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.
Ebert S et al. · 2005
This study determined the thermal regulatory and thermal breakdown thresholds for in-tube restrained B6C3F1 and NMRI mice exposed to radiofrequency electromagnetic fields at 905 MHz. The thermal regulatory threshold of the restrained mice was found at SAR levels between 2 W kg(-1) and 5 W kg(-1). The breakdown of regulation was determined at 10.1 +/- 4.0 W kg(-1) for B6C3F1 mice and 7.7 +/- 1.6 W kg(-1) for NMRI mice. NMRI mice were more sensitive to thermal stress and responded at lower SAR values with regulation and breakdown.
Cosquer B, Vasconcelos AP, Frohlich J, Cassel JC. · 2005
Bachmann M, Kalda J, Lass J, Tuulik V, Säkki M, Hinrikus H. · 2005
Researchers exposed 23 healthy volunteers to a 450 MHz microwave field with 7 Hz frequency on-off modulation, with a field power density of 0.16 mW cm(-2) at the scalp. The study compared traditional spectral analysis and a new non-linear method called analysis of the length distribution of low-variability periods to detect EEG changes from microwave exposure. The non-linear method detected a significant effect in six exposed subjects, while spectral analysis found a significant result for only one subject.
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.
Adair ER et al. · 2005
Researchers measured thermoregulatory responses in six adult volunteers during 45-minute whole-body exposures to 220 MHz radio frequency energy at three power densities and three ambient temperatures. Esophageal temperature showed small changes of no more than 0.35 °C and never exceeded 37.3 °C under any test condition. Vigorous sweating occurred at PD = 12 and 15 mW/cm(2), with sweating levels higher than those observed for equivalent PD at 100 MHz. The researchers concluded that exposed subjects thermoregulate efficiently through increased heat loss responses, particularly sweating.
Tkalec M, Malaric K, Pevalek-Kozlina B. · 2005
Researchers evaluated duckweed growth and peroxidase activity after exposure in a Gigahertz Transversal Electromagnetic (GTEM) cell to electric fields at frequencies of 400, 900, and 1900 MHz. Plants exposed for 2 h to a 23 V/m field at 900 MHz showed significantly decreased growth compared with the control, while the same field strength at 400 MHz did not have such an effect. Peroxidase activity in exposed plants varied depending on exposure characteristics, with a significant increase of 41% found in plants exposed for 2 h to 41 V/m at 900 MHz.
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.
Balmori A. 2004 · 2004
A large majority of independent researchers recognize non-thermal effects of these waves on living beings, which are not yet contemplated in Spanish legislation. Power density levels billions of times lower would provide sufficient coverage for mobile telephony to function.
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.
Anderson, L. · 2004
Researchers conducted a two-year chronic bioassay to determine whether long-term exposure to a 1.6 GHz radiofrequency field would affect cancer incidence in Fischer 344 rats. Timed-pregnant rats were assigned to far-field RF Iridium or sham groups, with whole-body exposures starting at 19 days gestation for 2 hours per day, 7 days per week until weaning. Offspring then received near-field head-first exposures 2 hours per day, 5 days per week from 36 days old until 2 years of age at brain SAR levels of 1.6 W/kg, 0.16 W/kg, or sham. No statistically significant differences were seen among groups for live pups per litter, survival index, weaning weights, clinical signs, or neoplastic lesions, and male survival was similar across groups while female cage controls had reduced survival time.
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.
Hook, G. · 2004
The study measured intracellular oxidants, glutathione disulfide accumulation, antioxidant enzyme activities, nitric oxide production, and cell viability. FMCW- and CDMA-modulated RF radiation did not alter any measured oxidative stress parameters or cell toxicity.
Unknown authors · 2004
Case reports of peripheral neurological effects of radiofrequency radiation describe mainly disturbances of noxious sensation called dysaesthesia. Cases have arisen after exposure to much of the frequency range from low MHz to GHz. After very high intensity exposures nerves may be grossly injured; however, after lower intensity exposures which may result in dysaesthesia, ordinary nerve conduction studies demonstrate no abnormality although current perception threshold studies may. Only a small proportion of similarly exposed persons develop symptoms. Some observations are not consistent with the hypothesis that all health effects of radiofrequency radiation arise from thermal mechanisms.
