3,138 Studies Reviewed. 77.4% Found Biological Effects. The Evidence is Clear.

Effects of a 60 Hz Magnetic Field Exposure Up to 3000 μT on Human Brain Activation as Measured by Functional Magnetic Resonance Imaging.

Bioeffects Seen

Legros A, Modolo J, Brown S, Roberston J, Thomas AW. · 2015

View Original Abstract
Share:

One-hour exposure to power-line magnetic fields caused lasting changes in brain activation patterns, even at levels found near electrical infrastructure.

Plain English Summary

Summary written for general audiences

Researchers scanned people's brains after one-hour exposure to 60 Hz magnetic fields from power lines. Brain scans showed altered activation patterns during tasks, even though performance stayed normal. This suggests magnetic field exposure can change how the brain functions, with effects lasting after exposure ends.

Why This Matters

This research provides compelling evidence that power-frequency magnetic fields can alter brain function in ways that persist after exposure ends. The 3000 μT exposure level, while higher than typical household levels (usually 0.5-4 μT), is well within the range found near power lines, electrical panels, and some appliances. What makes this study particularly significant is its use of fMRI technology to directly visualize brain changes, moving beyond subjective reports to objective neurological measurements. The fact that brain activation patterns changed without affecting task performance suggests these fields may influence neural processes in subtle but measurable ways. This adds to a growing body of evidence that our nervous systems can detect and respond to electromagnetic fields at levels regulators currently consider safe.

Exposure Details

Magnetic Field
1.8, 3.0 mG
Source/Device
60 Hz
Exposure Duration
one-hour

Exposure Context

This study used 1.8, 3.0 mG for magnetic fields:

Building Biology guidelines are practitioner-based limits from real-world assessments. BioInitiative Report recommendations are based on peer-reviewed science. Check Your Exposure to compare your own measurements.

Where This Falls on the Concern Scale

Study Exposure Level in ContextA logarithmic scale showing exposure levels relative to Building Biology concern thresholds and regulatory limits.Study Exposure Level in ContextThis study: 1.8, 3.0 mGExtreme Concern5 mGFCC Limit2,000 mGEffects observed in the Severe Concern range (Building Biology)FCC limit is 1,111x higher than this exposure level

Study Details

In this study, we have used functional Magnetic Resonance Imaging (fMRI) to characterize potential changes in functional brain activation following human exposure to a 60 Hz MF through motor and cognitive tasks.

First, pilot results acquired in a first set of subjects (N=9) were used to demonstrate the technica...

The results indicate significant changes in task-induced functional brain activation as a consequenc...

These results illustrate the potential of using fMRI to identify MF-induced changes in functional brain activation, suggesting that a one-hour 60 Hz, 3000 μT MF exposure can modulate activity in specific brain regions after the end of the exposure period (i.e., residual effects). We discuss the possibility that MF exposure at 60 Hz, 3000 μT may be capable of modulating cortical excitability via a modulation of synaptic plasticity processes.

Cite This Study
Legros A, Modolo J, Brown S, Roberston J, Thomas AW. (2015). Effects of a 60 Hz Magnetic Field Exposure Up to 3000 μT on Human Brain Activation as Measured by Functional Magnetic Resonance Imaging. PLoS One. 2015 Jul 27;10(7):e0132024.
Show BibTeX
@article{a_2015_effects_of_a_60_672,
  author = {Legros A and Modolo J and Brown S and Roberston J and Thomas AW.},
  title = {Effects of a 60 Hz Magnetic Field Exposure Up to 3000 μT on Human Brain Activation as Measured by Functional Magnetic Resonance Imaging.},
  year = {2015},
  
  url = {https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0132024},
}

Quick Questions About This Study

Researchers scanned people's brains after one-hour exposure to 60 Hz magnetic fields from power lines. Brain scans showed altered activation patterns during tasks, even though performance stayed normal. This suggests magnetic field exposure can change how the brain functions, with effects lasting after exposure ends.