The compounds known collectively as PFAS are like whack-a-moles: They pop up everywhere. The manmade substances are part of a huge class known as fluorochemicals, present in everything from house dust to dental floss. They persist in the environment for millennia and enter the body via drinking water, food and air, among other avenues. Babies can be exposed in utero, via the umbilical cord. The Centers for Disease Control and Prevention estimates that 98 percent of Americans have PFAS in their blood.

There are ways to avoid additional exposure. Here are some steps to steer clear of PFAS.

Major sources of PFAS water contamination are military installations, airports and firefighter training centers, where PFAS-laced firefighting foams are used.

The chemicals also leach into groundwater from wastewater plants, industrial sites and landfills. As a result, drinking water supplies for more than 6 million Americans are contaminated with higher-than-recommended levels of PFAS (or above 70 parts per trillion, the non-enforceable limit set by the Environmental Protection Agency in 2016).

Up to 100 million additional people are exposed to water with lower levels of PFAS, which also pose a health risk, according to the Environmental Working Group (EWG), a nonprofit public health advocate that tracks the contamination nationwide.

What you can do: Contact your water utility and ask about PFAS levels. The chemicals aren’t federally regulated, so utilities aren’t required to test for them in a consistent way. However, some states have taken action to require monitoring (New Mexico is not one of them).

If you think contamination is an issue, buy “granular activated carbon filters” or reverse osmosis filters for your home. Look for products that are certified to reduce PFAS. Both simple water pitchers and more extensive systems will do the job, the EWG says.

PFAS sometimes lurk in fast-food paper products, from the box holding your fries to the wrapper around your burger. A recent survey of 27 fast-food chains detected the highest levels of PFAS in wrappings for desserts, breads, Tex-Mex food and burgers.

Studies have also found them in microwave popcorn bags and take-out food cartons at stores like Albertsons, Safeway and Whole Foods.

What you can do: Eschew fast food. In particular, avoid giving fast food to children, who are most vulnerable to PFAS health impacts. Don’t heat food in slick, grease- or water-resistant paper, the hallmark of a PFAS product (the heat aids the process of substances migrating from paper to food).

Shun nonstick cookware – another PFAS harbinger – unless it’s explicitly advertised as PFAS-free. And make your popcorn the old-fashioned way, on the stove, in a PFAS-free pan.

Avoid items described as stain-resistant, water-resistant or grease-repellent – all are red flags for PFAS. The chemicals are used in carpeting, furniture fabrics, outdoor gear, raincoats, leather, waterproofing treatments, floor polish and more.

What you can do: Check the label. Avoid buying these and other types of products if you see “fluoro” or “perfluoro,” which can be code for PFAS.

The chemicals appear in Oral-B Glide dental floss, sunscreens, cosmetics and hair products, among many other items.

What you can do: Use floss with natural wax or beeswax. And consult the EWG’s “Skin Deep” searchable database, which lists ingredients for nearly 71,000 personal care products.

The “forever chemicals,” as PFAS and other slow-decaying substances are called, are also found in ski wax, sticky notes, pesticides, herbicides, windshield wipers and paints. They have been detected in flour, rice, fish and other foods around the world – and now, thanks to the U.S. Air Force, they have contaminated dairy milk in Clovis. If left unregulated, the chemicals will increasingly enter the food supply, activists say. Their shelf life could be, effectively, forever.

RELATED: Till the cows come home – Contamination devastates a New Mexico dairy

RELATED: Toxic timeline – A brief history of PFAS

Amy Linn has written about social issues and child well-being throughout her career, starting at the Miami Herald and including work for the Philadelphia Inquirer, San Francisco Examiner and Bloomberg...