It was believed that Ultraviolet light was the primary cause of human skin cancer.
Ultraviolet radiation is composed of three wavelengths: UVA, UVB and UVC. All are invisible to the naked eye. While UVC isn't a concern for skin cancer, UVA/ UVB play different roles when it comes to tanning, burning, and photoaging.
Be especially aware of water or snow, as these surfaces reflect up to 80% of UV radiation, giving you almost a double-dose!
A UV absorber can provide protection in one of two ways. Solids such as carbon black, titanium dioxide, and zinc oxide reduce UV light by either absorbing it in the case of carbon black, or reflecting it away in the case of the two oxides that are pure white in color. Sunscreens, paints and some plastics use combinations of titanium or zinc oxides to provide protection.