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
M. L. BELKHODE, D. L. JOHNSON and A. M. MUC · 1974
2.8 GHz microwaves showed no non-thermal effects on blood enzymes at extremely high power levels.
Plain English Summary
Summary written for general audiences
Researchers exposed human blood to 2.8 GHz microwave radiation at high power levels (500-1000 mW/cm²) to test effects on glucose-6-phosphate dehydrogenase, a key enzyme in cellular energy production. While heat from the microwaves reduced enzyme activity by up to 60%, the study found no non-thermal effects from the microwave radiation itself. This suggests microwave effects on this enzyme are purely due to heating, not electromagnetic fields.
Cite This Study
M. L. BELKHODE, D. L. JOHNSON and A. M. MUC (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_g5877,
author = {M. L. BELKHODE and D. L. JOHNSON and A. M. MUC},
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
The study used incident power densities between 500-1000 mW/cm², with absorbed power of 230±70 mW/cm². These levels are 250-1000 times higher than typical cell phone exposures of 1-2 mW/cm².
The microwave radiation caused thermal effects (up to 60% enzyme reduction from heating) but showed no statistically significant non-thermal electromagnetic effects. The observed non-thermal effect was only 10±14%, within measurement error.
They maintained fixed temperatures (37°, 46.7°, and 49.7°C) during microwave exposure, allowing them to distinguish between effects caused by heating versus electromagnetic fields themselves. This controlled approach isolated non-thermal mechanisms.
The study examined glucose-6-phosphate dehydrogenase enzyme activity in human blood and yeast. This enzyme is crucial for cellular energy metabolism and protecting cells from oxidative stress damage.
Yes, 2.8 GHz is close to WiFi (2.4 GHz) and some cellular frequencies. However, the extremely high power levels used in this 1974 study far exceed typical exposures from modern wireless devices.