Smoking, drinking, sunbathing and mobile phones have all been implicated in the surge in cancer diagnoses.
But now it seems another cause may soon be added to the ever-growing list: tattoos.
The U.S. Food and Drug Administration has launched an investigation after new research turned up troubling findings about toxic chemicals in tattoo ink.
Recently published studies have found that the inks can contain a host of dodgy substances, including some phthalates, metals, and hydrocarbons that are carcinogens and endocrine disruptors.
One chemical commonly used to make black tattoo ink called benzo(a)pyrene is known to be a potent carcinogen that causes skin cancer in animal tests.
Coloured inks often contain lead, cadmium, chromium, nickel, titanium and other heavy metals that could trigger allergies or diseases, scientists say.
Some pigments are industrial grade dyes 'suitable for printers' ink or automobile paint,' according to an FDA fact sheet.Now the FDA has launched an investigation into the long-term safety of the inks, including what happens when they break down in the body or fade from light exposure.
Joseph Braun, an environmental epidemiologist at Harvard University in Boston, Massachusetts, told Environmental Health News: 'The short answer is we don't know if the chemicals in tattoo inks represent a health hazard.'
An estimated 45million people in the U.S., including at least 36 per cent of adults in their late 30s, have at least one tattoo.
Particular concern surrounds the use of black tattoo inks, often made from soot containing products of combustion called polycyclic aromatic hydrocarbons (PAHs).
The PAHs in the inks include benzo(a)pyrene, a compound identified in an Environmental Protection Agency toxicity report as 'among the most potent and well-documented skin carcinogens.'
But serious epidemiological studies pose difficulties, since getting a tattoo is still risky behaviour.
Attempting to isolate whether these are the carcinogenic factors in a group of people who habitually engage in risk taking behaviours - like smoking - is impossible.
The FDA has the power to control tattoo inks under the Federal Food, Drug and Cosmetic Act, but up to now the agency has not flexed its regulatory muscles.
A spokesman for the agency said: 'Because the dyes and inks used in tattoos have not been approved by FDA, we do not know the specific composition of what these inks and dyes may contain.
'Therefore, we are unable to evaluate for chronic health concerns, such as cancer.'