The Safety of ELF Fields Generated in the Ionosphere
The HAARP facility can be used to study techniques that use very low and
extremely low frequencues for applications such as communication with deeply
submerged submarines and geophysical exploration. The HF transmitter and antenna
system at HAARP does not, itself, transmit any signals in the ELF frequency
range. Instead these signals would be generated in the ionosphere, at an
altitude of approximately 80 - 100 km.
The process of generating ELF within the ionosphere is very inefficient (the
conversion efficiency is about ). As a result, the
level of ELF signal reaching the ground is extraordinarily small. Measurements
of the ELF signal strength produced in the ionosphere by the HIPAS facility
during a recent test, for example, showed field strengths on the order of
5 pT or 0.00005 milligauss (mg). This field strength is too weak to
be detected with any commercially available instrument and is only useful for
low data rate communications or for geophysical sensing applications where
specialized correlating receivers can be employed.
The subject of ELF safety has received significant attention in the US and
around the world, primarily because of concerns over the fields produced by High
Voltage power lines, but also because of concerns over such common ELF sources as
household appliances and video display terminals (VDTs). Concise summaries of some of
these studies and additional information on radio frequency radiation (RFR)
can be found at EMF Link operated
by The EMF Clearinghouse.
Here are some comparisons between the signal levels
that could be produced by ionospheric heating and some more common, day-to-day
The Environmental Impact Process that was conducted during 1992 and 1993 for the
HAARP project considered these and many other factors related to RFR health and
safety. Measurements made between January and April, 1995 on the HAARP prototype in
Gakona, have confirmed that the careful attention to RFR safety, inherent in the
HAARP design, has been preserved. The conclusions presented in the final EIS
document, published in July 1993, prior to beginning any construction of the HAARP
facility, were that there would be no biological effects on humans or animals, and
that conclusion remains valid today.
- A draft report prepared for the Environmental Protection Agency (EPA) recommends
an ELF exposure limit of 2 mG for new day care centers, schools and playgrounds.
The EPA which funded this study, called it "the most comprehensive study ever on the
health effects of low frequency EMFs." . ELF fields that can be
produced by HAARP are 400,000 times weaker than this "safe" level."
- According to Consumer Reports , "US homes typically have a "background" field level
ranging from 0.1 to 2 milligauss (mG), the standard unit of measurement for magnetic
fields. Epidemiologic research on exposure to EMFs, then, has focused on fields
measuring above 2 or 3 mG." Background fields in a typical household are 400,000
times stronger than the strongest ELF field ever produced by ionospheric heating.
- The ELF field strength level at arm's length distance from a computer video
display terminal (VDT) is typically 2 mG. Consumer Reports suggests that users
"... practice "prudent avoidance" by sitting at this distance."  This is a
field strength 400,000 times stronger than the ELF field produced by ionospheric
- Concern over ELF fields has even extended to the field produced by stereo headphones.
According to a recent study , the field produced at the outer layer of
the brain by typical headphones was measured to be 0.15 - 0.75 mG. The study points
out that these levels of field are about half the level at which some researchers
have reported biological effects in animals. This still represents a field
strength approximately 100,000 times stronger than the ELF field that could be
produced by HAARP.
- Even if all appliances and all electric utilities were turned off, the ELF field
that could be produced by ionospheric heating would be less than the naturally
occurring background noise field caused by worldwide thunderstorm activity.
- Time varying magnetic fields can be produced simply by moving through the earth's
constant, static natural field. For example, magnetic field strengths that are
produced by running, driving a car, or even sitting still and nodding your head
rapidly are greater than the background ELF fields commonly found in homes .
Fields that could be produced by HAARP are, in turn 400,000 times weaker
We have provided a stereogram to illustrate the point that ionospheric ELF fields
are so weak that to detect them requires special processing methods. When you look
at this stereographic image, you will see a great
deal of "noise," in a direct analogy to the problem faced by ELF receivers which
must be sophisticated enough to pick out a very weak signal in the presence of
naturally occuring background noise or static. There is a message buried in this
noise along with a picture that is even more difficult to see. The message is
readable but only by using the special processing power provided by two eyes.
You need to sit about an arm's length from the monitor to view this message
(for safety reasons too!). Thanks to Tony Frazier-Smith of Stanford University
for creating this image
 McCarrick, M. J., et al, "Excitation of ELF waves in the Schumann resonance range
by modulated HF heating of the polar Electrojet," Radio Science, Vol 25, Nr 6,
pp 1291-1298, Nov - Dec 1990.
 New Scientist, October 7,1995, p. 4
 Consumer Reports, May 1994.
 Baumann, S and Alagarsamy, S., Meeting abstract from Bioelectromagnetics Society,
12th Annual Meeting, 10-14 June, 1990.
 Bennett, William R. Jr., Health and Low Frequency Electromagnetic Fields,
Edwards Brothers, Inc: Ann Arbor, MI 1994. p. 95.
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HAARP Home Page-> http://w3.nrl.navy.mil/haarp.html
Last updated July 17, 1998.