Extremely Low Frequency (ELF) magnetic fields are produced by the flow of electrical current. They are measured in milligauss (mG) or microtesla (µT). Unlike electric fields, magnetic fields easily penetrate walls and most materials.
Based on Building Biology Institute guidelines (mG (milligauss)):
See where common exposures fall on the scale:
Showing 443 studies with measured magnetic fields (elf) exposure
Cuccurazzu B et al. · 2010
Italian researchers exposed mice to 50 Hz electromagnetic fields (European power line frequency) for up to seven hours daily over one week. This significantly increased new brain cell growth in the hippocampus, improving long-term memory formation and suggesting potential therapeutic applications for brain regenerative medicine.
Canseven AG, Coskun S, Seyhan N · 2008
Researchers exposed guinea pigs to household power line magnetic fields (50 Hz) for several hours daily over five days. The magnetic field exposure disrupted cellular protective systems and increased damage markers in heart and liver tissues, suggesting everyday power frequency fields may harm vital organs.
Piacentini R, Ripoli C, Mezzogori D, Azzena GB, Grassi C. · 2008
Researchers exposed neural stem cells from newborn mice to extremely low frequency electromagnetic fields (50 Hz at 1 mT) and found that this exposure significantly promoted the development of these cells into mature neurons. The electromagnetic fields worked by increasing the activity of specific calcium channels in the cells, which are crucial for brain cell development. This suggests that power-frequency EMF exposure can directly influence how brain cells develop and mature.
Partsvania B, Sulaberidze T, Modebadze Z, Shoshiashvili L. · 2008
Researchers exposed isolated snail brain cells to extremely low-frequency magnetic fields at the same frequencies used in cell phones (8.34 and 217 Hz) and measured how the neurons responded to electrical signals. They found that EMF exposure disrupted the normal learning process in these nerve cells, causing them to lose their ability to filter out repeated stimuli. This suggests that EMF exposure can interfere with basic neural functions that are fundamental to learning and memory.
Erdal N, Gürgül S, Tamer L, Ayaz L · 2008
Researchers exposed rats to 50Hz magnetic fields (the same frequency as power lines) for 4 hours daily over 45 days to study liver damage. They found that female rats showed increased oxidative stress markers in their liver tissue, indicating cellular damage to proteins. This suggests that long-term exposure to power frequency magnetic fields may harm liver function, particularly in females.
Che Y, Sun H, Cui Y, Zhou D, Ma Y. · 2007
Researchers exposed young chicks to magnetic fields from power lines for 20 hours daily and tested their learning ability. Chicks with prolonged exposure showed significantly impaired learning and memory compared to unexposed chicks, suggesting extended magnetic field exposure may interfere with brain development.
Che Y, Sun H, Cui Y, Zhou D, Ma Y. · 2007
Researchers exposed young chickens to power line magnetic fields for either 20 hours or 50 minutes daily, then tested their learning ability. Chicks with prolonged exposure showed significant learning problems, while brief exposure caused no harm, suggesting extended magnetic field exposure may impair brain function.
Aksen F, Akdag MZ, Ketani A, Yokus B, Kaya A, Dasdag S. · 2006
Scientists exposed female rats to 50-Hz magnetic fields (household electrical frequency) for 50-100 days. The study found significant cellular damage in ovaries and uterus, including broken cell structures and increased oxidative stress. This suggests prolonged exposure to common electrical frequencies may harm female reproductive organs.
Frahm J, Lantow M, Lupke M, Weiss DG, Simkó M · 2006
Scientists exposed mouse immune cells to 50 Hz magnetic fields from power lines and found the cells became hyperactive. The fields increased the cells' ability to consume particles by 60% and boosted inflammatory chemicals 12-fold, suggesting everyday electrical frequencies can overstimulate immune responses.
Reale M et al. · 2006
Researchers exposed human immune cells called monocytes to 50 Hz magnetic fields (the same frequency as power lines) at 1 milliTesla overnight. They found the fields altered production of two important immune signaling molecules: reducing nitric oxide synthase (which helps fight infections) while increasing MCP-1 (which attracts immune cells to sites of inflammation). These changes suggest power-frequency magnetic fields can disrupt normal immune system function.
Lupke M, Rollwitz J, Simkó M. · 2004
German researchers exposed human immune cells (monocytes) to 50 Hz magnetic fields for 45 minutes and measured their production of reactive oxygen species (ROS), which are damaging molecules that contribute to cellular stress and disease. They found that magnetic field exposure increased ROS production by 20-50% in these immune cells. This matters because elevated ROS levels are linked to inflammation, aging, and various health problems.
Rollwitz J, Lupke M, Simkó M · 2004
Researchers exposed mouse immune cells to 50 Hz magnetic fields from power lines and found a 24-33% increase in free radical production. Free radicals are unstable molecules that damage cells and cause inflammation, suggesting household electricity frequencies may trigger harmful cellular responses.
Espinosa JM, Liberti M, Lagroye I, Veyret B. · 2006
Scientists exposed rat brain tissue to magnetic fields from power lines and found significant changes in serotonin receptors that control mood and sleep. One hour of exposure at levels found near electrical equipment altered brain chemistry, demonstrating that common magnetic field exposure can directly affect how brain cells function.
Lee BC et al. · 2004
Researchers exposed mice to 60 Hz magnetic fields (household electricity frequency) for 3 hours and found increased oxidative stress and elevated protective enzyme activity in brain tissue. This suggests the brain was working harder to defend against cellular damage from power-frequency magnetic field exposure.
Lahijani MS, Bigdeli MR, Kalantary S. · 2011
Researchers exposed chicken embryos to magnetic fields similar to power lines before incubation and studied their brain development for 14 days. The exposed embryos showed significant brain damage including increased cell death and tissue breakdown compared to unexposed controls. This suggests that magnetic field exposure during critical development periods can harm the developing nervous system.
Lahijani MS, Bigdeli MR, Kalantary S. · 2011
Researchers exposed chicken eggs to 50 Hz electromagnetic fields (like those from power lines) for 24 hours before incubation, then examined the developing embryos' brains after 14 days. The exposed embryos showed significant brain damage, including increased cell death (apoptosis) and tissue degeneration. This study demonstrates that even brief pre-development exposure to common electromagnetic frequencies can cause measurable harm to the developing nervous system.
Cheun BS, Yi SH, Baik KY, Lim JK, Yoo JS, Shin HW, Soh KS · 2007
Researchers exposed canine kidney cells to a 60 Hz magnetic field (the same frequency as household electricity) while measuring their light emission when stressed by hydrogen peroxide. The magnetic field altered how cells responded to oxidative stress, changing the pattern of light they emitted. This suggests that power frequency magnetic fields can influence cellular stress responses at the biochemical level.
Celik MS et al. · 2013
Researchers exposed rats to power line frequency magnetic fields while giving them manganese, a potentially toxic metal. The magnetic field exposure significantly increased manganese buildup in the brain, kidneys, and liver, suggesting EMF exposure may impair the body's ability to eliminate toxic substances.
Celik MS et al. · 2013
Researchers exposed rats to magnetic fields from power lines while giving them manganese, a potentially toxic mineral. Magnetic field exposure significantly increased manganese buildup in the brain, kidneys, and liver, suggesting everyday electrical exposures may enhance absorption of harmful metals.
Emre M, Cetiner S, Zencir S, Unlukurt I, Kahraman I, Topcu Z · 2011
Researchers exposed rats to extremely low frequency magnetic fields (1-40 Hz) for one hour daily over 30 days and measured liver damage markers in blood and cell death in tissues. They found increased oxidative stress indicators and changes in cell death patterns, suggesting that even low-level magnetic field exposure can trigger biological stress responses. This matters because these frequency ranges are common around power lines and household electrical systems.
Coşkun S, Balabanli B, Canseven A, Seyhan N. · 2009
Researchers exposed guinea pigs to 50 Hz magnetic fields (like power lines) for four hours daily over four days. Both continuous and intermittent exposure increased cellular damage in blood, liver, and brain tissue, showing that even brief magnetic field exposure can trigger harmful stress responses throughout the body.
Coşkun S, Balabanli B, Canseven A, Seyhan N. · 2009
Researchers exposed guinea pigs to 50 Hz magnetic fields (power line frequency) for four hours daily over four days. Both continuous and pulsed exposures increased cellular damage markers in blood, liver, and brain tissue, suggesting power-frequency fields can trigger harmful oxidative stress.
Legros A, Modolo J, Brown S, Roberston J, Thomas AW. · 2015
Researchers scanned people's brains after one-hour exposure to 60 Hz magnetic fields from power lines. Brain scans showed altered activation patterns during tasks, even though performance stayed normal. This suggests magnetic field exposure can change how the brain functions, with effects lasting after exposure ends.
Legros A et al. · 2012
Researchers exposed people to 60 Hz magnetic fields (like those from power lines) for one hour. The exposure reduced standing balance and increased hand tremors, suggesting these common electrical frequencies can affect nervous system control of movement without obvious brain changes.
Legros A et al. · 2012
Researchers exposed people to strong 60 Hz magnetic fields (like power lines emit) for one hour. The exposure impaired balance and increased hand tremor, even though brain waves stayed normal. This shows power-frequency fields can affect movement control in subtle ways.