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PubMed2002

Chronic electromagnetic field exposure decreases HSP70 levels and lowers cytoprotection.

Electromagnetic field (EMF) exposures have been shown to induce heat shock proteins (HSPs), which help to maintain the conformation of cellular proteins during periods of stress. We have previously reported that short-term exposure of chick embryos to either 60 Hz (extremely low frequency: ELF), or radio-frequency (RF: 915 MHz) EMFs induce protection against hypoxia. Experiments presented in the current report are based on a study in which long-term (4 days), continuous exposure to ELF-EMFs decreased protection against ultraviolet radiation. Based on this result, it was hypothesized that de-protection against hypoxia should also occur following long-term, continuous, or daily, repeated exposures to EMFs. To test this hypothesis, chick embryos were exposed to ELF-EMFs (8 microT) continuously for 4 days, or to ELF or RF (3.5 mW incident power)-EMFs repeated daily (20, 30, or 60 min once or twice daily for 4 days). Several of the exposure protocols yielded embryos that had statistically significant decreases in protection against hypoxic stress (continuous and 30 or 60 min ELF twice daily; or 30 or 60 min once daily RF). This is consistent with our finding that following 4 days of ELF-EMF exposure, HSP70 levels decline by 27% as compared to controls. In addition, the superposition of ELF-EMF noise, previously shown to minimize ELF-EMF induced hypoxia protection, inhibited hypoxia de-protection caused by long term, continuous ELF or daily, repeated RF exposures. This EMF-induced decrease in HSP70 levels and resulting decline in cytoprotection suggests a mechanism by which daily exposure (such as might be experienced by mobile phone users) could enhance the probability of cancer and other diseases.

Animals↗
PubMed2002

Decreased DNA repair rates and protection from heat induced apoptosis mediated by electromagnetic field exposure.

In this study, we demonstrate that electromagnetic field (EMF) exposure results in protection from heat induced apoptosis in human cancer cell lines in a time dependent manner. Apoptosis protection was determined by growing HL-60, HL-60R, and Raji cell lines in a 0.15 mT 60 Hz sinusoidal EMF for time periods between 4 and 24 h. After induction of apoptosis, cells were analyzed by the neutral comet assay to determine the percentage of apoptotic cells. To discover the duration of this protection, cells were grown in the EMF for 24 h and then removed for 24 to 48 h before heat shock and neutral comet assays were performed. Our results demonstrate that EMF exposure offers significant protection from apoptosis (P<.0001 for HL-60 and HL-60R, P<.005 for Raji) after 12 h of exposure and that protection can last up to 48 h after removal from the EMF. In this study we further demonstrate the effect of the EMF on DNA repair rates. DNA repair data were gathered by exposing the same cell lines to the EMF for 24 h before damaging the exposed cells and non-exposed cells with H2O2. Cells were allowed to repair for time periods between 0 and 15 min before analysis using the alkaline comet assay. Results showed that EMF exposure significantly decreased DNA repair rates in HL-60 and HL-60R cell lines (P<.001 and P<.01 respectively), but not in the Raji cell line. Importantly, our apoptosis results show that a minimal time exposure to an EMF is needed before observed effects. This may explain previous studies showing no change in apoptosis susceptibility and repair rates when treatments and EMF exposure were administered concurrently. More research is necessary, however, before data from this in vitro study can be applied to in vivo systems.

Apoptosis↗
PubMed1996

Effect of pulsed electromagnetic fields on bone formation and bone loss during limb lengthening.

We examined the effect of pulsed electromagnetic fields (PEMFs) on bone formation and disuse osteoporosis sustained during limb lengthening in a double-blind study. Seven males (mean age 13 years, range 11-19 years) and six females (mean age 12 years, range 9-19 years) were randomly allocated to receive either an active or an inactive PEMF coil. Limb lengthening was performed by the Villarubbias technique using either a unilateral or circular frame system. Sequential bone density measurements were made using dual energy X-ray absorptiometry and compared to traditional radiographs. Ten segments (eight tibial and two femoral) in seven patients were lengthened under the influence of active coils and eight segments (six tibial and two femoral) in six patients using inactive coils. There was no difference in the rate nor the amount of new bone formed at the site of distraction between the two groups. Bone loss in the segments of bone distal to the lengthening sites was observed in both groups but was significantly more marked using inactive coils (BMD reduced by 23% +/- SEM 3% and 33% +/- 4% control values after one and two months, respectively; p < 0.0001) than using active coils (BMD reduced by 10% +/- 2% at 2 months). These differences were greater at 12 months after surgery (reduced by 54% +/- 5% and 13% +/- 4%, respectively; p < 0.0001). Stimulation with pulsed electromagnetic fields has no effect on the regenerate bone, but does prevent bone loss adjacent to the distraction gap.

Absorptiometry, Photon↗
PubMed2001

Population exposure to electromagnetic fields generated by radio base stations: evaluation of the urban background by using provisional model and instrumental measurements.

Electromagnetic radiation, which is used by broadcasting and mobile telephone systems to transmit information, permeates the city environment. In order to properly evaluate population exposure to electromagnetic fields, knowledge of their intensity and spectral components is necessary. In this study the results of radiofrequency field monitoring carried out in Torino, a large town located in the north-west of Italy are shown: the variation of the electromagnetic field strength is evaluated as a function of the height from the ground, the location in the urban area and the frequency. separating the contributions of the different sources (broadcasting antennas and radio base stations for mobile phones). Furthermore, the contribution of the radio base stations is theoretically evaluated, adding the emissions off all installations situated in Torino and examining the field strength maps calculated, considering the orography, for different heights. The theoretical values are also compared with those measured in the frequency range of mobile telephony emissions.

Background Radiation↗
PubMed1996

Effects of pulsed high-frequency electromagnetic fields on human sleep.

In the present study we investigated the influence of pulsed high-frequency electromagnetic fields of digital mobile radio telephones on sleep in healthy humans. Besides a hypnotic effect with shortening of sleep onset latency, a REM suppressive effect with reduction of duration and percentage of REM sleep was found. Moreover, spectral analysis revealed qualitative alterations of the EEG signal during REM sleep with an increased spectral power density. Knowing the relevance of REM sleep for adequate information processing in the brain, especially concerning mnestic functions and learning processes, the results emphasize the necessity to carry out further investigations on the interaction of this type of electromagnetic fields and the human organism.

Adult↗
PubMed1981

[Measurement and hygienic evaluation of electromagnetic fields in the environment of diathermy, welding machines and induction heaters].

Measurements of electromagnetic field intensity at work-stations, as well as in the environment of 36 induction heaters, 24 welders and 6 diathermies have been taken. Maximum values of field E intensity at the work-stations with induction heaters ranged from below 2 V/m to 96 V/m, and for field H -- from below 0.5 A/m to 8.2 A/m. Maximum values of field E intensity at the work-stations with welders ranged from 25 V/m to 480 V/m. And Maximum values of field E with diathermy exceeded 300 V/m near electrodes. At the work-station of medical staff operating diathermy, the field intensity values ranged from 5.1 to 16 V/m. Basing on the obtained values of the e-m intensity at work-stations and in the environment of the mentioned instruments, protective zones ranges have been determined: intermediate, weerning and dangerous. In addition, effective e-m field exposure duration, at specific instruments, has been determined.

Diathermy↗
PubMed1986

Transferrin receptors and natural killer cell lysis. A study using Colo 205 cells exposed to 60 Hz electromagnetic fields.

The role of target cell transferrin receptors (TfR) in natural killer (NK) cell-induced cytolysis has been studied using Colo 205 cells in which prior exposure to 60 Hz electromagnetic fields produced constitutive expression of maximum numbers of TfR. It was found that NK cell cytolysis was decreased in those cells expressing the highest levels of TfR, while cells expressing the lowest level of TfR were lysed to the greatest extent. Furthermore, pretreatment of target cells with, and the continued presence in the assay medium of, iron transferrin produced, in general, only a slight decrease in cytolysis. Incubation of cells with apotransferrin also produced only a slight decrease in cytolysis, while incubation with zinc transferrin produced a greater decrease in cytolysis. This latter effect was particularly dramatic for cells that had been exposed previously to either a 60 Hz magnetic field alone (1.0 gauss) or to a combined electric + magnetic field (current density 300 mA/m2, 1.0 gauss). In addition to indicating a discordance between TfR expression on target cells and their sensitivity to NK cell cytolysis, the data presented provide a further indication of cellular membrane changes produced by exposure to 60 Hz electromagnetic fields.

Adenocarcinoma↗
PubMed1984

Pulsing electromagnetic field therapy in nerve regeneration: an experimental study in the cat.

A multidisciplinary approach to the study of peripheral nerve regeneration in the cat has been presented. The purpose of this work has been to determine if pulsing electromagnetic field (PEMF) therapy can enhance peripheral nerve regeneration after injury. In equal groups of animals, two types of pulsing electromagnetic field treatment were compared with untreated controls. All animals underwent quantitative electrophysiologic and morphologic assessment at the area of injury. In addition, muscle fiber sizing in the periphery and retrograde labeling of anterior horn motoneurons with horseradish peroxidase were studied. Results have shown no statistical differences between the groups in electrophysiologic or morphologic parameters. However, in animals treated with a pulse-burst electromagnetic field there was a statistically significant improvement in the labeling and localization of anterior horn cells in the central nervous system. These results indicate that pulse-burst electromagnetic radiation can increase the numbers of motor neurons that reestablish appropriate connections to the periphery after nerve injury. It remains to be seen if this improved spinal cord organization can translate to improved peripheral functional return.

Animals↗
PubMed2004

The efficiency of electromagnetic field treatment in Complex Regional Pain Syndrome Type I.

INTRODUCTION: Complex Regional Pain Syndrome Type I is a pathological condition that occurs without evident nerve injury and follows a course characterized by severe pain. PURPOSE: The aim of this study is to assess whether or not electromagnetic field treatment administered with calcitonin and exercise has positive effects on clinical improvement, scintigraphic assessment and bone markers compared to calcitonin and exercise administration. METHOD: In this randomized double-blind, placebo-controlled study, 40 patients with Complex Regional Pain Syndrome Type I, that developed after a Colles fracture were included in the assessments and were administered calcitonin and exercise treatment for 6 weeks. In addition to this treatment, half the patients received electromagnetic field treatment, and the other half received placebo treatment. The patients were evaluated at the beginning and end of treatment with clinical parameters, scintigraphic assessment and biochemical markers. RESULTS: Although we found some significant improvements in our evaluation criteria, we could not find a significant statistical difference between groups. CONCLUSIONS: The absence of a significant difference between the two groups in the assessment parameters has been interpreted as evidence that electromagnetic field treatment does not provide additional benefit to calcitonin and exercise treatment.

Adolescent↗
PubMed1988

Learning ability of young rats is unaffected by repeated exposure to a static electromagnetic field in early life.

Infant albino rats were exposed to a static electromagnetic field of 0.0 Tesla (control) or 0.5 Tesla (experimental) for 14 postnatal days. Following a 1-month rest period, the experimental (13 males and 10 females) and control (11 males and 14 females) rats were trained on four successive reversals of a position habit in a single-unit enclosed T-maze that was adapted for the use of escape-avoidance of mild foot shock as a motive. There was no significant difference in learning ability between the experimental and control groups in terms of total (initial combined with repetitive) errors committed over the four reversal problems. While the females tended to make more errors than the males, this difference was likewise insignificant.

Age Factors↗
PubMed1995

Recovery characteristics of a rigid, nonmetallic microdialysis probe for use in an electromagnetic field.

It is well known that metal objects perturb electromagnetic fields. Therefore, a conventional metal microdialysis probe cannot be used to determine the bioeffects of electromagnetic radiation. Using fused-silica tubing, we developed an inexpensive nonmetallic, rigid microdialysis probe for use in electromagnetic radiation research or during magnetic resonance imaging. This probe has a concentric tube design, with the membrane length adjustable to the size of the area to be dialyzed. The probes tested had regenerated-cellulose membranes that were 3 mm in length. This report describes how to make this probe. Average relative recovery rates at flow rates of 2.0, 1.0, and 0.5 microliters/min were 21%, 27%, and 42%, respectively. These rates were slightly lower than the 30%, 42%, and 68% obtained with the commercially available metallic CMA10 microdialysis probe with a 3 mm membrane. This may be due to the fused-silica probe and CMA10 probe being made with different types of dialysis membranes.

Amino Acids↗
PubMed1985

Geophysical variables and behavior: XXV. Alterations in memory for a narrative following application of theta frequency electromagnetic fields.

Subjects were asked to listen to a 3-min. narrative. During Min. 1, 2, or 3 of the narrative, subjects were exposed for 60 sec. to either 5-Hz or 20-Hz electromagnetic fields or to a sham field condition. The fields were generated by commercial devices and applied externally to the side of the head at the level of the temporal lobe. The transcript of each subject's version of the narrative was evaluated by discourse analyses for the numbers of direct recalls or of inferences for each of the three segments. Subjects who had received the 5-Hz fields during Min. 1 and 2 of the narrative displayed twice as many inferences for the material that had been presented during Min. 1 only compared to the 20-Hz groups who did not differ from the sham-field subjects. We hypothesize that there are small alterations in the processing of complex series of verbal stimuli by these weak, theta frequency electromagnetic fields. They might not affect the amount of recall but they may influence the details of recall.

Adolescent↗
PubMed2001

Population-based case-control study of occupational exposure to electromagnetic fields and breast cancer.

PURPOSE: This population-based case-control study examined occupational exposure to electromagnetic fields in relation to female breast cancer incidence among 843 breast cancer cases and 773 controls. METHODS: Exposure was classified based on work in the two longest-held jobs, and indices of cumulative exposure to magnetic fields based on a measurement survey. RESULTS: Female breast cancer was not associated with employment as an office or industrial worker. For the total study population, cumulative exposure over the entire career, and in the past 0-10 and 10-20 years generally showed odds ratios (ORs) close to the null. Moderately elevated risks were found for intermediate but not high levels of cumulative exposure accumulated 20 or more years ago (OR = 1.5; 95% CI = 1.1-2.0). Associations were stronger for premenopausal women (OR = 1.7; 95% CI = 1.1-2.7) in the past 10-20 years, and those with estrogen-receptor positive (ER+) breast tumors (OR = 2.06; 95% CI = 1.1-4.0). No consistent dose-response patterns were observed. CONCLUSIONS: These findings give little support to the hypothesis that electromagnetic fields cause cancer of the female breast.

Adult↗
PubMedDate not supplied

Automated external defibrillators appropriately recognize ventricular fibrillation in electromagnetic fields.

OBJECTIVES: Automated external defibrillators (AEDs) are increasingly available in industrial settings, but many industries have high electromagnetic fields (EMFs), which can interfere with the function of electronic devices. This study evaluated the performance of several AEDs when exposed to high EMFs. METHODS: Three commercially available AEDs were evaluated in the setting of a public utility coal-fired electrical generation plant. Each AED was placed in three areas of high EMF ranging from 310 to 1,600 milligauss. A signal generator, used to simulate various cardiac rhythms, was connected to the AEDs. Rhythms simulated were ventricular fibrillation, asystole, and normal sinus rhythm. Each of the AED's interpretations of various rhythms were evaluated in the different EMF settings. RESULTS: Rhythms of ventricular fibrillation, asystole, and normal sinus rhythm were correctly recognized by each AED in each of the three areas of high EMF. Each AED appropriately recommended defibrillation when presented with ventricular fibrillation. No misinterpretations or inappropriate defibrillations were observed. CONCLUSION: Electromagnetic fields generated by an electrical power plant did not interfere with three commercial AEDs' abilities to correctly interpret simulated rhythms and recommend appropriate defibrillation.

Cardiopulmonary Resuscitation↗
PubMed2004

Development of preincubated chicken eggs following exposure to 50 Hz electromagnetic fields with 1.33-7.32 mT flux densities.

The effects of applying extremely low-frequency (50 Hz) electromagnetic fields (ELF-EMF) for 24 hr and different densities (1.33-7.32 mT) were examined on healthy, freshly fertilized white leghorn chicken eggs (55-65 g). Results showed no increase in the rate of abnormalities in exposed groups, but were only significant in 4.19, 5.32 and 5.86, 6.65 mT densities. Alizarin red S and alcian blue 8GX staining showed some embryos with extra ribs, defects in ribs and vertebrae, anuria and abnormal beaks. Study of egg weight, after 9 days of incubation, showed no significant differences between control, sham-exposed and experimental groups. Analysis of crown-rump, beak-occipital length and weight of embryo, showed significant decrease in weight at 4.39 and 5.52 mT intensities, comparing with control and sham-exposed groups. These results revealed that 50 Hz electromagnetic fields can even induce developmental alterations in preincubated chick embryos and confirm that its strength could be a determinant factor for the embryonic response to extremely low frequency EMFs (window effects) prior to incubation.

Animals↗
PubMed1994

[Interactions of electromagnetic fields produced by magnetic resonance with prostheses and ferromagnetic materials].

This paper accounts for coupling modes and effects that NMR-induced electromagnetic fields (B0, dB/dt, RF) produce when interacting with prostheses and ferromagnetic materials. As for prostheses specifically, the paper reports an original contribution: an in vitro test performed on the NMR equipment mod. SISCO SIS 200/183 for research purposes installed at the Istituto Superiore di Sanità. Scope of this study was the evaluation of effects and malfunctionings induced by the above-mentioned electromagnetic fields on pacemakers inside a human trunk simulator exposed to NMR field intensity.

Electromagnetic Fields↗
PubMed2006

Growth of Escherichia coli under extremely low-frequency electromagnetic fields.

The influence of extremely low-frequency (ELF) electromagnetic fields on Escherichia coli cultures in submerse fermentation was studied. The fermentation processes were carried out recycling the culture medium externally through a stainless steel tube inserted in a magnetic field generator (solenoid). The exposure time and electromagnetic induction were varied in a range of 1 to 12 h and 0.010 to 0.10 T, respectively, according to a Box-Wilson Central Composite Designs of face centered with five central points. Growth of E. coli could be altered (stimulated or inhibited) under magnetic fieldinduced effects. E. coli cultures exposed at 0.1 T during 6.5 h exhibited changes in its viability compared to unexposed cells, which was 100 times higher than the control. The magnetic field generator associated with the cellular suspension recycle is a new way of magnetic treatment in fermentation processes and could be appropriate to industrial scale up.

Dose-Response Relationship, Radiation↗