Finnie JW. · 2005
Researchers exposed mice to 900 MHz radiofrequency fields using a purpose-designed exposure system, giving each animal a single, far-field, whole body exposure at a specific absorption rate of 4 W/kg. The study measured activation of the immediate early gene c-fos in mouse brain tissue after this acute exposure. Activation of c-fos in exposed and sham-exposed brains was comparable, but was greatly increased compared with freely moving controls. The results suggest that the majority of the acute genomic response detected by c-fos expression was due to immobilisation.
Aitken RJ, Bennetts LE, Sawyer D, Wiklendt AM, King BV. · 2005
Researchers exposed mice to 900 MHz RFEMR at a specific absorption rate of approximately 90 mW/kg inside a waveguide for 7 days at 12 h per day. Sperm number, morphology, and vitality were not significantly affected by the exposure. However, detailed DNA analysis using QPCR revealed statistically significant damage to both the mitochondrial genome and the nuclear beta-globin locus.
Yokus B, Cakir DU, Akdag MZ, Sert C, Mete N · 2005
Researchers examined the effects of extremely low frequency electromagnetic fields (50 Hz, 0.97 mT) on oxidative DNA damage and lipid peroxidation in rats. Measurements of 8OHdG and TBARS were taken at 50 and 100 days to look for time-dependent changes. The 8OHdG levels of the exposed group were significantly higher than the sham group at both 50 and 100 days (p<0.001). The extent of DNA damage and lipid peroxidation appeared to depend on exposure time.
Wolf FI et al. · 2005
Researchers exposed HL-60 leukemia cells, Rat-1 fibroblasts, and WI-38 diploid fibroblasts to 0.5–1.0-mT 50-Hz extremely low frequency electromagnetic fields for 24–72 hours. The treatment produced a dose-dependent increase in cell proliferation, with about a 30% increase after 72 hours of exposure to 1.0 mT. A dose-dependent increase in DNA damage was observed in all cell lines, with two peaks occurring at 24 and 72 hours. Both effects were prevented by pretreatment with α-tocopherol, suggesting that redox reactions were involved.
Belyaev IY et al. · 2005
Researchers exposed human lymphocytes from healthy subjects and from persons reporting hypersensitivity to electromagnetic field (EMF) to 915 MHz microwaves and 50 Hz magnetic field, then measured chromatin conformation and markers of DNA damage. Both exposures caused significant chromatin condensation, similar to heat shock at 41 °C, but no significant differences were found between hypersensitive and healthy subjects. Neither 915 MHz nor 50 Hz exposure induced 53BP1 foci, and no apoptosis was induced.
Baohong Wang et al. · 2005
Researchers studied whether 1.8 GHz radiofrequency field radiation (RFR) at a SAR of 3 W/kg could interact with four chemical mutagens to damage DNA in human lymphocytes in vitro. DNA damage was detected using comet assay at two incubation times after treatment. RFR alone showed no difference in DNA damage compared to the control group, but co-exposure with MMC or 4NQO produced significantly greater DNA damage than those chemicals alone. Co-exposure with bleomycin or methyl methanesulfonate did not significantly increase DNA damage compared with those chemicals alone.
Zotti-Martelli L et al. · 2005
Researchers exposed whole blood samples from nine healthy donors to continuous 1800-MHz microwave radiation at power densities of 5, 10 and 20 mW/cm2 for 60, 120 and 180 minutes, measuring genotoxic effects using the micronucleus assay. A statistically significant but rather low increase in micronuclei was observed depending on exposure time and applied power density. Both spontaneous and induced micronuclei frequencies varied significantly among donors, and the experiment was repeated three months later to test reproducibility.
Lai H, Singh NP · 2005
Researchers studied four groups of rats: one exposed to 2450-MHz microwaves at 1 mW/cm2, one to magnetic field noise at 45 mG, one to both simultaneously, and a sham-exposed group. Brain cells of microwave-exposed rats had significantly higher levels of DNA single- and double-strand breaks compared with sham-exposed animals. Noise exposure alone did not significantly affect DNA strand break levels, but simultaneous noise exposure blocked the microwave-induced increases.
Diem E, Schwarz C, Adlkofer F, Jahn O, Rudiger H. · 2005
Researchers exposed cultured human diploid fibroblasts and transformed GFSH-R17 rat granulosa cells to 1800 MHz RF-EMF at SAR levels of 1.2 or 2 W/kg, using both intermittent and continuous exposures. DNA strand breaks were determined by means of the alkaline and neutral comet assay. Effects occurred after 16 h exposure in both cell types, and intermittent exposure showed a stronger effect in the comet assay than continuous exposure. The researchers concluded that the induced DNA damage cannot be based on thermal effects.
Unknown authors · 2004
Researchers exposed whole blood samples from five donors to a 50 Hz, 1 mT magnetic field for 2 hours. They used comet assay, sister chromatid exchange, chromosome aberration, and micronucleus tests to assess DNA damage. No significant differences were found between exposed and unexposed samples in any genotoxicity test. A slight but significant decrease in cell proliferation occurred in exposed samples and in samples also exposed to X-rays.
Unknown authors · 2004
Unknown authors · 2004
Researchers investigated effects of magnetic fields from permanent magnets on different DNA sources in vivo and in vitro. They used Escherichia coli DNA, plasmid, and amplification products of different lengths as targets. In vivo assays showed no DNA alterations, while in vitro assays showed magnetic field exposure induces point mutations.
Unknown authors · 2004
Researchers exposed Escherichia coli strain XL-1Blue to a 300mT static magnetic field from permanent neodymium disks. They measured biomass by visible-light spectrometry and gene expression by RNA arbitrarily primed PCR. Exposed cells showed increased proliferation and changes in gene expression compared with controls. Three cDNAs were expressed only in exposed cells, one cDNA was more expressed in controls, and one exposed-only clone matched a putative transposase.
Unknown authors · 2004
They measured cytoplasmic free calcium using the ratiometric fura-2 technique and mitochondrial membrane potential using the JC-1 probe. Exposure caused a highly significant increase in DNA strand breaks measured by the comet assay. No changes were observed in JC-1 fluorescence or cytoplasmic free calcium compared to sham-exposed cells.
Unknown authors · 2004
Researchers exposed human peripheral blood samples to 50 Hz magnetic fields ranging from 0 to 100 microT rms for 4 hours at 37°C. The magnetic-field exposure had no detectable effect on expression of the genes encoding HSP27, HSP70A, or HSP70B. In contrast, heating at 42°C for 2 hours increased HSP27, HSP70A, and HSP70B expression by 10-, 5-, and 12-fold respectively. At 40°C, magnetic-field exposure did not increase gene expression compared to incubation at 40°C without field exposure. The findings suggest that power-frequency electromagnetic fields are not a universal stressor, unlike physical agents such as heat.
Vijayalaxmi, Logani MK, Bhanushali A, Marvin C · 2004
Researchers investigated the genotoxic potential of 42.2 GHz millimeter-wave radiation in adult male BALB/c mice exposed for 30 minutes daily over three days at an incident power density of 31.5 mW/cm². They assessed micronuclei in polychromatic erythrocytes of peripheral blood and bone marrow collected 24 hours after treatment. Cyclophosphamide significantly increased micronuclei, but millimeter-wave exposure did not modify this increase.
Unknown authors · 2004
Ono T et al. · 2004
A possible mutagenic effect of 2.45 GHz radiofrequency exposure was examined using lacZ-transgenic MutaTM mice. Offspring were exposed in utero for 16 hours a day from embryonic day 0 to 15 and examined at 10 weeks of age. Mutation frequencies at the lacZ gene in spleen, liver, brain, and testis were similar to those in non-exposed mice. Sequencing of mutant DNAs showed no appreciable difference in mutation quality between exposed and non-exposed samples.
Chemeris NK et al. · 2004
Researchers investigated genotoxic effects of HPPP EMF (8.8 GHz, 180 ns pulse width, peak power 65 kW, repetition rate 50 Hz) on erythrocytes of the frog Xenopus laevis. They used the alkaline comet assay to assess DNA single-strand breaks and alkali-labile lesions. Blood samples were exposed for 40 minutes in a rectangular waveguide with a specific absorption rate of about 1.6 kW/kg. The temperature rise in blood samples at steady state was 3.5 +/- 0.1 degrees C, and the increase in DNA damage was induced by this temperature rise.
Lagroye I et al. · 2004
Researchers exposed C3H 10T½ cells to 2450 MHz CW microwaves at 1.9 W/kg for 2 hours, then irradiated them with 4 Gy gamma rays, and used the single-cell gel electrophoresis assay to detect DNA damage. Ionizing radiation induced significant DNA damage, but microwave exposure alone caused no detectable DNA damage. Microwaves did not impede DNA migration induced by gamma rays, and no evidence of DNA–protein crosslinks or changes in DNA-associated protein was found after microwave exposure.
Lagroye I et al. · 2004
The study aimed to investigate the effect of 2450 MHz pulsed-wave microwaves on DNA damage in rat brain cells and whether proteinase K is needed to detect such damage. Rats exposed to γ-rays showed significant DNA damage using both comet assay versions independent of proteinase K. Neither assay version detected any difference in comet length or normalized comet moment between sham-exposed and microwave-exposed rats regardless of proteinase K inclusion. No DNA damage was detected in brain cells after exposure to 2450 MHz pulsed-wave microwaves at 1.2 W kg−1 regardless of proteinase K inclusion. The results support the conclusion that low-level 2450 MHz pulsed-wave microwave exposures do not induce DNA damage detectable by the alkaline comet assay.
Hook GJ et al. · 2004
Researchers exposed Molt-4 T lymphoblastoid cells to CDMA, FDMA, iDEN, and TDMA modulated RF radiation for up to 24 hours. DNA damage was measured with the single-cell gel electrophoresis assay and apoptosis with the annexin V affinity assay. No statistically significant difference in DNA damage or apoptosis was observed between sham and exposed cells for any frequency, modulation, or exposure time.
Prohofsky EW · 2004
Marinelli F et al. · 2004
Demsia G, Vlastos D, Matthopoulos DP. · 2004
The study aimed to investigate whether 910-MHz electromagnetic fields could be a noxious agent capable of inducing genotoxicity, and rats were exposed daily for 2 h over 30 consecutive days. Researchers examined bone marrow smears from EMF-exposed and sham-exposed animals and observed an almost threefold increase in micronuclei in polychromatic erythrocytes. An induction of micronuclei was also observed in polymorphonuclear cells.
