So-called "forever chemicals" have been found in 45% of the nation's tap water, according to a recent government study, but is your tap water affected? If you're wondering whether or not your tap water might contain synthetic chemicals known as PFAS, nonprofit Environmental Working Group created an interactive map using official records and data from public drinking water systems to show where forever chemicals were found to be above and below the advised maximum concentration level, 4 parts per trillion (PPT). EWG notes that while researchers used the highest quality data available, contamination levels are based on a single point in time and may not reflect changes to the water system or treatment efforts. PFAS is an umbrella term for thousands of chemicals that are used to make nonstick pans, food packaging, fire-fighting foams, to-go boxes, furniture, rugs, clothing and more. The chemicals are so ubiquitous it would be nearly impossible for most Americans to rid their home of them. The chemicals are both extremely common and potentially dangerous. Described as "forever chemicals" because they don't degrade naturally in the environment, PFAS have been linked to a variety of health problems, including liver and immune-system damage. Studies of lab animals have found potential links between PFAS chemicals and some cancers, including kidney and testicular, plus issues such as high blood pressure and low birth weight.