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
Giorgi G et al. · 2017
Researchers exposed human brain cells to power line magnetic fields alone and with cellular stress. While magnetic fields alone caused minor DNA changes, combining them with stress significantly altered DNA patterns that control genes. Most changes reversed, showing cells can recover.
Zheng Y, Dou JR, Gao Y, Dong L, Li G. · 2017
Researchers exposed brain neurons from mice to a 15 Hz magnetic field (the type found around power lines) and measured how it affected the channels that allow electrical signals to flow through nerve cells. The magnetic field disrupted these crucial channels, reducing their activity and changing how they function. This suggests that everyday magnetic field exposure could interfere with normal brain cell communication.
Falone S et al. · 2017
Researchers exposed human neuroblastoma cells (a type of brain cancer cell) to 50 Hz magnetic fields at levels similar to those found near power lines. The magnetic field exposure made the cancer cells grow faster and become more resistant to cancer treatment drugs by activating the cells' natural defense systems. This suggests that power-frequency magnetic fields might make certain brain cancers more aggressive and harder to treat.
Benassi B et al. · 2016
Italian researchers exposed brain cells to 50 Hz magnetic fields, then tested their response to a Parkinson's toxin. While EMF alone didn't harm cells, it weakened their antioxidant defenses, making them far more vulnerable to the toxin's damage, suggesting EMF might increase susceptibility to Parkinson's disease.
Falone S et al. · 2016
Researchers exposed human neuroblastoma cells (a type of brain cancer cell) to 50 Hz magnetic fields at 1 milliTesla and found the fields made the cancer cells grow faster and become more aggressive. The magnetic field exposure triggered protective mechanisms in the cancer cells that helped them survive and multiply more effectively. This suggests that power frequency magnetic fields might promote the growth of existing brain tumors.
Ma Q et al. · 2016
Researchers exposed embryonic brain stem cells to 50 Hz electromagnetic fields from power lines and electrical devices. The EMF exposure significantly enhanced the cells' development into neurons and promoted growth of neural connections. This suggests electromagnetic fields could influence brain formation during early development.
Salunke BP, Umathe SN, Chavan JG. · 2016
Researchers exposed mice to 50 Hz magnetic fields (the same frequency as power lines) for up to 120 days and found it caused significant anxiety-like behavior. The study identified that these fields disrupt brain chemistry by affecting NMDA receptors and increasing glutamate levels in key brain regions. This suggests that long-term exposure to power-frequency magnetic fields can alter brain function and behavior.
Calabrò E. · 2016
Researchers exposed human brain-like cells to a 50 Hz magnetic field (the type emitted by power lines and household appliances) for 4 hours and found significant changes in cellular proteins. The magnetic field caused proteins to clump together abnormally and altered their structural bonds, which are critical for proper brain cell function. These molecular changes suggest that everyday electromagnetic fields may disrupt normal cellular processes in brain tissue.
Duong CN, Kim JY · 2016
Researchers exposed human brain immune cells to magnetic fields at 50 Hz while depriving them of oxygen to mimic stroke conditions. The magnetic field exposure protected cells from dying by reducing harmful calcium and oxidative stress, suggesting potential therapeutic applications for stroke treatment.
Reale M et al. · 2016
Researchers exposed human brain cells to extremely low frequency electromagnetic fields (the type from power lines) for up to 48 hours to see if it would cause neurological damage. They found no significant harmful effects on the cells' ability to manage oxidative stress or inflammation, though there were minor changes in serotonin metabolism. The study suggests that ELF-EMF exposure at these levels is unlikely to contribute to neurodegenerative diseases.
Yang G, Ren Z, Mei YA. · 2015
Researchers exposed rat brain cells to power line frequency magnetic fields (50 Hz) and found they significantly boosted GABA receptor activity - the brain's main calming system. This change could potentially affect sleep, anxiety, and seizure control, showing how electromagnetic fields may influence brain function.
Jin H, Yoon HE, Lee JS, Kim JK, Myung SH, Lee YS. · 2015
Researchers exposed human lung cells to 60 Hz magnetic fields (1-2 mT) alone and combined with radiation or hydrogen peroxide to test whether EMFs might make cells more vulnerable to genetic damage. The magnetic fields alone caused no genetic damage, and they didn't make the cells more susceptible to damage when combined with other stressors. This suggests that power frequency magnetic fields at these levels don't compromise cellular genetic stability.
Benassi B et al. · 2015
Researchers exposed human brain cells to 50 Hz magnetic fields (the same frequency as power lines) and found that while the fields didn't harm the cells directly, they made the cells much more vulnerable to a chemical toxin that causes Parkinson's disease-like damage. The magnetic field exposure disrupted the cells' natural antioxidant defenses, causing normally survivable toxin levels to trigger cell death through oxidative stress.
Zhao QR, Lu JM, Yao JJ, Zhang ZY, Ling C, Mei YA. · 2015
Researchers exposed mice to 50 Hz magnetic fields from power lines for 12 hours daily, finding it impaired memory recognition and damaged brain cells in the hippocampus. The damage was reversible with protective proteins, showing power-line frequencies can measurably affect brain function.
Patruno A, Tabrez S, Pesce M, Shakil S, Kamal MA, Reale M · 2015
Italian researchers exposed leukemia cells to extremely low frequency electromagnetic fields (the type emitted by power lines and household appliances) for 24 hours at 50 Hz. They found significant changes in three key cellular enzymes that control oxidative stress and cellular metabolism. These enzyme disruptions could help explain how EMF exposure might contribute to health problems at the cellular level.
Duan W et al. · 2015
Researchers exposed mouse reproductive cells to electromagnetic fields from power lines and cell phones to compare DNA damage. Both types caused genetic damage through different mechanisms - power line fields broke DNA strands while cell phone radiation caused oxidative damage to DNA bases.
Duan W et al. · 2015
Researchers exposed mouse sperm cells to two types of electromagnetic fields - 50 Hz extremely low frequency (like power lines) and 1800 MHz radiofrequency (like cell phones) - to compare DNA damage. They found that high-intensity ELF fields caused DNA strand breaks, while high-intensity RF fields caused oxidative DNA damage through different mechanisms. The study suggests both types of EMF can damage DNA at high exposure levels, but through distinct biological pathways.
Yang ML, Ye ZM · 2015
Researchers exposed bone cancer cells to extremely low frequency electromagnetic fields (ELF-EMF) at 50 Hz and 1 milliTesla for up to 3 hours. They found the EMF exposure triggered cancer cell death (apoptosis) by increasing oxidative stress and activating specific cellular pathways. This suggests ELF-EMF might have potential therapeutic applications against bone cancer, though this was only tested in laboratory cell cultures, not living organisms.
de Groot MW, Kock MD, Westerink RH. · 2014
Researchers exposed nerve cells (PC12 cells) to 50 Hz magnetic fields at extremely high levels - up to 1000 microteslas, which is 10,000 times stronger than typical background exposure. They tested both healthy cells and chemically-stressed cells that were more vulnerable to damage. The study found no toxic effects on the nerve cells' calcium balance, oxidative stress levels, or cell membrane integrity, even at these extraordinarily high exposure levels.
Salunke BP, Umathe SN, Chavan JG. · 2014
Researchers exposed mice to 50 Hz magnetic fields from power lines for 8 hours daily up to 120 days. The mice developed obsessive-compulsive behaviors and showed increased nitric oxide levels in brain regions controlling behavior, suggesting power-frequency fields can alter brain chemistry.
Jin YB et al. · 2014
Researchers exposed four different types of human and mouse cells to 60 Hz magnetic fields (the same frequency as power lines) for 4 to 16 hours, both alone and combined with known DNA-damaging agents like radiation and hydrogen peroxide. They found no DNA damage from the magnetic field exposure alone, and the magnetic fields did not make other DNA-damaging agents more harmful. This suggests that power-frequency magnetic fields at 1 milliTesla may not directly damage cellular DNA.
de Groot MW, Kock MD, Westerink RH. · 2014
Dutch researchers exposed nerve cells (PC12 cells) to 50 Hz magnetic fields at levels up to 1,000 microtesla for periods ranging from 30 minutes to 48 hours. They found no effects on calcium levels, oxidative stress, or cell membrane integrity, even in cells that had been chemically stressed to make them more vulnerable. The exposure levels were 10,000 times higher than typical background magnetic field exposure.
Reale M et al. · 2014
Scientists exposed human brain cells to 50 Hz electromagnetic fields from power lines for 24 hours. The EMF exposure caused cellular damage and weakened the cells' natural defense systems, especially when cells were already stressed, suggesting potential links to brain degeneration.
Alsaeed I et al. · 2014
Researchers exposed pregnant mice and their newborn pups to 50 Hz magnetic fields (the same frequency as household electrical systems) during critical developmental periods. The exposed male mice later showed autism-like behaviors, including reduced social interaction and less interest in exploring new social situations, while their movement, coordination, and other basic functions remained normal. This suggests that magnetic field exposure during early brain development might contribute to autism spectrum disorders.
Salunke BP, Umathe SN, Chavan JG · 2014
Researchers exposed mice to 50 Hz magnetic fields (power line frequency) for 8 hours daily up to 120 days. This caused obsessive-compulsive behaviors by increasing nitric oxide levels in brain regions. The study suggests household electrical frequencies may affect brain chemistry and behavior.