Leitgeb N, Tropper K · 1993
Researchers investigated a worst-case scenario where a child observes the microwave oven interior with eyes as close to the door as possible. Significant microwave heating occurred only when safety contacts were inactivated and the door was opened. At a 2.3 cm door gap, microwaves contributed no more than 16% of a 5°C temperature rise after one hour, and at a 2.6 cm gap they contributed 50% of a 2°C rise after 15 minutes.
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.
Podkovkin VG · 1993
Researchers repeatedly exposed guinea pigs to microwave radiation at 1 mW/cm². This exposure inhibited anaphylactic response in some animals and increased blood levels of histamine, epinephrine, and norepinephrine. The increases were more pronounced in irradiated guinea pigs that died from anaphylactic shock compared with nonirradiated animals. Long-term stay in a perturbed weak geometric field reduced the microwave-induced effect.
Ouellet-Hellstrom R, Stewart WF · 1993
Researchers mailed questionnaires to 42,403 physical therapists in 1989 and used a nested case-control design with 1,753 miscarriage cases matched to 1,753 controls. A pregnancy was considered exposed if the mother reported using microwave or shortwave diathermy in the six months before or during the first trimester. Microwave use was associated with increased miscarriage odds (OR 1.28, 95% CI 1.02-1.59) with a dose-response trend, while shortwave diathermy was not associated (OR 1.07, 95% CI 0.91-1.24).
Maes A, Verschaeve L, Arroyo A, De Wagter C, Vercruyssen L · 1993
Researchers exposed human peripheral blood lymphocytes to 2450 MHz microwaves for 30 and 120 minutes at constant body temperature. Exposure caused a marked increase in chromosome aberrations, including dicentric chromosomes and acentric fragments, and micronuclei. Microwave exposure did not influence cell kinetics or sister chromatid exchange frequency.
Lim JI, Fine SL, Kues HA, Johnson MA. · 1993
The study investigated visual abnormalities associated with high-energy microwave exposure. A 44-year-old man was accidentally exposed to high-energy microwave irradiation and later reported a foreign body sensation and blurring of vision. Electroretinogram testing revealed a marked decrease in the flicker electroretinogram, and color vision tests were abnormal. Two years later, visual acuity was stable at 20/25 in both eyes, but the flicker electroretinogram remained markedly decreased.
Goldoni J, Durek M, Koren Z · 1993
Researchers examined two groups of workers occupationally exposed to microwaves and radiofrequency radiation and compared them with a control group. One group consisted of 49 radar operators from Zagreb Air Traffic Control who were examined twice over 18 months, and the other group comprised 46 workers at radio relay stations. A follow-up study found significant changes in haematological and biochemical parameters, electrical brain activity, and capillaroscopic and ophthalmological findings in the radar operators, and a cross-sectional analysis showed the highest rate of changes in general health status for that group.
Fisun OI · 1993
Researchers derived the dispersion relation for intrinsic cellular electrical oscillations from hydrodynamic equations for surface ions inside and outside a cell. They calculated properties for surface-plasmon modes and for a resonant response of a charged membrane bilayer to microwave pumping.
Verma M, Dutta SK. · 1993
The study aimed to investigate microwave induced alteration in neuron specific enolase gene expression. Researchers exposed pNGE7 cells containing the neuron specific enolase gene to 915 MHz, 16 Hz AM radiation at SAR 0.05 mW/kg. Exposure resulted in elevation of neuron specific enolase, a diagnostic marker for neuron and lung cancer. Ion-exchange chromatography separated neuron specific enolase activity from non-neuronal enolase activity and showed altered expression of both.
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.
Seaman RL, DeHaan RL · 1993
Researchers studied inter-beat intervals of aggregated cardiac cells from chicken embryos during 190-second exposures to 2.45 GHz microwaves. The inter-beat interval decreased during exposures at 42.0 W/kg and higher with continuous-wave or square-wave modulation, consistent with thermal effects. Increases occurred during continuous-wave exposures at 1.2-12.2 W/kg and decreases after pulse-modulated exposures at 8.4-12.2 W/kg, which were not consistent with simple thermal effects.
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.
Pakhomov AG · 1993
Researchers investigated effects of 915 MHz pulsed microwave radiation with peak SAR 20-30 W/g on isolated frog nerve cords. Nerve heating did not exceed 2.2°C due to intense Ringer's solution perfusion. Irradiation during stimulation significantly decreased action potential amplitude and peak latency, while conventional heating increased amplitude, supporting a non-thermal mechanism.
Litovitz TA, Krause D, Penafiel M, Elson EC, Mullins JM, · 1993
The study investigated the role of coherence time in the effect of microwaves on ornithine decarboxylase activity. Amplitude-modulated 915 MHz microwaves at SAR 2.5 W/kg modulated at 55, 60, or 65 Hz approximately doubled ornithine decarboxylase activity after 8 h, and switching modulation frequencies at coherence times of 1.0 s or less abolished the enhancement while times of 10 s or longer provided full enhancement.
Lange DG, D'Antuono ME, Timm RR, Ishii TK, Fujimoto JM. · 1993
Krylov IN, Iasnetsov VV, Dukhanin AS, Pal'tsev IuP · 1993
Researchers exposed rats to microwaves at 2375 MHz with a power density of 1 mW/cm2 and found that this induced retrograde amnesia. The study found roles for opioidergic, benzodiazepine, GABAergic, and cholinergic components in the memory-impairing effects of microwaves. Piracetam and oxiracetam each prevented the negative effects of microwaves on memory processes in the rats.
Field AS, Ginsburg K, Lin JC · 1993
Researchers studied the effects of pulsed microwaves on membrane input resistance and action potential interval statistics in spontaneously active ganglion neurons of land snails (Helix aspersa). Experiments were conducted at strictly constant temperature, so macroscopic heating was not responsible for any observed effects. Exposure significantly increased mean input resistance, while mean firing rate and mean input current were not affected. The net input current was found to be more variable in exposed neurons, though changes in interspike interval standard deviation and input current autocorrelation were not consistent across neurons.
Ellingsrud S, Johnsson A · 1993
Researchers studied the up-and-down rhythmic movements of the lateral leaflets of Desmodium gyrans when exposed to electromagnetic radiation in the radio-frequency range. The RF radiation was applied as homogeneous 27.12 MHz fields in specially-designed exposure cells, and in some cases as non-homogeneous radiation of 27 MHz amplitude modulated by 50 Hz in front of commercial diathermy equipment. The radiation caused temporary changes in amplitude, period, and phase, and could also cause temporary or complete cessations of the rhythms.
Unknown authors · 1992
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%.
Unknown authors · 1992
Researchers used transcription autoradiography to measure nascent RNA chains on Drosophila salivary gland chromosomes. After 20-minute exposures to five different extremely low frequency electromagnetic fields, transcriptional activity changed at 13 defined regions of chromosome 3R. The fields also altered translational patterns, increasing overall polypeptide synthesis and the number of polypeptides resolved.
Unknown authors · 1992
Unknown authors · 1992
The study used an ultrasensitive superconducting magnetometer to detect ferromagnetic material in various human brain tissues. High-resolution electron microscopy identified the minerals as belonging to the magnetite-maghemite family, with crystal morphologies resembling those produced by magnetotactic bacteria and fish. The measurements imply at least 5 million single-domain crystals per gram in most brain tissues and over 100 million per gram in the pia and dura.
Unknown authors · 1992
Researchers used a nuclear run-off assay to measure specific gene transcription in CEM-CM3 T-lymphoblastoid cells exposed to a 1 gauss, 60 Hz sinusoidal magnetic field for 15 to 120 minutes. They observed time-dependent and cell density-dependent changes in the transcription of c-fos, c-jun, c-myc, and protein kinase C beta-form. Slot-blot analysis showed that changes in transcript levels paralleled the changes in gene transcription.
Unknown authors · 1992
