A study by scientists from EWG, published in October 2020, used state testing data to estimate that more than 200 million Americans could have PFAS in their drinking water at concentrations of 1 part per trillion (ppt) or higher. That is the recommended safe limit, according to some scientists and health advocates, and is equivalent to one drop in 500,000 barrels of water.
“This really highlights the extent that these contaminants are in the drinking water across the country,” says EWG’s Andrews, who co-authored the paper. “And, in some ways, it’s not a huge surprise. It’s nearly impossible to escape contamination of drinking water.” He references research from the CDC that found the chemicals in the blood of 98% of Americans surveyed.