Controversies
on Electromagnetic Fields in Neurobiology of Organisms
Journal
of Chemical Neuroanatomy
Special
issue edited by Suleyman Kaplan and Devra Davis
Volume
75, Part B, Pages 41-140 (September 2016)
Süleyman Kaplan, Devra Davis. Editorial.
Pages 41-42
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Highlights
•Microwave EMFs activate
voltage-gated Ca2+ channels (VGCCs) concentrated in the brain.
•Animal studies show such low
level MWV EMFs have diverse high impacts in the brain.
•VGCC activity causes widespread
neuropsychiatric effects in humans (genetic studies).
•26 studies have EMFs assoc. with
neuropsychiatric effects; 5 criteria show causality.
•MWV EMFs cause at least 13
neuropsychiatric effects including depression in humans.
Abstract
Non-thermal
microwave/lower frequency electromagnetic fields (EMFs) act via voltage-gated
calcium channel (VGCC) activation. Calcium channel blockers block EMF effects
and several types of additional evidence confirm this mechanism. Low intensity
microwave EMFs have been proposed to produce neuropsychiatric effects,
sometimes called microwave syndrome, and the focus of this review is whether
these are indeed well documented and consistent with the known mechanism(s) of
action of such EMFs. VGCCs occur in very high densities throughout the nervous
system and have near universal roles in release of neurotransmitters and
neuroendocrine hormones. Soviet and Western literature shows that much of the
impact of non-thermal microwave exposures in experimental animals occurs in the
brain and peripheral nervous system, such that nervous system histology and
function show diverse and substantial changes. These may be generated through
roles of VGCC activation, producing excessive neurotransmitter/neuroendocrine
release as well as oxidative/nitrosative stress and other responses. Excessive
VGCC activity has been shown from genetic polymorphism studies to have roles in
producing neuropsychiatric changes in humans. Two U.S. government reports from
the 1970s to 1980s provide evidence for many neuropsychiatric effects of
non-thermal microwave EMFs, based on occupational exposure studies. 18 more
recent epidemiological studies, provide substantial evidence that microwave
EMFs from cell/mobile phone base stations, excessive cell/mobile phone usage
and from wireless smart meters can each produce similar patterns of
neuropsychiatric effects, with several of these studies showing clear
dose–response relationships. Lesser evidence from 6 additional studies suggests
that short wave, radio station, occupational and digital TV antenna exposures
may produce similar neuropsychiatric effects. Among the more commonly reported
changes are sleep disturbance/insomnia, headache, depression/depressive
symptoms, fatigue/tiredness, dysesthesia, concentration/attention dysfunction,
memory changes, dizziness, irritability, loss of appetite/body weight,
restlessness/anxiety, nausea, skin burning/ tingling/ dermographism and EEG
changes. In summary, then, the mechanism of action of microwave EMFs, the role
of the VGCCs in the brain, the impact of non-thermal EMFs on the brain,
extensive epidemiological studies performed over the past 50 years, and five
criteria testing for causality, all collectively show that various non-thermal
microwave EMF exposures produce diverse neuropsychiatric effects.
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Suleyman Kaplan, Omur Gulsum
Deniz, Mehmet Emin Önger, Aysın Pınar Türkmen, Kıymet Kübra Yurt, Işınsu Aydın,
Berrin Zuhal Altunkaynak, Devra Davis. Electromagnetic
field and brain development. Review Article. Pages 52-61.
Highlights
•Side effects of electromagnetic
field.
•How electromagnetic field
affects the brain development?
•Experimental and clinical
studies about the electromagnetic field.
Abstract
Rapid advances in technology
involve increased exposures to radio-frequency/microwave radiation from mobile
phones and other wireless transmitting devices. As cell phones are held close
to the head during talking and often stored next to the reproductive organs,
studies are mostly focused on the brain. In fact, more research is especially
needed to investigate electromagnetic field (EMF)’s effects on the central
nervous system (CNS). Several studies clearly demonstrate that EMF emitted by
cell phones could affect a range of body systems and functions. Recent work has
demonstrated that EMF inhibit the formation and differentiation of neural stem
cells during embryonic development and also affect reproductive and
neurological health of adults that have undergone prenatal exposure. The aim of
this review is to discuss the developing CNS and explain potential impacts of
EMF on this system.
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Highlights
•Overview to different
frequencies of electromagnetic field radiation exposure.
•Possible side effects of
microwave radiation on the central nervous system.
•Qualitative and quantitative
analysis to reveal the effects of the electromagnetic field exposure.
Abstract
Microwave radiation (MWR) leads
to hazardous effects on he central nervous system (CNS) for both human and
animals. The widespread use of mobile phones has increased the risks of health
problems in the CNS caused by radiofrequency (RF) electromagnetic fields. To
determine these effects various methodological approaches related to
neuroscience such as stereology, immunohistochemistry, and electron microscopy
have been used. These approaches examine the effects on cells exposed to MWR at
the light microscopic and ultrastructural levels, and novel information is
obtained. The main aim of this paper is to discuss possible side effects of MWR
in the light of current literature with different methodological approaches.
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Highlights
•Possible effects of
electromagnetic field.
•How electromagnetic field
affects the peripheral nerve structure?
•Experimental and clinical
studies of nervous system on the electromagnetic field.
Abstract
Electromagnetic field (EMF) is a
pervasive environmental presence in modern society. In recent years, mobile
phone usage has increased rapidly throughout the world. As mobile phones are
generally held close to the head while talking, studies have mostly focused on
the central and peripheral nervous system. There is a need for further research
to ascertain the real effect of EMF exposure on the nervous system. Several
studies have clearly demonstrated that EMF emitted by cell phones could affect
the systems of the body as well as functions. However, the adverse effects of
EMF emitted by mobile phones on the peripheral nerves are still controversial.
Therefore, this review summarizes current knowledge on the possible positive or
negative effects of electromagnetic field on peripheral nerves.
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Highlights
•Description of electromagnetic
fields and evaluation of its possible effects on biological systems.
•The association between the
electromagnetic field and neurodegenerative diseases.
•Experimental and clinical
studies on the electromagnetic field.
Abstract
In the modern world, people are
exposed to electromagnetic fields (EMFs) as part of their daily lives; the
important question is “What is the effect of EMFs on human health?” Most
previous studies are epidemiological, and we still do not have concrete
evidence of EMF pathophysiology. Several factors may lead to chemical,
morphological, and electrical alterations in the nervous system in a direct or
indirect way. It is reported that non-ionizing EMFs have effects on animals and
cells. The changes they bring about in organic systems may cause oxidative
stress, which is essential for the neurophysiological process; it is associated
with increased oxidization in species, or a reduction in antioxidant defense
systems. Severe oxidative stress can cause imbalances in reactive oxygen
species, which may trigger neurodegeneration. This review aims to detail these
changes. Special attention is paid to the current data regarding EMFs’ effects
on neurological disease and associated symptoms, such as headache, sleep
disturbances, and fatigue.
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Abstract
Wireless communication such as
cellular telephones and other types of handheld phones working with frequencies
of 900 MHz, 1800 MHz, 2100 MHz, 2450 MHz have been increasing rapidly.
Therefore, public opinion concern about the potential human health hazards of
short and long-term effect of exposure to radiofrequency (RF) radiation.
Oxidative stress is a biochemical condition, which is defined by the imbalance
between reactive oxygen species (ROS) and the anti-oxidative defense. In this
review, we evaluated available in vitro and in vivo studies carried out on the
relation between RF emitted from mobile phones and oxidative stress. The
results of the studies we reviewed here indicated that mobile phones and
similar equipment or radars can be thought as a factor, which cause oxidative
stress. Even some of them claimed that oxidative stress originated from
radiofrequencies can be resulted with DNA damage. For this reason one of the
points to think on is relation between mobile phones and oxidative stress.
However, more performance is necessary especially on human exposure studies.
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Highlights
•The 2100 MHz radiofrequency
radiation and oxidative DNA damage in brain.
•The effects of duration and
tissue type to DNA damage.
Abstract
We aimed to evaluate the effect
of 2100 MHz radiofrequency radiation emitted by a generator, simulating a
3G-mobile phone on the brain of rats during 10 and 40 days of exposure. The
female rats were randomly divided into four groups. Group I; exposed to 3G
modulated 2100 MHz RFR signal for 6 h/day, 5 consecutive days/wk for 2 weeks,
group II; control 10 days, were kept in an inactive exposure set-up for 6
h/day, 5 consecutive days/wk for 2 weeks, group III; exposed to 3G modulated
2100 MHz RFR signal for 6 h/day, 5 consecutive days/wk for 8 weeks and group
IV; control 40 days, were kept in an inactive exposure set-up for 6 h/day, 5
consecutive days/wk for 8 weeks. After the genomic DNA content of brain was
extracted, oxidative DNA damage (8-hydroxy-2′deoxyguanosine, pg/mL) and
malondialdehyde (MDA, nmoL/g tissue) levels were determined. Our main finding
was the increased oxidative DNA damage to brain after 10 days of exposure with
the decreased oxidative DNA damage following 40 days of exposure compared to their
control groups. Besides decreased lipid peroxidation end product, MDA, was
observed after 40 days of exposure. The measured decreased quantities of damage
during the 40 days of exposure could be the means of adapted and increased DNA
repair mechanisms.
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İkinci, Tolga Mercantepe, Deniz
Unal, Hüseyin Serkan Erol, Arzu Şahin, Ali Aslan, Orhan Baş, Havva Erdem, Osman
Fikret Sönmez, Haydar Kaya, Ersan Odacı. Morphological
and antioxidant impairments in the spinal cord of male offspring rats following
exposure to a continuous 900 MHz electromagnetic field during early and
mid-adolescence. Pages 99-104.
Highlights
•Spinal cords of male rats were
investigated following exposure to 900 MHz EMF.
•Tissue malondialdehyde and
glutathione levels increased in the EMF group.
•Light microscopy revealed
atrophy in the spinal cord in the EMF group.
•TEM revealed invagination into
the axon in the EMF group.
•TEM revealed loss of myelin
sheath integrity in the EMF group.
Abstract
The effects of devices emitting
electromagnetic field (EMF) on human health have become the subject of intense
research among scientists due to the rapid increase in their use. Children and
adolescents are particularly attracted to the use of devices emitting EMF, such
as mobile phones. The aim of this study was therefore to investigate changes in
the spinal cords of male rat pups exposed to the effect of 900 MHz EMF. The
study began with 24 Sprague-Dawley male rats aged 3 weeks. Three groups
containing equal numbers of rats were established—control group (CG), sham
group (SG) and EMF group (EMFG). EMFG rats were placed inside an EMF cage every
day between postnatal days (PD) 21 and 46 and exposed to the effect of 900 MHz
EMF for 1 h. SG rats were kept in the EMF cage for 1 h without being exposed to
the effect of EMF. At the end of the study, the spinal cords in the upper
thoracic region of all rats were removed. Tissues were collected for
biochemistry, light microscopy (LM) and transmission electron microscopic (TEM)
examination. Biochemistry results revealed significantly increased
malondialdehyde and glutathione levels in EMFG compared to CG and SG, while SG
and EMFG catalase and superoxide dismutase levels were significantly higher
than those in CG. In EMFG, LM revealed atrophy in the spinal cord,
vacuolization, myelin thickening and irregularities in the perikarya. TEM
revealed marked loss of myelin sheath integrity and invagination into the axon
and broad vacuoles in axoplasm. The study results show that biochemical
alterations and pathological changes may occur in the spinal cords of male rats
following exposure to 900 MHz EMF for 1 h a day on PD 21–46.
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Highlights
•The female rat pup cerebellum
was investigated following prenatal 900 MHz EMF exposure.
•Total Purkinje cell numbers were
estimated following prenatal 900 MHz EMF exposure.
•Purkinje cell numbers were lower
in the EMF group compared to the control and sham groups.
•Pyknotic neurons with dark
cytoplasm were observed in the EMF group.
Abstract
Large numbers of people are
unknowingly exposed to electromagnetic fields (EMF) from wireless devices.
Evidence exists for altered cerebellar development in association with prenatal
exposure to EMF. However, insufficient information is still available regarding
the effects of exposure to 900 megahertz (MHz) EMF during the prenatal period
on subsequent postnatal cerebellar development. This study was planned to
investigate the 32-day-old female rat pup cerebellum following exposure to 900
MHz EMF during the prenatal period using stereological and histopathological
evaluation methods. Pregnant rats were divided into control, sham and EMF
groups. Pregnant EMF group (PEMFG) rats were exposed to 900 MHz EMF for 1 h
inside an EMF cage during days 13–21 of pregnancy. Pregnant sham group (PSG)
rats were also placed inside the EMF cage during days 13–21 of pregnancy for 1
h, but were not exposed to any EMF. No procedure was performed on the pregnant
control group (PCG) rats. Newborn control group (CG) rats were obtained from
the PCG mothers, newborn sham group (SG) rats from the PSG and newborn EMF
group (EMFG) rats from the PEMFG rats. The cerebellums of the newborn female
rats were extracted on postnatal day 32. The number of Purkinje cells was
estimated stereologically, and histopathological evaluations were also
performed on cerebellar sections. Total Purkinje cell numbers calculated using
stereological analysis were significantly lower in EMFG compared to CG (p <
0.05) and SG (p < 0.05). Additionally, some pathological changes such as
pyknotic neurons with dark cytoplasm were observed in EMFG sections under light
microscopy. In conclusion, our study results show that prenatal exposure to EMF
affects the development of Purkinje cells in the female rat cerebellum and that
the consequences of this pathological effect persist after the postnatal
period.
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Abstract
The objective of this study was
to evaluate the effects of cellular phone radiation on oxidative stress
parameters and oxide levels in mouse brain during pentylenetetrazole (PTZ)
induced epileptic seizure. Eight weeks old mice were used in the study. Animals
were distributed in the following groups: Group I: Control group treated with
PTZ, Group II: 15 min cellular phone radiation + PTZ treatment + 30 min
cellular phone radiation, Group III: 30 min cellular phone radiation + PTZ
treatment + 30 min cellular phone radiation. The RF radiation was produced by a
900 MHz cellular phone. Lipid peroxidation, which is the indicator of oxidative
stress was quantified by measuring the formation of thiobarbituric acid
reactive substances (TBARS). The glutathione (GSH) levels were determined by
the Ellman method. Tissue total nitric oxide (NOx) levels were obtained using
the Griess assay. Lipid peroxidation and NOx levels of brain tissue increased
significantly in group II and III compared to group I. On the contrary, GSH
levels were significantly lower in group II and III than group I. However, no
statistically significant alterations in any of the endpoints were noted
between group II and Group III. Overall, the experimental findings demonstrated
that cellular phone radiation may increase the oxidative damage and NOx level
during epileptic activity in mouse brain.
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Abstract
Wireless
internet (Wi-Fi) providers have become essential in our daily lives, as
wireless technology is evolving at a dizzying pace. Although there are
different frequency generators, one of the most commonly used Wi-Fi devices are
2.4 GHz frequency generators. These devices are heavily used in all areas of
life but the effect of radiofrequency (RF) radiation emission on users is
generally ignored. Yet, an increasing share of the public expresses concern on
this issue. Therefore, this study intends to respond to the growing public
concern. The purpose of this study is to reveal whether long term exposure of
2.4 GHz frequency RF radiation will cause DNA damage of different tissues such
as brain, kidney, liver, and skin tissue and testicular tissues of rats. The
study was conducted on 16 adult male Wistar–Albino rats. The rats in the
experimental group (n = 8) were exposed to 2.4 GHz frequency radiation for over
a year. The rats in the sham control group (n = 8) were subjected to the same
experimental conditions except the Wi-Fi generator was turned off. After the
exposure period was complete the possible DNA damage on the rat’s brain, liver,
kidney, skin, and testicular tissues was detected through the single cell gel
electrophoresis assay (comet) method. The amount of DNA damage was measured as
percentage tail DNA value. Based on the DNA damage results determined by the
single cell gel electrophoresis (Comet) method, it was found that the% tail DNA
values of the brain, kidney, liver, and skin tissues of the rats in the
experimental group increased more than those in the control group. The increase
of the DNA damage in all tissues was not significant (p > 0.05). However the
increase of the DNA damage in rat testes tissue was significant (p < 0.01).
In
conclusion, long-term exposure to 2.4 GHz RF radiation (Wi-Fi) does not cause
DNA damage of the organs investigated in this study except testes. The results
of this study indicated that testes are more sensitive organ to RF radiation.
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Highlights
•Exposure to the pulse modulated
radio-frequency radiation could lead to increase in the permeability of
blood–brain barrier.
•New researches are needed to
discuss the effects of radio-frequency radiation on children.
•Efforts have to be made to
understand the mechanisms of the interaction of radio-frequency radiation and
the central nervous system.
Abstract
With the increased use of mobile
phones, their biological and health effects have become more important. Usage
of mobile phones near the head increases the possibility of effects on brain
tissue. This study was designed to investigate the possible effects of pulse
modulated 900 MHz and 1800 MHz radio-frequency radiation on the permeability of
blood–brain barrier of rats. Study was performed with 6 groups of young adult
male and female wistar albino rats. The permeability of blood-brain barrier to
intravenously injected evans blue dye was quantitatively examined for both
control and radio-frequency radiarion exposed groups. For male groups; Evans
blue content in the whole brain was found to be 0.08 ± 0.01 mg% in the control,
0.13 ± 0.03 mg% in 900 MHz exposed and 0.26 ± 0.05 mg% in 1800 MHz exposed
animals. In both male radio-frequency radiation exposed groups, the
permeability of blood–brain barrier found to be increased with respect to the
controls (p < 0.01). 1800 MHz pulse modulated radio-frequency radiation
exposure was found more effective on the male animals (p < 0.01). For female
groups; dye contents in the whole brains were 0.14 ± 0.01 mg% in the control,
0.24 ± 0.03 mg% in 900 MHz exposed and 0.14 ± 0.02 mg% in 1800 MHz exposed animals.
No statistical variance found between the control and 1800 MHz exposed animals
(p > 0.01). However 900 MHz pulse modulated radio-frequency exposure was
found effective on the permeability of blood-brain barrier of female animals.
Results have shown that 20 min pulse modulated radio-frequency radiation
exposure of 900 MHz and 1800 MHz induces an effect and increases the
permeability of blood-brain barrier of male rats. For females, 900 MHz was
found effective and it could be concluded that this result may due to the
physiological differences between female and male animals. The results of this
study suggest that mobile phone radation could lead to increase the
permeability of blood-brain barrier under non-thermal exposure levels. More
studies are needed to demonstrate the mechanisms of that breakdown.
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Highlights
•Fetal exposure to mobile phone
radiation causes apoptosis and oxidative damage in brain.
Abstract
Adverse
health effects of radiofrequency radiation (RFR) on the ongoing developmental
stages of children from conception to childhood are scientifically anticipated
subject. This study was performed to identify the effects of global system for
mobile communications (GSM) modulated mobile phone like RFR in 1800 MHz
frequency on oxidative DNA damage and lipid peroxidation beside the apoptotic
cell formation, using histopathological and immunohistochemical methods in the
brain tissue of 1-month-old male and female New Zealand White rabbits that were
exposed to these fields at their mother's womb and after the birth. Oxidative DNA
damage and lipid peroxidation levels were investigated by measuring the
8-hydroxy-2′-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) levels,
respectively. Histopathological changes were observed using by hematoxylin and
eosin (HE) staining. Apoptotic cells were detected in the examined organs by
terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)
staining.
For both male and female infants;
8-OHdG levels increased in the group exposed to RFR in both intrauterine and
extrauterine periods compared to the infants that were never exposed to RFR and
the ones were exposed when they reached one month of age (p < 0.05). MDA
results were different for male and female rabbits. There was no difference
between all female infant groups (p > 0.05), while only intrauterine
exposure significantly causes MDA level increase for the male infants. HE
staining revealed mild lessions in neuronal necrobiosis in brain tissues of
female rabbits that had only intaruterine exposure and male rabbits had only
extrauterine exposure. Gliosis were mildly positive in brain tissues of rabbits
that are exposed only intrauterine period, also the group exposed both
intrauterine and extrauterine periods. However, there was no apoptotic change
detected by TUNEL staining in the brain tissues of all groups.
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Highlights
•Oxidative stress plays important
role in biology of Wi-Fi (2.45 GHz)
•2.45 GHz increased
oxidative stress in brain and liver pregnant rats and their newborns
•Brain seems sensitive to
oxidative injury in the development of newborns.
Abstract
An excessive
production of reactive oxygen substances (ROS) and reduced antioxidant defence
systems resulting from electromagnetic radiation (EMR) exposure may lead to
oxidative brain and liver damage and degradation of membranes during pregnancy
and development of rat pups. We aimed to investigate the effects of
Wi-Fi-induced EMR on the brain and liver antioxidant redox systems in the rat
during pregnancy and development.
Sixteen
pregnant rats and their 48 newborns were equally divided into control and EMR groups.
The EMR groups were exposed to 2.45 GHz EMR (1 h/day for 5 days/week) from
pregnancy to 3 weeks of age. Brain cortex and liver samples were taken from the
newborns between the first and third weeks. In the EMR groups, lipid
peroxidation levels in the brain and liver were increased following EMR
exposure; however, the glutathione peroxidase (GSH-Px) activity, and vitamin A,
vitamin E and β-carotene concentrations were decreased in the brain and liver.
Glutathione (GSH) and vitamin C concentrations in the brain were also lower in
the EMR groups than in the controls; however, their concentrations did not
change in the liver.
In
conclusion, Wi-Fi-induced oxidative stress in the brain and liver of developing
rats was the result of reduced GSH-Px, GSH and antioxidant vitamin
concentrations. Moreover, the brain seemed to be more sensitive to oxidative
injury compared to the liver in the development of newborns.