According to a new Antarctic study, the amount of ‘forever chemicals’ reaching the remote continent has been increasing. New evidence from Antarctica indicates that toxic ‘fluorinated forever chemicals’ have increased significantly in the remote environment in recent decades, and scientists believe CFC replacements are one of the likely sources.
Perfluorocarboxylic acids (PFCAs), also known as forever chemicals because they do not degrade naturally in the environment, have a wide range of applications, including nonstick coatings for pans, water repellents for clothing, and fire-fighting foams. Perfluorooctanoic acid (PFOA), one of these chemicals, bioaccumulates in foodwebs and is toxic to humans, with links to immune system impairment and infertility.
In this new study, led by scientists from Lancaster University in collaboration with researchers from the British Antarctic Survey and the Hereon Institute of Coastal Environmental Chemistry in Germany, firn (compacted snow) cores were taken from the extremely remote, high and icy Dronning Maud Land plateau of eastern Antarctica.
The cores, which provide a historic record between 1957 and 2017, show that levels of these chemical pollutants have increased significantly in Antarctica’s remote snowpack over the last few decades. By far the most abundant chemical discovered was perfluorobutanoic acid, a shorter chain compound. From around the year 2000 until the core was taken in 2017, concentrations of this chemical in snow cores increased significantly.
The large increase in PFBA observed from the core, particularly over the last decade, suggests there is an additional global source of this chemical other than polymer production. We do know that some of the chemicals replacing the older ozone-depleting substances like CFCs and HCFCs, such as the hydrofluoroethers, are produced globally in high quantities as refrigerants but can breakdown in the atmosphere to form PFBA.
Professor Crispin Halsall
Professor Crispin Halsall of Lancaster University, and who led the study, believes this increase can be partly explained by a switch by global chemicals manufacturers around 20 years ago from producing long-chain chemicals like PFOA to shorter-chain compounds, such as PFBA due to health concerns associated with human exposure to PFOA.
Dr. Jack Garnett who conducted the chemical analysis on the snow samples, added: “The large increase in PFBA observed from the core, particularly over the last decade, suggests there is an additional global source of this chemical other than polymer production. We do know that some of the chemicals replacing the older ozone-depleting substances like CFCs and HCFCs, such as the hydrofluoroethers, are produced globally in high quantities as refrigerants but can breakdown in the atmosphere to form PFBA.
“The Montreal Protocol certainly provided huge benefits and protection to the ozone, the climate and to us all. However, the wider environmental and toxicity impact of some of these replacement chemicals is still unknown.”
PFOA levels in the snow core have increased since the mid-1980s, but there has been no evidence of a decline in recent years to correspond with the global industry phase out of this chemical. This suggests that PFOA production has remained stable or that volatile precursors to this chemical have remained abundant in the global atmosphere.
The chemicals are most likely reaching Antarctica due to the release of volatile ‘precursor’ chemicals into the atmosphere at industrial manufacturing sites, according to the researchers behind the study. These precursors float around the world’s atmosphere, eventually degrading in the presence of sunlight to form the more persistent PFCAs.
Successive snowfall over the years has deposited these chemicals from the atmosphere resulting in a historical record of global contamination that is now trapped in the snow pack.
The findings, which are consistent with modelled estimates of PFCA chemical emissions, add to evidence that shows increases in these forever chemicals in the Arctic and Tibetan Plateau, as well as providing a global picture and a better understanding of how chemicals like these are transported in the atmosphere.
The British Antarctic Survey’s Director of Science, Dr. Anna Jones, stated: “These findings serve as a stark reminder that our industrial activities have global ramifications. This next signal of human activity comes from emissions thousands of miles away in Antarctica, which is so far removed from industrial processes. Antarctica’s snow and ice are vital archives of our changing impact on the planet.”
“This is another example that, despite its extreme remoteness, human-made pollution does reach the Antarctic continent and is then archived in snow and ice, which allows us to establish a history of global atmospheric pollution and the effectiveness of mitigation measures,” said Dr. Markus Frey, co-author of the report.
