THE PAIN THRESHOLD FOR MICROWAVE AND INFRA-RED RADIATIONS
H. F. COOK · 1952
Early 1951 research confirmed microwave radiation causes measurable pain responses in humans, proving immediate biological effects.
Plain English Summary
This 1951 research investigated the pain threshold levels for both microwave and infrared radiation exposure in human subjects, measuring skin temperature responses to determine safety limits. The study represents early scientific recognition that electromagnetic radiation could cause immediate biological effects, including pain responses. This foundational work helped establish understanding of how microwave energy interacts with human tissue at levels that cause noticeable sensations.
Why This Matters
This 1951 study represents a crucial early recognition that microwave radiation produces measurable biological effects in humans, including pain responses at specific exposure levels. What makes this research particularly significant is that it was conducted during the dawn of the microwave age, when scientists were just beginning to understand how electromagnetic fields interact with living tissue. The fact that researchers were already documenting pain thresholds suggests they recognized potential health implications from the start.
The reality is that modern microwave exposure from devices like WiFi routers, cell phones, and microwave ovens operates at power levels designed to stay below these pain thresholds. However, the existence of immediate pain responses demonstrates that microwave radiation clearly affects human biology. This raises important questions about subtler, long-term effects that might occur below the pain threshold but above natural background levels.
Finding
The skin temperature corresponding to burning pain is independent of the area of exposure, radiation intensity, exposure time and anatomical site.
In their words
“The skin temperature corresponding to burning pain is independent of the area of exposure, radiation intensity, exposure time and anatomical site.”
Figures from the Original Paper
Diagrams extracted from the original research document.
Exposure Information
Specific exposure levels were not quantified in this study. Duration: prolonged exposure
Study Details
To present results obtained for the threshold for microwaves of 10 cm wavelength, to provide a physical analysis of the results, and to extend the physical analysis to the pain threshold work carried out by others using infra-red radiation.
Microwave radiation of 10 cm free-space wavelength (frequency =3 x 10^8/s) was transmitted from a ma...
Pain sensation with microwaves differed little from those felt when heating was produced by infra-re...
The tolerated microwave power (for a given exposed area) during prolonged exposures suffers relative small variations between individuals and anatomical sites. The tolerated intensity is greater for an exposed area of 9-5 cm2 than for smaller areas. The skin temperature corresponding to burning pain is independent of the area of exposure, radiation intensity, exposure time and anatomical site. Pain results when a critical skin temperature is achieved rather than from a critical temperature rise. With high intensities, the time of exposure is a function of radiation intensity. The results support the idea that pain occurs when energy absorption in a critical thickness of superficial tissues reaches a certain value. The energy absorption in a 1-5 mm depth is approximately the same for all radiations, suggesting that pain occurs at an approximately constant skin temperature for all thermogenic radiations.
Show BibTeX
@article{the_pain_threshold_for_microwave_and_infra_red_radiations_g5819,
author = {H. F. COOK},
title = {THE PAIN THRESHOLD FOR MICROWAVE AND INFRA-RED RADIATIONS},
year = {1952},
}