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PubMed1990

[Changes in mast cells after their exposure to constant electromagnetic field].

By means of luminescent histochemistry effect of a constant magnetic field with induction 60 mTl (exposition for 2, 6, 36 h and 7 days) has been studied in order to reveal contents of catecholamines in mesenteric mast cells and in the intestinal mesentery cells in 50 white Wistar rats. In 2-6 h specific luminescence of the mast cells increases, however, at prolongation of the exposure up to 30 h metabolism of catecholamines in the mast cells is inhibited noticeably++ (luminescence disappears). In 8 days amount of the mast cells and specific luminescence of catecholamines decrease. The essential shifts revealed in the system of the mast cells of the mammalian should be taken into consideration in the magnetic-therapeutic practice. Close spatial relations between the mast cells and the mesenteric adrenergic terminals have been elucidated, demonstrating their morphofunctional interconnection.

Animals↗
PubMed1990

[Effects of pulsing electromagnetic fields (PEMF) on the course of vertebral fusion callus. A histological study].

In this paper the findings concerning the effectiveness of PEMF on the evolution of the vertebral fusion callus are reported. The study has been carried on by preparing postero-lateral arthrodesis in the lumbar spinal tract in rats. In this tract the laminae have been decorticated, the articular processes prepared by decortication and removal of the articular cartilage, and the spinal processes removed and employed as osteoinductive material. The rats sacrificed after 4 and 8 weeks, show how the decorticated areas are clearly influenced from PEMF, an early appearance of the bony fusion callus is already evident in the treated group just after 4 weeks. Also the articular areas are influenced from PEMF but less markedly than the decorticated one; in these areas after 8 weeks the fusion callus is prevalently cartilaginous even if areas of calcification are detectable inside. This different behaviour can be explained with the absence of any form of spinal fusion by means of surgical tools.

Animals↗
PubMed1999

Occupational exposure to high frequency electromagnetic fields and its effect on human immune parameters.

The present study recorded a considerable excess of recommended exposure limits in the vicinity of shortwave diathermy devices used for medical treatment of patients. Different kinds of field probes were used to measure electric and magnetic field strength and the whole body exposure of medical personnel operating shortwave, decimeter wave and microwave units was calculated. To investigate the influence of chronic exposure on the immune system of operators, blood was sampled from physiotherapists working at the above mentioned devices. Eighteen exposed and thirteen control persons, matched by sex and age, were examined. Total leucocyte and lymphocyte counts were performed and leucocytic subpopulations determined by flow cytometry and monoclonal antibodies against surface antigens. In addition, to quantify subpopulations of immunocompetent cells, the activity of lymphocytes was measured. Lymphocytes were stimulated by mitogen phytohemagglutinin and their proliferation measured by a flow cytometric method. No statistically significant differences between the control and exposed persons were found. In both study groups all immune parameters were within normal ranges.

Adult↗
PubMed2000

Possible cocarcinogenic effects of ELF electromagnetic fields may require repeated long-term interaction with known carcinogenic factors.

Literature on cancer-related biological effects of extremely low frequency (ELF) magnetic fields (MF) is discussed in the light of the current understanding of carcinogenesis as a multistep process of accumulating mutations. Different animal models and study designs have been used to address possible cocarcinogenic effects of MFs. Based on a comparison of the results, we propose a hypothesis that MF exposure may potentiate the effects of known carcinogens only when both exposures are chronic. We also discuss possible mechanisms of MF effects on carcinogenesis and the adequacy of the classical two-step initiation/promotion animal experiments for simulating human exposure to the complex mixture of environmental carcinogens. We conclude that experiments designed according to the two-step concept may not be sufficient for studying the possible role of MF in carcinogenesis. Possible further animal studies are more likely to be productive if they include models that combine chronic exposure to MFs with long-term exposures to known carcinogens.

Animals↗
PubMed2001

Adverse human reproductive outcomes and electromagnetic fields: a brief summary of the epidemiologic literature.

Power frequency fields are of concern as risk factors for adverse reproductive outcomes. This report briefly summarizes the epidemiologic evidence of potential associations between a number of adverse reproductive outcomes and parental exposures to electric and magnetic fields (EMFs). Over the last decade numerous reviews of the human literature regarding these potential associations have been published. These reviews, in general, have concluded that: (1) evidence is lacking for a strong association between a woman's use of a video display terminal (VDT) and fetal loss, (2) evidence is lacking for a strong association between a woman's use of a VDT and adverse reproductive outcomes other than fetal loss, primarily a result of too few available data, and (3) the paucity of data on other parental EMF exposures and subsequent adverse outcomes of pregnancy limits drawing a valid scientific conclusion. Since those earlier reviews appeared, the number of new investigations have been relatively small. These new studies do not substantially alter the above summary conclusions. The lack of epidemiologic data in this area, coupled with some speculations about potential biological effects associated with EMFs, raises the importance of researching this area further.

Abortion, Spontaneous↗
PubMed1999

A Bayesian approach to hazard identification. The case of electromagnetic fields and cancer.

This paper discusses certain issues related to uncertainty in hazard identification. Research on the hypothesis that exposure to 50-60-Hz magnetic and electric fields (EMF) increases the risk of cancer has been ongoing for two decades. Epidemiological studies provide a somewhat consistent pattern indicating an increased risk for childhood leukemia and adult chronic lymphatic leukemia and possibly also for other leukemias and brain cancer. However, there is still no good candidate for a mechanism. Epidemiological studies have throughout the two decades been interpreted with great caution, and final evaluations as to carcinogenicity have been deferred. The reason for this carefulness may be the lack of knowledge about a plausible mechanism. The purpose of this paper is to discuss the process of weighing epidemiological data, experimental data, and other background information into a synthesis such that the evaluation can be based on all data combined. A Bayesian approach to this weighing is discussed along with some alternatives. The Bayesian approach provides a structure for the pooling of evidence and points out where subjective judgments come into play.

Adult↗
PubMed1997

Lack of a correlation between demyelinating plaques on MRI scan and clinical recovery in multiple sclerosis by treatment with electromagnetic fields.

A 50 year-old woman presented in January of 1995 with a prolonged history of symptoms of multiple sclerosis (MS) and was classified at the time with a remitting-progressive course. Her chief symptoms included slurring of speech, impairment of vision with intermittent diplopia, difficulties with gait and balance with spastic-ataxic gait, mental depression, insomnia, fatigue, impaired cognitive functions notably poor short term memory and recurrent urinary tract and sinus infections. An MRI scan showed multiple nodular demyelinating lesions scattered in the subcortical white matter and periventricularly of both cerebral hemispheres. Over the following 18 months, while receiving three treatment sessions per week with picotesla electro-magnetic fields (EMFs) which were applied extracranially, she showed a significant recovery in both physical and mental symptoms and additionally experienced decreased susceptibility to infections. In addition, the course of her disease appeared to have stabilized as opposed to the preceding 5 years during which time she experienced insidious, steady deterioration in her functioning. Despite this remarkable clinical recovery through the application of EMFs, and MRI scan obtained at the same diagnostic center 18 months after initiation of treatment with EMFs showed no changes in the number and size of the demyelinating plaques. These findings demonstrate lack of a correlation between recovery of symptoms and the number and extent of demyelinating plaques on MRI scan. It has been known since the days of Charcot in the latter half of the 19th century that in MS there is a great disparity between the histopathological changes of the disease and neurologic deficits. This report enhances the notion that demyelination may reflect an epiphenomenon of the disease.

Brain↗
PubMed2006

Public health impact of extremely low-frequency electromagnetic fields.

INTRODUCTION: The association between exposure to extremely low-frequency electric and magnetic fields (ELF) and childhood leukemia has led to the classification of magnetic fields by the International Agency for Research on Cancer as a "possible human carcinogen." This association is regarded as the critical effect in risk assessment. Creating effective policy in light of widespread exposure and the undisputed value of safe, reliable, and economic electricity to society is difficult and requires estimates of the potential public health impact and associated uncertainties. OBJECTIVES: Although a causal relationship between magnetic fields and childhood leukemia has not been established, we present estimates of the possible pubic health impact using attributable fractions to provide a potentially useful input into policy analysis under different scenarios. METHODS: Using ELF exposure distributions from various countries and dose-response functions from two pooled analyses, we calculate country-specific and worldwide estimates of attributable fractions (AFs) and attributable cases. RESULTS: Even given a wide range of assumptions, we find that the AF remains < 10%, with point estimates ranging from < 1% to about 4%. For small countries with low exposure, the number of attributable cases is less than one extra case per year. Worldwide the range is from 100 to 2,400 cases possibly attributable to ELF exposure. CONCLUSION: The fraction of childhood leukemia cases possibly attributable to ELF exposure across the globe appears to be small. There remain, however, a number of uncertainties in these AF estimates, particularly in the exposure distributions.

Bayes Theorem↗
PubMed2005

Effects of 50 Hz electromagnetic fields on electroencephalographic alpha activity, dental pain threshold and cardiovascular parameters in humans.

Recent studies indicate that exposure to extremely low frequency magnetic fields (ELF MFs) influences human electroencephalographic (EEG) alpha activity and pain perception. In the present study we analyse the effect on electrical EEG activity in the alpha band (8-13 Hz) and on nociception in 40 healthy male volunteers after 90-min exposure of the head to 50 Hz ELF MFs at a flux density of 40 or 80 microT in a double-blind randomized sham-controlled study. Since cardiovascular regulation is functionally related to pain modulation, we also measured blood pressure (BP) and heart rate (HR) during treatment. Alpha activity after 80 microT magnetic treatment almost doubled compared to sham treatment. Pain threshold after 40 microT magnetic treatment was significantly lower than after sham treatment. No effects were found for BP and HR. We suggest that these results may be explained by a modulation of sensory gating processes through the opioidergic system, that in turn is influenced by magnetic exposure.

Adult↗
PubMed2002

[Abnormal shift of connexin 43 gap-junction protein induced by 50 Hz electromagnetic fields in Chinese hamster lung cells].

OBJECTIVE: To study the effects of extremely low frequency magnetic fields(ELF MF) on the amount and localization of connexin 43(Cx43) gap-junction protein in the Chinese hamster lung(CHL) cells, and to explore the mechanism of ELF MF suppression on gap-junctional intercellular communication(GJIC). METHODS: The cells were irradiated for 24 h with 50 Hz sinusoidal magnetic field at 0.8 mT without or with 12-O-tetrade-canoylphorbol-3-acetate(TPA), 5 ng/ml for 1 h. The localization of Cx43 proteins were performed by indirect immunofluorescence histochemical analysis and detected by confocal microscopy. The second experiment was conducted to examine the quantity of Cx43 proteins level in nuclei or cytoplasm and detected by Western blotting analysis. RESULTS: The cells exposed to TPA for 1 h displayed less bright labelled spots in the regions of intercellular junction than the normal cells. Most of Cx43 labelled spots occurred in the cytoplasm and aggregated near the nuclei. At the same time, the amount of Cx43 protein in cytoplasm were increased[(2.03 +/- 0.89) in ELF group, (2.43 +/- 0.82) in TPA group] as compared to normal control(1.04 +/- 0.17) (P < 0.01). CONCLUSION: Inhibition on GJIC function by ELF MF alone or combined with TPA may be related with the shift of Cx43 from the regions of intercellular junction to the cytoplasm.

Animals↗
PubMed2006

Paternal occupational exposure to radiofrequency electromagnetic fields and risk of adverse pregnancy outcome.

BACKGROUND: During the last decades, public concern that radiofrequency radiation (RFR) may be related to adverse reproductive outcomes has been emerging. Our objective was to assess associations between paternal occupational exposure to RFR and adverse pregnancy outcomes including birth defects using population-based data from Norway. METHODS: Data on reproductive outcomes derived from the Medical Birth Registry of Norway were linked with data on paternal occupation derived from the general population censuses. An expert panel categorized occupations according to exposure. Using logistic regression, we analyzed 24 categories of birth defects as well as other adverse outcomes. RESULTS: In the offspring of fathers most likely to have been exposed, increased risk was observed for preterm birth (odds ratio (OR): 1.08, 95% confidence interval (CI): 1.03, 1.15). In this group we also observed a decreased risk of cleft lip (OR: 0.63, 95% CI: 0.41, 0.97). In the medium exposed group, we observed increased risk for a category of "other defects" (OR: 2.40, 95% CI: 1.22, 4.70), and a decreased risk for a category of "other syndromes" (OR: 0.75, 95% CI: 0.56, 0.99) and upper gastrointestinal defects (OR: 0.61, 95% CI: 0.40, 0.93). CONCLUSION: The study is partly reassuring for occupationally exposed fathers.

Abnormalities, Radiation-Induced↗
PubMed2007

Electromagnetic fields produced by GSM cellular phones and heart rate variability.

In this study, 26 healthy young volunteers were submitted to 900 MHz (2 W) GSM cellular phone exposure and to sham exposure in separate sessions. The study was designed to assess cardiac regulatory mechanism in different autonomic nervous system (ANS) states during exposure to low-intensity EMF. Rest-to-stand protocol was applied to evaluate ANS in quiet condition (rest, vagal prevalence) and after a sympathetic activation (stand). The procedure is conducted twice in a double-blind design: once with a genuine EMF exposure and once with a sham exposure (at least 24 h apart). During each session three-leads electrocardiograms were recorded and RR series extracted off-line. Time domain and frequency domain HRV parameters were calculated in every phase of the protocol and during different exposures. The analysis of the data show there was no statistically significant effect due to EMF exposure both on main (i.e., RR mean) and most of the other HRV parameters. A weak interaction between some HRV parameters (i.e., SDNN, TINN, and triangular index in time domain and LF power in frequency domain analysis) and RF exposure was observed and this effect seems to be gathered around the sympathetic response to stand.

Adult↗
PubMed2004

ELF electromagnetic fields increase hydrogen peroxide (H2O2)-induced mutations in pTN89 plasmids.

We have examined the mutational effects of hydrogen peroxide (H(2)O(2)) in the presence and absence of an extremely low-frequency magnetic field (ELFMF), using pTN89 plasmids. Mutations were detected in the supF gene carried by these plasmids in Escherichia coli. The plasmids were either treated with H(2)O(2) (1microM) alone at 37 degrees C for 4h, or were exposed to an ELFMF (60Hz, 5millitesla (mT)) simultaneously with H(2)O(2) treatment. The mutation frequency was 2.28 x 10(-4) for H(2)O(2) treatment alone, and 5.81 x 10(-4) for ELFMF exposure with H(2)O(2) treatment. We did not observe any mutations using treatment with ELFMF exposure alone. This indicates that the ELFMF may potentiate H(2)O(2)-induced mutation. Sequence analysis of the supF mutant plasmids revealed that base substitutions, G: C-->A :T transitions and G:C-->T:A transversions were dominant in both treatment groups, and there was no difference in the mutation spectrum or the hotspots between the groups. Therefore, ELFMFs may interact and potentiate the damage induced by H(2)O(2), resulting in an increase in the number of mutations.

Base Sequence↗
PubMed2001

Breast cancer, occupation, and exposure to electromagnetic fields among Swedish men.

BACKGROUND: Investigations of breast cancer among men may provide clues for environmental and occupational risk factors that may be difficult to study in women, because of confounding or effect modification from reproductive female characteristics. The objective was to estimate occupation-specific risks of male breast cancer and to assess the effect of occupational exposure to extremely low-frequency magnetic fields (ELFMF). METHODS: Standardized incidence ratios were computed for the period 1971-1989 among Swedish men who were 25-59 years of age at start of follow-up and gainfully employed in 1970. Log-linear Poisson models were fitted to adjust for geographical area. A job exposure matrix was used to classify occupational ELFMF exposure. RESULTS: A marked and consistent excess risk was found for machinery repairers. Increased relative risks based on few cases were also noted for librarians/archivists/curators, bank employees, non-specified clerical workers, metal processing workers, tanners/fur dressers, policemen, and custom surveillance officials. The relative risk among subjects with an estimated ELFMF exposure above the first quartile (0.12 microT) was 1.31 (95% confidence interval = 0.94-1.81), without a clear exposure-response pattern. Indications of an exposure-response relationship were found in workers with intermittent ELFMF exposure. CONCLUSIONS: The findings give no clear evidence for an etiological role of ELFMF in the development of breast cancer in men, but suggest that large variations in exposure over the work-day may be associated with an increased risk.

Adult↗
PubMed2006

Occupational exposure to ionizing radiation and electromagnetic fields in relation to the risk of thyroid cancer in Sweden.

OBJECTIVES: This study sought to ascertain the risk of thyroid cancer in relation to occupational exposure to ionizing radiation and extremely low-frequency magnetic fields (ELFMF) in a cohort representative of Sweden's gainfully employed population. METHODS: A historical cohort of 2 992 166 gainfully employed Swedish male and female workers was followed up from 1971 through 1989. Exposure to ELFMF and ionizing radiation was assessed using three job exposure matrices based on industrial branch or occupational codes. Relative risks (RR) for male and female workers, adjusted for age and geographic area, were computed using log-linear Poisson models. RESULTS: Occupational ELFMF exposure showed no effect on the risk of thyroid cancer in the study. However, female workers exposed to high intensities of ionizing radiation registered a marked excess risk (RR 1.85, 95% confidence interval (95% CI) 1.02-3.35]. This trend was not in evidence among the men. CONCLUSIONS: While the study confirms the etiologic role of ionizing radiation, with a higher incidence of thyroid cancer being recorded for the most-exposed female workers, our results do not support the possibility of occupational exposure to ELFMF being a risk factor for the development of thyroid cancer.

Adult↗
PubMedDate not supplied

[Epidemiological risk assessment of pathology development in occupational exposure to radiofrequency electromagnetic fields].

A cross-sectional study of working conditions and health of the personnel of the civil aircraft radar-tracking system has been conducted based on periodical health examinations. The personnel was divided into three occupational groups. Group I was exposed to EMF EHF, group II--to EMF HF and UHF and group III was not exposed to EMF (reference group). The groups didn't differ in any occupational and non-occupational parameters. Health status of 250 workers was examined. High prevalence rate of cardiovascular diseases (ICD-X I00-I99) was found in the exposed groups. Odds ratio (OR) was 3.78 (95% CI 1.96-7.27) in group I and 2.13 (95% CI 1.13-4.03) in group II. High prevalence rate of cardiovascular diseases is explained by arterial hypertension (ICD-X I10-I15) (OR = 1.96 95% CI 1.04-3.70 in group I and OR = 1.80 95% CI 0.93-3.50 in group II) and ischemic heart disease (ICD-X I20-I25) (OR = 7.9 95% CI 3.48-18.06 in group I; OR = 3.0 95% CI 1.23-7.33--in group II). In the exposed groups cardiovascular diseases were developed in young age. OR was 7.04 (95% CI 1.64-30.19) in group I and 4.33 (95% CI 0.96-19.65) in group II in 30-39 age sub groups. Myocardium infarction was found in 2 out of 16 persons of this age in the group exposed to EMF.

Adult↗
PubMed2002

Electromagnetic fields on a quantum scale. I.

This is the first in a series of two articles, the second of which provides an exact electro-magnetic field description of photon emission, absorption, and radiation pattern. Photon energy exchanges are analyzed and shown to be the triggered, regenerative response of a non-local eigenstate electron. This first article presents a model-based, hidden variable analysis of quantum theory that provides the statistical nature of wave functions. The analysis uses the equations of classical electro-magnetism and conservation of energy while modeling an eigenstate electron as a nonlocal entity. Essential to the analysis are physical properties that were discovered and analyzed only after the historical interpretation of quantum mechanics was established: electron non-locality and the standing electro-magnetic energy that accompanies and encompasses an active, electrically small volume. The standing energy produces a driving radiation reaction force that, under certain circumstances, is many orders of magnitude larger than currently accepted values. These properties provide a sufficient basis for the Schrödinger equation as a descriptor of non-relativistic eigenstate electrons in or near equilibrium. The uncertainty principle follows, as does the exclusion principle. The analysis leads to atomic stability and causality in the sense that the status of physical phenomena at any instant specifies the status an instant later.

Computer Simulation↗
PubMed2006

The sensitivity of human event-related potentials and reaction time to mobile phone emitted electromagnetic fields.

There is some evidence to suggest that exposure to mobile phones (MPs) can affect neural activity, particularly in response to auditory stimuli. The current investigation (n = 120) aimed to test recent findings in this area, namely that N100 amplitude and latency would decrease, and that P300 latency and reaction time (RT) would increase under active relative to sham exposure during an auditory task. Visual measures were also explored. A double blind, counterbalanced, crossover design was employed where subjects attended two sessions 1 week apart. In both sessions participants (1) performed auditory and visual oddball tasks while electroencephalogram (EEG) was recorded with a MP set to sham exposure mounted over the temporal region, and (2) performed the same tasks while the handset was set to active/sham. When active, the MP transmitted for 30 min at 895 MHz (average power 250 mW, pulse modulated at 217 Hz, average SAR 0.11 W/kg). Paired t-tests compared difference scores from the sham/sham session to those from the sham/active condition. The study was designed to detect differences of 1\4 of a standard deviation with a power of 0.80. There was no significant difference between exposure conditions for any auditory or visual event related potential (ERP) component or RT. As previous positive findings were not replicated, it was concluded that there is currently no evidence that acute MP exposure affects these indices of brain activity.

Adolescent↗