November 22, 2022
Postdoctoral researcher Jiaqi Zhou, PhD, and her faculty colleagues at the UNC Gillings School of Global Public Health have identified toxic chemicals called per- and polyfluoroalkyl substances (PFAS) in the air close to a fluoropolymer manufacturing plant in Fayetteville, North Carolina.
PFAS contamination is already a substantial concern for residents in the area, who face an elevated risk of health problems from exposure to these toxicants in soil and groundwater that flows into the nearby Cape Fear River. The new study, published in Environmental Science: Processes & Impacts, identified 13 PFAS compounds that have elevated concentrations in airborne fine particulate matter (PM2.5) within two kilometers of the plant, compared to concentrations farther away.
These measurements were made during and after the facility installed air pollution controls under a N.C. Department of Environmental Quality (DEQ) consent decree.
In total, the researchers identified 12 newer PFAS compounds (emerging) and 10 that were more commonly manufactured in the past (legacy).
“These results were not surprising,” said Zhou, “as fluoropolymer manufacturing facilities are major known sources of PFAS.”
The findings provide direct evidence that local airborne emissions contribute to PFAS contamination in the community. High levels of PFAS exposure can harm reproductive and immune system health, cause developmental delays, and put people at risk for certain types of cancers, including prostate, kidney and testicular cancers, according to the Environmental Protection Agency.
“Fluoropolymer manufacturing in Fayetteville is an environmental justice issue,” said Barbara Turpin, PhD, who is professor and chair of environmental sciences and engineering at the Gillings School and senior author on the study. “Many people of color live in the area, and high concentrations of PFAS pollution have been found in local well water, putting their health and livelihood at risk for years.”
Rain can transport airborne PFAS into water or soil in a process known as wet deposition, according to Turpin. She said there is strong evidence to suggest that well water contamination northeast of the plant predominately comes from air deposition.
“The study found elevated air concentrations of several PFAS compounds. This can lead to greater inhalation of PFAS, greater ingestion by drinking contaminated well water and dermal exposure through bathing. This is a particular concern because these communities are not hooked up to a regulated public water system,” she said.
PFAS are commonly known as “forever chemicals” because they do not break down naturally and can accumulate in the environment, people and animals over the course of decades-long exposure. They can be found in products we use daily, including in non-stick coating on food packaging and cookware, cosmetics, and water-repellant clothing and upholstery. People can also be exposed by consuming contaminated water or fish, or if they work in industries like firefighting or manufacturing.
Since 2017, DEQ has been responding to a specific type of PFAS in the Cape Fear River called GenX, which is manufactured along with several other chemicals at the nearby plant. This new study, funded by the N.C. Collaboratory, is the first to study airborne levels of PFAS near a fluoropolymer manufacturing facility in the U.S.
“It’s tricky to measure PFAS in air,” Turpin explained. “When DEQ started detecting it rainwater, it was clear that it was present in air, but there are significant analytical challenges involved in PFAS measurement. It is rare to find studies that have measured more than two PFAS compounds in airborne PM2.5. In this study, we measured a whole suite of airborne PFAS compounds.”
The researchers – including Zhou, Turpin, Karsten Baumann, PhD, and Jason Surratt, PhD, from the Gillings School’s Department of Environmental Sciences and Engineering – set up two sampling sites between 1-2 kilometers from the plant, each on different sides and in line with the prevailing wind directions for the area. They took measurements of PFAS in PM2.5 between September and December 2019, when the plant was implementing changes in emission controls to abide by the DEQ consent order.
“PM2.5 particles stay in the air for a week or two and can be transported downwind,” Turpin said. “We took each sample over a period of six days and then compared them to measurements from four background sites across the state, where concentrations of PFAS are usually below detection limits. We were able to measure more types of PFAS because the concentrations near the plant were higher.”
Because PFAS is so widely used, people can become exposed through many sources. Detection requires sophisticated measuring tools. Turpin said that while concentrations in water are typically small (a few grams per trillion grams of water), even at low levels they can impact human health. These chemicals stay in the environment for a very long time, and some accumulate in the human body over time. Thus, long-term exposure to contaminated sources increases the risk of harm.
Fortunately, UNC scientists across disciplines, including Frank Leibfarth, PhD, and Orlando Coronell, PhD, are working to remove pollutants like these from drinking water.
“For most of us, direct inhalation of PFAS is most problematic indoors,” Turpin explained. “PFAS are manufactured for use in consumer products because they are water resistant, stain resistant and heat resistant. It’s important for people to know if they’re bringing something into their home that increases their exposure to harmful chemicals, but most of the time we don’t know.”
Turpin said it has been challenging for the U.S. to address consumer product safety, given the structure of current regulation and the rapid evolution of the types of new compounds manufactured with unknown toxicologic properties.
“We are working on developing real-time methods for PFAS detection,” Zhou added, “and hopefully this will provide more insights.”
The N.C. Collaboratory funded this work and has been critical in funding research to remove PFAS from our state’s environment.
Contact the UNC Gillings School of Global Public Health communications team at firstname.lastname@example.org.
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