Solar UVR and cancer
Solar UVR (ultraviolet radiation) is invisible energy produced by the sun. It's made up of three wavelengths: UVA, UVB and UVC.
Both UVA and UVB can reach the earth's surface and are classified as human carcinogens. This means they cause cancer. Every time we overexpose our skin to radiation from the sun, some of our skin cells are damaged and we increase our risk of developing skin cancer.
A sunburn or a tan is a sign of skin being damaged by solar UVR. All skin types can be damaged, but fairer skin is at increased risk.
Solar UVR has also been linked with cancer of the eye, cataracts (clouding on the lens of the eye) and pterygium (a growth on the white of the eye).
Your cancer risk from solar UVR varies depending upon these environmental factors:
- solar elevation – when the sun is higher in the sky there will be higher levels of solar UVR
- ozone – ozone thickness changes daily. When the ozone layer is thicker, less UVB will reach the earth
- cloud cover – solar UVR can pass through light clouds so solar UVR levels on cloudy days may be similar to those on a cloud free day
- ground surface reflectivity – highly reflective surfaces can increase surrounding levels of solar UVR including concrete, snow, glass, water and polished metals
- altitude – higher altitude means higher solar UVR
- proximity to the equator – the closer you are to the equator, the higher solar UVR is generally.
More than 1.2 million Australian workers are exposed to solar UVR at levels five to 10 times more than indoor workers. As a result, if you are exposed to solar UVR at work you are at greater risk of developing skin cancer. Each year in Australia, it is estimated that 200 melanomas and 34,000 non-melanomas are caused by exposure to solar UVR at work.
