6,486 Studies Reviewed. 85.2% of Original Studies Found Biological Effects. The Evidence is Clear.
Shield Your Body
Whole Body / GeneralPart of the Glaser Archive

Effects of Microwave on Mankind - Second Annual Progress Report

Bioeffects Seen

H. P. Schwan, O. Salati, H. Pauly, A. Anne, C. D. Ferris, J. Twisdom · 1959

Share:

This pioneering 1959 research established foundational knowledge about how human tissues absorb microwave radiation.

Plain English Summary

Summary written for general audiences

This 1959 technical report by H.P. Schwan examined how microwave radiation affects human body tissues, focusing on absorption patterns and thermal effects. The research studied how microwaves interact with human biological systems and measured their absorption characteristics. This represents early foundational work on understanding microwave exposure effects on humans.

Why This Matters

This 1959 report represents a critical piece of early microwave research that helped establish the foundation for our understanding of how electromagnetic fields interact with human tissue. H.P. Schwan was a pioneer in bioelectromagnetics, and his work on absorption cross sections and thermal effects laid groundwork that still influences safety standards today. What makes this particularly relevant is the timing - this research began just as microwave technology was expanding beyond military applications into civilian use.

The focus on thermal flux meters and absorption patterns reflects the prevailing scientific view of the 1950s that heating was the primary concern with microwave exposure. Today we know the biological effects extend far beyond simple heating, but this early work established important baseline measurements. Understanding how your body absorbs microwave energy - whether from early radar systems in 1959 or your smartphone today - remains fundamentally important for assessing exposure risks.

Exposure Details

Power Density
10 mW/cm²
Electric Field
2 V/m

Exposure Context

This study used 10 mW/cm² for radio frequency:

This study used 2 V/m for electric fields:

Building Biology guidelines are practitioner-based limits from real-world assessments. BioInitiative Report recommendations are based on peer-reviewed science. Check Your Exposure to compare your own measurements.

Where This Falls on the Concern Scale

Study Exposure Level in ContextStudy Exposure Level in ContextThis study: 10 mW/cm²Extreme Concern - 1,000 µW/m²FCC Limit - 10M µW/m²Effects observed in the Extreme Concern range (Building Biology)This level is 10 times the FCC limit
A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 100 MHz to 3 GHz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 100 MHz to 3 GHzPower lines50/60 HzCell phones~1 GHzWiFi2.4 GHz5G mm28 GHzLogarithmic scale

Study Details

To investigate the effects of microwave on mankind, including development of electrical substitutes for human body tissues, techniques for determining relative absorption cross-section studies, development of test chambers for microwave scattering studies, and theoretical basis of thermal flux meters and dose meters.

Development of electrical substitutes for human body tissues using dioxan-water-electrolyte mixtures...

Developed electrical substitutes for body tissues using dioxan-water-electrolyte mixtures that permi...

Electrical substitutes for body tissues using dioxan-water-electrolyte mixtures can simulate any tissue of possible interest at any frequency throughout the microwave spectrum; thermal approach for measuring absorbed energy is feasible with proper equipment and methodology; test chamber design allows for accurate relative absorption cross-section measurements; thermal dosemeters using small spheres are effective for measuring microwave exposure levels with good frequency response; the linear part of the transient period should be used for quantitative work rather than steady state temperature measurements.

Cite This Study
H. P. Schwan, O. Salati, H. Pauly, A. Anne, C. D. Ferris, J. Twisdom (1959). Effects of Microwave on Mankind - Second Annual Progress Report.
Show BibTeX
@article{effects_of_microwave_on_mankind_second_annual_progress_report_g5562,
  author = {H. P. Schwan and O. Salati and H. Pauly and A. Anne and C. D. Ferris and J. Twisdom},
  title = {Effects of Microwave on Mankind - Second Annual Progress Report},
  year = {1959},
  
  
}
No DOI on file for this study.

Quick Questions About This Study

Herman Schwan was a pioneering bioelectromagnetics researcher whose 1950s work established fundamental principles of how electromagnetic fields interact with biological tissues. His research laid the groundwork for modern EMF safety standards and exposure assessment methods.
The research focused on absorption cross sections and thermal flux measurements to understand how microwave energy penetrates and heats human body tissues. This work established baseline data for how different body tissues absorb electromagnetic energy.
Thermal flux meters measured heat generation in tissues, which was considered the primary biological effect of microwave exposure in the 1950s. This thermal-focused approach influenced decades of safety standards, though we now know non-thermal effects also occur.
This foundational work established measurement techniques and absorption principles still used today. While modern research has expanded beyond thermal effects to include non-thermal biological impacts, the basic physics of tissue absorption remains relevant.
Early microwave research primarily focused on radar systems and industrial heating applications, as consumer microwave technology was just emerging. This military and industrial focus shaped early understanding of human exposure scenarios and safety considerations.