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How Bad Can Wi-fi Be?
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?"
Think of the children!!!
Seriously, it's sad that supposed "news" programs air things like this just to get ratings. What's even sadder is that lots of people believe them, so tech-savvy people like us now have to spend time explaining to Aunt Jane that the big evil wifi will not give her cat cancer.
this was all over the news and may cause wifi to be stopped in schools - so any feedback is useful
All day we're around Microwaves, XRays, High voltage lines, lights, televisions and Radio signals. There are TONS, of course... but how much more is actually from outside the atmosphere?
The only thing that's frying our kid's brains are their ideas. I'm not overlooking child safety, but there are WAY more harmful waves out there than WiFi.
In the meantime, their children are outside getting burnt without sunscreen.
"Please, shut up. Just when I think you can't say anything more stupid, you speak again." -Archie Bunker.
I suggest aluminum foil hats.
Typical wifi - 100mW. 2g Cell tower - 20-100W. In cities they are using micro cells, which typically have about 3W power. There are experiments which show cell phones are a little dangerous, and there are scientist, who tried for years to show there is big danger, but found none and converted to "no harm" camp. So YMMV.
Extreme Programming - Redundant Array of Inexpensive Developers
802.11b/g uses 2.4GHz radio waves. That's the same frequency range as microwave ovens. Microwave ovens work because the microwaves are absorbed by the bonds in the water molecules of food (which is why dry food does not cook in microwave ovens).
So yes, human tissue that contains water can absorb WiFi radiation. That is a fact.
What is not known is: how much absorption of that radiation is bad for the kids?
So... the news is that there's alarmism?
Thanks. I'll be sure to watch out for it.
--I'm so big, my sig has its own sig.
-- See?
Gah! Won't someone think of the children!?
If we use 802.11, the terrorists win.
I'm sure it's worth study, and I personally think WiFi is used too much. I'm not saying we shouldn't use it a lot, but I know some homes and businesses that might just be better off with some CAT cables. I mean, if all of your computers in your 1 bed apartment are desktops, why go WiFi?
And in other news from the BBC http://news.bbc.co.uk/2/hi/technology/6676129.stm
Of course they can. Everything does. Notice how when you put your head near a source of radiant heat it feels warm?
"Do not look into laser with remaining eye" is also appropriate here...
I quit!
not a pretty sight, is it?
the FCC has specifications of radiation density versus frequency that are limits in their rulebooks, limits used to isolate access to radio facilities from microwaves to commercial broadcasters... to ham radio operators burning electrons in the basement. these have been codified by medical research. if you're going for an advanced ham license, you have to study the milliwatts per meter limits, the question occasionally comes up on the test.
so there are 3/4 million americans who know this, not just ten academics in the tower.
where the hell did this whining of Luddites come from, and why wasn't it left there?
if this is supposed to be a new economy, how come they still want my old fashioned money?
Here
Basicaly in the old country they have a government official who is unprepared to admit radio waves, mobile phones etc, are safe; no matter what the evidence.
Old COBOL programmers never die. They just code in C.
Mobile phone towers are many, many times more total output. Yes, both transmit in the microwave spectrum, but the 'notch' in the microwave spectrum that resonates water (and thereby heats your food, cooks your brain) is extremely tight (2.45 Ghz). If you're above it or below it, the water molecules in your body (or food) simply won't vibrate/resonate and there's no heating. And yeah, people use 'radiation' all the time to invoke the panic of ionizing nuclear radiation (bad) with electromagnetic radiation (mostly harmless). (Meanwhile these same people go suntan in the name of health, basking in the glow of an unshielded fusion reactor. Yay humanity.) ...People who live by the sword get shot by those who dont.
Igor Presnyakov stole my hat
Frankly the BBC was irresponsible in showing this episode of Panorama. I'm against censorship, but informational programs produced by a tax-payer funded media outlet should not be spouting such paranoid, biased crap as Panorama did last night.
This is arguably the worst case of the BBC scrambling for ratings I've ever witnessed. Never before have I seen them stoop so low to try and raise viewing figures. I was sat watching it waiting for the part where they offer the opposing view of the situation to allow people to make their own minds up, unfortunately however, that never came - it was one sided anti-wifi propaganda all the way through, from start to finish.
About the only attempt at offering an opposing view was the brief mention that the WHO states that there is no known risk of wifi at this time, this brief mentioning was followed by a couple of minutes of slagging off the credibility of the WHO.
I'm no expert when it comes to wifi, radiation and so forth and I'm not claiming that wifi is 100% safe - it may well pose risks. The problem with the program however seemed to be that it's entire argument is based on the premise that there is some other danger to human health from radiation other than the heating effect, and from what I've read elsewhere, there is absolutely no evidence that there is any effect other than the heating effect. I'm sure those with better scientific knowledge may be able to correct me on this if I'm wrong, but if it's true as has been reported by other news outlets (and in fact even by the BBC themselves online) then the majority of the program was fundamentally flawed in it's arguments.
What bothers me most is that we've gone from one lazy teacher looking for an excuse to get time off work claiming that wifi gives him headaches to a national wifi scandal. The worst part is that most reports that refer to the teacher in question who sparked this row ignore the fact that in scientific tests the teacher could neither a) tell whether wifi was on or off and b) now claims he gets these headaches wherever he is, even when not around wifi!
If Wifi does indeed pose a threat then I agree we need to do something, but thus far this seems equivalent to the whole terrorism/think of the children/drugs/computer games make people kill FUD.
My son was diagnosed with leukaemia (AML15 for those interested) on his 1st birthday. My first trip home from the hospital I turned of the wireless router, cordless phones and my mobile/cell. He's now 3, built like an ox and hopefully fixed for good.
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.
hell, global warming. isn't that that piece of crap those european scientists promote just to anger and disgruntle the whole hummer-driving-air-conditioning-the-whole-place-am erican-folks? yeah, that's FUD at it's best. actually it's all about selling more european, pseudo-eco-friendly products in the states, to ruin the american markets and thus stopping the war against terrorism by an act of countercultural inner corrosion.
So if WiFi can give you cancer, what can a bunch of loose network cables strewn on the floor give you?
It's not the flight I'm afraid of, it's the notebook's landing that's the dealbreaker.
More Twoson than Cupertino
Damn that global conspiracy of nearly 100% of the world's climate scientists! Even the politicians are finally getting in on it, after decades of dedicated FUD spreading by those evil scientists. They must be laughing, laughing I say, all the way to the... err...
From TFS: Their evidence? Well, they admitted there wasn't any
Well, Your Honor, we've plenty of hearsay and conjecture. Those are kinds of evidence.
The operating frequency of microwave ovens was chosen to be in an unlicensed (ISM) frequency band, that would provide good penetration into foods, and lent itself to the mass production of inexpensive magnetron tubes.
The lowest resonant frequency for a water molecule is 22.235 GHz, or nearly 10X the operating frequency of a microwave oven.
Remember "News for Nerds, Stuff that Matters"? Help make it a reality again! http://soylentnews.org
Consequently, all packets transmitted through WiFi will now need to have the text, "WiFi Kills".
Unfortunately, in the UK at least, the number of scientifically trained journalists can probably be counted on one of Ben Goldacre's fingers.
Interesting that none of the phone mast posts seem to have remembered the inverse square law - sorry if you did and I missed you - which mean that radiation levels at the ground are a tiny fraction of what you get from the phone. And that nobody has mentioned all the radiation we used to get from TV and radio sets. As I recall, the radiation you get from an old tube superhet set (from the IF) is much more intense than the radiation from WiFi. It is lower frequency, but then the skin effect is less, and as anybody who ever played about with NMR will recall, VHF does things to organic molecules.
We'd better take action now. Let's get rid of all that nasty radioactivity - oops, Madam, there goes your granite kitchen work surfaces and your low-sodium salt. And all the radiation sources beginning with the most intense. So we've now turned off the Sun, mobile phones, radio, TV, electrical generating. We can't use coal (have you looked at what you get in the ash). So we can just sit in the dark and freeze.
As for the leukaemia cases - I have long believed that a far more convincing explanation is exposure to farm chemicals, pesticides, and the new virus and bacterial strains resulting from population movement. It is possible that farming overspray with chemicals which have been subsequently banned is a more probable cause of leukaemia clusters than, say, living near a rural electrical supply line. In the UK, and probably in the US too, the parts of Government which deal with farming tend to be extremely secretive and their decisions are often hard to understand. To my mind, they are far more likely to suppress information about such things than the relatively open parts of Government which deal with non-farming health and safety.
Pining for the fjords
admitting in the brief write-up that there isn't any science behind this?
/. against ANY suggestion that wifi or cell phone signals MAY cause some adverse health effects is sloppy, anti-science thinking.
/. != FUD.
/. is FUD. /. is only anti-FUD in regards to its pet causes.
Maybe they read the article, which points out various scientists who argue that there IS evidence about it.
I've got to say, the ridiculously emotional backlash I see on
I personally don't believe cell phone signals or wifi signals are strong enough to cause health problems. But I'm certainly not going to be arrogant enough to proclaim that there absolutely are no health problems and we shouldn't even look at the problem.
I thought
Please, half of
Actually, 2.45 GHz isn't the maximum of the absorbance for microwaves. If it was, all the energy would be dumped at the surface of food, and there would be virtually no penetration. Water absorbs over a broad spectral range, at least in the liquid phase, where quantised rotational bands can be ignored.
And what you say about the different energies of radiation is mostly true, although EM radiation covers a range that includes UV, x-rays and gamma radiation, which are not very good for you.
I've got two WiFi base stations. The minute I enter my house, I get a headache!
Strange, isn't it?
What's even stranger is that it only started when my girlfriend moved in with me.
8 of 13 people found this answer helpful. Did you?
Does this remind anyone of the current climate science "debate" where every single reputable phD feels strongly that humans are impacting the environment yet the shrillest and loudest of an incredibly small dissenting crowd (that happens to have powerful motives) are picked to broadcast their ignorance to the masses via the media?
Oh well. We might as well fold on this too, just like we'll fold on global warming and "democracy", let alone human rights. How can this not fail? It is in the conservative powers perceived best interest to make open communication and a free competative marketplace of ideas go away. It can only take power from the government. It will never empower the leaders.
http://iol.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.
Different parts of the EM-spectrum probe different aspects of molecules. (Visible light probes electronic structure, infrared light interacts with molecular vibrations, etc.) Even the radiofrequency range of the spectrum interacts with molecules in a chemically-specific way: microwave-region EM-radiation probes the rotational modes of molecules, and radiofrequency spectroscopy can also probe nuclear states (see NMR).
If I've misunderstood what you meant, please set me straight.
(By the way, I do agree that the energy from a WiFi signal will be absorbed by most common materials and lead to a barely noticeable increase in temperature. But that doesn't mean that the process is not chemical-specific. For instance, some materials will absorb more of the WiFi signal than others.)
I thought /. != FUD.
You thought wrong. Particularly when it comes to anything with the potential for political ramifications, \. = FUD.
"Alcohol, Tobacco, & Firearms" should be a convenience store, not a government agency.
That's why the FCC gave it to everyone as a free-for-all frequency range to use for anything and everything that is not intended for any critical usage/purpose. But ironically, users of 802.11b/g networking devices seem to keep *thinking* that their use of such devices is mission critical important. Fools, they are. 802.11b/g networking is a toy. It's intended for convenience and entertainment purposes, not mission critical data communications. The whole computer networking world has been sold a "bill of goods" with 2.4GHz wireless devices. PT Barnum would be proud.
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.
I did a little research while I was in college for using focused microwaves to create a "hot spot" in high speed flow and I found that water responds really really well in the 800MHz to 1 GHz microwave frequency range. You'd get the most rotation of the molecule on the rising edge of the wave at those frequencies (rotates back on the falling edge), hence the maximum friction between the molecules and maximum heat. Higher than that and the water doesn't have enough time to move before the wave is past it.
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.
NIIIICE.
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.
"Please, shut up. Just when I think you can't say anything more stupid, you speak again." -Archie Bunker.
Oblig. citation...
/ Documents/bulletins/oet56/oet56e4.pdf
http://www.fcc.gov/Bureaus/Engineering_Technology
see page 15 for limits on acceptable uncontrolled exposure in the relevant frequency range (1 mW/ cm^2).
Well I don't think programs that only exist to scare you are worthwhile. I've never seen a Panorama program that wasn't a scare-fest. When you watch one on a topic you know nothing about the scientists seem well informed and the threats seem genuine. It's only when you watch a Panorama program on a topic you're remotely familiar with that you realize what nonsense it is.
One of them was about the dangers of black holes. They'll boil the oceans, suck the life right off the planet, there's a super massive one at the center of our galaxy, they feed and then they stay silent, drifting through space until WHAM. Lots of sound bytes of scientists saying "it's only a matter of time", "you can't see them, but we know they're there", "we have no idea how many there are", etc. In only 5 billion years our galaxy will collide with another one, and we might drift right into that galaxy's super massive black hole, etc, etc.
It's that sort of programming, and if they convince laypeople that more money needs to be spent on researching this than is really necessary it only does damage.
// MD_Update(&m,buf,j);
You want a scientific reason why WiFi is harmless? How bout the fact that more radiation is emitted from a 60W light bulb than a 100mW AP.
That Scientific enough? It's not just that there is no science to back up harmful WiFi Theories, It's that their is evidence to the contrary.
Never attribute to malice that which can be adequately explained by stupidity
They got it all wrong. The problem isn't with WiFi, the problem is when the signal carries the kill bit, passing through your body and causing extreme cellular damage. That's why most of the time the studies show up nothing.
"A little knowledge is a dangerous thing. Drink deeply or not at all."
Y'know, I dislike people like you. Science is NOT a religion, whatever you might make of it. Entire fields have been fundamentally wrong about their area of study before, and will be again. Given that the modern anthropogenic global warming schema is being driven mainly by political funding it is highly possible such is the case here, especially since it's such a young science. Of course, getting the religious fanatics to admit this is next to impossible, and rather disconcerting. Especially given the amount of ostracization that anyone who begins to speak out about the matter experiences.
FYI, I know perfectly well how science operates. I was not making any personal judgement on whether global warming is real, caused by human activity, or by the flying spaghetti monster.
I was attacking the position (hopefully with a little humour) that global warming is all FUD. That position seems untenable; that a large majority of the world's scientists would all conspire to promote falsehood. They may be entirely wrong, but the majority are in broad agreement.
Given that the consequences of not acting on this information may be disastrous, the precautionary principle suggests that we listen to them. Taken to its logical extreme, you would be advocating never acting on any scientific advice, as it *might* be wrong.
Expect the USA to counter with "Freedom Packets"
If you're talking about cell towers, the maximum radiated wattage is a mere 16 Watts. For most "normal" WiFi, the max is about 100mW, or 0.1W. In reality, it may be a mere 28mW or 0.028W (Linksys, for example).
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.