Tattoo ink exposure is associated with lymphoma and skin cancers
82 points by achristmascarl 4 months ago | 53 comments- perdomon 4 months agoThe study's conclusion that tattoo ink causes cancer fails to convince due to major methodological flaws. The sample sizes for the most important analyses (matched twin pairs) were tiny, with fewer than 5 informative pairs for lymphoma. Meanwhile, known lymphoma risk factors like viral infections, alcohol consumption patterns, and occupational exposures weren't properly controlled for. What we're likely seeing is correlation driven by lifestyle clustering - people with tattoos often have different behavioral patterns that independently affect cancer risk, but the study's crude "ever/never" smoking measure and absence of other key controls can't disentangle these complex relationships.
- belter 4 months agoHere is another study.
"Possible association between tattoos and lymphoma" - https://news.ycombinator.com/item?id=40489486
- woleium 4 months agoUsually when studies are flawed like this there is someone with a vested interest in the outcome paying. I can’t imagine who that may be here though. Anyone have any suggestions?
- belter 4 months ago
- flir 4 months agoI wonder if tattoo removal bumps the risk even further - a bit like disturbing asbestos in a building. That would be a hard one to study.
- arisAlexis 4 months agoLaser drives all the chems through your kidneys and bladder. Removing the upper skin layer could be safer ?
- krisoft 4 months ago> Removing the upper skin layer could be safer ?
Tattoos are not in the upper skin layer though. Also removing any skin layers is quite dangerous, at least in a statistical sense.
- mordechai9000 4 months agoThere is a technique called salabrasion where the upper skin layers are rubbed off with a paste of salt. This doesn't remove the tattoo, but the ink is at least partially drawn up into the resulting scab during the healing process. It's probably not very safe, despite the use of salt, and removing skin like that over even a moderate area sounds brutal, but apparently it works well enough. And then, after one or more repetitions of the process, you are left with a highly visible scar, and maybe a faint tattoo, instead of just a tattoo.
- mordechai9000 4 months ago
- krisoft 4 months ago
- jan_Inkepa 4 months agoYeah - if there was just a risk of having one I'd probably get mine removed, but yeah - I think I remember looking into it once and coming away thinking it's probably best to leave it as is. (I can't remember the details).
- arisAlexis 4 months ago
- metayrnc 4 months ago> In the case-control study, individual-level analysis resulted in a hazard of skin cancer (of any type except basal cell carcinoma) that was 1.62 times higher among tattooed individuals (95% CI: 1.08–2.41)
- awestley 4 months agoIf lifestyle differences are not accounted for, I'd put little stock in this.
- queuebert 4 months agoThat's the entire point of twin studies and case controls. Did you read the article?
- theamk 4 months agono, that makes no sense. How does having identical genetics negate problem of different lifestyles?
Even the authors agree with awestley:
> Additionally, having a tattoo, especially among adolescents, has been suggested as an indicator of risky lifestyle highly associated with e.g. smoking [4] and alcohol consumption [46] – both risk factors of certain cancer types. Hence, evidence of an association between tattoo ink exposure and occurrence of cancer may be confounded by other health-related lifestyle factors. We intend to exploit the remainder of the information gathered in the survey in the future.
Indeed, it does seem like a big problem that should really be accounted in the initial analysis.
- mbreese 4 months agoTwin studies can help control for things like genetics and environmental factors in childhood (exposures, socio-economic factors, etc). They can't control for lifestyle choices made by adults. So, if a person has tattoos, are they more likely to smoke? To have sun exposure? To drink heavily? All of these factors would need to be addressed to see how confounding they are to having a tattoo.
You could also look at tattoo coverage, as in how much of the body is covered in ink? Would a small tattoo on the shoulder have as much risk as a full back tattoo? There are a lot of extra confounders here that could be better explored, but it gets difficult to get a full dataset. However, given their survey data, they should have more analysis options with more time.
The lack of confounder analysis is a bit surprising, but perhaps the paper was long enough already.
- theamk 4 months ago
- eastbound 4 months agoTatoo and tanning?
- mbreese 4 months agoAre people who have tattoos more likely to want to have their skin exposed to the sun (to show off the tattoos)? That seems like a reasonable association, but it's probably dependent upon tattoo location.
- mbreese 4 months ago
- queuebert 4 months ago
- hmmokidk 4 months agoAs someone with tattoos I am spending a lot of time in the sun without sunscreen and smoke enough nicotine to satiate some region in france probably.
- nerdjon 4 months agoIt would be interesting if they could somehow look at the ink itself but without this being basically a lifelong study I realize that could be difficult.
Especially given the recent report of issues with some ink being used. I don't remember the specifics.
I doubt this would stop people from getting tattoos, and I know it isn't stopping myself from planning on being fully covered... but it is still interesting.
- harimau777 4 months agoIt would be interesting to see if this applies to traditional tattoo inks as well. Are tāmoko still done with traditional inks? If so, then that might be an easy way to do a population study.
- jl6 4 months agoAssociated with. Causal connection not yet proved. On the other hand, let’s be realistic, tattoos are not going to turn out to be good for you, are they.
- code_runner 4 months agoPeople have been getting tattoos for a pretty long time. I don't really see this as stopping that?
If you have tattoos its entirely possible you'll actually be more careful in the sun by applying sunscreen.... but you also might be more prone to showing your ink off and therefore exposing a greater area of skin to the sun.
If there is some common ingredient that has been used in tattoo inks recently and we're concerned about that, let me know.... but generally speaking I don't think this is interesting information
- swatcoder 4 months agoIt's mostly only here on HN where people (in their commenter persona) take this kind of study so seriously and pretend that they must either live uncompromising teetotaling lives in pursuit of optimal and maximally long health, or that the study has to be nonsense/misleading.
In reality, all of us live lives that put at greater risk of this and lesser risk of that. The real value of learning that there's perhaps some association with one of our activities and a specific disease or other kind of harm is that we can be watchful of that disease or harm emerging in our own lives and thereby give ourselves more opportunity to respond. Or perhaps we might use it as reason to moderate, or to finally stop doing something we already feel conflicted about.
So this kind of thing is definitely interesting information for some people, but as often for HN, we can expect a lot of comments engaging with it only in extremes of condemnation or refutation.
- binoct 4 months agoScientific research doesn’t have to directly impact personal decision making to be useful and interesting. This study provides a data point suggesting a link between having tattoos and skin cancer - it’s certainly interesting to the medical field to better understand what increases the risk of cancer. A lot of research into smoking cigarettes and cancer also didn’t have much impact on people who decided to smoke, but it was also valuable knowledge.
- wiether 4 months ago> If you have tattoos its entirely possible you'll actually be more careful in the sun by applying sunscreen.... but you also might be more prone to showing your ink off and therefore exposing a greater area of skin to the sun.
Knowing multiple tattoo artists, that's exactly what they observe from their customers : some are very careful about their skin exposure while other are doing the exact opposite.
They are not healthcare professionnal so they don't study skin cancers, but they can easily tell which one is which based on how the tattoo evolve year after year.
This could probably be the easiest factor to check.
Regarding the inks, since there's little to no regulation, even in the EU, and people tend to get tattooed when away from home, it could be much, much trickier.
- kurthr 4 months agoMost inks up until the 20th century were carbon black (some vermilion and prussian blue). That changed with the introduction of both organic and inorganic color dyes over the last 100 years. Only recently has there been much regulation at all.
- tattooPAH 4 months agoInk composition and regulation might vary regionally. The original article mentions
> The most frequently used tattoo ink is black. Black ink typically contains soot products like carbon black, which is listed as possibly carcinogenic to humans (mainly based on studies of carbon black inhalation and risk of lung cancer) by the International Agency for Research on Cancer (IARC) [13]. Through the incomplete combustion used for carbon black production, polycyclic aromatic hydrocarbons (PAHs) are formed as byproducts. One of the most dangerous of these is benzo[a]pyrene (BaP), which is classified as carcinogenic to humans by the IARC [14].
You really don't want benzo[a]pyrene floating around your system, it's a potent carcinogen that's been firmly established by many studies. Some papers focus on directly on PAHs and tattoos, for example this PLoS One 2014 paper: https://pubmed.ncbi.nlm.nih.gov/24670978/
- tattooPAH 4 months ago
- 4 months ago
- spiderxxxx 4 months agoI don't think the result of this study would stop people from getting tattoos, but if you're on the fence, then perhaps it could sway you. Either way, it can provide information to doctors to perhaps screen them more often for skin cancer, or people to get screened, given that it might show a higher risk.
- ceedan 4 months ago> you also might be more prone to showing your ink off and therefore exposing a greater area of skin to the sun.
Seems likely
- anarticle 4 months agoCare and feeding of tattoos is largely a new thing. The vast majority of people do not care.
- swatcoder 4 months ago
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- tyronehed 4 months agoIn life it's often more important what you don't do, then what you do do
- 9991 4 months agoMaybe it's inflammation from the ink. Maybe the kind of personality that gets tattoos is also prone to other carcinogenic behavior.
- jahsome 4 months agoI have a bunch of tattoos, and I don't care much about cancer risk, but I wish someone had warned me about the risks of being so damn itchy for the rest of my life.
- tlavoie 4 months ago"For the rest of your life"? You shouldn't be feeling anything different once it's all healed up. For a couple weeks, sure. My current work-in-progress gets the "second skin" permeable dressing for several days, then it comes off. For a few days after that, moisturizer. Now it's just part of me, but darker.
- bn-l 4 months agoDo they cause a lot itching? This is the first time I’ve heard that.
- jahsome 4 months agoI think my situation is pretty rare, but mine flare up periodically, maybe every other year, almost on a schedule.
It usually starts in one of the reds, and spreads inch by inch over the course of a few weeks. It gets raised and itches like crazy, and lasts 2-3 days in a small area before spreading. It's a real struggle not to scratch.
Unfortunately 1/4 of my body is essentially one giant tattoo, so it's got plenty of room to spread. The small patches of surrounding un-inked skin are completely unaffected, so I suspect it's definitely the ink.
When the first red tattoo I got REALLY swelled up, the tattoer told me it's rare but he'd seem it before, and some people don't take red well. From what I understand the red ink 20 years ago was formulated differently than now. I'm not entirely convinced it's just that color, because all of mine itch.
- jahsome 4 months ago
- arisAlexis 4 months agoWhy would someone not care about cancer risks ?
- jahsome 4 months agoIt's already essentially a guarantee. I figure I might as well enjoy my time while I'm here instead of extending a boring (to my tastes) life.
- jahsome 4 months ago
- tlavoie 4 months ago
- jahsome 4 months ago
- pmdulaney 4 months agoAnd here I thought I disliked tattoos just because I'm an old fuddy-duddy.
- theshackleford 4 months agoI’m sure it’s still the reason so I wouldn’t worry too much.
- pmdulaney 4 months agoThe best response!
- pmdulaney 4 months ago
- 52-6F-62 4 months agoTattoos are much older than you…
- theshackleford 4 months ago
- yieldcrv 4 months agoIs this already known to the State of California because if those signs are missing, it’s feeling like a stimulus package has come my way
- dylan604 4 months agoFor every tattoo, you must also include as part of the tat the Prop 65 text?
- api 4 months agoI saw a shirt in Cali once that had the California flag and then the notice badge: "This shirt has been determined by the state of California..."
- api 4 months ago
- gosub100 4 months agoThis isn't the place for that.
- yieldcrv 4 months agoyou're right, this kind of entrepreneurial idea actually makes money
- yieldcrv 4 months ago
- dylan604 4 months ago