Unknown authors · 2001
Researchers examined responses of the small heat shock protein gene hsp-16 in transgenic Caenorhabditis elegans exposed to electromagnetic fields. Expression of the hsp-16-lacZ gene was enhanced when transgenic animals were exposed to magnetic fields up to 0.5 T at 60 Hz. The hsp-16 promoter was more efficiently expressed at the embryonic than at the post-embryonic stage irrespective of exposure. Promoter activity was more sensitive to the stimulus in the intestine at the post-embryonic stage.
Unknown authors · 2001
Unknown authors · 2001
German researchers exposed Syrian hamster embryo cells to 50 Hz magnetic fields (the same frequency as power lines) combined with known cancer-causing chemicals. They found that magnetic field exposure increased genetic damage by 80% when combined with the carcinogen benzo(a)pyrene. This suggests power line frequency fields may act as co-carcinogens, enhancing the effects of other cancer-causing agents.
Jauchem JR, Frei MR, Dusch SJ, Lehnert HM, Kovatch RM · 2001
Researchers exposed 100 C3H/HeJ mice to ultra-wideband electromagnetic pulses for 2 minutes once a week for 12 weeks, using 100 sham-control mice for comparison. There were no significant differences between groups in incidence of palpated mammary tumors, latency to tumor onset, rate of tumor growth, or animal survival. Histopathological evaluations also revealed no significant differences between the two groups in numbers of neoplasms across all tissues studied.
Unknown authors · 2001
The study examined 30 human volunteers. Volunteers were exposed to a 28 microT circularly polarized 50 Hz magnetic field for 50 minutes in a double-blind crossover design. The majority of cognitive measures showed no significant effect of exposure. Verbal recall of a 15-word list after interference was significantly impaired during field exposure. Performance on a trail-making task requiring executive functioning also decreased with exposure.
Unknown authors · 2001
Australian researchers tested 30 volunteers exposed to 28 microT 50 Hz magnetic fields (similar to occupational levels) for 50 minutes while performing cognitive tests. The study found significant impairment in short-term memory for word recall and decreased performance on executive functioning tasks requiring working memory. These findings suggest power frequency magnetic fields may affect specific brain functions related to learning and mental processing.
Unknown authors · 2001
The study examined the effect of a sinusoidal 50 Hz magnetic field on preimplantation CBA/S mouse embryos in vitro. Embryos were exposed to a field of 10 A/m rms corresponding to 13 microT rms while cultured at 37°C in a CO2 incubator. Vitality and developmental stages were similar between groups, though slightly more dead embryos appeared on day 1 in the exposed group (P<0.05) and development was slightly impaired. The authors concluded that the exposure did not significantly disturb development up to the blastocyst stage.
Trosic I. · 2001
Researchers exposed rats to microwave radiation at 2450 MHz (the same frequency used in microwave ovens and some WiFi devices) and examined lung cells. They found that exposure caused immune cells in the lungs to fuse together into abnormal giant cells with multiple nuclei - a sign of chronic lung inflammation. The effect became stronger with more radiation treatments, suggesting cumulative damage to the respiratory system.
Novoselova EG, Ogai VB, Sorokina OV, Novikov VV, Fesenko EE · 2001
Researchers studied the effect of fractionated low-intensity microwave exposure and a combined weak magnetic field on tumor necrosis factor production in macrophages of mice with experimental solid tumors. Exposure to both microwaves and magnetic field enhanced the adaptive response, with higher tumor necrosis factor production in peritoneal macrophages of exposed tumor-bearing mice compared to unexposed mice.
Palfia Z, Somosy Z, Rez G · 2001
Researchers evaluated murine jejunal epithelial tight junctions after whole-body X-ray and microwave exposure using freeze fracture replicas. X-ray treatment at 4 Gy caused partial dearrangement of the ZO strand network that only partially regenerated by 24 hours. Microwave treatment at 16 Hz-modulated 2.45 GHz and 1 mW/cm2 for 1 hour did not cause dearrangement but increased integration of the tight junctional structure. The microwave effect agreed with an increase in cytochemically detectable ZO-bound calcium.
Radicheva N, Mileva K, Georgieva B, Kristev I · 2001
Researchers exposed isolated frog muscle fibers to continuous 2.45 GHz microwave radiation at 20 mW/cm² for one hour. Repetitive stimulation at 200 ms intervals evoked intracellular action potentials and twitch contractions. The twitch amplitude curve showed a drastic fall in the first 5 seconds followed by an increase and then a decrease. After microwave exposure, the changes in amplitude and time parameters that characterize fatigue were attenuated and delayed compared to controls. The authors concluded that microwaves have a specific non-thermal influence causing some resistance to fatigue.
Yang R, Chen J, Deng Z, Liu X, · 2001
Researchers cultured pig retinal ganglion cells in vitro, added vitamin E at different concentrations, and exposed them to 2450 MHz microwave radiation at 30 mW/cm² for 1 hour. Microwave exposure caused cell congregation, axon disappearance, mitochondria and endoplasmic reticulum swelling, and apoptosis. Vitamin E groups showed no obvious changes under optical microscope, though electron microscopy revealed light mitochondria swelling with intact cristae. The researchers concluded that microwave induced morphological damage and vitamin E reduced this damage to some extent.
Unknown authors · 2001
Researchers evaluated leukemia mortality among adults and childhood leukemia incidence in a 10 km area around the Vatican Radio Station in Rome. The station transmitted up to 600 kW and electric field measurements near it ranged from 1.5 to 25 V/m. Childhood leukemia incidence was higher than expected within 6 km (SIR = 217; 95% CI 99-405), and Stone's test showed a significant decrease in risk with distance for male adult mortality (p = 0.03) and childhood incidence (p = 0.04).
Alhekail ZO. · 2001
Researchers surveyed microwave ovens used in households and restaurants in Riyadh city, Saudi Arabia. One oven leaked more than the 5 mW cm-2 limit, and fifteen others leaked 1 mW cm-2 or more, with the rest leaking less. The researchers concluded that a detrimental effect on health is an unlikely result of exposure to radiation from microwave ovens.
Trosic I · 2001
Researchers exposed rats to 2450 MHz microwaves at power densities of 5 to 15 mW/cm², in sessions of two hours each, with groups receiving 2, 8, 13, or 22 treatments. Multinucleated cells significantly increased (p<0.01) in treated animals, with the elevation being time- and dose-dependent. Cell viability did not significantly change in the irradiated animal group compared with the control group.
Fernie KJ, Bird DM. · 2001
Researchers investigated whether exposure to magnetic and electric fields similar to those from power lines induces an immune response and alters oxidative stress levels in American kestrels. Captive male kestrels were bred under control or EMF conditions equivalent to those experienced by wild kestrels. Short-term EMF exposure suppressed plasma total proteins, hematocrits, and carotenoids in the first half of the breeding season, and also suppressed erythrocyte cells and lymphocyte proportions while elevating granulosa proportions at the end of the breeding season. Long-term EMF exposure may be linked to higher levels of oxidative stress through EMF exposure only, and also suppressed hematocrits in the first half of the reproductive period.
Jajte J, Zmyślony M, Palus J, Dziubałtowska E, Rajkowska E. · 2001
Researchers used the alkaline comet assay to assess DNA damage in rat peripheral blood lymphocytes exposed in vitro to iron ions and a 50 Hz magnetic field. Cell samples were incubated for 3 hours in Helmholtz coils at 7 mT 50 Hz, and some were treated with ferrous chloride at 10 μg/ml during that exposure. A significant increase in cells with DNA damage was found only after simultaneous exposure to ferrous chloride and the 7 mT 50 Hz magnetic field, compared to control samples or those incubated with ferrous chloride alone. When cells were treated with melatonin before that combined exposure, the number of damaged cells was significantly reduced, with the reduction reaching about 50% at 0.5 mM and about 100% at 1.0 mM.
Simkó M, Droste S, Kriehuber R, Weiss DG · 2001
Researchers examined the effects of 50 Hz electromagnetic fields on phagocytosis and free radical production in mouse bone marrow-derived macrophages exposed in vitro to magnetic field densities of 0.5 to 1.5 mT. Short-time exposure of 45 minutes resulted in a significantly increased phagocytic uptake of 36.3% plus or minus 15.1%, as measured by the internalization rate of latex beads. A significant increase in superoxide production was also detected after exposure to electromagnetic fields. Because co-exposure to electromagnetic fields and TPA showed no additive increase in bead uptake, researchers concluded that the electromagnetic fields-induced stimulation does not involve the protein kinase C signal transduction pathway.
Unknown authors · 2000
Researchers conducted a pooled analysis based on individual records from nine studies. The analysis included 3203 children with leukaemia and 10 338 control children with estimated residential magnetic field exposures levels < 0.4 μT, and 44 children with leukaemia and 62 control children with exposures ≥ 0.4 μT. For exposures ≥ 0.4 μT the estimated summary relative risk was 2.00 (1.27–3.13), P value = 0.002, while for exposures < 0.4 μT risk estimates were near the no effect level. Adjustment for potential confounding variables did not appreciably change the results. No evidence was found for a wire-code paradox; the highest wire code category showed a relative risk of 1.24 (0.82–1.87).
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.
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.
