|
*
Studies Relevant to Wireless Communications and Data - The Story Of Ein
Hyam (Haifa, Israel) (13/10/02)
Tramčs per Klaus Rudolph (Citizens'
Initiative Omega)
An Overview of Radiofrequency/Microwave
Radiation Studies Relevant to Wireless Communications and Data International
Conference on Cell Tower Siting, Salzburg, Austria, June 7-8, 2000
by Cindy Sage, MA
Sage Associates
1225 Coast Village Road, Suite G
Santa Barbara, California 93108 USA
sage@silcom.com
for
Land Salzburg - Landessanitätsdirektion - Umweltmedizin
Federal State of Salzburg - Public Health Department. Environmental Health
Unit
Dr. med. Gerd Oberfeld, Postfach 527, A-5010 Salzburg, Austria
Introduction
Scientific certainty about the potential for health effects from low intensity
RF/MW radiation is not necessary for wise public health decision-making,
as long as research continues to identify what, if any, specific
exposure conditions may contribute to disease.
The basis for decision-making about a relationship between electromagnetic
fields radiofrequency and microwave radiation and adverse health effects
at low intensity exposures rests on two key areas. The first is
the "weight of the scientific evidence" pointing to a relationship
betweeen RF/MW and illness. The scientific evidence needs to be reported
to decision-makers in a format that is concise, understandable and accurate.
The second is definition of the basis on which the evidence is judged
to be sufficient to take interim or permanent public health steps to reduce
risk. Conclusive scientific evidence should not be implicitly
or explicitly set as the goal required before any action can be taken
to limit public exposure to RF/MW from wireless communications. Given
the potential for a very large world-wide public health impact if even
a small health risk is present, interim public health actions should
be proportionately triggered to the weight of scientific evidence as it
grows in support of adverse health effects at low-intensity exposure levels.
This paper summarizes key scientific papers reporting bioeffects and potentially
adverse health effects from exposure to RF/MW radiation. In the effort
to bring understandable scientific information on this subject to the
public and decision-makers, this paper provides text summaries of significant
articles and their relevant bioeffects, and also charts titled "Some
Reported Bioeffects from Radiofrequency and Microwave Radiation"
that may be used as overhead graphics in public presentations. The
intent of this paper is to provide information for public discussion to
guide decision-making about wireless communication devices and transmitting
facilities; and a future commitment to exclusive reliance on wireless
communication and data transmission.
Effectss on DNA
Lai and Singh (1995) first reported DNA strand breaks from microwave RFR
at low intensity levels. A dose-dependent increase in DNA single- and
double-strand breaks in brain cells exposed at 0.6 W/Kg and 1.2 W/Kg whole
body specific absorption rate (SAR) was found after two hours of exposure
to 2450 MHz RFR. Using the sensitive comet assay for DNA breakage
developed by NP Singh, it was reported that exposure to both continuous-wave
and pulsed RFR produced DNA damage. Published results appeared in two
peer-reviewed scientific journals: The International Journal of
Radiation Biology (1996;69-4:513-521) and Bioelectromagnetics (1995; 16:207-210)
A year later in 1998, Jerry Phillips et al reported DNA single-strand
DNA breaks exposed to cellular telephone frequencies 813.5 MHz and 836.5
MHz at low SAR (average 2.4 and 24 µW/g-1). Phillips used the same
comet assay techniques used by Lai and Singh. This assay is widely used
by researchers to detect DNA damage produced by ionizing radiation. Phillips
postulated that DNA-repair rates may be affected by exposure to RFR (Phillips
et al, 1998). Of related interest, Phillips reported that 60 Hz
ELF exposure caused a significant increase in DNA single-strand breaks
at 1 G in Molt-4 lymphoblastoid cells (Department of Energy Contractors
Conference, Tucson, Arizona, Abstract A-8, November 1998). He postulates
that ELF magnetic field exposure can affect both DNA damage and repair
processes, and lead to cell death (apoptosis).
Conventional wisdom has traditionally held that microwaves are not genotoxic
(directly damaging to the genome or DNA) unless high temperatures are
created (thermal effect of microwaves on genome).
Blank and Goodman (1997) postulate that the mechanism of EM signal transduction
in the cell membrane may be explained by direct interaction of electric
and magnetic fields with mobile charges within enzymes. Recent studies
on DNA show that large electron flows are possible within the stacked
base pairs of the double helix of DNA molecules. Therefore gene activation
by magnetic fields could be due to a direct interaction with moving electrons
within DNA. Electric fields as well as magnetic fields stimulate
gene transcription and both fields could interact with DNA directly.
Prior work on heat shock proteins by Goodman and Blank is referenced in
this paper showing that cellular reponse to EM fields is activation of
the same stress response system seen in heating, but at very much lower
energy than the response to heat shock (see Gene Transcription and Induction).
Chromosome Aberrations and Micronuclei
Garag-Vrhovac et al (1999) reported that exposure to microwave radiation
of only 10-20 µW/cm2 in workers chronically exposed to 1250-1350 MHz was
sufficient to cause an increase in micronuclei (an aberrent form of DNA).
Vijayalaxmi et al (1997, 1998) reported that the frequency of micronucleati
was increased in the peripheral blood and bone marrow of cancer-prone
mice chronically exposed to 2450 MHz microwave radiofrequency radiation.
The 1997 publication reported no significant increase in micronucleation;
the 1998 publication provided a correction in the calculations and found
a significant increase in micronucleation.
Maes et al (1993) exposed human peripheral blood lymphocytes to microwaves
at 2450 MHz. A marked increase in the frequency of chromosome aberrations
and micronuclei (the formation of abnormal chromosome fragments) was reported
at nonthermal levels. Chromosome aberrations increased with increasing
time exposure (a dose-response).
One type of damage seen (the creation of dicentric chromosomes) is considered
to be the "hallmark" of ionizing radiation exposure. These
results are consistent with results of microwave radiation damage at other
frequencies and power densities reported by other researchers (Leonard
et al, 1983; Garaj-Vrhovac et al, 1990, 1991; d'Ambrosio et al, 1992).
Maes et al (1995) reported that whole blood exposed to the radiating antenna
of a GSM base station showed increased chromosome aberrations when
placed within a distance of 5 cm or less with two hour exposures. Combined
effects of 954 MHz radiofrequency radiation and the chemical mutagen mitomycin
C were studied by the same authors using human lymphocytes. Blood
samples were exposed to AM radiation from a GSM base station at
an estimated SAR of 1.5 W/Kg. Microwave exposure enhanced the harmful
effect of the chemical mutagen and showed a clear increase in a form of
chromosome aberration (sister chromatid exchange). Single strand
DNA breaks were also reported.
Effects on ornithine decarboxylase (ODC)
Litovitz et al (1993, 1997a, 1997b) and Penafiel et al (1997) tested cells
for production of ornithine decarboxylase (ODC) which is an enzyme found
in rapidly growing tissues, particularly tumors. They report that
amplitude-modulated microwaves (but not FM or continuous wave) significantly
affect ODC activity in L929 cells at an SAR of about 2.5 W/Kg at 835 MHz
cellular telephone frequency. The effect was reported with several
types of amplitude modulation, including a TDMA cellular telephone.
The effect was notable at particular modulation frequencies from 16 Hz
to 65 Hz, but no effect was reported at 6 Hz or 600 Hz. Importantly, Litovitz
reported that no EMF-enhancement of ODC was observed if the field was
not constant in time over intervals of longer than 1-10 seconds.
If frequency was varied at intervals of 1 second or less, no enhancement
of ODC was reported.
Gene Transcription and Induction
Goswami et al (1999) report that proto-oncogene mRNA levels in fibroblast
cells exposed to cellular telephone frequency radiation show increased
expression of the Fos mRNA levels. Exposure to 835.62 MHz
(frequency modulated continuous wave) showed a 2-fold increase in Fos
mRNA levels that was statistically significant. The 847.74 MHz (code division
multiple access or CDMA) cellular telephone frequency exposure resulted
in a 40% and 90% increase in Fos mRNA that was also statistically
significant. These results indicate that specific genes (in this
case proto-oncogenes) may be affected by exposure to RFR signals from
cellular telephones.
Stress Response
Daniells et al (1998) found that nematodes respond to microwave radiation
with a stress response that can be assayed in the same fashion as for
stress related to heat and toxic chemicals. The nematode model for
measuring stress response induced by microwave radiation shows that lower
power levels induced larger stress responses (the opposite of a simple
heating effect). Microwave radiation caused measurable stress and
protein damage within cells (induction of hsp or heat shock protein) comparable
to damage from metal ions which are recognized to be toxic. The authors
conclude that clear biological effects of microwave radiation have been
demonstrated in terms of activation of cellular stress responses (hsp
gene induction).
DePomerai et all (2000) reported an increase in hsp or heatshock protein
equivalent to that produced with a 3 degree Centigrade rise in temperature
with low-level microwave irradiation at an SAR of only 0.001 W/Kg.
Non-thermal microwave radiation disruption of weak bonds that maintain
the active form of protein folding at 750 MHz continuous wave may increase
free radicals causing DNA damage and interfere with cell signaling that
controls cell growth.
Cellular Effects of Microwave Radiation
Calcium ion balance in living tissue is exquisitely important in the proper
function of cell communication, cell growth and other fundamental life
processes. Interactions of calcium at the cell membrane have been
identified as the first link in bioeffects from RFR. The seminal
work of W. Ross Adey and his research team, formerly at the Veterans Hospital
at Loma Linda, California has detailed much of the cascade of events by
which cellular processes are affected by RFR. Only selected work
is presented here, but the reader is referred to the extensive scientific
works and testimony on this topic (summarized in Adey, 1997).
Adey (1993) provides a comprehensive summary of microwave bioeffects at
the cellular level supporting the concept of athermal responses not mediated
by tissue heating. Amplitude-modulated or pulse-modulated microwave
exposure is a particular focus. Adey discusses the impact of free-radicals
in the brain and vascular systems and in the regulation of oxidative stress
diseases including Alzheimer's and Parkinson's disease, coronary heart
disease, aging and cancer. Microwave exposure at athermal levels
may act as a tumor promoter, leading to tumor formation in the absence
of other chemical promoters. He cautions that observed bioeffects
of low intensity microwave exposure require further investigation, particularly
for nonlinear, nonequilibrium cooperative processes.
Dutta et al (1989) reported that RFR caused changes in calcium ion efflux
from both bird and cat brain tissues, and from human neuroblastoma cells.
Significant calcium efflux was found at SAR values of 0.05 and 0.005 W/Kg
(a very low energy absorption rate) with RFR at 147 MHz when amplitude-modulated
at 16 Hz. Further, enhanced calcium efflux at 0.05 W/Kg peaked at 13-16
Hz and at the 57.5-60 Hz modulation ranges. According to the
authors "These results confirm that amplitude-modulated RFR can induce
responses in cells of nervous tissue origin from widely different animal
species, including humans. The results are also consistent with
the reports of similar findings in avian and feline brain tissues and
indicate the general nature of the phenomenon."
Immune System Cellular Effects
Fesenko et al (1999) reported that whole body microwave radiation of male
mice at a power density of 1 µW/cm2 caused a significant effect on the
immune system. Novoselova et al (1999) reported that five (5) hours
of irradiation with microwaves at 1 µW/cm2 stimulated the immune potential
of macrophages and T cells.
Lyle et al (1983) reported that exposure to sinusoidally amplitude-modulated
RFR at nonthermal levels can reduce immune function in cells. A
450 MHz radiofrequency field was modulated with a 60 Hz ELF field.
Tests showed that the unmodulated carrier wave of 450 MHz by itself
had no effect, and modulation frequencies of 40, 16 and 3 Hz had
progressively smaller effects than 60 Hz. Peak suppression of the
lymphocyte effectiveness (immune function effectiveness) was seen at 60
Hz modulation.
Veyret et al (1991) found that exposure to very low power, pulsed microwaves
significantly affects the immune system (either sharp increases or decreases
in immune response) at specific amplitude-modulated frequencies.
Pulsed microwaves at 9.4 GHz were amplitude-modulated at modulation frequencies
between 14 and 41 MHz and at power density of 30 µ/cm2, whole-body average
SAR of about 0.015 W/Kg. Importantly, in the absence of amplitude-
modulation, exposure to the microwave frequency alone did not affect immune
function. It was only with the addition of amplitude-modulation
that effects were seen.
Elekes (1996) found that the effect of amplitude-modulated RFR and continuous-
wave RFR induced moderate elevation of antibody production in male
mice (but not female mice). The carrier frequency was 2.45 GHz (which
is used in industry) with a modulation frequency of 50 Hz (which is similar
to the frequency of some mobile phone systems like TDMA and other ELF-modulated
mobile phone systems). Power density was 0.1 mW/cm2, which corresponds
to that allowed in the workplace for long-term exposure under Hungarian
standards. Exposure was short-term, and the authors remark that
the moderate increase in immune function may be related to the brevity
of exposure.
Blood-brain Barrier
The blood-brain barrier has a vital role in the body to exclude toxins
from the blood stream from reaching sensitive brain tissues. This
barrier is known to protect the brain from toxic or other harmful compounds.
It is selectively permeable, allowing some molecules like glucose to pass,
but restricting others. It has a dual role in preventing the brain
from damage, while stabilizing and optimizing the fluids surrounding the
brain.
Persson et al (1997) reported that pathological leakage of the blood-brain
barrier occurs with exposure to 915 MHz cell phone frequency with both
continuous wave (CW) and pulsed (PW) RF exposure. The impact is
worst at the lowest exposure levels (0.0004 W/Kg) and worse with continuous
wave as opposed to pulsed RF with a maximum effect at 8-50 Hz modulation.
55% of rats exposed to CW but not PW showed significant pathological changes
in blood-brain barrier integrity at higher SAR of 1/7-8.3 W/Kg.
Salford et al (1994) showed leakage through the blood-brain barrier (or
increased permeability) is caused by 915 MHz RFR. Both continuous wave
(CW) and pulsed microwave RFR have the ability to open up the blood-brain
barrier to leakage. Salford reported that the number of rats exposed to
SARs between 0.016 and 5 W/Kg which showed leakage of the blood-brain
barrier was 56 of 184 animals, compared to only 5 of 62 control animals.
Whether this constitutes a health hazard demands further investigation,
but the concept that the blood-brain barrier is clearly breached by both
types of low power microwave radiation is concerning. At least ten
other scientific papers cited in his reference list also show blood-brain
barrier effects of RFR.
Blood Pressure
Lu et al (1999) reported that exposure to ultrawide-band electromagnetic
pulses induced low blood pressure or hypotension in rats. Cardiovascular
functions were evaluated from 45 minutes to 4 weeks following exposure
to 0.121 W/Kg. A significant decrease in arterial blood pressure
(hypotension) was reported but heart rate was not altered.
The authors note the UWB radiation-induced hypotension was a robust, consistent
and persistent effect.
Reproductive Tract
Dasdag et al (199) reported that mice exposed to cell phone RFR transmissions
had significant changes in structure of their testis. With only 0.141
W/Kg intensity of exposure to both the speech mode and stand-by mode of
cell phone transmission, seminiferous tubules in the testes were shrunken
in diameter. Exposure was for one minute three times per hour for
two hours per day for one month. Histological changes were reported
in the testes of rats when the cell phone was in the speech transmission
mode, but not in the stand-by mode.
Cancer
From the genetic building blocks of life to the whole organism, ELF/RFR
has been demonstrated to produce bioeffects, which may be deleterious
to health. The basic functions of the body, which control proper
cell growth, cell proliferation, immune surveillance and toxin protection
is shown to be adversely affected, in many cases at environmental levels
of exposure. Cancer as a disease endpoint of RFR exposure has been studied
for two decades, and both animal and human studies point to a link between
exposure under some conditions and cancer. The major concern with
mobile telephone technology is its rapid growth around the world, putting
millions of users at potential risk, and the emerging evidence for brain
tumors.
Guy et al (1984) conducted studies for the US Air Force on rats in the
first major research specifically designed to approximate effects of microwaves
on human beings. Guy remarked there were more than 6000 articles
on the biological effects of RFR by 1984, but the question of low-level
exposure as a human health hazard was unanswered.
In historical perspective, this study provided the first and, to that
time, the best study of potential effects from long-term exposure to RFR.
John Mitchell (1992), Brooks Air Force Base Armstrong Laboratory, the
sponsor of the Guy et al rat study concluded "at our request, Bill
Guy took up this challenge and conducted a landmark long-term study that
was longer and better conceived and conducted than anything done previously
with RFR. To expose animals continuously for more than two years,
as envisioned by the experimental protocol, a whole new concept
of exposure facilities had to be created."
Objectives of the study were "in a population of experimental animals
throughout their natural lifetimes, to simulate the chronic exposure of
humans to 450 MHz RFR at an incident power density of 1 mW/cm2.
Our primary interest was to investigate possible cumulative effects on
general health and longevity." (USAFSAM-TR-85-64).
The first publication of the Guy rat study was in the 1985 US Air Force
USAFSAM-TR-85-64 report "Effects of long-term low-level radiofrequency
radiation exposure on rats". It reported a four-fold statistically
significant increase in primary malignancies.
Chou and Guy (1992) later reported the results of their 1984 cancer studies
on rats which found a four-fold statistically significant increase in
primary malignant tumors in the 1992 Biolelectromagnetics Journal honoring
Dr. Guy on his retirement. The article restated the 1984-85 finding
of increased cancer in rats with microwave exposure over the lifetime
of the animals. Exposure conditions involved SARs of 0.15
to 0.4 W/Kg of 2450 MHz pulsed microwave (square wave modulated at 8 Hz).
Note that the current standard for public exposure is 0.4 W/Kg SAR.
Although the Guy study urged immediate follow-up and verification studies,
no such studies were conducted for more than a decade.
Repacholi et al (1997) conducted mice studies using 900 MHz mobile phone
frequency radiation and found a statistically significant 2.4-fold increase
in lymphomas. Lymphoma risk was found to be significantly higher
in the exposed mice. He concluded that long-term intermittent exposure
to RFR can enhance the probability that mice will develop lymphomas.
It is noteworthy that the animals were exposed to normal cell phone frequency
RFR for only two one-half hour periods per day for eight months.
Current human use of mobile phones can exceed 2000 minutes per day for
business travelers.
A second study of mice and cancer conducted by Repacholi (Harris et al,
1998) with 50 Hz magnetic fields alone did not result in increased cancer
rates. The authors conclude that "in contrast, when Pim1 mice
were exposed to pulse-modulated radiofrequency fields (900 MHz), a highly
significant increase in lymphoma incidence from 22% to 43% occurred.
Perhaps the increased incidence of cancer that in some epidemiological
studies has been associated with residential proximity to high-current
power-distribution wiring results from exposure to high-frequency transients
rather than the primary 50/60 Hz magnetic fields. In our study, the magnetic
fields to which the mice were exposed were switched on and off in a manner
that minimized the production of
transients."
Hardell (1999) has reported increased risk of brain tumors in humans using
cellular telephones. The main type of brain tumors found to occur
were malignant glioblastomas and astrocytomas and non-malignant meningiomas
and acoustical neuromas. An increased risk (although statistically insignificant)
was found for malignant brain tumors on the same side of the head on which
the cell phone was used for analog cell phones. The increased risk
was 2.45-fold for right side use, and 2.40-fold for left side. GSM
users did not have adequate use over time for there to be adequate evaluation
of risk. No association between RFR and acoustical neuromas was
reported.
Adey (1996) found a slight protective effect of microwave mobile phone
exposure with respect to brain tumors in rats, where a reduced number
of the expected brain tumors resulted. The exposure was for NADC
(North American digital cellular) producing a TDMA signal at 836.55 MHz.
No brain tumor enhancing effect was found. Apparent "protective"
effects (fewer tumors) were discussed but did not reach statistical significance.
The authors conclude that TDMA field had no enhancing effect on incidence,
type or location of nervous system tumors, although some protective effect
may be possible and further research is warranted.
Brain Symptoms Reported Using Mobile Phones
Mild et al (1998) reported on a joint Swedish-Norwegian epidemiological
study of cases using both GSM digital and analogue mobile phones.
A statistically significant association between calling time/number of
calls per day and the prevalence of warmth behind/around the ear, headaches
and fatigue was reported. However, GSM digital phones were less
associated with these symptoms than analogue phones. The Swedish
data show that GSM users reported less headache and fatigue than for analogue
users. Warmth sensations were also reported lower among GSM users.
Mobile phone usage was tested in humans (Hocking, 1998) to investigate
whether normal use could result in immediate symptoms of the head and
neck. He reported that of 40 respondents, headaches with pain radiating
to the jaw, neck, shoulders or arm in a few respondents. A majority
reported that sensations of head pain started in less than five minutes
after commencing phone calls, and another 12 felt the sensation build
up as the day progressed. All could distinguish the headaches as
different in quality from typical headaches. Eleven cases reported transient
effects on vision such as blurring. Fifteen cases reported feelings
of nausea or dizziness or a "fuzziness" in the head, which made
thinking difficult. One case had long-standing tinnitus, but after
a prolonged mobile phone call developed deafness and vertigo lasting five
hours. Three cases transferred the mobile phone to a belt. One reported
pain in the area at nighttime and another felt a cold area over the place
it was worn on the hip. A third person reported pain similar to
injured muscles. Twenty eight cases reported symptoms using GSM
digital mobile phones and ten with analogue mobile phones. Of the former,
thirteen said they had used analogue phones without developing symptoms
felt with GSM digital phones. Twenty two said they used mobile phones
more than five times per day, and thirty four had changed their use of
mobile phones as a result of symptoms.
Neurological Effects (Nervous System)
Neurologic effects of RFR have been examined at several levels in living
organisms. At the ion and molecular levels there are many effects
reported and replicated at nonthermal levels. These effects include
calcium changes (essential cell communication and growth regulation),
neurotransmitters (chemicals that conduct nerve signals and control such
things as appetite, mood, behavior, drug responses, sleep, learning and
memory), behavioral (memory and learning impairment in rats and humans),
and on sleep disorders.
Lai (1994a) prepared a review of the literature on neurological effects
of RFR on the central nervous system. It provides a concise overview
of how the central nervous system (CNS) should normally work, and how
RFR has been reported to affect functions of the CNS. The nervous
system coordinates and controls an organism's response to the environment
through autonomic and voluntary muscular movements and neurohumoral functions.
Behavioral changes could be the most sensitive effects of RFR exposure.
The movement of calcium ions in brain tissue is changed by RFR.
Calcium ions control many brain and body functions including the release
and receptor function of neurotransmitters, and any change in their functioning
could significantly affect health.
Psychoactive Drugs
The action of psychoactive drugs depends on proper functioning of neurotransmitters.
RFR changes some neurotransmitter functions, which lead to changes in
the actions of psychoactive drugs. Lai reports that RFR alters pentobarbital-induced
narcosis and hypothermia at 0.6 W/Kg in rats. The nervous system becomes
more sensitive to convulsions induced by drugs like pentylenetetrazol.
RFR exposure makes the nervous system less susceptible to curare-like
drugs that are used in anesthesia to paralyze patients during surgery.
Antianxiety drugs like valium and librium may be potentiated in the body
with RFR exposure. Lai has postulated that the endogenous opioids
are activated by low-level RFR exposure (Lai, 1992, 1994b). This hypothesis
can explain increased alcohol consumption seen in rats during RFR exposure,
and the lessening of withdrawal symptoms in morphine-dependent rats. RFR-psychoactive
drug interactions can be selectively blocked by pretreating animals with
narcotic antagonists (i.e., compounds that block the actions of endogenous
opioids) before exposure to RFR, suggesting that the endogenous opioid
system is activated by RFR (Lai et al, 1986).
Serotonin
Serotonin activity is reported to be affected by RFR. Drugs which
cause a depletion of serotonin (like fenfluramine) by themselves cause
a severe and long-lasting depletion of serotonin together with RFR exposure
(Panksepp, 1973 in Lai, 1994). Lai (1984) reported that hyperthermic effects
of RFR could be blocked by pre-treatment by serotonin antagonists suggesting
that the hyperthermia was caused by activation of serotonergic activity
by RFR. Drugs which decrease serotonin activity in the brain are
shown to suppress aggressive behavior (Panksepp et al, 1973 in Lai, 1994).
Serotonin-related functions include sleep, learning, regulation of hormone
secretion, autonomic functions, responses to stress and motor functions
(Lai et al, 1984). In humans, a cluster of symptoms called serotonin-irritation
syndromes include anxiety, flushing, headache and migraine headache and
hyperperistalsis which are related to hyperserotonergic states (Lai
et al, 1984). Further work to define the relationship between RFR
and serotonin has not taken place.
Eye Damage
Drugs can also enhance the adverse effect of RFR on the eyes. Kues
et al (1992) reported that a drug treatment used for glaucoma could worsen
the effect of RFR on corneal eye damage.
Behavioral Changes
Seamans et al (1999) reported that hyperactivity in mice that was induced
by drugs was counteracted by exposure to ultrawide-band (UWB) pulsed exposure.
The authors indicate the effect may be related to an increase in nitric
oxide (NO) production by NOS induced by UWB exposure. The action,
or actions of UWB pulses appears to be more effective on locomotor activity
than on thermal nociception.
Behavioral changes due to RFR are reported in many scientific studies
(D'Andrea, 1999). The performance disruption paradigm that is based
acceptable levels of RFR on thermal limits does not take into account
reports of microwave effects on cognitive performance. D'Andrea
(1999) discusses that "it is likely that effects on cognitive performance
may occur at lower SARs than those required for elicitation of behavioral
thermoregulation at levels that totally disrupt ongoing behaviors".
Further, "the current literature on heat stress does not provide
data or models that predict the behavioral effects of microwave absorption
at low SAR levels". Finally, he notes that "the whole-body
and partial-body absorption of microwaves (hotspots) is unique at each
frequency in the range of 10 MHz to 100 GHz". Hotspots vary
dramatically with RFR frequency, shape and size of the mammal and the
animal's orientation in the field (D'Andrea, 1999). Performance
of cognitively mediated tasks may be disrupted at levels of exposure lower
than that required to behavioral changes due to thermal effects of RFR
exposure. "Unlike the disruption of performance of a simple
task, a disruption of cognitive functions could lead to profound errors
in judgment due to alteration of perception, disruption of memory processes,
attention, and/or learning ability, resulting in modified but not totally
disrupted behavior." (D'Andrea, 1999).
Nervous and behavioral effects of RFR on humans have been reported for
five decades. Silverman (1973) is an early reviewer of health effects
linked to microwave exposure. She recounts that "the little
experimental work that has been done on man has pointed towards possible
alterations of the sensitivity of various sense organs, particularly auditory
and olfactory threshold changes. There have been numerous case reports,
rumors and speculations about the role of microwave radiation in a variety
of disorders of the brain and nervous system, such as a causitive role
in severe neurotic syndrome, astrocytoma of the brain, and a protective
role in multiple sclerosis. In the main, however, the nervous and
behavioral effects attributed to microwave irradiation at issue are those
found in clinical studies of groups occupationally exposed to various
intensities and frequencies of microwaves for variable but generally long
periods of time." She discusses nonthermal effects of low-dose,
long-term exposure in nine clinical studies of workers exposed to microwave-generating
equipment in Czechslovakia, Poland, the USSR and USA. All studies
show nervous system effects. Silverman notes that such published studies
"virtually ceased in the USA after the 1950's while considerable
investigation continued to be reported from the USSR and other eastern
European countries".
Raslear et al (1993) reported that significant effects on cognitive function
in rats were clearly observed with RFR exposure, particularly in the decision-making
process.
Learning and Memory
Lai et al (1994) found that rats exposed for 45 minutes to 2450 MHz RFR
at whole-body SAR of 0.6 W/Kg showed a learning deficit in the radial-arm
maze which is a behavioral task involving short-term spatial memory function.
In searching for the mechanisms for this deficit in learning and memory,
Lai found that a drug that enhances cholinergic activity in the brain
could block this microwave-induced learning deficit in the maze.
Cholinergic systems in the brain are well known to be involved in spatial
learning in the radial-arm maze (Lai et al, 1994).
Cognitive Functions
Koivisto et al (2000) reported that the attention function of the brain
and brain responses may be speeded up with exposure to 902 MHz cell phone
radiation. Cognitive function in 48 healthy humans was tested following
exposure to the cell phone radiation field. The results showed that
the exposure speeded up response times in simple reaction time and vigilance
tasks and that the cognitive time needed in a mental arithmetics task
was decreased. The authors suggest that the electromagnetic field
emitted by a cellular telephone may have a facilitatory effect on brain
function, expecially ub tasks requiring attention and manipulation of
information in working memory.
Krause (2000) reported on effects of RFR from cell phones does not alter
the resting EEG but modifys the brain responses significantly during a
memory task. At 0.3 to 0.44 W/Kg SAR, exposure to cell phone radiation
results in changes to cognitive thinking and mental tasks related to auditory
memory retrieval.
Preece (1999) reported that RFR at cell phone frequencies speeded the
rate at which humans responded to tasks (reaction time) but did not affect
memory. Students were exposed to both analog and GSM digital phone
signals for one half an hour, and then were tested for memory and speed
and accuracy on cognitive tests. The higher the power from the cell
phone signal, the faster the response time was reported, indicating the
cell phone signal is not biologically neutral but can affect the brain's
activity.
Sleep
Sleep disruption related to RFR has been reported in several scientific
studies. Mann et al (1996) reported that RFR similar to digital
mobile telephones reduced REM sleep in humans and altered the EEG (brain
wave) signal in humans during REM sleep. REM sleep is essential
for information processing in the brain, particularly with respect to
learning and memory functions. It is thought to be needed for selecting,
sorting and consolidating new experiences and information received during
the waking state, and linking them together with old experiences.
Borbely et al (1999) reported tha sleep patterns and EEG are changed with
900 MHz cell phone exposure during sleep. Alternating 15-minute
on-and off-intervals in RFR exposure produced a reduction in the
amount of waking after sleep onset from 18 to 12 minutes. The maximum
rise occurred in the 10-11 Hz and 13.6-14 Hz bands during the initial
part of sleep. The results demonstrate that cell phone radiofrequency
exposure may promote sleep and modify the sleep EEG.
Message from Cindy Sage, MA
The Story Of Ein Hyam
(Haifa, Israel) from a friend living in Israel
Three cellular companies want to operate 4 cellular towers, one near another
with three antennes on each tower, and very close to a neighbourhood,
in this neighbourhood there are already antennes near a kindergarden.
The people oppose that totally: Every time the cellular people worker
came, they attacked him, they blocked the street, they burnt the equipement.
Then the cellular people started coming in groups, because they were afraid
of these people. But they couldn't operate. Then the people burnt the
one transformator, and they cellular companies took away the generator
and put a garder near the other transformators. Many times these people
come to the city council and they block their meetings, making noise etc.
The cellular companies call all the time to the head of the fight and
BEG him. They said to him: you are a bully! So he said: And you are a
bully in the name of the law! You come to me with documents as the bully
of the law!! They also offered a bribe!!! But the people didn't want.
This determination and strength is something everybody can take example
from. They also took a lawyer.
The attitude of the Mayor- he doesn't care, he also told them it is completly
safe and that these are serious companies. He talks to them in a very
badly. The people are going to keep fighting. They also got a lecture
on the subject and they know many things about the dangers and the standards.
|
