The effects of extremely low frequency electromagnetic fields exposure at 1 mT on hemogram and blood biochemisgtry in rats.

The biological effects of extremely low-frequency electromagnetic fields (ELF-EMF) exposure are not fully clarified. We conducted this investigation to explore the effects of ELF-EMF on hematologic and biochemical indexes in adult rats. Thirty adult male Sprague-Dawley rats were exposed to ELF-EMF at 1 mT for 24 weeks, while another 30 SD rats were sham exposed. During the exposure, peripheral blood was collected every 4 weeks to analyze the hematologic parameters and biochemical indexes. The morphology of liver and kidney was detected by hematoxylin-eosin staining at the end of the experiment. Exposed to ELF-EMF at 1 mT did not exert any statistic difference on hematologic parameters including total white blood cell count, neutrophil ratio, lymphocyte ratio, red blood cells, hemoglobin concentration and platelets count, compared to the control group. Similarly, biochemical indexes, such as glucose, lipid profile, liver function and renal function, were not affected by ELF-EMF exposure. In addition, no morphological change was observed in the liver and kidney from the exposure group. The exposure to ELF-EMF at the intensity of 1 mT for 24 weeks did not affect hematologic and biochemical indexes in adult rats.

An Investigation Into the Effects of Long-Term 50-Hz Power-Frequency Electromagnetic Field Exposure on Hematogram, Blood Chemistry, Fibrosis, and Oxidant Stress Status in the Liver and the Kidney From Sprague-Dawley Rats.

Power-frequency electromagnetic fields (PF-EMFs) at 50 Hz are potential health risk factors. This study aimed to explore the effects of long-term exposure to 50-Hz PF-EMFs on general physiological conditions in Sprague-Dawley (SD) rats. During a 24-week exposure period, the body mass and water and food intake of the animals were recorded regularly. The hematologic parameters were detected every 12 weeks, and blood chemistry analyses were performed every 4 weeks. After sacrifice, morphology was identified by hematoxylin-eosin, Masson, and immunohistochemical staining. Fibrosis-related gene expression and oxidative stress status were also detected. Compared with the control group, exposure to 30, 100, or 500 µT PF-EMF did not exert any effect on body mass, food intake, or water intake. Similarly, no significant differences were found in hematologic parameters or blood chemistry analyses among these groups. Furthermore, morphological assays showed that exposure to PF-EMFs had no influence on the structure of the liver or kidney. Finally, fibrosis-related gene expression and oxidative stress status were unaltered by PF-EMF exposure. The present study indicates that 24 weeks of exposure to PF-EMFs at intensities of 30, 100, or 500 µT might not affect hemograms, blood chemistry, fibrosis, or oxidative stress in the liver or kidney in SD rats. © 2020 Bioelectromagnetics Society.

Power-frequency magnetic fields at 50 Hz do not affect fertility and development in rats and mice.

In the present study, the effects of power-frequency magnetic fields (PF-MF) on fertility and development were investigated in rats and mice. Adult Sprague-Dawley rats and C57BL/6J mice were divided into four groups: a sham exposure group and 30-µT, 100-µT and 500-µT PF-MF exposure groups. The rats were exposed for 24 weeks, and the exposure time for mice ranged from 18 d to 12 weeks, dependent on the different investigated end points. The rats and mice were exposed for 20 h/d. Plasma hormone levels in rats and mice were analyzed. Furthermore, pregnancy rates and implanted embryos were recorded in pregnant mice. Finally, the neonatal growth of mice was evaluated. The results showed that none of the three intensities affected the body weight and paired ovary weight in female rats. Meanwhile, none of the three intensities affected the body weight, weights of paired testes, weights of paired epididymis and sperm count in male rats. Similarly, no significant differences were found in plasma sex hormone levels between the different PF-MF exposure groups and the sham exposure group. In addition, the pregnancy rates and implanted embryos were not significantly different between the four groups. Moreover, PF-MF exposures had no effects on either the number of fetuses in pregnant mice or the growth and development of neonatal mice.

Examination of the Effect of a 50-Hz Electromagnetic Field at 500 µT on Parameters Related With the Cardiovascular System in Rats.

Background: Whether electromagnetic field (EMF) exposure affects the function of the cardiovascular system is under debate. The present study aimed to investigate the effects of 500 µT EMF exposure on the cardiovascular system in rats. Methods: Forty-eight-week-old male Sprague-Dawley rats were randomly divided into two groups: the sham group and the exposure group. During 24-week EMF exposure (20 h per day), the blood pressure and pulse rate were recorded every 4 weeks. Before sacrifice, electrocardiography, echocardiography, and cardiac catheterization analysis were conducted to evaluate the cardiac function. Meanwhile, hematoxylin-eosin (HE) staining, Western blot, and real-time polymerase chain reaction (PCR) were performed to identify morphological and molecular changes indicative of cardiac remodeling. Results: The heart rate, blood pressure, and pulse rate were not influenced by EMF exposure compared with the control group. In addition, HE staining showed no change in the morphology and arrangement of cardiomyocytes. Further, we found that the mRNA and protein levels of cardiac hypertrophy-related genes were not affected by EMF exposure. Finally, no significant difference was observed in cardiac function between the two groups by echocardiography and cardiac catheterization detection. Conclusion: The 24-week exposure to EMF at 500 µT did not have apparent effects on the cardiovascular system in rats, at least for the variables studied.

Effects of continuous exposure to power frequency electric fields on soybean Glycine max.

With the increasing density of high voltage transmission systems, the potential risks and hazards of environmental electric fields (EFs) generated by these systems to surrounding organisms is becoming a source of public concern. To evaluate the effect of environmental EFs on plants, we used soybean as a model and systematically evaluated the effect of continuous exposure to different intensities (0 kV/m, 2 kV/m, and 10 kV/m) of power frequency EFs on agronomic characters, yield, nutrient contents, protective enzyme activities, and gene transcription. We found that the effects on soybean were more pronounced when plants were exposed to EF during development (especially at the seedling stage) than when they were exposed at maturity. The functional leaf number, stem diameter, plant dry weight, and pod number were largely unaffected by EF, while the germination rate and protective enzyme activities increased with increasing EF intensity. In plants exposed to low-intensity EF (2 kV/m), some agronomic characters, including chlorophyll content, plant height, and bean dry weight, as well as the soluble sugar and total protein contents, were significantly higher than those of plants exposed to high-intensity EF (10 kV/m) and control plants (0 kV/m). Through transcriptome analysis, we found that 2,977 genes were significantly up-regulated and 1,462 genes were down-regulated when plants were exposed to EF. These differentially expressed genes mainly encode ribosome proteins and related enzymes involved in carbon metabolism pathway, providing a novel perspective for understanding molecular mechanisms underpinning the responses to EF stress in soybean.

Effect of transformer noise on the neurophysiology of SD rats.

Transformer noise is a type of environmental sound that causes discomfort to individuals. The aim of the present study was to determine the effect of relatively long-term periods of transformer noise on the behavior and neurophysiology of SD rats. A total of 90 healthy SD rats with normal hearing were randomly divided into two experimental groups (65 and 60 dB group) and a control group. The experimental groups were exposed to recorded transformer noise for 8 weeks (sound level limits: 65 or 60 dB) and the control group was maintained under the same conditions without noise stimulation. Changes in physiological growth (weight tests), behavior (tail suspension and open field behavior tests) and neurophysiology (glutamate, γ-aminobutyric acid, dopamine, 5-hydroxytryptamine, the morphologies of hippocampi) following noise exposure were recorded and compared. The results revealed that rats exhibited normal physiological growth, with no significant difference between the experimental and control groups. Following noise exposure, no significant differences were observed in the results of behavioral experiments (tail suspension and open field behavior tests) between the experimental and control groups. In addition, there were no significant differences in glutamate, γ-aminobutyric acid, dopamine and 5-hydroxytryptamine levels or in the morphologies of hippocampi between groups. In conclusion, exposure to transformer noise with a sound level limit of 65 dB sound pressure level (SPL) or 60 dB SPL (spectral range, 100-800 Hz) for 8 weeks (10 h/day) had no significant impact on the behavior and neurophysiology of SD rats.

Exposure to a 50†Hz magnetic field at 100†µT exerts no DNA damage in cardiomyocytes.

The effects of exposure to magnetic fields (MFs) at electric frequencies (50-60 Hz) on carcinogenicity are still in debate. Whether exposure to MFs affects the heart is also a debated issue. This study aimed to determine whether exposure to extremely low frequency MFs (ELF-MFs) induced DNA damage in cardiomyocytes both in vitro and in vivo Human ventricular cardiomyocytes were exposed to 50 Hz ELF-MF at 100 µT for 1 h continuously or 75 min intermittently. The effects of the treatments were evaluated by DNA damage, redox status changes and relative signal molecular expression. Moreover, ten male Sprague-Dawley rats were exposed to a 50 Hz MF at 100 µT for 7 days, while another 10 rats were sham exposed. The protein levels of p53 and Hsp70 in heart tissue were analyzed by western blot. The results showed that exposure to ELF-MF did not induce DNA damage, changes to cell cycle distribution or increased reactive oxygen species level. No significant differences were detected in p53 and Hsp70 expression level between the ELF-MF and sham-exposure groups both in vitro and in vivo All these data indicate that MFs at power-frequency may not cause DNA damage in cardiomyocytes.This article has an associated First Person interview with the first author of the paper.

Effects of extremely low frequency electromagnetic fields (100µT) on behaviors in rats.

Recently, extremely low frequency electromagnetic fields (ELF-EMF) have received considerable attentions for their potential pathogenicity. In the present study, we explored the effects of ELF-EMF on behaviors of adult male rats. Sixty adult male rats were randomly divided into two groups, the sham exposure group and the 50Hz/100µT ELF-EMF exposure group. During the 24 weeks exposure, body weight, as well as food and water intake were recorded. Results showed that food and water intake and the body weight of the rats were not affected by the exposure. After 24 weeks exposure, open field test and elevated plus maze were conducted to evaluate the anxiety-like behavior, the tail suspension test and forced swim test were conducted to evaluate depression-like behavior and Morris water maze and fear conditioning tests were used to evaluate the cognitive and memory ability. Exposure to ELF-EMF did not induce any anxiety-like or depression-like behaviors compared with the sham exposure. Moreover, the cognitive and memory ability was not impaired by the ELF-EMF exposure. Furthermore, ELF-EMF exposure did not affect the morphology and histology of the brain. In conclusion, 24 weeks exposure to 50Hz/100µT ELF-EMF had no effect on the behaviors of the adult male rats.

The effects of a 50-Hz magnetic field on the cardiovascular system in rats.

A 50-Hz magnetic field (MF) is a potential health-risk factor. Its effects on the cardiovascular system have not been fully investigated. This study was conducted to explore the effects of long-term exposure to a 50-Hz MF on the cardiovascular system. In the study, an exposure system was constructed, and the distribution of the 50-Hz MF was determined. Sixty-four Sprague-Dawley (SD) rats were exposed to a 50-Hz MF at 100 µT for 24 weeks, 20 h per day, while another 64 rats were sham exposed. During the exposure, blood pressure was measured every 4 weeks. After 24 weeks, echocardiography, cardiac catheterization and electrocardiography were performed. Moreover, heart and body weight were recorded, and haematoxylin-eosin staining and real-time PCR were conducted. The results showed that compared with the sham group, exposure to a 50-Hz MF did not exert any effects on blood pressure, pulse rate, heart rate or cardiac rhythm. Furthermore, echocardiography and cardiac catheterization showed that there were no significant differences in the cardiac morphology or haemodynamics. In addition, histopathological examination showed that exposure to a 50-Hz MF had no effects on the structure of the heart. Finally, expression of the cardiac hypertrophy-related genes did not show any significant differences between the 50-Hz MF exposure group and the sham group. Taken together, in SD rats, exposure to a 50-Hz/100 µT MF for 24 weeks did not show any obvious effects on the cardiovascular system.

Long-term exposure to ELF-MF ameliorates cognitive deficits and attenuates tau hyperphosphorylation in 3xTg AD mice.

Although numerous studies have reported the influence of extremely low frequency magnetic field (ELF-MF) exposure on human health, its effects on cognitive deficits in Alzheimer's disease (AD) have remained under debate. Moreover, the influence of ELF-MF on hyperphosphorylated tau, which is one of the most common pathological hallmarks of AD, has not been reported to date. Therefore, transgenic mice (3xTg) were used in the present study. 3xTg mice, which express an APP/PS1 mutation combined with a tau (P301L) mutation and that develop cognitive deficits at 6 months of age, were subjected to ELF-MF (50Hz, 500µT) exposure or sham exposure daily for 3 months. We discovered that ELF-MF exposure ameliorated cognitive deficits and increased synaptic proteins in 3xTg mice. The protective effects of ELF-MF exposure may have also been caused by the inhibition of apoptosis and/or decreased oxidative stress levels that were observed in the hippocampus tissues of treated mice. Furthermore, tau hyperphosphorylation was decreased in vivo because of ELF-MF exposure, and this decrease was induced by the inhibition of GSK3ß and CDK5 activities and activation of PP2Ac. We are the first to report that exposure to ELF-MF can attenuate tau phosphorylation. These findings suggest that ELF-MF exposure could act as a valid therapeutic strategy for ameliorating cognitive deficits and attenuating tau hyperphosphorylation in AD.

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.

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 (Aß) 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 Aß 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 Aß 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.

Extremely low-frequency magnetic fields induce developmental toxicity and apoptosis in zebrafish (Danio rerio) embryos.

Extremely low-frequency (ELF) magnetic field (MF), as a widespread ecological factor, has an influence on all living beings. In the present study, biological effects of ELF-MF on the development of zebrafish (Danio rerio) embryos were investigated. Fertilized embryos were divided into seven groups as control, sham, and five experimental groups. Embryos of experimental groups were continuously exposed to 50-Hz sinusoidal MF with intensities of 30, 100, 200, 400, and 800 µT for 96 h. The sham group was treated as the experimental groups, but without any ELF-MF exposure. The control group was not subjected to anything. The results showed that ELF-MF exposure caused delayed hatching and decreased heart rate at the early developmental stages of zebrafish embryos, whereas no significant differences in embryo mortality and abnormality were observed. Moreover, acridine orange staining assays showed notable signals of apoptosis mainly in the ventral fin and spinal column. The transcription of apoptosis-related genes (caspase-3, caspase-9) was significantly upregulated in ELF-MF-exposed embryos. In conclusion, the overall results demonstrated that ELF-MF exposure has detrimental effects on the embryonic development of zebrafish by affecting the hatching, decreasing the heart rate, and inducing apoptosis, although such effects were not mortal threat. The results also indicate that zebrafish embryos can serve as a reliable model to investigate the biological effect of ELF-MF.