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PubMed1999

Intrauterine effects of electromagnetic fields--(low frequency, mid-frequency RF, and microwave): review of epidemiologic studies.

Electromagnetic radiations are named according to frequency or to wavelength (which is inversely proportional to frequency) and create electromagnetic fields (EMFs). Frequencies widely vary according to sources: high-voltage power lines, electrically heated beds, MRI, VDTs, microwave ovens, satellite, and radio/TV transmissions or cellular phone transmitters/receivers. Public concern has increased about the potential health effects of EMFs. There are arguments in favour of EMFs being biologically active, but no mechanism has been identified that explains the link between EMFs and bioeffects. Human data reviewed concern the potential reproductive effects (mainly spontaneous abortions, low birthweight and congenital malformations) of exposure to sources of EMFs: maternal residence, electrically heated beds, occupational exposure (mainly video display terminals), and medical exposures. The available epidemiologic studies all have limitations that prevent to draw clearcut conclusions on the effects of EMFs on human reproduction. EMFs are ubiquitous and unavoidable exposures. The matter of possible effects cannot be considered closed, but until our understanding of the biologic important parameters of EMFs exposures is stronger,design of new studies will be difficult and small epidemiologic studies are unlikely to provide definitive answers and should not be given high priority. No conclusion can be drawn for radiofrequencies and microwaves because of lack of data. There is no convincing evidence today that EMFs of the sort pregnant women or potential fathers meet in occupational or daily life exposures does any harm to the human reproductive process.

Electromagnetic Fields↗
PubMedDate not supplied

Effect of 50-Hz electromagnetic field on the retention of toxic radionuclides in rat tissues.

The effect of electromagnetic field (EMF) 50 Hz, 10 mT, on the tissue retention of radiotoxic polonium-210 and thorium-234 was studied in a rat model. Regarding 210Po in the ionic state, small but significant effects were obtained by exposure of rats to EMF either before the intravenous injection of 210Po (pre-exposure) or after the rats had already been injected with 210Po (post-exposure). When compared with control values, pre-exposure to EMF caused a significant 28% decrease in the retention of 210Po in the skin and a 10% decrease in total 210Po retention in the investigated tissues. Relative to controls, post-exposure resulted in a 131% increase in 210Po retention only in the thymus. Regarding carrier-free 234Th in the ionic state, both types of EMF exposure caused a substantial increase in 234Th retention in the liver and spleen and a decrease of 234Th in the bones. A different effect of EMF on the retention of 234Th in the body was obtained when the mass of thorium was increased by adding as carrier 232Th (50 micrograms kg-1 body mass). With pre-exposure, a significant 10% decrease in the high retention of 234Th in the liver (77% of injected radioactivity) was observed. On the other hand, with post-exposure no significant changes in retention of 234Th were found in the tissues.

Animals↗
PubMed2006

[Global gene response to GSM 1800 MHz radiofrequency electromagnetic field in MCF-7 cells].

OBJECTIVE: To investigate whether GSM 1800 MHz radiofrequency electromagnetic field (RF EMF) can change the gene expression profile in MCF-7 cells and to screen RF EMF responsive genes. METHODS: Subcultured MCF-7 cells were intermittently (5-minute fields on/10-minute fields off) exposed or sham-exposed to GSM 1800 MHz RF EMF, which was modulated by 217 Hz EMF, for 24 hours at an average specific absorption rate (SAR) of 2.0 W/kg or 3.5 W/kg. Immediately after RF EMF exposure or sham-exposure, total RNA was isolated from MCF-7 cells and then purified. Affymetrix Human Genome U133A Genechip was applied to examine the change of gene expression profile according to the manufacturer's instruction. Data was analyzed by Affymetrix Microarray Suite 5.0 (MAS 5.0) and Affymetrix Data Mining Tool 3.0 (DMT 3.0). Quantitative reverse transcription polymerase chain reaction (RT-PCR) was used to validate the differentially expressed genes identified by Genechip analysis. RESULTS: A small number of differential expression genes were found in each comparison after RF EMF exposure. Through reproducible and consistent analysis, no gene or five up-regulated genes were screened out after exposure to RF EMF at SAR of 2.0 W/kg or 3.5 W/kg, respectively. However, these five genes could not be further confirmed by RT-PCR. CONCLUSION: The present study did not provide clear evidence that RF EMF exposure might distinctly change the gene expression profile in MCF-7 cells under current experimental conditions, implying that the exposure might not affect the MCF-7 cell physiology, or this cell line might be less sensitive to the RF EMF exposure.

Cell Line, Tumor↗
PubMed1983

[Immunobiological effects of a decimeter-range electromagnetic field in its exposure over the area of the thyroid gland].

The immunological effect caused by the influence of the local action of the ultrahigh frequency (UHF) electromagnetic field on the projection zone of the thyroid gland was studied. The action of UHF waves shown to be capable of producing both immunostimulating and immunosuppressing effects; their manifestation depended on the period of immunogenesis, affected by the action of UHF waves. The synthesis of nonspecific immunoglobulins showed greater resistance to the suppressive action of UHF waves than the synthesis of specific immunoglobulins, i.e. antibodies. The activation of the thyroid gland under the influence of UHF waves occurred before the immunostimulating effect was observed.

Animals↗
PubMed1985

Potassium ion influx measurements on cultured Chinese hamster cells exposed to 60-hertz electromagnetic fields.

Potassium ion influx was measured by monitoring 42KCl uptake by Chinese hamster ovary (CHO) cells grown in suspension culture and exposed in the culture medium to 60-Hz electromagnetic fields up to 2.85 V/m. In the presence of the field CHO cells exhibited two components of uptake, the same as previously observed for those grown under normal conditions; both these components of influx were decreased when compared to sham-exposed cells. Although decreases were consistently observed in exposed cells when plotted as loge of uptake, the differences between the means of the calculated fluxes of exposed and sham-exposed cells were quite small (on the order of 4-7%). When standard deviations were calculated, there was no significant difference between these means; however, when time-paired uptake data were analyzed, the differences were found to be statistically significant. Cells exposed only to the magnetic field exhibited similar small decreases in influx rates when compared to sham-exposed cells, suggesting that the reduction in K+ uptake could be attributed to the magnetic field. Additionally, intracellular K+ levels were measured over a prolonged exposure period (96 h), and no apparent differences in intracellular K+ levels were observed between field-exposed and sham-exposed cultures. These results indicate that high-strength electric fields have a small effect on the rate of transport of potassium ions but no effect on long-term maintenance of intracellular K+.

Animals↗
PubMed1994

[Electromagnetic fields from high-voltage installations and cancer in childhood].

The objective of this population-based case-control study has been to investigate whether residence before and after birth near 50 Hz high voltage installations increases a child's risk of cancer and whether risk correlates with the strength of the magnetic field. One thousand seven hundred and seven children under the age of 15 with either leukaemia, a tumour of the central nervous system, or malignant lymphoma diagnosed in 1968-86 were identified in the Danish Cancer Registry and matched with 4788 population controls. Measures of exposure were proximity before and after birth to existing or former 50-400 kV electrical transmission connections and substations and associated historical electromagnetic fields calculated on the basis of current load on line, phase ordering of line, and distance from the dwelling. A significant association was seen between all major types of childhood cancer combined and exposure to magnetic fields from high voltage installations of > or = 0.4 microT (odds ratio 5.6). At > or = 0.25 microT no significant association was seen (odds ratio 1.5). A possible association was also seen with cases of Hodgkin's disease separately at > or = 0.1 microT. On the basis of these results and additional descriptive data on electricity consumption and incidence of childhood cancer in Denmark since the 1940s it was concluded that the proportion of childhood cancer possibly caused by 50 Hz electromagnetic fields must be small.

Central Nervous System Neoplasms↗
PubMed1989

[The impulse electromagnetic field in the treatment of dystrophic lesions of the retina].

The paper describes a new method proposed for treatment of dystrophic changes in the retina by means of impulse electromagnetic field and a device for its realization. It was used as an independent method of treatment in 283 eyes (177 patients) with macular dystrophies of a sclerotic genesis. The treatment has shown a positive influence on the pathologic process in the eye, its stabilization after treatment. In 152 eyes, visual acuity remained unchanged, in 131--improved. Stabilization of the process was accompanied by authentic improvement of rheographic and electrophysiologic indices. In 72 eyes, the results of treatment were followed up for 6 years, the effectiveness of the method was confirmed. Long-term observations have shown the necessity to repeat the course of treatment each 3-5 months (within a year) to prevent progression of the dystrophic process.

Adult↗
PubMed1989

Neuroendocrine mediated effects of electromagnetic-field exposure: possible role of the pineal gland.

Reports from recent epidemiological studies have suggested a possible association between extremely low frequency (ELF; including 50- or 60-Hz) electric- and magnetic-field exposure, and increased risk of certain cancers, depression, and miscarriage. ELF field-induced pineal gland dysfunction is a possible etiological factor in these effects. Work in our laboratory and elsewhere has shown that ELF electromagnetic-field exposure can alter the normal circadian rhythm of melatonin synthesis and release in the pineal gland. Consequences of reduced or inappropriately timed melatonin release on the endocrine, neuronal, and immune systems are discussed. Laboratory data linking ELF field exposure to changes in pineal circadian rhythms in both animals and humans are reviewed. The authors suggest that the pineal gland, in addition to being a convenient locus for measuring dyschronogenic effects of ELF field exposure, may play a central role in biological response to these fields via alterations in the melatonin signal.

Animals↗
PubMed1983

Effects of high-peak pulsed electromagnetic field on the degeneration and regeneration of the common peroneal nerve in rats.

Apart from preliminary notices of present work, previous reports of experimental and clinical trials of the effects of a high-peak pulsed electromagnetic field (PEMF) on degeneration and regeneration of peripheral nerves lacked statistical analysis. Therefore, we designed experiments with standardised operative, histological, cytological and morphometric techniques to assess the effect of PEMF on lesions of the common peroneal nerves in paired male rats matched for age, environmental conditions and level and type of lesion. One of two types of lesion was induced in the left common peroneal nerve: in 12 pairs of rats the nerve was crushed just above the knee and in the remaining 12 pairs the nerve was cut and immediately sutured at the same level. The right common peroneal nerve of each rat served as a control. Animals received 15 minutes of PEMF produced by a Diapulse machine or sham treatment daily for periods ranging from three and a half days to eight weeks after injury. Healthy nerves were unaffected, but after damage there were statistically significant differences between PEMF treated and sham treated rats. PEMF accelerated the recovery of injured limbs and the degeneration, regeneration and maturation of myelinated axons; epineural, perineural and intraneural fibrosis was reduced; and the luminal cross-sectional area of intraneural vessels increased after both types of lesion. Findings are discussed and the need for clinical trials is stressed.

Animals↗
PubMed1994

Effects of gamma rays, ultraviolet radiation, sunlight, microwaves and electromagnetic fields on gene expression mediated by human immunodeficiency virus promoter.

Previous work by our group and others has shown the modulation of human immunodeficiency virus (HIV) promoter or long terminal repeat (LTR) after exposure to neutrons and ultraviolet radiations. Using HeLa cells stably transfected with a construct containing the chloramphenicol acetyl transferase (CAT) gene, the transcription of which is mediated by the HIV-LTR, we designed experiments to examine the effects of exposure to different types of radiation (such as gamma rays, ultraviolet and sunlight irradiations, electromagnetic fields and microwaves) on HIV-LTR-driven expression of CAT. These results demonstrated ultraviolet-light-induced transcription from the HIV promoter, as has been shown by others. Exposure to other DNA-damaging agents such as gamma rays and sunlight (with limited exposures) had no significant effect on transcription mediated by HIV-LTR, suggesting that induction of HIV is not mediated by just any type of DNA damage but rather may require specific types of DNA damage. Microwaves did not cause cell killing when cells in culture were exposed in high volumes of medium, and the same cells showed no changes in expression. When microwave exposure was carried out in low volumes of medium (so that excessive heat was generated) induction of HIV-LTR transcription (as assayed by CAT activity) was evident. Electromagnetic field exposures had no effect on expression of HIV-LTR. These results demonstrate that not all types of radiation and not all DNA-damaging agents are capable of inducing HIV. We hypothesize that induction of HIV transcription may be mediated by several different signals after exposure to radiation.

Chloramphenicol O-Acetyltransferase↗
PubMed2001

Calibration and evaluation of uncertainty in the measurement of environmental electromagnetic fields.

After a brief description of the reference systems for the calibration of the electromagnetic field meters set up at IEN and the Ivrea Department of ARPA, the procedures for the evaluation of the measurement uncertainty are discussed, with reference to the problem of identifying and quantifying the different uncertainty components. which are due both to the field meter characteristics and to the measurement procedure and conditions. The problem of how to compare a measurement result, which consists of the measurement value and its associated uncertainty, with a limit fixed by the standards is also faced.

Calibration↗
PubMed1998

Biological effects of electromagnetic fields and radiation.

There is much debate and controversy surrounding the effects of low intensity electromagnetic fields and radiation. A few subtle biological effects have been observed in experiments using animals and volunteers, but there is no convincing evidence to suggest that exposure to the fields commonly encountered in the environment will cause any significant adverse health effect in humans.

Animals↗
PubMed1976

[Sudden, unexpected death of infants and electromagnetic fields (author's transl)].

The examination of 337 cases of Sudden Infant Death Syndorme (SIDS) ro Crib Deaths in Philadelphia, Penn., USA, and 294 cases in Hamburg, Federal Republic of Germany, shows regional concentrations which are close to uncommon magnetic fields or stray electric currents in the ground. The risk in the cellar and first floor of houses is higher than in the other floors. Therefore a possible causal relationship between electromagnetic fields and SIDS cases must be considered and checked by on-site measurements, animal experiments, and by more research on magnetic fields as stressor for infants.

Age Factors↗
PubMed1981

[Immunomorphologic changes in the testes upon exposure to a microwave electromagnetic field].

The experiments have been performed on 77 mature male rabbits. Light and electron microscopic, as well as immunofluorescent methods have demonstrated that a single local application of superhigh-frequent electromagnetic field of nonthermal intensity to the testes results in structural disturbance and in disorders of permeability of the hemato-testicular barrier, in ultrastructural changes of the tunica propria of the convoluted seminiferous tubules, and is accompanied with the development of auto-immune process in the testes; that causes certain distrophic changes in the spermatogenic epithelium and destruction of sex cells, predominantly those at the latest developmental stages. According to individual sensitivity, 3 groups of the animals have been revealed that variously respond to the damaging effect of the superhigh-frequency electromagnetic field. The damaging effect is produced by two immunologic mechanisms-humoral (antibodies) and cellular (sensitized lymphocytes).

Animals↗
PubMed1987

Electromagnetic field focusing (EFF) probe--a new neurosurgical tool.

The electromagnetic field focusing (EFF) probe is capable of producing well circumscribed, intense heat at the point of contact with the tissue. Experimental studies were carried out to assess this probe as a neurosurgical tool using 38 rats and 4 mice with mammary carcinoma. The study on the rats included study of the cutting, coagulating and vaporizing effect on brain tissue including study of blood brain barrier disruption and heat dissipation. The study on the mice included the study of vaporizing property of the probe on solid tumours. The probe proved to be an excellent tool for cutting, coagulating and vaporizing purposes with very minimal disruption of blood brain barrier and demonstrated well circumscribed heating pattern. The study indicates that this tool combines the beneficial effect of both the YAG and CO2 laser.

Animals↗
PubMed1980

[Effect of fluctuating electromagnetic fields on the processes of growth and blastomogenesis].

Rats were exposed to low-frequency electromagnetic field, adequate to the natural background, with Gaussian energy distribution, spectrum width 15 kHz, and field intensity 5 V/cm. Electric fluctuations were shown to have an inhibitory action on the normal growth of the animals and on blastoma development. This action reaches maximum with the greatest build-up gradient. As the frequency band of the field of action increase, the inhibitory effect declines.

Animals↗
PubMed2000

Electromagnetic fields: low dose exposure, current update.

OBJECTIVES: The controversial discussion of low-dose electromagnetic field (EMF) effects on human health derives from a lack of knowledge of the mechanism of action and proven results of cellular, animal and human experiments. The paper gives an overview of the current results of scientific research. METHODS: Review based on the legal measurements of the EU parliament, the ICNIRP guidelines, the current literature and personal contacts with scientist in the field. RESULTS: Epidemiologic research shows a low degree of association, inconsistency and missing dose-effect relations. A biologic mechanism of action is still debatable. When observing ICNIRP guideline values, no harm to human health has been shown; but the statement, "EMF are not harmful", cannot be made. Implanted electric devices, like pace-makers, are more sensitive to EMF and need special attention. CONCLUSION: There is no scientific basis as to the harmful effects of EMFs on human health, when ICNIRP guidelines are observed. Hypersensitivity to EMF has not been clinically proved.

Animals↗