Ultraviolet Radiation

Every day, just about every Australian is exposed to ultraviolet radiation (UVR) from the sun.

How the sun affects our skin depends on the type of UVR, the amount we’re exposed to, as well as our behaviour and personal traits.

Types of UVR

There are three types of wavelengths that form solar UVR: UVA, UVB and UVC.

• UVA – causes premature ageing and wrinkling of the skin and is a cause of skin cancer
• UVB – is more dangerous than UVA and causes sunburn, cataracts and skin cancer
• UVC – is extremely dangerous but does not reach the earth’s surface

 

All of the UVC is absorbed by the earth’s upper atmosphere and less than 10% of UVB reaches the earth’s surface. UVA on the other hand, reaches the earth’s surface with little change. Therefore, most of the UVR that reaches the earth’s surface is UVA and some UVB.

Overexposure to UVR can cause serious damage to your skin and eyes. The effects of tanning build up over your lifetime, even if you haven’t been burnt often. Most Australians' lifetime exposure to UVR happens during childhood to young adulthood. It’s important to protect your skin throughout your life but particularly during these life stages.

Amount of UVR

While we can't control the type of UVR that reaches the earth's surface, we can control the amount of UVR our skin receives. We can do this by protecting our skin and by being aware of the changing intensity of UVR.

Because Australia is relatively close to the equator, we receive higher overall levels of UVR than countries such as Canada, Germany or the United Kingdom.

The amount of UVR our skin receives is also influenced by the sun's position in the sky. The higher the sun, the higher the levels of UVR. This is why the biggest danger-zone for our skin is the four hour period around noon. During daylight savings, it's best to seek shade between the hours of 11am and 3pm.

While heavy cloud cover can reduce UVR levels, in certain situations clouds can actually increase the amount of ambient UVR. Due to the changing nature of clouds, it's best to be prepared with sun protection.

Click here to find out more about the UV Index and what it means

Interesting links:
Bureau of Meteorology: www.bom.gov.au/info/about_uv.shtml