[Gllug] Norman Lamb MP

[Chris Bell]

On Mon 13 Oct, John Hearns wrote:
> 
> On Sun, 12 Oct 2003, Chris Bell wrote:
> 
> > On Sun 12 Oct, Christopher Hunter wrote:
> > > Oh dear.  Another one fooled by the anti-technology lobby.
> > > Radio energy is radio energy regardless of frequency / wavelength.  Perhaps a 
> > > little basic EM theory would help?  Look up "inverse-square law".....
> Not really.
> The frequency does matter.
> Electromagnetic radiation covers a whole spectrum - from VLF used to 
> communicate with submarines right across to gamma rays.
> You can't say that 
> 
> Even in the RF region, I'd be much more concerned about high frequency, 
> near infrared stuff than VLF.
> 
> > > 
> > > Chris
> > > 
> >    I do not think there is a problem at the levels we are likely to
> > encounter, and any problems would first become obvious with persons employed
> > in the communications industry. I have worked in areas such as broadcast
> Points very much taken about the communications industry.
> 
> >    Persons worried about radiation should definitely not travel by air
> > because of interstellar radiation, they should never go to places like
> > Cornwall, Wales, Northern England, and Scotland because of natural nuclear
> But sorry - you make a sudden jump here to ionising radiation.
> There IS a threshold of frequency where EM radiation causes ionisation,
> which is at the high range of the frequency spectrum (X-rays, gamma rays).
> Ionisation is well known to cause molecular damage, and hence cause such
> things as radiation sickness, genetic damage etc. - of course given 
> sufficient doses. And ionising radiation is quite properly regulated.
> (Cue gruesome stories of early X-ray pioneers).
> 
   I did include a mention of the roof of the Guy's Hospital tower, and a
paragraph about the frequencies used in mobile phones:-


>    However I have heard that there is continuing research into the effects
> of some frequencies used by mobile phones because they are very close to a
>  resonant frequency of water, and there is a slight possibility that water
> could be ionised, leaving very short lived reactive ions in sensitive areas
> of the body. The frequencies that are most likely to produce any effect like
> this are the ones used in microwave ovens; they produce a surface heating
> effect but do not penetrate far below the surface. The stray radiation from
> a microwave oven is very much higher than that emitted by a mobile phone
> transmitter.

   There were very high power levels from the aerial farm on the roof of the
Guy's Hospital tower, with numerous dipoles and mobile-phone-style
radiators. We positioned a standard broadcast camera and cameraman on the
edge of the roof for the Jubilee fireworks displays, with excellent views of
the barges moored on the Thames. We had to use so much aluminium foil to
protect it from the RF interference that the camera kept overheating, so we
kept it switched off as much as possible, and I had to stand by on the roof
with a stack of spares in case it failed.

   Some of the frequencies now used by mobile phones were previously used
for temporary radio links, there were numerous frequency slots available in
the VHF to SHF bands which were used for local or point-to-point links. Some
tended to be better on partially obstructed paths at different times of the
year, depending on whether there were leaves on the trees, the state of the
tide, and the weather conditions.


-- 
Chris Bell


-- 
Gllug mailing list  -  Gllug at linux.co.uk
http://list.ftech.net/mailman/listinfo/gllug