Toxicity Effects And Mechanism Of PFOS And Its Substitute F-53B On Earthworm And Wheat

Perfluoroalkyl substances(PFASs)are widely used in production and life due to their unique physical and chemical properties.Research has found that PFASs are a class of highly fluorinated persistent organic pollutants with characteristics such as bioaccumulation and toxicity,long-range migration ability,and difficulty in degradation.Perfluorooctane sulfonic acid(PFOS)is the most important PFASs,which is widely used in industry,leading to widespread detection in the environment and causing great harm to organisms,many countries and regions have restrictions on the use of PFOS.With the completion of the PFOS-related product elimination and restriction act,new PFOS alternatives have emerged.The 6:2 chlorinated perfluoroether sulfonate(F-53B)has a similar structure to PFOS and is a typical substitute for PFOS in industry.Research has shown that F-53 B is highly detectable in various environmental media,wild animals,and humans.F-53 B has received widespread attention due to its potential risks to the ecosystem.However,its toxic effects and mechanisms on soil invertebrates and crops are still unclear.This study conducted a comprehensive comparative study on the toxicity of F-53 B and PFOS to soil animals and plants,providing data support for the ecological and environmental risk assessment of new PFOS alternatives.In the study of the toxicity of F-53 B and PFOS to earthworms,it was found that the acute toxicity of F-53 B to earthworms is greater than that of PFOS.Both F-53 B and PFOS can lead to oxidative stress in earthworms,which can lead to increased activities of superoxide dismutase(SOD),peroxidase(POD),catalase(CAT),and malondialdehyde(MDA)levels.F-53 B can cause oxidative stress that is higher than that of PFOS.In transcriptomics and metabolomics studies,F-53 B and PFOS have been observed to have interference effects on various metabolic processes in earthworms,including protein digestion and amino acid absorption,lipid metabolism,and immune responses.Compared to PFOS,F-53 B has a weaker interference with lipid metabolism,a comparable interference with immune responses,and a stronger induction of extracellular matrix(ECM)destruction,apoptosis,and ferroptosis.Therefore,the results of this study indicate that F-53 B is more toxic to earthworms than PFOS,and these findings provide some new insights into the potential toxicity of F-53 B to soil organisms.This study investigated the toxic effects of F-53 B and PFOS on wheat germination and seedling growth.The experimental results showed that both F-53 B and PFOS significantly inhibited wheat germination.The changes in wheat germination rate,relative germination rate,germination potential,germination inhibition rate,relative root elongation,and seed vigor index confirmed that both F-53 B and PFOS caused wheat seed germination toxicity,among which,compared to PFOS,F-53 B had a stronger toxic effect on wheat germination;F-53 B and PFOS have significant inhibitory effects on the growth of wheat seedlings,especially on root growth.In addition,exposure to F-53 B and PFOS resulted in an increase in chlorophyll and malondialdehyde(MDA)content,a decrease in anthocyanin content,in wheat seedling.These results indicate that F-53 B and PFOS can cause photosynthesis disorders,oxidative stress,and lipid peroxidation in wheat seedlings;both F-53 B and PFOS caused changes in SOD,POD,and CAT in wheat seedlings,and F-53 B induced higher oxidative stress than PFOS.Metabolomic analysis showed that the toxic mechanisms of F-53 B and PFOS on wheat seedlings were different.The toxicity of PFOS was mainly manifested as amino acid metabolism interference,while F-53 B mainly caused lipid metabolism interference.In conclusion,compared with PFOS,F-53 B has a stronger toxic effect on wheat seed germination and seedling growth.