Low Frequency Electromagnetic Fields Research Articles

Independent, modified, and interacting effects of long-term noise, extremely low-frequency electromagnetic fields, and shift work exposures on liver enzymes

To quantify long-term independent, modified, and interacting effects of noise, extremely low-frequency electromagnetic fields (ELF-EMFs), and shift work exposures on liver enzymes, a four-year repeated measures study was performed among male workers in a thermal power plant industry from 2016 to 2020. The 8-h equivalent sound pressure levels (Leq) were measured at weighting channels of Z, A, and C for octave-band frequencies. The 8-h time-weighted average of ELF-EMFs levels was measured for each participant. Shift work schedule was determined based on job titles, including 3-rotating night shift work and fixed day shift work schedules. The fasting blood samples were taken to determine liver enzymes (AST, Aspartate transaminase; ALT, Alanine transaminase). The percentage change (PC) and 95% confidence interval (CI) of AST and ALT enzymes were estimated by the different bootstrapped-mixed-effects linear regression models. Per 10-dB noise increase, we found a significantly higher PC (95% CI) of AST and ALT (only LAeq) levels in all regression models with the highest changes for LAeq. For the octave-band noise analysis, there was an upward trend from 31.5 Hz to 1 kHz frequencies and a downward trend from 1 to 8 kHz frequencies. Per 1 mG ELF-EMFs increase, we observed a significantly higher PC (95% CI) of AST and ALT enzymes in the main adjusted and the main adjusted + shift work models. The 3-rotating night than fixed day shift workers had a significant PC in the unadjusted model for AST enzyme and the fully adjusted and the main adjusted + ELF-EMFs models for ALT enzyme. Significant negative two-way or/and three-way interaction effects among the noise, ELF-EMFs, and shift work were observed for both AST and ALT enzymes. Our findings indicated long-term noise, ELF-EMFs, and 3-rotating night shift work exposures may be significantly associated with changes in the levels of liver enzymes.

Interdyscyplinarna koncepcja leczenia porażenia Bella – opis przypadku

Background. Bell’s palsy is a spontaneous paralysis of the facial nerve (i.e. cranial nerve VII). It presents with muscle weakness leading to facial asymmetry, with a drooping corner of the mouth, loss of the ability to whistle, blink, close the eyelid, purse lips or grin. The forehead on the affected side becomes smooth and the patient is not able to frown or raise eyebrows. Objective. The aim of the study was to evaluate the effect of combined electrophysical and physiotherapeutic methods on accelerating recovery from facial nerve palsy. Material and Methods. The authors describe two cases of Bell’s palsy, treated with simulta-neous application of electrophysical agents, in the form of an extremely low-frequency elec-tromagnetic field (ELF-EMF) and high-energy LED light, and physiotherapy modalities, i.e. proprioceptive neuromuscular facilitation (PNF) and kinesiotaping (KT). Results. After four weeks of electrophysical and physiotherapeutic treatments, a fully satis-factory and stable therapeutic effect was achieved. Conclusions. The interdisciplinary therapy using ELF-EMF + LED combined with PNF and KT treatments proved to be effective in accelerating recovery from facial nerve palsy. Further studies are needed to establish appropriate protocols.

Comparative Study of Extremely Low-Frequency Electromagnetic Field, Radiation, and Temozolomide Administration in Spheroid and Monolayer Forms of the Glioblastoma Cell Line (T98).

Glioblastoma is the most common primary malignant tumor of the central nervous system. The patient's median survival rate is 13.5 months, so it is necessary to explore new therapeutic approaches. Extremely low-frequency electromagnetic field (EMF) has been explored as a noninvasive cancer treatment. This study applied the EMF with previous conventional chemoradiotherapy for glioblastoma. In this study, we evaluated the cytotoxic effects of EMF (50 Hz, 100 G), temozolomide (TMZ), and radiation (Rad) on gene expression of T98 glioma cell lines in monolayer and spheroid cell cultures. Treatment with Rad and EMF significantly increased apoptosis-related gene expression compared to the control group in monolayers and spheroids (p<0.001). The expression of apoptotic-related genes in monolayers was higher than the similar spheroid groups (p<0.001). We found that treatment with TMZ and EMF could increase the gene expression of the autophagy cascade markers compared to the control group (p<0.001). Autophagy-related gene expression in spheroids was higher than in the similar monolayer group (p<0.001). We demonstrated that coadministration of EMF, TMZ, and Rad significantly reduced cell cycle and drug resistance gene expression in monolayers and spheroids (p<0.001) compared to the control group. The combinational use of TMZ, Rad and, EMF showed the highest antitumor activity by inducing apoptosis and autophagy signaling pathways and inhibiting cell cycle and drug resistance gene expression. Furthermore, EMF increased TMZ or radiation efficiency.

Synergistic cytotoxic effects of an extremely low-frequency electromagnetic field with doxorubicin on MCF-7 cell line

Breast cancer is one of the leading causes of cancer deaths in women worldwide. Magnetic fields have shown anti-tumor effects in vitro and in vivo as a non-invasive therapy method that can affect cellular metabolism remotely. Doxorubicin (DOX) is one of the most commonly used drugs for treating breast cancer patients. It can be assumed that combining chemotherapy and magnetotherapy is one of the most effective treatments for breast cancer. This study aimed to investigate the potential cytotoxic effect of DOX at low concentrations in combination with extremely low-frequency electromagnetic fields (ELF–EMF; 50 Hz; 20 mT). The breast cancer cell line MCF-7 was examined for oxidative stress, cell cycle, and apoptosis. MCF-7 cells were treated with various concentrations of DOX as an apoptosis-inducing agent and ELF–EMF. Cytotoxicity was examined using the MTT colorimetric assay at 12, 24, and 48 h. Consequently, concentration- and time-dependent cytotoxicity was observed in MCF-7 cells for DOX within 24 h. The MTT assay results used showed that a 2 μM concentration of DOX reduced cell viability to 50% compared with control, and as well, the combination of ELF–EMF and DOX reduced cell viability to 50% compared with control at > 0.25 μM doses for 24 h. In MCF-7 cells, combining 0.25 μM DOX with ELF–EMF resulted in increased ROS levels and DOX-induced apoptosis. Flow cytometry analysis, on the other hand, revealed enhanced arrest of MCF-7 cells in the G0-G1 phase of the cell cycle, as well as inducing apoptotic cell death in MCF-7 cells, implying that the synergistic effects of 0.25 μM DOX and ELF–EMF may represent a novel and effective agent against breast cancer.

Some considerations on the challenges related to the use of the new ICNIRP restrictions for human exposure to radiofrequency fields.

ICNIRP 2020 guidelines for limiting exposure to radiofrequency fields replace the radiofrequency part of the ICNIRP 1998 guidelines for limiting exposure to time-varying electric, magnetic and electromagnetic fields. Besides setting new restrictions that prevent thermal effect they also took over the 100kHz to 10MHz part of the ICNIRP 2010 guidelines for limiting exposure to low-frequency electromagnetic fields, which provides restrictions that prevent nerve stimulation effect. The latest guidelines brought many changes to the system of protection against exposure to radiofrequency fields starting with the physical quantities used to express restrictions and continuing with specific restrictions and new exposure metrics employed. For the first time, the case of brief local exposure to intense radiofrequency fields was accounted by ICNIRP for setting new types of exposure restrictions. All these changes led to more detailed and complex guidelines, but their provisions are more difficult to apply in practice. Our paper presents some of the challenges related to the use in practice of the new ICNIRP restrictions for human exposure to radiofrequency fields.

Numerical and Analytical Analysis of the Low-Frequency Magnetic Fields Generated by Three-Phase Underground Power Cables with Solid Bonding

There is a special concern for measuring and simulating low-frequency magnetic fields generated by underground power cables, particularly in human exposure studies. In the present study, an accurate 2D finite element model for computing magnetic fields generated by three-phase underground power cables with solid bonding is proposed. The model is developed in ANSYS Maxwell 2D low-frequency electromagnetic field simulation software for a typical 12/20 kV (medium-voltage) three-phase underground power cable in both trefoil and flat formations, but it can be adapted to any cable system. Model validation is achieved by analytical computations conducted with a software tool based on the Biot–Savart law and the superposition principle. RMS magnetic flux density profiles calculated at various heights above the ground with these two methods correlate very well. This is also true for induced shield currents. The application of the finite element model to multiple three-phase power cables laid together is also considered.

Machine learning-based electro-magnetic field guided localization technique for autonomous underwater vehicle homing

Precise guidance is the primary requirement for the reliable homing of autonomous underwater vehicles (AUV). The necessity for accurate short-range position tracking arises due to the limitations of the inertial sensors’ cumulative integral drift, unreliable acoustic positioning system in very short ranges, and non-propagation of high-frequency electromagnetic signals of the GPS system. In this article, a very low-frequency electro-magnetic (EM) field is generated for very short-range guidance for the homing operation of underwater vehicles. The design and modeling of the 3-axis low-frequency EM-based shallow water submerged Docking Station (DS) at 10 m depth is explained and the EM field is generated for a 20 m range in the 3-axis plane using two perpendicular coils operated in distinct frequencies. The stochastic magnetometer measurement model is used to estimate the relative kinematics of the underwater vehicle with respect to the EM docking coil. The EM field datasets generated from EM field maps around DS are used for training and validating with different Machine Learning (ML) algorithms. The designed ML aided EM-based tracking technique guidance algorithms are validated for underwater vehicle localization that requires a precise and reliable homing process to the DS even in turbid waters, bio-fouling environment, and reflective boundaries though it has limitations in presence of ambient ferromagnetic sources. Numerical simulations have been carried out with conventional methods and ML algorithms on the generated EM data. The results indicate that the position accuracy achieved is within 1% for ML-aided EM based guidance techniques when compared to the conventional algorithm which has a position accuracy of 3%. ML aided techniques are advantageous as they are independent of the dynamic ocean environment and the underwater vehicle configuration and the Time to Home (ToH) to the DS is simulated in different scenarios, is 160 s–200 s with a vehicle speed of 0.25 m/s. It is observed that the vehicle can choose the shortest path for homing operation with the measured EM field values and with aid of ML techniques.

Research of the Influence of the Combined Electromagnetic Field on Biogas Output

The purpose of research is determining the conditions of stimulating effect of the combined influence of constant and variable electromagnetic fields on the substrate and microorganisms in the bioreactor. This goal is achieved by solving the following tasks: development of mathematical model, conducting numerical simulation to determine the distribution of magnetic field in active zones of the stator-bioreactor system; conducting experimental researches during the fermentation of pig’s manure with litter from wheat straw in the mesophilic mode of fermentation. One category of bioreactors (control samples) was not exposed to influence of magnetic field, for the other, periodically were made treatment simultaneously with a low-frequency electromagnetic field and constant magnetic field synchronously with the process of mixing the substrate. The most significant results are: an experimental proof of effectiveness of the proposed method of intensification of the biogas output and increasing its quality, high accuracy of mathematical model of distribution the magnetic field in active zones of the stator-bioreactor system; assessment of the levels of consumption of nutrients by microorganisms from the substrate under the influence of the combined magnetic field and without influence of the magnetic field. The significance of obtained results lies in the fact that the proposed approach to intensification of the biogas output provides increase of the level production, the quality of biogas, and cumulative rate of methane output per unit of organic mass in the reactor.

Effects of extremely low frequency electromagnetic fields on the tumor cell inhibition and the possible mechanism

Low-frequency magnetic fields exert a significant inhibitory effect on tumor growth and have been developed as a therapeutic modality. However, the effect of a low-frequency magnetic field on the interaction between cells is still poorly understood. This study aimed to preliminarily evaluate the direct effect of magnetic field ditectely on cultured cells and indirect effect mediated by cell-environment (conditioned medium). 293 T cells, Hepg2 cells, A549 cells have been cultured at 37 ± 0.18 °C in presence of an extremely low-frequency magnetic field of 20 Hz, 5-mT. The adherent tumor cells were more sensitive to magnetic field inhibition in the original environment (conditioned medium) with adherence inhibition rate for Hepg2 and A549 estimated at 18% and 30% respectively. The inhibition effect was suppressed when the suspended cells separated or clump density at a low density. The nontumor cell lines showed no inhibitory effect on exposure to a low-frequency magnetic field. The intracellular ion fluorescence (IIF) showed that the magnetic field significantly altered the membrane potential, indicating hyperpolarization of the adherent cells (ΔIIF 293 T cells: − 25%, ΔIIF Hepg2 cells: − 20% and ΔIIF A549 cells: − 13%) and depolarization of the suspended cells (ΔIIF Raji cells: + 9%). In addition, the conditioned media collected after magnetic field exposure acted on unexposed tumor cells and caused inhibition. Our findings might provide a basis for the mechanism of magnetic field interaction between cells and cell environment in the future.

Human osteosarcoma cells in response to ELF-MF: Morphological remodeling compared to cell proliferation.

The present study aimed to assess the effects of extremely low-frequency electromagnetic fields (ELF-MF) on structural changes of human osteosarcoma cells by analyzing the stained cytoskeleton for assessing the relationship between the fractal dimension parameter and proliferation rate of radiation-induced cells. In this study, 2-mT magnetic fields with various waveforms, including sinusoidal, triangular, and pulsed shapes, were employed to determine the biological effects of ELF-EMF on the human osteosarcoma MG-63 cell line. All experiments were performed in two modes: continuous exposure at 3 h and fractionated irradiations at 3 consecutive days. Afterward, the proliferation assay was implemented for assessing the cell proliferation in each group. Moreover, immunofluorescence staining and confocal imaging were performed to determine the cell shape index. Furthermore, fractal dimension analysis was carried out by processing morphological images. The proliferation and shape index parameters of radiation-induced osteosarcomas significantly decreased compared with non-irradiated cells. In addition, fractal dimensions significantly increased following fractionated exposure at 3 consecutive days. Assessing the fractal dimensions can be considered as a new morphological index for the prognosis of the structural remodeling of human osteosarcoma cells in response to fractionated irradiation of ELF-MF. In addition, various waveforms induce a similar effect on morphological remodeling and cell proliferation.

Combined Rehabilitation Protocol in the Treatment of Osteoarthritis of the Knee: Comparative Study of Extremely Low-Frequency Magnetic Fields and Soft Elastic Knee Brace Effect.

The investigation of this observational case-control study aimed at determining the effectiveness of a combined treatment of extremely low-frequency electromagnetic fields (ELF) with a soft elastic knee brace versus ELF alone in knee osteoarthritis (KOA) with respect to a reduction in pain and functional recovery. We hypothesized that the combined use of ELF and a soft elastic knee brace may provide better results. Thirty-five patients (N = 35, divided into Group 1 = ELF and Group 2 = ELF with the soft elastic knee brace) were analyzed. The rehabilitative protocol consisted of 10 sessions of antiphlogistic and antiedema programs (first cycle) for 2 weeks, followed by twelve sessions of bone repair and connective tissue repair programs (second cycle) in patients with knee osteoarthritis (KOA) for 4 weeks. Patient evaluations were conducted at baseline (T0) and after 2 (T1) and 4 (T2) weeks of treatment. A follow-up evaluation was conducted 6 weeks after treatment (T3). The LIMFA© Therapy System was used to create multifrequency magnetoelectric fields with an intensity of 100 µT and a low-frequency field. The Incrediwear Cred 40 knee sleeve (Incred) was used for alleviating knee pain. The Visual Analogue Scale (VAS), the Knee Injury and Osteoarthritis Outcome Score (KOOS), and the Lysholm score (Ls) were used as outcome measures. The results showed that pain at rest (Vr), pain in motion (Vm), KOOS, and Ls were significantly affected by ELF over time. In conclusion, Group 2 had a better response in terms of pain resolution at rest (p < 0.05) and a concurrent better response at T3 in terms of functional recovery (p < 0.05).

Effect of Low Frequency (50Hz) Electromagnetic Field on Germination Process of Wheat (Triticum aestivum L.)

Electromagnetic field (EMF) and geomagnetic field (GMF) are inescapable environmental factors experienced by all living organisms including plants. Despite the progresses made in the field of plant-senses, the impact of Electromagnetic field (EMF) and geomagnetic field (GMF) on plant growth and development is not fully explored. In this context influence of exposure intensity and duration of exposure to low frequency (50 Hertz) electromagnetic field produced by a locally designed monoaxial Helmholtz Coil on germination parameters of Triticum aestivum L. (Wheat) has been studied in the present work. Wheat seeds were exposed to magnetic field strengths of 30, 60 and 75 Gauss for different periods of time (10, 20 and 30 minutes) inside the Helmholtz Coil. Control plants were grown under the local geomagnetic field (50 micro Tesla). Germination parameters like mean germination time, germination percentage, co- efficient of germination etc. were calculated for each test condition. Results indicated that among all the test conditions the alternating magnetic field with exposure rate of 60 Gauss/30 minutes found most conducive to Wheat germination which is reported here for the first time. These results are encouraging to work further on the effect of magnetic field on biochemical and molecular changes that may be resulting these observed phenomena.

Electromagnetic Field of a HED in the Spherical “Earth-Ionosphere” Model and Its Application in Geophysics

The controlled source extremely low frequency (CSELF) method bears the potential for deep resource exploitation utilizing the skywave. The “Skywave” denotes the electromagnetic wave propagating through the waveguide formed by the Earth and ionosphere. It has a considerable penetration depth into the lithosphere due to its low-frequency band. Previous research on extremely low-frequency electromagnetic fields with the coupled lithosphere, atmosphere, and planar ionosphere models ignored the effect of the Earth’s curvature. Thus, we aimed to present the exact formulas for horizontal electric dipoles (HED) in a spherical “Earth-ionosphere” model. These new formulas consider the Earth’s curvature as a multilayer medium rather than a homogeneous underground. We introduce three techniques: function combination pairs, addition and subtraction terms, and Padé approximants, to handle slow convergence in numerical calculation. In the spherical waveguide, electromagnetic fields are mutually interfered with and produce oscillations, which is different from the planar model. The influence of Earth’s curvature cannot be neglected with the increase in source–receiver distance, though it is negligible within 3000 km. Furthermore, it is worth noting that apparent resistivity ρθφ enters the waveguide area earlier than ρφθ. This method can be used as Green’s function to simulate the electromagnetic field of actual antennas and 3-D models.

50 Hz Magnetic Field Exposure Inhibited Spontaneous Movement of Zebrafish Larvae through ROS-Mediated syn2a Expression.

Extremely low frequency electromagnetic field (ELF-EMF) exists widely in public and occupational environments. However, its potential adverse effects and the underlying mechanism on nervous system, especially behavior are still poorly understood. In this study, zebrafish embryos (including a transfected synapsin IIa (syn2a) overexpression plasmid) at 3 h post-fertilization (hpf) were exposed to a 50-Hz magnetic field (MF) with a series of intensities (100, 200, 400 and 800 μT, respectively) for 1 h or 24 h every day for 5 days. Results showed that, although MF exposure did not affect the basic development parameters including hatching rate, mortality and malformation rate, yet MF at 200 μT could significantly induce spontaneous movement (SM) hypoactivity in zebrafish larvae. Histological examination presented morphological abnormalities of the brain such as condensed cell nucleus and cytoplasm, increased intercellular space. Moreover, exposure to MF at 200 μT inhibited syn2a transcription and expression, and increased reactive oxygen species (ROS) level as well. Overexpression of syn2a could effectively rescue MF-induced SM hypoactivity in zebrafish. Pretreatment with N-acetyl-L-cysteine (NAC) could not only recover syn2a protein expression which was weakened by MF exposure, but also abolish MF-induced SM hypoactivity. However, syn2a overexpression did not affect MF-increased ROS. Taken together, the findings suggested that exposure to a 50-Hz MF inhibited spontaneous movement of zebrafish larvae via ROS-mediated syn2a expression in a nonlinear manner.

Low-frequency electromagnetic fields increase oxidative stress in tobacco plants

Increasing interest on biological effects of electromagnetic radiation, particularly extremely-low-frequency electromagnetic fields (ELFEMFs) has been observed. Although harmful effects of magnetic fields in humans remain to be demonstrated, it has been proposed that oxidative stress may represent one of the causes of ELF- EMFs adverse effects. We investigated the influence of ELF-EMFs on enzyme activity in tobacco plants under oxidative stress. Nicotiana tabacum (L.) seedlings of the Xanthi variety were continuously exposed to 2.0 mT and 60 Hz frequency ELF-EMFs for 24, 48, 72, and 96 h. The biochemical endpoints measured involved leaf and root extracts ascorbate peroxidase (APX) and catalase (CAT) activities, which were increased in leaf extracts after 48, 72, and 96 h of magnetic field exposure, whereas APX and CAT activities in root extracts increased after 48 and 72 h and 48, 72, and 96 h of continuous exposure to magnetic fields. In contrast, ELF-EMF exposure for 24 h did not alter APX and CAT activities in leaf and root extracts. All treatment regimens were matched with a properly sham-exposed control. These results suggest that ELF-EMFs induce an oxidative stress, which may potentiate the oxidative defense system in tobacco plants

Impact of ketamine administration on chronic unpredictable stress-induced rat model of depression during extremely low-frequency electromagnetic field exposure: Behavioral, histological and molecular study.

In the study, we examined the effects of ketamine and extremely low-frequency electromagnetic fields (ELF-EMF) on depression-like behavior, learning and memory, expression of GFAP, caspase-3, p53, BDNF, and NMDA receptor in animals subjected to chronic unpredictable stress (CUS). After applying 21 days of chronic unpredictable stress, male rats received intraperitoneal (IP) of ketamine (5mg/kg) and then were exposed to ELF-EMF (10-Hz, 10-mT exposure conditions) for 3 days (3h per day) and behavioral assessments were performed 24h after the treatments. Instantly after the last behavioral test, the brain was extracted for Nissl staining, immunohistochemistry, and real-time PCR analyses. Immunohistochemistry (IHC) was conducted to assess the effect of ketamine and ELF-EMF on the expression of astrocyte marker (glial fibrillary acidic protein, GFAP) in the CA1 area of the hippocampus and medial prefrontal cortex (mPFC). Also, real-time PCR analyses were used to investigate the impacts of the combination of ketamine and ELF-EMF on the expression of caspase3, p53, BDNF, and NMDA receptors in the hippocampus in rats submitted to the CUS procedure. Results were considered statistically significant when p<.05. Our results revealed that the combination of ketamine and ELF-EMF increased depression-like behavior,increased degenerated neurons and decreased the number of GFAP (+) cells in the CA1 area and mPFC, incremented the expression of caspase-3, and reduced the expression of BDNF in the hippocampus but showed no effect on the expression of p53 and NMDA-R. These results reveal that combining ketamine and ELF-EMF has adverse effects on animals under chronic unpredictable stress (CUS).

Effects of Low-Frequency Electromagnetic Field on the Physicochemical Properties of Freeze-Thawed Mongolian Cheese.

To verify whether a low-frequency electromagnetic field (LFE field) can help reduce structural damage during the freeze-thaw process and maintain shelf life, Mongolian cheese was frozen at -10, -20, and -30 °C, then thawed at microwave or room temperature. Results showed that LFE field-assisted frozen treatment could reduce ice crystal size and protect the protein matrix structure of cheese. Frozen-thawed cheese retained 96.5% of its hardness and showed no significant difference from the fresh one in elasticity, cohesion, and chewiness. Frozen cheese showed similar but slower ripening behavior during storage, suggesting a potential application of the LFE field in the frozen storage of high-protein foods.

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.