Original article

Scand J Work Environ Health 1995;21(5):335-344    pdf


A double blind study of skin symptoms after reduction of electric fields from VDUs

by Oftedal G, Vistnes AI, Rygge K

Objectives The objective of this work was to determine whether facial skin symptoms are reduced by decreasing static and low-frequency electric fields produced by visual display units.

Methods The electric fields were reduced by electric-conducting screen filters. Twenty subjects took part in the study while working at their ordinary jobs, first two weeks without any filter, then two weeks with an inactive filter and two weeks with active filters (or in reversed order). The inactive filters were identical to the active ones except that the ground cable was cut. Measurements showed that the inactive filters reduced the static electric fields nonsignificantly less than the active filters. For extremely low-frequency fields the difference was greater, and the active filters reduced the very low-frequency fields significantly more than the inactive ones.

Results Most symptoms were less pronounced when active filters were used than when inactive filters were used. The differences were small, and for one symptom only, tingling, pricking or itching, the result was statistically significant. The recorded physical and psychosocial factors did not explain the reduction with the use of active filters. Days with a long time spent near a visual display unit resulted in significantly more pronounced symptoms than days with short time. The findings registered by a dermatologist did not reveal any consistent difference between the two periods with filters.

Conclusion The results weakly support the hypothesis that skin symptoms may be reduced by a reduction of electric fields.

The following article refers to this text: 2001;27(2):140-145