Electromagnetic Field Bioeffects Research Articles

Studying the bioeffects of complexly organized electromagnetic impacts of low intensity

Introduction. One of the modern tasks of hygienic assessment of the human environment is the accumulation of data on the bioeffects of electromagnetic fields (EMF), formed by the simultaneous action of several microwave sources. There is virtually no literature on the corresponding comparative analysis of the results of identical in conditions and energy effects on animals and humans. The purpose of this work is to compare bioeffects and analyze possible mechanisms of their formation, as a result of the action of electromagnetic fields (EMF) of one, two and three carrier frequencies, within 0.9-1.4 GHz with equivalent energy and modulation characteristics. Materials and methods. The work was performed in experiments on 11 rabbits (2.5-3 kg) of the Chinchilla breed and clinical- physiological studies involving 14 volunteers - men, aged 40-50 years. Irradiation was subjected mainly to the head of the object. The series differed in the number of carrier frequencies, their specific value and modulation within different EEG ranges, while maintaining an energy flux density (EPR) in the total pulse - 300 μW/cm2. We analyzed a set of indicators related to the functional assessment of central nervous, cardiovascular, respiration and muscular vbody systems. Results. The results on the dependence of the EMF effect of complex organization on the carrier frequency, their number and modulation nature are presented. It was established that each of the observed reactions was within the physiological norm, but along with the gain in the number of carrier frequencies and the specific modulation value, their qualitative and quantitative characteristics increased. Analysis of their phenomenology (of the alpha EEG range only at one carrier; + delta with a reflection of the reaction in other indicators - at two; an increase in the percentage of reactions in a complex of indicators, especially EMG - at three) indicated a different degree of synchronization of the bioelectric activity of the brain and the neurophysiological mechanism of their formation. The information obtained, of course, is limited to specific EMF parameters. It complements the relevant information available by highlighting the need for more research on a case-by-case basis. Limitations. The study of the phenomenology and mechanism of bioeffects of several low-intensity EMFs at the same time is a complex task that requires the involvement of a larger number of electromagnetic sources and a variety of indicators of the body’s response than this work was limited to and which, undoubtedly, is promising in the development of this area of research. Conclusion. In this study, there were no reactions that would go beyond the physiological norm. However, further strengthening of synchronization processes in the central nervous system, according to the analysis of the literature, can lead to such changes. This circumstance dictates the need to take it into account in the formation of the appropriate sanitary and hygienic assessment.

Biological Effects of Atmospheric Fields and Radiation

Our atmosphere is full of electromagnetic fields emitted from wireless communication transmitters. At the same time the bio-systems (including humans, animals & birds and vegetation as well) are complex electrical systems. Naturally therefore, they are likely to have interaction and to be affected in some way or the other. Research into this field started with the knowledge about pleasing presence of negative charges and unpleasant presence of positive charges around us, concentrating effects of static or pulsating fields. Also came the explanation (and experimental verification) of Hindu mythological effects of geomagnetic fields coupled with solar activity. The effects of power line radiation and radiation from video game TV sets, microwave oven and other domestic instruments like electric blankets also figured in the research. At last the fastest emerging mobile telephony overpowered all others. Though the results of researches into possible harmful effects of mobile phone radiation and those of radiation from base station towers remain inconclusive partly because of influencing pressure from manufacturing and service providing companies, some of the researchers conclusively assert the harmfulness of the radiation at some level of field intensity present near the tower or the handset relating it to the specific absorption ratio (SAR) value. Recent increased observation of infertility among young couples is also attributed by some researchers to the effect of radiation from mobile kept in pantaloons pockets which becomes near their genitals affecting sperm or ovum. This review explains all these researches into bio-effects of electromagnetic fields and concludes that there is certainly some possible harmfulness of radiation above some level of intensity of fields.

Possible molecular and cellular mechanisms at the basis of atmospheric electromagnetic field bioeffects

Mechanisms of how electromagnetic (EM) field acts on biological systems are governed by the same physics regardless of the origin of the EM field (technological, atmospheric...), given that EM parameters are the same. We draw from a large body of literature of bioeffects of a man-made electromagnetic field. In this paper, we performed a focused review on selected possible mechanisms of how atmospheric electromagnetic phenomena can act at the molecular and cellular level. We first briefly review the range of frequencies and field strengths for both electric and magnetic fields in the atmosphere. Then, we focused on a concise description of the current knowledge on weak electric and magnetic field bioeffects with possible molecular mechanisms at the basis of possible EM field bioeffects combined with modeling strategies to estimate reliable outcomes and speculate about the biological effects linked to lightning or pyroelectricity. Indeed, we bring pyroelectricity as a natural source of voltage gradients previously unexplored. While very different from lightning, it can result in similar bioeffects based on similar mechanisms, which can lead to close speculations on the importance of these atmospheric electric fields in the evolution.

Exposure to 50 Hz electromagnetic fields enhances hair follicle regrowth in C57BL/6 mice.

In this study, our experiments confirmed that 50 Hz EMF affected hair follicle regrowth, and 50 Hz EMF enhanced K15+ stem cells proliferation in the hair bulb and follicular outer root sheath of hair follicles. Those results indicated that 50 Hz EMF may be beneficial for functional healing of hair loss.

Electromagnetic fields instantaneously modulate nitric oxide signaling in challenged biological systems

This study shows that a non-thermal pulse-modulated RF signal (PRF), configured to modulate calmodulin (CaM) activation via acceleration of Ca2+ binding kinetics, produced an immediate nearly 3-fold increase in nitric oxide (NO) from dopaminergic MN9D cultures (P<0.001). NO was measured electrochemically in real-time using a NO selective membrane electrode, which showed the PRF effect occurred within the first seconds after lipopolysaccharide (LPS) challenge. Further support that the site of action of PRF involves CaM is provided in human fibroblast cultures challenged with low serum and exposed for 15min to the identical PRF signal. In this case a CaM antagonist W-7 could be added to the culture 3h prior to PRF exposure. Those results showed the PRF signal produced nearly a two-fold increase in NO, which could be blocked by W-7 (P<0.001). To the authors’ knowledge this is the first report of a real-time effect of non-thermal electromagnetic fields (EMF) on NO release from challenged cells. The results provide mechanistic support for the many reported bioeffects of EMF in which NO plays a role. Thus, in a typical clinical application for acute post operative pain, or chronic pain from, e.g., osteoarthritis, EMF therapy could be employed to modulate the dynamics of NO via Ca/CaM-dependent constitutive nitric oxide synthase (cNOS) in the target tissue. This, in turn, would modulate the dynamics of the signaling pathways the body uses in response to the various phases of healing after physical or chemical insult or injury.

Effect of 50‐Hz‐Powerline‐Exposed Water on Hematological Parameters in Rats

Double distilled water samples were exposed for 24 hr and 48 hr to 50 Hz‐powerline electromagnetic field (EMF) strength of 51.2 μT (36.2 RMS). This EMF exposed water was made available to experimental adult Charles‐Foster male rats for drinking ad libitum for 90 days. Blood samples were collected on day 0 (base line), 30, 60, and 90. Hematological parameters (e.g., total leukocyte counts [TLC], differential leukocyte counts [DLC], and platelet counts) were analyzed statistically. There was significant increase in TLC platelet counts on day 30, whereas significant reduction was observed on day 60. On day 90, significant increase in TLC and significant decrease in platelet counts was observed. For DLC, neutrophils exhibited nonsignificant alteration on day 90, whereas, although lymphocytes and monocytes showed significant increase throughout the experiment though on day 90, there was a slight tendency to decline in monocytes. The present study clearly demonstrates a strong influence of EMF exposed water on day 30 (leukocytosis and thrombocytosis) and day 60 (leukopenia and thrombopenia) with differential results on day 90. This study provides further evidence for EMF bioeffects connected to EMF‐exposed water.

Mechanism for action of electromagnetic fields on cells

A biophysical model for the action of oscillating electric fields on cells, presented by us before [Biochem. Biophys. Res. Commun. 272(3) (2000) 634–640], is extended now to include oscillating magnetic fields as well, extended to include the most active biological conditions, and also to explain why pulsed electromagnetic fields can be more active biologically than continuous ones. According to the present theory, the low frequency fields are the most bioactive ones. The basic mechanism is the forced-vibration of all the free ions on the surface of a cell’s plasma membrane, caused by an external oscillating field. We have shown that this coherent vibration of electric charge is able to irregularly gate electrosensitive channels on the plasma membrane and thus cause disruption of the cell’s electrochemical balance and function [Biochem. Biophys. Res. Commun. 272(3) (2000) 634–640]. It seems that this simple idea can be easily extended now and looks very likely to be able to give a realistic basis for the explanation of a wide range of electromagnetic field bioeffects.

EVIDENCE OF SYNCHRONIZATION OF NEURONAL ACTIVITY OF MOLLUSCAN BRAIN GANGLIA INDUCED BY ALTERNATING 50 Hz APPLIED MAGNETIC FIELD

Experimental evidence for the appearance of synchronized bioelectric activity in neurons under applied extremely low frequency (ELF) magnetic fields is shown. We have studied the synchronizing process by recording the intracellular bioelectric activity from pairs of neurons randomly chosen from the brain ganglia of the snail Helix aspersa. The recordings were made in real time under exposure to sinusoidal low frequency (50 Hz) weak (B0=1–15 mT) magnetic fields. Synchronization was observed in 27% of the pairs tested. A linear dependence of the firing frequency f with the energy density of the applied magnetic field (i.e., f∝B02) was presented. The ability of low frequency sinusoidal weak magnetic fields to promote “magnetic synchronization” is exciting and opens new avenues for induced electromagnetic field bioeffects.

EMF signals and ion/ligand binding kinetics: prediction of bioeffective waveform parameters

The kinetics of an electromagnetic field (EMF) target pathway are used to estimate frequency windows for EMF bioeffects. Ion/ligand binding is characterized via first order kinetics from which a specific electrical impedance can be derived. The resistance/capacitance properties of the binding pathway impedance, determined by the kinetics of the rate-determining step, define the frequency range over which the target pathway is most sensitive to external EMF. Applied signals may thus be configured such that their spectral content closely matches that of the target, using evaluation of the signal to thermal noise ratio to optimize waveform parameters. Using the approach proposed in this study, a pulsed radio frequency (PRF) waveform, currently employed clinically for soft tissue repair, was retuned by modulation of burst duration, producing significant bioeffects at substantially reduced signal amplitude. Application is made to Ca 2+/Calmodulin-dependent myosin phosphorylation, for which the binding time constants may be estimated from reported kinetics, neurite outgrowth from embryonic chick dorsal root explants and bone repair in a fracture model. The results showed that the retuned signal produced increased phosphorylation rates, neurite outgrowth and biomechanical strength that were indistinguishable from those produced by the clinical signal, but with a tenfold reduction in peak signal amplitude, ≈800-fold reduction in average amplitude and ≈10 6-fold reduction in average power.

Magnetic iron biomineralization in rat brains: effects of iron loading.

Isothermal remanent magnetization was measured in 14 Wistar and five Porton rat brains. Results indicate that magnetic iron biominerals are present in most of the samples and the formation of these minerals in the rat brain is influenced by transfusion and dietary iron loading when compared to control samples. The high level of consistency in the concentrations and the lack of magnetic material in several of the measured samples indicates that a genetic mechanism may be responsible for magnetic iron biomineralization in the rat brain. Comparison with human studies indicates that extrapolation of the results of rat studies of electromagnetic field bioeffects may not be accurately extrapolated to humans in all cases.

Enhancement of the interaction between low-intensity R.F. e.m. fields and ligand binding due to cell basal metabolism

Power absorption by biological tissues, due to low-intensity electromagnetic exposure at radio frequencies, as those generated by personal telecommunication systems, is typically negligible. Nevertheless, the electromagnetic field is able to affect biological processes, like the binding of a messenger ion to a cell membrane receptor, if some specific conditions occur. The depth of the attracting potential energy well of the binding site must be comparable with the radio frequency photon energy. The dependance of the binding potential energy on the spatial coordinates must be highly non-linear. The ion--receptor system, in absence of the exogenous electromagnetic exposure, must be biased out of thermodynamic equilibrium by the cell basal metabolism. When the above conditions concur a low-intensity radio frequency sinusoidal field is able to induce a steady change of the ion binding probability, which overcomes thermal noise. The model incorporates the effects of both thermal noise and basal metabolism, so that it offers a plausible biophysical basis for potential bioeffects of electromagnetic fields, e.g., those generated by mobile communication systems.

A perspective on electromagnetic field bioeffects and risk assessment

There is evidence to suspect that a human health risk could exist from exposure to power frequency electromagnetic fields (EMFs). Summary analyses of epidemiological evidence suggest that, if the effects seen are real, they are small, with relative risks of the order 1.5–2.5. The past several years of epidemiological results are consistent with those of previous years, but do not add markedly to the understanding of potential human health risk. A similar situation has existed with benzene. Health concerns for benzene originated in the workplace with case reports. For many years, epidemiology studies alone provided the information on risks from benzene; until recently, animal models did not yield any tumors. Finally after 50 years of laboratory studies, an animal model provided tumors, but not the primary one associated with benzene exposure to humans. A brief history of the benzene story is presented to provide a perspective on the progress in understanding the potential risk of EMFs. Radon and toxic chemicals, which are present in indoor air, have been examined qualitatively only in a few EMF epidemiological studies. Because these materials have the potential to overshadow any signal coming from EMF exposures, they must be treated quantitatively. No classical cancer studies have been completed as yet for EMFs, but a variety of promotion or copromotion animal studies have been reported. Results of these and other studies lend support for consideration of EMF not being a complete carcinogen, but possibly a promoter. Qualitatively, whole animal studies, together with results of epidemiological works, suggest that greater intensities (magnetic flux densities) may be associated with greater responses (or lower p values). Other laboratory studies have been designed to examine more basic mechanisms, but the use of these types of studies in risk assessment is not straightforward. A methodology, based on relative potency concepts, is introduced; it can be used to assist in the assessment of the degree of hazard which EMF poses. EMF researchers can contribute to the use of this type of analysis by including positive controls in their experimental designs.

Gap junction impedance, tissue dielectrics and thermal noise limits for electromagnetic field bioeffects

The model presented in this study quantitatively examines the effect of gap junctions and gap junction impedance on electromagnetic field (EMF) dosimetry in a tissue target. A simple linear distributed-parameter electrical model evaluates the effect of tissue structure on the thermal threshold (signal-to-thermal-noise ratio) for detectable induced transmembrane voltage. Analysis of the angular frequency response of the array model, using a membrane impedance which includes ion binding and coupled surface chemical reaction kinetics, suggests that the frequency range, over which maximum detectable induced transmembrane voltage could be achieved, is orders of magnitude lower than that for a single cell. Gap junction impedance has negligible effect on both the frequency response and the increased transmembrane voltage due to a cell array unless its value becomes as high as that of an artificial bilayer lipid membrane. This results in a threshold for induced electric field bioeffects of approximately 10 μV cm −1 at the target site for a 1–10 mm cell array. Physiological variations in gap junction impedance appear to have little effect on this threshold. Thus, cells in gap junction contact in developing, repairing or resting state tissue structures would be expected to be able to detect significantly weaker EMF signals than isolated single cells. The lowered frequency response of a cell array reinforces the suggestion that the spectral density of the input signal should be adjusted to the bandpass of the detector pathway for dose-efficient and selective EMF bioeffects.

Effects of Intermittent Electromagnetic Fields on Mitosis and Respiration

We have previously shown that continuous exposure of the slime mold Physarum polycephalum to extremely low frequency electromagnetic fields (75 Hz, 2.0 G, 0.7 V/m) lengthens the mitotic cell cycle and depresses the rate of respiration. In this paper, we report that exposing Physarum polycephalum to intermittent fields (16 hrs/day, 5 days/wk) of 76 Hz, 1.0 G, 1.0 V/m lengthens the cell cycles and increases rather than decreases the respiration rate. these results imply in addition to field intensity and waveform, the length of exposure is an important parameter in elucidating the bioeffects of electromagnetic fields.