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Brain & Nervous SystemPart of the Glaser Archive

CEREBROVASCULAR PERMEABILITY TO 14C-SUCROSE IN THE RAT FOLLOWING 2450 MHZ CW MICROWAVE IRRADIATION

No Effects Found

Ohno, K., Pettigrew, K.D., Rapoport, S.I. · 1978

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2450 MHz microwave radiation showed no effect on blood-brain barrier permeability in this controlled study.

Plain English Summary

Summary written for general audiences

Researchers exposed rats to 2450 MHz microwave radiation (the same frequency used in microwave ovens and WiFi) for 30 minutes to test whether it damages the blood-brain barrier. They found no changes in the barrier's permeability to sucrose, suggesting this level of microwave exposure doesn't compromise brain protection.

Finding

An effect of microwave treatment on barrier permeability cannot be concluded at this point, and the results support negative findings reported earlier in which Brain Uptake Index measurements were used.

In their words

“An effect of microwave treatment on barrier permeability cannot be concluded at this point, and the results support negative findings reported earlier in which Brain Uptake Index measurements were used.”
Cite This Study
Ohno, K., Pettigrew, K.D., Rapoport, S.I. (1978). CEREBROVASCULAR PERMEABILITY TO 14C-SUCROSE IN THE RAT FOLLOWING 2450 MHZ CW MICROWAVE IRRADIATION.
Show BibTeX
@article{cerebrovascular_permeability_to_14c_sucrose_in_the_rat_following_2450_mhz_cw_mic_g5402,
  author = {Ohno and K. and Pettigrew and K.D. and Rapoport and S.I.},
  title = {CEREBROVASCULAR PERMEABILITY TO 14C-SUCROSE IN THE RAT FOLLOWING 2450 MHZ CW MICROWAVE IRRADIATION},
  year = {1978},
  
  
}
No DOI on file for this study.

Quick Questions About This Study

This study found no damage to the blood-brain barrier after 30-minute exposure to 2450 MHz microwaves at power densities of 1-10 mW/cm². The barrier's permeability to sucrose remained unchanged compared to sham-exposed control rats.
Researchers tested two power density levels: 1 mW/cm² and 10 mW/cm². These levels are higher than typical consumer device exposures but within ranges that might occur near industrial microwave equipment or very close to high-powered transmitters.
Each rat was exposed for exactly 30 minutes while positioned 5 meters away from the microwave horn antenna. This represents an acute, single exposure rather than the chronic daily exposures humans typically experience from wireless devices.
Scientists injected radioactive sucrose (14C-sucrose) into the rats' bloodstream 10 minutes after microwave exposure, then measured how much crossed into brain tissue over 25 minutes. Increased sucrose penetration would indicate barrier damage.
Yes, 2450 MHz is exactly the frequency used in microwave ovens, older WiFi systems, and some Bluetooth devices. This makes the study relevant to understanding potential effects from common household and wireless communication technologies.