UV Radiation

"Taking steps to protect yourself from the sun is a year-round responsibility. Protect yourself and others from the sun with shade, a shirt, or sunblock (SPF 15+) all year long.

Ultraviolet (UV) radiation is a form of non-ionizing radiation that is emitted by the sun and artificial sources, such as tanning beds. While it has some benefits for people, including the creation of Vitamin D, it also can cause health risks.

• Our natural source of UV radiation:
  • The sun
• Some artificial sources of UV radiation include:
  • Tanning beds
  • Mercury vapor lighting (often found in stadiums and school gyms)
  • Some halogen, fluorescent, and incandescent lights
  • Some types of lasers

What are the different types of UV radiation rays?

UV radiation is classified into three primary types: ultraviolet A (UVA), ultraviolet B (UVB), and ultraviolet C (UVC). These groups are based on the measure of their wavelength, which is measured in nanometers (nm= 0.000000001 meters or 1×10-9 meters).

Wave Type	UVA	UVB	UVC
Wavelength	315- 399 nm	280-314 nm	100-279 nm
Absorption Level	Not absorbed by the ozone layer	Mostly absorbed by the ozone layer, but some does reach the Earth’s surface	Completely absorbed by the ozone layer and atmosphere

All of the UVC and most of the UVB radiation is absorbed by the earth’s ozone layer, so nearly all of the ultraviolet radiation received on Earth is UVA. UVA and UVB radiation can both affect health. Even though UVA radiation is weaker than UVB, it penetrates deeper into the skin and is more constant throughout the year. Since UVC radiation is absorbed by the earth’s ozone layer, it does not pose as much of a risk..."
UV radiation