Tanning can cause skin cancer, as it represents damage to the skin at the cellular level, according to the Skin Cancer Foundation. Tanning is caused by the reaction of harmful ultraviolet (UV) rays with melanin, a hormone in the skin that regulates color.
The way a tan is acquired can also make a difference. People who tan indoors at a salon which uses UV radiation are 74 percent more likely to develop melanoma, the deadliest form of skin cancer, than people who have never tanned indoors. In fact, a study has shown that there are more cases of skin cancer caused by indoor tanning salons than cases of lung cancer caused by smoking.
Exposure to UV rays can also cause other types of skin cancers, including basal cell carcinoma, squamous cell carcinoma, ocular melanoma, or cancer of the eye, and cataracts.