Lai H, Singh NP · 1995
Researchers measured DNA single-strand breaks in brain cells of rats acutely exposed to low-intensity 2450 MHz microwaves, using an alkaline microgel electrophoresis method. After 2 hours of exposure to pulsed microwaves, no significant effect was observed immediately after exposure, but a dose rate-dependent increase in DNA single-strand breaks was found in brain cells at 4 hours postexposure. In rats exposed for 2 hours to continuous-wave 2450 MHz microwaves at 1.2 W/kg SAR, increases in brain cell DNA single-strand breaks were observed both immediately and at 4 hours postexposure.
Lai H, Singh NP, · 1995
Researchers exposed rats to microwave radiation at levels similar to cell phone use and found that it caused DNA breaks in brain cells. The damage appeared 4 hours after exposure, even at relatively low power levels (0.6 W/kg). This suggests that microwave radiation can damage the genetic material in brain cells at exposure levels considered 'safe' by current standards.
Roy S et al. · 1995
Researchers investigated whether a low-frequency, low-intensity magnetic field could affect the oxidative burst triggered by PMA in rat peritoneal neutrophils. In the presence of the magnetic field, a 12.4% increase in the fluorescence signal was observed in PMA-stimulated neutrophils (n = 5, P < 0.02, 18 pairs of measurements). The researchers described this as what they believed to be the first experimental observation of a magnetic field influencing free radical species generated during signal transduction in living cells.
Unknown authors · 1995
The study used quantitative Northern analysis to measure MYC and beta-actin mRNA levels in human leukemic HL60 cells. Cells were exposed to 60 Hz sinusoidal magnetic fields at 0.57, 5.7, or 57 microT for 20 minutes using a new field-exposure system designed to optimize any response. No significant effect of the electromagnetic fields on gene expression was observed with any of the exposure systems or analytical methods.
Unknown authors · 1995
Researchers exposed human leukemia cells to 60 Hz magnetic fields at various strengths for 20 minutes to test whether power line frequency EMF could activate cancer-related genes. Despite using improved methods and testing conditions similar to previous positive studies, they found no effect on MYC or beta-actin gene expression. This contradicts earlier claims that EMF exposure rapidly activates genes involved in cell growth.
Lacy-Hulbert et al. · 1995
Researchers exposed human leukemia cells (HL60) to 60 Hz magnetic fields at various strengths for 20 minutes, then measured whether genes linked to cancer growth (MYC and beta-actin) became more active. Despite using conditions similar to previous studies that claimed to find effects, they found no changes in gene activity from the electromagnetic field exposure.
Unknown authors · 1995
Researchers performed an extensive series of experiments with human HL60 and Daudi cells incorporating blind exposures and internal standards. Exposure conditions covered flux densities from 5.7 microT to 10 mT and durations from 20 to 60 minutes. No alteration in the human MYC gene (c-myc) or beta-actin steady-state mRNA levels was observed.
Kakita Y et al. · 1995
Researchers studied the effect of microwave irradiation on the survival of bacteriophage PL-1 specific for Lactobacillus casei using a commercial 2,450 MHz microwave oven. Phage inactivation followed almost first-order reaction kinetics and was unaffected by continuous versus intermittent irradiation or phage concentration but was affected by suspension volume which prevented heat loss. Phage genome DNA breakage was primarily caused by heat generated by microwave irradiation, while the same temperature from external heat did not affect phage DNA.
Sherry CJ, Blick DW, Walters TJ, Brown GC, Murphy MR · 1995
Researchers examined the effect of acute ultrawideband electromagnetic radiation exposure on monkeys performing a Primate Equilibrium Platform task. The exposure had no effect on task performance when tested immediately after exposure. Each monkey was exposed twice for 2 minutes at a pulse repetition rate of 60 Hz with a peak electric field strength of 250 kV/m.
Unknown authors · 1995
Researchers exposed human lymphoid cells immortalized by Epstein-Barr virus and HL60 leukemic cells to 50 Hz magnetic fields at 10 μT or 1 mT for periods ranging from 20 minutes to 72 hours. C-myc transcript levels were measured by Northern blot analysis normalized to the GaPDH gene. No statistically significant difference in c-myc transcript levels was observed between exposed and control cells for either cell type at any exposure duration, and the same result was found in cells synchronized in G0/G1 phase.
Pakhomov AG, Dubovick BV, Degtyariov IG, Pronkevich AN · 1995
Researchers studied the combined effects of microwave radiation and drugs on an isolated frog auricle preparation. Exposure to pulse-modulated 915 MHz microwaves for up to 40 minutes had no effect on the rate or amplitude of spontaneous auricle twitches unless the absorbed power caused heating. Caffeine (1 mM) strongly increased the average heart power, and this effect was significantly augmented by about 15% under burst-type pulsed microwaves with an average SAR of 8-10 W/kg, while heating was only approximately 0.1°C.
Grigor'ev IuG, Luk'ianova SN, Makarov VP, Rynskov VV · 1995
Researchers exposed thirty rabbits to thirty-minute microwave irradiation at 1.5 GHz with a pulse intensity of 0.3 mW/cm2 and tested several pulsed modes. A reliable effect was detected only in the hippocampus, shown as an amplification of theta-range activity within normal functioning. The total bioelectrical activity of the cortex, caudate nucleus, hypothalamus, amygdala, and septum was not reliably changed.
Yoshida Y et al. · 1995
Researchers exposed pregnant rats to whole-body microwaves at 10 mW/cm2 and 2,450 MHz and measured placental blood flow and five endocrine indicators. Placental blood flow at 45-90 minutes after exposure was significantly decreased in exposed rats. Microwave exposure increased corticosterone and decreased estradiol regardless of angiotensin II pretreatment, increased progesterone and prostaglandin F2 alpha without pretreatment, and did not change prostaglandin E2. Pretreatment with angiotensin II increased placental blood flow at 15 and 30 minutes, but this effect was absent in microwave-exposed rats.
Dimbylow PJ, Mann SM. · 1994
Researchers built a mathematical model of the human head from MRI slices and used finite-difference time-domain (FDTD) calculations to estimate the specific energy absorption rate (SAR) at 900 MHz and 1.8 GHz. The generic transceiver was represented by a quarter-wavelength monopole on a metal box, and three placement geometries were examined: vertical in front of the eye, and vertical and horizontal at the side of the ear. For the most typical position at the side of the head, the maximum SAR averaged over 10 g of tissue was 2.1 and 3.0 W kg(-1) per W of radiated power at 900 MHz and 1.8 GHz. Placement in front of the eye gave values of 3.1 and 4.6 W kg(-1) per W averaged over 10 g of tissue at 900 MHz and 1.8 GHz.
Salford LG, Brun A, Sturesson K, Eberhardt JL, Persson BRq · 1994
Researchers exposed male and female Fischer 344 rats to 915 MHz microwaves as continuous wave and pulse-modulated at 8, 16, 50, and 200 Hz in a transverse electromagnetic transmission line chamber. Albumin leakage occurred in 56 of 184 exposed rats versus 5 of 62 controls, and continuous wave exposure yielded 14 positive findings out of 35 that were significantly different from controls (P = 0.002). The specific energy absorption rate varied between 0.016 and 5 W/kg, and rats were exposed for 2 hours without anesthesia.
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.
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.
Unknown authors · 1994
Unknown authors · 1994
Two pulse waveforms were tested, with rise and fall times of 85 microseconds (PMF-A) or 2.1 microseconds (PMF-B). After exposure, the eggs incubated for nine more days without fields, then embryos were examined blind. Both exposed groups had more developmental anomalies than controls, but only the PMF-B group showed a statistically significant increase (P=0.007) and a high rate of early embryonic death, while the PMF-A group's increase was not significant (P=0.173).
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.
Thuroczy G, Kubinyi G, Bodo M, Bakos J, Szabo LD, · 1994
At 30 mW/cm², total EEG power increased, while at 10 mW/cm² EEG did not change but cerebral blood flow increased. Brain-localized 4 GHz continuous-wave exposure at 42 mW/g SAR increased EEG delta power and REG amplitude simultaneously.
D'Andrea JA, Thomas A, Hatcher DJ · 1994
Researchers exposed four male rhesus monkeys to high-peak-power 5.62-GHz microwave pulses while the monkeys performed an operant task for food pellet rewards. Compared to sham exposures, significant alterations of lever responding, reaction time, and earned food pellets occurred at 4 and 6 W/kg but not at 2 W/kg. There were no differences between radar pulses and SLED pulses in producing behavioral effects.
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).
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.
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.
