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

Role of Sod Gene in Response to Static Magnetic Fields in Pseudomonas aeruginosa

Hanini R, Chatti A, Ghorbel SB, Landoulsi A. · 2017

Researchers exposed bacteria (Pseudomonas aeruginosa) to a static magnetic field of 200 mT and found that strains lacking protective antioxidant enzymes suffered significantly more cellular damage than normal strains. The magnetic field exposure increased oxidative stress markers and triggered the bacteria's natural defense systems, with weaker strains showing higher levels of cellular damage. This demonstrates that even static magnetic fields can cause biological stress that cells must actively defend against.

Mercury release from dental amalgam restorations after magnetic resonance imaging and following mobile phone use

Mortazavi SM et al. · 2008

Researchers tested whether electromagnetic fields from MRI machines and mobile phones increase mercury release from dental fillings. They found that 30-minute MRI exposure increased mercury levels in saliva by 31%, and mobile phone use significantly increased mercury in urine compared to controls. This suggests that common EMF exposures may accelerate the release of toxic mercury from dental amalgam fillings.

Biochemical and biomolecular effects induced by a static magnetic field in Saccharomyces cerevisiae: Evidence for oxidative stress.

Kthiri A, Hidouri S, Wiem T, Jeridi R, Sheehan D, Landouls A · 2019

Researchers exposed baker's yeast (Saccharomyces cerevisiae) to a strong static magnetic field of 250 millitesla for 6 to 9 hours to study biological effects. They found the magnetic field initially reduced yeast growth and survival, then triggered oxidative stress - a harmful cellular condition where damaging molecules overwhelm the cell's natural defenses. The study demonstrated that even simple organisms like yeast respond to magnetic field exposure with measurable biological changes.

Static Magnetic Field Stimulation Enhances Oligodendrocyte Differentiation and Secretion of Neurotrophic Factors.

Prasad A et al. · 2017

Researchers exposed brain cells called oligodendrocytes to a moderate-strength magnetic field (0.3 Tesla) for two hours daily over two weeks. The magnetic field exposure enhanced the cells' ability to mature and produce protective substances for nerve fibers, while also increasing their release of growth factors that help brain cells survive and function. This suggests that certain magnetic field exposures might actually support brain cell health and repair processes.

Behavioural profile of Wistar rats with unilateral striatal lesion by quinolinic acid (animal model of Huntington disease) post-injection of apomorphine and exposure to static magnetic field.

Giorgetto C et al. · 2015

Researchers exposed rats with brain lesions (modeling Huntington's disease) to 3,200 Gauss static magnetic fields for seven days. Magnetic field exposure preserved brain neurons and improved movement compared to untreated rats, suggesting static magnetic fields may help brain healing in neurological conditions.

Neuropathology and behavioral impairments in Wistar rats with a 6-OHDA lesion in the substantia nigra compacta and exposure to a static magnetic field.

Bertolino G, Dutra Souza HC, de Araujo JE. · 2013

Researchers exposed rats with chemically-induced brain damage (mimicking Parkinson's disease) to static magnetic fields of 3200 gauss for 14 days. The magnetic field exposure helped preserve neurons in the brain region affected by Parkinson's and improved motor function compared to rats that didn't receive magnetic treatment. This suggests static magnetic fields might have therapeutic potential for protecting brain cells from neurodegenerative damage.

Extremely low frequency magnetic fields regulate differentiation of regulatory T cells: Potential role for ROS-mediated inhibition on AKT

Tang R, Xu Y, Ma F, Ren J, Shen S, Du Y, Hou Y, Wang T · 2016

Researchers exposed mice with lung cancer to extremely low frequency magnetic fields (7.5 Hz, 0.4 Tesla) for 2 hours daily over 27 days and found the treatment significantly reduced tumor spread in the lungs. The magnetic fields worked by altering immune cell behavior - specifically reducing regulatory T cells (immune cells that normally suppress anti-tumor responses) and increasing cellular stress molecules called reactive oxygen species. This suggests that certain magnetic field exposures might enhance the body's natural ability to fight cancer by modifying immune system function.

Effect of a static magnetic fields and fluoride ions on the antioxidant defense system of mice fibroblasts.

Kurzeja E et al. · 2013

Researchers exposed mouse cells to static magnetic fields while also treating them with fluoride (a known toxic substance). They found that magnetic field exposure actually helped protect the cells from fluoride damage by reducing oxidative stress and normalizing antioxidant enzymes. The magnetic fields appeared to improve cellular energy production and reduce harmful cellular byproducts.

Effects of magnetic stray fields from a 7 Tesla MRI scanner on neurocognition: a double-blind randomised crossover study.

van Nierop LE et al. · 2011

Researchers tested 31 healthy volunteers in a double-blind study to see how magnetic fields from a 7 Tesla MRI scanner affected brain function. They found that exposure to these magnetic fields impaired attention, concentration, and spatial orientation by 5% to 47% depending on the field strength. This demonstrates that even temporary exposure to strong magnetic fields can measurably affect cognitive performance.

Simultaneous exposure to MRI-related static and low-frequency movement-induced time-varying magnetic fields affects neurocognitive performance: A double-blind randomized crossover study.

van Nierop LE, Slottje P, van Zandvoort M, Kromhout H. · 2014

Researchers exposed 36 healthy volunteers to magnetic fields from a 7 Tesla MRI scanner to test effects on brain function. They found that exposure to both static magnetic fields (1.0 Tesla) combined with time-varying fields created by head movement significantly impaired verbal memory and visual acuity, while static fields alone had no effect. This suggests that movement within strong magnetic fields may be particularly problematic for cognitive performance.

Cellular ATP content was decreased by a homogeneous 8.5 T static magnetic field exposure: role of reactive oxygen species.

Zhao G et al. · 2011

Scientists exposed human cells to extremely powerful magnetic fields (8.5 Tesla) and found cellular energy production dropped significantly while harmful molecules increased. The strongest magnetic fields disrupted the cells' ability to make energy, suggesting very intense magnetic exposure could interfere with basic cellular functions.

Magnetic field-induced oxidative stress and DNA damage in Mediterranean flour moth Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) larvae

Pandir D, Sahingoz R · 2014

Researchers exposed Mediterranean flour moth larvae to extremely strong magnetic fields (1.4 Tesla at 50 Hz) for periods ranging from 3 to 72 hours and found significant DNA damage and oxidative stress. The longer the exposure, the more severe the genetic damage and cellular stress became, as measured by multiple biochemical markers. This study demonstrates that magnetic field exposure can cause measurable biological harm at the cellular level.

Change of nitric oxide concentration in men exposed to a 1.5 T constant magnetic field

Sirmatel O, Sert C, Tümer C, Oztürk A, Bilgin M, Ziylan Z · 2007

Researchers exposed 33 healthy young men to the strong magnetic field from an MRI machine (1.5 Tesla) for 30 minutes and measured changes in nitric oxide, a molecule that helps regulate blood flow and cellular function. They found that nitric oxide levels increased significantly after the magnetic field exposure compared to before. This suggests that even brief exposure to strong magnetic fields can trigger measurable biological changes in the body.

Total antioxidant capacity, total oxidant status and oxidative stress index in the men exposed to 1.5 T static magnetic field.

Sirmatel O, Sert C, Sirmatel F, Selek S, Yokus B · 2007

Researchers exposed 33 men to the strong magnetic field from an MRI machine (1.5 Tesla) and measured markers of oxidative stress in their blood before and after exposure. Surprisingly, they found that the magnetic field actually reduced oxidative stress by increasing the body's antioxidant capacity and decreasing harmful oxidants. This suggests that short-term exposure to strong static magnetic fields may have protective rather than harmful effects on cellular health.

Genotoxic effects of 3 T magnetic resonance imaging in cultured human lymphocytes.

Lee JW, Kim MS, Kim YJ, Choi YJ, Lee Y, Chung HW. · 2011

Researchers exposed human immune cells (lymphocytes) to electromagnetic fields from clinical 3 Tesla MRI scanners for different time periods, from 22 to 89 minutes. They found that longer exposures caused increasing levels of DNA damage, including single-strand breaks and chromosome abnormalities. This suggests that the powerful electromagnetic fields used in high-strength MRI machines may pose genetic risks that increase with exposure time.

Effects of low-field magnetic stimulation on brain glucose metabolism.

Volkow ND et al. · 2010

Researchers exposed 15 healthy people to pulsed magnetic fields (920 Hz) while measuring brain glucose metabolism using PET scans. They found that areas of the brain exposed to stronger electric fields showed decreased metabolic activity compared to unexposed areas. The stronger the field, the greater the reduction in brain metabolism, suggesting that electromagnetic fields can directly alter brain function.

DNA & Genetic DamageNo Effects Found

Bacterial mutation in high magnetic fields and radiofrequency radiation

Mineta M et al. · 1999

Japanese researchers exposed bacteria commonly used in genetic testing to extremely strong magnetic fields (6.3 Tesla) combined with radiofrequency radiation similar to what's found in MRI machines for up to one hour. They found no increase in genetic mutations compared to unexposed bacteria, suggesting that MRI-level electromagnetic exposures don't cause DNA damage in this bacterial model.