Study finds ultrashort-chain PFAS built up in Wilmington residents' blood before GenX scandal

A new study by NC State shows residents in one North Carolina town carried high levels of ultrashort-chain PFAs in their blood years before the region learned its drinking water was polluted, raising fresh questions about the safety of ultrashort-chain PFAS, part of a newer generation of chemicals that emerged as industry shifted away from older, long-chain compounds..

The analysis examined 119 blood samples collected from residents in Wilmington between 2010 and 2016. Two ultrashort-chain compounds, TFA and PFMOAA, were present in nearly every sample and made up close to half of all PFAS measured.

“Finding these tiny compounds at such high levels changes our understanding of exposure,” said Dr. Jane Hoppin, who leads NC State’s GenX Exposure Study. “They were assumed to pass through the body quickly, but sustained exposure through drinking water appears to have driven accumulation. The question now is what that means for health.”

A clearer picture of past exposure

Previous blood testing in Wilmington, conducted in late 2017 after the public discovered the contamination, revealed elevated PFAS, including GenX. The new analysis fills in the years before that discovery and shows residents were also carrying other compounds that had not been measured at the time.

“It gives us a more complete picture of the alphabet soup of PFAS people here were exposed to,” Hoppin said. “This snapshot tells us what was in people’s bodies before they ever knew their water was contaminated.”

Levels far above international guidance

TFA levels in river water during that period were measured at roughly 110,000 nanograms per liter. Dutch authorities suggest a guideline of 2,200 nanograms per liter, meaning Cape Fear levels were around 50 times higher.

There is no federal drinking-water limit for TFA in the United States.

Dr. Lan Cheng, who co-authored the study, said the blood concentrations were significantly higher than what has been reported in other regions.

“Even though ultrashort-chain PFAS are believed to leave the body faster, very high exposure can still result in very high blood levels,” Cheng said. “And animal studies show these compounds may be toxic at high levels.”

Chemours cites current controls

Chemours, which operates the Fayetteville Works facility believed to be the primary historical source of PFAS in the Cape Fear River, noted the samples in the study were collected before the company was ordered to install pollution controls.

In a statement, the company said it has since added a thermal oxidizer that it says destroys “over 99.99%” of PFAS sent to it, as well as a barrier wall and groundwater treatment system. Chemours also pointed to recent testing showing finished drinking water in the region meets guidance levels used in parts of Europe, though those thresholds are not U.S. standards.

The company said it does not intentionally manufacture TFA or PFMOAA, but acknowledged they are produced as byproducts of its processes. TFA, the company added, can also come from sources such as refrigerants, agriculture and pharmaceuticals.

What comes next

NC State researchers will now analyze blood collected in late 2017 and 2018 to determine whether ultrashort-chain PFAS declined once Chemours was ordered to reduce discharges.

They also plan to study whether past exposure is linked to health effects.

“People who lived in Wilmington between 2010 and 2017 were highly exposed to PFAS,” Hoppin said. “Even if we cannot measure these ultrashort-chain chemicals in blood today, past exposure can still matter.”

The National Academies recommends screening for cholesterol, thyroid function, and certain cancers in people with elevated PFAS exposure. NC DHHS has issued clinical guidance for doctors.

Residents still seeking clarity

For Wilmington resident and Clean Cape Fear co-founder Emily Donovan, the findings feel familiar and unsettling.

“I raised my children on this water,” Donovan said. “Parents here are still asking the same questions they asked eight years ago. We still do not have clear guidance on what this means for our health.”

She said the study underscores the need to regulate PFAS as a class rather than one chemical at a time.

“We are the case study in regrettable substitution,” Donovan said. “Industry pushed the idea that ultrashort-chain PFAS were safer. This shows they were not.”

Cape Fear Riverkeeper Kemp Burdette said the results highlight ongoing regulatory gaps.

“This is more evidence that we need to regulate these compounds at the source,” he said. “People downstream should not be the filtration system.”

Burdette urged North Carolina to require manufacturers to treat PFAS onsite rather than discharging them into public waterways.

“The technology exists. It works. Chemours uses it now because they were forced to,” Burdette said. “It should not fall on families to protect themselves.”

Why it matters now

Researchers say ultrashort-chain PFAS will likely become a growing focus nationwide. While EPA’s new PFAS drinking-water rule covers several compounds, it does not include these smaller ones.

“Things you were exposed to in the past can have effects today,” Hoppin said. “This is a first step toward understanding that exposure and what it means.”