Perhaps the most useful type of fluorescent lamps in terms of its application to medicine is the UV light bulbs or ultraviolet light bulbs. In medicine, UV light is effectively used in phototherapy or light therapy. Patients are exposed to the UV light in a period of time depending on the dose necessary for treatment. It is used primarily in treating skin problems such as acne vulgaris.
Ultraviolet light is not visible to the naked eye. It surpasses the purple range of what the human eye is capable of detecting. The visible spectrum is from red to violet while those below and above this range are either ultraviolet or infrared. The ultraviolet spectrum or range is divided into UVA, UVB and UVC. These are wavelength classifications between 100-400 nanometers which is the full range of the UV spectrum. UVA which is 315-400 nm is effective as insect traps, phototherapy, blacklight, stage effects and in sun tanning. The UVB has a wavelength of 280-360 nm which causes sun burns. It is also used in inspection, analysis and phototherapy. The UVC range is germicidal at 253.7 nm and ozone producing at 185 nm.
The UV-A Blacklight bulbs are UV light bulbs that allow only the benign long wave UVA ray to pass through its “black” glass tube coated in a special type of phosphor. It blocks almost all visible light and absorbs the harmful UVB and UVC lights.
UV light bulbs which emit the UVB light are used in skin phototherapy, tests or inspections of the ultraviolet resistance of materials such as in thermoplastics and other types of plastics. They are also used in scientific analysis.
Germicidal bulbs are UV-C bulbs that are used in material and surface purification as well as in air and water purification. These lamps contain no phosphor making them technically, as discharge lamps. The ultraviolet light emitted by these lamps can kill germs by stimulating the breakdown of any microorganism as it removes their reproductive capabilities. They may also be used by scientists to identify certain minerals. Germicidal bulbs are often seen in kitchens especially of restaurants and other commercial establishments that sell food. They are also used in food conveyor purification, ink curing applications, aquacultural water treatment and wastewater treatment.
Prolonged exposure to UV light is a health hazard and should always be considered in the application of these lamps. UVA and UVB may cause premature aging while UVC causes skin and eye damage. The use of protective wear is of chief importance in dealing with these materials.