I think cell phones have been around long enough
where we would be, at least seeing the beginning
of any negative issues of their use
How many cellphones are there in the world ?
500 million maybe ? So where is all the brain damage
? Apparently it only affects lawyers.
2 watts of 900 MHz – 2100 MHz RF
I just looked up my cell phone on the FCC
Maximum ERP is 29.4 dBm at
the antenna connection at 836 MHz.
is 29.5 at 1850 MHz.
So maximum effective radiated
power is about 1 watt. Now even if we put the phone
up against our head and assumed that our head did
not change the radiation pattern, less than 1/2
watt could go into our head. Can 1/2 watt make a
detectable change in temperature of the tissue or
fluids ? I honestly do not know. And I have tried
to understand all that "SAR" stuff, but still do
not. (SAR = "specific absorption rate") What is
the "skin depth" of 850 MHz and 1900 MHz? I expect
that some of the highly educated readers of RFcafe
will be able to tell me.
I ask this, because
one of my favorite professors in college, and chairman
of my thesis committee was K5AAK, Dr. Jefferson
Lindsey III. He told us of working on the antenna
for the backpack that astronauts wore on the moon.
The RF link from the backpacks to the lunar lander
was 297 MHz (as close as I remember). They determined
that a LIVE human head absorbed 297 MHz. (They were
surprised to discover that this was not the case
when testing with cadavers.) It was too late to
change the frequency. So off they went to the moon
with a cardiod radiation pattern. (The null being
the direction the astronaut was facing). From this
I infer that 300 MHz would be a risk to humans,
not 1900 MHz.
But still.... where are all
the people damaged by cellphones. We have 10s of
millions of people using them for long periods every
day and we have many years of 'exposure'.
RE: Low frequency fields
"Possible Health Effects of Exposure to Residential
Electric and Magnetic Fields"
published by the National Research Council (National
Academy Press 1997) ISBN 0-309-05447-8 .
There is precisely ONE effect from athermal non-ionizing
radiation; it causes broken bones to heal faster.
I am amazed how many people quote some seriously
flawed 'research'. The most prevalent quotation
of crap is a research project where an idiot subject
rats to 35 millwatt per square centimeter of microwave
radiation. He pulsed the radiation at 15 Hz. His
moronic conclusion is that 15 Hz (low frequency
radiation) is harmful. How anyone would quote a
guy that thinks 2450 MHz is "low frequency" is beyond
me. Also, this power level was enough to actually
change the body temperature of the rats. Thus this
is not even in the category of 'athermal radiation'.
I am also amazed at how many people think that
microwave ovens are dangerous. Well, if you mess
up your door 'seal', I would call it dangerous also.
But they seem to think that 12 cm radiation causes
cancer. Hmmm.. they feel perfectly safe cooking
their food in an electric oven. And many people
love to 'broil'. Well.. 'broiling' is pretty much
cooking with wavelengths of a micron through hundreds
of microns. (Note to many people that were educated
in the USA, a micron is 1/1000 of a millimeter,
it is not in anyway related to that freaky unit
of measurement that is called an inch.)
see what sunlight does to everything it hits. So
much 200 nanometer and shorter radiation .....
Seems to me that cooking with 12cm electromagnetic
waves would be a heck of a lot safer than cooking
with 1 micron waves.