If anyone thought the jury was still out on the danger of tanning machines, new research may provide the clincher.

A study from Dartmouth Medical School in Lebanon, NH, links tanning device use to basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), the most common forms of skin cancer. With all factors accounted for, tanning device users had 2.5 times the risk of SCC and 1.5 times the risk of BCC, compared to non-users. Six more recent, rigorously designed studies have found an association between indoor tanning and the development of melanoma. While these studies remain inconclusive, they were enough for the American Medical Association to call for a ban on tanning beds.