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 A 60 Hz Magnetic Field of Up to 50 milliTesla on Human Tremor and EEG: A Pilot Study.

Davarpanah Jazi S, Modolo J, Baker C, Villard S, Legros A. · 2017

Ten healthy volunteers were exposed to 11 MF conditions (60 Hz, 0 to 50 mTrms, 5 mTrms increments) while physiological tremor and EEG from motor and somatosensory brain regions were measured. Exposure had no significant effect on any physiological tremor characteristics, and no significant EEG effects were observed for electrodes C1, C3, C5 and CP1. At electrodes CP3 and CP5, a decreased mu-rhythm spectral power with increasing MF flux density was suggested, but this was not confirmed by Bonferroni corrected pairwise comparisons.

Magnetoreception Regulates Male Courtship Activity in Drosophila.

Wu CL, Fu TF, Chiang MH, Chang YW, Her JL, Wu T. · 2016

Researchers found that male Drosophila exposed to a static magnetic field of at least 20 Gauss showed significantly increased courtship activity compared with behavior in the natural environment at 0 Gauss. This increase in courtship activity depended on the photoreceptor cryptochrome, as flies lacking CRY did not show an increased courtship index in a magnetic field. Restoring CRY expression in CRY-deficient flies brought back the magnetic-field-related increase in male courtship index.

In vitro developmental neurotoxicity following chronic exposure to 50 Hz extremely low frequency electromagnetic fields (ELF-EMF) in primary rat cortical cultures.

de Groot MW, van Kleef RG, de Groot A, Westerink RH · 2015

Researchers exposed primary rat cortical neurons for 7 days to 50 Hz ELF-EMF at field strengths ranging from 0 to 1000 μT, then measured cell viability, calcium levels, neurite outgrowth, and spontaneous neuronal activity. Cell viability was not affected by exposure across the full range tested, and neuronal activity appeared largely unaltered. The researchers concluded that chronic ELF-EMF exposure has only limited neurotoxic potential in vitro.

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

van Nierop LE et al. · 2012

Researchers exposed 31 healthy volunteers to magnetic fields from a 7 Tesla MRI scanner while they performed cognitive tests. They found that attention, concentration, and spatial orientation abilities declined significantly when people moved their heads in these strong magnetic fields. The effects were dose-dependent, with stronger magnetic fields causing greater impairment in brain function.

Effects of Low-Frequency Electromagnetic Field on Oxidative Stress in Selected Structures of the Central Nervous System.

Budziosz J et al. · 2018

Researchers exposed male Wistar rats to an electromagnetic field with a frequency of 50 Hz, intensity of 10 kV/m, and magnetic induction of 4.3 pT for 22 hours a day to evaluate oxidative stress in central nervous system structures. Mean malondialdehyde levels and total oxidant status in the CNS structures did not differ significantly between the experimental and control groups. Antioxidant enzyme activities in brain structure homogenates were decreased, with the exception of frontal cortex catalase, glutathione peroxidase, and hippocampal glutathione reductase.

Neurodevelopmental anomalies of the hippocampus in rats exposed to weak intensity complex magnetic fields throughout gestation.

Fournier NM, Mach QH, Whissell PD, Persinger MA. · 2012

Researchers exposed pregnant rats to different intensities of complex magnetic fields throughout pregnancy to study brain development effects. They found that exposure to low-intensity magnetic fields (30-50 nanotesla) caused permanent damage to the hippocampus - the brain region crucial for learning and memory - and impaired fear learning behavior in the offspring. Surprisingly, weaker and stronger magnetic field exposures didn't cause these problems, suggesting a specific vulnerability window.

Extra-low-frequency magnetic fields alter cancer cells through metabolic restriction

Ying Li and Paul Heroux · 2014

Researchers exposed five cancer cell lines to extra-low-frequency magnetic fields in the range of 0.025 to 5 µT and examined them for karyotype changes after 6 days. All cancer cell lines lost chromosomes from magnetic field exposure, with a mostly flat dose-response. The researchers suggest these karyotype contractions are caused by magnetic field interference with mitochondria's adenosine triphosphate synthase, compensated by the action of adenosine monophosphate-activated protein kinase. Constant magnetic field exposures for three weeks allowed a rising return to baseline, unperturbed karyotypes, but small increases or decreases in field strength were again capable of inducing karyotype contractions.

Whole Body / General
Not an original health-effects study

Occupational exposure to intermediate frequency and extremely low frequency magnetic fields among personnel working near electronic article surveillance systems.

Roivainen P, Eskelinen T, Jokela K, Juutilainen J · 2014

Researchers measured intermediate frequency and extremely low frequency magnetic fields at cashiers' seats in Finnish stores. At the cashier's seat, IF magnetic fields ranged from 0.2 to 4 µT and ELF magnetic fields ranged from 0.03 to 4.5 µT, both well below exposure limits. However, when cashiers walked through EAS gates, peak IF fields reached up to 189 µT, exceeding the ICNIRP occupational reference level of 141 µT.

Influence of electromagnetic field (1800 MHz) on lipid peroxidation in brain, blood, liver and kidney in rats

Bodera P et al. · 2015

Researchers measured malondialdehyde (MDA), a marker of lipid peroxidation, in the blood, liver, kidneys, and brain of Wistar rats that were healthy or had inflammation, and exposed them repeatedly to 1800 MHz EMF. The exposure was repeated five times for 15 minutes and was studied both alone and combined with the opioid painkiller tramadol. MDA levels were slightly elevated in the blood, kidney, and brain of healthy rats in EMF-exposed groups treated with tramadol, while MDA in the liver remained at the same level across all groups. Overall, results for healthy rats and animals with inflammation did not differ significantly.

Suppressive effect of electromagnetic field on analgesic activity of tramadol in rats

Bodera P et al. · 2012

Researchers studied how high-frequency electromagnetic fields affect pain perception and the pain-relieving activity of tramadol in rats. Exposures at 1500 MHz and modulated 1800 MHz were applied, and paw withdrawal latency to a thermal stimulus was measured before and after injections of either tramadol or a vehicle. EMF exposure alone produced no differences in pain perception compared with controls, but EMF at both frequencies transiently suppressed the analgesic effect of tramadol at 30 minutes after drug injection.

Effect of weak combined static and extremely low-frequency alternating magnetic fields on spatial memory and brain amyloid-β in two animal models of Alzheimer's disease.

Bobkova NV et al. · 2018

Researchers studied the effects of a weak combined magnetic field on spatial memory and brain amyloid-β in two mouse models of Alzheimer's disease. Exposure to the magnetic fields for 4 hours per day for 10 days decreased amyloid-β levels in the brains of OBE mice and reduced the number of amyloid-β plaques in the cortex and hippocampus of transgenic mice. Memory improvement was seen in transgenic mice only, not in OBE animals.

Neoplastic transformation of C3H/10T1/2 cells following exposure to 120-Hz modulated 2.45-GHz microwaves and phorbol ester tumor promoter.

Balcer-Kubiczek EK, Harrison GH. · 1991

Researchers exposed actively growing cultures of C3H/10T1/2 cells for 24 hours to 2.45-GHz microwaves pulse-modulated at 120 Hz. The electromagnetic fields alone had no effect on cell survival or induction of neoplastic transformation. When combined with the tumor promoter TPA, the enhancement of transformation was highly significant and ranged up to a level equivalent to that produced by 1.5 Gy of X rays. The frequency of neoplastic transformation was dependent on the level of electromagnetic exposure and was additive with doses of X rays given as a cocarcinogen.

Occupational exposure to extremely low-frequency magnetic fields and risk for central nervous system disease: an update of a Danish cohort study among utility workers.

Pedersen C et al. · 2017

Researchers investigated risks for several central nervous system diseases among 32,006 men employed at 99 utility companies that supplied Denmark with electricity during 1900–1993. The cohort was followed during 1982–2010, and cases were identified in the Danish National Patient Registry. For the highest exposure level of 1.0 µT or more, incidence rate ratios of 1.44, 1.78, 1.40 and 1.34 were observed for dementia, motor neurone disease, multiple sclerosis and epilepsy, respectively. Risk for Parkinson disease was lower among workers exposed to ≥0.1 µT compared with the Danish population (IRR 0.81, 95% CI 0.67–0.97).

Brain & Nervous SystemNo Effects Found

Magnetoreception in the wood mouse (Apodemus sylvaticus): influence of weak frequency-modulated radio frequency fields.

Malkemper EP et al. · 2015

The researchers tested the wood mouse Apodemus sylvaticus for magnetoreception using a simple behavioural assay in which mice were allowed to build nests overnight in a visually symmetrical, circular arena. When plotted with respect to magnetic north, the nests were bimodally clustered in the northern and southern sectors, indicating the animals used magnetic cues. Wood mice exposed to a 0.9 to 5 MHz frequency sweep changed their preference from north-south to east-west. A constant frequency field tuned to the Larmor frequency (1.33 MHz) had no effect on mouse orientation. The study demonstrated magnetoreception in wood mice and provided first evidence for a radical-pair mechanism in a mammal.

Using medaka embryos as a model system to study biological effects of the electromagnetic fields on development and behavior

Lee W, Yang KL · 2014

Researchers used medaka fish embryos (Oryzias latipes) to study how electromagnetic fields affect development and behavior. Newly fertilized embryos were randomly assigned to groups exposed to an EMF at 3.2 kHz at intensities of 0.12, 15, 25, or 60 µT, with the 0.12 µT group serving as the control. Embryos exposed to all three EMF levels developed significantly faster across several endpoints, including somite number, eye dimensions, eye pigmentation density, midbrain width, head growth, and day to hatch. The group exposed to 60 µT showed significantly higher levels of anxiety-like behavior than the other groups.