Low Frequency Electromagnetic Fields Research Articles

Positive effects of pulsed electromagnetic fields on behavior, immune function, and oxidative and inflammatory state in old mice

ABSTRACT The establishment of chronic oxidative and inflammatory stress with aging leads to the deterioration of the nervous and immune systems and, consequently, to the loss of health. The aim of this work was to study the effect of exposure to low-frequency pulsed electromagnetic fields (PEMFs) produced by the NEURALTER® system (15 min/day for 4 weeks) in the behavior, immune functions, and oxidative and inflammatory state of old mice. Female old CD1 mice were divided into three groups: control group, handling control group and Neuralter group. Then, behavioral tests were performed, and peritoneal leukocytes were extracted to analyze function, oxidative and inflammatory parameters. In peritoneal leukocytes from old mice, the effects in vitro of 15 min with NEURALTER® were studied on function and oxidative parameters. The results show that after this type of treatment, old mice had greater coordination and locomotion, better immune function, and an oxidative-inflammatory state. Similarly, the immune function and oxidative state of leukocytes showed an improvement when these cells were exposed directly to the NEURALTER® system. In conclusion, the exposure to low-frequency PEMFs produced by the NEURALTER® system has beneficial effects on health in aging. In addition, this effect is direct, at least in part, on immune cells.

Phagocytosis of latex beads by a human monocytic Mono Mac 6 cell line and effects of low-frequency electromagnetic field interaction.

Some studies have shown that electromagnetic fields (EMFs) may impact immune response cells and their functions. The first stage of the defense from pathogens is innate immunity encompassing phagocytosis and phagocytosis-related intracellular effects. Our work aimed to determine the influence of a low-frequency electromagnetic field (7 Hz, 30 mTrms) on the phagocytosis process of latex beads (LBs), the production of reactive oxygen species (ROS), and viability changes in a human monocytic Mono Mac 6 (MM6) cell line as an experimental model of the phagocytosing cells in in vitro cell culture conditions. For these purposes, cells were firstly activated with infectious agents such as lipopolysaccharide (LPS), Staphylococcal enterotoxin B (SEB), or the proliferatory agent phytohaemagglutinin (PHA), and then a phagocytosis test was performed. Cell viability and range of phagocytosis of latex beads by MM6 cells were measured by flow cytometry, and the level of ROS was evaluated with the use of a cytochrome C reduction test. The obtained results revealed that applied EMF exposure mainly increased the necrosis parameter of cell death when they were pre-stimulated with SEB as an infectious factor and subsequently phagocytosed LBs (P=0.001). Prestimulation with other agents like LPS or PHA preceding phagocytosis resulted in no statistically significant changes in cell death parameters. The level of ROS depended on the used stimulatory agent, phagocytosis, and/or EMF exposure. The obtained effects for EMF exposure indicated only a slight decrease in the ROS level for cells phagocytosing latex beads and being treated with SEB or PHA, while the opposite effect was observed for LPS pre-stimulated cells (data not statistically significant). The results concerning the viability of phagocytosing cells, the effectiveness of the phagocytosis process, and the level of radical forms might result from applied EMF parameters like signal waveform, frequency, flux density, and especially single EMF exposure.

Measuring and assessing the effects of extremely low-frequency electromagnetic fields (ELF-EMF) on blood parameters and liver enzymes of personnel working in high voltage power stations in a petrochemical industry

IntroductionExposure to electric and magnetic fields (EMF) is a phenomenon that has always been present. In the last two decades, there have been numerous worries about the possible effects of extremely low-frequency (ELF) fields on human health. Consequently, this study aims to measure and evaluate the effect of ELF fields on blood parameters and liver enzymes of personnel working in high-voltage power stations in the petrochemical industry. MethodsThis cross-sectional, descriptive-analytical study was done in a petrochemical industry in southern Iran in 2021. Two groups of 50 people were selected to attain the research goals and classify jobs with the risk of exposure to extremely low-frequency electromagnetic fields (ELF-EMF) and the time spent on work. One group was exposed to ELF-EMF, and the other was regarded as the control group. Electromagnetic fields were measured using the HI-3604 device and the standard method of IEEE 1994-644. The workers' demographic data, blood parameters, and liver enzymes were also obtained from the workers’ medical records. The course of changes in each of the blood parameters and liver enzymes and demographic variables in the control and case groups were then examined. In the last stage, the effect of the electric field and magnetic field on the blood parameters and liver enzymes of the two control and subject groups was conducted using the multiple regression model. ResultsThe measured points in all stations are 200, and the minimum and maximum values of the magnetic field was 0.8 and 2019 mG, respectively. The minimum and maximum values of the electric field intensity was 0.003 and 215 V/m, respectively. The average results of the demographic variables and blood and liver indices in the control and case groups from 2018 to 2020 revealed that the average variables were not significantly different in the case and control groups (p-value>0.05). Moreover, workers' exposure to ELF-EMF was below the permissible limit. ConclusionBased on the results of the present study, ELF-EMF does not have any significant effects on demographic factors, blood parameters, and liver enzymes.

Ультранизкочастотные осцилляции интенсивности люминесценции полимерной мембраны в водных растворах солей

The paper studies luminescence from the Nafion polymer membrane surface at its swelling in the isotonic aqueous solutions and bi-distilled water using the experimental photo luminescent spectroscopy. Liquid samples were preliminarily treated with the electric pulses with duration of 1 µs and amplitude of 0.1 V using antenna in the form of a flat capacitor. Experiments in photo luminescent spectroscopy were carried out 20 min after the electric pulse treatment. Typical luminescence intensity dependence on the membrane swelling time could be represented as the exponentially decreasing function. Characteristic decay time of the corresponding functions and stationary level of the membrane luminescence intensity depend on the electrical pulses repetition rate. The obtained dependencies could well be reproduced. However, dependence of the luminescence intensity at certain pulse repetition rates appears to be a random function, and the reproducibility is missing. It could be assumed that these stochastic effects are associated with exposure to random external force of the electromagnetic nature acting on the polymer membrane during swelling. Low-frequency pulsations of neutron stars or white dwarfs are the source of this random force according to the authors of the work. This effect is associated with depolarization during the low-frequency electromagnetic field scattering caused by the neutron stars pulsation. Depolarization effect arises due to scattering on long-living anisotropic clusters of nano-bubbles, which, in turn, are becoming anisotropic in the external field of a flat capacitor. Depolarized scattered radiation causes stochastic oscillations of the polymer fibers unwound into the bulk liquid. In this case, luminescence should also acquire the stochastic character taking into account the effect of resonant luminescence energy transfer from a donor to the luminescence acceptor

Extremely Low Frequency-Electromagnetic Fields (ELF-EMF) Can Decrease Spermatocyte Count and Motility and Change Testicular Tissue.

Substantial evidence indicates that exposure to extremely low frequency-electromagnetic fields (ELF-EMFs) affects male reproductive system. The goal of this study was to evaluate the effects of long-term irradiation with ELF-EMF on sperm quality and quantity and testicular structure. In this case-control study, sixty male Sprague-Dawley rats were randomly divided into six groups. Experimental groups were exposed to ELF-EMF (50 Hz EMF, 100 µT) for either 1 h/day for 52 days (Group 1), 4 h/day for 52 days (Group 3), 1 h/day for 5 days (Group 5), 4 h/day for 52 days (Group 7). Groups 2, 4, 6 and 8 were only sham exposed at durations equal to Groups 1, 3, 5 and 7, respectively. Both count and motility of sperms were significantly decreased in animals exposed to ELF-EMF (1 h/day for 52 days, 4 h/day for 52 day, and 4 h/day for 5 days) compared to the sham-exposed groups (P<0.05). Serum testosterone levels showed a significant decrease in the animals exposed to ELF-EMF (4 h/day for 5 days) compared to the control groups (P<0.05). A significant decrease was observed in the volume of the seminiferous tubules, seminiferous tubules epithelium and interstitial tissue in the animals exposed to ELF-EMF for 4 h/day for 5 days. Tubules length was also reduced by 18% in animals exposed to ELF-EMF (4 h/day for 5 days). Our results show that ELF-EMF can reduce spermatocyte count and motility and is able to induce structural changes in testicular tissue.

Effect of prenatal stress and extremely low-frequency electromagnetic fields on anxiety-like behavior in female rats: With an emphasis on prefrontal cortex and hippocampus.

Prenatal stress (PS) is a problematic situation resulting in psychological implications such as social anxiety. Ubiquitous extremely low-frequency electromagnetic fields (ELF-EMF) have been confirmed as a potential physiological stressor; however, useful neuroregenerative effect of these types of electromagnetic fields has also frequently been reported. The aim of the present study was to survey the interaction of PS and ELF-EMF on anxiety-like behavior. A total of 24 female rats 40 days of age were distributed into four groups of 6 rats each: control, stress (their mothers were exposed to stress), EMF (their mothers underwent to ELF-EMF), and EMF/stress (their mothers concurrently underwent to stress and ELF-EMF). The rats were assayed using elevated plus-maze and open field tests. Expressions of the hippocampus GAP-43, BDNF, and caspase-3 (cas-3) were detected by immunohistochemistry in Cornu Ammonis 1 (CA1) and dentate gyrus (DG) of the hippocampus and prefrontal cortex (PFC). Anxiety-like behavior increased in all treatment groups. Rats in the EMF/stress group presented more serious anxiety-like behavior. In all treatment groups, upregulated expression of cas-3 was seen in PFC, DG, and CA1 and downregulated expression of BDNF and GAP-43 was seen in PFC and DG and the CA1. Histomorphological study showed vast neurodegenerative changes in the hippocampus and PFC. The results showed ,female rats that underwent PS or/and EMF exhibited critical anxiety-like behavior and this process may be attributed to neurodegeneration in PFC and DG of the hippocampus and possibly decreased synaptic plasticity so-called areas.

Relationship between low-frequency electromagnetic field and computer vision syndrome.

This study aimed to determine the prevalence of computer vision syndrome (CVS) among secretaries working in different departments of a university hospital in Turkey and its relationship with low-frequency electromagnetic field (LF-EMF) exposure. This cross-sectional study included 143 secretaries working in different departments of the hospital. Besides eye examinations, CVS Syndrome Questionnaire (CVS-Q) Scale and Ocular Surface Disease Index Scale (OSDI) were applied to the participants. LF-EMF of the work environment were measured with a 6010 Gauss/Teslameter device and the light intensity with an LX-1102 Device. The mean age of participants was 39.6 years, with a male-to-female ratio of 25.2% to 74.8%. CVS-Q scale revealed 83.9% of computer vision syndrome among participants. A weak positive correlation was found between CVS-Q and LF-EMF, while a moderately strong, negative correlation was found between LF-EMF and Schirmer test of both eyes. The work environment LF-EMF values were significantly higher among the participants diagnosed with CVS (p<0.05). The risk of CVS was found to increase 3.27 times when the ambient LF-EMF was >1,725 µT and an increase of 0.004 units in the CVS-Q score was calculated for each one-unit increase in the LF-EMF of the environment. A relationship between CVS, dry eye and EMF was observed among people exposed to LF-EMF. Regular measurement of EMF in work environments, and developing protective behaviours (work-break intervals, 20-20-20 rule, etc.) can be recommended.

Controlled-source electromagnetic modeling using a high-order finite-difference time-domain method on a nonuniform grid

Simulation of 3D low-frequency electromagnetic (EM) fields propagating in the earth is computationally expensive. We have developed a fictitious wave-domain high-order finite-difference time-domain (FDTD) modeling method on nonuniform grids to compute frequency-domain 3D controlled-source EM data. The method overcomes the inconsistency issue widely present in the conventional second-order staggered-grid finite-difference scheme over a nonuniform grid, achieving high accuracy with an arbitrarily high-order scheme. The finite-difference coefficients adaptive to the node spacings can be accurately computed by inverting a Vandermonde matrix system using an efficient algorithm. A generic stability condition applicable to nonuniform grids is established, revealing the dependence of the time step and these finite-difference coefficients. A recursion scheme using fixed-point iterations is designed to determine the stretching factor to generate the optimal nonuniform grid. The grid stretching in our method reduces the number of grid points required in the discretization, making it more efficient than the standard high-order FDTD with a densely sampled uniform grid. Instead of stretching in vertical and horizontal directions, better accuracy of our method is observed when the grid is stretched along the depth without horizontal stretching. The efficiency and accuracy of our method are demonstrated by numerical examples.

Effects of extremely low-frequency magnetic fields on human MDA-MB-231 breast cancer cells: proteomic characterization

Extremely low-frequency electromagnetic fields (ELF-MF) can modify the cell viability and regulatory processes of some cell types, including breast cancer cells. Breast cancer is a multifactorial disease where a role for ELF-MF cannot be excluded. ELF-MF may influence the biological properties of breast cells through molecular mechanisms and signaling pathways that are still unclear. This study analyzed the changes in the cell viability, cellular morphology, oxidative stress response and alteration of proteomic profile in breast cancer cells (MDA-MB-231) exposed to ELF-MF (50 Hz, 1 mT for 4 h). Non-tumorigenic human breast cells (MCF-10A) were used as control cells. Exposed MDA-MB-231 breast cancer cells increased their viability and live cell number and showed a higher density and length of filopodia compared with the unexposed cells. In addition, ELF-MF induced an increase of the mitochondrial ROS levels and an alteration of mitochondrial morphology. Proteomic data analysis showed that ELF-MF altered the expression of 328 proteins in MDA-MB-231 cells and of 242 proteins in MCF-10A cells. Gene Ontology term enrichment analysis demonstrated that in both cell lines ELF-MF exposure up-regulated the genes enriched in “focal adhesion” and “mitochondrion”. The ELF-MF exposure decreased the adhesive properties of MDA-MB-231 cells and increased the migration and invasion cell abilities. At the same time, proteomic analysis, confirmed by Real Time PCR, revealed that transcription factors associated with cellular reprogramming were upregulated in MDA-MB-231 cells and downregulated in MCF-10A cells after ELF-MF exposure. MDA-MB-231 breast cancer cells exposed to 1 mT 50 Hz ELF-MF showed modifications in proteomic profile together with changes in cell viability, cellular morphology, oxidative stress response, adhesion, migration and invasion cell abilities. The main signaling pathways involved were relative to focal adhesion, mitochondrion and cellular reprogramming.

The Effect of an Extremely Low-Frequency Electromagnetic Field on the Drought Sensitivity of Wheat Plants.

Extremely low-frequency magnetic fields are thought to be capable of modulating the resistance of plants to adverse factors, particularly drought. Magnetic fields in this frequency range occur in nature in connection with so-called Schumann resonances, excited by lightning discharges in the Earth-ionosphere cavity. The aim of this work was to identify the influence of a magnetic field with a frequency of 14.3 Hz (which corresponds to the second Schumann harmonic) on the transpiration and photosynthesis of wheat plants under the influence of drought. The activity of photosynthesis processes, the crop water stress index, relative water content and leaf area were determined during drought intensification. At the end of the experiment, on the 12th day of drought, the length, and fresh and dry weight of wheat shoots were measured. The results obtained indicate a protective effect of the magnetic field on plants in unfavorable drought conditions; the magnetic field delayed the development of harmful changes in the transpiration and photosynthesis processes for several days. At the same time, in the absence of the stressor (drought), the effect of the electromagnetic field was not detected, except for a decrease in relative transpiration. In favorable conditions, there were only minimal modifications of the photosynthetic processes and transpiration by the magnetic field.

Extremely low-frequency electromagnetic field (ELF-EMF) induces alterations in epigenetic regulation in the myometrium – An in vitro study

Previous research by the authors indicated that an extremely low-frequency electromagnetic field (ELF-EMF) evokes molecular alterations in the porcine myometrium. It was hypothesized that the ELF-EMF could induce alterations in the epigenetic regulation of gene expression in the myometrium. In the current study, slices of the porcine myometrium during the peri-implantation period (n = 4) were used for further in vitro exposition to ELF-EMF (50 Hz, 8 mT, 2 h treatment duration). The study tested whether the ELF-EMF may affect: 1/the expression of DNA (cytosine-5)-methyltransferase 1 (DNMT1) and DNA (cytosine-5)-methyltransferase 3a (DNMT3a), 2/the level of genomic DNA methylation, and 3/the level of amplification of methylated and unmethylated variants of promoter regions of selected genes with altered expression in response to ELF-EMF. It was found that ELF-EMF treatment increased DNMT1, decreased DNMT3a mRNA transcript and protein abundance, and increased the level of genomic DNA methylation. The direction of alterations in the level of amplification of methylated and unmethylated variants of the promoter region of selected genes with altered expression, i.e. prodynorphin (PDYN), interleukin 15 (IL15) signal transducer and activator of transcription 5A (STAT5A), tumor necrosis factor (TNF), and between down-regulated genes were early growth response 2 (EGR2), hyaluronan and proteoglycan link protein 1 (HAPLN1), and uteroferrin associated basic protein-2 (UABP2), mostly involving the direction of changes in their transcriptional activity, which was evaluated in a previous study by the authors. Thus, ELF-EMF radiation disturbs epigenetic mechanisms, which may underlay ELF-EMF-related transcriptomic alterations in the myometrium.

Effect of extremely low frequency electromagnetic field on the pathogenicity of Magnaporthe oryzae

Numerous works have reported that extremely low frequency electromagnetic fields (ELF-EMFs) were associated with human health; however, little is known about their effects on the occurrence of agricultural diseases. In this study, Magnaporthe oryzae was used as a model organism, and its pathogenicity under 50 Hz, 3 mT ELF-EMF was studied. Our results showed that the pathogenicity, growth rate, and conidia generation of M. oryzae were enhanced under ELF-EMF exposure. In addition, M. oryzae exposed to ELF-EMF showed enhanced tolerance to cell wall-perturbing agents sodium lauryl sulphate, and increased expression of cell wall integrity-related genes, including RAC1, CDC42, RHO2, and NOX2. In addition, the level of reactive oxygen species (ROS) and the expression level of ROS scavenger system-related gene MoAP1 increased in ELF-EMF-exposed samples, whereas the total antioxidant capacity and the activities of superoxide dismutase and catalase did not change. Results of our study demonstrated that exposure to 50 Hz, 3 mT ELF-EMF enhanced the infection ability of M. oryzae, which present new important challenges for understanding the effect of ELF-EMF exposure on farmland ecology, especially on agricultural diseases.

Impact Computation of Electric and Magnetic Field on Farmers Working Near High Voltage Transmission Lines in Pakistan by Developing Software

In this revolutionized era, electricity has become an essential necessity of humans. People all over the world are concerned about the effects of HVTL (high voltage transmission lines) and their severe effects impacting on their health. Over the last two decades, developed countries have become increasingly concerned about an increase in electromagnetic fields, which poses health risks. The electromagnetic field emitted by HVTL will cause a low current to pass through the bodies. The electricity system produces low frequency electromagnetic field, which lead to the health hazards. The critical problem to those who are living near HVTL, therefore our fundamental task is to let them aware of the risk. Due to harmful exposures of electric and magnetic field, farmers working under HVTL or having their residences, suffering through severe effects in the form of different diseases. The main aim behind this research is to design GUI based software having two parts which helps to bring output of the electromagnetic field exposures with the help of various parameters includes different weather conditions affecting electric field, how people of different ages are being affected through it, identification of the regions need further protection by developing a proper mathematical model. Two approaches were used, one is to interface GUI with different sensors and second is user define function. On the basis of output EMF it will be able to find out the possible disease by using the data of WHO, ICNIRP and the data which is collected from surveys of different regions.

Three-dimensional geoelectrical model of the central part of the Zvizdal-Zaliska and Brusyliv fault zones of the Ukrainian Shield

To study the deep structure of the geoelectrically complex junction zone of three megablocks of the western part of the Ukrainian Shield (Volyn', Podil, and Ros'), a three-dimensional model of the central part of the Zvizdal-Zaliska and Brusyliv fault zones was created. It is based on modern experimental observations of the Earth's natural low-frequency electromagnetic field in a wide range of periods. Synchronous experimental data of deep magnetotelluric sounding and magnetovariational profiling, obtained by the Institutes of the National Academy of Sciences of Ukraine in 2009—2019, were analyzed. The main issues of the geoelectrical modeling methodology using the Mtd3fwd software complex were considered, such as model elements, stages, alternative models, examples of calculations and comparison of observations, errors, etc. The constructed model analysis showed that of the large number of near-surface anomalies with low resistivity (5 to 100 Ohm · m), most sink to 500 m and only a few reach a depth of 1 km and are followed up to 11 km. It was established that there are connections between conductivity and structural features of the Zvizdal-Zaliska, Brusyliv, Nemyriv fault zones, the Samgorod fault and the Kocheriv synclinorium. Most of the isolated conductors appear in a mosaic pattern along the extended fault zones and form interspersed chains of high and low resistivity. Regional anomalies were confirmed and detailed both in the deep part of the crust and in the upper mantle; part of the Zvizdal-Zaliska fault zone appeared at depths of 15—30 km as a contact zone of abnormally high and low resistivities. Anomalies are confined to elongated zones of metasomatization and graphitized rock areas, some of the surface anomalies correspond to areas of the weathering crust. Most of the anomalies coincide with ore occurrences, ore-bearing fields and mineral deposits. The conducted geological-geoelectrical analysis of the model made it possible for the first time to identify two promising areas for further study that meet the geoelectrical criteria for the mineral search: along the Zvizdal-Zaliska fault zone between the Samgorod and Unava faults; along the Samgorod fault in the area of its intersection with the Kocheriv and Taboriv faults.

Cytoprotective effects of low-frequency pulsed electromagnetic field against oxidative stress in glioblastoma cells.

The low-frequency pulsed electromagnetic field (PEMF) may have possible cytoprotective effects against the destructive effects of oxidative stress. The goal was to investigate if shortterm low-frequency PEMF has cytoprotective effects in glioblastoma cell line following high-dose hydrogen peroxide (H2O2) treatment. U87-MG cells were divided into four groups: Sham-control group; PEMF group (cells exposed to PEMF); H2O2 group (cells treated with H2O2 at time intervals 30 min and 48 h, respectively); H2O2+PEMF group (cells exposed to PEMF after H2O2 treatment at time intervals 30 min and 48 h, respectively). The cell viability, levels of reactive oxygen species, glutathione peroxidase activity, and the amount of glutathione were measured. The cytoprotective effect of PEMF against deleterious effects of oxidative stress triggered by different time interval of H2O2 treatment might be mediated by the increase in the cell viability, the elevation in the antioxidant enzyme activity/amount, and the decrease in the reactive oxygen species level. In addition, the cytoprotective effect of PEMF varies depending on different time intervals of H2O2 treatment. In the light of these findings, further in vivo and/or in vitro studies on neurophysiological effects of PEMFs and their underlying molecular mechanisms are needed to elucidate neurotoxic or neuroprotective role against antioxidant defense mechanisms.

Effect of soil pH on thermally enhanced desorption of m-xylene by zero-valent iron particles under an electromagnetic field.

This study, for the first time, evaluates a novel method for the desorption of contaminants from soil that uses the heat generated by zero-valent iron (ZVI) under low-frequency electromagnetic fields (EMF), and elucidates the specific effects of soil pH upon the process. It was found that the temperature of soil mixed with ZVI could reach up to ∼60°C within 20min under the applied EMF, and after 60min the residual fraction of m-xylene in soil decreased by 86.4% compared to no-ZVI soil. The most efficient desorption of m-xylene occurred at a soil of pH 5. Desorption was related to the net heating capacity of the ZVI particles, which was defined by pH-dependent formation of surface corrosion products. The preservation of metal iron and formation of Fe(II) species was favored for heat generation. Soil pH also affected m-xylene retention and the local thermal conduction from ZVI to m-xylene by regulating the surface properties of fulvic acid and ZVI. This study provides valuable information regarding the impact of pH on the thermal desorption of soil contaminants by ZVI coupled with EMF and illustrates the potential of the method in the remediation of contaminated sites.

Intercomparison of the Averaged Induced Electric Field in Learning-Based Human Head Models Exposed to Low-Frequency Magnetic Fields

Anatomical human models have been widely used in the assessment of induced field strength for low-frequency (LF) electromagnetic field exposure. One bottleneck is the assignment of a single electrical conductivity to all the voxels of the corresponding tissue. This simplification is known to cause computational artifact; therefore, a large reduction factor was considered in international guidelines and standards. Recently, head models with nonuniform conductivities generated using deep learning networks were proposed, and the effect on the reduction of staircasing artifacts was demonstrated. If the effectiveness of the models is confirmed for different models and codes, it would be useful to derive the relationship between the internal and external field strengths needed for setting the exposure limit. The Subcommittee 6 of the IEEE International Committee on Electromagnetic Safety Technical Committee 95 launched a working group to conduct the first intercomparison study of the induced electric field in learning-based head models exposed to LF magnetic fields. Seven international research groups have cooperated in this joint study. The highest relative difference (RD) in averaged electric fields was 23%, which is attributable to the difference caused the by scalar potential finite difference (SPFD) method and finite element method. Except for one group, the RDs in the 100 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> and 99 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> percentile values of the averaged electric field using the SPFD method with different solvers and codes were below 1%, indicating that the uncertainty due to different codes is sufficiently small under the same exposure scenarios. The findings would be informative for future revision of exposure limits and reduction factors in the exposure standard, which is closely related to computational uncertainty.

Extremely low-frequency electromagnetic field exposure alters DNA methylation levels in the endometrium of pigs during the peri-implantation period.

Extremely low-frequency electromagnetic field (ELF-EMF) emission is increasing due to substantial technological progress. The results of previous research provided evidence that ELF-EMF may exert changes in molecular mechanisms that control female reproduction. We hypothesised that short-term ELF-EMF treatment alters the DNA methylation level of genes in the endometrium. Hence, the research aimed to determine the methylation level of selected genes whose expression was altered in response to ELF-EMF radiation in the endometrium of pigs during the peri-implantation period (days 15-16 of pregnancy). Porcine endometrial slices (100±5mg) were collected during the peri-implantation period and exposed to ELF-EMF at a frequency of 50Hz for 2h in vitro . The control endometrium was not exposed to ELF-EMF. The level of DNA methylation in the promoter regions of EGR2 , HSD17B2 , ID2 , IL1RAP, MRAP2, NOS3, PTGER4, SERPINE1, VDR and ZFP57 was tested using qMS-PCR. In the endometrium exposed to ELF-EMF, the level of methylation of HSD17B2 , MRAP2 , SERPINE1, VDR and ZFP57 was not altered; the level of methylation of EGR2 , ID2 and PTGER4 increased, and the level of methylation of IL1RAP and NOS3 decreased. ELF-EMF may alter the level of DNA methylation in the endometrium during the peri-implantation period. Changes in the DNA methylation induced by ELF-EMF may affect the transcriptomic profile of the endometrium and disturb physiological processes accompanying implantation and embryo development.

ІНТЕРПРЕТАЦІЯ 3D ГЕОЕЛЕКТРИЧНОЇ МОДЕЛІ РАЙОНУ ПЕРЕТИНУ ЗВІЗДАЛЬ-ЗАЛІСЬКОЇ ТА НЕМИРІВСЬКОЇ ЗОН РОЗЛОМІВ

The interpretation of the deep three-dimensional geoelectricalal model of the central part of the Zvizdal-Zaliska and Brusyliv fault zones of the Ukrainian shield, which was built with the involvement of data from experimental observations of the Earth's low-frequency electromagnetic field conducted in 2019 by the Institute of Geophysics named after S.I. Subotin of the National Academy of Sciences of Ukraine, within the Ordyntsi-Lobachiv and Zoziv-Stryzhavka profiles was done. Experimental materials were processed with the PRC_MTMV software package, tipper estimates were obtained for periods of geomagnetic variations from 50 to 3400 s and curves of apparent resistivity (amplitude values and impedance phases) from 10 to 10000 s. Based on the qualitative analysis of magnetovariational profiling parameters, magnetotelluric sounding curves and pseudo-sections, several local near-surface structures of complex orientation in space were identified, which are confined to the Pogrebyshchensky and Ogiivskyi faults, areas of separate parts of the Zvizdal-Zaliska, Brusyliv and Nemyriv fault zones, as well as their convergence , and outside the fault zones in the crystalline massive of the Ukrainian shield. The main result of the geological-geoelectrical interpretation of the 3D model is the discovery of new anomalies of low resistivity in the near-surface part of the earth's crust (from the surface to 0.5-2 km), which correspond to the structural and metallogenic features of the study area; confirmation and detailing of the anomalously heterogeneous distribution of resistivity in the tops of the upper mantle at depths from 70 to 120 km west of the Ukrainian shield. The area of intersection of the Zvizdal-Zaliska and Nemyrivs fault zones is characterized by both a galvanically connected spatially diverse system and local separate near-surface anomalies with low resistivity from 5 to 100 Ohm·m, most of which dip to 0.5-1 km. It is shown that there are connections between conductivity and structural features of the Zvizdal-Zaliska, Brusyliv and Nemyriv fault zones. In addition, some anomalies are found in the granite migmatites of the Ros' structural-formation zone, outside the tectono-metasomatic mineragenic zones. As a rule, anomalies are confined to zones of disintegration of crystalline basement rocks, elongated zones of metasomatization, and areas of distribution of graphitized rocks; moreover, some of the surface anomalies correspond to regions of weathering crusts. The conducted geological-geoelectrical analysis of the model showed that several areas require further study, namely the sub-latitude anomaly west of the Zoziv-Stryzhavka profile and the complex-shaped anomaly in the eastern part of the study area. As promising for the search for minerals, which meets the geoelectrical criteria, the area of the anomaly within the Brusyliv fault zone with a depth of up to 2 km is highlighted.

PHYSICO-CHEMICAL PROCESSES OF METHANOGENESIS UNDER THE INFLUENCE OF THE ELECTROMAGNETIC FIELD

Currently, waste disposal is strictly regulated by governments to reduce soil, water and air pollution caused by burial and direct discharge of waste into water. Anaerobic digestion has been touted as a means of dealing with organic waste while meeting humanity's energy needs. The process involves the production of biogas by microbial decomposition of organic compounds without oxygen, reducing the amount of organic matter to be removed. Anaerobic digestion produces a nutrient-rich digestate that can have agricultural value and produces methane-rich biogas that can be used as fuel directly or can be converted to compressed natural gas and liquefied natural gas. The purpose of the study is to determine the influence of magnetic fields on the physicochemical processes of methanogenesis and the output of biogas during the fermentation of pig manure. The work highlights the issue of the influence of a low-frequency electromagnetic field on the physicochemical processes of anaerobic fermentation of pig manure. The kinetics of chemical reactions in substrates under the influence of a magnetic field and its effect on the solubility of salts, acids and alkalis in solutions, as well as on the redox potential, pH value and electrophysical parameters of the substrate in the process of methanogenesis are considered. The yield of biogas under the influence of a low-frequency electromagnetic field on the process of anaerobic fermentation of the substrate and without influence was studied.