Pictures that get under your skin
Twenty years ago, tattoos still stigmatized their wearer as an outsider, today they are socially acceptable.
Almost ten percent of Germans wear roses, eagles, geometric patterns and other things as body jewelry. Some tattoos adorn the arm or shoulder, others are only revealed to the intimate partner, and a third variant should not be recognized as a tattoo at all: so-called permanent make-up, which widens lips or makes eyebrows appear darker.
Because the cells of the top layer of skin (epidermis) are renewed regularly, paint applied there disappears after a few weeks. Most of the color pigments are only retained in the leather skin (dermis), which is one to four millimeters deeper. The body's he alth policemen try to destroy the macrophages (scavenger cells) enzymatically or chemically. But to do this, they have to absorb the pigments. Not only can the tiny crystals not be mined, they also use this opportunity to bake together. The scavenger cells swell and many can no longer even transport their cargo into the blood and lymphatic vessels. From the point of view of the immune system, the pigments are rendered harmless by encapsulating them with a protein shell.
In order to reach deeper layers, the skin must be injured. Tattoo artists use tattoo machines in which three to fifteen needles move up and down at fifty to three thousand stitches per minute. Beforehand, they are dipped in the desired color, which is drawn into the guide of the needles by capillary force. When tattooing, this suspension flows down the outside of the needles - they don't have a cavity like a syringe. Parts of it penetrate with the metal into the dermis and are wiped off there.
The larger the image or pattern, the larger the area of the injured skin. As with any wound, there is a risk of infection. "A good tattoo studio therefore pays scrupulous attention to hygiene, only uses disposable needles, ink containers and gloves as well as sterilized handles and uses other parts of the tattoo machines properly," explains Rald Michel from the ink manufacturer Deep Colours! in Neuburg. By the way, corresponding regulations in Germany are a matter for the federal states.
Nevertheless: The dyes pose a he alth risk that is difficult to calculate. According to the Berlin Federal Institute for Risk Assessment, there are no legal regulations for purity, quality and harmlessness to he alth. Since no substances are applied to the skin, regulations for cosmetics are not valid. Regulations from the pharmaceutical sector are also not applied, because due to the lack of scientific models for the biological effects, there are neither binding positive nor negative lists of tattoo inks. That's why contamination with heavy metals and bacteria is not uncommon, warns the dermatologist Wolfgang Bäumler from the University of Regensburg. Some of the popular azo pigments that produce brightly colored images come from large-scale production for automotive coatings - with the associated low purity requirements. Researchers have particular concerns about these colors because some of them decompose under UV light into harmful or carcinogenic substances such as amines, nitrotoluene or methyl-niroaniline.
Especially doctors who are supposed to remove tattoos want color data sheets, because this is the only way they can determine the right laser wavelength. But tattoo studios could also benefit from positive lists, because the American Food and Drug Administration sounded the alarm about the dye problem in July 2004: the first claims for damages are only a matter of time.
For anyone who regrets getting a tattoo after a while - skeptics claim almost half of those adorned do so at some point - dermatologists offer a time-consuming and relatively expensive laser treatment. It is supposed to bleach or destroy the color pigments – with the risk that the harmful substances mentioned are produced in the process. However, since hardly anyone knows which of the several hundred color mixtures are under the skin, such treatments can fail. Then only creativity helps, as with Pamela Anderson: After separating from her husband, "Tommy" became her "Mommy".
Did you know?
- The term tattoo was coined by explorer James Cook, who saw tattooed people in 1769 on Tahiti, one of the main islands of French Polynesia. There was the word "tatau" for "to mark".
- A slight tickle, a sharp sting - the pain that the customer has to endure in the tattoo parlor varies. They come from the nerve cells in the dermis that are hit during needling. The skin is usually more sensitive directly over bones than over muscle pads, which is why a shoulder tattoo hurts more than one on the upper arm. The skill of the tattoo artist is also important, as the tattoo must be deep enough to reach the dermis, but too deep an incision will hurt and bleed unnecessarily.
- The pharmacokinetics of tattoos has hardly been researched so far. Studies on corpses in forensic medicine show, however, that some of the pigments do get into the body and remain, for example, in the lymph nodes or in the filter organs of the liver, spleen and kidneys.
- Many fashion-conscious people opt for temptoos or organic tattoos, which cosmetic studios promise will disappear again after a few weeks or months. Because the color is only brought into the 0.04 to 1.5 millimeter thick epidermis, which is renewed within thirty days. But because this layer is so thin, the needle often sticks too deep and leaves a real tattoo.
The Heidelberger Verlag Spektrum der Wissenschaft is the operator of this portal. Its online and print magazines, including "Spektrum der Wissenschaft", "Gehirn&Geist" and "Spektrum – Die Woche", report on current research findings.
