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Sun Safety

Ultraviolet Radiation

What is Ultraviolet Radiation (UVR)?

  • UV radiation is a type of light from the sun or certain kinds of artificial light such as the light in tanning beds. The earth's ozone layer protects us from too much exposure to UVR from the sun. As the ozone layer thins, the amount of UVR reaching us increases.
  • UVR causes skin cancer and other forms of skin damage (e.g. wrinkling and photoaging of the skin) and causes harm to the eyes.
  • UVR that is harmful to the skin is primarily present in the sun’s rays from 11 a.m. to 3 p.m. between April and September in Canada. UVR that is harmful to the eyes is present in the sun’s rays all year round and throughout the day. In both cases, UVR can be harmful, even when it’s cloudy.

Types of UV Rays?

There are three types of UV rays

  • UVA rays cause tanning, premature aging and wrinkling of the skin and weaken the immune system. They are common in tanning beds. 
  • UVB rays cause the skin to tan and burn. 
  • UVC rays are the most damaging type but are filtered by the ozone layer. 

What is the UV index?

The UV index tells us how intense the sun's UVB rays are - Remember these are the rays that cause the skin to tan and burn.

There are five categories - low, moderate, high, very high and extreme.

You should always take precautions when the UV index is 3 (moderate category) or higher.

To learn more about the UV Index and how to protect yourself visit Environment and Climate Change Canada pages at Government of Canada. 

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