3,138 Studies Reviewed. 77.4% 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

Exposure to an additional alternating magnetic field affects comb building by worker hornets.

Ishay JS et al. · 2007

Researchers exposed worker hornets to weak 50 Hz magnetic fields (similar to power line frequency) for two weeks and found dramatic disruptions in their natural building behavior. The exposed hornets built 35-55% fewer cells, created deformed hexagonal structures, and produced more fragile comb stems compared to unexposed hornets. This demonstrates that even very low-level magnetic field exposure can interfere with complex biological processes that insects rely on for survival.

Extremely-low-frequency magnetic fields disrupt rhythmic slow activity in rat hippocampal slices

Bawin SM, Satmary WM, Jones RA, Adey WR, Zimmerman G. · 1996

Scientists exposed rat brain tissue to extremely low frequency magnetic fields at power line frequencies (1-60 Hz). Fields at 56 and 560 microtesla disrupted normal brain rhythms linked to memory, but only when specific brain chemicals were present. This shows magnetic fields can interfere with brain function.

Project NEMESIS: perception of a 50 Hz electric and magnetic field at low intensities (laboratory experiment)

Mueller CH, Krueger H, Schierz C · 2002

Researchers tested 63 people to see if they could detect weak electrical fields from household wiring. Seven participants could reliably sense these fields during blind testing, but having electromagnetic sensitivity symptoms didn't predict detection ability, suggesting perception and symptoms are separate phenomena.

Extremely low frequency electromagnetic fields activate the ERK cascade, increase hsp70 protein levels and promote regeneration in Planaria

Reba Goodman et al. · 2009

Researchers exposed flatworms (planaria) to 60 Hz magnetic fields at 80 milliGauss for one hour twice daily during regeneration after being cut in half. The EMF-exposed worms regenerated faster than unexposed controls, with tail portions growing eyes 48 hours earlier and showing increased levels of stress proteins typically associated with healing and repair processes.

Myocardial function improved by electromagnetic field induction of stress protein hsp70.

George I et al. · 2008

Researchers exposed rats to extremely low frequency magnetic fields (60 Hz at 8 microTesla) for 30 minutes before inducing heart attacks, then measured heart function recovery. The electromagnetic field exposure triggered production of a protective protein called HSP70, which significantly improved the heart's ability to recover from oxygen deprivation. This suggests that certain EMF exposures might actually help protect heart tissue from damage during cardiac events.

Chronic electromagnetic field exposure decreases HSP70 levels and lowers cytoprotection.

Di Carlo A, White N, Guo F, Garrett P, Litovitz T. · 2002

Researchers exposed chick embryos to electromagnetic fields (both extremely low frequency and radio frequency) for 4 days and found that chronic exposure reduced levels of HSP70, a protective protein that helps cells survive stress. The EMF exposure made the embryos 27% less able to protect themselves against cellular damage. This suggests that daily EMF exposure, like what mobile phone users experience, could weaken the body's natural defense systems and potentially increase disease risk.

Effects of extremely low frequency electromagnetic fields on turkeys.

Laszlo AM et al. · 2018

Researchers exposed turkeys to 50 Hz magnetic fields (the type from power lines) for three weeks and found it disrupted their stress response system by reducing a key cellular signaling pathway called beta-adrenoceptor function. The birds' systems returned to normal after five weeks without exposure, suggesting the effects were reversible. This matters because it shows even relatively low-level magnetic field exposure can alter fundamental biological processes in living animals.

DNA & Genetic DamageNo Effects Found

No evidence of DNA damage by co-exposure to extremely low frequency magnetic fields and aluminum on neuroblastoma cell lines

Villarini M et al. · 2017

Italian researchers exposed brain cancer cells (neuroblastoma) to 50 Hz magnetic fields and aluminum compounds, both separately and together, to see if they would cause DNA damage. After exposing the cells to magnetic field levels ranging from 0.01 to 1 mT for up to 5 hours, they found no DNA damage, no changes in cellular stress markers, or any harmful synergistic effects when the exposures were combined. This suggests that short-term exposure to these power-frequency magnetic fields, even in combination with aluminum, does not appear to damage DNA in these particular brain cell types.

Induction of micronuclei and superoxide production in neuroblastoma and glioma cell lines exposed to weak 50 Hz magnetic fields.

Kesari KK, Juutilainen J, Luukkonen J, Naarala J. · 2016

Researchers exposed brain cells to extremely low frequency magnetic fields (the type from power lines) at levels as low as 10 microtesla for 24 hours. The study found significant DNA damage in human neuroblastoma cells and increased oxidative stress in rat brain cells. These effects occurred at magnetic field levels that are commonly encountered near electrical appliances and power infrastructure.

The effect of electromagnetic field on reactive oxygen species production in human neutrophils in vitro.

Poniedzialek B et al. · 2013

Polish researchers exposed human immune cells called neutrophils to extremely low frequency magnetic fields at three different strengths (10, 40, and 60 microTesla) to see how it affected their production of reactive oxygen species - molecules that can damage cells. They found that only magnetic fields tuned to a specific frequency that affects calcium ions could change how these immune cells behaved, with the effect depending on the field strength.

Magnetic-field-induced DNA strand breaks in brain cells of the rat.

Lai H, Singh NP · 2004

Researchers exposed rats to extremely low-frequency magnetic fields (the type from power lines) at levels commonly found in homes and workplaces. After 24-48 hours of exposure, they found significant DNA damage in brain cells, with longer exposure causing more damage. The study suggests this damage occurs through iron-mediated free radical formation, potentially leading to brain cell death.

Provocation study of persons with perceived electrical hypersensitivity and controls using magnetic field exposure and recording of electrophysiological characteristics.

Lyskov E, Sandström M, Mild KH · 2001

Researchers exposed 20 people with electromagnetic hypersensitivity and 20 healthy controls to magnetic fields while monitoring their bodies. Magnetic fields didn't affect either group, but hypersensitive individuals showed different heart rate and stress patterns, suggesting they may have heightened sensitivity to environmental stressors generally.

Behavioral testing of mice exposed to intermediate frequency magnetic fields indicates mild memory impairment.

Kumari K et al. · 2017

Researchers exposed mice to intermediate frequency magnetic fields (7.5 kHz) for 5 weeks and tested their learning and memory abilities. Mice exposed to higher field levels showed impaired memory performance and increased brain inflammation markers. This suggests that magnetic fields from common sources like induction cooktops and security systems may affect cognitive function.

RF exposure during use of electrosurgical units Electromag.

Liljestrand B, Sandström M, Hansson Mild K. · 2003

Researchers measured radiofrequency (RF) electromagnetic fields around electrosurgical units (devices used in surgery to cut and seal tissue) operating at 0.3-1 MHz frequencies. They found that surgeons' hands are exposed to electric fields exceeding 15,000 volts per meter and magnetic fields of 16 microtesla during typical use. These exposure levels are 25 times higher for electric fields and 4 times higher for magnetic fields than international safety guidelines recommend.

Exposure to extremely low-frequency magnetic field restores spinal cord injury-induced tonic pain and its related neurotransmitter concentration in the brain.

Kumar S et al. · 2013

Researchers exposed rats with spinal cord injuries to extremely low-frequency magnetic fields (50 Hz, similar to power lines) for 2 hours daily over 8 weeks. They found that this exposure helped restore normal pain responses and brain chemistry that had been disrupted by the spinal injuries. The magnetic field treatment appeared to normalize levels of key brain chemicals like serotonin and GABA that control pain perception.

Effect of magnetic field on food and water intake and body weight of spinal cord injured rats.

Kumar S, Jain S, Behari J, Avelev VD, Mathur R. · 2010

Researchers exposed rats with spinal cord injuries to extremely low frequency magnetic fields (50 Hz, 17.9 microT) for 2 hours daily over 8 weeks. The magnetic field exposure restored normal food intake, water consumption, and body weight in the paralyzed rats, all of which had decreased after their spinal cord injuries. This suggests that specific magnetic field frequencies might help support basic physiological functions in spinal cord injury patients.

Extremely low frequency magnetic field protects injured spinal cord from the microglia- and iron-induced tissue damage.

Dey S, Bose S, Kumar S, Rathore R, Mathur R, Jain S. · 2017

Researchers exposed rats with severed spinal cords to extremely low frequency magnetic fields (50 Hz at 17.96 µT) for 2 hours daily over 8 weeks. The magnetic field treatment significantly improved locomotion and reduced inflammation, tissue damage, and iron buildup at the injury site compared to untreated injured rats. This suggests that certain EMF exposures might actually help the nervous system heal from traumatic injuries.

Exposure to extremely low-frequency magnetic field restores spinal cord injury-induced tonic pain and its related neurotransmitter concentration in the brain

Kumar S et al. · 2013

Researchers exposed rats with spinal cord injuries to extremely low-frequency magnetic fields (50 Hz, similar to power line frequencies) for 2 hours daily over 8 weeks. The magnetic field exposure restored normal pain responses and corrected abnormal brain chemical levels that had developed after the spinal injury. This suggests that specific EMF exposures might have therapeutic potential for certain neurological conditions.

Effect of extremely low frequency magnetic field in prevention of spinal cord injury-induced osteoporosis.

Manjhi J, Kumar S, Behari J, Mathur R. · 2013

Researchers studied whether extremely low frequency magnetic fields could prevent bone loss in rats with spinal cord injuries. They exposed injured rats to 50 Hz magnetic fields (17.96 microTesla) for 2 hours daily over 8 weeks and found the treatment significantly prevented osteoporosis, maintaining bone density and mineral content compared to untreated injured rats. This suggests that specific magnetic field therapy might help preserve bone health after spinal cord injury.

Exposure to ELF- magnetic field promotes restoration of sensori-motor functions in adult rats with hemisection of thoracic spinal cord

Das S, Kumar S, Jain S, Avelev VD, Mathur R. · 2012

Researchers exposed rats with severed spinal cords to extremely low frequency magnetic fields (50 Hz at 17.96 microTesla) for 2 hours daily over 6 weeks. The magnetic field exposure significantly accelerated recovery of movement, sensation, and bladder control compared to untreated injured rats. This suggests that specific EMF exposures might actually promote nerve healing and functional recovery after spinal cord injuries.

Exposure to ELF- magnetic field promotes restoration of sensori-motor functions in adult rats with hemisection of thoracic spinal cord.

Das S, Kumar S, Jain S, Avelev VD, Mathur R. · 2012

Researchers exposed rats with severe spinal cord injuries to extremely low-frequency magnetic fields (50 Hz at 17.96 μT) for 2 hours daily over 6 weeks. The magnetic field exposure significantly accelerated recovery of motor functions, bladder control, and pain responses compared to untreated injured rats. This suggests that specific EMF exposures might have therapeutic potential for spinal cord injury rehabilitation.