'Forever chemicals' linked to cancer and developmental issues lurk in the blood of almost every American. Here's how to avoid them.

• The chemical class known as PFAS became popular in the US around the 1940s, since they resist heat, grease, stains, and water.
• Today, PFAS are considered toxic and have been linked to cancer, liver damage, thyroid disease, and developmental issues.
• Most humans get exposed to PFAS by ingesting contaminated food or water, though the chemicals have also been found in clothing and cosmetics.
• PFAS are difficult to avoid, but there are still ways to screen your household items.
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A class of "forever chemicals" is found in the bloodstreams of 99% of Americans.

Last month, Congress held a hearing about per- and polyfluoroalkyl substances (PFAS), which have been linked to cancer, liver damage, thyroid disease, and developmental issues. The chemicals can linger in water and air for thousands of years, so consuming or inhaling them means they could stay in the body for life - hence the "forever" nickname.

At the July hearing, Harley Rouda, chairman of the House environmental subcommittee, called PFAS a "national emergency."

Here's how to reduce your PFAS exposure.