Large Quantities of Previously Undetectable PFAS Compounds in Six Watersheds on Cape Cod
Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) found large quantities of previously undetectable compounds of per- and polyfluoroalkyl substances (PFAS) in six watersheds on Cape Cod.
This discovery was achieved using a new method created by the team to quantify and identify PFAS compounds, reported Phys.org. The testing method revealed large quantities of previously undetected PFAS from fire-retardant foams as well as other unknown sources and the total concentrations of PFAS present in these watersheds were above state maximum contaminant levels for drinking water safety.
According to Elsie Sunderland, the Gordon McKay Professor of Environmental Chemistry at SEAS and senior author of the paper, the new method developed by the team essentially uses chemical forensics.
The researchers measure all the organofluorine in a sample and then, using another technique, oxidize the precursors in that sample and transform them into their terminal forms, which can then be measured. Using a method of statistical analysis, the researchers can reconstruct the original precursors, fingerprint their manufacturing origin, and measure their concentration within the sample, reported Phys.org.
The team tested six watersheds on Cape Cod with this method, using samples collected between August 2017 and July 2019 from the Childs, Quashnet, Mill Creek, Marstons Mills, Mashpee and Santuit watersheds on Cape Cod, reported Phys.org.
The sampling sites in the Childs, Quashnet and Mill Creek watersheds are downstream from a source of PFAS from fire retardant foams and the Quashnet and Childs from The Joint Base Cape Cod military facility and Mill Creek from Barnstable County Fire Training Academy, according to Phys.org.
"We developed a method to fully capture and characterize all PFAS from fire-retardant foams, which are a major source of PFAS to downstream drinking water and ecosystems, but we also found large amounts of unidentified PFAS that couldn't have originated from these foams," said Bridger Ruyle, a graduate student at SEAS and first author of the study, reported Phys.org. "Traditional testing methods are completely missing these unknown PFAS."
The research will be published in Environmental Science & Technology.
Sunderland and her team were able to identify 100% of all PFAS compounds in the types of fire-retardant foams used for decades at Joint Base Cape Cod and Barnstable County Fire Training Academy, reported Phy.org. The testing also revealed quantities of PFAS from unknown sources, so 37 to 77% of the organofluorine measured could not be identified.
This research is part of a collaboration with the United States Geological Survey and a research center funded by the National Institutes of Health and led by the University of Rhode Island that focuses on the sources, transport, exposure and effects of PFAS, according to Phys.org.
As a follow up on these findings, Ruyle is currently working with NIH to identify some of the health impacts of PFAS from contemporary firefighting foams using toxicology studies. Sunderland's team will continue to study the unknown PFAS to identify their sources and potential for accumulation in marine food webs on Cape Cod, reported Phy.org.
