The regular use of tanning beds and skin cancer has been a concern for many years, but only recently in the 21st century has mounting scientific evidence been available to link the two conditions definitively. The fundamental issue behind the investigation is the known fact that skin exposure to ultraviolet radiation in human beings increases their likelihood of developing skin cancer. Whether this ultraviolet radiation is from a natural source such as sunlight or an artificially generated one such as a tanning bed appears to make little difference.
Tanning, in general, has a detrimental effect on human skin even though the coloring agent known as tannin produced during the process is meant to serve a protective function. Even if a sunburn does not occur while getting a tan, ultraviolet radiation is still damaging skin cells. This damage includes premature aging of the skin, such as lost elasticity leading to wrinkles, permanent discolorations, and other effects. Tanning beds and skin cancer rates also present a higher risk to individuals with a sensitivity to freckling of the skin, fair skin, and blue eyes. Subjects with red hair and natural freckles are also at increased risk, and have a tendency to not develop a tan at all regardless of exposure levels.
A World Health Organization (WHO) group known as the International Agency for Research on Cancer (IARC), headquartered in France, has gathered research on the evidence that a skin tan is triggered by ultraviolet-induced DNA damage. The initial stage of tanning is triggered by ultraviolet-A (UVA) exposure, which is seen as less dangerous than ultraviolet-B (UVB) light, though UVA light can still trigger melanoma, or the growth of skin tumors. After a few hours of initially using a tanning bed, a more permanent tan is developed by the exposure of UVB light in the tanning light spectrum, which is more likely to cause sunburn and skin damage. Some equipment utilizes UVB filters to minimize the dangers of a tanning bed, but evidence at the IARC shows that this does not suppress the stimulating effect that leads to melanoma growth.
A 2005 study in the Journal of the National Cancer Institute, produced through the US National Institutes of Health (NIH), found that tanning bed use increased the risk of squamous cell cancer by a factor of 2.5 over those who didn't use them, and basal cell cancer by a factor of 1.5. A 2010 study of 2,300 patients at the University of Minnesota in the US also concluded that tanning beds and skin cancer risks from melanoma were significantly increased. Another study in 2011 from Australia showed that the earlier in age someone began to use a tanning bed and the more frequently they did so, the greater their risk was of developing melanoma.
Increasing evidence of the risks that sunbeds pose has led the US states of New York and California to seek bans on the equipment. Tanning for teenagers has also been banned in the UK, with the implementation of the United Kingdom's Sundbeds Regulation Act. A push is on in the US to ban access to the devices for all minors as well, with warnings of the dangers of the practice especially for children being issued by such prestigious organizations as the American Academy of Pediatrics (AAP) and American Medical Association (AMA).
The IARC views preventing skin cancer from tanning beds in a category of dangers equivalent to that of exposure to radioactive radon gas and ultraviolet radiation from the sun. It has classified tanning beds as a Group I carcinogenic form of radiation as of 2009. This is due to the fact that 90% of all skin cancer is caused by UV light exposure, even though most of this occurs due to excessive exposure to sunlight.
The extensive Minnesota study of tanning beds and skin cancer found that tanning bed use tripled or quadrupled the risk of developing melanoma. Indoor tanners had a 74% higher likelihood of such cancer than people who had never used such a device. The conclusion was that there was no such thing as a safe tanning bed.