STUDIES OF THERMAL INJURY - V. The Predictability and the Significance of Thermally Induced Rate Processes Leading to Irreversible Epidermal Injury
F. C. HENRIQUES Jr., Ph.D. · 1947
This foundational 1947 thermal injury research still underlies today's EMF safety standards, despite growing evidence of non-thermal biological effects.
Plain English Summary
This 1947 research by Henriques established fundamental mathematical principles for predicting how heat exposure causes permanent skin damage. The study developed rate process equations to determine when thermal injury becomes irreversible in human skin tissue. This foundational work created the scientific framework still used today to assess thermal damage from any heat source.
Why This Matters
While this 1947 study predates modern EMF research by decades, Henriques' work on thermal injury mechanisms remains critically relevant to today's EMF health debates. The mathematical principles he established for predicting irreversible tissue damage form the foundation of current safety standards for microwave radiation, including the SAR (Specific Absorption Rate) limits used to regulate cell phones and wireless devices. The reality is that our current EMF safety guidelines rely heavily on preventing the thermal effects that Henriques first quantified, while largely ignoring non-thermal biological effects that modern research increasingly documents. This thermal-only approach to EMF safety represents a significant gap in protection, as it assumes that if radiation doesn't heat tissue enough to cause the burns Henriques studied, it must be safe. The science demonstrates this assumption is increasingly questionable.
Exposure Information
Specific exposure levels were not quantified in this study.
Study Details
To establish the rate process inherent in the irreversible changes of epidermis injured by heat and to invite speculation as to the base nature of these changes.
Data were derived from investigations in which a limited area of the skin was brought immediately to...
Thresholds A, B and C were identified as the three threshold values for epidermal injury as related ...
The success with which equations 11 and 12 predict these time-temperature relationships is shown in table 1. It can be seen that in general the experimental threshold data agree excellently with those predicted, and thus the applicability of equation 4 which has been tacitly assumed throughout this section is demonstrated. The nature of the changes induced in epidermis by hyperthermia was shown to conform to that of most chemical and physical rate processes. The rate of any conceivable process that may result in cell death depends on a critical energy content for the participants. The fraction of the participants, collectively considered, having this energy is determined by the activation energy and temperature. The kinetics of a considerable number of physical and chemical phenomena has been studied in detail, and it is possible to classify all rate processes, and hence, in particular, those mechanisms which may result in thermal injury, according to the order of magnitude of their net activation energy. The only biokinetic phenomena known to date that can account for epidermal cell death are the thermally induced changes in protein structure which have an activation energy in the neighborhood of 150 kilocalories per mol.
Show BibTeX
@article{studies_of_thermal_injury_v_the_predictability_and_the_significance_of_thermally_g3656,
author = {F. C. HENRIQUES Jr. and Ph.D.},
title = {STUDIES OF THERMAL INJURY - V. The Predictability and the Significance of Thermally Induced Rate Processes Leading to Irreversible Epidermal Injury},
year = {1947},
}