There is good news from environmental research: the pollution of the oceans with so-called PFAS chemicals appears to be declining. As a recent study shows, the concentration of these pollutants in the bodies of pilot whales in the North Atlantic has fallen by around 60 percent from its peak level.
The results are based on analyses of tissue samples from the years 1986 to 2023. Liver and muscle samples from pilot whales (Globicephala melas) were examined. As toothed whales at the top of the marine food chain, they are considered important indicators of ocean pollution. The study was conducted by a research team from Harvard University and published in the scientific journal PNAS.
PFAS (per- and polyfluoroalkyl substances) have been produced industrially since the late 1940s. Because of their extremely stable carbon–fluorine bonds, they are also referred to as “forever chemicals.” They are used in numerous everyday and industrial products, such as cosmetics, coated cookware, textiles, firefighting foams, or electronic devices. Residues of these substances can be detected worldwide in the environment and in living organisms, including the human body.
Due to their proven health and environmental risks, particularly long-chain PFAS have been gradually banned since the early 2000s. The present study demonstrates that these measures are having an effect. Although four older-generation PFAS accounted for around three quarters of the measured organic fluorine compounds in whale tissue, levels declined significantly by 2023 after peaking in 2011.
The researchers deliberately refrained from measuring individual PFAS compounds. Instead, they determined the total amount of organic fluorine compounds, since newer PFAS alternatives with shorter chains are more difficult to detect. Modeling calculations also show that the time lag between bans and measurable declines is due to slow transport processes in the ocean.
“Stopping production—initially on a voluntary basis and later through legal regulations—has proven to be very effective in reducing the concentrations of these chemicals both near their sources and in distant ecosystems,” explains lead author Jennifer Sun.
The study thus provides a rare positive signal: consistent regulation of persistent pollutants can, in the long term, lead to a measurable reduction in contamination even in remote marine ecosystems.
Rosamaria Kubny, Polarjournal