Malignant melanoma is the most harmful because it can spread quickly and be fatal if it's not treated early. Skin cancer used to be considered a disease of old or middle age, but the number of cases in younger people has risen steadily due to increased exposure to the sun. Some researchers believe depletion of the atmosphere's protective ozone layer, which allows more of the sun's rays to hit the earth, is also responsible for the increase in cases of skin cancer. Artificial sources of UV radiation, such as sun lamps and tanning booths, can cause skin cancer as well. People with any of the characteristics listed below are at higher risk for skin cancer and they should be particularly careful of sun exposure.
Light skin is most vulnerable because it has less melanin, the pigment that helps prevent burning.
Place of residence. People who live in areas that get high levels of UV radiation from the sun are more likely to get skin cancer. In the United States, for example, skin cancer is more common in Texas than in Minnesota, where the sun is not as strong. Long-term exposure to UV radiation. 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 highest risk of developing skin cancer.