New Research Reveals Decreasing PFAS Exposure in the Subarctic Ocean
The pervasive presence of PFAS, or per- and polyfluoroalkyl substances, in our daily lives has sparked significant concern. These chemicals, first introduced at the end of World War II, are now found in everything from furniture and cosmetics to food packaging, non-stick cookware, and clothing. Their infiltration of water, soil, and food has raised serious questions about human and ecological health.
A recent study from Harvard University has shed light on a promising development. Since the phase-out of some of the most common and well-studied PFAS in the early 2000s, driven by industry shifts and international regulations, North Atlantic pilot whales have shown a 60% decrease in these chemical concentrations in their bodies.
The study, published in the Proceedings of the National Academy of Sciences, addresses a long-standing challenge in detecting and measuring PFAS concentrations. While older, or legacy, PFAS are well-understood and easy to detect, newer generations of these chemicals present a more complex picture.
Lead author Jennifer Sun, a recent Ph.D. graduate and postdoctoral fellow, explains, "With legacy PFAS, we have a comprehensive understanding of their environmental transport and impacts on organisms. However, we have significantly less information about the behavior of many newer compounds that have been developed to replace the phased-out legacy PFAS."
Elsie Sunderland, the Fred Kavli Professor of Environmental Chemistry and senior author, compares the PFAS problem to the game of whack-a-mole. As researchers gain insight into the exposure and health implications of one chemical, a new one emerges. To tackle this challenge, the researchers adopted a novel approach. Instead of measuring individual PFAS, they focused on bulk organofluorine, which captures the fluorine present in most PFAS compounds.
By utilizing these measurements as a proxy for total PFAS concentrations, including the newer types that are more challenging to identify individually, the researchers studied whale tissue samples from the North Atlantic Ocean's Faroe Islands. These islands house a unique, long-term archive of pilot whale tissues, making them ideal for studying marine pollution.
The findings revealed that the overall organofluorine levels were primarily composed of four legacy PFAS, which peaked in the mid-2010s and had significantly decreased by over 60% by 2023. This reduction is particularly notable, as it coincides with a time when global production of new PFAS is on the rise.
Sun emphasizes the positive impact of production phase-outs, stating, "These voluntary and regulated phase-outs have proven highly effective in reducing chemical concentrations in near-source communities and more remote ecosystems."
However, the study also raises intriguing questions. If most of the newer PFAS are not accumulating in ocean ecosystems like their legacy counterparts, where are they accumulating? Sunderland poses this thought-provoking question, suggesting that further investigation is needed to understand the fate of these chemicals.
The study's co-authors include Euna Kim, Heidi Pickard, Bjarni Mikkelsen, Katrin Hoydal, Halla Reinert, and Colin Thackray. The research was supported by the National Science Foundation (ICER-2108452) and the National Institutes of Environmental Health Sciences Superfund Research Program (P42Es027706).
This research offers a glimmer of hope for ocean contamination, but it also highlights the need for stronger regulations on ongoing PFAS production to prevent future environmental impacts.
