8,655 Studies Reviewed. 86.9% Found Biological Effects. The Evidence is Clear.

Penetration and Thermal Dissipation of Microwaves in Tissues

Bioeffects Seen

A. Anne, M. Saito, O. M. Salati, H. P. Schwan · 1962

Share:

This foundational 1962 research revealed how microwaves penetrate tissue and generate internal heat, establishing the scientific basis for understanding biological exposure effects.

Plain English Summary

Summary written for general audiences

This 1962 technical report examined how microwave radiation penetrates into biological tissues and how that energy converts to heat within the body. The research focused on understanding the physical mechanisms of microwave absorption and thermal effects in tissue, laying groundwork for safety assessments. This early work helped establish the scientific foundation for understanding how microwave exposure affects living systems.

Why This Matters

This 1962 research represents pioneering work in understanding how microwave radiation interacts with biological tissue. At a time when microwave technology was rapidly expanding beyond military applications into civilian use, scientists recognized the need to understand penetration depths and heating patterns in living tissue. The science demonstrates that microwave energy doesn't just heat the surface of tissue like a conventional oven heats food from the outside. Instead, microwaves penetrate into tissue and create heat from within, with the depth depending on frequency and tissue type. What this means for you is that when you use microwave-emitting devices like cell phones, WiFi routers, or microwave ovens, the energy penetrates into your body and converts to heat at the cellular level. While this 1962 work focused on thermal effects, we now know that biological effects can occur at power levels far below those needed to cause detectable heating.

Exposure Information

A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 400 MHz to 10 GHz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 400 MHz to 10 GHzPower lines50/60 HzWiFi2.4 GHz5G mm28 GHzLogarithmic scale

Specific exposure levels were not quantified in this study.

Study Details

To determine the absorption cross section of human beings to electromagnetic energy and to provide information on the total scattering as well as absorption of energy by lossy dielectric objects.

The research was carried out in two phases: theoretical and experimental. In the theoretical phase, ...

For objects of the size of adult man, the relative absorption cross section is of the order of 50-pe...

The results are in good agreement with theory for the homogeneous sphere. It therefore appears reasonable to account for the layers of skin and fat which are above the muscle tissue in the results upward somewhat.

Cite This Study
A. Anne, M. Saito, O. M. Salati, H. P. Schwan (1962). Penetration and Thermal Dissipation of Microwaves in Tissues.
Show BibTeX
@article{penetration_and_thermal_dissipation_of_microwaves_in_tissues_g5784,
  author = {A. Anne and M. Saito and O. M. Salati and H. P. Schwan},
  title = {Penetration and Thermal Dissipation of Microwaves in Tissues},
  year = {1962},
  
  
}
No DOI on file for this study.

Quick Questions About This Study

This early technical report studied how microwave energy penetrates into biological tissues and converts to heat within the body, establishing fundamental understanding of microwave-tissue interactions that informed later safety research.
This research laid the scientific groundwork for understanding microwave biological effects during the early expansion of microwave technology from military to civilian applications, influencing decades of subsequent safety assessments.
Unlike surface heating, microwaves penetrate into tissue and cause molecules to vibrate rapidly, generating heat from within the tissue rather than just at the surface level.
The research investigated thermal dissipation patterns, studying how microwave energy spreads and converts to heat throughout different tissue types after initial penetration and absorption.
This foundational work on microwave tissue penetration helps explain how modern devices like cell phones and WiFi routers deposit energy in your body, though at much lower power levels.