For years, John Bonitz drank Pittsboro’s tap water without knowing it was contaminated with PFAS. Then a blood test showed just how heavily he had been exposed.
Bonitz had the highest combined concentration of seven PFAS among 206 Pittsboro participants in an NC State University study, putting him in the 99th percentile across the broader study population.
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PFAS, often called “forever chemicals” because they persist in the environment, are a large class of synthetic chemicals that have contaminated drinking water across North Carolina and the country.
The results were especially unsettling for Bonitz because he had been struggling with persistent pain that specialists had been unable to explain. His family had other health questions, too. Bonitz said testing showed one of his children did not develop immunity to one component of the MMR vaccine after being vaccinated.
Scientists cannot say PFAS caused either. But questions like those are exactly why researchers want to keep following families who were exposed.
Pittsboro now filters PFAS from its drinking water, and Bonitz said levels in his blood have fallen about 60% over four years. But reducing his exposure cannot undo the years that came before it — or answer what those years may mean for his health.
NC State researchers are now trying to get closer to an answer.
A new $4.2 million federal grant will allow the GenX Exposure Study to continue following nearly 1,200 people across the Cape Fear River Basin for another four years, with a greater focus on long-term health.
Researchers will examine cholesterol, weight, liver function and thyroid health, looking for changes as PFAS levels in participants' bodies decline.
“There’s a lot of evidence that people with higher PFAS in their blood have higher cholesterol levels as well,” said Jane Hoppin, an NC State epidemiologist leading the study. “So, what happens to those cholesterol levels when your serum PFAS goes down?”
The study began in Wilmington in 2017 after GenX and other PFAS were discovered in the lower Cape Fear River. It has since expanded to include people in Wilmington and Brunswick County, residents with contaminated private wells near the Chemours Fayetteville Works plant and people in Pittsboro.
Researchers have found that PFAS levels in people's blood decline when exposure through drinking water is reduced. Some chemicals leave the body relatively quickly; others can remain for years.
But even in the study's most recent sampling, participants in all three areas still had higher levels of several widely studied PFAS than the general U.S. population. And a blood test today cannot show the full extent of someone's past exposure.
Hoppin said some residents in Wilmington and Brunswick County may have consumed water with elevated PFAS for decades. Researchers will use residential histories and past water testing to help estimate those earlier exposures and look for potential health effects over time.
“It would be fantastic if they never left an imprint in people's bodies,” Hoppin said.
What scientists know about PFAS and health
Research has already linked exposure to some PFAS with health problems, although scientists know much more about older, widely studied chemicals than newer compounds such as GenX.
A National Academies review found sufficient evidence of an association between PFAS exposure and higher cholesterol, reduced antibody response, decreased fetal and infant growth and increased risk of kidney cancer. It found more limited evidence for several other health effects.
That reduced antibody response is one reason researchers are interested in how PFAS may affect the immune system. It does not establish that PFAS caused the vaccine response Bonitz described in his child.
Chemours has said there are no human epidemiological studies showing health effects specifically from exposure to GenX or other PFAS associated with its Fayetteville Works facility.
GenX itself has been studied primarily in animals. EPA's toxicity assessment identified effects on the liver, kidneys, immune system and development, along with some cancers in animal studies. Scientists do not yet have the human research needed to determine whether those findings translate to people exposed to GenX in their environment.
That gap is part of what makes long-term studies of exposed communities important.
The NC State researchers have already found that participants with higher levels of some older PFAS also had higher levels of non-HDL cholesterol. But because the researchers measured PFAS and cholesterol at the same time, they could not determine whether PFAS contributed to the higher cholesterol.
Now they can watch what happens as exposure declines.
For Bonitz, the study has become a record of both what was in his body and how that is changing.
He has participated in repeated blood draws and shared the results with his doctors. His wife and children have participated, too.
“The long-term health effects are definitely a concern,” Bonitz said. “I'm really reassured that Dr. Hoppin and her team will be able to continue to follow the members of the cohort over time, because it really is important that we understand this from a long-term science perspective.”
Hoppin said participants routinely come to researchers with questions about illnesses and health problems in their families. Science cannot necessarily tell them whether PFAS caused an individual diagnosis.
“Each person has their own story,” she said.
What Hoppin hopes the next four years can do is begin turning years of exposure data into answers that are useful beyond the people enrolled in the study.
“We can generate information, but there's over a million people who drink the Cape Fear River, and we're only studying 1,200 people,” Hoppin said. “How do the people who've been impacted for so long, how can we help them get the help they need to protect their health?”