Fritze K et al. · 1997
Researchers studied the effect of GSM microwave exposure on gene activity in the rat brain by measuring messenger RNAs of hsp70, c-fos, c-jun, and GFAP using in situ hybridization histochemistry. The study used specific absorption rates of 0.3 W/kg, 1.5 W/kg, and 7.5 W/kg. Immediately after exposure, slight hsp70 messenger RNA induction was found in the cerebellum and hippocampus at 7.5 W/kg, but not at lower intensities. At 24 hours and seven days after exposure, no lasting protein changes, altered glial marker expression, or increased cell proliferation were observed.
Lai, H, Singh, NP, · 1997
Researchers investigated the effects of microwave exposure on DNA strand breaks in rat brain cells. They found that treating rats with either melatonin or the spin-trap compound PBN immediately before and after radiofrequency electromagnetic radiation exposure blocked the DNA strand breaks. Because both substances are free radical scavengers, the researchers hypothesized that free radicals are involved in the radiofrequency electromagnetic radiation-induced DNA damage.
Lai H, Carino MA, Singh NP · 1997
Researchers exposed rats to 2450 MHz pulsed radiofrequency radiation at a power density of 2 mW/cm2 for 2 hours and then measured DNA double strand breaks in brain cells. The RFR exposure significantly increased DNA double strand breaks in rat brain cells, and the effect was partially blocked by naltrexone treatment. The researchers concluded that endogenous opioids play a mediating role in RFR-induced DNA strand breaks in brain cells of the rat.
Grayson JK · 1996
A nested case-control study investigated electromagnetic field exposures and brain tumor risk in the US Air Force. Cumulative extremely low frequency and radiofrequency/microwave exposures were estimated from a job-exposure matrix, and ionizing radiation exposures came from personal dosimetry records. Nonionizing electromagnetic field exposure showed a small excess risk with extremely low frequency OR 1.28 (95% CI 0.95-1.74) and radiofrequency/microwave OR 1.39 (95% CI 1.01-1.90), while ionizing radiation had OR 0.58 (95% CI 0.22-1.52). Military rank was consistently associated with brain tumor risk, with officers having OR 2.11 (95% CI 1.48-3.01) versus enlisted men and senior officers OR 3.30 (95% CI 1.99-5.45) versus all others.
Szmigielski, S · 1996
Researchers compared cancer morbidity between occupationally exposed and non-exposed personnel using observed and expected rates to calculate an observed/expected ratio. The overall cancer morbidity rate was 119.1 per 100 000 annually in exposed personnel versus 57.6 in non-exposed, yielding an OER of 2.07 (P < 0.05). Higher rates were seen for alimentary tract neoplasms (OER = 3.19–3.24), brain tumours (OER = 1.91), and haemopoietic/lymphatic malignancies (OER = 6.31).
Ohmoto Y et al. · 1996
Kittel A, Siklos L, Thuroczy G, Somosy Z · 1996
Bielski J, Sikorski M · 1996
The study examined 50 workers exposed to electromagnetic radiation in the form of radiowaves. Average glucose levels were 155 mg% at 30 minutes, 180 mg% at 60 minutes, 153 mg% at 90 minutes, and 124 mg% at 120 minutes. Among those with glucose tolerance disturbances, 10 persons (32%) also had abnormal EEG records indicating disorders in brain bioelectric activity.
Kubinyi G, Thuroczy G, Bakos J, Boloni E, Sinay H, Szabo LD, · 1996
Pregnant CFLP mice were exposed to 2.45 GHz microwave radiation for 100 minutes each day throughout gestation in an anechoic chamber. Brain aminoacyl-tRNA synthetase activity decreased significantly after continuous-wave exposure but not after amplitude-modulated exposure. Liver enzyme activity increased after both continuous-wave and amplitude-modulated exposure, while body and organ weights were unaffected.
Lai H, Singh NP · 1996
Researchers investigated single- and double-strand DNA breaks in rat brain cells after acute exposure to radiofrequency electromagnetic radiation. Rats received acute 2-hour exposure to pulsed or continuous-wave 2450-MHz radiofrequency electromagnetic radiation, producing a whole-body average-specific absorption rate of 1.2 W/kg. An increase in both types of DNA strand breaks was observed after exposure to either the pulsed or continuous-wave radiation, with no significant difference between the two forms.
Chou CK, McDougall JA, Can KW · 1995
Researchers tested the possibility of tissue heating from an auditory brainstem implant and a modified cochlear implant during MRI using a full-sized human phantom with simulated skull, brain, and muscle. Thermograms were taken before and after a 26-minute MRI scan with 94 excitations and 25 ms echo time set to induce maximum radiofrequency heating. Results showed no observable heating associated with either implant during worst-case MRI of the head.
Rittweger J, Lambertz M, Kluge W, Kramer K, Langhorst P · 1995
The study examined magnetoencephalogram, heart frequency and ventilatory parameters before and after occipital application of the fields. Differences in these measures indicated that the effects can be explained by an influence on the common brainstem system.
Reiser H, Dimpfel W, Schober F · 1995
Researchers conducted a single-blind, cross-over, placebo-controlled study with 36 volunteers. Volunteers were exposed to a MEGA-WAVE therapy instrument and a mobile digital telephone, and also underwent a no-exposure control. The MEGA-WAVE instrument increased EEG power in Alpha2, Beta1, and Beta2 bands during and after exposure. The mobile telephone increased EEG power in the same bands after a delay of about 15 minutes.
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.
Anderson V, Joyner KH · 1995
Researchers measured electric fields induced within a phantom head from exposure to three different advanced mobile phone system (AMPS) hand-held telephones using an implantable E-field probe. The phones were positioned alongside the phantom head as in typical use and were configured to transmit at maximum power (600 mW nominal). The SARs induced in the eye ranged from 0.007 to 0.21 W/kg, and maximum levels in the brain ranged from 0.12 to 0.83 W/kg, all below recommended safety limits.
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.
Ikeda N, Hayashida O, Kameda H, Ito H, Matsuda T · 1994
Researchers investigated thermal damage to normal dog brain using 8 MHz radiofrequency interstitial hyperthermia. The heating limits were 42 degrees C for 45 min or 43 degrees C for 15 min. Breakdown of the BBB was observed at 43 degrees C for 60 min.
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.
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.
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.
Mickley GA, Cobb BL, Mason PA, Farrell S · 1994
Researchers exposed rats to various doses of microwave radiation between training and testing to study effects on working memory. Memory was assessed by measuring relative exploration time of a familiar versus a new object, with extensive re-exploration of the familiar object indicating memory loss. Rats exposed to more than 5 W/kg developed hyperthermia, and microwave-exposed rats at doses of 1, 5, 8.5, 9.3, and 10 W/kg did not show a preference for the new object, unlike normothermic controls. Microwave hyperthermia evoked prominent c-fos expression in periventricular strata, hypothalamic nuclei, amygdala, and several cortical areas.
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.
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.
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.
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.
