Cathode ray tubes (CRT), once the only option for computer monitors, have been largely replaced by liquid crystal display screens (LCDs). Though CRTs still have an edge in speed and color fidelity, LCDs are slimmer, lighter and more energy-efficient. LCDs also have advantages when it comes to radiation, though there are many kinds of radiation. Monitors emit light and they radiate sound energy. They also emit other kinds of radiation and interference. Neither one is completely free of this, but LCDs come out ahead.
The CRT makes visible light when electrons inside the tube hit the phosphor coating just behind the screen. The LCD is a light filter, giving color to white light that passes through it. It needs a separate light source to work. Two types are currently used: fluorescent lighting and light-emitting diodes (LEDs). Fluorescent lamps are inexpensive, bright and compact. LEDs are more durable, but in 2009, the brightest ones are still more expensive.
CRTs can generate X-rays. While these X-rays are "soft," or low-energy, the CRTs are made with leaded glass as shielding so no harmful radiation reaches the user. The X-rays come from high voltages used to run the CRT. LCD screens run on much lower voltages, so they don't create X-rays.
CRTs are notorious for making a soft, high-pitched whine. The horizontal scan rate, the frequency at which the electron gun "paints" across the screen, is at the upper range of human hearing. It can be a bother for some people. Though LCD monitors work on a totally different principle, they, too, can whine.
CRTs can emit a small amount of ultraviolet (UV) light. Other than a possible link to eyestrain from long-term use, no health hazards are apparent. Most LCD monitors have a fluorescent backlight. Fluorescent lamps have the potential for some UV, but only if they're deliberately designed for it. UV emissions for LCDs are lower than CRTs.
Both LCD and CRT monitors emit some form of electromagnetic interference (EMI). Federal Communications Commission (FCC) regulations for computer equipment sold in the United States limit how much interference a monitor can make. These limits are low, but still detectable if you have the right equipment. The FCC limits are meant for practical use in home and office. Higher-priced monitors are available for specialty applications where interference must be as low as possible.
- Photo Credit dno1967, creativecommons.org
Do LCD Computer Monitors Emit Radiation?
Since computers began dominating home and work environments, health concerns have arisen about prolonged computer usage. In the late 1970s and 1980s,...
How to Lower the Radiation From a Plasma TV
Plasma TVs emit radiation, but they are safer than CRT televisions.
Common CRT TV Problems
... there is little to no danger of health hazards from CTR TVs regarding radiation or ... cathode ray tube ... television...
Health Risks of Computer Screens
... there has also been concern regarding the emission of radiation from monitors. ... Dell LCD monitors display the video as directed...
Advantages & Disadvantages of Monitors
Computer monitor manufactures are continuously seeking ways to improve liquid crystal display (LCD) and cathode ray tube ... radiation and microwave radiation,...
The Health Hazards of Plasma TVs
How to Lower the Radiation From a Plasma TV; Radiation Emitted From Plasma Vs. LCD; Hazards of LCD TVs; Comments You May...
Dangers of LED TVs
How to Lower the Radiation From a Plasma TV. X-ray radiation is the most dangerous ... Light-Emitting Diode (LED) ... How to...
Laptop Radiation Effects
The common issue of "eye fatigue" usually comes from the set-up from your computer. A brightness setting too high, ... How Much...
Negative Effects of LCD Monitors
Radiation Emitted by Cathode Ray Tube Vs. LCD Screen. How to Fix LCD Monitors. The Best Ways to Clean LCD Monitors. Difference...