Cranfield CG, Wieser HG, Dobson J. · 2003
Researchers exposed magnetic bacteria to simulated mobile phone RF radiation and found no impact on mortality. Repeat experiments with only the GSM RF component in a waveguide system showed no significant change in cell mortality compared to sham exposures. A nonmagnetite control strain also showed no significant change in mortality between RF and sham samples.
McNamee et al. · 2003
Researchers examined the effect of 24-hour continuous-wave and pulsed-wave 1.9 GHz radiofrequency fields on primary DNA damage and micronucleus induction in human leukocyte cultures. No significant differences in primary DNA damage were observed between sham controls and any exposed cultures when assessed by the alkaline comet assay immediately after exposure. Similarly, no significant differences were found in micronucleus incidence, micronucleated binucleated cells, binucleated cell frequency, or proliferation index between sham and exposed cultures.
Jayanand, Behari J, Lochan R. · 2003
Researchers exposed rats with sciatic neurectomy-induced osteoporosis to modulated pulsed electromagnetic fields at a 14 MHz carrier frequency modulated at 16 Hz with 10 V peak-to-peak amplitude. The exposure produced a statistically significant increase in bone mineral density and a deceleration in the bone resorption process in the femur and tibia. The authors suggest that this effective window of pulsed radio frequency fields may be used therapeutically for osteoporosis treatment.
Weisbrot D, Lin H, Ye L, Blank M, Goodman R. · 2003
Researchers exposed fruit flies to a discontinuous RF signal from a GSM multiband phone at 900/1,900 MHz with SAR approximately 1.4 W/kg for 10 days from egg laying through pupation. The non-thermal radiation increased offspring numbers, elevated hsp70 levels, increased SRE DNA-binding, and induced ELK-1 phosphorylation.
Desta AB, Owen RD, Cress LW. · 2003
Researchers exposed L929 murine fibroblast cells to radiofrequency radiation from a time division multiple access wireless phone operating at 835 MHz to determine the effect on ornithine decarboxylase activity. Exposure lasted 8 hours at average specific absorption rates ranging from less than 1 W/kg up to 15 W/kg, after which cells were harvested and ODC activity was measured. No statistically significant difference in ODC activity was found between exposed and sham-exposed cells at non-thermal specific absorption rates. At SARs that caused measurable heating, a dose-dependent decrease in enzymatic activity was observed and was consistent with a comparable decrease caused by non-RF-radiation heating.
Mashevich M et al. · 2003
Researchers examined whether in vitro exposure of human peripheral blood lymphocytes to continuous 830 MHz electromagnetic fields causes losses and gains of chromosomes, a condition called aneuploidy. Cells were irradiated at SAR levels ranging from 1.6 to 8.8 W/kg for 72 hours. A linear increase in chromosome 17 aneuploidy was observed as a function of the SAR value, which the researchers described as a genotoxic effect. Control experiments conducted without any RF radiation across a temperature range of 34.5 to 38.5 °C showed that elevated temperature was not associated with the increased aneuploidy or the changes in centromeric DNA replication seen after RF exposure.
Logani MK, Agelan A, Ziskin MC. · 2002
The study examined the effect of millimeter electromagnetic waves on catalase activity in mouse blood to understand mechanisms involved in its reduction. SKH-1 hairless mice were irradiated on their midbacks with 42.2±0.2 GHz millimeter waves at an incident power density of 31±5 mW/cm2 and a peak SAR of 622±100 W/kg. MW irradiation before or after cyclophosphamide administration did not significantly reduce the toxic effect of cyclophosphamide on catalase activity in mouse blood.
McNamee JP et al. · 2002
Blood cultures from human volunteers were exposed to an acute 1.9 GHz pulse-modulated radiofrequency (RF) field for 2 h using a series of six circularly polarized, cylindrical waveguides. Mean specific absorption rates (SARs) ranged from 0 to 10 W/kg and the temperature within the cultures during the exposure was maintained at 37.0 ± 0.5°C. DNA damage was quantified in leukocytes by the alkaline comet assay and the cytokinesis-block micronucleus assay. No evidence of increased primary DNA damage was detected by the comet assay and no significant differences in micronucleus frequency were found at any SAR tested.
McNamee JP et al. · 2002
Human blood cultures were exposed to a 1.9 GHz continuous-wave radiofrequency field for 2 hours at SARs of 0.0, 0.1, 0.26, 0.92, 2.4, and 10 W/kg while temperature was maintained at 37.0 ± 0.5°C. DNA damage was measured immediately after exposure using the alkaline comet assay with four parameters, and micronucleus formation was assessed using the cytokinesis-block micronucleus assay. No evidence of increased primary DNA damage was detected at any SAR tested. There was no significant difference in micronucleus incidence between exposed cultures and sham controls at any SAR.
Pacini S et al. · 2002
Researchers exposed human skin fibroblasts to GSM cellular phone radiofrequency for 1 hour. GSM exposure induced alterations in cell morphology and increased expression of mitogenic signal transduction genes, cell growth inhibitors, and apoptosis-related genes. A significant increase in DNA synthesis and intracellular mitogenic second messenger formation corresponded with high expression of MAP kinase family genes.
Higuchi Y et al. · 2002
Researchers performed a left-sided hemilaminectomy in adult Sprague-Dawley rats to expose the C6 dorsal root ganglion. Rats received pulsed radiofrequency, continuous radiofrequency, or sham treatment with the electrode on the ganglion for 120 seconds. Pulsed radiofrequency significantly increased cFOS-immunoreactive neurons in the superficial dorsal horn laminae three hours after treatment, while continuous radiofrequency did not. The authors concluded that pulsed radiofrequency activates pain-processing neurons in the dorsal horn without tissue heating.
Tice RR, Hook GG, Donner M, McRee DI, Guy AW. · 2002
DNA damage in leukocytes was assessed with the alkaline comet assay and chromosomal damage in lymphocytes with the micronucleus assay. No significant increase in DNA damage was seen after 3 or 24 hours, and no increase in micronucleated lymphocytes occurred after 3 hours. However, 24-hour exposures at 5.0 or 10.0 W/kg significantly increased micronucleated lymphocytes about fourfold, regardless of signal type, modulation, or frequency.
Testylier G, Tonduli L, Malabiau R, Debouzy JC · 2002
Rats were exposed to 2.45 GHz continuous wave at 2 or 4 mW/cm(2) for 1 h during the day, or to 800 MHz modulated at 32 Hz at 200 mW/cm(2) for 1 or 14 h during the night. Exposure at 4 mW/cm(2) caused a significant 40% decrease in mean acetylcholine release from hippocampus, maximal at 5 h post exposure. Fourteen-hour nighttime exposure at 800 MHz induced a significant 43% decrease in acetylcholine release during 11 p.m.-4 a.m. compared to control rats.
Kolomytseva MP, Gapeev AB, Sadovnikov VB, Chemeris NK. · 2002
Di Carlo A, White N, Guo F, Garrett P, Litovitz T. · 2002
Chick embryos were exposed to ELF-EMFs at 8 microT continuously for 4 days, or to ELF or RF EMFs repeated daily for 4 days in sessions of 20, 30, or 60 minutes once or twice daily. Several exposure protocols produced statistically significant decreases in protection against hypoxic stress, including continuous ELF and 30 or 60 minute ELF twice daily, or 30 or 60 minute once daily RF. Following 4 days of ELF-EMF exposure, HSP70 levels declined by 27% compared to controls.
Bisht KS, Moros EG, Straube WL, Baty JD, Roti Roti JL · 2002
Researchers exposed C3H 10T½ cells to 835.62 MHz FDMA or 847.74 MHz CDMA modulated radiofrequency radiation to determine whether it caused micronuclei to form. Cells were exposed at power levels of 3.2 or 4.8 W/kg for CDMA and 3.2 or 5.1 W/kg for FDMA, for durations of 3, 8, 16, or 24 hours. In three repeat experiments, no exposure condition produced a significant increase in micronuclei compared to sham-exposed cells.
Trosic I, Busljeta I, Kasuba V, Rozgaj R. · 2002
Researchers exposed adult male Wistar rats to continuous 2450 MHz radiofrequency microwave radiation for 2 hours a day, 7 days a week, for up to 30 days, at a power density of 5–10 mW/cm2. Peripheral blood smears were examined for micronuclei in polychromatic erythrocytes as an indicator of genotoxicity. Micronuclei per 1000 PCEs were significantly increased after eight irradiation treatments compared with sham-exposed controls. The researchers noted that an adaptive mechanism in both erythrocytopoiesis and genotoxicity likely appeared during the subchronic irradiation treatment.
Vijayalaxmi et al. · 2001
Eight adult male Sprague-Dawley rats were exposed to 2450 MHz RFR in circularly polarized waveguides, and eight sham-exposed rats were kept in similar waveguides without RFR transmission. Four rats treated with mitomycin-C served as positive controls, and all rats were necropsied 24h after exposure to examine peripheral blood and bone marrow smears for micronuclei in polychromatic erythrocytes. The incidence of micronuclei per 2000 polychromatic erythrocytes was not significantly different between RFR-exposed and sham-exposed rats.
Vijayalaxmi et al. · 2001
Researchers exposed peripheral blood samples from four healthy nonsmoking volunteers to 847.74 MHz CDMA radiation at SARs of 4.9 or 5.5 W/kg for 24 hours. Sham-exposed and gamma-irradiated (1.5 Gy) samples served as controls. No significant differences were found between RF-exposed and sham-exposed lymphocytes in mitotic indices, frequencies of exchange aberrations, excess fragments, binucleate cells, or micronuclei. Gamma-irradiated lymphocytes showed significantly different responses for all indices compared to both RF-exposed and sham-exposed cells. The authors concluded there was no evidence for induction of chromosome aberrations and micronuclei under these exposure conditions.
Vijayalaxmi et al. · 2001
Researchers exposed diluted peripheral blood from four healthy volunteers to 835.62 MHz RF radiation at SARs of 4.4 or 5.0 W/kg for 24 hours. Sham-exposed and gamma-irradiated (1.50 Gy) samples served as negative and positive controls, and lymphocytes were cultured for 48 or 72 hours to assess chromosomal aberrations, micronuclei, mitotic indices, and binucleate cells. No significant differences were found between RF-exposed and sham-exposed lymphocytes for any of the measured endpoints, while gamma radiation produced significantly different responses. The authors concluded there is no evidence for induction of chromosomal aberrations and micronuclei under these exposure conditions.
Roti Roti JL et al. · 2001
Researchers measured the effect of 835.62 MHz FDMA and 847.74 MHz CDMA radiation on neoplastic transformation frequency using the in vitro C3H 10T(1/2) cell transformation assay system. Cells were exposed at 37°C to either radiation at a specific absorption rate of 0.6 W/kg for 7 days to test for genotoxic effects, or after 4.5 Gy X-ray exposure for 42 days to test for epigenetic promotion effects. After both the 7-day and 42-day exposures, no statistically significant differences in transformation frequencies were found between incubator controls, sham-exposed groups, and RF-exposed groups.
Maes A, Collier M, Verschaeve L · 2001
Researchers investigated cytogenetic effects of 900 MHz radiofrequency fields using chromosome aberration and sister chromatid exchange frequency methods. They studied three exposure modes (continuous, pseudo-random, dummy burst) at power outputs from 0 to 50 W. Specific absorption rates ranged from 0 to 10 W/kg. The study examined effects of radiation alone and combined with mitomycin C and X-rays. Overall, no mutagenic or co-mutagenic effect was found.
Higashikubo R et al. · 2001
Researchers exposed mouse C3H 10T(1/2) fibroblasts and human U87MG glioma cells to two types of radiofrequency fields at 0.6 W/kg. Five cell cycle parameters including transit through G1, G2, and S phase and probability of cell division were measured immediately and up to 100 hours. No changes in cell cycle parameters were observed in exposed cells compared to sham-exposed cells in either cell line during the entire experimental period.
Li L et al. · 2001
Researchers exposed murine C3H 10T(1/2) fibroblasts to radiofrequency fields at specific absorption rates of 3.2 to 5.1 W/kg. Cell cultures were exposed to 847.74 MHz CDMA and 835.62 MHz FDMA modulated radiations in radial transmission line irradiators with temperature regulated to 37.0 ± 0.3 °C. Using the alkaline comet assay, they found no statistically significant differences in comet moment or comet length between sham-exposed and exposed cells after 2, 4, or 24 hours of exposure, for both exponentially growing and plateau-phase cells. A 4-hour incubation after a 2-hour exposure also resulted in no significant changes in comet moment or comet length. The authors concluded that exposure at 37°C up to 5.1 W/kg did not induce measurable DNA damage.
Sebastian JL, Munoz S, Sancho M, Miranda JM · 2001
Researchers calculated electric field intensity using the finite element method in single- and multilayer spherical, cylindrical, and ellipsoidal mammalian cell models exposed to 900 and 2450 MHz plane waves. They analyzed how cell geometry and orientation relative to the external field influence the electric field induced in the membrane and cytoplasm. The study found that cytoplasmic and extracellular bound water layers play a significant role in determining electric field intensity for cylindrical and ellipsoidal models.
