What is UV radiation?
Ultraviolet (UV) radiation is responsible for more than 95% of all skin cancers. The sun emits UV radiation but it isn’t connected to sunshine or heat like many think. This means we can’t see or feel it, so it can be difficult to understand.
Our sun emits different kinds of energy:
- infrared radiation that we can feel (heat or temperature)
- visible light that we can see (sunlight)
- UV radiation (that can’t be seen or felt).
When it comes to sun protection, we need to think UV, not heat!
Types of UV radiation
There are three types of UV radiation:
- UVA: transmits freely through the earth’s atmosphere.
- UVB: about 15% of UVB transmits through to the earth’s atmosphere. The rest is absorbed by ozone.
- UVC: is absorbed by ozone and does not reach the earth’s surface.
UVA and UVB both contribute to skin cancer, sunburn, skin ageing and eye damage.
Exposure to UV radiation is the main factor that causes skin cells to become cancer cells. Almost all skin cancers (approximately 99% of non-melanoma skin cancers and 95% of melanoma) are caused by over exposure to UV radiation.
The simplest way to reduce your risk of skin cancer is to use sun protection when the UV index is 3 or above. When the UV is 3 or above, it is strong enough to damage your skin and in NSW, this is most days of the year.
The UV Index is an internationally standardised, open ended, numerical scale developed by the World Health Organization. The UV index measures the amount of UV radiation reaching the earth’s surface. It begins at zero and has no upper limit, the rating usually finishes at 11+, which is extreme.
Read more about how UV leads to skin cancer.