NC State researchers using pine needles to study forever chemicals

Researchers at North Carolina State University are using pine needles to monitor the presence of forever chemicals in the state.

According to the Food and Drug Administration, per- and polyfluoroalkyl substances (PFAs) are defined as a "diverse group of human-made chemicals used in a wide range of consumer and industrial products ... many PFAs are resistant to grease, oil, water and heat."

Tiny particles of these chemicals get into groundwater or air as a side effect of manufacturing processes.

Local researchers are currently using pine needle samples removed from trees in six North Carolina counties since 1961 to study the proliferation of PFAs.

When studied, the pine needles provide a look at the evolution of PFAs in the state over the last 50 years.

The waxy coating on pine needles protects them from weather elements while helping to trap airborne contaminants like PFAs, researchers say.

Pine needles are also "everywhere in the state and free, so it’s very easy to sample numerous locations and time points without having to build and retrieve expensive sampling equipment,” said Erin Baker, associate professor of chemistry at N.C. State and co-corresponding author of the work.

Since pine trees drop their needles on a regular schedule, scientists can easily determine what time of the year they are studying.

According to a press release, Baker and two colleagues obtained 60 pine needle samples from sites in Durham, Wayne, Cumberland, Robeson, Onslow and Brunswick counties.

They also used 15 pine needle samples from N.C. State's and Duke University's collection of dried plants.

“We were focused primarily on locations we have modern data for, as well as locations that are associated with PFAs, like airports, firefighter training sites and chemical plants like the Chemours facility,” said Scott Belcher, an associate professor of biology at N.C. State and co-corresponding author of the research. “We took samples at those sites and at sites three to 11 miles away for comparison.”

"We were able to see the exposure gradients for these chemicals – how the concentrations fell off from high levels at the source of the contamination versus lower levels farther away," said Ph.D. candidate and lead author Kaylie Kirkwood.

The three researchers hope their work will inspire scientists around the world.

“This is way bigger than North Carolina – it’s applicable to sites all over the world,” Baker says. “Beyond N.C. and beyond pine needles, this shows the capability of plants with waxy coatings to serve as sentinels of environmental contamination.”