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ELECTROMAGNETIC POWER DEPOSITION IN MAN EXPOSED TO HIGH-FREQUENCY FIELDS AND THE ASSOCIATED THERMAL AND PHYSIOLOGIC CONSEQUENCES

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Arthur W. Guy, Curtis C. Johnson, James C. Lin, Ashley F. Emery, Kenneth F. Kramar · 1973

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1972 thermal modeling study found low-frequency EMF requires massive power to heat body, but ignored non-thermal biological effects.

Plain English Summary

Summary written for general audiences

This 1972 study used mathematical models to calculate how high-frequency radio waves are absorbed by the human body and converted to heat. Researchers found that at 20 MHz and below, power absorption is extremely low - requiring exposure levels hundreds of times higher than microwave safety standards to cause significant body temperature increases.

Why This Matters

This foundational thermal modeling study reveals a crucial gap in our understanding of EMF safety standards. While the researchers concluded that high-frequency fields below 20 MHz would require massive power densities to cause thermal effects, their analysis was purely theoretical and focused only on heating mechanisms. The reality is that this study helped establish the flawed premise that EMF safety should be based solely on thermal effects - ignoring the growing body of evidence showing biological impacts at non-thermal levels.

What's particularly striking is that even using their thermal-only framework, the researchers acknowledged that maintaining normal body temperature under EMF exposure would come at 'physiologic cost' including increased heart rate and altered blood flow. This early recognition that the body must work harder to maintain homeostasis under EMF exposure hints at the non-thermal biological stress we now know occurs at much lower exposure levels than those modeled in this 1970s research.

Exposure Information

Specific exposure levels were not quantified in this study.

Cite This Study
Arthur W. Guy, Curtis C. Johnson, James C. Lin, Ashley F. Emery, Kenneth F. Kramar (1973). ELECTROMAGNETIC POWER DEPOSITION IN MAN EXPOSED TO HIGH-FREQUENCY FIELDS AND THE ASSOCIATED THERMAL AND PHYSIOLOGIC CONSEQUENCES.
Show BibTeX
@article{electromagnetic_power_deposition_in_man_exposed_to_high_frequency_fields_and_the_g3853,
  author = {Arthur W. Guy and Curtis C. Johnson and James C. Lin and Ashley F. Emery and Kenneth F. Kramar},
  title = {ELECTROMAGNETIC POWER DEPOSITION IN MAN EXPOSED TO HIGH-FREQUENCY FIELDS AND THE ASSOCIATED THERMAL AND PHYSIOLOGIC CONSEQUENCES},
  year = {1973},
  
  
}

Quick Questions About This Study

The study calculated that 590 milliwatts per square centimeter of 20 MHz radiation would raise core body temperature by 2-4 degrees Celsius - levels hundreds of times higher than current environmental exposures from most sources.
Scientists used spherical mathematical models representing a 70-kilogram human to calculate electromagnetic field penetration and power absorption, combining quasi-static electric and magnetic field solutions for theoretical predictions.
Yes, the study showed that for field impedances below 1200π ohms, magnetic-field-induced absorption predominates over electric field absorption, making magnetic field measurements critical for exposure assessment.
The mathematical model predicted that steady-state thermal conditions would be achieved within 100-120 minutes of continuous high-level EMF exposure, with the body reaching a new temperature equilibrium.
Even when core temperature remains stable, the body pays physiological costs including increased skin blood flow, elevated heart rate, higher cardiac output, and diverted blood flow from internal organs.