Extremely Low Frequency Fields Research Articles

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.

Estimation of RF and ELF dose by anatomical location in the brain from wireless phones in the MOBI-Kids study

Wireless phones (both mobile and cordless) emit not only radiofrequency (RF) electromagnetic fields (EMF) but also extremely low frequency (ELF) magnetic fields, both of which should be considered in epidemiological studies of the possible adverse health effects of use of such devices. This paper describes a unique algorithm, developed for the multinational case-control MOBI-Kids study, that estimates the cumulative specific energy (CSE) and the cumulative induced current density (CICD) in the brain from RF and ELF fields, respectively, for each subject in the study (aged 10–24 years old). Factors such as age, tumour location, self-reported phone models and usage patterns (laterality, call frequency/duration and hands-free use) were considered, as was the prevalence of different communication systems over time.Median CSE and CICD were substantially higher in GSM than 3G systems and varied considerably with location in the brain. Agreement between RF CSE and mobile phone use variables was moderate to null, depending on the communication system. Agreement between mobile phone use variables and ELF CICD was higher overall but also strongly dependent on communication system. Despite ELF dose distribution across the brain being more diffuse than that of RF, high correlation was observed between RF and ELF dose.The algorithm was used to systematically estimate the localised RF and ELF doses in the brain from wireless phones, which were found to be strongly dependent on location and communication system. Analysis of cartographies showed high correlation across phone models and across ages, however diagonal agreement between these cartographies suggest these factors do affect dose distribution to some level. Overall, duration and number of calls may not be adequate proxies of dose, particularly as communication systems available for voice calls tend to become more complex with time.

To the issue of organization of the communication system in microorganisms

The role of EMF (electromagnetic field) in biological systems is considered in a large number of works performed by various foreign scientists. The energy imparted to the EMF system by the ELF (extremely low frequency) field is much less than the energy of thermal movements. But no work discusses the issues of impulse exchange in biological systems, and first of all, between the molecules of the (flexible) γ-protein and membranes that act as a capacitor of electrical impulses. The purpose of the article is to fill this gap in science by discussing the literature data on the effect of ELF and ULF (ultra-low frequency) EMFs on biological systems, primarily, the protein envelope of the virus + the host cell membrane.

ELF field measurements near Hortobágy and Magyargencs

Extremely low frequency (ELF) field measurements were organized near Hortobágy in 2019 and near Magyargencs in 2020 to survey the observability of Schumann resonances (SR) and properties of the ELF noise environment in the magnetic field in Hungary. The measurements serve our aim to find an appropriate location for a new permanent magnetic SR station. The location of the second test site (near Magyargencs) was selected on the base of experience we gathered from reprocessing high frequency magnetotelluric (MT) measurements in Hungary. Initial evaluation of the field measurements confirmed that it is not easy, but possible to find places of such low ELF noise levels in Hungary, which are suitable for monitoring SR.

Exposure and health risks perception of extremely low frequency and radiofrequency electromagnetic fields and the effect of providing information

Given that regardless of actual exposure levels, high-risk perceptions of electromagnetic fields of non-ionizing radiation (EMF-NIR) may cause health effects, it is important to understand the mechanisms behind perceptions in the general population. The aims of this study were to assess perceptions of both exposure and health-risk among mothers of the INMA (Environment and childhood)-Gipuzkoa child cohort; to explore possible determinants that explain such perceptions; and to evaluate whether providing information on exposure levels has any effect on perceptions. Overall, 387 mothers completed a questionnaire composed of four questions on perceived exposure and perceived health-risk of exposure to extremely low frequency (ELF) and radiofrequency (RF) fields answered on a Likert-type scale from 0 to 10. Later, measurements of ELF and RF fields were conducted in the houses of a subsample of 104 participants. All measured levels were far below the levels established by the European Council recommendation. This was explained in the individual reports sent to the families. After reading the results, mothers completed the aforementioned questionnaire a second time, plus two additional questions regarding the role of public health bodies in risk communication.The association between perceived and measured levels as categorical variables was assessed with a chi-square test. Multiple linear regressions were conducted for each of the questions related to perceived exposure and health-risk perceptions. Wilcoxon signed-rank test was conducted to assess the effect of receiving information.Both exposure and health risk were perceived to be very high for both ELF and RF fields, with mean and medians of 7 on a 10-point scale. Reporting higher perception levels was not associated with higher levels of exposure measured at home. Variables that were repeatedly associated with higher perceptions included: manual social class, not having the feeling of living in a good neighborhood, difficulty getting by financially, not having a television antenna within 600 m, being younger and having fewer devices at home. Providing information on EMF-NIR exposure levels at home did not alter health-risk perceptions, but mean perceived RF exposure decreased significantly (by 0.7 points). Most of the participants claimed to have received no or insufficient information regarding exposure and health-risks of EMF-NIR from public bodies and considered it very important that they should.

Gradient/Extremely Low-Frequency Magnetic Field Affects Metamorphic Behaviors in Thyroxine-Administrated Axolotls: Regulation of Amphibian Metamorphosis Depending on Field Strength and Exposure Timing

In this paper, we investigated the influences of a gradient magnetic field or extremely low-frequency (ELF) fields on the forced metamorphosis of the Mexican axolotls, which was induced with a thyroid hormone. After the adaptation of the axolotls to our experimental environment, they were individually kept in an L-thyroxine (T4) solution under exposure to a gradient field of 17 T/m or ELF fields of 1.0–5.0 mT at 10 Hz. In order to remove unnecessary stress for the axolotls, we recently developed an original water-renewing system equipped with siphonage, velocity, and temperature controls. The number of days required for the perfect metamorphosis into salamanded axolotls under the ELF exposure of 5.0 mT was 16.9 days on average, contrary to the time period for a control (15.1 days). We assumed that the morphological delays of up to 26% among the ELF-exposed axolotls might be due to the competing situation between alternating field effects and biological adaptive responses to the magnetic forces in the axolotl subjects’ bodies. In addition, we did found that the initiation timings of the gradient-field exposure did affect the survival rates of the following salamanded axolotls. A decrease in the rates was noticeable in the case of an exposure just before the time point of the morphological completion. Our data greatly support the idea that magnetic field exposures might modify axolotl metamorphosis minutely, depending on the exposure timing, the field strength, the frequency, and so on. We strongly propose investigating the magnetic control of axolotl metamorphosis induced with a thyroid hormone.

Magnetocarcinogenesis: is there a mechanism for carcinogenic effects of weak magnetic fields?

Extremely low-frequency (ELF) magnetic fields have been classified as possibly carcinogenic, mainly based on rather consistent epidemiological findings suggesting a link between childhood leukaemia and 50-60 Hz magnetic fields from power lines. However, causality is not the only possible explanation for the epidemiological associations, as animal and in vitro experiments have provided only limited support for carcinogenic effects of ELF magnetic fields. Importantly, there is no generally accepted biophysical mechanism that could explain such effects. In this review, we discuss the possibility that carcinogenic effects are based on the radical pair mechanism (RPM), which seems to be involved in magnetoreception in birds and certain other animals, allowing navigation in the geomagnetic field. We review the current understanding of the RPM in magnetoreception, and discuss cryptochromes as the putative magnetosensitive molecules and their possible links to cancer-relevant biological processes. We then propose a hypothesis for explaining the link between ELF fields and childhood leukaemia, discuss the strengths and weaknesses of the current evidence, and make proposals for further research.

The antitumor effect of static and extremely low frequency magnetic fields against nephroblastoma and neuroblastoma.

Certain magnetic fields (MF) have potential therapeutic antitumor effect whereas the underlying mechanism remains undefined. In this study, a well-characterized MF was applied to two common childhood malignancies, nephroblastoma and neuroblastoma. This MF has a time-averaged total intensity of 5.1 militesla (mT), and was generated as a superimposition of a static and an extremely low frequency (ELF) MF in 50 Hertz (Hz). In nephroblastoma and neuroblastoma cell lines including G401, CHLA255, and N2a, after MF exposure of 2 h per day, the cell viability decreased significantly after 2 days. After 3 days, inhibition rates of 17-22% were achieved in these cell lines. Furthermore, the inhibition rate was positively associated with exposure time. On the other hand, when using static MF only while maintaining the same time-averaged intensity of 5.1 mT, the inhibition rate was decreased. Thus, both time and combination of ELF field were positively associated with the inhibitory effect of this MF. Exposure to the field decreased cell proliferation and induced apoptosis. Combinational use of MF together with chemotherapeutics cisplatin (DDP) was performed in both in vitro and in vivo experiments. In cell lines, combinational treatment further increased the inhibition rate compared with single use of either DDP or MF. In G401 nephroblastoma tumor model in nude mice, combination of MF and DDP resulted in significant decrease of tumor mass, and the side effect was limited in mild liver injury. MF exposure by itself did not hamper liver or kidney functions. In summary, the antitumor effect of an established MF against neuroblastoma and nephroblastoma is reported, and this field has the potential to be used in combination with DDP to achieve increased efficacy and reduce side effects in these two childhood malignancies. Bioelectromagnetics. 39:375-385, 2018. © 2018 Wiley Periodicals, Inc.

Approximated Solutions for ELF Near-Field Propagation Due to a Horizontal Electric Dipole Excitation Near the Sea-Rock Boundary

In this paper, the near-field propagation of extremely low frequency (ELF) wave due to a horizontal electric dipole excitation has been investigated near the boundary between two dielectrics. First, a novel quasi-static approximation is assumed with $\gamma _{2}\approx -i\lambda $ so that the integrands of the Fourier–Bessel representations for ELF field are approximated near the poles by adopting Maclaurin’s Expansion. Second, by the conditions of $k_{2}\rho \ll 1$ , $\textit {z} / {\rho \ll 1}$ , and $d / \rho \ll 1$ , the ratio of wave numbers for rock and sea $k_{2} /k_{1}$ is equivalent to an infinitesimal that only fundamental terms of $| k_{2}^{2}\gamma _{2} |/ | k_{1}^{2}\gamma _{1} |$ are reserved for the electromagnetic components. Third, the approximated formulas are derived for ELF near-field propagation generated by a horizontal electric dipole with the above simplifications. Finally, the simplified formulas are verified by an analogy with the exact and approximated formulas, respectively. It demonstrates that the proposed formulas are complementarily essential for evaluations of ELF near field and the plotted Poynting vectors indicate approximately the propagation direction of the energy flow.

A Novel Detection Method for Underwater Moving Targets by Measuring Their ELF Emissions with Inductive Sensors.

In this article, we propose a novel detection method for underwater moving targets by detecting their extremely low frequency (ELF) emissions with inductive sensors. The ELF field source of the targets is modeled by a horizontal electric dipole at distances more than several times of the targets’ length. The formulas for the fields produced in air are derived with a three-layer model (air, seawater and seafloor) and are evaluated with a complementary numerical integration technique. A proof of concept measurement is presented. The ELF emissions from a surface ship were detected by inductive electronic and magnetic sensors as the ship was leaving a harbor. ELF signals are of substantial strength and have typical characteristic of harmonic line spectrum, and the fundamental frequency has a direct relationship with the ship’s speed. Due to the high sensitivity and low noise level of our sensors, it is capable of resolving weak ELF signals at long distance. In our experiment, a detection distance of 1300 m from the surface ship above the sea surface was realized, which shows that this method would be an appealing complement to the usual acoustic detection and magnetic anomaly detection capability.

Direction-Dependent Effects of Combined Static and ELF Magnetic Fields on Cell Proliferation and Superoxide Radical Production.

Proliferation of human umbilical vein endothelial cells was stimulated by a nearly vertical 60 or 120 μT static magnetic field (MF) in comparison to cells that were shielded against MFs. When the static field was combined with an extremely low frequency (ELF) MF (18 Hz, 30 μT), proliferation was suppressed by a horizontal but not by a vertical ELF field. As these results suggested that the effects of an ELF MF depend on its direction in relation to the static MF, independent experiments were carried out to confirm such dependence using 50 Hz MFs and a different experimental model. Cytosolic superoxide level in rat glioma C6 cells exposed in the presence of a nearly vertical 33 μT static MF was increased by a horizontal 50 Hz, 30 μT MF, but not affected by a vertical 50 Hz MF. The results suggest that a weak ELF MF may interact with the static geomagnetic field in producing biological effects, but the effect depends on the relative directions of the static and ELF MFs.

A Touch Sensing Technique Using the Effects of Extremely Low Frequency Fields on the Human Body.

Touch sensing is a fundamental approach in human-to-machine interfaces, and is currently under widespread use. Many current applications use active touch sensing technologies. Passive touch sensing technologies are, however, more adequate to implement low power or energy harvesting touch sensing interfaces. This paper presents a passive touch sensing technique based on the fact that the human body is affected by the surrounding extremely low frequency (ELF) electromagnetic fields, such as those of AC power lines. These external ELF fields induce electric potentials on the human body—because human tissues exhibit some conductivity at these frequencies—resulting in what is called AC hum. We therefore propose a passive touch sensing system that detects this hum noise when a human touch occurs, thus distinguishing between touch and non-touch events. The effectiveness of the proposed technique is validated by designing and implementing a flexible touch sensing keyboard.

Control of the Flickering Light Sensation Based on Superimposed Electromagnetic Fields

This paper was studied to investigate whether superimposed electromagnetic fields could control flickering light perceptions caused by the activity of a stimulated retina. To show the capabilities of electromagnetic control, we designed two coil systems, and investigated the magnetic flux distributions of superimposed extremely low-frequency (ELF) magnetic fields from the coils. Furthermore, we examined the superimposed effect for the modification of perception, and discovered that the ELF costimuli can control retinal sensitivities partially for perception. When the ELF field frequencies were varied in the range of 10–50 Hz, threshold variations for the perception were observed as the effect of the costimuli to the temporal side at 40 Hz and to the eyeball side at 20 Hz. These results show a definite advantage by employing the superimposed ELF fields on the two previously mentioned locations with a close examination of the properties of the flicker sensations.

Positive correlation between ELF and RFelectromagnetic fieldon cancer risk

Extremely low frequency (ELF) and Radio frequency (RF) electromagnetic field may affect biological systems by raising generation free radicals by decline activities of glutathione peroxidase dismutase or increase in the lifetime of free radicals with inhibited pretreatment of cells antioxidant like that alpha tocopherol. ELF and RF electromagnetic field maycan damaged DNA with raising level hydroxyl radicals in cells and it is can interact DNA and form mainly 8-hydroxy-2′–deoxyguanosine( 8-OHdG) adducts. Many study showed Electromagnetic field radiation(EMF) can change gene expression and conformation of protein. It may declineexpression of some genes such as superoxide dismutase orraise expressionof certain genes such as Hsps (heat shock proteins). ELF and RFelectromagnetic field can effects on homeostasis Ca 2+ and alteration in important cellular and molecular processes such as differentiation, proliferation, gene expression, cytoskeletal reorganization and metabolism. Use of radio frequency electromagneticfield onsatellite jamming in Iran and some country may can harmful to human health and it could be a risk factor for cancer.

Association between ELF and RF electromagnetic field and Leukemia

Extremely low frequency (ELF) electromagnetic field (ELF-EMFs) are widely employed in electrical appliances and different equipment such as television sets, ELF-EMFs can affect biological systems by increasing production ROS. The altered balance between ROS generation and elimination plays a critical role in a variety of pathologic conditions. ROS levels have been observed in several hematopoietic malignancies including acute and chronic myeloid leukemia. ELF-EMFs exposure significantly decreased Nitric oxide synthase (iNOS) protein expression Lower levels of NO have been demonstrated to exert a protective function in leukemic and melanoma cells and to inhibit effector caspases by S-nitrosylation. Also ELF-EMFs can decrease melatonin production by effects on N-acetyltransferase. Melatonin is an antioxidant, effective in protecting nuclear DNA. Transmitters emitting radio frequency electromagnetic fields (RF-EMFs) are usually not located in populated areas but some epidemiology studies showed association distance transmitters from residential area and leukemia.

P14.06 * MOBI-KIDS STUDY: EXPOSURE TO COMMUNICATION TECHNOLOGIES AND BRAIN TUMOUR RISK IN CHILDREN AND ADOLESCENTS

The rapid worldwide increase in mobile phone use and the often controversial results of the studies on their possible health effects has generated considerable concern in the public, especially when considering the increasing exposure of children and adolescents. MOBI-Kids, a prospective case-control study conducted in 15 countries and spanning a target population of almost 40 million individuals, was initiated to assess the potential effects of exposure to radiofrequency fields (RF) and extremely low frequency fields (ELF) from mobile phones on the development of central nervous system tumours among people aged 10 to 24 years old. This study faces a high level of complexity and methodological challenges, including the need to reduce potential bias, heterogeneity of the malignancies affecting people in this age range, strict ethic legislations, and assessment of exposure to RF and ELF. The study builds upon the experience of INTERPHONE, the 13-country study investigating mobile phone use and risk of brain cancer in adults in 2000-2004. It aims to include approximately 1,000 brain tumour cases and 2,000 matched controls. Such numbers will ensure 80% power to detect an increased risk of 40% assuming 10% have used a mobile phone for 10 years or longer. An interview is administered to all participants and their parents to assess lifestyle, residential, occupational and school history, use of communication technologies, exposure to environmental risk factors, medical history and family history of cancer. Reported mobile phone use is validated with phone records provided by operators. Biological samples for DNA isolation are collected in several countries. Clinical data and images needed for diagnosis verification and tumour classification are collected from all available medical files. Tumour images will be mapped on 3D head models by neuroradiologists. MOBI-Kids started on the Feb 1st, 2009, and cases' recruitment is scheduled to finish at the end of 2014. To date, 790 cases and 1958 controls have been identified. Of these, 587 cases and 1059 controls answered the full questionnaire, 101 answered a short non response questionnaire on mobile phone use and socioeconomic status, which will be used to assess potential selection bias. MOBI-Kids results, by contributing to the understanding of potential brain tumour risks associated with the use of mobile phones and other communication technologies among young people, will have a strong impact in terms of public health and protection of the population.

Evaluations of Occupational Exposure and Magnetic Field Levels at Hospital Environments

Electromagnetic field levels at the typical hospital environments analyzed with this study. Typical center laboratory has been selected for the research. There are a lot of devices at this center such as Centrifugal, biochemistry auto-analyzer, Hemogram units etc. Electromagnetic fields at the laboratory environment are the Extremely Low Frequency field. Therefore, occupants that they may be exposed to the electromagnetic field levels were measured, and the results are evaluated in the light of occupational exposure safety limits.

Invited Commentary: Extremely Low-Frequency Magnetic Fields and Breast Cancer--Now It Is Enough!

Research on an association between extremely low frequency (ELF) magnetic fields and breast cancer has been conducted since the 1980s, based on the hypothesis that ELF fields suppress melatonin production and melatonin protects against breast cancer development. In this issue of the Journal, Li et al. (Am J Epidemiol. 2013;178(7):1038-1045) present a well-designed study on occupational exposure to ELF fields and breast cancer that adds to the already large pool of data that has not supported the hypothesis. Over time, the quality and statistical power of studies within this research area have increased considerably, and advances in exposure assessment have reduced exposure misclassification. The evidence is consistently negative. A World Health Organization health risk assessment concluded in 2005 that the evidence from experimental and epidemiologic studies is sufficient to give confidence that ELF magnetic fields do not cause breast cancer. The new study adds even more confidence to this conclusion. We should now focus our time and research resources on more promising hypotheses, the results of which could make a difference for public health and advance science. Further epidemiologic studies on ELF fields and breast cancer are likely to have little new knowledge to add.

The change of electric potentials in the oral cavity after application of extremely low frequency pulsed magnetic field

Electric potentials occurring in the oral cavity deserve attention as they may cause various diseases and subjective feelings, which are very difficult to treat. The aim of this study was to evaluate the electric potentials within the oral cavity in patients with metal fillings and metal prosthetic restorations, after using a pulsed electromagnetic field. The study was carried out on 84 patients. The Viofor JPS Classic device was used in the treatment. It generates a pulsed electromagnetic field with low induction of the extremely low frequency (ELF) range. Average values of electric potentials in the preliminary test were about the same in both groups; they were 148.8 mV and 145.5 mV. After another appliance of ELF fields there was found a steady decline in the average value of electric potentials in the study group. This decrease was statistically highly significant, while mean values of electric potentials in the control group were characterized by a slightly upward tendency. The obtained statistically significant reduction of electric potentials in the oral cavity of patients having metal fillings and metal prosthetic restorations, after application of the Viofor JPS Classic device, implies a huge impact of ELF pulsed electromagnetic field on inhibition of electrochemical processes, as well as on inhibition of dental alloy corrosion.

Electric fields caused by blood flow modulate vascular endothelial electrophysiology and nitric oxide production

Endothelial cells are exposed to a ubiquitous, yet unexamined electrical force caused by blood flow: the electrokinetic vascular streaming potential (EVSP). In this study, the hypothesis that extremely low frequency (ELF) electric fields parameterized by the EVSP have significant biological effects on endothelial cell properties was studied by measuring membrane potential and nitric oxide production under ELF stimulation between 0 and 2 Hz and 0-6.67 V/m. Using membrane potential and nitric oxide sensitive fluorescent dyes, bovine aortic endothelial cells (BAECs) in culture were studied in the presence and absence of EVSP-modeled electric fields. The transmembrane potential of BAECs was shown to depolarize between 1 and 7 mV with a strong dependency on both the magnitude and frequency of the isolated ELF field. The findings also support a field interaction with a frequency-dependent tuning curve. The ELF field complexly modulates the nitric oxide response to adenosine triphosphate stimulation with potentiation seen with up to a sevenfold increase. This potentiation was also frequency and magnitude dependent. An early logarithmic phase of NO production is enhanced in a field strength-dependent manner, but the ELF field does not modify a later exponential phase. This study shows that using electric fields on the order of those generated by blood flow influences the essential biology of endothelial cells. The inclusion of ELF electric fields in the paradigm of vascular biology may create novel opportunities for advancing both the understanding and therapies for treatment of vascular diseases.