Last year, Americans spent $1.6 billion on getting their skin inked.

According to Harris, a polling firm, nearly half of Millennials (47 percent) and over a third of Gen Xers (36 percent) have at least one tattoo, compared to 13 percent of Baby Boomers and one in ten “Matures” (10 percent).

In Alaska summers, body art becomes particularly noticeable as people show off  their arms, legs, shoulders, and other inked surfaces. Some of it is artistic; other tattoos leave much to be desired.

Inking of skin on the Last Frontier is as old as Alaska itself: Natives have been practicing it for hundreds of years, although now they use modern tattoo ink rather than the ancient method of using soot.

[Read: Vanishing tattoos of the early hunter-gatherers]

When it comes to political persuasion, it’s all about the same: Republicans-27 percent, Democrats-29 percent and Independents-28 percent.

With tattoos ubiquitous, some are beginning to have doubts about health consequences and even regrets. As with mercury in tooth fillings, are there heavy metals in tattoo ink that can leach into the bloodstream? Will they grow out of their tattoo designs, or regret the way the art turned out? Changing one’s mind about a tattoo is expensive, painful, and there’s no guarantee of a clean removal. But there are other concerns: Infection and toxicity.

JUST HOW SAFE?

Few consumers know of the health risks of having  ink embedded in the lower layers of their skin. It’s an issue not widely studied with any scientific rigor. We’ve compiled some food for thought culled from the FDA’s Office of Cosmetics and Colors and other medical sources:

Although it’s rare, you can get serious infections from equipment that isn’t sterile, or infections from ink contaminated with bacteria or mold. Using non-sterile water to dilute the pigments (ingredients that add color) is a common culprit, although not the only one.

There’s no way to tell if the ink is safe, as it can be contaminated even if the container is sealed or the label says the product is sterile. It can be counterfeit ink, made in China or other unregulated places.

In 2015, the FDA alerted tattoo artists not to not use tattoo inks marketed and distributed by A Thousand Virgins, in certain shades of grey. The ink was found to be contaminated with mycobacterium chelonae in unopened bottles the ink, a problem discovered after the Florida Department of Health investigated an outbreak of mycobacterial infections in people who recently got tattoos.

WHAT ABOUT INFECTION?

If you get a tattoo, guard it with your life while your skin heals. A 31-year-old man died recently after he reportedly ignored warnings about swimming. He contracted a flesh-eating bacteria infection while swimming in the Gulf of Mexico five days after he got a tattoo on his leg: It was a design of a crucifix and pair of praying hands.

You might see a rash, red bumps and you may develop a fever, accompanies by  shaking, chills, and sweats. A rash may also indicate an allergic reaction; because the inks are permanent, the reaction maybe something you end up living with — permanently.

WHAT OTHER RISKS ARE THERE?

Tattoo ink can contain the same pigments used in printer toner or car paint. The FDA hasn’t actually approved any pigments for injection into the skin for cosmetic purposes.

Some people are concerned about heavy metals being introduced into the body from a variety of environmental pollutant sources. At a time when many people look for pesticide-free foods and are trying to eliminate chemicals from their personal care products, few who are getting tattoos know what is in the ink.

Some common elements found in tattoo ink are carbon, titanium, copper, chromium and iron.

Some heavy metals are known toxins. In one study of 30 tattoo inks, the most commonly identified elements were aluminum (87 percent of the pigments), oxygen (73 percent of the pigments), titanium (67 percent of the pigments), and carbon (67 percent of the pigments). Other studies have found heavy metals cadmium, cobalt, nickel, and mercury.

At least one nutritionist is warning about heavy metal toxins in her liver due to her tattoos. But the vetted medical literature on this possible health concern is lacking.

WHAT ABOUT SCARRING?

Scar tissue can form or you can get small bumps around the tattoo, as your body mounts a defense to a “foreign” material. It’s rare but it happens.

WHAT DO I LOOK FOR IN A STUDIO?

The University of Michigan health department has posted a “know before you go” guide for students:

• The staff and studio area should be very clean. The studio should have separate areas for piercing and tattooing.
• The studio should have and use an autoclave (equipment used to sterilize the necessary equipment). If there is not an autoclave, do not agree to a procedure.
• Needles and other “sharps” should only be used once and should be opened (from individual packages) in front of you before the procedure.
• Staff should wear new latex gloves during each procedure.
• Piercings should not be done with a piercing gun as the “gun” cannot be properly sterilized in an autoclave and can spread infections.
• Jewelry used for piercings should be non-allergenic only (stainless steel-300 series, gold, niobium, titanium or platinum) and should be available in a variety of sizes.
• Inks used in tattooing should be placed in a single-use cup and then disposed. Ink should never be taken directly from the main source bottle or returned to that bottle.
• Ask about after-care instructions. Read and understand the instructions before getting a tattoo or piercing.
• Ask questions! How long has the person been piercing or tattooing? Are they knowledgeable? Ask to see photos of their work. Do you like it?
• Ask if you can watch the preparation for and an actual piercing or tattooing of another person. Not all studios will let people watch, but this may give you a chance to check out sterilization and techniques.
• If you feel uncomfortable in a studio or with the staff, leave.