Skin cancer is the most common type of cancer in the United States. Since 1973, new cases of the most serious form of skin cancer, melanoma, have increased approximately 150%. During the same period, deaths from melanoma have increased approximately 44%. Approximately 65%--90% of melanomas are caused by ultraviolet (UV) radiation. More than one half of a person's lifetime UV exposure occurs during childhood and adolescence because of more opportunities and time for exposure.
Exposure to UV radiation during childhood plays a role in the future development of skin cancer. Persons with a history of blistering sunburns during childhood or adolescence are two times as likely to develop melanoma than those who did not have such exposures. Studies indicate that protection from UV exposure during childhood and adolescence reduces the risk for skin cancer. These studies support the need to protect young persons from the sun beginning at an early age. School staff can play a major role in protecting children and adolescents from UV exposure and the future development of skin cancer by instituting policies, environmental changes, and educational programs that can reduce skin cancer risks among young persons.
Skin cancer is largely preventable by limiting exposure to the primary source of UV radiation, sunlight. Sunlamps and tanning beds are other sources. Persons with high levels of exposure to UV radiation are at an increased risk for all three major forms of skin cancer. Approximately 65%--90% of melanomas are caused by UV exposure. The epidemiology implicating UV exposure as a cause of melanoma is further supported by biologic evidence that damage caused by UV radiation, particularly damage to DNA, plays a central role in the development of melanoma. Total UV exposure depends on the intensity of the light, duration of skin exposure, and whether the skin was protected by sun-protective clothing and sunscreen. Severe, blistering sunburns are associated with an increased risk for both melanoma and basal cell carcinoma. For these cancers, intermittent intense exposures seem to carry higher risk than do lower level, chronic, or cumulative exposures, even if the total UV dose is the same. In contrast, the risk for squamous cell carcinoma is strongly associated with chronic UV exposure but not with intermittent exposure.