The US government has officially identified ultraviolet radiation (UVR) both from the sun and from tanning machines as a known cause of cancer in humans. UVR produces DNA damage that may lead to mutations (abnormalities) in genes involved in the development of skin cancer. Therefore, along with other sun safety strategies, sunscreens that absorb or block UVR serve an important protective function.
Here are some facts to consider:
Photoaging, or UV-induced skin aging, is another long-term result of sun exposure. While not threatening to life, it is threatening to quality of life. Excessive unprotected time in the sun leads to premature wrinkling, sagging, a leathery texture and hyperpigmentation (so-called “aging spots” or “liver spots” that are really the result of sun damage).
An estimated 90 percent of skin aging is caused by the sun. Sun damage is cumulative. Only about 23 percent of lifetime exposure occurs by age 18. People who use sunscreen with an SPF of 15 or higher daily show 24 percent less skin aging than those who do not use sunscreen daily.