8,700 Studies Reviewed. 87.0% Found Biological Effects. The Evidence is Clear.
Shield Your Body
Brain & Nervous System

Microwave irradiation of rats at 2.45 GHz activates pinocytotic-like uptake of tracer by capillary endothelial cells of cerebral cortex.

Bioeffects Seen

Neubauer C, Phelan AM, Kues H, Lange DG · 1990

View Original Abstract
Share:

Microwave radiation at 2.45 GHz compromises the blood-brain barrier at power levels comparable to everyday wireless device exposure.

Plain English Summary

Summary written for general audiences

Researchers exposed rats to 2.45 GHz microwave radiation (WiFi frequency) at low power levels and found it increased blood-brain barrier permeability after just 30-120 minutes. This protective barrier normally prevents harmful substances from entering brain tissue, suggesting microwave exposure could compromise brain protection.

Why This Matters

This study reveals a concerning mechanism by which microwave radiation affects brain physiology at relatively low exposure levels. The blood-brain barrier serves as a critical defense system, and any compromise of its integrity could have serious neurological implications. What makes this research particularly relevant is that the 2.45 GHz frequency tested is identical to that used in microwave ovens, WiFi routers, and many wireless devices. The power densities that caused effects (5-10 mW/cm²) are within range of what people experience from wireless technology in daily life. The researchers' use of colchicine to block the effect provides strong evidence that the mechanism involves disruption of cellular transport processes. This adds to a growing body of evidence suggesting that current safety standards, which focus only on heating effects, may be inadequate to protect against biological impacts of wireless radiation.

Exposure Details

SAR
2 W/kg
Power Density
5, 10 µW/m²
Source/Device
2.45 GHz
Exposure Duration
30-120 min

Exposure Context

This study used 5, 10 µW/m² for radio frequency:

This study used 2 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: 5, 10 µW/m²Extreme Concern - 1,000 uW/m2FCC Limit - 10M uW/m2Effects observed in the Slight Concern rangeFCC limit is 2,000,000x higher than this level
A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 2.45 GHz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 2.45 GHzPower lines50/60 Hz5G mm28 GHzLogarithmic scale

Study Details

To investigate whether microwave irradiation of rats at 2.45 GHz activates pinocytotic-like uptake of tracer by capillary endothelial cells of cerebral cortex or not.

Far-field exposures of male albino rats to 2.45-GHz microwaves (10-microseconds pulses, 100 pps) at ...

Cite This Study
Neubauer C, Phelan AM, Kues H, Lange DG (1990). Microwave irradiation of rats at 2.45 GHz activates pinocytotic-like uptake of tracer by capillary endothelial cells of cerebral cortex. Bioelectromagnetics 11(4):261-268, 1990.
Show BibTeX
@article{c_1990_microwave_irradiation_of_rats_1224,
  author = {Neubauer C and Phelan AM and Kues H and Lange DG},
  title = {Microwave irradiation of rats at 2.45 GHz activates pinocytotic-like uptake of tracer by capillary endothelial cells of cerebral cortex.},
  year = {1990},
  
  url = {https://pubmed.ncbi.nlm.nih.gov/2285411/},
}
PubMed: 2285411

Cited By (92 papers)

View all 92 citing papers on Semantic Scholar

Quick Questions About This Study

Yes, a 1990 study found that 2.45 GHz microwave radiation increased blood-brain barrier permeability in rats after just 30-120 minutes of exposure. This protective barrier normally prevents harmful substances from entering brain tissue, suggesting WiFi frequencies could compromise brain protection mechanisms.
Research shows microwave radiation at 2.45 GHz can increase blood-brain barrier permeability in as little as 30 minutes. The study found that exposures lasting 30-120 minutes caused measurable increases in barrier permeability, with effects depending on both power density and exposure duration.
The study found that 10 mW/cm² of 2.45 GHz pulsed microwave radiation increased blood-brain barrier permeability, while 5 mW/cm² for 15 minutes showed no effect. This suggests there's a threshold power level where brain barrier function becomes compromised.
Yes, researchers found that pretreating rats with colchicine nearly completely blocked the microwave-induced increase in blood-brain barrier permeability. Since colchicine inhibits microtubular function, this suggests the radiation damage occurs through a cellular transport mechanism called pinocytosis.
The 1990 study suggests a pinocytotic-like mechanism is responsible for microwave-induced blood-brain barrier permeability. This cellular process involves the formation of small vesicles that transport substances across the protective barrier, potentially allowing harmful materials to enter brain tissue.