The effect of moving air on detection of a 60-Hz electric field

Two potential mechanisms in detection of a 60-Hz electric field by albino rats were examined: field-induced movement of the vibrissae and field-induced vibration of the skin. Specifically, the experiment tested field detection in a moving stream of air designed to mask field-induced movement of the skin, fur, and vibrissae. Rats were trained to detect electric fields and were then tested at field intensities from 0–25 kV/m rms. As previously reported, rats demonstrate unmistakable behavioral evidence of field detection at all intensities above 7.5 kV/m. After establishing detection in still air, field detection was re-examined in moving air (average air velocity approximately 2.8–6.8 m/s). The primary result is that the wind produced no change in detection at field intensities above threshold (> 7.5 kV/m). Indeed, at these intensities detection was virtually identical in still and moving air. A secondary finding is that moving air produced statistically significant (P < .05) but apparently contradictory effects on detection when the field intensity was below threshold. On no-field trials the wind lowered scores (i.e., fewer presses on the field-off lever); however, on subthreshold field trials, the wind actually increased detection scores (i.e., more presses on the field-on lever). While this no-field and subthreshold field result is interesting and deserves further study, we place primary emphasis on the finding that, if the field was detectable in still air, it was also detectable in moving air. This result leads us to believe that movement of the vibrissae, fur, or skin is not likely to be the main mechanism of electric-field detection in our subjects. © 1993 Wiley-Liss. Inc.     

Dominant lethal studies in male mice after exposure to a 50-Hz electric field

Male C3H/He mice were sham-exposed or exposed continuously for 2 weeks to a vertical, 50-Hz, electric field at 20 kV/m rms. Densities of currents induced in the testes are estimated to be near 100 microA/m2. After the exposure, each male was mated with two different female mice each week during a period of 8 weeks. By this schedule, female mice were impregnated with sperm that had been exposed to the electric field at different stages of the spermatogenic cycle. No significant differences as a function of exposure condition were observed in pregnancy rates or in survival of embryos before or after implantation. The absence of effects was not due to insensitivity of assays; other mice that were exposed to X-rays (dose to testes = 1.5 Gy) presented reliable evidence of mutagenesis.     

Development and evaluation of intermediate frequency magnetic field exposure system for studies of in vitro biological effects

We have developed an intermediate frequency (IF) magnetic field exposure system for in vitro studies. Since there are no previous studies on exposure to heating-frequency magnetic fields generated from an induction heating (IH) cook top, there is a strong need for such an exposure system and for biological studies of IF magnetic fields. This system mainly consists of a magnetic-field-generating coil housed inside an incubator, inside which cultured cells can be exposed to magnetic field. Two systems were prepared to allow the experiment to be conducted in a double-blind manner. The level of the generated magnetic field was set to 532 microT rms in the exposure space, 23 kHz, 80 times the value in the International Commission on Non-ionizing Radiation Protection (ICNIRP) guidelines, with a spatial field uniformity better than 3.8%. The waveforms were nearly sinusoidal. It was also confirmed that the parasitic electric field was 157 V/m rms and the induced electric field was 1.9 V/m rms. The temperature was maintained at 36.5 +/- 0.5 degrees C for 2 h. Furthermore, leaked magnetic flux density was 0.7 microT rms or lower at extremely low frequency (ELF) and IF in the stopped system when the other system was being operated, and the environmental magnetic flux density was 0.1 microT rms or lower at the center of the coils. As a result, it was confirmed that this system could be successfully used to evaluate the biological effects of exposure to IF magnetic fields.     

Occupational exposure to electric and magnetic fields during work tasks at 110 kV substations in the Tampere region

The occupational exposure to electric and magnetic fields during various work tasks at seven 110 kV substations in Finland's Tampere region was studied. The aim was to investigate if the action values (10 kV/m for the E‐field and 500 µT for the B‐field) of the EU Directive 2004/40/EC were exceeded. Electric and magnetic fields were measured during the following work tasks: (1) walking or operating devices on the ground; (2) working from a service platform; (3) working around the power transformer on the ground or using a ladder; and (4) changing a bulb from a man hoist. In work task 2 “working from a service platform” the measured electric field (maximum value 16.6 kV/m) exceeded 10 kV/m in three cases. In the future it is important to study if the limit value (10 mA/m²) of Directive 2004/40/EC is exceeded at 110 kV substations. The occupational 500 µT action value of the magnetic flux density field (B‐field) was not exceeded in any working situation. Bioelectromagnetics 31:252–254, 2010. © 2009 Wiley‐Liss, Inc.     

Effects of exposure to a 60-kV/m, 60-Hz electric field on the social behavior of baboons.

We found in a previously reported study that exposure to a 30-kV/m, 60-Hz electric field had significant effects on the social behavior of baboons. However, it was not established whether or not the effects were related specifically to the 30-kV/m intensity of the field. A new experiment was conducted to determine whether or not exposure to a 60-Hz electric field at 60 kV/m would produce like changes in the baboons' social behavior. We exposed one group of eight male baboons to an electric field 12 hours a day, 7 days a week, for 6 weeks. A second group of eight animals was maintained under sham-exposure (control) conditions. Rates of performing on each of six categories of social behavior and on four categories of nonsocial behavior were used as criteria for comparing exposed with unexposed subjects and for within-group comparisons during three six-week experimental periods: Pre-Exposure, Exposure, and Post-Exposure. The results indicate that (1) during the exposure period, exposed animals exhibited statistically significant differences from controls in means of performance rates based on several behavioral categories; (2) across all three periods, within-group comparisons revealed that behaviors of exposed baboons were significantly affected by exposure to the electric field; (3) changes in performance levels probably reflect a stress response to the electric field; and (4) the means of response rates of animals exposed at 60 kV/m were higher, but not double, those of animals exposed at 30 kV/m. As in the 30-kV/m experiment, animals exposed at 60 kV/m exhibited significant differences in performances of Passive Affinity, Tension, and Stereotypy. Mean rates of performing these categories were 122% (Passive Affinity), 48% (Tension), and 40% (Stereotypy) higher in the exposed group than in the control group during exposure to the 60-kV/m field.     

Rats avoid exposure to HVdc electric fields: A dose response study

Rats, given the choice, avoid exposure to alternating current (ac) 60-Hz electric fields at intensities ? 75 kV/m. This study investigated the generality of this behavior by studying the response of rats when exposed to high voltage direct current (HV dc) electric fields. Three hundred eighty male Long Evans rats were studied in 9 experiments with 40 rats per experiment and in one experiment with 20 rats to determine 1) if rats avoid exposure to HVdc electric fields of varying field strengths, and 2) if avoidance did occur, what role, if any, the concentration of air ions would have on the avoidance behavior. In all experiments a three-compartment glass shuttlebox was used; either the left or right compartment could be exposed to a combination of HVdc electric fields and air ions while the other compartment remained sham-exposed. The third, center compartment was a transition zone between exposure and sham-exposure. In each experiment, the rats were individually assessed in 1-h sessions where half of the rats (n = 20) had the choice to locomote between the two sides being exposed or sham-exposed, while the other half of the rats'(n = 20) were sham-exposed regardless of their location, except in one experiment where there was no sham-exposed group. The exposure levels for the first six experiments were 80, 55, 42.5, 30, ?36, and ?55 kV/m, respectively. The air ion concentration was constant at 1.4 × 10⁶ ions/cc for the four positive exposure levels and ?1.4 × 10⁶ ions/cc for the two negative exposure levels. Rats having a choice between exposure and non-exposure relative to always sham-exposed control animals significantly reduced the amount of time spent on the exposed side at 80kV/m (P < .002) as they did at both 55 and ?55 kV/m (P < .005). No significant differences between groups were observed at 42.5, 30, or -36 kV/m. To determine what role the air ion concentration might have had on the avoidance behavior at field strengths of 55 kV/m or greater, four additional experiments were conducted. The HVdc exposure level was held constant at either ?55 kV/m (for three experiments) or -55 kV/m (for 1 experiment) while the air ion concentration was varied between experiments at 2.5 × 10⁵ ions/cc, 1.0 × 10⁴ for two of the experiments and was below the measurement limit (< ± 2 × 10³ ions/cc) for the other two experiments at 55 and ?55 kV/m. The exposed rats significantly reduced the amount of time spent on the exposed side at 55 and ?55 kV/m, relative to the sham-exposed rats regardless of air ion concentration (all at P < .005). Thus, HVdc electric fields of ? + or ?55 kV/m are sufficient to produce avoidance behavior in rats. Positive or negative air ion concentrations were not significant factors in these avoidance outcomes. © 1993 Wiley-Liss, Inc.     

紫膜碎片的电二色性研究

悬浮在水中的嗜盐菌紫膜碎片,在外电场作用下产主定向排列.在20℃时,568nm的电二色性研究表明:外加电场为2kV/m时取向程度可达60%以上;大于5.5kV/m时,取向作用趋于饱和状态;饱和时简约电二色性为-0.437左右,视黄醛生色团的跃迁矩方向与电偶极矩方向形成60.9°夹角;紫膜的永久偶极短为9.2×10~(-24)C、M,剩余电极化率为3.0×10~(-27)m~2;紫膜的旋转扩散常数为0.53秒~(-1).曲线拟合分析表明,感应偶极对紫膜碎片的定向的贡献应予考虑.本文对紫膜碎片的定向机理进行了讨论.     

60-Hz electric field alters the steroidogenic response of rat adrenal tissue, in vitro

Exposure to a 60-Hz electric field at 10 kV/m but not at 5 kV/m, 100 kV/m or 1000 kV/m caused a highly significant, threefold elevation in the steroidogenic response of rat adrenal cortical tissue after the administration of 10 mU of adrenocorticotrophic hormone (ACTH) under in vitro, superfusion conditions. A 60-Hz electric field can directly influence the function of mammalian tissue in the absence of central-nervous-system mediation.     

The effect of pulse field strength on electric field stimulated biosorption of uranium by Kluyveromyces marxianus IMB3

Summary Improved biosorption of uranium by Kluyveromyces marxianus IMB3 biomass was achieved by increasing the electric field strength of delivered pulses from 1.25kV/cm to 2.5kV/cm. Although this had little or no effect on the maximum biosorption capacity (q_max), at low concentrations of uranium the amount bound to the biomass increased from 70 to 140mg uranium/g biomass. Significant increases in the maximum biosorption capacities (119–180 mg uranium/g biomass) were observed when the pulse field strength was increased from 2.5kV/cm to 3.25kV/cm.     

Miniature-probe measurements of electric fields and currents induced by a 60-Hz magnetic field in rat and human models

A miniaturized probe was designed and built to provide detailed data on fields induced by a uniform 60-Hz magnetic field in homogeneous models of rat and human. The probe employed three silver wires twisted and potted in an 8-cm hypodermic needle. The exposed tips of the wires formed three sensing electrodes with a centered ground; highly sensitive voltage measurements were enabled by a lock-in amplifier. Tests were conducted in a 1-mT rms field that was uniform within +/- 5%. The models were made by casting 1.5% agar at 1-S/m conductivity into plastic-foam molds. The rat model was scaled 1:1 as an adult (22 cm length; mass about 640 g). The human model was scaled 1:4 as an adult (height = 46.5 cm; mass 1.4 kg). The probe was inserted into each model in several regions, and readings of induced fields were made under different exposure geometries. Maximal strengths of fields induced near the surface of the torso were as high as 120 microV/cm in the laterally exposed rat model. Data extrapolated from the quarter-scale human model revealed that an induced field as high as 700 microV/cm could occur at the torso of a frontally exposed human adult. An overall size-scale factor of about 5 appears to be appropriate for experimental exposures of rats that are intended to simulate currents induced in human beings by magnetic fields. The average strength of electric fields induced in the torso by a 1-mT magnetic field is comparable to that by a vertical electric-field at 60 kV/m and 28 kV/m, respectively, for the rat and human.     

Relationship between field strength and arousal response in mice exposed to 60-Hz electric fields

White-footed mice, Peromyscus leucopus, were exposed to 60-Hz electric fields to study the relationship between field strength and three measures of the transient arousal response previously reported to occur with exposures at 100 kV/m. Five groups of 12 mice each were given a series of four 1-h exposures, separated by an hour, with each group exposed at one of the following field strengths: 75, 50, 35, 25, and 10 kV/m; 8 additional mice were sham-exposed with no voltage applied to the field generator. All mice were experimentally naive before the start of the experiment, and all exposures occurred during the inactive (lights-on) phase of the circadian cycle. The first exposure produced immediate increases in arousal measures, but subsequent exposures had no significant effect on any measure. These arousal responses were defined by significant increases of gross motor activity, carbon dioxide production, and oxygen consumption, and were frequently recorded with field strengths of 50 kV/m or higher. Significant arousal responses rarely occurred with exposures at lower field strengths. Responses of mice exposed at 75 and 50 kV/m were similar to previously described transient arousal responses in mice exposed to 100-kV/m electric fields. Less than half of the mice in each of the field strength groups below 50 kV/m showed arousal responses based on Z (standard) scores, but the arousals of the mice that did respond were similar to those of mice exposed at higher field strengths. Polynomial regression was used to calculate the field strength producing the greatest increases for each of the arousal measures. The results show that the amplitude of the transient arousal response is related to the strength of the electric field, but different measures of arousal may have different relationships to field strength.     

Comparison of 60-Hz electric fields and incandescent light as aversive stimuli controlling the behavior of rats

Rats were exposed to two procedures which enabled them to press a lever to turn off a 90 or 100 kV/m 60-Hz electric field or, later in the study, illumination from an incandescent lamp. Under one procedure, a response turned off the stimulus for a fixed duration, after which the stimulus was turned on again. A response during the off-period restarted the fixed duration. None of the rats turned the field off reliably. Next, under an alternative procedure, pressing one lever turned the field off; pressing the other lever turned it back on; responding under those conditions differed little from that seen at 0 kV/m. Under both procedures, when illumination from an incandescent lamp served as the stimulus, each rat did turn the stimulus off, and performances varied with stimulus intensity. The results show that a 100 kV/m 60-Hz electric field is not sufficient to function as an aversive stimulus under two procedures where illumination from a lamp does function as an aversive stimulus.     

In vitro exposure to electromagnetic fields: changes in tumour cell properties

Two human colon cancer cell lines, Colo 205 and Colo 320 DM, have been studied for their responses to 60 Hz-generated electromagnetic fields (EMF) using soft agar cloning and monoclonal antibody binding assays to assess exposure-induced changes. Cellular responses have been studied after 24 h continuous exposure of cells concurrently to four experimental conditions; i.e. no EMF (E-M-), magnetic field only (M+, 1.0 G rms), electric field only (E+, 300 mA/m2 rms), and combined electric plus magnetic fields at these intensities (E+M+). Under these conditions, both cell lines demonstrated significantly increased colony formation in soft agar and increased expression of tumor associated antigens after exposure to E+M+ and to M+ as compared to unexposed controls.     

Perception of local DC and AC electric fields in humans

The goal of this study was to address some of the factors that contribute to the human ability to detect the presence of weak electric fields generated by direct current (DC) and alternating current (AC) sources. An exposure chamber allowed us to expose a limited surface of the body (forearm and hand) to DC fields of up to 65 kV/m and AC fields up to a maximum of 35 kV/m (frequency 60 Hz). Perception was examined using a staircase procedure and a rating procedure derived from signal detection theory. Sixteen subjects participated in the experiments, and none detected the local DC fields. In contrast, 9/16 subjects were sensitive to local AC electric fields, although detection thresholds (index of sensitivity, d' = 1.0) were widely variable between subjects. When regional exposure was limited to the dorsal forearm, performance was similar to that seen when the forearm and hand were exposed. In contrast, subjects did not reliably detect the AC electric fields when exposure was limited to the hand (either hairy or glabrous skin), although a minority of subjects (3/9) showed some evidence of detecting fields presented to the glabrous palm. Subjects were unable to detect AC electric fields when the hair was removed from the forearm and hand, suggesting that the evoked sensation is mainly dependent on movement of hair located in the exposed region.     

Attempts to produce taste-aversion learning in rats exposed to 60-Hz electric fields

A measure of taste-aversion (TA) learning was used in three experiments to 1) determine whether exposure to intense 60-Hz electric fields can produce TA learning in male Sprague-Dawley rats, and 2) establish a dose-response function for the behavior in question. In Experiment 1, four groups of eight rats each were distributed into one of two exposures (69 ± 5 kV/m or 133 ± 10 kV/m) or into one of two sham-exposure groups. Conditioning trials paired 0.1% sodium saccharin in water with 3 h of exposure to a 60-Hz electric field. Following five conditioning trials, a 20-min, two-bottle preference test between water and saccharin-flavored water failed to reveal TA conditioning in exposed groups. In Experiment 2, four groups of eight rats each (34 ± 2 kV/m or 133 ± 10 kV/m and two sham-exposed groups) were treated as before. Electric-field exposure had no effect on TA learning. Experiment 3 tested for a possible synergy between a minimal dose (for TA learning) of cyclophosphamide (6 mg/kg) and 5 h of exposure to 133 ± 10 kV/m electric fields in a dark environment under conditions otherwise similar to those of Experiments 1 and 2. The results indicated no TA learning as reflected in the relative consumption of saccharin.     

高压静电场对绵羊精子存活率的影响

采用不同剂量的高压静电场处理绵羊精液,经分析发现,高压静电场对绵羊精具有激活作用。能提高绵羊精液品质,表现在适当剂量的高压静电场能显著地提高绵羊精子存活率,其中以６００ｋＶ／ｍ剂量处理效果最佳。１００ｋＶ／ｍ和３００ｋＶ／ｍ剂量对精子刺激不足,而９００ｋＶ／ｍ剂量则对精子刺激过程,导致部分精子损伤和死亡,同样达不到预期的效果。     

Dynamics of lysozyme and its hydration water under an electric field

The effects of a static electric field on the dynamics of lysozyme and its hydration water are investigated by means of incoherent quasi-elastic neutron scattering (QENS). Measurements were performed on lysozyme samples, hydrated respectively with heavy water (D ₂O) to capture the protein dynamics and with light water (H ₂O), to probe the dynamics of the hydration shell, in the temperature range from 210 < T < 260 K. The hydration fraction in both cases was about ～ 0.38 gram of water per gram of dry protein. The field strengths investigated were respectively 0 kV/mm and 2 kV/mm ( ～2 × 10 ⁶ V/m) for the protein hydrated with D ₂O and 0 kV and 1 kV/mm for the H ₂O-hydrated counterpart. While the overall internal protons dynamics of the protein appears to be unaffected by the application of an electric field up to 2 kV/mm, likely due to the stronger intra-molecular interactions, there is also no appreciable quantitative enhancement of the diffusive dynamics of the hydration water, as would be anticipated based on our recent observations in water confined in silica pores under field values of 2.5 kV/mm. This may be due to the difference in surface interactions between water and the two adsorption hosts (silica and protein), or to the existence of a critical threshold field value E _c ～2–3 kV/mm for increased molecular diffusion, for which electrical breakdown is a limitation for our sample.     

Influence of 50-Hz electric and magnetic fields on human blood pressure

This investigation studied the effects of 50-Hz electric and magnetic fields on the pulse rate and blood pressure in humans. Electrocardiograms (ECG) and the blood pressure of 41 male volunteers were recorded using ambulatory methods. Twenty-six subjects were measured in and outside real fields and 15 subjects in and outside `sham' fields. The results of the ECG recordings have been presented earlier. This article deals with the analysis of the blood pressure measurements. Measurement took 3 hrs. First, the subjects spent 1 h outside the fields, then 1 h in real or `sham' fields, followed by 1 h outside the fields. The electric field strength varied from 3.5 to 4.3 kV/m and the magnetic flux density from 1.4 to 6.6 μT. When analysing the blood pressure, which was measured with a non-invasive cuff method, it could not be shown that the fields (<4.3 kV/m and <6.6 μT) affected diastolic or systolic blood pressure. Received: 6 June 1994 / Accepted in revised form: 11 March 1996     

Phantom Model Testing of Active Implantable Cardiac Devices at 50/60 Hz Electric Field

Exposure to external extremely low-frequency (ELF) electric and magnetic fields induces the development of electric fields inside the human body, with their nature depending on multiple factors including the human body characteristics and frequency, amplitude, and wave shape of the field. The objective of this study was to determine whether active implanted cardiac devices may be perturbed by a 50 or 60 Hz electric field and at which level. A numerical method was used to design the experimental setup. Several configurations including disadvantageous scenarios, 11 implantable cardioverter-defibrillators, and 43 cardiac pacemakers were tested in vitro by an experimental bench test up to 100 kV/m at 50 Hz and 83 kV/m at 60 Hz. No failure was observed for ICNIRP public exposure levels for most configurations (in more than 99% of the clinical cases), except for six pacemakers tested in unipolar mode with maximum sensitivity and atrial sensing. The implants configured with a nominal sensitivity in the bipolar mode were found to be resistant to electric fields exceeding the low action levels, even for the highest action levels, as defined by the Directive 2013/35/EU. Bioelectromagnetics. 2020;41:136–147. © 2020 Bioelectromagnetics Society.