To understand health effects of PFAS polluted water, residents submit blood samples
Hundreds of Pittsboro residents volunteered hours over one weekend last month to be poked, prodded, weighed and measured in an attempt to learn more about the presence of chemicals in their bodies and, by extension, in their water systems.
The effort was the latest iteration in what’s become a long-term study of per- and poly-fluoralkyl substances, a class of thousands of chemicals known collectively as PFAS, in North Carolina residents who’ve been exposed via water and, at times, air pollution.
Steve Ferrin came out with his wife Ruta and three boys to spend hours on Nov. 14, a sunny Sunday morning, indoors at a local agricultural extension office. All but their youngest gave blood and urine samples, had their height and weight measured, and answered questionnaires for ongoing studies being led by researchers from North Carolina State University.
Steve Ferrin and his wife Ruta came out with their sons Matthew, 11, Benjamin, 10 and Christopher, 4 to the testing event in Pittsboro on Nov 14. All but Benjamin had their blood tested for PFAS. Photo credit: Rose Hoban
“There have been a lot of concerns about the PFAS being in the water. They test for all of them, apparently,” Ferrin said. “Testing for the PFAS, that's an expensive process. Here, we can do it, we get it for free and find out if we're being exposed to something we shouldn't be.”
The past two decades have brought intensive study of PFAS and their health effects which include immune disruption, damage to the livers, kidneys and thyroids - among other problems - of exposed people. But there’s still no comprehensive understanding of how they move through people and the environment.
The 209 people tested in Pittsboro are part of the latest round of research being conducted to determine the extent to which North Carolina residents are being affected by the industrial pollution. The PFAS problem came to wider notice in June 2016 when the same researchers noted the presence of high levels of one form of PFAS — GenX — in the Cape Fear River downstream from the Chemours Fayetteville Works facility in Bladen County.
Since then, the NCSU researchers have tested residents’ blood in Wilmington and Fayetteville, and now Pittsboro, looking for signs of the contamination in residents’ bodies. Along the way, they’ve learned a lot about the persistence of different forms of PFAS in people, been confounded by some results, and contributed to the growing body of knowledge that’s led for some to call for a halt to the chemicals’ use altogether.
No GenX ≠ no problem
November’s testing event in Pittsboro came only days after the same study team released the results of similar biological testing among residents in the Fayetteville area.
During a public meeting held on Nov. 10, the researchers reported that in blood samples collected from 153 people in 2019, they did not find GenX in people’s blood.
“Similar to the results of previous studies, the blood test results from the Fayetteville area that were announced in the GenX Exposure Study demonstrate that again GenX was not found in the blood of participants,” said a statement from Chemours, the following day.
Earlier studies had similarly not found much GenX in the blood of people who had been drinking Wilmington water.
“Once again the results showed that legacy compounds not associated with Chemours manufacturing were the compounds most prevalent in participants,” the Chemours statement continued.
Jane Hoppin, a professor from NC State University who is the lead scientist on the research, said conclusions are not so cut and dry.
“The fact that we can't measure Gen X in people's bodies today means that we can't measure it in you today,” she said. “It doesn't mean that you haven't been exposed in the past.”
What Hoppin and her team have been able to determine from all their testing is that GenX doesn’t stick around in human bodies for as long as older chemicals in the same class.
That doesn’t mean GenX’s passage through those bodies is benign. Hoppin made a comparison to alcohol.
“You could go and drink at a bar and we could measure your blood alcohol level within the next 24 hours and have some maybe idea of what you drank. But we wouldn't ever be able to estimate a lifetime of drinking alcohol by a biological sample that we collect today,” she said. “It doesn't mean that drinking alcohol doesn't have health consequences.”
Mapping human exposure
Hoppin said that what’s needed in these studies is a better way to understand and reconstruct human exposure to industrial chemicals.
“We know that people in Wilmington were drinking 700 parts per trillion of GenX for maybe 40 years,” she said. “That may or may not have any health consequences, but to say that just because we can't measure it in them today doesn't mean it's not toxic, it means that biological markers are a bad way to estimate that exposure.”
NC State University researcher Jane Hoppin explained the consent forms for blood, urine and other biometric measurement testing to several local Pittsboro residents during a large testing event in November. Photo credit: Rose Hoban
The EPA recently released an updated assessment of the toxicity of GenX and the chemical hexafluoropropylene oxide dimer acid (HFPO-DA), which GenX degrades into once it’s in water. The agency found that the chemical was more toxic than it originally thought. The EPA concluded that people should only be exposed to a maximum of about 3 parts trillion for each kilogram of weight of either chemical — GenX or HFPO-DA — an amount that adds up to about 200 parts per trillion for a 150 lb adult.
North Carolina’s Department of Environmental Quality had issued an interim assessment setting a daily maximum of about 70 parts per trillion per day for all PFAS combined.
According to the EPA assessment: “Animal studies following oral exposure have shown health effects including on the liver, kidneys, the immune system, development of offspring, and an association with cancer. Based on available information across studies of different sexes, lifestages, and durations of exposure, the liver appears to be particularly sensitive from oral exposure to GenX chemicals.”
In a statement given to Chemical and Engineering News in October, Chemours says it is reviewing the technical information that the EPA used in the toxicity assessment. “We are unaware of data that would support the conclusions drawn by the agency.”
What are PFAS?
Per- and polyfluoroalkyl substances (PFAS) are a group of man-made chemicals that includes PFOA, PFOS, GenX, and an estimated 5,000 types of PFAS, none of which are federally regulated. PFAS have been manufactured and used by industries worldwide since the 1940s, used in everything from Teflon pans to raincoats to dental floss. They are also used in firefighting foams.
The two most extensively produced and studied, PFOA and PFOS, have been phased out in the U.S., but they don’t break down easily and can accumulate in the environment and in the human body. There is evidence that exposure to PFAS can lead to adverse human health effects.
Prior studies hold disturbing clues
The largest study of PFAS and its effects on humans came as a result of a long running contamination event in the Ohio River Valley, downriver of a Dupont plant near Parkersburg, West Virginia. There, the company was found to be contaminating both ground and river water with multiple PFAS chemicals for close to 50 years, despite the company knowing that the chemicals were toxic to humans and animals.
A massive class action lawsuit was settled in 2005 on behalf of about 80,000 local residents.
As part of resolving the lawsuit, scientists conducted a massive study that took blood and medical histories from close to 70,000 of those people and tracked them. The results, published in 2012, found that there was a likely link between the PFOA and six conditions: testicular cancer, kidney cancer, thyroid disease, ulcerative colitis, pregnancy-induced hypertension and high cholesterol.
It’s these results that concern many people in the Cape Fear River basin and other places that have experienced PFAS contamination. It’s clear that the chemicals remain in the environment for a long time, but what’s not clear is what that means for those exposed over prolonged periods of time.
“Even though some PFASs may partially degrade in the environment and biota, they will all ultimately transform into highly stable end products,” wrote East Carolina University researcher Jamie DeWitt, along with other researchers, in a paper published in the journal Environmental Science and Technology in 2017.
Johnny Wilson shows off where he had blood drawn during the PFAS study testing event in Pittsboro on Nov. 14. Photo credit: Rose Hoban
It’s that stability that’s earned PFAS the moniker “forever chemicals.”
Hoppin said that the West Virginia study is the only reason that the EPA has regulated two legacy PFAS compounds, PFOS and PFOA, the chemical that GenX replaced in manufacturing. Although the North Carolina studies will only have a total of about a thousand people, Hoppin said she thinks their data can answer some important questions.
“The hope is that this will eventually move to health studies that will regulate the class of chemicals, hopefully in less time than it took for the Parkersburg, West Virginia case,” said Emily Sutton, the Haw River riverkeeper.
What studies have been done in NC?
Wilmington - Blood collected in November 2017 from 310 people, and resampled 44 people the following spring.
Results: Newly identified PFAS chemicals called Nafion by-product 2, PFO4DA, PFO5DoDA, and Hydro-EVE were found in most blood samples, along with historically used, or “legacy”, chemicals called PFOA, PFOS, PFHxS, PFNA, and PFDA. Nafion by-product 2 is a byproduct of production at the Fayetteville Works Facility. High levels of GenX were not detected.
The study also found people in New Hanover County had higher levels of PFAS in their bodies than national estimates.
Fayetteville - Blood collected in February 2019 from 153 people.
Results: Residents had five PFAS (PFHxS, PFOS, PFNA, PFOA and PFHpS) in more than 90 percent of samples, similar to many people around the country. The study also detected Nafion by-product 2 in over half (56%) of participants’ samples.
The results also showed varying presence of other PFAS in about half of the people tested.
GenX was not detected.
Pittsboro - Blood collected in Nov. 2021 from 209 people. Results expected in 2022.
‘On everyone’s minds’
The folks who came out for the testing event in Pittsboro were not worried by the chemicals released in Fayetteville, 50 miles downstream. Instead, they were alarmed by repeated reports of PFAS and other chemicals entering the Haw River from locations upstream, such as Greensboro.
Sutton noted that just a few days before the Pittsboro study weekend, officials in Greensboro notified the state that a different chemical, called 1,4 dioxane, had been dumped into the Haw.
“This is on everybody's mind in Pittsboro,” Sutton said. “Pittsboro is about to expand eventually by 60,000 people… there’s a 30 year plan to expand that size. And all that water is gonna come from the town of Pittsboro, so the same water source” – the Haw River.
The town is in the process of installing activated carbon filters in their water treatment plant, which should be online in the summer of 2022.
To provide clean drinking water to residents before then, the town approved a plan in October that allows Pittsboro residents to pick up five gallon jugs of reverse osmosis treated water at a local store for free.
Residents, meanwhile, are taking matters into their own hands.
“The first time we learned there was anything problematic with the water we did the fastest, most basic thing we could do, we got the standard kind of on-the-counter pitcher-type filter, Britta-type filter,” said Lesley Starke, a conservation ecologist who bought in Pittsboro three years ago. “We learned through extra research that it doesn't do really anything for PFAS.”
So Starke and her husband shelled out several hundred dollars for an under-the-sink reverse osmosis system in their kitchen.
“The whole (house) system didn't feel available to us for a multitude of reasons, it just has extra needs, extra cost, complications that felt out of our reach. But the countertop drinking water filter system did seem within a price range we could manage,” she said. “That way we can adjust, at least, the water we're drinking and cooking with.”
Starke said she’s glad that she’s able to help fellow scientists gain a better understanding of what the effects of PFAS are on people who drink the water, but she also said she was reassured that she’ll learn their exposure too.
Sutton said the study and its results won't necessarily change Pittsboro minds overnight, if ever, but there are bigger considerations at play.
“We’re hoping for more federal guidance, federal limits and regulatory standards,” she said.