Unknown authors · 2004
This comprehensive Danish study followed utility workers exposed to 50 Hz power line EMF and 420,000 mobile phone users to examine cancer and disease risks. The research found no increased cancer risks from either exposure type, but identified a significant link between utility work and ALS (Lou Gehrig's disease). The findings provide important evidence about EMF safety while raising questions about specific neurological effects.
Lupke M, Rollwitz J, Simkó M. · 2004
Researchers investigated how 50 Hz extremely low frequency magnetic fields activate human cells to release reactive oxygen intermediates. They examined free radical production in human umbilical cord blood-derived monocytes and in human Mono Mac 6 cells. Exposure to 1 mT ELF-MF for 45 minutes produced a significant increase in superoxide radical anion production of up to 1.4 fold and an increase in ROS release of up to 1.2 fold in monocytes. Mono Mac 6 cells showed superoxide radical anion and ROS production of up to 1.4 and 1.5 fold, respectively, leading the researchers to suggest these cells are more sensitive to ELF-MF than monocytes.
Unknown authors · 2004
Researchers conducted a population-based case-control study in Norway to assess residential and occupational exposure to 50-Hz magnetic fields and breast cancer risk. Cases of breast cancer diagnosed from 1980 to 1996 were identified in a cohort of women living near a high-voltage power line, and each case was matched to two controls by year of birth, municipality, and cohort entry year. Residential exposure was calculated from the magnetic fields generated by the power lines before diagnosis, while occupational exposure was based on an exposure matrix. Women with residential exposure had an odds ratio of 1.58 (95% CI: 1.30, 1.92) for breast cancer, whereas the highest occupational exposure yielded an odds ratio of 1.13 (95% CI: 0.91, 1.40).
Unknown authors · 2004
Researchers compared two Sprague-Dawley substrains, SD1 and SD2, for magnetic field effects on cell proliferation, susceptibility to DMBA-induced mammary cancer, and tumor development in the DMBA model. The SD1 substrain was considered MF-sensitive and was compared with SD2 from the same breeder. Magnetic field exposure significantly increased mammary tumor development and growth in SD1 rats but not in SD2 rats. No enhanced cell proliferation was determined after magnetic field exposure in SD2 rats, unlike in SD1 rats. The researchers concluded that genetic background plays a pivotal role in magnetic field exposure effects.
Unknown authors · 2004
German researchers found that 50 Hz power-line magnetic fields significantly increased breast cancer development in one substrain of laboratory rats but had no effect on another genetically similar substrain. This finding helps explain why different research teams studying the same EMF exposure have reached conflicting conclusions about cancer risks.
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
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.
Zmyslony M, Rajkowska E, Mamrot P, Politanski P, Jajte J · 2004
Researchers tested whether weak 50 Hz magnetic fields affect the number of free oxygen radicals in rat lymphocytes in vitro. Rat lymphocytes were exposed for one hour to 50 Hz magnetic fields at 20, 40, or 200 μT, with the field axis either along or crosswise to Earth's static magnetic field. Only at 40 μT, when the field was directed along Earth's static magnetic field, was there a decrease in fluorescence compared to non-exposed samples.
Ding GR et al. · 2004
Researchers tested whether exposure to an extremely low frequency magnetic field affects hydrogen peroxide-induced cell death in human leukaemia HL-60 cells. Simultaneous treatment with the magnetic field and hydrogen peroxide for 24 hours significantly increased the number of apoptotic and necrotic cells compared with cells treated with hydrogen peroxide alone. The researchers found that active caspase-7 protein levels were higher in cells exposed to both the magnetic field and hydrogen peroxide than in those treated with hydrogen peroxide alone, and that poly(ADP-ribose) polymerase cleavage occurred earlier under combined exposure.
Zmyślony M et al. · 2004
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.
Vorobyov V, Pesic V, Janac B, Prolic Z. · 2004
Researchers exposed rats repeatedly for three days to low-intensity 915 MHz microwaves modulated at 4 Hz and recorded EEG from the somatosensory cortex. Microwave exposure alone significantly enhanced fast EEG rhythms (18-30 Hz), an effect not seen in sham-exposed or radiation-naïve rats. In microwave-exposed rats, scopolamine did not cause the EEG slowing observed in non-exposed rats, and its effect resembled that of physostigmine in naive animals.
Koyama S et al. · 2004
Researchers tested whether an extremely low-frequency magnetic field (ELFMF) could affect mutations caused by hydrogen peroxide in pTN89 plasmids. Mutations were detected in the supF gene carried by the plasmids in Escherichia coli. The mutation frequency was 2.28×10−4 for hydrogen peroxide treatment alone, and 5.81×10−4 when the ELFMF was applied at the same time. No mutations were observed with ELFMF exposure alone, and the researchers indicated that the ELFMF may potentiate hydrogen peroxide-induced mutation.
Lee BC et al. · 2004
Researchers investigated whether a 60 Hz magnetic field could affect the antioxidant defense system in mouse brain by measuring chemiluminescence and superoxide dismutase (SOD) activity in brain homogenates. A chemiluminescence measure linked to oxidative stress was significantly increased in mice exposed to 60 Hz, 12 G for 3 hours compared to the sham-exposed control group. Brain SOD activity was also significantly increased in the exposed group. The researchers suggest these results indicate the field could deteriorate the antioxidant defensive system through reactive oxygen species other than superoxide radicals.
Rollwitz J, Lupke M, Simkó M · 2004
Researchers studied the effects of 50 Hz magnetic fields on free radical production in mouse bone marrow-derived macrophages and monocytes. Exposure to the magnetic fields at a flux density of 1 mT produced a significant increase in free radical production in both cell types. The radicals produced were mainly superoxide anion radicals, found in macrophages at 33% and in their precursor cells at 24%.
Unknown authors · 2004
Unknown authors · 2003
Researchers exposed cultured human diploid fibroblasts to intermittent ELF electromagnetic fields. DNA damage was measured using alkaline and neutral comet assays. Exposure at 50 Hz sinusoidal, 1-24 h, 20-1,000 mu T, with a 5 min on/10 min off pattern induced dose-dependent and time-dependent DNA single-strand and double-strand breaks. Effects were observed at magnetic flux densities as low as 35 mu T, well below ICNIRP guidelines. The induced comet tail factors returned to normal within 9 h after exposure ended.
Unknown authors · 2003
Austrian researchers exposed human skin cells to 50 Hz electromagnetic fields (the same frequency as power lines) and found it caused DNA breaks in both single and double strands. The damage occurred at magnetic field strengths as low as 35 microTesla, well below international safety guidelines, and got worse with higher exposures and longer duration.
Unknown authors · 2003
Austrian researchers exposed human skin cells to 50 Hz electromagnetic fields (the same frequency as power lines) and found DNA damage occurred in a dose-dependent manner. The damage included both single and double-strand DNA breaks, starting at magnetic field levels as low as 35 microTesla - well below current safety guidelines. This provides laboratory evidence supporting epidemiological studies linking power line EMF exposure to increased cancer risk.
Unknown authors · 2003
This study examined cultured fibroblasts from six donors of varying ages exposed to 50 Hz ELF-EMF at 1 mT for 1-24 hours. Basal DNA strand break levels correlated with donor age, with maximum response observed at 15-19 hours of exposure, and this response was more pronounced in cells from older donors.
Huber R et al. · 2003
De Mattei M et al. · 2003
Researchers exposed bovine articular cartilage explants to a 75 Hz, 2,3 mT electromagnetic field in vitro, with and without interleukin-1. EMF exposure significantly increased proteoglycan synthesis and residual tissue proteoglycan content compared with controls, without affecting proteoglycan release or nitric oxide production. In interleukin-1-treated explants, EMF increased proteoglycan synthesis and kept tissue proteoglycan content at control levels while not changing proteoglycan release. Lactate production increased in both experimental conditions with EMF exposure.
Kramarenko AV, Tan U. · 2003
Researchers used a 16-channel telemetric electroencephalograph to record EEG changes during exposure of the human skull to EMF from a mobile phone. During exposure, median frequency increased in areas close to the antenna after 10-15 seconds, and slow-wave activity (2.5-6.0 Hz) appeared in contralateral frontal and temporal areas after 20-40 seconds. The slow waves lasted about one second and repeated every 15-20 seconds, and both the slow-wave activity and increased median frequency disappeared after the phone was turned off.
Unknown authors · 2003
The study investigated electrosensibility in 708 adults aged 17 to 60 years using perception thresholds to 50 Hz electric currents. Analysis of perception threshold distributions revealed a subgroup with significantly increased electrosensibility that could be differentiated from the general population. The variation in electrosensibility was significantly larger than estimated by nonionizing radiation protection bodies but much smaller than claimed by hypersensitivity self-aid groups. The investigation method presented is capable of exclusion diagnostics for persons suffering from the hypersensitivity syndrome.
D'Costa H et al. · 2003
Researchers recorded EEG from ten awake subjects while a mobile phone behind the head emitted radiofrequency fields. The study tested a GSM phone at full radiated power and a phone in active standby mode, each with five active and five sham exposures in randomized five-minute intervals. The experiment was single-blind and compared average EEG band power between active and sham recordings. Statistical tests showed significant differences in the full-power trial for EEG alpha (8-13 Hz) and beta (13-32 Hz) bands. Analysis of median spectral power across 32 discrete frequencies found significant differences in 7 frequencies overall.
