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

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−1, 447 pg L−1, and 0.67 pg m−3 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. [Display omitted] •PFAS were measured in Southern Ocean seawater, surface microlayer and aerosols.•Enrichment factors of PFAS in the sea-surface microlayer ranged from 1.2 to 5.•Enrichment factors of PFAS in sea-spray aerosols ranged between 522 and 4690.•Sea-spray aerosols may be relevant for atmospheric long-range transport of PFAS. 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.