Final
Work, Assembly & Research; Geet Duggal
Page 1
Page 2
Effects of Low Level Radiation on Genetics Material
Foreward
Site 1- Neurological Effects
Blood Brain Barrier
Standards
Flourescein
Electrophysiology
EEG
Cytogenetics
Site 2 - A General Picture
Inconclusive
Standards
Government
Conclusions
Foreward
As with the last research, I have
gone through various sites and read through a lot of them. I have copied and
pasted information relavent information at this point. In between the itallic
print, there is little side notes by me. This time, I decided to focus more on
finding specific theoretical incidences/statistics to support long-term
electromagnetic effects on genetic and other finer biological material.
Site 1: Neurological Effects;
http://www.mapcruzin.com/radiofrequency/henry_lai1.htm
On the other hand, since a
relatively constant amount of body tissue is exposed, cumulative effect could
occur and lead to an eventual breakdown of homeostasis and adverse health
consequences. Data from some of the experiments described below do suggest that
RFR effects are cumulative over time.
The key here, is cumulative over
time. That and the fact that the data obtained is very theoretical and only
speculatve at this point.
Blood-Brain-Barrier
The blood-brain-barrier is a
biological barrier surrounding the brain. It blocks the entry of certain, and
possibly harmful, molecules in the general blood circulation from entering the
central nervous system. Studies on the effects of RFR on the blood-brain-barrier
were performed on animals in vivo, and SARs, if reported, are mostly given as
average whole body SAR. Local SARs at the surface of the brain, where the
blood-brain-barrier is located, were usually not known.
With regard to the intensity of
exposure, the conclusion from most of the studies is that a high intensity of
RFR is required to alter the permeability of the blood-brain-barrier.
Significant changes in brain or body temperature seem to be a necessary
condition for the effect to occur. For example, Chang et al. [4] studied in the
dog the penetration of 131I-labeled albumin into the brain. The head of the dog
was irradiated with 1000-MHz continuous-wave RFR at 2, 4, 10, 30, 50, or 200 mW/cm2.
At 30 mW/cm2, 4 of the 11 dogs studied showed a significant increase in albumin
penetration compared to that of sham-exposed animals, whereas no significant
difference was seen at the other power densities. Lin and Lin [5] reported no
significant change in the permeability of sodium fluorescein and Evan's blue
into the brain of rats with focal exposure at the head for 20 min to pulsed
2450-MHz RFR at 0.5-1000 mW/cm2 (local SARs 0.04-80 W/kg), but an increase was
reported [6] after similar exposure of the head at an SAR of 240 W/kg, which
increased the brain temperature to 43 oC. In another study, Goldman et al. [7]
used 86Rb as a tracer to study the permeability of the blood-brain-barrier in
the rat after 5, 10, or 20 min of exposure to 2450-MHz pulsed RFR at an average
power density of 3 W/cm2 (SAR 240 W/kg) on the left side of the head. Brain
temperature of the animals was increased to 43 oC by the radiation. Increases in
86Rb uptake in various regions in the left hemisphere of the brain were
observed. That increase in brain temperature played a critical role in the
effect of RFR on the permeability of the blood-brain-barrier was further
supported in an experiment by Neilly and Lin [8], in which they found that
ethanol infusion could attenuate RFR-induced increase in penetration of Even's
blue into the rat brain. Ethanol reduced RFR-induced increase in brain
temperature.
So from the above text and its
sourroundings in the article, the key points I got out of it was the fact that
only fairly intense radiation (that above 30 mw/sq cm) which is far greater than
the 1.2 mW/sq cm that a cellular phone outputs. (see subsite)
Subsite 1:
http://www.mcw.edu/gcrc/cop/cell-phone-health-FAQ/toc.html
These radiofrequency standards are expressed in "plane wave power density",
which is measured in mW/cm-sq (milliwatts per square
centimeter) [8, 169]. For PCS (about 1800-2000 MHz) antennas, the 1992 ANSI/IEEE
exposure standard for the general public is 1.2
mW/cm-sq. For analog mobile phones (about 900 MHz), the ANSI/IEEE exposure
standard for the general public is 0.57 mW/cm-sq [9]. The
ICNIRP standards are slightly lower and the NCRP standards are essentially
identical [10].
Another key point is the relation
between radiation intensity and brain temperature level. As expected, there is,
for the most part, a direct proportionality for middle values.
Even though most studies
indicate that changes in brain-brain-barrier occurs only after exposure to RFR
of high intensities with significant increase in tissue temperature, several
studies have reported increases in permeability after exposure to RFR of
relatively low intensities. Frey et al. [18] reported an increase in fluorescein
in brain slices of rats injected with the dye and exposed for 30 min to
continuous-wave 1200-MHz RFR (2.4 mW/cm2, SAR 1.0 W/kg) as compared with control
animals.
OK, so there is evidence (still
greater than the typical cell phone intensity) that lower levels of radiation
have an effect. But an increase in flouroscien levels means absolutly nothing to
me at this point. I need to look up what flouroscien levels in the brain
actually mean.
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Subsite 2:
http://www.emory.edu/COLLEGE/NBB/students/projects.html
I have been doing research in
the department of ophthalmology, under the direction of Henry Edelhauser, Ph.D.
I have been investigating the effects of intraocular pressure on the
permeability of human sclera to certain drugs, namely, rhodamine 6G (from
solution and on a coil), dexamethasone-fluorescein, and methotrexate-fluorescein.
Understanding how drugs permeate the sclera will provide avenues for treatment
of certain diseases of the posterior eye, and could be applicable to neuroactive
compounds as well. These investigations involve the use of perfusion apparatus
which simulates an intraocular pressure by perfusing BSS (balanced salt
solution) on the uveal side of the sclera. The drugs are placed on the
extraocular side of the sclera and allowed to permeate for up to 21 hours. This
data has allowed a constant(K Trans) to be calculated for each of the drugs, as
a measure of its ability to cross the sclera.
Easily said, there is evidince from
this and other stuff I've seen on the net that greater flouroscien actually
increases permeability to the sclera, which in this case (kinda funny) is a good
thing because certain drugs can be induced for treatment! I'm sure (but haven't
quite researched it yet) that this increased permability also opens itself to
more dangerous conditions.
Frankly, the rest of the section is
basically using more examples to state the same idea that only more intense
radiations actually have a significant difference. Note that this never really
hit into long-term type effects.
Neural Electrophysiology
Exposure of neural tissue to
RFR can conceivably cause electrophysiological changes in the nervous system.
Changes in neuronal electrophysiology, evoked potentials, and EEG have been
reported. Again, the possible involvement of of RFR-induced tissue heating
cannot be ruled out in some of the experiments. However, some effects were
observed at low intensities and after repeated exposure suggesting cumulative
effect. Chou and Guy [34] exposed temperature-controlled samples of isolated
frog sciatic nerves, cat saphenous nerve, and rabbit vagus nerve to 2450-MHz RFR.
They reported no significant change in the characteristics of the compound
action potentials in their samples during exposure to either continuous-wave (SARs
0.3-1500 W/kg) or pulsed (peak SARs 0.3-220 W/kg) radiation. Thus, no direct
field stimulation of neural activity was observed.
Same idea, small intensities don't
induce stimulation of neural activity.
Several studies reported
changes in EEG after prolonged repeated exposure to RFR. In some of these
studies, RFR of relatively low power densities was used. Dumansky and Shandala
[44] reported in the rat and rabbit that changes in EEG rhythm occurred after
chronic RFR exposure (120 days, 8 hr/day) using a range of power densities. The
researchers interpreted their results as an initial increase in excitability of
the brain after RFR exposure followed by inhibition (cortical synchronization
and slow wave) after prolonged exposure. Shandala et al. [45] exposed rabbits to
2375-MHz RFR (0.01-0.5 mW/cm2) 7 h/day for 3 months. A pitfall of this study is
that metallic electrodes were implanted in various regions of the brain (both
subcortical and cortical areas) for electrical recording during the exposure
period and post exposure. Metallic electrodes can interfere with the RFR fields.
After 1 month of exposure at 0.1 mW/cm2, they observed in the sensory/motor and
visual cortex an increase in alpha rhythm, an EEG pattern indicative of relaxed
and resting states of an animal. An increase in activity in the thalamus and
hypothalamus was also observed later. Similar effects were also seen in animals
exposed to the RFR at 0.05 mW/cm2; however, rats exposed to a power density of
0.5 mW/cm2 showed an increase in delta waves of high amplitude in the cerebral
cortex after 2 weeks of exposure, suggesting a suppressive effect on EEG
activity.
OK, some good evidence for
longer-term cell phone usage to actually make a difference. But the question is
what kind of difference? There is conclusive evidence for suppressive effects on
EEG activity, but what does that mean?
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Subsite 3:
http://www.crhsc.umontreal.ca/dreams/zinfo.htm
An electroencephalogram (EEG) is a visible record of the amplified
electrical activity generated by neurons in the brain. The word EEG as ancient
Greek roots and means: electro = electrical, encephalo = brain, and gram(ma) =
picture.
So I didn't include more details
about EEG that were givin in the website, but the main idea is that suppressed
EEG activity means your neurons are, in general, less electrically active (for
example, high activity is commonly associated with the REM stage of sleeping
where the most vivid dreams occur). So although I won't go into detailed
biological ramifications, basically, suppressed EEG values can be interpreted as
a not-so-good thing. The evidince above is really the only real evidence I've
seen so far in strong support for prolonged cell phone usage.
A good point to bring up is the
fact that this is not very related to humans. All of these experiments are
laboratory experiments, on other species. The upshot of this is the fact that
these data might not translate into bad things for humans, even though the
thought is they will.
(For further information on EEGs
and Electrophysiology refer to Diagnositic EM)
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Cytogenetic Effects
Recently, several studies have
reported cytogenetic changes in brain cells by RFR, and these results could have
important indication on the health effects of RFR. Singh et al. [90] reported
significant decreases in poly-ADP-ribosylation, a process involved in chromatin
functions, in the brain of rats after sixty days of exposure to 2450-MHz RFR (1
mW/cm2). Sarkar et al. [91] reported changes in DNA sequences in mouse brain
cells after exposure to RFR (1 mW/cm2, 2 hr/day for 120, 150, and 200 days). Lai
and Singh [92] reported an increase in single strand DNA breaks in brain cells
of rats after 2 hours of exposure to 2450-MHz RFR (whole body SAR 0.6 and 1.2
W/kg). Genetic damages to glial cells can result in carcinogenesis.
OK, good, there is some more
longer-term low-level exposure evidence. This time, it hits even more of what I
want to cover, which is genetic and other lower level biological effects.
However, since neurons do not
undergo mitosis, a more likely consequence of neuronal genetic damage is changes
in functions and cell death, which could either lead to or accelerate the
development of neurodegenerative diseases. We have recently reported [93] an
increase in DNA double strand breaks in brain cells of rats after acute exposure
to RFR. Double strand breaks, if not probably repaired, is known to lead to cell
death. Indeed, we have observed an increase in apoptosis (scheduled cell death)
in cells exposed to RFR (unpublished results).
So relating back to last time's research, the explanation for this increase in
apoptosis can be linked "electromagnetically" (oh God, terrible joke) to the
Lorentz Effect. So I'm piecing together some things here. The only real studied
theoretical explanation for genetic damage that I've found so far is the Lorentz
Effect I described last time. Now, we have specific evidence on DNA molecules of
the celular results of this.
6.00 radicals also play an
important role in aging processes, which have been ascribed to be a consequence
of accumulated oxidative damage to body tissues [98, 99], and involvement of
6.00 radicals in neurodegenerative diseases, such as Alzheimer's, Huntington,
and Parkinson, has also been suggested [100,101]. Furthermore, the effect of
6.00 radicals could depend on the nutritional status of an individual, e.g.,
availability of dietary antioxidants [102], consumption of alcohol [103], and
amount of food consumption [104]. Various life conditions, such as psychological
stress [105] and strenuous physical exercise [106], have been shown to increase
oxidative stress and enhance the effect of 6.00 radicals in the body. Thus, one
can also speculate that some individuals may be more susceptible to the effects
of RFR exposure.
The above, of course, is just some
additional information, the end of it which is not quite tested yet.
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Site 2:
http://infoventures.com/emf/federal/ota/ot95-11c.html
This site is particularly good at giving a good picture. Which is nice to know.
I've seen a lot of other sites with similar information to what I've already
stated (but in various, weird ways).
Research Is Inconclusive
While considerable research has
been conducted on the effects of electromagnetic fields generally, very little
work has yet been done on the possible health effects of exposures in the
specific frequency and intensity ranges generated by wireless communications
devices and systems. A particular weakness in the existing literature is the
lack of research on the impact of long-term exposures.
There are two fundamental
issues concerning radio-frequency electromagnetic radiation and human exposure.
The most obvious is the thermal or heating effect of such radiation on tissue.
It is well known that high-power radio waves will generate heat in exposed
tissues. Microwave ovens, high- powered radars, and other high-power microwave
devices, for example, radiate energy--a small portion of which is absorbed by
body tissues. The rate at which this energy is absorbed is called the specific
absorption rate (SAR). Absorbed energy raises the temperature of the tissues
through the excitation of water molecules (the typical microwave oven operates
at about 600 watts at 2450 MHz). The higher the power level the more heat is
generated at a given distance for a given sample, and the higher the frequency,
the more of the incident energy is superficially absorbed.
The thermal effects of radio
communication devices are generally not considered harmful. Wireless devices are
required to comply with well- established standards governing human exposure to
electromagnetic radiation. These standards incorporates a substantial safety
factor as a cushion against unanticipated effects or exposure in unusual
situations. As a result, researchers have been unable to measure heating of
tissue at the low power levels used by hand-held cellular telephones. Microwaves
do not penetrate metal, so shielding against them is fairly straightforward. In
addition, power densities decline rapidly with distance from the source, so
exposure can be reduced by lowering the power level and maintaining proper
distances from operating antennas.
The second, and more
controversial, issue is the possibility that RF radiation may cause nonthermal
effects, including changes in genetic structure, the changes in the permeability
of cell membranes, and disturbances in cell metabolism. These nonthermal effects
theoretically could occur at lower power levels and under different modulation
schemes than would be necessary to generate thermal effects. Much research in
this area remains to be done, as government, industry and the academic
communities agree. While there is no evidence that low-power, high-frequency
radio signals cause cancer in cells, the possibility has been raised that such
low-power radio waves could stimulate the growth of cancerous or precancerous
cells, although early evidence is very weak (see box 11-1). Some preliminary
evidence of microwave effects on DNA has also been reported, but not yet confi
rmed
All self explanatory. Supports some
conclusions I made earlier!
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Exposure Standards Are Still Being
Debated
Disputes over biological and
health effects revolve around the continued acceptability of this standard as
new research is performed. (see footnote 15) As of spring 1995, the FCC was
still considering whether to adopt the C95.1-1992 standard for all devices
operating at microwave radio frequencies. Analog cellular telephones are
presently exempt from testing under FCC rules because of their low power levels.
However, the FCC indicated in 1994 that PCS phones would be subject to testing
and SAR level limitations unless their maximum power output was less than 0.1
watt and a 2.5 centimeter separation was maintained between the user and any
radiating structures. (see footnote 16) The standard has been endorsed by the
cellular industry and the FDA's Center for Devices and Radiological Health, but
EPA, the National Institute for Occupational Safety and Health and others have
objections. (see footnote 17)
The above paragraph really simply
highlights the debates. The other parts of the section pretty much talk about
the IEEE standards set now.
Government Initiatives
Skipping the section on research
activities (which is what a lot of my past stuff involved)...
The General Accounting Office
(GAO) completed a short study of research performed on the safety of analog
cellular telephones in November, 1994. The report notes that no one federal
regulatory agency in the United States has responsibility for wireless
communications device emissions; EPA has overall responsibility for advising the
government on EMF exposures, the FDA establishes standards for devices that emit
radiation, and the FCC approves wireless communications devices for use and
assures that their emission levels meet safety standards.
Just a quick overview of what
government organization does what :)
Conclusions and Further
research:
So now I think I have some decent
evidence to show the physical cause for teh E&M damage (first research...) and
now, the linked effects of that damage. A huge thing to get out of this is the
true infancy of the whole research situation. There aren't 50 theories to debate
upon, and there certainly isn't too much realistic long-term experimental
evidence, but nevertheless, the topic is important and actually could have a
very strong electromagnetic link (that could be brought up in future E&M courses
decades from now, eh?...taught to 5th graders by then, of course).
For future research. I plan on
simply going over this stuff, making sure there's no other major ideas out
there, and possible (I have some speculations of my own) bringing up some of my
own thoughts on the matter.
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Northwestern University Physics &
Astronomy Department - Phyx 135-2 (General Physics) -- Professor Donald Ellis (Student
Projects)
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