Note: This study found no significant biological effects under its experimental conditions. We include all studies for scientific completeness.
Thermal and athermal effects of microwave radiation on the activity of glucose-6-phosphate dehydrogenase in human blood
No Effects Found
Belkhode M., Johnson DL., Muc AM. · 1974
High-power 2.8 GHz microwaves caused no enzyme damage beyond normal heating effects in this controlled study.
Plain English Summary
Summary written for general audiences
Researchers exposed human blood samples to 2.8 GHz microwave radiation at high power levels (500-1000 mW/cm²) to test whether microwaves could damage an important enzyme called glucose-6-phosphate dehydrogenase through non-thermal effects. They found that while heat from the microwaves reduced enzyme activity by up to 80%, the microwaves themselves caused no statistically significant damage beyond what heat alone would cause.
Cite This Study
Belkhode M., Johnson DL., Muc AM. (1974). Thermal and athermal effects of microwave radiation on the activity of glucose-6-phosphate dehydrogenase in human blood.
Show BibTeX
@article{thermal_and_athermal_effects_of_microwave_radiation_on_the_activity_of_glucose_6_g6661,
author = {Belkhode M. and Johnson DL. and Muc AM.},
title = {Thermal and athermal effects of microwave radiation on the activity of glucose-6-phosphate dehydrogenase in human blood},
year = {1974},
}Quick Questions About This Study
Researchers used extremely high power densities of 500-1000 mW/cm², which absorbed 230 mW/cm² into the blood samples. These levels are roughly 1000 times higher than typical cell phone exposures today.
No statistically significant damage was found beyond normal heating effects. While heat reduced enzyme activity by up to 80%, the microwaves themselves caused only a non-significant 10.4% effect.
They conducted treatments at fixed temperatures of 37°C, 56.7°C, and 80.7°C, allowing them to distinguish between damage caused by heat versus damage caused by the microwaves themselves.
It's a crucial enzyme in human blood cells that helps protect against oxidative damage. Researchers studied it because enzyme damage could indicate whether microwaves cause harmful biological effects beyond heating.
The study used two different treatment times that resulted in absorbed energies of 35 and 62 J/cm². The exact exposure durations weren't specified in the available abstract.