Sea Spray Aerosol (SSA) as a Source of Perfluoroalkyl Acids (PFAAs) to the Atmosphere: Field Evidence from Long-Term Air Monitoring.

Bo Sha,Ian T Cousins,Matthew E Salter,Pernilla Bohlin-Nizzetto,Peter Tunved,Jana H Johansson

doi:10.1021/acs.est.1c04277

Abstract

The effective enrichment of perfluoroalkyl acids (PFAAs) in sea spray aerosols (SSA) demonstrated in previous laboratory studies suggests that SSA is a potential source of PFAAs to the atmosphere. In order to investigate the influence of SSA on atmospheric PFAAs in the field, 48 h aerosol samples were collected regularly between 2018 and 2020 at two Norwegian coastal locations, Andøya and Birkenes. Significant correlations (p < 0.05) between the SSA tracer ion, Na+, and PFAA concentrations were observed in the samples from both locations, with Pearson’s correlation coefficients (r) between 0.4–0.8. Such significant correlations indicate SSA to be an important source of atmospheric PFAAs to coastal areas. The correlations in the samples from Andøya were observed for more PFAA species and were generally stronger than in the samples from Birkenes, which is located further away from the coast and closer to urban areas than Andøya. Factors such as the origin of the SSA, the distance of the sampling site to open water, and the presence of other PFAA sources (e.g., volatile precursor compounds) can have influence on the contribution of SSA to PFAA in air at the sampling sites and therefore affect the observed correlations between PFAAs and Na+.

Highlights

Perfluoroalkyl acids (PFAAs), including perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkanesulfonic acids (PFSAs), are a group of persistent organic contaminants that have been found worldwide in abiotic environments, biota, and humans.[1−9] Long-range atmospheric transport is considered to substantially contribute to the ubiquitous presence of PFAAs,[3,10] especially in remote areas such as the Arctic and Antarctic
perfluorooctanoic acid (PFOA) transported via sea spray aerosols (SSA) since they are closer to open water (Andøya ∼1.3 km and Zeppelin ∼ 2km) than Alert (∼4 km from the coast and the surrounding water was covered by sea ice for most of the year).[21]
C7−C12 PFCAs were frequently detected in samples from both Andøya (n = 57) and Birkenes (n = 58), with detection frequencies > 50%

Summary

INTRODUCTION

Perfluoroalkyl acids (PFAAs), including perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkanesulfonic acids (PFSAs), are a group of persistent organic contaminants that have been found worldwide in abiotic environments, biota, and humans.[1−9] Long-range atmospheric transport is considered to substantially contribute to the ubiquitous presence of PFAAs,[3,10] especially in remote areas such as the Arctic and Antarctic. PFOA transported via SSA since they are closer to open water (Andøya ∼1.3 km and Zeppelin ∼ 2km) than Alert (∼4 km from the coast and the surrounding water was covered by sea ice for most of the year).[21] the PFOS concentrations were not significantly different between the three Arctic stations.[21] It is hypothesized that, if SSA was an important source of PFAAs to the atmosphere, significant correlations between the concentrations of SSA tracer ions (e.g., Na+) and PFAAs should be observed in aerosol samples obtained in the marine atmosphere or at coastal locations where the atmospheric burden of SSA is highest. PFAAs and SSA tracer ions were measured in the same samples so that the correlations between the concentrations of PFAAs and SSA tracer ions could be determined to help improve our understanding of the importance of SSA as a source of PFAAs to the atmosphere

MATERIAL AND METHODS

RESULTS AND DISCUSSION

■ ACKNOWLEDGMENTS

■ REFERENCES