Microbial Plankton Responses to Perfluoroalkyl Acids and Their Alternatives in the Aquatic Environment

Perfluoroalkyl acid (PFAA) pollution of freshwaters has attracted a great deal of attention and poses a challenge to the restoration of river ecosystems. However, detailed studies on the impact of PFAAs and their alternatives on microbial plankton communities are lacking, and few studies have examined the adaptability of those communities to PFAAs. In this study, water samples were obtained from water bodies in the vicinity of the largest perfluorinated industrial park in Asia for comparative analysis. The spatial distribution of 19 PFAAs and 4 alternatives as well as their effect on microbial community structure were investigated through field sampling. The maximum total concentration of perfluoroalkyl carboxylic acids (PFCAs) at an industrial wastewater treatment plant was 2423.48 ng/L. The primary components included perfluorooctanoic acid (PFOA, 43.15%, 1045.82 ng/ L), perfluorohexanoic acid (PFHxA, 27.10%, 656.70 ng/L) and perfluorobutanoic acid (PFBA, 20.13%, 487.85 ng/L). The maximum total concentration of PFAA alternatives was 48.59 ng/L, with hexafluoropropylene oxide dimer acid (HFPO-DA) accounting for 97.43%. The microbial community was mainly composed of Proteobacteria, Actinobacteriota, Bacteroidota, and Cyanobacteria. While Verrucomicrobiota tolerated PFAAs, significant effects on microbial community structure were determined for PFCAs and PFSAs, albeit with clear differences. Short-chain PFAAs had a similar impact on the microbial community as the restricted long-chain PFAAs. Thus, our study demonstrated the potentially negative impact of PFAAs on the microbial plankton community in the natural environment and the combined effect of poor water quality. The result provides new directions for investigations of PFAA pollution in freshwater environments.