title: Photochemical cleavage of a tattoo pigment by UVB radiation or natural sunlight.
abstract: BACKGROUND
  Millions of people have at least one tattoo. Complex and light absorbing molecules are implanted in the skin. When tattooed skin receives UV radiation or natural sunlight, photochemical cleavage of the pigments may occur. As a first step, we dissolved pigments in a suitable solvent and analyzed them after light irradiation.
  
  
  METHODS
  The widespread Pigment Red 22 was dissolved in different solvents. The solutions were irradiated with either UVB radiation (up to 8 h) or with natural sunlight (110 days). After irradiation, the solutions were analyzed by means of liquid chromatography and mass spectrometry.
  
  
  RESULTS
  A clear cleavage of the pigment was detected in all solvents and the primary decomposition products were identified. In tetrahydrofuran and dioxane, the pigment concentration decreased significantly during UVB irradiation, whereas the pigment was completely destroyed during sunlight exposure. In chloroform and dichloromethane, the pigment concentration decreased slightly during UVB irradiation, whereas the pigment was almost completely destroyed during sunlight exposure.
  
  
  CONCLUSIONS
  Since chloroform and dichloromethane do not affect the cleavage process, these solvents are optimal for such in vitro experiments. We have shown the cleavage of the tattoo pigment Red 22 when exposed to UVB radiation or natural sunlight. The decomposition products are hazardous showing a potential risk of being toxic or even carcinogenic. At present, a risk assessment is not feasible since the concentration of pigments and their decomposition products in skin are unknown.
authors.affiliation: Department of Dermatology, University of Regensburg, Germany.
authors.forename: Eva
authors.initials: E
authors.lastname: Engel
authors.forename: Andrea
authors.initials: A
authors.lastname: Spannberger
authors.forename: Rudolf
authors.initials: R
authors.lastname: Vasold
authors.forename: Burkhard
authors.initials: B
authors.lastname: König
authors.forename: Michael
authors.initials: M
authors.lastname: Landthaler
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Bäumler
mesh_terms: D001391:Azo Compounds / Q000737:chemistry* / Q000528:radiation effects*; D004396:Coloring Agents / Q000737:chemistry* / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D010777:Photochemistry / Q000379:methods*; D011829:Radiation Dosage; D012997:Solvents / Q000737:chemistry / Q000528:radiation effects; D013653:Tattooing; D014466:Ultraviolet Rays
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D012997:Solvents; C069430:Pigment Red 22