By Alejandro Dávila Fragoso, originally posted on August 9, 2016

The drinking water of some six million people across the country may have elevated levels of unregulated toxic chemicals widely used in the past in many household products — notably pans coated with Teflon — a Harvard-led study published Tuesday found.

Resistant to heat, water, and oil, perfluoroalkyl substances (PFAS) are a class of chemicals that have been used for decades to coat fabric or food packaging, and to manufacture fire-fighting foams and Teflon pans. Now mostly phased out in the U.S., PFAS went unregulated and were often disposed in watersheds. These chemicals are persistent in the environment and have been linked to adverse health effects in animals, according to the EPA. In humans, PFAS have been linked to a wide range of illnesses, including birth defects, cancer, and immune system dysfunction, according to multiple studies.

“These compounds have been used for over 60 years and it is only in the most recent years that we’ve began to understand how serious this pollution is, and how toxic [PFAS] are,” Philippe Grandjean, co-author and adjunct professor of environmental health at Harvard University, told ThinkProgress.

According to the study published in Environmental Science & Technology Letters, 75 percent of public water systems that exceeded PFAS federally recommended safety levels (updated this year) were found in 13 states: Alabama, Arizona, California, Florida, Georgia, Illinois, Minnesota, Massachusetts, New Jersey, North Carolina, New York, Ohio, and Pennsylvania. While PFAS are largely on their way out, the substitutes are at times chemically related and could still be toxic, recent studies have found.

National sampling of PFASs and some related chemicals like PFOAs began in 2013, under an EPA program that requires all public water systems serving at least 10,000 people to test for unregulated contaminants. While the EPA uses this assessment to figure out if contamination warrants regulation, the Harvard study used EPA data compiled from 2013 through 2015 to map the link between potential sources of pollution and drinking water contamination.

“If we establish some association between point sources and having contamination in drinking water, then we can use this model to predict where we are more likely to have this contamination,” Xindi C. Hu, co-author and a doctoral candidate at Harvard University, told ThinkProgress.

In doing so, researchers geo-coded PFAS manufacturing sites, military sites, and airports likely to have used PFASs for fire suppression, as well as wastewater treatment plants with municipal water systems, watersheds, and population centers. They then examined sites against the data using computer algorithms and came up with the frequency and concentration of these hazardous chemicals in public water supplies, as well as the estimated figure of six million people at risk of contamination.

Researchers also found that being near a manufacturing site makes a public water system 81 percent more likely to have elevated levels of PFAS pollution. “That’s a big increase,” said Hu. Military sites carry a 35 percent increase while wastewater treatment plants bring a much lower risk of some 2 percent. Proximity to an airport brought no statistically significant risk.

“This is not a short-term problem and exactly for this reason we ought to do something about it as soon as possible,” said Grandjean.

In May, the EPA lowered the recommended safety levels of PFOA and PFOS — substances that come from PFAS — to no more than 70 parts per trillion. This means water providers have to notify water safety agencies and residents when concentrations are over this limit. Industry experts note lowering safety levels and the monitoring is likely the preamble of an EPA rule on PFASs that could be released in the coming years. “There is absolutely a probability [PFASs] could become regulated,” said Pauli Undesser, deputy executive director at Water Quality Association, in an interview with ThinkProgress.

Meanwhile, some like Grandjean, who in another study published Tuesday found that PFAS can lower children’s response to vaccination, believes EPA’s safety levels are overwhelmingly high to protect against adverse health effects.

“I have used the EPA’s calculations, their methodology to calculate where an exposure limit should be to protect against the adverse effects,” he said. “I end up with a limit which is about 100-fold lower than what EPA is now applying.”

In a statement to ThinkProgress, the EPA said they are looking forward to reviewing the studies.

It’s unclear how the EPA will use the Harvard model, but both studies are likely to raise new questions about water pollution in the U.S. at an already sensitive time. The water catastrophe of Flint, Michigan, is still fresh in people’s minds. In addition, PFOA — the infamous cousin of PFAS — has been under the spotlight for much of this year, too.

Apart from the thousands of recent lawsuits directed toward PFOA manufacturers like Dupont, two months ago New York found elevated levels of PFOA in Hoosick Falls drinking water. In fact, just last week Politico reported that about 1,000 Hoosick Falls residents had on average more than 30 times the national level of PFOA.

The study could also bring renewed pleas that the EPA should move faster in regulating PFAS and push for remediation. Particularly because 97 percent of people have traces of PFAS, which are chemicals known to take years to break down and accumulate in humans. Indeed, already some state lawmakers are asking the EPA to use its new powers under the revised Toxic Substances Control Act to review if a ban should be considered.

In the past “ we didn’t know anything about the toxicology of those compounds but we used [them] anyway,” said Hu. “Now we are facing the severe consequence of having to fix the problem.”

For municipal agencies those fixes could mean hundreds of thousands of dollars in new equipment,” said Undesser, adding people shouldn’t wait for the EPA to come up with a rule to install “inexpensive” filtering systems if they feel uncomfortable with their water supply.

There “are products that are tested and certified for the reduction of these substances,” she said. “People really do have options … they don’t have to wait.”