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

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

Bioeffects Seen

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

View Original Abstract
Share:

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 ContextA logarithmic scale showing exposure levels relative to Building Biology concern thresholds and regulatory limits.Study Exposure Level in ContextThis study: 1 mGExtreme Concern5 mGFCC Limit2,000 mGEffects observed in the Severe Concern range (Building Biology)FCC limit is 2,000x higher than this exposure level

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

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.