6,486 Studies Reviewed. 85.2% of Original Studies 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:

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

Showing 486 studies with measured magnetic fields (elf) exposure

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 investigated the effects of 100 and 217 Hz extremely low-frequency pulsed electromagnetic fields on cell proliferation, actin reorganization, and ROS generation in human breast carcinoma cells (T47D). Cells were exposed for 24-72 h, at 100 and 217 Hz, 0.1 mT. The treatment induced a time dependent decrease in cell growth after 72 h and revealed an increase in fluorescence intensity in cytoplasm and actin aggregations around the nucleus as detected by fluorescence microscopy. Exposure to 217 Hz for 72 hours caused a dramatic increase in intracellular ROS generation, while exposure to 100 Hz left ROS nearly unchanged.

Study of the frequency parameters of EEG influenced by zone-dependent local ELF-MF exposure on the human head.

Shafiei SA et al. · 2012

Researchers exposed different parts of the brain to extremely low-frequency magnetic fields locally and investigated EEG power spectrum changes at the frequency of stimulation. EEG relative power spectrum was evaluated at 3, 5, 10, 17, and 45 Hz frequencies at T4, T3, F3, Cz, and F4 points, when those points were exposed to magnetic fields at similar frequencies and 100 μT intensity. EEG power did not change significantly at the frequency of stimulation, but significant changes were observed in different EEG bands.

Effects of acute and chronic low frequency electromagnetic field exposure on PC12 cells during neuronal differentiation

Morabito C, Guarnieri S, Fanò G, Mariggiò MA · 2010

Researchers studied how extremely low frequency electromagnetic fields (ELF-EMFs) of different intensities and durations affected PC12 cells, a cell line used as a neuronal model, during neuronal differentiation. Long-lasting ELF-EMF exposure did not appear to significantly affect proliferation or neuritogenesis. During acute exposure lasting 30 minutes, ROS levels were increased and catalase activity was decreased in undifferentiated PC12 cells, while chronic exposure at 1.0 mT increased catalase activity. Acute exposure affected spontaneous intracellular calcium variations, and basal intracellular calcium was increased after chronic exposure.

Effects of Extremely Low-Frequency Magnetic Field on Caspase Activities and Oxidative Stress Values in Rat Brain

Akdag MZ, Dasdag S, Ulukaya E, Uzunlar AK, Kurt MA, Taşkin A · 2010

Researchers exposed rats to extremely low-frequency magnetic fields for 2 hours per day for 10 months, then measured apoptosis and oxidative stress markers in brain tissue. Apoptosis scores and MPO activity were not significantly different between the exposed and sham groups. MDA, TOS, and OSI values were found to be higher in the ELF-500 group than in the ELF-100 and sham groups, and total antioxidative capacity was lower in the ELF-500 group.

Oxidative StressNo Effects Found

A Study on the effects of 50 Hz magnetic fields on UV-induced radical reactions in murine fibroblasts.

Markkanen A, Naarala J, Juutilainen J · 2010

Murine L929 fibroblast cells were exposed to 50 Hz magnetic fields of 100 or 300 μT during or before UV exposure. No significant magnetic field effects were found, and the results did not support the hypothesis that such fields modify biological responses to UV radiation by changing oxidative reactions.

Effects of extremely low-frequency magnetic field on caspase activities and oxidative stress values in rat brain.

Akdag MZ et al. · 2010

Researchers exposed rats to extremely low-frequency magnetic fields at levels matching current safety standards for 2 hours daily over 10 months. They found that these exposures significantly increased oxidative stress (cellular damage from free radicals) and weakened the brain's natural antioxidant defenses, though they didn't trigger cell death. This suggests that even magnetic field exposures within current safety limits may cause harmful biochemical changes in brain tissue over time.

Modulation of redox status and calcium handling by extremely low frequency electromagnetic fields in C2C12 muscle cells: A real-time, single-cell approach.

Morabito C et al. · 2010

Researchers used C2C12 cells as an in vitro model of the skeletal muscle phenotype to study the effects of short-term exposure to extremely low frequency electromagnetic fields on muscle cell differentiation and function. ELF-EMFs induced reactive oxygen species production in myoblasts and myotubes with a concomitant decrease in mitochondrial membrane potential. The cellular detoxification system was activated, with increases in catalase and glutathione peroxidase activities. ELF-EMFs also altered intracellular calcium homeostasis, increasing the spontaneous activity of myotubes and enhancing cellular reactivity to a depolarizing agent or an agonist of intracellular store calcium channels.

Fifty hertz extremely low-frequency magnetic field exposure elicits redox and trophic response in rat-cortical neurons.

Di Loreto S et al. · 2009

Researchers investigated the effects of exposures to two different 50 Hz sinusoidal ELF magnetic field intensities, 0.1 and 1 mT, on maturing rat cortical neurons. Exposure positively affected cell viability and reduced apoptotic death, with no significant effects on the main antioxidative defences. Linear regression analysis suggested a positive correlation between reduced glutathione and ROS levels in 1 mT magnetic-field-exposed cells. The researchers also observed brain-derived neurotrophic factor over-expression and interleukin 1β-dependent regulation of pro-survival signaling pathways following exposure.

Chronic exposure to 50 Hz magnetic fields causes a significant weakening of antioxidant defence systems in aged rat brain

Falone S et al. · 2008

Researchers continuously exposed female Sprague-Dawley rats to a sinusoidal 50 Hz, 0.1 mT magnetic field for 10 days. The study examined antioxidant protection systems and neurotrophic support in brain cortices, as a function of the age of the subjects. Exposure significantly affected antioxidant capability in both young and aged animals, but in opposite ways. The researchers suggested that exposure to these fields may act as a risk factor for oxidative stress-based nervous system pathologies associated with ageing.

Nonlinear EEG activation evoked by low-strength low-frequency magnetic fields.

Carrubba S, Frilot C, Chesson AL, Marino AA. · 2007

Researchers exposed eight people to weak 60 Hz magnetic fields (1 gauss) for 2 seconds and measured their brain activity using specialized electrodes. They discovered that human brains can detect these low-level magnetic fields and respond in complex, nonlinear ways that standard testing methods miss. This suggests humans may have an evolutionary magnetic sensing ability that makes us vulnerable to artificial electromagnetic fields in our environment.

Pulsed magnetic fields enhance nitric oxide synthase activity in rat cerebellum

Noda Y, Mori A, Liburdy RP, Packer L · 2000

Researchers investigated the effect of pulsed magnetic fields on nitric oxide synthase (NOS) activity in the rat brain. A significant increase in NOS activity was observed in the cerebellum at 111.2±2.0% (P<0.05) for a 1 Gauss (0.1 mT) pulsed DC field, across five separate experiments. Neither AC nor static DC field treatment showed any significant change in NOS activity. In the hippocampus, cortex, medulla oblongata, hypothalamus, striatum, and midbrain, only a slight change or no effect was observed.

Oxidative Stress129 citations

The phorbol 12-myristate 13-acetate (PMA)-induced oxidative burst in rat peritoneal neutrophils is increased by a 0.1 mT (60 Hz) magnetic field.

Roy S et al. · 1995

Researchers investigated whether a low-frequency, low-intensity magnetic field could affect the oxidative burst triggered by PMA in rat peritoneal neutrophils. In the presence of the magnetic field, a 12.4% increase in the fluorescence signal was observed in PMA-stimulated neutrophils (n = 5, P < 0.02, 18 pairs of measurements). The researchers described this as what they believed to be the first experimental observation of a magnetic field influencing free radical species generated during signal transduction in living cells.

On the Etiology of Disorders Caused by Combined Ultrahigh Frequency Electromagnetic Waves

Petrov IR · 1968

The study examined disorders caused by combined ultrahigh frequency electromagnetic waves, using measurement of electromagnetic fields, biological monitoring, and epidemiological approaches. Effects were observed in human subjects and animal models. Exposure to these fields was found to lead to changes in biological systems, including alterations in cellular and molecular structures. Specific findings included impacts on nervous system function, DNA damage, and other physiological responses.