A new method for measuring airborne “forever chemicals”
August 16, 2024
By Ethan Chupp, UNC Gillings School Communications Fellow
Per- and polyfluoroalkyl substances (PFAS) are a group of toxic chemicals that have earned the name “forever chemicals” because they do not break down naturally and can accumulate in the environment and the body. New research from the UNC Gillings School of Global Public Health has developed a new method for measuring these chemicals in real-time, directly from the air.
PFAS are man-made chemicals found in products we use daily, including in non-stick coating on food packaging and cookware, cosmetics, and water-repellent clothing and upholstery. High levels of PFAS contamination can lead to cancer, heart disease, hormone disruption and immune disorders. Waterborne PFAS pollution is well documented, especially from industrial sites like the manufacturing plant near Fayetteville, North Carolina.
Since 2021, the US Environmental Protection Agency (EPA) has cracked down on PFAS pollution in drinking water. Public water systems must now monitor PFAS levels for compliance and inform the public. The N.C. Department of Environmental Quality (NC DEQ) has added permit conditions to address PFAS wastewater release.
Some PFAS can also leak from industrial sites into the atmosphere. These chemicals can transform in the atmosphere into more water-soluble forms and spread through rain into groundwater. The latter is a source of drinking water for many N.C. residents.
“The existing methods used to measure PFAS in the air require weeks to months of sampling to get enough material. Because of the lack of air measurements, there is currently no guidance on reasonable exposure levels to mitigate health effects,” said Jason Surratt, PhD, professor in the Department of Environmental Sciences and Engineering.
Dr. Jason Surratt
Surratt explained that air inside people’s homes can absorb PFAS from consumer products. Food packaging and cookware, waterproof clothing, and other PFAS-containing materials release some of these chemicals into the environment. The goal has been to develop a method that can detect PFAS directly out of the air in real time. This approach has previously encountered challenges with sensitivity and calibration for effective deployment.
Surratt’s lab modified this method using the chemical iodide to measure airborne PFAS from sources such as microwave popcorn and rain jackets. Michael Davern, a current doctoral student in Surratt’s lab, has led this work and developed a liquid calibration system to help make this method quantitative for airborne PFAS. This work has been in close collaboration with Professor Barbara Turpin’s lab in the Department of Environmental Sciences and Engineering.
Dr. Barbara Turpin
Michael Davern
“We have a reactor before the instrument that is flooded with a high concentration of iodide. And iodide loves to tag or stick to airborne PFAS. And then iodide is like a chaperone guiding PFAS into the instrument,” said Surratt.
With this calibration, the instrument can measure relevant PFAS at a concentration of a few parts per trillion or lower, similar to standard water measurement capabilities.
The technology can measure outdoor airborne PFAS levels as well. Surratt’s team is preparing for a field deployment of this technology at the Chemours plant near Fayetteville. The team and their collaborators at Texas A&M University will mount the instrument in a mobile research laboratory van to measure airborne PFAS levels outside of the factory. This new technology will generate more accurate and detailed data on what chemicals are being emitted by industrial sites.
Surratt believes that better measurements of airborne PFAS will help create new and better environmental regulations and protect residents of the area.
“Our goal is to give the community a better sense of what’s being released to the air,” he said.
Contact the UNC Gillings School of Global Public Health communications team at sphcomm@unc.edu.
