Radiation surveys of video display terminals: report of a two-year study, June 1983-June 1985.

Abstract

Growing concern about possible harmful visual display terminal (VDT) radiation emissions by East-West Center (EWC) staff members, particularly secretarial staff, resulted in the formation of a VDTs Health Effects Committee in August, 1982. The Committee recommended that all EWC VDTs currently in use be surveyed for X-ray and ultraviolet radiation emissions to determine if staff members were being exposed to potentially hazardous levels of radiation. The committee also recommended that all VDTs falling into one of the following categories be surveyed: those that were being used for the first time; those that had just been repaired or serviced; those that were five years old; or those that were being used after being in storage. In total, 186 VDTs were surveyed for X-ray and ultraviolet radiation emissions by the University of Hawaii radiation safety of ficer and the East-West Center health of ficer between April 1983 and June 1985. The surveys were done in two phases. In the first phase, 101 VDTs were surveyed during April and May, 1983. This constituted all the available terminals in use at that time. Over the next two years, 85 VDTs were surveyed when they experienced one of the four conditions mentioned above. The majority of VDTs surveyed (163 or 87.6% of the sample size) were from one manufacturer and the remaining 23 terminals (12.3% of the sample size) were from eight different manufacturers. All surveys were done during work hours and disruption of the employee's work routines was minimal. All terminals surveyed were being used by EWC employees. Two instruments were used to measure ultraviolet radiation in the range of 254 to 400 nanometers (nm). This is the known range of carcinogenic effects in humans. All the measurements with the instruments were taken on contact with the VDT screen. Two instruments that were capable of detecting low energy X-rays (the type potentially emitted by VDTs) were used to measure X-ray radiation. The radiation levels emitted by VDTs are very low compared to current occupational exposure standards. The results from the 186 VDTs surveyed at the EWC demonstrated that exposure to ultraviolet and X-ray radiation was below the detection capability of the survey Instruments and thus well below current occupational exposure standards. Based on this survey data, it appears that VDTs do not present a radiation hazard to the employee working on or near a terminal.