GenX study shows contamination in 80% of wells tested; mice studies show liver damage from Nafion Byproduct 2
Raw water supplies for at least 150 public utilities in North Carolina contained some level of toxic PFAS, underscoring the call of many scientists this week to regulate the thousands of perfluorinated compounds as a class.
Some of those raw water samples contained GenX and Nafion Byproduct 2, which new findings published this month show the detrimental health effects of these compounds on mice. Other studies have suggested similar effects on humans.
Samples of raw water — which has not yet been treated at the plant — were collected by scientists with the NC PFAST Testing Network from April through November 2019. The NC PFAST Testing Network is composed of scientists from seven universities working under the auspices of the NC Policy Collaboratory, which is funded by the state legislature and grants.
The sampling sites were chosen in consultation with the NC Department of Environmental Quality. The full dataset was released this month.
- Researchers looked for 15 to 47 types of PFAS compounds in raw water supplies, either from wells or surface water, depending on the utility.
- Of the 320 public utilities whose raw water supply was tested, nearly half had a sample that contained PFAS concentrations above the reporting detection level. (See chart below.)
- When broken down by the number of samples, of the 405 collected — 44%, or 178 — had at least one type of PFAS compound above the reporting detection level.
Because of a lack of federal regulations, there are a wide range of goals and thresholds for these compounds in drinking water — none of them enforceable. The state health department has set an provisional goal of 140 ppt for GenX. The EPA has set a recommended threshold of 70 ppt for PFOA and PFOS combined. And NC DEQ has stated that no one should drink water with levels of any individual PFAS above 10 ppt.
None of the samples exceeded the thresholds for GenX or PFOS and PFOA combined. However, 42 of the raw water samples had individual PFAS levels of 10 ppt or greater.
The scope of the study did not trace the industrial sources of the contaminants, only their presence or absence.
The highest total PFAS concentration was detected in the Haw River, the water supply for Pittsboro, at 844.8 ppt. For GenX, the highest level was 29.3 ppt in Pender County, which gets its water from the Cape Fear River. And the sum of PFOA and PFOS, two compounds that have been phased out, reached 57.5 ppt in the raw water supply for the Orange County Water and Sewer Authority. OWASA gets its water from the Cane Creek Reservoir and University Lake; it serves customers in Chapel Hill and Carrboro.
The hotspots in eastern North Carolina were primarily in the Lower Cape Fear River Basin, part of which has been contaminated with PFAS by the Chemours Fayetteville Works plant. However, farther upstream there were also spikes — in Smithfield, West Johnston County, Harnett County, Cary and the Harris Nuclear Plant Water Supply system.
In the Upper Cape Fear River Basin some industrial users and airports in Greensboro, Burlington and Reidsville are responsible for contaminated discharge. Even water systems not typically associated with PFAS contamination had hits, including Bessemer City, South Granville County and Tarboro.[perfectpullquote align=”full” bordertop=”false” cite=”” link=”” color=”” class=”” size=””] [table id=83 /]
*Spike at Wrightsville Beach was at a well that had been closed.
Fields marked with dashes mean concentrations were below reporting limits. Some water system supplies were tested more than once and on different dates. Water systems without detections are not listed.
(Source: NC PFAST Testing Network) [/perfectpullquote]
More evidence that Nafion Byproduct 2 harms the liver
One of the PFAS found in several utilities’ raw water is Nafion Byproduct 2, which is produced as part of Chemours’ manufacturing process. Like many manufacturing byproducts, Nafion Byproduct 2 did not have to go through a federal review under the Toxic Substances Control Act.
A team of scientists, including civil engineer Johnsie Lang, formerly of the EPA, and Mark Strynar currently with the EPA, fed mice a range of doses of Nafion Byproduct 2 for one week, then analyzed the levels in their blood and livers. The results have implications for people living near and downstream of the Chemours Fayetteville Works plant, where the compound has been found in the Cape Fear River, the drinking water and in the some residents’ blood.
Nafion Byproduct 2 was detected in the blood of the mice, but more disturbing was the effect on the liver. When mice were exposed to even moderate doses, their livers doubled in size. Cholesterol levels increased, as did liver enzymes, which indicated the liver function was impaired by the chemical.
The effects became more pronounced at higher dosages. Male mice were more affected than female mice.
In North Carolina, people have been exposed to Nafion Byproduct 2 through their drinking water. “This is definitely linked to Chemours,” Lang said. “It’s one of the only places in the world that produces it.”
The NC PFAST Testing Network found Nafion Byproduct 2 in the raw water entering the Bladen Bluffs plant, as well as Bladen County East and West facilities.
However, Chemours no longer is allowed to discharge water containing Nafion Byrproduct 2 or any other contaminant into the Cape Fear River, as part of a state consent order. “That’s the good thing in that it’s almost gone in the drinking water because they cut it off,” Lang said. “But this study highlights the fact that more work needs to be done on this compound. It’s more important to test blood than water.”
In 2017 and 2018, NC State scientists Jane Hoppin and Nadine Kotlarz with the Center for Human Health and the Environment led a study of the blood of 345 New Hanover County residents, 56 of them children, for a variety of PFAS. Nafion Byproduct 2 was detected in 99% of blood sampled, but the concentrations decreased after six months.
[perfectpullquote align=”full” bordertop=”false” cite=”” link=”” color=”” class=”” size=””] [table id=84 /] Source: NC PFAST Testing Network [/perfectpullquote]
Two years after Chemours stopped discharging GenX, it persists in drinking water
PFAS persist for hundreds and possibly thousands of years. This could explain why GenX was still present in the raw water of several utilities, even though Chemours had ostensibly stopped discharging it into the Cape Fear River two years prior, in September 2017. At time of the sampling, Chemours had also installed carbon scrubbers to remove 92% of PFAS from its air emissions; in December 2019, after the sampling was finished, the company upgraded that technology to eliminate 99% of the contaminants.
On May 29, 2019, elevated levels of GenX were found in unfinished water in Pender County, Brunswick County and the Cape Fear Public Utility Authority. (A well that served the Wrightsville Beach treatment plant contained 47.8 parts per trillion of GenX, but that well had already been shut down. The contamination was the result of an aquifer that had been injected with water that contained the compounds.)
Three months later, in August 2019, raw water at several utilities in Bladen County also had levels of GenX ranging from 11.7 ppt to 18.2 ppt.
The Harris Lake Nuclear Plant Water System had levels of GenX at 2.8 ppt. It lies adjacent, but is not hydrologically connected, to Jordan Lake.
However, low but detectable levels of GenX were also found in the water supplies outside of the Cape Fear River Basin: In Norwood, in Stanly County; Tuckaseegee in Jackson County, as well as in Perquimans and Martin counties.
Earlier this month, Hoppin and Kotlarz announced the results of a separate study, including Nafion Byproduct 2 and GenX, in 85 drinking water wells in Bladen and Cumberland counties, near the Fayetteville Works plant.
Researchers also collected blood and urine samples from 153 people, but since labs have been closed because of COVID-19, the results aren’t available yet.
The samples were taken in February 2019, the week before Chemours signed the consent order with the NC Department of Environmental Quality and Cape Fear River Watch that prohibited not only water discharges but also required the company to eliminate contaminated air emissions by 99%.
Scientists found 70 of 85 drinking water wells were contaminated with GenX at a median level of 103 parts per trillion. That means half of the wells had higher levels than 103 and half had lower. Thirty-three wells sampled had concentrations higher than the state’s 140 ppt provisional health goal.
Wells with higher levels of GenX also tended to be contaminated with other PFAS, including Nafion Byproduct 2.
Researchers are expanding the five-year study to 1,000 participants, whose urine and blood will be tested for the presence of PFAS, as well as thyroid hormone levels. (To participate, contact the researchers through the NC State website.)
Regulating PFAS individually is like a game of Whac-A-Mole
The proliferation and persistence of PFAS both nationwide and in North Carolina prompted several scientists to publish a peer-reviewed article in Environmental Science & Technology Letters yesterday recommending that the EPA regulate all PFAS as a class.
Although several thousand chemicals are classified as PFAS, the EPA has signaled it would prefer to regulate them individually, which would take decades. The EPA has yet to regulate any of the compounds, even those with proven health effects.
Exposure to PFAS can damage the liver, kidneys and thyroid, depress the immune system, result in low birth weight and high blood pressure during pregnancy, and lead to high cholesterol.
PFAS are found in many products, including fast food packaging, cosmetics, microwave popcorn bags, carpet, stainproof and waterproof clothing, firefighting foam and flame-resistant furniture. People can be exposed through drinking water, air and food.
“Despite the variety, PFAS have many things in common that allow us to group them as a class,” said NC State scientist Detlef Knappe, one of the paper’s co-authors. PFAS have strong carbon-fluorine bonds, move easily and for great distances through air and water, and are extremely persistent in the environment, earning them the nickname “forever chemicals.”
“We’ve seen an accumulation of PFAS in the environment and their harm to human health,” Knappe said. “With a class-based approach, we can think about the totality of PFAS exposure rather than individually.”
DEQ also supports regulating PFAS as a class.
Toxicologist Linda Birnbaum, who is the former director of the National Institute for Environmental Health Sciences in Research Triangle Park, as well as the National Toxicology Program, said there is a precedent for regulating PFAS as a class. For example, the EPA regulates PCBs, which are known to cause cancer. They have been phased out and their manufacture has been banned for decades, but because PCBs persist in the environment, they remain widespread.
“We learned 50 years ago that we didn’t want chemicals that never go away,” Birnbaum said. “We can provide safe drinking water but we can’t clean up the environment in total. That’s why the class approach is so appropriate.”
The American Chemistry Council, a trade group, issued a statement refuting the article, calling it “misleading.”
“Different types of PFAS have different properties and uses, as well as different environmental and health profiles. A one-size-fits-all approach to regulating PFAS is neither scientifically accurate nor appropriate and threatens to take away important products that families and businesses rely on,” the statement read in part. “Our goal is to ensure that PFAS are regulated appropriately – which means they should be regulated by their specific properties and potential risks rather than by a sweeping, broad brush approach with the potential to severely impact the functionality and safety of numerous products we rely on every day.”
In the most recent legislative session, several Democratic lawmakers introduced House Bill 1109, which would prohibit the manufacture of PFAS and their exports, “except for products specifically authorized or required to contain PFAS under federal law.” The bill languished in the Rules Committee.
In the case of PFOS and PFOA, the chemical industry has phased out those compounds because of their harm to human health. Industry then formulated new, allegedly less toxic but chemically similar compounds to replace them, such as GenX. But those replacements — known in industry parlance as “regrettable substitutions” — have been linked to similar health problems as the originals.
The scientists called for a phasing out of more PFAS if they are intended for non-essential use. Several European countries, such as Denmark, as well two states, Washington and Maine, have already done so. Tom Bruton, a scientist for the Green Science Policy Institute, said the elimination of these chemicals from the marketplace happens too slowly. “They’re phased out only after years after study. By that time the harm is done.”
Our stories may be republished online or in print under Creative Commons license CC BY-NC-ND 4.0. We ask that you edit only for style or to shorten, provide proper attribution and link to our web site. Please see our republishing guidelines for use of photos and graphics.