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Single vs. repeated microwave exposure: effects on benzodiazepine receptors in the brain of the rat.

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Lai H, Carino MA, Horita A, Guy AW · 1992

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Microwave radiation at cell phone levels triggered brain stress receptors in rats, suggesting wireless devices may create biological stress responses.

Plain English Summary

Summary written for general audiences

Researchers exposed rats to microwave radiation (2450 MHz) for 45 minutes and measured changes in brain receptors that respond to anxiety and stress. A single exposure increased these stress-related receptors in the brain's cortex, but repeated exposures over 10 days showed the brain adapted to the radiation. The findings suggest that microwave radiation at levels similar to some wireless devices can trigger a stress response in the brain.

Why This Matters

This study provides compelling biological evidence that microwave radiation exposure triggers measurable stress responses in the brain. The researchers found that benzodiazepine receptors - the same receptors that respond to anxiety medications like Valium - increased after just one 45-minute exposure to 2450 MHz radiation. The exposure level (0.6 W/kg SAR) is within the range of modern cell phones and WiFi devices, making these findings directly relevant to everyday EMF exposure. What's particularly significant is that the brain showed adaptation after repeated exposures, which could mask ongoing biological effects in chronic exposure scenarios. The science demonstrates that even at relatively low intensities, microwave radiation isn't biologically inert - it's triggering detectable stress responses at the cellular level. This adds to the growing body of evidence that our wireless devices may be creating subtle but measurable biological stress, even when we don't consciously feel it.

Exposure Details

SAR
0.6 W/kg
Power Density
1 µW/m²
Source/Device
2450 MHz
Exposure Duration
45 min And repeated ten daily 45-min sessions

Exposure Context

This study used 1 µW/m² for radio frequency:

This study used 0.6 W/kg for SAR (device absorption):

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 µW/m²Extreme Concern1,000 uW/m2FCC Limit10M uW/m2Effects observed in the Slight Concern range (Building Biology)FCC limit is 10,000,000x higher than this exposure level

Study Details

The aim of this study is to observe Single vs. repeated microwave exposure: effects on benzodiazepine receptors in the brain of the rat.

We studied the effects of single (45 min) and repeated (ten daily 45-min sessions) microwave exposur...

Immediately after a single exposure, an increase in the concentration of receptor was observed in th...

Because benzodiazepine receptors in the brain are responsive to anxiety and stress, our data support the hypothesis that low-intensity microwave irradiation can be a source of stress.

Cite This Study
Lai H, Carino MA, Horita A, Guy AW (1992). Single vs. repeated microwave exposure: effects on benzodiazepine receptors in the brain of the rat. Bioelectromagnetics 13(1):57-66, 1992.
Show BibTeX
@article{h_1992_single_vs_repeated_microwave_1136,
  author = {Lai H and Carino MA and Horita A and Guy AW},
  title = {Single vs. repeated microwave exposure: effects on benzodiazepine receptors in the brain of the rat.},
  year = {1992},
  
  url = {https://pubmed.ncbi.nlm.nih.gov/1312845/},
}

Quick Questions About This Study

Researchers exposed rats to microwave radiation (2450 MHz) for 45 minutes and measured changes in brain receptors that respond to anxiety and stress. A single exposure increased these stress-related receptors in the brain's cortex, but repeated exposures over 10 days showed the brain adapted to the radiation. The findings suggest that microwave radiation at levels similar to some wireless devices can trigger a stress response in the brain.