A survey of electric and magnetic-fields among VDT operators in offices

• In this study, the ambient electric and magnetic fields as well as the electromagnetic fields associated with VDT's at 150 offices are measured. The aim of the study is to find out the general level of the various electromagnetic parameters in offices and establish a technical base for a case referent study of skin symptoms among VDT workers. The median value of the 50-Hz background field in the 150 offices is 0.07 muT. Seven of the offices have background levels higher than 0.5 muT, which is high enough to cause distortion of the picture on the screen. The dominating source for electric fields in the ELF range is electric equipment in the office, not the VDT's. The median value of the electric field in the VLF range is 1.5 V/m. The equivalent surface potential is less than 0.5 kV for 63% of the measured VDT's. The computer monitor is a major source for magnetic fields in the offices. The median value of the magnetic field in the ELF range in front of the VDT is 0.21 muT, and in the VLF range 0.03 muT.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Hälsovetenskap -- Arbetsmedicin och miljömedicin (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Health Sciences -- Occupational Health and Environmental Health (hsv//eng)

Keyword

Video display terminals

frequency

employees

units

work

Publication and Content Type

ref (subject category)

art (subject category)