Forever chemicals contamination found on the rise in firn, the accumulated snow layer
(Sustainabilityenvironment.com) – Chemical contamination has come to affect even the most remote regions of the Planet, such as Antarctica: these are the results of the study “Increasing Accumulation of Perfluorocarboxylate Contaminants Revealed in an Antarctic Firn Core (1958-2017)“ of the University of Lancaster in collaboration with the British Antarctic Survey and the German Hereon Institute of Coastal Environmental Chemistry and published in the journal Environmental Science & Technology. Research has shown an increase in contamination by forever chemicals, fluorinated toxic chemicals that are highly stable and therefore difficult to degrade. The increase in the presence of these pollutants would have resulted from the substitution of CFCs, chemical compounds containing chlorine, fluorine and carbon, in recent decades, due to their environmental impacts.
The survey analyzed the firn, the layer of compacted snow preserved from past seasons, of the plateau of Dronning Maud Land in eastern Antarctica: the results showed a historical record of accumulation of chemical pollutants between 1957 and 2017, increasing in recent decades.
Forever chemicals are substances that do not decompose in nature, among these we find products such as perfluorocarboxylicperfluoro carboxylicrally used in the production of non-stick, water-repellent and fire-fighting coatings. One of the best known is perfluorooctanoic acid (PFOA), which can accumulate in food and enter the human body with negative health consequences that can lead to impairment of the immune system and infertility.
Markus Frey of the British Antarctic Survey commented: “This is another example of the fact that, despite its extreme remoteness, man-made pollution reaches the Antarctic continent and is then stored in snow and ice, and allows us to establish a history of global air pollution and the effectiveness of mitigation measures”.
Contamination by forever chemicals in Antarctica
The most abundant substance found is perfluorobutanoic acid (PFBA), a short-chain compound whose presence increased significantly from 2000 to 2017.
According to Professor Crispin Halsall of Lancaster University, this increase can be explained by the substitution of long-chain products such as PFOA, which are considered dangerous for health, with short-chain products such as PFBA. The passage was decreed in 1987 by the Montreal Protocol, a global agreement that provided for the gradual elimination of all chemicals that reduced the earth’s stratospheric ozone layer.
The analysis of snow samples was carried out by Dr Jack Garnett, who commented on this passage: “The Montreal Protocol has certainly provided enormous benefits and protection to ozone, climate and all of us. However, the wider environmental and toxicological impact of some of these replacement chemicals is still unknown“.
From the analysis of the different layers of snow, scientists have found that it is possible to test the increase of PFOA from the mid-80’s, but that there is no such decline as to be consistent with the elimination of these substances from global industrial production. This may reveal that there has been no real stop in their production or that, despite the arrest, their volatile precursors have remained concentrated in the atmosphere.
The causes of contamination in Antarctica
According to the team, it is the fact that the substances found derive from volatile precursors released from production sites that have remained suspended in the atmosphere, degrading by sunlight, to form the most resistant PFCA. With the passage of time and the accumulation of layers of snow, the contaminants would then be trapped in the snowpack.
The results of the study are consistent with the estimates of chemical emissions of PFCA and give us a global picture of how these products move in the atmosphere, confirming the increase in their presence in the Arctic as well as in the Tibetan plateau.
Dr Anna Jones, director of the British Antarctic Survey, said: “These findings remind us that our industrial activities have global consequences. Antarctica, so far from industrial processes, contains this signal of human activity from emissions thousands of miles away. The snow and ice of Antarctica are critical archives of our impact on the Planet”.
