LETTER TO THE EDITOR
High UV-A exposure from sunbeds
Article first published online: 6 AUG 2012
© 2012 John Wiley & Sons A/S
Pigment Cell & Melanoma Research
Volume 25, Issue 5, pages 639–640, September 2012
How to Cite
Nilsen, L. T. N., Aalerud, T. N., Hannevik, M. and Veierød, M. B. (2012), High UV-A exposure from sunbeds. Pigment Cell & Melanoma Research, 25: 639–640. doi: 10.1111/j.1755-148X.2012.01035.x
- Issue published online: 28 AUG 2012
- Article first published online: 6 AUG 2012
- Accepted manuscript online: 7 JUL 2012 08:35AM EST
Sunbeds have become an important source of UV-A exposure; up to 95–100% of the body is exposed in a sunbed compared to 15–50% during outdoor activities (Berwick, 2008). Recent publications in this journal have studied the effects of both UV-A (315–400 nm) and UV-B (290–315 nm) exposure on skin mutagenesis and carcinogenesis (e.g., Bennett, 2008), and this is further supported by Noonan et al. (2012). Fisher (2011) and Fears et al. (2011) emphasized that the use of sunbeds for indoor tanning is common and increases melanoma risk. Coelho and Hearing (2010) and Miyamura et al. (2011) described how UV-A exposure does not increase melanin production and confers little or no protection against subsequent UV exposure. However, as recently pointed out by authors such as Autier et al. (2011), it is important to understand which UV wavelengths actually increase melanoma risk, and at present, UV wavelengths from sunbeds have only rarely been measured in epidemiological studies.
In an effort to try and fill this knowledge gap, we compare herein our recent findings on UV-A and UV-B exposure from sunbeds and natural sun. Spectral (unweighted) UV irradiance was measured in 191 sunbeds in 78 tanning facilities throughout Norway using a mini spectroradiometer (Nilsen et al., 2011). Mean unweighted UV-A and UV-B irradiances and erythema weighted UV irradiance (W/m2) were presented for the bench, canopy and facial position of the sunbed. The erythema weighted UV irradiance was found by multiplying the unweighted total UV irradiance by the reference action spectrum for UV-induced erythema in human skin (Commission Internationale de L’Eclairage, 1999). UV irradiances from natural sun at 35°N (Crete, Greece) and 60°N (Oslo, Norway) were also estimated for a clear day in summer at noon (when the sun’s intensity is at its maximum). Figure 1 shows these values normalized to values from natural sun at 35°N. Normalized values were calculated for 10 min of sunbed exposure and 10 min of natural sun exposure, that is, the typical duration of a sunbed session. However, these normalized values would have been the same if we had used somewhat longer exposure times or if we had used UV irradiances alone (i.e., measured intensity without considering exposure time). Compared to natural sun, UV-A exposure from sunbeds was highest at the facial position (five times higher), although it was also higher at the bench and canopy (3.2 and 3.4 times higher, respectively). UV-B exposure from sunbeds was lower at all sunbed positions compared to that from natural sun (0.7–0.8 times), whereas the erythema weighted UV exposure was about the same from sunbeds and natural sun at 35°N. The 10-min UV exposure values (in kJ/m2) above each bar in Figure 1 show the higher UV-A exposure compared to UV-B and erythema weighted UV exposure. It is important to note that these estimates are based on mean values and that large variations were observed between the different sunbeds. Indeed, UV-B and UV-A irradiances from the measured sunbeds were 0.05–2 and 1.5–19 times, respectively, higher than those from the summer sun at 35°N. Mean erythema weighted UV exposure from sunbeds was similar to that from natural sun at 35°N (Figure 1C).
Sunbed regulations have focused on minimizing erythema with little emphasis on whether harmful effects are caused by UV-A or UV-B radiation (European Commission Health and Consumer Protection Directorate General Scientific Committee on Consumer Products, 2006; European Committee for Electrotechnical Standardization, 2010). The high values of UV-A exposure from modern sunbeds are alarming in light of the increased focus on UV-A irradiance as a carcinogen (El Ghissassi et al., 2009; Noonan et al., 2012).
- 2011). Epidemiological evidence that UVA radiation is involved in the genesis of cutaneous melanoma. Curr. Opin. Oncol. 23, 189–196. , , , and (
- 2008). Ultraviolet wavebands and melanoma initiation. Pigment Cell Melanoma Res. 21, 520–524. (
- 2008). Are tanning beds “safe”? Human studies of melanoma. Pigment Cell Melanoma Res. 21, 517–519. (
- 2010). UVA tanning is involved in the increased incidence of skin cancers in fair-skinned young women. Pigment Cell Melanoma Res. 23, 57–63. , and (
- Commission Internationale de L’Eclairage. (1999). Erythema Reference Action Spectrum and Standard Erythema Dose, ISO 17166:1999/CIE S 007-1998. (Vienna: CIE).
- 2009). A review of human carcinogens – Part D: radiation. Lancet Oncol. 10, 751–752. , , et al. (
- European Commission Health and Consumer Protection Directorate General Scientific Committee on Consumer Products. (2006). Opinion on Biological Effects of Ultraviolet Radiation Relevant to Health with Particular Reference to Sunbeds for Cosmetic Purposes. (Brussels: European Commission Health and Consumer Protection Directorate General). Available at: http://ec.europa.eu/health/ph_risk/committees/04_sccp/docs/sccp_o_031b.pdf.
- European Committee for Electrotechnical Standardization. (2010). Household and Similar Electrical Appliances – Safety. Part 2-27: Particular Requirements for Appliances for Skin Exposure to Ultraviolet and Infrared Radiation. (Brussels: CENELEC).
- 2011). Sunbeds and sunlamps: who uses them and their risk for melanoma. Pigment Cell Melanoma Res. 24, 574–581. , , , , , , and (
- 2011). UV-tanning behavior: a problem that doesn’t go away. Pigment Cell Melanoma Res. 24, 724. (
- 2011). The deceptive nature of UVA-tanning versus the modest protective effects of UVB-tanning on human skin. Pigment Cell Melanoma Res. 24, 136–147. , , et al. (
- 2011). UVB and UVA irradiances from indoor tanning devices. Photochem. Photobiol. Sci. 10, 1129–1136. , , , and (
- 2012). Melanoma induction by ultraviolet A but not ultraviolet B radiation requires melanin pigment. Nat. Commun. 3, 884, DOI: 10:1038/ncomms1893. , , et al. (