bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hypothesis: The risk of childhood leukemia is related to combinations of power‐frequency and static magnetic fields
Authors: Bowman J. D. , Thomas D. C. , London S. J. , Peters J. M. 
Published: February 2006

AbstractWe present a hypothesis that the risk of childhood leukemia is related to exposure to specific combinations of static and extremely‐low‐frequency (ELF) magnetic fields. Laboratory data from calcium efflux and diatom mobility experiments were used with the gyromagnetic equation to predict combinations of 60 Hz and static magnetic fields hypothesized to enhance leukemia risk. The laboratory data predicted 19 bands of the static field magnitude with a bandwidth of 9.1 μT that, together with 60 Hz magnetic fields, are expected to have biological activity. We then assessed the association between this exposure metric and childhood leukemia using data from a case‐control study in Los Angeles County. ELF and static magnetic fields were measured in the bedrooms of 124 cases determined from a tumor registry and 99 controls drawn from friends and random digit dialing. Among these subjects, 26 cases and 20 controls were exposed to static magnetic fields lying in the predicted bands of biological activity centered at 38.0 μT and 50.6 μT. Although no association was found for childhood leukemia in relation to measured ELF or static magnetic fields alone, an increasing trend of leukemia risk with measured ELF fields was found for subjects within these static field bands (P for trend = 0.041). The odds ratio (OR) was 3.3 [95% confidence interval (CI) = 0.4–30.5] for subjects exposed to static fields within the derived bands and to ELF magnetic field above 0.30 μT (compared to subjects exposed to static fields outside the bands and ELF magnetic fields below 0.07 μT). When the 60 Hz magnetic fields were assessed according to the Wertheimer‐Leeper code for wiring configurations, leukemia risks were again greater with the hypothesized exposure conditions (OR = 9.2 for very high current configurations within the static field bands: 95% CI = 1.3–64.6). Although the risk estimates are based on limited magnetic field measurements for a small number of subjects, these findings suggest that the risk of childhood leukemia may be related to the combined effects of the static and ELF magnetic fields. Further tests of the hypothesis are proposed. © 1995 Wiley‐Liss, Inc.
Specific absorption rate levels measured in a phantom head exposed to radio frequency transmissions from analog hand‐held mobile phones
Authors: Anderson V. , Joyner K. H. 
Published: February 2006

AbstractElectric fields (E‐fields) induced within a phantom head from exposure to three different advanced mobile phone system (AMPS) hand‐held telephones were measured using an implantable E‐field probe. Measurements were taken in the eye nearest the phone and along a lateral scan through the brain from its centre to the side nearest the phone. During measurement, the phones were positioned alongside the phantom head as in typical use and were configured to transmit at maximum power (600 mW nominal). The specific absorption rate (SAR) was calculated from the in situ E‐field measurements, which varied significantly between phone models and antenna configuration. The SARs induced in the eye ranged from 0.007 to 0.21 W/kg. Metal‐framed spectacles enhanced SAR levels in the eye by 9–29%. In the brain, maximum levels were recorded at the measurement point closest to the phone and ranged from 0.12 to 0.83 W/kg. These SARs are below peak spatial limits recommended in the U.S. and Australian national standards [IEEE Standards Coordinating Committee 28 (1991): C95.1‐1991 and Standards Australia (1990): AS2772.1‐1990] and the IRPA guidelines for safe exposure to radio frequency (RF) electromagnetic fields [IRPA (1988): Health Phys 54:115–123]. Furthermore, a detailed thermal analysis of the eye indicated only a 0.022°C maximum steady‐state temperature rise in the eye from a uniform SAR loading of 0.21 W/kg. A more approximate thermal analysis in the brain also indicated only a small maximum temperature rise of 0.034°C for a local SAR loading of 0.83 W/kg. © 1995 Wiley‐Liss, Inc.
Pulsed magnetic field from video display terminals enhances teratogenic effects of cytosine arabinoside in mice
Authors: Chiang H. , Wu R. Y. , Shao B. J. , Fu Y. D. , Yao G. D. , Lu D. J. 
Published: February 2006

AbstractEighty‐nine Swiss Webster mice were randomly divided into four groups: a control group, a pulsed magnetic field (PMF) group, a cytosine arabinoside (ara‐C, a teratogen) group, and, a combined PMF + ara‐C group. Mice in the PMF and PMF + ara‐C groups were irradiated with a PMF (a sawtooth waveform with 52 μs rise time, 12 μs decay time, and 15.6 kHz frequency) at a peak magnetic flux density of 40 μT for 4 hours daily on days 6–17 of gestation. The mice in the ara‐C and the PMF + ara‐C groups were injected intraperitoneally on day 9 of gestation with 10 mg/kg of ara‐C. The incidence of resorption and dead fetuses was not affected by PMF but was increased by ara‐C injection. The malformation incidence of cleft palate (CP) and/or cleft lip (CL) was significantly higher in all three of the treated groups than in the control group (P < 0.05). If, however, statistical analyses had been done on litters rather than on individual fetuses, they would show that the incidence of CP and/or CL in the PMF group is not significantly greater than that in the control group. A significantly higher incidence of CP and/or CL was found in the PMF + ara‐C group (49%) than the ara‐C alone group (26.1%). These data suggest that PMF might enhance the development of ara‐C‐induced CP and/or CL. The incidence of minor variations in skeletal development, including reduction of skeletal calcification and loss of skeleton, was not statistically significant in the PMF group. However, it was higher in the two ara‐C‐treated groups, and there was no significant difference between the ara‐C alone group and the ara‐C + PMF group. From these results it is concluded that the very weak embryotoxic effects of PMF exposure may be revealed and enhanced in combination with a teratogenic agent. © 1995 Wiley‐Liss, Inc.
Childhood cancer in relation to indicators of magnetic fields from ground current sources
Authors: Wertheimer Nancy , Savitz David A. , Leeper Ed 
Published: February 2006

AbstractThis study examines childhood cancer risk in relation to certain factors likely to indicate magnetic field exposure from ground currents in the home. Substantial ground currents are most often found in homes having conductive plumbing, in which an uninterrupted metallic path in the water pipes and water main connects the grounding systems of neighboring houses. Information on plumbing conductivity was obtained from water suppliers for the homes of 347 cases and 277 controls identified in an earlier study of magnetic field exposure and childhood cancer in the Denver area. An increased cancer risk was observed for children in homes with conductive plumbing: The matched odds ratio was 1.72 (1.03–2.88) and increased to 3.00 (1.33–6.76) when analysis was limited to cases and controls who were residentially stable from the reference date to the study date. A measurement metric likely to indicate active ground currents (measurements having above‐median intensity and a nonvertical orientation of <55° from the horizontal) was identified. In contrast to measured field intensity alone, for which only modest associations with cancer have been reported, this metric shows a high and significant cancer risk [matched O.R. = 4.0 (1.6–10.0)] consistent over a range of intensity and angle cutpoints. Such elevated nonvertical fields were also associated with cancer in an independent data set, which was gathered to study adult nonlymphocytic leukemia in the Seattle area. The associations of cancer with conductive plumbing and with this exposure metric both suggest that cancer risk is increased among persons with elevated magnetic field exposure from residential ground currents. © 1995 Wiley‐Liss, Inc.
Recovery characteristics of a rigid, nonmetallic microdialysis probe for use in an electromagnetic field
Authors: Mason P. A. , Romano W. F. 
Published: February 2006

AbstractIt 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 μl/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. © 1995 Wiley‐Liss, Inc.
Melatonin and puberty in female lambs exposed to EMF: A replicate study
Authors: Lee J. M. , Stormshak F. , Thompson J. M. , Hess D. L. , Foster D. L. 
Published: February 2006

AbstractIn an earlier study, we found no effects of 60 Hz electric and magnetic fields (EMF) from a 500 kV transmission line on serum melatonin patterns or on puberty in ten female Suffolk lambs (Ovis aries). We conducted a larger replicate study of 15 lambs exposed to a mean electric field of 6.3 kV/m and a mean magnetic field of 3.77 μT and 15 controls exposed to EMF two orders of magnitude weaker than in the line area. The replicate produced essentially the same results as our previous study. © 1995 Wiley‐Liss, Inc.
Millimeter microwave effect on ion transport across lipid bilayer membranes
Authors: Alekseev S. I. , Ziskin M. C. 
Published: February 2006

AbstractThe effects of millimeter microwaves in the frequency range of 54–76 GHz on capacitance and conductance of lipid bilayer membranes (BLM) were studied. Some of the membranes were modified by gramicidin A and amphotericin B or by tetraphenylboron anions (TPhB−). The millimeter microwaves were pulse‐modulated (PW) at repetition rates ranging from 1 to 100 pps, PW at 1000 pps, or unmodulated continuous waves (CW). The maximum output power at the waveguide outlet was 20 mW. It was found that CW irradiation decreased the unmodified BLM capacitance by 1.2% ± 0.5%. At the same time, membrane current induced by TPhB transport increased by 5% ± 1%. The changes in conductance of ionic channels formed by gramicidin A and amphotericin B were small (0.6% ± 0.4%). No “resonance‐like” effects of mm‐wave irradiation on membrane capacitance, ionic channel currents, or TPhB transport were detected. All changes in membrane capacitance and currents were independent of the modulation employed and were equivalent to heating by approximately 1.1 °C. © 1995 Wiley‐Liss, Inc.
Measurement and analysis of static magnetic fields that block action potentials in cultured neurons
Authors: Cavopol A. V. , Wamil A. W. , Holcomb R. R. , McLean M. J. 
Published: February 2006

AbstractTo characterize the properties of static magnetic fields on firing of action potentials (AP) by sensory neurons in cell culture, we developed a mathematical formalism based on the expression for the magnetic field of a single circular current loop. The calculated fields fit closely the field measurements taken with a Hall effect gaussmeter. The biological effect induced by different arrays of permanent magnets depended principally on the spatial variation of the fields, quantified by the value of the gradient of the field magnitude. Magnetic arrays of different sizes (macroarray: four center‐charged neodymium magnets of ˜14 mm diameter; microarray: four micromagnets of the same material but of ˜0.4 mm diameter) allowed comparison of fields with similar gradients but different intensities at the cell position. These two arrays had a common gradient value of ˜1 mT/mm and blocked >70% of AP. Alternatively, cells placed in a field strength of ˜0.2 mT and a gradient of ˜0.02 mT/mm produced by the macroarray resulted in no significant reduction of firing; a microarray field of the same strength but with a higher gradient of ˜1.5 mT/mm caused ˜80% AP blockade. The experimental threshold gradient and the calculated threshold field intensity for blockade of action potentials by these arrays were estimated to be ˜0.02 mT/mm and −0.02 mT, respectively. In conclusion, these findings suggest that spatial variation of the magnetic field is the principal cause of AP blockade in dorsal root ganglia in vitro. © 1995 Wiley‐Liss, Inc.
Magnetic field exposure among utility workers
Authors: Bracken T. Dan , Rankin Richard F. , Senior Russell S. , Alldredge J. Richard , Sussman Stanley S. 
Published: February 2006

AbstractThe Electric and Magnetic Field Measurement Project for Utilities—the Electric Power Research Institute (EPRI) Electric and Magnetic Field Digital Exposure (EMDEX) Project (the EPRI EMDEX Project)—was a multifaceted project that entailed technology transfer, measurement protocol design, data management, and exposure assessment analyses. This paper addresses one specific objective of the project: the collection, analysis, and documentation of power‐frequency magnetic field exposures for a diverse population of utility workers. Field exposure data measured by an EMDEX system were collected by volunteer utility employees at 59 sites in four countries between September, 1988, and September, 1989. Specially designed sampling procedures and data collection protocols were used to ensure uniform implementation across sites. Volunteers within 13 job classifications recorded which of eight work or three nonwork environments they occupied while wearing an EMDEX meter. Approximately 50,000 hours of magnetic field exposure records taken at 10 s intervals were obtained, about 70% of which were from work environments. Exposures and time spent in environments were analyzed by primary work environment, by occupied environment, and by job classification. Generally, for utility‐specific job classifications related to the generation, transmission, and distribution of electricity, the field and exposure measurements in terms of workday mean field were higher than in more general occupations. The job classifications with the highest (median workday mean) exposure were substation operators (0.7 μT) and electricians (0.5μT). Total variance also tended to be largest for utility‐specific job classifications. For these workers, the contributions of between‐worker and within‐worker variances to total variance were about the same. Measurements in utility‐specific environments were higher than in more general environments. Estimates of time‐integrated exposure indicated that utility‐specific job classifications received about one‐half or more of their total exposure on the job. The nonwork field and exposure distributions for workers in all job categories were comparable with median nonworkday means of about 0.09 μT. © 1995 Wiley‐Liss, Inc.
Microwave influence on the isolated heart function: I. Effect of modulation
Authors: Pakhomov Andrei G. , Dubovick Boris V. , Degtyariov Igor G. , Pronkevich Anatoly N. 
Published: February 2006

AbstractDependence of the microwave effect on modulation parameters (pulse width, duty ratio, and peak intensity) was studied in an isolated frog auricle preparation. The rate and amplitude of spontaneous auricle twitches were measured during and after a 2 min exposure to 915 or 885 MHz microwaves and were compared to preexposure values. The studied ranges of modulation parameters were: pulse width, 10−6–10−2 s; duty ratio, 7:100000, and peak specific absorption rate, 100‐3000 W/kg. Combinations of the parameters were chosen by chance, and about 400 various exposure regimes were tested. The experiments established that no regime was effective unless the average microwave power was high enough to induce preparation heating (0.1–0.4°C). The twitch rate instantly increased, and the amplitude decreased, as the temperature rose; similar changes could be induced by equivalent conventional heating. The data provide evidence that the effect of short‐term microwave exposure on the isolated heart pacemaker and contractile functions depends on pulse modulation just as much as modulation determines the average absorbed power. These functions demonstrated no specific dependence on exposure parameters such as frequency or power windows. © 1995 Wiley‐Liss, Inc.
Membrane potential perturbations induced in tissue cells by pulsed electric fields
Authors: Cooper Mark S. 
Published: February 2006

AbstractPulsed electric fields directly influence the electrophysiology of tissue cells by transiently perturbing their transmembrane potential. To determine the magnitude and time course of this interaction, electrotonic cable theory was used to calculate the membrane potential perturbations induced in tissue cells by a spatially uniform, pulsed electric field. Analytic solutions were obtained that predict shifts in membrane potential along the length of cells as a function of time in response to an electrical pulse. For elongated tissue cells, or groups of tissue cells that are coupled electrotonically by gap junctions, significant hyperpolarizations and depolarizations can result from millisecond applications of electric fields with strengths on the order of 10–100 mV/cm. The results illustrate the importance of considering cellular cable parameters in assessing the effects of transient electric fields on biological systems, as well as in predicting the efficacy of pulsed electric fields in medical treatments. © 1995 Wiley‐Liss, Inc.
Neurochemical effects of a 20 kHz magnetic field on the central nervous system in prenatally exposed mice
Authors: Dimberg Yvonne 
Published: February 2006

AbstractC57/B1 mice were exposed during pregnancy (gestation days 0–19) to a 20 kHz magnetic field (MF). The asymmetric sawtooth‐wave form magnetic field in the exposed racks had a flux density of 15 μT (peak to peak). After 19 days, the exposure was terminated, and the mice were housed individually under normal laboratory conditions. On postnatal day (PD) 1, PD21, and PD308, various neurochemical markers in the brains of the offspring were investigated and the brains weighed. No significant difference was found in the whole brain weight at PD1 or PD21 between exposed offspring and control animals. However, on PD308, a significant decrease in weight of the whole brain was detected in exposed animals. No significant differences were found in the weight of cortex, hippocampus, septum, or cerebellum on any of the sampling occasions, nor were any significant differences detected in protein‐, DNA‐level, nerve growth factor (NGF), acetylcholine esterase‐ (AChE), or 2′,3′‐cyclic nucle‐otide 3′‐phosphodiesterase‐ (CNP; marker for oligodendrocytes) activities on PD21 in cerebellum. Cortex showed a more complex pattern of response to MF: MF treatment resulted in a decrease in DNA level and increases in the activities of CNP, AChE, and NGF protein. On PD308, the amount of DNA was significantly reduced in MF‐treated cerebellum and CNP activity was still enhanced in MF‐treated cortex compared to controls. Most of the effects of MF treatment during the embryonic period were similar to those induced by ionizing radiation but much weaker. However, the duration of the exposure required to elucidate the response of different markers to MF seems to be greater and effects appear later during development compared to responses to ionizing radiation. © 1995 Wiley‐Liss, Inc.
Effects of 50 Hz magnetic fields on C‐myc transcript levels in nonsynchronized and synchronized human cells
Authors: Desjobert Hélène , Hillion Josette , Adolphe Monique , Averlant Geneviève , Nafziger Joëlle 
Published: February 2006

AbstractThe effects of 50 Hz electromagnetic fields (EMFs) on the expression of the c‐myc oncogene, known to be involved in normal cell proliferation and possibly also in tumor processes, were investigated in nonsynchronized human lymphoid cells immortalized by Epstein‐Barr virus. Viral injury to such cells makes them a good model for exploring the possible cancer‐promoting effects of 50 Hz magnetic fields. Parallel experiments were conducted on human HL60 leukemic cells. Cells were exposed to sinusoidal 50 Hz EMFs at 10 μT or 1 mT for 20 min, 1 h, 24 h, or 72 h. Exposure was performed either immediately after refeeding or 1.5 h after refeeding. C‐myc transcript values were assessed by Northern blot analysis and normalized to those of the noninducible gene GaPDH. No statistically significant difference between the c‐myc transcript levels of control and exposed cells was found in lymphoid or leukemic cells under our experimental conditions, either after short exposures of 20 min and 1 h or after longer exposures of 24 and 72 h. Other experiments were carried out with pseudosynchronized cells in an attempt to establish whether cells were especially sensitive to 50 Hz magnetic field exposure in any particular phase of the cell cycle. Accordingly, cells were pseudosynchronized in G0/G1 by serum deprivation and exposed for 20 min to a 50 Hz magnetic field, at 10 μT for lymphoid cells and 1 mT for HL60 cells. No significant difference was observed between the c‐myc transcript levels of control and exposed cells for either of the synchronized cell types. These results for synchronized cells correlated with those for nonsynchronized cells. © 1995 Wiley‐Liss, Inc.
Exposure to oscillating magnetic fields influences sensitivity to electrical stimuli. I. experiments on pigeons
Authors: Seppia Cristina Del , Ghione Sergio , Luschi Paolo , Papi Floriano 
Published: February 2006

AbstractThe comparison of two measurements of the pigeon threshold for electrical stimuli, performed 2 h apart, reveals stress‐induced analgesia as a result of stressful manipulations between the two tests. When pigeons are exposed to a weak, oscillating magnetic field between the two measurements, the analgesic response is inhibited and a hyperalgesic effect is recorded. The present findings are in agreement with previous studies showing that magnetic treatments may alter pigeons' emotional state and some of their behavioral patterns. © 1995 Wiley‐Liss, Inc.
Exposure to oscillating magnetic fields influences sensitivity to electrical stimuli. II. experiments on humans
Authors: Papi Floriano , Ghione Sergio , Rosa Caterina , Seppia Cristina Del , Luschi Paolo 
Published: February 2006

AbstractTo assess the effect of a magnetic treatment on pain perception, we compared the sensory threshold in 18 healthy volunteers. We determined the threshold by noninvasive electrical stimulation of the tooth pulp and skin before and after exposure to an altered magnetic field of low intensity and to a sham treatment. Five different parameters were recorded: the sensory and pain thresholds for the tooth and the sensory, pain, and tolerance thresholds for the skin. Two hours of exposure to a weak, oscillating magnetic field induced a significant decrease in three parameters (dental sensory and cutaneous pain and tolerance thresholds), whereas the other two parameters showed a similar tendency. When the same subjects were exposed to a sham treatment, only marginal, nonsignificant variations in all parameters were observed. These results represent the first piece of evidence that weak alterations of the magnetic field may induce hyperalgesia in humans. © 1995 Wiley‐Liss, Inc.