A physical model of acoustic effects of ultrahigh frequency fields on biological systems

A physical model of radiosound based on the stimulation of mechanical oscillations in liquid media at adsorption of SHF impulse energy is presented. It is shown that a limited liquid volume can be considered as an acoustic resonator with self oscillation frequency. At definite relationships between the succession frequency and impulse duration interference takes place. Oscillograms of recorded mechanical oscillations are presented. The low frequency type of radiosound is explained. A conclusion is made concerning the reliability of the proposed method for investigating radiosound.     

Effects of microwave and radio frequency electromagnetic fields on lichens

The effects of electromagnetic fields on lichens were investigated. Field experiments of long duration (1–3 years) were combined with laboratory experiments and theoretical considerations. Samples of the lichen species Parmelia tiliacea and Hypogymnia physodes were exposed to microwaves (2.45 GHz; 0.2, 5, and 50 m W/cm²; and control). Both species showed a substantially reduced growth rate at 50 m W/cm². A differentiation between thermal and nonthermal effects was not possible. Temperature measurements on lichens exposed to microwaves (2.45 GHz, 50 m W/cm²) showed a substantial increase in the surface temperature and an accelerated drying process. The thermal effect of microwave on lichens was verified. The exposure of lichens of both species was repeated near a short-wave broadcast transmitter (9.5 MHz, amplitude modulated; maximum field strength 235 V/m, 332 mA/m). No visible effects on the exposed lichens were detected. At this frequency, no thermal effects were expected, and the experimental results support this hypothesis. Theoretical estimates based on climatic data and literature showed that the growth reductions in the initial experiments could very likely have been caused by drying of the lichens from the heating with microwaves. The results of the other experiments support the hypothesis that the response of the lichens exposed to microwaves was mainly due to thermal effects and that there is a low probability of nonthermal effects. © 1996 Wiley-Liss, Inc.     

New mechanisms of biological effects of electromagnetic fields

The production of ATP in mitochondria depends on the magnesium nuclear spin and magnetic moment of a Mg2+ ion in creatine kinase and ATPase. This suggests that enzymatic synthesis of ATP is an ion-radical process and thus depends on the external magnetic field (magnetobiology originates from this fact) and microwave fields, which control the spin states of ion-radical pairs and affect the ATP synthesis. The chemical mechanism of ATP synthesis and the origin of biological effects of electromagnetic (microwave) fields are discussed.     

New mechanisms of biological effects of electromagnetic fields

ATP production in mitochondria depends on the nuclear spin and magnetic moment of Mg²⁺ ion in creatine kinase and ATPase. Consequently, the enzymatic synthesis of ATP is an ion-radical process and depends on the external magnetic field and microwave fields that control the spin states of ion-radical pairs and influence the ATP synthesis. The chemical mechanism of ATP synthesis and the origin of biological effects of electromagnetic (microwave) fields are discussed.     

Effects of low level pulsed radio frequency fields on induced osteoporosis in rat bone

Effect of modulated pulsed electromagnetic fields (PEMFs; carrier frequency, 14 MHz. modulated at 16 Hz of amplitude 10 V peak to peak) on sciatic neurectomy induced osteoporosis in rat femur and tibia resulted in statistically significant increase in bone mineral density, and deceleration in bone resorption process and consequently further osteoporosis in rat bone. These results suggest that such an effective window of pulsed radio frequency fields may be used therapeutically for the treatment of osteoporosis.     

Immunological effects of amplitude-modulated radio frequency radiation: B lymphocyte capping

B lymphocytes collected from normal ICR Swiss mouse spleens were exposed in vitro in a Crawford cell to 147-MHz radiofrequency (RF) radiation, amplitude modulated by a 9-, 16-, or 60-Hz sine wave. The power densities ranged between 0.11 and 48 mW/cm2. The irradiated samples and the controls were maintained at 37 degrees C or 42 degrees C, with temperature variations less than 0.1 degrees C. Immediately after a 30-minute exposure, the distribution of antigen-antibody (Ag-Ab) complexes on the cell surface was evaluated at 37 degrees C by immunofluorescence. Under normal conditions (37 degrees C, no RF), Ag-Ab complexes are regrouped into a polar cap by an energy-dependent process. Our results demonstrate that the irradiated cells and the nonirradiated controls capped Ag-Ab complexes equally well after exposure at 37 degrees C. Capping was equally inhibited at 42 degrees C in both the controls and irradiated cells. No statistically significant differences in capping were observed between the RF-exposed and control samples at any of the modulation frequencies and power densities employed as long as both preparations were maintained at the same temperature.     

The synchronizing effect of infralow frequency magnetic fields on biological systems]

Time-organization of lipid peroxidation and thiol groups exchange was examined. It was shown that one-divisible 3-hours effect of the extremely low magnetic fields depending on the frequency ensured formation of definite rhythm of the investigated processes. The obtained results are considered as an evidence of frequency-dependent adoption of the magnetic fields by the living systems according to the mechanism of forced synchronization of elementary cyclic processes underlain by integral oscillations.     

Effects of protracted exposure to low intensity radio frequency fields on CHO cells in culture

This study was performed in order to investigate the biological effects of chronic exposure to low intensity radio frequency fields. By using CHO cells in culture, it was possible to extend exposure to several cell generations. The RF field consisted of a 27 MHz magnetic field (6 A/m), which produces a specific absorption rate of 1 W/kg. Exposure was continued for two to five days. The cells were then studied with respect to certain cell biological parameters: vital staining, plating efficiency, growth rate, volume and physical properties of the intracellular water, as measured by NMR. Scanning electron microscopy studies were also performed. A significant difference between exposed and control cells was found only with respect to intracellular water. A 10% decrease in line width which may indicate a corresponding increase in the spin-spin relaxation time was noted after exposure. A change in the colony forming pattern was also observed in thin cultures after two days of exposure.     

Membrane potential and currents of isolated heart muscle cells exposed to pulsed radio frequency fields

The influence of radio frequency (RF) fields of 180, 900, and 1800 MHz on the membrane potential, action potential, L-type Ca(2+) current and potassium currents of isolated ventricular myocytes was tested. The study is based on 90 guinea-pig myocytes and 20 rat myocytes. The fields were applied in rectangular waveguides (1800 MHz at 80, 480, 600, 720, or 880 mW/kg and 900 MHz, 250 mW/kg) or in a TEM-cell (180 MHz, 80 mW/kg and 900 MHz, 15 mW/kg). Fields of 1800 and 900 MHz were pulsed according to the GSM-standard of cellular phones. The specific absorption rates were determined from computer simulations of the electromagnetic fields inside the exposure devices by considering the structure of the physiological test arrangement. The electrical membrane parameters were measured by whole cell patch-clamp. None of the tested electrophysiological parameters was changed significantly by exposure to RF fields. Another physical stimulus, lowering the temperature from 36 degrees C to 24 degrees C, decreased the current amplitude almost 50% and shifted the voltage dependence of the steady state activation parameter d(infinity) and inactivation parameter f(infinity) of L-type Ca(2+) current by about 5 mV. However, at this lower temperature RF effects (900 MHz, 250 mW/kg; 1800 MHz, 480 mW/kg) on L-type Ca(2+) current were also not detected.     

Electric fields,small air ions and biological effects

Early growth of barley seedlings supplied with ion-depleted air in a controlled microenvironment was used as the criterion of physiological action in experiments designed to separate electrical field and air ion effects. The essential element in this work was the fact that³H foils, functioning as bias electrodes at applied voltages of 67.5-955 V and providing field strengths of 4.6 V/cm to 90 V/cm will produce 2.7×10⁴–1.7×10⁵ small air ions/cm³ — concentrations sufficient to yield a statistically valid increase in growth rate. In contrast, seedlings exposed to equivalent electrical fields in ion-depleted air exhibited no increase in rate of growth. These results indicate that this particular physiological response is produced by small negative air ions and is not dependent on the accompanying electrical fields.     

Primary physical mechanism of the biological effects of weak magnetic fields

The primary physical mechanism of the magnetoreception of weak magnetic fields is considered. It imposes limits on the magnetic biological effect at the stage prior to the involvement of specific biophysical and biochemical mechanisms, i.e., regardless of the nature of the target of the magnetic field. It has been shown that the biological effects of weak magnetic fields have, in general, non-linear and spectral properties. Observation of these characteristics gives information not only on the gyromagnetic ratio, but also on the parameters of the interaction between the target and its immediate surroundings. This makes it possible for one to develop schemes for the identification of the biophysical mechanisms of magnetoreception.     

A study of the biological effects of certain ELF electromagnetic fields

Experiments were performed to detect possible physiological effects of air and simulated earth return electromagnetic fields of 45 and 75 Hz at 100 V/m on young mice. The criteria used were growth rate, serotonin metabolism and alteration in susceptibility to infection with influenza virus. There were no changes in these three categories.     

K+,H+ and Cl- fluxes across erythrocyte membrane irradiated with radio frequency electromagnetic fields

The effect of 460 MHz microwave radiation on the ion-transporting properties of the isolated rat erythrocytes was studied with the use of K+, H+ and Cl(-)-selective electrodes. In comparison with the control cells kept at 0 degree C the most significant changes were observed in the K+ transport system. Particularly, microwave radiation (specific absorbed rate 280 W/kg) caused an increased loss of K+ during treatment and 2-fold decrease in the rate of K+ efflux from the irradiated erythrocytes, when the latter were incubated in the isoosmotic, unbuffered sucrose. The same changes were observed when the erythrocytes were conventionally heated up to 39 degrees C for 20 minutes. It is concluded that high levels of microwave radiation cause temperature-induced changes of the membrane structure resulting in alterations in potassium transport across the membrane.     

The theory of the frequency response of ellipsoidal biological cells in rotating electrical fields

In this paper we have presented in as compact a form as possible the theoretical formalism that is needed to predict the frequency response of a biological cell of arbitrary ellipsoidal shape to a frequency dependant rotating external field. The formalism is much more complicated than that for a spherical or cylindrical cell where the radial vector is always parallel to the surface normal at each point of the surface. In addition to providing the theory we have demonstrated that the spin rate and its frequency dependance is very intimately related to the electrical properties of the cell interior and to that of the suspending fluid. It is possible to probe these properties of the cell and its environment by utilizing this technique. This aspect has been demonstrated by examining rotational changes as a function of the conductivity of both the cell interior and its suspending liquid. We also have shown, by considering a very simple model for the cell and the two dielectric constants, that the frequency spectrum is shape dependant. All our calculations have been carried out for "lossy" systems with frictional dissipation where energy minimization methods are no longer applicable. The invariant form of the Poynting vector forms the basis of the method.     

Behavioral effects in monkeys exposed to extremely low frequency electromagnetic fields

Several experiments with rhesus and squirrel monkeys on the influence of extremely low frequency (ELF) electromagnetic fields found no effects on behavior. Magnetic fields of 0.3 and 1.0 mT with electric fields of below 1 to 29 V/m at frequencies of 7, 10, 15, 45, 60 and 75 Hz were used. Small differences in ambulatory activity and response rate were occasionally observed, but no consistent effects between or within animals on any measures were obtained. No effects on reaction time, interresponse time, match-to-sample performance, and blood constituents were observed. Such previously reported effects may not be a consequence of ELF values alone, but are probably related to other environmental variables.Presented at the Seventh International Biometeorological Congress, 17–23 August 1975, College Park, Maryland, USA.     

Electric fields induced by low frequency magnetic fields in inhomogeneous biological structures that are surrounded by an electric insulator

Electric fields induced by low-frequency magnetic fields into inhomogeneous structures, which have electric conductivities and dielectric permittivities of typical biological substances, are evaluated. Closed-form approximate and numerical solutions are obtained for nonconcentric cylinders with different electric properties (such as bone embedded in muscle), which are surrounded by a good electrical insulator (such as air). It is shown that even a single inhomogeneity in an otherwise homogenous cylinder, which is exposed to a uniform, axially directed magnetic field, can lead to substantial deviations from the direction and distribution of the induced electric field that would exist in the homogenous cylinder. Thus the induced field is not everywhere circumferential, nor does it magnitude at all angular positions increase linearly with the radial distance. Radially and circumferentially directed field components depend on size, electrical properties, and eccentricity of the inhomogeneities. Equations as well as graphical presentations are given that describe the induced fields when the enclosed inhomogeneities consist either of eccentrically located single cylinders or pairs of coaxial cylinders with different electrical conductivities or dielectric permittivities.     

Quantum mechanical aspects of effects of weak magnetic fields upon biological objects

Possible mechanisms of action of weak combined magnetic fields on biological systems have been discussed in terms of quantum mechanics. The approaches proposed make it possible to solve the problem of the failure to compare the energy of active factors with the energy of thermal motion (kT problem). A mechanism of action of combined magnetic fields on biosystems has been proposed.     

Operant behavior and colonic temperature of Macaca mulatta exposed to radio frequency fields at and above resonant frequencies

Five food-deprived rhesus monkeys were exposed to 225-MHz continuous-wave, and 1.3-GHz, and 5.8-GHz pulsed radiation to determine the minimal power densities affecting performance. The monkeys were trained to press a lever (observing-response) thereby producing signals that indicated availability of food. In the presence of the aperiodically appearing food signals, a detection response on a different lever was reinforced by a food pellet. Continuous, stable responding during 60-min sessions developed and was followed by repeated exposures to radiofrequency radiation. The subjects, restrained in a Styrofoam chair, were exposed to free-field radiation while performing the task. Colonic temperature was simultaneously obtained. Observing-response performance was impaired at increasingly higher power densities as frequency increased from the near-resonance 225 MHz to the above-resonance 5.8 GHz. The threshold power density of disrupted response rate at 225 MHz was 8.1 mW/cm²; at 1.3 GHz it was 57 mW/cm², and at 5.8 GHz it was 140 mW/cm². These power densities were associated with reliable increases in colonic temperatures above sham-exposure levels. The mean increase was typically in the range of 1°C, and response-rate changes were not observed in the absence of concomitant temperature increases. In these experiments increase of colonic temperature was a much better predictor of behavioral disruption than was either the power density of the incident field or estimates of whole-body-averaged rates of energy absorption.