Unknown authors · 2001
Researchers conducted a population-based case-control study across former West Germany. They measured 24-hour residential magnetic fields for 514 children with acute leukemia and 1,301 control children. Childhood leukemia and 24-hour median magnetic fields showed only a weak relationship. However, a significant association emerged for magnetic field exposure during the night.
Unknown authors · 2001
Each woman provided data over a 72-hour period in two different seasons, including bedroom magnetic field and ambient light measured every 30 seconds, personal magnetic field measured at 30-second intervals, and complete nighttime urine samples on three consecutive nights. Lower nocturnal urinary 6-sulfatoxymelatonin levels were associated with more hours of daylight, older age, higher body mass index, current alcohol consumption, and current use of beta blockers, calcium channel blockers, or psychotropics. After adjusting for these factors, higher bedroom magnetic field levels were associated with significantly lower urinary 6-sulfatoxymelatonin concentration during the same night, primarily in women using those medications and during times of year with the fewest hours of darkness.
Unknown authors · 2001
Researchers measured magnetic fields and melatonin levels in 203 women's bedrooms over 72-hour periods across different seasons. They found that higher bedroom magnetic field levels were associated with significantly lower nighttime melatonin production, particularly in women taking certain medications. This suggests that common household magnetic fields can disrupt the body's natural sleep hormone production.
Unknown authors · 2001
Researchers independently replicated a study testing whether a 1.2 microT, 60 Hz magnetic field alters the effects of melatonin and tamoxifen on MCF-7 human breast cancer cells. In the melatonin experiment, repeated three times, melatonin reduced cell numbers by 16.7% after seven days, but this reduction disappeared when cells were exposed to the magnetic field. In the tamoxifen experiment, repeated nine times, tamoxifen reduced cell growth by 18.6% and 25% on days six and seven without the field, but only by 8.7% and 13.1% with the field. The results were consistent with the original findings of Harland and Liburdy.
Unknown authors · 2001
EPA researchers tested whether 60 Hz magnetic fields at 1.2 microT could interfere with melatonin and tamoxifen's ability to inhibit breast cancer cell growth. They found that magnetic field exposure completely blocked melatonin's cancer-fighting effects and significantly reduced tamoxifen's effectiveness. This suggests power line frequency EMF may interfere with the body's natural cancer protection mechanisms.
Lyskov E, Sandström M, Mild KH · 2001
Researchers investigated possible neurophysiological effects of an intermittent 15 sec on/off cycle, 60 Hz, 10 μT magnetic field on patients with perceived electromagnetic hypersensitivity (EHS) and control subjects during rest and a mental arithmetic task. Magnetic field exposure did not affect autonomic system or electroencephalographic variables in either group. EHS patients and controls showed significant differences in heart rate, heart rate spectrum ratio, and electrodermal activity, while EEG characteristics did not differ between groups.
Unknown authors · 2001
Unknown authors · 2001
Japanese researchers exposed breast cancer cells to 50 Hz magnetic fields at extremely low levels (1.2 microT and 100 microT) and found these fields disrupted melatonin's cancer-fighting signals. The magnetic fields prevented melatonin from properly inhibiting cellular pathways that normally help control cancer cell growth.
Boscol P et al. · 2001
The study investigated the immune systems of 19 women with a mean age of 35 years who had been exposed to electromagnetic fields from radiotelevision broadcasting stations in their residential area for at least 2 years, with a mean exposure duration of 13 years. The exposed group had mean field levels of 4.3 plus or minus 1.4 V/m in the range 500 KHz to 3 GHz, while the control group had nearby residential exposure of less than 1.8 V/m. The exposed women showed statistically significant reductions in several immune cell types and lower in vitro production of IL-2 and interferon-gamma by peripheral blood mononuclear cells. The researchers concluded that high frequency electromagnetic fields reduce cytotoxic activity in the peripheral blood of women without a dose-response effect.
Unknown authors · 2001
Researchers demonstrated that a 50- to 60-Hz magnetic field interacts with cell differentiation through two opposing mechanisms. The field antagonizes the shift in cell membrane surface charges during early differentiation and modulates hyperpolarizing K channels by increasing intracellular calcium. The simultaneous onset of both mechanisms prevents alterations in cell differentiation. The authors propose that cells are normally protected against electromagnetic insult.
Sebastian JL, Munoz S, Sancho M, Miranda JM · 2001
Researchers calculated electric field intensity using the finite element method in single- and multilayer spherical, cylindrical, and ellipsoidal mammalian cell models exposed to 900 and 2450 MHz plane waves. They analyzed how cell geometry and orientation relative to the external field influence the electric field induced in the membrane and cytoplasm. The study found that cytoplasmic and extracellular bound water layers play a significant role in determining electric field intensity for cylindrical and ellipsoidal models.
Vijayalaxmi et al. · 2001
Eight adult male Sprague-Dawley rats were exposed to 2450 MHz RFR in circularly polarized waveguides, and eight sham-exposed rats were kept in similar waveguides without RFR transmission. Four rats treated with mitomycin-C served as positive controls, and all rats were necropsied 24h after exposure to examine peripheral blood and bone marrow smears for micronuclei in polychromatic erythrocytes. The incidence of micronuclei per 2000 polychromatic erythrocytes was not significantly different between RFR-exposed and sham-exposed rats.
Unknown authors · 2001
Researchers induced dopamine neuron damage in newborn rats by infusing 6-OHDA into the brain ventricles on postnatal day 3. At two months of age, the rats were exposed to a 10 Hz, 1.8–3.8 mT magnetic field for one hour daily over 14 days, while a sham-exposed group had the solenoid turned off. After exposure, magnetic-field-exposed rats with dopamine damage showed reduced irritability and oral activity when given a D1 receptor agonist and increased catalepsy when given a D1 receptor antagonist. The authors concluded that extremely low frequency magnetic fields reduce the reactivity of central dopamine D1 receptors.
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.
Hanada E, Kodama K, Takano K, Watanabe Y, Nose Y. · 2001
Researchers measured electric field intensity from radio waves entering an 11-floor hospital that was under construction. The highest level recorded was about 200 V/m at 2.79 GHz, coming from airport surveillance radar. The maximum intensity from cellular phone base stations was 1.78 V/m. The researchers concluded that each hospital in urban areas should measure its own electromagnetic environment to help prevent interference with electronic medical equipment.
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.
