HEATING OF LIVING TISSUES
H. P. Schwan, A. Anne, L. Sher · 1966
This foundational 1966 research established thermal-based EMF safety standards that still govern wireless device limits today.
Plain English Summary
This 1966 government report by researcher H.P. Schwan examined how electromagnetic fields heat living tissues, a fundamental biological effect that became the basis for modern EMF safety standards. The research established scientific understanding of thermal effects from electromagnetic exposure. This work laid the groundwork for current regulatory limits that focus primarily on preventing tissue heating.
Why This Matters
Schwan's 1966 research on tissue heating represents a pivotal moment in EMF science that still shapes regulatory policy today. This government-sponsored work established the scientific foundation for thermal-based safety standards, which assume that preventing tissue heating prevents all biological harm. The reality is that this thermal-only approach has dominated EMF regulation for decades, essentially ignoring mounting evidence of non-thermal biological effects at exposure levels well below heating thresholds.
What this means for you is that current safety limits for cell phones, WiFi, and other wireless devices are based on 1960s science that only considered one mechanism of biological interaction. The evidence shows that biological systems respond to EMF exposure through multiple pathways beyond simple heating, yet our safety standards remain anchored to this narrow thermal paradigm established over 50 years ago.
Finding
Subjective awareness of warmth was found to be only a rough indication of personal hazard, based upon the currently accepted safety standard of 75 mw/cm² for 2 min.
In their words
“Subjective awareness of warmth was found to be only a rough indication of personal hazard, based upon the currently accepted safety standard of 75 mw/cm² for 2 min.”
Exposure Information
Specific exposure levels were not quantified in this study.
Study Details
To investigate whether a person, in absence of knowledge of the value of power density, can realize the hazard through the sensation of warmth. Another reason is given by the desire to learn more about the mechanism responsible for heat sensation.
Human subjects were irradiated with 10 cm electromagnetic waves to determine threshold sensations of...
The reaction time varies between different subjects. This variation in reaction time may only in par...
The subjective awareness of warmth is not a very good indication of personal hazard. It can, however, be roughly used for that purpose. Two of the four subjects are northerners and the other two are southerners. The southern subjects have higher thresholds of sensation of warmth than those from northern climates. The original hope of free field procedure to obtain uniform irradiation over the forehead could not be fulfilled despite considerable efforts. However, the experimental technique used is good, but the same results might have been obtained by pressing the aperture of a waveguide against the necessary part of the body. Because of high power density level at the forehead, it is better to choose some other part of the body. This will also remove fear of brain damage and uncertainty of applied energy due to the thinness of the skin over the skull.
Show BibTeX
@article{heating_of_living_tissues_g4011,
author = {H. P. Schwan and A. Anne and L. Sher},
title = {HEATING OF LIVING TISSUES},
year = {1966},
}