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

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

Researchers exposed 10 healthy volunteers to 60 Hz magnetic fields up to 50 milliTesla (extremely high levels) while measuring brain activity and hand tremor. They found subtle changes in brain wave patterns related to touch sensation, but no effects on motor control or hand tremor. The study provides preliminary evidence that power-frequency magnetic fields can influence specific brain regions even when they don't cause obvious physical symptoms.

Magnetoreception Regulates Male Courtship Activity in Drosophila.

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

Researchers exposed male fruit flies to static magnetic fields as low as 20 Gauss (about 40 times Earth's natural magnetic field) and found it significantly increased their courtship behavior. The effect depended on cryptochrome, a protein that helps animals sense magnetic fields and is also found in humans. This study demonstrates that relatively weak magnetic fields can alter behavior through biological magnetic sensing mechanisms.

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

Dutch scientists exposed developing rat brain cells to power line magnetic fields for seven days. They found minimal effects only at extremely high exposures (1000 microtesla) - about 10,000 times stronger than typical home levels. Normal residential exposures showed no significant developmental impacts.

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 rats to power-line frequency electromagnetic fields (50 Hz) for 28 days to study effects on brain oxidative stress, which occurs when harmful molecules damage cells. While overall oxidative stress markers remained unchanged, the study found decreased activity of protective antioxidant enzymes in most brain regions. This suggests that even when obvious damage isn't apparent, the brain's defense systems may be working harder under EMF exposure.

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.

Trends in residential exposure to electromagnetic fields from 2006 to 2009.

Tomitsch J, Dechant E. · 2012

Researchers measured electromagnetic field exposure in bedrooms over a three-year period (2006-2009) to track how our daily EMF exposure is changing. They found that while electric and magnetic fields from power lines decreased slightly, radiofrequency radiation from wireless devices nearly doubled, increasing from 41.35 to 59.56 microwatts per square meter. This reflects the rapid expansion of cell towers, WiFi networks, and wireless technologies in residential areas during this period.

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 extremely weak magnetic fields (similar to power line levels) throughout pregnancy and found that specific exposure levels caused permanent brain damage in the offspring. The baby rats exposed to low-intensity fields (30-50 nT) developed smaller hippocampus regions and showed impaired learning abilities as adults. Interestingly, both weaker and stronger magnetic field exposures didn't cause these problems, suggesting a narrow 'danger zone' of exposure intensity.

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

Ying Li and Paul Heroux · 2014

Researchers exposed five different types of cancer cells to extremely low-frequency magnetic fields at levels commonly found in our environment (0.025-5 microTesla). After six days, all cancer cell types lost chromosomes, suggesting the magnetic fields disrupted cellular energy production in the mitochondria (the cell's power plants). The researchers found this effect was similar to what happens when cells are treated with drugs that block energy production.

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 electromagnetic field exposure for store cashiers working near security gates that detect unpaid merchandise. While normal workplace exposure stayed within safety limits, magnetic field levels briefly exceeded international guidelines when cashiers walked through the gates themselves, suggesting potential health risks.

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

Bodera P et al. · 2015

Researchers exposed rats to 1800 MHz radiofrequency radiation (the same frequency used in cell phones) for 15 minutes, five times daily, and measured oxidative damage in their organs. They found increased lipid peroxidation (cellular damage from oxidation) in the brain, blood, and kidneys of exposed animals. This suggests that repeated cell phone-frequency radiation exposure may cause oxidative stress damage to vital organs.

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

Bodera P et al. · 2012

Polish researchers exposed rats to cell phone-frequency electromagnetic fields (1500 MHz and 1800 MHz) for 15 minutes and tested how well the painkiller tramadol worked afterward. While the EMF exposure alone didn't change pain sensitivity, it significantly reduced tramadol's pain-relieving effects when the two were combined. This suggests that EMF exposure from devices like cell phones might interfere with how certain medications work in the body.

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

Russian researchers exposed Alzheimer's mice to extremely weak magnetic fields for 4 hours daily over 10 days. The treatment reduced toxic brain plaques and improved memory in some mice, suggesting specific magnetic frequencies might help clear harmful proteins in early neurodegenerative diseases.

Modulation of heat shock protein response in SH-SY5Y by mobile phone microwaves

Calabrò E et al. · 2012

Italian researchers exposed human brain cells to cell phone radiation at 1800 MHz for 2-4 hours and measured stress protein responses. They found that the radiation triggered cellular stress responses in the neurons, specifically decreasing one protective protein (Hsp20) and increasing another (Hsp70) after longer exposure. This suggests that cell phone radiation can activate stress pathways in brain cells even at levels considered safe by current standards.

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 mouse cells to microwave radiation (same frequency as WiFi) plus a tumor-promoting chemical. While microwaves alone caused no harm, the combination significantly increased cancer-like cell transformation to levels matching X-ray exposure, suggesting microwaves may promote cancer under certain conditions.

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

Danish researchers followed 32,006 utility workers for three decades, studying exposure to magnetic fields from power lines and electrical equipment. Workers with highest exposures showed 44% higher dementia rates and 78% higher motor neuron disease rates, suggesting occupational magnetic field exposure may increase neurological disease risk.

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

Researchers tested whether wood mice can sense magnetic fields by observing where they built nests in circular arenas. They found that mice normally oriented their nests north-south using Earth's magnetic field, but when exposed to weak radio frequency fields (0.9-5 MHz), the mice switched to building nests east-west instead. This demonstrates that low-level RF exposure can disrupt an animal's natural magnetic navigation system.

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 exposed medaka fish embryos to extremely low frequency electromagnetic fields (3.2 kHz) throughout their development to study potential biological effects. They found that EMF exposure accelerated embryonic development and caused anxiety-like behavior in the hatched fish, with higher anxiety levels at stronger field strengths. This study provides evidence that even low-level EMF exposure during critical developmental periods can alter both physical development and behavior.

Analgetic effects of non-thermal GSM-1900 radiofrequency electromagnetic fields in the land snail Helix pomatia.

Nittby H et al. · 2012

Swedish researchers exposed land snails to cell phone radiation at 1900 MHz (the same frequency used by many mobile phones) for one hour, then tested their response to painful heat. The radiation-exposed snails showed significantly reduced sensitivity to pain compared to unexposed snails, suggesting the electromagnetic fields had an anesthetic-like effect on their nervous systems.

Ets1 oncogene induction by ELF-modulated 50 MHz radiofrequency electromagnetic field

Romano-Spica V, Mucci N, Ursini CL, Ianni A, Bhat NK · 2000

Italian researchers exposed blood and reproductive cells to radiofrequency radiation (50 MHz) combined with extremely low frequency modulation (16 Hz) to study effects on gene activity. They found that this specific combination activated the ets1 gene, which is associated with cancer development, but only when the low-frequency modulation was present. This suggests that the pulsing or modulation of RF signals may be more biologically active than continuous exposure.

Reproductive HealthNo Effects Found

The lack of effects of nonthermal RF electromagnetic fields on the development of rat embryos grown in culture.

Klug S, Hetscher M, Giles S, Kohlsmann S, Kramer K, · 1997

German researchers exposed developing rat embryos to radio frequency electromagnetic fields at various power levels for up to 36 hours to test whether EMF exposure during critical development stages causes birth defects or growth problems. The study found no significant effects on embryo development, growth, or cellular structure across all tested exposure levels, including levels far exceeding typical telecommunication device emissions. This suggests that RF fields at these intensities may not pose developmental risks during embryonic growth.