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Thermophysiological responses of human volunteers during controlled whole‐body radio frequency exposure at 450 MHz
Author(s) -
Adair Eleanor R.,
Kelleher Sharon A.,
Mack Gary W.,
Morocco Tamara S.
Publication year - 1998
Publication title -
bioelectromagnetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.435
H-Index - 81
eISSN - 1521-186X
pISSN - 0197-8462
DOI - 10.1002/(sici)1521-186x(1998)19:4<232::aid-bem5>3.0.co;2-2
Subject(s) - specific absorption rate , zoology , skin temperature , dorsum , metabolic rate , medicine , absorption (acoustics) , thermoregulation , thermal sensation , radio frequency , chemistry , audiology , materials science , biology , thermal comfort , anatomy , biomedical engineering , meteorology , physics , telecommunications , computer science , antenna (radio) , composite material
Thermoregulatory responses of heat production and heat loss were measured in seven adult volunteers (four women and three men, aged 21–57 yr) during 45‐min dorsal exposures of the whole body to 450 MHz continuous wave radio frequency (RF) fields. Two power densities (PD) (local peak PD = 18 and 24 mW/cm 2 ; local peak specific absorption rate = 0.320 [W/kg]/[mW/cm 2 ]) were tested in each of three ambient temperatures (T a = 24, 28, and 31 °C) plus T a controls (no RF). No changes in metabolic heat production occurred under any exposure conditions. Vigorous increases in sweating rate on back and chest, directly related to both T a and PD, cooled the skin and ensured efficient regulation of the deep body (esophageal) temperature to within 0.1 °C of the normal level. Category judgments of thermal sensation, comfort, sweating, and thermal preference usually matched the measured changes in physiological responses. Some subtle effects related to gender were noted that confirm classic physiological data. Our results indicate that dorsal exposures of humans to a supra‐resonant frequency of 450 MHz at local peak specific absorption rates up to 7.68 W/kg are mildly thermogenic and are counteracted efficiently by normal thermophysiologic heat loss mechanisms, principally sweating. Bioelectromagnetics 19:232–245, 1998. Published 1998 Wiley‐Liss, Inc.