2100-MHz electromagnetic fields have different effects on visual evoked potentials and oxidant/antioxidant status depending on exposure duration

Expression levels of tam receptors and ligands in the testes of rats exposed to short and middle-term 2100 MHz radiofrequency radiation

With advances in technology, the emission of radiofrequency radiation (RFR) into the environment, particularly from mobile devices, has become a growing concern. Tyro 3, Axl, and Mer (TAM) receptors and their ligands are essential for spermatogenesis and testosterone production. RFR has been shown to induce testicular cell apoptosis by causing inflammation and disrupting homeostasis. This study aimed to investigate the role of TAM receptors and ligands in the maintenance of homeostasis and elimination of apoptotic cells in the testes (weeks), short-term sham exposure (sham/1 week), and middle-term sham exposure (sham/10 weeks). Testicular morphology was assessed using hematoxylin-eosin staining, while immunohistochemical staining was performed to assess expression levels of TAM receptors and ligands in the testes of all groups. The results showed that testicular morphology was normal in the control, sham/1 week, and sham/10 weeks groups. However, abnormal processes of spermatogenesis and seminiferous tubule morphology were observed in RFR exposure groups. Cleaved Caspase 3 immunoreactivity showed statistically significant difference in 1 and 10 weeks exposure groups compared to control group. Moreover, there was no significant difference in the immunoreactivity of Tyro 3, Axl, Mer, Gas 6, and Pros 1 between groups. Moreover, Tyro 3 expression in Sertoli cells was statistically significantly increased in RFR exposure groups compared to the control. Taken together, the results suggest that RFR exposure negatively affects TAM signalling, preventing the clearance of apoptotic cells, and this process may lead to infection and inflammation. As a result, rat testicular morphology and function may be impaired.

The roles of intensity, exposure duration, and modulation on the biological effects of radiofrequency radiation and exposure guidelines

In this paper, we review the literature on three important exposure metrics that are inadequately represented in most major radiofrequency radiation (RFR) exposure guidelines today: intensity, exposure duration, and signal modulation. Exposure intensity produces unpredictable effects as demonstrated by nonlinear effects. This is most likely caused by the biological system's ability to adjust and compensate but could lead to eventual biomic breakdown after prolonged exposure. A review of 112 low-intensity studies reveals that biological effects of RFR could occur at a median specific absorption rate of 0.0165 W/kg. Intensity and exposure duration interact since the dose of energy absorbed is the product of intensity and time. The result is that RFR behaves like a biological "stressor" capable of affecting numerous living systems. In addition to intensity and duration, man-made RFR is generally modulated to allow information to be encrypted. The effects of modulation on biological functions are not well understood. Four types of modulation outcomes are discussed. In addition, it is invalid to make direct comparisons between thermal energy and radiofrequency electromagnetic energy. Research data indicate that electromagnetic energy is more biologically potent in causing effects than thermal changes. The two likely functionthrough different mechanisms. As such, any current RFR exposure guidelines based on acute continuous-wave exposure are inadequate for health protection.

Zinc affects nuclear factor kappa b and DNA methyltransferase activity in C3H cancer fibroblast cells induced by a 2100 MHz electromagnetic field

The use of mobile phones is becoming widespread with the development of technology, and as a result, its effects on human health are becoming more and more important every day. Studies have reported that the electromagnetic field (EMF) emitted by mobile phones may have adverse effects on the biological systems. In order to evaluate the effect of zinc (Zn) on C3H cancer fibroblast cells exposed to 2100 MHz EMF, we analyzed cell viability%, nuclear factor kappa b (NF-κB) and DNA methyltransferase (DNMT) activities. Cells were divided to following groups: Control, sham control, 2100 MHz EMF, 50 µM Zn + 2100 MHz EMF, 100 µM Zn + 2100 MHz EMF, and 200 µM Zn + 2100 MHz EMF for 2 h. We measurement cell viability, NF-κB and DNMT activities. There was increased cell viability % in the 2100 MHz EMF group compared to the control group, while the cell viability % was decreased in the 50, 100 and 200 µM Zn + 2100 MHz EMF groups compared to 2100 MHz EMF. NF-κB and DNMT activities were a significant increase in the 2100 MHz EMF group compared to the control group, although were statistically decreased in the 50, 100 and 200 µM Zn + 2100 MHz EMF groups compared to the 2100 MHz EMF group. Our results demonstrate that 2100 MHz EMF exposure in cancer fibroblast cells induce NF-κB and DNMT activities, whereas zinc supplementation reduce NF-κB and DNMT activities-induced 2100 MHz EMF.

The effect of 4.5 G (LTE Advanced-Pro network) mobile phone radiation on the optic nerve

PURPOSE

Rapid development in mobile phone technologies increase the average mobile phone usage duration. This increase also triggers exposure to radiofrequency radiation (RF), which is a risk factor for the health. In this study, it was aimed to investigate the effect of mobile phone working with LTE-Advanced Pro (4.5 G) mobile network on the optic nerve, which is responsible for the transmission of visual information.

MATERIAL AND METHODS

Thirty-two rats divided into two groups as control (no RF, sham exposure) and experimental (RF exposure using a mobile phone with LTE-Advanced Pro network; 2 hours/day, 6 weeks). The visual evoked potential (VEP) was recorded and determined amplitudes and latencies of VEP waves. Optic nerve malondialdehyde level, catalase and superoxide dismutase activities were determined. Furthermore, ultrastructural and morphometric changes of optic nerve were evaluated.

RESULTS

In VEP recordings, the mean VEP amplitudes of experimental group were significantly lower than control group. In ultrastructural evaluation, myelinated nerve fibres and glial cells were observed in normal histologic appearance both in sham and experimental group. However, by performing morphometric analysis, in the experimental group, axonal diameter and myelin thickness were shown to be lower and the G-ratio was higher than in the sham group. In the experimental group, malondialdehyde level was significantly higher and superoxide dismutase and catalase activities were significantly lower than sham group. There was a high correlation between VEP wave amplitudes and oxidative stress markers.

CONCLUSION

Findings obtained in this study support optic nerve damage. These results point out an important risk that may decrease the quality of life.

An Evaluation of the Genotoxic Effects of Electromagnetic Radiation at 900 MHz, 1800 MHz, and 2100 MHz Frequencies with a SMART Assay in Drosophila melanogaster

With the development of today's technology, the electromagnetic radiation spread by mobile phones and base stations is also rapidly increasing, and this causes serious concerns about the environment and human health. The Drosophila model organism is widely used in genetic toxicology studies because its genome is highly similar to the genes identified in human diseases. In this study, the genotoxic effects of radiofrequency electromagnetic radiation were evaluated by the wing Somatic Mutation and Recombination Test (SMART) in Drosophila melanogaster at 900 MHz, 1800 MHz, and 2100 MHz. The SMART method is based on the observation of genetic changes occurring in the trichomes of the Drosophila wings appearing as mutant clones under the microscope. Throughout the study, total clone parameters were evaluated by exposing the Drosophila larvae to electromagnetic fields for two, four, and six hours per day for two days. As a result of the study, it was observed that the number of mutant clones was statistically increased according to the negative control group in all applications except for the six-hour application at 1800 MHz.

Analysis of thiol/disulphide homeostasis and oxidant-antioxidant status as a result of exposure to radio-frequency electromagnetic fields

The aim of the current study is to investigate the effect of daily long-term radio-frequency electromagnetic field (RF-EMFs) exposure on thiol/disulphide homeostasis and oxidant-antioxidant status in the serum of rats. Fourteen male Sprague Dawley rats were divided into two equal groups (n = 7). They were grouped as group 1 (sham-control) and group 2 (2100 MHz exposed). Group 2 rats were exposed to GSM-like signals for 5 h/day, 7 days per week for 14 days. In serum of blood samples, the native, total and native/total thiol levels and antioxidant-oxidant parameters were analyzed. The study revealed that the mean serum total thiol levels of GSM exposure group was rather higher than sham-control group (p = 0,219); the mean serum native thiol levels of GSM exposure group was rather higher than sham-control group (p = 0,416), and the mean serum disulphide levels of GSM exposure group was rather higher than sham-control group (p = 0,566). On the other hand, the mean serum total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI) of GSM exposure group were higher than sham-control group. There are no data in the literature, that examine the effects of RF-EMFs on thiol/disulphide homeostasis. The results of this study, indicate that RF-EMFs did not cause oxidative stress and statistically changes in thiol/disulphide homeostasis. More sample sizes and longer-term exposures are needed to confirm the results of this study.

The effects of acute and chronic exposure to 900 MHz radiofrequency radiation on auditory brainstem response in adult rats

The aim of this study was to determine the effects of short and long-term RFR exposure on ABR by evaluating lipid peroxidation and antioxidant status in adult rats. Sixty male albino Wistar rats were randomly divided into four groups. S1:1 week sham, S10:10 weeks sham, E1:1 week RFR, E10:10 weeks RFR. Experimental group rats were exposed to RFR 2 h/day, 5 days/week during the test period. Sham rats were kept in the same conditions without RFR. After the experiment, ABRs were recorded from the mastoids of rats using tone burst acoustic stimuli. Biochemical investigations in rat brain and ultrastructural analysis in temporal cortex were performed. ABR wave I latency prolonged in E1-group and shortened in E10-group compared to their shams. TBARS level increased in E1-group, decreased in E10-group, on the contrary, SOD and CAT activities and GSH level decreased in E1-group, increased in E10-group compared to their sham groups. Edema was present in the neuron and astrocyte cytoplasms and astrocyte end-feet in both E1 and E10 groups. Our results suggest that 900 MHz RFR may have negative effects on the auditory system in acute exposure and no adverse effects in chronic exposure without weekends.

Pathological Findings Observed in the Kidneys of Postnatal Male Rats Exposed to the 2100 MHz Electromagnetic Field

BACKGROUND

The widespread use by young people of modern communication devices such as mobile phones means that they are particularly exposed to electromagnetic fields (EMF) and other problems. However, few studies have researched the effects of long-term exposure to EMF in the kidney. We therefore investigated oxidative stress and apoptosis in long-term exposure to 2100 megahertz (MHz) in a rat model.

MATERIALS AND METHODS

Twenty-four Sprague Dawley rats were divided into a control group (n = 8, no EMF exposure), a group exposed to 2100 MHz for 6 h for 30 d (n = 8), and a group exposed to 2100 MHz for12 h for 30 d (n = 8). Immunohistochemical analysis was performed, using caspase-3 to evaluate apoptosis. Immediately after treatment, reduced glutathione (GSH), malondialdehyde (MDA) in kidney tissue and serum levels of various biochemical compounds were measured to detect oxidative stress.

RESULTS

Deterioration was observed in the brush border in renal tubules of the EMF groups. The results of the immunohistochemical analysis revealed a greater number of positively stained renal tubular epithelial cells in the EMF groups as compared with that in the control group. In the EMF groups, renal MDA levels increased, and renal GSH levels decreased compared with those in the control group, as shown by a biochemical examination (p = 0.00 and p = 0.00, respectively).

CONCLUSION

The findings showed that exposure to 2100 MHz for 6 and 12 h induced oxidative stress-mediated acute renal injury, depending on the length of exposure and dosage.

Multivariable quantitative relation between cell viability and the exposure parameters of 9.33 GHz RF-EMP irradiation

Qualitative analysis of the influence of a certain exposure parameter is commonly performed in bioelectromagnetic studies. However, since the exposure condition requires the control of multiple parameters, the diverse results caused by different combinations of these parameters requires further quantitative study of the multivariable (exposure parameters)-bioeffect relation to identify the rule describing bioelectromagnetic effects. The present work investigated the relation between cell viability and the three main exposure parameters (electric intensity (E_s), pulse duration (τ) and pulse number (N)) of 9.33 GHz radiofrequency electromagnetic field (RF-EMP). Experiments showed that the inhibitory rate of cell viability (ρ) had a proportional relationship with E_s and exponential relationship with N; the equation [Formula: see text] is proposed to quantitatively describe the relation between the cell viability and these three exposure parameters. This equation can be used to predict the significance of a 9.33 GHz RF-EMP-induced bioeffect under the conditions E_s <10⁶ kV/m, N < 100, and 300 < τ < 750 ns, under which nonthermal bioeffects dominate for 9.33GHz RF-EMP exposure.

Exposure to radiation from single or combined radio frequencies provokes macrophage dysfunction in the RAW 264.7 cell line

PURPOSE

The aim of this study was to determine whether exposure to radiation from single or multiple radio-frequency (RF) signals at 900 and 2450 MHz would induce effects in the RAW 264.7 cell line.

MATERIALS AND METHODS

Cell cultures were exposed to single or combined RF for 4, 24, 48, or 72 h in a GTEM electromagnetic test chamber. At the end of the radiation exposure time, viability and cell growth were analyzed by flow cytometry, nitric oxide (NO) production was measured by colorimetry, the expression of HSP70 and TNF-α was ascertained by qPCR, and the phagocytic activity was observed by microscopy.

RESULTS

NO production increased after 48 h exposure at 2450 MHz, compared with controls. The group subjected to the combined interaction of two RFs showed an increase of HSP70 after 48 h exposure and a significant increase of NO and TNF-α after 72 h. The phagocytic activity of macrophages decreased in all groups as exposure time increased.

CONCLUSIONS

Our results indicated a decrease in phagocytic activity and an increase in inflammatory, cytoprotective, and cytotoxic responses in macrophages after continuous and combined exposure of multiple RF signals. Multiple RF interact in everyday life, the immune response in humans is unknown.