Tattoos may increase the risk of developing certain cancers, concludes a study recently published by Danish and Finnish researchers.
“Over the last few years, there have been at least four or five good quality studies showing an epidemiological association between tattoos and cancer,” said Dr. Elena Netchiporouk, from the dermatology division of the McGill University Health Centre.
The authors of the most recent analysis carried out a cohort study of 2,367 randomly selected twins and a case-control study of 316 twins born between 1960 and 1996. Cancer diagnoses were extracted from the Danish Cancer Registry and tattoo ink exposure from the 2021 Danish Twin Tattoo Survey.
Members of the cohort study who had a tattoo larger than the palm of their hand multiplied their risk of skin cancer by 2.4 and their risk of lymphoma by 2.7.
In the case-control study, the risk of skin cancer was almost quadrupled and the risk of basal cell carcinoma almost tripled.
The interaction between tattoo ink and neighbouring cells could therefore have “serious consequences,” warn the authors of the study.
Larger tattoos may have a greater effect, either because of a higher dose of exposure, or because of a longer duration of exposure for tattoos acquired over time, they add.
“It should be borne in mind, however, that in all cases we are talking about an increase in the basic risk, and that this risk is also influenced at a personal level by factors such as smoking or exposure to the sun,” said Netchiporouk. “It’s difficult to incorporate these data on an individual basis, because individual risk is so variable, and when we put all the risk factors together, our immune system will eventually no longer be able to defend itself and cancer will manifest itself.”
But in general, the incidence of skin cancer has been rising steadily in recent years, Dr Netchiporouk pointed out, under the influence of factors such as environmental exposure, air pollution and climate change, “and that adds another risk.”
Up to two-thirds of the volume of tattoo ink is made up of organic or inorganic pigments, she pointed out. The colour black, for example, contains benzene, a very strong carcinogen whose association with various human cancers is well established, said Netchiporouk.
These inorganic compounds are usually made up of metals and salts, and even if less dangerous metals such as nickel are used, often the presence of heavy metals such as cadmium and lead are found, she added.
As for colours such as red, yellow or orange, they come from organic pigments that are rapidly degraded into hydrocarbons under the effect of UV rays.
“Organic pigments can be broken down into hydrocarbons, and hydrocarbons are in the same family as benzene, and that’s never good for your health,” said Netchiporouk.
Human and animal studies have already shown that tattoo ink does not remain in the skin but rather migrates to the lymph nodes, she continued, leading to systemic absorption.
“From a biological point of view, it is logical to think that the combined effect of UV rays and the hydrocarbons found in pigments will increase the risk of cancer,” said Netchiporouk.
The study findings were published in the medical journal BMC Public Health.
This report by The Canadian Press was first published in French on March 15, 2025.
