Tattoos: Are They Toxic?

Hi, I'm Rose Rimler, filling in for Wendy Sookerman, and this is Science vs. Today, we are talking about tattoos. Tattos are more popular than ever, but lately they've been getting some flat. Online, we're hearing that tattoos are toxic. What is a toxic guy tattoo? Upper chest, Roman numerals. That is always a toxic guy. Everyone knows one of those guys. No, not that kind of toxic, like poisonous. It turns out tattoos are actually pretty unhealthy for us. You're constantly being poisoned by the toxins. If I were to go back in time with the knowledge I have now, I would not have the tattoos that I have. People are pointing to tattoo ink, saying that it's full of stuff that you don't want in your body. Every single person who has a tattoo has metals leaching into the bloodstream. Mercury, lead, nickel, and other harmful heavy metals that will slowly release in your body, adding to your toxic burden daily. And ultimately, they say that the consequences can be serious. A new study has found a good, increased risk of developing cancer. 21% chance of getting a malignant lymphoma with even small tattoos. And if this risk is real, it would affect a lot of people. According to surveys in the US and Australia, a third of adults are tattooed. And globally, that number is one in five. So, are these people making a terrible mistake? If you get a tattoo, are you poisoning yourself and upping your risk of cancer? And finally, to a science found any benefits to getting inked? Because when it comes to tattoos, there's a lot of. They're science. Science versus tattoos is coming up after the break. Welcome back. We are here to talk about tattoos. I'm Rose Rimmler, and I'm here with Science versus Editor and Tattoo Haver. Black Thrill. Hi, Black. Hi, Rose. Famed Tattoo Haver, I will say. So, how many tattoos do you have? Where are they? Spill it. So, the first one I got, I got my good friend when it's 18. We both got flowers. It's just like, I'm 18. I have a flower. My husband and I have one. That's kind of like I love you in sign language. It's stylized. I have a stylized double helix on my ankle. Very nerdy, very on theme. And then my other one is the Batman logo. But it is the 1960s Batman. I've always kind of been curious about it. Why Batman? So, my initials are BAT. And so, it's been like a running joke. Okay. You're the Batman. Revealed on this podcast. Have you ever worried about your tattoos? I mean, my mom worried that I wouldn't get jobs. But, like, health wise. I mean, I guess only to the extent that I was like, "Okay, is this guy getting like a clean needle out of the pack?" But beyond that, no. Has it ever come up for me? Yeah. And I was pretty surprised myself when I saw this stuff pop up online about tattoos being toxic. I don't have any tattoos myself. But I know so many people who do. So, I really want to know, is this true or is this just, yes. Yeah. Very curious to know what you found. So, you know, obviously, tattoos have been around thousands of years, but interestingly, scientists have only recently begun to study how the tattoo ink interacts with our biology. This is kind of on the newer side of things. Scientists like Santiago Gonzales. He is a toxicologist and immunologist at the University of Lugano in Switzerland. Actually started by chance, so we were not primarily oriented on the tattoo. Here's what happened. Santiago needed to label mice for an experiment. They were doing about the immune system. The way they had been doing that was putting a tag on the mouse's ear, like tagging their ears, which is very common. Yeah. But. I never like it because it's a bit heavy and the animal is a bit annoying for the animal. So, instead of tagging their ears, the scientists in his lab decided they were going to try tattooing the animals in order to mark them. We basically have a tattoo machine, which is exactly the same as the tattoo that a machine that is used by your tattoo artist. And we just do it normally like. Is it like teeny tiny? Yeah, it's very small, so obviously you have to be very careful. So, they're chugging along, tagging their mice to do their next experiment, which all seem to work fine. But then something unexpected happened. My students told me, you know, the lymph nodes of the animals are completely full with the ink of the tattoo. Oh, gross. And just as a reminder, lymph nodes are structures in the body that are part of the immune system. They filter out lymph, which is a fluid that comes from the blood. So, Santiago's team was looking at one of the lymph nodes in the mouse's leg near its foot, which is what had been tattooed. And they found that it got stained with the tattoo ink. Ooh, okay. That's not. It's not what they expected. And it kind of messed up that experiment. Right. That's not what they were studying. Right. It's not what they were studying. They were just using the tattoos to label a mice for another experiment. But, after seeing this, they decided to do an experiment, where they tattooed the mice and then watched where the ink went in a more controlled way. Okay. So, we did all this again, and then took photos of the lymph nodes two months later. So, let me show you. Oh. Oh, yeah. You can really see. You can really see the ink in there. It's bright. Yeah. It's a few different colors of ink. And you can see when one mouse has a pretty bright blue lymph node, like bulbous little goopy thing. So, how did that happen? Well, okay. So, your body has these white blood cells. They're called macrophages. That go around gobbling up stuff that they think shouldn't be there. So, this is typically like bacteria, broken bits of cells. When you get a tattoo, macrophages in your skin, they go around and they slurp up some of that ink. And it turns out that they're also bringing that ink to the lymph nodes. And scientists have also seen this in people. We've had case studies documenting it, like if someone with tattoos goes in to get their lymph node biopsy for whatever reason. Pathologists will sometimes find ink in the lymph node. And Santiago's team also found this when they looked at lymph nodes from people, which led him to conclude. When you are tattooing your skin, you are also tattooing your lymph nodes. Okay. So, we have tattooed lymph nodes, but does that automatically equal some kind of a problem? Well, it's possible. I mean, if the lymph node is involved, that means the immune system is involved in some way. So, Santiago's team also checked levels of immune markers in the mice's bodies to see if they were elevated. That would suggest that they were stressed out, basically. These are molecules that are part of the body's stress response to injuries or illness. And he did find that these molecules increased in both the lymph taken from the lymph node and in the mice's blood. But most of that activation went back to normal after a week or so from getting the tattoo, which makes sense. Of course, you'd have a temporary inflammatory response to a bunch of needles in your skin. But there was one exception, a molecule associated with chronic inflammation. It's actually called a lerman. Great. Yeah. What was the lerman doing, Rose? It was alarmed. It was raised even two months post tattooing, which Santiago argues should have been passed the initial healing phase of the tattoo. Uh-huh. Okay. So, how worried should we be about that? Well, you know, Santiago's study was kind of exploratory. It showed some hints of some immune system weirdness in mice. It wasn't looking at long-term issues in real people. So zooming out to other studies, we do start to see that this activation of the immune system might be a problem for some people. I read this case study, um, a guy from Poland, he had a full-blown immune reaction to his tattoo four months after he got it. He lost his hair. He developed the dalago. What's that? That's like a skin change in the color of your skin. Okay. And he had to get the tattoo essentially cut out of his arm. Whoa. There's another series of cases that was published recently in Australia about people who got this allergic reaction to their tattooing and it attacked their eyes. Oh, my God. And some of them even had vision loss. Those examples are extreme, and they're not that common, but in general, we do see a lot of allergic reactions to tattoos. Just typically, it's confined to the skin. Actually, you know what that makes me think of Rose. So the other day I was sitting with my husband and he looked at me and he was like, "Dear tattoos ever, itch?" And I was like, "No." "Dear tattoos ever, itch." And he know what else Rose? He has some like immune system stuff going on a little bit, another auto immune system thing. So I kind of had this feeling, as you say this, I'm like, "Oh, I wonder if like suddenly there's this change." And like the itchy, like, "Jack's tattoos are getting a little itchy. I wonder if it's related." Okay. Interesting. Well. The best numbers I could find on how common this is this like sort of skin reaction to tattoos It comes from a survey of people with tattoos in Germany and it found that about 9% of people reported Persistent skin problems at least a month after they got their tattoo Okay, and so it sounds like he might be in that unlucky sliver of people Lucky lucky in love unlucky and tattoos obviously So this happens to a fraction of unlucky people 9% In that German study, but there are other reasons to be concerned about tattoo ink. That's more universal for everyone who gets tattooed One of those things is the fact that a lot of tattoo ink contains chemicals that we think are possibly carcinogenic Hmm, and that includes black ink, you know, black a lot of your tattoos are black. I noticed. I think they're yeah, most of them are black Okay, great. What are you going to tell me about black ink rose carcinogenic? Black ink is basically so Sorry, great. So it's like yeah, like I'm fine. If I were a chimney sweep But this is what makes some people worried that tattoos might cause cancer Hmm, and we're gonna need some more science to figure that out. Okay, so we're gonna have to go to Sweden I'm ready. All right. That is ready is coming up after the break Welcome back. We're talking about tattoos today. I'm here with Blight Terrell. Hi, Blight. Hey Rose So it turns out there are some reasons to be concerned about tattoos We know that the ink doesn't just stay put static in our skin It's actually interacting with our immune system getting into our lymph nodes We know that some of the ink might be bad for us might be even carcinogenic But we want to know like what are the consequences? Right besides just you feeling superior to me because you don't have tattoos and I do We know that people with out tattoos are better But are they healthier? I spoke about this with Kristal Nielsen. She works at Lund University in Sweden She is an epidemiologist who focuses on environmental toxins typically stuff like forever chemicals But a few years ago, she got curious about potential toxins in tattoos and I might have one or two tattoos myself So that's triggered the interest. What do you have? I have a dragon on my arm and I was awesome And I'm job I was young in the 90s. So I might have a Chinese sign on my lower back a Chinese character on your lower back I know I'm just laughing because yeah, yeah, you laugh. It's the stereo type But I don't have a tribal I have to say that what does the Chinese character mean? It's supposed to mean horse because I'm born in the year of the horse But but I showed it to my daughter's friend who knows Chinese and she said I've never seen that sign before This is the classic tattoo horse story of the 90s So she's relatable is what I'm saying. Yes, she's very relatable So she decided to learn Chinese. No, no she decided to look into tattoos and how I was ready to go with you on She zoomed in on cancer for the reasons we talked about before the potential carcinogenic Inc and also we know that chronic inflammation can lead to cancer So she dove into that beautiful Scandinavian public health data that we love so much here at science Versus in Sweden. We have these Very very in terms of research useful national registries where we all end up whether we like it or not So it's it has full population coverage And especially for cancer. We have the national cancer registry So if you get diagnosed with cancer in Sweden any cancer you will end up there So she entertained decided to focus on two types of cancer that they could see plausibly being connected to tattoos Skin cancers including melanoma. It's kind of obvious But also lymphoma it's cancer of the lymph system Right, because we know that this ink is in the lymph system. Right, so that makes sense Okay, right and so they pulled the records of everyone in Sweden who had been diagnosed with those cancers between the ages of 20 and 60 And then they set out to find who among them had tattoos so we contacted all of them and I mean lymphoma is a severe disease. So not everyone who were diagnosed 10 years ago. We're still alive Right, and in that case we contacted their next of kin. I see with a main point then of understanding whether they're Relative had had the two so not And they also gathered a group of like matched people who did not have cancer Sort of like matched controls and they sent out questionnaires to them as well a lot of lifestyle stuff But also like lots of questions about tattoos. Not just like do you have a tattoo? But how many do you have how big is it when do you get it where do you get it all that kind of stuff? People really got excited about this. They sent Kristal like all these emails and stuff like they want to tell her all about their tattoos It's nice to get to know your Participants in a way and some still send me postcards. It's really it's really really sweet So the data started coming back and Kristal was working closely with one of her co-authors But this is during the pandemic they weren't together that much So one day Kristal found herself just crunching the data alone I was you know in my house. It was just me and I had a date there and I just I just needed to have a look And then there were the preliminary results and I just threw myself at the phone and told her that well we might actually have something here Yeah, so she found something when it came to cancer risk. So first lymphoma We saw an increased risk of lymphoma among those with tattoos Compared to those who did not have tattoos their risk was 20% increased They also found about a 30% increased risk of melanoma Wow that seems big. Is that big? Well Here's Kristal on that. So we're talking about relative risk increases. So the risk on an individual level is small people shouldn't be freaking out Because it's like It's that sort of situation where a 20% increase risk is serious, but the original risk might be very small So the new risk even 20% higher is still not like astronomical is that the idea exactly So like in the US according to the National Cancer Institute The absolute risk of getting lymphoma is about 2.2% So if we apply Kristal's finding to that it suggests that a tattoo might make that risk go from 2.2 to 2.64% And then for melanoma, it would be like starting at 2.2% going to 2.9% Like sort of for the average person. Okay. I mean right. So it's not nothing obviously yeah, and So maybe if you're a person who's already like at increased risk or whatever That's something maybe you want to factor that in exactly And there are a couple other studies that have looked into this um and not all of them find this link to cancer But the strongest and biggest studies do find this link like a similar one that was done in Denmark. Well, but what about like is there any Reason to think there might be some confounders like to people who have tattoos How they had tend to have a different kind of lifestyle or like be slightly more likely to party or engage in other behaviors Rose that like my contribute to cancer risk or that kind of stuff So the these studies do try to adjust for that as best they can um, but yeah, it's probably not perfect And there is some evidence that uh people who have tattoos might do some on the whole are more likely to do some risky behavior Compared to people who don't have tattoos. So smoking is something that has come up in the literature Um, I think it's like these cancers are not particularly associated with smoking. Okay, so it sounds like you think there's something here Yes, I do and I do um partly because I think the studies Crystals and the other city from Denmark are good studies and also it seems like we have a mechanism that's plausible It just it does make some sense Rose should I get all my tattoos removed? Because you can right like if you are ways to get tattoos removed. Yeah, you can get them removed with lasers um and You might want to do that if you're freaked out about what I just said or you know, you got a Chinese character on your lower back You actually don't know what it means and in fact outside of this studies do find that something like 20 to 25% of people Regret at least one tattoo. Crystals says the thing about that is For as little as we know about the effect of tattoo ink on the body You know, even less about what happens when we shoot lasers at tattoos So what people need to know is I mean don't Lace or tattoos and they evaporating to see there. I mean, that's not what happens They need to get through the body to get out in the other end basically The laser blasts the ink into smaller fragments that the immune system then can go and clean up But you're still like getting your immune system to you know, you're triggering an immune response And you're also changing the molecules Um, and some of those are worse than the original molecules in the ink. So for example example, we know that a lot of the colors in tattooings are made with nitrogen groups called Azo's. And when Azo's are broken apart, they can form compounds that we know are carcinogenic. So we might set off a cascade of exposure to something that we don't know what it is, but it might be worse in the original exposure. Might be. I mean, there's a lot we don't know. We should be getting more information about tattoos generally over the next five or 10 years. Crystal is going to keep studying people. She's got this cohort, you know, she's going to keep studying them. There's another project that's back by the World Health Organization that's getting off the ground following people with tattoos over a number of years. So we're going to find out more about tattoos and health. I think that we, as a society, we will continue to get inked. And then we need to make sure that it's safe to do it. Absolutely. And I think what we do in the show right is like try to give you the information to make that decision for yourself, you know, we're not cops. But even when I think about it, I'm like, I, knowing all this, like, I don't know, you know, like, maybe I still would have gotten my tattoos because I like them. You know what I mean? Like, I'm not sure if knowing this would have been quite enough for me to be like, never. Right. Well, yeah. I mean, and the thing is like with anything that we talk about, it's always like risk versus benefit, you know? Benefit looks cool. No, there are real benefits, but it's more than just looking cool. And I have one final guess to introduce you to to tell us a little bit more about that. His name is Veer and Swammy. He is a professor of social psychology at Anglia Raskin University in the UK. Being tattooed or being able to get a tattoo is a small marker of agency. He says, I am allowed to own my own body and do what I want with my body. He essentially tattoos were the preserve of what psychologists have called out groups, and out groups who simply mean marginalized communities. So like in the West and in communities colonized by the West, tattooing has been associated with being in an out group, like think of sailors and the 1700s, but it's mainstream and other parts of the world like in Polynesia. And even though today in the West, tattoos are not as stigmatized, researchers still find an echo of that motivation. So this is interesting. The demographic in the West that is most likely to get tattooed. This is according to a Pew research survey from a few years ago. Queer women. 68% of people who identify as queer women have at least one tattoo. Interesting. And that makes a lot of sense to Veer and it goes back to the idea of being part of an out group. Many communities that has a history of marginalization will try and reclaim the body in some way. It's also the same reason why some researchers have talked about how women who have had a history of sexual or physical abuse tend to get tattooed again. It's a way of reclaiming the body and saying this body is mine. And we do have some evidence that getting tattooed can help people feel better about themselves. A few years ago, Veer and went to a tattoo shop in London and he surveyed people before and after they got their first tattoo and also followed up with them a little bit later. He did stuff like he was assessing their self-esteem, he asked them how do you feel about your body? How do you feel about how you look? And it turns out that after they got their tattoo. People reported being happier with their bodies appreciating their bodies more, feeling like they were more unique as a result of getting tattoos and feeling lower anxiety about their appearance. Another study found this too, this study actually had college students design a temporary tattoo that an artist painted on them. It lasted a couple weeks and they measured their self-esteem and how they felt before and after that temporary tattoo and it did also give them a boost. That's fun. And I think it's telling that most people don't regret their tattoos even years later. Remember that stat I told you earlier, it's like maybe 20 percent of people regret their tattoos. And that means 80 percent don't. Yeah, totally. I'm among the 80 percent rose. Okay, I was going to ask you, how are you feeling about tattoos after all that information and your husband's into your arm? Well, yeah, I guess I should tell him to keep an eye out for anything else that might go on that's unnerving here, right? But yeah, I mean, I think for the generally speaking, I go into things thinking like, "Uh, it's an internet meme, people are freaking out or whatever, it's toxic, don't do it." And so I expect those things to be kind of not true, that's my baseline, I'm skeptical, I guess. So I think it's really useful to know that maybe there is something there. I don't know. Overall, I guess, it doesn't freak me out about the tattoos that I have now. Yeah. Well, let me ask you this, would you get another one? I don't know. Do you want to? Do you have any planned? I have been thinking about it. I've had a particular stegosaurus in mind for a while. Of course, well, I will say one thing we didn't talk about was like, "Are you more at risk if you have more tattoos?" Yeah. Well, that's it. Yeah. And Kristell's study found no, but the Denmark study found yes, or like bigger tattoos. And Kristell actually thinks that her finding was sort of an artifact of the way she asked the question. So she thinks it's very possible. The more tattoos or the more ink if you get like a really ink-filled tattoo, very likely could have a higher risk associated with it. You don't have all the receipts for that, something to consider. Okay. I can do that Rose. I can consider it. Consider it. Thank you so much. Thank you. And that's science versus. Live. You should know that there are 77 citations in this week's episode. Wow. Okay. And you can tell the folks where to find them live? Yes. We can find them in our transcripts which we link to in our show notes. All right. This episode was produced by Rose Rummler with help from Bleb Threl, Aketty Foster Keys, Meryl Horn, and Michelle Deng. When Nizokerman is our executive producer, we're edited by Bleb Threl, fact-checking by Diane Kelly, mixed in sound design by Boomi Haraka and Bobby Lorde, music written by Bobby Lorde, Boomi Haraka, so Wiley, Emma Munger, and Peter Leonard. Special thanks to all the experts we spoke with for this episode, including Dr. Simea Clemenson, Professor David Creeble, Dr. John Swirk, Natasha Chinote, Dr. Sundreen Henri, Professor Chris Lynn, and Trisha Allen. Science versus is a Spotify studio's original. Listen for free on Spotify or wherever you get your podcasts. 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