Ultraviolet radiation absorbed by living cells damages sensitive substances that influence the skin's normal growth and appearance.
Higher-energy UV rays are a form of ionizing radiation.
Studies show that ultraviolet radiation similar to sunlight causes skin cancer in animals. Unrepaired photoproducts in the p53 gene are transformed into mutations thereby initiating the process of carcinogenesis. For people with darker skin, it may just feel irritated, tender or itchy.
Occasional mistakes during the repair of this damage leads to the incorporation of wrong bases into the genetic material. The US Centers for Disease Control and Prevention CDC has also recommended ways for communities to help prevent skin cancer by reducing sun exposure, including educational interventions in schools and providing shade at schools, recreational sites, and work sites.
There are 2 main types of UV rays that damage our skin. This is less of a factor near the equator.
These types of mistakes often result in mutation leading to loss or inappropriate expression of affected genes. The skin also becomes thicker.