Following the discovery of high levels of per- and polyfluoroalkyl substances (PFAS) in the blood of GenX Exposure Study participants, researchers are working quickly to report their findings back to the North Carolina communities and address their concerns.
Led out of North Carolina State University (NCSU), the study started in 2017 when PFAS were found in the drinking water of Wilmington, North Carolina, residents. Their water is sourced from the Cape Fear River Basin, which is downstream of a fluorochemical plant that manufactures building blocks for fluoropolymers and previously discharged high concentrations of PFAS, including fluoroethers, to the river. Fluoroethers, such as GenX, are new PFAS created to replace legacy PFAS like perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS), which have been phased out.
In 2020, with funding from the NIEHS Superfund Research Program (SRP), the team expanded the study to include other communities along the Cape Fear River: Pittsboro, a town upstream of the fluorochemical plant, and Fayetteville, where the fluorochemical plant is located. For this new phase of their study, and in response to residents’ concerns, the researchers also broadened their focus to uncover not only PFAS exposures but also potential health effects.
2020-2021 PFAS results
Between 2020 and 2021, the NCSU team collected blood samples from 1,020 participants across the three communities and analyzed them for 44 different PFAS. They found four legacy PFAS — PFOS, PFOA, perfluorononanoic acid (PFNA), and perfluorohexane sulfonate (PFHxS) — in almost all samples and at levels higher than the U.S. national averages. The researchers communicated these results to participants during an October 2022 community meeting.
They also found two fluoroethers in most people in Wilmington and in some Fayetteville residents — Nafion byproduct 2 and 3,5,7,9,11-pentaoxadodecanoic acid (PFO5DoA). GenX, the chemical that started the study, was not detected in participants’ blood.
“GenX only lasts in blood for a very short time, so it is difficult to measure, but long-term exposures can still harm health later in life,” said NCSU SRP Center project lead Jane Hoppin, Sc.D. “We plan to follow people for up to 20 years to identify how GenX exposure can result in changes in health.”
Focus on health effects
The researchers put their measured PFAS levels in the context of the health effects outlined in a report by the National Academies of Sciences, Engineering, and Medicine (NASEM) titled “Guidance on PFAS Exposure, Testing, and Clinical Follow-Up,” for which Hoppin was a committee member. That report was commissioned by NIEHS and the Agency for Toxic Substances and Disease Registry.
The team analyzed blood PFAS levels and compared the total concentration to the NASEM guidance. They found that about 69% of participants had total PFAS levels between 2-20 nanograms (ng) per milliliter (mL), which means that there is potential for adverse health effects in sensitive populations, according to the NASEM guidance.
Twenty-nine percent of participants were in the highest exposure group, over 20 ng/mL. According to the NASEM guidance, people in this group are at a higher risk of adverse health effects and should be tested for thyroid function, kidney and testicular cancer, and ulcerative colitis.
The researchers sent study participants an 11-page letter including an overview of the overall study findings, individual blood PFAS results, and NASEM recommendations.
Answering community concerns
The second half of the October meeting included a panel of experts who listened to and responded to questions from study participants and other concerned residents.
In response to a question about the safety of public drinking water, NCSU SRP Center researcher Detlef Knappe, Ph.D., said that public utilities in Wilmington and Pittsboro are investing in upgrades, such as granular activated carbon filters, to improve filtration of PFAS from tap water.
“There are also several home treatment options that can provide PFAS-free water, such as under-sink filters and refrigerator water filters,” Knappe said.
Panelist David Collier, M.D., of East Carolina University, also urged community members to talk to their health providers if they have health concerns or are experiencing symptoms that could be related to the conditions outlined in the NASEM guidance.
(Mali Velasco is a research and communication specialist for MDB Inc., a contractor for the NIEHS Division of Extramural Research and Training.)