View Full Version : Wi-Fi Is It Damaging Childrens Health
After watching Panorama tonight and seeing the case study results it seems that Wi-Fi signals are 3 times stronger than Cellular.
Directives were set up after studies showed that cellular masts close to schools could pose a danger to kids.
Wi-Fi is being pushed into school classrooms around the country which means the children are spending hours subjected to very strong radiation.
The goverment dont seem to care that its possible it could be harming our children, they have even ignored the information one of its main advisers has given.
Do schools really need Wi-Fi ? the way i see it NO
Discuss
Dymetrie
21-05-2007, 21:56
I've never been a fan of wifi... Mainly because I've found it to be unreliable and unsecure.
I didn't see the program but if it's like you say (despite me having no worries about cellular signals, it's not done me no harm!) then I think putting wifi into schools is a bloody stupid idea!
As it stands then it's not difficult or expensive to set up a decent hard-wired network in any building (I've done it here :)), so if there is a risk of health problems from wifi signals then combined with the need for security in schools anyway (yes, I'd put money on at least some paedophiles knowing something about computers and networks) then I'd say it would be incredibly irresponsible for any school to allow wifi technology to be installed as even part of its network.
Hmm, I find this quite tricky to understand, and I have an RF background. Cellular transmitters run multiple thousands of watts and will have an extremely strong field strength close to the masts whereas wi-fi is limited in the amount of power it can run to something particularly low. I don't understand how the signals can be three times stronger.
Matblack
22-05-2007, 09:58
I didn't watch the programme but I am interested in the title, am I to understand that Wi-Fi is only damaging childrens health and is of no risk to adults?
MB
They say children are more at risk because they have thinner skulls. I'm with Feek - sceptical at the moment. It all reads a bit sensationalist to me.
Dym has a point though. In many cases installing copper is not only very efficient but also more cost effective than Wifi LANs. Perhaps it's one of those decisions that could be dictated by cost before you even get to the vagueness of RF safety.
In my view, wi-fi is only useful when there are laptops about or there are physical or cost barriers to going wired.
As I'm not sure about the prevalence of laptops in schools I can't comment on the need for wi-fi, but it should certainly only be installed where there is a need for it. Having helped install one of the first school computer networks in the country I know it really isn't that hard to go wired.
I'm with Feek on the RF side, though I suspect that the issue here is proximity combined with power, rather than power alone.
It's just another source of RF... which in turn is another source of interference, which in turn is just more radiation permeating through our bodies... However GSM vs WiFi even with a high gain antenna omni directional antenna, will not be at the same level of a several dBW GSM mast - the mast next to my office is transmitting at 28dBW = just over 600W (630W)... Not really comparable ;)
My parents have a mast pretty close to their new home, and there's several kids living very close by. I'm more worried about that than wi-fi.
My parents have a mast pretty close to there new home, and there's several kids living very close by. I'm more worried about that than wi-fi.
If it's up high - I'd be less worried as they're not designed with a 360 degree coverage, though I'm not sure how wide the transmission angle is. However I'd agree with you on that one. I'd asked them to move it - put it elsewhere but residential areas.
God I can't believe I just did that - grammar nazis would be up in arms. :eek:
Anyway, I don't know where it is, but both Orange and Voda signal is pretty poor so unless it's one of the other networks you're not wrong. :)
It's just another source of RF... which in turn is another source of interference, which in turn is just more radiation permeating through our bodies... However GSM vs WiFi even with a high gain antenna omni directional antenna, will not be at the same level of a several dBW GSM mast - the mast next to my office is transmitting at 28dBW = just over 600W (630W)... Not really comparable ;)
Oh, I have to chuckle at that - Not any of the comments but the dBW. I hate dBW with a passion and it annoyed me when all the official quoted figures changed from Watts to dBW a few years ago. I'm allowed to run 400 Watts from home (26dBW).
People still think in Watts, not dee bee doubleya!
/edit - The thing is that aerial gain is also incredibly important, it's not the transmitter output that's so relevant, but the ERP.
Sorry Feeky poos :( I was taught it at uni and at school and it's kinda stuck :embarassed: I agree, I tend to use Watts, but tend to fall into dBW without really thinking... feel free to castigate me suitably! (I enjoy it when you do it anyway).
Agreed about antenna gain and effective radiated power, it's a function of the gain and the tx power isn't it? So it ends up being a BIIIG number. High gain antennas used in wifi are usually more likely directional no?
Not necessarily. I have a 9dB omni which I was using when trying to get wi-fi working across the house. Since I gave up that I've dropped back to a 5dB omni. In both cases the antenna was two feet from my head. :eek:
I was talking about BIIIIIIG gains, like 30dB + :p
And the figures you quote, Mark will be theoretical, another pet hate of mine, the dBi/dBd farce.
You loooove the old school don't you Feek? :D
semi-pro waster
22-05-2007, 12:21
I'm not totally sure of the purpose of wireless for most schools since every one I know already has wired LANs installed which makes it a bit redundant since most kids don't need a laptop (well I didn't when I was at school anyway). Plus wireless seems to hate me, I almost never get a decent stable signal. :D
As for the wireless being more dangerous than cellular - I'm far from an expert but I didn't think wireless used as much power or was capable of providing as much power as cellular anyway which seems to have been confirmed in the posts above anyway. If one is unsafe then surely both are?
You loooove the old school don't you Feek? :D
Not as such, but what I hate is the deliberate quoting of dBi instead of dBd to make a product look better when dBi is the gain over an isotropic in open space and is an impossible to reach figure.
Anyway, I'm off to warm up the vacuum tubes to get the light programme on the wireless. If that doesn't work then I'll listen to the gramophone instead ;)
I love theoretical values - they make everything look so much better! You're obviously setting up your wireless wrong if you don't get isotropic propagation ;)
Very interesting article by Guy Kewney about this on El Reg (http://www.theregister.co.uk/2007/05/22/wifi_science_bunk/). I like Kewney, he's been around for a long time and I've found he knows his stuff. Plus I was faster around the Silverstone stage of the RAC Rally circuit a few years ago than he was on a Packard Bell press day!
I was talking about BIIIIIIG gains, like 30dB + :p
True. Biggest omni I've seen I think was rated at 15 dBi.
And the figures you quote, Mark will be theoretical, another pet hate of mine, the dBi/dBd farce.
Also true. Otherwise it'd have actually worked instead of running home to mama every time I showed it a 1GB file.
Another thing to consider is the frequency these systems operate at.
I've been so far out of the loop on cellular that I don't know what the run on anymore, but wireless networks run at 2.4GHz, which, btw is almost identical to the 2.45GHz that microwave ovens operate at.
So, how happy are you now to know that every time you log in on your laptop you are sitting with your head a couple feet from a 5W microwave oven? 5W not a big deal you say? Remember microwave exposure is a cumulative effect over time....
Most wifi devices run something between 20 and 200 milliwatts, it's hardly 5 Watts and the output isn't focussed at all, it's nothing even remotely resembling the output of a microwave oven.
My parents have a mast pretty close to their new home, and there's several kids living very close by. I'm more worried about that than wi-fi.
But the whole point is that when they are outside close to a mast the effect is minimal, but sitting less than a foot away from a laptop connecteed via WI-FI for at least an hour per school day will be subjecting them to way more radiation
I'm afraid you're not quite right there as Feek has pointed out, the overall power of an AP transmitting is minimal, especially compared to a gsm mast. My main issue would be as has been discussed the security aspect/paedophile issue and the need for it. I agree that one more bit of radiation is not a good thing - don't get me wrong, I don't think they should add any more to the atmosphere where children are going to be spending a lot of time in. However the effects of the APs wouldn't be that great. It's more damaging for your brain/cells to be out in the sun during a solar storm, or talking on a mobile phone, or even listening to their ipods for hours than spending a year in a room with an AP.
Dymetrie
22-05-2007, 21:41
My main issue would be as has been discussed the security aspect/paedophile issue and the need for it.
Thanks for highlighting this again Will.
Whilst I don't discount the possible radiation danger then I feel this is one of the most important things and can't understand how it could be overlooked by a school :/
I'm afraid you're not quite right there as Feek has pointed out, the overall power of an AP transmitting is minimal, especially compared to a gsm mast. .
So you are both saying the tests they showed were fixed/fake ?
I think they were using theoretical isotropic values and sensationalising the "facts". Yes it's more radiation and that's not good, however it's not as bad as they make out.
However I agree there is no need for wifi in school at all. So I'm completely behind you on that one. I feel the scaremongering is a little baseless - it's not completely trivial obviously as there is necessarily going to be extra EM/RF radiation - but the amount of increase is so negligible that it's really making a mountain out of a molehill.
Had they focused on the security aspects of it I'd have been more concerned and more in agreement with a little over zealous reporting.
I didn't see the program so I can't comment on whether what they said was fixed or fake but I read the related article on the website and it was a load of garbage. As Will says, it was sensationalising, scaremongering and making a mountain out of a molehill in the pretence of investigative journalism.
Dymetrie
23-05-2007, 12:41
Straight from the BBC site (http://news.bbc.co.uk/1/hi/technology/6676129.stm)
And this bit made me giggle :p
This is not to say that all electromagnetic radiation is necessarily harmless - sunlight, for example, poses a significant cancer risk; so if you are using your laptop on the beach make sure and get some shade.
I'm of the opinion that this is sensationalisim although do agree that wireless in schools is a little pointless. Here some info one of the science bods at my work emailed earlier, a pretty interesting read.
A WLAN device only ever transmits a total power of a tenth of a watt - that's about the same as the power that sunlight delivers to a 1 cm square of your skin in summer.
Only a small proportion of the WLAN emissions reach a persons body since the device transmits in all directions at once in order to function. For example if a person is standing 5 meters away, and assuming a person's frontal surface area is about 1m square, they may receive about 1/300th of the total output power. That's about 0.3 mW over the whole body. If they stand 10m away this drops by a factor of 4. In addition, the WLAN terminal typically only transmits when files are actively being moved which tends to be a very small proportion of the time. Finally, much of the energy that is incident on the body will actually reflect from or pass through without being absorbed.
Obviously this discussion applies to the stated concern of children being in areas where WLAN systems are in operation. If they are using a WLAN enabled system themselves, the levels are higher, but the basic argument still applies... Lower power than a phone, emitted only during data transfer, and emitted from a point many times further away from the head than a mobile would be held.
To compare, A GSM base station can transmit up to 20W of power, although smaller basestations, and the phones themselves transmit around 1W. Power control is used so that the mobile and the basestation try to use just enough power for the job. This is the basis for the argument that exposure is actually reduced by placing a base site on the roof of a school or hospital. However the reality is that at medium or long range (or even when using a phone indoors) both the phone and the base site will turn the power up. It is a technicality to say that a WLAN terminal can transmit more power than a cellular base site. This is not the case for the majority of the time.
To make the comparison between levels still more clearly, the WLAN devices are designed to operate down to a pico Watt. That's a millionth of a millionth of a watt. (Apologies to all techies). Ie, in reality, the power received from a WLAN access point in the corner of a classroom by the people in it will typically be between a millionth and a billionth of a watt... When it is operating... and that's over the whole body. Compared to a tenth of a watt over every cm of skin, every second that a person is exposed to sunlight.
It is true that different frequencies of electromagnetic radiation have different effects. X Rays for example, much higher in frequency and energy than visible radiation, do more damage to biology. This is why X Rays are considered dangerous even in low doses. Visible light as we all know can be slightly dangerous in large doses and is known to be harmful over long time frames. Microwave radiation is much lower again in frequency. Its effects are thermal rather than ionizing. ie - it will warm you up rather than smash your molecules.
It is also true that the full effects of long term exposure haven't been very well studied and therefore are poorly known. However the amount of power in a WLAN signal is very very low. If you use a Mobile phone for an hour this is a much higher dose - perhaps 1000 times as high - as the energy received from either a cellular base station on the roof of a school, or a WLAN terminal used heavily all day. Which is itself maybe a thousand times higher than simply being in a classroom with an access point. In fact it may be the case that TV broadcast signals expose many of us to more electromagnetic energy than the WLAN device on the wall.
I have a recording of the TV programme should anyone wish to watch it (you'll have to forgive the guy in the corner waving his hands about though) :)
PS - they were comparing a mobile phone mast at 100m against a wi-fi transmitter at about 2ft, arguing that that's a typical distance that a user would be from the equipment. Fair point I guess.
100 meters or miles? I'm very rarely every 100m from a mobile phone mast...?!
Allegedly 100m is the point at which the signal from a phone mast peaks at ground level. I'm not entirely convinced.
GSM masts typically don't have that large a range hence why there are so many of them. I can see a mast from my window, I reckon I'm about 300m away from it.
We just had - last weekend for some stupid reason given when this broke - wifi emitters or some form installed all over work.
In the last 4 days one of the guys has been complaining of 3 headaches, he normally gets 1 a year at most apparently. Dunno, hope it's not a problem though I only just went wireless at home!
Come to think about it, if I spend more than a few hours in front of my pc (where the wireless router is) I get major headaches. Its only on weekends too. hmmm.
Thats all the pron nothing to do with the wireless
;D
Thats all the pron nothing to do with the wireless
I said headache not wristache:p
Well it does make you go blind you know ;)
Who said that?;D
OMG and deaf as well ;D
eh? Speak up. Im old...
Coincidence.
Given we've now been told they were only turned off for half a day last week due to concerns, I think your def. right :D
There are some people are work feeling really stupid right now, one person complained of sore eyes ???
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