Fate of ‘forever chemicals’ in the global cryosphere

The cryosphere serves as a significant sink in the global circulation of organic pollutants. Among them, per- and polyfluoroalkyl substances (PFAS), known as “forever chemical”, are of great concern as their concentrations surpass the Earth's planetary safety boundary. In this review, we synthesize knowledge on the fate of PFAS in the cryosphere, focusing on their sources, accumulation, release process, and ecological effects. Long-range atmospheric transport leads to widespread of PFAS in the cryosphere, whereas local activities are primarily responsible for the regional PFAS pollution. Because of the wide replacements of the ozone-depleting chlorofluorocarbons after the Montreal Protocol, the ultra-short chain (C