By Catherine Clabby
Mark Strynar and Andy Lindstrom have not had high profiles in the dramas playing out in public since chemical contamination of Cape Fear River drinking water was made public last June.
But without research the chemists from the Environmental Protection Agency started five years ago, all that followed may never have happened at all. That includes citizen outrage in and near Wilmington, water system moves to protect their customers, political spats, newly funded research, and multiple lawsuits.
Based at the EPA site in Research Triangle Park, Strynar and Lindstrom were the first to identify GenX and related chemicals in the Cape Fear, downstream from a chemical plant DuPont built in the 1970s and operated until 2015. GenX is one of many per- and polyfluoroalkyl substances (PFAS), a family of engineered compounds with some possibly harmful to human health. GenX is among the engineered chemicals of this ilk that most drinking water treatment can’t touch.
“Detectives of the environmental world, especially when it comes to identifying emerging contaminants,” is how East Carolina University toxicologist Jamie DeWitt describes the work of environmental analytical chemists such as Strynar and Lindstrom.
Origin story
Big news regarding GenX has emerged regularly since a Wilmington newspaper in June published word that GenX and related PFAS chemicals had been detected in the river water that feeds public water systems.
Chemours, the DuPont spinoff now operating the plant that released GenX, possibly for decades, has not said much publicly about the contamination. In its few statements the company has said GenX amounts released from its Fayetteville Works facility are small and pose no health threat.
But just this week, the Cape Fear Public Water Utility Authority filed a federal lawsuit against DuPont and Chemours, accusing them of “a conscious disregard of and indifference to the rights and safety of others” by polluting water, river sediments, soil and air. The companies released “fluoropollutants” for decades, despite knowing of potential health risks from such compounds, the utility charged.
And the state Department of Environmental Quality directed Chemours to provide bottled water to owners of nine more contaminated residential wells near the Bladen County Chemours plants. Testing of 35 residential wells near the plant in recent weeks has detected GenX at levels exceeding a state health guideline.
Strynar and Lindstrom, affiliated with the EPA’s National Exposure Research Laboratory, could not have envisioned any of that when they started dipping water sample containers into the Cape Fear River in 2012. They were on a specific mission, however.
The pair for years have participated in studies detecting human-made PFAS chemicals in everything from river water and household dust to human blood and food wrappers. A decade ago, they documented the success of a new method to detect various PFAS downstream of DuPont’s Fayetteville Works industrial campus in Bladen County.
“If you are going to find new things, you’re likely to find them around places where they make or use them. If you don’t find them at the source, you are not going to find them anywhere else,” Strynar said in an interview with NC Health News.
Persistent chemicals
PFAS attract the attention of many environmental health researchers around the world today. Used widely to make cookware, stain resistant fabric, solar power technology, firefighting foam and much more, the compounds degrade slowly, if at all, in nature. Some have been detected in waterways, wildlife and people all over our planet.
That raises alarms because studies have shown some PFAS may affect developing fetuses and children by affecting growth, learning, and behavior; decrease fertility and interfere with hormones; increase cholesterol; affect immune responses; and increase cancer risk.
DuPont and other U.S. companies voluntarily stopped making some suspect PFAS this decade, in particular, those featuring long molecular chains. That included perfluorooctanoic acid, known as PFOA, a longer chain chemical previously produced at Fayetteville Works. But scientists eager to assess risks from their replacement compounds are often in the dark about their structures, the very qualities that determine their environmental and health risks.
Companies submit such structures to EPA but they can be designated confidential business information under the Toxic Substances Control Act, a law passed in 1976 intended to give EPA power to require information about industrial chemicals and assess their potential risks before it gets into the environment.
“We took the approach that used our instruments and our chemical knowledge to figure it out rather than use information that had confidentially built into it,” Strynar said.
The scientists deployed a “non-targeted” strategy. They used a very sensitive (high-resolution) mass spectrometer, a device that sorts atoms by their mass, to reveal the building blocks of fragments of chemicals that they found in the river but which were unknown to them. Painstakingly, they used their experience with PFAS and computer-aided modelling to build a blueprint for polyfluorinated compounds with shorter molecular chains.
That led to the first detection of GenX in the environment.
They confirmed their finding using the description of the structure in documents DuPont had submitted to West Virginia regulators as part of a pre-manufacturing notice.
“It was a sort of ‘ah ha’ moment. ‘This is a real chemical…’” Strynar said. “Up to that point we were still grasping at straws.”
Strynar and Lindstrom described the research at scientific meetings in 2012 and 2014 before publishing the findings, including the structure, in 2015. Significant findings from others followed quickly. In 2015, researchers abroad detected the PFOA alternative GenX for the first time in waterways in China and Germany, for instance.
Closer to home, Strynar and Lindstrom collaborated with a North Carolina State University laboratory and found GenX in drinking water. At a Cape Fear Public Utility water intake from the Cape Fear, they detected an average GenX concentration of 631 parts per trillion (ppt) and levels as high as 4,500 ppt. That greatly exceeds the state Department of Health and Human Services’ 140 ppt health goal for GenX concentrations in water.
Using scientific expertise to pinpoint where these chemicals move once they’re released is vital, said Detlef Knappe, the N.C. State environmental chemist collaborating with the EPA chemists.
“We understand very little about the overall nature of what is being produced, how it is used, and where it might enter the environment,” Knappe said.
Moving forward
Strynar and Lindstrom’s findings prompted DeWitt, the ECU toxicologist, to pursue a GenX study published in 2017 that found the compound leaves a body sooner and may be less potent than PFOA. That said, the chemical did generate some of the same physiological changes observed in lab mice after exposure to older generation PFAS compounds at lower concentrations.
“Without Mark and Andy’s work, I would not have performed a toxicity study with GenX when I performed it,” DeWitt said.
Dewitt hopes soon to work with the EPA pair directly to help assess whether GenX and related compounds can be detected in people living in the Cape Fear basin. N.C. State epidemiologist Jane Hoppin is awaiting approval of a National Institutes of Health grant expected to allow her, DeWitt, Strynar, Lindstrom and Knappe to measure the concentrations of GenX and related compounds in people’s blood and urine.
Studies by the EPA team has helped sell North Carolina environmental regulators on the need for more monitoring. That message is reinforced by Knappe’s finding in 2014 that another unregulated industrial chemical — 1,4 dioxane — was polluting Cape Fear River water feeding water supplies, including one serving Fayetteville.
DEQ has since expanded river water monitoring to look for 1,4 dioxane in the Neuse and Yadkin river basins. And the agency is developing a strategy for regular monitoring for emerging contaminants, something a newly appointed Science Advisory Board will assist with, DEQ communications director Jamie Kritzer said this week.
A monitoring program could reduce unpleasant surprises, suggested Strynar, whose laboratory tested Cape Fear water for DEQ in recent months as the agency pushed Chemours to stop releasing GenX, Nafion and related chemicals into the Cape Fear.
“They have asked us: ‘How do we not have this happen again?’” Strynar said, referring to DEQ officials. “The only way is to continue looking.”
Correction: An earlier version of this article misspelled Mark Strynar’s first name. It has been corrected.
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