Extremely Low Frequency Magnetic Fields Research Articles

Analytic Hierarchy Process (AHP)-Based Evaluation of Extremely-Low-Frequency Magnetic Field Contribution Rates

The extremely-low-frequency (ELF) magnetic fields of submarines serve as key characteristics for target detection, with their formation mechanisms being complex and diverse. Effectively manipulating a submarine to reduce its magnetic signature is crucial for enhancing its magnetic stealth capabilities. However, current research on the impact of various causative factors is insufficient. This study proposes a contribution rate assessment method based on the Analytic Hierarchy Process (AHP) model, aiming to provide a theoretical basis for effective manipulation. Initially, a thorough analysis of the threat causes of a submarine’s ELF magnetic fields is conducted, and a corresponding hierarchical threat structure model is established. Subsequently, magnetic field signal characteristics generated by different causes are obtained through simulation, and threat matrices and characteristic matrices are constructed. Finally, the contribution rates of different causative magnetic fields to the total magnetic field are calculated, and the simulation results validate the effectiveness of the method. At the stern detection line, the contribution rate of the wake magnetic field is the highest, reaching 0.7649. Along the radial detection line, the contribution rate of the shaft frequency magnetic field is the highest and gradually decays, eventually falling below the wake magnetic field at 150 m and remaining at an approximately 0.5 contribution rate. This study calculates the contribution rates under different operational conditions and detection scenarios, laying a technical foundation for research on the comprehensive active control strategies of submarine ELF magnetic fields in different scenarios.

Pre-Earthquake Oscillating and Accelerating Patterns in the Lithosphere–Atmosphere–Ionosphere Coupling (LAIC) before the 2022 Luding (China) Ms6.8 Earthquake

The coupling processes among the lithosphere, atmosphere, and ionosphere (LAI) during the earthquake preparation phase are still an open scientific debate. Comprehensive LAI coupling effects around the 2022 Ms6.8 Luding earthquake in China are investigated with a multi-parameter and multi-layer approach, including the b-value, revised accelerated moment release, Earth resistivity, ELF magnetic field emissions, atmospheric electric field, surface temperature, foF2 from ionosonde, GNSS TEC, Ne and magnetic field from CSES and Swarm satellites, and energetic electrons from CSES and NOAA satellites. It is found that the anomalies start from the lithospheric parameters as Earth resistivity and b-values 1–2 years before to reflect the local stress loading in the seismic region, then the ionospheric and atmospheric disturbances occur and accelerate −50 days before and −15 days before, and finally the electrons precipitate a few days before. The simultaneous perturbations in LAI illustrate the thermodynamic coupling channel, such as on 24 August, −12 days before. Meanwhile, the abundant developed ionospheric anomalies without atmospheric disturbances demonstrate the electromagnetic coupling way from the lithosphere to the ionosphere directly. Finally, the results demonstrate a two-way model of LAIC: one way is characterized by a slow chain of processes, of thermodynamic nature, starting from the ground and proceeding to the above atmosphere and ionosphere, showing an exponential trend in the cumulative number of anomalies; the second way is characterized by oscillating electromagnetic coupling between the lithosphere and ionosphere, showing intermittent fluctuations in the corresponding cumulative number of anomalies.

ANALYSIS OF RESISTANCE OF CASSAVA TAPE BY EXPOSURE TO 1000 μT INTENSITY ELF MAGNETS

Extremely Low Frequency (ELF) electromagnetic waves are electromagnetic waves with a frequency range of 0 to 300 Hz. ELF electromagnetic wave radiation produces non-thermal effects on the biological objects used, meaning that it does not cause temperature changes when interacting with or inducing the system. Electromagnetic waves are waves that arise due to changes in electric fields and strong magnetic fields. This research aims to prove the effect of Extremely low frequency (ELF) magnetic field on the food resilience process. The research method used is experimental research method. This research was carried out in the basic physics laboratory at the University of Jember. Data collection techniques using observation. Based on the research, it can be concluded that ELF magnetic field radiation has the potential as an alternative method in increasing the nutritional value and durability of fermented food ingredients. Exposure to Extremely Low Frequency magnets with an intensity of 1000 μT for 45 minutes resulted in changes in pH value and physical quality that affect food durability in cassava tape.

A STUDY OF THE MATURITY PROCESS OF RED GUTTY KETAN FOOD INGREDIENTS IN TERMS OF THE TASTE: EXTREMELY LOW FREQUENCY MAGNETIC FIELD RADIATION

This study explores the novel effect of an Extremely Low Frequency (ELF) magnetic field on the durability of glutinous tape food, a traditional Indonesian food made from fermented glutinous rice. ELF magnetic field is a spectrum of electromagnetic waves with frequencies less than 300 Hz that can influence microbial activity and the chemical changes in food. The study uses a unique experimental method that exposes 20 glutinous tape samples, divided into a control group and an experimental group, each with 10 samples, to an ELF magnetic field of 1,000μT intensity for 45 minutes. The study uses a Complete Randomized Design (RAL) and analyzes the data using the One Way Anova test with LSD and Kruskal-Wallis tests using IBM SPSS Statistics 23. The results show that the experimental group’s glutinous tape samples did not experience spoilage compared to the control group’s. The study proves the ELF magnetic field's effect on the durability of glutinous tape food and provides insights for developing new food preservation techniques. The study demonstrates the innovation and applicability of using the ELF magnetic field for food durability.

Bioethanol production in bioreactor assisted by magnetic field: Correlation between S. cerevisiae H+ effluxes and fermentative efficiency

This study simultaneously evaluated fermentation kinetics and H+ fluxes during fermentation by Saccharomyces cerevisiae in order to elucidate the biochemical mechanisms behind bioethanol production induced by ELF magnetic fields. Fermentation kinetics were monitored by glucose uptake, ethanol production, secondary products (glycerol), pH, biomass, and biochemical characterization of ATPase activity through proton efflux density measurements.A face-centered central composite design 22 was performed, considering independent variables such as recycling arrangements (bioreactor with a spiral-shaped tube, whole bioreactor, and bioreactor with a U-shaped tube) and magnetic flux density (5, 10, and 15 mT), while alcoholic fermentation efficiency and H+ efflux density of the P-ATPase were the response variables.ELF magnetic fields induced substrate consumption and bioethanol formation in all experimental configurations when compared to fermentations without the field. However, the whole bioreactor exposed to 10 mT was the most attractive condition, resulting in an average increase of approximately 40 % and 18 % in the overall volumetric productivity of glucose consumption and ethanol production, respectively, compared to the control experiment. The effect of magnetic flux density on fermentative efficiency and H+ efflux density was statistically significant (p < 0.1). A direct correlation between H+ efflux and yeast performance during fermentation under magnetic fields was found through the application of a method for simultaneous optimization of the experimental results. The data are discussed in relation to the biological mechanism of action involved and the potential applications of this technology at an industrial scale are envisioned.

Biological Effects of Magnetic Storms and ELF Magnetic Fields.

Magnetic fields are a constant and essential part of our environment. The main components of ambient magnetic fields are the constant part of the geomagnetic field, its fluctuations caused by magnetic storms, and man-made magnetic fields. These fields refer to extremely-low-frequency (<1 kHz) magnetic fields (ELF-MFs). Since the 1980s, a huge amount of data has been accumulated on the biological effects of magnetic fields, in particular ELF-MFs. However, a unified picture of the patterns of action of magnetic fields has not been formed. Even though a unified mechanism has not yet been generally accepted, several theories have been proposed. In this review, we attempted to take a new approach to analyzing the quantitative data on the effects of ELF-MFs to identify new potential areas for research. This review provides general descriptions of the main effects of magnetic storms and anthropogenic fields on living organisms (molecular-cellular level and whole organism) and a brief description of the main mechanisms of magnetic field effects on living organisms. This review may be of interest to specialists in the fields of biology, physics, medicine, and other interdisciplinary areas.

Occupational exposure to electromagnetic fields from dental devices: A descriptive study

Abstract&#x0D; &#x0D; Objective: Electromagnetic Field sources which are widely used as part of the operating mechanism occupational exposure occurs with the electricity is generated, distributed or usage in the everyday environment. We aimed to obtain the Extremely Low Frequency-Magnetic Field exposure profile for dental health workers from electrical devices used in dentistry. &#x0D; Methods: Measurements were performed while appliances under working conditions, 10 cm distance with the device for 6 minutes and for 7 days. The highest measured value in every 10 second was recorded. The mean ± SD of minimum and maximum Extremely Low Frequency-Magnetic Field for high-speed dental handpiece with LED, low-speed dental handpiece, model-trimming machine, automatic boil-out unit, steam machine, vacuum device, and polishing machine were recorded in milliGauss. &#x0D; Results: The values which obtains from model-trimming machine and polishing machine were remarkable (809.17 ± 37.70 / 975.00 ± 10.27, 649.33 ± 201.37 / 1367.00 ± 32.17, respectively). Conclusion: The results show that periodic Electromagnetic Field exposure measurements should be conducted to obtain more detailed information about workplace exposures and sources.&#x0D; &#x0D; Keywords: Health, electromagnetic field, extremely low-frequency field, exposure, occupational

Extremely Low Frequency Electromagnetic Field Radiation (50 Hz, 200 µT &amp; 300 µT) to Increase Edamame Productivity and Safety Risks to Health

More and more research results report that exposure to Extremely Low Frequency (ELF) magnetic fields at low intensity can increase cell proliferation. The ELF magnetic field interacts directly with cell membranes, capable of increasing intracellular calcium and under certain conditions affecting cell proliferation. This study wanted to prove the potential of ELF magnetic field radiation with intensity of 200 µT and 300 µT on edamame productivity. The research design used a completely randomized design. The research sample was 250 edamame soybeans of the Ryokkoh-75 variety which were divided into 5 groups. Samples were soaked in warm water for 3 hours and then cured for about 12 hours and exposed to ELF magnetic fields of intensity of 200 µT and 300 µT with variations in exposure time of 60 minutes and 120 minutes. Then it is seeded and planted in the field. Observation of the number of edamame pods and the number of pods was carried out when they were already fruiting, namely day 29 to day 43. The results of the study proved that the number of pods and the number of edamame pods in the group exposed to the 200 µT and 300 µT ELF magnetic fields was higher than the control. It appears that the highest number of fruits and pods occurred in the sample group exposed to the ELF magnetic field intensity of 300 µT. The conclusion is that exposure to the ELF magnetic field intensity of 300 µT has the potential to increase edamame productivity

EFFECT OF EXTREMELY LOW FREQUENCY (ELF) MAGNETIC FIELD EXPOSURE OF 700µT AND 1200µT INTENSITIES ON THE DEGREE OF ACIDITY (pH) AND MASS OF LEMURU FISH (Sardinella lemuru)

The Extremely Low Frequency (ELF) magnetic field is included in electromagnetic waves which have a frequency range of 0-300 Hz. In foodstuffs, the use of magnetic fields can be used for food security. Lemuru fish is a fish that is consumed by many people. In general, lemuru fish will last approximately 8 hours after arriving from capture. The purpose of this study was to examine the effect of exposure to the ELF magnetic field on the degree of acidity (pH) and density in lemuru fish. The research design used was Completely Randomized Design (CRD). Extremely Low Frequency (ELF) magnetic field exposure treatment is used to increase lemuru fish resistance by inhibiting pathogenic bacteria. The research sample was 110 lemuru fish and divided into 5 groups. One group served as a control, 2 experimental groups were exposed to an ELF magnetic field intensity of 700µT for 60 minutes and 120 minutes, and the other 2 groups were exposed to an ELF magnetic field with an intensity of 1200µT for 60 minutes and 120 minutes. The variables studied included the pH value and the density of lemuru fish. Measurements of pH and density were carried out at the 8th and 20th hours after exposure to the ELF magnetic field. The research data were analyzed using statistical analysis, namely the Kruskall Wallis Test. The results of this study indicated that the intensity of 1200µT for 60 minutes was effective for maintaining the pH value of lemuru fish, while the intensity which was effective for maintaining the density value was 1200µT for 60 minutes and 120 minutes until the 20th hour.

Calculated residential exposure to power frequency magnetic fields for an epidemiological study in France and comparison to measurements

The GEOCAP epidemiological study of paediatric cancers in relation with various environmental factors is currently being carried out in France. Proximity to high voltage overhead lines (63–400 kV) related to exposure to extremely low frequency magnetic field (ELF-MF) is one of studied factors. The study covers the mainland French territory and includes 4174 leukaemia cases and 45 000 controls recruited from 2002 to 2010. Residential exposure was calculated for 1124 subjects whose distance to power lines was small enough for their residential exposure to possibly exceed the background reference level 0.1 μT. Residential exposure was calculated by modelling all the influencing spans close to the subjects’ residences. At final, 371 subjects out of 1124 have a calculated exposure over 0.1 μT, including 123 subjects over 0.4 μT, i.e. 0.25% of the study population. These 371 calculated exposures exceeding 0.1 μT have been matched to an existing database of ELF-MF measurements performed in inhabited areas crossed by power lines, and measurements were found for 206 subjects. Comparison was possible for 156 of them. After extrapolation of the measured values to match to calculation conditions, the difference between calculations and adjusted measurements was lower than 30% for 124 subjects (80%), with no clear tendency for over/under estimation. Differences higher than 30% have been analysed and explained.

Numerical and Analytical Modeling of Electromagnetic Fields From Offshore Power Distribution Cables

The rapid proliferation of power-sharing interconnectors and offshore wind farms has brought with it the need for assuring compliance with regulatory requirements. One regulatory requirement for both federal and state permitting is the evaluation of quasi-static, extremely low frequency (ELF) electric and magnetic fields from proposed power cables that bring electricity from offshore utility projects to shore. The three power cores of alternating current cables twist helically around one another within a single cable. Here ELF magnetic field model calculations are provided, using both numerical and analytical approaches, in the vicinity of submarine power cables in a helically twisted three-core configuration. The numerical simulations were performed by finite element analysis (FEA) and substantiated with analytical solutions for the same cable geometries. The methodology described here represents a sound approach to conduct such analyses - providing an upper bound on the resulting field values without computationally demanding metallic screening parameters - and demonstrates the feasibility of using a combination of analytical solutions for simpler geometries in conjunction with FEA for more complicated cable paths.

Review on the Association between Exposure to Extremely Low Frequency-Magnetic Fields (ELF-MF) and Childhood Leukemia

Review on the Association between Exposure to Extremely Low Frequency-Magnetic Fields (ELF-MF) and Childhood Leukemia

Effects of long-term exposure to 50 Hz magnetic fields on cell viability, genetic damage, and sensitivity to mutagen-induced damage

Until today, it remains controversial whether long-term exposure to extremely low-frequency magnetic fields (ELF-MF) below the legislative exposure limits could result in adverse human health effects. In the present study, the effects of long-term in vitro MF exposure on three different study endpoints (cell viability, genetic damage, and sensitivity to damage induced by known mutagens) were investigated in the human B lymphoblastoid (TK6) cell line. Cells were exposed to 50 Hz MF at three selected magnetic flux densities (i.e., 10, 100, and 500 μT) for different exposure periods ranging from 96h up to 6 weeks. Cell viability following MF exposure was assessed using the ATP-based cell viability assay. Effects of MF exposure on cell genetic damage and cell sensitivity to mutagen-induced damage were evaluated using the in vitro alkaline comet assay and the in vitro cytokinesis block micronucleus assay. The results showed that long-term exposure up to 96h to 50 Hz MF at all tested flux densities could significantly increase TK6 cell viability. In contrast, long-term MF exposure did not affect cell genetic damage, and long-term pre-exposure to MF did not change cell sensitivity to damage induced by known mutagens. At certain time points, statistically significant difference in genotoxicity test results were observed between the MF-exposed cells and the control cells. However, these observations could not be confirmed in the repeat experiments, indicating that they are probably not biologically significant.

Can extremely low frequency magnetic field affect human sperm parameters and male fertility?

Exposure to extremely low frequency magnetic fields (ELF-MF) may have different effects on spermatozoa depending on the waveform, magnetic flux density, frequency of ELF-MF, and duration of exposure. In this study, we investigated the possible role of ELF-MF (50 Hz; 1 mT) exposure in altering sperm parameters. In this study we found that exposure to ELF-MF at the frequency of 50 Hz (1 mT) for two hours induces statistically significant alterations in progressive motility, morphology and reactive oxygen species (ROS) production of human spermatozoa, suggesting a role of ELF-MF in altering reproductive function of spermatozoa. Our results represent an important discovery in the field since occupational exposure to the sine waveform 1 mT 50 Hz ELF-MF used in our study is possible in workplace. Moreover, these electromagnetic fields are product by many electronic devices and household appliances. Thus, alterations of progressive motility and morphology of spermatozoa would be important consequences of human exposures to ELF-MF.

A Review of Aspects of Synaptic Plasticity in Hippocampus via mT Extremely Low-Frequency Magnetic Fields.

The subthreshold magnetic modulation technique stimulates cells with mT extremely low-frequency magnetic fields (ELF-MFs), which are insufficient to induce neuronal action potentials. Although they cannot directly induce resting neurons to discharge, mT magnetic stimulation can regulate the excitability of the nervous system, which regulates learning and memory by some unknown mechanisms. Herein, we describe the regulation of mT ELF-MFs with different parameters on synaptic plasticity in hippocampal neurons. Additionally, we summarize the latest research on the possible mechanism of the effect of ELF-MFs on synaptic plasticity. Some studies have shown that ELF-MFs are able to inhibit long-term potentiation (LTP) by increasing concentration of intracellular Ca2+ concentration ([Ca2+ ]i ), as well as concentration of reactive oxygen species. The research in this paper has significance for the comprehensive understanding of relevant neurological mechanisms of learning and memory by mT ELF-MFs stimulation. However, more high-quality research is necessary to determine the regulatory mechanism of mT ELF-MFs on synaptic plasticity in order to optimize this technique as a treatment for neurological diseases. © 2023 Bioelectromagnetics Society.

Extremely low frequency magnetic fields emitted by cell phones

Cell phones expose significant parts of the human brain and head to extremely low frequency (ELF) magnetic fields (MF) classified by the IARC as a 2B carcinogen. ELF MF was measured on the front and back sides of 15 cell phones in standby, speaking, and listening modes for 2G and 3G standards in two frequency bands, LF1: 5 Hz–200 Hz and LF2: 120 Hz—10 kHz. The highest MF value was 70.03 µT (RMS) in LF1 (2G, listening mode, front side) and 12.67 µT (RMS) in LF2 (2G, speaking mode, front side). The 3G cell phones consistently emitted a lower ELF MF compared to the 2G ones. The exposure to ELF MF was also simulated at various locations (head, thorax, pelvis) using the CST Studio Suite. The simulations revealed 8.45 µT, 7.5 µT, and 6.09 µT in the middle of the head (midbrain), 3.89 µT, 3.98 µT, and 2.83 µT for the middle of the thorax (heart), and 2.03 µT, 1.96 µT, and 1.56 µT in the middle of the pelvis (scrotum) for 10 Hz, 50 Hz, and 200 Hz, respectively. These values are comparable to those reported to induce biological and health effects, including those related to carcinogenesis. The results can be used in future studies concerning the ELF exposure or the combined effects of electromagnetic fields of radiofrequency and ELF.

Estimating exposure to extremely low frequency magnetic fields near high-voltage power lines and assessment of possible increased cancer risk among Slovenian children and adolescents.

Some previous research showed that average daily exposure to extremely low frequency (ELF) magnetic fields (MF) of more than 0.3 or 0.4 μT could potentially increase risk of childhood leukaemia. To allow calculations of ELF MF around high voltage (HV) power lines (PL) for the whole Slovenia, a new three-dimensional method including precision terrain elevation data was developed to calculate the long-term average ELF MF. Data on population of Slovenian children and adolescents and on cancer patients with leukaemia's aged 0-19 years, brain tumours at age 0-29, and cancer in general at age 0-14 for a 12-year period 2005-2016 was obtained from the Slovenian Cancer Registry. According to the large-scale calculation for the whole country, only 0.5% of children and adolescents under the age of 19 in Slovenia lived in an area near HV PL with ELF MF density greater than 0.1 μT. The risk of cancer for children and adolescents living in areas with higher ELF MF was not significantly different from the risk of their peers. The new method enables relatively fast calculation of the value of low-frequency magnetic fields for arbitrary loads of the power distribution network, as the value of each source for arbitrary load is calculated by scaling the value for nominal load, which also enables significantly faster adjustment of calculated estimates in the power distribution network.

Proof of Concept of an ELF Magnetic Field Exposure System with Biphasic Magnetic Pulses: Effects on Human Dermal Fibroblast Proliferation

The aim of this work was to validate the usefulness of an Extremely Low Frequency (ELF) magnetic field exposure system with a magnetotherapy device of common use in clinical practice that generates Biphasic Magnetic Pulses (BMP), in order to study the effects of the BMP on the proliferation of Human Dermal Fibroblasts (HDF). In that regard, HDF were exposed 2h in the morning and 2h in the afternoon for 2 days to BMP of 1.41mT peak value at 5, 10, 25Hz continuous and 50Hz intermittent (2s on/ 1.5s off). MTT assay was performed to assess proliferation. The 10Hz BMP showed a significant decrease in proliferation of 6.6% (p = 0.001) with respect to controls, but no significant changes in proliferation were seen with the other BMP. In order to analyze whether these results could be related to the exposure protocol, a 50Hz power line intermittent signal (1s on/ 1s off) was generated and tested but exposure time was increased to 48h to cover the complete cells doubling time. A significant increase in proliferation of 9% (p < 0.001) was found in this case. The results validate the in vitro exposure system for its use with the BMP. Though the MTT proliferation assay alone is not enough to make definitive claims, the results might indicate that exposure time plays a key role in the outcome of the experiments. Therefore, special attention should be paid to the exposure time on in vitro protocols and how they relate to in vivo experiments and current treatments.

Calculation of Electric Field Induced in the Human Body for Simultaneous Exposure to Spatially Uniform ELF Electric and Magnetic Fields With a Phase Difference

Calculation of Electric Field Induced in the Human Body for Simultaneous Exposure to Spatially Uniform ELF Electric and Magnetic Fields With a Phase Difference

Physical Quality of Cow's Milk by Exposure to Magnetic Fields Extremely Low Frequency (ELF) 300 μT and 500 μT by inhibiting Salmonella and Escherichia Coli Growth

Extremely Low Frequency (ELF) magnetic field, high intensity (more than 100 µT), can suppress the growth of pathogenic bacteria, but the impact of low intensity (≤ 500 µT) needs to be proven. This study aimed to analyze the physical resistance of cow's milk exposed to a magnetic field of 300 µT and 500 µT ELF by inhibiting the proliferation of Salmonella and Escherichia Coli bacteria. Completely Randomized Design (CRD) research design. Samples were 210 bottles of cow's milk (@ 50 ml) divided into seven groups. Exposure to the ELF magnetic field intensity of 300 μT and 500 μT with exposure variations of 60, 90, and 120 minutes. Result: Exposure to an ELF magnetic field with an intensity of 500 µT for 60 minutes significantly (p &lt; 0.05) reduced the Salmonella sp. population but not Escherichia coli. Even though the physical condition showed the color and smell of fresh milk, lumps did not appear until the 10th hour. Conclusion: exposure to the ELF magnetic field intensity of 300 μT and 500 μT has not been able to maintain the quality of cow's milk.