The ultraviolet (UV) radiation in sunlight is the major cause of skin cancer. Some types of skin cancer, such as squamous cell carcinoma, can be directly attributed to damage from exposure to UV-B. However, the incidence of skin cancers such as melanoma is more complex, being influenced by genetics and additional factors such as the type and frequency of UV exposure.
Click on the buttons to the left to find out about the types of skin cancer, how sunlight affects your skin cells, some ways to prevent cancerous results, and the factors that influence the development of skin cancer.
Sunlight and cancer
Memorial Sloan-Kettering Cancer Center
Lets take Italy for an example – there are lighter skinned individuals in the north of Italy and dark skinned individuals in the south of Italy, so the incidence of melanoma has kind of evened out.
Even though the distance from the equator is different, it evens out over the skin colors, so that it's almost equal through out Italy, which makes sense actually. So the two factors are very important.
Australia, overall, has an incidence of melanoma about 49 cases per hundred thousand people, which is a very high rate. If you get closer, this is overall, if you get closer to the equator – in Queensland – the incidence is 60 per hundred thousand.
In the United States our incidence is 1/3 that of Australia – it's approximately 19 or 20 per hundred thousand – and it used to be that it went with latitude but now that people are so mobile it's changed quite a bit.
There are certain many more different complexions in the United States than there are in Australia – although that's changing in Australia now – most people in Australia have come from the UK so they are light skinned.
In a place like Ireland, where people should be at highest risk because they have often red hair and fair skin, their incidence is 1/3 that of the Unites States so it really depends a lot on the interaction of a person's phenotype, that is what they look like and the sun exposure that they get.