Enrichment of perfluoroalkyl substances in the sea-surface microlayer and sea-spray aerosols in the Southern Ocean

• Published in: Environmental Pollution
• Main Authors: Casas, Gemma, Martínez-Varela, Alicia, Roscales, José L., Vila-Costa, Maria, Dachs, Jordi, Jiménez, Begoña
• Other Authors: Ministerio de Economía y Competitividad (España), Generalitat de Catalunya
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Elsevier 2020
• Subjects: Perfluoroalkyl substances; Sea-surface microlayer; Antarctica; Sea-spray aerosol; Organic pollutants; Southern ocean; Livingston Island; South Bay; Southern Ocean; Antarc*
• Online Access: http://hdl.handle.net/10261/220976; https://doi.org/10.1016/j.envpol.2020.115512; https://doi.org/10.13039/501100002809; https://doi.org/10.13039/501100003329

The accumulation of Perfluoroalkyl substances (PFAS) in the SML and their enrichment in SSA is consistent with marine aerosols as a vector for PFAS transport.Sea-spray (or sea-salt) aerosol (SSA) formation and their subsequent atmospheric transport and deposition have been suggested to play a prominent role in the occurrence of ionizable perfluoroalkyl substances (PFAS) in the maritime Antarctica and other remote regions. However, field studies on SSA's role as vector of transport of PFAS are lacking. Following a multiphase approach, seawater (SW), the sea-surface microlayer (SML) and SSA were sampled simultaneously at South Bay (Livingston Island, Antarctica). Average PFAS concentrations were 313 pg L, 447 pg L, and 0.67 pg m in SW, the SML and SSA, respectively. The enrichment factors of PFAS in the SML and SSA ranged between 1.2 and 5, and between 522 and 4690, respectively. This amplification of concentrations in the SML is consistent with the surfactant properties of PFAS, while the large enrichment of PFAS in atmospheric SSA may be facilitated by the large surface area of SSA and the sorption of PFAS to aerosol organic matter. This is the first field work assessing the simultaneous occurrence of PFAS in SW, the SML and SSA. The large measured amplification of concentrations in marine aerosols supports the role of SSA as a relevant vector for long-range atmospheric transport of PFAS. the mass of PFAS and Naþin SSA are in line with reported mea-surements. Such large enrichment factors in SSA have also beendescribed for experiments simulating the formation of SSA underlaboratory conditions (Reth et al., 2011). Underfield conditions,Casal et al. (2017a,2017b)has shown that the profile of PFCA inAntarctic fresh snow is particularly enriched with long-chain PFCA,consistent with the results reported here of high EFSSAfor PFOA,PFNA and PFDA. As snowflakes scavenge aerosols during deposi-tion, the large concentrations of PFAS in SSA are consistent withsnow deposition being a relevant source of PFAS in cold ...