Toxicity of per- and polyfluoroalkyl substances to aquatic vertebrates

Abstract

Rapid industrial development and extensive use of chemicals have resulted in elevated concentrations of emerging contaminants worldwide, posing a substantial threat to the ecological environment and human health. Per- and polyfluoroalkyl substances (PFASs) have been recognized as emerging pollutants that are widely distributed and accumulated in the environment and they have drawn the attention of scholars for several decades. The variety, long-term use, and long-distance transmission of PFASs have resulted in the ubiquitous contamination of global ecosystems, especially in aquatic environments. Ever since perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were added to the Stockholm Convention on Persistent Organic Pollutants (POPs), they have become the most typical, eye-catching, and frequently investigated PFASs. Owing to the high stability and bioaccumulation of PFASs, as well as the adverse impact on the endocrine, immune, and nervous systems, investigating their contamination levels, risk of transfer along the food chain, and ecotoxicity should be prioritized. In addition to the important evolutionary significance as primitive vertebrates and the main consumers of aquatic environment, fishes generally exist in various aquatic food chains from the bottom to the top and occupy a critical position in terms of aquatic ecology protection; while amphibians, as the key link from aquatic to terrestrial organisms, are highly sensitive to different environmental pollutants. This review is a comprehensive summary of the toxic effects and toxicity-related factors of PFASs on aquatic vertebrates, mainly Pisces and Amphilla organisms, the characteristics of different aquatic vertebrates in toxicity investigations, and the evaluation of the feasibility of PFASs substitute applications.

Per- and Polyfluoroalkyl Substances: Impacts on Morphology, Behavior and Lipid Levels in Zebrafish Embryos

“…Yang et al [85] saw similar disruptions to PC and PE levels in zebrafish embryos exposed to PFOA and PFAS and indicated that this dysregulation could result in oxidative stress with impacts on developmental malformations similar to those seen in this study. Perturbations in PC levels have been shown to effect proper cognitive function [106], and oxidative stress and reactive oxygen species have been linked to impaired swim bladder inflation in zebrafish exposed to PFAS and other toxic chemicals [107,108]. Furthermore, PFASs have been implicated in disruptions to proper thyroid function, which can affect proper swim bladder formation and disrupt lipid metabolism [31,[109][110][111] While this study found PFOS, PFOA, and PFHxS to generally decrease levels of lipids in 120 hpf zebrafish embryos, the impacts on lipids in developing zebrafish embryos from these chemicals are complex.…”

Combining Passive Sampling and Dosing to Unravel the Contribution of Hydrophobic Organic Contaminants to Sediment Ecotoxicity

“…Sediments are frequently the most contaminated environmental compartment, harboring complex mixtures of (un)­known contaminants. − The high cost management decisions on large-scale remediation, removal, relocation, and incineration of contaminated sediment should be well informed by adequate risk assessment. To isolate a specific part of the chemical stressors, the presently developed PSPD test sampled hydrophobic organic toxicants from a series of contaminated sediments which were dosed to an aqueous bioassay with larvae of the nonbiting midge C.…”

Toxicity of Per- and Polyfluoroalkyl Substances to Nematodes

“…Additionally, D. rerio , with human genetic similarities as high as 87%, is the second-most-used animal model in medical sciences and life research, as it is an excellent vertebrate model for estimating the toxicity of chemicals with substantial advantages [ 61 ]. The toxic effects of PFASs on zebrafish have been studied for many years, revealing more extensive effects on the reproductive, developmental, cellular structure, neurologic, oxidative, metabolic, immune, and endocrine systems [ 62 , 63 , 64 ] than those achieved using C. elegans . Moreover, juvenile dietary exposure of D. rerio to PFASs could induce multigenerational behavioral effects similar to those observed in C. elegans [ 64 ].…”

“…Current studies on PFASs are primarily focused on macroscopic indicators (survival, body weight, and avoidance behavior) [ 67 , 68 ], reproductive disruption [ 67 ], molecular responses (enzyme activity and DNA damage), metabolic responses [ 68 ], and combined toxicity with other pollutants [ 69 ]. In the toxicity evaluation of PFOS and its alternatives, such as perfluorinated butyl organic ammonium salt cationic surfactant, textile finishing agent, C4 finishing agent, and C6 finishing agent, F. candida showed a higher sensitivity to the toxicity of the alternatives than Gobiocypris rarus , even when the cultivation time was longer [ 62 , 70 , 71 ]. Nevertheless, the indicator screening, sensitivity, and adept systems of different soil species should be compared.…”