RADIATION SURVEYS—MEASUREMENT OF LEAKAGE EMISSIONS AND POTENTIAL EXPOSURE FIELDS
David E. Janes, Jr. · 1979
1979 research surveyed actual radiation leakage from electronics, establishing foundational methods for measuring real-world EMF exposure levels.
Plain English Summary
This 1979 technical study by Janes examined radiation leakage from electronic equipment and measured the electromagnetic fields people might be exposed to. The research focused on surveying actual emission levels from various radiofrequency sources to understand potential human exposure scenarios. This type of foundational measurement work helped establish early understanding of EMF exposure levels in real-world environments.
Why This Matters
This 1979 research represents crucial foundational work in EMF exposure assessment, conducted during an era when electronic devices were rapidly proliferating but safety standards were still developing. What makes this study significant is its focus on actual leakage emissions rather than theoretical calculations. The reality is that many electronic devices emit more radiation than their specifications suggest, and this type of survey work helps identify those gaps between design intentions and real-world performance.
The timing of this research is particularly relevant today. In 1979, we had far fewer EMF sources in our environment, yet researchers were already concerned enough about leakage emissions to conduct systematic surveys. Fast-forward to today's environment with smartphones, Wi-Fi routers, smart meters, and countless wireless devices, and you can see why understanding actual emission patterns becomes even more critical for protecting public health.
Figures from the Original Paper
Diagram extracted from the original research document.
Exposure Information
Specific exposure levels were not quantified in this study.
Study Details
To present results of measurements of radiofrequency electromagnetic fields from various sources and to characterize both general and specific source radiofrequency environments.
Measurements were made in 15 U.S. cities using a sophisticated measurement system consisting of spec...
In the general radiofrequency environment, median exposure levels in 15 U.S. cities ranged from 0.00...
The multisource, multifrequency, general radiofrequency environment is dominated by low-level radio and television transmission. Microwave radio relays, low-power radars, mobile communications systems, and microwave ovens make almost negligible contributions to the general radiofrequency environment. The largest multisource radar field measured in the general environment of one urban area was less than the median value for the broadcast band (54-900 MHz.). It is estimated that most of the population (over 99%) is continuously exposed to levels less than 1 μW/cm². This level is well below current American National Standards Institute standard of 10,000 μW/cm² and below extremely conservative standards of the U.S.S.R. (2 V/m. = 1 μW/cm² for frequencies between 30 and 300 MHz., 5 μW/cm² for frequencies between 300 MHz. and 300 GHz.). The specific source environment for most broadcast sources is below 100 μW/cm². The only fields in excess of this value occur on the antenna towers, in the immediate vicinity of the base of some FM antenna towers, and on the roofs of tall buildings that are located within a city block or so of FM and TV broadcast antennas. Intermittent, partial body exposures to high levels can and do occur, particularly from medical diathermy units, electrosurgical units, industrial sources, and fields near mobile communications equipment.
Show BibTeX
@article{radiation_surveys_measurement_of_leakage_emissions_and_potential_exposure_fields_g6049,
author = {David E. Janes and Jr.},
title = {RADIATION SURVEYS—MEASUREMENT OF LEAKAGE EMISSIONS AND POTENTIAL EXPOSURE FIELDS},
year = {1979},
}