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Permeability of the blood-brain barrier induced by 915 MHz electromagnetic radiation, continuous wave and modulated at 8, 16, 50, and 200 Hz.

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Salford LG, Brun A, Sturesson K, Eberhardt JL, Persson BRq · 1994

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Microwave radiation at cell phone frequencies caused blood-brain barrier leakage in 30% of exposed animals versus 8% of controls.

Plain English Summary

Summary written for general audiences

Swedish researchers exposed rats to 915 MHz microwave radiation for two hours and found it caused the blood-brain barrier to leak. This protective barrier normally keeps harmful substances out of the brain. The finding suggests microwave radiation can compromise the brain's natural defenses.

Why This Matters

This landmark 1994 study from Lund University provides compelling evidence that radiofrequency radiation can breach the blood-brain barrier, your brain's primary defense against toxins and pathogens. The researchers found significant barrier leakage at exposure levels as low as 0.016 W/kg - well below current safety limits and comparable to what you might experience during a long cell phone call. What makes this research particularly significant is that it demonstrates a clear biological mechanism by which EMF could potentially cause neurological harm. The blood-brain barrier exists for a reason: when it's compromised, substances that should never reach brain tissue can cross over and potentially cause inflammation or damage. While this study used rats, the consistency of blood-brain barrier function across mammalian species makes these findings highly relevant to human health.

Exposure Details

SAR
0.016 and 5 W/kg
Source/Device
915 MHz
Exposure Duration
2h

Where This Falls on the Concern Scale

Study Exposure Level in ContextStudy Exposure Level in ContextThis study: 0.016 and 5 W/kgExtreme Concern - 0.1 W/kgFCC Limit - 1.6 W/kgEffects observed in the Severe Concern rangeFCC limit is 100x higher than this level
A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 915 MHz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 915 MHzPower lines50/60 Hz5G mm28 GHzLogarithmic scale

Study Details

In the present investigation we exposed male and female Fischer 344 rats in a transverse electromagnetic transmission line chamber to microwaves of 915 MHz as continuous wave (CW) and pulse-modulated with repetition rates of 8, 16, 50, and 200 s-1.

The specific energy absorption rate (SAR) varied between 0.016 and 5 W/kg. The rats were not anesthe...

The results show albumin leakage in 5 of 62 of the controls and in 56 of 184 of the animals exposed ...

Cite This Study
Salford LG, Brun A, Sturesson K, Eberhardt JL, Persson BRq (1994). Permeability of the blood-brain barrier induced by 915 MHz electromagnetic radiation, continuous wave and modulated at 8, 16, 50, and 200 Hz. Microsc Res Tech 27(6):535-542, 1994.
Show BibTeX
@article{lg_1994_permeability_of_the_bloodbrain_1304,
  author = {Salford LG and Brun A and Sturesson K and Eberhardt JL and Persson BRq},
  title = {Permeability of the blood-brain barrier induced by 915 MHz electromagnetic radiation, continuous wave and modulated at 8, 16, 50, and 200 Hz. },
  year = {1994},
  
  url = {https://pubmed.ncbi.nlm.nih.gov/8012056/},
}
PubMed: 8012056

Cited By (240 papers)

View all 240 citing papers on Semantic Scholar

Quick Questions About This Study

Yes, Swedish researchers found that 915 MHz microwave radiation caused the blood-brain barrier to leak in rats after just two hours of exposure. This protective barrier normally keeps harmful substances out of the brain, suggesting microwave radiation can compromise the brain's natural defenses.
In this 1994 study, just two hours of exposure to 915 MHz microwave radiation was enough to cause blood-brain barrier leakage in rats. The researchers found 56 of 184 exposed animals showed barrier damage compared to only 5 of 62 control animals.
The study found continuous wave 915 MHz radiation caused significant blood-brain barrier damage, with 14 positive findings out of 35 exposed animals. This was statistically significant compared to controls, though the research also tested modulated frequencies at 8, 16, 50, and 200 Hz.
The 1994 Salford study used 915 MHz electromagnetic radiation, both as continuous waves and modulated at 8, 16, 50, and 200 Hz. This frequency is in the microwave range commonly used by wireless communication devices and caused significant blood-brain barrier leakage in exposed rats.
In the Salford study, 56 out of 184 rats exposed to 915 MHz microwaves showed blood-brain barrier leakage, compared to only 5 out of 62 control rats. This represents a dramatic increase in barrier permeability following microwave radiation exposure.