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.
Garaj-Vrhovac V, Horvat D, Koren Z, · 1991
Researchers exposed Chinese hamster cells to microwave radiation at 7.7 GHz (similar to some radar frequencies) for up to one hour and found significant DNA damage. The microwaves caused chromosome breaks and abnormal chromosome formations, with damage increasing based on exposure time. This demonstrates that microwave radiation can directly damage the genetic material inside cells, even at relatively low power levels.
Veyret B et al. · 1991
Researchers exposed Balb/C mice to pulsed microwaves at 9.4 GHz, both with and without amplitude modulation at frequencies between 14 and 41 MHz, to assess effects on the immune system. Exposure took place for five consecutive days at 10 hours per day, at a whole-body-averaged SAR of approximately 0.015 W/kg. When the pulsed field was combined with amplitude modulation, immune responses were significantly augmented or weakened depending on the AM frequency used, while the pulsed field alone did not greatly alter immune responsiveness.
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.
Nageswari KS et al. · 1991
Researchers exposed fourteen male Belgian white rabbits to microwave radiation at 5 mW/cm2, 2.1 GHz, three hours daily, six days a week for three months, while seven rabbits received sham exposure for the same duration. Significant suppression of T lymphocyte numbers was found in the microwave group at two months and during follow-up. Despite lower T lymphocyte counts in the blood, no significant variation was observed in tissue T lymphocyte counts, and a functional immune response test showed no impairment.
Akyel Y, Hunt EL, Gambrill C, Vargas C Jr, · 1991
Researchers studied the behavioral effects of high-peak-power microwave pulses on Wistar rats trained to press a lever for food pellets. Each animal was exposed for 10 min to 1.25-GHz microwave radiation at 1-MW peak-power, with total doses set to 0.50, 1.5, 4.5, and 14 kJ/kg. At the highest dose, rats showed an average colonic temperature rise of 2.5 °C and failed to respond for about 13 minutes after exposure. No behavioral effects were found at the lower dose levels, and researchers concluded the effects were thermal in nature.
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.
Brown HD, Chattopadhyay SK · 1991
Researchers studied how 9.14 GHz continuous-wave microwave radiation affected ouabain inhibition of Na+/K+-ATPase from dog kidney. Exposure for 5 minutes to 9.14 GHz radiation at an estimated SAR of 20 W/kg was applied at several stabilized temperatures between 7.0 and 43.8 °C. The efficacy of ouabain as an inhibitor of ATPase activity was severely diminished by the microwave field, and at 24.9 °C a 23% decrease in activity occurred.
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.
Garaj-Vrhovac V, Horvat D, Koren Z · 1991
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
Garaj-Vrhovac V, Horvat D, Koren Z, · 1990
Researchers exposed Chinese hamster cells to microwave radiation at 7.7 GHz (similar to radar frequencies) for up to one hour and found significant DNA damage. The radiation completely blocked cells from entering their normal DNA replication phase and caused chromosome abnormalities that persisted even after exposure ended. This demonstrates that microwave radiation can directly interfere with genetic processes at the cellular level.
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.
Ray S, Behari J · 1990
Researchers studied the effects of exposure to sublethal levels of microwaves. Young albino rats of both sexes were exposed for 60 days to 7.5-GHz microwaves at 0.6 mW/cm2 for 3 hours daily. The exposed animals tended to eat and drink less and showed a smaller gain in body weight. Some hematological parameters and organ weights were significantly different in exposed rats. The authors proposed that a nonspecific stress response mediated through the central nervous system caused the changes.
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.
