8,700 Studies Reviewed. 87.0% Found Biological Effects. The Evidence is Clear.
All Exposure Types

Magnetic Fields (ELF)

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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.

Concern Level Thresholds

Based on Building Biology Institute guidelines (mG (milligauss)):

No Concern
< 0.2 mG
Slight Concern
0.2 – 1 mG
Severe Concern
1 – 5 mG
Extreme Concern
> 5 mG

See where common exposures fall on the scale:

Your RF Exposure in ContextA logarithmic scale showing your reading relative to Building Biology concern thresholds and FCC regulatory limits.Your RF Exposure in ContextNo ConcernSlightSevereExtreme0.215FCC Limit 0.0110,000 mG

Showing 443 studies with measured magnetic fields (elf) exposure

Brain & Nervous SystemNo Effects Found

Short-term effects of extremely low frequency electromagnetic fields exposure on Alzheimer's disease in rats.

Zhang Y, Liu X, Zhang J, Li N. · 2015

Researchers exposed rats to extremely low frequency electromagnetic fields (the type emitted by power lines and electrical devices) for 12 weeks to see if it would affect memory and brain health, particularly markers associated with Alzheimer's disease. They found no changes in the rats' memory performance, brain tissue structure, or levels of amyloid-beta proteins that are linked to Alzheimer's. This suggests that short-term exposure to these fields at the levels tested did not harm cognitive function in this animal model.

Brain & Nervous SystemNo Effects Found

Effects of extremely low frequency electromagnetic fields (100μT) on behaviors in rats.

Lai J et al. · 2015

Researchers exposed adult male rats to 50 Hz magnetic fields at 100 microtesla for 24 weeks and tested their behavior, memory, and brain structure. The study found no effects on anxiety, depression, learning ability, or brain tissue compared to unexposed rats. This suggests that prolonged exposure to this level of extremely low frequency magnetic fields may not cause behavioral or cognitive problems.

The effect of melatonin on the liver of rats exposed to microwave radiation.

Djordjevic B et al. · 2015

Serbian researchers exposed rats to 900 MHz microwave radiation (similar to cell phone frequencies) for 4 hours daily over 20-60 days and found significant liver damage, including increased oxidative stress and cellular damage markers. When rats were also given melatonin supplements, the treatment partially protected against some of the radiation-induced liver damage. This suggests that microwave radiation can harm liver function, but natural antioxidants like melatonin may offer some protection.

DNA & Genetic DamageNo Effects Found

Genomic instability induced by 50Hz magnetic fields is a dynamically evolving process not blocked by antioxidant treatment.

Kesari KK, Luukkonen J, Juutilainen J, Naarala J · 2015

Researchers exposed human brain cells to 50 Hz magnetic fields (the type from power lines) for 24 hours and tracked genetic damage for up to 45 days afterward. They found that the magnetic field exposure caused DNA damage that persisted for at least 30 days, and this damage wasn't prevented by antioxidants, suggesting the fields directly affect cellular genetics rather than just causing oxidative stress.

Pulsed electromagnetic field enhances brain-derived neurotrophic factor expression through L-type voltage-gated calcium channel- and Erk-dependent signaling pathways in neonatal rat dorsal root ganglion neurons

Li Y, Yan X, Liu J, Li L, Hu X, Sun H, Tian J. · 2014

Researchers exposed newborn rat nerve cells to 50 Hz electromagnetic fields for two hours and found increased production of BDNF, a protein essential for nerve growth and brain health. The fields activated specific calcium channels and cellular pathways, demonstrating how electromagnetic exposure directly influences nerve cell function and brain development.

Synaptosomal acetylcholinesterase activity variation pattern in the presence of electromagnetic fields.

Afrasiabi A et al. · 2014

Researchers exposed brain tissue samples from sheep to electromagnetic fields at power line frequencies (50-230 Hz) and found that certain field strengths reduced the activity of acetylcholinesterase, an enzyme that breaks down the brain chemical acetylcholine. This enzyme is crucial for memory, learning, and cognitive function. The findings suggest that EMF exposure could potentially disrupt normal brain chemistry by affecting how neurotransmitters are regulated.

Effects of Electromagnetic Radiation Exposure on Stress-Related Behaviors and Stress Hormones in Male Wistar Rats.

Mahdavi SM, Sahraei H, Yaghmaei P, Tavakoli H. · 2014

Researchers exposed rats to extremely low frequency electromagnetic fields (1 and 5 Hz) for 21 days and measured changes in stress hormones and behavior. They found that these EMF exposures altered key stress hormones - increasing ACTH while decreasing noradrenaline - and changed glucose levels differently depending on frequency. The study demonstrates that even very low frequency electromagnetic fields can disrupt the body's stress response system.

Induction of genomic instability, oxidative processes, and mitochondrial activity by 50Hz magnetic fields in human SH-SY5Y neuroblastoma cells.

Luukkonen J, Liimatainen A, Juutilainen J, Naarala J · 2014

Finnish researchers exposed human brain cells to 50Hz magnetic fields from power lines for 24 hours. The exposure caused lasting genetic damage and cellular stress that persisted for up to 15 days, suggesting common household magnetic fields can trigger long-term harmful effects in cells.

Investigation of EEG changes during exposure to extremely low-frequency magnetic field to conduct brain signals.

Shafiei SA, Firoozabadi SM, Tabatabaie KR, Ghabaee M. · 2014

Researchers exposed different areas of the brain to extremely low-frequency magnetic fields (3-45 Hz) at various intensities and measured changes in brain wave patterns using EEG. They found significant alterations in brain electrical activity, particularly reductions in alpha waves in frontal and central brain regions. The findings suggest these magnetic fields can measurably alter brain function, which the researchers propose could be developed into therapeutic protocols.

Brain & Nervous SystemNo Effects Found

Disturbance of the magnetic field did not affect spatial memory.

Li Y, Zhang C, Song T. · 2014

Researchers exposed rats to 50 Hz magnetic fields at 100 microT (similar to levels near some electrical appliances) for 90 days while testing their spatial memory and learning abilities using a water maze. The magnetic field exposure did not impair the rats' ability to learn or remember spatial tasks, nor did it interfere with improvements from previous training. This suggests that this level of extremely low frequency magnetic field exposure does not harm basic learning and memory functions.

Effects of exposure to an extremely low frequency electromagnetic field on hippocampal long-term potentiation in rat.

Komaki A, Khalili A, Salehi I, Shahidi S, Sarihi A. · 2014

Researchers exposed rats to power line frequency electromagnetic fields (50 Hz) for 90 days and found it enhanced the brain's ability to form memories in the hippocampus. This suggests chronic EMF exposure can alter fundamental brain functions, though long-term health implications remain unknown.

Brain & Nervous SystemNo Effects Found

Short term effects of extremely low frequency electromagnetic fields exposure on Alzheimer's disease in rats.

Zhang Y, Liu X, Zhang J, Li N. · 2014

Researchers exposed rats to extremely low frequency magnetic fields (the same type emitted by power lines and household appliances) for 12 weeks to see if it would cause Alzheimer's-like brain changes. They found no effects on memory, learning ability, or brain proteins associated with Alzheimer's disease. The study suggests that short-term exposure to these magnetic fields at typical environmental levels may not directly cause cognitive problems.

Age-Dependent Effects of ELF-MF on Oxidative Stress in the Brain of Mongolian Gerbils.

Selaković V, Rauš Balind S, Radenović L, Prolić Z, Janać B. · 2013

Researchers exposed young adult and middle-aged gerbils to 50 Hz magnetic fields at three different intensities for seven days, then measured oxidative stress markers in their brains. They found that magnetic field exposure increased oxidative stress in all brain regions tested, with stronger effects at higher field intensities and in older animals. The effects were still detectable three days after exposure ended, particularly in the middle-aged gerbils.

Reproductive HealthNo Effects Found

Can safe and long-term exposure to extremely low frequency (50 Hz) magnetic fields affect apoptosis, reproduction, and oxidative stress?

Akdag MZ et al. · 2013

Researchers exposed rats to 50 Hz magnetic fields (the same frequency as power lines) for 10 months to test effects on sperm health, cell death, and oxidative stress. They found no impact on sperm count or quality, and no oxidative damage at either exposure level tested. However, higher exposure (500 μT) did increase markers of programmed cell death in testicular tissue.

Brain & Nervous SystemNo Effects Found

Extremely Low-Frequency Magnetic Exposure Appears to Have No Effect on Pathogenesis of Alzheimer’s Disease in Aluminum-Overloaded Rat

Zhang C, Li Y, Wang C, Lv R, Song T · 2013

Researchers exposed rats to extremely low frequency magnetic fields (50 Hz at 100 µT) for 12 weeks to test whether EMF exposure could worsen Alzheimer's disease symptoms caused by aluminum poisoning. The magnetic field exposure alone showed no effect on brain health, and it didn't make aluminum-induced brain damage any worse. This suggests that EMF exposure at these levels doesn't contribute to Alzheimer's disease development.

Age-dependent effects of ELF-MF on oxidative stress in the brain of mongolian gerbils.

Selaković V, Rauš Balind S, Radenović L, Prolić Z, Janać B. · 2013

Scientists exposed gerbils to power line frequency magnetic fields for seven days. The exposure increased brain cell damage in all tested regions, with stronger effects in older animals and at higher field strengths. Younger brains recovered better after exposure ended, suggesting age affects vulnerability.

Do 100- and 500-μT ELF magnetic fields alter beta-amyloid protein, protein carbonyl and malondialdehyde in rat brains?

Akdag MZ, Dasdag S, Cakir DU, Yokus B, Kizil G, Kizil M. · 2013

Researchers exposed rats to magnetic fields at levels considered safe by current standards for 10 months. The exposure significantly increased two markers of brain cell damage and aging, suggesting that even "safe" magnetic field levels may cause harmful oxidative stress in brain tissue over time.

Brain & Nervous SystemNo Effects Found

Extremely low-frequency magnetic exposure appears to have no effect on pathogenesis of Alzheimer's disease in aluminum-overloaded rat.

Zhang C, Li Y, Wang C, Lv R, Song T. · 2013

Researchers exposed rats to 50 Hz magnetic fields (the type from power lines) for 12 weeks to see if this exposure would worsen Alzheimer's-like symptoms caused by aluminum poisoning. They found that magnetic field exposure alone had no effect on brain function or Alzheimer's markers, and it didn't make aluminum-induced brain damage any worse. This suggests that power-frequency magnetic fields may not contribute to Alzheimer's disease development.

Effects of extremely low-frequency pulsed electromagnetic fields on morphological and biochemical properties of human breast carcinoma cells (T47D).

Sadeghipour R et al. · 2012

Researchers exposed human breast cancer cells to low-frequency electromagnetic fields and found the EMF slowed cancer cell growth while increasing cellular stress. Higher frequencies (217 Hz) caused more dramatic effects than lower ones (100 Hz), showing cancer cells respond differently to specific EMF frequencies.