DC ELECTRICAL ENVIRONMENT IN PROXIMITY TO VDTS
Jonathan M. Charry, William H. Bailey, T. Dan Bracken · 1985
Computer monitors raised DC electric fields to as much as 5,000 V/m close to the screen and lowered air ion concentrations, but the effects were small and comparable to everyday indoor variation.
Plain English Summary
This 1985 study measured the electrical environment around computer monitors (VDTs) to investigate reports of skin rashes and health complaints among operators. Researchers found that VDTs reduced both negative and positive ion concentrations in their immediate vicinity and created DC electric fields up to 5,000 volts per meter at close range, though these levels were comparable to common indoor electrical charges.
Why This Matters
This early research provides crucial baseline data on the electrical environment created by computer displays, predating our modern understanding of EMF health effects. The finding that VDTs lowered ion concentrations and raised DC electric fields close to the screen came with the authors' conclusion that the absolute magnitude of the effects was small, comparable to everyday variations in the indoor environment. What's particularly significant is that these DC field strengths of 5,000 V/m at 10 centimeters were deemed 'normal' for indoor environments in 1985. The reality is that we've normalized exposure to artificial electrical fields that didn't exist throughout human evolution. While the study authors dismissed these levels as comparable to static charges from clothing and carpets, this comparison misses the point that chronic occupational exposure differs fundamentally from brief static encounters.
Finding
This study determined that while it was possible to detect an influence of VDTs on the DC electrical environment close to the screen, the absolute magnitude of the effects observed was small. Moreover, the relative magnitude of these effects is comparable to everyday variations in the indoor environment that might be related to such variables as atmospheric changes and the wearing of synthetic clothing materials.
In their words
“This study determined that while it was possible to detect an influence of VDTs on the DC electrical environment close to the screen, the absolute magnitude of the effects observed was small. Moreover, the relative magnitude of these effects is comparable to everyday variations in the indoor environment that might be related to such variables as atmospheric changes and the wearing of synthetic clothing materials.”
Figures from the Original Paper
Diagram extracted from the original research document.
Show BibTeX
@article{dc_electrical_environment_in_proximity_to_vdts_g6155,
author = {Jonathan M. Charry and William H. Bailey and T. Dan Bracken},
title = {DC ELECTRICAL ENVIRONMENT IN PROXIMITY TO VDTS},
year = {1985},
}