Tatuaggi, pregi, problemi e soluzioni (Il viaggio dei coloranti ai linfonodi)

Il nuovo studio di scienziati tedeschi e dell’Esrf pubblicato su «Scientific Reports» avverte sui rischi piuttosto gravi connessi ai tatuaggi.

Chi ha un tatuaggio sa di avere un elemento decorativo sulla pelle, non sa quali sono le  conseguenze che i coloranti provocheranno all’interno del suo corpo.

Avvalendosi delle più recenti nanotecnologie, grazie al Sincrotrone ed a microscopi elettronici a scansione, un team di scienziati tedeschi e dell’Esrf (1) è riuscito a fotografare il percorso degli elementi che costituiscono l’inchiostro.

Infatti i tatuaggi, a differenza di quanto si pensa, non rimangono immobili, ma iniziano un percorso e le loro micro e nano particelle di inchiostro si muovono. “E’ dimostrato il trasporto simultaneo di pigmenti organici, metalli pesanti e titanio dalla pelle ai linfonodi regionali” (2).

Negli inchiostri da tatuaggio analizzati, erano presenti, oltre alle consuete sostanze colorate organiche, alcuni conservanti ed un certo numero di contaminanti, tra i quali il cobalto, il cromo, il manganese, il nichel, il piombo.

Le quantità di cromo, rame e piombo sono risultate superiori ai livelli massimi consentiti dalla risoluzione ResAP 2008 del Consiglio d'Europa. Inoltre, erano presenti sostanze vietate da quanto stabilito dalla risoluzione ResAP 2008, in particolare Blue 15, Green 7, Violet 23 ed altre (3).

Uno dei pigmenti più utilizzati, oltre al Carbon black (già elencato dalla IARC come potenzialmente cancerogeno per l'uomo), è Biossido di titanio, anche presente  con il numero E171 nella lista degli additivi alimentari (4).

In particolare, il Biossido di titanio, (un composto chimico, un pigmento bianco che crea una colorazione bianca oppure opaca), in forma di nano particelle riesce a superare le normali difese del corpo umano per cui è confermata la relazione tra le nanoparticelle del Biossido di titanio e il processo EMT nelle cellule tumorali del colon-retto (5).

Oltretutto, il tatuaggio con inchiostri neri comporta un'iniezione di notevoli quantità di fenolo e idrocarburi aromatici policiclici nella pelle. La maggior parte di questi idrocarburi aromatici policiclici sono cancerogeni e possono inoltre generare deleterio ossigeno "singoletto" all'interno del derma quando la pelle è esposta ai raggi UVA (ad esempio radiazione solare) (6).

 Bernhard Hesse, uno degli autori di una complessa ricerca scientifica sull’argomento tatuaggi, ha confermato il viaggio dei pigmenti attraverso il corpo fino ai linfonodi ed ha ribadito quello che era peraltro noto da tempo e cioè che, da prove visive, i linfonodi assumevano una colorazione simile a quella dei tatuaggi e si ingrossavano.

Quindi, oggi, grazie agli studi condotti dall’Esrf, Ludwig-Maximilians University e Physikalisch-Technische Bundesanstalt, alle misurazioni con la spettrofotometria XRF, sappiamo la verità sul posizionamento del Biossido di titanio, degli altri coloranti inseriti dentro la pelle e sulle conseguenze che ne possono derivare.

Nel 2019 sono stati svolti ulteriori studi per accertare la quantità, il diametro e la presenza di metalli pericolosi per la salute umana. Negli inchiostri italiani sono stati rilevati 18 metalli e le concentrazioni più elevate erano Titanio e Cromo. Rimane quindi il pericolo dell'esposizione a nano e sub-micro particelle di metalli pesanti (7).

Bibliografia_________________________________________________________________________

 (1) Viaggio nei linfonodi     www.esrf.eu

 (2) Synchrotron-based ν-XRF mapping and μ-FTIR microscopy enable to look into the fate and effects of tattoo pigments in human skin, I. Schreiver (a), B. Hesse (b), C. Seim (c), H. Castillo-Michel (b), J. Villanova (b), P. Laux (a), N. Dreiack (a), R. Penning (d), R. Tucoulou (b), M. Cotte (b) and A. Luch (a), Scientific Reports 7, 11395 (2017); doi: 10.1038/s41598-017-11721-z.

Abstract. The increasing prevalence of tattoos provoked safety concerns with respect to particle distribution and effects inside the human body. We used skin and lymphatic tissues from human corpses to address local biokinetics by means of synchrotron X-ray fluorescence (XRF) techniques at both the micro (μ) and nano (ν) scale. Additional advanced mass spectrometry-based methodology enabled to demonstrate simultaneous transport of organic pigments, heavy metals and titanium dioxide from skin to regional lymph nodes. Among these compounds, organic pigments displayed the broadest size range with smallest species preferentially reaching the lymph nodes. Using synchrotron μ-FTIR analysis we were also able to detect ultrastructural changes of the tissue adjacent to tattoo particles through altered amide I α-helix to β-sheet protein ratios and elevated lipid contents. Altogether we report strong evidence for both migration and long-term deposition of toxic elements and tattoo pigments as well as for conformational alterations of biomolecules that likely contribute to cutaneous inflammation and other adversities upon tattooing.

(3) Assessment of Toxic Metals and Hazardous Substances in Tattoo Inks Using Sy-XRF, AAS, and Raman Spectroscopy   Manso, M., Pessanha, S., Guerra, M. et al. Biol Trace Elem Res (2019) 187: 596. https://doi.org/10.1007/s12011-018-1406-y

Abstract. Synchrotron radiation X-ray fluorescence spectroscopy, in conjunction with atomic absorption and Raman spectroscopy, was used to analyze a set of top brand tattoo inks to investigate the presence of toxic elements and hazardous substances. The Cr, Cu, and Pb contents were found to be above the maximum allowed levels established by the Council of Europe through the resolution ResAP(2008)1 on requirements and criteria for the safety of tattoos and permanent makeup. Raman analysis has revealed the presence of a set of prohibited substances mentioned in ResAP(2008)1, among which are the pigments Blue 15, Green 7, and Violet 23. Other pigments that were identified in white, black, red, and yellow inks are the Pigment White 6, Carbon Black, Pigment Red 8, and a diazo yellow, respectively. The present results show the importance of regulating tattoo ink composition.

(4) Nano-TiO2 Drives Epithelial-Mesenchymal Transition in Intestinal Epithelial Cancer Cells.  Setyawati MI, Sevencan C, Bay BH, Xie J, Zhang Y, Demokritou P, Leong DT.  Small. 2018 Jul 2:e1800922. doi: 10.1002/smll.201800922.

Black Tattoos Entail Substantial Uptake of Genotoxicpolycyclic Aromatic Hydrocarbons (PAH) in Human Skin and Regional Lymph Nodes  Karin Lehner, Francesco Santarelli, Rudolf Vasold, Randolph Penning, Alexis Sidoroff, Burkhard König, Michael Landthaler and Wolfgang Bäumler  doi: 10.1371/journal.pone.0092787

Abstract. Hundreds of millions of people worldwide have tattoos, which predominantly contain black inks consisting of soot products like Carbon Black or polycyclic aromatic hydrocarbons (PAH). We recently found up to 200 μg/g of PAH in commercial black inks. After skin tattooing, a substantial part of the ink and PAH should be transported to other anatomical sites like the regional lymph nodes. To allow a first estimation of health risk, we aimed to extract and quantify the amount of PAH in black tattooed skin and the regional lymph nodes of pre-existing tattoos. Firstly, we established an extraction method by using HPLC-DAD technology that enables the quantification of PAH concentrations in human tissue. After that, 16 specimens of human tattooed skin and corresponding regional lymph nodes were included in the study. All skin specimen and lymph nodes appeared deep black. The specimens were digested and tested for 20 different PAH at the same time.PAH were found in twelve of the 16 tattooed skin specimens and in eleven regional lymph nodes. The PAH concentration ranged from 0.1-0.6 μg/cm2 in the tattooed skin and 0.1-11.8 μg/g in the lymph nodes. Two major conclusions can be drawn from the present results. Firstly, PAH in black inks stay partially in skin or can be found in the regional lymph nodes. Secondly, the major part of tattooed PAH had disappeared from skin or might be found in other organs than skin and lymph nodes. Thus, beside inhalation and ingestion, tattooing has proven to be an additional, direct and effective route of PAH uptake into the human body.

(5) Nano-TiO2 Drives Epithelial-Mesenchymal Transition in Intestinal Epithelial Cancer Cells.  Setyawati MI, Sevencan C, Bay BH, Xie J, Zhang Y, Demokritou P, Leong DT.  Small. 2018 Jul 2:e1800922. doi: 10.1002/smll.201800922.

(6) Tattoo inks contain polycyclic aromatic hydrocarbons that additionally generate deleterious singlet oxygen.  Regensburger J, Lehner K, Maisch T, Vasold R, Santarelli F, Engel E, Gollmer A, König B, Landthaler M, Bäumler W.  Exp Dermatol. 2010 Aug;19(8):e275-81. doi: 10.1111/j.1600-0625.2010.01068.x.

Abstract. In the past years, tattoos have become very popular worldwide, and millions of people have tattoos with mainly black colours. Black tattoo inks are usually based on soot, are not regulated and may contain hazardous polycyclic aromatic hydrocarbons (PAHs). Part of PAHs possibly stay lifelong in skin, absorb UV radiation and generate singlet oxygen, which may affect skin integrity. Therefore, we analysed 19 commercially available tattoo inks using HPLC and mass spectrometry. The total concentrations of PAHs in the different inks ranged from 0.14 to 201 microg/g tattoo ink. Benz(a)pyrene was found in four ink samples at a mean concentration of 0.3 +/- 0.2 microg/g. We also found high concentrations of phenol ranging from 0.2 to 385 microg/g tattoo ink. PAHs partly show high quantum yields of singlet oxygen (Phi(Delta)) in the range from 0.18 to 0.85. We incubated keratinocytes with extracts of different inks. Subsequent UVA irradiation decreased the mitochondrial activity of cells when the extracts contained PAHs, which sufficiently absorb UVA and show simultaneously high Phi(Delta) value. Tattooing with black inks entails an injection of substantial amounts of phenol and PAHs into skin. Most of these PAHs are carcinogenic and may additionally generate deleterious singlet oxygen inside the dermis when skin is exposed to UVA (e.g. solar radiation).

(7) Quantitative analysis of metals and metal-based nano- and submicron-particles in tattoo inks.  Battistini B, Petrucci F, De Angelis I, Failla CM, Bocca B.  Chemosphere. 2019 Dec 16;245:125667. doi: 10.1016/j.chemosphere.2019.125667.