A new study reveals that the accelerating melting of Arctic ice is causing increased leakage of polyfluoroalkyl and perfluoroalkyl substances (PFAS), known as 'forever chemicals,' into the environment. PFAS are not native to the Arctic but are present due to their use in various human-made products. When released into the atmosphere, they become trapped in Arctic ice floes. The study found that the concentrations of PFAS in bulk sea ice are closely linked to the salinity of the water. This means that higher salinity leads to higher concentrations of these persistent chemicals.
As the planet warms, melting and freezing cycles form pockets of highly saline ocean water, where PFAS become concentrated. Eventually, these highly concentrated chemicals are released into the general circulation. The changing nature of sea ice, with earlier and irregular thawing periods, may affect the processing and release of pollutants, impacting the marine food web. PFAS are known to be toxic to humans and animals, and their release into the food chain raises concerns about their detrimental effects on organisms.
Previous studies have shown that PFAS concentrations in surface seawater near melting Arctic ice floes are up to twice as high as in the North Sea. Another study indicates that many of these chemicals enter the Arctic through snowfall on top of the ice. To investigate the release of PFAS in more detail, the researchers conducted controlled experiments using an artificial sea-ice chamber to measure the movement of chemicals between water and ice during phase shifts. They found that as the ice melts, the water carries a significant amount of PFAS, especially the shorter chain varieties. As the meltwater becomes fresher, the PFAS chains become somewhat longer.
The increasing prevalence of one-year ice in the Arctic Ocean, replacing older ice, is a concern. This younger ice contains more mobile brine that can interact with snow and further concentrate PFAS contaminants. Organisms at the bottom of the Arctic food chain, which rely on ice floes and consume brine channels, are at immediate risk of increased exposure to these chemicals.
The study is part of the EISPAC project (Effects of Ice Stressors and Pollutants on the Arctic marine Cryosphere), conducted by organizations from the UK and Germany. The research team calls for stricter regulations on using PFAS in the future. Further controlled experiments and observational studies are needed to understand these complex processes and the potential impact on organisms at the base of the marine food web.
Comments / 0