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Sunbeds & UV radiation

4. What are the health and safety implications of sunbeds?

  • 4.1 Can sunbeds harm health?
    • 4.1.1 Acute and non skin cancer effects
    • 4.1.2 Chronic
  • 4.2 Can sunbeds improve health?

4.1 Can sunbeds harm health?

    • 4.1.1 Acute and non skin cancer effects
    • 4.1.2 Chronic

4.1.1 Acute and non skin cancer effects

The SCCP opinion states:

The use of tanning devices has been associated with acute adverse reactions such as a form of skin fragility known as pseudoporphyria (Murphy et al, 1990; Weiss and Jung, 1990) and lentigines (Salisbury et al, 1989; Kadunce et al, 1990) that have been noted in case reports. There have also been case reports of induction (Fruchter and Edoute, 2004) and exacerbation (Stern and Docken, 1986) of systemic lupus erythematosus.

There is a risk of phototoxic reactions with people using certain medications (Bisland, 1990) or applying topical aromatherapy products, such as bergamot oil, that contain photosensitising chemicals (Kaddu and Wolf, 2001) or eating plants that contain such chemicals (Ljunggren, 1990).

Devices with a higher UVB/UVA ratio or a high UVB irradiance will be more effective at tanning and will require a shorter exposure time. However, this also increases the likelihood of a burn (doses > 1 MED) because there is a lower margin of error in the determination of exposure time (see Section 5). Burns have also been reported due to equipment failure (Eltigani and Mathews, 1994).

Studies in the late 1980s showed that the use of tanning devices has an adverse effect on human immune function (Hersey et al, 1987; Rivers et al, 1989). More recently, Whitmore and Morison (2000) reported that 10 full-body exposures over a two-week period suppressed immunity as assessed by the induction and elicitation arms of the contact hypersensitivity response (CHS). These authors also studied the effect of 10 full-body tanning exposures in 11 volunteers and, not surprisingly, reported the presence of CPD and p53 protein expression in keratinocytes in vivo (Whitmore et al, 2001). One study used a Cleo Natural source (see Figure 1) to assess the immunological effects of repeated whole-body sub-erythemal exposure (1.2 SED) on 165 skin types II and III for up to 30 consecutive days (Narbutt et al, 2005). The results showed a cumulative UVR dose-dependent reduction of the primary allergic response and the elicitation arm of the CHS response and suggest that there is no adaptation to these immunological responses.

Comment on UVA-induced immunosuppression

The role of UVB in immunosuppression is well established in mice and humans. The role of UVA is much less clear. Much of the evidence for the role of UVA in humans has come from sunscreen studies in which the addition of UVA filters has been shown to improve immunoprotection (Fourtanier et al 2005). In mice, there is evidence that UVA abrogates UVB- induced immunosuppression (Tyrrell and Reeve, 2006) but there is evidence of a positive interaction of UVB and UVA in human immunosuppression (Poon et al, 2005), i.e. the combined effect is greater than the sum of the parts. It should be noted that immunosuppression is a complex issue and that the above brief comments are a necessary simplification.

Source & ©: SCCP "Opinion on Biological effects of ultraviolet radiation relevant to health with particular reference to sunbeds for cosmetic purposes (2006)", Acute and non skin cancer effects, p. 19

4.1.2 Chronic

The SCCP opinion states:

Skin Cancer

Very few studies have been done on the relationship between sunbed use and non-melanoma skin cancer risk. Two hospital-based case-control studies in Ireland, in the mid to late 1980s, did not show any relationship between the use of tanning devices and non-melanoma skin cancer (O’Loughlin et al, 1985; Herity et al, 1989). A similar conclusion, at about the same time, was reached by Bajdik et al (1996) in British Columbia, Canada, who evaluated 406 controls (population based) against 180 SCC cases and 226 BCC cases. About 10% of each group had “ever” used a sunlamp. The adjusted OR for BCC and SCC for “ever” having used a sunlamp were 1.2 (0.7-2.2) and 1.4 (0.7-2.7) respectively, which are clearly non-significant. One small study from 2002, using the “generalized estimating equation method” reported no significant effect of tanning devices for BCC, even though the total lifetime exposure to tanning devices was almost twice as high in patients compared with controls (Boyd et al, 2002). In the same year, Karagas et al (2002) assessed the relationship between use of tanning devices and BCC and SCC in a population-based case control study. In this study there was greater use of tanning devices ranging from 9.2% (male controls) to 28.4% (female patients). The OR for BCC and SCC were 1.5 (1.1-2.1) and 2.5 (1.7-3.8) respectively and adjustment for a variety of factors made no difference to these results. The results of Karagas et al (2002) indicated that the use of tanning devices is a risk factor for non-melanoma skin cancer.

Sunbed usage has increased considerably in recent years (Rafnsson et al, 2004) but the data on melanoma risk are scanty. There are a number of case-control studies but the details on exposure for the majority was small and all, as case-control studies, were subject to bias of recall and the effect of confounders. There is a single cohort study (Verierod et al, 2003) in which risk of melanoma was addressed. A number of case-control studies reported no evidence of sunbed use as a risk factor for melanoma (Osterlind et al, 1988; Holly et al, 1995; Westerdal et al, 1994; Zanetti et al, 1988; Chen et al, 1998; Dunn-Lane et al, 1993; Naldi et al, 2000; Bataille et al 2004, 2005). The majority of these studies were, however, small and the prevalence of sunbed usage in cases and controls was very low. Others were supportive of weak evidence or evidence in “at risk” groups (Walter et al, 1990; Westerdahl et al, 2000). Walter et al (1990) showed some suggestion of a trend to increased risk of melanoma with longer duration of use. In the study by Westerdahl et al (2000) an increased risk of melanoma was demonstrated only for use of sunbeds before the age of 35 years (OR, 2.3; CI, 1.2–4.2). Swerdlow et al (1988) showed a significantly increased risk for any use of sunbeds OR 2.94 (95% CI 1.4-6.17) with a significant trend for increased duration of use. Autier et al (1994) showed little evidence of risk overall when corrected for skin type etc but did show evidence of increased risk for usage of sunbeds for 10 hours or more, when burning was reported after use of the sunbed or when the users reported use of the sunbed to tan.

The only cohort study to address risk associated with solaria followed more than 100,000 Norwegian and Swedish women for an average of 8 years, and 187 melanomas developed. This study identified use of a solarium for 1 or more times per month as a risk factor for melanoma. When the exposures occurred between the ages of 20 – 29 years the adjusted relative risk was 2.58 (95%CI 1.48-4.50). Among women who had used a solarium once or more per month, in at least one of the three decades between ages 10 and 39, the adjusted relative risk of melanoma compared to women that had never or rarely used a solarium during these three decades, was 1.55 (95%CI 1,4-2.32) (Veierød et al, 2003). This is probably the most persuasive evidence for a role for sunbeds in causing melanoma but the data are as yet relatively weak and support the view only that frequent use is deleterious.

Gallagher et al (2005) carried out a meta-analysis of 9 case-control studies and the one cohort study and came to the conclusion that sunbed use significantly increased the risk of melanoma with an OR of 1.25 (1.1-1.5) “ever” versus “never” used. This increased to 1.69 (1.3 –2.2) using the metric “first exposure as a young adult”.

There seems to be no published literature on the photoageing effects of sunbed use but this would be expected from the long-term use of sunbeds because photoageing is associated with solar exposure (Fisher et al, 2002). Some studies have looked at the effect of repeated sub- erythemal exposure of UVB and UVA in human skin and reported some changes that are associated with photoageing (Lavker et al, 1995a, 1995b; Lavker and Kaidby, 1997).

As with the sun, tanning devices emit infrared radiation (IR: 760nm to 1mm). The effects of IR on skin are poorly understood but in vitro studies suggest that it may play a role in photoageing, which has been suggested by animal studies (Schieke et al, 2003).

Effects on the eye
Four studies have assessed the relationship between sunbed use and ocular melanoma and found varying degrees of association Tucker et al, 1985; Seddon et al, 1990; Holly et al, 1996). The most recent study (Vajdic et al, 2004) provides “moderately strong” evidence, with several metrics, that sunbed use results in ocular melanoma, after adjustment for confounding factors including exposure to solar radiation. The OR for use (never vs ever) was 1.7 (95% CI 1.0 – 2.8) and 2.4 (95% CI 1.0 – 6.1) for first use under 21 years. There was a significant trend (p = 0.04) for duration of use. This study also suggested a protective effect from wearing goggles with an OR = 2.2 (95% CI 0.5 - 9.7) in those who did not always wear goggles but this was not significant (p = 0.3).

Source & ©: SCCP "Opinion on Biological effects of ultraviolet radiation relevant to health with particular reference to sunbeds for cosmetic purposes (2006)" Chronic, p. 20

Estimates have been made of the risk of basal and squamous cell skin cancers arising from sunbed use (AGNIR 2002) and what constitutes an “acceptable” risk is a matter of judgment. For most people, who may use sunbeds 10 or 20 times a year for 10 years or so in young adulthood, the estimated additional lifetime risk of non-melanoma skin cancer, compared with non-users, is up to 10% (AGNIR 2002).

Case-control studies, particularly more recent ones, have generally found an association between sunbed use and melanoma (Young 2004) with an odds ratio of around 1.5 (Veierød et al. 2003). In communicating this risk to policy makers (Heller et al 2003), it may be helpful to estimate the potential number of cases and deaths prevented each year in a population if sunbeds were eliminated. These are given in Table 3 for the UK, where the relative risk of incidence and mortality of sunbed users is taken to be 1.5 relative to non-users. The figure of 1.5 is used for illustrative purposes since different studies have yielded different relative risks (Young 2004) and so the population impacts in Table 3 should be treated with caution (B. Diffey). Melanoma incidence and mortality data refer to the year 2002 (Cancer Research UK, 2005).

Non-use of tanning devices might have resulted in about 54 fewer deaths from melanoma in 2002 than the 1644 that were observed in the UK]

An alternative approach to estimating the mortality associated with sunbeds is through modelling population exposure to both sunlight and sunbeds, assuming that the patterns of exposure from these two sources are equally carcinogenic, that the melanomas that result are equally fatal, and that the fraction of deaths due to sunbed use is equal to the population exposure from sunbeds expressed as a fraction of the total population exposure from sunlight and sunbeds. Using this approach Diffey (2003) estimates the mortality due to sunbed use each year in the UK is around 100, with a range of about 50 to 200. The estimates from this approach and that illustrated in Table 3 are not inconsistent given the many uncertainties and assumptions involved. If it is assumed that the use of sunbeds increased the risk of melanoma by 50%, the additional lifetime risk of dying from melanoma will be of the order 1x10-3. From the above discussion it is clear that there is no limit value of total dose of artificial UVR below which adverse health effects will not occur and that any limit is subjective and arbitrary. Based on data available the risk of developing skin cancer in connection with the use of sunbeds is high in comparison to the “acceptable” risk of developing cancer from other consumer products (WHO, in press).

Source & ©: SCCP "Opinion on Biological effects of ultraviolet radiation relevant to health with particular reference to sunbeds for cosmetic purposes (2006)"  3.6, p. 24

4.2 Can sunbeds improve health?

The SCCP opinion states:

Vitamin D status

Tanning with UVB-emitting sunbeds would be expected to improve vitamin D status and this has been reported in a recent study (Tangpricha et al, 2004) that showed that people who used a sunbed at least once a week for at least 6 months had a mean serum concentration of 25 hydroxyvitamin D (25(OH)D) of 115.5 ± 8.0 (SEM) nmol/L compared with the controls who had levels of 60.3 ± 3.0 nmol/L (P < 0001). The tanners also had significantly higher hipbone mineral density. However, this study has several flaws; (i) it relied on recall of sunbed use without establishing serum 25(OH)D before sunbed use, (ii) the tanning group had much greater sunlight exposure and (iii) there was a much greater proportion of white-skinned people in the tanning group. Furthermore, there were no data on the spectral output of the tanning devices used.

Feel good factor

Many people claim to feel better after sunbed use (Diffey 1986) but studies using primarily UVA emitting sunbeds showed that mood effects could not be attributed to circulating serotonin or melatonin (Gambichler et al, 2002a) or opioid peptides (Gambichler et al, 2002b). The possible role of UVB-induced keratinocyte-derived β-endorphin (Gilchrest et al, 1996) has yet to be investigated.

Source & ©: SCCP "Opinion on Biological effects of ultraviolet radiation relevant to health with particular reference to sunbeds for cosmetic purposes (2006)"  3.4.2 Positive Effects, p.22

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