This is because their skin cells have less malanin, the pigment that helps prevent burning. People who work outdoors, such as farmers and construction workers, and those who go boating often, play a lot of outdoor sports, or sunbathe, are at the highest risk of developing skin cancer. Children, in particular, should be protected from the sun because of the possible link between severe sunburns in childhood and greatly increased risk of melanoma later in life. Certain moles make it more likely that a person will develop melanoma. One type of mole, the dysplastic nevus, has varying shades of brown, black, and pink within a single mole, and irregular or uneven borders, with the coloring fading into the skin around the moles.
Some people have many such moles, but just one is enough to increase the risk of melanoma.
Another type of mole linked to melanoma is present at birth. This is the congenital melanocytic nevus, often called a birthmark.