Ultraviolet (UV) Light

Ultraviolet light, known as UV light, is electromagnetic radiation with a shorter wavelength than visible light but a longer wavelength than x-rays (non visible). Although Ultraviolet Light is invisible to the human eye, it got its name due to the association with the colour violet that is visible when UV is used in lighting such as blacklights.

UV rays are found in sunlight, most people are aware of the benefits and also health complications that it can cause such as sunburn. Most UV Light can be classified as non ionizing radiation, and can cause chemical reactions, and make many substances glow or fluoresce under it.

Ultraviolet Fluorescent Lamps

Fluorescent lights that do not use a phosphorescent coating in order to convert UV to visible light, emit ultraviolet light with two peaks at 253.7nm and 185nm, this is down to the mercury within the bulb. Germicidal Lamps use glass covered in a preservative which is used to block the 185nm wavelength. With the additional use of appropriate phosphorescent coating, they can be modified to produce UVA, UVB or even a visible light spectrum. 

Health

There are many health aspects that surround the exposure and handling of UV rays. Exposure can help with the development of vitamin D which is vital for calcium metabolism which has its uses around the body for bone growth etc. Over exposure to UVB radiation may cause sunburn which is usually painful and can even cause some forms of skin cancer. The most risky form, being malignant melanoma which is mostly caused by indirect DNA damage. In humans, over exposure to solar UV radiation may result in acute and chronic health affects on the skin, eye and possibly immune system.

On a much brighter note, when the method of UV light is harnessed accordingly for commercial lighting the benefits are rewarding, producing lighting and lamps which we use an a day to day basis.