A new tool detects and fingerprints previously undetected PFAS compounds in the Cape Cod basin-ScienceDaily

Researchers at Harvard John A. Paulson’s School of Engineering and Applied Sciences (SEAS) have previously used a new method for quantifying and identifying PFAS compounds from the family of chemicals known as PFAS in the six basins of Cape Cod. We found a large number of compounds that could not be detected. Exposure to some PFAS, which is widely used for its ability to repel heat, water and oil, is associated with a variety of health risks such as cancer, immunosuppression, diabetes and low birth weight.

The new test method revealed large amounts of previously undetected PFAS from flame-retardant foam and other unknown sources. The total concentration of PFAS present in these basins was above the state’s maximum pollutant level (MCL) for drinking water safety.

“We have developed a method to completely capture and characterize all PFAS, from flame-retardant foams, which are the main source of PFAS, to downstream drinking water and ecosystems, and may be derived from these foams. We also found a large number of unidentified PFAS without any. ” Bridger Ruyle, a graduate student at SEAS and the lead author of the study, said. “Traditional test methods are completely missing these unknown PFAS.”

The study will be published at Environmental science and technology..

PFAS (Perfluoroalkyl and Polyfluoroalkyl) are found in products from flame-retardant foams to non-stick pans. PFAS is called an “eternal chemical” because of its long lifespan and has been accumulated in the environment since it was first used in the 1950s.

Despite the associated health risks, there are no legally enforceable federal regulations on PFAS chemicals in drinking water. The Environmental Protection Agency’s Provisional Health Guidelines for Public Water Services cover only the two common types of PFAS, PFOS and PFOA. Massachusetts, along with several other states, is taking it further by including six PFASs in its new MCL in drinking water. However, there are thousands of PFAS chemical structures known to exist, hundreds of which have already been detected in the environment.

“We haven’t tested most PFAS compounds, so we don’t know the total exposure to these chemicals, and health data associated with such exposures is still lacking,” said Gordon McKay of SEAS. Elsie Sunderland, a professor of environmental chemistry, said. And the senior author of the treatise.

The standard test method used by EPAs and state regulators tests only 25 or less known compounds. The problem is that the overwhelming majority of PFAS compounds are unique and regulators cannot find out that there is something they do not know.

A new method developed by Sunderland and her team can overcome that barrier and explain all PFAS in the sample. CSI: PFAS

PFAS is made by combining carbon and fluorine atoms to form one of the strongest bonds in organic chemistry. Fluorine is one of the most abundant elements on the planet, but naturally occurring organic fluorine is extremely rare and is produced only by some toxic plants in the Amazon and Australia. Therefore, the amount of organic fluorine detected in the environment is always artificial.

There are two forms of PFAS compounds found in the environment: precursor and terminal. Most of the monitored PFAS compounds, including PFOS and PFOA, are terminal compounds, which means they do not degrade under normal environmental conditions. However, precursor compounds, which often make up the majority of PFAS chemicals in a sample, can be converted to their final form through biological or environmental processes. Therefore, EPAs or state agencies may monitor PFAS concentrations, but still do not detect many of the vast pools of PFAS precursors.

That’s where this new method comes in.

Researchers first measure all organic fluoride in the sample. Another technique can then be used to oxidize the precursors of that sample, convert them to their final form, and measure them. From there, the team reconstructed the original precursors, fingerprinted their manufacturers, and developed statistical analysis methods to measure their concentration in the sample.

“We are essentially doing chemical forensics,” Sunderland said.

Using this method, Sunderland and her team explored Cape Cod’s six watersheds as part of a collaboration with a research center funded by the US Geological Survey and the National Institutes of Health and led by the University of Rhode Island. I tested it. Transport, exposure and effects of PFAS.

The team focused on identifying PFAS from the use of flame-retardant foam. Widely used in military bases, private airports, and local fire departments, these forms are a major source of PFAS and pollute hundreds of public waterworks throughout the United States.

The research team applied forensic techniques to samples collected from the Childs, Quashnet, Milk Creek, Marstons Mills, Mashpie, and Santuit basins in Cape Cod between August 2017 and July 2019. The waterproof gear is treated with PFAS, so team members had to be careful about what they wore during the collection process. The team arrived at Wader decades ago to prevent pollution.

Sampling sites in the Childs, Quashnet and Milk Leak basins are downstream of the source of PFAS from flame-retardant foam. Quashnet and Childs are from the joint base Cape Cod Military Facility, and Milk Creek is from the Barnstable County Fire Drill Academy.

Current testing can identify only about 50% of PFAS from past forms (products that were discontinued in 2001 due to high levels of PFOS and PFOA) and less than 1% of PFAS from the latest forms. ..

Sunderland and her team use a new method to identify 100% of all PFAS compounds in the flame-retardant foam types that have been used for decades at the Joint Base Cape Cod and Barnstable County Fire Training Academy. I was able to.

“Our test method was able to find these deficient compounds that have been used in the chemical industry for over 40 years,” says Sunderland.

Testing also revealed a large amount of PFAS from an unknown source.

“The calculation of PFAS from fire extinguishing bubbles could not explain 37-77 percent of the measured organic fluoride,” Ruyle said. “This has a significant impact not only on our understanding of human exposure, but also on how much PFAS is released into the ocean and accumulated in marine life.”

To follow up on these findings, Ruyle is currently working with NIH to identify some of the health effects of PFAS from modern fire-fighting foam using toxicological studies. The Sunderland team continues to study the unknown PFAS, better identifying its potential and its source in Cape Cod’s abundant marine food web.

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