Zeng Y, Shen Y, Hong L, Chen Y, Shi X, Zeng Q, Yu P · 2017
Researchers evaluated the biological effects of different patterns of extremely low frequency magnetic field exposure on primary cultured hippocampal neurons, looking at viability, apoptosis, genomic instability, and oxidative stress. Repeated exposure to a 50-Hz 2-mT field for 8 hours per day decreased cell viability and increased the production of intracellular reactive oxygen species. The researchers noted that none of the repeated exposure patterns had significant effects on DNA damage, apoptosis, or autophagy, suggesting no severe biological consequences in the cultured neurons.
Medina-Fernandez FJ et al. · 2017
Researchers injected rats with a single dose of 150 μg of myelin oligodendrocyte glycoprotein (MOG, fragment 35–55) to produce experimental multiple sclerosis. The MOG injection caused motor symptoms such as tail paralysis and limb paresis/paralysis, along with oxidative stress and cell death similar to MS. Rats were then treated with extremely low-frequency electromagnetic fields applied as transcranial magnetic stimulation (TMS) at 60 Hz and 0.7 mT for 2 hours a day, once a day, 5 days a week, for 3 weeks. The researchers found that TMS attenuated motor symptoms and oxidative and cell damage, and also increased the antioxidant system.
Giorgi G et al. · 2017
Researchers exposed human neural cells (BE(2)C) to an extremely low frequency pulsed magnetic field (50 Hz, 1 mT) for 24 and 48 hours, alone and combined with oxidative stress, to study DNA methylation changes. Exposure to the magnetic field alone or oxidative stress alone produced only weak changes in DNA methylation levels at different CpG sites. When the two exposures were combined, a significant decrease in DNA methylation levels was found at different CpG sites, and most of those changes were transient.
Falone S et al. · 2017
Researchers investigated whether a 50 Hz, 1 mT ELF magnetic field promoted hyperproliferation and improved defence against reactive oxygen species in SH-SY5Y human neuroblastoma cells. The field activated antioxidant and detoxification pathways linked to more aggressive cell behavior, along with upregulation of major sirtuins and increased NRF2 signaling. Exposure to a 50 Hz magnetic field as low as 100 µT may still be able to alter cancer cell behavior and responses to clinically relevant drugs.
Djordjevic NZ, Paunović MG, Peulić AS · 2017
Researchers investigated whether short-term exposure to ELF-EMF at 50 Hz could produce anxiety-like behaviour in rats through changes in hypothalamic oxidative stress and nitric oxide. Ten adult male Wistar albino rats were divided into a control group with no exposure and an experimental group exposed to the field during 7 days, after which open field and elevated plus maze tests measured anxiety-like behaviour. The exposed rats showed anxiety-like behaviour and higher concentrations of superoxide anion and nitric oxide in the hypothalamus, while peroxynitrite concentration was not affected.
Cichoń N et al. · 2017
Patients were divided into two groups, both undergoing the same 4-week rehabilitation program, with one group also receiving daily ELF-EMF exposure. The ELF-EMF group was exposed to a field of 40 Hz and 7 mT for 15 minutes per day. ELF-EMF significantly increased 3-nitrotyrosine and nitrate/nitrite levels, while NOS2 expression was insignificantly decreased in both groups. The researchers concluded that ELF-EMF therapy is capable of promoting recovery in poststroke patients.
Cichoń N, Bijak M, Miller E, Saluk J. · 2017
Researchers investigated the effect of ELF-EMF on clinical and antioxidant status in post-stroke patients. Fifty-seven patients were divided into two groups: ELF-EMF and non-ELF-EMF, and both groups underwent the same 4-week rehabilitation program. The ELF-EMF group was additionally exposed to a field of 40 Hz, 7 mT for 15 min/day for 4 weeks, 5 days a week. ELF-EMF significantly increased enzymatic antioxidant activity, though total antioxidant status levels did not change in either group.
Wang K et al. · 2017
Researchers examined the effects of a single 30-minute exposure to 1.8 GHz radiofrequency electromagnetic radiation on recognition memory in mice, using the novel object recognition task. Exposure at an intensity above 2.2 W/kg SAR produced a significant, density-dependent increase in the recognition memory index, with no corresponding changes in spontaneous locomotor activity. The researchers also found that exposure increased dendritic-spine density and length in hippocampal and prefrontal cortical neurons, and significantly altered neuronal excitability in pyramidal neurons. The SAR used in the study was 3.3 W/kg, which the researchers noted was outside the range encountered in normal daily life.
Wang H et al. · 2017
Researchers exposed 220 male Wistar rats to a 2.856 GHz radiation source at power densities of 0, 2.5, 5, and 10 mW/cm² for 6 min/day, 5 days/week, for up to 6 weeks. Rats in the 10 mW/cm² group showed declines in spatial learning and memory and EEG disorders, including decreased EEG frequencies and increased amplitudes and delta wave powers. Changes in the basic structure and ultrastructure of the hippocampus were found in the 10 and 5 mW/cm² groups. The researchers suggested that continuous microwave exposure could cause dose-dependent long-term impairment of spatial learning and memory, and that decreases in NMDAR key subunits and phosphorylation of NR2B might contribute to cognitive impairment.
Kim JH, Yu DH, Huh YH, Lee EH, Kim HG, Kim HR. · 2017
Researchers exposed C57BL/6 mice to 835 MHz RF-EMF at a specific absorption rate of 4.0 W/kg for 5 hours per day during 12 weeks. The study found that RF-EMF exposure led to myelin sheath damage and that mice displayed hyperactivity-like behavior. Autophagy-related proteins including LC3B-II and Beclin1 were increased in neuronal cell bodies, and the researchers suggest autophagy may act as a protective pathway during radiofrequency exposure.
Unknown authors · 2016
Researchers treated induced human bone marrow mesenchymal stem cells with pulsed electromagnetic fields. PEMF increased the expression of neural markers NF-L, NeuroD1, and Tau. PEMF greatly decreased cell death in a dose- and time-dependent manner. PEMF exposure dramatically increased phosphorylation of Akt, Rsk, Creb, Erk, Bcl-xL, and Bad. PEMF-dependent cell protection was reversed by a PI3K inhibitor, and the data suggest the PI3K/Akt/Bad pathway may mediate the protective effects.
Unknown authors · 2016
Researchers examined the effect of combined RF radiation on amyloid-beta-induced cytotoxicity in HT22 rat hippocampal neurons. Amyloid-beta suppressed HT22 cell proliferation in a concentration-dependent manner. RF exposure did not affect cell proliferation and had only a marginal effect on amyloid-beta-induced growth suppression. Amyloid-beta increased ROS generation and apoptosis markers including annexin V/PI-positive cells, PARP and caspase-3 degradation. Amyloid-beta stimulated a DNA damage pathway and enhanced beta-site amyloid precursor protein expression, while RF had no effect on these events.
Unknown authors · 2016
Researchers used a transgenic C. elegans strain with fluorescently tagged α-synuclein to measure aggregation via FRET. They exposed worms to RF fields at 1.0 GHz CW (0.002-0.02 W kg−1) and 1.8 GHz CW or GSM (1.8 W kg−1) using two exposure systems. No statistically significant changes in aggregation were observed at 2.5, 24, or 96 h across several independent runs. The model responded to chemical promoters like mercury but showed no similar response to RF exposures.
Güler G, Ozgur E, Keles H, Tomruk A, Vural SA, Seyhan N · 2016
Researchers exposed newborn rabbits to GSM-modulated 1800 MHz radiation before and after birth and measured oxidative DNA damage, lipid peroxidation, histopathology, and apoptosis in brain tissue. Oxidative DNA damage measured as 8-OHdG increased in rabbits exposed during both intrauterine and extrauterine periods compared to unexposed rabbits and those exposed only after birth. Lipid peroxidation measured as MDA rose only in males with intrauterine exposure, while females showed no difference across exposure groups. Mild neuronal necrobiosis appeared in intrauterine-exposed females and extrauterine-exposed males; gliosis was mildly positive in intrauterine-only and combined-exposure groups, but no apoptosis was detected in any group.
Son Y et al. · 2016
Researchers exposed 5xFAD mice to 1950 MHz RF-EMF at 5 W/kg SAR for 2 hours daily, 5 days a week, for 3 months. They used Y-maze, Morris water maze, and novel object recognition tests to assess spatial and non-spatial memory. They also measured Aβ deposition, APP and CTFβ levels in hippocampus and cortex, and plasma Aβ peptides. The 3-month exposure did not affect Aβ-related memory impairment or Aβ accumulation.
Schwarze S et al. · 2016
Researchers tested European robins' magnetic compass orientation in an electromagnetically silent laboratory under four narrow-band electromagnetic fields at the Larmor frequency, double the Larmor frequency, 1.315 MHz, and 50 Hz, and broadband electromagnetic noise covering ~2 kHz to ~9 MHz. None of the relatively strong narrow-band fields disrupted the robins' magnetic compass orientation. The weak broadband field very efficiently disrupted the robins' magnetic compass orientation.
Sato Y, Kiyohara K, Kojimahara N, Yamaguchi N. · 2016
Petitdant N et al. · 2016
Researchers used rats to assess whether astrocyte reactivity, perception, and emotionality were affected by RF EMF exposures during adolescence. They also investigated if adolescent brains were more sensitive to RF EMF exposures after neurodevelopmental inflammation. Results did not show any neurobiological impairment in healthy and vulnerable RF EMF-exposed rats compared to sham-exposed controls. Data did not support the hypothesis of a specific cerebral sensitivity to RF EMF of adolescents, even after neurodevelopmental inflammation.
McNamee JP et al. · 2016
Adult male C57BL/6 mice were exposed to 1.9 GHz pulse-modulated or continuous-wave radiofrequency fields for 4 hours per day over 5 days at specific absorption rates of 0, 0.2, and 1.4 W/kg. Total RNA was isolated from the auditory cortex, amygdala, caudate, cerebellum, hippocampus, hypothalamus, and medial prefrontal cortex and gene expression was analyzed using Illumina MouseWG-6 (v2) BeadChip arrays. When controlling the false discovery rate, no differentially expressed genes were identified in any brain region compared to sham controls. Some genes showed differences without multiple-comparison correction, but no consistent pattern emerged across exposure levels or modulations.
Leng L, Zhang Y. · 2016
Reale M et al. · 2016
Researchers exposed SH-SY5Y neuroblastoma cells to 50 Hz/1 mT ELF-EMF for short (1h-3h) and sub-chronic (48 h) periods. Exposed cells showed an increased intracellular 5-hydroxyindoleacetic acid/5-hydroxytryptamine ratio reflecting transmitter synthesis, catabolism, and release. Matrix metalloproteinases involved in neuronal cell death were not significantly altered. The balance between reactive oxygen species generation and elimination, and between pro- and anti-inflammatory cytokines, was maintained. The changes were minor compared to damage expected to underlie neurodegeneration or cognitive impairment.
Roser K, Schoeni A, Röösli M · 2016
The HERMES study sample consisted of 439 Swiss adolescents aged 12–17 years. Researchers assessed behavioral problems with the Strengths and Difficulties Questionnaire and concentration capacity with a standardized computerized cognitive test named FAKT. Cross-sectional analyses showed behavioral problems associated with self-reported wireless device use but not operator-recorded mobile phone use, while concentration capacity was associated with both self-reported and operator-recorded exposures. Longitudinal analyses found no consistent associations between RF-EMF exposure measures and either outcome. The authors suggest information bias and reverse causality likely explain the cross-sectional findings.
Redmayne M et al. · 2016
Researchers recruited 619 fourth-grade students aged 8 to 11 from 37 schools in Melbourne and Wollongong, Australia. Participants completed a questionnaire, a computerised cognitive test battery, and the Stroop colour-word test while parents reported the children's mobile and cordless phone call frequencies. Phone use was categorised by weekly call count into none, some (≤ median) or more (> median), with medians of 2.5 calls for mobile phones and 2.0 for cordless phones. Only 5 of 78 comparisons were statistically significant; higher mobile phone use was linked to slower reaction time on a response-inhibition task, and higher cordless phone use was linked to slower Stroop interference time and poorer accuracy on visual recognition, episodic memory, and identification tasks.
Calvente I et al. · 2016
Bhagat S, Varshney S, Bist SS, Goel D, Mishra S, Jha VK · 2016
Each participant's phone-using ear was compared to the non-phone-using ear, and subjects were grouped by daily use duration of 60 minutes or less versus more than 60 minutes. No statistically significant differences were found in high-frequency pure-tone averages or brainstem evoked response audiometry interpeak latencies between phone-using and control ears, and no subjective symptoms were reported.
