2
static
ELF
static
ELF
LF
HF
0 Hz (1 Hz -
0 Hz
(1 Hz-
(1 kHz- (1 MHz-
100 Hz)
100 Hz) 10 kHz)
10 MHz)
magnetic field
electric field
alternating elec-
[Gauss=10
-4
T]
[V/m
tromagnetic field
Fig. 1.1: Discussion about limits
Limits for professional exposition (electronics engineers) and
Limits for non-professional exposition (population in general)
according to the Recommendation of IRPA/INIRC
.
Limits according to VDE 0848 / 1989
Limits according to VDE 0848 / 1992
experimentally determined threshold values of reactions of
biological systems
:
1
Increase of the activity of movement of birds
2
deflection of divining-rods
3
influence on the time of reaction of men
4
conditional reflexes of fish without electrical organs
5
conditional reflexes of fish with electrical organs
6
conditional muscular reflexes of men
taken from:
: H.L. Konig: Unsichtbare Umwelt (Wetterfuhligk.), 5. Aufl., Bild 111, S. 123
Verlag Moos & Partner Munchen, ISBN 3-89164-O58-7
: Habiger u.a., EMV, Verlag Technik, Berlin 1992, S. 152
Introduction
3
1.1 Discussion about limits
Whoever follows the public discussions concerning electro smog always sees two arguing
parties, whose standpoints lie so far apart that they inevitably talk at cross purposes and
there can be found no consensus.
On one side the "affected" find together who maintain to have found the electromagnetic
radiation as the damaging cause for their problems. They are to be taken serious, even
when only their personal sensitivity serves as means of measurement and proof and a more
or less distinct sensitivity against electromagnetic phenomena. This group occasionally
finds support of homeopaths who can base on reproducible laboratory results that fit as
few into the view of life of science as the empirical statements of affected and possibly
hurt people.
On the other side stand the representatives of the energy-supply companies and the
runners of radio networks who argue with the needs of our modern industrial society and
give "limits" prescribed to them by scientists. These, for their part, proceed according to
strictly scientific methods. Their presented results are reproducible and there's no doubt
about them.
The limits after all are fixed far below those that are recommended from a scientific
viewpoint. Nevertheless both groups are separated from consensus by powers of ten.
When we want to know how deep the ditch is we want to bridge, we should take a look at
the determined limits (Fig. 1.1).
The limits stem from the 1RPA (International Radiation Protection Association) an organ
of the World Health Organization that in turn has appointed the INIRC (International Non
Ionizing Radiation Committee). These now state to have used all available scientific
research results as basis for the given guidelines.
Moreover a safety range was worked into them. So the limits were fixed at substantially
lower levels to guarantee that no health damage arises. In this way first the limits were
determined for the people who for reasons of profession are exposed to electromagnetic
fields.
For the population in general the limits for the so called non-professional exposition were
reduced further to one half till one fifth for reasons of caution and care. In Fig. 1.1 these
limits are registered. Thereby is distinguished between magnetic fields and electric fields
that appear stationary or at extremely low frequencies (ELF describes frequencies between
1 Hz and 100 Hz). Moreover limits for low-frequency (1-10 kHz) and high-frequency (1-
10 MHz) alternating electromagnetic fields are given.
The graph should serve as a rough orientation and show us the proportion of scale. As
further information some thresholds of measured reactions of biological systems are
registered (after Konig*
1
*). Because a logarithmic scale was chosen to fit all the values on
one graph it becomes clear that between the first reactions and the recommended limits
there lie up to five powers often. The ditch seems to be insurmountable.
4
Wireless telephones
Fig. 1.2: Set of problems of environmental compatibility by
means of the example of the handheld wireless
telephones (handy).
: L.v.Klitzing: Neurophysiologische Einflusse durch elektromagnetische Felder
wahrend und nach der Exposition, Med. Universitat zu Lubeck
Introduction
5
1.2 Wireless telephones
Measuring technical surveys with regard to the influence of brain currents by digital radio
signals by the university hospital in Lubeck have startled handy manufacturers and users
equally
. Although in this case measurement errors could be detected, the ,,bugaboo on
the wall" remains that we are sitting unsuspecting in a restaurant and a neighbour draws
his handy out of his pocket to make a digital telephone call. Thereby synchronizing the
brain currents within a radius of 100 meters on the broadcasting signal and occupying our
brain useless with technical signals. The derivation will show that from the start this can't
happen to all visitors, because as a prerequisite conditions of resonance must be fulfilled.
But would there be an affected, he or she for sure would have considerable problems,
because informations that are not picked up over the sense organs can neither be classified
timely nor as regards content.
An affected whose brain has picked up technical signals not even is able to register by
itself that it was fed with incorrect informations. It would be reasonable when the visitors
of the restaurant would defend themselves and put the radio operator on the doorstep. The
number of restaurants where apart from cats and dogs also handy's have to stay outside is
increasing. How should we keep out of the way of electromagnetic fields? Should we walk
around permanently with a steel helmet or even better in a knight's armour and even go to
bed with them? It would be worse than in the dark middle ages.
Summarizing: it should be guaranteed that the operation of electro technical apparatus
causes neither health damage nor unintentional influence or irritation. A systematic and
scientific procedure should investigate in the laboratory all relevant physical phenomena
individually for their interaction. Electro physics bases on two phenomena in connexion
with electro-smog: on the one hand the radiation and on the other hand the thermal effect,
but at a close look both factors prove to be of only little importance!
In radiation measurements the intensity of the electromagnetic wave at a certain place is
determined. In laboratory experiments the field strength is increased so long till biological
reactions are observed. Thermal limits are determined in a similar way. As said, the values
lie about powers of ten above those that possibly bother you when you hold a handy to
your ear. It is true that the microwave radiation penetrates into your head but we also
know that it marches out again on the other side and this visit in your head happens with
the speed of light.
Exactly like this are guest in your body constantly your local radio station, your local
television station the satellites with hundreds of programs and anyway the whole radio
technical world even when you did not invite them.
For an electromagnetic wave to become receivable, the field strength must lie clearly
above the common noise signal and this can only be achieved by a permanent overlap, by
standing waves, like in a cavity tuned to a specific frequency or an antenna. As long as
people don't let themselves grow antennas on their heads they hardly have to fear direct
biological effects of electromagnetic waves.
That leaves as the second phenomenon the thermal effect. With a handy held to your
cheek there comes into being a local fever in your head. But that is not at all unusual or
unnatural for the human body. Something like that happens to a far greater degree when
you take a hot foot bath or let yourself be irradiated at one side from the sun at a tourist
grill.