Identification And Compound-Contamination Risk Assessment Of PFAS Characteristic Pollution Factors In Aquatic Products

PFAS（per-and polyfluoroalkyl substances）is a new class of pollutants（Emerging Contaminants,ECs）.PFAS has high bond energy C-F bond,strong thermal,and chemical stability,resulting in widespread,persistent,high bioaccumulation and various physiological toxicity.As the sink of many pollutants,the water environment often accumulates more PFAS.The aquatic organisms in the water environment not only have a complex living environment,but also have a high bioaccumulation effect on PFAS.Herein,the content of PFAS in aquatic products is generally higher than that of other foods,which has potential risks to ecological security and human health.PFAS will cause adverse effects on aquatic products,marine ecology,and human health.However,the lack of research on the identification of characteristic pollution factors and the risk assessment of combined pollution of multi-component PFAS in aquatic products restricts the safety supervision and effective prevention and control of PFAS.Therefore,this study can simultaneously realize the three technical capabilities of accurate detection of multiple residues of PFAS in aquatic products,non-targeted screening,and structural analysis through the construction of PFAS high-throughput monitoring information database.The characteristic pollution factors of PFAS in aquatic products were accurately identified with the monitoring information database as the technical support.Further,the combined toxic effects of multiple exposure of several characteristic pollution factors and the dietary exposure risk assessment were analyzed through biological experiments.Obtained results were as follows:（1）Using Django+My SQL model to write software.The construction of PFAS high-throughput monitoring information database in aquatic products was completed with compound,classification,and mass spectrometry detection parameters as the core content.A solid phase extraction（SPE）column was assembled with DUT-5-2 as adsorbent for enrichment and purification.A rapid analytical method for the determination of multicomponent PFAS in drinking water was established based on the simultaneous qualitative and quantitative function of liquid chromatography-tandem quadrupole/linear ion trap mass spectrometry.At the same time,a high throughput screening technique for aquatic organisms was established,and 133 PFAS compounds can be quickly screened.The high-throughput monitoring information base of PFAS takes compound structure information as the core content and monitoring information of the above detection technology as the supplement.It also has the information input,search,expansion,visualization,and other basic functions.The scientific management of monitoring information of emerging contaminants in aquatic products is realized.（2）The current study monitored a survey of 23 PFAS in 1,049 aquatic products from the coasts of the Yellow-Bohai Sea in China to comprehensively investigate the concentrations and distributions of PFAS.PFOA,PFOS,PFNA,PFOSA,PFHx S,and PFUd A were more predominantly detected than other PFAS in all samples,dominating PFAS patterns in aquatic products.The mean levels of∑PFAS in different species followed the order:marine shellfish>marine crustaceans>fish>cephalopods>sea cucumber.Profiles of PFAS differ between species,suggesting species-specific accumulation plays a role.Various aquatic species are potential environmental bioindicators that signal individual PFAS contamination.For instance,clams can act as a potential PFOA bioindicator.High∑PFAS levels in some sites（such as Binzhou,Dongying,Cangzhou,and Weifang）could be attributed to industrial activities involving fluoropolymer manufacture.The differences between PFAS concentrations and profiles in aquatic products across the study regions have been proposed as PFAS fingerprints of the Yellow-Bohai Sea coasts.Analyses of principal components and Spearman correlations indicated that the precursor biodegradation possibly contribute to C₈-C₁₀PFCAs in the study samples.（3）Mussels were exposed to 4 PFAS characteristic pollution factors（PFOA,PFNA,PFHx S,and PFOS）,and the combined toxicity effects and dietary exposure risk were analyzed.The results showed that there were great differences between the accumulation and metabolism of PFAS in mussels under the single exposure of PFOA,PFOS,and the combined exposure of 4 PFAS.The combined exposure of PFOA,PFNA and PFHx S could significantly inhibit the accumulation of PFOS.Comprehensive analysis of the effects of mussels on the oxidative stress and histopathological damage of PFAS on mussel visceral mass and gill were performed.The results showed that exposure to PFOS,PFOA single component,and combined stress of four PFAS can cause oxidative stress damage and histopathological damage to mussels.Moreover,the oxidative stress damage to mussels was more serious under the combined exposure stress of 4 PFAS.Dietary exposure risk assessments for 4 PFAS characteristic contamination factors in actual samples of mussels showed that the health risks associated with current contamination levels in mussels remained low.