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DNA And The Microwave Effect
Post From MailBag 4/8/2002: DNA and the Microwave Effect
Dear Technical staff,
I am a private researcher based in Perth, Western Australia. I believe
that the major contributing factor to the 'microwave effect' is actually a
reciprocating lorentz-force (force exerted on a charge-carrying substance in
the presence of mutually perpendicular electric and magnetic fields - such
as in a microwave) exerted on the uneven charge distribution of the DNA/RNA
molecule. Thus providing a non-thermal explanation for this phenomenon. If
that is the case, then the frequencies involved would almost certainly be
very different to the conventional 2450 MHz, since the structures and the
forces involved are so different. It would become a microscopic structural
resonance issue, as opposed to a purely thermal or purely chemical effect.
This would also explain the similarities between the microwave effect and
the external-heating method.
Please post this on your site as it may assist research in this important
area.
DNA And The Microwave Effect
Penn State University
January 20, 2001
Can microwaves disrupt the covalent bonds of
DNA? The fundamentals of thermodynamics and physics indicate this is
impossible. Numerous studies have concluded that there is no evidence to
support the existence of the 'Microwave Effect', and yet, some recent
studies have demonstrated that microwaves are capable of breaking the
covalent bonds of DNA. The exact nature of this phenomenon is not well
understood, and no theory currently exists to explain it. This report
summarizes the history of the controversy surrounding the microwave effect,
and the latest research results.
The effectiveness of microwaves for
sterilization has been well established by numerous studies over the
previous decades (Latimer 1977, Sanborn 1982, Brown 1978, Goldblith 1967).
The exact nature of the sterilization effect and whether it is due solely to
thermal effects or to the 'microwave effect' has been a matter of
controversy for decades.
The dielectric effect on polar molecules has
been known since 1912 (DeBye 1929). Polar molecules are those which possess
an uneven charge distribution and respond to an electromagnetic field by
rotating. The angular momentum developed by these molecules results in
friction with neighboring molecules and converts thereby to linear momentum,
the definition of heat in liquids and gases. Because the molecules are
forced to rotate first, there is a slight delay between the absorption of
microwave energy and the development of linear momentum, or heat. There are
some minor secondary effects of microwaves, including ionic conduction,
which are negligible in external heating. Microwave heating is, therefore,
not identical to external heating, at least at the molecular level, and the
existence of a microwave effect is not precluded simply because the
macroscopic heating effects of microwaves are indistinguishable from those
of external heating.
During the 1930s the effects of low frequency
electromagnetic waves on biological materials were studied in depth by
physicists, engineers and biologists. Studies of the effects of microwaves
on bacteria, viruses and DNA were performed in the 1960s and included
research on heating, biocidal effects, dielectric dispersion, mutagenic
effects and induced sonic resonance. Some of the early biophysicists
investigating microwave absorption claimed evidence of a 'microwave effect'
which was distinct in its biocidal effects from the effects of external
heating (Barnes 1977, Cope 1976, Furia 1986). Most biologists in turn
claimed there was no evidence of a microwave effect and that the biocidal
effects of microwaves were either due entirely to heating or were
indistinguishable from external heating (Goldblith 1967, Lechowich 1969,
Vela 1978, Jeng 1987, Fujikawa 1991, Welt 1994). These experiments were
repeated with increased sophistication right up to the present with the
majority consensus being that the microwave effect did not exist.
These experiments typically fell into two
categories, 'controlled temperature' experiments and 'dry' experiments. In
the controlled temperature experiments the researchers controlled the
temperature of the irradiated specimen through various timing, pulsing or
cooling techniques (Welt 1994, Lechowich 1968).
For example, Welt (1994) investigated the
effects of microwave irradiation on Clostridium spores and found no
additional lethality caused by microwaves that could not be accounted for by
conventional heating. However, spores may not be representative of microwave
irradiation effects on active growing bacterial cells. The results of this
and other experiments showed that controlling the temperature prevented
biocidal effects, and this was taken as conclusive evidence that the
microwave effect did not exist. However, the assumption that the microwave
effect is independent of, and separable from, temperature was always
implicit in these studies, but was never acknowledged.
The second type of experiment, the dry
experiment, also contains unacknowledged assumptions. Studies have shown
that in the absence of water or moisture, biocidal effects of microwaves are
severely diminished, or require considerably longer exposures (Jeng 1987,
Vela 1979). This was typically taken as evidence that nonthermal microwave
effects did not exist, however, since water is the primary medium by which
microwaves are converted to heat, the absence of biocidal effects in the
absence of water would only indicate that water is necessary for
sterilization whether or not heating is the cause. Furthermore, the
possibility that the specific frequency used, 2450 MHz, only affects water
and not bacteria or spores was overlooked. DNA has a dielectric dispersion,
where microwaves are readily absorbed, at much lower frequencies than water
(Takashima 1984). The experiments may simply be indicating that the wrong
frequency is being used for targeting 'dry' bacteria and spores.
Most of the studies mentioned above concluded
that the microwave effect, if it existed, was indistinguishable from the
effects of external heating. However, it was recently demonstrated (Kakita
1995) that the microwave effect is distinguishable from external heating by
the fact that it is capable of extensively fragmenting viral DNA, something
that heating to the same temperature did not accomplish. This experiment
consisted of irradiating a bacteriophage PL-1 culture at 2450 MHz and
comparing this with a separate culture heated to the same temperature.
The DNA was mostly destroyed, a result that does not occur from heating
alone. These photos are borrowed from Kakita et al (1995), permission
pending.
In the Kakita experiment the survival
percentage was approximately the same whether the samples were heated or
irradiated with microwaves, but evaluation by electrophoresis and electron
microscopy showed that the DNA of the microwaved samples had mostly
disappeared. In spite of the evolving complexity of all the previous
experiments, electrophoresis had not been used to compare irradiated and
externally heated samples prior to this. Electron microscopy had been used
to study the bacteriocidal effects of microwaves (Rosaspina 1993, 1994) and
these results also showed that microwaves had effects that were
distinguishable from those of external heating.
The energy level of a microwave photon is
only 10-5 eV, whereas the energy required to break a covalent bond is 10 eV,
or a million times greater. Based on this fact, it has been stated in the
literature that "microwaves are incapable of breaking the covalent bonds of
DNA" (Fujikawa 1992, Jeng 1987), but this has apparently occurred in the
Kakita experiment, even though this may be only an indirect effect of the
microwaves.
There is, in fact, plenty of evidence to
indicate that there are alternate mechanisms for causing DNA covalent bond
breakage without invoking the energy levels of ionizing radiation (Watanabe
1985, 1989, Ishibashi 1982, Kakita 1995, Kashige 1995, Kashige 1990, 1994).
Still, no theory currently exists to explain the phenomenon of DNA
fragmentation by microwaves although research is ongoing which may elucidate
the mechanism (Watanabe 1996).
The results of microwave irradiation affected
two bacteria, S. aureus and E. coli. The death curves exhibited classic
exponential decay with ab appararent shoulder, as well as a possible second
stage. These curves are based on data from Kakita etal (1999).
The microwave frequency used in the Kakita
study was the standard 2450 MHz used in conventional microwave ovens. This
is the same frequency that was used in essentially all prior studies, except
for the earliest studies (which looked at lower frequencies), and sonic
resonant studies, which looked at much higher frequencies. The early studies
showed that DNA tended to absorb microwave radiation "in the kilocycle
range" (Takashima 1963, 1966, Grant 1978, Grandolfo 1983), but no biocidal
effects in the range of 1 MHz to 60 MHz were observed.
One notable exception, however, was an early
experiment which found that frequencies between 11 and 350 MHz had lethal
effects on bacteria, with a peak at 60 MHz (Fleming 1944). As far as could
be determined, the contradiction between the results of Fleming and those of
Takashima has never been resolved or re-addressed. In any event, there is no
evidence in these studies to indicate any undue attention was paid to
control the actual absorbed dose or the precise geometry of the irradiation
cell, and therefore the differences in the results of these investigators
may reflect differences in their cell geometries, among other things.
In summary, it would seem there
is reason to believe that the microwave effect does indeed exist, even if it
cannot yet be adequately explained. What we know at present is somewhat
limited, but there may be enough information already available to form a
viable hypothesis. The possibility that electromagnetic radiation in the
non-ionizing frequency range can cause genetic damage may have profound
implications on the current controversy involving EM antennae, power lines,
and cell phones.
A Theory of Microwave Induced
DNA Covalent Bond Breakage A review of the data from the various referenced
experiments shows a common pattern -- for the first few minutes of
irradiation there is no pronounced effect, and then a cascade of microbial
destruction occurs. The data pattern greatly resembles the dynamics of a
capacitor; first there is an accumulation of energy, and then a catastrophic
release. It may simply indicate a threshhold temperature has been reached,
or it may indicate a two-stage process is at work.
The second stage of this process may very
well be the accumulation of oxygen radicals, which would certainly seem to
be primary suspects as they have a considerable propensity for dissociating
the covalent bonds of DNA. Oxygen radicals can be generated by the
disruption of a hydrogen bond on a water molecule. Water molecules exist
alongside DNA molecules as "bound" water, two or three layers thick. These
water molecules share a hydrogen bond with component atoms of the DNA
backbone, including carbon, nitrogen and other oxygen atoms. At any given
point in time one of the hydrogen atoms may be primarilly bonded to either
an oxygen atom on the water molecule, or to an oxygen (or other) atom on the
DNA backbone.
The fluctuating character of these shared and
exchanged bonds is enhanced by temperature and by the dynamics induced by
microwaves. Although the amount of oxygen radicals which may be produced by
this process cannot presently be determined, the production of some number
of oxygen radicals is inevitable in these circumstances. It must be noted
here though, that most of the oxygen radicals produced in this manner would
exist only briefly, as they would almost immediately bond to the nearest
available site. If this site is an oxygen atom on the DNA backbone, we get a
covalent bond break, albeit probably only a brief one. Although DNA tends to
repair itself naturally, the simultaneous breakage of a sufficient number of
covalent bonds would lead to a catastrophic failure of the entire DNA
molecule.
Due to the exceedingly large number of bonds
involved, the matter boils down to a reproducible function of pure
probabilities. In other words, after a set and reproducible amount of time
determined by probability functions, you would expect to see DNA
disintegration. And so, what we have is a two-stage process of DNA covalent
bond breakage resulting from oxygen radicals generated by microwave
irradiation. This is one theory, and it awaits experimental verification.
An alternate theory comes from investigators
at Fukuoka University in Japan. In a series of studies not specifically
involving microwaves, these investigators established that certain ions can
stimulate DNA breakage and OH radical production (Kashige eta al 1990,
Kashige et al 1994). They also determined that amino sugars and derivatives
could induce DNA strand breakage (Kashige et al 1991). It is possible that
microwaves may be causing generation of cupric ions and hydroxyl radicals,
and that auto-oxidation of aminosugars in solution are involved in DNA
strand breakage (Watanabe et al 1990, Watanabe et al 1986). The link between
microwaves and these secondary products remains to be established.
-
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