Wang, BM, Lai, H · 2000
Rats were trained in six sessions to locate a submerged platform in a circular water maze. They were exposed to pulsed 2450-MHz microwaves for 1 hour before each training session. Microwave-exposed rats were slower than sham-exposed and cage control rats in learning to locate the platform. During the probe trial, microwave-exposed animals spent significantly less time in the quadrant that had contained the platform. There was no significant difference in swim speed among the three groups.
Unknown authors · 2000
Researchers exposed rats to pulsed 2450-MHz microwaves (similar to microwave oven frequency) for one hour before each water maze training session. The microwave-exposed rats were significantly slower to learn the maze and showed impaired spatial memory compared to unexposed controls. The findings suggest that even brief exposure to pulsed microwaves can disrupt learning and memory formation.
Unknown authors · 2000
Researchers exposed rats to pulsed 2450-MHz microwaves (similar to microwave oven frequency) for one hour before each training session in a water maze test. The microwave-exposed rats learned significantly slower and showed impaired spatial memory compared to unexposed controls, suggesting the radiation disrupted their ability to navigate and remember locations.
Unknown authors · 2000
Researchers exposed rats to pulsed 2450 MHz microwaves (similar to microwave oven frequency) for one hour before each training session in a water maze learning task. The microwave-exposed rats took longer to learn the maze location and showed impaired spatial memory compared to control groups. This suggests that acute microwave exposure can interfere with learning and memory processes in the brain.
Unknown authors · 2000
Researchers incubated isolated rat lymphocytes for three hours in 7 mT static or 50 Hz magnetic fields, with some samples receiving iron chloride or hydrogen peroxide. Magnetic field exposure alone did not increase DNA damage in the comet assay. Iron chloride alone also did not produce detectable DNA damage. However, combined exposure to iron chloride and magnetic fields significantly increased damaged cells to about 20 percent for static fields and 15 percent for 50 Hz fields. Control samples showed about 97 percent of cells without DNA damage.
Adey WR et al. · 2000
Researchers exposed Fischer 344 rats to a frequency-modulated signal at 836.55 MHz in a two-year bioassay, testing for effects on spontaneous and chemically induced central nervous system tumors. The study used six groups of offspring totaling 540 rats, with some groups receiving the chemical ENU and others sham or field exposure. No FM field-mediated changes were observed in number, incidence, or histological type of either spontaneous or ENU-induced brain tumors, nor were gender differences detected in tumor numbers.
Hietanen M, Kovala T, Hamalainen AM · 2000
Researchers analyzed EEG activity of 19 volunteers exposed to five different cellular phones operating at 900 MHz or 1800 MHz. Each subject completed six 30-minute experiments including one sham exposure, with real exposure lasting 20 minutes. Exposure to one phone caused a statistically significant change in absolute delta power, but relative delta power did not change and no effects were seen with other phones. The authors concluded that the observed difference was likely due to chance and that radiofrequency fields from cellular phones have no abnormal effects on EEG activity.
Schirmacher A et al. · 2000
Unknown authors · 2000
The researcher studied the incidence of central nervous system diseases in 30,631 persons employed in Danish utility companies between 1900 and 1993, linked the cohort to the Danish National Register of Patients and compared cases from 1978 to 1993 with general population rates, and fitted a multiplicative Poisson regression model to estimated 50-Hz electromagnetic field exposure levels. Overall there was an increase in risk for senile dementia and motor neuron diseases combined, while Parkinson disease, Alzheimer disease, and other central nervous system diseases were essentially unrelated to exposure. A decreased risk of epilepsy compared with the general population probably reflects a healthy worker effect, but internal comparisons showed an increased risk of epilepsy.
Sienkiewicz ZJ et al. · 2000
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.
Zotti-Martelli L, Peccatori M, Scarpato R, Migliore L, · 2000
Italian researchers exposed human immune cells (lymphocytes) to microwave radiation at frequencies of 2.45 and 7.7 GHz to see if it would damage their DNA. They found that high-power exposures (30 mW/cm²) for 30 and 60 minutes caused significant genetic damage, creating abnormal cell structures called micronuclei that indicate DNA breaks. This matters because it demonstrates that microwave radiation can directly damage human genetic material under laboratory conditions.
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
Harvey C, French PW · 2000
Researchers exposed a human mast cell line, HMC-1, to continuous wave microwave radiation at 864.3 MHz at an average specific absorption rate of 7 W/kg. Cells were given three exposures each of 20-min duration daily for 7 days. Expression of three genes out of 588 screened was affected, including the proto-oncogene c-kit, the transcription factor Nucleoside diphosphate kinase B, and the apoptosis-associated gene DAD-1. No significant effect on morphology or on F-actin distribution was detected.
