Definition of Ultraviolet Radiation:
- Ultraviolet (UV) radiation is a form of electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays.
- UV radiation is traditionally divided into four regions: near, middle, far, and extreme, based on the interaction of wavelengths of ultraviolet radiation with biological materials.
- Based on their wavelengths, UV radiation is divided into three main groups: UVA, UVB, and UVC.
- UV radiation has shorter wavelengths (higher frequencies) compared to visible light but has longer wavelengths (lower frequencies) compared to X-rays.
Positive Effects of Ultraviolet Radiation:
- Ultraviolet radiation stimulates the production of vitamin D in the skin.
- UV radiation can be used as a therapeutic agent for diseases such as psoriasis.
- Ultraviolet radiation is useful as a sterilizing agent due to its bactericidal capabilities at wavelengths of 260–280 nm.
Negative Effects of Ultraviolet Radiation:
- Too much ultraviolet radiation from sunlight is dangerous and can cause skin aging, eye damage, and skin cancer.
- UVA rays cause skin aging and eye damage, and can lower the bodys ability to fight off illness. UVA rays also contribute to the risk of skin cancer.
- UVB rays cause sunburns, skin cancer, skin aging, and snow blindness, and can lower the bodys ability to fight illness.
- UVC rays do not reach the Earths surface because they are completely absorbed by the atmosphere.
Materials that Produce Ultraviolet Radiation:
- Ultraviolet radiation is produced by high-temperature surfaces, such as the Sun, in a continuous spectrum and by atomic excitation in a gaseous discharge tube as a discrete spectrum of wavelengths.
- Some artificial sources of UV radiation include tanning beds, mercury vapor lighting, some halogen, fluorescent, and incandescent lights, and some types of lasers.
- When UV radiation falls on certain materials, it may cause them to fluoresce.
