A new federal study estimates that toxic “forever chemicals” can be found in nearly half of U.S. tap water.
“Forever chemicals,” also known as PFAS or per- and polyfluoroalkyl substances, can found in at least 45 percent of the country’s tap water, according to the study from the U.S. Geological Survey (USGS) released Wednesday.
The study, which used modeling based on samples collected from 716 locations across the country over several years, found urban areas are more at risk than rural ones when it comes to PFAS contamination.
The chemicals were found 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.
“What we’ve been reading about PFAS is that PFAS is everywhere,” lead author Kelly Smalling, a USGS Research Hydrologist, said 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.”
PFAS refer to a group of thousands of substances that linger in the human body and nature. Exposure to the substances has been linked to health problems including kidney and testicular cancer, thyroid disease and high cholesterol.
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.
In the USGS study, the latter type was found in 14 percent of the samples, though Smalling noted that this does not necessarily correspond to 14 percent of American taps.
Smalling 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.
Overall, she said that the study was “the most comprehensive study of PFAS at the tap or in a person’s water glass across the country.”