Interaction of Microwave and Radio Frequency Radiation with Biological Systems
Herman P. Schwan · 1971
This 1971 thermal-only EMF safety model underlies current standards but predates extensive non-thermal bioeffects research.
Plain English Summary
This landmark 1971 study by Herman Schwan examined how microwave and radio frequency radiation interacts with human tissues, establishing foundational principles still used today. The research found that non-thermal biological effects only occur at field strengths that are already thermally dangerous, and proposed a safety guideline of 3 mA/cm² current density for frequencies between 1-1000 MHz.
Why This Matters
This foundational work by Herman Schwan represents one of the earliest comprehensive analyses of EMF bioeffects, establishing principles that shaped decades of safety standards. Schwan's conclusion that non-thermal effects require thermally dangerous field strengths became a cornerstone argument for current exposure limits. However, this 1971 perspective predates thousands of studies showing biological effects at non-thermal levels. The reality is that Schwan's thermal-only paradigm, while groundbreaking for its time, has been challenged by extensive research demonstrating cellular and molecular changes at exposure levels far below those causing tissue heating. What this means for you: the safety standards based on this early thermal model may not account for the growing body of evidence showing biological responses to everyday EMF exposures from phones, WiFi, and other wireless devices.
Exposure Information
Specific exposure levels were not quantified in this study.
Show BibTeX
@article{interaction_of_microwave_and_radio_frequency_radiation_with_biological_systems_g4456,
author = {Herman P. Schwan},
title = {Interaction of Microwave and Radio Frequency Radiation with Biological Systems},
year = {1971},
}