[sci.electronics] VDT Electric Fields - Long reply, with resource pointers

antenna@well.sf.ca.us (Robert Horvitz) (02/22/91)

In article <2343@njitgw.njit.edu> jfa0522@hertz.njit.edu (john f andrews ece) writes:
>While on the topic of EM fields and vdt's, can anyone point me to a source for 
>information on health effects of em fields? I have a few callers interested,
>and would like to repost whatever I can find for wider dissemination.
>
>Thanks for any comments.
>
>
>-----------------------------------------------------------------------------
>john f andrews                SYSOP           The Biomedical Engineering BBS


 
The following article and resource pointers appeared in the Fall 1990
issue of Whole Earth Review, which retains the copyright:
 
 
INHABITING THE ELECTROMAGNETIC ENVIRONMENT - by Robert Horvitz
 
It's a puzzle.
 
On the one hand you have folks sticking their heads in
electronic "tuning" fields, as some sort of brain-boost or
nonchemical psychedelic, and on the other you have folks afraid
of leakage from video monitors, microwave ovens and powerlines.
Are electromagnetic fields (EMFs) a neat high or a lethal hazard?
 
Maybe both, maybe neither.  Maybe we just don't know.
 
There's been an upsurge recently in public concern about the
invisible fog of electromagnetism we live in.  It must concern
us because that fog has thickened so much this century, and it
permeates our bodies.  Every electric motor, appliance and
current-carrying wire radiates energy as a byproduct of normal
operation.  We also use radio to communicate, as in
broadcasting, cordless and cellular phones, beepers and CBs.
Microwave ovens are popular.  So are electric blankets and
stoves.  Radar is used by police departments, meteorologists,
aviators and navies around the world.  Metal detectors, remote
controlled toys...the list goes on and on.
 
We can't see these emissions.  That used to mean we ignored
them.  But now that a wide range of biochemical effects has been
attributed even to weak EMFs, invisibility feeds fear:  we
don't know when or how much we're being exposed.  Exposure is
likely anywhere that electricity flows, and our dependence on
things electric grows daily.
 
There's some consolation in knowing that this wave energy
penetrates our bodies precisely because we absorb so little of
it:  we are nearly transparent to radio.  And compared to
sunlight, which can sear flesh in a few hours, low frequency
EMFs are "soft."  The sun's ultraviolet rays are a much more
immediate health threat.
 
Which partly explains why research on the biological impact of
EMFs got off to a slow, faltering start.  Another reason is
that bioelectricity seems to attract charlatans and quacks like
no other subject.  That has made funding agencies and serious
scientists leery.  Plus, some people in high places oppose
research whose findings could impede "progress," raise business
costs, establish liability, or encourage regulation.  Shutting
down the Environmental Protection Agency's research program on
EMFs in 1986 was one of the Reagan Administration's many
low-points.
 
Despite the prevailing skepticism and lack of funding, interest
in EMF bioeffects increased during the 1980s, after some curious
results were found in lab experiments, and statistical studies
started showing associations between EMFs and serious illness.
Federal inaction in the face of growing public fear led some
local governments to impose tight restrictions on EMF sources.
As the patchwork of local standards spreads, it's starting to
look like the cost of *not* doing the research needed to
establish consistent and reasonable safety standards may be
higher than doing it right.
 
A few hints of consensus have started to emerge from the work
done so far.  With caveats galore (I'm no doctor, we still don't
understand the mechanisms, not everyone agrees), this fool
rushes in where a lot of other fools have already been mucking
around:
 
*  Many bio-effects seem to occur at specific combinations of
frequency and power, suggesting that molecular resonance is
involved.  If that's the case, setting exposure limits across
the broad spectrum will be difficult.  (To use a plumbing
analogy, your pipes may "sing" when water flows through them at
a specific rate.  Decreasing the flow will stop the singing;
but so will INCREASING it.  And when the water is at a different
temperature, the singing starts and stops at different
flow-rates.  This kind of nonlinear relationship between "dose"
and effect means that at certain frequencies, a weak EMF might
have more impact on a specific chemical reaction than than a
stronger one does.)  Until we sort everything out, minimizing
exposure in general is the safest strategy.
 
*  The orientation of the field, the coherence and shape of the
waves, the way they're modulated (AM, FM or pulse), the peak
versus average power density - any or all of these may be
important variables.  They complicate setting exposure limits,
too.
 
*  Magnetic fields may be more of a health problem than
electrical fields, though they are often found together.  TVs
and video terminals, small motors (hairdriers, fans and plug-in
clocks), flourescent lights and electric blankets, are typical
sources of magnetic fields in the home.  Magnetic shielding (as
opposed to electrical shielding) is generally impractical.
However, the magnetic fields from most appliances fade to
below the background level a few feet or yards away. 
 
*  The magnetic fields of powerlines have a farther reach. They
are more intense where there's an unbalanced load and the
voltage is stepped down by a transformer.  You can easily check
for "hot-spots" in your neighborhood by walking around with a
portable radio tuned to a vacant channel at the low end of the
AM band.  As you near a radiating section, you'll hear a
loudening buzz.
 
*  If you have a microwave oven, have a professional repairman
check the seal around the door at least once a year.
 
*  Electric blankets have been singled out as something to avoid
because they create strong fields and are meant to be used close
to the body for long periods of time.  Consider a down comforter
instead.
 
It's important to keep in mind that not all of the recently
discovered effects are necessarily harmful.  Some may have no
health impact at all, and some may ultimately prove beneficial.
The real pay-off in EMF bioeffects research may not be just in
minimizing risks, but in the development of positive
applications.  It is already clear that there are therapeutic
uses - in bone-healing and pain relief - as well as new imaging
techniques which eliminate the need for exploratory surgery.  If
EMFs can in fact promote or inhibit certain chemical reactions,
we may able to harness that ability for desirable ends.
 
As we learn more about these invisible energies, we may well
come to regard our current fears as just part of the shock of
seeing with "new eyes."  As I. M. Sechenov once wrote:
 
   "...it is highly instructive to hear people born blind
   describe their impressions of the world around them in the
   first few days following an operation restoring their sight
   at an adult age.  Although such people had already had clear
   spatial notions concerning all the objects around them...the
   whole field of vision appeared to them to be filled in some
   solid manner, which seemed in some way to touch their eyes,
   and they were even afraid to move lest they should stumble
   upon this or that image."
 
 
 
NATURAL EMFS
 
 
To keep our emissions in perspective, note that the
Earth has a very active electromagnetic field.  Its churning
iron core generates a halo that reaches far beyond the
atmosphere.  "Ground currents" seep through rock and soil,
sometimes causing geomagnetic storms that disrupt powerline
transmissions.  Lightning releases some of the enormous static
charges that build up in the atmosphere.  Meanwhile, solar
flares and sunlight ionize the upper air, producing swirls of
charged particles that swaddle the Earth.  We rarely notice it,
but our environment is permanently electrified by the
interaction of geomagnetic and solar weather.
 
Natural EMFs buffet us intangibly.  Whatever effect they may
have, we've had eons to adapt.  Human-generated EMFs have only
been around for a few generations, and are quite different from
natural fields in terms of frequency, waveform, coherence,
distribution, etc.  We don't yet know what difference these
differences make.
 
"THE EARTH'S ELECTRICAL ENVIRONMENT" is a collection of papers
surveying what is known, and not known, about lightning,
aurorae, ground currents and the ionosphere, how they interact
with each other and with human systems.  There's only a few
oblique references to bioeffects, but this is the only book I
know of that tries to pull together the various aspects of the
Electric Earth.
 
     The Earth's Electrical Environment
          E. Philip Krider, Raymond G. Roble, Co-chairmen
          Geophysics Study Committee, National Research Council
          1986;  263 pp.
          $28.95 postpaid from:
  
             National Academy Press
             2101 Constitution Ave., NW
             Washington, DC 20418
             202/334-3313
 
If you have a shortwave radio, you can tune in current solar and
geomagnetic weather reports on stations WWV and WWVH.  Audible
throughout North America and beyond, they're broadcast at 18
minutes past the hour on 5, 10, 15 and 20 MHz.
 
For more detailed current information, if you have a computer
and modem, you can call the NOAA Space Environment Services
Center's Forecast and Advisory BBS in Boulder, Colorado
(303-497-5000 at 1200/300 baud, 8-N-1;  or 303-497-5042 at 2400
baud, 8-N-1).
 
 
 
MONITORING EQUIPMENT
 
One of the neatest widgets I've ever seen is the "AMBIENT POWER
MODULE," invented by Joe Tate, the Harbormaster of Sausalito.
It's essentially an untuned, broadband radio receiver, simple
enough to build yourself.  Attach a long piece of wire as an
antenna (100+ feet, preferably) and a connection to ground, and
the Module will draw a small trickle of current right out of the
air.  (Cross a "cat-whisker" crystal radio with a solar cell,
and you have the basic idea.)  Output varies with the quality of
the antenna, ground, and the energy in your air-space.
Typically it's a couple of milliwatts - just enough to run a
digital watch or calculator.  Not many people will want to put
up a 100-foot antenna to drive a calculator.  However, you can
also use it as a crude measuring device for EMFs, by hooking it
up to a meter, a strip-chart recorder or a computer (with
appropriate interfaces).  It won't tell you anything about the
frequencies, modulation or where the signals come from,
just the cumulative field-strength.  Pre-built units aren't
available;  instead you can order an illustrated booklet
containing easy-to-follow instructions on how to built it
yourself.  All the parts are cheap and widely available.
 
   THE AMBIENT POWER MODULE
       by Joseph Tate
       16 pp., 1987
       $5 postpaid from:
 
            Ambient Research
            P.O. Box 153
            Sausalito, CA 94966
 
 
"MICROWAVE NEWS" (reviewed below) recently surveyed equipment
marketed for the measurement of EMFs in ways relevant to the
health issue.  The 15 listed units range from sophisticated lab
equipment, to simple consumer products;  in price from $75
(Model 116, from Electric Field Measurements, Box 326, West
Stockbridge, MA 01266, 413-637-1929), to $9500 (Model 3D-MFDM,
Sydkraft AB, Carl Gustafs Vag 4, S-217 01 Malmo, Sweden).  The
majority of these devices have been on the market for less than
a year;  no one has yet done rigorous comparative testing.
Since they measure different bands in different ways, they
aren't exactly comparable anyway.  And since there's so little
agreement about what bands and features are important to
measure, we won't venture a recommendation...though we do have a
sentimental favorite:  Model 42B ($350 from Monitor Industries,
6112 Fourmile Canyon, Boulder, CO 80302, 303-442-3773).  This is
produced by Ed Leeper, who built the magnetic field gauge used
by Nancy Wertheimer in her trailblazing study of powerlines and
leukemia in Denver (described at the opening of Paul Brodeur's
"CURRENTS OF DEATH".  We all owe Ed a great deal for his
contribution not just to that project, but to the revolution in
attitudes it sparked.
 
 
ARTIFICIAL EMFS
 
Research is moving so fast in this field that newsletters are the
only way to keep up.  "MICROWAVE NEWS" and "VDT NEWS," both
edited by Louis Slesin, are widely acclaimed by all sides as the
best sources of reliable and current information.  Slesin
believes that emissions from computer monitors, and EMFs
generally, are a serious health issue.  But he's established a
reputation as an "honest broker."  When a well-done study is
published showing no evidence of harm, or refuting a study that
found something scary, Slesin reports it just as carefully, and
with just as prominent a headline, as reports favoring the other
side.  As a result, he's been much more effective in changing the
attitudes of researchers than more partisan reporters.  Almost
every study cited in "CURRENTS OF DEATH" was first reported in
either "Microwave" or "VDT News."
 
As you might have guessed, "VDT News" covers emissions from computer
monitors, and worker-health issues related to office equipment in
general.  "Microwave News" is less accurately titled.  It covers
the entire radio spectrum, not just microwaves, increasingly
focusing on the low end of the spectrum (macrowaves?).  "MN" is
the more expensive of the two, but it has a lot more news per
issue.
 
     Microwave News                   VDT News
     $250/year (6 issues)             $87/year (6 issues)
       $285/year foreign                $97/year foreign
     P.O. Box 1799                    P.O. Box 1799
     Grand Central Station            Grand Central Station
     New York, NY 10163               New York, NY 10163
     212/517-2800                     212/517-2802
 
 
 
For a one-off summary, a background paper published by the US
Congress' Office of Technology Assessment is a reasonable place to
start.  "Biological Effects of Power Frequency Electric and
Magnetic Fields" addresses powerline issues, summarizing the
research in a relatively accessible, non-alarmist way.  Also
discusses policy issues, recent regulatory actions, and ongoing
research programs.  It might be out-of-stock already, but should
be browsable at most Government Document Depositories.
 
     "Biological Effects of Power Frequency Electric and
          Magnetic Fields"
     Office of Technology Assessment
     103 pp., 1989
     Stock No. #052-003-01152-2
     $4.75 from:
 
          Superintendent of Documents
          Government Printing Office
          Washington, DC 20402
          202-783-3238.
 
Among recent books on these subjects, "CURRENTS OF DEATH" has
certainly attracted the most attention.  Brodeur gives a pretty
good overview of material originally published in Slesin's
newsletters.  But he differs sharply from Slesin in taking any
skepticism about even the flakiest claims of injury from EMFs as
proof that the doubter must be part of a massive conspiracy
hatched by the US military, the electric utilities and the
computer manufacturers, who want to wreak a Holocaust on the
public and cover up their evil plan.  For Brodeur, there's no
such thing as a different interpretation of ambiguous data.
There are no errors in the research of the pro-harm camp, fatal
errors in every study from the no-harm camp.  Reasonable people
don't disagree:  you're either pro-Life or pro-Death.
 
This is nonsense.  It does a real disservice to the complexity
of the scientific issues, and to the honest researchers in both
camps trying to figure them out.  The breakthroughs in
understanding which are likely to emerge from this controvery
are probably still cloaked in unresolved questions that Brodeur
would dismiss as lame excuses for reactionary caution.  If you
read this book, make sure you read the OTA paper for some sort
of balance.
 
     CURRENTS OF DEATH
        Power Lines, Computer Terminals, and the Attempt to
             Cover Up Their Threat to your Health
        by Paul Brodeur
        333 pp., 1989
        $19.95 from:
 
            Simon & Schuster
            1230 Ave. of the Americas
            New York, NY 10020
            212/698-7541
 
 
Robert Becker is one of the pioneers of modern bioelectrical
research.  Now retired, he was an orthopedic surgeon who devoted
most of his life to the study of bone-healing and "currents of
injury" - weak electrical flows in the body that seem to
stimulate tissue repair.  "THE BODY ELECTRIC" (with co-author
Gary Selden) presents a radical new theory of bioelectricity,
based on Albert Szent-Gyorgyi's hunch that parts of the body are
capable of acting as semiconductors.  When tissues with
different electronic properties meet in the salty fluid of the
body, a sort of diode is formed.  By analogy with solid-state
semiconductors, where tiny changes in chemical composition
drastically alter the electrical response, one must ask:  could
tiny changes in body chemistry radically alter the body's
electrical fields?  Could changes in the electrical fields
impinging on the body cause subtle changes in body chemistry?
 
For a long time, Becker's primary interest was regeneration.
There are some mind-blowing passages in the book describing what
so-called lower animals can do (regrow hearts, cure induced
cancer).  Becker sees bioelectricity as a possible key to
unlock the regenerative powers he believes still reside in
our genes.  The ideas in this book are powerful.  The vistas it
opened will keep medical researchers busy for decades.
 
Becker's "CROSS-CURRENTS" is newer and written at a less
technical level.  As the subtitle suggests, it explores the
"perils of electropollution" and the "promise of
electromedicine."  Covering some of the same material as "THE
BODY ELECTRIC" and "CURRENTS OF DEATH," but in a friendlier
tone, there are numerous comments on alternative medicine,
holistic thinking, natural healing.  His explanation of how
acupuncture actually works is the best I've read.  At
the end, Becker gives some helpful low-cost suggestions on ways
to minimize risk and exposure to EMFs.
 
   THE BODY ELECTRIC                 CROSS-CURRENTS
     Electromagnetism and the          The Perils of Electropollution
        Foundation of Life             The Promise of Electromedicine
     by Robert O. Becker, MD, and      by Robert O. Becker, MD
        Gary Selden                    336 pp., 1990
     [o.p in hardback, in print        $19.95 from:
     in paper]                           
                                             Jeremy P. Tarcher, Inc.
                                             5858 Wilshire Blvd.
                                             Los Angeles, CA 90036
                                             213/935-9980
     
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Robert Horvitz    1122-1/2 E St. SE    Washington, DC 20003-2232    USA
antenna@well.sf.ca.us     ...{apple,pacbell,hplabs,ucbvax}!well!antenna