BfRshort forGerman Federal Institute for Risk Assessment FAQ, 12 October 2017
Scientists of the German Federal Institute for Risk Assessment (BfRshort forGerman Federal Institute for Risk Assessment) proved in the course of an international research project that nanometric pigments from tattoo inks can permanently accumulate in lymph nodes. The study has been published in the Scientific Reports magazine of the Nature Publishing Group on 12 September 2017 (External Link:https://www.nature.com/articles/s41598-017-11721-z).
By using X-rays from the particle accelerator in Grenoble (European Synchrotron Radiation Facility, ESRF) during the investigations it has been found out where the pigments accumulate in the tissue. Until now, the accumulation of pigments from tattooed persons has been known by optical colouring of the lymph nodes only, as they often had been of the same colour as the tattoo as such. Both skin and lymph nodes have now been characterized in terms of their chemical composition, pigment identity and size.
In the following, the BfRshort forGerman Federal Institute for Risk Assessment compiled frequently asked questions and answers on the study.
[Accordion] Questions and answers on the study lead of BfRshort forGerman Federal Institute for Risk Assessment investigating the distribution of tattoo ink as nano-sized particles in lymph nodes
In the cooperation project inorganic iron oxide and titanium dioxide were found. All organic pigments are hydrocarbons, e.g. copper phthalocyanine and azo pigments. Each pigment has different properties in terms of toxicity. By now, there is still a lack of data to clearly state their impact on human health after tattooing.
The difference in toxicity will depend on the chemical structure and impurities of the pigments used to create a certain pigment. Earth-toned iron oxide pigments are more likely contaminated with metals like nickel and chromium which are both sensitizing as well as carcinogenic when present in certain oxidation states. These elements are often impurities of the pigments or their synthesis. The effects of the different pigments deposited in the lymph nodes are unknown so far.
Organic azo pigments may release carcinogenic or sensitizing substances after sun light or laser irradiation as shown in previous studies. Red and pink color shades are often associated with allergic reactions of tattoos. Black colors are more often associated with granuloma formation.
Nanoparticles are smaller than 100 nanometers (nmshort fornanometre) in diameter. As shown in our study, titanium dioxide and iron oxide pigments are bigger in size but are still transported to the lymph nodes. The copper phthalocyanine green pigment contained particles as low as 50 nmshort fornanometre which were preferably found in the lymph nodes. From other studies it is also known that especially carbon black pigments are generally smaller than 100 nmshort fornanometre.
As we can state from our studies, all chemical types of pigments accessible with our methods were found in skin and lymph node tissue in one or multiple samples.
In the future, the BfRshort forGerman Federal Institute for Risk Assessment will analyze further samples of patients who suffered from adverse effects in their tattoos together with other cooperation partners. We would like to find an association between the effects observed and the chemical and structural properties of the pigments used to create these tattoos.
The BfRshort forGerman Federal Institute for Risk Assessment will also be looking at pigment and heavy metal burden of other, more distant internal organs and tissues. The biodistribution, metabolism and possible excretion of substances are key points necessary to assess the toxicity of compounds. Especially when organic pigments will be transported to the liver, a higher metabolic turnover can be expected. The metabolites again have unknown toxicological properties.
The deposition of elements in lymph nodes has never been investigated before. However, data on the exposure against toxic elements are necessary for risk assessment in terms of chronic diseases. Since we do not have such data yet, people should be aware of the unknown risks that might come along with tattooing rather than presuming that the colors are safe.
For general information about tattooing see the BfR-FAQ on tattoo inks.
About the BfR
The German Federal Institute for Risk Assessment (BfRshort forGerman Federal Institute for Risk Assessment) is a scientifically independent institution within the portfolio of the Federal Ministry of Food and Agriculture (BMELshort forGerman Federal Ministry of Food and Agriculture) in Germany. It advises the Federal Government and Federal States (“Länder”) on questions of food, chemical and product safety. The BfRshort forGerman Federal Institute for Risk Assessment conducts its own research on topics that are closely linked to its assessment tasks.