A suntan, whether you get it from the sun, a tanning bed or incidental exposure is bad, however you acquire it. Tans are caused by harmful ultraviolet (UV) radiation from the sun or tanning lamps and a tan is a sign you’ve sustained skin cell damage. Indoor tanning is increasingly popular with teenagers and people in their twenties, especially women. The International Agency for Research on Cancer (IARC), a branch of the World Health Organization (WHO) has unequivocally linked sunbed tanning among young people to melanoma, the deadliest form of skin cancer. The weight of current evidence also points to youthful sunbed use as a cause of squamous cell carcinoma (SCC), the second most common skin cancer, as well as other health problems.
See the following links for more information:
2. Article in the journal, Preventing Chronic Disease: Public Health Research, Practice and Policy (published by the Centers for Disease Control and Prevention) that focuses on indoor tanning: http://www.cdc.gov/pcd/issues/2008/oct/07_0194.htm
3. Information on tanning behaviors of teens and tanning salon practices in 100 of the most populous U.S. cities can be found here: http://indoortanningreportcard.com
4. World Health Organization information on Sunbeds and UV Radiation.