A new federal study estimates that toxic “forever chemicals” can be found in 45 percent of U.S. tap water.
“Forever chemicals,” also known as PFAS, refer to a group of thousands of substances that linger in the human body and nature; they bioaccumulate instead of breaking down. Exposure to PFAS, which stands for per- and polyfluoroalkyl substances, has been linked to health problems including kidney and testicular cancer, thyroid disease and high cholesterol.
A new study announced Wednesday from the U.S. Geological Survey (USGS) used modeling based on samples taken from 716 locations to determine that nearly half of the country’s tap water contains the substances.
The study found that urban areas are more at risk than rural areas, finding the substances in about 70 percent of areas that are either urban or have a known history of PFAS contamination, compared to just 8 percent of rural areas.
It also found that the substances may be more common in the Great Plains, Great Lakes, Eastern Seaboard and Central and Southern California regions.
The Environmental Protection Agency (EPA) has taken some steps toward curbing two of the most infamous types of PFAS, known as PFOA and PFOS, in drinking water, proposing national drinking water limits in March.
PFOA was found in 14 percent of the samples, though lead author Kelly Smalling noted that this does not necessarily correspond to 14 percent of American taps. She said that of the samples where PFOA was found, 48 percent of them had contained the chemical at levels higher than the EPA’s proposed limit.
“What we’ve been reading about PFAS is that PFAS is everywhere,” noted Smalling, a USGS research hydrologist in an interview. “What this study has shown us is that even though it’s estimating that 45 percent of U.S. taps could have at least one PFAS, we also show that there are huge swaths of the country where PFAS was not detected, and I think that’s good news.”