How can DNA be damaged?

Sun light, water, and even oxygen can all trigger chemical reactions that damage our cells’ DNA.

Actually, the main reason why people use sun cream when they go to the beach is to prevent (or reduce) damage of DNA in skin cells. DNA can absorb ultraviolet light in sun rays, and this brings about a photochemical reaction which alters DNA’s structure. As a result, the stored genetic information can no longer be accessed, not at least until DNA has been repaired.