1998년 7월에 발표한 WHO Fact Sheet No. 201은 영상출력장치(VDU)와 인체영향에 대해 다루었습니다. 1998년 당시 전형적인 VDU는 CRT(브라운관) 모니터나 TV가 대표적이었으며, VDU로부터 발생하는 전자파가 두통, 현기증, 피로, 백내장, 임신과정의 영향, 피부 발진 등의 발생 원인이 되는지 선 연구된 결과들을 종합적으로 분석하여 발표하였습니다. 연구들은 VDU에서 발생되는 전자파로 인한 인체영향은 증명되지 않았으며, 연관관계를 찾기 어렵다고 언급하였습니다. 최근에 사용되는 LCD, LED 등은 CRT(브라운관)에 비해 전자파 노출량이 극히 적어 더욱 영향이 없습니다.

WHO Fact Sheet No. 201 원문, 현재 해당 문서를 업데이트 중

VIDEO DISPLAY UNITS (VDUs) AND HUMAN HEALTH

Over 30 years have passed since the introduction of mass-produced video display units (VDUs) into the workplace. These machines are also called video display terminals (VDTs) and most commonly take the form of computer screens. The rapid proliferation of computers has lead to a large increase in VDU use in both the workplace and at home. It is estimated that by the year 2000, 60% of the North American workforce will be using VDUs and more than 150 million units will be in service worldwide.

What are VDUs?

A VDU is essentially a television-type monitor that displays information received from a computer rather than from a broadcast signal for television. The typical VDU creates images in a large evacuated cathode-ray tube (CRT) by directing a beam of high-energy electrons from the cathode onto a special phosphor-coated, glass screen. This coating emits light when struck by the fast-moving electrons. The electron beam creates the image from computer signals that control coils, at the back of the CRT, that sweep the electrons in the vertical and horizontal directions. These coils are called vertical and horizontal deflection coils. The electronic circuitry used to create the image gives rise to static electric and magnetic fields, as well as low and high frequency electromagnetic fields.

Radiation and Fields

Almost the entire electromagnetic spectrum is included in the electric and magnetic fields and optical radiation produced by VDUs. The optical radiation emitted includes long-wavelength ultraviolet (UV), visible, and infrared (IR) radiation. Visible light forms the image that the VDU is intended to produce. IR appears as heat dissipated by the unit. Very small amounts of UV are emitted from the tube, much less than that coming through the window on a winter's day.

Electric and magnetic fields are emitted in three different frequency ranges. The horizontal deflection coils emit fields operating predominantly in the frequency range 15-35 kHz. Extremely low frequency (ELF) fields at 50 or 60 Hz come from the power supply, transformers and the vertical deflection coils. Finally, weak signals at higher radio frequencies (RF) come from the VDU's interior electronic circuitry and signals received from the computer.

Static electric fields are also present, particularly when there is low humidity, from the build-up of electric charge by electrons striking the front of the screen. In addition, high frequency sound or ultrasound radiation, possibly detected as a high pitch noise, is emitted from various VDU components, mostly by the horizontal deflection circuits.

Very low-energy X-rays are produced inside the CRT, but the glass screen is thick enough to completely absorb them before they escape from the VDU.