Tsurita G, Nagawa H, Ueno S, Watanabe S, Taki M, · 2000
Male Sprague-Dawley rats were exposed to a 1439 MHz TDMA field. Exposure lasted one hour a day for two or four weeks. The study assessed blood-brain barrier permeability, cerebellar morphology, and body mass.
Wagner P et al. · 2000
Researchers aimed to investigate human sleep EEG under pulsed radio frequency electromagnetic fields using polysomnographies with submaximal high power flux densities. They applied a submaximal power flux density of 50 W/m(2). All-night polysomnographies were recorded from 20 healthy male subjects with and without exposure to a circularly polarized EMF at 900 MHz pulsed at 217 Hz with 577 microsecond pulse duration. The results showed no significant effect of the field application on conventional sleep parameters or sleep EEG power spectra.
Unknown authors · 2000
Researchers measured personal magnetic field exposure, ambient light, and excretion of the melatonin metabolite 6-hydroxymelatonin sulfate over three consecutive workdays in electric utility workers. Men working more than two hours daily in substation and three-phase environments showed a magnetic field-dependent reduction in adjusted mean nocturnal and post-work metabolite levels, while those working two hours or less showed no effect. No changes were observed in men working in single-phase environments.
Unknown authors · 2000
Researchers measured melatonin levels in electric utility workers exposed to 60-Hz magnetic fields from substations and 3-phase power lines. Workers with more than 2 hours daily exposure showed significantly reduced melatonin production, while those with shorter exposures showed no effect. This suggests that power frequency magnetic fields can disrupt the body's natural sleep hormone production.
Unknown authors · 2000
Researchers cultured mouse pre-antral follicles for 5 days and exposed them to pulsed ELF-EMF at 33 Hz or 50 Hz. ELF-EMF did not affect follicular growth over 3 days, but on day 5 the 33 Hz exposure significantly reduced growth compared to controls, while 50 Hz did not. ELF-EMF severely impaired antrum formation at both frequencies, with control follicles forming antral cavities at 79% versus 30% at 33 Hz and 51.6% at 50 Hz. Oocytes from exposed follicles showed a reduced ability to resume meiotic maturation compared to controls.
Unknown authors · 2000
Italian researchers exposed developing mouse egg follicles to extremely low frequency electromagnetic fields at 33 Hz and 50 Hz for 5 days. The EMF exposure severely disrupted normal follicle development, with only 30-52% of exposed follicles forming essential antral cavities compared to 79% of unexposed follicles. This impairment could reduce female fertility by preventing eggs from reaching the developmental stage needed for successful reproduction.
Vijayalaxmi, Leal BZ, Szilagyi M, Prihoda TJ, Meltz ML, · 2000
Researchers exposed human blood cells to 2450 MHz radiofrequency radiation (the same frequency used in microwave ovens and some WiFi) for 2 hours to see if it would damage DNA. They found no evidence of DNA damage - the cells looked identical to unexposed cells, while cells exposed to ionizing radiation showed clear damage. This suggests that RF radiation at these levels doesn't break DNA strands in human immune cells.
Unknown authors · 2000
The researchers studied the effect of extremely low frequency electromagnetic fields combined with mild heat shock on reporter gene expression in two transgenic strains of Caenorhabditis elegans. Reporter gene expression was measured by scoring animals with induced beta-galactosidase activity after staining in toto or by biochemical quantitation of enzyme activity. They defined experimental conditions where electromagnetic fields strongly enhanced the expression of the reporter gene.
Unknown authors · 2000
Researchers used Escherichia coli strain XL-1 Blue as the host and hydroxylamine-mutagenized plasmid pUC8 as the vector for assessment. Bacterial transformants exposed to a 50 Hz magnetic field showed lower percentages of white colonies than unexposed transformants. The lower white colony percentage indicated that DNA repair efficiency had improved. The improvement was mediated by induced overproduction of heat shock proteins DnaK/J (Hsp70/40).
Peinnequin A et al. · 2000
Unknown authors · 2000
Researchers investigated whether exposure to 60-Hz sinusoidal magnetic fields (0.3-1.2 G for 3-72 h) would cause proliferation of human astrocytoma cells. Sixty-Hertz magnetic fields caused a time- and dose-dependent increase in proliferation of astrocytoma cells, measured by (3)H-thymidine incorporation and by flow cytometry, and strongly potentiated the effect of two agonists. However, magnetic fields had no effect on DNA synthesis of rat cortical astrocytes, which are similar nontransformed cells. A protein kinase C inhibitor and down-regulation of protein kinase C inhibited the effect of magnetic fields on basal and agonist-stimulated thymidine incorporation.
Unknown authors · 2000
University of Washington researchers exposed human brain tumor cells (astrocytomas) to 60-Hz magnetic fields at household appliance levels (0.3-1.2 gauss) for up to 72 hours. The magnetic fields caused these cancer cells to multiply faster in a dose-dependent manner, while having no effect on normal brain cells. This provides a potential biological mechanism for epidemiological studies linking magnetic field exposure to increased brain tumor risk.
Unknown authors · 2000
Lebedeva NN et al. · 2000
EEG was recorded from 16 standard leads during eyes-open and eyes-closed conditions and analyzed with custom non-linear dynamics software that computed a multichannel global correlation dimension. A significant increase in global correlation dimension occurred during and after exposure, more pronounced with eyes closed. The authors interpreted this increase as a manifestation of cortex activation under phone EMF exposure.
Unknown authors · 2000
Bornhausen M, Scheingraber H · 2000
Unknown authors · 2000
Researchers used a bacterial conjugation assay with Escherichia coli carrying the transposable element Tn5 as the donor strain. Donor cultures exposed to a 50 Hz, 1.2 mT magnetic field showed stimulated transposition of chromosomal Tn5 to an extrachromosomal episome and subsequent transfer to recipient cells. The transposition increase was mediated by induced synthesis and accumulation of the heat shock proteins DnaK/J. Magnetic field exposure was found to be stimulatory to transposition activity, similar to heat shock and UV irradiation.
Gos P, Eicher B, Kohli J, Heyer WD · 2000
Researchers exposed actively growing and resting yeast cells to 900 MHz fields at specific absorption rates of 0.13 and 1.3 W/kg. Assays measured forward mutation rates at CAN1, petite clone formation, intrachromosomal deletion formation, and intragenic recombination in the ADE2 gene. Fields were also tested in combination with the alkylating agent methyl methansulfonate to assess whether they could enhance genotoxic damage. Fluctuation tests failed to detect any significant effect on any of these measures, in the absence or presence of methyl methansulfonate.
Unknown authors · 2000
Researchers examined the effect of 50 mT, 60 Hz ELFMF on heat-induced HSP-70 expression in HL60RG cells. Exposure to 50 mT ELFMF alone did not increase HSP-70 production. Combined exposure to 50 mT ELFMF and mild heat at 40°C and 42°C suppressed heat-induced HSP-70 expression. This suppression required simultaneous exposure for more than 5 hours. Lower magnetic densities of 5 mT and 0.5 mT did not suppress HSP-70.
Unknown authors · 2000
Researchers from Löscher's group in Germany exposed Sprague-Dawley rats to 50-Hz magnetic fields at microtesla flux densities for 13 or 27 weeks using a DMBA breast cancer model. The exposure significantly increased mammary tumor development and growth in those experiments. A similar study by Battelle in the United States did not replicate the effect.
Unknown authors · 2000
German researchers found that 50 Hz magnetic fields at 100 microtesla significantly increased mammary tumor development in rats treated with a cancer-causing chemical. However, when U.S. researchers tried to replicate the study using similar methods, they could not reproduce these findings, highlighting challenges in EMF research reproducibility.
Lu ST et al. · 2000
Researchers studied retinal effects of 1.25 GHz high peak power microwaves in Rhesus monkeys. Preexposure and postexposure fundus pictures and angiograms were all within normal limits. Cone photoreceptor response to light flash was enhanced at 8.4 and 20.2 W/kg R-SAR but not at 4.3 W/kg R-SAR. Enhanced glycogen storage in photoreceptors was observed in sham, 8.4, and 20.2 W/kg groups but not in the 4.3 W/kg group. No degenerative changes or ERG depression were observed, and retinal injury was considered very unlikely at 4 W/kg.
Marino C et al. · 2000
Researchers examined possible effects of 900 MHz microwave exposure on the cochlear epithelium of rats. Two experiments used male Sprague-Dawley rats with far-field exposure in a cubic chamber. No statistically significant evidence was obtained at both SAR values. The exposure system and diagnostic apparatus were considered useful for investigating auditory effects, but no evidence was observed with the parameters applied.
Unknown authors · 2000
Unknown authors · 2000
Scientists exposed human mammary and leukemia cells to 60 Hz magnetic fields (the frequency from power lines) for 24 hours to see if this would change cancer-related gene activity. While some genes showed temporary changes, no consistent pattern emerged across repeated experiments, and the researchers found no reliable evidence that power line frequency magnetic fields alter cancer gene expression.