Low Frequency Electromagnetic Field Exposure Research Articles

Chemoprotective action of lotus seedpod procyanidins on oxidative stress in mice induced by extremely low-frequency electromagnetic field exposure.

With the increasing use of electromagnetic technology, the effects of extremely low-frequency electromagnetic fields (ELF-EMF) on biological systems, central neurotransmitter systems, and human health have attracted extensive attention worldwide. In this study, lotus seedpod procyanidins (LSPCs) were evaluated for their protective effects on ELF-EMF induced oxidative stress injury in mice. Sixty male ICR mice were used for the experiment. The mice were randomly divided into five equal groups. The control group did not receive LSPCs or ELF-EMF but orally received normal saline. The ELF-EMF group received ELF-EMF exposure plus normal saline orally. The other three groups received ELF-EMF exposure plus LSPCs orally (60, 90, or 120mg kg(-1).bw, respectively). Each group exposed to ELF-EMF at 8 mT, 4h day(-1) for 28 consecutive days after administration daily of LSPCs or normal saline to mice for 15 consecutive days with the exception of the control group. Thereafter, blood and cerebral cortex of the mice were analyzed for antioxidant indices, including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR), glutathione-S-transferase (GST) and malondialdehyde (MDA). LSPCs administration at different doses significantly inhibited oxidative stress damage of mice induced by ELF-EMF. LSPCs treatment augmented SOD, CAT, GSH-Px, GR and GST activity. Furthermore, administration significantly lowered MDA level in LSPCs treatment groups LSPCs. All results indicated LSPCs can effectively prevent oxidative stress injury induced by ELF-EMF exposure, which may be related to its ability of scavenging free radicals and stimulating antioxidant enzyme activity.

Protective effect of procyanidins extracted from the lotus seedpod on immune function injury induced by extremely low frequency electromagnetic field.

This study aimed to evaluate the protective effect of Lotus seedpod procyanidins (LSPCs) from extremely low frequency electromagnetic field (ELF-EMF) exposure (50Hz, 8mT, 28 days) and their protective mechanism against radiation damage. The results showed that LSPCs increased the organ index of mice and made the damaged blood-producing function and cytokine(INF-γ, TNF-α, IL-2, IL-6 and IL-10 in spleen) levels by ELF-EMF-irradiation recovered to normal appearance. And experimental results proved that dosing LSPCs inhibit more stagnation of splenocytes in G0/G1 phase caused by ELF-EMF, thus the spleen cells from G0/G1 phase to S phase shift, restore normal cell metabolism, promote the splenocytes proliferation, reduced the apoptosis of spleen cells, effective protect the damage induced by the ELF-EMF radiation. In addition, LSPCs prevented the decline of DNA content caused by ELF-EMF. Western blot determinated the levels of apoptosis genes including Bcl-2, Bax, Bcl-cl, Caspase-3 and Caspase-9. The results revealed that a significant suppression in Bcl-2 expression and increase in Bax, Caspase-3 and Caspase-9 expression in splenic cells in ELF-EMF group. However, LSPCs restored these changes. Taking these results together, it may be summarized that LSPCs could protect hematopoietic tissues and the immune system from ELF-EMF. And it may be hypothesized that ELF-EMF-induced apoptosis in splenocytes might occur via triggers the trans-activation of Bax and activates caspases-3 and -9, which then cleaves the death substrates, leading to apoptosis in splenocytes of mice treated with ELF-EMF.

Effects of 100-μT extremely low frequency electromagnetic fields exposure on hematograms and blood chemistry in rats.

The aim of this study was to test whether extremely low frequency electromagnetic fields (ELF EMFs) affect health or not. Here, we constructed a 100-μT/50 Hz electromagnetic field atmosphere. A total of 128 rats were randomly assigned into two groups: the ELF EMF group and the sham group. The ELF EMF group was exposed to 100-μT/50-Hz ELF EMF for 20 h per day for three months; at the same time the other group was exposed to a sham device without ELF EMF. During the three months, the weight was recorded every 2 weeks, and the water intake and food intake of the animals were recorded weekly. The hematologic parameters were detected before and after the exposure, whereas blood chemistry analysis was performed every 4 weeks. The general condition of the exposed rats was not affected by ELF EMF. Compared with the sham group, the hematograms were not significantly altered in the ELF EMF group. Similarly, the blood chemistry (including lipid profile, blood glucose, liver function and renal function of rats) from the ELF EMF group showed no difference compared with rats from the control group during the three months exposure. The present study indicated that short-term exposure of 100-μT/50-Hz ELF EMF may not affect hematograms and blood chemistry in rats.

Common behaviors alterations after extremely low-frequency electromagnetic field exposure in rat animal model

ABSTRACTNaturally, the presence of electromagnetic waves in our living environment affects all components of organisms, particularly humans and animals, as the large part of their body consists of water. In the present study, we tried to investigate the relation between exposure to the extremely low-frequency electromagnetic field (ELF-EMF) and common behaviors such as body weight, food and water intake, anorexia (poor appetite), plasma glucose concentration, movement, rearing and sniffing in rats. For this purpose, rats were exposed to 40 Hz ELF-EMF once a day for 21 days, then at days 1, 3, 7, 14 and 21 after exposure, any changes in the above-mentioned items were assessed in the exposed rats and compared to the non-exposed group as control. Body weight of irradiated rats significantly increased only a week after exposure and decreased after that. No significant change was observed in food and water intake of irradiated rats compared to the control, and the anorexia parameter in the group exposed to ELF-EMF was significantly decreased at one and two weeks after irradiation. A week after exposure, the level of glucose was significantly increased but at other days these changes were not significant. Movements, rearing and sniffing of rats at day 1 after exposure were significantly decreased and other days these changes did not follow any particular pattern. However, the result of this study demonstrated that exposure to ELF-EMF can alter the normal condition of animals and may represent a harmful impact on behavior.

Effects of extremely low-frequency electromagnetic fields (ELF-EMF) exposure on B6C3F1 mice

Long-term exposure study was conducted to investigate the effects of extremely low-frequency electromagnetic field on the tumor promotion process and fertility. Ten pregnant C57BL/6NCrj mice were exposed to 50 Hz field 500 mG for 1 week (12 h per day), and 24 male and 42 female B6C3F1mice born from them were further exposed up to 15.5 months. As a control group, 10 pregnant mice were bred without exposure, and 30 produced male and 32 female mice were observed without exposure for the same period. Mean body weights of exposed groups of male and female mice were decreased significantly than those of the control groups. In exposed mice, there was no increased incidence of liver and lung tumor. In female mice, the incidence of chronic myeloid leukemia [3/42 (7%)] in the exposed group was significantly greater than in the control group. The size of seminiferous tubules in the EMF exposed groups were significantly less than the control group. These data support the hypothesis that long-term exposure of 50 Hz magnetic fields is a significant risk factor for neoplastic development and fertility in mice.

Extremely low frequency electromagnetic fields enhance neuronal differentiation of human mesenchymal stem cells on graphene-based substrates

Graphene is a non-cytotoxic and biocompatible material which serves as a powerful platform for cell growth, differentiation, and fate conversion. The unique features of this nanomaterial are exploited in regenerative medicine and tissue engineering as a scaffold for biological tissues. Graphene-based substrates support neuronal differentiation of stem cells and hence can potentially be applied in nerve regeneration. Since the exact differentiation mechanism mediated by graphene substrate is not fully understood, the efficiency of the process remains to be improved. Herein, the extremely low frequency electromagnetic fields (ELF-EMF; 50 Hz, 1 mT) exposure synergistically increased biological efficacy of neuronal differentiation in bone marrow-derived human mesenchymal stem cells (hMSCs) grown on graphene-coated substrate. We show that such enhancement in neurogenesis is achieved by altering global gene expression profile thereby up-regulating cell adhesion through intracellular calcium influx and activated focal adhesion kinase signaling pathway, which is stimulated by extracellular matrix production. Our findings may provide the framework for a useful therapeutic strategy in regenerative medicine.

The Energy Metabolism in Caenorhabditis elegans under The Extremely Low-Frequency Electromagnetic Field Exposure.

A literal mountain of documentation generated in the past five decades showing unmistakable health hazards associated with extremely low-frequency electromagnetic fields (ELF-EMFs) exposure. However, the relation between energy mechanism and ELF-EMF exposure is poorly understood. In this study, Caenorhabditis elegans was exposed to 50 Hz ELF-EMF at intensities of 0.5, 1, 2, and 3 mT, respectively. Their metabolite variations were analyzed by GC-TOF/MS-based metabolomics. Although minimal metabolic variations and no regular pattern were observed, the contents of energy metabolism-related metabolites such as pyruvic acid, fumaric acid, and L-malic acid were elevated in all the treatments. The expressions of nineteen related genes that encode glycolytic enzymes were analyzed by using quantitative real-time PCR. Only genes encoding GAPDH were significantly upregulated (P < 0.01), and this result was further confirmed by western blot analysis. The enzyme activity of GAPDH was increased (P < 0.01), whereas the total intracellular ATP level was decreased. While no significant difference in lifespan, hatching rate and reproduction, worms exposed to ELF-EMF exhibited less food consumption compared with that of the control (P < 0.01). In conclusion, C. elegans exposed to ELF-EMF have enhanced energy metabolism and restricted dietary, which might contribute to the resistance against exogenous ELF-EMF stress.

A cross-sectional study on oxidative stress in workers exposed to extremely low frequency electromagnetic fields

Purpose: To investigate whether extremely low frequency electromagnetic field (ELF-EMF) exposure could induce oxidative stress in workers performing tour-inspection near transformers and distribution power lines.Materials and methods: Occupational short-term ‘spot’ measurements were performed. In total, 310 inspection workers exposed to ELF-EMF were selected as the exposure group and 300 logistical staff as the control group. Plasma total antioxidant capacity (T-AOC) and glutathione peroxidase (GPx) activity were tested by the colorimetric method. Superoxide dismutase (SOD) activity was tested using the xanthine oxidase method. Plasma malondialdehyde (MDA) concentration was determined with a thiobarbituric acid assay. The micronucleus cell frequency (MCF) and Micronuclei frequency (MN) were also tested for genotoxic assessment.Results: No significant changes of enzyme activities or MDA concentration were found. Neither the frequency of micronucleus lymphocytes nor micronuclei frequency changes were statistically significant.Conclusion: Continual ELF-EMF exposure might not induce oxidative stress in workers from a power supply bureau.

Low-Frequency Electromagnetic Field Exposure Enhances Extracellular Trap Formation by Human Neutrophils through the NADPH Pathway

Low-frequency (LF) electromagnetic fields (EMFs) are abundantly present in modern society, and the potential biological consequences of exposure to these fields are under intense debate. Immune cells are suggested as possible target cells, though a clear mechanism is lacking. Considering their crucial role in innate immune activation, we selected an ex vivo exposure set-up with human neutrophils to investigate a possible correlation between neutrophil extracellular trap (NET) formation and LF EMF exposure. Our study shows that formation of NETs is enhanced by LF EMF exposure. Enhanced NET formation leads to increased antimicrobial properties as well as damage to surrounding cells. We found that LF-EMF-induced NET formation is dependent on the NADPH oxidase pathway and production of reactive oxygen species. Additionally, LF EMF exposure does not influence autophagy and PAD4 activity. Our study provides a mechanism by which exposure to LF EMFs could influence the innate immune system.

Формирование понятия «доза воздействия электромагнитного поля низкочастотного диапазона на организм человека»

Формирование понятия «доза воздействия электромагнитного поля низкочастотного диапазона на организм человека»

Short-term effects of extremely low frequency electromagnetic fields exposure on Alzheimer's disease in rats

Purpose: With the development and widespread use of electromagnetic field (EMF) technology, recent studies are focusing on the effects of EMF on human health. Recently, extremely low frequency electromagnetic fields (ELF-EMF) have been studied with great interest due to their possible effects on Alzheimer's disease (AD). The objective of the present study was to investigate the interaction between ELF-EMF exposure and memory impairment in rats.Materials and methods: Twenty healthy male Sprague Dawley (SD) rats were randomly divided into two groups (n = 10). Animals were exposed to 100 μT/50 Hz ELF-EMF or subjected to sham exposure when 12 weeks old. After 12 weeks, the Morris water maze (MWM) was used to test the changes in cognitive and memory ability. Amyloid-beta (Aβ) content in cortex, hippocampus and plasma were measured by ELISA assays. The morphology of neuron was detected by H&E staining.Results: After exposure, the body weight of rats showed no difference compared with the control group. The application of ELF-EMF did not induce any cognitive and memory impairment compared with the sham-exposure group. The determination of Aβ showed no significant change between the two groups, and there was no histological change in ELF-EMF exposure group.Conclusion: The present study indicated that short-term exposure of 100 μT/50 Hz ELF-EMF had no effects on cognition and memory of rats, and did not alter the expression of Aβ and the neuron morphology. However, more comprehensive studies are still required to elucidate the possible effects and underlying mechanisms of ELF-EMF exposure on living organisms.

Exposure to extremely low frequency electromagnetic fields alters the calcium dynamics of cultured entorhinal cortex neurons

Previous studies have revealed that extremely low frequency electromagnetic field (ELF-EMF) exposure affects neuronal dendritic spine density and NMDAR and AMPAR subunit expressions in the entorhinal cortex (EC). Although calcium signaling has a critical role in control of EC neuronal functions, however, it is still unclear whether the ELF-EMF exposure affects the EC neuronal calcium homeostasis. In the present study, using whole-cell recording and calcium imaging, we record the whole-cell inward currents that contain the voltage-gated calcium currents and show that ELF-EMF (50Hz, 1mT or 3mT, lasting 24h) exposure does not influence these currents. Next, we specifically isolate the high-voltage activated (HVA) and low-voltage activated (LVA) calcium channels-induced currents. Similarly, the activation and inactivation characteristics of these membrane calcium channels are also not influenced by ELF-EMF. Importantly, ELF-EMF exposure reduces the maximum amplitude of the high-K+-evoked calcium elevation in EC neurons, which is abolished by thapsigargin, a Ca2+ ATPase inhibitor, to empty the intracellular calcium stores of EC neurons. Together, these findings indicate that ELF-EMF exposure specifically influences the intracellular calcium dynamics of cultural EC neurons via a calcium channel-independent mechanism.

Residential exposure to extremely low frequency electromagnetic fields and the risk of ALS.

Several studies have reported on the possible association between the risk of developing amyotrophic lateral sclerosis (ALS) and employment in the electrical industry, which may be related to extremely low frequency electromagnetic field (ELF-EMF) exposure or the risk of experiencing an electric shock, although no direct association has been proven.1 Three previous studies reported on ALS risk related to living near power lines, an important source of ELF-EMF exposure for the general population.2–4 These studies reported a null finding but had some shortcomings as they were based on registry data and had no detailed clinical data available. We therefore performed a large population-based case-control study with detailed phenotypic data to assess the relation between residential exposure to ELF-EMF from power lines and the risk of ALS. Acknowledgment: The authors thank Petra Berk, PhD (University Medical Center Utrecht), Hermieneke Vergunst (University Medical Center Utrecht), and Dorien Standaar (Amsterdam Medical Center) for technical assistance; all neurologists, consultants in rehabilitation medicine, and other health care providers for enrolling patients with ALS; and the patients with ALS and controls.

Neuronal cellular responses to extremely low frequency electromagnetic field exposure: implications regarding oxidative stress and neurodegeneration.

Neurodegenerative diseases comprise both hereditary and sporadic conditions characterized by an identifying progressive nervous system dysfunction and distinctive neuopathophysiology. The majority are of non-familial etiology and hence environmental factors and lifestyle play key roles in their pathogenesis. The extensive use of and ever increasing worldwide demand for electricity has stimulated societal and scientific interest on the environmental exposure to low frequency electromagnetic fields (EMFs) on human health. Epidemiological studies suggest a positive association between 50/60-Hz power transmission fields and leukemia or lymphoma development. Consequent to the association between EMFs and induction of oxidative stress, concerns relating to development of neurodegenerative diseases, such as Alzheimer disease (AD), have been voiced as the brain consumes the greatest fraction of oxygen and is particularly vulnerable to oxidative stress. Exposure to extremely low frequency (ELF)-EMFs are reported to alter animal behavior and modulate biological variables, including gene expression, regulation of cell survival, promotion of cellular differentiation, and changes in cerebral blood flow in aged AD transgenic mice. Alterations in inflammatory responses have also been reported, but how these actions impact human health remains unknown. We hence evaluated the effects of an electromagnetic wave (magnetic field intensity 1mT; frequency, 50-Hz) on a well-characterized immortalized neuronal cell model, human SH-SY5Y cells. ELF-EMF exposure elevated the expession of NOS and O2 −, which were countered by compensatory changes in antioxidant catylase (CAT) activity and enzymatic kinetic parameters related to CYP-450 and CAT activity. Actions of ELF-EMFs on cytokine gene expression were additionally evaluated and found rapidly modified. Confronted with co-exposure to H2O2-induced oxidative stress, ELF-EMF proved not as well counteracted and resulted in a decline in CAT activity and a rise in O2 − levels. Together these studies support the further evaluation of ELF-EMF exposure in cellular and in vivo preclinical models to define mechanisms potentially impacted in humans.

Extremely low frequency electromagnetic field exposure causes cognitive impairment associated with alteration of the glutamate level, MAPK pathway activation and decreased CREB phosphorylation in mice hippocampus: reversal by procyanidins extracted from the lotus seedpod.

Lotus seedpod procyanidins (LSPCs) could effectively prevent learning and memory damage and oxidative damage caused by extremely low frequency electromagnetic field (ELF-EMF) exposure. However, LSPCs protect neurons from ELF-EMF-induced damage by mechanisms currently not clear. An excessive release of glutamate is considered to be one of the molecular mechanisms of neuronal damage in several neurological diseases. In this study we determined whether the ELF-EMF (50 Hz, 8 mT, 28 days) exposure induced alterations of glutamate release in mice hippocampus and explored the possible mechanism, and if LSPC treatment normalized its alterations. The results showed that ELF-EMF exposure induced the increased contents of glutamate, GABA, excessively activated NMDA receptors, increasing the number of NMDA receptor 2B (NR2B) and intracellular Ca(2+) concentration [Ca(2+)]i in hippocampus. In addition, ELF-EMF exposure decreased the ERK1/2 and CREB phosphorylation, which suggested that the Ca(2+) influx induced by the ELF-EMF exposure stimulated activity of the ERK, in turn, influences the expression of downstream proteins in this signaling pathway. Besides, ELF-EMF exposure also increased JNK1/2 phosphorylation through the activated ASK1, which plays a pivotal role in hippocampal neuronal cell death. However, oral administration of LSPCs (especially 60 and 90 mg kg(-1)) markedly improved expressions of p-CREB, p-ERK1/2 and p-JNK1/2, accompanied by decreased levels of glutamate, GABA, [Ca(2+)]i and NR2B. Thus, the results from the present study suggest that p-ERK1/2, p-JNK1/2, [Ca(2+)]i and p-CREB expression normalized, possibly via a NMDA receptor-channel through the changes of GABA, glutamate and NR2B, which might be responsible for the neuroprotective or memory enhancing effects of LSPCs.

Reexamining Biological Studies of Effect of Low-Frequency Electromagnetic Field Exposure on Cells in Culture [Health Effects

The first study on health effects of power line fields, published in 1979, suggested that long-term exposure to residential 50/60 Hz electromagnetic fields (EMFs) may be associated with the risk of childhood leukemia [1]. A large number of epidemiological studies have been completed since then worldwide. Results were evaluated in two pooled analyses [2], [3], which showed that an excess risk may exist for average exposures exceeding 0.3?0.4 4 nT. The authors cautioned that it is unclear whether the results of their analyses can be interpreted as showing a causal relationship between magnetic fields and childhood leukemia.

Early Apoptosis Difference and Mechanism of Hepatic Cell Lines Treated by Extremely Low Frequency Altering Electro-Magnetic Field Combined with Magnetic Nano Fe&lt;sub&gt;3&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt; Particles &lt;i&gt;In Vitro&lt;/i&gt;

Extremely low frequency electro-magnetic field (ELFF) exposure could induce hepatoma Bel-7402 and SMMC-7721 cells lines into early apoptosis without some significant effects to healthy hepatic cells HL-7702 cells in low exposure dose through affecting cellular membrane ion metabolism. Magnetic nanoFe3O4 particles (MNPs) presence with low effects to all hepatic cells lines strengthened ELFF bio-effects to tumor cells inducing more amount of tumor cells into early apoptosis with low effects to HL-7702 cells. Western-blot results indicated the early apoptosis signal channel Bcl protein family of tumor cells was activated significantly more effectively than HL-7702 cells due to higher MNPs uptake ratio of tumor cells and higher cellular membrane ion exchanging current than HL-7702 cells. Patch-clamp results showed MNPs combined with ELFF treatment inducing cells into early apoptosis should be partially based on ion metabolism disturbance of cells with similar to ELFF bio-effects to cells.

Reassessing laboratory results of low-frequency electromagnetic field exposure of cells in culture [telecommunications health and safety

A systematic measurement has shown that the background static and ELF magnetic fields in biological incubators can vary by orders of magnitude within a single incubator and between different incubators. Measured incubator fields varied from below levels that the IARC had classified as possibly carcinogenic to humans (0.3 μT to 0.4 μT) to as high as 240 μT, above the Earth or natural geomagnetic field range (23 μT to 65 μT). The significance is that studies of biological effects of ELF field exposure on cell cultures involved magnetic fields ranging from 0.1 μT to 50 μT. The inconsistency or variability of in vitro laboratory data prompted many to declare that there was no compelling evidence that biological effects are causally related to ELF magnetic-field exposure. Most in vitro investigations involving cell cultures in the laboratory were unaware of and therefore did not account for the large variations in background static and ELF magnetic fields in cell-culture incubators. Given the potential confounding of unspecified incubator fields, it seems only reasonable to reassess the data and reevaluate the validity of any conclusions to date, positive or negative. Are we back to square one? In some sense, it may be so: the reported background static and ELF magnetic-field variations in cell-culture incubators could be a game changer.

Effect of low-frequency electromagnetic field exposure on oocyte differentiation and follicular development

Background:The effect of electromagnetic field (EMF) as an environmental factor on different organs including female reproductive system is of critical concern. The aim of the present study is to evaluate the effect of low-frequency (LF)-EMF on oocyte differentiation and follicular development.Materials and Methods:The experiment was carried out in animal lab of Faculty of Medicine Tabriz University of Medical Sciences. For this purpose, the BALB/c mice were divided into control and experimental group in animal lab. The pregnant mice in the experimental group were exposed to 3 mT EMF field, 4 h/day during the pregnancy period. The LF-EMF was produced by a system using 50 Hz alternative current, in the control group the pregnant mice were kept in a similar condition without exposure to EMF. The neonatal mice from both groups were sacrificed immediately after birth and their ovary was dissected apart and prepared for light and electron microscopy.Result:Microscopy revealed that in the experimental group, in comparison to control group, oocyte nests were mostly broken and irregularly arranged. The primordial follicles were less developed and nuclei of oocytes with an electron microscope appeared heterochromatic, shrunken and had vacuolated cytoplasm.Conclusion:It is concluded that exposure to EMF during the developmental period could affect both oocyte differentiation and folliculogenesis and may result in reduced fertility, by decreasing ovarian reservoir.

No effects of power line frequency extremely low frequency electromagnetic field exposure on selected neurobehavior tests of workers inspecting transformers and distribution line stations versus controls

We aimed to evaluate the interference of 50 Hz extremely low frequency electromagnetic field (ELF-EMF) occupational exposure on the neurobehavior tests of workers performing tour-inspection close to transformers and distribution power lines. Occupational short-term "spot" measurements were carried out. 310 inspection workers and 300 logistics staff were selected as exposure and control. The neurobehavior tests were performed through computer-based neurobehavior evaluation system, including mental arithmetic, curve coincide, simple visual reaction time, visual retention, auditory digit span and pursuit aiming. In 500 kV areas electric field intensity at 71.98% of total measured 590 spots were above 5 kV/m (national occupational standard), while in 220 kV areas electric field intensity at 15.69% of total 701 spots were above 5 kV/m. Magnetic field flux density at all the spots was below 1,000 μT (ICNIRP occupational standard). The neurobehavior score changes showed no statistical significance. Results of neurobehavior tests among different age, seniority groups showed no significant changes. Neurobehavior changes caused by daily repeated ELF-EMF exposure were not observed in the current study.