THE EFFECT OF MICROWAVES ON BONE AND BONE MARROW AND ON ADJACENT TISSUES
Joseph P. Engel, J. F. Herrick, Khalil G. Wakim, John H. Grindlay, Frank H. Krusen · 1950
This pioneering 1950 research established early scientific interest in how microwave energy affects bone marrow and blood-forming tissues.
Plain English Summary
This 1950 study by Joseph Engel examined how microwave radiation affects bone, bone marrow, and surrounding tissues in laboratory animals. The research focused on microwave diathermy effects and tissue temperature changes. This represents some of the earliest scientific investigation into how microwave energy interacts with skeletal and blood-forming tissues.
Why This Matters
This research holds remarkable historical significance as one of the earliest investigations into microwave biological effects, published just five years after World War II when microwave technology was emerging from military radar applications. The focus on bone and bone marrow is particularly important because these tissues are critical for blood cell production and immune function. What makes this study especially relevant today is that bone marrow contains some of our most rapidly dividing cells, which research consistently shows are among the most vulnerable to electromagnetic radiation damage. The temperatures generated by microwave diathermy in 1950 medical applications were likely far higher than what we experience from modern devices, but the fundamental biological mechanisms Engel was studying remain the same. Today's wireless devices operate at similar microwave frequencies, and while the power levels are lower, we're exposed continuously rather than in controlled medical sessions.
Finding
Thirty minutes of exposure at 65 watts produced an average temperature rise of 4.1 degrees (C.) in the subcutaneous tissue, 5.0 degrees in the tibial cortex; 3.4 degrees in the tibial marrow and 4.3 degrees in the gastrocnemius muscle.
In their words
“Thirty minutes of exposure at 65 watts produced an average temperature rise of 4.1 degrees (C.) in the subcutaneous tissue, 5.0 degrees in the tibial cortex; 3.4 degrees in the tibial marrow and 4.3 degrees in the gastrocnemius muscle.”
Figures from the Original Paper
Diagrams extracted from the original research document.
Exposure Information
Specific exposure levels were not quantified in this study. Duration: 5 to 30 minutes
Study Details
To determine the temperature relationships produced between bone and soft tissue following microwave diathermy.
Two groups of large dogs were used: Those of group I were anesthetized with pentobarbital sodium, an...
Heating Effects on Subcutaneously Located Bone: The average initial temperatures in 5 anesthetized d...
The presence of bone aids in raising the temperature of the overlying muscle following microwave diathermy. An increase in the circulation is then produced which provides a good means for the dispersal of heat. The rectangular director placed parallel to the longitudinal axis of the extremity was found to be more suitable than other types of directors for heating subcutaneously located bone. This is due to the fact that the maximal concentration of energy is on the bone. When the lateral aspect of the leg was exposed to microwaves, higher temperatures were developed in the tibialis anterior, which overlies bone, than in the gastrocnemius, which does not overlie bone, provided the time of exposure did not exceed fifteen minutes. An impedance-matching transformer placed in the field of microwave irradiation caused an increase in the tissue temperature of approximately 300 per cent over the values obtained when no transformer was used.
Show BibTeX
@article{the_effect_of_microwaves_on_bone_and_bone_marrow_and_on_adjacent_tissues_g3869,
author = {Joseph P. Engel and J. F. Herrick and Khalil G. Wakim and John H. Grindlay and Frank H. Krusen},
title = {THE EFFECT OF MICROWAVES ON BONE AND BONE MARROW AND ON ADJACENT TISSUES},
year = {1950},
}