Mason PA et al. · 1997
Researchers measured extracellular amino acid concentrations in the hypothalamus and caudate nucleus of rats using in vivo microdialysis before and during exposure to RFR. Rats were exposed to 5.02 GHz radiation (10 microseconds pulse width, 1000 pulses/s) for 40 minutes while brain temperatures were maintained at approximately 41.2 and 41.7 degrees C. Aspartic acid, serine, and glycine concentrations increased significantly in both regions during exposure. Glutamic acid and glutamine changes were not statistically significant.
Jensh RP · 1997
This review examined whether chronic prenatal microwave exposure in rats caused adverse effects at birth or alterations in offspring development and growth. Pregnant rats were exposed throughout pregnancy to continuous wave 915 MHz, 2450 MHz, or 6000 MHz radiation at power density levels of 10, 20, or 35 mW/cm2, respectively. Animals exposed to 915 MHz did not exhibit any consistent significant alterations in any of the parameters measured. Offspring exposed to 6000 MHz showed an initial slight but significant retardation in term weight, delayed eye opening, lower weekly weights that recovered by the fifth week, and changes in water T-maze and open field performance.
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.
French PW, Donnellan M, McKenzie DR, · 1997
Researchers exposed a human astrocytoma cell line, U-87 MG, to 835 MHz electromagnetic radiation for 20 min, 3 times per day for 7 days, at power densities of either 40 ± 15 mW cm−2 or 8.1 ± 3 mW cm−2. At the lower power density, the rate of DNA synthesis decreased and the cells flattened and spread out compared to unexposed cultures. At 40 mW cm−2 there were no effects on cell proliferation, but changes in cell shape included increased spreading and the appearance of actin-containing blebs on the membrane.
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, Singh NP · 1997
Researchers investigated whether melatonin and the spin-trap compound N-tert-butyl-alpha-phenylnitrone (PBN) could block the effect of magnetic fields on brain cell DNA. Rats were injected with melatonin or PBN immediately before and after two hours of exposure to a 60-Hz magnetic field at an intensity of 0.5 mT. Both drug treatments blocked the magnetic field-induced DNA single- and double-strand breaks in brain cells, as measured by a microgel electrophoresis method.
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.
Unknown authors · 1996
Researchers examined 21,744 male electrical utility workers in Québec and identified 49 suicide deaths between 1970 and 1988. Cumulative and current exposures to electric, magnetic, and pulsed electromagnetic fields were estimated using a job exposure matrix and both arithmetic and geometric means. The highest risk was seen in the medium exposure group for the geometric mean of electric fields, with a rate ratio of 2.76 (95% CI 1.15-6.62), while other fields showed mostly small non-significant increases.
Unknown authors · 1996
Rats were trained in ten daily sessions on a 12-arm radial maze to assess spatial memory. Exposure to a 60 Hz magnetic field at 0.75 mT for 45 minutes before each session significantly retarded learning.
Unknown authors · 1996
The ferromagnetic transduction model proposes that biogenic magnetic particles in the brain coupled to mechanosensitive ion gates may mediate interactions with environmental magnetic fields. The authors show that pulsed fields, square waves, and DC fields could force open these membrane gates long enough to disrupt normal neurophysiological processes. The extended model may explain central nervous system effects in epileptic patients exposed to low frequency square wave and DC magnetic fields.
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.
Andersson B, Berg M, Arnetz BB, Melin L, Langlet I, Lidén S. · 1996
Seventeen patients were randomly assigned to a treatment group or a waiting-list control group in a pretest-posttest control group design. Patients participated in double-blind provocation tests before and after treatment. Subjective symptom ratings and blood samples for stress-related variables were collected. The experimental group reduced disability evaluations more than the control group, but no significant between-group differences were found in psychophysiological measures or subjective reactions to provocation. The provocation test concluded that alleged hypersensitive patients did not react to electromagnetic fields.
Violanti JM, Marshall JR · 1996
Talking more than 50 minutes per month on a cellular phone in a vehicle was associated with a 5.59-fold increased risk of a traffic accident. Combined use of cellular phones with motor and cognitive activities while driving was also associated with increased accident risk. The authors cautioned that the study had a small sample, showed only statistical associations, and did not conclude that talking on cellular phones while driving is inherently dangerous.
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
Mann, K, Roschke, J · 1996
Researchers investigated the influence of pulsed high-frequency electromagnetic fields from digital mobile radio telephones on sleep in healthy humans. They found a hypnotic effect that shortened sleep onset latency and a REM suppressive effect that reduced REM sleep duration and percentage. Spectral analysis showed qualitative alterations of the EEG signal during REM sleep with increased spectral power density.
Kolodynski AA, Kolodynska VV · 1996
Kittel A, Siklos L, Thuroczy G, Somosy Z · 1996
Grigor'ev IuG · 1996
The study aims to investigate the role of modulation in biological effects of electromagnetic radiation. Research outcomes indicate that nervous and immune system responses depend on the type of modulation at low exposure levels. The authors formulate the necessity of accounting for modulation in electromagnetic danger evaluation. Data describing the role of modulation in the development of biological effects are considered.
Bortkiewicz A, Gadzicka E, Zmyslony M, · 1996
The study compared 71 workers at medium-frequency broadcast stations with 22 non-exposed radio link station workers. Age and work tenure distributions did not differ significantly between groups. Heart rate variability was measured from 512 normal heart evolutions at rest using a Medea-HV system. Time-domain and frequency-domain HRV parameters showed no statistically significant differences between exposed and non-exposed groups. In the exposed group, maximum EM field intensity correlated negatively with high-frequency power spectrum.
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.
Kolosova LI, Akoev GN, Avelev VD, Riabchikova OV, Babu KS · 1996
Researchers examined the effect of low-intensity millimeter wave electromagnetic radiation on regeneration of the rat sciatic nerve after transection and microsurgical reapproximation. At the twentieth postoperative day, treated animals showed a 32% increase in regeneration distance and a 26% increase in conduction velocity compared to controls.
Bawin SM, Satmary WM, Jones RA, Adey WR, Zimmerman G. · 1996
Researchers used rat hippocampal slices to study how extremely-low-frequency (ELF) magnetic fields affect rhythmic slow activity (RSA), a brain rhythm associated with memory functions. Slices were exposed for 10-minute epochs to 1 or 60 Hz magnetic fields at intensities of 5.6, 56, or 560 μT, or were sham exposed. 1 Hz fields at 56 and 560 μT, but not at 5.6 μT, triggered irreversible destabilization of RSA intervals, while 60 Hz fields showed similar but not statistically significant trends. The field effects on RSA did not occur when nitric oxide (NO) synthesis was pharmacologically inhibited.
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.
