Search for Internal Cancers in Mice Tattooed with Inks of High Contents of Potential Carcinogens: A One-Year Autopsy Study of Red and Black Tattoo Inks Banned in the Market

Abstract

Background and Objective: Tattoo ink stock products often contain potential carcinogens, which on large-scale population exposure may be clinically relevant. The aim of this autopsy study in mice was to screen major organs for clinical and subclinical cancers. Methods: Mice were tattooed on their backs. In total, 48 mice were included and divided into 4 groups; 11 mice tattooed black, 10 tattooed red, and 5 mice serving as untreated controls. A group of 22 mice with black tattoos and exposed to ultraviolet radiation (UVR) were also studied. The black and red inks were both stock products banned on the Danish market due to the measured contents of potential carcinogens; benzo(a)pyrene and 2-anisidine, respectively. The mice were housed for 1 year after tattooing, and autopsy study on internal organs was performed. Tissue samples were systematically taken from major organs for screening of subclinical changes, not detected by visual examination. Any observed deviation from normal structure was subject to biopsy and light microscopy. Results: All mice survived the 1-year observation period. Autopsy revealed no macroscopic signs of cancer. Microscopic search of internal organs showed no subclinical or clinical cancer. Conclusion: Despite extensive tattoos with 2 banned inks, the long-term observation in mice showed no internal cancers nor was the combination of carcinogen and UVR associated with cancer. Lack of observed malignancy might be explained by the fact that tattooing is only a single dose exposure. Registered data on carcinogens relies on repeated or chronic exposures. The study does not support the hypothesis that tattooing causes cancer.

Red tattoos, ultraviolet radiation and skin cancer in mice

“…After our mice were euthanized, autopsies were performed and reported in a separate study by Sepehri et al [20] No cancers in internal organs were found in red (or black)-tattooed mice neither macroscopically nor by systematic microscopy of the organs. [20] It was also documented that deposits originating from red (and black) tattoos were observed in the liver, in the Kupffer cells, by electron microscopy. [21] The internal organs of highest exposure were the lymph nodes and the liver.…”

Hautmodifikation

“…Der Nachweis von PAH in vivo konnte in den wesentlichen Organen der Exkretion und des Metabolismus wie der Leber, Milz und Niere noch nicht erbracht werden. In Anbetracht der hohen Konzentrationen von PAH in der Tinte und der deutlich erniedrigten Werte in der Dermis und in den Lymphknoten kann angenommen werden, dass eine große Menge metabolisiert, ausgeschieden und abtransportiert wird [16,17]. Im Rahmen der Elimination über den Lymph-und Blutflussweg erfolgt mit anderen Organen entsprechender Kontakt, und daraus resultiert eine mögliche Interaktion [4].…”

“…Die oftmals herangezogenen freien Konzentrationen von potenziell toxischen Elementen entsprechen nicht jenen im Körper, die durch den Metabolismus und die Ausscheidung modifiziert werden [17,25].…”

“…Zur Imitierung der Interaktion mit dem UV-Licht wurde eine der 4 Kohorten diesem ausgesetzt. Nach einjährigem Follow-up konnten weder makroskopische Läsionen an der Haut noch mikroskopische systemische kanzerogene Herde (Haut, Lymphknoten, Leber, Milz, Lunge) nachgewiesen werden [17].…”

Late-onset pseudoepitheliomatous hyperplasia developing within a red ink tattoo

“…The maximum permitted concentrations of carcinogenic, mutagenic and reproduction-toxic substances in tattoo inks were established, and 2. The necessary conditions for risk evaluation prior to performing tattoos and for the appropriate information of customers about the health risks of the latter were described [2,32,36].…”