AN ATTEMPT TO EVALUATE THE EXPOSURE OF OPERATORS OF PORTABLE RADIOS AT 30 MHZ
O. Balzano, O. Garay, F.R. Steel · 1970
Early 1970s research on 30 MHz portable radio exposure helped establish methods still used to assess RF safety today.
Plain English Summary
This 1970 technical report examined RF energy exposure levels from portable radio operators using 30 MHz frequencies. Researchers used phantom models and tissue simulation techniques to measure how much radiofrequency energy was deposited in human tissue during radio operation. The study represents early efforts to quantify occupational RF exposure from handheld communication devices.
Why This Matters
This study marks an important milestone in EMF research history - one of the first systematic attempts to measure real-world RF exposure from handheld communication devices. While 30 MHz portable radios might seem antiquated today, the exposure assessment methods developed here laid groundwork for evaluating modern wireless devices. The reality is that radio operators in 1970 faced significant RF exposure during transmission, often holding devices close to their bodies for extended periods. What this means for you: the fundamental physics of RF energy absorption hasn't changed, only the frequencies and power levels of our devices. Today's smartphones, tablets, and wireless headsets operate at much higher frequencies (typically 700 MHz to 5 GHz) but use similar transmission principles. The tissue simulation techniques pioneered in studies like this continue to inform modern SAR (Specific Absorption Rate) testing standards.
Finding
The temperature measurements show that a deposition rate substantially smaller than 1 mW/gr is caused by the radios used in the tests.
In their words
“The temperature measurements show that a deposition rate substantially smaller than 1 mW/gr is caused by the radios used in the tests.”
Figures from the Original Paper
Diagram extracted from the original research document.
Exposure Information
Specific exposure levels were not quantified in this study. Duration: 1 minute
Study Details
To evaluate the exposure of operators of portable radios at 30 MHz by measuring energy deposition in simulated human tissue.
Simulated human tissue was used in the form of muscle and fat/bone phantoms. The muscle mixture had ...
No detectable temperature increase was found in the phantoms for a one-minute exposure, even when an...
No thermal hazard is present for the low deposition rates caused by portable radios at 30 MHz. The power densities near the radios and antennas were evaluated and plotted in Figures 2 and 3.
Show BibTeX
@article{an_attempt_to_evaluate_the_exposure_of_operators_of_portable_radios_at_30_mhz_g4594,
author = {O. Balzano and O. Garay and F.R. Steel},
title = {AN ATTEMPT TO EVALUATE THE EXPOSURE OF OPERATORS OF PORTABLE RADIOS AT 30 MHZ},
year = {1970},
}