The Fate of Forever Chemicals

In the late 1930s, a researcher working for the chemical manufacturer DuPont accidently discovered a new compound, polytetrafluorethylene. Within 10 years, DuPont was producing millions of pounds a year of the substance, more commonly known by its trademark name, Teflon. Within a few decades, PTFE and similar chemicals binding together carbon and fluorine were being used in everything from non-stick pans and fast food wrappers to firefighting foam and pesticides. At that time, these chemicals, lauded for their water resistance and durability, were known as “miracle chemicals.” Today, they’re more commonly — and critically — referred to as “forever chemicals.”

Though people now often refer to ‘PFAS’ as a single chemical, in reality, over 9,000 per- and polyfluoroalkyl substances have been developed. Though not all have been widely studied, many of those that have, have been found to increase the risk of cancer. They can also disrupt hormonal and reproductive systems, leading to development issues, increased cholesterol levels, decreased fertility, and even a weakened immune system. The Centers for Disease Control have found traces of four of the most common PFAS in the blood serum of nearly everyone they’ve tested since 1999. Ironically, many of the thousands of PFAS in circulation today were developed as replacements for the original compounds. But each iteration showed the same problematic behavior and posed similar risks.

Few areas of Maine have been left untouched by PFAS contamination. Thousands of agricultural operations across the state, for example, used to regularly apply PFAS-contaminated sewage sludge to their farms as fertilizer, and the Department of Environmental Protection has found that 20% of homes they’ve sampled close to those sites so far have levels of PFAS that exceed Maine’s interim drinking water standards. In 2021, a National Oceanic and Atmospheric Administration study of mussels in the Gulf of Maine also found PFAS at 40% of their sampling sites.

On the flipside, though, the state is at the forefront of efforts to address this widespread problem. Maine is one of the few states, for example, that has established screening levels for PFAS contamination in agricultural products like milk, and last year, Maine became the first state to ban the use of sludge on farms. In 2021, the legislature also passed a law banning the sale of most products that contain PFAS after 2030.

“The problem has been around for a while, but I think just now people are realizing the scale of it – like how much is around, how prevalent they are, and how little regulation there was of most of these compounds,” said Senior Research Scientist Christoph Aeppli.

For Aeppli, one of the biggest challenges with PFAS is just the lack of understanding of how these complex pollutants are impacting ecosystem health and their long-term fate in the environment. To-date, most of his research has focused on oil spills.

“With oil, though, you can look back to 50-plus years of research that has been done,” Aeppli said. “With PFAS, the research is all much newer.”

There are other chemical differences between PFAS and what Aeppli calls “legacy pollutants” like oil. The latter are hydrophobic, so they don’t easily dissolve in water and, instead, build up on sediments and in fatty tissue. PFAS, in contrast, are much more soluble in water and can bind, not just to fat, but to proteins in blood.

Aeppli highlights several other gaps in our understanding of PFAS at an ecosystem level, everything from how it is getting into the marine ecosystem to how it is transforming as it moves through systems and species. He says we are only starting to develop good models to understand the toxicity of various PFAS and how they move through the food web.

Aeppli is working on a Sea Grant-funded project to start answering those questions. He’ll be sampling for PFAS in water, sediments, and mussels at two sites in Casco Bay starting this summer and fall, and then again next spring. Mussels are not only commercially important in Maine, but they also provide a good proxy for the uptake of pollutants in other species. The seasonal sampling, meanwhile, will give them a chance to see how PFAS concentration changes over the course of the year.

As for the sites themselves, Aeppli said they were chosen both to capture a range of potential sources of PFAS, such as Brunswick Naval Air Base, but also to leverage the work that local community groups, like the Friends of Casco Bay and Friends of Merrymeeting Bay, have already done. These groups have long-running monitoring programs so they have a good understanding of the ecosystem and a lot of water quality data. Combining the funding and analytical expertise of Bigelow Laboratory with that deep, local knowledge can help inform the development of robust monitoring programs to identify PFAS hotspots and understand what that contamination means for aquatic organisms like shellfish.

Even closer to home, Aeppli and Senior Research Scientist Rachel Sipler, who directs Bigelow Laboratory’s Water Health and Humans Initiative, are also working with the Boothbay Region Clean Drinking Water Initiative and the Boothbay Region Water District to assess PFAS in local freshwater sources.

“This effort will fill gaps and help us really understand our system so that we can better predict and mediate changes long term,” Sipler said.

Working with the Clean Drinking Water Initiative, a collaborative that includes various local stakeholders like the water district, she is trying to develop a better understanding of PFAS contamination locally and how it might be changing. Sipler hopes that this is the first step to a long-term collaboration to ensure the health and prosperity of our community.

“We’re hoping to help Boothbay get ahead of the curve,” she said.

When it comes to being ahead of the curve, Bigelow Laboratory is also one of just two labs recently funded by the state to increase capacity within Maine and get state accreditation to process PFAS samples, which requires a high level of technical expertise and advanced instrumentation. To that end, Aeppli’s lab just installed an advanced PFAS-dedicated liquid chromatography-mass spectrometer, the same type of instrument used for shellfish toxin testing.

Once the accreditation is official, hopefully by the end of the year, Bigelow Laboratory will begin taking samples from the Department of Environmental Protection and other potential clients – from agencies like the Department of Marine Resources to nonprofit groups and private citizens. In the meantime, though, they process the samples collected for various research projects. Aeppli and fellow Senior Research Scientist Manoj Kamalanathan, for example, will have a student this summer looking at the possibility of using algae to remove PFAS from water.

It’s that sort of research expertise that makes Bigelow Laboratory’s new testing service so potentially useful.

“For research, we’re always pushing the detection limit and expanding the number of compounds we can detect, and that expertise helps us offer a cutting-edge service that keeps up with evolving regulations,” he said. “It’s a beneficial relationship, between helping the state address a real problem and contributing to a growing area of research.”

Sipler agrees about the need for more data regarding the water quality threats facing Maine communities. But she stresses that it’s not just to highlight risks but also to develop strategies to address problems before they get out of hand and maintain the good health of the resources we have.

“We need to have information to be in the hopeful state,” she said.

Infographic: The first PFAS were designed with eight linked carbon molecules. As people realized the risks of those original compounds, scientists experimented with altered chemical formulas. They created new iterations of chemicals but never solved some of the basic environmental challenges. Most of these new substances are not yet part of the standard testing kit for PFAS.

Photo 1: Bigelow Laboratory researchers are working with community groups, such as Friends of Casco Bay, to develop a robust monitoring program to identify PFAS hotspots across Maine. Robby Lewis-Nash

Photo 2: Research Associate Erin Beirne gathers water samples in Casco Bay for a new project monitoring PFAS in Maine waterways and mussels. Christoph Aeppli

Photo 3: Research Associate Erin Beirne samples sediments as part of a PFAS monitoring program. Christoph Aeppli

Photo 4: Senior Research Scientist Christoph Aeppli examines the new liquid chromatography-mass spectrometer installed in his lab to process PFAS samples. Collin Sheehan