Fate and effects of poly‐ and perfluoroalkyl substances in the aquatic environment: A review

Abstract

Polyfluoroalkyl and perfluoroalkyl substances (PFASs) are distributed ubiquitously in the aquatic environment, which raises concern for the flora and fauna in hydrosystems. The present critical review focuses on the fate and adverse effects of PFASs in the aquatic environment. The PFASs are continuously emitted into the environment from point and nonpoint sources such as sewage treatment plants and atmospheric deposition, respectively. Although concentrations of single substances may be too low to cause adverse effects, their mixtures can be of significant environmental concern. The production of C 8 -based PFASs (i.e., perfluorooctane sulfonate [PFOS] and perfluorooctanoate [PFOA]) is largely phased out; however, the emissions of other PFASs, in particular short-chain PFASs and PFAS precursors, are increasing. The PFAS precursors can finally degrade to persistent degradation products, which are, in particular, perfluoroalkane sulfonates (PFSAs) and perfluoroalkyl carboxylates (PFCAs). In the environment, PFSAs and PFCAs are subject to partitioning processes, whereby short-chain PFSAs and PFCAs are mainly distributed in the water phase, whereas long-chain PFSAs and PFCAs tend to bind to particles and have a substantial bioaccumulation potential. However, there are fundamental knowledge gaps about the interactive toxicity of PFAS precursors and their persistent degradation products but also interactions with other natural and anthropogenic stressors. Moreover, because of the continuous emission of PFASs, further information about their ecotoxicological potential among multiple generations, species interactions, and mixture toxicity seems fundamental to reliably assess the risks for PFASs to affect ecosystem structure and function in the aquatic environment.

Coupled production and emission of short chain perfluoroalkyl acids from a fast developing fluorochemical industry: Evidence from yearly and seasonal monitoring in Daling River Basin, China

“…Currently, research on the sources of PFAAs has mostly focused on sewage treatment plants, atmospheric deposition, aqueous firefighting foams used at military bases, airports, and fire training facilities, as well as other non-fluorochemical sources in those countries or regions with strict regulation on PFAAs production (Post et al, 2012;Ahrens and Bundschuh, 2014). However, in China the most important source of PFAAs comes directly from fluoropolymer/-telomer manufacture due to the production shift in recent years.…”

Mixture-specific gene expression in zebrafish ( Danio rerio ) embryos exposed to perfluorooctane sulfonic acid (PFOS), perfluorohexanoic acid (PFHxA) and 3,3′,4,4′,5-pentachlorobiphenyl (PCB126)

“…The selected concentrations are high when compared to environmental levels: PFOS and PFHxA in surface water have been reported from contaminated sites up to the low μg/L range (Ahrens and Bundschuh, 2014;Kärrman et al, 2011;Skutlarek et al, 2006) and PCB126 in the ng/L range (Ge et al, 2014). However, the focus of the present study was to gain understanding of changes in key-pathways altered by PCB126 when it is in combination with chemosensitizers such as PFOS and PFHxA.…”

“…Particularly, the 8-carbon perfluoroalkyls, perfluorooctanoic acid and perfluorooctane sulfonic acid (PFOS), have attracted most attention as these chemicals were extensively used in industrial applications and represent final degradation products of many PFASs. Consequently, they can be found at concentrations from the ng/L up to the µg/L in the environment (Ahrens and Bundschuh, 2014;Ahrens et al, 2009;Kannan et al, 2005;Kärrman et al, 2011;Skutlarek et al, 2006). In fish, they cause abnormal development, reduced offspring survival, and endocrine disruption (Ahrens and Bundschuh, 2014).…”

“…Consequently, they can be found at concentrations from the ng/L up to the µg/L in the environment (Ahrens and Bundschuh, 2014;Ahrens et al, 2009;Kannan et al, 2005;Kärrman et al, 2011;Skutlarek et al, 2006). In fish, they cause abnormal development, reduced offspring survival, and endocrine disruption (Ahrens and Bundschuh, 2014). The toxicity of PFOS is related to reactive oxygen species production, causing lordosis and pericardial edemas (Shi et al, 2008;Shi and Zhou, 2010;Zheng et al, 2011).…”

Fluorinated pyridinium and ammonium cationic surfactants

“…Additionally, alternative fluorinated materials, including surfactants, with improved environmental properties have been the subject of significant recent attention and review [15][16][17][18][19][20][21][22].…”