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DC ELECTRICAL ENVIRONMENT IN PROXIMITY TO VDTS

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Jonathan M. Charry, William H. Bailey, T. Dan Bracken · 1985

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Computer monitors create DC electric fields up to 5,000 V/m and deplete beneficial negative ions, potentially explaining early reports of operator health complaints.

Plain English Summary

Summary written for general audiences

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 beneficial negative ions 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 deplete negative ions while creating substantial DC electric fields helps explain the non-specific health complaints reported by early computer users. 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.

Exposure Information

Specific exposure levels were not quantified in this study.

Cite This Study
Jonathan M. Charry, William H. Bailey, T. Dan Bracken (1985). DC ELECTRICAL ENVIRONMENT IN PROXIMITY TO VDTS.
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},
  
  
}

Quick Questions About This Study

Yes, this study found VDTs generate DC electric fields ranging from 5,000 volts per meter at 10 centimeters to 300 volts per meter at 180 centimeters from the screen during operation.
VDTs reduce both positive and negative ion concentrations in their immediate vicinity, with the lowest values observed closest to the monitors, ranging between 100-1,000 ions per cubic centimeter.
The highest DC electric fields of 5.0 kV/m were measured at 10 centimeters from energized VDT screens, decreasing significantly with distance to normal indoor levels.
Researchers classified these DC electric field levels as within the same magnitude as common indoor charges from materials like clothing and carpets, though VDT operation consistently increased field strength.
Reports in literature and news media linked VDT use to facial skin rashes and non-specific health complaints among computer operators, prompting investigation of the electrical environment.