Effects of radiofrequency electromagnetic field exposure on neurophysiology

Exposure to Radiofrequency Induces Synaptic Dysfunction in Cortical Neurons Causing Learning and Memory Alteration in Early Postnatal Mice

The widespread use of wireless communication devices has necessitated unavoidable exposure to radiofrequency electromagnetic fields (RF-EMF). In particular, increasing RF-EMF exposure among children is primarily driven by mobile phone use. Therefore, this study investigated the effects of 1850 MHz RF-EMF exposure at a specific absorption rate of 4.0 W/kg on cortical neurons in mice at postnatal day 28. The results indicated a significant reduction in the number of mushroom-shaped dendritic spines in the prefrontal cortex after daily exposure for 4 weeks. Additionally, prolonged RF-EMF exposure over 9 days led to a gradual decrease in postsynaptic density 95 puncta and inhibited neurite outgrowth in developing cortical neurons. Moreover, the expression levels of genes associated with synapse formation, such as synaptic cell adhesion molecules and cyclin-dependent kinase 5, were reduced in the cerebral cortexes of RF-EMF-exposed mice. Behavioral assessments using the Morris water maze revealed altered spatial learning and memory after the 4-week exposure period. These findings underscore the potential of RF-EMF exposure during childhood to disrupt synaptic function in the cerebral cortex, thereby affecting the developmental stages of the nervous system and potentially influencing later cognitive function.

Recycled Polypropylene/Strontium Ferrite Polymer Composite Materials with Electromagnetic Shielding Properties

This paper presents the obtaining and characterization of recycled polypropylene/strontium ferrite (PP/SrFe12O19) polymer composite materials with applications in the electromagnetic shielding of vehicle interiors (mainly automotive electronics-carcasses) from the electromagnetic radiation emitted mainly by exterior sources-electrical lines and supply sources-in terms of the development of the new electrical vehicles. With this aim, suitable polymer composite materials were developed using SrFe12O19 filler in two forms (powder and concentrate). The recycled PP polymer and composite materials with a PP/SrFe12O19 weight ratio of 75/25 and 70/30 were obtained in two stages, i.e., pellets by extrusion and samples for testing through a melt injection process. The characterization of the obtained materials took into account the requirements imposed by the desired applications. It consisted of determining the mechanical and dielectric properties, and microstructure analyses, along with the determination of the resistance to the action of a temperature of 70 °C, which is higher than the temperatures created during the summer inside vehicles. The performance of these materials as electromagnetic shields was assessed through functional tests consisting of the determination of magnetic permeability and the estimation of the electromagnetic shielding efficiency (SE). The obtained results confirmed the improvement of the mechanical, dielectric, and magnetic properties of the PP/SrFe12O19 composites compared to the selected PP polymers. It is also found that all the composite materials exhibited reflective shielding properties (SER from -71.5 dB to -56.7 dB), with very little absorption shielding. The most performant material was the composite made of PP/SrFe12O19 powder with a weight ratio of 70/30. The promising results recommend this composite material for potential use in automotive shielding applications against electromagnetic pollution.

Unveiling the biological effects of radio-frequency and extremely-low frequency electromagnetic fields on the central nervous system performance

Introduction

Radiofrequency electromagnetic radiation (RF-EMR) and extremely low-frequency electromagnetic fields (ELF-EMF) have emerged as noteworthy sources of environmental pollution in the contemporary era. The potential biological impacts of RF-EMR and ELF-EMF exposure on human organs, particularly the central nervous system (CNS), have garnered considerable attention in numerous research studies.

Methods

This article presents a comprehensive yet summarized review of the research on the explicit/implicit effects of RF-EMR and ELF-EMF exposure on CNS performance.

Results

Exposure to RF-EMR can potentially exert adverse effects on the performance of CNS by inducing changes in the permeability of the blood-brain barrier (BBB), neurotransmitter levels, calcium channel regulation, myelin protein structure, the antioxidant defense system, and metabolic processes. However, it is noteworthy that certain reports have suggested that RF-EMR exposure may confer cognitive benefits for various conditions and disorders. ELF-EMF exposure has been associated with the enhancement of CNS performance, marked by improved memory retention, enhanced learning ability, and potential mitigation of neurodegenerative diseases. Nevertheless, it is essential to acknowledge that ELF-EMF exposure has also been linked to the induction of anxiety states, oxidative stress, and alterations in hormonal regulation. Moreover, ELF-EMR exposure alters hippocampal function, notch signaling pathways, the antioxidant defense system, and synaptic activities.

Conclusion

The RF-EMR and ELF-EMF exposures exhibit both beneficial and adverse effects. Nevertheless, the precise conditions and circumstances under which detrimental or beneficial effects manifest (either individually or simultaneously) remain uncertain.

Curing, Properties and EMI Absorption Shielding of Rubber Composites Based on Ferrites and Carbon Fibres

In this work, magnetic soft ferrites, namely manganese-zinc ferrite, nickel-zinc ferrite and combinations of both fillers, were incorporated into acrylonitrile-butadiene rubber to fabricate composite materials. The total content of ferrites was kept constant-300 phr. The second series of composites was fabricated with a similar composition. Moreover, carbon fibres were incorporated into rubber compounds in constant amount-25 phr. The work was focused on investigation of the fillers on absorption shieling performance of the composites, which was investigated within the frequency range 1-6 GHz. Then, the physical-mechanical properties of the composites were evaluated. The achieved results demonstrated that the absorption shielding efficiency of both composite types increased with increasing proportion of nickel-zinc ferrite, which suggests that nickel-zinc ferrite demonstrated better absorption shielding potential. Higher electrical conductivity and higher permittivity of composites filled with carbon fibres and ferrites resulted in their lower absorption shielding performance. Simultaneously, they absorbed electromagnetic radiation at lower frequencies. On the other hand, carbon fibres reinforced the rubber matrix, and subsequent improvement in physical-mechanical properties was recorded.

Mechanical, Thermal, Electrical Characteristics and EMI Absorption Shielding Effectiveness of Rubber Composites Based on Ferrite and Carbon Fillers

In this work, rubber composites were fabricated by incorporation of manganese-zinc ferrite alone and in combination with carbon-based fillers into acrylonitrile-butadiene rubber. Electromagnetic parameters and electromagnetic interference (EMI) absorption shielding effectiveness of composite materials were examined in the frequency range 1 MHz-3 GHz. The influence of ferrite and fillers combination on thermal characteristics and mechanical properties of composites was investigated as well. The results revealed that ferrite imparts absorption shielding efficiency to the composites in tested frequency range. The absorption shielding effectiveness and absorption maxima of ferrite filled composites shifted to lower frequencies with increasing content of magnetic filler. The combination of carbon black and ferrite also resulted in the fabrication of efficient EMI shields. However, the EMI absorption shielding effectiveness was lower, which can be ascribed to higher electrical conductivity and higher permittivity of those materials. The highest conductivity and permittivity of composites filled with combination of carbon nanotubes and ferrite was responsible for the lowest absorption shielding effectiveness within the examined frequency range. The results also demonstrated that combination of ferrite with carbon-based fillers resulted in the enhancement of thermal conductivity and improvement of mechanical properties.

Does the Use of Mobile Phone Affect Male Fertility? A Mini-Review

Presently, there is a rise in the use of mobile phones, laptops, and wireless internet technologies such as Wi-Fi and 5G routers/modems across the globe; these devices emit a considerable amount of electromagnetic radiation (EMR) which could interact with the male reproductive system either by thermal or nonthermal mechanisms. The aim of this review was to examine the effects of mobile phone use on male fertility. Related studies that reported on the effects of EMR from mobile phones on male fertility from 2003 to 2020 were evaluated. PubMed database was used. The Medical Subject Heading system was used to extract relevant research studies from PubMed. Based on the outcomes of both human and animal studies analyzed in this review, animal and human spermatozoa exposed to EMR emitted by mobile phones had reduced motility, structural anomalies, and increased oxidative stress due to overproduction of reactive oxygen species. Scrotal hyperthermia and increased oxidative stress might be the key mechanisms through which EMR affects male fertility. However, these negative effects appear to be associated with the duration of mobile phone use.

Antimicrobial activity of rosemary leaf extracts and efficacy of ethanol extract against testicular damage caused by 50-Hz electromagnetic field in albino rats

Rosemary is a restorative plant that has numerous utilizations in traditional medicine. In this investigation, rosemary leaf extracts were examined for their antimicrobial and antioxidant activities. The antimicrobial activity was tested against 8 bacterial strains. The antioxidant feature of rosemary extract on rat testicular tissue after exposure to the electromagnetic field. Sixty adult male albino rats weighing 180-200 g (aged 2 months) were divided into six groups: control group, rosemary group (receiving rosemary extract at a dose of 5 mg/kg b.wt), EMF (2 h) group (exposed to 50 Hz and 5.4 kV per meter of magnetic field for 2 h), EMF (4 h) group (exposed to 50 Hz and 5.4 kV per meter of magnetic field for 4 h), EMF (2 h) + rosemary group (receiving both magnetic field for 2 h and extract), and EMF (4 h) + rosemary group (receiving both magnetic field for 4 h and extract). After 30 days, the rats were sacrificed, and some estimates were determined. Results exhibited that the ethanolic extract of rosemary leaves was active against pathogenic bacteria. Results also demonstrated that exposure to EMF diminished level of male hormones (e.g., follicle stimulating hormone (FSH), testosterone, and luteinizing hormone (LH)) in serum and catalase (CAT) activity remarkably and increased the malondialdehyde (MDA) levels in comparison to the control group. Signs of improvement in the male hormones, CAT activity, and MDA levels were noticed during the treatments with rosemary. Histological results showed that the rosemary extract inhibited the destructive effect of electromagnetic fields on testicular tissue. This research reveals that the ethanolic extract of rosemary has many beneficial effects that can be compelling in supporting individuals living with EMF ecological contamination.