Wearing sunscreen is one of the best ways to prevent melanoma . Comment: Photos : Your worst sunburns ever . SPF 15 blocks 93 % of UVB rays , SPF 30 blocks 97 % . About 3.5 million cases of skin cancer will be diagnosed this year .
Wearing sunscreen is one of the best ways to prevent melanoma . Comment: SPF 15 blocks 93 % of UVB rays , SPF 30 blocks 97 % . About 3.5 million cases of skin cancer will be diagnosed this year .