Higher-than-recommended concentrations of industrial chemicals known as PFASs have been found in American drinking water, according to a 2016 study published in Environmental Science & Technology Letters. Polyfluoroalkyl and perfluoroalkyl substances (PFASs) have been linked to cancer, obesity, hormone suppression and high cholesterol. The highest levels of PFASs were found near industrial sites, military bases and wastewater treatment plants.

The man-made chemicals degrade slowly and are found in everyday items like fabrics, pizza boxes and popcorn bags, nonstick cookware and firefighting foams. PFASs can eventually make their way into drinking water, thus posing a health risk to the developmental, immune, metabolic, and endocrine health of millions of Americans.

Learn more:
Overview of the PFAS study at CNN.com
Black Berkey® Elements: The Final Barrier against PFOA and Other PFCs in Drinking Water