EMF Research Studies

Circularly polarized 50-Hz magnetic field exposure reduces pineal gland and blood melatonin concentrations of Long- Evans rats

Unknown authors · 1994

Influence of microwaves on different types of receptors and the role of peroxidation of lipids on receptor-protein shedding.

Philippova TM, Novoselov VI, Alekseev SI · 1994

Researchers studied the effects of continuous wave and pulse-modulated 900 MHz microwave fields on rat chemoreceptors using in vitro assays. Binding of H3-glutamic acid to hippocampal cells was unchanged after 15 minutes of continuous wave exposure at 1 W/kg, while binding of H3-dihydroalprenolol to neonatal liver-cell membranes decreased fivefold under the same conditions. The decrease was due to shedding of receptor elements into solution and correlated with oxygen concentration in the suspension.

Interactive developmental toxicity of radiofrequency radiation and 2-methoxyethanol in rats.

Nelson BK et al. · 1994

Researchers exposed rats to RF radiation that maintained colonic temperature at 42.0 degrees C for 0, 10, 20, or 30 min and to 2ME at doses of 0, 75, 100, 125, or 150 mg/kg on gestation days 9 or 13. Fetuses were examined on gestation day 20 for external, skeletal, and visceral malformations. Synergistic effects were observed for some treatment combinations but not others, with highly significant effects on gestation day 13 but little effect on day 9. Statistical analyses showed no global synergistic effect but evidence of synergism at intermediate dose levels.

Effects of 2.45-GHz microwave radiation and phorbol ester 12-O-tetradecanoylphorbol-13-acetate on dimethylhydrazine-induced colon cancer in mice.

Wu RY, Chiang H, Shao BJ, Li NG, Fu YD · 1994

The study used 115 Balb/c mice that were 4 weeks old, divided into control, DMH, DMH plus microwave, and DMH plus TPA groups. The microwave exposure was 2.45 GHz radiation at 10 mW/cm2 delivered dorsally in an anechoic chamber. Radiation was administered 3 hours daily, 6 days per week for 5 months, and DMH was injected once per week. Tumor incidence did not differ significantly among the three DMH treatment groups. Group D had more tumors, larger tumors, and more protuberant and infiltrative tumor types than groups B and C, and groups B and C did not differ.

Effects of modulated microwave and X-ray irradiation on the activity and distribution of Ca(2+)-ATPase in small intestine epithelial cells

Somosy Z, Thuroczy G, Koteles GJ, Kovacs J · 1994

Researchers investigated the distribution and activity of Ca(2+)-ATPase in small intestine epithelial cells of mice after total body exposure to 2450 MHz microwave irradiation modulated at 16 Hz and X-ray irradiation. In control animals, enzyme activity was present in the brush border and lateral membranes, and lateral membrane activity was inhibited by quercetin. Microwave irradiation immediately decreased Ca(2+)-ATPase activity on lateral membranes, 1 Gy X-ray caused a similar reversible decrease within 24 hours, and 5 Gy X-ray reduced activity on both apical and lateral membranes persisting up to 24 hours.

Effect of low power microwave on the mouse genome: a direct DNA analysis.

Sarkar S, Ali S, Behari J · 1994

Animals were exposed to microwave at a power density of 1 mW/cm2 for 2 h/day at a frequency of 2.45 GHz over a period of 120, 150 and 200 days. HinfI digested DNA samples from testis and brain of control and exposed animals were hybridized with a synthetic oligo probe (OAT 36) comprising nine repeats of 5'-GACA-3'. As compared to control animals, band patterns in exposed animals were found to be distinctly altered in the range of 7-8 kb which was also substantiated by densitometric analysis.

Influence of microwave exposure on chlordiazepoxide effects in the mouse staircase test.

Quock RM, Klauenberg BJ, Hurt WD, Merritt JH · 1994

Researchers tested male mice in the staircase test after pretreatment with chlordiazepoxide at 8, 16, and 32 mg/kg and a 5-min exposure to microwave radiation at 4, 12, and 36 W/kg (1.8 or 4.7 GHz). In sham-irradiated mice, increasing CDP doses first increased steps ascended without affecting rears, then increased steps ascended and decreased rears, and finally decreased both measures. Microwave exposure did not alter steps ascended or rears at lower CDP doses, but at 32 mg/kg CDP, 36 W/kg microwave at 4.7 GHz significantly reversed the reductions in both measures.

Athermal alterations in the structure of the canalicular membrane and ATPase activity induced by thermal levels of microwave radiation.

Phelan AM, Neubauer CF, Timm R, Neirenberg J, Lange DG · 1994

Researchers exposed Sprague-Dawley rats to microwave radiation at 2.45 GHz and 80 mW/cm² for 30 minutes daily over four days, raising rectal temperature by 2.2°C. A separate group received radiant heat producing the same temperature rise. Microwave exposure reduced Mg(++)-ATPase activity by 48.5% and increased Na+/K(+)-ATPase activity by 170%, while radiant heat caused no significant changes in either enzyme. Microwave exposure also decreased the ratio of saturated to unsaturated fatty acids, whereas radiant heat increased it. Membrane fluidity measured by EPR differed among sham, microwave, and radiant heat groups, reflecting the fatty acid changes.

[The effect of low-intensity prolonged impulse electromagnetic irradiation in the UHF range on the testes and the appendages of the testis in rats].

Lokhmatova SA, · 1994

Researchers studied the effect of long-term impulsive electromagnetic irradiation at a power density of 0.25 mW/cm2 for 4 months, 2 hours per day, on rat testes and epididymides. The irradiation was at 3 GHz and the results demonstrated high sensitivity of the rat testes and epididymides, with destructive changes in seminiferous tubules and testicular tissue. Full recovery was not observed even 4 months after irradiation ended.

Alteration of life span of mice chronically exposed to 2.45 GHz CW microwaves.

Liddle CG, Putnam JP, Huey OP · 1994

Female CD1 mice were exposed from the thirty-fifth day of age for the remainder of their lives to 2.45 GHz CW microwave radiation at 3 or 10 mW/cm2. Exposures took place 1 h/day, 5 day/week in an anechoic chamber at an ambient temperature of 22 degrees C and a relative humidity of 50%. There were 25 animals in each exposure group, and an equal number of controls were concurrently sham exposed. The average life span of animals exposed at 10 mW/cm2 was significantly shorter than that of sham-exposed controls (572 days vs. 706 days; P = .049; truncation > 20%). In contrast, the average lifespan of the animals exposed at 3 mW/cm2 was slightly, but not significantly, longer (738 days) than that of controls (706 days).

Intraseptal microinjection of beta-funaltrexamine blocked a microwave-induced decrease of hippocampal cholinergic activity in the rat.

Lai H, Carino MA, Horita A, Guy AW, · 1994

Researchers exposed rats to pulsed 2450-MHz microwaves for 45 minutes at a power density of 1 mW/cm2 with a whole body specific absorption rate of 0.6 W/kg. This exposure decreased cholinergic activity in the hippocampus as measured by sodium-dependent high-affinity choline uptake. Microinjection of beta-funaltrexamine (1 microgram) into the septum before exposure blocked the microwave-induced decrease.

Microwave irradiation affects radial-arm maze performance in the rat.

Lai H, Horita A, Guy AW, · 1994

After 45 minutes of exposure to pulsed 2450 MHz microwaves at 1 mW/cm², rats showed retarded learning in a radial-arm maze task, indicating a spatial working memory deficit. The memory deficit was reversed by pretreatment with the cholinergic agonist physostigmine or the opiate antagonist naltrexone, but not by the peripheral opiate antagonist naloxone methiodide. The researchers concluded that both cholinergic and endogenous opioid neurotransmitter systems in the brain are involved in the microwave-induced spatial memory deficit.

[The effect of ultrahigh-frequency electromagnetic radiation on learning and memory processes].

Krylova IN et al. · 1994

The study aimed to investigate the effect of ultrahigh-frequency electromagnetic radiation on learning and memory processes. Low-intensity electromagnetic field (12.6 cm, 2375 MHz, power density 1 mW/cm2) produced retrograde amnesia in the rat passive avoidance test. No effect was registered of microwave irradiation on the open field behavior and the pain sensitivity.

Characteristics of microwave evoked body movements in mice.

Brown DO, Lu ST, Elson EC · 1994

Researchers studied microwave evoked body movements in mice using head and neck exposure to pulsed and gated continuous wave 1.25 GHz microwaves delivered via a resonant cavity. The incidence of body movements increased proportionally with specific absorption dose when the whole-body average specific absorption rate was held constant at 7300 W/kg, reaching a plateau at 0.9 kJ/kg. For doses higher than 0.9 kJ/kg, response incidence was proportional to the specific absorption rate and reached a plateau at 900 W/kg.

Modification of lethal radiation injury in mice by postradiation exposure to low-intensity centimeter-band radio frequency waves

Akoev IG, Mel'nikov VM, Usachev AV, Kozhokaru AF, · 1994

Researchers studied whether exposure to low-intensity radiofrequency radiation after a lethal dose of gamma-radiation could modify the resulting injury in mice. The radiofrequency exposure lasted up to 23 hours at an intensity of 5 plus or minus 1.5 microwatts per square centimeter, covering frequency ranges of 2-8, 8-18, and 19-27 GHz with a swing frequency of 12-14 Hz. A clearly pronounced modification of acute radiation injury was obtained when the radiofrequency exposure was applied immediately after the gamma-radiation.

Tumor promotion in a breast cancer model by exposure to a weak alternating magnetic field

Unknown authors · 1993

DMBA was given orally at 5 mg/kg on the first day and weekly thereafter up to a total dose of 20 mg per rat. Eight weeks after DMBA application, the magnetic-field-exposed rats exhibited significantly more tumors than sham-exposed animals. At the end of the three-month exposure, tumor incidence in the exposed group was 50% higher than in the sham group, a statistically significant difference. Tumor size as estimated by palpation was also significantly larger in the magnetic-field-exposed rats compared with sham-exposed rats.

Effects of microwaves on membranes of hematopoietic cells in their structural and functional organization.

Rotkovska D, Bartonickova A, Kautska J · 1993

Effect of amplitude-modulated radio frequency radiation on cholinergic system of developing rats.

Kunjilwar KK, Behari J · 1993

Researchers exposed developing rats to amplitude-modulated radio frequency radiation at 147 MHz and its sub-harmonics for 30 to 35 days, three hours per day. A significant decrease in acetylcholine esterase activity was found in exposed rats compared to controls. The decrease in enzyme activity was independent of the carrier wave frequencies used. Short-term exposure did not significantly affect acetylcholine esterase activity.

Effects of modulated and continuous microwave irradiation on pyroantimonate precipitable calcium content in junctional complex of mouse small intestine.

Somosy Z, Thuroczy G, Kovacs J · 1993

Researchers investigated pyroantimonate-precipitable calcium in mouse intestinal epithelial cells after whole-body exposure to 2450 MHz continuous and 16 Hz square-modulated microwaves. Immediately after modulated irradiation at 0.5 and 1 mW/cm², calcium deposits rapidly appeared on the cytoplasmic side of lateral membranes and in the junctional complex including tight junctions. These changes were reversible, with calcium distribution returning to control-like patterns after 24 hours. Continuous-wave exposure at the same energy did not alter calcium distribution.

Temporal bisection in rats: the effects of high-peak-power pulsed microwave irradiation

Raslear TG, Akyel Y, Bates F, Belt M, Lu ST · 1993

Researchers studied the effects of high-peak-power pulsed microwaves on a time perception and discrimination task in rats. Time perception, response bias, and total trials did not change with power level. Dose-response effects were observed for discriminability, session time, and trial completions (null responses). Exposures used the TEMPO system with 80 nanosecond pulses exceeding 700 megawatts peak power, whole-body SAR of 0.072 W/kg, well below the 0.4 W/kg limit.

Differential response of the permeability of the rat liver canalicular membrane to sucrose and mannitol following in vivo acute single and multiple exposures to microwave radiation (2.45 GHz) and radiant-energy thermal stress.

Lange DG, D'Antuono ME, Timm RR, Ishii TK, Fujimoto JM. · 1993

The stimulatory effect of magnetic fields on regeneration of the rat sciatic nerve is frequency dependent

Rusovan A, Kanje M, Mild KH · 1992

Researchers studied the effects of sinusoidal magnetic fields on regeneration of the rat sciatic nerve. The rats were exposed to a 0.1-mT magnetic field of various frequencies (50-2000 Hz) inside a pair of Helmholtz coils for various periods of time. Regeneration was measured by the pinch test or by immunocytochemical staining for neurofilaments 3, 4, or 6 days after the lesioning. Frequencies of 250, 500, and 1000 Hz significantly increased the regeneration distance, while higher (2000 Hz) and lower (50 Hz) frequencies had no effect. Maximal stimulation was obtained at 1000 Hz, and at this frequency the rate of regeneration was increased by 24%.

Modification of acoustic startle by microwave pulses in the rat: a preliminary report.

Seaman RL, Beblo DA · 1992

Researchers presented single 1.25-GHz microwave pulses of 0.8- to 1.0-microseconds duration to four rats 100 ms before a startle-inducing acoustic stimulus. At a lower energy dose of 22-43 mJ/kg per pulse, the mean startle latency was longer and the mean amplitude was smaller compared to control responses to acoustic stimuli alone. At a higher energy dose of 59-107 mJ/kg per pulse, the mean latency and amplitude were not statistically different from controls.

Effects of hyperthermia induced by microwave irradiation on brain development in mice.

Fukui Y, Hoshino K, Inouye M, Kameyama Y · 1992

Researchers exposed pregnant mice to 2.45 GHz microwave radiation for 15 or 20 minutes on day 13 of gestation. Pyknotic cell incidence in the ventricular zone was 1.83% after 15 minutes and 3.06% after 20 minutes of microwave exposure. Microwave radiation for 20 minutes produced effects comparable to immersion in 42°C hot water for 15 minutes. Brain weight was significantly lower and neuron density higher in the 20-minute exposure group compared to controls. The researchers concluded that microwave radiation at the tested dose mainly has a thermal effect.

[Effect of extremely high-frequency electromagnetic radiation on the function of skin sensory endings].

Enin LD, Akoev GN, Potekhina IL, Oleiner VD · 1992

The study aimed to investigate the effect of extremely high-frequency electromagnetic radiation on skin sensory endings in albino rats. Researchers recorded impulse activity from solitary fibers of the tibial nerve and found that receptor units responded to mechanical stimulation of the skin. Irradiation with low-intensity millimeter-band fields at 55.61 and 73 GHz reduced receptor unit sensitivity to mechanical stimulation. Half of the receptor units stopped responding 25 minutes after irradiation, while the other half continued responding after 35 minutes but with a significantly changed response character.