Analysis of global DNA methylation changes in human keratinocytes immediately following exposure to a 900 MHz radiofrequency field

The increasing use of nonionizing radiofrequency electromagnetic fields (RF-EMFs) in a wide range of technologies necessitates studies to further understanding of biological effects from exposures to such forms of electromagnetic fields. While previous studies have described mechanisms for cellular changes occurring following exposure to low-intensity RF-EMFs, the role of molecular epigenetics has not been thoroughly investigated. Specifically unresolved is the effect of RF-EMFs on deoxyribonucleic acid (DNA) methylation, which is a powerful epigenetic process, used by cells to regulate gene expression. DNA methylation is dynamic and can be rapidly triggered in response to external stimuli such as exposure to RF-EMFs. In the present study, we performed a global analysis of DNA methylation patterns in human keratinocytes exposed to 900 MHz RF-EMFs for 1 h at a low dose rate (estimated mean specific absorption rate (SAR) < 10 mW/kg). We used a custom system to allow stable exposure of cell cultures to RF-EMFs under biologically relevant conditions (37 °C, 5% CO₂, 95% humidity). We performed whole genome bisulfite sequencing directly following RF-EMF exposure to examine the immediate changes in DNA methylation patterns and identify early differentially methylated genes in RF-EMF-exposed keratinocytes. By correlating global gene expression to whole genome bisulfite sequencing, we identified six common targets that were both differentially methylated and differentially expressed in response to RF-EMF exposure. The results highlight a potential epigenetic role in the cellular response to RF-EMFs. Particularly, the six identified targets may potentially be developed as epigenetic biomarkers for immediate responses to RF-EMF exposure. Bioelectromagnetics. 1–13, © 2023 Bioelectromagnetics Society. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.     

Acute exposure to low-level CW and GSM-modulated 900 MHz radiofrequency does not affect Ba 2+ currents through voltage-gated calcium channels in rat cortical neurons

We have studied the non-thermal effects of radiofrequency (RF) electromagnetic fields (EMFs) on Ba(2+) currents (I Ba 2+) through voltage-gated calcium channels (VGCC), recorded in primary cultures of rat cortical neurons using the patch-clamp technique. To assess whether low-level acute RF field exposure could modify the amplitude and/or the voltage-dependence of I Ba 2+, Petri dishes containing cultured neurons were exposed for 1-3 periods of 90 s to 900 MHz RF-EMF continuous wave (CW) or amplitude-modulated according to global system mobile communication standard (GSM) during whole-cell recording. The specific absorption rates (SARs) were 2 W/kg for CW and 2 W/kg (time average value) for GSM-modulated signals, respectively. The results obtained indicate that single or multiple acute exposures to either CW or GSM-modulated 900 MHz RF-EMFs do not significantly alter the current amplitude or the current-voltage relationship of I Ba 2+, through VGCC.     

No Increased DNA Damage Observed in the Brain,Liver, and Lung of Fetal Mice Treated With Ethylnitrosourea and Exposed to UMTS Radiofrequency Electromagnetic Fields

The widespread use of mobile phones and Wi-Fi-based communication devices makes exposure to radiofrequency electromagnetic fields (RF-EMF) unavoidable. Previous experiments have revealed the tumor-promoting effects of non-ionizing RF-EMF in adult carcinogen-treated mice in utero. To extend these investigations, we tested whether these effects are due to the co-carcinogenicity of RF-EMF which would manifest as elevated DNA damage. Similar to previous experiments, pregnant mice were exposed to RF-EMF (Universal Mobile Telecommunication System [UMTS] standard, approximately 1,960 MHz) from day 7 post-conception (p.c.) at 0 (sham), 0.04, and 0.4 W/kg SAR. At day 14 p.c., the mice were injected with the carcinogen ethylnitrosourea (ENU, 40 mg/kg). At three time-points specifically 24, 36, and 72 h later, the pregnant females were sacrificed and the fetuses (n = 24–57) were removed. A dye (cy3) specific for adenyl adducts was used to detect DNA damage by fluorescence microscopy in the brain, liver, and lung of each fetus. Compared to control (0 W/kg SAR), exposure to RF-EMF had no effect on the formation of DNA adducts in the inspected tissues. We conclude that increased adenyl formation of DNA by RF-EMF exposure is not a valid explanation for the previously reported tumor-promoting effects of RF-RMF. Our findings may help to gain a deeper insight into the biological effects of RF-EMF exposure in the context of malignancy. © 2020 The Authors. Bioelectromagnetics published by Wiley Periodicals LLC on behalf of Bioelectromagnetics Society     

Non-thermal DNA breakage by mobile-phone radiation (1800 MHz) in human fibroblasts and in transformed GFSH-R17 rat granulosa cells in vitro

Cultured human diploid fibroblasts and cultured rat granulosa cells were exposed to intermittent and continuous radiofrequency electromagnetic fields (RF-EMF) used in mobile phones, with different specific absorption rates (SAR) and different mobile-phone modulations. DNA strand breaks were determined by means of the alkaline and neutral comet assay. RF-EMF exposure (1800 MHz; SAR 1.2 or 2 W/kg; different modulations; during 4, 16 and 24h; intermittent 5 min on/10 min off or continuous wave) induced DNA single- and double-strand breaks. Effects occurred after 16 h exposure in both cell types and after different mobile-phone modulations. The intermittent exposure showed a stronger effect in the comet assay than continuous exposure. Therefore we conclude that the induced DNA damage cannot be based on thermal effects.     

Lymphoma development of simultaneously combined exposure to two radiofrequency signals in AKR/J mice

There are public concerns regarding possible carcinogenic or cancer-promoting effects of radiofrequency electromagnetic fields (RF-EMFs) because of the extensive use of wireless mobile phones and other telecommunication devices in daily life. However, so far it is unclear if non-thermal exposure of single EMF exposure in animal studies has a direct influence on carcinogenesis. Here, carcinogenic effects of combined signal RF-EMFs on AKR/J mice, which were used for the lymphoma animal model, were investigated. Six-week-old AKR/J mice were simultaneously exposed to two types of RF signals: single code division multiple access (CDMA) and wideband code division multiple access (WCDMA). AKR/J mice were exposed to combined RF-EMFs for 45 min/day, 5 days/week, for a total of 42 weeks. The whole-body average specific absorption rate (SAR) of CDMA and WCDMA fields was 2.0 W/kg each, 4.0 W/kg in total. When we examined final survival, lymphoma incidence, and splenomegaly incidence, no differences were found between sham- and RF-exposed mice. However, occurrence of metastasis infiltration to the brain in lymphoma-bearing mice was significantly different in RF-exposed mice when compared to sham-exposed mice, even though no consistent correlation (increase or decrease) was observed between male and female mice. However, infiltration occurrence to liver, lung, and spleen was not different between the groups. From the results, we suggested that simultaneous exposure to CDMA and WCDMA RF-EMFs did not affect lymphoma development in AKR/J mice.     

Impact of 900 MHz electromagnetic field exposure on main male reproductive hormone levels: a Rattus norvegicus model

This work analyzes the effects of radiofrequency-electromagnetic field (RF-EMF) exposure on the reproductive system of male rats, assessed by measuring circulating levels of FSH, LH, inhibin B, activin B, prolactin, and testosterone. Twenty adult male Sprague–Dawley rats (180?±?10 g) were exposed to 900 MHz RF-EMF in four equal separated groups. The duration of exposure was 1, 2, and 4 h/day over a period of 30 days and sham-exposed animals were kept under the same environmental conditions as the exposed group except with no RF-EMF exposure. Before the exposure, at 15 and 30 days of exposure, determination of the abovementioned hormone levels was performed using ELISA. At the end of the experiment, FSH and LH values of the long time exposure (LTE) group were significantly higher than the sham-exposed group (p?p?p?相似文献   

1950 MHz射频电磁场对人脐带间充质干细胞增殖和成骨分化的影响研究

目的:间充质干细胞(Mesenchymal stem cells,MSCs)具有广阔的临床应用前景,但由于其体外增殖和定向分化等问题,制约了其进一步应用。本研究拟探讨1950MHz射频电磁场(Radio-frequency electromagnetic fields,RF-EMF)对人脐带间充质干细胞(Human umbilical cord mesenchymal stem cells,hUC-MSCs)增殖和成骨方向分化的影响,以期为MSCs的体外增殖和定向分化提供一条新途径。方法:华通氏胶组织块法分离培养人脐带间充质干细胞,流式细胞仪检测间充质干细胞特异性标志物。选择鉴定后的第3至第6代(P3-P6)hUC-MSCs用于实验。将hUC-MSCs细胞暴露或假暴露于频率为1950 MHz,比吸收率(Specific absorption rate,SAR)分别为0.5,1.0和2.0 W/kg的RF-EMF中,每天暴露1 h(5 min开,10 min关),连续暴露7 d。暴露结束后,流式细胞仪检测细胞周期,免疫荧光检测增殖相关蛋白Ki67表达,连续6天用CCK-8方法检测细胞数。在成骨分化研究中,将P3代的hUC-MSCs随机分为假暴露(sham)组,射频辐射暴露(RF)组,成骨诱导培养基组(Induction medium,OM)和成骨诱导培养基联合射频辐射暴露(OM+RF)组,暴露SAR值为2.0 W/kg,其它参数不变。暴露结束后立即检测细胞的碱性磷酸酶(Alkaline phosphatase,ALP)活性。结果:原代培养的细胞具有MSC典型外观,且表达MSCs特异性表面抗原。与sham组相比,不同SAR值RF暴露后,hUC-MSCs的增殖能力无明显变化,S期细胞比例及Ki67蛋白水平也无显著改变。此外,hUC-MSCs经SAR值为2.0W/kg的RF暴露7 d,与sham组相比其ALP活性无显著变化。与OM组相比,OM+RF组的ALP活性亦无显著改变。结论:华通氏胶组织块法能够培养出纯度较高的间充质干细胞,本实验条件下的1950 MHz射频电磁场对hUC-MSCs的增殖和成骨分化均无显著影响。     

ROS release and Hsp70 expression after exposure to 1,800 MHz radiofrequency electromagnetic fields in primary human monocytes and lymphocytes

The aim of this study is to investigate if 1,800 MHz radiofrequency electromagnetic fields (RF-EMF) can induce reactive oxygen species (ROS) release and/or changes in heat shock protein 70 (Hsp70) expression in human blood cells, using different exposure and co-exposure conditions. Human umbilical cord blood-derived monocytes and lymphocytes were used to examine ROS release after exposure to continuous wave or different GSM signals (GSM-DTX and GSM-Talk) at 2 W/kg for 30 or 45 min of continuous or intermittent (5 min ON/5 min OFF) exposure. The cells were exposed to incubator conditions, to sham, to RF-EMF, or to chemicals in parallel. Cell stimulation with the phorbol ester phorbol-12-myristate-13-acetate (PMA; 1 μM) was used as positive control for ROS release. To investigate the effects on Hsp70 expression, the human monocytes were exposed to the GSM-DTX signal at 2 W/kg for 45 min, or to heat treatment (42°C) as positive control. ROS production and Hsp70 expression were determined by flow cytometric analysis. The data were compared to sham and/or to control values and the statistical analysis was performed by the Student’s t-test (P<0.05). The PMA treatment induced a significant increase in ROS production in human monocytes and lymphocytes when the data were compared to sham or to incubator controls. After continuous or intermittent GSM-DTX signal exposure (2 W/kg), a significantly different ROS production was detected in human monocytes if the data were compared to sham. However, this significant difference appeared due to the lowered value of ROS release during sham exposure. In human lymphocytes, no differences could be detected if data were compared either to sham or to incubator control. The Hsp70 expression level after 0, 1, and 2 h post-exposure to GSM-DTX signal at 2 W/kg for 1 h did not show any differences compared to the incubator or to sham control.     

Radio-frequency electromagnetic radiation alters the electric potential of Myriophyllum aquaticum

Electric signaling pathways are important for rapid and long-distance communication within a plant. Changes in the electric potential (EP) inside plants have been observed during the propagation of electric signals. Increasing radiofrequency electromagnetic radiation (EMR) in the environment raise the question about possible effects of EMR on the EP of plants. In the present experiment, we investigated the effect of 2, 2.5, 3.5, and 5.5 GHz EMR with a maximum field intensity of 23–25 V m^?1 on the EP in emergent Myriophyllum aquaticum plants. The 2 and 5.5 GHz exposures caused significant (16 and 13 %) decreases in the standard deviation of rapid fluctuations observed in the EP. The greatest change was caused by 2.5 GHz EMR (23 % increment), although it was not statistically significant. A recovery of the EP was only after 2.5 GHz EMR exposure. The temperature of the plants was not changed by the EMR exposure. These findings confirm the frequency-dependent non-thermal effects of EMR on the EP of plants.     

Cell Type-Dependent Induction of DNA Damage by 1800 MHz Radiofrequency Electromagnetic Fields Does Not Result in Significant Cellular Dysfunctions

Background

Although IARC clarifies radiofrequency electromagnetic fields (RF-EMF) as possible human carcinogen, the debate on its health impact continues due to the inconsistent results. Genotoxic effect has been considered as a golden standard to determine if an environmental factor is a carcinogen, but the currently available data for RF-EMF remain controversial. As an environmental stimulus, the effect of RF-EMF on cellular DNA may be subtle. Therefore, more sensitive method and systematic research strategy are warranted to evaluate its genotoxicity.

Objectives

To determine whether RF-EMF does induce DNA damage and if the effect is cell-type dependent by adopting a more sensitive method γH2AX foci formation; and to investigate the biological consequences if RF-EMF does increase γH2AX foci formation.

Methods

Six different types of cells were intermittently exposed to GSM 1800 MHz RF-EMF at a specific absorption rate of 3.0 W/kg for 1 h or 24 h, then subjected to immunostaining with anti-γH2AX antibody. The biological consequences in γH2AX-elevated cell type were further explored with comet and TUNEL assays, flow cytometry, and cell growth assay.

Results

Exposure to RF-EMF for 24 h significantly induced γH2AX foci formation in Chinese hamster lung cells and Human skin fibroblasts (HSFs), but not the other cells. However, RF-EMF-elevated γH2AX foci formation in HSF cells did not result in detectable DNA fragmentation, sustainable cell cycle arrest, cell proliferation or viability change. RF-EMF exposure slightly but not significantly increased the cellular ROS level.

Conclusions

RF-EMF induces DNA damage in a cell type-dependent manner, but the elevated γH2AX foci formation in HSF cells does not result in significant cellular dysfunctions.     

Long-term effects of 900 MHz radiofrequency radiation emitted from mobile phone on testicular tissue and epididymal semen quality

The purpose of this study is to bridge this gap by investigating effects of long term 900?MHz mobile phone exposure on reproductive organs of male rats. The study was carried out on 14 adult Wistar Albino rats by dividing them randomly into two groups (n: 7) as sham group and exposure group. Rats were exposed to 900?MHz radiofrequency (RF) radiation emitted from a GSM signal generator. Point, 1?g and 10?g specific absorption rate (SAR) levels of testis and prostate were found as 0.0623?W/kg, 0.0445?W/kg and 0.0373?W/kg, respectively. The rats in the exposure group were subject to RF radiation 3?h per day (7?d a week) for one year. For the sham group, the same procedure was applied, except the generator was turned off. At the end of the study, epididymal sperm concentration, progressive sperm motility, abnormal sperm rate, all-genital organs weights and testis histopathology were evaluated. Any differences were not observed in sperm motility and concentration (p?>?0.05). However, the morphologically normal spermatozoa rates were found higher in the exposure group (p?p?p?相似文献   

Influence of microwave radiation on bacterial community structure in biofilm

Organic matter exposed to microwave radiation triggers standard thermal effects as well as a range of so called non-thermal effects. The present work examined the non-thermal effects of microwave radiation on the biofilm in bioreactors with immobilised biomass. Microwave-exposed and conventionally heated reactors were used and both groups of reactors operated on analogous technological parameters. The analysis of the treated sewage demonstrated a significant increase in nitrification and denitrification efficiency in the bioreactors treated with microwave radiation. An analysis of bacteria diversity based on DGGE method showed significantly different bacterial communities developed in the reactors exposed to the microwave radiation in comparison to the control reactors. Moreover, bacterial richness measured by Shannon index was significantly higher in the microwave treated samples (Mann–Whitney's test, p < 0.05). These findings indicate that microwave radiation can affect the structure and function of bacterial communities independent of thermal effects.     

Cell oxidation–reduction imbalance after modulated radiofrequency radiation

Abstract

Aim of this study was to evaluate an influence of modulated radiofrequency field (RF) of 1800?MHz, strength of 30?V/m on oxidation–reduction processes within the cell. The assigned RF field was generated within Gigahertz Transversal Electromagnetic Mode cell equipped by signal generator, modulator, and amplifier. Cell line V79, was irradiated for 10, 30, and 60?min, specific absorption rate was calculated to be 1.6?W/kg. Cell metabolic activity and viability was determined by MTT assay. In order to define total protein content, colorimetric method was used. Concentration of oxidised proteins was evaluated by enzyme-linked immunosorbent assay. Reactive oxygen species (ROS) marked with fluorescent probe 2′,7′-dichlorofluorescin diacetate were measured by means of plate reader device. In comparison with control cell samples, metabolic activity and total protein content in exposed cells did not differ significantly. Concentrations of carbonyl derivates, a product of protein oxidation, insignificantly but continuously increase with duration of exposure. In exposed samples, ROS level significantly (p?<?0.05) increased after 10?min of exposure. Decrease in ROS level was observed after 30-min treatment indicating antioxidant defence mechanism activation. In conclusion, under the given laboratory conditions, modulated RF radiation might cause impairment in cell oxidation–reduction equilibrium within the growing cells.     

Genotoxic effects of exposure to radiofrequency electromagnetic fields (RF-EMF) in cultured mammalian cells are not independently reproducible

Conflicting results have been published regarding the induction of genotoxic effects by exposure to radiofrequency electromagnetic fields (RF-EMF). Using the comet assay, the micronucleus test and the chromosome aberration test with human fibroblasts (ES1 cells), the EU-funded "REFLEX" project (Risk Evaluation of Potential Environmental Hazards From Low Energy Electromagnetic Field Exposure Using Sensitive in vitro Methods) reported clearly positive effects for various exposure conditions. Because of the ongoing discussion on the biological significance of the effects observed, it was the aim of the present study to independently repeat the results using the same cells, the same equipment and the same exposure conditions. We therefore exposed ES1 cells to RF-EMF (1800 MHz; SAR 2 W/kg, continuous wave with intermittent exposure) for different time periods and then performed the alkaline (pH>13) comet assay and the micronucleus test (MNT). For both tests, clearly negative results were obtained in independently repeated experiments. We also performed these experiments with V79 cells, a sensitive Chinese hamster cell line that is frequently used in genotoxicity testing, and also did not measure any genotoxic effect in the comet assay and the MNT. Appropriate measures of quality control were considered to exclude variations in the test performance, failure of the RF-EMF exposure or an evaluation bias. The reasons for the difference between the results reported by the REFLEX project and our experiments remain unclear.     

Effect of 900 MHz radio frequency radiation on beta amyloid protein, protein carbonyl, and malondialdehyde in the brain

Recently, many studies have been carried out in relation to 900 MHz radiofrequency radiation (RF) emitted from a mobile phone on the brain. However, there is little data concerning possible mechanisms between long-term exposure of RF radiation and biomolecules in brain. Therefore, we aimed to investigate long-term effects of 900 MHz radiofrequency radiation on beta amyloid protein, protein carbonyl, and malondialdehyde in the rat brain. The study was carried out on 17 Wistar Albino adult male rats. The rat heads in a carousel were exposed to 900 MHz radiofrequency radiation emitted from a generator, simulating mobile phones. For the study group (n: 10), rats were exposed to the radiation 2 h per day (7 days a week) for 10 months. For the sham group (n: 7), rats were placed into the carousel and the same procedure was applied except that the generator was turned off. In this study, rats were euthanized after 10 months of exposure and their brains were removed. Beta amyloid protein, protein carbonyl, and malondialdehyde levels were found to be higher in the brain of rats exposed to 900 MHz radiofrequency radiation. However, only the increase of protein carbonyl in the brain of rats exposed to 900 MHz radiofrequency radiation was found to be statistically significant (p<0.001). In conclusion, 900 MHz radiation emitted from mobile/cellular phones can be an agent to alter some biomolecules such as protein. However, further studies are necessary.     

Effect of 900 MHz radiofrequency radiation on oxidative stress in rat brain and serum

The increasing use of mobile telephones raises the question of possible adverse effects of the electromagnetic fields (EMF) that these phones produce. In this study, we examined the oxidative stress in the brain tissue and serum of rats that resulted from exposure to a 900-MHz EMF at a whole body average specific absorption rate (SAR) of 1.08 W/kg for 1 h/day for 3 weeks. We also examined the antioxidant effect of garlic powder (500 mg/kg/day) given orally to EMF-exposed rats. We found that malondialdehyde (MDA) (p < 0.001) and advanced oxidation protein product (AOPP) (p < 0.05) increased in rat brain tissue exposed to the EMF and that garlic reduced these effects (p < 0.05). There was no significant difference in the nitric oxide (NO) levels in the brain. Paraoxonase (PON) was not detected in the brain. There was a significant increase in the levels of NO (p < 0.001) detected in the serum after EMF exposure, and garlic intake did not affect this increase in NO. Our results suggest that there is a significant increase in brain lipid and protein oxidation after electromagnetic radiation (EMR) exposure and that garlic has a protective effect against this oxidative stress.     

Microwave radiation (2.45 GHz)-induced oxidative stress: Whole-body exposure effect on histopathology of Wistar rats

Man-made microwave and radiofrequency (RF) radiation technologies have been steadily increasing with the growing demand of electronic appliances such as microwave oven and cell phones. These appliances affect biological systems by increasing free radicals, thus leading to oxidative damage. The aim of this study was to explore the effect of 2.45 GHz microwave radiation on histology and the level of lipid peroxide (LPO) in Wistar rats. Sixty-day-old male Wistar rats with 180 ± 10 g body weight were used for this study. Animals were divided into two groups: sham exposed (control) and microwave exposed. These animals were exposed for 2 h a day for 35 d to 2.45 GHz microwave radiation (power density, 0.2 mW/cm²). The whole-body specific absorption rate (SAR) was estimated to be 0.14 W/kg. After completion of the exposure period, rats were sacrificed, and brain, liver, kidney, testis and spleen were stored/preserved for determination of LPO and histological parameters. Significantly high level of LPO was observed in the liver (p < 0.001), brain (p < 0.004) and spleen (p < 0.006) in samples from rats exposed to microwave radiation. Also histological changes were observed in the brain, liver, testis, kidney and spleen after whole-body microwave exposure, compared to the control group.

Based on the results obtained in this study, we conclude that exposure to microwave radiation 2 h a day for 35 d can potentially cause histopathology and oxidative changes in Wistar rats. These results indicate possible implications of such exposure on human health.     

Effect of previous feeding by Falconia intermedia (Hemiptera: Miridae) on subsequent feeding activity on the invasive shrub Lantana camara (Verbenaceae)

After initially building up to high densities, populations of a promising biological control agent, Falconia intermedia (Distant) (Hemiptera: Miridae), imported to control the invasive plant Lantana camara L. (Verbenaceae) in South Africa, disappeared at almost all release sites in the Eastern Cape, Mpumalanga, KwaZulu-Natal and Limpopo provinces. In an attempt to explain this phenomenon, laboratory trials were conducted to determine the effect of previous feeding on the subsequent performance of F. intermedia on L. camara varieties from two of the Eastern Cape release sites; Lyndhurst Farm and Whitney Farm. F. intermedia feeding damage, number of adults, number of nymphs and oviposition on Whitney Farm, L. camara plants were 40.8% (p<0.001), 106% (p<0 .001), 81.5% (p <0.001) and 80% (p<0.001) higher, respectively, than on Lyndhurst Farm, indicating the superior suitability and quality of Whitney Farm plants for F. intermedia performance. A defence response was observed by plants from Lyndhurst Farm that were previously fed on (i.e. induced). The induced plants had significantly lower F. intermedia feeding damage (21.4% less, p=0.007), numbers of adults (187.5% less, p=0.034), numbers of nymphs (110% less, p=0.071) and oviposition (99.8% less, p=0.021) than plants that were not previously fed on. The defence responses were elicited and expressed throughout the plant in both damaged and undamaged leaves within five weeks after insect release (rapidly induced response). The significant decrease in herbivore performance suggests that some L. camara varieties possess factors that enable them to resist subsequent feeding activity, offering us some understanding of one of the factors that might have contributed to the failure of F. intermedia in South Africa.     

Effect of 900 MHz Radio Frequency Radiation on Beta Amyloid Protein,Protein Carbonyl,and Malondialdehyde in the Brain

Recently, many studies have been carried out in relation to 900 MHz radiofrequency radiation (RF) emitted from a mobile phone on the brain. However, there is little data concerning possible mechanisms between long-term exposure of RF radiation and biomolecules in brain. Therefore, we aimed to investigate long-term effects of 900 MHz radiofrequency radiation on beta amyloid protein, protein carbonyl, and malondialdehyde in the rat brain. The study was carried out on 17 Wistar Albino adult male rats. The rat heads in a carousel were exposed to 900 MHz radiofrequency radiation emitted from a generator, simulating mobile phones. For the study group (n: 10), rats were exposed to the radiation 2 h per day (7 days a week) for 10 months. For the sham group (n: 7), rats were placed into the carousel and the same procedure was applied except that the generator was turned off. In this study, rats were euthanized after 10 months of exposure and their brains were removed. Beta amyloid protein, protein carbonyl, and malondialdehyde levels were found to be higher in the brain of rats exposed to 900 MHz radiofrequency radiation. However, only the increase of protein carbonyl in the brain of rats exposed to 900 MHz radiofrequency radiation was found to be statistically significant (p < 0.001).

In conclusion, 900 MHz radiation emitted from mobile/cellular phones can be an agent to alter some biomolecules such as protein. However, further studies are necessary.     

Residential characteristics and radiofrequency electromagnetic field exposures from bedroom measurements in Germany

The objectives of this study were to assess total exposure to radiofrequency electromagnetic fields (RF-EMF) in bedrooms and the contribution of different radioservices (FM radio, analogue TV and DVB-T, TETRA, GSM900 downlink, GSM1800 downlink, UMTS downlink, DECT, and wireless LAN and blue tooth) to the total exposure. Additional aims were to describe the proportion of measuring values above the detection limit of the dosimeters and to characterize the differences in exposure patterns associated with self-reported residential characteristics. Exposure to RF sources in bedrooms was measured using Antennessa^? EME Spy 120 dosimeters in 1,348 households in Germany; 280 measures were available for each frequency band per household. Mean electrical field strengths and power flux densities were calculated. Power flux densities allow the calculation of proportions of different radioservices on total exposure. Exposure was often below the detection limit (electrical field strength: 0.05 V/m) of the dosimeter. Total exposure varied, depending on residential characteristics (urban vs. rural areas and floor of a building the measurement took place). Major sources of exposure were cordless phones (DECT standard) and wireless LAN/blue tooth contributing about 82% of total exposure (20.5 μW/m²). Exposure to RF-EMF is ubiquitous, but exposure levels are—if at all measurable—very low and far below the ICNIRP’s exposure reference levels.