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Effects of extremely low frequency magnetic field on anxiety level and spatial memory of adult rats.

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He LH, Shi HM, Liu TT, Xu YC, Ye KP, Wang S. · 2011

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Chronic magnetic field exposure increased anxiety while improving spatial memory in rats, showing EMF can simultaneously harm and enhance different brain functions.

Plain English Summary

Summary written for general audiences

Researchers exposed adult rats to 50 Hz magnetic fields (the same frequency as power lines) for either 1 or 4 hours daily over 4 weeks. Rats exposed for 4 hours showed increased anxiety-like behaviors but surprisingly improved spatial learning and long-term memory. This suggests that chronic exposure to power frequency magnetic fields can alter brain function in complex ways, affecting both emotional and cognitive processes.

Why This Matters

This study reveals the complex neurological effects of extremely low frequency magnetic fields at levels far exceeding typical household exposure. At 2 mT (2,000 milligauss), the exposure was roughly 4,000 times stronger than average home magnetic field levels, yet still within ranges found near power lines or electrical equipment. The dual finding of increased anxiety alongside improved spatial memory demonstrates that EMF effects on the brain aren't simply 'good' or 'bad' but can simultaneously impair some functions while enhancing others. What makes this research particularly significant is that it used chronic exposure patterns that better reflect real-world scenarios than acute studies. The science demonstrates that magnetic fields can cross-talk with brain chemistry in ways that alter both emotional regulation and cognitive performance, adding to the growing body of evidence that EMF exposure affects nervous system function.

Exposure Details

Magnetic Field
2 mG
Source/Device
50 Hz
Exposure Duration
1 h/day or 4 h/day for 4 weeks

Exposure Context

This study used 2 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: 2 mGExtreme Concern5 mGFCC Limit2,000 mGEffects observed in the Severe Concern range (Building Biology)FCC limit is 1,000x higher than this exposure level

Study Details

The present study examined the effects of chronic exposure to ELF MF on anxiety level and spatial memory of adult rats.

The 50-Hz ELF MF was used during the whole experimental procedures and the value of magnetic field (...

Rats in MF 4 hours group had increased anxiety-like behaviors with unaltered locomotor activity. In ...

Chronic ELF MF exposure has anxiogenic effect on rats, and the promoting effects on spatial learning and long-term retention of spatial memory.

Cite This Study
He LH, Shi HM, Liu TT, Xu YC, Ye KP, Wang S. (2011). Effects of extremely low frequency magnetic field on anxiety level and spatial memory of adult rats. Chin Med J (Engl). 124(20):3362-3366, 2011.
Show BibTeX
@article{lh_2011_effects_of_extremely_low_257,
  author = {He LH and Shi HM and Liu TT and Xu YC and Ye KP and Wang S. },
  title = {Effects of extremely low frequency magnetic field on anxiety level and spatial memory of adult rats.},
  year = {2011},
  
  url = {https://journals.lww.com/cmj/Fulltext/2011/10020/Effects_of_extremely_low_frequency_magnetic_field.28.aspx},
}

Quick Questions About This Study

Researchers exposed adult rats to 50 Hz magnetic fields (the same frequency as power lines) for either 1 or 4 hours daily over 4 weeks. Rats exposed for 4 hours showed increased anxiety-like behaviors but surprisingly improved spatial learning and long-term memory. This suggests that chronic exposure to power frequency magnetic fields can alter brain function in complex ways, affecting both emotional and cognitive processes.