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Effects of exposure to 50 Hz magnetic field of 1 mT on the performance of detour learning task by chicks

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Che Y, Sun H, Cui Y, Zhou D, Ma Y. · 2007

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Twenty hours of daily magnetic field exposure significantly impaired learning in chicks, while 50 minutes had no effect, showing duration matters.

Plain English Summary

Summary written for general audiences

Researchers exposed young chickens to power line magnetic fields for either 20 hours or 50 minutes daily, then tested their learning ability. Chicks with prolonged exposure showed significant learning problems, while brief exposure caused no harm, suggesting extended magnetic field exposure may impair brain function.

Why This Matters

This study adds important evidence to our understanding of how ELF magnetic fields affect brain function, particularly learning and memory processes. The 1 mT exposure level used here is quite high compared to typical household exposures, which usually range from 0.01 to 0.2 mT near appliances. However, the key finding is the clear dose-response relationship: 20 hours of daily exposure caused measurable cognitive impairment, while 50 minutes did not. This demonstrates that duration of exposure matters significantly. What makes this research particularly valuable is that it shows functional brain effects in living animals, not just cellular changes in laboratory dishes. The reality is that while most people aren't exposed to 1 mT fields for 20 hours daily, this study reinforces the principle that chronic EMF exposure can have measurable biological consequences.

Exposure Details

Magnetic Field
1 mG
Source/Device
50 Hz
Exposure Duration
20 h/day and 50 min/day

Exposure Context

This study used 1 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: 1 mGExtreme Concern - 5 mGFCC Limit - 2,000 mGEffects observed in the Severe Concern rangeFCC limit is 2,000x higher than this level
A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 50 Hz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 50 HzCell phones~1 GHzWiFi2.4 GHz5G mm28 GHzLogarithmic scale

Study Details

In the present study, we examined the effects of exposure to an extremely low-frequency magnetic field of 1 mT intensity on learning and memory in Lohmann brown domestic chicks using detour learning task.

These results show that 20 h/day exposure to a low-frequency magnetic field induces a significant im...

Cite This Study
Che Y, Sun H, Cui Y, Zhou D, Ma Y. (2007). Effects of exposure to 50 Hz magnetic field of 1 mT on the performance of detour learning task by chicks Brain Res Bull. 74(1-3):178-182, 2007.
Show BibTeX
@article{y_2007_effects_of_exposure_to_228,
  author = {Che Y and Sun H and Cui Y and Zhou D and Ma Y.},
  title = {Effects of exposure to 50 Hz magnetic field of 1 mT on the performance of detour learning task by chicks},
  year = {2007},
  
  url = {https://www.sciencedirect.com/science/article/abs/pii/S0361923007001955},
}

Quick Questions About This Study

Research shows prolonged exposure to power line magnetic fields can impair learning ability. A 2007 study found young chickens exposed 20 hours daily to 50 Hz magnetic fields showed significant learning problems, while brief 50-minute exposures caused no harm.
Yes, extended magnetic field exposure can impair learning. Researchers found chickens exposed to power line frequencies for 20 hours daily performed poorly on learning tasks, but those exposed for just 50 minutes showed no learning deficits.
Extended exposure may be harmful to developing brains. A study on young chickens showed 20-hour daily exposure to 50 Hz magnetic fields significantly impaired their ability to learn detour tasks, suggesting potential developmental effects.
Brief exposures appear safer than prolonged ones. Research found 50 minutes daily of magnetic field exposure caused no learning problems in young chickens, while 20 hours daily significantly impaired their cognitive performance on learning tasks.
Power line magnetic fields may impair cognitive function with prolonged exposure. A 2007 study demonstrated young chickens exposed 20 hours daily to 50 Hz fields showed significant learning deficits compared to unexposed controls and briefly exposed animals.