[1st-mile-nm] WiFi to the Home: Revision
Steve Ross
editorsteve at gmail.com
Tue Jun 3 18:34:43 PDT 2008
Well done.
I'd quibble about the cell phone frequencies. GSM and PCS in
the US are up around 1900 MHz -- darn close to WiFi -- with
the 800 MHz band mainly old analog. Yes, analog cellular is
not uncommon, especially in rural areas, and 700 MHz mobile
is coming, but the biggest carriers are all GSM or PCS/CDMA
in the US.
Worldwide, GSM can be 800, 1800, etc. So studies done
elsewhere may be examining different frequencies.
Segmented cellular antennas produce more signal strength
farther way from the base stations than calculated in this
paper, and cell phone antennas (on the hand sets) have
widely varying propagation/radiation patterns.
Cordless phones are generally 2.4 or 5.8 GHz, too.
Microwave ovens operate at 2.4 GHz, and anyone who has used
a 2.4 GHz cordless phone near one while it is operating
knows that legally escaping microwave radiation can interfere.
My argument (and the stuff of this paper) has been that
holding a cell phone or cordless phone to your head is going
to give you a lot more exposure than pretty much any wifi
scenario except of course wifi PHONES. So why single out
wifi base stations for special attention?
(BTW, Head gets singled out as most likely to be harmed
because the circulation system there does not dissipate heat
as well as rest of body, and density of electric impulses is
far, far higher.)
All that being said, why DO the studies scatter so much? And
what should we make of it? Having investigated a cancer
cluster in NJ that was suspected to be caused by
high-intensity microwaves, and having taught epidemiology
stats and consulted for several high-rank schools of public
health (Harvard, Columbia), I offer these guidelines:
1. The scatter is natural, and usually (almost always,
really) due to difficulty measuring real exposure and
following a large enough sample. People don't simply stay
home. People get exposures to RF in many settings. They also
get exposed to lots of stuff. The small studies control
well. The large studies do not, and can not. THUS THE
STUDIES DO NOT IN GENERAL HAVE ENOUGH STATISTICAL POWER,
EVEN WHEN THEIR AUTHORS SAY THEY DO. Scatter they will. It's
the way God made numbers, bless her.
2. In the studies we see (and some unpublished ones I've
seen), when we see this kind of scatter, we can usually
assume that there is no problem from KNOWN effects of
exposure. That is, we know about thermal effects. We know
about EF. We know that these wavelengths and fluxes do not
ionize. To say that another way, given KNOWN effect
mechanisms, these frequencies and signal strengths can be
considered extremely low risk and probably zero risk.
3. Previously unknown effects mechanisms have bitten us in
the past, however. The classic example in health studies is,
of course, prions and "mad cow" disease. I once saw a clutch
of papers that noted men who work with CRTs were more likely
to father girls (and I have three daughters, no sons...).
People worried about wifi are going to focus on that sort of
stuff, not on this great paper.
4. So far, the best alternative mechanism opponents to wifi
have come up with is "allergy" to wifi. Is it credible?
Certainly within the realm of possibility, although there
does not seem to be a single controlled study proving it
exists. There are several such studies that strongly suggest
it does NOT exist (can't say "disprove because you can't
disprove a negative). What if the folks who say they have it
acutely are just psychosomatic, as seems likely? Even so,
people who ARE RF-allergic at a low level would never know
it, and could show up as "scatter on the high side" in the
studies. And we do know that implants of various kinds can
act as RF receivers/antennas (tooth fillings and pacemakers
have been studied quite a bit). One big problem, though: All
those other RF sources (cell phones, microwaves, cordless
phones) operating at about the same frequency as wifi and at
far greater ubiquity and levels of exposure, for much longer
use histories in the home.
5. It is well known that people will accept far higher risks
voluntarily than they will involuntarily. So they talk on
the cell phone 12 hours nonstop, but don't want their
neighbor's wifi spillover. OK, it's an issue, and also not
one this paper can address. Too logical. and we may come up
with other mechanisms. Maybe wifi only affects folks who
drink beer. At 5 AM. On Thursdays.
As for me: I'm not in the wifi biz. My magazine mainly
pushes fiber to the home. But given all this background, I
just can't get all that excited about exposure to wifi, or
people who (sincerely) claim allergies to it.
Steven S. Ross
Editor-in-Chief
Broadband Properties
steve at broadbandproperties.com
www.bbpmag.com
SKYPE: editorsteve
+1 781-284-8810
+1 646-216-8030 fax
+1 201-456-5933 mobile
Richard Lowenberg wrote:
> Jim Cummings asked that I forward his slightly corrected and updated version of
> his paper (including output ratings for some non-Airport routers).
> A .pdf version is attached, or see his web site.
> rl
>
> ----- Forwarded message --------------------
> Date: Tue, 03 Jun 2008 08:05:36 -0600
> From: Jim Cummings <jim at acousticecology.org>
> Subject: WiFi in the home
>
> The report seems to have stabilized in this form for now; you can share
> it....and I'd love any input, comments.
>
> I will also post it at:
> http://www.AcousticEcology.org/srwifi.html
>
> Thanks
> Jim
>
> Jim Cummings
> Executive Director, Acoustic Ecology Institute
> <http://www.AcousticEcology.org>
> Sound-related Environmental Coverage: Wildlands, Ocean, Urban Issues
> News Digest, Special Reports, Science Coverage, Educators' Resource Center
>
> Needle clusters shirring in the wind‹listen close, the sound gets better
> ---Gary Snyder, Mountains and Rivers Without End
>
> ----- End forwarded message -----
>
>
> Richard Lowenberg
> 1st-Mile Institute
> P.O. Box 8001, Santa Fe, NM 87504
> 505-989-9110; 505-603-5200 cell
> rl at 1st-mile.com www.1st-mile.com
>
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