Article

Electromagnetic fields and DNA damage

April 2009
Pathophysiology 16(2-3):79-88

DOI:10.1016/j.pathophys.2008.11.005

Source
PubMed

Authors:

Jerry L. Phillips

University of Colorado Colorado Springs

Narendra Pal Singh

University of Washington Seattle

A major concern of the adverse effects of exposure to non-ionizing electromagnetic field (EMF) is cancer induction. Since the majority of cancers are initiated by damage to a cell's genome, studies have been carried out to investigate the effects of electromagnetic fields on DNA and chromosomal structure. Additionally, DNA damage can lead to changes in cellular functions and cell death. Single cell gel electrophoresis, also known as the 'comet assay', has been widely used in EMF research to determine DNA damage, reflected as single-strand breaks, double-strand breaks, and crosslinks. Studies have also been carried out to investigate chromosomal conformational changes and micronucleus formation in cells after exposure to EMF. This review describes the comet assay and its utility to qualitatively and quantitatively assess DNA damage, reviews studies that have investigated DNA strand breaks and other changes in DNA structure, and then discusses important lessons learned from our work in this area.

Methodology of Studying Effects of Mobile Phone Radiation on Organisms: Technical Aspects

Article

Full-text available

Nov 2021
Int J Environ Res Publ Health

The negative influence of non-ionizing electromagnetic radiation on organisms, including humans, has been discussed widely in recent years. This paper deals with the methodology of examining possible harmful effects of mobile phone radiation, focusing on in vivo and in vitro laboratory methods of investigation and evaluation and their main problems and difficulties. Basic experimental parameters are summarized and discussed, and recent large studies are also mentioned. For the laboratory experiments, accurate setting and description of dosimetry are essential; therefore, we give recommendations for the technical parameters of the experiments, especially for a well-defined source of radiation by Software Defined Radio.

Assessment of Genotoxicity in Human Cells Exposed to Modulated Electromagnetic Fields of Wireless Communication Devices

Article

Full-text available

Mar 2020

Modulated electromagnetic fields (wEMFs), as generated by modern communication technologies, have raised concerns about adverse health effects. The International Agency for Research on Cancer (IARC) classifies them as "possibly carcinogenic to humans" (Group 2B), yet, the underlying molecular mechanisms initiating and promoting tumorigenesis remain elusive. Here, we comprehensively assess the impact of technologically relevant wEMF modulations on the genome integrity of cultured human cells, investigating cell type-specificities as well as time- and dose-dependencies. Classical and advanced methodologies of genetic toxicology and DNA repair were applied, and key experiments were performed in two separate laboratories. Overall, we found no conclusive evidence for an induction of DNA damage nor for alterations of the DNA repair capacity in cells exposed to several wEMF modulations (i.e., GSM, UMTS, WiFi, and RFID). Previously reported observations of increased DNA damage after exposure of cells to GSM-modulated signals could not be reproduced. Experimental variables, presumably underlying the discrepant observations, were investigated and are discussed. On the basis of our data, we conclude that the possible carcinogenicity of wEMF modulations cannot be explained by an effect on genome integrity through direct DNA damage. However, we cannot exclude non-genotoxic, indirect, or secondary effects of wEMF exposure that may promote tumorigenesis in other ways.

Genotoxic Effects of Radiofrequency-Electromagnetic Fields

Article

Jun 2021

Osman Demirhan

Genotoxic Effects of Radiofrequency-Electromagnetic Fields. IntroductionRadiation is energy emission in the form of electromagnetic waves emitted from the solar system and natural resources on earth. The currents produced by the elementary particles formed by the electric current create the magnetic field. Earth's surface is under the influence of the geomagnetic field emanating from the sun. However, the outer liquid also has a magnetic field created as a result of heat transfer in the core. Therefore, all living organisms on earth live under the influence of electromagnetic fields (EMF). Today, besides these natural energy resources, rapidly developing technological developments provide most of the convenience in our lives and expose people to artificial electromagnetic fields. However, man's magnetic field is also under the influence of other natural and artificial magnetic fields around him. In particular, by ionizing radiation, which carries enough energy to break down the genetic material, die cells as a result of DNA damaging, and other diseases, especially cancer, can develop as a result of tissue damage. Electromagnetic Fields in Our LivesToday, apart from natural geomagnetic fields, radiation is emitted from many technological devices. The spectrum of these fields includes many different types of radiation, from subatomic radiation such as gamma and X-rays to radio waves, depending on their wavelengths. Though, as a result of the rapid increase of technological growth, the duration and amount of exposure to EMF is also steadily increasing. On the other hand, wireless gadgets such as computers, smartphones and medical radiological devices have become a necessity for humans. Almost everyone is exposed to radiofrequency electromagnetic fields (RF-EMF) from cell phone and base station antennas or other sources. Thus, the damage caused by the radiation to the environment affects living organisms even many kilometres away unlimitedly. All organisms in the world live under the influence of these negative environmental changes and a large part of the world population is exposed to radiofrequency (RF) radiation for a long time in their daily lives. So, though we are not aware of it, our organs and tissues are constantly exposed to radiation. Therefore, radiation adversely affects human, animal and plant health and disrupts the environment and ecological balance. An example of negative effects, radiation can cause genetic changes in the body (Figure 1). Radiation is divided into ionizing and non-ionizing. Ionizing radiations cause electron loss or gain in an atom or group of atoms in the medium they pass through. Thus, positively or negatively charged ions are formed. High energy X, gamma, ultraviolet and some visible rays in the ionized region of the electromagnetic spectrum can be counted. Since gamma rays, X rays and ultraviolet rays can ionize the molecules in living things more, they can easily disrupt the chemical structure of tissues, cells and DNA molecules in living organisms. Therefore, they can be very dangerous and deadly to living things. The energy of the waves in the non-ionizing region of the electromagnetic spectrum is low and the energy levels are insufficient for the ionization of molecules. Electricity, radio and TV waves, microwaves, and infrared rays are not ionizing because they have low energy. Waves emitted from electronic devices (cell phones, computers, microwave ovens, etc.) are absorbed by the human and animal body. The amount of energy absorbed by the unit biological tissue mass per unit time is called the specific absorption rate (SAR), and its unit is W/kg. Risks of Electromagnetic Fields on Living ThingsDepending on the structure of the tissues and organs, the radiation must reach a certain threshold dose for the effect to occur. Radiation levels below the threshold dose are not effective. Depending on the structure of the tissues and organs, the radiation must reach a certain threshold dose. The effects of small doses of waves are negligible. However, the clinical effects of waves above a certain threshold may increase. High dose waves can cause cell death in tissues. Damages in the cell may increase the risk of cancer and hereditary damage after a while, and somatic effects in people exposed to radiation may cause cancer to appear years later. There is much research on the effects of RF fields. In vitro and in vivo studies on rats, plants and different tissues of humans; suggests that the RF fields are not genotoxic and the fact that harmful effect is due to the heat effect. The contradictory results on this issue have brought about discussions. Therefore, there are still concerns about the potential adverse effects of RFR on human health. A good understanding of the biological effects of RF radiation will protect against potential damages. Due to these uncertainties, with the electromagnetic field project of the World Health Organization, experimental and modelling studies on the biological effects of RF radiation have been accelerated. In 2011, the International Agency for Research on Cancer decided that RF-EMR waves could be potentially carcinogenic to humans (2). Considering that almost everyone, including young children, uses mobile phones in addition to other technological devices, the danger of electromagnetic waves has increased social interest. Genotoxic Effects of EMFIn addition to stimulating apoptosis and changes in ion channels, RF-EMF waves also have a potential effect on genetic material. The radiation absorbed by organisms causes the ionization of target molecules. In particular, biological damage may occur as a result of stimulation/ionization of atoms and disruption of molecular structures while ionizing radiation passes through tissue. As a result of ionization in the cell, electron increases and free electrons cause damage, especially in macromolecules and DNA. Free electrons move directly or indirectly. Free electrons directly affect the phosphodiester or H-bonds of DNA. As a result, the phosphodiester bonds of DNA in the cell are broken, single or double-stranded breakages and chemical toxins increase. DNA double-strand breaks are the most relevant biologic damage induced by ionizing radiation (3,4). There are no cells that are resistant to radiation. The nucleus of the cell and especially the chromosomes in dividing cells are very sensitive to radiation. One of the most important effects of radiation on the cell is to suppress cell growth. In particular, growth is impaired in cells exposed to radiation during cell division (mitosis). Consequently, cells with a high division rate are more sensitive to radiation. DNA damage in somatic cells can lead to cancer development or cell death. Cell death can occur as a result of breaking down DNA because ionizing radiation has enough energy to break down the cell's genetic material. Thus, tissues are damaged and cancer development may be triggered. DNA damage caused by radiation in cells is repaired by metabolic repair processes. If the breaks in DNA as a result of DNA damage caused by radiation in cells are not too large, they can be repaired by metabolic repair processes. Still, errors may occur during this repair. Chromosomes containing different genetic codes and information may also occur. In the cell, the released electrons interact with water molecules, indirectly causing the water to be reactively divided into two parts. Free radicals carry an electron that is not electrically shared in their orbits. Free radicals can cause genetic damage in DNA such as nucleotide changes, double and single-strand breaks. Radiation can cause chromosomes to break, stick together and rearrange. All these changes can lead to mutations or even further, the death of the cell. However, in addition to ionizing radiation, extracellular genotoxic chemicals and intracellular oxidative metabolic residues can also create stress in cells during DNA replication and cell division. Damage may occur during DNA replication under such environmental stress conditions. To date, conflicting results have been reported regarding the genotoxic effects of RF-EMF waves on genetic material. It has been reported that the energy of low EM fields is not sufficient to break the chemical bonds of DNA, but the increase in exposure time is effective on the formation of oxygen radicals and the disruptions in the DNA repair process. The absorption of microwaves can cause significant local warming in cells. For example, an increase in temperature has been observed in cells in culture media exposed to waves of high SAR levels. However, there is evidence that reactive oxygen species are formed in cells indirectly and experimentally exposed to RF-EMF waves. Free oxygen radicals can create nucleotide entries in DNA as well as bind cellular components to DNA bases (5). The frequency of polymorphisms observed in DNA repair mechanism genes in children with acute leukaemia living close to high energy lines reveals the effect of this energy on the repair process. Significant evidence has been reported that genotoxic effects occur in various cell types when exposed to RF-EMF waves (6-10). Here, it has been reported that cells exposed to RF-EMF waves (1.800 MHz, SAR 2 W/kg) cause oxidative damage in mitochondrial DNA, DNA breaks in neurons and DNA breaks in amniotic cells (6,10). Similarly, the damage has been reported in lymphocytes exposed to various RF-EMF waves (8). However, exposure to RF-EMF waves is known to cause chromosome imbalance, changes in gene expression, and gene mutations. Such deleterious genetic effects have also been reported in neurons, blood lymphocytes, sperm, red blood cells, epithelial cells, hematopoietic tissue, lung cells, and bone marrow (1,11,12). It has been found that exposure to RF-EMF radiation also increases chromosome numerical aberrations (6,13). It has also been reported that increased chromosome separation in mouse oocytes exposed to EM and increased DNA fragmentation and apoptosis in fly egg cells (14,15). However, increased DNA breaks have been reported in the blastomeres of embryos of pregnant mice exposed to a frequency of 50 Hz, and a decrease in the number of blastocysts has been reported (16). Genetic damages to sex cells can lead to persistent genetic diseases in subsequent generations. Today, X-ray devices used for medical diagnosis have become one of the largest sources of radiation. These radiological procedures used for diagnosis constitute an important part of ionizing radiation. During these processes, the human body is visibly or invisibly affected by X-rays. As a matter of fact, X-rays have effects of disrupting the structure and biochemical activities of DNA, RNA, proteins and enzymes that are vital in the organism (17). Many studies on this subject have revealed that radiation has suppressive and mutational effects on DNA synthesis. These effects can cause serious damage to the cell as well as DNA and chromosome damage. In a recent study, chromosome damage was investigated in patients with X-ray angiography and personnel working in radiological procedures (18). Our findings showed that the beams used in interventional radiological procedures caused chromosomal damage and the rate of chromosomal abnormalities (CAs) increased significantly in patients after the procedure and this damage increased with the amount of radiation dose. Therefore, the radiation dose to be given to the patient should be chosen carefully. Besides, our findings showed that the frequency of CA is significantly higher in personnel working in radiological procedures. This reveals that interventional cardiologists are exposed to high radiation exposure. For this reason, we can say that the personnel working in radiological procedures (physician, health technician and nurse) are very likely to get diseases after years because they are exposed to low doses but long-term X-rays. Therefore, both the potential risks and safety of exposure to medical radiological devices must be continuously monitored. Furthermore, the fact that chromatid and chromosome breaks are very common among structural CAs in our findings suggests that they may be the cause of malignancy. Because, there are many cancer genes, tumour suppressor genes, enzyme genes involved in DNA repair and important genes or candidate genes responsible forapoptosis on these chromosomes. All this information shows that patients are more susceptible to DNA damage and inappropriate radiological examinations should be avoided. Therefore, X-ray and other diagnostic imaging techniques should not be applied unless necessary, and physicians and patients should be more careful in this regard. It has been reported that RF-EMR waves emitted from wireless communication device mobile phones have a genotoxic effect on human and mammalian cells (6,19). In a recent study; The effects of 900 and 1800 MHz cell phone frequencies on human chromosomes were investigated in amniotic cell cultures (6). Here, it has been reported that chromosome packing delays, damage and breaks occur in amniotic cells exposed to 900 and 1800 MHz every day at 3, 6 and 12 hours for twelve days. However, it was found that the frequency of 1800 MHz caused more CAs than 900 MHz, and the amount of damage increased with increasing usage time. These results confirm that GSM-like RF-EMR causes direct genotoxic effects in human in vitro cultures and has adverse effects on human chromosomes, and these effects increase in parallel with exposure time. This shows us that the mobile phone carries a risk for human health and these genetic damages can cause cancer. Therefore, necessary precautions should be taken for these harmful effects of mobile phones. Among these measures, the periods of mobile phone use should be kept short, especially the exposure of developing children and infants to mobile phones should be prevented, and avoiding excessive use of mobile phones may be one of the precautions against cancer. However, in order to evaluate it in more detail, the effects of mobile phones with environmental mutagens and/or carcinogens should be considered in subsequent researches. Conclusion Today, in parallel with the increasing technological developments, the demand of the society for electronic devices and phones and the frequency ranges of electronic devices are constantly increasing. Waves emitted from electronic devices are absorbed by human and animal bodies. Especially, the use of phones by contact with our body and the increase in usage time affects not only adults but also young children. Therefore, there is increasing concern in society about the negative biological effects of EM waves emitted from phones and other electronic devices. Results from all studies show that RF-EMF waves may be carcinogenic due to their genotoxic effect. Because cancer is a disease that occurs as a result of genetic damage. Considering these negative and harmful effects, regulations following international standards regarding the use of electronic devices should be made and society should be made aware of the risks.References Kim JH.; Lee K.; Kim HG.; Kim KB.; Kim HR. Possible Effects of Radiofrequency Electromagnetic Field Exposure on Central Nerve System. Biomol Ther. 2019, 27(3), 265-275. Baan R.; Grosse Y.; Lauby-Secretan B.; et al. WHO International Agency for Research on Cancer Monograph Working Group. Carcinogenicity of radiofrequency electromagnetic fields. Lancet Oncol. 2011, 12, 624–626. Berrington De Gonzalez A.; Darby S. Risk of cancer from diagnostic X-rays: estimates for the UK and 14 other countries. Lancet. 2004, 363, 345-351. Löbrich M.; Jeggo PA.The impact of a negligent G2/M checkpoint on genomic instability and cancer induction. Nat Rev Cancer. 2007, 861–869. M Valko.; M Izakovic.; M Mazur.; CJ Rhodes.; J Telser. Role of oxygen radicals in DNA damage and cancer incidence. Cell. Biochem. 2004, 266, 37–56. Uslu N.; Demirhan O.; Emre M.; Seydaoğlu G. The chromosomal effects of GSM-like electromagnetic radiation exposure on human fetal cells. Biomed Res Clin Prac. 2019, 4, 1-6. Lee S.; Johnson D.; Dunbar K Dong H.; Ge X.; Kim YC.; Wing C.; Jayathilaka N.; Emmanuel N.; Zhou CQ.; Gerber HL.; Tseng CC.; Wang SM. 2.45 GHz radiofrequency fields alter gene expression in cultured human cells. FEBS Lett. 2005, 579, 4829-4836. Phillips JL.; Singh NP.; Lai, H. Electromagnetic fields and DNA damage. Pathophysiology. 2009, 16, 79-88. Ruediger HW. Genotoxic effects of radiofrequency electromagnetic fields. Pathophysiology. 2009, 16, 89-102. Xu S.; Zhou Z.; Zhang L.; Yu Z.; Zhang W.; Wang Y.; Wang X.; Li M.; Chen Y.; Chen C.; He M.; Zhang G.; Zhong M. Exposure to 1800 MHz radiofrequency radiation induces oxidative damage to mitochondrial DNA in primary cultured neurons. Brain Res. 2010, 1311, 189-196. Demsia G.; Vlastos D.; Matthopoulos DP. Effect of 910-MHz electromagnetic field on rat bone marrow. 2004, 2, 48-54. Zhao TY.; Zou SP.; Knapp PE. Exposure to cell phone radiation up-regulates apoptosis genes in primary cultures of neurons and astrocytes. Lett. 2007, 412, 34-38. Mashevich M.; Folkman D.; Kesar A.; Barbul A.; Korenstein R.; Jerby E.; Avivi L. Exposure of human peripheral blood lymphocytes to electromagnetic fields associated with cellular phones leads to chromosomal instability. Bioelectromagnetics. 2003, 24, 82-90. Panagopoulos DJ.; Chavdoula ED.; Nezis IP.; Margaritis LH. Cell death induced by GSM 900-MHz and DCS 1800-MHz mobile telephony radiation. Mutat Res. 2007, 626(1–2), 69–78. Sagioglou NE.; Manta AK.; Giannarakis IK.; Skouroliakou AS.; Margaritis LH. Apoptotic cell death during Drosophila oogenesis is differentially increased by electromagnetic radiation depending on modulation, intensity and duration of exposure. Electromagn Biol Med. 2015, 1-14. Borhani N.; Rajaei F.; Salehi Z.; Javadi A. Analysis of DNA fragmentation in mouse embryos exposed to an extremely low-frequency electromagnetic field. Electromagn Biol Med. 2011, 30(4), 246–252. Rowley R.; Phillips EN.; Schroeder AL. Effects of ionizing radiation on DNA synthesis in eukaryotic cells. Int J Radiat Biol. 1999, 75( 3), 267-283. Çetinel N.; Demirhan O.; Demirtaş M.; Çağlıyan ÇE.; Cüreoğlu A.; Uslu IN.; Sertdemir Y. The Genotoxic Effect Of Interventional Cardiac Radiologic Procedures On Human Chromosomes. Clinical Medical Reviews and Reports. 2020, 3(1), 1-10. Aitken RJ.; Bennetts LE.; Sawyer D.; Wiklendt AM.; King BV. Impact of radio frequency electromagnetic radiation on DNA integrity in the male germline. Int J Androl. 2005, 28(3), 171–179.

Amyotrophic lateral sclerosis, occupational exposure to extremely low frequency magnetic fields and electric shocks: a systematic review and meta-analysis

Article

Full-text available

Sep 2023

Exposure to extremely low frequency magnetic fields (ELF-MF) and electric shocks occurs in many workplaces and occupations but it is unclear whether any of these exposures cause Amyotrophic lateral sclerosis (ALS). The aim of this systematic review and meta-analysis is to explore whether occupational exposure to ELF-MF and/or electric shocks are risk factor for ALS. We searched PubMed, Embase, and Web of Science databases up to the end of 2019. Pooled risk estimates were calculated using random-effects meta-analysis including exploration of the sources of heterogeneity between studies and publication bias. Twenty-seven publications fulfilled the inclusion criteria. We found a weak, significant, association between occupational exposure to ELF-MF and the risk of ALS (RR Pooled estimate : 1.20; 95%CI: 1.05, 1.38) with moderate to high heterogeneity (I 2 =66.3%) and indication of publication bias (P Egger's test =0.03). No association was observed between occupational exposure to electric shocks and risk of ALS (RR Pooled estimate : 0.97; 95%CI: 0.80, 1.17) with high heterogeneity (I 2 =80.5%), and little indication for publication bias (P Egger's test =0.24). The findings indicate that occupational exposure to ELF-MF, but not electric shocks, might be a risk factor for ALS. However, given the moderate to high heterogeneity and potential publication bias, the results should be interpreted with caution.

Influence of Knitting Structure and Metal Wire Amount on Electromagnetic Shielding Effectiveness of Knitted Fabrics

Article

Oct 2022
TEKST KONFEKSIYON

The aim of this study is to investigate the influence of knitting structure and metal wire amount on the electromagnetic shielding effectiveness (EMSE) of knitted fabrics comparatively. Single jersey, single pique, weft locknit, and cross miss fabrics involving stainless steel or copper wires were produced on a flat knitting machine. A free space measurement technique was used for the EMSE measurements in an anechoic chamber. The variance analysis results of the EMSE values reveal that the effect of knitting structure, metal wire type, metal wire amount, and incident wave frequency is highly significant. It was observed that fabrics with tuck and miss loop structures had higher EMSE values than single jersey fabrics. It was found that single pique fabrics had higher EMSE values than single jersey fabrics that contain twice as much metal wire. It indicates that changing the knitting structure is more effective than changing the metal wire amount.

Immunotoxicity of radiofrequency radiation

Article

Jul 2022
ENVIRON POLLUT

Growing evidence recommends that radiofrequency radiations might be a new type of environmental pollutant. The consequences of RFR on the human immune system have gained considerable interest in recent years, not only to examine probable negative effects on health but also to understand if RFR can modulate the immune response positively. Although several studies have been published on the immune effects of RFR but no satisfactory agreement has been reached. Hence this review aims to evaluate the RFR modulating impacts on particular immune cells contributing to various innate or adaptive immune responses. In view of existing pieces of evidence, we have suggested an intracellular signaling cascade responsible for RFR action. The bio-effects of RFR on immune cell morphology, viability, proliferation, genome integrity, and immune functions such as ROS, cytokine secretion, phagocytosis, apoptosis, etc. are discussed. The majority of existing evidence point toward the possible shifts in the activity, number, and/or function of immunocompetent cells, but the outcome of several studies is still contradictory and needs further studies to reach a conclusion. Also, the direct association of experimental studies to human risks might not be helpful as exposure parameters vary in real life. On the basis of recent available literature, we suggest that special experiments should be designed to test each particular signal utilized in communication technologies to rule out the hypothesis that longer exposure to RFR emitting devices would affect the immunity by inducing genotoxic effects in human immune cells.

Compact Exposimeter Device for the Characterization and Re- cording of Electromagnetic Fields from 78 MHz to 6 GHz with Several Narrow Bands (300 kHz)

Article

Full-text available

Nov 2021
SENSORS-BASEL

A novel compact device with spectrum analyzer characteristics has been designed, which allows the measuring of the maximum power received in multiple narrow frequency bands of 300 kHz, recording the entire spectrum from 78 MHz to 6 GHz; the device is capable of measuring the entire communications spectrum and detecting multiple sources of electromagnetic fields using the same communications band. The proposed device permits the evaluation of the cross-talk effect that, in conventional exposimeters, generates a mistake estimation of electromagnetic fields. The device was calibrated in an anechoic chamber for far-fields and was validated against a portable spectrum analyzer in a residential area. A strong correlation between the two devices with a confidence higher than 95% was obtained; indicating that the device could be considered as an important tool for electromagnetic field studies.

Brain magnetic resonance imaging without contrast significantly increased serum levels of IL-6, but not IL-10, IL-17A and TGF-β

Article

Sep 2021

Introduction: Magnetic Resonance Imaging (MRI) is a non-invasive imaging modality. However, the effects of MRI on the immune system in the in vivo conditions are yet to be clarified. In this study we explored the effects of routine brain MRI on the protein and mRNA peripheral blood levels of interleukin-6 (IL-6), IL-10, IL-17A and transforming growth factor-beta (TGF-β). Material and methods: 40 subjects, who referred for brain MRI, were entered for evaluating effects of routine brain MRI on the protein and mRNA peripheral blood levels of IL-6, IL-10, IL-17A and TGF-β. Accordingly, peripheral blood were collected before and 3 hours after MRI from the participants. Protein levels of the cytokines were evaluated using ELISA. Also, mRNA levels were analyzed using Real-Time PCR techniques. Results: Brain MRI without contrast led to an increase in protein levels of IL-6 in the peripheral serum, but did not change protein and mRNA levels of IL-10, IL-17A and TGF-β. IL-6 mRNA levels after MRI were higher in the participants with mild anxiety compared to those without anxiety. Conclusion: brain MRI without contrast can induce secretion of IL-6 and may be associated with its functions, such as development of plasma cells or induction of inflammation.

Development of health-based exposure limits for radiofrequency radiation from wireless devices using a benchmark dose approach

Article

Full-text available

Jul 2021
ENVIRON HEALTH-GLOB

Background Epidemiological studies and research on laboratory animals link radiofrequency radiation (RFR) with impacts on the heart, brain, and other organs. Data from the large-scale animal studies conducted by the U.S. National Toxicology Program (NTP) and the Ramazzini Institute support the need for updated health-based guidelines for general population RFR exposure. Objectives The development of RFR exposure limits expressed in whole-body Specific Absorption Rate (SAR), a metric of RFR energy absorbed by biological tissues. Methods Using frequentist and Bayesian averaging modeling of non-neoplastic lesion incidence data from the NTP study, we calculated the benchmark doses (BMD) that elicited a 10% response above background (BMD 10 ) and the lower confidence limits on the BMD at 10% extra risk (BMDL 10 ). Incidence data for individual neoplasms and combined tumor incidence were modeled for 5% and 10% response above background. Results Cardiomyopathy and increased risk of neoplasms in male rats were the most sensitive health outcomes following RFR exposures at 900 MHz frequency with Code Division Multiple Access (CDMA) and Global System for Mobile Communications (GSM) modulations. BMDL 10 for all sites cardiomyopathy in male rats following 19 weeks of exposure, calculated with Bayesian model averaging, corresponded to 0.27–0.42 W/kg whole-body SAR for CDMA and 0.20–0.29 W/kg for GSM modulation. BMDL 10 for right ventricle cardiomyopathy in female rats following 2 years of exposure corresponded to 2.7–5.16 W/kg whole-body SAR for CDMA and 1.91–2.18 W/kg for GSM modulation. For multi-site tumor modeling using the multistage cancer model with a 5% extra risk, BMDL 5 in male rats corresponded to 0.31 W/kg for CDMA and 0.21 W/kg for GSM modulation. Conclusion BMDL 10 range of 0.2—0.4 W/kg for all sites cardiomyopathy in male rats was selected as a point of departure. Applying two ten-fold safety factors for interspecies and intraspecies variability, we derived a whole-body SAR limit of 2 to 4 mW/kg, an exposure level that is 20–40-fold lower than the legally permissible level of 0.08 W/kg for whole-body SAR under the current U.S. regulations. Use of an additional ten-fold children’s health safety factor points to a whole-body SAR limit of 0.2–0.4 mW/kg for young children.

Temporal recovery of soil biological activity and diversity after 915-MHz microwave treatments

Article

Full-text available

Jul 2021
BIOL FERT SOILS

Two 915-MHz microwave treatments (2 kW-8 min and 4 kW-4 min) were applied to soil and their effects were monitored just after treatments (T0) and 26 days (T26) in soil microcosms. Densities of culturable bacteria, fluorescent pseudomonads and nematodes, hydrolysis activity and soil DNA content declined by over 50% immediately after both microwave treatments (T0), excluding the total fungal 18S rRNA (−13 or −17%) and bacterial 16S rRNA copies (non-significant). A rapid shift in bacterial community composition occurred from T0 towards a large increase in the relative abundance of Firmicutes (+1650%) and a concomitant decrease in various phyla (e.g. Acidobacteria, Actinobacteria, Bacteroidetes, Proteobacteria) from −85 to −61%. At T26 and for both treatments, fluorescein diacetate hydrolysis, density of culturable bacteria, 18S rRNA gene numbers, Simpson diversity, relative abundances of Bacteroidetes and Proteobacteria regained levels similar to controls. Alpha, Delta and Gamma classes Proteobacteria also end up reaching a similar level. In contrast, fluorescent pseudomonad density, nematode diversity and abundance, soil DNA content and relative abundances of some phylum (Acidobacteria, Actinobacteria, Chloroflexi) did not increase in such proportions. Most of the soil biological properties have not been permanently impacted. Nevertheless, the recovery kinetics highly differed according properties, with resilience indices at T26 varying from −87 to +99%.

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

Article

Feb 2021

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.

Effects of Electromagnetic Waves with LTE and 5G Bandwidth on the Skin Pigmentation In Vitro

Article

Full-text available

Dec 2020
INT J MOL SCI

With the rapid growth of wireless communication devices, the influences of electromagnetic fields (EMF) on human health are gathering increasing attention. Since the skin is the largest organ of the body and is located at the outermost layer, it is considered a major target for the health effects of EMF. Skin pigmentation represents one of the most frequent symptoms caused by various non-ionizing radiations, including ultraviolet radiation, blue light, infrared, and extremely low frequency (ELF). Here, we investigated the effects of EMFs with long-term evolution (LTE, 1.762 GHz) and 5G (28 GHz) bandwidth on skin pigmentation in vitro. Murine and Human melanoma cells (B16F10 and MNT-1) were exposed to either LTE or 5G for 4 h per day, which is considered the upper bound of average smartphone use time. It was shown that neither LTE nor 5G exposure induced significant effects on cell viability or pigmentation. The dendrites of MNT-1 were neither lengthened nor regressed after EMF exposure. Skin pigmentation effects of EMFs were further examined in the human keratinocyte cell line (MNT-1-HaCaT) co-culture system, which confirmed the absence of significant hyper-pigmentation effects of LTE and 5G EMFs. Lastly, MelanoDerm™, a 3D pigmented human epidermis model, was irradiated with LTE (1.762 GHz) or 5G (28 GHz), and image analysis and special staining were performed. No changes in the brightness of MelanoDerm™ tissues were observed in LTE- or 5G-exposed tissues, except for only minimal changes in the size of melanocytes. Collectively, these results imply that exposure to LTE and 5G EMFs may not affect melanin synthesis or skin pigmentation under normal smartphone use condition.

A Study on the Effects of Cellular Mobile Networks on People in Tikrit City Based on Power Density Measurements and Calculations

Article

Full-text available

Jun 2019

In this paper, the emitted electromagnetic waves (EMW) from different cellular mobile base stations (BSs) have been measured and calculated in order to study their effects on public health. Moreover, a comparison between the effect of radiated power from the BSs on people who live near them and those who live away has been made by using OpenSignal software and calculated theoretically. The values of power density for different cells were also calculated to compare them with the maximum permissible exposure limit-the acceptable range values of power density. The measurements were done in Tikrit City considering ten cells and various locations and distances. The results show that most of the power density and EMV for the tested cells are within the acceptable range. However, power density and EMV for two of tested cells have hurtful effects in the long term for people who live near the BSs.

Comparing chromosome damage induced by mobile telephony radiation and a high caffeine dose: Effect of combination and exposure duration

Article

Full-text available

Nov 2020
GEN PHYSIOL BIOPHYS

Dimitris J. Panagopoulos

I recently reported induction of chromatid-type aberrations in human peripheral blood lymphocytes after a single 15 min exposure to Universal Mobile Telecommunications System (UMTS) Mobile Telephony (MT) electromagnetic field (EMF) from a mobile phone. Lymphocytes from six healthy subjects were stimulated for mitosis, and exposed during the G2/M phase at 1 cm distance from the handset during an active phone call in “talk” mode (Panagopoulos 2019a). The same type of cells from the same subjects treated with a high caffeine dose (~290 times above the permissible single dose for an adult human) exhibited the same type of aberrations in a little smaller but comparable degree. The combination of this caffeine dose and the 15 min MT EMF exposure increased dramatically the number of aberrations in all subjects. The combined effect increased almost linearly with increasing duration of exposure to the MT EMF. Thus, MT EMF exposure ~136 times below the official limit (ICNIRP 2020) exerts a genotoxic action even greater than that of a caffeine dose ~290 times above the corresponding limit. Therefore, with a reasonable approximation, the limit for MT EMFs should be lowered by at least 40000 times (136x290) for short-term exposures, and 4000000 times for long-term exposures.

The assessment of electromagnetic fields-caused genetic diversity of Tea Camellia sinensis L. using ISSR and SCoT markers

Article

Sep 2020
Rev Bras Botânica

The effects of electromagnetic fields on plants have been studied during the last decades. The electromagnetic fields as abiotic stress can induce genetic variation in living organisms including plants by different mechanisms. The aim of the present study is to assay the possible electromagnetic fields-caused genetic diversity of Tea Camellia sinensis L. which is known as favorite herbal beverages by many biochemical constituents. To do so, intersimple sequence repeats (ISSR) and start codon targeted (SCoT) loci were used as molecular markers. Different electromagnetic field treatments by 1, 2, 4 and 6 mT of intensity, for 30 and 60 min per day, for 7 continuous days were imposed, following by DNA extraction and PCR amplification. AMOVA, PCoA and STRUCTURE analysis based on the ISSR and SCoT markers showed that regardless of the EMFs intensity, 30 min of radiation causes more genetic variation than that of 60 min does until the intensity was increased up to 6 mT, due to direct and indirect mechanisms such as guanine modification, methylation of cytosines, Fenton reaction and direct DNA strands breaking. ISSR sequences, however, underwent more variation than SCoT.

Morphological and cytophysiological changes in selected lines of normal and cancer human cells under the influence of a radio-frequency electromagnetic field

Article

Full-text available

Mar 2020

Introduction: Currently, mobile phones and Wi-Fi are the most commonly used forms of telecommunication. The popularity of mobile telecommunications has made it necessary to investigate the problem more comprehensively and cautiously assess the possible risks, because never before in history has such a substantial proportion of the population been exposed to microwaves at comparably high levels. Some studies indicate that the high frequency electromagnetic radiation emitted by mobile phone and Wi-Fi connections can have a negative effect on human health, and can cause cancer. Objective: The aim of the study was to investigate the influence of the radiofrquency electromagnetic field (RF-EMF) on the metaboloc activity and morphology of normal human cells (fibroblasts) and cancer cells (prostate cancer cells). Material and methods: The cell cultures (human fibroblasts and prostate cancer cells) were exposed to RF-EMF at the frequency of 2.5 GHz for 24, 48 and 72h. To quantify changes in cell viability, the Cell Counting Kit - 8 was used. Results: It was found that the RF electromagnetic field exposure caused a significant decrease in the viability of fibroblasts, and a significant increase in cancer cells. Morphological analysis did not show significant changes in both cell lines after exposure to RF-EMF. Conclusions: On the basis of the obtained results, the hypothesis can be formulated that a high frequency electromagnetic field can have harmful effects on human cells.

Multifunctional Stretchable Conductive Woven Fabric Containing Metal Wire with Durable Structural Stability and Electromagnetic Shielding in the X-Band

Article

Full-text available

Feb 2020

Elastomeric, conductive composite yarns have recently received attention around the opportunity for them to offer special protective fields. A straightforward approach for fabricating tri-component elastic-conductive composite yarns (t-ECCYs) containing stainless steel wire (SSW) was proposed previously. This work mainly focuses on the electromagnetic shielding effectiveness (EMSE) of weft-stretchable woven fabric containing t-ECCY over the X-band under different testing conditions, e.g., single step-by-step elongation, cyclic stretch and lamination events. Results showed that a woven cotton fabric with weft yarn of t-ECCY not only exhibited superior weft stretch-ability to a higher elongation (>40%) compared with a pure cotton control but also had an acceptable 15-cyclic stability with 80% shape recovery retention. The t-ECCY weft fabric was effective in shielding electromagnetic radiation, and its EMSE was also enhanced at elevated elongations during stretch at parallel polarization of EM waves. There was also no decay in EMSE before and after the t-ECCY fabric was subject to 15 stretch cycles at extension of 20%. In addition, a 90° by 90° cross lamination of t-ECCY fabric remarkably improved the EMSE compared to a 0°/90° one. The scalable fabrication strategy and excellent EMSE seen in t-ECCY-incorporated fabrics represent a significant step forward in protective fields.

Mechanisms of Environmental and Occupational Carcinogenesis

Chapter

Feb 2020

Carcinogenesis is a complex, multistep process, involving accumulation of genetic and epigenetic alterations that confer a growth and/or survival advantage, through which cells gradually achieve unchecked growth and eventually become fully malignant and invasive. There are numerous sources of physical, chemical, and biological exposures that stem from endogenous and exogenous sources—including occupational settings—that can induce such genetic and epigenetic alterations. This damage is repaired through a high-fidelity DNA repair process that operates through multiple pathways, although the system is imperfect and varies by repair mechanism, potentially resulting in incorporation of DNA damage and epigenetic alterations. This chapter provides an introduction to mechanisms of environmental and occupational carcinogenesis and DNA repair, and provides examples of physical and chemical carcinogens and epigenetic effectors.

Effect of low-frequency electric field screening on motility of human sperm

Article

Full-text available

Jan 2020

Introduction: The human body is constantly exposed to an extremely low electromagnetic field (ELF-EMF), in particular at 50 Hz, emitted by power lines, domestic distribution lines, electrical appliances, etc. It is assumed that the increase in electromagnetic exposure may cause adverse effects upon human health, as well as raising concerns regarding the impact on human fertility. Objective: The aim of this in vitro study was to investigate the influence of ELF-EMF with a frequency of 50 Hz on the motility of human sperm. At the same time, the effectiveness of the dielectric screen constructed by ADR Technology ® in absorbing the emitted radiation was examined. Material and methods: Semen samples of 20 patients were exposed to the influence of an extremely low electromagnetic field. After 5, 15 and 30 min., spermatozoa motility was analysed using a computer-assisted spermatozoa motility analysis system. The following sperm motility parameters were examined: 1) velocity straight linear motility; 2) cross-beat frequency; 3) lateral head displacement; 4) homogeneity of progressive motility velocity. Results: It was found that the ELF-EMF presented a negative effect on the motility of human spermatozoa. A significant decrease in spermatozoa motility speed and a significant increase in lateral head deviation values were observed under the influence of the electromagnetic field. ELF-EMF did not show an effect on either lateral head displacement or homogeneity of progressive motility velocity. Conclusions: A positive effect of the dielectric screen ADR Technology® was found. This effect compensated spermatozoa motility changes induced with ELF-EMF.

Specific Absorption Rate Variability in Long Term Exposure In Vivo Experiments

Conference Paper

Full-text available

Mar 2023

Elektromanyetik Radyasyonun (2.45 GHz) Lenfosit DNA Hasarına ve Hematolojik Parametrelere Etkisi: Vitamin C'nin Koruyucu RolüEffect of Electromagnetic Radiation (2.45 GHz) on Lymphocyte DNA Damage and Hematological Parameters: The Protective Role of Vitamin C

Article

Apr 2023

Amaç: Bu çalışmanın amacı, kanda hematolojik ve biyokimyasal değişikliklere neden olabilen 2.45 GHz elektromanyetik radyasyonun (EMR) etkilerini araştırmaktır. EMR maruziyetinin etkilerine karşı koruyucu özelliği olan Vitamin C'yi (Vit C) tercih ettik. Materyal-Metot: Bu çalışma için 18 dişi Sprague Dawley sıçanı rastgele her birinde altı hayvan bulunan üç gruba ayrıldı: Kontrol, EMR ve EMR+Vit C grupları. Kontrol grubu: gavaj ile 30 gün boyunca 0.1 ml/gün salin; EMR grubu: EMR, 30 gün boyunca 1 saat/gün; EMR+Vit C grubu: EMR, 30 gün boyunca 1 saat/gün C vitamini 250 mg/kg/gün, gavaj ile. Beyaz Kan Hücresi (WBC), Nötrofil, Lenfosit, Monosit, Eozinofil, Bazofil, Kırmızı Kan Hücresi (RBC), Hemoglobin (Hb), Hematokrit (Htc), Ortalama Eritrosit Hacmi (MCV), Kırmızı Hücre Dağılım Genişliği-SD (RDW- SD), Kırmızı Hücre Dağılım Genişliği-CV (RDW-CV), Trombosit (PLT), Ortalama Trombosit Hacmi (MPV), Trombosit Dağılım Genişliği (PDW), Trombosit Krit (PCT) ve Trombosit Büyük Hücre Oranı (P-LCR) sayıları ölçülmüştür. Comet testi ile lenfosit DNA hasarı değerlendirildi, ayrıca malondialdehit (MDA) seviyesi ve katalaz (CAT) aktivitesi değerlendirildi. Bulgular: Comet analiz skoru ve P-LCR sayıları EMR grubunda Kontrol grubuna göre arttı (p<0,05). C vitamini tedavisi sonrası comet analiz skorunda ve P-LCR sayılarında EMR grubuna göre azalma gözlemledik (p<0,05). Sonuç: Sonuçlar, bir cep telefonu tarafından üretilen frekansta EMR'nin lenfosit DNA kırılmasına neden olduğunu ve P-LCR seviyesini artırdığını göstermektedir. C vitamini, EMF maruziyetinin neden olduğu lenfosit DNA hasarını ve P-LCR seviyesini azaltıyor gibi görünmektedir.

The effect of electromagnetic waves of mobile phones on DNA, RNA content and kidney function in rats before, during and after pregnancy and their offspring

Article

Full-text available

Oct 2022

Increasing use of mobile phones in daily life with increasing adverse effects of electromagnetic radiation cause many concerns about their effects on human health. This study was designed to investigate the effect of exposure to a 900-MHz electromagnetic waves (EMW) produced by mobile phones on nucleic acids (DNA and RNA), protein content, kidney function (levels of urea and creatinine) and oxidative stress (malondialdehyde, MDA level) in rats before, during and after pregnancy periods and their offspring. A total of 32 Wistar albino female rats were divided into 4 equal groups (8 each): 1- unexposed (control group); 2- pre-pregnancy (2 h/d for 21 d) EMW-exposed group; 3- during pregnancy (2 h/d for 21 d) EMW-exposed group; 4- during and after pregnancy (2 h/d for each period) EMW-exposed group. Dams, new born and young rats (40-50 g) of all groups were sacrificed and kidney tissues were harvested for determination of parameters under investigation. A high significant decrease in DNA, RNA and protein levels were found of all periods in exposed groups compared to control. No difference in protein, DNA and RNA content in new born and young rats of pre-pregnancy EMW exposed rats, however these parameters were increased significantly in new born and young rats of both during and during and after pregnancy exposed groups compared to control. There was no difference in new born kidney function and oxidative stress of all exposed groups compared to control. However, these parameters were increased significantly in young rats of both during and during and after pregnancy exposed groups as well in all exposed groups compared to control. In conclusion, the EMW propagated from mobile phones have harmful effects on DNA, RNA and protein content as well kidney function and oxidative stress of exposed rats and their offspring. Therefore, people may use various antioxidants and avoid exposure to EMW for a long periods to prevent the potential adverse effects of exposure to EMW.

Biological Effects On Radio Frequency Smog

Article

Full-text available

May 2022

Why electrohypersensitivity and related symptoms are caused by non-ionizing man-made electromagnetic fields: An overview and medical assessment

Article

May 2022
ENVIRON RES

Much of the controversy over the cause of electrohypersensitivity (EHS) lies in the absence of recognized clinical and biological criteria for a widely accepted diagnosis. However, there are presently sufficient data for EHS to be acknowledged as a distinctly well-defined and objectively characterized neurologic pathological disorder. Because we have shown that 1) EHS is frequently associated with multiple chemical sensitivity (MCS) in EHS patients, and 2) that both individualized disorders share a common pathophysiological mechanism for symptom occurrence; it appears that EHS and MCS can be identified as a unique neurologic syndrome, regardless its causal origin. In this overview we distinguish the etiology of EHS itself from the environmental causes that trigger pathophysiological changes and clinical symptoms after EHS has occurred. Contrary to present scientifically unfounded claims, we indubitably refute the hypothesis of a nocebo effect to explain the genesis of EHS and its presentation. We as well refute the erroneous concept that EHS could be reduced to a vague and unproven “functional impairment”. To the contrary, we show here there are objective pathophysiological changes and health effects induced by electromagnetic field (EMF) exposure in EHS patients and most of all in healthy subjects, meaning that excessive non-thermal anthropogenic EMFs are strongly noxious for health. In this overview and medical assessment we focus on the effects of extremely low frequencies, wireless communications radiofrequencies and microwaves EMF. We discuss how to better define and characterize EHS. Taken into consideration the WHO proposed causality criteria, we show that EHS is in fact causally associated with increased exposure to man-made EMF, and in some cases to marketed environmental chemicals. We therefore appeal to all governments and international health institutions, particularly the WHO, to urgently consider the growing EHS-associated pandemic plague, and to acknowledge EHS as a new real EMF causally-related pathology.

AI-enabled, implantable, multichannel wireless telemetry for photodynamic therapy

Article

Full-text available

Apr 2022

Photodynamic therapy (PDT) offers several advantages for treating cancers, but its efficacy is highly dependent on light delivery to activate a photosensitizer. Advances in wireless technologies enable remote delivery of light to tumors, but suffer from key limitations, including low levels of tissue penetration and photosensitizer activation. Here, we introduce Dee-pLabCut (DLC)-informed low-power wireless telemetry with an integrated thermal/light simulation platform that overcomes the above constraints. The simulator produces an optimized combination of wavelengths and light sources, and DLC-assisted wireless telemetry uses the parameters from the simulator to enable adequate illumination of tumors through high-throughput (<20 mice) and multi-wavelength operation. Together, they establish a range of guidelines for effective PDT regimen design. In vivo Hypericin and Foscan mediated PDT, using cancer xenograft models, demonstrates substantial suppression of tumor growth, warranting further investigation in research and/or clinical settings.

2012-2018 - Peer Reviewed Published Research Studies On Wi-Fi And 2.4 GHz Wireless Frequencies

Book

Full-text available

Oct 2018

Eric John Horsfield

2012-2018 - Peer Reviewed Published Research Studies On Wi-Fi And 2.4 GHz Wireless Frequencies

Human‑made electromagnetic fields: Ion forced‑oscillation and voltage‑gated ion channel dysfunction, oxidative stress and DNA damage (Review)

Article

Full-text available

Oct 2021

Exposure of animals/biological samples to human‑made electromagnetic fields (EMFs), especially in the extremely low frequency (ELF) band, and the microwave/radio frequency (RF) band which is always combined with ELF, may lead to DNA damage. DNA damage is connected with cell death, infertility and other pathologies, including cancer. ELF exposure from high‑voltage power lines and complex RF exposure from wireless communication antennas/devices are linked to increased cancer risk. Almost all human‑made RF EMFs include ELF components in the form of modulation, pulsing and random variability. Thus, in addition to polarization and coherence, the existence of ELFs is a common feature of almost all human‑made EMFs. The present study reviews the DNA damage and related effects induced by human‑made EMFs. The ion forced‑oscillation mechanism for irregular gating of voltage‑gated ion channels on cell membranes by polarized/coherent EMFs is extensively described. Dysfunction of ion channels disrupts intracellular ionic concentrations, which determine the cell's electrochemical balance and homeostasis. The present study shows how this can result in DNA damage through reactive oxygen species/free radical overproduction. Thus, a complete picture is provided of how human‑made EMF exposure may indeed lead to DNA damage and related pathologies, including cancer. Moreover, it is suggested that the non‑thermal biological effects attributed to RF EMFs are actually due to their ELF components.

Effects of excessive use of mobile phone technology in India on human health during COVID-19 lockdown

Article

Full-text available

Nov 2021
Tech Soc

Objective: The global health crisis in the form of COVID-19 has forced people to shift their routine activities into a remote environment with the help of technology. The outbreak of the COVID-19 has caused several organizations to be shut down and forced them to initiate work from home employing technology. Now more than ever, it's important for people and institutions to understand the impact of excessive use of mobile phone technology and electronic gadgets on human health, cognition, and behavior. It is important to understand their perspective and how individuals are coping with this challenge in the wake of the COVID-19 pandemic. The investigation is an effort to answer the research question: whether dependency on technology during lockdown has more effects on human health in comparison to normal times. Methods: The study included participants from India (n = 122). A questionnaire was framed and the mode of conducting the survey chosen was online to maintain social distancing during the time of the Pandemic. The gathered data was statistically analysed employing RStudio and multiple regression techniques. Results: The statistical analysis confirms that lockdown scenarios have led to an increase in the usage of mobile phone technology which has been confirmed by around 90% of participants. Moreover, 95% of the participants perceive an increased risk of developing certain health problems due to excessive usage of mobile phones and technology. It has been evaluated that participants under the age group 15-30 years are highly affected (45.9%) during lockdown due to excessive dependence on technology. And, amongst different professions, participants involved in online teaching-learning are the most affected (42.6%). Conclusion: The findings indicate that dependency on technology during lockdown has more health effects as compared to normal times. So, it is suggested that as more waves of pandemics are being predicted, strategies should be planned to decrease the psychological and physiological effects of the overuse of technology during lockdown due to pandemics. As the lockdown situation unfolds, people and organization functioning styles should be rolled back to the limited dependency on technology.

Inactivation of antibiotic resistant bacterium Escherichia coli by electrochemical disinfection on molybdenum carbide electrode

Article

Sep 2021
CHEMOSPHERE

Antibiotic-resistant bacteria (ARB) pose a substantial threat to public health worldwide. Electrochemistry, as a low energy consumption and environmentally friendly technique, is ideal for inactivating ARB. This study explored the utility of electrochemical disinfection (ED) for inactivating ARB (Escherichia coli K-12 LE392 resistant to kanamycin, tetracycline, and ampicillin) and the regrowth potential of the treated ARB. The results revealed that 5.12-log ARB removal was achieved within 30 min of applying molybdenum carbide as the anode and cathode material under a voltage of 2.0 V. No ARB regrowth was observed in the cathode chamber after 60 min of incubation in unselective broth, demonstrating that the process in the cathode chamber was more effective for permanent inactivation of ARB. The mechanisms underlying the ARB inactivation were verified based on intercellular reactive oxygen species (ROS) measurement, membrane integrity detection, and genetic damage assessment. Higher ROS production and membrane permeability were observed in the cathode and anode groups (p < 0.001) compared to the control group (0 V). In addition, the DNA was more likely to be damaged during the ED process. Collectively, our results demonstrate that ED is a promising technology for disinfecting water to prevent the spread of ARB.

Electromagnetic Field Mobile Phone Radiation Toxicity

Chapter

Jan 2022

Over the last decade, the exponential growth of mobile communication has been accompanied by a parallel increase in density of electromagnetic fields (EMF). The continued expansion of mobile phone usage raises important questions as EMF, especially radio frequency (RF), have long been suspected of having biological effects. Because mobile phones and other wireless gadgets are held close to the body and are also used very frequently, these devices are potentially the most dangerous sources of EM radiation. This gave rise to an increasing concern for any unknown effects that may prove to be detrimental to human health.

Oxidative Stress and NADPH Oxidase: Connecting Electromagnetic Fields, Cation Channels and Biological Effects

Article

Full-text available

Sep 2021
INT J MOL SCI

Electromagnetic fields (EMFs) disrupt the electrochemical balance of biological membranes, thereby causing abnormal cation movement and deterioration of the function of membrane voltage-gated ion channels. These can trigger an increase of oxidative stress (OS) and the impairment of all cellular functions, including DNA damage and subsequent carcinogenesis. In this review we focus on the main mechanisms of OS generation by EMF-sensitized NADPH oxidase (NOX), the involved OS biochemistry, and the associated key biological effects.

Germicidal efficacy of the pulsed magnetic field against pathogens and spoilage microorganisms in food processing: An overview

Article

Aug 2021
FOOD CONTROL

In addition to excessive use of chemical and physical antiseptics in food, any harmful microorganisms present in food are potentially the cause of food safety issues and even cause foodborne diseases to threaten human health. Thermal processing of food as a conventional sterilization technology has been widely used in the food industry to ensure food safety. However, heat treatment has some inevitable adverse effects on nutrition, flavor, color, texture, and aesthetics of the food products. Therefore, it is necessary to research novel nonthermal, green technologies to minimize the impact of undesirable changes on food, and enhance the inactivation efficiency of microorganisms that can cause foodborne illnesses. This review presents a general perspective of the pulsed magnetic field (PMF) as a novel nonthermal sterilization technology. The operating principle, characteristics, and biological effects on microorganisms of PMF are described. Furthermore, the possible inactivation mechanisms and their application in food processing are also addressed. PMF sterilization is considered to be an effective and efficient microorganism eliminating technology that exerts its germicidal ability by magnetoporation and electromagnetic effects, mainly including induced current effect, Lorentz force effect, oscillation effect, and ionization effect. Compared to thermal treatment, PMF sterilization technique meets the requirements of commercial food sterilization standards without impacting food flavor, taste, and texture. The findings of our review suggest that PMF itself would be beneficial as a bacteria inactivation technique or could be readily combined with other suitable methods. Besides, we recommend conceivable paths to adopt this sustainable technique in the food industry.

The Effect of Contrast Enhanced Abdominopelvic Magnetic Resonance Imaging on Expression and Methylation Level of ATM and AKT Genes

Article

Full-text available

Aug 2021

Objective: To evaluate the effect of contrast enhanced abdominopelvic magnetic resonance imaging (MRI), using a 3 Tesla scanner, on expression and methylation level of ATM and AKT genes in human peripheral blood lymphocytes. Materials and methods: In this prospective in vivo study, blood samples were obtained from 20 volunteer patients with mean age of 43 ± 8 years (range 32-68 years) before contrast enhanced MRI, 2 hours and 24 hours after contrast enhanced abdominopelvic 3 Tesla MRI. After separation of mononuclear cells from peripheral blood, using Ficoll-Hypaque, we analyzed gene expression changes of ATM and AKT genes 2 hours and 24 hours after MRI using quantitative reverse transcription polymerase chain reaction (qRT-PCR). We also evaluated methylation percentage of the above mentioned genes in before, 2 hours and 24 hours after MRI, using MethySYBR method. Results: Fold change analysis, in comparison with the baseline, respectively showed 1.1 ± 0.7 and 0.8 ± 0.5 mean of gene expressions in 2 and 24 hours after MRI for ATM, while the results were 1.4 ± 0.6 and 1.4 ± 1 for AKT (P>0.05). Methylation of the ATM gene promoter were 8.8 ± 1.5%, 9 ± 0.6% and 9 ± 0.8% in before contrast enhanced MRI, 2 and 24 hours after contrast enhanced MRI, respectively (P>0.05). Methylation of AKT gene promoter in before contrast enhanced MRI, 2 hours and 24 hours after contrast enhanced MRI was 5.4 ± 2.5, 5 ± 3.2, 4.9 ± 2.9 respectively (P>0.05). Conclusion: Contrast enhanced abdominopelvic MRI using 3 Tesla scanner apparently has no negative effect on the expression and promoter methylation level of ATM and AKT genes involved in the repair pathways of genome.

Effects of non-ionizing electromagnetic fields on flora and fauna, Part 2 impacts: How species interact with natural and man-made EMF

Article

Jul 2021

Ambient levels of nonionizing electromagnetic fields (EMF) have risen sharply in the last five decades to become a ubiquitous, continuous, biologically active environmental pollutant, even in rural and remote areas. Many species of flora and fauna, because of unique physiologies and habitats, are sensitive to exogenous EMF in ways that surpass human reactivity. This can lead to complex endogenous reactions that are highly variable, largely unseen, and a possible contributing factor in species extinctions, sometimes localized. Non-human magnetoreception mechanisms are explored. Numerous studies across all frequencies and taxa indicate that current low-level anthropogenic EMF can have myriad adverse and synergistic effects, including on orientation and migration, food finding, reproduction, mating, nest and den building, territorial maintenance and defense, and on vitality, longevity and survivorship itself. Effects have been observed in mammals such as bats, cervids, cetaceans, and pinnipeds among others, and on birds, insects, amphibians, reptiles, microbes and many species of flora. Cyto- and geno-toxic effects have long been observed in laboratory research on animal models that can be extrapolated to wildlife. Unusual multi-system mechanisms can come into play with non-human species — including in aquatic environments — that rely on the Earth’s natural geomagnetic fields for critical life-sustaining information. Part 2 of this 3-part series includes four online supplement tables of effects seen in animals from both ELF and RFR at vanishingly low intensities. Taken as a whole, this indicates enough information to raise concerns about ambient exposures to nonionizing radiation at ecosystem levels. Wildlife loss is often unseen and undocumented until tipping points are reached. It is time to recognize ambient EMF as a novel form of pollution and develop rules at regulatory agencies that designate air as ‘habitat’ so EMF can be regulated like other pollutants. Long-term chronic low-level EMF exposure standards, which do not now exist, should be set accordingly for wildlife, and environmental laws should be strictly enforced — a subject explored in Part 3.

Radiofrequency EMF irradiation effects on pre-B lymphocytes undergoing somatic recombination

Article

Full-text available

Jun 2021

Intense electromagnetic fields (EMFs) induce DNA double stranded breaks (DSBs) in exposed lymphocytes.We study developing pre-B lymphocytes following V(D)J recombination at their Immunoglobulin light chain loci (IgL). Recombination physiologically induces DNA DSBs, and we tested if low doses of EMF irradiation affect this developmental stage. Recombining pre-B cells, were exposed for 48 h to low intensity EMFs (maximal radiative power density flux S of 9.5 µW/cm2 and electric field intensity 3 V/m) from waves of frequencies ranging from 720 to 1224 MHz. Irradiated pre-B cells show decreased levels of recombination, reduction which is dependent upon the power dose and most remarkably upon the frequency of the applied EMF. Although 50% recombination reduction cannot be obtained even for an S of 9.5 µW/cm2 in cells irradiated at 720 MHz, such an effect is reached in cells exposed to only 0.45 µW/cm2 power with 950 and 1000 MHz waves. A maximal four-fold recombination reduction was measured in cells exposed to 1000 MHz waves with S from 0.2 to 4.5 µW/cm2 displaying normal levels of γH2AX phosphorylated histone. Our findings show that developing B cells exposure to low intensity EMFs can affect the levels of production and diversity of their antibodies repertoire.

The Protective Effects of EMF-LTE against DNA Double-Strand Break Damage In Vitro and In Vivo

Article

Full-text available

May 2021
INT J MOL SCI

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.

Comparison of networking technology in relationship with cellular phone radiation as a potential threat to the population

Conference Paper

May 2020

Electromagnetic pollution alert: Microwave radiation and absorption in human organs and tissues

Article

Feb 2021
ELECTROMAGN BIOL MED

Nantakan Wongkasem

Electromagnetic radiation from communication and electronic devices, networks, systems and base stations has drawn concern due to excessive global usage with increasing power and operating frequency level. Numerous previous researches only focus on how the radiation from certain frequency ranges of particular devices could harm specific human organs and tissues, resulting in distinct symptoms. In this research, electromagnetic propagation and properties in 14 human organs and tissues were analyzed and investigated based on the organs and tissues' electromagnetic and mechanical parameters, and chemical composition. Counting the organs and tissues as electromagnetic materials, their permittivity and conductivity, computed by a 4-Cole-Cole mode, directly respective to the operating frequency, are interrelated to wave behavior and hence influence the organs' response. Tests were conducted in 1 GHz to 105 GHz system settings, covering most microwave frequency uses: 2.4 GHz of 4G-LTE, Wi-Fi, Bluetooth, ZigBee and the 5G ranges: 28 GHz of 5G-mmW and 95 GHz of 5G-IoT. Trial human organs and tissues were placed in the wave propagation direction of 2.4 GHz and 28 GHz dipole antennas, and a waveguide port operating from 95 to 105 GHz. The quantitative data on the effects of 5G penetration and dissipation within human tissues are presented. The absorbance in all organs and tissues is significantly higher as frequency increases. As the wave enters the organ-tissue model, the wavelength is shortened due to the high organ-tissue permittivity. Skin-Bone-Brain layer simulation results demonstrate that both electric and magnetic fields vanish before passing the brain layer at all three focal frequencies of 2.4 GHz, 28 GHz and 100 GHz.

Effects of 2600 MHz Radiofrequency Radiation in Brain Tissue of Male Wistar Rats and Neuroprotective Effects of Melatonin

Article

Jan 2021

The debate on the biological effects of radiofrequency radiation (RFR) still continues due to differences in the design of studies (frequency, power density, specific absorption rate [SAR], exposure duration, cell, tissue, or animal type). The current study aimed to investigate the effects of 2,600 MHz RFR and melatonin on brain tissue biochemistry and histology of male rats. Thirty‐six rats were divided into six groups randomly: cage‐control, sham, RFR, melatonin, sham melatonin, and RFR melatonin. In RFR groups, animals were exposed to 2,600 MHz RFR for 30 days (30 min/day, 5 days/week) and the melatonin group animals were subcutaneously injected with melatonin (7 days/week, 10 mg/kg/day) for 30 days. SAR in brain gray matter was calculated as 0.44 and 0.295 W/kg for 1 and 10 g averaging, respectively. RFR exposure decreased the GSH, GSH‐Px, and SOD levels and increased the MPO, MDA, and NOx levels (P < 0.005) significantly. RFR exposure also led to an increase in structural deformation and apoptosis in the brain tissue. This study revealed that exogenous high‐dose melatonin could reduce these adverse effects of RFR. Limiting RFR exposure as much as possible is recommended, and taking daily melatonin supplements may be beneficial. Bioelectromagnetics. © 2021 Bioelectromagnetics Society

Effects of Low‐Intensity Microwave Radiation on Oxidant‐Antioxidant Parameters and DNA Damage in the Liver of Rats

Article

Full-text available

Dec 2020

The continuously increasing usage of cell phones has raised concerns about the adverse effects of microwave radiation (MWR) emitted by cell phones on health. Several in vitro and in vivo studies have claimed that MWR may cause various kinds of damage in tissues. The aim of this study is to examine the possible effects of exposure to low‐intensity MWR on DNA and oxidative damage in the livers of rats. Eighteen Sprague–Dawley male rats were divided into three equal groups randomly (n = 6). Group 1 (Sham‐control): rats were kept under conditions the same as those of other groups, except for MWR exposure. Group 2: rats exposed to 1800 MHz (SAR: 0.62 W/kg) at 0.127 ± 0.04 mW/cm2 power density, and Group 3: rats exposed to 2,100 MHz (SAR: 0.2 W/kg) at 0.038 ± 0.03 mW/cm2 power density. Microwave application groups were exposed to MWR 2 h/day for 7 months. At the end of the exposure period, the rats were sacrificed and DNA damage, malondialdehyde (MDA), 8‐hydroxydeoxyguanosine (8‐OHdG), and total oxidant‐antioxidant parameter analyses were conducted in their liver tissue samples. It was found that 1800 and 2100 MHz low‐intensity MWR caused a significant increase in MDA, 8‐OHdG, total oxidant status, oxidative stress index, and comet assay tail intensity (P < 0.05), while total antioxidant status levels (P < 0.05) decreased. The results of our study showed that whole‐body exposure to 1800 and 2100 MHz low‐intensity MWR emitted by cell phones can induce oxidative stress by altering oxidant‐antioxidant parameters and lead to DNA strand breaks and oxidative DNA damage in the liver of rats. Bioelectromagnetics. © 2020 Bioelectromagnetics Society Keywords: microwave radiation; liver; DNA damage; 8‐OHdG; MDA

Cumulative effects of manganese nanoparticle and radiofrequency radiation in male Wistar rats Cumulative effects of manganese nanoparticle and radiofrequency radiation in male Wistar rats

Article

Oct 2020

Radiofrequency radiation (RFR) is a type of non-ionizing electromagnetic radiation that includes radio-waves and microwaves with a frequency range between 3 KHz and 300 GHz. Mobile phones operate with RFR and are used tremendously resulting in increased and continuous exposure of humans to these radiations. On the other hand, nanoparticles are also being used extensively in various fields. The increasing use of radiofrequency radiations and nanoparticles has become a concern to the general public. Not many studies have reported the cumulative effect of these stressors. Hence, the present investigation was aimed to find out their cumulative effect on the mammalian system. In this study manganese nanoparticles (MNPs) were synthesized and characterized. Adult male Wistar rats were exposed to MNPs and mobile phone radiation for 45 days and their separate, as well as cumulative impact, was investigated. The effect of the MNPs and RFR on liver, kidney, and reproductive parameters were studied. Histopathology as well as liver and kidney parameters were altered when exposed to MNPs and RFR separately. However, their combined treatment did not show a synergistic toxic response in liver and kidney functions which may be due to the fact that the radiation level is low, specific absorption rate (SAR) is subthermal (0.04 W/kg) and liver and kidney are located intra abdominally , hence they would absorb comparatively lesser radiation than the testicles. MNPs and RFR both caused a highly significant decrease in sperm count, which further decreased in the combined treatment (MNPs þ RFR). These results indicate that the combined treatment of these stressors can have an additive toxic response to the male reproductive system. ARTICLE HISTORY

Electromagnetic radiation: a new charming actor in hematopoiesis?

Article

Sep 2020

Introduction: Electromagnetic waves play indispensable roles in life. With technology improvements, the biologic effects of waves are quite imperative. Many studies addressed the outcomes of Electromagnetic field (EMF) on various biological functions such as cell proliferation, gene expression, epigenetic alterations, genotoxic, and carcinogenic effects, and its therapeutic applications in medicine. The impact of EMF on bone marrow (BM) is of high importance, however, EMF effects on BM hematopoiesis is not well understood. Areas covered: Publications in English were searched in ISI Web of Knowledge and Google Scholar with no restriction on publication date. A literature review has been conducted on the consequences of EMF exposure on BM non-hematopoietic stem cells, mesenchymal stem cells, and the application of these waves in regenerative medicine. Human blood cells such as lymphocytes, red blood cells and their precursors are altered qualitatively and quantitatively following electromagnetic radiation. Therefore, studying the impact of EMF on related signaling pathways in hematopoiesis and hematopoietic stem cell (HSC) differentiation could give a better insight into its efficacy on hematopoiesis and its potential therapeutic usage. Expert opinion: In this review, authors evaluated the possible biologic consequences of EMF on the hematopoiesis process in addition to its probable application in the treatment of hematologic disorders.

Amyotrophic lateral sclerosis, occupational exposure to extremely low frequency magnetic fields and electric shocks: a systematic review and meta-analysis

Article

Sep 2020
Rev Environ Health

Exposure to extremely low frequency magnetic fields (ELF-MF) and electric shocks occurs in many workplaces and occupations but it is unclear whether any of these exposures cause Amyotrophic lateral sclerosis (ALS). The aim of this systematic review and meta-analysis is to explore whether occupational exposure to ELF-MF and/or electric shocks are risk factor for ALS. We searched PubMed, Embase, and Web of Science databases up to the end of 2019. Pooled risk estimates were calculated using random-effects meta-analysis including exploration of the sources of heterogeneity between studies and publication bias. Twenty-seven publications fulfilled the inclusion criteria. We found a weak, significant, association between occupational exposure to ELF-MF and the risk of ALS (RRPooled estimate: 1.20; 95%CI: 1.05, 1.38) with moderate to high heterogeneity (I2=66.3%) and indication of publication bias (PEgger's test=0.03). No association was observed between occupational exposure to electric shocks and risk of ALS (RRPooled estimate: 0.97; 95%CI: 0.80, 1.17) with high heterogeneity (I2=80.5%), and little indication for publication bias (PEgger's test=0.24). The findings indicate that occupational exposure to ELF-MF, but not electric shocks, might be a risk factor for ALS. However, given the moderate to high heterogeneity and potential publication bias, the results should be interpreted with caution.

Absorption of 5G Radiation in Brain Tissue as a Function of Frequency, Power and Time

Article

Full-text available

Jul 2020

David Gultekin

The rapid release of 5G wireless communications networks has spurred renewed concerns regarding the interactions of higher radiofrequency (RF) radiation with living species. We examine RF exposure and absorption in ex vivo bovine brain tissue and a brain simulating gel at three frequencies: 1.9 GHz, 4 GHz and 39 GHz that are relevant to current (4G), and upcoming (5G) spectra. We introduce a highly sensitive thermal method for the assessment of radiation exposure, and derive experimentally, accurate relations between the temperature rise ( ΔT ), specific absorption rate (SAR) and the incident power density ( F ), and tabulate the coefficients, ΔT/ΔF and Δ (SAR)/ ΔF , as a function of frequency, depth and time. This new method provides both ΔT and SAR applicable to the frequency range below and above 6 GHz as shown at 1.9, 4 and 39 GHz, and demonstrates the most sensitive experimental assessment of brain tissue exposure to millimeter-wave radiation to date, with a detection limit of 1 mW. We examine the beam penetration, absorption and thermal diffusion at representative 4G and 5G frequencies and show that the RF heating increases rapidly with frequency due to decreasing RF source wavelength and increasing power density with the same incident power and exposure time. We also show the temperature effects of continuous wave, rapid pulse sequences and single pulses with varying pulse duration, and we employ electromagnetic modeling to map the field distributions in the tissue. Finally, using this new methodology, we measure the thermal diffusivity of ex vivo bovine brain tissue experimentally.

Insights in the biology of extremely low-frequency magnetic fields exposure on human health

Article

Full-text available

Jul 2020
MOL BIOL REP

The extremely low-frequency magnetic fields (ELF-EMF) are generated by electrical devices and power systems (1 to 300 Hz). In recent decades, exposure to ELF-EMF has emerged potential concerns on public health. Here, we discuss recent progress in the understanding of ELF-EMF biology with a focus on mechanisms of ELF-EMF-mediated disease and summarize the results of more recent experimental and epidemiological studies of ELF-EMF exposure effects on cancer, neurological, cardiovascular, and reproductive disorders. Current views on genomic instability effects, as well as scientific evidence about ELF-EMF therapy, are put forth. According to our literature review, exposure to ELF-EMF has an adverse biological effect depending on the current intensity, strength of the magnetic field, and duration of exposure. Accumulated epidemiologic evidence indicates a correlation between exposure to ELF-EMF and childhood cancer incidence, Alzheimer's disease (AD), and miscarriage. However, adult cancer does not show augmented risk caused by the ELF-EMF. Also, no consistent evidence exists in cardiovascular disease mortality due to ELF-EMF exposure. There is a lack of comprehensive mechanisms for explaining the biological effect of ELF-EMF. Eventually, more studies are needed to clarify the mechanisms of these magnetic fields.

High-strength protective polyester textiles incorporated with metallic materials: Characterizations and radiation-shielding effectiveness

Article

Mar 2020

In this study, wrapping and weaving techniques are used to produce fibrous composites that can block electromagnetic radiation and ultraviolet radiation. Stainless steel filaments are used as the core, and high-strength ultraviolet resistant polyester (PET) filaments are used as the sheath materials to manufacture functional wrapped yarns. The wrapped yarns are made into woven fabric via weaving process. The electromagnetic shielding effectiveness and ultraviolet resistance of woven fabrics are evaluated in order to examine the influence of the number of laminated layer and laminated angles. The test results show that the two-layered woven fabrics that are laminated at 90° have the optimal ultraviolet resistance and electromagnetic shielding effectiveness. Stainless steel/ultraviolet resistance PET woven fabrics are also light weight and can be custom-made into planar protective textile composites based on users’ commands and also can be used in the outdoor domains.

Radio Frequency and Microwave Effects on Biological Tissues

Book

Oct 2019

Jitendra Behari

Nature Environment and Pollution Technology An International Quarterly Scientific Journal Original Research Paper Effect of Population Density and Surroundings on the Environmental RF Radiation

Article

Jan 2019

The cell-phone radiation is a potential health hazard not only to the singular user but to the whole population through the environmental pollution. The environmental radiation density may vary from place to place depending upon its absorption or reflection by surroundings, e.g., trees, buildings, human population, water bodies, etc. The present work was taken to study the effect of population density and surroundings on the environmental radiation. The power density values of radiation were measured using a hand-held portable power density meter TES 593, and specific absorption rates (SAR) were estimated from the measured values. The SAR values were compared with the safe limit of 1 mW/kg above which biological system of humans and animals starts getting affected. The studies indicated that the average environmental radiation power density values were higher in unpopulated and open areas than densely populated regions by 300%. Nat. Env. & Poll. Tech. Website: www.neptjournal.com

Effect of Population Density and Surroundings on the Environmental RF Radiation

Article

Full-text available

Sep 2019

Genetic susceptibility may modify the association between cell phone use and thyroid cancer: A population-based case-control study in Connecticut

Article

Dec 2019

Emerging studies have provided evidence on the carcinogenicity of radiofrequency radiation (RFR) from cell phones. This study aims to test the genetic susceptibility on the association between cell phone use and thyroid cancer. Population-based case-control study was conducted in Connecticut between 2010 and 2011 including 440 thyroid cancer cases and 465 population-based controls with genotyping information for 823 single nucleotide polymorphisms (SNPs) in 176 DNA genes. We used multivariate unconditional logistic regression models to estimate the genotype-environment interaction between each SNP and cell phone use and to estimate the association with cell phone use in populations according to SNP variants. Ten SNPs had P < 0.01 for interaction in all thyroid cancers. In the common homozygote groups, no association with cell phone use was observed. In the variant group (heterozygotes and rare homozygotes), cell phone use was associated with an increased risk for rs11070256 (odds ratio (OR): 2.36, 95% confidence interval (CI): 1.30-4.30), rs1695147 (OR: 2.52, 95% CI: 1.30-4.90), rs6732673 (OR: 1.59, 95% CI: 1.01-2.49), rs396746 (OR: 2.53, 95% CI: 1.13-5.65), rs12204529 (OR: 2.62, 95% CI: 1.33-5.17), and rs3800537 (OR: 2.64, 95% CI: 1.30-5.36) with thyroid cancers. In small tumors, increased risk was observed for 5 SNPs (rs1063639, rs1695147, rs11070256, rs12204529 and rs3800537), In large tumors, increased risk was observed for 3 SNPs (rs11070256, rs1695147, and rs396746). Our result suggests that genetic susceptibilities modify the associations between cell phone use and risk of thyroid cancer. The findings provide more evidence for RFR carcinogenic group classification.

Bimodal effect of phorbol ester on B cell activation

Article

Full-text available

Mar 1991

The role of protein kinase C PKC in B cell activation is controversial. These studies were undertaken to determine whether protein kinase C has a stimulatory or inhibitory role in B cell activation. We found that treatment of B cells for a short period of time (30 min) with the PKC activator phorbol 12,13-dibutyrate (PDBU) primed the cells for enhanced proliferative responses to anti-immunoglobulin (anti-Ig) antibody whereas treatment for a longer period of time (3 h or more) resulted in suppression of proliferation. The enhanced proliferative response to treatment of B cells with PDBU for short periods of time was associated with inhibition of anti-Ig-stimulated increases in phosphatidyl 4,5-bisphosphate (PIP2) hydrolysis and inhibition of increases in [Ca²⁺]i, indicating that activation of PKC per se might be sufficient for enhancing B cell activation. The time-dependent effect of phorbol esters on the inhibition of B cell proliferation was found to be closely correlated with the kinetics of disappearance of PKC as measured by Western blot and by enzymatic activity but not with inhibition of [Ca²⁺]i and PIP2. These data demonstrate a bimodal time-dependent effect of PDBU on B cell activation and suggest that (a) the inhibitory effect of phorbol ester on anti-Ig-induced proliferation may be due to the disappearance of PKC rather than to the inhibition of PIP2 and Ca²⁺; and (b) the early activation of PKC is a stimulatory rather than an inhibitory signal in the induction of B lymphocyte proliferation by anti-Ig.

Mobile phone use and risk of acoustic neuroma: Results of the Interphone case-control study in five North European countries

Article

Full-text available

Aug 2005

There is public concern that use of mobile phones could increase the risk of brain tumours. If such an effect exists, acoustic neuroma would be of particular concern because of the proximity of the acoustic nerve to the handset. We conducted, to a shared protocol, six population-based case–control studies in four Nordic countries and the UK to assess the risk of acoustic neuroma in relation to mobile phone use. Data were collected by personal interview from 678 cases of acoustic neuroma and 3553 controls. The risk of acoustic neuroma in relation to regular mobile phone use in the pooled data set was not raised (odds ratio (OR)=0.9, 95% confidence interval (CI): 0.7–1.1). There was no association of risk with duration of use, lifetime cumulative hours of use or number of calls, for phone use overall or for analogue or digital phones separately. Risk of a tumour on the same side of the head as reported phone use was raised for use for 10 years or longer (OR=1.8, 95% CI: 1.1–3.1). The study suggests that there is no substantial risk of acoustic neuroma in the first decade after starting mobile phone use. However, an increase in risk after longer term use or after a longer lag period could not be ruled out.Keywords: neuroma, acoustic, telephone, epidemiology, aetiology

Microwaves from GSM Mobile Telephones Affect 53BP1 and Æ -H2AX Foci in Human Lymphocytes from Hypersensitive and Healthy Persons

Article

Full-text available

Apr 2005

The data on biologic effects of nonthermal microwaves (MWs) from mobile telephones are diverse, and these effects are presently ignored by safety standards of the International Commission for Non-Ionizing Radiation Protection (ICNIRP). In the present study, we investigated effects of MWs of Global System for Mobile Communication (GSM) at different carrier frequencies on human lymphocytes from healthy persons and from persons reporting hypersensitivity to electromagnetic fields (EMFs). We measured the changes in chromatin conformation, which are indicative of stress response and genotoxic effects, by the method of anomalous viscosity time dependence, and we analyzed tumor suppressor p53-binding protein 1 (53BP1) and phosphorylated histone H2AX (gamma-H2AX), which have been shown to colocalize in distinct foci with DNA double-strand breaks (DSBs), using immunofluorescence confocal laser microscopy. We found that MWs from GSM mobile telephones affect chromatin conformation and 53BP1/gamma-H2AX foci similar to heat shock. For the first time, we report here that effects of MWs from mobile telephones on human lymphocytes are dependent on carrier frequency. On average, the same response was observed in lymphocytes from hypersensitive and healthy subjects.

Original Communication - Genetic damage in mobile phone users: some preliminary findings

Article

Full-text available

Dec 2005

Gursatej Gandhi

BACKGROUND: The impact of microwave (MW)/radio frequency radiation (RFR) on important biological parameters is probably more than a simply thermal one. Exposure to radio frequency (RF) signals generated by the use of cellular telephones have increased dramatically and reported to affect physiological, neurological, cognitive and behavioural changes and to induce, initiate and promote carcinogenesis. Genotoxicity of RFR has also been reported in various test systems after in vitro and/or in vivo exposure but none in mobile phone users. AIMS: In the present study, DNA and chromosomal damage investigations were carried out on the peripheral blood lymphocytes of individuals using mobile phones, being exposed to MW frequency ranging from 800 to 2000 MHz. METHODS: DNA damage was assessed using the single cell gel electrophoresis assay and aneugenic and clastogenic damage by the in vivo capillary blood micronucleus test (MNT) in a total of 24 mobile phone users. RESULTS: Mean comet tail length (26.76 ± 0.054 mm; 39.75% of cells damaged) in mobile phone users was highly significant from that in the control group. The in vivo capillary blood MNT also revealed highly significant (0.25) frequency of micronucleated (MNd) cells. CONCLUSIONS: These results highlight a correlation between mobile phone use (exposure to RFR) and genetic damage and require interim public health actions in the wake of widespread use of mobile telephony.

Genetic damage in mobile phone users: Some preliminary findings

Article

Full-text available

Jul 2005
Indian J Hum Genet

Bimodal effect of phorbol ester on B cell activation. Implication for the role of protein kinase C

Article

Full-text available

Apr 1991

The role of protein kinase C PKC in B cell activation is controversial. These studies were undertaken to determine whether protein kinase C has a stimulatory or inhibitory role in B cell activation. We found that treatment of B cells for a short period of time (30 min) with the PKC activator phorbol 12,13-dibutyrate (PDBU) primed the cells for enhanced proliferative responses to anti-immunoglobulin (anti-Ig) antibody whereas treatment for a longer period of time (3 h or more) resulted in suppression of proliferation. The enhanced proliferative response to treatment of B cells with PDBU for short periods of time was associated with inhibition of anti-Ig-stimulated increases in phosphatidyl 4,5-bisphosphate (PIP2) hydrolysis and inhibition of increases in [Ca2+]i, indicating that activation of PKC per se might be sufficient for enhancing B cell activation. The time-dependent effect of phorbol esters on the inhibition of B cell proliferation was found to be closely correlated with the kinetics of disappearance of PKC as measured by Western blot and by enzymatic activity but not with inhibition of [Ca2+]i and PIP2. These data demonstrate a bimodal time-dependent effect of PDBU on B cell activation and suggest that (a) the inhibitory effect of phorbol ester on anti-Ig-induced proliferation may be due to the disappearance of PKC rather than to the inhibition of PIP2 and Ca2+; and (b) the early activation of PKC is a stimulatory rather than an inhibitory signal in the induction of B lymphocyte proliferation by anti-Ig.

Topoisomerase II-reactive Chemotherapeutic Drugs Induce Apoptosis in Thymocytes1

Article

Full-text available

Mar 1991

The effects of topoisomerase II-reactive epipodophyllotoxins etoposide and teniposide as well as amsacrine on the viability of thymocytes in primary culture has been examined. All three drugs were shown to produce DNA cleavage detectable by resolving isolated DNA by pulsed field agarose gel electrophoresis. The DNA cleavage was found to have two components. The first was due to the interaction of the drugs with topoisomerase II, whereas the second component was due to endonuclease cleavage caused by the drug-induced entry of the thymocytes into programmed cell death or apoptosis. This second component of the DNA cleavage was also detected in thymocytes undergoing apoptosis following exposure to the glucocorticoid analogue, dexamethasone. The effect of the drugs on programmed cell death is dependent upon new protein and RNA synthesis, indicating that topoisomerase II has a role in the very first stages of the process. These results are discussed in terms of the use of this class of topoisomerase II-reactive drugs in chemotherapy.

Acute low-intensity microwave exposure increases DNA single-Strand breaks in rat brain cells

Article

Full-text available

Jan 1995

Levels of DNA single-strand break were assayed in brain cells from rats acutely exposed to low-intensity 2450 MHz microwaves using an alkaline microgel electrophoresis method. Immediately after 2 h of exposure to pulsed (2 microseconds width, 500 pulses/s) microwaves, no significant effect was observed, whereas a dose rate-dependent [0.6 and 1.2 W/kg whole body specific absorption rate (SAR)] increase in DNA single-strand breaks was found in brain cells of rats at 4 h postexposure. Furthermore, in rats exposed for 2 h to continuous-wave 2450 MHz microwaves (SAR 1.2 W/kg), increases in brain cell DNA single-strand breaks were observed immediately as well as at 4 h postexposure.

Single- and double-strand DNA breaks in rat brain cells after acute exposure to radiofrequency electromagnetic radiation

Article

Full-text available

May 1996

We investigated the effects of acute (2-h) exposure to pulsed (2-micros pulse width, 500 pulses s(-1)) and continuous wave 2450-MHz radiofrequency electromagnetic radiation on DNA strand breaks in brain cells of rat. The spatial averaged power density of the radiation was 2mW/cm2, which produced a whole-body average-specific absorption rate of 1.2W/kg. Single- and double-strand DNA breaks in individual brain cells were measured at 4h post-exposure using a microgel electrophoresis assay. An increase in both types of DNA strand breaks was observed after exposure to either the pulsed or continuous-wave radiation, No significant difference was observed between the effects of the two forms of radiation. We speculate that these effects could result from a direct effect of radiofrequency electromagnetic energy on DNA molecules and/or impairment of DNA-damage repair mechanisms in brain cells. Our data further support the results of earlier in vitro and in vivo studies showing effects of radiofrequency electromagnetic radiation on DNA.

Measurement of DNA Damage after Exposure to 2450 MHz Electromagnetic Radiation

Article

Full-text available

Jan 1998

Recent reports suggest that exposure to 2450 MHz electromagnetic radiation causes DNA single-strand breaks (SSBs) and double-strand breaks (DSBs) in cells of rat brain irradiated in vivo (Lai and Singh, Bioelectromagnetics 16, 207-210, 1995; Int. J. Radiat. Biol. 69, 513-521, 1996). Therefore, we endeavored to determine if exposure of cultured mammalian cells in vitro to 2450 MHz radiation causes DNA damage. The alkaline comet assay (single-cell gel electrophoresis), which is reportedly the most sensitive method to assay DNA damage in individual cells, was used to measure DNA damage after in vitro 2450 MHz irradiation. Exponentially growing U87MG and C3H 10T1/2 cells were exposed to 2450 MHz continuous-wave (CW) radiation in specially designed radial transmission lines (RTLs) that provided relatively uniform microwave exposure. Specific absorption rates (SARs) were calculated to be 0.7 and 1.9 W/kg. Temperatures in the RTLs were measured in real time and were maintained at 37 +/- 0.3 degrees C. Every experiment included sham exposure(s) in an RTL. Cells were irradiated for 2 h, 2 h followed by a 4-h incubation at 37 degrees C in an incubator, 4 h and 24 h. After these treatments samples were subjected to the alkaline comet assay as described by Olive et al. (Exp. Cell Res. 198, 259-267, 1992). Images of comets were digitized and analyzed using a PC-based image analysis system, and the "normalized comet moment" and "comet length" were determined. No significant differences were observed between the test group and the controls after exposure to 2450 MHz CW irradiation. Thus 2450 MHz irradiation does not appear to cause DNA damage in cultured mammalian cells under these exposure conditions as measured by this assay.

P53 is involved in regulation of the DNA repair gene O-6-methylguanine-DNA methyltransferase (MGMT) by DNA damaging agents

Article

Full-text available

Sep 1998
ONCOGENE

The DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) is inducible by genotoxic stress. MGMT induction results from transcriptional activation of the MGMT gene which is a specific response to DNA damage. A possible factor involved in triggering MGMT induction might be p53, because both p53 and MGMT are activated by DNA breaks. To study the effect of p53 on induction of the MGMT gene, we compared the presence of functional wild-type (wt) and mutant p53 with MGMT expression level in various mouse fibroblasts and rat hepatoma cell lines upon genotoxic treatment. Cells which responded to ionizing radiation (IR) by MGMT induction displayed functional p53, whereas in cells not expressing wt p53, MGMT induction was not observed. Also, the cloned MGMT promoter was inducible by IR upon transfection into p53 wt cells, but not in cells deficient for p53. Thus, expression of wt p53 appears to be required for induction of MGMT mRNA and protein by IR. On the other hand, transfection of a MGMT-promoter-CAT construct together with p53 (either wt or mutant) in cells expressing wt p53 markedly reduced the basal activity of the MGMT promoter whereas cotransfection with a p53 antisense construct slightly increased MGMT promoter activity. Furthermore, cotransfection of MGMT promoter with wt or mutant p53 in p53 wt cells reduced radiation evoked MGMT promoter induction. Thus, transfection mediated high level expression of p53 has inhibitory effect both on basal MGMT promoter activity and its activation by IR. The results give evidence for involvement of p53 in DNA damage-induced MGMT promoter activation.

Comet Assay: Rapid Processing of Multiple Samples

Article

Full-text available

Apr 2000
MUTAT RES-FUND MOL M

The present study describes modifications to the basic comet protocol that increase productivity and efficiency without sacrificing assay reliability. A simple technique is described for rapidly preparing up to 96 comet assay samples simultaneously. The sample preparation technique allows thin layers of agarose-embedded cells to be prepared in multiple wells attached to a flexible film of Gelbond, which improves the ease of manipulating and processing samples. To evaluate the effect of these modifications on assay sensitivity, dose-response curves are presented for DNA damage induced by exposure of TK6 cells to low concentrations of hydrogen peroxide (0-10 microM) and for exposure of human lymphocytes to X-irradiation (0-100 cGy). The limit of detection of DNA damage induced by hydrogen peroxide in TK6 cells was observed to be 1 uM for all parameters (tail ratio, tail moment, tail length and comet length) while the limit of detection of DNA damage in human lymphocytes was 10 cGy for tail and comet length parameters, but 50 cGy for tail ratio and tail moment parameters. These results are similar to those previously reported using the conventional alkaline comet assay. The application of SYBR Gold for detection of DNA damage was compared to that of propidium iodide. Measurements of matching samples for tail length and comet length were similar using both stains. However, comets stained with SYBR Gold persisted longer and were much brighter than those obtained with propidium iodide. SYBR Gold was found to be ideal for measuring tail length and comet length but, under present assay conditions, impractical for measuring tail ratio or tail moment due to saturation of staining in the head region of the comets.

Dose- and time-dependent bimodal effects of kappa-opioid agonists on locomotor activity in mice

Article

Dec 2000

The kappa -opioid agonists U50488H, bremazocine, and BRL52537, and the mu -opioid agonist morphine were compared in their ability to modify spontaneous motor activity in male NMRI mice. Higher, analgesic doses of the kappa -agonists reduced rearing, motility, and locomotion in nonhabituated mice. These effects, as well as the analgesic action of U50488H, were blocked by the selective kappa -opioid antagonists nor-binaltorphimine and DIPPA. In contrast, lower, subanalgesic doses (1.25 and 2.5 mg/kg for U50488H; 0.15 and 0.075 mg/kg for bremazocine, and 0.1 mg/kg for BRL52537) time dependently increased motor activity. The stimulatory effects of U50488H and bremazocine were not observed in habituated animals and were reduced by dopamine depletion. Surprisingly, the stimulatory effects of U50488H and bremazocine were not blocked by nor-binaltorphimine and DIPPA but they were completely eliminated by naloxone (0.1 mg/kg). The effects of morphine were dose-dependent; an initial limited suppression was followed by increased motility and locomotion (but not rearing) with a peak effect at 20 mg/kg both in habituated and nonhabituated mice. The selective mu -opioid antagonist beta -funaltrexamine blocked morphine-induced motor stimulation and analgesia but failed to affect the analgesic and motor stimulatory effects of U50488H. The results indicate that kappa -opioid agonists interact with different functional subtypes of opioid receptors. A stimulatory, naloxone-sensitive but nor-binaltorphimine- and DIPPA-insensitive subtype of opioid receptor appears to operate only when the dopamine system is tonically active in nonhabituated animals. At higher doses, kappa -agonists produce analgesia and motor suppression, effects mediated by a "classic" (inhibitory) kappa -opioid receptor.

Peroxidant states and tumor promotion

Article

Jan 1985

Cerutti Peter

There is convincing evidence that cellular prooxidant states--that is, increased concentrations of active oxygen and organic peroxides and radicals--can promote initiated cells to neoplastic growth. Prooxidant states can be caused by different classes of agents, including hyperbaric oxygen, radiation, xenobiotic metabolites and Fenton-type reagents, modulators of the cytochrome P-450 electron-transport chain, peroxisome proliferators, inhibitors of the antioxidant defense, and membrane-active agents. Many of these agents are promoters or complete carcinogens. They cause chromosomal damage by indirect action, but the role of this damage in carcinogenesis remains unclear. Prooxidant states can be prevented or suppressed by the enzymes of the cellular antioxidant defense and low molecular weight scavenger molecules, and many antioxidants are antipromoters and anticarcinogens. Finally, prooxidant states may modulate the expression of a family of prooxidant genes, which are related to cell growth and differentiation, by inducing alterations in DNA structure or by epigenetic mechanisms, for example, by polyadenosine diphosphate-ribosylation of chromosomal proteins.

Aging and DNA-repair capability

Article

Jan 1978

Raymond R Tice

The aging process is best defined as a general loss in biological competence for both the individual cell and the organism as a whole. At the cellular level, this loss is expressed as decreasing replicative ability in proliferating cells and decreasing functional activity in postmitotic cells (Little, 1976). For the organism, the aging process expresses itself as decreased viability and increased vulnerability to the normal forces of mortality (Goldstein, 1971a).

What Mad Pursuit: A Personal View of Scientific Discovery

Article

Jan 1988

Francis Crick

Scitation is the online home of leading journals and conference proceedings from AIP Publishing and AIP Member Societies

Time-dependency for the bimodal effect of melatonin on calcium uptake in rat hypothalamus

Article

Oct 1991

Summary The activity of 0.01-1 µM of melatonin on depolarization-induced45Ca2+ influx by hypothalamic synaptosomes of rats killed at late evening (2000 h) depended on melatonin preincubation time, exhibiting an early (10 min) stimulation of uptake and an inhibition after 30 min of incubation. Both stimulatory and inhibitory effects were maximal at 2000 h and tended to a minimum at 2400 h, exhibiting intermediate values at 400 h. At 1000 h, only inhibitory effects of melatonin (1 µM) on Ca2+ uptake were found

Neurological Effects of Radiofrequency Electromagnetic Radiation

Article

Jan 1998

Henry Lai

Many reports in the literature have suggested the effect of exposure to radiofrequency electromagnetic radiation (RFR) (10 kHz-300,000 MHz) on the functions of the nervous system. Such effects are of great concern to researchers in bioelectromagnetics, since the nervous system coordinates and controls an organism’s responses to the environment through autonomic and voluntary muscular movements and neurohumoral functions. As it was suggested in the early stages of bioelectromagnetics research, behavioral changes could be the most sensitive effects of RFR exposure. At the summary of session B of the proceedings of an international symposium held in Warsaw, Poland, in 1973, it was stated that “The reaction of the central nervous system to microwaves may serve as an early indicator of disturbances in regulatory functions of many systems” [Czerski et al., 1974].

Conjectures and Refutations: The Growth of Scientific Knowledge

Book

Jan 1963

Karl R. Popper

Interaction of Microwaves and a Temporally Incoherent Magnetic Field on Single and Double DNA Strand Breaks in Rat Brain Cells

Article

Jul 2009

The effect of a temporally incoherent magnetic field noise on microwave-induced DNA single and double strand breaks in rat brain cells was investigated. Four treatment groups of rats were studied: microwave-exposure (continuous-wave 2450-MHz microwaves, power density 1 mW/cm2, average whole-body specific absorption rate of 0.6 W/kg), noise-exposure (45 mG), microwave + noise-exposure, and sham-exposure. Animals were exposed to these conditions for 2h. DNA single- and double-strand breaks in brain cells of these animals were assayed 4h later using a microgel electrophoresis assay. Results show that brain cells of microwave-exposed rats had significantly higher levels of DNA single- and double-strand breaks when compared with sham-exposed animals. Exposure to noise alone did not significantly affect the levels (i.e., they were similar to those of the sham-exposed rats). However, simultaneous noise exposure blocked microwave-induced increases in DNA strand breaks. These data indicate that simultaneous exposure to a temporally incoherent magnetic field could block microwave-induced DNA damage in brain cells of the rat.

DNA damage in zebrafish larvae induced by exposure to low-dose rate ??-radiation: Detection by the alkaline comet assay

Article

Nov 2003
MUTAT RES-FUND MOL M

This study has determined the sensitivity of the alkaline comet assay for the detection of strand breaks in the DNA of cells taken from a whole organism rather than a single cell type as in previously reported studies. The assay has been performed on cells from whole zebrafish larvae irradiated for 1 or 24 h at dose rates of 0.4, 1.2 or 7.2 mGy/h. Zebrafish larvae exposed to only 1.2 mGy/h of gamma-radiation for 1h showed a statistically significant increase in DNA damage compared to controls. This represents a high sensitivity of this animal model for DNA damage and of the comet assay protocol used for detecting such damage. Increasing the exposure time from 1 to 24 h caused significant increases in DNA damage in zebrafish larvae, although the modest size of these increases in damage for the relatively large increases (24 times) in total absorbed dose indicates that dose rate may be the major factor in determining the level of DNA damage observed under the conditions of these experiments.

DNA damage in rat lymphocytes treated in vitro with iron cations and exposed to 7 mT magnetic fields (static or 50 HZ)

Article

Oct 2000
MUTAT RES-FUND MOL M

The present study was undertaken to verify a hypothesis that exposure of the cells to static or 50 Hz magnetic fields (MF) and simultaneous treatment with a known oxidant, ferrous chloride, may affect the oxidative deterioration of DNA molecules.The comet assay was chosen for the assessment of DNA damage. The experiments were performed on isolated rat lymphocytes incubated for 3 h in Helmholtz coils at 7 mT static or 50 Hz MF. During MF exposure, part of the cell samples were incubated with 0.01 μM H2O2 and another one with 10 μg/ml FeCl2, the rest serving as controls.Lymphocyte exposure to MF at 7 mT did not increase the number of cells with DNA damage in the comet assay. Incubation of lymphocytes with 10 μg/ml FeCl2 did not produce a detectable damage of DNA either. However, when the FeCl2-incubated lymphocytes were simultaneously exposed to 7 mT MF, the number of damaged cells was significantly increased and reached about 20% for static MF and 15% for power frequency MF. In the control samples about 97% of the cells did not have any DNA damage.It is not possible at present to offer a reasonable explanation for the findings of this investigation — the high increase in the number of lymphocytes showing symptoms of DNA damage in the comet assay, following simultaneous exposure to the combination of two non-cytotoxic factors —10 μg/ml FeCl2 and 7 mT MF. In view of the obtained results we can only hypothesise that under the influence of simultaneous exposure to FeCl2 and static or 50 Hz MF, the number of reactive oxygen species generated by iron cations may increase substantially. Further studies will be necessary to confirm this hypothesis and define the biological significance of the observed effect.

Protective effect of melatonin against in vitro iron ions and 7 mT 50 Hz magnetic field-induced DNA damage in rat lymphocytes

Article

Dec 2001
MUTAT RES-FUND MOL M

We have previously shown that simultaneous exposure of rat lymphocytes to iron ions and 50 Hz magnetic field (MF) caused an increase in the number of cells with DNA strand breaks. Although the mechanism of MF-induced DNA damage is not known, we suppose that it involves free radicals. In the present study, to confirm our hypothesis, we have examined the effect of melatonin, an established free radicals scavenger, on DNA damage in rat peripheral blood lymphocytes exposed in vitro to iron ions and 50 Hz MF.The alkaline comet assay was chosen for the assessment of DNA damage. During pre-incubation, part of the cell samples were supplemented with melatonin (0.5 or 1.0 mM). The experiments were performed on the cell samples incubated for 3 h in Helmholtz coils at 7 mT 50 Hz MF. During MF exposure, some samples were treated with ferrous chloride (FeCl2, 10 μg/ml), while the rest served as controls.A significant increase in the number of cells with DNA damage was found only after simultaneous exposure of lymphocytes to FeCl2 and 7 mT 50 Hz MF, compared to the control samples or those incubated with FeCl2 alone. However, when the cells were treated with melatonin and then exposed to iron ions and 50 Hz MF, the number of damaged cells was significantly reduced, and the effect depended on the concentration of melatonin. The reduction reached about 50% at 0.5 mM and about 100% at 1.0 mM. Our results indicate that melatonin provides protection against DNA damage in rat lymphocytes exposed in vitro to iron ions and 50 Hz MF (7 mT). Therefore, it can be suggested that free radicals may be involved in 50 Hz magnetic field and iron ions-induced DNA damage in rat blood lymphocytes.The future experimental studies, in vitro and in vivo, should provide an answer to the question concerning the role of melatonin in the free radical processes in the power frequency magnetic field.

DNA damage in MOLT-4 lymphoblastoid cells exposed to cellular telephone radiofrequency fields in vitro

Article

Mar 1998
Bioelectrochem Bioenerg

Molt-4 T-lymphoblastoid cells have been exposed to pulsed signals at cellular telephone frequencies of 813.5625 MHz (iDEN® signal) and 836.55 MHz (TDMA signal). These studies were performed at low SAR (average=2.4 and 24 μW g−1 for iDEN® and 2.6 and 26 μW g−1 for TDMA) in studies designed to look for athermal RF effects. The alkaline comet, or single cell gel electrophoresis, assay was employed to measure DNA single-strand breaks in cell cultures exposed to the radiofrequency (RF) signal as compared to concurrent sham-exposed cultures. Tail moment and comet extent were calculated as indicators of DNA damage. Statistical differences in the distribution of values for tail moment and comet extent between exposed and control cell cultures were evaluated with the Kolmogorov–Smirnoff distribution test. Data points for all experiments of each exposure condition were pooled and analyzed as single groups. It was found that: 1) exposure of cells to the iDEN® signal at an SAR of 2.4 μW g−1 for 2 h or 21 h significantly decreased DNA damage; 2) exposure of cells to the TDMA signal at an SAR of 2.6 μW g−1 for 2 h and 21 h significantly decreased DNA damage; 3) exposure of cells to the iDEN® signal at an SAR of 24 μW g−1 for 2 h and 21 h significantly increased DNA damage; 4) exposure of cells to the TDMA signal at an SAR of 26 μW g−1 for 2 h significantly decreased DNA damage. The data indicate a need to study the effects of exposure to RF signals on direct DNA damage and on the rate at which DNA damage is repaired.

Microwave enhanced kinetics observed in ORD studies of a protein

Article

Jan 2000

Microwaves are shown to affect the kinetics of conformational changes of the protein beta-lactoglobulin. Microwaves can accelerate conformational changes in the direction towards the equilibrium state. This applies both for the folding and the unfolding processes. Cold denaturing thermal unfolding of the proteins is accelerated by negative temperature gradients. Microwave irradiation of the protein solution heated it by about 0.3 degree, and hence the observed acceleration of denaturing is therefore non-thermal.

Detection of DNA Damage by the Alkaline Comet Assay after Exposure to Low-Dose Gamma Radiation

Article

Apr 1998

The alkaline comet assay as described by Olive et al. (Exp. Cell Res. 198, 259-267, 1992) was used to detect DNA damage in cells exposed to low doses (0-5 cGy) of gamma radiation. Experiments were performed using lymphocytes isolated from whole blood of rats. The comet parameters, normalized comet moment and comet length, described by Kent et al. (Int. J. Radiat. Biol. 67, 655-660, 1995), were used as measurements of DNA damage. It was observed that the alkaline comet assay can detect DNA damage at doses as low as 0.6 cGy. The results of the experiments using low-dose gamma radiation are comparable with published results obtained using the alkaline comet assay according to the method of Singh et al. (Int. J. Radiat. Biol. 66, 23-28, 1994). Based on this observation and analysis of results published previously, we conclude that the version of the alkaline comet assay described by Olive et al. is as sensitive as other modifications of the comet assay reported in literature for the detection of DNA damage in cells exposed to low doses of ionizing radiation.

Time-dependency for the bimodal effect of melatonin on calcium uptake in rat hypothalamus. Short communication

Article

Feb 1991

The activity of 0.01-1 microM of melatonin on depolarization-induced 45Ca2+ influx by hypothalamic synaptosomes of rats killed at late evening (2000 h) depended on melatonin preincubation time, exhibiting an early (10 min) stimulation of uptake and an inhibition after 30 min of incubation. Both stimulatory and inhibitory effects were maximal at 2000 h and tended to a minimum at 2400 h, exhibiting intermediate values at 400 h. At 1000 h, only inhibitory effects of melatonin (1 microM) on Ca2+ uptake were found.

The Yield of DNA Double-strand Breaks Produced Intracellularly by Ionizing Radiation: A Review

Article

Jul 1990

John Francis Ward

The mechanisms of radiation damage production are used to examine the following premises: (1) the number of DNA double-strand breaks per unit dose increases with dose; (2) cell type to cell type variations in yield of DNA dsb per dose occur. Two stages of damage production are identified as possible sources of damage yield modulation; numbers of OH. free radicals reacting with the target, and amount of chemical repair occurring on the target radicals. These factors are discussed in the light of the structures within which cellular DNA is packaged and the known rate constants for the reactions involved. It is concluded from our current knowledge that, in the presence of oxygen: (a) the number of DNA dsb is linearly related to dose, and (b) the yields of DNA damage per dose among cell types are constant. There is a caveat to the latter conclusion: the chromatin structure may be different in radiosensitive cell lines. In the absence of such a difference, variations in radiosensitivity with dose or with cell type are assigned to differences in repair speed and/or accuracy.

The effects of X-irradiation, N-ethyl-N-nitrosourea or combined treatment on O6-alkylguanine-DNA alkyltransferase activity in fetal rat brain and liver and the induction of CNS tumours

Article

Mar 1990

Wistar rats were treated in utero on day 16 of gestation either by X-irradiation (1 and 2 Gy), N-ethyl-N-nitrosourea (ENU, 50 mg/kg), or both in combination. The O6-alkylguanine-DNA alkyltransferase (AT) activity of the fetal brain and liver was analyzed and long-term observations were made to reveal any relationship between the O6-ethylguanine repair capability and tumour incidence in the organs of the offspring. The AT activity in the brain was affected to the same extent in the fetuses as in the dams. There was a 60.9% decrease in AT activity in fetuses 24 h after ENU treatment. This correlates with a significant increase in the incidence of brain tumours in the treated offspring (44.1%) compared to control animals. The inductive effect of X-irradiation on AT activity (131.3% for 1 Gy and 201.6% for 2 Gy) corresponded in turn with a reduction of the incidence of tumours after the combined treatment (26.8% and 8.3% tumour incidence, 103.1% and 157.8% AT activity). In the liver of the rat fetuses, there was generally no effect of treatment on AT activity in contrast to the results obtained for the dams, where an increased AT activity (127.70% and 157.4% after X-irradiation, 149.0% and 156.1% after combined treatment) was observed. There were no tumours of the liver observed in the offspring after either treatment alone or after combined treatment. Comparing biochemical and morphological results, it is suggested that X-irradiation of rat fetuses--with relatively low doses--and subsequent treatment with the ethylating carcinogen ENU, could significantly reduce the incidence of brain tumours in adult life. This is possibly a result of the corresponding induction of AT.

Endogenous DNA damage as related to cancer and aging

Article

Oct 1989
MUTAT RES-FUND MOL M

Bruce Ames

The endogenous background level of oxidant-induced DNA damage in vivo has been assayed by measuring 8-hydroxydeoxyguanosine (oh8dG), thymine glycol and thymidine glycol in urine and oh8dG in DNA. The level of oxidative DNA damage as measured by oh8dG in normal rat liver is shown to be extensive (1/130,000 bases in nuclear DNA and 1/8000 bases in mitochondrial DNA), especially in mtDNA. The methylation adduct 7-methylguanine (m7G) has also been found. m7G is one of about 5 adducts found on methylating DNA, and oh8dG is one of about 20 adducts found on oxidizing DNA, e.g., by radiation. We also discuss 3 hitherto unrecognized antioxidants in man.

Endogenous Oxidative DNA Damage, Aging, and Cancer

Article

Feb 1989
Free Radic Res Comm

Bruce Ames

Progress in identifying the important endogenous processes damaging DNA and developing methods to assay this damage in individuals is presented. This approach may aid studies on modulation of cancer and aging. The endogenous background level of oxidant-induced DNA damage in vivo has been assayed by measuring 8-hydroxydeoxyguanosine (oh8dG), thymine glycol and thymidine glycol in urine and oh8dG in DNA. oh8dG is one of about 20 adducts found on oxidizing DNA, e.g., by radiation. The level of oxidative DNA damage as measured by oh8dG in normal rat liver is shown to be extensive, especially in mtDNA (1/130,000 bases in nuclear DNA and 1/8,000 bases in mitochondrial DNA). We also discuss three hitherto unrecognized antioxidants in man.

Cerutti PAProoxidant states and tumor promotion. Science 227: 375-381

Article

Feb 1985

Cerutti Peter

Correlation Between Deoxyribonucleic Acid Excision-Repair and Life-Span in a Number of Mammalian Species

Article

Jul 1974

The ability of fibroblasts to perform unscheduled DNA synthesis (a measure of excision-repair) after UV irradiation was measured radioautographically for seven species at several times after several UV fluences. Both the initial rate and the maximum incorporation of [(3)H]dThd increased with the life-span of the species (shrew, mouse, rat, hamster, cow, elephant, man). Unscheduled DNA synthesis was approximately proportional to the logarithm of life-span.

The single cell gel electrophoresis/comet assay: A potential tool for detecting radiation-induced DNA damage in humans

Article

Jun 1995

This review evaluates the applicability of the single cell gel (SCG)/comet assay as a tool for the biomonitoring of individuals accidently, environmentally or occupationally exposed to ionizing radiation. This technique detects single-strand DNA breaks, alkali-labile damage, incomplete excision repair sites and DNA:DNA crosslinking at the level of the individual cell. The advantages of this technique include: (a) data are collected at the level of the individual cell, providing information on the intercellular distribution of damage and repair; (b) only small numbers of cells are required (i.e., only a few thousand); (c) virtually any eukaryotic cell population can be used; and (d) the assay is relatively sensitive (detection limit of 5 cGy gamma rays in human lymphocytes), simple and cost effective. What the assay lacks is specificity for radiation-induced DNA damage. However, the possibility of identifying types of DNA damage specific for ionizing radiation in selected subtypes of cells may be feasible. While additional research is required before the SCG assay can readily be applied as a standard biomonitoring tool for exposure to ionizing radiation, the data collected thus far support a conclusion that such research is clearly warranted.

Effect of low power microwave on the mouse genome: A direct DNA analysis

Article

Feb 1994
MUTAT RES-FUND MOL M

The potential mutagenic effect of low power microwave at the DNA sequence level in the mouse genome was evaluated by direct DNA analysis. Animals were exposed to microwave at a power density of 1 mW/cm2 for 2 h/day at a frequency of 2.45 GHz over a period of 120, 150 and 200 days. HinfI digested DNA samples from testis and brain of control and exposed animals were hybridized with a synthetic oligo probe (OAT 36) comprising nine repeats of 5'-GACA-3'. As compared to control animals, band patterns in exposed animals were found to be distinctly altered in the range of 7-8 kb which was also substantiated by densitometric analysis. Though the mechanism of this rearrangement is not yet clear, the results obtained at the present dose are of significance. This dose, which has been set as the safe limit for general public exposure by the Non-Ionizing Radiation Committee of the International Radiation Protection Association, may imply a need for (re)evaluation of the mutagenic potential of microwaves at the prescribed safe limit for the personnel and people who are being exposed.

Topoisomerase inhibitors induce apoptosis in thymocytes

Article

Feb 1993
Biochim Biophys Acta

The effects of the inhibitors of topoisomerase I and II, camptothecin and etoposide, as well as novobiocin and adriamycin, on the DNA fragmentation and viability of mouse thymocytes in primary culture were examined. All inhibitors were shown to produce dose-dependent internucleosomal DNA cleavage by resolving isolated DNA by agarose-gel electrophoresis. The DNA fragmentation seemed to precede cell death, determined on the basis of LDH release, by a few hours. Etoposide-induced DNA fragmentation progressively increased after incubation and was enhanced by pretreatment with phorbol 12,13-dibutyrate, a phorbol ester capable of activating protein kinase C, whereas camptothecin-induced DNA fragmentation increased progressively after 12 h incubation and was unaffected by phorbol 12,13-dibutyrate-pretreatment. The process was also energy-dependent and required RNA and protein synthesis and protein phosphorylation, since it was inhibited by sodium azide, actinomycin D, cycloheximide and 1-(5-isoquinoline-sulfonyl)-2-methylpiperazine hydrochloride, a protein kinase inhibitor. DNA fragmentation was also inhibited by zinc ions, suggesting the involvement of a specific endonuclease in DNA cleavage. These phenomena are similar to those detected in thymocytes undergoing apoptosis following exposure to glucocorticoids (Cohen, J.J. and Duke, R.C. (1984) J. Immunol. 132, 38-42). Considering that topoisomerases function in cellular proliferation and differentiation by altering DNA topology, the results suggest that topoisomerases have important roles in T-lymphocyte ontogeny in the thymus and are in part involved in the elimination of autoreactive or harmful cells by an apoptotic process.

A safe and rapid method for analyzing apoptosis-induced fragmentation of DNA extracted from tissues or cultured cells

Article

Apr 1993
J IMMUNOL METHODS

Electromagnetic fields and DNA damage

Abstract

No full-text available