Ultraviolet light
Most melanomas are caused by ultraviolet (UV) rays damaging the DNA in cells. The primary source of UV light is sunlight, and it is further divided into three types.
- ultraviolet A
- ultraviolet B
- ultraviolet C
Ultraviolet C is most dangerous to the skin cells, but is mostly filtered out by the Earth’s atmosphere. The other two types damage pale skin over time and make it more likely for melanoma to develop. In general, ultraviolet B is thought to be the leading cause of skin cancer, but it is not yet known whether ultraviolet A also plays a role in triggering melanoma.
Besides direct exposure to sunlight, artificial sources of light, such as tanning beds and sunlamps, also increase the risk of developing skin cancer. Studies have revealed that repeated sunburn, either by the UV rays or artificial sources of light, can trigger the risk of skin cancer in people of all ages.