Systematic Derivation of Safety
Limits for Time-Varying 5G Radiofrequency Exposure Based on Analytical Models
and Thermal Dose
Neufeld E, Kuster N. Systematic Derivation of Safety Limits for Time-Varying 5G
Radiofrequency Exposure Based on Analytical Models and Thermal Dose. Health
Phys. 2018 Sep 21. doi: 10.1097/HP.0000000000000930.
Abstract
Extreme broadband wireless devices operating above 10 GHz may transmit data in
bursts of a few milliseconds to seconds. Even though the time- and
area-averaged power density values remain within the acceptable safety limits
for continuous exposure, these bursts may lead to short temperature spikes in
the skin of exposed people. In this paper, a novel analytical approach to
pulsed heating is developed and applied to assess the peak-to-average
temperature ratio as a function of the pulse fraction α (relative to the
averaging time [INCREMENT]T; it corresponds to the inverse of the
peak-to-average ratio). This has been analyzed for two different
perfusion-related thermal time constants (τ1 = 100 s and 500 s) corresponding
to plane-wave and localized exposures. To allow for peak temperatures that considerably
exceed the 1 K increase, the CEM43 tissue damage model, with an
experimental-data-based damage threshold for human skin of 600 min, is used to
allow large temperature oscillations that remain below the level at which
tissue damage occurs. To stay consistent with the current safety guidelines,
safety factors of 10 for occupational exposure and 50 for the general public
were applied. The model assumptions and limitations (e.g., employed thermal and
tissue damage models, homogeneous skin, consideration of localized exposure by
a modified time constant) are discussed in detail. The results demonstrate that
the maximum averaging time, based on the assumption of a thermal time constant
of 100 s, is 240 s if the maximum local temperature increase for continuous-wave
exposure is limited to 1 K and α ≥ 0.1. For a very low peak-to-average ratio of
100 (α ≥ 0.01), it decreases to only 30 s. The results also show that the
peak-to-average ratio of 1,000 tolerated by the International Council on
Non-Ionizing Radiation Protection guidelines may lead to permanent tissue
damage after even short exposures, highlighting the importance of revisiting
existing exposure guidelines.
--
Temperature Increase and Specific
Absorption Rate Distribution in Human Breast from Cell Phone Radiation
Kunter, FC, Gündüz C, Seker
SS. Temperature increase and Specific Absorption Rate distribution in
human breast from cell phone radiation.J Med Imaging Health Informatics.
8(6):1186-1191.
DOI: 10.1166/jmihi.2018.2418.
Aug 2018.
Abstract
This study describes the cell
phone
radiation
effect on the healthy and unhealthy female breast tissue to establish safety
criteria and to detect the cancerous tissue. A computational modeling is
performed at 900 MHz and 1800 MHz with a sphere shaped breast and cancerous
tissue in different configurations. Thermal investigation is performed through
the heat transfer equation to determine temperature and specific absorption
rate elevation in the female breast tissue. First, healthy breast tissue is
excited with an antenna of which distances to the breast is varying. Next, the
distribution of temperature and specific absorption rate are estimated on the
different radius of cancerous breast tissue which is located at the center and
at the bottom of the breast, respectively. The simulated temperature and the
specific absorption rate values imply that the values are ascending with the
size of the tumor whereas descending as the source is positioned further.
--
Personal
Exposure to RF EMF among Australian Adults
Zeleke BM, Brzozek C, Bhatt CR, Abramson MJ, Freudenstein F, Wiedemann P, Geza
Benke G. Personal Exposure to Radio Frequency Electromagnetic Fields among
Australian Adults. Published Oct 12, 2018 Int. J. Environ. Res. Public Health
2018, 15(10), 2234; https://doi.org/10.3390/ijerph15102234
(This article belongs to the Special Issue
Electric, Magnetic, and Electromagnetic Fields in Biology and Medicine: From
Mechanisms to Biomedical Applications)
Abstract
The measurement of personal exposure to radiofrequency
electromagnetic fields (RF-EMFs) is important for epidemiological studies.
RF-EMF exposure can be measured using personal exposimeters that register
RF-EMFs over a wide range of frequency bands. This study aimed to measure and
describe personal RF-EMF exposure levels from a wide range of frequency bands. Measurements
were recorded from 63 participants over an average of 27.4 (±4.5) hours. RF-EMF
exposure levels were computed for each frequency band, as well as from downlink
(RF from mobile phone base station), uplink (RF from mobile phone handsets),
broadcast, and Wi-Fi. Participants had a mean (±SD) age of 36.9 ± 12.5 years;
66.7% were women; and almost all (98.2%) from urban areas. A Wi-Fi router at
home was reported by 61 participants (96.8%), with 38 (61.2%) having a Wi-Fi
enabled smart TV. Overall, 26 (41.3%) participants had noticed the existence of
a mobile phone base station in their neighborhood. On average, participants
estimated the distance between the base station and their usual residence to be
about 500 m. The median personal RF-EMF exposure was 208 mV/m. Downlink
contributed 40.4% of the total RF-EMF exposure, followed by broadcast (22.4%),
uplink (17.3%), and Wi-Fi (15.9%). RF-EMF exposure levels on weekdays were
higher than weekends (p < 0.05). Downlink and broadcast are the main contributors
to total RF-EMF personal exposure. Personal RF-EMF exposure levels vary
according to day of the week and time of day.
--
Estimation of TETRA radio use in the
Airwave Health Monitoring Study of the British police forces
Vergnaud AC, Aresu M, Kongsgård HW, McRobie D, Singh D, Spear J, Heard A, Gao
H, Carpenter JR, Elliott P. Estimation of TETRA radio use in the Airwave Health
Monitoring Study of the British police forces. Environ Res. 2018
Nov;167:169-174. doi: 10.1016/j.envres.2018.07.015.
Abstract
BACKGROUND: The Airwave Health Monitoring Study aims to investigate the
possible long-term health effects of Terrestrial Trunked Radio (TETRA) use
among the police forces in Great Britain. Here, we investigate whether
objective data from the network operator could be used to correct for
misreporting in self-reported data and expand the radio usage availability in
our cohort.
METHODS: We estimated average monthly usage of personal radio in the 12 months
prior to enrolment from a missing value imputation model and evaluated its
performance against objective and self-reported data. Factors associated with
TETRA radio usage variables were investigated using Chi-square tests and
analysis of variance.
RESULTS: The imputed data were better correlated with objective than
self-reported usage (Spearman correlation coefficient = 0.72 vs. 0. 52 and
kappa 0.56 [95% confidence interval 0.55, 0.56] vs. 0.46 [0.45, 0.47]),
although the imputation model tended to under-estimate use for higher users.
Participants with higher personal radio usage were more likely to be younger,
men vs. women and officer vs. staff. The median average monthly usage level for
the entire cohort was estimated to be 29.3 min (95% CI: [7.2, 66.6]).
CONCLUSION: The availability of objective personal radio records for a large
proportion of users allowed us to develop a robust imputation model and hence
obtain personal radio usage estimates for ~50,000 participants. This
substantially reduced exposure misclassification compared to using
self-reported data and will allow us to carry out analyses of TETRA usage for
the entire cohort in future work.
--
Nonparticipation selection bias in
the MOBI-Kids Study
Turner MC, Gracia-Lavedan E, Momoli F, Langer CE, Castaño-Vinyals G, Kundi M,
Maule M, Merletti F, Sadetzki S, Vermeulen R, Albert A, Alguacil J, Aragones N,
Badia F, Bruchim R, Carretero G, Kojimahara N, Lacour B, Morales-Suarez-Varela
M, Radon K, Remen T, Weinmann T, Yamaguchi N, Cardis E. Nonparticipation
selection bias in the MOBI-Kids Study. Epidemiology. Oct 1, 2018. doi:
10.1097/EDE.0000000000000932.
Abstract
BACKGROUND: MOBI-Kids is a 14-country
case-control study designed to investigate the potential effects of
electromagnetic field exposure from mobile telecommunications devices on brain
tumor risk in children and young adults conducted from 2010-2016. This work
describes differences in cellular telephone use and personal characteristics
among interviewed participants and refusers responding to a brief
non-respondent questionnaire. It also assesses the potential impact of
non-participation Drafts selection bias on study findings.
METHODS: We compared non-respondent
questionnaires completed by 77 case and 498 control refusers with responses
from 683 interviewed cases and 1,501 controls (suspected appendicitis patients)
in six countries (France, Germany, Israel, Italy, Japan, and Spain). We derived
selection bias factors and estimated inverse probability of selection weights
for use in analysis of MOBI-Kids data.
RESULTS: The prevalence of ever
regular use was somewhat higher among interviewed participants than
non-respondent questionnaire respondents aged 10-14 years (68% vs 62% controls,
63% vs 48% cases); in those 20-24 years, the prevalence was ≥ 97%. Interviewed
controls and cases in the 15-19- and 20-24-year age groups were more likely to
have a time since start of use of 5+ years. Selection bias factors generally
indicated a small underestimation in cellular telephone odds ratios (ORs)
ranging from 0.96-0.97 for ever regular use and 0.92-0.94 for time since start
of use (5+ years), but varied in alternative hypothetical scenarios considered.
CONCLUSIONS: Although limited by
small numbers of non-respondent questionnaire respondents, findings generally
indicated a small underestimation in cellular telephone ORs due to selective
non-participation.
--
Letter to the Editor concerning the
paper “A novel database of bio-effects from non-ionizing radiation”
Drießen S, Dechent D, Graefrath D,
Petri A-K, Bodewein L, Emonds T, Kraus T. Letter to the Editor concerning the
paper “A novel database of bio-effects from non-ionizing radiation."
Reviews on Environmental Health. Oct 11, 2018. https://doi.org/10.1515/reveh-2018-0056
Excerpts
Over the past decade my colleagues
and I have provided the EMF-Portal, a database on non-ionizing electromagnetic
fields, launched by RWTH Aachen University, Germany. Today, the database of the
EMF-Portal consists of more than 27,000 scientific publications, and the number
is growing every day. The World Health Organization has also honored our EMF
platform for many years and recommends it as a reference database.
Over the last 10 years, the
EMF-Portal was mainly funded by German institutions, in spite of the fact that
about 80% of our users are from other countries. However, because the debate in
Germany about electromagnetic fields in the radiofrequency area has greatly
decreased, we no longer have the same financial resources at our disposal as in
previous years. As a result, we had to stop reviewing and uploading new
articles about radiofrequency and mobile communications. Papers on biological
effects caused by extremely low frequency fields (<10 MHz) have never been
affected by this decision and have been continuously imported into the EMF-Portal.
All this information is available on our homepage.
In the meantime, thanks to the
financial support of our valuable users, we were able once again, to import
articles from the radiofrequency range into the EMF-Portal (up to April 30,
2018). We hope to find a solution that allows for this service to continue past
this date.
In addition, we would like to make a
comment about the “effect/no effect” feature in the ORSAA database presented by
the authors. According to Table 2 in their article, every study is indicated as
an “effect study” if an observed change of status occurred in one or more
parameters examined. Thus, as an example, the study by Sommer et al. (2)
on lymphoma development is counted as an “effect study”, because the body
weight of the investigated animals increased, although survival rate and
lymphoma incidence did not differ between exposed mice and mice in the control
group.
In our opinion, such a global
categorization biases studies towards an “effect study” classification although
the main outcome was “no effect”. Results of this analysis, as presented in
their article, where 3 times more biological “Effect” than “No Effect” papers
have been identified, might rather indicate this strong bias. For us, this is a
real shortcoming in a self-declared non-biased database. To prevent such a bias
and to promote a critical and differentiated discussion, we have decided not to
offer such a feature in the EMF-Portal.
https://www.ncbi.nlm.nih.gov/pubmed/30307899
--
Probing Origins of 1,800 MHz RF EMR
Induced Damage in Mouse Immortalized Germ Cells and Spermatozoa in vitro
Houston BJ, Nixon B, King BV, Aitken RJ, De Iuliis GN. Probing the origins of
1,800 MHz radio frequency electromagnetic radiation induced damage in mouse
immortalized germ cells and spermatozoa in vitro. Front. Public Health. 2018
Sep 21. https://doi.org/10.3389/fpubh.2018.00270
As the use of mobile phone devices is now highly prevalent, many studies have
sought to evaluate the effects of the radiofrequency-electromagnetic radiation
(RF-EMR) on both human health and biology. While several such studies have
shown RF-EMR is capable of inducing cellular stress, the physicobiological
origin of this stress remains largely unresolved. To explore the effect of RF-EMR
on the male reproductive system, we exposed cultured mouse spermatogonial GC1
and spermatocyte GC2 cell lines, as well as cauda epididymal spermatozoa to a
waveguide generating continuous wave RF-EMR (1.8 GHz, 0.15 and 1.5 W/kg). This
study demonstrated that a 4 h exposure is capable of inducing the generation of
mitochondrial reactive oxygen species (ROS) in populations of GC1 (7 vs. 18%; p
< 0.001) and GC2 cells (11.5 vs. 16 %; p < 0.01), identifying Complex III
of the electron transport chain (ETC) as the potential source of electrons
producing ROS. Assessing the generation of ROS in the presence of an
antioxidant, penicillamine, as well as measuring lipid peroxidation via
4-hydroxynonenal levels, indicated that the elevated incidence of ROS generation
observed under our exposure conditions did not necessarily induce an overt
cellular oxidative stress response. However, exposure to RF-EMR at 0.15 W/kg
for 3 h did induce significant DNA fragmentation in spermatozoa (that was no
longer significant after 4 h), assessed by the alkaline comet assay (p <
0.05). Furthermore, this fragmentation was accompanied by an induction of
oxidative DNA damage in the form of 8-hydroxy-2′-deoxyguanosine, which was
significant (p < 0.05) after spermatozoa were exposed to RF-EMR for 4 h. At
this exposure time point, a decline in sperm motility (p < 0.05) was also
observed. This study contributes new evidence toward elucidating a mechanism to
account for the effects of RF-EMR on biological systems, proposing Complex III
of the mitochondrial ETC as the key target of this radiation.
--
The effect of 2.45 GHz non-ionizing radiation on the structure and
ultrastructure of the testis in juvenile rats
Šimaiová V, Almášiová V, Holovská K, Kisková T, Horváthová F, Ševčíková Z, Tóth
Š, Raček A, Račeková E, Beňová K, Dvořák P, Cigánková V. The effect of 2.45 GHz
non-ionizing radiation on the structure and ultrastructure of the testis in
juvenile rats. Histol Histopathol. 2018 Sep 27:18049. doi: 10.14670/HH-18-049.
Abstract
BACKGROUND: Nowadays, mobile devices that emit non-ionizing electromagnetic
radiation (EMR) are predominantly used by juveniles and pubescents. The aim of
the present study was to evaluate the effect of whole body pulsed EMR on the
juvenile Wistar albino rat testis at a frequency of 2.45 GHz and mean power
density of 2.8 mW/cm².
METHODS: The investigated animals (n=24) were divided into two control and two
EMR groups (5 and 6 week old rats; 6 rats per group). Both EMR groups were
irradiated continually for 3 weeks (2h/day) from postnatal days 14 and 21,
respectively.
RESULTS: EMR caused an irregular shape of seminiferous tubules with desquamated
immature germ cells in the lumen, a large number of empty spaces along the
seminiferous epithelium and dilated and congested blood vessels in the
interstitial tissue of the testis. The cytoplasm of Sertoli cells showed strong
vacuolization and damaged organelles, with the cytoplasm full of different
heterophagic and lipid vacuoles or the cytoplasm of spermatocytes with swollen
mitochondria in both irradiated groups. A significant increase in the total
tubular area of seminiferous tubules was observed in both EMR groups compared
with controls (P<0.001). A significant increase in the TUNEL-positive
apoptotic nuclei (P<0.01) was accompanied by a significant rise in both
Cu-Zn-SOD (P<0.01) and Mn-SOD (P<0.001) positive cells in the 6 week old
experimental rats compared to control animals.
CONCLUSION: Our results confirmed a harmful effect of non-ionizing radiation on
the structure and ultrastructure of the juvenile rat testis.
All experimental rats were exposed to whole-body pulsed non-ionizing
electromagnetic radiation at a frequency of 2.45 GHz and mean power density of
2.8 mW/ cm² in a purpose-designed chamber (Fig. 1). The uniformity of the
electromagnetic field was monitored with a spectral analyser.
--
The
effect of 20-week continuous 60 Hz magnetic field exposure on
testicular function in Sprague-Dawley rats
Park S, Kim YJ, Kim MS, Kim HS, Kim MW, Kang YM, Lee SK, Choi KC, Kim N, Gimm
YM, Kim YW. The effect of 20-week continuous 60 Hz
magnetic field exposure on testicular function in Sprague-Dawley rats.
Bioelectromagnetics. 2018 Oct 5. doi: 10.1002/bem.22146.
Abstract
Accumulating evidence does not yet confirm the effect of power line frequency
magnetic field (MF) on human health and fertility. We recently reported that,
at continuous 60 Hz MF exposure in mice, the
dose given as magnetic flux density (tesla; T) and duration of exposure was
related to induce testicular germ cell apoptosis. We aimed to characterize the
effect of a 20-week continuous exposure to 60 Hz
MF on the motility, morphology, and number of sperm as well as the apoptosis of
testicular germ cell in rats. Sprague-Dawley rats were exposed for 20 weeks to
60 Hz MF of 2, 20, or 200 μT
for 24 h/day with rats exposed to sham
conditions, serving as the control. The exposure to 60 Hz
MF of 2 and 20 μT had no effects on testicular
in this study. The exposure to 60 Hz MF of 200 μT
for 20 weeks induced increases of the apoptotic cells (P < 0.001)
in germ cells and decreases of sperm numbers (P < 0.05).
However, the MF did not significantly affect the body or testis mass,
seminiferous tubule diameter, or the motility or morphology of sperm. This
study concluded that exposure to 60 Hz MF of 200 μT
can increase testicular germ cell apoptosis, especially spermatogonia, and
reduce sperm count. Also compared to previous mice studies, rats are less
sensitive than mice to exposure to 60 Hz MF.
--
Effects
of exposure to ELF-EMF on spatial & passive avoidance learning &
memory, anxiety-like behavior & oxidative stress in male rats
Asaad Karimi S, Salehi I, Shykhi T, Zare S, Komaki A. Effects of exposure to
extremely low-frequency electromagnetic fields on spatial and passive avoidance
learning and memory, anxiety-like behavior and oxidative stress in male rats.
Behav Brain Res. 2018 Oct 2. pii: S0166-4328(18)31074-X. doi:
10.1016/j.bbr.2018.10.002.
Abstract
There are many controversies about the safety of extremely low-frequency
electromagnetic field (ELF-EMF) on body health and cognitive performance. In
the present study, we explored the effects of ELF-EMF on oxidative stress and
behaviors of rats. Seventy-two adult male Wistar rats were randomly divided
into following groups, control, sham exposure group and the ELF-EMF exposure
groups (1 µT, 100 µT, 500 µT, and 2000 µT). After 60 days exposure (2 h/day),
elevated plus maze (EPM), Morris water maze (MWM) and Passive avoidance
learning (PAL) tasks were used to evaluate the anxiety-like behavior, spatial
and passive learning and memory, respectively. Some days after behavioral
examination, oxidative stress markers were measured. During spatial reference
memory test, animals in ELF-EMF exposure groups (100, and 2000 µT) spent more
time in target zone (F (4, 55) = 5.699,
P = 0.0007,
One-way ANOVA). In PAL retention, the step through latency in the retention
test (STLr) in ELF-EMF exposure groups (100,500, and 2000 µT) was significantly
greater than control group (F (4, 55) = 29.13,
P < 0.0001,
One-way ANOVA). In EPM test, ELF-EMF exposure (500 and 2000 µT) decreased the
percentage of the entries into the open arms (F (4, 55) = 26.31,
P < 0.0001,
one-way ANOVA). ELF-EMF exposure (100, and 500 µT) increased Malondialdehyde
(MDA) concentration (F (4, 25) = 79.83,
P < 0.0001,
One-way ANOVA). Our results may allow the conclusion that exposure to ELF-EMFs
can improve memory retention (but not acquisition) in the adult male rats.
Although exposure to ELF-EMFs could be a factor in the development of anxious
state or oxidative stress.
--
Low-intensity EMFs induce human
cryptochrome to modulate intracellular reactive oxygen species
Sherrard RM, Morellini N, Jourdan N,
El-Esawi M, Arthaut LD, Niessner C, Rouyer F, Klarsfeld A, Doulazmi M, Witczak
J, d'Harlingue A, Mariani J, Mclure I, Martino CF, Ahmad M. Low-intensity
electromagnetic fields induce human cryptochrome to modulate intracellular
reactive oxygen species. PLoS Biol. 2018 Oct 2;16(10):e2006229. doi: 10.1371/journal.pbio.2006229.
Abstract
Exposure to man-made electromagnetic fields (EMFs), which increasingly pollute
our environment, have consequences for human health about which there is
continuing ignorance and debate. Whereas there is considerable ongoing concern
about their harmful effects, magnetic fields are at the same time being applied
as therapeutic tools in regenerative medicine, oncology, orthopedics, and
neurology. This paradox cannot be resolved until the cellular mechanisms
underlying such effects are identified. Here, we show by biochemical and
imaging experiments that exposure of mammalian cells to weak pulsed
electromagnetic fields (PEMFs) stimulates rapid accumulation of reactive oxygen
species (ROS), a potentially toxic metabolite with multiple roles in stress
response and cellular ageing. Following exposure to PEMF, cell growth is
slowed, and ROS-responsive genes are induced. These effects require the
presence of cryptochrome, a putative magnetosensor that synthesizes ROS. We
conclude that modulation of intracellular ROS via cryptochromes represents a
general response to weak EMFs, which can account for either therapeutic or
pathological effects depending on exposure. Clinically, our findings provide a
rationale to optimize low field magnetic stimulation for novel therapeutic
applications while warning against the possibility of harmful synergistic
effects with environmental agents that further increase intracellular ROS.
Author summary
Repetitive low-intensity magnetic stimulation has been used in the treatment of
disease for over 50 years. Associated benefits have included alleviation of
depression, memory loss, and symptoms of Parkinson disease, as well as
accelerated bone and wound healing and the treatment of certain cancers, independently
of surgery or drugs. However, the cellular mechanisms underlying these effects
remain unclear. Here, we demonstrate that repetitive magnetic field exposure in
human cells stimulates production of biological stress response chemicals known
as reactive oxygen species (ROS). At moderate doses, we find that reactive
oxygen actively stimulates cellular repair and stress response pathways, which
might account for the observed therapeutic effects to repetitive magnetic
stimulation. We further show that this response requires the function of a
well-characterized, evolutionarily conserved flavoprotein receptor known as
cryptochrome, which has been implicated in magnetic sensing in organisms
ranging from plants to flies, including migratory birds. We conclude that
exposure to weak magnetic fields induces the production of ROS in human cells
and that this process requires the presence of the cryptochrome receptor.
--
Cryptochrome: The magnetosensor with
a sinister side?
No abstract.
--
Coupling
of oxidative stress responses to tricarboxylic acid cycle & prostaglandin
E2 alterations in Caenorhabditis elegans under ELF-EMF
Sun Y, Shi Z, Wang Y, Tang C, Liao Y, Yang C, Cai P. Coupling of oxidative
stress responses to tricarboxylic acid cycle and prostaglandin E2 alterations
in Caenorhabditis elegans under extremely low-frequency electromagnetic field.
Int J Radiat Biol. 2018 Oct 11:1-8. doi: 10.1080/09553002.2019.1524943.
Abstract
PURPOSE: With all-pervasive presence of extremely low-frequency
electromagnetic field (ELF-EMF) in modern life, ELF-EMF has been regarded as an
essential factor which may induce changes in many organisms. The objective of
the present study was to investigate the physiological responses of
Caenorhabditis elegans (C. elegans) to 50 Hz, 3 mT
ELF-EMF exposure.
MATERIALS AND METHODS: Worms were exposed to ELF-EMF from the egg stage until
reaching the fourth larva (L4) stage. After exposure, expressions of the
tricarboxylic acid (TCA) cycle enzymes were examined by qRT-PCR and western
blot analysis. Two lipid metabolites were detected by GC-MS. Reactive oxygen
species (ROS) level was detected by dichlorofluorescein staining and worm antioxidant
system was investigated by enzymatic activity analysis, including detection of
the superoxide dismutase and catalase (CAT) activity and the total antioxidant
capacity (T-AOC).
RESULTS: The TCA cycle enzyme, fumarase was found with decreased expression
under ELF-EMF exposure. And arachidonic acid (ArA) and prostaglandin E2(PGE2)
showed elevated concentrations, with increased expression of prostaglandin E2
synthase (PGES-2) in ELF-EMF exposed worms. Significant elevation of ROS level
was identified accompanied with the significant depression of T-AOC in response
to ELF-EMF.
CONCLUSIONS: Our results suggested that exposure to 50 Hz,
3 mT ELF-EMF in C. elegans can
elicit disruptions of the TCA cycle metabolism and PGE2 formation, coupling
ELF-EMF-induced oxidative stress responses. Our study probably will attract
increasing attentions to the controllable application of ELF-EMF associated
with health and disease.
https://www.ncbi.nlm.nih.gov/pubmed/30307357
--
Effects
of weak static magnetic fields on the gene expression of seedlings of
Arabidopsis thaliana
Dhiman SK, Galland P. Effects of weak static magnetic fields on the gene
expression of seedlings of Arabidopsis thaliana. J Plant Physiol. 2018 Sep
3;231:9-18. doi: 10.1016/j.jplph.2018.08.016.
Abstract
Magnetic-field reception of animals and plants is currently discussed in the
framework of a cryptochrome-based radical-pair mechanism. Efforts to unravel
magnetoreception in plants suffered historically from several shortcomings,
most prominently, the conspicuous absence of detailed stimulus-response relationships.
To determine the sensitivity of seedlings of Arabidopsis thaliana to weak
static magnetic fields we generated stimulus-response curves between near zero
and 188 μT for the transcript levels of the genes rbcl, cab4, pal4 and ef1. The
moderate magneto-responsiveness of dark-grown seedlings was greatly enhanced
under blue light, and for rbcl and pal4 also under red light. The
stimulus-response curves obtained under blue light of constant photon-fluence
rate displayed multiple maxima and thus a pattern fundamentally different from
that prevalent in plant and animal physiology. A double mutant lacking
cryptochromes 1 and 2 displayed altered stimulus-response curves without
losing, however, magneto-responsiveness completely. A reversal of the magnetic
field direction substantially affected the gene expression and the quantity of
CAB-protein (chlorophyll a,b-binding protein). The majority of our results are
at variance with the notion of cryptochromes acting as the only magnetic-field
sensors. They do not, however, exclude the possibility that cryptochromes
participate in the magnetic field reception of Arabidopsis. The findings have
the unexpected implication that cryptochrome- and phytochrome-mediated plant
responses can be modulated by the strength and the orientation of the local
geomagnetic field.
--
Some
recommendations for experimental work in magnetobiology, revisited
Makinistian L, Muehsam DJ, Bersani F, Belyaev I. Some recommendations for
experimental work in magnetobiology, revisited. Bioelectromagnetics. 2018 Oct
10. doi: 10.1002/bem.22144.
No
abstract.
--
Weak
power frequency magnetic fields induce microtubule cytoskeleton reorganization
depending on epidermal growth factor receptor & calcium signaling
Wu X, Du J, Song W, Cao M, Chen S, Xia R. Weak power frequency magnetic fields
induce microtubule cytoskeleton reorganization depending on the epidermal
growth factor receptor and the calcium related signaling. PLoS One. 2018 Oct
12;13(10):e0205569. doi: 10.1371/journal.pone.0205569.
Abstract
We have shown previously that a weak 50 Hz magnetic field (MF) invoked the
actin-cytoskeleton, and provoked cell migration at the cell level, probably
through activating the epidermal growth factor receptor (EGFR) related motility
pathways. However, whether the MF also affects the microtubule
(MT)-cytoskeleton is still unknown. In this article, we continuously
investigate the effects of 0.4 mT, 50 Hz MF on the MT, and try to understand if
the MT effects are also associated with the EGFR pathway as the
actin-cytoskeleton effects were. Our results strongly suggest that the MF
effects are similar to that of EGF stimulation on the MT cytoskeleton, showing
that 1) the MF suppressed MT in multiple cell types including PC12 and FL; 2)
the MF promoted the clustering of the EGFR at the protein and the cell levels,
in a similar way of that EGF did but with higher sensitivity to PD153035
inhibition, and triggered EGFR phosphorylation on sites of Y1173 and
S1046/1047; 3) these effects were strongly depending on the Ca2+ signaling through
the L-type calcium channel (LTCC) phosphorylation and elevation of the
intracellular Ca2+ level. Strong associations were observed between EGFR and
the Ca2+ signaling to regulate the MF-induced-reorganization of the
cytoskeleton network, via phosphorylating the signaling proteins in the two
pathways, including a significant MT protein, tau. These results strongly
suggest that the MF activates the overall cytoskeleton in the absence of EGF,
through a mechanism related to both the EGFR and the LTCC/Ca2+ signaling
pathways.
