Scientists have discovered five previously undocumented per- and polyfluoroalkyl substances, also known as "forever chemicals," in the blubber samples of killer whales in the Arctic. These new PFAS behave in ways that challenge what scientists previously understood about them.
Per- and polyfluoroalkyl substances (PFAS) are a group of highly toxic chemicals found in common household products, including non-stick cookware, water-resistant fabrics, personal care products, and more. Their pervasive nature in everyday products has led to the accumulation of PFAS in the bodies of humans and wildlife, particularly found in blood, which scientists have used to gauge PFAS exposure.
PFAS have earned the nickname of "forever chemicals" because they can take anywhere from hundreds to thousands of years to break down.
Even now, researchers continue to identify new kinds of PFAS, like the ones that scientists at Stockholm University and the Swedish Museum of Natural History recently found.
Their new study, published in Environmental Science and Technology Letters, explored the use of advanced mass spectrometry techniques to study killer whale tissue samples collected in Greenland and Sweden.
The scientists discovered five new compounds of PFAS that had not been previously documented. These new compounds differed from previously well-studied PFAS in that they are neutral-charged and fat-loving (lipophilic), as opposed to polar and protein-binding (binding to liver tissues or blood).
According to the study, these new PFAS accounted for up to 75% of fluorine-containing substances in blubber tissue samples, per a Stockholm University press release. Yet, none of those compounds were found in liver tissues, which PFAS are known to bind to.
"We may be underestimating the PFAS body burden in marine mammals. Blubber can represent up to half a marine mammal's body mass, so neglecting fat-soluble PFAS could significantly undermine the accuracy of exposure assessments," said Jonathan Benskin, a Stockholm University professor, per the university's press release.
Based on these findings, the scientists urge for deeper studies on fat-soluble PFAS to understand how PFAS affect marine mammals in Arctic ecosystems.
PFAS have one of the strongest carbon-fluorine bonds to exist in chemistry, which is why these toxic chemicals take so long to break down. These chemicals contaminate the soil, water, and air, and accumulate in the bodies of humans and wildlife, and they have been linked to worrying health effects.
Chinese researchers have found that PFAS can alter gene expression and cellular function, potentially leading to gene damage and adverse health effects that may persist for generations. PFAS have also been linked to increased risk of certain cancers in the "digestive, endocrine, oral cavity/pharynx, and respiratory systems," per a study published in Nature.
In wildlife, PFAS moves up the food chain, reaching apex predators, which are even more exposed to these chemicals, causing them to suffer from potential long-term health complications.
Though PFAS are so widespread in daily household products, governments and environmental organizations are taking steps to address and limit these chemicals from causing long-term harm.
In 2025, at least 36 states have introduced bills targeting PFAS in product manufacturing, as well as setting maximum limits to minimize the harmful extent of PFAS.
Organizations like Toxic Free Future are working to eliminate PFAS use in products, advocating for policies that will permanently ban these toxic chemicals from society.