Causes of Skin Cancers
The most common cause of skin cancers are ultraviolet (UV) rays, either from the sun, or from UV-emitting lamps like those in tanning saloons. Both UV-A and UV-B rays may cause skin cancer.
Other possible causes of skin cancers include:
- High dose or repeated X-ray exposure (1,2)
- Exposure to arsenic (pesticides, wood preservatives, miners, sheep shearers, farmers) (1), pitch (from distillation of wood or coal tar), creosote, or radium (5)
- Therapy that destroys immune cells – chemotherapy, radiotherapy, immunosuppression in organ or bone marrow transplantation (2)
- Smoking increases risk for squamous cell carcinoma (4)

