ARE MOBILE PHONES SAFE ?
The recent widespread use and availability of mobile phones has lead some
people to worry about
the safety issues of these useful devices. There are a number of issues
that relate to the safty of
mobile phones. Firstly the devices are radio transmitters and although low
power transmitters
such as cordless phones, walkie talkies, radio control transmiters in toys,
remote control
garage doors, to name but a few, are accepted as harmless there are some
additional problems
associated with hand held mobile phones that make such a straight forward
assumption harder.
There is also the additional debate as to the rights of mobile phone
companies to establish
the transmitter / relay stations in public areas (such as near schools
etc.).
A number of issues need to be examined:
* The problem of the safety of a transmitter antenna that is very close to
the brain or
other delicate / essential organ. In scientific terms, it is the problem
that the power of
any radiating energy source follows the inverse square law (very near to
the source its
actualy more complicated and of course does not go to infinity at 'zero' distance). This predicts that the field strength will increase
rapidly when very
near to the source - unfortunatly the head is near to the antenna (source)
on a mobile
phone - hence the possible safety / health problem.
* Are the screening devices that are avaliable on the market effective ? Do
they really
help reduce the power that is in the vacinity of the head or can
diffraction, for example,
occur around the screens ?
* Earphone / microphone extensions are avaliable that mean you dont have to have the antenna close to the head so greatly reducing the problem mentioned above. However some have seen these as being worse, as the earpiece wire can act as an antenna and so there is the possibility of transmitting the signal straight into the ear! Plastic tube devices have been made that direct the sound from an earpiece which is some way away from the head. Are there going to be social
problems getting
people using 'safe' solutions that might not look 'cool'. For example,
people may not use
the extensions because thay are going worry about looking like they are
talking to
themselves as they walk down the road ! judging by the street this does not seem to be a problem.
* The problem of long term use of apparently 'safe' levels of radio radiation.
* The relative safety comparisons between a digital and an analogue signal.
Digital
systems use a 'pulsed' (output On or Off) method of transmission as
compared to an
analogue system where the output is constantly changing. The (time) average
emission
may be higher on the digital system. However in practice it may be that
digital systems
work effectively on much lower powers levels which might actually be an
advantage to
the health issues. Is this true ?
Two very good articles are:
RADHAZ, Brian Collins, Electronics World, Oct 2004, P.30-36
and
Radiation Hazard, special issue Elector Magazine, June 2005
For some press articles and links of interest click below:
Articles
For information about a wave meter to pick up the mobile phone signal:
Wave meter
THE CREATIVE SCIENCE CENTRE
Dr Jonathan Hare, Room 3R253, Chichester Bldg. CPES, The University of Sussex
Brighton, East Sussex. BN1 9QJ. 01273 606755 x3171
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