title: UVA tanning devices interact with solar-simulated UV radiation in skin tumor development in hairless mice.
abstract: The carcinogenic effect of three UVA tanning sources was studied in lightly pigmented hairless mice. The three tanning sources (Bellarium-S SA-1-12, Philips TL 09R and Philips TL 10R) have different emission spectra, and emit different amounts of UVB. Radiation from the tanning sources was administered for 20 min/day, 5 day/week in daily doses equivalent to those used in suntan salons. The radiation was given alone or after 12 weeks of exposure to solar-simulated UV radiation (SOLAR UV) (10 min/day, 4 day/week; daily dose, 19.5 kJ/m2 UVA and 3.9 kJ/m2 UVB). Irradiation with Bellarium-S SA-1-12 for 47 weeks and Philips TL 09R for 74 weeks induced skin tumours in 20/20 and 13/20 of the animals, respectively. When irradiation with Bellarium-S SA-1-12 and PHilips TL 09R was administered after 12 weeks of SOLAR-UV exposure, a strong enhancement of SOLAR-UV-induced photocarcinogenesis was observed (p < 0.001). Irradiation with Philips TL 10R was only slightly carcinogenic, and during 85 weeks of irradiation only one skin tumor appeared in a group of 20 mice. However, when irradiation with Philips TL 10R was administered after 12 weeks of exposure to SOLAR UV, an enhancement of SOLAR-UV-induced carcinogenesis was observed (p < 0.001). Our results suggest that the hazards of exposure to commercial tanning devices are increased when they are used after a period of natural sun exposure. Even tanning sources with a low carcinogenic potential are able to increase SOLAR-UV-induced carcinogenesis significantly.
authors.affiliation: Department of Dermatology, Copenhagen University Hospital, Denmark.
authors.forename: N
authors.initials: N
authors.lastname: Bech-Thomsen
authors.forename: T
authors.initials: T
authors.lastname: Poulsen
authors.forename: F G
authors.initials: FG
authors.lastname: Christensen
authors.forename: K
authors.initials: K
authors.lastname: Lundgren
authors.forename: H C
authors.initials: HC
authors.lastname: Wulf
mesh_terms: D000818:Animals; D005260:Female; D051379:Mice; D008812:Mice, Hairless; D008809:Mice, Inbred C3H; D009381:Neoplasms, Radiation-Induced / Q000209:etiology*; D012878:Skin Neoplasms / Q000209:etiology*; D014466:Ultraviolet Rays / Q000009:adverse effects*