Levels and Seasonal Trends of C 1 –C 4 Perfluoroalkyl Acids and the Discovery of Trifluoromethane Sulfonic Acid in Surface Snow in the Arctic

• Main Authors: Maria K. Björnsdotter (7410536), William F. Hartz (11705533), Roland Kallenborn (2521792), Ingrid Ericson Jogsten (11705536), Jack D. Humby (11705539), Anna Kärrman (1461370), Leo W. Y. Yeung (7410539)
• Format: Other Non-Article Part of Journal/Newspaper
• Language: unknown
• Published: 2021
• Subjects: Biophysics; Microbiology; Cell Biology; Ecology; Sociology; Inorganic Chemistry; Environmental Sciences not elsewhere classified; Biological Sciences not elsewhere classified; Chemical Sciences not elsewhere classified; highly persistent chemicals; 79 – 16; 22 – 1800; 19 – 170; trifluoromethane sulfonic acid; subsequent degradation plays; remote arctic locations; wave solar radiation; perfluoroalkyl carboxylic acids; including samples collected; 4 </ sub; solar radiation; perfluoroalkyl acids; trifluoroacetic acid; atmospheric degradation; norwegian arctic; arctic environments; volatile precursors; transport mechanism; surface snow; seasonal variation; seasonal trends; range processes; major role; globally distributed; findings suggest; downward short; consequential deposition; atmospheric transport; Arctic; Spitsbergen
• Online Access: https://doi.org/10.1021/acs.est.1c04776.s001

C 1 –C 4 perfluoroalkyl acids (PFAAs) are highly persistent chemicals that have been found in the environment. To date, much uncertainty still exists about their sources and fate. The importance of the atmospheric degradation of volatile precursors to C 1 –C 4 PFAAs were investigated by studying their distribution and seasonal variation in remote Arctic locations. C 1 –C 4 PFAAs were measured in surface snow on the island of Spitsbergen in the Norwegian Arctic during January–August 2019. Trifluoroacetic acid (TFA), perfluoropropanoic acid (PFPrA), perfluorobutanoic acid (PFBA), and trifluoromethane sulfonic acid (TFMS) were detected in most samples, including samples collected at locations presumably receiving PFAA input solely from long-range processes. The flux of TFA, PFPrA, PFBA, and TFMS per precipitation event was in the ranges of 22–1800, 0.79–16, 0.19–170, and 1.5–57 ng/m 2 , respectively. A positive correlation between the flux of TFA, PFPrA, and PFBA with downward short-wave solar radiation was observed. No correlation was observed between the flux of TFMS and solar radiation. These findings suggest that atmospheric transport of volatile precursors and their subsequent degradation plays a major role in the global distribution of C 2 –C 4 perfluoroalkyl carboxylic acids and their consequential deposition in Arctic environments. The discovery of TFMS in surface snow at these remote Arctic locations suggests that TFMS is globally distributed. However, the transport mechanism to the Arctic environment remains unknown.