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At least 1,675 records · Page 93Linked to original sources
PubMed2001

Leukemia, brain tumors, and exposure to extremely low frequency electromagnetic fields in Swiss railway employees.

Railway engineers provide excellent opportunities for studying the relation between exposure to extremely low frequency magnetic fields and leukemia or brain tumors. In a cohort study of Swiss railway personnel with 2.7 x 10(5) person-years of follow-up (1972--1993), the authors compared occupations with high average exposures (line engineers: 25.9 microT) to those with medium and low exposures (station masters: 1 microT). The mortality rate ratio for leukemia was 2.4 (95% confidence interval (CI): 1.0, 6.1) among line engineers (reference category: station masters). The mortality rate ratio for brain tumors was 1.0 (95% CI: 0.2, 4.6) among line engineers and 5.1 (95% CI: 1.2, 21.2) among shunting yard engineers (compared with station masters). Two exposure characteristics were evaluated: cumulative exposure in microT-years and years spent under exposure to magnetic fields of > or =10 microT. There was a significant increase in leukemia mortality of 0.9% (95% CI: 0.2, 1.7) per microT-year of cumulative exposure to extremely low frequency magnetic fields. The increase by years spent under exposure of > or =10 microT was even stronger: 62% per year (95% CI: 15, 129). Brain cancer risk did not show a dose-response relation. This study contributes to the evidence for a link between heavy exposure to extremely low frequency magnetic fields and leukemia. Its strengths include reliable measurements and reliable historical reconstruction of exposures.

Adult↗
PubMedDate not supplied

[Coherent electromagnetic fields in the remote intercellular interaction].

The distant interactions various organisms and their communities and the effect of coherent electromagnetic radiation on intercellular relations were studied. The ability of fruit crops male gametophyte to control the germination of pollen tube at the field level (nonchemical) was established. The cooperative character of this process is shown. It is stimulated directly or indirectly, by low-intensity coherent radiation through a bioinductor. The conclusion is made that spontaneous chemiluminescence cannot be considered as an information channel of distant intercellular interaction.

Cell Communication↗
PubMed1999

Electromagnetic fields may act directly on DNA.

A wide variety of environmental stimuli induce the expression of stress response genes, including high temperatures, hypoxia, heavy metal ions, and amino acid analogs. Stress genes are also induced by low frequency magnetic fields. The cellular response to magnetic fields is activated by unusually weak stimuli, and involves pathways only partially associated with heat shock stress. Since magnetic fields interact with moving charges, as we have shown in enzymes, it is possible that magnetic fields stimulate the stress response by interacting directly with moving electrons in DNA. In this paper, we review several lines of evidence that support this hypothesis.

Animals↗
PubMed2000

Electromagnetic fields for a spheroidal particle with an arbitrary embedded source.

A spheroidal coordinate separation-of-variables solution has been developed for the determination of the internal, near-surface, and scattered fields of a spheroid (either prolate or oblate) with an embedded source of arbitrary type, location, and orientation. Presented results for (1,0) and (1,1) electric multipoles embedded in 2:1 axis ratio prolate and oblate spheroids (equal volume sphere size parameter equal to 20) illustrate that the presence of the spheroid interface can have a profound effect on the corresponding far-field scattering pattern. The calculation procedure could be used, for example, to model the emission of inelastic scattered light (Raman, fluorescence, etc.) from biological particles of appreciably elongated (prolatelike) or appreciably flattened (oblatelike) geometries.

Electromagnetic Fields↗
PubMed1993

Influence of electromagnetic fields on endochondral bone formation.

Endochondral ossification is a basic physiological process in limb development and is central to bone repair and linear growth. Factors which regulate endochondral ossification include several biophysical and biochemical agents and are of interest from clinical and biological perspectives. One of these agents, electric stimulation, has been shown to result in enhanced synthesis of extracellular matrix, calcification, and bone formation in a number of experimental systems and is the subject of this review. The effects of electric stimulation have been studied in embryonic limb rudiments, growth plates, and experimental endochondral ossification induced with decalcified bone matrix and, in all these models, endochondral ossification has been enhanced. It is not known definitively whether electric fields stimulate cell differentiation or modulate an increased number of molecules synthesized by committed cell population and this is a fertile area of current study.

Animals↗
PubMed2002

Electromagnetic fields: human safety issues.

Most of the recently revised safety standards worldwide are set in terms of internal rates of electromagnetic energy deposition (specific absorption rates or SAR) at radio frequencies (RF) and microwave frequencies, and of induced electric fields or current densities at lower frequencies up to 10 MHz. Numerical methods have been developed that use millimeter resolution anatomically based models of the human body to determine SAR or the induced electric fields and current densities for real-life EM exposure conditions. A popular method for use at RF and microwave frequencies is the finite-difference time-domain method. This method is described and illustrated for SAR distributions due to cellular telephones for head models based on human anatomy. A method often used for calculations of induced electric fields and current densities at low frequencies is the impedance method. Use of this method is illustrated by an example of an electronic article surveillance (EAS) system for anatomic models of an adult and 10- and 5-year-old children. Experimental phantoms using a fluid to simulate the dielectric properties of the brain may be used for determination of peak 1- or 10-g SAR needed for compliance with the various safety standards.

Adult↗
PubMed2001

Health problems among workers of iron welding machines: an effect of electromagnetic fields.

The possible effects of EMFs on 100 workers were studied by means of structured interview and rating of subjective symptoms. As control 41 sewing machine operators and assembly workers were chosen, interviewed and likewise tested. The present Indian ceiling value of 250 Tesla for the equivalent power density was exceeded in more than 50% of the machines. The highest leakage fields, for EMFs, were found near machines, which gave a high exposure to the hands. Eye irritation complaints were reported by 40% of the workers. The fertility outcome did not show any significant result.

Adult↗
PubMed1995

Suspension osteopenia in mice: whole body electromagnetic field effects.

Whole-body fields were tested for their efficacy in preventing the osteopenia caused by tail suspension in mice. The fields had fundamental frequencies corresponding to the upper range of predicted endogenous impact-generated frequencies (0.25-2.0 kHz) in the long bones. Three distinct whole-body EMFs were applied for 2 weeks on growing mice. Structural, geometric, and material properties of the femora, tibiae, and humeri of suspended mice were altered compared to controls. Comparison of suspended mice and mice subjected to caloric restriction indicates that the changes in caloric intake do not explain either the suspension or the field-induced effects. In agreement with past studies, rather, unloading appears to cause the suspension effects and to be addressed by the EMFs. The EMF effects on bone properties were apparently frequency dependent, with the lower two fundamental frequencies (260 and 910 Hz) altering, albeit slightly, the suspension-induced bone effects. The fields are not apparently optimized for frequency, etc., with respect to therapeutic potential; however, suspension provides a model system for further study of the in vivo effects of EMFs.

Animals↗
PubMed2004

The repair of gamma-ray-induced chromosomal damage in human lymphocytes after exposure to extremely low frequency electromagnetic fields.

G(0) human blood lymphocytes were irradiated with 2.0 Gy gamma-rays and cultured to metaphase whilst held in a 50-Hz power frequency magnetic field of 0.23, 0.47 or 0.7 mT. No differences were found in the frequencies of gamma-induced chromosome aberrations observed in cells held in the EM fields compared with replicates held in a sham coil. Similar field conditions have been reported to increase the frequency of gamma-induced HPRT mutations, leading to a suggestion that the EM fields alter the fidelity of repair of genomic lesions. This was not confirmed by the chromosome aberration assay described here.

Adult↗
PubMed2006

Scalp localization of human auditory cortical activity modified by GSM electromagnetic fields.

PURPOSE: This study attempted to determine whether there is a localized effect of GSM (Global System for Mobile communications) microwaves by studying the Auditory Evoked Potentials (AEP) recorded at the scalp of nine healthy subjects and six epileptic patients. MATERIALS AND METHODS: We determined the influence of GSM RadioFrequency (RF) on parameters characterizing the AEP in time or/and frequency domains. A parameter selection method using SVM (Support Vector Machines)-based criteria allowed us to estimate those most altered by the radiofrequencies. The topography of the parameter modifications was computed to determine the localization of the radiofrequency influence. A statistical test was conducted for selected scalp areas, in order to determine whether there were significant localized alterations due to the RF. RESULTS: The epileptic patients showed a lengthening of the scalp component N100 (100 ms latency) in the frontal area contralateral to the radiation, which may be due to an afferent tract alteration. For the healthy subjects, an amplitude increase of the P200 wave (200 ms latency) was identified in the frontal area. CONCLUSIONS: The present study suggests that radiofrequency fields emitted by mobile phones modify the AEP. Nevertheless, no direct link between these findings and RF-induced damages in brain function was established.

Adult↗
PubMed1992

Mixed function oxidase demethylase and dealkylase activity in an electromagnetic field.

In contrast to the increase in reaction rate of microsomal NADPH-cytochrome-P450 reductase activity resulting from low-level microwave perturbation (reported earlier) transformations involving the entire MFO-pathway were inhibited by a microwave field. Dealkylation of 7-ethoxycoumarin was inhibited 25% and demethylation of p-nitroanisole was inhibited 40% when the reaction was carried forward in a 9.14 GHz CW field. Microsomal preparations from the liver of mature chickens had enzymic characteristics (kinetic constants, inhibitor-response spectrum) for these substrates similar to those reported for rodent and human MFO complex.

7-Alkoxycoumarin O-Dealkylase↗
PubMed1991

[Hemodynamics in the organs of small pelvis during complex treatment using electromagnetic fields in patients with tubal infertility of inflammatory etiology].

Hydrotubation treatment of uterine tube impotency of an inflammatory origin results in many cases in stubborn hemodynamic disorders in the small pelvis organs, that may be normalized after exposure to a permanent magnetic field (magnetophores). Multiple-modality treatment results in recovery of the uterine tube patency in 50% of cases and in pregnancy coming within a year in 22.6% of cases.

Adnexa Uteri↗
PubMed2003

Exposure to electromagnetic fields during pregnancy.

QUESTION: Several of my patients quote recent media coverage claiming that working with home appliances could increase the risk of misarriages. What is your advice? ANSWER: Two recent epidemiologic studies from California have suggested an increased risk of miscarriages associated with exposure to magnetic fields. Even if the threshold associated with such risk is a biologic and true risk (and not just an association), it does not appear to arise from typical use of hair dryers, microwave ovens, vacuum cleaners, and similar home appliances.

Abortion, Spontaneous↗
PubMed2003

[Biological effects produced by the influence of low frequency electromagnetic fields on hormone secretion].

The article discusses the role of (electro)magnetic fields in hormone secretion in humans and animals. The best known hormone whose secretion may be disturbed by magnetic field is melatonin. The level of serotonin positively reacts to the presence of magnetic field in the environment-its level is raised. The effect of magnetic fields on other hormones has not as yet been described. It seems necessary to continue experimental and epidemiological research on living organisms (their hormone secretion) to standardise the norms of exposure with the aim of diagnostic and therapeutic application.

Electromagnetic Fields↗