Indoor tanning, skin cancer, and vitamin D
In June 2009, the IARC published a special report reviewing human carcinogens. Of note, the Working Group raised the classification of UV-emitting tanning devices to Group 1, “carcinogenic to humans,” based on data that strongly link tanning devices to increased risk of melanoma of the skin and ocular melanoma (7).
In contrast, although there are data to suggest the association of vitamin D with incidence and outcomes of various cancers, including melanoma, no clear causal relationship has been established, and optimal serum levels remain to be defined. Given the relative inefficiency of UVA-emitting tanning devices in increasing serum vitamin D levels, especially in those most at risk of vitamin D deficiency, indoor tanning is not recommendable as a way to achieve optimal vitamin D levels in the general public.
Furthermore, a sufficient vitamin D level can be established with 5–30 minutes of midday sun exposure twice a week to the face, arms, legs, or back; a healthy diet; or oral supplements. The American Academy of Dermatology currently recommends a daily total dose of 1000 IU of vitamin D for those at risk of vitamin D insufficiency or those who regularly and properly practice photoprotection (65).
Indoor tanning regulation
The FDA regulates equipment specifications, exposure schedules, use of eyewear, and warning statements. Current FDA tanning bed warnings include the increased risk of skin cancer and premature aging (22). The FDA has recommended exposure schedules for first-time users based on skin type, suggesting that exposure be limited to no more than 0.75 MED three times the first week, followed by a gradual increase to maintenance doses of a maximum of 4.0 MED delivered weekly or biweekly (66). However, in San Diego, only 6% complied with these maximum tanning frequency recommendations (67). In North Carolina, 95% of patrons exceeded recommended limits and 33% began tanning at the maximum doses recommended for maintenance indoor tanning (23). In one survey, 58% of users reported burns from indoor tanning, which was significantly associated with the frequent use of indoor tanning, greater or equal to six sessions within the past year (16). Previous studies have also reported that indoor tanning causes burns and erythema in 18–55% of users (68–70).
The increased risk of skin cancer, especially with early use of tanning devices, coupled with the increasing prevalence of indoor tanning in adults and adolescents, all point toward the need for interventions and regulations on indoor tanning use, in particular, for minors. The WHO has recommended a complete ban on indoor tanning for anyone under the age of 18 years. The IARC states, “policymakers should strongly consider enacting measures, such as prohibiting minors and discouraging young adults from using indoor tanning equipment, in order to protect the general population from additional risk for melanoma and squamous cell skin cancer”(21). Currently, around 30 states have considered or adopted legislation to regulate the use of tanning facilities by minors. Most states require written parental consent to tan for minors, and some states require that a parent accompany minors or impose a minimum age at which adolescents are allowed to use indoor tanning facilities, generally age 14 years.
Although an electronic survey found that most indoor tanning facility operators believed that minimum age (92%) and parental consent (80%) regulations for indoor tanning should be required, in practice, compliance with youth access laws is low (71). In Minnesota and Massachusetts, laws require parental permission for those younger than 16 or 18 years of age, respectively, for indoor tanning. In one study in these two states, 81% of 200 indoor tanning businesses sold a session to 15-year-old girls who tried to purchase a tanning session without parental consent, on at least one of two tries (72). In North Carolina, only 13% of facilities complied with a required guardian consent form for youths, whereas 43% of facilities complied with parental consent regulations in San Diego (67,73).
Other aspects of indoor tanning, including customer notification of risks, UV exposure control, equipment standards, facility operations, operator training and responsibilities, sanitation, enforcement/legal issues, and penalties for violations, are also regulated at the state level (74). However, enforcement of state indoor tanning laws leaves much to be desired. In 2008, one study surveyed contacts, mostly state or local city health agencies' employees, who were knowledgeable about, and responsible for, enforcement practices in 28 states with tanning legislation at the time (75). The study found that at least 32% of the cities did not inspect indoor tanning facilities for compliance with the state law, and another 32% conducted inspections less than annually. Slightly less than half of the cities gave citations to tanning facilities that violated the state law.
The provision of informed consent by indoor tanning facility operations has also been found to be inadequate. In a survey of 400 facilities in four states, 87% advised patrons of the potential risk of sunburn from indoor tanning, but in three of four states, less than half of facility operations informed patrons about the risk of skin cancer and premature aging (76). Similarly, only 19% of North Carolina tanning facilities provided consumers with a statement outlining the risks of UV tanning, and only 17 and 32% of San Diego facility operators stated that sunburn and skin cancer were a risk, respectively (67,73). It is clear that future evaluations of indoor tanning legislation need to measure not only the written law, but also its implementation and enforcement.