Posted By Nicholas Cornwell-Smith Not the usual issue of driving whilst using a mobile phone, but about increased exposure to radiation emmissions. Over the years there has been some concern expressed about using a mobile phone in a vehicle without an external aerial. This allegedly increases the level of radiation exposure to the individual due to a Faraday Cage effect where the radiation bounces around inside the vehicle due to its metallic strcuture. I have even heard that opening the window will help. Following some heated discussion at work I am now trying to gather any information for or against this issue. Using the precautionary principle, the further away the phone is from your head, the less exposure you will recieve. Similarly if you move the aerial to the outside of the vehicle, there will be even more reduction. I realise that the case is still not proven one way or the other about harm from mobile phones but I would be interested in hearing any views. (Via this forum rather than on my mobile!) Regards and thanks Nick

Posted By John Murgatroyd If you go by powerwatch, you'd not only have no mobile phones, but no electricity at all. Try: http://www.nrpb.org/pres...bile_telephony/index.htm As for "radiation"...what sort ? Ionising radiation ? Non-ionising radiation ? If mobile phones...there has never been ANY evidence at all for any harmful effects, if you go to go to the NRPB site and read, you'll note all this anyway. I've been operating radios' at power levels exceeding 100 watts for protracted periods of time, and I'm not dead yet (54). I've operated at frequencies from 1.6 MHZ up to 10 GHZ... As for the "faraday cage" effect...the RF goes straight through the windows, unless your car has metal in place of glass that is. I think we can assume that the window sides are greater than a quarter wave ? In any case, the phone power output is unlikely to be any higher than a half watt...and your microwave oven at home leaks more than that....much more. Personally, all the concerned mums moaning about mobile masts make me laugh...they buy their kids mobile phones which subject them to higher radiation exposure than masts. And I won't even mention the 100 kilowatt approach radar at heathrow...at 3000 mhz...and you're worried about a quarter watt ?

Posted By Ken Taylor Hi Nick - so you are stil around! Whilst the protective nature of a car upon lightning strike is generally attributed to the 'Faraday effect', I believe that the conductivity of the metal providing a route of least resistance is also an influential factor as the car should not be strictly considered a true Faraday cage due to the size of the perforations. The classic experiment with a Faraday cage demonstrates that radio waves do not penetrate to a receiver placed inside. However, there will be some minor degree of attenuation of electromagnetic radiation within the vehicle - but as this will be acting upon very low-level emissions at relatively large distances from the head, I cannot see that this would deserve any comparison with ambient levels. This, therefore, will be insignificant compared with the issue of the proximity of the emitter to the skull (which varies in thickness and density with age). Ken

Posted By fats van den raad I overheard a group of young students discuss this issue the other day. They were all pretty convinced that mobile phones have serious health risks from radiation and were all saying how they "now only use my mobile phone when I have to" and how the government and the phone companies are covering up the facts, and how these companies just do not appreciate that modern society places personal health above all else. The venue for this conversation..... McDonalds!!! Interesting to note that in South Africa majority of the phone masts are in school grounds. Extra revenue for the schools... you betcha!!!!

Posted By John Murgatroyd Ok, so mobiles are risky, maybe, possibly. Lets quantify said risk. The phone radiates a signal at either 900 (GSM900) mhz or 1800 (GSM1800) mhz. Television transmitters have been radiating signals from 470 to about 700 mhz for decades, at powers ranging from a few kilowatts to several hundred KILOWATTS. FRom this you would expect deaths in the thousands within a few miles of the masts. Zilch. The new digital transmitters radiate at about 10 kilowatts per multiplex, at around 800 mhz. Radars have been operating since the second war...today the approach radars at main airports radiate pulses of, again, several hundred kilowatts. Don't see too many corpses though. Mind you, there is that little problem of power decreasing as the square of the distance...ie: double the distance, quarter the power. That lets out phone masts. If you want irony, here it is. Because many places don't want, and won't have, phone masts, the mobile is more "dangerous" than it would be. Their handheld mobile actually INCREASES its power when in a poor signal area. In a good signal strength area it will radiate at a power of about a quarter of a watt (250 milliwatts) going up to a watt or two when in a poor signal strength area. Maybe I'd better not mention the sun, which radiates from dc to many millions of megahertz, at a power of 3 x 10*26 watts. I could go on, but. As I said. Risk management. Risk assessment.

Posted By Robert Douglas Why is it that see on a daily basis, people driving in London big flash cars worth five figures yet their owners will not spend £20-£40 on a hands free kit, it beggars belief. Aye Rod

Posted By John Murgatroyd Oh that's ok, I get out lots...I also know how to use google to get the stuff I want fast. Plus, my hobby involves radio...and I have several transmitters... It just seems peculiar to me that someone would seriously consider the health effects of mobile phones in a car. Given that several thousand are killed in car accidents and many more are injured. Whereas there are no deaths recorded due to operating a mobile phone ! If anyone is that worried about the effects of a mobile, they should seriously consider not getting in a car.

Posted By Alasdair Philips I have just seen the comments about "Powerwatch" and wish to respond. We are not anti-technology. I have an electrical and electronics first degree and post grad qualifications in the biological sciences and have worked in these areas since the early 1970s. In the 1960's, as a schoolboy, I was using ex WW2 comms sets and designing and building early walkie-talkies. I have also worked extensively as an EMC engineer measuring RF signals. Mobile phone use inside cars without an external antenna do decrease the external availability of a signal from a mobile phone handset by up to 100-fold. This means that the nadset incereases its power by the same amount to compensate. Handsets can all operate over a transmit power control 500:1 range and modern ones ofen 1000:1. They set their power by feedback from the local base station that they are communicating with. So, if you have to use a mobile inside a car I strongly advice a PROPER HFK with an external antenna on the roof of the car. I personally believe that the HFK should be an air-tube (stethoscope) type or voice operated with audio through loudspeaker. The Health Minister has now formally approved a senior stakholder group (with us and National Grid and NRPB and HSE and etc etc) to move forward on reducing public exposure to power-frequency EMFs to ALARP. (i.e. far below NRPB/ICNIRP levels). This is happening. I predict that it will also happen in the next few years as regards mobile phones and, especially, base stations near to bedrooms. This formum is not the place to debate this. Any of you wanting to be on a (relatively quiet!) update list should email me their details: alasdair@powerwatch.org.uk Also, remember that current DH advice is that children under 16 should only use a mobile phone in an emergency. It is NOT a power issue (re John Murgatroyd) but a living systems (i.e. us) EMC (signal interference) issue. I have also used high-power AM and FM TX sets with no problem. GSM and 3G pulsing seems to be far more biologically active. Alasdair Philips Director Powerwatch Scientific Advisor CHILDREN with LEUKAEMIA (see: www.leukaemiaconference.org )

Posted By John Murgatroyd I suggest reading various reports of measurements conducted at various sites on this: http://www.nrpb.org/radiation_topics/emf/index.htm Which tells you how the tests are conducted and gives the readings of same...you may be surprised at some of the measurements, and not the mobile ones. You may like to look at the scale at the side, giving percentage of allowed radiation exposure: http://www.nrpb.org/radi..._surveys/base.cfm?site=7 note the broadcast tv readings.

Posted By Alasdair Philips There is some lack of understanding here. The signal bars on a mobile phone indicate received signal. The handset can work down to about 0.00003 volts/metre (marginal) - within 500 metres of a base station you typically get about 1 volt/metre. You are unlkiely to see changes in a car/van on the bars other than in weak signal areas. All GSM handsets have active up-link power control in order to save battery energy (and this also reduces the microwave exposure of the user’s head). The base station measures the incoming signal and instructs the handset, where possible, to decrease to the minimum power needed to maintain the call. This is in 15 by 2dB ( x 1.58) steps, so there are many levels that may be used: 2, 1.25, 0.8, 0.5, 0.3, 0.2, 0.125, 0.08, 0.05, 0.03, 0.02, 0.0125, 0.008, 0.004, 0.002 watts transmit power. The casual user without an RF power meter will be unaware of this when sing a hndset in a vehicle. The NRPB school with the higher TV/FM broadcast signals is most untypical (the NRPB confirmed this to me). Typically TV & FM signals are down in the millivolt/metre area and within 500 metres of a macrocell base station GSM (and 3G) signals are in the order of 1 volt/metre - i.e. 1000 times more signal strength; 1000,0000 times more power. In a car with an internal handset the levels are many tens of V/m. My father smoked 50 a day for most of his life, but lived until aged 87 with no known smoking related health problems (with the possible exception of macular degeneration of eyesight). New Japanese work shows that people born with a particular genetic marker are at least 50 times more likely to develop leukaemia during their life from exposure to ionisng (nuclear) radiation. i.e. we are lookng a susceptible sub-groups in the population. This seems to hold true to most hostile expsoures - some people are better survivors than others. We can go the eugenics route and let the weak die off (maybe that would be best for the Earth!) or we can enable children to survive childhood (like we do) - then we have to decided at what level we apply H&S protection. Or we can at least tell them that certain activities (like extensive mobile phone use) should be done with caution and let them take what possible risky they want. I believe that this wireless revolution is already leading to chronic disability in a smallish (few %) sub-group and that we should use the technology with great care. Surely insisting that firms who require people to use mobile handsets for work should at least offer a full hands-free kit with external roof-mounted antenna for their employees is not too much to ask?