoned any further research with X-rays. Not to mention Marie Curie death due to exposure to radiation and countless others that worked in her field.
Back then of course people thought drinking radium was a good health product and that shoe sales man could operate their x-ray on a casual basis to fit shoes giving them more REM exposure in a day than a modern nuclear power plant worker is allowed a year.
I'm not saying that WiFi is dangerous, but as a precedent people have often generally underestimated some dangers with emerging technologies and we should never discount such a thing could happen. Of course we due scientific study than complete news worthy paranoia.
Re:FUD (Score:3, Interesting)
Re:FUD (Score:3, Interesting)
What about the power level of the handset's TX? I know that (falcon series) iDEN handsests are 600mW, what's CDMA and GSM running at?
As I recall the FCC limits the max power output to 2 Watts in the Cellular (850mhz) band and 1 Watt in the PCS (1900mhz) band. The actual power output is typically much lower though. CDMA requires strict power control of the handsets in order to function (the base station needs to receive all of the incoming signals at the same power level -- otherwise one will overwhelm the others) and even GSM reduces the power of the handset whenever it can in order to prolong battery life.
Also, GSM and iDEN use TDMA (time division multiple access) so the handset isn't transmitting 100% of the time.
Ever noticed your cell phone get hotter then normal when using it in a low signal area? It's consuming more power to boost the TX in order to reach the base station.
Re:Won't somebody please... (Score:3, Interesting)
Um, if you can't prove that it's 100% safe, then why are you so upset like there IS no threat? You have to be honest with people. Some people will be crazy no matter what you do.
And if over-reaction is such a bad thing, why don't you stop. Just like you, when I hear people over-reacting, I start to suspect they're crazy, especially when they start telling me about how safe cars and sharks and vaccines are, relatively, because it starts to sound like they're bullshitting me on their side, when all they have to do to win me, is be honest, and less dramatic.
"...despite massed ranks of scientific and medical studies and scientists saying there was no danger from MMR vaccinations..."
Re:Won't somebody please... (Score:3, Interesting)
Telephone Masts vs. WiFi... (Score:3, Interesting)
So, on one hand, 16W (cell) vs 0.028W (WiFi) is quite the difference.
However, the distance falls off in a square inverse fashion. If you're 1M away, you get 100 times the power as if you're 10M away, so as for how much power you get, it's all relative to distance.
If you are 1M from your Linksys and 10Km from a cell tower, I'd bet the cell tower "loses" (lay of land, atmosphere, and walls in home may change things, of course). If you're on the other side of concrete from your Linksys, in that scenario, the cell tower may "win".
If your Linksys or cell tower were VHF, instead of the high-frequency UHF that they both are, skin "absorption" might be quite different.