Prevalent Per- and Polyfluoroalkyl Substances (PFASs) Pollution in Freshwater Basins in China: A Short Review.

Abstract

Organic pollutants like per- and polyfluoroalkyl substances (PFASs) exhibit persistence, bioaccumulation, resistance to degradation, and high toxicity, garnering significant attention from scholars worldwide. To better address and mitigate the environmental risks posed by PFASs, this paper employs bibliometric analysis to examine the literature on PFASs' concentrations collected in the Web of Science (WoS) database between 2019 and 2024. The results show that the overall trend of PFASs' pollution research is relatively stable and increasing. In addition, this study also summarizes the pollution status of traditional PFASs across different environmental media in typical freshwater basins. It analyzes PFASs' concentrations in surface water, sediment, and aquatic organisms, elucidating their distribution characteristics and potential sources. While perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) levels in water environments are declining annually, short-chain PFASs and their substitutes are emerging as primary pollutants. Short-chain PFASs are frequently detected in surface water, whereas long-chain PFASs tend to accumulate in sediments. In aquatic organisms, PFASs are more likely to concentrate in protein-rich organs and tissues. The environmental presence of PFASs is largely influenced by human activities, such as metal plating, fluoride industry development, and industrial wastewater discharge. Currently, the development of PFASs in China faces a complex dilemma, entangled by policy and legal constraints, industrial production demands, the production and use of new alternatives, and their regulation and restriction, creating a vicious cycle. Breaking this deadlock necessitates continuous and active scientific research on PFASs, particularly PFOS, with an emphasis on detailed investigations of environmental sources and sinks. Furthermore, ecological and health risk assessments were conducted using Risk Quotient (RQ) and Hazard Quotient (HQ) methods. Comprehensive comparison indicates that PFASs (such as PFOA) in the majority of freshwater basins are at a low-risk level (RQ < 0.1 or HQ < 0.2), PFOS in some freshwater basins is at a medium-risk level (0.1 < RQ < 1), and no freshwater basin is at a high-risk level. The adsorption and removal approaches of PFASs were also analyzed, revealing that the combination of multiple treatment technologies as a novel integrated treatment technology holds excellent prospects for the removal of PFASs.