Postresonance electromagnetic absorption by man and animals

A surface integral equation (SIE) method is used to calculate the specific absorption rate (SAR) in spherically capped cylindrical models irradiated by an axially incident electromagnetic plane wave (K polarization) in a frequency range for which calculations previously have not been available (80–400 MHz for man models). In the SIE method, the electromagnetic (EM) field relations are formulated in terms of electric and magnetic currents on the surface of the model. The average SAR is calculated from the far scattered EM fields by means of the forward scattering theorem. SAR data calculated by the SIE method agree with data calculated by the extended boundary condition method (EBCM) for frequencies up to 80 MHz (the upper frequency limit of the EBCM) for man models. For rat models exposed to 1–3 GHz radiation, reasonable agreement was also obtained with the limited experimental data available.     

Electromagnetic absorption in an inhomogeneous model of man for realistic exposure conditions

The advances made in quantifying electromagnetic absorption and its distribution for various exposure profiles are described. The conditions that have been studied extensively are: free-space irradiation and its variations, such as the presence of ground and reflecting surfaces and other humans in close proximity. Using an inhomogeneous block model of man, work has recently been extended to leakage-type near-fields such as those from RF heat sealers and other electronic equipment. Projections are made for the extension of this work to evaluate coupled near-fields, design of multielement near-field applicators to obtain physician-prescribed uniform or nonuniform rates of regional heating, and for the inverse scattering problem necessary for electromagnetic biomedical imaging. Accurate information about the dielectric properties of various tissues becomes increasingly important for proper inhomogeneous modeling of man.     

Vibrational resonances in biological systems at microwave frequencies

Many biological systems can be expected to exhibit resonance behavior involving the mechanical vibration of system elements. The natural frequencies of such resonances will, generally, be in the microwave frequency range. Some of these systems will be coupled to the electromagnetic field by the charge distributions they carry, thus admitting the possibility that microwave exposures may generate physiological effects in man and other species. However, such microwave excitable resonances are expected to be strongly damped by interaction with their aqueous biological environment. Although those dissipation mechanisms have been studied, the limitations on energy transfers that follow from the limited coupling of these resonances to the electromagnetic field have not generally been considered. We show that this coupling must generally be very small and thus the absorbed energy is so strongly limited that such resonances cannot affect biology significantly even if the systems are much less strongly damped than expected from basic dissipation models.     

Elf Dosage in Ellipsoidal Models of Man Due to High Voltage Transmission Lines

The fields, flux, and power density produced inside an ellipsoidal model of man by overhead high-voltage transmission lines have been calculated. The values depend strongly on the conductivity and the shape of the ellipsoid and, in general, vary from point to point within it. The maximum energy flux is the more reliable indicator of exposure to the electromagnetic field.     

Kinetocardiogram recording from a freely moving person]

Radiokinetocardiogram (RKCG) recorded with the aid of telemetric system and electromagnetic kinetotransducer was sufficiently differentiated and was of the shape identical to the directly recorded kinetogram. A possibility of reliable recording of the RKCG in a freely moving man (during a micropause in the process of movement) was demonstrated under laboratory and natural working conditions.     

Retardation of embryogenesis by extremely low frequency 60 Hz electromagnetic fields

Fertilized Medaka fish eggs were used to determine if electromagnetic fields, designed to simulate those beneath a high voltage power line, have biological effects on vertebrate embryo development. The newly fertilized eggs were exposed to a 60 Hz electrical field of 300 mA/m2 current density, a 60 Hz magnetic field of 1.0 gauss RMS, or to the combined electric plus magnetic fields for 48 hours. No gross abnormalities were observed in any of the embryos as they developed, but significant development delays were seen in those embryos exposed to either the magnetic or to the combined electromagnetic fields; delays were not seen in the embryos exposed to the electrical field. Thus, a 60 Hz magnetic field like that encountered in a man made powerline environment was shown to retard development of fish embryos.     

Pulsating Electromagnetic Field in the Therapy of Headache

We investigated the effects of exposure to environmental electromagnetic fields (EMFs) in 1170 subjects. Neutrophil phagocytosis was enhanced in the low-intensity exposure groups, but reduced significantly at relatively high intensities. Visual reaction time was prolonged and the scores of short-term memory tests were lower in some high-intensity exposure groups. EMFs may affect the central nervous and immune systems in man.     

Dissipative functions of processes of electromagnetic radiation interaction with biological objects

Entropy generation rate inside the biological systems due to internal irreversible processes of the interaction with electromagnetic radiation is calculated for the processes of chemical free-energy increase. The irreversibility of several processes (photosynthesis in plants, eyesight of man, bioresonance effects of high frequencies of microwaves) is estimated under concrete experimental conditions. It is shown that the irreversible of five biological processes differs very much (by 10(8) times).     

Electromagnetic and ultrasonic induction of hyperthermia in tissue-like substances

Summary The potential of electromagnetic radiation and ultrasound for generating hyperthermia in tissues is discussed. Electrical properties, propagation parameters for electromagnetic and ultrasonic radiation and reflection problems yield limitations on most suitable frequency choices. Considerable insight has been gained in electromagnetic induced heat deposition patterns for the case of whole body irradiation and for local irradiations which can cause hot spot type of heating patterns. Pertinent results are compared and indicate that frequencies near 1000 MHz may be optimal for the electromagnetic case. But RF-frequencies using frequencies sufficiently low to reduce the magnetically induced term provide probably greater reproducibility. Finally recent work on mm-wave therapy and diagnosis is indicated. Emphasis is on the comparative merits of the various possible approaches.     

电磁场曝露对生物组织电磁特性的影响

电磁辐射严重影响着人体的健康.电磁场生物效应的发生机制与电磁场本身的特性相关,同时也与生物组织在电磁场作用下电磁特性的改变密切相关.生物体内的信号分子、自由基以及磁颗粒等处于外加电磁场中时其电磁特性会发生变化,尤其是不同频率电磁场曝露作用下生物组织的导电、介电以及磁学等特性会有非常显著的区别.明确不同频率电磁场作用下生物组织电磁特性的变化规律是研究电磁场生物效应发生机制以及预防问题的关键.综述了近年来电磁场对于生物组织电磁特性影响的研究成果,并对未来的研究方向做了展望.     

人体电磁兼容系统与电磁场处理水--Ⅲ.电磁水对人体电磁场的作用

《人体电磁兼容系统与电磁场处理水》一文分三篇写。第一篇“Ⅰ.人体电磁兼容系统”,讨论了人体体内电磁场;第二篇“Ⅱ·电磁水的特性”,讨论了电磁水的电磁场。二文均已发表于《生物磁学》。本文是第三篇,讨论电磁水电磁场对人体电磁场的作用,重点阐明饮用电磁水后,主要是电磁水的电磁场作为入射场与体内场发生迭加作用,产生耦合电磁场,从而实现其对体内场的调节作用,达到维系身体健康的目的。由于有关水的问题非常复杂,动态性强,故大多数关于耦合场的研究均服从于“统计学规律”。     

Harmful effects of 41 and 202 MHz radiations on some body parts and tissues

Many types of invisible electromagnetic waves are produced in our atmosphere. When these radiations penetrate our body, electric fields are induced inside the body, resulting in the absorption of power, which is different for different body parts and also depends on the frequency of radiations. Higher power absorption may result into health problems. In this communication, effects of electromagnetic waves (EMW) of 41 and 202 MHz frequencies transmitted by the TV tower have been studied on skin, muscles, bone and fat of human. Using international standards for safe exposure limits of specific absorption rate (SAR), we have found the safe distance from TV transmission towers for two frequencies. It is suggested that transmission towers should be located away from the thickly populated areas and people should keep away from the transmission towers, as they radiate electromagnetic radiations that are harmful to some parts/tissues of body.     

Radiofrequency and microwave interactions between biomolecular systems

The knowledge of mechanisms underlying interactions between biological systems, be they biomacromolecules or living cells, is crucial for understanding physiology, as well as for possible prevention, diagnostics and therapy of pathological states. Apart from known chemical and direct contact electrical signaling pathways, electromagnetic phenomena were proposed by some authors to mediate non-chemical interactions on both intracellular and intercellular levels. Here, we discuss perspectives in the research of nanoscale electromagnetic interactions between biosystems on radiofrequency and microwave wavelengths. Based on our analysis, the main perspectives are in (i) the micro and nanoscale characterization of both passive and active radiofrequency properties of biomacromolecules and cells, (ii) experimental determination of viscous damping of biomacromolecule structural vibrations and (iii) detailed analysis of energetic circumstances of electromagnetic interactions between oscillating polar biomacromolecules. Current cutting-edge nanotechnology and computational techniques start to enable such studies so we can expect new interesting insights into electromagnetic aspects of molecular biophysics of cell signaling.     

Expert System for Modeling and Simulating the Action of Electric and Electromagnetic Fields on Biological Membranes

The biological effects and applications in the developing technology involving electric and electromagnetic fields are as promising as they are diverse. Their effects, leading to remission in certain patients, can be obtained through electroporation, electrochemotherapy, electrotherapy, electroimmunotherapy, and gene electrotherapy. The main therapeutic uses of electromagnetic fields (EMF) are the introduction of chemical or organic substances into opportunely opened cells (electro-chimiotherapy) and the stimulation of specific elements of the immune system (electro-immunotherapy). Their benefits can be modeled by the use of expert systems, constructed to mimic human reasoning. As well as testing new therapies, such systems can analyze and synthesize existing data, and provide a new pedagogical device, and can be implemented on the Internet network. These techniques can be performed conjointly with other therapies like X-ray therapy, neutrotherapy and, in certain conditions, will optimize their effects. Some mathematical models, representing the electromagnetic field's action on cellular membranes, have been elaborated by means of the SADT method (a structured hierarchy modular method) and implanted into the expert system SEI4. This expert system simulates the immune system's behavior when facing electromagnetic fields, in the face of immunodeficient illness such as some cancers or AIDS.     

EMP simulators and public safety: an analysis

Effects produced by electromagnetic fields from exoatmospheric nuclear detonations, known as electromagnetic pulses (EMPs) and devices, which simulate these EMPs are analyzed for their potential danger to human beings in contact with large energy collectors. Comparison is made with ANSI guidelines established for radio-frequency electromagnetic fields.     

A simple and rapid method for electromagnetic field distortion correction when using two Fastrak sensors for biomechanical studies

The article presents a simple and rapid method for the correction of electromagnetic distortions when using electromagnetic Fastrak (Polhemus, USA) sensors. It is based on the minimization of objective functions composed of derivative polynomial functions, hence estimating the distortion of the electromagnetic field. The polynomial functions composing the objective function each contain 35 deformation coefficients. These coefficients are then used to correct the electromagnetic measures in position and orientation. Preliminary results on the efficacy of the method are presented for two subjects who walked on a treadmill, and for whom relative movement of the lower leg with respect to the thigh was recorded using two Fastrak sensors. The corrected Fastrak measurements were compared with optoelectronic measurements (Vicon, USA), which are not affected by distortions as electromagnetic sensors are. Results showed that after 3 min of calibrating a volume of approximately 1m(3), the method proved to be efficient in correcting errors in orientation (56% (2.72-1.12 degrees ), 78% (4.4-0.89 degrees ), and 56% (2.25-0.90 degrees ) of error reduction in the respective flexion/extension, ab/adduction and tibial internal/external rotation) and position (53% (18.9-8.9 mm), 21% (6.6-4.6mm), and 48% (15.9-8.1mm) of error reduction in the respective medial/lateral, anterior/posterior and proximal/distal translations) (values are overall means for two subjects and four calibration procedures). That amount of correction compared favorably with values presented in the literature.     

The influence of a low- and high-frequency electromagnetic fields on seeds

It was shown that the exposure of seeds in the rest phase to a low-frequency pulse electromagnetic field leads to substantial changes in seed physiology during germination. The changes at the physiological level in sprouting seeds depend not only on the frequency of the external EMF and its power characteristics but also on the kind of seeds. Low- and high-frequency electromagnetic fields are able to produce a biostimulation effect; however, the mechanisms of its appearance are different in their nature. The biochemical studies of seeds after EMF treatment in the modes resulting in expressed biological effects showed an increase in the activity of alpha-amylase, which testifies an increase in the gibberellin output and in the activity of the hydrolytic enzyme sour phosphatase. The response of seeds to EMF treatment demonstrates the possibility of electromagnetic control of growth processes.     

Electromagnetic cellular interactions

Chemical and electrical interaction within and between cells is well established. Just the opposite is true about cellular interactions via other physical fields. The most probable candidate for an other form of cellular interaction is the electromagnetic field. We review theories and experiments on how cells can generate and detect electromagnetic fields generally, and if the cell-generated electromagnetic field can mediate cellular interactions. We do not limit here ourselves to specialized electro-excitable cells. Rather we describe physical processes that are of a more general nature and probably present in almost every type of living cell. The spectral range included is broad; from kHz to the visible part of the electromagnetic spectrum. We show that there is a rather large number of theories on how cells can generate and detect electromagnetic fields and discuss experimental evidence on electromagnetic cellular interactions in the modern scientific literature. Although small, it is continuously accumulating.     

Influence of Electromagnetic Radiation Produced by Mobile Phone on Some Biophysical Blood Properties in Rats

Effects of electromagnetic radiation produced by mobile phone on blood viscosity, plasma viscosity, hemolysis, Osmotic fragility, and blood components of rats have been investigated. Experimental results show that there are significant change on blood components and its viscosity which affects on a blood circulation due to many body problems. Red blood cells, White blood cells, and Platelets are broken after exposure to electromagnetic radiation produced by mobile phone. Also blood viscosity and plasma viscosity values are increased but Osmotic fragility value decreased after exposure to electromagnetic radiation produced by mobile phone.