North Atlantic pilot whales have been found to have 60% lower concentrations of PFAS (per- or polyfluoroalkyl substances) in their bodies following a phasing-out of some of the most commonly used chemicals.

PFAS, often referred to as forever chemicals, were first produced at the end of World War II and can now be found in everything from furniture and cosmetics to food packaging, non-stick pans and clothing. But due to their widespread use, they can now be found in our water supplies, soil and food, making them a major concern for human and ecological health. 

Beginning in the early 2000s, some of the most common and well-studied PFAS were phased out through a combination of industry shifts and international regulations. 

Now, a new Harvard University study has found that since that phase-out, North Atlantic pilot whales have 60% lower concentrations of these chemicals in their bodies. However, while older, legacy PFAS are well understood and easy to detect, newer generations of chemicals are harder to pinpoint.

“With legacy PFAS, we know a lot more about their environmental transport and impacts on organisms,” said lead author Jennifer Sun. “But we have a lot less information about what is going on with many newer compounds that have been produced to replace the phased-out legacy PFAS.”

Instead of measuring individual PFAS, the researchers measured bulk organofluorine, which captures the fluorine in most PFAS compounds. They used these measurements as a proxy for total concentrations of PFAS, including newer types of PFAS that are harder to identify on their own.

With this approach, the researchers studied whale tissue samples in collaboration with long-time research partners in the North Atlantic Ocean’s Faroe Islands, who maintain a unique, long-term archive of pilot whale tissues. As apex predators, the whales are considered sentinels of marine pollution because their bodies retain chemical exposures for long periods, and they exist in the outer ocean, demonstrating how far harmful compounds can travel into the environment.

The researchers found that overall organofluorine levels were primarily made up of four legacy PFAS that all peaked in the mid-2010s and had declined by 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, which I think is very positive and important to emphasise,” said Sun.

But this reduction comes at a time when global production of new PFAS is actually on the rise, leading scientists to question where else they could be accumulating.

“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?” Sun asked. “While our results are good news for ocean contamination, it suggests newer PFAS may behave differently from the legacy ones. It underscores the need to place stronger regulations on ongoing PFAS production to mitigate future impacts.”