Scientists know that per- and polyfluoroalkyl substances, or PFAS, are a major concern for the environment and human health. These “forever chemicals” are widespread in environmental waters, fish, and people, and they can negatively affect ecosystems and human organs alike.
However, until recently, scientists faced limitations when trying to efficiently and accurately detect PFAS — and other concerning chemicals like pharmaceuticals — out in the environment. Now, thanks to recent research funded by Ohio Sea Grant, scientists are starting to solve these problems with new techniques and technologies.
“You can basically bring the lab on-site without having to bring samples back to the lab,” Dr. Emanuela Gionfriddo, associate professor of chemistry at The University of Toledo, said of the technology her team developed to detect PFAS and other chemicals.
Gionfriddo and her team successfully developed methods to accurately measure PFAS on-site in surface water, drinking water, lake water, river water, and even melted snow and sea water. Researchers created a miniaturized probe that can quickly detect PFAS at very low concentrations, and they’ve also applied the techniques to measure pesticides and pharmaceuticals.
Next, the team is taking the research a step further: learning how to detect forever chemicals in fish tissue “in vivo” — while the fish is still alive. Doing so requires a thorough understanding of the challenges these chemicals present.
PFAS are a family of over 5,000 chemicals that are used to make nonstick cookware, water-repellent clothing, stain-resistant fabrics, cosmetics and other products that resist grease, water, and oil. The chemicals have become ubiquitous at very low concentrations, meaning that they can be found throughout the environment and in most people’s bloodstreams.
The chemicals present a number of concerns: They hardly biodegrade in the environment, they can move through soils and contaminate drinking water sources, and they can build up or “bioaccumulate” in wildlife. Studies have shown that exposure to certain levels of PFAS can affect the body’s reproductive, immune, and endocrine systems, and the chemicals are linked to some cancers as well.
“So theoretically, every time we have a spill or release of PFAS into the environment, these chemicals will just circulate and eventually reach humans,” Gionfriddo said. “And concentrations of PFAS in biological tissues can actually be orders of magnitude higher than what we can detect in the environment because of the bioaccumulation.”
What’s more, current methods of quantifying these chemicals can lead to cross-contamination. PFAS are so common in the manufacturing industry that they’re even found in laboratory supplies and equipment that researchers use, potentially hindering results, Gionfriddo said.
“There is a high risk of cross-contamination every time we do analysis,” she said. “Another challenge is that PFAS’ physical chemical properties make them stick on the labware and plastic equipment.”
To avoid these biases and ensure the chemicals are measured precisely, Gionfriddo’s team developed a unique “microextraction” process. The miniature probes have a metal fiber made of thin, elastic alloy that is 200 micrometers — a millionth of a meter — thick. That alloy is coated with polymers that can selectively extract PFAS, leaving behind any material that could introduce bias.
“We tested our approach with drinking water and other environmental waters, and it worked beautifully,” Gionfriddo said. “Then we decided to add another layer of complexity and applied these methodologies to fish tissues.”
When PFAS bioaccumulate in fish, this endangers wildlife as well as human health through fish consumption. Through the project, researchers are studying how to isolate chemicals in fish using materials that are biocompatible — not harmful to living tissue — in their sampling probes.
The technology developed so far offers several advantages. The miniature probes are very portable and can rapidly detect concerning chemicals at low concentrations. Subsequent analysis of collected PFAS can occur on-site, rather than back at the lab.
“What we learned, especially with PFAS, is that providing a very robust methodology — that starts with sample preparation and extraction — is essential to obtain reliable data,” Gionfriddo explained. “There’s a lot of work that can be done before the sample reaches the instrument. Even if you have the most powerful instrument but are injecting dirty samples, you’re not always going to get the results you need.”
Moving forward, accurate PFAS measurements will help scientists understand how humans are exposed to the chemicals and improve manufacturing processes to avoid future contamination.
Gionfriddo said she hopes the scientific community will embrace the use of microextraction technologies moving forward. The techniques can save significant amounts of time in the laboratory and cut down on laboratory waste, all while giving results that are often superior to existing methods.
“This type of technique can be useful for not only understanding PFAS and other environmental pollutants but also for the pharmaceutical industry and the food industry,” Gionfriddo said. “So we hope people will see the potential through our research and create as many applications as possible.”
Ohio Sea Grant is supported by The Ohio State University College of Food, Agricultural, and Environmental Sciences (CFAES) School of Environment and Natural Resources, Ohio State University Extension, and NOAA Sea Grant, a network of 34 Sea Grant programs nation-wide dedicated to the protection and sustainable use of marine and Great Lakes resources. Stone Laboratory is Ohio State’s island campus on Lake Erie and is the research, education, and outreach facility of Ohio Sea Grant and part of CFAES School of Environment and Natural Resources.