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Levels of ‘forever chemicals’ reaching Antarctica have been increasing

Levels of 'forever chemicals' reaching Antarctica have increased

Take a firn core sample. Credit: Dr. Markus Frey, British Antarctic Survey

New evidence from Antarctica shows that toxic ‘fluorinated forever chemicals’ have increased significantly in the remote environment in recent decades and scientists think CFC substitutions could be one of the possible sources.

Chemicals such as perfluorocarboxylic acids (PFCAs) are known as always chemicals because they do not break down naturally in the environment. They have a wide range of uses, such as in making non-stick pans, water repellents for clothing and in fire retardants. fighting foam. One of these chemicals, perfluorooctanoic acid (PFOA), builds up in food webs and is toxic to people associated with immune system damage and infertility.

In this new study, published by the journal Environmental Science and Technologyand led by scientists from Lancaster University along with researchers from the British Antarctic Survey and the Hereon Institute of Coastal Environmental Chemistry, Germany, firn (snow) cores were taken from the extremely remote, high and glacial Dronning Maud Land plateau in the east of Antarctica.

The cores, which set a historic record between 1957 and 2017, provide evidence that levels of these chemical pollutants have seen marked increases in Antarctica’s remote snowpack in recent decades.

By far the most discovered chemical was the shorter-chain compound, perfluorobutanoic acid (PFBA). The concentrations of this chemical in the snow cores increased significantly from around the year 2000 until the core was ingested in 2017.

Professor Crispin Halsall of the University of Lancaster, who led the study, believes that this increase could be partly explained by a switch of global chemical manufacturers about 20 years ago from producing long-chain chemicals such as PFOA to shorter-chain compounds. , such as PFBA due to health problems associated with human exposure to PFOA.

dr. Jack Garnett, who conducted the chemical analysis of the snow samples, added that “the large increase in PFBA observed from the core, particularly over the past decade, suggests that there is a different global source of this chemical than know that some of the chemicals that replace the older ozone-depleting substances such as CFCs and HCFCs, such as the hydrofluoroethers, are produced in large quantities worldwide as refrigerants, but can break down in the atmosphere to form PFBA.”

“The Montreal Protocol has certainly delivered tremendous benefits and protection for the ozone layer, the climate and for all of us. However, the broader environmental and toxicity impact of some of these substitute chemicals is still unknown.”

PFOA shows an increase in snow core from the mid-1980s, but with no evidence of a decrease in more recent years to match the global industrial phase-out of this chemical. This indicates that the production of PFOA has been maintained or that volatile precursors of this chemical have remained high in the global atmosphere.

The researchers behind the study believe the chemicals are likely reaching Antarctica through the release of volatile “precursor” chemicals into the atmosphere at industrial manufacturing sites. These precursors float in the global atmosphere until they finally break down in the presence of sunlight to form the more persistent PFCAs.

Successive snowfalls over the years have deposited these chemicals from the atmosphere, leading to a historic record of global contamination now trapped in the snowpack.

The results, which are consistent with modeled estimates of PFCA chemical emissions, further add to the evidence showing an increase in these ever-present chemicals in the Arctic and Tibetan Plateau and help provide a global picture and better understanding of how chemicals like these are transported in the atmosphere.

dr. Anna Jones, scientific director of the British Antarctic Survey, says that “these findings are a sobering reminder that our industrial activities have global impacts. Antarctica, so far removed from industrial processes, has this next signal of human activity due to emissions of thousands from miles away. Antarctica’s snow and ice are critical records of our evolving impact on our planet.”

dr. Markus Frey, scientist with the British Antarctic Survey and co-author of the report, says that “this is another example that despite its extreme remoteness, man-made pollution reaches the Antarctic continent and is then archived in snow and ice, which allows us to establish a history of global air pollution and the effectiveness of mitigation measures.”


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More information:
Jack Garnett et al, Increasing Accumulation of Perfluorocarboxylate Impurities Revealed in an Antarctic Firn Core (1958-2017), Environmental Science and Technology (2022). DOI: 10.1021/acs.est.2c02592

Provided by Lancaster University


Quote: Levels of ‘forever chemicals’ reaching Antarctica have increased (2022, July 28) retrieved July 28, 2022 from https://phys.org/news/2022-07-chemicals-antarctica.html

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