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Note: This study found no significant biological effects under its experimental conditions. We include all studies for scientific completeness.

Cardiovascular

Cardiovascular and thermal effects of microwave irradiation at 1 and/or 10 GHz in anesthetized rats.

No Effects Found

Jauchem JR, Ryan KL, Freidagger MR · 2000

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This study examined lethal microwave exposures 240 times higher than cell phones, finding frequency-dependent heating patterns but no unusual cardiovascular responses.

Plain English Summary

Summary written for general audiences

Researchers exposed anesthetized rats to microwave radiation at 1 GHz, 10 GHz, or both frequencies combined at high power levels (12 W/kg) until the animals died from overheating. They found that rats exposed to 1 GHz died fastest, while those exposed to 10 GHz survived longest, with combined exposure falling in between. This study was designed to understand how different microwave frequencies affect heat distribution in the body and cardiovascular responses during extreme thermal stress.

Why This Matters

This Air Force-funded study examined lethal exposures at 12 W/kg - roughly 240 times higher than typical cell phone exposures (around 0.05-2 W/kg). While the research provides insights into how different frequencies distribute heat in biological tissue, the extreme exposure levels make it difficult to draw conclusions about everyday EMF exposure risks. The study's focus on thermal death rather than subtle biological effects reflects the military's traditional approach of studying only heating effects. What's more relevant for public health is understanding how chronic, lower-level exposures affect cardiovascular function over time, which this acute heating study cannot address.

Exposure Details

SAR
12 W/kg
Source/Device
1-GHz, 10-GHz

Exposure Context

This study used 12 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 ContextStudy Exposure Level in ContextThis study: 12 W/kgExtreme Concern - 0.1 W/kgFCC Limit - 1.6 W/kgEffects observed in the Extreme Concern range (Building Biology)This level is 8 times the FCC limit
A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 1 GHz - 10 GHz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 1 GHz - 10 GHzPower lines50/60 Hz5G mm28 GHzLogarithmic scale

Study Details

This study compares the thermal distribution and cardiovascular effects of exposure to a single MW frequency with effects of simultaneous exposure to two frequencies.

Ketamine-anesthetized male Sprague-Dawley rats (n = 58) were exposed individually to one of three co...

In both E and H orientations, survival time (i.e., time from colonic temperature of 37.5 degrees C u...

The results indicate that no unusual physiological responses occur during multi-frequency MW exposure, when compared with results of single-frequency exposure.

Cite This Study
Jauchem JR, Ryan KL, Freidagger MR (2000). Cardiovascular and thermal effects of microwave irradiation at 1 and/or 10 GHz in anesthetized rats. Bioelectromagnetics 21(3):159-166, 2000.
Show BibTeX
@article{jr_2000_cardiovascular_and_thermal_effects_3112,
  author = {Jauchem JR and Ryan KL and Freidagger MR},
  title = {Cardiovascular and thermal effects of microwave irradiation at 1 and/or 10 GHz in anesthetized rats.},
  year = {2000},
  
  url = {https://pubmed.ncbi.nlm.nih.gov/10723015/},
}
PubMed: 10723015

Cited By (13 papers)

View all 13 citing papers on Semantic Scholar

Quick Questions About This Study

A 2000 study exposed rats to high-power microwave radiation at 1 GHz and 10 GHz frequencies until death from overheating. Researchers found no unusual cardiovascular responses during exposure, with blood pressure and heart rate changes following predictable patterns during extreme thermal stress.
Research on rats exposed to 1 GHz versus 10 GHz microwave radiation found similar cardiovascular response patterns for both frequencies. Blood pressure initially increased then decreased, while heart rate increased throughout exposure, with no frequency-specific differences in heart function.
A study comparing single-frequency versus combined 1 GHz and 10 GHz exposure in rats found no unusual physiological responses during multi-frequency exposure. The combined exposure produced effects that fell between the single-frequency groups, suggesting no additive health risks.
Laboratory research exposing rats to high-power microwave radiation showed blood pressure initially increased then decreased during extreme heating. These cardiovascular changes were consistent across different frequencies (1 GHz and 10 GHz) and appeared related to thermal stress rather than radiation-specific effects.
A controlled study found no unusual cardiovascular effects from 1 GHz or 10 GHz microwave exposure in rats, even at high power levels. Heart rate and blood pressure changes observed were consistent with normal responses to extreme thermal stress rather than radiation-specific harm.