--
Gaps in Knowledge Relevant to the "ICNIRP
Guidelines for Limiting Exposure to Time-Varying Electric, Magnetic and
Electromagnetic Fields (100 kHz TO 300 GHz)"
International Commission on Non-Ionizing
Radiation Protection (ICNIRP). Gaps in Knowledge Relevant to the "ICNIRP
Guidelines for Limiting Exposure to Time-Varying Electric, Magnetic and
Electromagnetic Fields (100 kHz TO 300 GHz)". Health Phys. 2025 Feb
1;128(2):190-202. doi: 10.1097/HP.0000000000001944. Epub 2024 Dec 13.
PMID: 39670836.
Abstract
In the last 30 y, observational as well as experimental studies have
addressed possible health effects of exposure to radiofrequency
electromagnetic fields (EMF) and investigated potential interaction
mechanisms. The main goal of ICNIRP is to protect people and the
environment from detrimental exposure to all forms of non-ionizing
radiation (NIR), providing advice and guidance by developing and
disseminating exposure guidelines based on the available scientific
research on specific parts of the electromagnetic spectrum. During the
development of International Commission on Non-Ionizing Radiation
Protection's (ICNIRP's) 2020 radiofrequency EMF guidelines some gaps in
the available data were identified. To encourage further research into
knowledge gaps in research that would, if addressed, assist ICNIRP in
further developing guidelines and setting revised recommendations on
limiting exposure, data gaps that were identified during the development
of the 2020 radiofrequency EMF guidelines, in conjunction with
subsequent consideration of the literature, are described in this
Statement. Note that this process and resultant recommendations were not
intended to duplicate more traditional research agendas, whose focus is
on extending knowledge in this area more generally but was tightly
focused on identifying the highest data gap priorities for guidelines
development more specifically. The result of this distinction is that
the present data gap recommendations do not include some gaps in the
literature that in principle could be relevant to radiofrequency EMF
health, but which were excluded because either the link between exposure
and endpoint, or the link between endpoint and health, was not
supported sufficiently by the literature. The evaluation of these
research areas identified the following data gaps: (1) Issues concerning
relations between radiofrequency EMF exposure and heat-induced pain;
(2) Clarification of the relation between whole-body exposure and core
temperature rise from 100 kHz to 300 GHz, as a function of exposure
duration and combined EMF exposures; (3) Adverse effect thresholds and
thermal dosimetry for a range of ocular structures; (4) Pain thresholds
for contact currents under a range of exposure scenarios, including
associated dosimetry; and (5) A range of additional dosimetry studies to
both support future research, and also to improve the application of
radiofrequency EMF exposure restrictions in future guidelines.
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Sensory Processing Sensitivity, and Not Gender, Drives Electromagnetic Hypersensitivity and Nature Connection
Watten
RG, Volden F, Visnes H. Sensory Processing Sensitivity, and Not Gender,
Drives Electromagnetic Hypersensitivity and Nature Connection.
Ecopsychology. Nov 28, 2024.
https://doi.org/10.1089/eco.2024.0027
Abstract
Electromagnetic
hypersensitivity (EHS) is a biomedical condition associated with
exposure to man-made radio-frequency electromagnetic fields. Common
sources are devices like mobile phones, wireless networks, base
stations, computers, TVs, and more. Identifying individuals at risk of
developing EHS is important. Those with heightened sensory processing
sensitivity (SPS; the ability to perceive, process, and react to
environmental stimuli, approximately 25% to 30% of the population) are
of special interest. SPS could also be associated with connectedness to
nature (CNS) and EHS. In the current gender-matched cross-sectional
study (n = 450; 225 men and 225 women) we assessed gender
differences in environmental sensitivity assessed as SPS, EHS, and CNS.
Women had higher general EHS prevalence than men (13.3% vs. 5.3%),
higher mean values on perceived sensitivity for 5 out of 9 categories of
electromagnetic equipment (computers, electrical appliances,
fluorescent lighting, mobile phones, and television) and they had higher
scores on the three EHS Scales EHS General, EHS Scale, and EHS Index,
in addition to higher SPS and CNS scores. The gender differences
vanished when adjusting for SPS in the multivariate analyses of variance
(MANOVA) analyses, suggesting that the differences in these scales were
associated with SPS. The statistical equation modeling (SEM) results
showed a significant positive direct effect of SPS on CNS, and a
significant indirect effect mediated by EHS. The present study provides
the first empirical evidence that highly sensitive individuals are
capable of perceiving electromagnetic radiation. The results indicate
that perceived EHS and CNS are driven by SPS and not by gender.
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Effect of Exposure to Mobile Phones on
Electrical Cardiac Measurements: Multivariate Analysis & Variable
Selection Algorithm to Detect Relationship With Mean Changes
Alharbi N, Alassiri M. The Effect of Exposure to Mobile Phones on
Electrical Cardiac Measurements: A Multivariate Analysis and a Variable
Selection Algorithm to Detect the Relationship With Mean Changes. Int J
Cell Biol. 2024 Oct 3;2024:7093771. doi: 10.1155/2024/7093771.
Abstract
Background: The exponential growth in mobile phone usage has raised concerns about electromagnetic field (EMF) exposure and its health risks. Blood pressure and BMI, which impair heart function due to decreased adrenoreceptor responsiveness, parasympathetic tone withdrawal, and increased sympathetic activity, may further exacerbate these risks. However, the effects of radiofrequency electromagnetic (RF-EM) exposure from mobile phones on electrocardiograms (ECGs) and heart rate variability (HRV) in individuals remain unclear.
Purpose: Building upon our previous findings on HRV changes due to mobile phone proximity, this study is aimed at significantly enhancing the analytical approach used to assess the effects of mobile phones on cardiac parameters. This study exploits data from a previous study but with a different purpose. The aim of this study is twofold: (a) to examine whether exposure to mobile phones changes the five variables (P-R, QRS, QT, ST, and HR) in a multivariate manner and (b) to examine whether the blood pressure and/or the body mass index (BMI), which acts as a proxy for obesity, have an effect on the change of these five variables. For both aspects of the study, four cycles are performed.
Method: We conducted multivariate analysis on previously collected electrical cardiac measurement data from 20 healthy male subjects exposed to mobile phone EMF, with the mobile phones placed at four different body locations. The one-sample
Hotelling
T2
test on the mean vector of differences was utilised instead of multiple paired t-tests. This multivariate method comprehensively analyzes data features and accounts for variable correlations, unlike multiple univariate analyses. Given our small sample size, we employed the MMPC variable selection algorithm to identify predictor variables significantly related to mean changes.
Results: Significant alterations in ECG intervals and heart rate were noted in the subjects before and after the first EMF exposure cycle, independent of their BMI. Notably, heart rate, P-R, and QRS intervals fell postexposure while QT and ST intervals increased. These changes were influenced by variations in systolic blood pressure, with BMI showing no significant effect.
Conclusion: The observed modifications in cardiac electrical measurements due to mobile phone EMF exposure are attributed to the effects of EMF itself, with no impact from BMI on the extent of these changes.
Note: iPhone 5 Plus was used.
Conclusion
Given the evidence linking EMFs from mobile phones to
adverse effects on heart health, it is crucial for regular users of such
devices, especially those at risk of CVDs, to take steps towards
reducing their overall exposure. This can be achieved through measures
such as limiting talk time or using hands-free headsets during calls.
Additionally, ongoing research in this area is essential to deepen our
understanding of how these potentially harmful frequencies impact our
bodies over both short- and long-term periods.
The Role of Excess Charge Mitigation in Electromagnetic Hygiene: An Integrative review
Jamieson IA, Bell JNB, Holdstock P. The Role of Excess Charge Mitigation in Electromagnetic Hygiene: An Integrative review. Biomedical Journal. 2024, doi: 10.1016/j.bj.2024.100801.
Abstract
The electromagnetic characteristics of many environments have changed significantly in recent decades. This is in large part due to the increased presence of equipment that emits electromagnetic radiation and materials that may often readily gain excess charge. The presence of excess charge can often increase risk of infection from pathogens, and likelihood of individuals experiencing compromised performance, respiratory problems and other adverse health issues from increased uptake of particulate matter. It is proposed that adopting improved electromagnetic hygiene measures, including optimized humidity levels, to reduce the presence of inappropriate levels of electric charge can help reduce the likelihood of ill health, infection and poor performance arising from contaminant inhalation and deposition, plus reduce the likelihood of medical devices and other electronic devices getting damaged and/or having their data compromised. It is suggested that such measures should be more widely adopted within clinical practice guidelines and water, sanitation and hygiene programs.
Highlights
Electric fields can increase localized deposition of pathogens.
High charge of either polarity increases contaminant deposition.
40-60% relative humidity reduces likelihood of infection.
Proper specification of materials reduces infection risks.
Electromagnetic hygiene can reduce risk of infection.
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5G RF-EMF Effects on the Human Sleep Electroencephalogram: A Randomized Controlled Study in Healthy Volunteers (pre-print, not peer-reviewed)
My
note: Most studies to date that claim to evaluate the effects
of 5G exposure did not employ a 5G signal generator. This study, however, used an exposure
system (sXh5G) developed by the IT’IS Foundation that provides a controlled and well-characterized 5G EMF
exposure at two different carrier frequencies.
Sousouri
G, Eicher
C, D'Angelo
RM, Billecocq
M, Fussinger
T, Studler
M, Capstick
M, Kuster
N, Achermann
P, Huber
R, Landolt
H-P.
5G Radio-Frequency-
Electromagnetic-Field Effects on the Human Sleep
Electroencephalogram: A Randomized Controlled Study in
CACNA1C Genotyped
Healthy Volunteers
. MedRxiv.
Dec 26, 2024. doi: 10.1101/2024.12.16.24319082.
Abstract
Background: The introduction of 5G technology as the latest standard in
mobile telecommunications has raised concerns about its potential health
effects. Prior studies of earlier generations of radiofrequency
electromagnetic fields (RF-EMF) demonstrated narrowband spectral
increases in the electroencephalographic (EEG) spindle frequency range
(11-16 Hz) in non-rapid-eye-movement (NREM) sleep. However, the impact
of 5G RF-EMF on sleep remains unexplored. Additionally, RF-EMF can
activate L-type voltage-gated calcium channels (LTCC), which have been
linked to sleep quality and EEG oscillatory activity.
Objective: This study investigates whether the allelic variant rs7304986
in the CACNA1C gene, encoding the α1C subunit of LTCC, modulates 5G
RF-EMF effects on EEG spindle activity during NREM sleep.
Methods: Thirty-four healthy, matched participants, genotyped for
rs7304986 (15 T/C and 19 T/T carriers), underwent a double-blind,
sham-controlled study with standardized left-hemisphere exposure to two
5G RF-EMF signals (3.6 GHz and 700 MHz) for 30 min before sleep. Sleep
spindle activity was analyzed using high-density EEG and the Fitting
Oscillations & One Over f (FOOOF) algorithm.
Results: T/C carriers reported longer sleep latency compared to T/T
carriers. A significant interaction between RF-EMF exposure and
rs7304986 genotype was observed, with 3.6 GHz exposure in T/C carriers
inducing a faster spindle center frequency in the central, parietal, and
occipital cortex compared to sham.
Conclusion: These findings suggest 3.6 GHz 5G RF-EMF modulates spindle
center frequency during NREM sleep in a CACNA1C genotype-dependent
manner, implicating LTCC in the physiological response to RF-EMF and
underscoring the need for further research into 5G effects on brain
health.
Excerpts
All participants completed three experimental nights with different, standardized exposure conditions according to a randomized, double-blind, cross-over design: 1) 30-min, pre-sleep exposure to an active 5G EMF at a carrier frequency of 700 MHz, 20 MHz bandwidth, and 12.5 Hz applied power control, 2) 30-min, pre-sleep exposure to an active 5G EMF at a carrier frequency of 3.6 GHz, 100 MHz bandwidth, and 12.5 Hz applied power control, and 3) a 30-min sham exposure without an active field....
All exposure conditions were administered with the same exposure system (sXh5G), provided by the IT’IS Foundation for Research on Information Technologies in Society (IT'IS Foundation, Zurich, Switzerland), which ensures controlled and well-characterized 5G EMF exposure. Following detailed simulated dosimetry (Figure 1), the signal intensity was calibrated to ensure the specific absorption rate (SAR) for the head (averaged over 10 g of tissue) did not exceed 2 W/kg. The active field remained within the SAR limit for the general population established by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) and posed no known health risks. The two active fields administered are 5G uplink signals generated in the 5G frequency range. The lower frequency signal has a carrier frequency of 700 MHz, 20 MHz bandwidth, Frequency Division Duplexing/Orthogonal Frequency-Division Multiplexing (FDD/OFDM) with 24 resource blocks, 16 time slots, 60 kHz sub-carrier spacing and Quadrature Phase Shift Keying (QPSK) modulation, with an output power of 4.28 W. The higher frequency signal has a carrier frequency of 3.6 GHz, 100 MHz bandwidth, Time Division Duplexing (TDD)/QPSK OFDM with 135 resource blocks, 16 time slots, 60 kHz sub-carrier spacing and QPSK modulation, with an output power of 1.63 W. In the signals used, only uplink communication is implemented, and all frames are identical with 16 time slots. Both signals have identical power control applied that introduces low frequency amplitude modulation at 12.5 Hz on top of the modulation due to the occupied time slots which have a dominant power modulation frequency of 200 Hz resulting in a 14.2 dB peak to average power ratio (PAPR) (Supp. Figure 1, 2 & 3). The exposure levels in grey and white matter, thalamus and all tissues in the brain averaged over 0.125 g which is a cube of side length ~5 mm are reported in Table 1 for both 700 MHz and 3.6 GHz....
... we found a significant interaction between exposure and the genetic variant in the center frequency of sleep spindles. Specifically, we demonstrated a topographically widespread acceleration of spindle center frequency in the T/C carriers after exposure to the 3.6 GHz RF-EMF in comparison to sham....
By leveraging the strengths of spectral parameterization, we demonstrated a widespread shift in the center frequency of sleep spindles towards faster oscillatory activity in T/C allele carriers after exposure to a 5G RF-EMF with a carrier frequency of 3.6 GHz. This effect was evident in central, parietal, and occipital cortical areas coinciding with areas that predominantly express faster spindles. A number of previous studies also reported enhanced EEG spectral power in the upper spindle range after exposure to RF-EMF of earlier generation (Huber et al., 2000, 2002; Schmid, Loughran, et al., 2012; Schmid, Murbach, et al., 2012)....
The discrepancy between the deeper penetration of the 700 MHz signal revealed by the simulated SAR distribution in the brain and the more pronounced effects on the EEG sleep spindles observed following exposure to the 3.6 GHz signal remains unclear. Notably, the pulse modulation, which has been identified as critical for the biological effects of RF-EMF (Huber et al., 2002), was identical at 12.5 Hz in both fields and the psSAR10gr was consistently set at 2 W/kg. The findings underscore the necessity for a comprehensive investigation into the complex characteristics of the new 5G signals. Furthermore, they may suggest that the dielectric and conductive properties of the tissues associated with the minor allele may not be adequately represented by the current simulation parameters. Alternatively, the observed effects may indicate a distinct mode of action that is unrelated to SAR distribution....
The differential effects observed between the 700 MHz and 3.6 GHz exposures highlight the importance of considering signal characteristics and tissue properties in understanding RF-EMF interactions. Overall, our results provide new insights into the genetic and biophysical factors underlying RF-EMF effects on sleep, emphasizing the need for more targeted studies to elucidate these mechanisms.
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RF-EMF Exposure near 5G NR Small Cells
Aerts S,
Deprez K, Verloock L,
Olsen RG, Martens L,
Tran P,
Joseph W.
RF-EMF Exposure near 5G NR Small Cells. Sensors. 2023; 23(6):3145. doi: 10.3390/s23063145.
Abstract
Of particular interest within fifth generation (5G) cellular networks
are the typical levels of radiofrequency (RF) electromagnetic fields
(EMFs) emitted by ‘small cells’, low-power base stations, which are
installed such that both workers and members of the general public can
come in close proximity with them. In this study, RF-EMF measurements
were performed near two 5G New Radio (NR) base stations, one with an
Advanced Antenna System (AAS) capable of beamforming and the other a
traditional microcell. At various positions near the base stations, with
distances ranging between 0.5 m and 100 m, both the worst-case and
time-averaged field levels under maximized downlink traffic load were
assessed. Moreover, from these measurements, estimates were made of the
typical exposures for various cases involving users and non-users.
Comparison to the maximum permissible exposure limits issued by the
International Commission on Non-Ionizing Radiation Protection (ICNIRP)
resulted in maximum exposure ratios of 0.15 (occupational, at 0.5 m) and
0.68 (general public, at 1.3 m). The exposure of non-users was
potentially much lower, depending on the activity of other users
serviced by the base station and its beamforming capabilities: 5 to 30
times lower in the case of an AAS base station compared to barely lower
to 30 times lower for a traditional antenna.
Excerpt
Scaled to small-cell powers, the measured exposure
levels in this study were below the MPE limits for both occupational (at
distances between 0.5 m and 1 m from the base station) and general
public exposure (>1 m) issued by the International Commission on
Non-Ionizing Radiation Protection (ICNIRP) [17]:
the maximum exposure ratios were 0.15 (occupational) and 0.68 (general
public). These theoretical worst-case exposures were higher than the
actual maxima measured in situ by maximizing the downlink traffic load,
and both types of worst-case exposures were much higher (3–12 times)
than the exposures of a typical user, which in turn were much higher
(4–9 times) than the exposures without any users. Finally, the exposure
of a non-user within a mature 5G NR network depends on the distribution
of users, their usage, and the AAS capabilities of the base station
radio.
Although adverse health effects at non-thermal exposure levels cannot be ruled out [20],
the ICNIRP reference levels are still relevant to calculate exposure
ratios against. The measurement values obtained in this study and
reported in this paper can be directly compared to other reference or
limit levels (e.g., from legislation or scientific literature),
depending on the scope of the study.
For a 5G NR AAS base station, the actual exposure of a given user will generally be less than the theoretical maximum exposure Emax
for several reasons. First, other users (the number may vary) may be in
beams other than the one the given user is using. Hence, the RF energy
directed toward these users will not add (much) to the exposure of the
given user. Second, the usage by the given user will generally be less
than the maximum assumed for which Emax
was defined. Third, there may be dynamic power control to reduce base
station power to the minimum needed for communication. This was not
taken into account in this study. Finally, the base station beam may be
narrower or wider than that used to measure Emax.
Hence, the problem of determining actual RF exposure becomes a
statistical one that depends on several different variables. However,
the exposure will almost always be less than Emax.
Similarly,
for the non-user, the difference lies in whether they are in a beam or
not. Generally, the RF exposure from the base station for the non-user
will be smaller than that for a user (here by at least a factor of 5 for
an AAS), unless there are many users around and the MaMIMO capabilities
of the base station are limited (Table 4) [19].
Open access paper: https://www.mdpi.com/1424-8220/23/6/3145
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Improving Monitoring of Indoor RF-EMF Exposure Using IoT-Embedded Sensors and Kriging Techniques
Jabeur R, Alaerjan A.
Improving Monitoring of Indoor RF-EMF Exposure Using IoT-Embedded Sensors and Kriging Techniques. Sensors. 2024; 24(23):7849.
https://doi.org/10.3390/s24237849
Abstract
Distributed wireless sensor networks (WSNs) are widely used to enhance
the quality and safety of various applications. These networks consist
of numerous sensor nodes, often deployed in challenging terrains where
maintenance is difficult. Efficient monitoring approaches are essential
to maximize the functionality and lifespan of each sensor node, thereby
improving the overall performance of the WSN. In this study, we propose a
method to efficiently monitor radiofrequency electromagnetic fields
(RF-EMF) exposure using WSNs. Our approach leverages sensor nodes to
provide real-time measurements, ensuring accurate and timely data
collection. With the increasing prevalence of wireless communication
systems, assessing RF-EMF exposure has become crucial due to public
health concerns. Since individuals spend over 70% of their time indoors,
it is vital to evaluate indoor RF-EMF exposure. However, this task is
complicated by the complex indoor environments, furniture arrangements,
temporal variability of exposure, numerous obstructions with unknown
dielectric properties, and uncontrolled factors such as people’s
movements and the random positioning of furniture and doors. To address
these challenges, we employ a sensor network to monitor RF-EMF exposure
limits using embedded sensors. By integrating Internet of
Things-embedded sensors with advanced modeling techniques, such as
kriging, we characterize and model indoor RF-EMF downlink (DL) exposure
effectively. Measurements taken in several buildings within a few
hundred meters of base stations equipped with multiple cellular antennas
(2G, 3G, 4G, and 5G) demonstrate that the kriging technique using the
spherical model provides superior RF-EMF prediction compared with the
exponential model. Using the spherical model, we constructed a
high-resolution coverage map for the entire corridor, showcasing the
effectiveness of our approach.
Conclusions
This
study proposes the use of WSN to monitor the indoor RF-EMF exposure
induced by cellular networks. To this end, we first proposed a
measurement system based on the Narda NBM-550 and Nucleo-F401RE
microcontroller board. The aim is to characterize and model indoor
RF-EMF DL exposure using the collected measurements and kriging
technique. First, several indoor measurements are conducted in an area
covered by various frequency bands, including those used for 5G. By
comparing the spherical and exponential models, we demonstrated that the
spherical model provides a superior fit for predicting RF-EMF exposure
levels. The high-resolution coverage map constructed using the spherical
model revealed that the maximum average RF-EMF DL exposure levels
within the corridor are well below the limits established by the ICNIRP.
These findings underscore the effectiveness of the kriging technique in
accurately modeling and predicting RF-EMF exposure in complex indoor
environments.
For future work, several avenues
can be explored to enhance the understanding and assessment of indoor
RF-EMF exposure. Firstly, expanding the measurement campaign to include a
wider variety of indoor environments, such as residential buildings,
offices, and public transport, would provide a more comprehensive
dataset. Additionally, incorporating temporal variations by conducting
long-term measurements could offer insights into the fluctuations of
RF-EMF exposure over time. Furthermore, integrating advanced machine
learning algorithms with the kriging technique could improve the
accuracy and efficiency of exposure predictions. Another important
research axis involves the analysis of measurement uncertainty, which is
planned for future investigation. For large-scale deployments, the
Narda NBM-550 can be replaced with frequency-selective equipment such as
the ExpoM-RF4, MVG EME Spy Evolution, or Narda SRM-3006. This
substitution ensures that only downlink bands are considered and enables
the reconstruction of RF-EMF exposure maps for each frequency band,
facilitating a more detailed assessment by frequency band. Finally,
investigating the impact of emerging wireless technologies, such as
beyond 5G, on indoor RF-EMF exposure will be crucial as these
technologies become more widespread. These future directions will
contribute to a more thorough understanding of indoor RF-EMF exposure
and help address public concerns regarding wireless communication
systems.
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AI-based optimization of EM radiation estimates from GSM base stations using traffic data
Lal R, Singh RK, Nishad DK, et al. AI-based optimization of EM radiation estimates from GSM base stations using traffic data.
Discov Appl Sci 6, 655 (2024). doi: 10.1007/s42452-024-06395-y
Abstract
The fast expansion of mobile networks has sparked worries regarding base
station EM radiation's health impacts. Traffic load is commonly ignored
when evaluating EM radiation levels using maximum power output. This
study proposes utilizing AI and ML on real network traffic data to
optimize GSM base station EM radiation estimations. We obtained EM
radiation measurements and traffic data from selecting GSM base stations
by location and configuration. To predict EM radiation levels, traffic
patterns were used to train linear regression, random forests, and
neural networks. Base stations were clustered by radiation profile using
unsupervised learning. Considering regulatory restrictions and
measurement feasibility, an optimization methodology was created to
minimize EM radiation estimate inaccuracy. The results show better
prediction accuracy than power-based estimations and high
generalisability across base station types. Site-specific factors
influenced daily EM radiation patterns after clustering. EM radiation
levels can be monitored using traffic data and the optimized AI/ML
model. This research helps telecom operators and regulators analyze EM
radiation more accurately and efficiently. Future projects should
include 5G and small cell network extensions and intelligent city
platform integration. The suggested method develops data-driven,
AI-powered Public Safety and mobile network trust solutions.
--
Advancements in electromagnetic microwave absorbers: Ferrites and
carbonaceous materials
Mohapatra PP, Singh HK, Dobbidi P.
Advancements in electromagnetic microwave absorbers: Ferrites and
carbonaceous materials. Adv Colloid Interface Sci. 2024 Dec
14;337:103381. doi: 10.1016/j.cis.2024.103381.
Abstract
Heightened levels of electromagnetic (EM) radiation emitted by
electronic devices, communication equipment, and information processing
technologies have become a significant concern recently. So, substantial
efforts have been devoted for developing novel materials having high EM
absorption properties. This critical review article provides an
overview of the advancements in understanding and developing such
materials. It delves into the interaction between EM radiation and
absorbing materials, focusing on phenomena like multiple reflections,
scattering, and polarization. Additionally, the study discusses various
types of losses that impact microwave absorber performance, like
magnetic loss, and dielectric loss. Each of these losses has distinct
implications for microwave absorbers' effectiveness. Furthermore, the
review offers detailed insights into different microwave-absorbing
materials, such as metal composites, magnetic materials, conducting
polymers, and carbonaceous materials (composites with carbon fiber,
porous carbon, carbon nanotube, graphene oxide, etc.). Overall, it
highlights the progress achieved in microwave-absorbing materials and
emphasizes optimizing various loss mechanisms for enhanced performance.
Conclusions
This
study provides a comprehensive overview of recent advancements in
magnetic and carbon-based dielectric composites, showcasing their
potential as promising materials for microwave absorption. The examples
underscore that a single dielectric or magnetic system alone cannot
consistently achieve optimal microwave absorption performance,
necessitating the formulation of composite mixtures that incorporate
dielectric and magnetic fillers. These composites' exceptional microwave
absorption capabilities can be attributed to several key factors:
optimizing intrinsic properties: The amalgamation of a carbon-based
material with dielectric components yields distinctive complementary
responses in their intrinsic properties, resulting in optimized
impedance matching. Inducing Interfacial Polarization:
Ample heterogeneous interfaces between different components effectively
induce strong interfacial polarization, enhancing the overall microwave
absorption performance. Facilitating Conductive Networks:
Integrating multiple components facilitates the formation of a
conductive network, hopping electrons and fostering the migration and
fortifying conductivity loss. Precision in Microstructure Design:
Meticulously designed microstructures offer additional propagation
paths for incident electromagnetic waves, stimulating multiple
reflections and scatterings that efficiently consume electromagnetic
energy.
Despite remarkable progress in carbon-based dielectric systems, persistent challenges warrant a strategic approach: In-Depth Exploration of EM Loss Characteristics:
A meticulous exploration of the electromagnetic loss characteristics of
each component is crucial. It emphasizes the need for a rational
combination of elements rather than arbitrarily preparing multicomponent
composites. Defect Engineering: While defects like
grain boundaries, atom vacancies, and heteroatoms positively affect
polarization and conductivity losses, the intricate relationship between
defect sites and microwave absorption performance necessitates further
exploration. Defect engineering is pivotal in guiding the fabrication of
high-performance magnetic and carbon-based dielectric composites. Expanding the Effective Frequency Range:
The effective frequency range of most composites is confined to
8.0–18.0 GHz, limiting their applicability in the electronics industry,
where many devices operate at frequencies lower than 8.0 GHz. A rational
construction approach for multicomponent composites with well-designed
microstructures holds the potential to overcome this limitation and
enhance low-frequency attenuation capabilities. Simplified Preparation Methods:
The preparation methods, especially for multicomponent composites, are
often complicated, posing challenges for large-scale production.
Streamlining these methods is crucial for overcoming production
difficulties.
In
conclusion, the future outlook for high-performance materials against
electromagnetic pollution lies in developing novel carbon-based
dielectric systems, magnetic fillers with well-balanced compositions,
and intricate microstructures. Addressing the outlined challenges will
contribute to realizing these materials' potential to mitigate
electromagnetic interference.
--
Effect of radiation emitted from mobile phone on innate immunity in mice
Pei, Y., Gao, H., Zhang, M., Zhou, F., Zhu, Y., Wang, X., & Sun, J.
(2024). Effect of radiation emitted from mobile phone on innate immunity
in mice.
Radiation Effects and Defects in Solids,
179(11–12), 1585–1596.
https://doi.org/10.1080/10420150.2024.2352845
Abstract
This present study aims to explore the potential impact of cell phone
radiation on innate immunity in mice. Ninety-six male BALB/C mice aged
2–3 weeks were randomly distributed into 4 groups as blank control,
control, TD-SCDMA and LTE-Advanced respectively, with 32 mice in each
group. Mice were designed to be exposed to cell phone radiation for 4–8
weeks. Eight mice in each group were taken out for measurement given
exposure periods were 4, 6 and 8 weeks respectively. Cell biological
technique was conducted to assess the chemotaxis of neutrophils, and a
morphological method was performed for the detection of phagocytosis of
neutrophil and macrophage, while microbiological means was carried out
to test the relative activity of lysozyme in serum of mice. As a result,
the chemotaxis ratio of neutrophils was with little statistical
difference among the four groups given a shorter exposure period.
However, the ratios in TD-SCDMA and LTE-Advanced groups were decreased
significantly on the condition that the exposure period was more than 6
weeks. No statistical difference was observed among the four groups
during the entire exposure period in terms of the chemotaxis index.
Phagocytosis of the innate cells as neutrophil and macrophage showed
little change in the two control groups during the whole experimental
stages, while the percentage in the two treated groups decreased
statistically, and this kind of reduction was prone to feature time
dependence. The activities of lysozyme in TD-SCDMA and LTE-Advanced
groups declined significantly, further to that, the impact was climbing
paralleled with the prolonged duration. It could be deduced that
radiation from cell phones could weaken innate immunity in experimental
mice; moreover, this adverse effect was seemingly more severe as the
radiation exposure continued.
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Numerical
dosimetry of specific absorption rate of insects exposed to far-field
radiofrequency electromagnetic fields
Jeladze V, Nozadze T, Partsvania B,
Thielens A, Shoshiashvili L, Gogoladze T (2025). Numerical
dosimetry of specific absorption rate of insects exposed to far-field
radiofrequency electromagnetic fields. International Journal of Radiation Biology, 1–14. doi: 10.1080/09553002.2024.2442693.
Abstract
Purpose This paper reports a study of electromagnetic field (EMF) exposure of several adult insects: a ladybug, a honey bee worker, a wasp, and a mantis at frequencies ranging from 2.5 to 100 GHz. The purpose was to estimate the specific absorption rate (SAR) in insect tissues, including the brain, in order to predict the possible biological effects caused by EMF energy absorption.
Method Numerical dosimetry was executed using the finite-difference time-domain (FDTD) method. Insects were modeled as 3-tissue heterogeneous dielectric objects, including the cuticle, the inner tissue, and the brain tissue. The EMF source was modeled as sinusoidal plane waves at a single frequency (far-field exposure).
Results The whole-body averaged, tissue averaged, and 1 milligram SAR values were determined in insects for all considered frequencies for 10 different incident plane waves. SAR values were normalized to the incident power density of 1 mW/cm2. Maximal EMF absorption in the inner and brain tissues was observed at 6, 12, and 25 GHz for the considered insects, except the brain tissue of a ladybug (max at 60 GHz).
Conclusion The paper presented the first estimation of the SAR for multiple insects over a wide range of RF frequencies using 3-tissue heterogenous insect 3D models created for this specific research. The selection of tissues’ dielectric properties was validated. The obtained results showed that EMF energy absorption in insects highly depends on frequency, polarization, and insect morphology.
Conclusion
The paper presented a study of RF-EMF dosimetry of honeybee worker,
wasp, mantis, and ladybug from 2.5 to 100 GHz, including frequencies
that will be utilized in future 5 G technologies.
Discrete, 3-tissue heterogenous insect 3D models were created and used for FDTD modeling.
The
whole-body averaged SAR values and tissue-averaged SAR values were
estimated in insects’ tissues for 9 considered frequencies and 10
polarizations of incident plane wave. For the first time, 1 mg SAR
values were determined in insect tissues.
The obtained results
showed SAR values in honeybee, wasp, ladybug, and mantis body tissues,
which depend on the direction of the incident plane wave and
polarization, frequency, and the insects’ body sizes and peculiarities.
The
highest values of the peak 1 mg SAR for the honeybee and wasp −
39.2 W/kg and 169.2 W/kg for an incident field strength of 1 mW/cm2, were observed when E-field polarization was directed along the insect’s length (pol. E3, E5, E9).
The
obtained results showed maximal tissue-specific SAR values in the brain
at 25 GHz for the honeybee (3.6 W/kg), 12 GHz for the wasp (5.4 W/kg),
25 GHz for the mantis (5.2 W/kg), and 60 GHz for the ladybug (10 W/kg),
all for an incident power density of 1 mW/cm2. Maximal EMF
absorption in the inner tissue was observed at 12 GHz, 4.3 W/kg,
5.9 W/kg, 4.8 W/kg for the honey bee, wasp, and ladybug, respectively,
and for the mantis 3.3 W/kg at 6 GHz for an incident power density of
1 mW/cm2. The absorption in insects’ cuticles increased
proportionally with frequency. For example, for the ladybug, the
tissue-specific SAR in the cuticle was 0.1 W/kg at 2.5 Ghz and 11.9 W/kg
at 100 GHz for the same incident power density of 1 mW/cm2.
Future
studies will consider introducing insect models that will be obtained
using micro-CT scanning, examining the effects of high-frequency
electromagnetic fields on other insects of different forms and sizes,
conducting thermal simulations along with EM simulations, and evaluating
temperature rise in insect tissues.
Based on the
present results, we expect this research to have an impact on
(environmental) policymaking and standardization and regulation
regarding RF-EMF emissions. We expect to contribute to the harmonization
of 5G EMF safety and compliance doses and to the development of future
recommendations about safe frequencies and doses of 5G-EMF on the
organisms studied in the present research.
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Emerging cancer therapies: targeting physiological networks and cellular
bioelectrical differences with non-thermal systemic electromagnetic
fields in the human body – a comprehensive review
Costa FP, Wiedenmann B, Schöll E, Tuszynski J. Emerging cancer therapies: targeting physiological networks and cellular bioelectrical differences with non-thermal systemic electromagnetic fields in the human body – a comprehensive review. Frontiers in Network Physiology. Vol. 4, 2024. doi: 10.3389/fnetp.2024.1483401.
Abstract
A steadily increasing number of publications support the concept of physiological networks, and how cellular bioelectrical properties drive cell proliferation and cell synchronization. All cells, especially cancer cells, are known to possess characteristic electrical properties critical for physiological behavior, with major differences between normal and cancer cell counterparts. This opportunity can be explored as a novel treatment modality in Oncology. Cancer cells exhibit autonomous oscillations, deviating from normal rhythms. In this context, a shift from a static view of cellular processes is required for a better understanding of the dynamic connections between cellular metabolism, gene expression, cell signaling and membrane polarization as states in constant flux in realistic human models. In oncology, radiofrequency electromagnetic fields have produced sustained responses and improved quality of life in cancer patients with minimal side effects. This review aims to show how non-thermal systemic radiofrequency electromagnetic fields leads to promising therapeutic responses at cellular and tissue levels in humans, supporting this newly emerging cancer treatment modality with early favorable clinical experience specifically in advanced cancer.
Open access paper:
https://www.frontiersin.org/journals/network-physiology/articles/10.3389/fnetp.2024.1483401
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Effect of 6 GHz radiofrequency
electromagnetic field on the development of fetal bones
Karamazı Y, Emre M, Uçar S, Aksoy G,
Emre T, Tokuş M. (2024). Effect of 6 GHz radiofrequency
electromagnetic field on the development of fetal bones. Electromagnetic Biology and Medicine, 1–9. doi: 10.1080/15368378.2024.2438608.
Abstract
This study examined the
impact of 6 GHz (0.054 W/kg SAR) Radiofrequency-Electromagnetic Field
(RF-EMF) on prenatal bone development. In this study, 20 female and 20
male Wistar Albino rats divided into four groups. The Control group
received no treatment, while in Group-I, only male rats were exposed to
RF-EMF, female rats had no exposure. Group-II, both male and female rats
received RF-EMF treatment. While in Group-III, only female rats were
exposed to RF-EMF, male rats had no exposure. The exposure lasted
4 hours per day for 6 weeks. The rats were then allowed to mate within
the group. After pregnancy, pregnant rats (Group-II and III) were
exposed 4 hours per day for 18 days. On the 18th day of gestation,
fetuses were removed and their weight and various lengths were measured.
The skeletal system development of fetuses was examined with double
skeletal staining method and assessed ossification in the extremities.
In the study, fetal weights, head-tail length, occipital-frontal and
parietal-parietal lengths significantly increased in all exposure groups
when compared to the control group (p < 0.001). Although
occipital-frontal length was smallest in Group-I, Group-II and Group-III
were more higher than the control group (p < 0.001). The
bones of the anterior and posterior extremities showed significant
increases in length, ossification zone length, and ossification
percentage in all experimental groups compared to the control group (p < 0.001).
Our study showed that rats exposed to 6 GHz (0.054 W/kg) RF-EMF during
the prenatal period had significant increases in bone development.
Plain-Language Summary
Radiofrequency
Electromagnetic Field (RF-EMF) sources are one of the most widely used
technology systems in daily life. This study examined the impact of
6 GHz RF-EMF on prenatal bone development. In this study, 20
female and 20 male Wistar Albino rats divided into four groups. The
control group rats received no treatment, while in Group-I, only male
rats, Group-II, both male and female rats, while in Group-III, only
female rats were exposed to RF-EMF. The exposure lasted 4 hours/day for
6 weeks. The rats were then allowed to mate within the group. After
pregnancy, pregnant rats (Group-II and III) were exposed 4 hours/day for
18 days. On the 18th day of gestation, fetuses were removed 10 fetuses
each group were randomly selected in each group and their weight and
various lengths were measured. The skeletal system development of
fetuses was examined with double skeletal staining method. The ImageJ
program was used assess ossification in the extremities.
https://www.tandfonline.com/doi/full/10.1080/15368378.2024.2438608
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Effects of 4G Long-Term Evolution Electromagnetic Fields
on Thyroid Hormone Dysfunction and Behavioral Changes in Adolescent
Male Mice
Kim H-Y,
Son Y, Jeong YJ,
Lee S-H, Kim N,
Ahn YH, Jeon SB,
Choi H-D, Lee
H-J.
Effects of 4G Long-Term Evolution Electromagnetic Fields
on Thyroid Hormone Dysfunction and Behavioral Changes in Adolescent
Male Mice. International Journal of Molecular Sciences. 2024; 25(20):10875. doi: 10.3390/ijms252010875.
Abstract
Radiofrequency electromagnetic fields
(RF-EMFs) can penetrate tissues and potentially influence endocrine and
brain development. Despite increased mobile phone use among children and
adolescents, the long-term effects of RF-EMF exposure on brain and
endocrine development remain unclear. This study investigated the
effects of long-term evolution band (LTE) EMF exposure on thyroid
hormone levels, crucial for metabolism, growth, and development.
Four-week-old male mice (C57BL/6) were exposed to LTE EMF (whole-body
average specific absorption rate [SAR] 4 W/kg) or a positive control
(lead; Pb, 300 ppm in drinking water) for 4 weeks. Subsequently, the
mice underwent behavioral tests including open field, marble burying,
and nest building. Blood pituitary and thyroid hormone levels, and
thyroid hormone-regulating genes within the
hypothalamus–pituitary–thyroid (HPT) axis were analyzed. LTE exposure
increased T3 levels, while Pb exposure elevated T3 and T4 and decreased
ACTH levels. The LTE EMF group showed no gene expression alterations in
the thyroid and pituitary glands, but hypothalamic Dio2 and Dio3
expressions were significantly reduced compared to that in the
sham-exposed group. Pb exposure altered the hypothalamic mRNA levels of Oatp1c1 and Trh, pituitary mRNA of Trhr, and Tpo and Tg expression in the thyroid. In conclusion, LTE EMF exposure altered hypothalamic Dio2 and Dio3
expression, potentially impacting the HPT axis function. Further
research is needed to explore RF-EMF’s impacts on the endocrine system.
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Evaluation of the Thyroids of Offsprings Exposed to 2450 MHz Radiofrequency Radiation During Pregnancy: A Sixth Month Data
Ozyilmaz C, Oktay MF, Dasdag S, Ulukaya E, Genel ME, Tansuker HD, Emre F, Yeğin K.
Evaluation of the Thyroids of Offsprings Exposed to 2450 MHz Radiofrequency Radiation During Pregnancy: A Sixth Month Data. Journal of International Dental & Medical Research, 2024, 17(2): 925-930.
Abstract
This study aimed to determine whether the exposure to radiofrequency emitted by wireless internet providers (2450 MHz) throughout the day during rats’ pregnancy causes a problem in the thyroid tissues of their offspring.
The pregnant rats in the experimental group were exposed to radiofrequency radiation (RFR) (24 hours/day) at a 2450 MHz frequency in pulse wave mode with 1 W output strength by a generator simulating Wi-Fi waves. The offspring in the control and experimental groups were randomized selected (n:8). At the end of the sixth month, the thyroid tissues were removed and evaluated histopathologically and biochemically. Mann‒Whitney U-tests and T-tests were used for statistical analysis. The threshold for statistical significance was p <0.05.
There was a significant difference in mononuclear cell infiltration (p=0.03) and vascular increase in congestion (p<0.001). There was no difference in the TUNEL-positive cell percentage (p=0.62) and H2A.X antibody levels (p=0.68) between the rats in the control and experimental groups. In this study, 2450 MHz RFR exposure during the prenatal period did not cause a statistically significant difference in terms of H2A.X levels and TUNEL-positive cell percentages in the thyroid tissue of rats.
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Effects of extremely low frequency magnetic fields on animal cancer and
DNA damage: a systematic review and meta-analysis
Brabant C, Honvo G, Demonceau C, Tirelli E, Léonard F, Bruyère O.
Effects of extremely low frequency magnetic fields on animal cancer and
DNA damage: a systematic review and meta-analysis. Prog Biophys Mol
Biol. 2024 Dec 31:S0079-6107(24)00116-0. doi:
10.1016/j.pbiomolbio.2024.12.005.
Abstract
The objective of this systematic review and meta-analysis is to
assess the carcinogenic effects of extremely low frequency magnetic
fields (ELF-MF) by analyzing animal and comet assay studies. We have
performed a global meta-analysis on all the animal studies on the
relation between ELF-MF and cancer incidence and separate meta-analyses
on the incidence of cancer, leukemia, lymphoma, breast cancer, brain
cancer and DNA damage assessed with the comet assay. Of the 5145
references identified, 71 studies have been included in our systematic
review and 22 studies in our meta-analyses. Our global meta-analysis
indicated that ELF-MF exposure had no significant impact on the
incidence of cancers in rodents (19 studies, OR = 1.10; 95% CI
0.91-1.32). However, our separate meta-analyses showed that ELF-MF
increased the odds of developing leukemia in mice (4 studies, OR = 4.45;
95% CI 1.90-10.38) but not in rats. Our systematic review also suggests
that ELF-MF can damage DNA in certain cell types like brain cells.
Nevertheless, a meta-analysis on three comet assay studies indicated
that ELF-MF did not increase DNA damage in neuroblastoma cells (SMD =
-0.08; 95% CI -0.18-0.01). Overall, our results suggest that exposure to
ELF-MF does not represent a major hazard for mammals and the
carcinogenic effects of these magnetic fields could be limited to
leukemia.
Highlights
ELF-MF do not affect the odds of lymphoma, brain cancer and breast cancer in rodents
ELF-MF could increase the odds of developing leukemia in mice but not in rats
ELF-MF have no influence on survival and body weight in rodents
ELF-MF do not increase DNA damage in neuroblastoma cells
ELF-MF could damage DNA of certain cell types like brain cells in rodents
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Effects of extremely
low-frequency (50 Hz) electromagnetic fields on vital organs of adult
Wistar rats and viability of mouse fibroblast cells
Tekam CKS, Majumdar S, Kumari P, Prajapati
SK, Sahi AK, Singh R, Krishnamurthy S, Mahto SK. Effects of extremely
low-frequency (50 Hz) electromagnetic fields on vital organs of adult
Wistar rats and viability of mouse fibroblast cells. Radiat Prot
Dosimetry. 2024 Dec 4:ncae220. doi: 10.1093/rpd/ncae220.
Abstract
In recent years, scientific communities have been concerned about the
potential health effects of periodic electromagnetic field exposure (≤1
h/d). The objective of our study is to determine the impact of extremely
low-frequency pulsed electromagnetic fields (ELF-PEMF) (1-3 mT, 50 Hz)
on mouse fibroblast (red fluorescent protein (RFP)-L929) cells and adult
Wistar rats to gain a comprehensive understanding of biological
effects. We observed that RFP-L929 exhibits no significant changes in
cell proliferation and morphology but mild elevation in aspartate
aminotransferases, alanine aminotransferases, total bilirubin, serum
creatinine, and creatine kinase-myocardial band levels in ELF-PEMF
exposed groups under in vitro and in vivo conditions. However, the
histological examination showed no significant alterations in tissue
structure and morphologies. Our result suggests that 50-Hz ELF-PEMF
exposure (1-3 mT, 50 Hz) with duration (<1 h/d) can trigger mild
changes in biochemical parameters, but it is insufficient to induce any
pathological alterations.
Conclusions
The present study demonstrates the effects of 50-Hz ELF-PEMF (1–3 mT) using in vitro (RFP-L929 mouse fibroblast cells) and in vivo
(adult male Wistar rats) models. The results reveal that exposure
duration of 20 min (each) with a 4-h gap is non-destructive for RFP-L929
cells and causes mild alterations in biochemical parameters but not in
organ coefficient, tissue structure, and morphology of adult Wistar
rats. The results demonstrated that 50-Hz ELF-PEMF exposure did not
cause significant cellular fragmentation and changes in the morphology
of mouse fibroblast cells. We observed mild alterations in the
biochemical parameters of rats among MF exposed and control groups.
Conversely, histological analysis of the selected liver, kidney, and
heart sections following ELF-PEMF exposure revealed no significant
changes in tissue structure and morphology. Our efforts provide
conceptual and experimental support to establish a link between 50-Hz
ELF-PEMF exposure and biological systems/tissues in residential and
occupational environments.
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Extremely Low-Frequency Electromagnetic Field (ELF-EMF)
Increases Mitochondrial Electron Transport Chain Activities and
Ameliorates Depressive Behaviors in Mice
Teranishi M,
Ito M, Huang Z,
Nishiyama Y, Masuda A,
Mino H,
Tachibana M, Inada T,
Ohno K.
Extremely Low-Frequency Electromagnetic Field (ELF-EMF)
Increases Mitochondrial Electron Transport Chain Activities and
Ameliorates Depressive Behaviors in Mice. International Journal of Molecular Sciences. 2024; 25(20):11315.
https://doi.org/10.3390/ijms252011315
Abstract
Compromised mitochondrial electron transport chain (ETC) activities are
associated with depression in humans and rodents. However, the effects
of the enhancement of mitochondrial ETC activities on depression remain
elusive. We recently reported that an extremely low-frequency
electromagnetic field (ELF-EMF) of as low as 10 μT induced hormetic
activation of mitochondrial ETC complexes in human/mouse cultured cells
and mouse livers. Chronic social defeat stress (CSDS) for 10 consecutive
days caused behavioral defects mimicking depression in mice, and using
an ELF-EMF for two to six weeks ameliorated them. CSDS variably
decreased the mitochondrial ETC proteins in the prefrontal cortex (PFC)
in 10 days, which were increased by an ELF-EMF in six weeks. CSDS had no
effect on the mitochondrial oxygen consumption rate in the PFC in 10
days, but using an ELF-EMF for six weeks enhanced it. CSDS inactivated
SOD2 by enhancing its acetylation and increased lipid peroxidation in
the PFC. In contrast, the ELF-EMF activated the Sirt3-FoxO3a-SOD2
pathway and suppressed lipid peroxidation. Furthermore, CSDS increased
markers for mitophagy, which was suppressed by the ELF-EMF in six weeks.
The ELF-EMF exerted beneficial hormetic effects on mitochondrial energy
production, mitochondrial antioxidation, and mitochondrial dynamics in a
mouse model of depression. We envisage that an ELF-EMF is a promising
therapeutic option for depression.
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Effects
of light, electromagnetic fields and water on biological rhythms
Martel J, Rouleau N, Murugan NJ, Chin WC, Ojcius DM, Young JD. Effects
of light, electromagnetic fields and water on biological rhythms. Biomed
J. 2024 Dec 11:100824. doi: 10.1016/j.bj.2024.100824.
Abstract
The circadian rhythm controls a wide range of functions in the
human body and is required for optimal health. Disruption of the
circadian rhythm can produce inflammation and initiate or aggravate
chronic diseases. The modern lifestyle involves long indoor hours under
artificial lighting conditions as well as eating, working, and sleeping
at irregular times, which can disrupt the circadian rhythm and lead to
poor health outcomes. Seasonal solar variations, the sunspot cycle and
anthropogenic electromagnetic fields can also influence biological
rhythms. The possible mechanisms underlying these effects are discussed,
which include resonance, radical-pair formation in retina
cryptochromes, ion cyclotron resonance, and interference, ultimately
leading to variations in melatonin and cortisol. Intracellular water,
which represents a coherent, ordered phase that is sensitive to infrared
light and electromagnetic fields, may also respond to solar variations
and man-made electromagnetic fields. We describe here various factors
and underlying mechanisms that affect the regulation of biological
rhythms, with the aim of providing practical measures to improve human
health.
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The origins of
light-independent magnetoreception in humans
Shibata T, Hattori N, Nishijo H, Kuroda S, Takakusaki K. The origins of
light-independent magnetoreception in humans. Front Hum Neurosci. 2024
Nov 29;18:1482872. doi: 10.3389/fnhum.2024.1482872.
Abstract
The Earth's abundance of iron has played a crucial role in both
generating its geomagnetic field and contributing to the development of
early life. In ancient oceans, iron ions, particularly around deep-sea
hydrothermal vents, might have catalyzed the formation of
macromolecules, leading to the emergence of life and the Last Universal
Common Ancestor. Iron continued to influence catalysis, metabolism, and
molecular evolution, resulting in the creation of magnetosome gene
clusters in magnetotactic bacteria, which enabled these unicellular
organisms to detect geomagnetic field. Although humans lack a clearly
identified organ for geomagnetic sensing, many life forms have adapted
to geomagnetic field-even in deep-sea environments-through mechanisms
beyond the conventional five senses. Research indicates that zebrafish
hindbrains are sensitive to magnetic fields, the semicircular canals of
pigeons respond to weak potential changes through electromagnetic
induction, and human brainwaves respond to magnetic fields in darkness.
This suggests that the trigeminal brainstem nucleus and vestibular
nuclei, which integrate multimodal magnetic information, might play a
role in geomagnetic processing. From iron-based metabolic systems to
magnetic sensing in neurons, the evolution of life reflects ongoing
adaptation to geomagnetic field. However, since magnetite-activated,
torque-based ion channels within cell membranes have not yet been
identified, specialized sensory structures like the semicircular canals
might still be necessary for detecting geomagnetic orientation. This
mini-review explores the evolution of life from Earth's formation to
light-independent human magnetoreception, examining both the magnetite
hypothesis and the electromagnetic induction hypothesis as potential
mechanisms for human geomagnetic detection.
Conclusion
Eukaryotic cells, and vertebrates have developed
magnetoreception systems to adapt to the geomagnetic field. Numerous studies on magnetoreception in birds, particularly concerning the upper beak and inner ear, suggest that in humans, the trigeminal nerve, vestibular nerve, and hindbrain might be involved in light-independent magnetoreception pathways. However, the specific sensory organ in humans that detects the geomagnetic field has not yet been identified. Unlike traditional senses, geomagnetic information is transmitted without attenuation through the scalp, bones, and cerebrospinal fluid, similar to gravity. It also generates eddy currents and lorentz forces accompanying the relative movement of the geomagnetic field (Arago and Flourens, 1856). Considering these unique properties, vertebrates might have evolved to detect the geomagnetic field in a light-independent manner, not only through direct detection using torque-based magnetic particles but also through indirect detection of electric potentials using electromagnetic induction. Further research into this evolutionary adaptation could help unravel the mystery of geomagnetic field detection in humans.
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Effects of anthropogenic
electromagnetic fields used for subsurface oil and gas exploration
(controlled-source electromagnetics, CSEM) on the early development of
Atlantic haddock
Guillebon C, Perrichon P, Browman HI, Cresci
A, Sivle LD, Skiftesvik AB, Zhang G, Durif CMF. Effects of anthropogenic
electromagnetic fields used for subsurface oil and gas exploration
(controlled-source electromagnetics, CSEM) on the early development of
Atlantic haddock (Melanogrammus aeglefinus). Mar Pollut Bull. 2024 Dec
12;211:117425. doi: 10.1016/j.marpolbul.2024.117425.
Abstract
Controlled source electromagnetics (CSEM) uses electromagnetic fields
(EMF) to detect oil reservoirs. Atlantic haddock, Melanogrammus
aeglefinus, is a commercially important demersal fish species that can
potentially be impacted by such surveys due to potential overlap with
egg distribution. In this study, haddock eggs were exposed to EMF,
replicating CSEM survey conditions in a laboratory. Three different EMF
intensities were used to replicate different distances between the EMF
source and the organism. Exposures lasted for 15 min. A worst-case
scenario, i.e. 1 h exposure at the highest EMF level was also carried
out. None of the treatments caused malformations, mortality or affected
hatching of eggs. However, EMF exposure induced tachycardia in newly
hatched larvae and reduced the size of their yolk sac reserve. The
effect was significant at the lowest EMF intensity (corresponding to
1000 m between the EMF source and the exposed subject) and increased
with exposure time and intensity
