In the same week that global discussions to develop a legally-binding multilateral Plastics Treaty to tackle the plastic pollution, microplastics, and their associated harmful chemicals crisis collapsed, scientists identified a class of PFAS in the blubber of killer whales that had previously gone undocumented.
The new study – published in Environmental Science and Technology Letters – details the presence of five fluorotelomer sulfones (highly fluorinated, fat-loving chemicals) never before reported in wildlife. And it would appear that whales and other marine mammals could be particularly vulnerable to their exposure.
That’s because, unlike well-studied PFAS, which typically accumulate in protein-rich tissues such as liver and blood, these new substances accumulate in fat-rich blubber.
“This is the first time that highly fluorinated PFAS have been shown to preferentially accumulate in fat,” said lead author, Mélanie Lauria, formerly a doctoral student at the Department of Environmental Science at Stockholm University and currently at the Swiss Federal Institute of Aquatic Science and Technology.
“It challenges the long-held assumption that PFAS primarily bind to proteins and accumulate in the liver of blood. Research has so far focused on a subgroup of PFAS that is ‘charged’ or ‘polar’, and therefore interact mainly with proteins.
“The results of this study show that we have overlooked PFAS that are neutral and can interact and accumulate in neutral fats such as blubber.”
Researchers were able to analyse tissue samples from killer whales in Greenland and Sweden. The newly identified compounds accounted for up to 75% of fluorine-containing substances in blubber, but were undetectable in liver tissue – evidence of their ‘fat-loving’ nature.