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Investigation of Co-genotoxic Effects of Radiofrequency Electromagnetic Fields In Vivo

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Abstract

We investigated the possible combined genotoxic effects of radiofrequency (RF) electromagnetic fields (900 MHz, amplitude modulated at 217 Hz, mobile phone signal) with the drinking water mutagen and carcinogen 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX). Female rats were exposed to RF fields for a period of 2 years for 2 h per day, 5 days per week at average whole-body specific absorption rates of 0.3 or 0.9 W/kg. MX was given in the drinking water at a concentration of 19 microg/ml. Blood samples were taken at 3, 6 and 24 months of exposure and brain and liver samples were taken at the end of the study (24 months). DNA damage was assessed in all samples using the alkaline comet assay, and micronuclei were determined in erythrocytes. We did not find significant genotoxic activity of MX in blood and liver cells. However, MX induced DNA damage in rat brain. Co-exposures to MX and RF radiation did not significantly increase the response of blood, liver and brain cells compared to MX exposure only. In conclusion, this 2-year animal study involving long-term exposures to RF radiation and MX did not provide any evidence for enhanced genotoxicity in rats exposed to RF radiation.
... However, earlier studies have reported both DNA damage and no DNA damage in the brain after exposure to varying doses and durations of RF-EMR (Belyaev, 2015;Lagroye et al., 2004;Singh, 1995, 2005;Prihoda, 2019). Few animal studies also reported increased DNA damage with an increase in frequency (Alkis et al., 2019;Deshmukh et al., 2015;Megha et al., 2015) and others did not observe significant DNA damage irrespective of frequencies (Verschaeve et al., 2006). Variability in these results could be attributed to the difference in exposure and biological parameters (Belyaev, 2010). ...
Article
A mobile phone is now a commonly used device for digital media and communication among all age groups. Young adolescents use it for longer durations, which exposes them to radiofrequency electromagnetic radiation (RF-EMR). This exposure can lead to neuropsychiatric changes. The underlying cellular mechanism behind these changes requires detailed investigation. In the present study, we investigated the effect of RF-EMR emitted from mobile phones on young adolescent rat brains. Wistar rats (5 weeks, male) were exposed to RF-EMR signal (2,115 MHz) at a head average specific absorption rate (SAR) of 1.51 W/kg continuously for 8 h. Higher level of lipid peroxidation, carbon-centered lipid radicals, and single-strand DNA damage was observed in the brain of rat exposed to RF-EMR. The number of BrdU-positive cells in the dentate gyrus (DG) decreased in RF-EMR-exposed rats, indicating reduced neurogenesis. RF-EMR exposure also induced degenerative changes and neuronal loss in DG neurons but had no effect on the CA3 and CA1 neurons of the hippocampus and cerebral cortex. The activity of Pro-caspase3 did not increase upon exposure in any of the brain regions, pointing out that degeneration observed in the DG region is not dependent on caspase activation. Results indicate that short-term acute exposure to RF-EMR induced the generation of carbon-centered lipid radicals and nuclear DNA damage, both of which likely played a role in the impaired neurogenesis and neuronal degeneration seen in the young brain's hippocampus region. The understanding of RF-EMR-induced alteration in the brain at the cellular level will help develop appropriate interventions for reducing its adverse impact.
... Many studies have found that RF radiation can cause DNA damage in human cells, such as the epithelial cells in the lens and human hair follicles [13,14]. In contrast, other studies have found no significant impact of RF exposure on DNA damage [15][16][17]. It seems that the impact of RF exposure on DNA damage is dependent on flux densities, frequencies, and exposure patterns of EMF [18]. ...
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With the rapid growth of the wireless communication industry, humans are extensively exposed to electromagnetic fields (EMF) comprised of radiofrequency (RF). The skin is considered the primary target of EMFs given its outermost location. Recent evidence suggests that extremely low frequency (ELF)-EMF can improve the efficacy of DNA repair in human cell-lines. However, the effects of EMF-RF on DNA damage remain unknown. Here, we investigated the impact of EMF-long term evolution (LTE, 1.762 GHz, 8 W/kg) irradiation on DNA double-strand break (DSB) using the murine melanoma cell line B16 and the human keratinocyte cell line HaCaT. EMF-LTE exposure alone did not affect cell viability or induce apoptosis or necrosis. In addition, DNA DSB damage, as determined by the neutral comet assay, was not induced by EMF-LTE irradiation. Of note, EMF-LTE exposure can attenuate the DNA DSB damage induced by physical and chemical DNA damaging agents (such as ionizing radiation (IR, 10 Gy) in HaCaT and B16 cells and bleomycin (BLM, 3 μM) in HaCaT cells and a human melanoma cell line MNT-1), suggesting that EMF-LTE promotes the repair of DNA DSB damage. The protective effect of EMF-LTE against DNA damage was further confirmed by attenuation of the DNA damage marker γ-H2AX after exposure to EMF-LTE in HaCaT and B16 cells. Most importantly, irradiation of EMF-LTE (1.76 GHz, 6 W/kg, 8 h/day) on mice in vivo for 4 weeks reduced the γ-H2AX level in the skin tissue, further supporting the protective effects of EMF-LTE against DNA DSB damage. Furthermore, p53, the master tumor-suppressor gene, was commonly upregulated by EMF-LTE irradiation in B16 and HaCaT cells. This finding suggests that p53 plays a role in the protective effect of EMF-LTE against DNA DSBs. Collectively, these results demonstrated that EMF-LTE might have a protective effect against DNA DSB damage in the skin, although further studies are necessary to understand its impact on human health.
... Radio waves also induce NADH oxidase enzyme, which might play a key role in the various cellular adverse effects [36,40]. Various cellular and physiological processes can be affected as a consequence of increased levels of free radicals, including gene expression, cell growth, apoptosis, and release of calcium from intracellular storage sites [32,36,[41][42][43][44][45][46][47][48][49]]. ...
... Radio waves also induce NADH oxidase enzyme, which might play a key role in the various cellular adverse effects [36,40]. Various cellular and physiological processes can be affected as a consequence of increased levels of free radicals, including gene expression, cell growth, apoptosis, and release of calcium from intracellular storage sites [32,36,[41][42][43][44][45][46][47][48][49]]. ...
... Contrary to these studies, it has been suggested in many studies that RFR exposure does not constitute significant cellular DNA damage. Verschaeve et al. (2006) reported that long-term exposure (2 h/day, 5 days/week, 2 years) of 900-MHz GSM signal at 0.3 and 0.9 W/kg SAR to rats did not significantly affect DNA strand breakdown levels in their cells. Trosic et al. (2011) reported that RFR radiation exposure (1 h/day) in mobile phone frequency range (915MHz GSM, power density; 2.4 W/m 2 , SAR; 0.6 W/kg) did not cause DNA damage in brain tissues of rats. ...
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Ubiquitous and ever increasing use of mobile phones led to the growing concern about the effects of radiofrequency radiation (RFR) emitted by cell phones on biological systems. The aim of this study is to explore whether long-term RFR exposure at different frequencies affects DNA damage and oxidant-antioxidant parameters in the blood and brain tissue of rats. 28 male Sprague Dawley rats were randomly divided into four equal groups (n = 7). They were identified as Group 1: sham-control, Group 2: 900 MHz, Group 3: 1800 MHz, and Group 4: 2100 MHz. Experimental groups of rats were exposed to RFR 2 h/day for 6 months. The sham-control group of rats was subjected to the same experimental condition but generator was turned off. Specific absorption rates (SARs) at brain with 1 g average were calculated as 0.0845 W/kg, 0.04563 W/kg, and 0.03957, at 900 MHz, 1800 MHz, and 2100 MHz, respectively. Additionally, malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), total antioxidant status (TAS), and total oxidant status (TOS) analyses were conducted in the brain tissue samples. Results of the study showed that DNA damage and oxidative stress indicators were found higher in the RFR exposure groups than in the sham-control group. In conclusion, 900-, 1800-, and 2100-MHz RFR emitted from mobile phones may cause oxidative damage, induce increase in lipid peroxidation, and increase oxidative DNA damage formation in the frontal lobe of the rat brain tissues. Furthermore, 2100-MHz RFR may cause formation of DNA single-strand breaks.
... A series of studies conducted with human lymphocytes cultured for various time periods reported that no chromosome aberration, micronuclei, or sister chromatid change was observed after exposure with a 900-MHz RFR (SAR 0.2-10 W/kg) (Nikolova et al., 2005;Scarfi et al., 2006;Zeni et al., 2003). Verschaeve et al. (2006) reported that long term (2 h/day, 5 days/week, 2 years) exposure to a 900-MHz RFR with 0.3 and 0.9 W/kg SAR did not lead to any significant increase in DNA strand breaks in rats. Takahashi et al. (2002) exposed rats to a 1500-MHz RFR at 2.0, 0.67, or 0 W/ kg SAR for 4 weeks with 5 days a week and 90 min a day, and they did not found any mutagenic effect in the brain of the rat. ...
Article
The aim of this study was to investigate effect of radiofrequency radiation (RFR) emitted from mobile phones on DNA damage in follicle cells of hair in the ear canal. The study was carried out on 56 men (age range: 30–60 years old)in four treatment groups with n = 14 in each group. The groups were defined as follows: people who did not use a mobile phone (Control), people use mobile phones for 0–30 min/day (second group), people use mobile phones for 30–60 min/day (third group) and people use mobile phones for more than 60 min/day (fourth group). Ear canal hair follicle cells taken from the subjects were analyzed by the Comet Assay to determine DNA damages. The Comet Assay parameters measured were head length, tail length, comet length, percentage of head DNA, tail DNA percentage, tail moment, and Olive tail moment. Results of the study showed that DNA damage indicators were higher in the RFR exposure groups than in the control subjects. In addition, DNA damage increased with the daily duration of exposure. In conclusion, RFR emitted from mobile phones has a potential to produce DNA damage in follicle cells of hair in the ear canal. Therefore, mobile phone users have to pay more attention when using wireless phones.
... However, effects were observed mainly in studies with small sample size, and evidence of publication bias was found in the meta-analyses. As the photon energy of RF radiation is too low to cause direct genotoxicity, it is important to assess not only genotoxicity from RF radiation alone, but also the possibility that RF radiation enhances the effects of genotoxic physical and chemical agents (Verschaeve et al. 2006(Verschaeve et al. , 2010Juutilainen et al. 2007;Prihoda 2008, 2012;Luukkonen et al. 2009Luukkonen et al. , 2010. IARC (2013) classified RF electromagnetic fields as possibly carcinogenic to humans (Group 2B). ...
Article
Purpose: We examined genotoxicity, co-genotoxicity and induced genomic instability (IGI) in primary astrocytes exposed to radiofrequency (RF) radiation. Materials and methods: Rat primary astrocytes were exposed to 872 MHz GSM-modulated or continuous wave (CW) RF radiation at specific absorption rates of 0.6 or 6.0 W/kg for 24 h. Menadione (MQ) and methyl methanesulfonate (MMS; only in genotoxicity experiments) were used as co-exposures. Alkaline Comet assay and flow cytometric micronucleus scoring were used to detect genetic damage. Results: No IGI was observed from RF radiation alone or combined treatment with MQ. RF radiation alone was not genotoxic. RF radiation combined with chemical exposure showed some statistically significant differences: increased DNA damage at 6.0 W/kg but decreased DNA damage at 0.6 W/kg in cells exposed to GSM-modulated RF radiation and MQ, and increased micronucleus frequency in cells exposed to CW RF radiation at 0.6 W/kg and MMS. Conclusion: Exposure to GSM modulated RF radiation at levels up to 6.0 W/kg did not induce or enhance genomic instability in rat primary astrocytes. Lack of genotoxicity from RF radiation alone was convincingly shown in multiple experiments. Co-genotoxicity of RF radiation and genotoxic chemicals was not consistently supported by the results.
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Mobile phone is now a commonly used communication device in all age groups. Young adolescents use it for longer duration and effect of its radiofrequency electromagnetic radiation (RF-EMR) on their brain structure and function need detailed investigation. In the present study, we investigated the effect of RF-EMR emitted from mobile phones, on young adolescent rat brain. Wistar rats (5 weeks, male) were exposed to RF-EMR signal (2,115 MHz) from a mobile phone at a whole body averaged specific absorption rate (SAR) of 1.15 W/kg continuously for 8 h. Higher level of lipid peroxidation, carbon centered lipid radicals and DNA damage were observed in the brain of rat exposed to RF-EMR. Number of neural progenitor cells (NPCs) in dentate gyrus (DG) were found to be relatively low in RF-EMR exposed rats that may be due to reduced neurogenesis. Acute exposure to RF-EMR induced neuronal degeneration in DG region with insignificant variation in CA3, CA1 and cerebral cortex sub regions of hippocampus. Findings of this study, indicate that acute exposure of high frequency RF-EMR at relatively higher SAR may adversely impact the neurogenesis and function of adolescent rat brain. Generation of carbon centered lipid radicals, and nuclear DNA damage might be playing critical role in reduced neurogenesis and higher neuronal degeneration in the cortex and hippocampus of brain. Detailed understanding of RF-EMR induced alteration in brain function will be useful to develop appropriate interventions for reducing the impact caused by RF-EMR damage.
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Behavioral impairments are the most pragmatic outcome of long-term mobile uses but the underlying causes are still poorly understood. Therefore, the Aim of the present study to determine the possible mechanism of mobile induced behavioral alterations by observing redox status, cholinesterase activity, cellular, genotoxic damage and cognitive alterations in rat hippocampus. This study was carried out on 24 male Wistar rats, randomly divided into four groups (n = 6 in each group): group I consisted of sham-exposed (control) rats, group II-IV consisted of rats exposed to microwave radiation (900 MHz) at different time duration 1 h, 2 h, and 4 h respectively for 90 days. After 90 days of exposure, rats were assessing learning ability by using T-Maze. A significantly increased level of malondialdehyde (MDA) with concomitantly depleted levels of superoxide dismutase (SOD), catalase (CAT) and redox enzymes (GSH, GPX, GR, GST, G-6PDH) indicated an exposure of mobile emitted EMR induced oxidative stress by the depleted redox status of brain cells. The depletion in the acetylcholinesterase (AChE) level reveals altered neurotransmission in brain cells. Resultant cellular degeneration was also observed in the radiation-exposed hippocampus. Conclusively, the present study revealed that microwave radiation induces oxidative stress, depleted redox status, and causes DNA damage with the subsequent reduction in working memory in a time-dependent manner. This study provides insight over the associative reciprocity between redox status, cellular degeneration and reduced cholinergic activity, which presumably leads to the behavioral alterations following mobile emitted electromagnetic radiation.
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We tested the genotoxicity of 3-chloro-4-(dichloromethyl)-5-hydroxy-2[5H]-furanone (MX) in the mouse in 6 organs (liver, lung, kidney, brain, spleen, and bone marrow) and in the mucosa of stomach, jejunum, ileum, colon, and bladder using the alkaline single-cell gel electrophoresis (SCG) (Comet) assay modified by us. Mice were sacrificed 1, 3, 6, and 24 h after oral administration of the mutagen at 100 mg/kg. MX yielded statistically significant DNA damage in the liver, kidney, lung, and brain and in all the mucosa samples. While DNA damage persisted in the gastrointestinal and urinary tract for 6–24 h after a single oral dosing, it peaked in the liver at 1 h and returned to almost the control level at 3 h. Our present results suggest that MX is genotoxic for various mouse organs, but not for the hematopoietic system, and that the alkaline SCG assay with a homogenization technique can be used to predict genotoxicity in the gastrointestinal and urinary tracts.
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The mouse has traditionally been used for the micronucleus test, with bone marrow the usual target organ. The aim of the 9th collaborative study by CSGMT was to evaluate the suitability of the rat for the micronucleus test, with bone marrow and peripheral blood as the target organ. Since the rat spleen eliminates circulating micronucleated erythrocytes, a rat peripheral blood micronucleus assay might not be feasible. Thirty-four Japanese laboratories and six overseas laboratories participated in this collaboration, and 40 chemicals were studied. As a rule, rat bone marrow and peripheral blood were analyzed using acridine orange staining. Among 36 mouse micronucleus-positive rat carcinogens, 34 of which had been evaluated by CSGMT, we observed 33 positive and three negative results with rat bone marrow and 30 positive, three equivocal, and three negative responses with rat peripheral blood. Of the two mouse micronucleus-negative rat carcinogens, acrylonitrile was positive in rat bone marrow and 4,4′-methylene bis(2-chloroaniline) was negative in both rat bone marrow and peripheral blood. Two chemicals reported to be mouse micronucleus-negative and rat-positive, azobenzene and Solvent Yellow 14, and one chemical reported to be mouse-positive and rat-negative, 1,2-dimethylhydrazine, gave positive responses in rat bone marrow and peripheral blood. The concordance between bone marrow and peripheral blood with rats was 92%. The concordance between rat and mouse erythrocytes was 88%. We concluded that the rat micronucleus assay, using either bone marrow or peripheral blood, can be used as an alternative to the mouse micronucleus assay. Environ. Mol. Mutagen. 32:84–100, 1998. © 1998 Wiley-Liss, Inc.
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Whether radiofrequency (RF) fields are carcinogenic is controversial; epidemiological data have been inconclusive and animal tests limited. The aim of the present study was to determine whether long-term exposure to pulse-modulated RF fields similar to those used in digital mobile telecommunications would increase the incidence of lymphoma in E mu-Pim1 transgenic mice, which are moderately predisposed to develop lymphoma spontaneously. One hundred female E mu-Pim1 mice were sham-exposed and 101 were exposed for two 30-min periods per day for up to 18 months to plane-wave fields of 900 MHz with a pulse repetition frequency of 217 Hz and a pulse width of 0.6 ms. Incident power densities were 2.6-13 W/m2 and specific absorption rates were 0.008-4.2 W/kg, averaging 0.13-1.4 W/kg. Lymphoma risk was found to be significantly higher in the exposed mice than in the controls (OR = 2.4. P = 0.006, 95% CI = 1.3-4.5). Follicular lymphomas were the major contributor to the increased tumor incidence. Thus long-term intermittent exposure to RF fields can enhance the probability that mice carrying a lymphomagenic oncogene will develop lymphomas. We suggest that such genetically cancer-prone mice provide an experimental system for more detailed assessment of dose-response relationships for risk of cancer after RF-field exposure.
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In our laboratories we are conducting investigations of potential interactions between radio-frequency electromagnetic radiation (RFR) and chemicals that are toxic by different mechanisms to mammalian cells. The RFR is being tested at frequencies in the microwave range and at different power levels. We report here on the 1) ability of simultaneous RFR exposures to alter the distribution of cells in first and second mitoses from that after treatment by adriamycin alone, and 2) on the ability of simultaneous RFR exposure to alter the extent of sister chromatid exchanges (SCEs) induced by adriamycin alone. This chemical was selected because of its reported mechanism of action and because it is of interest in the treatment of cancer. In our studies, Chinese hamster ovary (CHO) cells were exposed for 2 h simultaneously to adriamycin and pulsed RFR at a frequency of 2,450 MHz and a specific absorption rate of 33.8 W/Kg. The maximal temperature (in the tissue-culture medium) was 39.7 +/- 0.2 degrees C. The experiments were controlled for chemical and RFR exposures, as well as for temperature. Verified statistically, the data indicate that the RFR did not affect changes in cell progression caused by adriamycin, and the RFR did not change the number of SCEs that were induced by the adriamycin, which adriamycin is known to affect cells by damaging their membranes and DNA.
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Unique sequences, chromosomal subregions, or entire genomes can be specifically highlighted in metaphase or interphase cells by fluorescence in situ hybridization (FISH). This technique can be used to identify chromosomes, detect chromosomal abnormalities or determine the chromosomal location of specific sequences. FISH plays an increasingly important role in a variety of research areas, including cytogenetics, prenatal diagnosis, tumor biology, gene amplification and gene mapping.