Effect of modified SHF and acoustic stimulation on spectral characteristics of the electroencephalograms of the cat brain

The effect of modulated electromagnetic fields on the spectral parameters of bioelectric brain activity in awake cats was studied by registering the electroencephalogram from the skin surface in the vertex area using carbon electrodes. In the normal electroencephalogram, spectral components in the range above 20 Hz predominated. It was shown that, upon irradiation with electromagnetic field (basic frequency 980 MHz, power density 30-50 microW/cm2), spectral components in the range of 12-18 Hz begin to prevail. A similarity in the redistribution of the power of spectral components upon both acoustic and modulated electromagnetic influences was revealed. The results suggest that there is a a common neurophysiological mechanism by which modulated electromagnetic radiation and acoustic stimulation affect the electrical activity of the brain. This ia consistent with the assumption that the effect of the electromagnetic field on the central nervous system is mediated through the acoustic sensory system.     

Effect of microwaves of nonthermal intensity on the number of aberrant hepatocytes in rats

It was shown on rats that the effect of permanently generated electromagnetic field (a whole-body exposure) during 45 days (7h a day, the energy flux density of 10 microW/cm2) caused a decrease in number of hepatocytes with the affected chromosomes. Some part of animals exposed to higher energy loading (PD - 50 microW/cm2, 20 days, 7 h/day) showed the increase of aberrant cells level. A single exposure at 500 microW/cm2 and a ten-fold exposure at 50 microW/cm2 (10 days, 7h a day) were shown to be ineffective.     

The effect of microwave irradiation on the peroxide modification of low density lipoproteins in human blood serum

In experiments in vitro the electromagnetic field of 2375 mHz, 500 microW/cm2 was shown to influence peroxide modification of low density lipoproteids. It was also shown that this modifying effect was prevented by high density lipoproteids that decreased the level of lipid peroxidation.     

Effects of an increased air gap on the in vitro interaction of wireless phones with cardiac pacemakers

Several clinical and laboratory studies have demonstrated electromagnetic interaction between implantable cardiac pacemakers and hand-held wireless phones operated in close proximity. Current FDA and HIMA labeling guidelines indicate that a minimum separation of 6 in (15 cm) should be maintained between a hand-held wireless phone and an implanted pacemaker. This separation requirement does not distinguish between lateral locations on the chest and a perpendicular air gap. Evidence is provided here for a substantially reduced separation threshold when measured across an air gap rather than near the saline conductive media of a simulated torso. Twenty pacemaker-phone combinations involving 6 pacemakers and 9 phones were evaluated in vitro under worst-case conditions with respect to phone output power and pacemaker sensitivity. The phones represented CDMA, TDMA-11 Hz, TDMA-22 Hz, TDMA-50 Hz, and TDMA-217 Hz digital wireless technologies. Small increases in the perpendicular air gap between the phone and the saline surface resulted in a dramatic reduction in interaction. Approximately half of the 208 test runs exhibiting interaction at an air gap of 1 cm no longer resulted in interaction when the gap was increased to 2 cm. At a gap of 7.4 cm, the percentage of runs with interaction decreased to 1.4%. The overall interaction rate, considering a total of 8296 test runs from an earlier study, was less than 0.07% at a total perpendicular distance of 8.6 cm from the saline surface to the phone antenna axis. The perpendicular distance threshold of 8.6 cm was significantly less than the horizontal plane projection threshold of 19 cm previously reported. This difference is a function of the electromagnetic field coupling to the saline bath rather than field strength changes along the axis of the phone antenna. The results have implications for those making recommendations to pacemaker patients who may be unaware of this distinction.     

Augmentation of antibiotic activity by low-frequency electric and electromagnetic fields examining Staphylococcus aureus in broth media

Systemic treatment of biomaterial‐associated bacterial infections with high doses of antibiotics is an established therapeutic concept. The purpose of this in vitro study was to determine the influence of magnetic, electromagnetic, and electric fields on gentamicin‐based, antibiotic therapy. It has been previously reported that these fields are successful in the treatment of bone healing and reducing osteitis in infected tibia‐pseudarthroses. Four separate experimental setups were used to expose bacterial cultures of Staphylococcus aureus both in Mueller‐Hinton broth (MHB) and on Mueller‐Hinton agar (MHA), in the presence of gentamicin, to (1) a low‐frequency magnetic field (MF) 20 Hz, 5 mT; (2) a low‐frequency MF combined with an additional alternating electric field (MF + EF) 20 Hz, 5 mT, 470 mV/cm; (3) a sinusoidal alternating electric field (EF AC) 20 Hz, 470 mV/cm; and (4) a direct current electric field (EF DC) 588 mV/cm. No significant difference between samples and controls was detected on MHA. However, in MHB each of the four fields applied showed a significant growth reduction of planktonically grown Staphylococcus aureus in the presence of gentamicin between 32% and 91% within 24 h of the experiment. The best results were obtained by a direct current EF, decreasing colony‐forming units (CFU)/ml more than 91%. The application of electromagnetic fields in the area of implant and bone infections could offer new perspectives in antibiotic treatment and antimicrobial chemotherapy. Bioelectromagnetics 32:367–377, 2011. © 2011 Wiley‐Liss, Inc.     

The effect of an electromagnetic field on the indices of conditioned reflex activities in rats]

The formation of defensive conditional reflexes in rats exposed to 10 cm electromagnetic field of different power densities during 4-months-long experiment has been studied. Stability of conditional reflectory reactions for the whole period of exposure is shown. The after-exposure period is characterized by the prevalence of excitatory processes.     

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”。     

Neuroeffects of prolonged exposure to microwaves: systemic, neuronal and electron microscope study

Cats were kept in the electromagnetic field (2375 mHz, 500 microW/cm2) for 200 h. A functional disorder was noted in the neuronal activity of the studied brain formations associated with a physical injury to axo-dendritic synapses involved in the promotion of the morphological relationship between the brain departments.     

Changes in the activity and conditioned-reflex behavior of white rats during and after chronic microwave irradiation

Albino rats were exposed to chronic (1-3 months) electromagnetic radiation (2375 MHz; 1, 5, 10, 50 and 500 microW/cm2; 7 hours a day). Inhibition of the activity during the open field tests and diminution of consolidation of the defence conditioned reflexes in a shuttle chamber occurred during exposure (5 to 500 microW/cm2) while the activity increased and reflexes consolidation gradually normalized during the post-irradiation period.     

Effect of low-level, 60-Hz electromagnetic fields on human lymphoid cells: I. Mitotic rate and chromosome breakage in human peripheral lymphocytes

Dividing human peripheral lymphocytes from 10 normal adults (5 males and 5 females) were exposed in vitro to low level 60-Hz electromagnetic fields for 69 hours. The current density of the electrical field was 30 microA/cm2, while the magnetic field was either 1 or 2 gauss. The cytological endpoints measured were mitotic rate and chromosome breakage. No statistically significant differences, indicative of a field effect, were observed between treated and control cells whether exposed to an electric field, a magnetic field, or to various combinations of the two.     

Physical properties of biophotons and their biological functions

Biophotons (BPHs) are weak photons within or emitted from living organisms. The intensities of BPHs range from a few to several hundred photons s(-1) x cm(-2). BPH emission originates from a de-localized coherent electromagnetic field within the living organisms and is regulated by the field. In this paper based on the experimental results of Poisson and sub-Poisson distributions of photocount statistics, the coherent properties of BPHs and their functions in cell communication are described. Discussions are made on functions which BPHs may play in DNA and proteins functioning including the process of DNA replication, protein synthesis and cell signalling and in oxidative phosporylation and photosynthesis.     

Temperature changes in chicken embryos exposed to a continuous-wave 1.25 GHz radiofrequency electromagnetic field

A total of 550 fertile chicken eggs (White Leghorn) were exposed to a radiofrequency (RF) electromagnetic field of 1.25 GHz (continuous wave) at six different power flux densities in the range of 9.0-0.75 mW/cm(2). The eggs were exposed either continuously throughout the whole 21 days of incubation (long-term exposure) or in a short-term exposure (1-2 h/day). The temperatures of the embryonic tissue and the amniotic fluid, respectively, were measured with inserted temperature probes. This study was designed to investigate the relationship between exposure and temperature changes in exposed tissues, without considering biological and medical effects. This knowledge is of general interest for studies of nonthermic teratological or embryo-lethal effects of exposure to electromagnetic fields (EMFs). Throughout the entire 21 days of embryonic development, the mean temperature increases in the eggs during the exposure were found to be up to 0.25 degrees C for a power flux density of 1.25 mW/cm(2) and increased to 2.3 degrees C for 9.0 mW/cm(2). The corresponding maximum whole-body SARs for the embryos over the 21 days of embryonic development were 1.45 and 10.44 W/kg, respectively. At 0.75 mW/cm(2) (0.87 W/kg) the extent of the RF-field induced hyperthermia was within the measurement accuracy (+/-0.1 degrees C) of the temperature probes used in the tests. The field-induced temperature increase was greatest in the first week of incubation and was less pronounced in the last (third) week before hatching. In both the short- and the long-term exposures, the temperature of the exposed tissue and the amniotic fluid, respectively, reached its maximum (asymptotic) approximately 40-50 min after the RF field was switched on. After the field was switched off, the temperature inside the exposed eggs returned to its initial value within 40-50 min.     

Study of effects of low level microwave field by method of face masking

The aim of this study was to examine experimentally effects of low level, modulated microwaves on human central nervous system function utilizing the phenomenon of visual masking. Ten healthy volunteers, four males and six females, were exposed to electromagnetic field (450 MHz, 0.16 mW/cm2) with 7 Hz modulation frequency. Two photo series (visual stimuli) of unfamiliar, young male faces were presented to the subjects, one picture after another. All the photos were frontal views of unfamiliar faces, which could be recognized only by their unique combinations of features. The task was to identify the pictures from a group of six photos and to decide which order they were presented in. The phenomenon of visual masking is revealed as anamorphosis in subject's perception of two instantaneous visual stimuli presented within a short time interval. When both stimuli were to be recognized correctly and put in the right order, there was a statistically significant difference (P < 0.05) between the identification of the stimulus with microwave electromagnetic field and sham exposure. Recognition of both stimuli in a pair was better under the sham exposure conditions but the actual difference was only 5%. It was concluded that early stages of visual information processing are overwhelmingly robust and routine (and adaptively significant) activities, so that the low level 7 Hz modulated electromagnetic field effects exerted upon it are extremely weak.     

Primary mechanisms of the biological effect of electromagnetic fields

Based on the model of a bulk knitted structure, a possible mechanism of action of an external electromagnetic field on biological systems was proposed. The electromagnetic field affects biological processes through changes in the rates of biochemical reactions in response to changes in the conformational properties of water in the electromagnetic field.     

Cell surface changes during electromagnetic field exposure

Fibroblasts from 5 1/2-day-old chick embryos go through a sequential series of changes when exposed to a constant electromagnetic field (EMF) of 10 V/cm. These changes include rounding up, becoming bipolar in shape, assuming a cylindrical profile, elongating perpendicular to the EMF, and migrating to the cathode. These morphological changes are associated with changes of the cell surface, which include the formation of filopodia and extensive sheet-like contacts on the cathodic cell surface, the retraction of processes and the formation of focal contacts on the anodic cell surface.     

MRI中电磁场对神经及心脏刺激的研究进展

电磁场对人体产生的生物效应近年来引起人们的极大关注。文章先简单介绍了电磁场生物效应的早期研究,然后着重介绍现代磁共振医学成像应用中时变电磁场对神经和心脏刺激的潜在危险,并对该领域的研究方法和研究进展做出综述和展望。     

Radio-frequency electromagnetic fields associated with cellular-radio cell-site antennas.

Because of a heightened public awareness of issues pertaining to the use of electromagnetic energy, concurrent with a rapid growth of the cellular telephone industry, a study was initiated to characterize the electromagnetic environment associated with typical cell-site antennas. In particular, the radio-frequency electromagnetic (RF) fields in the vicinity of several antenna towers, ranging in height from 46-82 m, were characterized by measurement. In all cases, the antennas were omnidirectional co-linear arrays. The maximal power densities considered representative of public exposure were found to be less than 100 microW/m2 (10 nW/cm2) per radio channel. Comparison of measured values with the corresponding values that were calculated from the free-space transmission formula indicated that the analytical technique is conservative (i.e., overestimates field levels). The measured and corresponding analytical values were found to be well below accepted exposure limits even when extrapolated to simultaneous and continuous operation of the maximal number of transmitters that would be expected to be installed at a cell-site. Additional measurements were made in the near field of the same antenna type in a roof-mounted configuration. At a distance of 0.7 m from the antenna, the maximal power density in the main beam was found to be less than 30 W/m2 (3 mW/cm2) when normalized to sixteen radio channels (the maximal number used on a single antenna) and less than 30 mW/m2 (3 microW/m2) at 70 m. In all cases, the effective radiated power (ERP) by each radio channel was 100 W referenced to a half-wave dipole. This paper describes the instrumentation and measurement techniques used for this study and provides a summary of the results.     

No effects of pulsed radio frequency electromagnetic fields on melatonin, cortisol, and selected markers of the immune system in man

There is growing public concern that radio frequency electromagnetic fields may have adverse biological effects. In the present study eight healthy male students were tested to see whether or not radio frequency electromagnetic fields as used in modern digital wireless telecommunication (GSM standard) have noticeable effects on salivary melatonin, cortisol, neopterin, and immunoglobulin A (sIgA) levels during and several hours after exposure. In a specifically designed, shielded experimental chamber, the circularly polarized electromagnetic field applied was transmitted by an antenna positioned 10 cm behind the head of upright sitting test persons. The carrier frequency of 900 MHz was pulsed with 217 Hz (average power flux density 1 W/m2). In double blind trials, each test person underwent a total of 20 randomly allotted 4 hour periods of exposure and sham exposure, equally distributed at day and night. The results obtained show that the salivary concentrations of melatonin, cortisol, neopterin and sIgA did not differ significantly between exposure and sham exposure.     

Enhanced responsiveness to parathyroid hormone and induction of functional differentiation of cultured rabbit costal chondrocytes by a pulsed electromagnetic field

Pulsed electromagnetic fields promote healing of delayed united and ununited fractures by triggering a series of events in fibrocartilage. We examined the effects of a pulsed electromagnetic field (recurrent bursts, 15.4 Hz, of shorter pulses of an average of 2 gauss) on rabbit costal chondrocytes in culture. A pulsed electromagnetic field slightly reduced the intracellular cyclic adenosine 3',5'-monophosphate (cAMP) level in the culture. However, it significantly enhanced cAMP accumulation in response to parathyroid hormone (PTH) to 140% of that induced by PTH in its absence, while it did not affect cAMP accumulation in response to prostaglandin E1 or prostaglandin I2. The effect on cAMP accumulation in response to PTH became evident after exposure of the cultures to the pulsed electromagnetic field for 48 h, and was dependent upon the field strength. cAMP accumulation in response to PTH is followed by induction of ornithine decarboxylase, a good marker of differentiated chondrocytes, after PTH treatment for 4 h. Consistent with the enhanced cAMP accumulation, ornithine decarboxylase activity induced by PTH was also increased by the pulsed electromagnetic field to 170% of that in cells not exposed to a pulsed electromagnetic field. Furthermore, stimulation of glycosaminoglycan synthesis, a differentiated phenotype, in response to PTH was significantly enhanced by a pulsed electromagnetic field. Thus, a pulsed electromagnetic field enhanced a series of events in rabbit costal chondrocytes in response to PTH. These findings show that exposure of chondrocytes to a pulsed electromagnetic field resulted in functional differentiation of the cells.     

Low frequency magnetic emissions and resulting induced voltages in a pacemaker by iPod portable music players

Background

Recently, malfunctioning of a cardiac pacemaker electromagnetic, caused by electromagnetic interference (EMI) by fields emitted by personal portable music players was highly publicized around the world. A clinical study of one patient was performed and two types of interference were observed when the clinicians placed a pacemaker programming head and an iPod were placed adjacent to the patient's implanted pacemaker. The authors concluded that "Warning labels may be needed to avoid close contact between pacemakers and iPods". We performed an in-vitro study to evaluate these claims of EMI and present our findings of no-effects" in this paper.

Methods

We performed in-vitro evaluations of the low frequency magnetic field emissions from various models of the Apple Inc. iPod music player. We measured magnetic field emissions with a 3-coil sensor (diameter of 3.5 cm) placed within 1 cm of the surface of the player. Highly localized fields were observed (only existing in a one square cm area). We also measured the voltages induced inside an 'instrumented-can' pacemaker with two standard unipolar leads. Each iPod was placed in the air, 2.7 cm above the pacemaker case. The pacemaker case and leads were placed in a saline filled torso simulator per pacemaker electromagnetic compatibility standard ANSI/AAMI PC69:2000. Voltages inside the can were measured.

Results

Emissions were strongest (≈ 0.2 μT pp) near a few localized points on the cases of the two iPods with hard drives. Emissions consisted of 100 kHz sinusoidal signal with lower frequency (20 msec wide) pulsed amplitude modulation. Voltages induced in the iPods were below the noise level of our instruments (0.5 mV pp in the 0 - 1 kHz band or 2 mV pp in the 0 - 5 MHz bandwidth.

Conclusion

Our measurements of the magnitude and the spatial distribution of low frequency magnetic flux density emissions by 4 different models of iPod portable music players. Levels of less than 0.2 μT exist very close (1 cm) from the case. The measured voltages induced inside an 'instrumented-can' pacemaker were below the noise level of our instruments. Based on the observations of our in-vitro study we conclude that no interference effects can occur in pacemakers exposed to the iPod devices we tested.