[LINK] Our wireless world...

[Stewart Fist]

Ivan wrote:
> The boffins step in:

>> But Chris Guy, head of Reading University's School of Systems
>> Engineering said: "The amount of power emitted by wi-fi devices is
>> about a tenth of that given out by mobile phones. It is very, very
>> unlikely that it is harmful because the power levels are so low. I
>> just do not believe wi-fi is damaging people's health."

I agree with "unlikely", but I have problems with "boffins".

The head of a school of Systems Engineering would know as much about
cell-biology as I know about the sex-life of the earthworm ... and quite
possibly, much less.

Power levels are only one of the factors involved anyway.  And power is
relative -- it needs to be related to biological functions.  For instance,
what is the power-level of the brain-synapse which triggers the release of
hormone from the parathyroid?  Does anyone in the Link Institute know?  Do
you think Chris Day does?

> The electromagnetic fields in your home, due to it's internal
> wiring, is much larger and more powerful than anything your
> consumer wi-fi electronics is capable of creating and the same is
> true for your computer monitor and or television set.

It probably is at 50Hz.  But cell DNA is of a size more likely to respond to
much higher frequencies.  There have been many attempts to find which
frequencies are more likely to produce biological effects, but the whole
area is confused by the complexity of the bio-electrical resonant circuits
in the body which vary from the microscopic up to brain-cavity size.

And don't forget that wavelength in body tissue is not the same as it is in
air.  The wavelength of a cellphone signal in the the boney skull (which has
stem-cells) is quite different to that within the cranial cavity in brain
tissue.

Power pulsation rates also appears to make a different.  Hearing-aid users
discovered this when GSM arrived.


> Just a few millionths of an amp flow through the wearer's body, so
> there should be no nasty tingling effect. ...


The fully-dark adapted eye on a really dark night can see distant stars
which, astronomical measurements reveal, must be optical sensations
triggered by the impact of a single photon.  That photon is of light --
which is below the energy level believed by radiation standards-setters to
be capable of breaking chemical bonds of "effecting biological systems".

So we have a neuro-chemical cell system in the body which can react to a
single-photon -- and produce a chain of chemical and electrical effects in
the nerves and brain -- which respond with a conscious sensation. At higher
levels of photons, these same sensation effect the release of hormones in
the body (SAD, Jet-lag, etc)

Yet, I would guess that the power of a single proton is only measurable in
terms of a few trillionths of an amp -- or even less.  So "just a few
millionths of an amp" is not a measure of the trivial, but of the magnitude
of such effects when compared to the way some parts of the body function.

Fortunately, the body appears to be well adapted to such currents and
fields, and appears to have robust repair mechanisms to handle transient
damage.  So, I personally doubt that Wi-Fi will cause any harm, even in the
long-term, and even with school-kids.

But with my paramedical background and many years of writing and
investigating the subject, I don't have the cocky certainties exhibited by
many ignorant electrical engineers.

-- 
Stewart Fist, writer, journalist, film-maker
70 Middle Harbour Road, LINDFIELD, 2070, NSW, Australia
Ph +61 (2) 9416 7458