Latest research shows new ‘forever chemicals’ present in otters

In a recent study, scientists have uncovered the ongoing presence of perfluorooctanoic acid (PFOA) pollution and the rise of new per- and polyfluoroalkyl substances (PFASs) in English freshwaters, using the Eurasian otter (Lutra lutra) as a sentinel species. This research sheds light on the lasting environmental impact of industrial activities and the potential risks associated with replacement chemicals.

Persistent PFOA Pollution Near PTFE Production Sites

The study focused on a transect away from a factory that used PFOA in the manufacture of polytetrafluoroethylene (PTFE) until 2012. Despite the cessation of PFOA use over a decade ago, high concentrations of this pollutant were still found in the local environment. In otters sampled between 2015 and 2019, PFOA levels remained alarmingly high near the factory, with concentrations exceeding 298 μg/kg wet weight within 20 kilometers of the site. These levels gradually decreased with distance, dropping to below 57 μg/kg wet weight at locations more than 150 kilometers away.

Legacy vs. Replacement PFASs

The researchers analyzed concentrations of 33 different PFASs in 20 otters, revealing that long-chain legacy PFASs, such as perfluorooctane sulfonate (PFOS), PFOA, perfluorodecanoic acid (PFDA), and perfluorononanoic acid (PFNA), dominated the chemical profile. These compounds have long been associated with significant environmental and health concerns due to their persistence and bioaccumulation potential.

Interestingly, the study also detected several replacement PFASs, including PFECHS, F-53B, PFBSA, PFBS, PFHpA, and 8:2 FTS, in at least 19 otters. Notably, this is the first report of PFBSA and PFECHS in Eurasian otters. While the concentrations of these newer compounds were generally lower than those of the legacy PFASs, with maximum levels reaching 70.3 μg/kg wet weight compared to 4,640 μg/kg wet weight for legacy PFASs, their presence raises important questions about their long-term environmental impact and safety.

Otters as Environmental Sentinels

The use of Eurasian otters as sentinel species in this study underscores their value in monitoring environmental health and the effectiveness of pollution mitigation strategies. Otters, being apex predators in freshwater ecosystems, accumulate contaminants from their prey, making them excellent indicators of pollution levels.

The findings highlight the need for continued monitoring of PFASs in the environment to assess the effectiveness of regulatory measures and to understand the persistence and spread of both legacy and replacement PFASs. The lower concentrations of replacement PFASs observed in this study likely reflect their more recent introduction and potentially lower bioaccumulation potential compared to legacy compounds. However, their long-term effects remain largely unknown.

The Road Ahead

The ongoing use and environmental release of PFASs pose a significant threat to both ecosystems and human health. The persistence of PFOA near its historical production site, despite being phased out, illustrates the long-lasting impact these chemicals can have. As industries shift to replacement PFASs, comprehensive research is essential to understand their fate, toxicity, and bioaccumulation potential.

This study serves as a critical reminder of the importance of stringent environmental regulations and proactive measures to limit PFAS contamination. Without proper control, the continued use of these chemicals will inevitably lead to increased exposure for wildlife and humans alike. As we move forward, it is crucial to balance industrial advancements with environmental and public health protection to ensure a sustainable future.

For more information on this study, please refer to the original research article published in Environmental Science & Technology.

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