Occurrence, partitioning and transport of perfluoroalkyl acids in gas and particles from the southeast coastal and mountainous areas of China

Perfluoroalkyl acids (PFAA) in gas and particles were analyzed in southeast coastal and mountainous cities, including Fuzhou, Xiamen, Zhangzhou and Nanping, to study the pollution characteristics, particle size distribution, phase partitioning and atmospheric transport. PFAA ranged from 7.8 to 290 pg m(-3) in gaseous phase, 27 - 1200 pg m(-3) in particulate phase, and perfluorobutanoic acid (PFBA), perfluorooctanoic acid (PFOA) were main compounds. PFAA had the highest concentration in Nanping with perfluorohexanoic acid (PFHxA) dominant, which could be related to the emission of PFAS from local industrial plants. Perfluorocarboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) exhibited different particle size distribution characteristics, with PFSAs preferring to distribute on coarse particles, which could be affected by the salt, minerals and organic matter in different particle sizes. The gas - particle partitioning coefficient (K-PA) had a line relationship with the fluorinated carbon chain length of PFAA, suggesting that long-chain PFAA tended to exist in particulate phase. The Winter Monsoon could transport to the study area and drive atmospheric PFAS to southern cities.

Automated summary

Gas and particle samples were collected from southeast coastal and mountainous cities in China to analyze the levels and characteristics of perfluoroalkyl acids (PFAA). PFAA concentrations varied in the ranges of 7.8-290 pg/m³ in gas phase and 27-1200 pg/m³ in particulate phase, with perfluorobutanoic acid (PFBA) and perfluorooctanoic acid (PFOA) being the dominant compounds. The study found that PFAA distribution was influenced by particle size and the length of fluorinated carbon chain, with PFSAs preferring to distribute on coarse particles and long-chain PFAA tending to exist in particulate phase. The Winter Monsoon was identified as a potential driver for atmospheric transport of PFAS to southern cities.