Phelan AM, Lange DG, Kues HA, Lutty GA · 1992
Researchers exposed B16 melanoma cells to 2.45-GHz pulsed microwaves at 10 mW/cm² for 1 hour and measured membrane ordering using electron paramagnetic resonance. The exposure shifted the cell membrane from a more fluid-like phase to a more solid, ordered state. Similar membrane ordering occurred in melanin-reconstituted liposomes, but not in amelanotic cells or liposomes without melanin. Superoxide dismutase inhibited the microwave-induced ordering, implicating oxygen radicals as a cause.
Inaba R, Shishido K, Okada A, Moroji T. · 1992
Maillefer RH, Quock RM · 1992
Male Swiss Webster mice were exposed to 10, 15, and 20 mW/cm2 RFR at 2450 MHz for 10 minutes at SARs of 23.7, 34.6, and 45.5 W/kg, then tested in the abdominal constriction paradigm. Confinement alone did not appreciably alter body temperature but appeared to induce stress-associated analgesia that was not blocked by naltrexone. RFR exposure raised body temperature and further increased analgesia in an SAR-dependent manner. The high SAR-induced analgesia was blocked by naltrexone, but the hyperthermia was not.
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.
Veyret B et al. · 1991
French researchers exposed mice to low-power pulsed microwaves (similar to radar frequencies) for 10 hours daily over five days to test effects on immune system function. They found that simple pulsed signals had little effect, but when the signals included additional amplitude modulation, the mice showed significant changes in antibody production - some frequencies strengthened immune responses while others weakened them.
Ciaravino V, Meltz ML, Erwin DN · 1991
Researchers exposed Chinese hamster ovary cells to adriamycin and pulsed RFR at 2,450 MHz and 33.8 W/Kg for 2 h. The maximal temperature in the tissue-culture medium was 39.7 +/- 0.2 degrees C. The experiments were controlled for chemical and RFR exposures as well as for temperature. Verified statistically, the data indicate that the RFR did not affect changes in cell progression caused by adriamycin and did not change the number of sister chromatid exchanges induced by adriamycin.
Garson OM, McRobert TL, Campbell LJ, Hocking BA, Gordon I. · 1991
Researchers studied chromosome damage in 38 radio-linemen exposed to radio-frequency radiation and 38 matched controls. They analyzed Two hundred metaphases per person, scored blind, and found the rate of aberrant cells was the same in both groups. There were no statistically significant differences in the types of chromosome aberrations.
Lai H, Carino MA, Wen YF, Horita A, Guy AW · 1991
Rats were repeatedly exposed to pulsed, circularly polarized microwaves at 2,450 MHz with 2-microsecond pulses at 500 pps, a power density of 1 mW/cm², and a whole-body SAR of 0.6 W/kg. Ten 45-minute sessions increased muscarinic cholinergic receptor concentration in the hippocampus, while ten 20-minute sessions decreased concentration in the frontal cortex and hippocampus. Pretreatment with naltrexone at 1 mg/kg IP before each exposure session blocked these microwave-induced changes in cholinergic receptors.
Lange DG, Sedmak J · 1991
Microwave exposure produced a dose-dependent increase in JEV-induced lethality. Hypercarbia at 5, 10, and 20% CO2 also produced a dose-dependent increase in JEV-induced lethality.
Somosy Z, Thuroczy G, Kubasova T, Kovacs J, Szabo LD · 1991
Researchers exposed mouse embryo 3T3 cells to 2450 MHz continuous and 16 Hz square-modulated microwaves at absorbed energies from 0.0024 to 2.4 mW/g. Modulated waves caused more morphological changes than continuous waves at the same intensity. Cell surface negative charge decreased after modulated-wave exposure but was unchanged after continuous-wave exposure at the same dose. Modulated waves at 0.024 mW/g increased cell ruffling and caused cytoplasmic ultrastructural alterations, while continuous waves required higher doses of 0.24 and 2.4 mW/g for similar effects.
Saalman E et al. · 1991
Researchers studied how 2.45 GHz microwave radiation affects the permeability of unilamellar liposomes containing a fluorescent marker. After 10 minutes of exposure, microwave-treated liposomes showed significantly greater marker release than those heated conventionally. The experiments were conducted above the lipid membrane's phase transition temperature, unlike earlier studies.
Krause D, Mullins JM, Penafiel LM, Meister R, Nardone RM, · 1991
Researchers studied the effects of 2.45-GHz continuous-wave microwaves on interferon-regulated enzymes in murine L929 cells. Radioactive 2-5A binding to RNase L was 14.5% above control in sham-exposed samples and 36.4% above control in microwave-exposed samples. RNase L specific activity rose along with the increased 2-5A binding, but 2-5A synthetase specific activity showed no change. No detectable differences were noted in cell viability, plating efficiency, or proliferation rate after exposure.
Koveshnikova IV, Antipenko EN · 1991
Researchers studied whether thyroid hormones play a role in modifying the mutagenic effect of microwaves in rats. The mutagenic effect of microwaves at 2,450 or 2,750 MHz, 500 microW/cm2, for 30 days at 7 hours a day increased when rats had either low or high thyroid hormone levels. The researchers concluded that normal thyroid gland functioning appears to be an important condition for maintaining chromosome integrity under microwave exposure.
Spiers DE, Baummer SC · 1991
Researchers exposed Japanese quail eggs to 2,450 MHz microwaves at 5 or 20 mW/cm² for 8 hours daily from day 1 to 15 of incubation. At 30 °C ambient temperature, microwave exposure increased wet-embryo mass on day 16 by 9% at 5 mW/cm² and 61% at 20 mW/cm² compared to predicted masses without microwaves. Post-treatment tests showed no reliable indication that repeated microwave exposure resulted in abnormal physiological development. The authors concluded that microwave radiation can increase egg temperature and embryonic growth rate at below-normal incubation temperatures without altering basic metabolic and thermal characteristics.
Balcer-Kubiczek EK, Harrison GH. · 1991
Researchers exposed actively growing cultures of C3H/10T1/2 cells for 24 hours to 2.45-GHz microwaves pulse-modulated at 120 Hz. The electromagnetic fields alone had no effect on cell survival or induction of neoplastic transformation. When combined with the tumor promoter TPA, the enhancement of transformation was highly significant and ranged up to a level equivalent to that produced by 1.5 Gy of X rays. The frequency of neoplastic transformation was dependent on the level of electromagnetic exposure and was additive with doses of X rays given as a cocarcinogen.
Koveshnikov IV, Antipenko EN · 1991
Neubauer C, Phelan AM, Kues H, Lange DG · 1990
Researchers exposed male albino rats to 2.45-GHz microwaves with 10-microseconds pulses at 100 pps. Exposure at 10 mW/cm2 for 30 to 120 minutes increased tracer uptake through the blood-brain barrier. The uptake depended on both power density and exposure duration. At 5 mW/cm2, a 15-minute exposure had no effect. Pretreating rats with colchicine nearly completely blocked the microwave-induced uptake.
Kerbacher JJ, Meltz ML, Erwin DN, · 1990
Cleary SF, Liu LM, Merchant RE · 1990
Researchers exposed whole human blood in vitro for 2 hours to 27 or 2,450 MHz radio-frequency electromagnetic radiation under isothermal conditions at 37 degrees C. At SARs below 50 W/kg, exposure produced a dose-dependent, statistically significant increase in lymphocyte proliferation, while exposure at 50 W/kg or higher suppressed proliferation relative to sham-exposed cells. The researchers concluded that these biphasic, dose-dependent effects on lymphocyte proliferation were not dependent on heating. There were no detectable effects of RF radiation on lymphocyte morphology or viability.
Meltz ML, Eagan P, Erwin DN · 1990
Researchers studied forward mutation at the thymidine kinase locus in L5178Y mouse leukemic cells exposed to 2.45-GHz pulsed-wave RFR and proflavin. Exposures used 500 or 600 W net forward power, giving a SAR of approximately 40 W/kg, for 4 hours with temperature controls. No statistically significant increase in mutant frequency was found with combined RFR and proflavin versus proflavin alone, no change in colony-size distribution occurred, and RFR alone showed no mutagenic action.
Unknown authors · 1989
Unknown authors · 1989
Researchers exposed rats to low-level pulsed microwave radiation at 2.45 GHz (the same frequency as microwave ovens) and found significant changes in brain chemistry, including alterations to the cholinergic system that controls memory and learning. The study revealed that even brief 20-minute exposures affected brain receptor concentrations in key regions like the hippocampus and frontal cortex.
Unknown authors · 1989
University of Washington researchers exposed rats to pulsed 2.45 GHz microwaves (the same frequency as microwave ovens) and found significant changes to brain chemistry systems involved in memory and learning. The study showed that even low-level microwave exposure altered choline uptake and muscarinic receptors in brain regions critical for cognitive function. These neurochemical changes occurred at power levels well below current safety standards.
Parker JE, Kiel JL, Winters WD · 1988
Researchers exposed four rodent cell lines to 2450 MHz microwave radiation at a Specific Absorption Rate of 103.5 +/- 4.2 W/kg at temperatures of 37, 40, 42, and 45 degrees C. The researchers extracted mRNA from exposed and sham-exposed cells and used DNA probes of oncogenes, heat shock protein, or long terminal repeat sequences to look for differences in mRNA expression. With the cell lines and probes used, no significant differences in mRNA expression were observed after microwave exposure.
D'Andrea JA, DeWitt JR, Portuguez LM, Gandhi OP. · 1988
Two experiments tested whether frequency-specific hotspot formation in the body and tail of rats would have behavioral consequences. Rats were placed in a cage where occupying one side triggered microwave exposure and occupying the other side ended it. Reduced exposure to 360-MHz and 2450-MHz microwaves at 1, 2, 6 and 10 W/kg were significantly different from 700-MHz microwaves. A second experiment found the threshold for reduced exposure to 2450-MHz microwaves fell between whole-body SARs of 2.1 and 2.8 W/kg.
