ABSTRACT

The ultraviolet (UV) light is an electromagnetic wave with a wavelength from 400 to 100 nm. UV spectral region is divided into three sub-regions, based on a convention established during the Second International Congress on Light in 1932. UV light with wavelengths from 315 to 400 nm is classified as UV-A which can penetrate the atmosphere without significant absorption. It damages the deeper layers of the skin or cause cataracts. UV-B ranges from 280 to 315 nm, which is partially absorbed in the atmosphere, and may cause skin cancer. UV light with wavelengths shorter than 280 nm is referred to as UV-C, or deep UV (DUV) which does not reach the earth’s surface due to absorption by ozone and oxygen molecules in the stratosphere. UV-C light has the special ability to destroy the DNA and RNA polymerase of microbes including bacteria, viruses, and cancer cells and to treat dermatological diseases with minimum impact on the human body (Gaska et al. 2004; Schubert 2006).