In a significant environmental breakthrough, a Harvard study has revealed a 60% reduction in per- or polyfluoroalkyl substances (PFAS) in North Atlantic pilot whales since the early 2000s. These findings, published in the Proceedings of the National Academy of Sciences, mark a promising development in the ongoing battle against these pervasive chemicals.
PFAS, first produced at the end of World War II, have become ubiquitous in modern life, found in everything from non-stick cookware to water-repellent clothing. Their presence in water, soil, and food has raised alarms over potential health risks. However, the new study highlights a positive trend following the phaseout of some common PFAS compounds due to industry shifts and international regulations.
Legacy PFAS and New Challenges
The study addresses a longstanding challenge in tracking PFAS: while older, well-studied PFAS are easier to detect, newer generations of these chemicals are more elusive. Lead author Jennifer Sun, a postdoctoral fellow, explained, “With legacy PFAS, we know a lot more about their environmental transport and impacts on organisms. But we have a lot less information about what is going on with many newer compounds.”
Senior author Elsie Sunderland, a professor of environmental chemistry, compared the PFAS issue to a game of whack-a-mole: as soon as one chemical is understood, another emerges. To tackle this, researchers measured bulk organofluorine, a proxy for total PFAS concentrations, including newer, harder-to-identify compounds.
Whales as Environmental Sentinels
The research team collaborated with partners in the Faroe Islands, utilizing a unique archive of pilot whale tissues. As apex predators, these whales serve as sentinels of marine pollution, reflecting chemical exposures over time. The study found that four legacy PFAS compounds peaked in the mid-2010s, with a decline of more than 60% by 2023.
“Production phase-outs, which were initially voluntary and later driven by regulation, have been quite effective at reducing concentrations of these chemicals in near-source communities as well as more remote ecosystems,” Sun emphasized.
This decline is notable given the rise in global production of new PFAS. The study raises critical questions about the behavior of these newer compounds. Sunderland noted, “Generally, the ocean is thought to be the terminal sink for human pollution on land. But we are not seeing substantial accumulation of the newest PFAS in the open ocean. So, where are they?”
Implications and Future Directions
The findings suggest that newer PFAS may behave differently from their predecessors, underscoring the need for stronger regulations on ongoing PFAS production. This study, supported by the National Science Foundation and the National Institutes of Environmental Health Sciences, points to a need for continued research to understand the environmental pathways and impacts of these chemicals.
Co-authors Euna Kim, Heidi Pickard, Bjarni Mikkelsen, Katrin Hoydal, Halla Reinert, and Colin Thackray contributed to this groundbreaking research. As the scientific community continues to unravel the complexities of PFAS, the study highlights both the progress made and the challenges that lie ahead in mitigating the impact of these persistent pollutants.
The decline in PFAS levels in the subarctic ocean is a positive signal for marine ecosystems, but it also prompts further investigation into the fate of newer PFAS compounds. As regulatory bodies consider future actions, the study serves as a reminder of the intricate interplay between human activity and environmental health.
