Sun lamp is an electrical device that produces artificial ultraviolet radiation. The energy given off by a sun lamp is similar to the ultraviolet radiation found in natural sunlight. Sun lamps are used primarily to produce a suntan, but they also have therapeutic uses.
Most sun lamps operate with an electric current that passes between two electrodes and is surrounded by a gas vapor, often mercury. The electric current and the gas vapor react to produce ultraviolet radiation–that is, ultraviolet light. Wavelengths of ultraviolet light are shorter than wavelengths in the visible spectrum and thus cannot be seen by the human eye. However, most sun lamps also produce some visible light.
The majority of sun lamps are designed for home use. They are small and lightweight, and they can be plugged into a standard household electric outlet. Many health clubs and tanning parlors feature large booths equipped with ultraviolet lights and reflectors to provide an even, allover tan. However, people should exercise great care when using these devices because the intensity of light they produce is much more powerful than sunlight.
Most sun lamp users can achieve a tan with repeated moderate exposures over a period of several weeks. But individuals with fair skin may suffer severe sunburns after only a few seconds of exposure to sun lamps and thus should not use these devices. Repeated exposure to sun lamps leads to premature aging of the skin and skin cancer. In addition, concentrated amounts of ultraviolet radiation can cause a variety of eye disorders, ranging from mild irritation to temporary blindness. To help prevent injuries caused by overexposure, laws require sun lamp manufacturers to provide protective eye goggles, timing switches that limit the length of exposure, and other safety features.
Some dermatologists use sun lamps to treat certain skin diseases. A type of sun lamp known as a germicidal lamp emits short ultraviolet wavelengths that kill bacteria and viruses. These lamps are used to disinfect the air in hospital operating rooms and to sterilize surgical equipment.
