Calota V, Dragoiu S, Meghea A, Giurginca M · 2006
Researchers investigated the decrease of luminol chemiluminescence upon exposure of human blood serum to 50 Hz electric fields. After 1 and 2 hours of in vitro exposure to 50 Hz electric fields of different intensities, the chemiluminescence of luminol decreased compared to controls. The authors indicate this reflects a field-induced decrease in free radical concentration.
Jeong JH, Kum C, Choi HJ, Park ES, Sohn UD. · 2006
Researchers investigated the effect of 60 Hz ELF-MF on hyperalgesia in mice using a hot plate test. Exposure to ELF-MF lowered pain threshold and elevated NO synthesis in brain and spinal cord. The hyperalgesic effects were blocked by an NOS inhibitor and a Ca2+ channel blocker but not by an NMDA receptor antagonist.
Wolf FI et al. · 2005
Researchers exposed HL-60 leukemia cells, Rat-1 fibroblasts, and WI-38 diploid fibroblasts to 0.5-1.0 mT 50-Hz ELF-EMF for 24-72 hours. The treatment caused a dose-dependent increase in proliferation rate, about 30% after 72 hours at 1.0 mT. DNA damage increased dose-dependently with peaks at 24 and 72 hours. Pretreatment with the antioxidant alpha-tocopherol prevented both the proliferation increase and DNA damage, implicating redox mechanisms.
Loughran SP et al. · 2005
Researchers examined whether sleep architecture is sensitive to electromagnetic fields from digital mobile phone handsets. Fifty participants were exposed to electromagnetic fields for 30 minutes before sleep. Exposure decreased rapid eye movement sleep latency and increased electroencephalogram spectral power in the 11.5-12.25 Hz range during the initial part of sleep. The authors concluded that mobile phone exposure before sleep may promote rapid eye movement sleep and modify the sleep electroencephalogram in the first non-rapid eye movement sleep period.
Yokus B, Cakir DU, Akdag MZ, Sert C, Mete N · 2005
Researchers examined the effects of extremely low frequency electromagnetic fields (50 Hz, 0.97 mT) on oxidative DNA damage and lipid peroxidation in rats. Measurements of 8OHdG and TBARS were taken at 50 and 100 days to look for time-dependent changes. The 8OHdG levels of the exposed group were significantly higher than the sham group at both 50 and 100 days (p<0.001). The extent of DNA damage and lipid peroxidation appeared to depend on exposure time.
Unknown authors · 2005
Researchers exposed cultured cells from different tissues to intermittent 50 Hz, 1 mT ELF-EMF for 1-24 hours. They used alkaline and neutral comet assays to assess ELF-EMF-induced DNA strand breaks. The study identified three responder cell types (human fibroblasts, human melanocytes, rat granulosa cells) and three non-responder cell types (human lymphocytes, human monocytes, human skeletal muscle cells).
Unknown authors · 2005
Researchers exposed six different types of human and animal cells to power line frequency electromagnetic fields (50 Hz, 1 milliTesla) for up to 24 hours. They found that three cell types showed DNA damage while three others remained unaffected, demonstrating that EMF sensitivity varies significantly between different tissues and cell types.
Unknown authors · 2005
Researchers exposed cultured human fibroblasts to intermittent 50 Hz ELF-EMF (5 minutes on, 10 minutes off) at 1 mT for 2 to 24 hours. Micronuclei frequency increased in a time-dependent manner, becoming statistically significant after 10 hours and plateauing at roughly three times the basal level after about 15 hours. Chromosomal aberrations were also elevated, reaching up to 10-fold above baseline.
Unknown authors · 2005
Researchers exposed human skin cells to 50 Hz electromagnetic fields (like power lines) in an on-off pattern and found significant chromosomal damage. The cells showed three times more micronuclei (broken chromosome fragments) and up to 10 times more chromosomal breaks after 10-15 hours of exposure. This suggests power-frequency EMFs can damage DNA in human cells.
Harakawa S et al. · 2005
The effects of exposure to extremely low frequency electric fields (ELF EFs) on plasma lipid peroxide levels and antioxidant activity (AOA) in Sprague–Dawley rats were studied. The test compared rats treated with a combination of the oxidizing agent AAPH and a 50 Hz EF of 17.5 kV/m for 15 min per day for 7 days, as well as AAPH alone, EF alone, or no treatment. EF significantly decreased the plasma peroxide level in rats treated with AAPH, similar to treatment by ascorbic acid or the superoxide dismutase.
Unknown authors · 2005
Researchers exposed two clones of MCF-7 breast cancer cells to 50Hz electromagnetic fields and calculated IC(50) values from tamoxifen dose-response curves. The dose-response curves shifted to higher tamoxifen concentrations in an intensity-dependent manner, with a maximal response at 1.2muT. The authors hypothesized that electromagnetic field exposure could contribute to tamoxifen resistance observed in breast cancer after long-term treatment.
Unknown authors · 2005
German researchers exposed breast cancer cells to 50 Hz electromagnetic fields (the same frequency as power lines) and found that EMF exposure made the cells more resistant to tamoxifen, a common breast cancer drug. The effect was strongest at 1.2 microTesla field strength, suggesting that power-frequency EMF exposure could interfere with cancer treatment effectiveness.
Unknown authors · 2005
Residential exposure was calculated as time-weighted average magnetic fields from power lines from 1967 to diagnosis, while occupational exposure was assessed via job titles classified by hours per week above 0.1 μT from 1955 to diagnosis. The two highest residential exposure categories showed elevated odds ratios for all brain tumours (OR = 1.6, 95% CI 0.9–2.7 and OR = 1.3, 95% CI 0.7–2.3), but the risk was not statistically significant and no clear exposure-response pattern emerged. Occupational exposure showed no association with brain tumours for any site, and the occupational exposure groups showed an inverse association.
Unknown authors · 2005
Researchers exposed 24 male Wistar rats to 50 Hz electromagnetic fields at 100-300 microT for 4 hours daily over one month. Skin and thyroid samples were analyzed using immunohistochemistry and stereology with markers for serotonin, substance P, CGRP, PGP 9.5, and NPY. Exposed rats had significantly more serotonin-positive mast cells in skin and NPY-containing nerve fibers in thyroid compared to controls.
Unknown authors · 2005
Researchers investigated whether acute magnetic-field exposure could elicit DNA damage in brain cells from adult rats, adult mice, and immature mice. Rodents were exposed to a 60 Hz magnetic field at 0, 0.1, 1, or 2 mT for 2 h and brain cells were analyzed at 0, 2, and 4 h after exposure using the alkaline comet assay. No significant increase in DNA damage was detected at any magnetic-field strength or time point.
Unknown authors · 2005
Researchers exposed two-month-old Wistar male rats to 50 Hz electromagnetic fields at 100-300 microT and 54-160 V/m for 4 h a day, seven days a week for one month. After sacrifice, skin and thyroid samples were processed for toluidine blue staining or indirect immunohistochemistry, and stereological analysis was performed using an M42 grid and a special microscopic frame. The numerical and volume density of intact type A mast cells in the thyroid was significantly higher in the exposed group compared to controls. Mast cells and immunoreactive nerve fibers were observed in the skin, and histamine-immunoreactive mast cells were observed in the thyroid of exposed animals. However, the differences in stereological data were not statistically significant by the Mann-Whitney test.
Unknown authors · 2005
Serbian researchers exposed male rats to 50 Hz electromagnetic fields (the same frequency as power lines) for 4 hours daily over one month. They found significant increases in specific immune cells called mast cells in the thyroid gland, along with changes to nerve fibers in skin tissue. These cellular changes suggest the body's immune and nervous systems respond to power-frequency EMF exposure.
Unknown authors · 2005
Researchers exposed human placental cotyledons to magnetic fields of 2 mT and 5 mT at 50 Hz for 3 hours in vitro. They measured the concentration of 8-hydroxy-2'-deoxyguanosine (8-OH-dG) in cellular DNA. The results suggest that placental tissues possess a capacity to protect DNA against oxidative alterations from magnetic field intensities that have caused DNA damage in rat brain cells and electrolyte imbalances in cotyledons.
Unknown authors · 2005
Researchers exposed insulin solution to a pulsed electric field of 0.7 V/m at 50 Hz for 20 minutes and then added it to human hepatocyte cultures. They investigated insulin signaling events including ligand-receptor binding, tyrosine phosphorylation, gene transcription, and cell proliferation using multiple methods. PEF exposure caused a conformational change in insulin, reduced its receptor binding capacity to 87% of control, and decreased intracellular tyrosine phosphorylation by 11%. The expression of 55 out of 12000 genes was altered, including increased expression of human tyrosine phosphatase and a small GTP-binding protein.
Unknown authors · 2005
Researchers exposed insulin to a pulsed electric field at 50 Hz (0.7 V/m) for 20 minutes, then tested it on human liver cells. The exposed insulin lost effectiveness, binding 13% less effectively to cell receptors and reducing cellular signaling, which led to decreased cell proliferation. This demonstrates that EMF exposure can alter the molecular structure of hormones, potentially disrupting their biological function.
Wolf FI et al. · 2005
Researchers exposed HL-60 leukemia cells, Rat-1 fibroblasts, and WI-38 diploid fibroblasts to 0.5–1.0-mT 50-Hz extremely low frequency electromagnetic fields for 24–72 hours. The treatment produced a dose-dependent increase in cell proliferation, with about a 30% increase after 72 hours of exposure to 1.0 mT. A dose-dependent increase in DNA damage was observed in all cell lines, with two peaks occurring at 24 and 72 hours. Both effects were prevented by pretreatment with α-tocopherol, suggesting that redox reactions were involved.
Regoli F et al. · 2005
Lai H, Singh NP · 2004
Researchers investigated how magnetic field exposure affected brain cell DNA in rats. Exposure to a 60-Hz magnetic field at 0.01 mT for 24 hours caused a significant increase in DNA single- and double-strand breaks, and prolonging the exposure to 48 hours caused a larger increase. Acute magnetic field exposure also increased apoptosis and necrosis of brain cells in the rat.
Unknown authors · 2004
The authors conducted an extensive literature review and propose that ELF EMF exposure increases free radical levels. They suggest EMF might induce an activated state such as phagocytosis, enhancing free radical release and leading to genotoxic events. The proposed mechanisms include direct activation of macrophages leading to phagocytosis and free radical production, and direct stimulation of free radical production by EMF-induced macrophage activation. They also propose that EMF increases the lifetime of free radicals causing persistently elevated concentrations, and that long-term exposure leads to chronically increased free radicals that inhibit melatonin effects. Taken together, these reactions could lead to higher DNA damage incidence and increased tumor risk.
Unknown authors · 2004
This 2004 research review examined how extremely low frequency (ELF) electromagnetic fields affect cells at the molecular level. The scientists proposed that EMF exposure triggers cellular activation by increasing free radical production, which could explain the wide variety of biological effects observed in EMF studies. This mechanism could potentially lead to DNA damage and increased cancer risk through chronic exposure.
