Both indoor and outdoor ultraviolet radiation (UVR) tanning are proven causes of skin cancer, but the average indoor tanning machine in England is 2.3 times more cancer-causing than the midday Mediterranean sun. In fact, some British tanning machines are up to six times as dangerous, according to researchers who measured ultraviolet A (UVA) and ultraviolet B (UVB) radiation output from hundreds of tanning machines.
In the US, tanning beds have been found to be comparably dangerous. A 2003 study found that the average tanning bed emitted four times the UVA radiation, and two times the UVB radiation, of the midday summer sun in Washington, DC. Furthermore, high-speed sunlamps emit a UVA dose six times, and high-pressure sunlamps 12 times, that of the Washington, DC, summer sun.
Melanoma, the deadliest form of skin cancer, will kill an estimated 9,480 people in the US in 2013, and a single indoor tanning session increases users’ chances of developing melanoma by 20 percent. Regular tanners also have 2.5 times the risk of developing squamous cell carcinoma and 1.5 times the risk of developing basal cell carcinoma compared to non-tanners.
The British study’s authors, writing in the British Journal of Dermatology, determined that nine out of 10 tanning beds in England emit more UV radiation than recommended by British and European safety standards, typically almost double the recommended amount. These excessive levels are especially worrisome considering that any UV tanning causes DNA damage that ages the skin and can ultimately cause skin cancers.