Assessing the environmental occurrence of the anthropogenic contaminant trifluoroacetic acid (TFA)

Trifluoroacetic acid (TFA) is a very persistent contaminant that has gained attention due to its multitude of anthropogenic sources, widespread occurrence in the environment, and expected accumulation in (semi-)closed drinking water cycles. Here, we summarize and assess the current knowledge on the anthropogenic sources of TFA to better understand the human-induced environmental TFA burden and highlight future research needs. Formation of TFA from the degradation of volatile precursors leads to diffuse and ubiquitous contamination of the environment. The analyses of ice core and archived leaf records have undoubtedly demonstrated that atmospheric depositions of TFA have increased considerably over the last decades in the Northern Hemisphere. Moreover, many point sources of TFA have been identified, which can lead to contamination hotspots posing a potential threat to human and environmental health. Also, unintentional formation of TFA during per- and polyfluoroalkyl substance (PFAS) remediation might become a major secondary source of TFA.