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Long-term exposure to extremely low-frequency magnetic fields impairs spatial recognition memory in mice.

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Fu Y, Wang C, Wang J, Lei Y, Ma Y · 2008

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Long-term exposure to 50 Hz magnetic fields impaired spatial memory in mice, suggesting everyday electrical frequencies may affect cognitive function.

Plain English Summary

Summary written for general audiences

Researchers exposed mice to magnetic fields from power lines for 25 days, then tested their memory using mazes. Long-term exposure impaired the mice's ability to recognize new environments, suggesting that prolonged exposure to common household magnetic fields may interfere with spatial memory abilities.

Why This Matters

This study provides compelling evidence that the magnetic fields we encounter daily from power lines, electrical wiring, and household appliances can impair cognitive function with prolonged exposure. The 50 Hz frequency tested here is exactly what's used in European electrical systems, and 25 Hz falls within the range of harmonics and variations common in North American 60 Hz systems. What makes this research particularly significant is that it demonstrates duration-dependent effects. The mice showed no memory problems after one week of exposure, but clear cognitive impairment after 25 days at the same field strength. This suggests that chronic, everyday exposure to ELF magnetic fields may be more concerning than brief encounters. The science demonstrates that these fields can cross the blood-brain barrier and interfere with normal brain function, supporting growing concerns about the neurological effects of our electromagnetic environment.

Exposure Details

Magnetic Field
0.6,0.9 mG
Source/Device
25 Hz
Exposure Duration
7 (short term) or 25 days (long term)

Exposure Context

This study used 0.6,0.9 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 ContextStudy Exposure Level in ContextThis study: 0.6,0.9 mGExtreme Concern - 5 mGFCC Limit - 2,000 mGEffects observed in the Slight Concern rangeFCC limit is 3,333x higher than this level
A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 25 Hz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 25 HzCell phones~1 GHzWiFi2.4 GHz5G mm28 GHzLogarithmic scale

Study Details

In the present study, we investigated the short- and long-term effects of extremely low-frequency (ELF) magnetic fields on spatial recognition memory in mice by using a two-trial recognition Y-maze that is based on the innate tendency of rodents to explore novel environments.

Mice were exposed to 25 or 50 Hz electromagnetic fields for either 7 (short term) or 25 days (long t...

The results indicated that neither short- nor long-term exposure to magnetic fields affected the loc...

Our findings suggest that ELF magnetic fields impair spatial recognition memory in the Y-maze depending on the field strength and/or duration of exposure.

Cite This Study
Fu Y, Wang C, Wang J, Lei Y, Ma Y (2008). Long-term exposure to extremely low-frequency magnetic fields impairs spatial recognition memory in mice. Clin Exp Pharmacol Physiol. 35(7):797-800, 2008.
Show BibTeX
@article{y_2008_longterm_exposure_to_extremely_251,
  author = {Fu Y and Wang C and Wang J and Lei Y and Ma Y},
  title = {Long-term exposure to extremely low-frequency magnetic fields impairs spatial recognition memory in mice.},
  year = {2008},
  
  url = {https://pubmed.ncbi.nlm.nih.gov/18346171/},
}
PubMed: 18346171

Cited By (48 papers)

View all 48 citing papers on Semantic Scholar

Quick Questions About This Study

Yes, a 2008 study found that 25-day exposure to 25 Hz magnetic fields impaired spatial recognition memory in mice. The mice showed reduced ability to recognize novel environments in maze tests, suggesting power line frequencies may interfere with spatial memory abilities.
Research shows long-term exposure is needed for memory effects. A 2008 study found that 25 days of 25 Hz magnetic field exposure impaired spatial memory in mice, while short-term exposure showed no effects on memory performance.
Yes, mice exposed to household-level magnetic fields for 25 days showed impaired performance in Y-maze tests. They had reduced recognition of novel maze arms, indicating that common magnetic field exposures may affect spatial navigation abilities.
Researchers tested 25 Hz and 50 Hz magnetic fields in a 2008 mouse study. Both frequencies impaired spatial recognition memory after long-term exposure, with effects depending on field strength and exposure duration according to the findings.
No, the 2008 study found that neither short-term nor long-term exposure to extremely low frequency magnetic fields affected locomotor activity in mice. The magnetic fields specifically impaired memory recognition without changing general movement patterns.