Potential sources and sediment-pore water partitioning behaviors of emerging per/polyfluoroalkyl substances in the South Yellow Sea

A review on the advancement in photocatalytic degradation of poly/perfluoroalkyl substances in water: Insights into the mechanisms and structure-function relationship

Poly/perfluoroalkyl substances (PFAS) are persistent organic pollutants and ubiquitous in aquatic environment, which are hazardous to organisms and human health. Several countries and regions have taken actions to regulate or limit the production and emission of some PFAS. Even though a series of water treatment technologies have been developed for removal of PFAS to eliminate their potential adverse effects, the removal and degradation performance are usually unsatisfactory. Photocatalytic degradation of PFAS is considered as one of the most effective approaches due to the mild operation conditions and environmental friendliness. This review systematically summarized the recent advances in photocatalytic degradation of PFAS based on heterogeneous photocatalysts, including TiO2-, Ga2O3-, In2O3-, ZnO-, Bi-based, and others. Overall, two mainly degradation mechanisms were involved, including photo-oxidation (involving the holes and oxidative radicals) and photo-reduction types (by e- and reductive radicals). The band structures of the photocatalysts, degradation pathways, structure-function relationship, and impacting factors were further discussed to elucidate the essential reasons for the enhanced degradation of PFAS. Furthermore, the review identified the major knowledge gaps to solve the issues of photocatalysis in real application. This paper also propounded several strategies to promote the design and optimization of high-efficient photocatalysts, and meet the challenges to remove PFAS through photodegradation technologies.

The investigation of the enrichment behavior of identified PFAS and unknown PFAA-precursors in water and suspended particulate matter of the surface microlayer: A case study in Tianjin (China)

The surface microlayer (SML) is an important air water interface layer, known as the skin of the ocean, which has chemical enrichment properties. Chemical enrichment in the SML can affect the occurrence of pollutants in the underlying water and air samples. Although the enrichment of per- and polyfluorinated substances (PFAS), a class of persistent organic pollutants of high concern, has been reported in the SML, information on the behavior of unknown PFAA-precursors in SML is lacked, and it is not clear whether there is a similar PFAS enrichment in suspended particulate matter (SPM) in the SML. Therefore, to investigate these questions, we conducted a systematic survey of 24 PFAS in 11 paired water and SPM samples from the SML and underlying water (U50cm and U2m) from the Duliujian River, which flows to the Bohai sea in Tianjin, China. The ∑PFAS mean concentrations in the water and SPM samples were 38.2 ng/L and 64.6 ng/g dw, respectively. The PFAS concentrations of PFAS in the SML were higher than those in the underlying water, and the enrichment factors (EFs) were greater in the SPM than that in the water. The long-chain PFAS EFs were greater than those for short-chain PFAS, indicating that the EFs were positively correlated with the hydrophobicity. Moreover, by applying the total oxidizable precursor (TOP) assay, the unknown PFAA-precursors (C5-C12) in the water and SPM contributed 11.4∼86.4 mol% and 7.1∼88.0 mol% to total PFAS, respectively. The ecological risk of the targeted PFAS in the SML was relatively higher than that in the underlying water, indicating that PFAS in the SML require more attention. Preliminary estimates indicate that the PFAS-enriched SML is an important exposure route that poses a potential risk to wildlife in rivers and oceans.

Legacy and emerging per- and polyfluoroalkyl substances (PFASs) in agricultural soils affected by fluorochemical manufacturing facilities, North China: Occurrence, region-specific distribution, substitution trend and source appointment

Accompanied with restriction of legacy per- and polyfluoroalkyl substances (PFASs), numbers of emerging PFASs are widely detected in the environment. However, information on environmental occurrences and behaviors of emerging PFASs were scarce in agricultural soils. In this study, the spatial distributions, sources, substitution trends and ecological risk assessment of 31 legacy and emerging PFASs were investigated in 69 agricultural soils from Fuxin, North China. The 26 out of 31 PFASs were detected with concentrations of 57.36 - 1271.06 pg/g dry weight. Perfluorooctanoic acid (PFOA) and hexafluoropropylene oxide dimer acid (HFPO-DA) were predominant in legacy and emerging PFASs, respectively. Based on principal component and dual carbon-nitrogen stable isotope analysis, atmosphere, fluorochemical activities and river irrigation were main sources of PFASs. Substitution trends indicated HFPO-DA and short chain perfluoroalkyl carboxylic acids (C4 - C7) as main alternatives of PFOA, and 6:2 fluorotelomer sulfonic acid (6:2 FTSA) and sodium p-perfluorous nonenoxybenzene sulfonate (OBS) as major substitutes to perfluorooctanesulfonic acid (PFOS). The calculated risk quotient values (< 0.006) only indicated potential low ecological risk of 7 target PFASs in agricultural soils. The results of this study broadened out the information of PFAS contamination in agricultural soils, which were significant for PFAS supervision in China.

Occurrence and prevalence of per- and polyfluoroalkyl substances in the sediment pore water of mariculture sites: Novel findings of PFASs from the Bohai and Yellow Seas using a newly established analytical method

A new method for the determination of 26 legacy and emerging per- and polyfluoroalkyl substances (PFASs) in marine sediment pore water was developed using online solid phase extraction coupled with liquid chromatography-tandem mass spectrometry. The proposed method requires only about 1 mL of pore water samples. Satisfactory recoveries of most target PFASs (83.55-125.30 %) were achieved, with good precision (RSD of 1.09-16.53 %), linearity (R2 ≥ 0.990), and sensitivity (MDLs: 0.05 ng/L-5.00 ng/L for most PFASs). Subsequently, the method was applied to determine PFASs in the sediment pore water of five mariculture bays in the Bohai and Yellow Seas of China for the first time. Fifteen PFASs were detected with total concentrations ranging from 150.23 ng/L to 1838.48 ng/L (mean = 636.80 ng/L). The ∑PFASs and PFOA concentrations in sediment pore water were remarkably higher than those in surface seawater (tens of ng/L), indicating that the potential toxic effect of PFASs on benthic organisms may be underestimated. PFPeA was mainly distributed in pore water, and the partition of PFHpA (50.99 %) and PFOA (49.01 %) was almost equal in the solid and liquid phases. The proportions of all other PFASs partitioned in marine sediments were significantly higher than those in pore water.

Angiotoxic effects of chlorinated polyfluorinated ether sulfonate, a novel perfluorooctane sulfonate substitute, in vivo and in vitro

Chlorinated polyfluorinated ether sulfonate (Cl-PFESA), a substitute for perfluorooctane sulfonate (PFOS), has been widely used in the Chinese electroplating industry under the trade name F-53B. The production and use of F-53B is keep increasing in recent years, consequently causing more emissions into the environment. Thus, there is a growing concern about the adverse effects of F-53B on human health. However, related research is very limited, particularly in terms of its toxicity to the vascular system. In this study, C57BL/6 J mice were exposed to 0.04, 0.2, and 1 mg/kg F-53B for 12 weeks to assess its impact on the vascular system. We found that F-53B exposure caused aortic wall thickening, collagen deposition, and reduced elasticity in mice. In addition, F-53B exposure led to a loss of vascular endothelial integrity and a vascular inflammatory response. Intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were found to be indispensable for this process. Furthermore, RNA sequencing analysis revealed that F-53B can decrease the repair capacity of endothelial cells by inhibiting their proliferation and migration. Collectively, our findings demonstrate that F-53B exposure induces vascular inflammation and loss of endothelial integrity as well as suppresses the repair capacity of endothelial cells, which ultimately results in vascular injury, highlighting the need for a more thorough risk assessment of F-53B to human health.

Constraining global transport of perfluoroalkyl acids on sea spray aerosol using field measurements

Perfluoroalkyl acids (PFAAs) are highly persistent anthropogenic pollutants that have been detected in the global oceans. Our previous laboratory studies demonstrated that PFAAs in seawater are remobilized to the air in sea spray aerosols (SSAs). Here, we conducted field experiments along a north-south transect of the Atlantic Ocean to study the enrichment of PFAAs in SSA. We show that in some cases PFAAs were enriched >100,000 times in the SSA relative to seawater concentrations. On the basis of the results of the field experiments, we estimate that the secondary emission of certain PFAAs from the global oceans via SSA emission is comparable to or greater than estimates for the other known global sources of PFAAs to the atmosphere from manufacturing emissions and precursor degradation.

Hepatotoxicity induced in rats by chronic exposure to F-53B, an emerging replacement of perfluorooctane sulfonate (PFOS)

A plethora of studies have shown the prominent hepatotoxicity caused by perfluorooctane sulfonate (PFOS), yet the research on the causality of F-53 B (an alternative for PFOS) exposure and liver toxicity, especially in mammals, is largely limited. To investigate the effects that chronic exposure to F-53 B exert on livers, in the present study, male SD rats were administrated with F-53 B in a certain dose range (0, 1, 10, 100, 1000 μg/L, eight rats per group) for 6 months via drinking water and the hepatotoxicity resulted in was explored. We reported that chronic exposure to 100 and 1000 μg/L F-53 B induced remarkable histopathological changes in liver tissues such as distinct swollen cells and portal vein congestion. In addition, the increase of cytokines IL-6, IL-2, and IL-8 upon long-term administration of F-53 B demonstrated the high level of inflammation. Moreover, F-53 B exposure was revealed to disrupt the lipid metabolism in the rat livers, mainly manifesting as the upregulation of some proteins involved in lipid synthesis and degradation, including ACC, FASN, SREBP-1c as well as ACOX1. These findings provided new evidence for the adverse effects caused by chronic exposure to F-53 B in rodents. It is crucial for industries, regulatory agencies as well as the public to remain vigilant about the adverse health effects associated with the emerging PFOS substitutes such as F-53 B. Implementation of regular monitoring and risk assessments is of great importance to alleviate environmental concerns towards PFOS alternatives exposure, and furthermore, to minimize the latent health risks to the public health.

Spatial distribution, isomer signature and air-soil exchange of legacy and emerging poly- and perfluoroalkyl substances

Widespread occurrences of various poly- and perfluoroalkyl substances (PFAS) in terrestrial environment calls for the growing interest in their transport behaviors. However, limited studies detected PFAS with structural diversity in tree barks, which reflect the long-term contamination in atmosphere and play a vital role in air-soil exchange behaviors. In this study, 26 PFAS congeners and typical branched isomers were investigated in surface soils and tree barks at 28 sites along the Taihu Lake, Taipu River, and Huangpu River. Concentrations of total PFAS in soils and tree barks were 0.991-29.4 and 7.99-188 ng/g dw, with PFPeA and PFDoA were the largest contributors in the two matrices. The highest PFAS levels were found in the Taihu Lake watershed, where textile manufacturing and metal plating activities highly prosper. With regard to the congener and isomer signatures, short-chain homologs dominated in soils (65.5%), whereas long-chain PFAS showed a major proportion in barks (41.9%). The composition of linear isomers of PFOS, PFOA and PFHxS implied that precursor degradation might be an important source of PFAS in addition to the 3M electrochemical fluorination (ECF). Additionally, the distance from the emission source, total organic carbon (TOC), logKOA and logKOW were considered potential influencing factors in PFAS distributions. Based on the multi-media fugacity model, about 71% of the fugacity fraction (ffs) values of the PFAS were below 0.3, indicating the dominant deposition from the atmosphere to the soil. The average fluxes of air-soil exchange for PFAS were -0.700 ± 11.0 ng/(m2·h). Notably, the estimated daily exposure to PFAS ranged from 9.57 × 10-2 to 8.59 × 10-1 ng/kg·bw/day for children and 3.31 × 10-2 to 3.09 × 10-1 ng/kg·bw/day for adults, suggesting low risks from outdoor inhalation and dermal uptake. Overall, results from distribution with structural diversity, air-soil exchange and preliminary risk assessment. This study provided in-depth insight of PFAS in multi-medium environment and bridged gaps between field data and policy-making for pollution control.

Emerging and legacy per- and polyfluoroalkyl substances in Daling River and its estuary, Northern China

Strict restriction on legacy per- and polyfluoroalkyl substances (PFASs) has caused a dramatic increase in production and usage of emerging PFASs over the last decades. However, the environmental behaviors of emerging PFASs is largely unknown in Daling River, Northern China. In this study, the potential sources, sediment-water partitioning and substitution trends of PFASs were investigated in overlying water and sediments from Daling River and its estuary. Perfluorooctane sulfonate and 6:2 fluorotelomer sulfonic acid were major compounds, and sodium p-perfluorous nonenoxybenzene sulfonate was first detected. Firefighting foam manufacturing and fluoropolymer production were the main sources of PFASs. Compared to legacy PFASs (C8), the emerging PFASs (C6 - C9) were more incline to distribute into overlying water. Substitution trends indicated 6:2 fluorotelomer sulfonic acid and hexafluoropropylene oxide trimer acid as the important alternatives of perfluorooctane sulfonate and perfluorooctanoic acid, respectively. The results were meaningful for understanding the environmental behaviors of emerging PFASs.

Structure-Related Thyroid Disrupting Effect of Perfluorooctanesulfonate-like Substances in Zebrafish Larvae

Chlorinated polyfluorooctane ether sulfonate (6:2 Cl-PFESA), hydrogenated polyfluorooctane ether sulfonate (6:2 H-PFESA), and chlorinated polyfluorooctanesulfonate (Cl-PFOS) share structural similarities with the regulated perfluorooctanesulfonate (PFOS), but their toxic potential is rarely known. Here, the thyroid disrupting potential of these four compounds in zebrafish larvae has been comparably investigated. PFOS, Cl-PFOS, and 6:2 Cl-PFESA were accumulated in the larvae at similar levels, approximately 1.3-1.6 times higher than 6:2 H-PFESA. Additionally, PFOS, Cl-PFOS, and 6:2 Cl-PFESA exhibited stronger disruption than 6:2 H-PFESA on genetic regulation, particularly concerning thyroid hormone (TH) activation and action and on TH homeostasis in both free and total forms of thyroxine (T4) and 3,5,3'-triiodothyronine (T3). These results indicate that chlorination or oxygen insertion does not substantially alter the thyrotoxicity of PFOS, but hydrogenation mitigates it. Molecular docking analysis and the luciferase reporter gene assay provided mechanistic perspectives that the PFOS-like substances could competitively replace THs to bind with TH plasma and membrane transporters, thereby disrupting TH transport and action, respectively. Moreover, they are also potent to disrupt TH synthesis and activation through Na+/K+-dependent transport of I- or competitive binding to the sites of deiodinases.

The sources and bioaccumulation of per- and polyfluoroalkyl substances in animal-derived foods and the potential risk of dietary intake

Per- and polyfluoroalkyl substances (PFAS) have attracted increasing attention due to their environmental persistence and potential toxicity. Diet is one of the main routes of human exposure to PFAS, particularly through the consumption of animal-derived foods (e.g., aquatic products, livestock and poultry, and products derived from them). This review summarizes the source, bioaccumulation, and distribution of PFAS in animal-derived foods and key influential factors. In most environmental media, perfluorooctanoic acid and perfluorooctane sulfonate are the dominant PFAS, with the levels of short-chain PFAS such as perfluorobutyric acid and perfluorohexane sulfonate surpassing them in some watersheds and coastal areas. The presence of PFAS in environmental media is mainly influenced by suspended particulate matter, microbial communities as well as temporal and spatial factors, such as season and location. Linear PFAS with long carbon chains (C ≥ 7) and sulfonic groups tend to accumulate in organisms and contribute significantly to the contamination of animal-derived foods. Furthermore, PFAS, due to their protein affinity, are prone to accumulate in the blood and protein-rich tissues such as the liver and kidney. Species differences in PFAS bioaccumulation are determined by diet, variances in protein content in the blood and tissues and species-specific activity of transport proteins. Carnivorous fish usually show higher PFAS accumulation than omnivorous fish. Poultry typically metabolize PFAS more rapidly than mammals. PFAS exposures in the processing of animal-derived foods are also attributable to the migration of PFAS from food contact materials, especially those in higher-fat content foods. The human health risk assessment of PFAS exposure from animal-derived foods suggests that frequent consumption of aquatic products potentially engender greater risks to women and minors than to adult males. The information and perspectives from this review would help to further identify the toxicity and migration mechanism of PFAS in animal-derived foods and provide information for food safety management.

Characterizing the long-term occurrence and anthropogenic drivers of per- and polyfluoroalkyl substances in surface water of the Rhine River

Per- and polyfluoroalkyl substances (PFAS) raise significant concerns due to their persistence, bioaccumulation potential, and toxicity to both ecosystems and human health. However, the long-term trends of PFAS in aquatic environments remain inadequately explored. In this study, we systematically assessed the spatiotemporal distribution, periodic fluctuations, source apportionment, and risk evaluation of 12 PFAS in the Rhine River based on the long-term measuring data collected from 2007 to 2019. The study revealed that the mean concentration and mass flux of total PFAS during this period were 32.83 ng L-1 and 6.36 × 104 μg s-1, declining at an annual rate of 3.70% and 3.82%, respectively. Wavelet analysis demonstrated that the most prominent periodic oscillation of PFAS was 40-60 months. Regarding the sources of PFAS, we employed the self-organizing map (SOM) and the positive matrix factorization (PMF) model for source apportionment. The results indicated that the primary sources of PFAS were agrochemical, pharmaceutical and textile industries, accounting for 38.1% of the total concentration. The contribution from household contamination, tannery industry, and coating materials has increased annually. In contrast, the share of electrochemical fluorination and chemical recycling has shown a continuous decline. The risk quotient (RQ) and hazard quotient (HQ) calculations for three age groups indicated that PFAS exposure did not pose a significant risk to ecological or human health. Implementing source-oriented mitigation strategies is crucial to effectively reduce the ecological and human health risks of PFAS in receiving waters.

Immunotoxicity and Transcriptome Analyses of Zebrafish (Danio rerio) Embryos Exposed to 6:2 FTSA

As a new alternative to perfluorooctane sulfonic acid (PFOS), 6:2 fluorotelomer sulfonic acid (6:2 FTSA) has been widely produced and used in recent years, and its concentration and frequency of detection in the aquatic environment and aquatic organisms are increasing. However, studies of its toxicity in aquatic biological systems are alarmingly scarce, and the relevant toxicological information needs to be improved. In this study, we investigated AB wild-type zebrafish (Danio rerio) embryos subjected to acute 6:2 FTSA exposure for immunotoxicity using immunoassays and transcriptomics. Immune indexes showed significant decreases in SOD and LZM activities, but no significant change in NO content. Other indexes (TNOS, iNOS, ACP, AKP activities, and MDA, IL-1β, TNF-α, NF-κB, TLR4 content) all showed significant increases. These results indicated that 6:2 FTSA induced oxidative stress and inflammatory responses in zebrafish embryos and exhibited immunotoxicity. Consistently, transcriptomics showed that genes involved in the MAPK, TLR and NOD-like receptor signaling pathways (hsp70, hsp701, stat1b, irf3, cxcl8b, map3k8, il1b, tnfa and nfkb) were significantly upregulated after 6:2 FTSA exposure, suggesting that 6:2 FTSA might induce immunotoxicity in zebrafish embryos through the TLR/NOD-MAPK pathway. The results of this study indicate that the safety of 6:2 FTSA should be examined further.

Mechanisms of propeller jet-induced migration, release, and distribution of perfluoroalkyl acids in sediment-water systems

Perfluoroalkyl acids (PFAAs) are continuously accumulated in surface sediments due to extensive and long-term application. However, the mechanisms through which disturbances induced by ship propeller jets at the riverbed cause secondary release of PFAAs from sediments remain unclear. In this study, the effects of different propeller rotational speeds on PFAA migration, release, and distribution in multiphase media were investigated by performing indoor flume experiments combined with particle tracking velocimetry. Moreover, key factors influencing PFAA migration and distribution were identified, and partial least squares regression (PLS) method was applied to develop quantitative prediction models of relationships among hydrodynamics, physicochemical parameters, and PFAA distribution coefficients. The total PFAA concentrations (ΣPFAAs) in overlying water under propeller jet action exhibited transient characteristics and hysteresis with time after the disturbance. In contrast, the ΣPFAAs in suspended particulate matter (SPM) exhibited an upward trend throughout the process with consistent characteristics. The spatial distribution trends of PFAAs in overlying water and SPM at different propeller rotational speeds featured vertical variability and axial consistency. Furthermore, PFAA release from sediments was driven by axial flow velocity (V_x) and Reynolds normal stress R_yy, while PFAA release from porewater was inextricably linked to Reynolds stresses R_xx, R_xy, and R_zz (p < 0.05). PLS regression models showed that variations in Vorticity, dissolved organic carbon, and pH influenced the decreases in PFAA distribution coefficients between SPM and overlying water (K_D-SW) as propeller rotational speed increased, except for very long-chain PFAAs (C > 10). The increases in PFAA distribution coefficients between sediment and porewater (K_D-SP) were mainly determined by physicochemical parameters of sediments, and the direct effect of hydrodynamics was relatively weak. Our study provides valuable information regarding the migration and distribution of PFAAs in multiphase media under propeller jet disturbance (both during and after disturbance).

Synthesis and characterization of PCN-222 metal organic framework and its application for removing perfluorooctane sulfonate from water

Poly- and perfluoro alkyl substances (PFAS) are a group of man-made, notoriously persistent, and highly toxic contaminants in the environment reported worldwide. Many adsorbents including granular activated carbon, graphene, biochar, zeolites, and clay minerals have been tested for PFAS removal from water, but most of these materials suffer from high cost and/or poor removal performance. Here, we synthesized, characterized, and examined the efficiency of PCN-222(Fe), a new porous metal organic framework (MOF) with high water stability, for adsorptive removal of a frequently occurring PFAS, perfluorooctane sulfonate (PFOS), from water. The adsorption isotherm and kinetic studies revealed high PFOS adsorption capacity of PCN-222 (2257 mg/g), with rapid PFOS removal rate (within 30 min). The structure of PCN-222 was unaffected in water in the pH range of 2-10 but disintegrated and lost its PFOS removal ability at pH > 10. The PFOS adsorption on PCN-222 was an endothermic reaction. Electrostatic attraction was a dominant mechanism for PFOS adsorption at < 1694 mg/g PFOS concentration, while hydrophobic interaction accompanied with hydrogen-bonding was responsible at ≥ 1694 mg/g PFOS concentration. The interlayer morphology of PCN-222 did not change due to increasing PFOS loading. The findings of this study demonstrated superior features of PCN-222 over other conventional adsorbents for its potential application in removing PFOS from contaminated water to reduce PFOS transfer from water to living organisms.

Hexafluoropropylene oxide trimer acid causes fibrosis in mice liver via mitochondrial ROS/cGAS-STING/NLRP3-mediated pyroptosis

Hexafluoropropylene oxide trimer acid (HFPO-TA) causes hepatotoxicity, however, its underlying mechanisms have not been conclusively determined. We investigated the effects of HFPO-TA on mice liver after 28 days of orally administered 0 or 0.5 mg/kg/d HFPO-TA. Administration of HFPO-TA induced mitochondrial ROS (mtROS) overexpression, cGAS-STING signaling activation, pyroptosis and fibrosis in mice liver. To determine the HFPO-TA-associated hepatotoxic mechanisms, mtROS, cGAS-STING signaling and pyroptosis intervention assays were performed in HFPO-TA-exposed mice liver. First, mtROS was found to be an upstream regulatory target of cGAS-STING signaling, pyroptosis and fibrosis. Second, cGAS-STING signaling was established to be an upstream regulatory mechanism of pyroptosis and fibrosis. Finally, pyroptosis was shown to regulate fibrosis. The above results confirm that HFPO-TA causes mice liver fibrosis via mtROS/cGAS-STING/NLRP3-mediated pyroptosis.

Direct evidence of the important role of proteins in bioconcentration and biomagnification of PFASs in benthic organisms based on comparison with OPEs

Despite the wide acceptance that bioconcentration and biomagnification of per/polyfluoroalkyl substances (PFASs) is related to proteins in organisms, few direct evidences are available. Here, bioconcentration and biomagnification of 9 organophosphate esters (OPEs) and 16 PFASs, which have similar range of log K_ow (octanol-water partitioning coefficient) values, were compared in the benthic food chain of biofilm-snail in Taihu Lake, China. The ∑OPEs level in water (150-23,036 ng/L) was significantly higher than ∑PFASs (57.3-351 ng/L). Although the logarithm of bioconcentration factors of both OPEs and PFASs in biofilm positively correlated with their log K_ow, the slope of PFASs was 4 times of that of OPEs, which might be due to the strong interactions of PFASs with biofilm extracellular proteins. Additionally, PFASs exhibited distinctly greater biomagnification factors from biofilm to snails (3.09-17.8) than OPEs (0.39-3.48). Significant correlations between the concentrations and protein contents in snails were observed for most long-chain PFASs, but not for any OPEs. Multiple receptor models identified polyurethane foam (77.9 %) and food packaging/metal plating (56.9 %) were the primary sources of OPEs and PFASs in Taihu Lake, respectively. We provided strong and direct evidences that proteins facilitated bioconcentration and biomagnification of PFASs.

Hexafluoropropylene oxide trimer acid (HFPO-TA) disturbs embryonic liver and biliary system development in zebrafish

Hexafluoropropylene oxide trimer acid (HFPO-TA), a novel alternative to perfluorooctanoic acid (PFOA), has emerged as a potential environmental pollutant. Here, to investigate the toxic effects of HFPO-TA on liver and biliary system development, zebrafish embryos were exposed to 0, 50, 100, or 200 mg/L HFPO-TA from 6 to 120 h post-fertilization (hpf). Results showed that the 50 % lethal concentration (LC₅₀) of HFPO-TA was 231 mg/L at 120 hpf, lower than that of PFOA. HFPO-TA exposure decreased embryonic hatching, survival, and body length. Furthermore, HFPO-TA exerted higher toxicity at the specification stage than during the differentiation and maturation stages, leading to small-sized livers in Tg(fabp10a: DsRed) transgenic larvae and histopathological changes. Significant decreases in the mRNA expression of genes related to liver formation were observed. Alanine transaminase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), and direct bilirubin (DBIL) levels were significantly increased. HFPO-TA decreased total cholesterol (TCHO) and triglyceride (TG) activities, disturbed lipid metabolism through the peroxisome proliferator-activated receptor (PPAR) pathway, and induced an inflammatory response. Furthermore, HFPO-TA inhibited intrahepatic biliary development in Tg(Tp1:eGFP) transgenic larvae and interfered with transcription of genes associated with biliary duct development. HFPO-TA reduced bile acid synthesis but increased bile acid transport, resulting in disruption of bile acid metabolism. Therefore, HFPO-TA influenced embryonic liver and biliary system morphogenesis, caused liver injury, and may be an unsafe alternative for PFOA.

Transport and transformation of perfluoroalkyl acids, isomer profiles, novel alternatives and unknown precursors from factories to dinner plates in China: New insights into crop bioaccumulation prediction and risk assessment

Perfluoroalkyl acids (PFAAs) are contaminants of global concern, and the inadvertent consumption of PFAA-contaminated crops may pose a threat to public health. Therefore, systematically studying their source tracing, bioaccumulation prediction and risk assessments in crops is an urgent priority. This study investigated the source apportionment and transport of PFAAs and novel fluorinated alternatives (collectively as per- and polyfluoroalkyl substances, PFASs) from factories to agricultural fields in a fluorochemical industrial region of China. Furthermore, bioaccumulation specificities and prediction of these chemicals in different vegetables were explored, followed by a comprehensive risk assessment from agricultural fields to dinner plates which considered precursor degradation. A positive matrix factorization model revealed that approximately 70 % of PFASs in agricultural soils were derived from fluorochemical manufacturing and metal processing. Alarming levels of ∑PFASs ranged 8.28-84.3 ng/g in soils and 163-7176 ng/g in vegetables. PFAS with short carbon chain or carboxylic acid group as well as branched isomers exhibited higher environmental transport potentials and bioaccumulation factors (BAFs) across a range of vegetables. The BAFs of different isomers of perfluorooctanoic acid (PFOA) decreased as the perfluoromethyl group moved further from the acid functional group. Hexafluoropropylene oxide dimer acid (GenX) showed relatively low BAFs, probably related to its ether bond with a high affinity to soil. Vegetables with fewer Casparian strips (e.g., carrot and radish), or more protein, possessed larger BAFs of PFASs. A bioaccumulation equation integrating critical parameters of PFASs, vegetables and soils, was built and corroborated with a good contamination prediction. After a total oxidizable precursors (TOP) assay, incremental perfluoroalkyl carboxylic acids (PFCAs) were massively found (325-5940 ng/g) in edible vegetable parts. Besides, precursor degradation and volatilization loss of PFASs was firstly confirmed during vegetable cooking. A risk assessment based on the TOP assay was developed to assist the protection of vegetable consumers.

Distribution of per- and poly-fluoroalkyl substances and their precursors in human blood

Many studies have examined per- and poly-fluoroalkyl substances (PFASs) in human blood. However, the distribution of PFASs in human blood remains not well known, especially for perfluorooctane sulfonate (PFOS) precursors. In this study, human blood samples (n = 162) were collected from general Chinese population, and then the isomer-specific partitioning of PFASs between human plasma and red blood cells (RBCs) were investigated. Perfluorooctanoate (PFOA) and PFOS were consistently the predominant PFASs in both human plasma and RBCs. In human blood, among C₄-C₇ perfluoroalkyl carboxylates (PFCAs), the calculated mean mass fraction in plasma (F_p) values increased from 0.76 to 0.82 with the increasing chain length. C₇-C₁₃ PFCAs exhibited a trend of gradually decreasing mean F_p with chain length. Among PFAS precursors, 6:2 fluorotelomer phosphate diester had the highest mean F_p value (0.87 ± 0.11). Calculated F_p values of N-methyl perfluorooctanesulfonamide (N-MeFOSA) and N-ethyl perfluorooctanesulfonamide (N-EtFOSA) were 0.66 ± 0.13 and 0.70 ± 0.12, respectively. Individual branched isomers consistently had greater F_p values than their corresponding linear isomers for PFOA, PFHxS, and perfluoroctane sulfonamide. To our knowledge, this study first reports the distribution of N-MeFOSA and N-EtFOSA in human blood, contributing to the better understanding of the occurrence and fate of PFASs in humans.

Monitoring and eco-toxicity effect of paraben-based pollutants in sediments/seawater, north of the Persian Gulf

The current work is documented as the first record of the characteristics, removal efficiency, partitioning behavior, fate, and eco-toxicological effects of paraben congeners in a municipal wastewater treatment plant (WWTP, stabilization ponds) and hospital WWTPs (septic tank and activated sludge), as well as seawater-sediments collected from runoff estuarine stations (RES) and coastal stations (CS) of the north of the Persian Gulf. The median values of Σparabens at the raw wastewater and effluent of the studied WWTPs were 1884 ng/L and 468 ng/L, respectively. The activated sludge system had a greater removal efficiency (56.10%) in removing ∑parabens than the septic tank (45.05%) and stabilization pond (35.54%). The discharge rates of methyl paraben (MeP) was computed to be 2.23, 21.18, and 9.12 g/d/1000 people for stabilization ponds, septic tank, and activated sludge, respectively. Median concentrations of Σparabens in seawater (103.42 ng/L) and sediments (322.05 ng/g dw) from RES stations were significantly larger than from CS stations (61.2 and 262.0 ng/g dw in seawater and sediments, respectively) (P < 0.05). The median of field-based k_oc for Σparabens was 130.81 cm³/g in RES stations and 189.51 cm³/g in CS stations. It was observed that the concentration of parabens could have negative impacts on some living aquatic populations (invertebrates and bacteria), but the risk was not significant for fishes and algae.

Occurrence, fate and risk assessment of per- and polyfluoroalkyl substances in wastewater treatment plants in Shaanxi, China

Wastewater treatment plants (WWTPs) are considered as major sinks for per- and polyfluoroalkyl substances (PFASs). However, conventional WWTPs with low efficiency are also a secondary point source of PFASs entering the environment. Herein, a large-scale investigation of PFASs was conducted in 44 WWTPs throughout Shaanxi Province in the transitional zone between North and South China. The composition profiles of target PFASs differed between wastewater and sludge samples. Perfluorobutanoic acid was dominant in wastewater influent and effluent samples, with maximum concentrations of 59.8 and 11.4 ng/L, respectively. Perfluorooctane sulfonic acid occurred predominantly in sludge samples, with a maximum concentration of 73.2 ng/g. Through wastewater treatment, short-chain PFASs with an even number of carbon atoms were mostly removed, whereas short-chain PFASs with an odd number of carbon atoms were primarily discharged into receiving water. Long-chain PFASs (perfluoroalkyl carboxylic acids: C ≥ 8; perfluoroalkane sulfonic acids: C ≥ 6) were not removed efficiently and secondary production might occur during treatment. Based on the risk quotient, PFASs residues in wastewater effluent posed minimal ecological risk, but the residues in sludge posed low to high potential risk. The mass loadings of PFASs discharged through wastewater and sludge were 15.5 and 3.74 kg/year, respectively, from all WWTPs in Shaanxi Province.

First report on per- and polyfluoroalkyl substances (PFASs) in coral communities from the Northern South China sea: Occurrence, seasonal variation, and interspecies differences

In this study, the contamination levels and seasonal variation of 22 PFASs were investigated in coastal reef-building corals (n = 68) from the northern South China Sea (SCS) during wet and dry seasons. Perfluorohexane sulfonate (PFHxS) was the predominant PFASs in all coral samples, representing 43% of the total PFAS. Long-chain PFASs, as well as PFAS alternatives, were frequently detected above the MQL (>88%) but showed relatively low concentrations compared to short-chain PFASs in most species and seasons. Seasonal variation of PFAS concentrations were observed in branching corals, indicating that the accumulation of PFASs may be associated with coral morphological structures. Interspecies differences in PFAS levels agree well with different bioaccumulation potentials among coral species. Redundancy analysis (RDA) showed that seasonal factor and coral genus could partly influence PFAS concentrations in coral tissues. In summary, our study firstly reported the occurrence of PFASs in coral communities from the SCS and highlights the necessity for future investigations on more toxicity data for coral communities.

The Need for Testing Isomer Profiles of Perfluoroalkyl Substances to Evaluate Treatment Processes

Many environmentally relevant poly-/perfluoroalkyl substances (PFASs) including perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) exist in different isomeric (branched and linear) forms in the natural environment. The isomeric distribution of PFASs in the environment and source waters is largely controlled by the source of contamination and varying physicochemical properties imparted by their structural differences. For example, branched isomers of PFOS are relatively more reactive and less sorptive compared to the linear analogue. As a result, the removal of branched and linear PFASs during water treatment can vary, and thus the isomeric distribution in source waters can influence the overall efficiency of the treatment process. In this paper, we highlight the need to consider the isomeric distribution of PFASs in contaminated matrices while designing appropriate remediation strategies. We additionally summarize the known occurrence and variation in the physicochemical properties of PFAS isomers influencing their detection, fate, toxicokinetics, and treatment efficiency.

Non-target and target screening of per- and polyfluoroalkyl substances in landfill leachate and impact on groundwater in Guangzhou, China

Landfills are the main destination of many urban wastes containing per- and polyfluoroalkyl substances (PFAS), and PFAS may leach out from the waste and contaminate the surrounding groundwater. Here we investigated the occurrence of PFAS in leachate and surrounding groundwater from three landfills in Guangzhou, China by using a combined target and non-target approach. Non-target screening showed that a total of 651 PFAS with 96 classes were identified, including 17 legacy PFAS and 637 emerging PFAS. The quantitative target analysis of some PFAS revealed that the average removal rate of PFAS from the raw leachates were ranged between 62 % and 99 %. Statistical analysis and source analysis suggested that landfill leachate was a major source of PFAS in the groundwater within the landfills and downstream sites. The results from the combined target and non-target analyses demonstrated that PFAS in landfills could leach into the surrounding groundwater, and may affect the sustainable use of groundwater as a source of drinking water and pose a potential risk to human health.

Analysis of Specific Perfluorohexane Sulfonate Isomers by Liquid Chromatography-Tandem Mass Spectrometry: Method Development and Application in Source Apportionment

Characterization of perfluorohexane sulfonate (PFHxS) isomers, a chemical proposed for listing under the Stockholm Convention, is important to elucidate its environmental behaviors and sources. Optimized chromatographic separation coupled with monitoring of the characteristic fragments enabled the identification of four mono-substituted and two di-substituted branched PFHxS isomers. The transitions of molecular ions m/z 399 to the fragments m/z 80 (n-), m/z 169 (iso-), m/z 319 (1m-), m/z 80 (2m-), and m/z 180 (3m-) were selected for quantifying the mono-substituted isomers. Method accuracy of the established LC-MS/MS was verified by comparing the results of technical products with those determined by ¹⁹F-nuclear magnetic resonance (NMR). The developed method was then used to quantify the isomeric compositions of PFHxS in the perfluorooctane sulfonate (PFOS) industrial products which contained PFHxS as an impurity, as well as in several kinds of water samples, with the limits of detection for all isomers in the range of 4 to 30 pg/L. For the first time, a liquid chromatography-tandem mass spectrometry method was established to separate and quantify the PFHxS isomers. The isomeric profiling of water samples suggested that PFHxS in the waters was mainly due to the direct contamination of PFHxS rather than from PFOS contamination.

Occurrence of Perfluoroalkyl and Polyfluoroalkyl Substances in Ice Cream, Instant Noodles, and Bubble Tea

Food consumption is a significant exposure route to perfluoroalkyl and polyfluoroalkyl substances (PFAS). The concentrations of 27 PFAS in fast food were determined by ultrahigh-performance liquid chromatography-high resolution mass spectrometry. In ice cream, instant noodles, and bubble tea, some PFAS were detected, among which perfluorooctanoic acid, perfluoro-n-butanoic acid, and 6:2 polyfluoroalkyl phosphate monoester showed relatively high concentrations. PFAS migrating from bubble tea cups to the food simulant of 50% ethanol aqueous solution showed a difference compared with those migrating into bubble tea matrices. The migration of 27 PFAS to bubble tea samples indicated that long storage time increased PFAS levels (up to 4.8 times) and so did high storage temperature (up to 7.3 times). The hazard ratio, defined as the ratio of the estimated daily intake and the reference dose, was calculated, and it suggests that the total PFAS exposure risk due to consumption of bubble tea should be of concern.

Spatiotemporal distribution, ecological risk assessment and source analysis of legacy and emerging Per- and Polyfluoroalkyl Substances in the Bohai Bay, China

The Bohai Sea is one of the most polluted hotspots by per- and Polyfluoroalkyl substances (PFASs) in the world and studies on the vertical distribution of PFASs at different water layers and phase partitioning between water and suspended particulate matter (SPM) were still limited. 23 legacy and emerging PFASs were investigated in seawater and SPM throughout the Bay in this study. The average concentrations of ∑PFASs in seawater were 48.21 ng/L and 52.71 ng/L during the periods of wet and normal water, respectively. In general, the concentrations of ∑PFASs in surface water were higher than that in deep water. Legacy PFASs in seawater were dominated by PFOA and short-chain PFASs, while the emerging alternative HFPO-DA was detected in the whole water layer of the Bohai Bay with an average concentration of 1.09 ng/L. The spatial distribution showed that ∑PFASs were higher nearshore than inside the bay and higher in the south than that in the north of the bay. The average concentration of ∑PFASs in SPM was 9.02 ng/g. Long-chain PFASs and the emerging alternative 6:2 Cl-PFESA accounted for the major contaminants. The partition coefficients log K_d and φ_spm-w showed a linear positive correlation with carbon chain length. Preliminary risk assessments revealed that the ecological risk of common PFASs in the Bohai Bay was low, while PFOA was at moderate risk. The principal component analysis demonstrated that the production process of traditional fluorochemical factories, fire-fighting and emerging electroplating industries were the main sources of PFASs. This was the first comprehensive survey of emerging PFASs in different water depths and in SPM of the Bohai Bay during different seasons, which provided important scientific data for studying the ecological risks and pollution prevention of PFASs.

Exploring the source, migration and environmental risk of perfluoroalkyl acids and novel alternatives in groundwater beneath fluorochemical industries along the Yangtze River, China

The widely used legacy perfluoroalkyl acids (PFAAs) with serious environmental hazards are gradually restricted and being replaced by novel alternatives. Here, for an efficient control of emerging environmental risks in groundwater, we systematically studied the source apportionment, spatial attenuation, composition change and risk zoning of 12 PFAAs and five novel alternatives within a region of ~200 km² around a mega fluorochemical industrial park (FIP) along the Yangtze River, and in-depth explored potential association between groundwater and soil pollution as well as influencing factors on contaminant migration and risk distribution in the aquifer. Short-chain PFAAs and novel alternatives together accounted for over 70% in groundwater, revealing their prevalence in replacing legacy perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). Novel alternatives for PFOA were mainly hexafluoropropylene oxide dimer acid (GenX) and hexafluoropropylene oxide trimer acid (HFPO-TA), while those for PFOS were 6:2 chlorinated polyfluorinated ether sulfonic acid (6:2 Cl-PFESA) and 6:2 fluorotelomer sulfonic acid (6:2 FTS). PFAAs (maximum total: 1339 ng/L) and novel alternatives (maximum total: 208 ng/L) in groundwater were mostly derived from the FIP, and exhibited an exponentially decreasing trend with increasing distance. Compared with those in groundwater, more diverse sources of PFAAs and novel alternatives in surface soil were identified. The transport of these chemicals may be retarded by clayed surface soils with high organic matter contents. High aquifer permeability could generally promote the dilution and migration of PFAAs and novel alternatives in groundwater, as well as reduce the differences in their spatial distribution. Shorter-chain components with smaller molecules and higher hydrophilicity exhibited greater migration capacities in the aquifer. In addition, different levels of health risk from PFOS and PFOA were zoned based on drinking groundwater, and high risks tended to be distributed in areas with relatively poor aquifer water yield due to higher pollutant accumulation.

Profiling biotoxicities of hexafluoropropylene oxide trimer acid with human embryonic stem cell-based assays

Hexafluoropropylene oxide trimer acid (HFPO-TA), an emerging replacement of perfluorooctanoic acid (PFOA), has recently been reported to be a potential environmental contaminant. Due to the similar structure to PFOA, HFPO-TA may cause comparable adverse effects on human health. Therefore, evaluating the toxic profiles of HFPO-TA has become an urgent task. In this study, we investigated the cytotoxicity and hepatoxicity of HFPO-TA using human embryonic stem cell (hESC)-based assays. Results showed that HFPO-TA reduced hESCs' viability in a dose dependent manner, and the calculated IC50 for 24, 48 and 72 hr were 222.8, 167.4, and 80.6 μmol/L, respectively. Significant intracellular ROS accumulation and mitochondrion membrane potential reduction were detected with HFPO-TA exposure, and increased apoptotic/necrotic cells were also observed in high dose of HFPO-TA treated group. Moreover, HFPO-TA at noncytotoxic concentrations also significantly impaired the functions of induced hepatocytes by diminishing cell glycogen storage ability and deregulating specific functional genes. Transcriptome sequencing analysis identified a set of hepatic associated biological processes responding to HFPO-TA exposure. PPAR was the most significantly enriched pathway. Genes including FGA, FGB, FGG, AHSG, HRG, ITIH2, ALB were characterized as hub genes by cytoHubba plug-in. These data indicated that HFPO-TA is a potential hepatotoxicant, and may not be a safe replacement for PFOA.

Insights into the Competitive Mechanisms of Per- and Polyfluoroalkyl Substances Partition in Liver and Blood

Some per- and polyfluoroalkyl substances (PFASs) tend to be accumulated in liver and cause hepatotoxicity. However, the difficulty to directly measure liver concentrations of PFASs in humans hampers our understanding of their hepatotoxicity and mechanisms of action. We investigated the partitioning of 11 PFASs between liver and blood in male CD-1 mice. Although accumulation of the perfluoroalkanesulfonic acids (PFSAs) in mice serum was higher than their carboxylic acids (PFCAs) counterparts as expected, the liver-blood partition coefficients (R_L/S) of PFSAs were lower than the PFCAs R_L/S, implying a competition between liver and blood. The in vitro experiments further indicated that the partitioning was dominantly determined by their competitive binding between human liver fatty acid binding protein (hL-FABP) and serum albumin (HSA). The binding affinities (K_d) of PFASs to both proteins were measured. The correlations between the R_L/S and log K_d (hL-FABP)/log K_d (HSA) were stronger than those with log K_d (hL-FABP) alone, magnifying that the partitioning was dominantly controlled by competitive binding between hL-FABP and HSA. Therefore, the liver concentrations of the selected PFASs in humans could be predicted from the available serum concentrations, which is important for assessing their hepatotoxicity.

Natural biofilm as a potential integrative sample for evaluating the contamination and impacts of PFAS on aquatic ecosystems

Natural biofilm can be a suitable medium for the monitoring of pollutants. Limited information is currently available regarding the occurrence of per- and polyfluoroalkyl substances (PFAS) in periphytic biofilm and low-trophic level organisms of freshwater ecosystems. In this study, surface water, biofilm, phytoplankton, and freshwater snails were collected from Taihu Lake, China, and characterized for 16 PFAS, including legacy compounds (PFSAs/PFCAs) and PFAS of emerging concern (fluorotelomer sulfonates and F-53B). The colonized biofilms effectively bioaccumulated PFAS from water, with the total concentration (∑PFAS) in the range of 1.96-20.1 ng/g wet weight, and the bioaccumulation factor increased with the PFAS log K_ow values. As compared with phytoplankton, the ∑PFAS in biofilms displayed a stronger correlation with those in water. PFAS distinctly biomagnified from the biofilm to freshwater snail, with the biomagnification factor in the range of 3.09 ± 2.03 - 17.8 ± 10.2, implying the important role of biofilm in PFAS transfer in aquatic environment. Extracellular proteins production in biofilm increased with the water PFAS concentrations. The total extracellular polymeric substances (EPS) content increased with the water PFAS concentration firstly and then declined to a steady level, while the algal chlorophyll level exhibited a similar relationship with the PFAS in biofilm. High PFAS levels were also associated with depressed alpha diversity of fungal community in biofilms. Biofilm appears as a relevant indicator to characterize the occurrence of PFAS in aquatic ecosystems.

Quantifying Indirect Contribution from Precursors to Human Body Burden of Legacy PFASs Based on Paired Blood and One-Week Duplicate Diet

The restriction on legacy perfluoroalkyl substances (PFASs) has led to increasing application and contamination of their precursors and novel alternatives. However, the indirect contribution from precursors has not been well characterized. In this study, 24 PFASs were measured in the paired human blood and urine from general volunteers (n = 20), as well as their corresponding exposure matrices (7 day duplicate diet, drinking water and dust). Perfluorooctanoic acid (PFOA) was predominant, followed by 6:2 chlorinated polyfluoroalkyl ether sulfonate (6:2 Cl-PFESA), contributing 21.6-47.0 and 6.6-20.0% of the total concentrations, respectively. Total oxidable precursor (TOP) assay and isomeric analysis coupled with a toxicokinetic model suggested that around 19% of perfluorooctane sulfonate (PFOS) in human was contributed by its precursors. The strong correlation between the estimated daily intake (EDI) and human blood concentration for 6:2 Cl-PFESA suggested that it was mainly contributed by direct exposure. The bioavailability of 6:2 Cl-PFESA in the food matrices was estimated as 18.6% by comparing the estimated and measured blood concentrations, implying that human exposure might be overestimated if the bioavailability of PFASs in food was not considered. Assuming that they had a similar bioavailability, it was estimated that ca. 20% of PFOS body burden was from indirect exposure to its precursors, which was supported by TOP assay.

Spatiotemporal distribution, partitioning behavior and flux of per- and polyfluoroalkyl substances in surface water and sediment from Poyang Lake, China

Thirty-five legacy and emerging per- and polyfluoroalkyl substances (PFAS) were analyzed in surface water and sediments collected from Poyang Lake, the largest freshwater lake in China. The ƩPFAS concentrations ranged from 23 to 1000 ng/L in water dissolved phase, 1.3-9.8 ng/L in suspended particulate matters, and 0.26-2.9 ng/g dry weight in sediments. Short-chain and emerging PFAS were predominant in surface water and sediments, rather than legacy perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). Hexafluoropropylene oxide dimer/trimer acid (HFPO-DA/TA), 6:2 and 8:2 chlorinated polyfluorinated ether sulfonic acids (6:2 and 8:2 Cl-PFESAs), 6:2 fluorotelomer sulfonate (6:2 FTS), and sodium p-perfluorous nonenoxybenzene sulfonate (OBS) were detected in all samples, indicating that these emerging PFAS have been widely produced and used in this region. The high concentrations of HFPO-DA/TA, 6:2 FTS, 6:2, 8:2 Cl-PFESAs, and OBS in sediments and their higher water-sediment distribution coefficients than those of predecessors (PFOA or PFOS) suggest that lake sediments could be an important long-term sink for these emerging alternatives. The positive matrix factorization model demonstrated that food packaging and textile treatments (50%) and fluoropolymer manufacturing (26% for alternative sources and 8.2% for legacy sources) were the two major sources of PFAS in Poyang Lake. The influx and outflux of total PFAS in Poyang Lake were 9.0 and 12.8 ton/year, respectively, and the OBS flux was estimated for the first time. The results provide insights into the environmental behavior and fate of emerging PFAS in freshwater ecosystems.

Co-occurrence and correlations of PFASs and chlorinated volatile organic compounds (cVOCs) in subsurface in a fluorochemical industrial park: Laboratory and field investigations

Fluorochemical industrial park (FIP) represents an important source of per- and polyfluoroalkyl substances (PFASs) and chlorinated volatile organic compounds (cVOCs). Exploring the co-occurrence and correlations of PFASs and cVOCs is a key step towards the understanding their distributions in the field. In this study, perfluorooctanoic acid (PFOA) was the dominant compound in groundwater and aquifer solids, and elevated concentrations of short-chain perfluoroalkyl carboxylic acids (PFCAs) and hexafluoropropylene oxide oligomers were also detected in the field, suggesting their wide applications as substitutes for PFOA. Correlation analyses between PFASs and cVOCs suggested that cVOCs had a significant influence on the distribution and composition of PFASs in the field. In addition, the presence of cVOCs in the form of dense non-aqueous-phase organic liquids (DNAPL) affected the distribution and migration of PFASs at various depths, as evidenced by the relatively high PFASs concentrations (204 μg/L) and PFOA abundance (85.4%) in the deep aquifer, likely due to DNAPL-water interfaces sorption or partition into bulk DNAPL. The log K_d values, determined in the laboratory, were found to increase in the presence of DNAPL, especially for PFOA, with more than one time higher than those of perfluorobutanoic acid (PFBA) and hexafluoropropylene oxide dimer acid (HFPO-DA). This conclusion further demonstrated that PFOA had a higher potential to participate into DNAPL, which can migrate with DNAPL to the deep aquifer, supporting the higher abundance of PFOA in the deep aquifer mentioned above. However, the log K_d-field values of PFBA and HFPO-DA in the field were higher than that of PFOA, and no significant correlations (p > 0.05) were found between log K_d-field values and the chain-length of PFCAs at various depths, suggesting that the phenomena observed in the field are a result of composite influencing factors.

Activated carbon versus metal-organic frameworks: A review of their PFAS adsorption performance

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a class of fluorinated aliphatic compounds considered as emerging persistent pollutants. Owing to their adverse effects on human health and environment, efficient methods of their removal from various complex matrices need to be developed. This review focuses on recent results addressing the adsorption of PFAS on activated carbons (AC) and metal-organic frameworks (MOF). While the former are well-established adsorbents used in water treatment, the latter are relatively new and still not applied at a large scale. Nevertheless, they attract research interests owing to their developed porosity and versatile surface chemistry. While AC provide high volumes of pores and hydrophobic surfaces to strongly attract fluorinated chains, MOF supply sites for acid-base complexation and a variety of specific interactions. The modifications of AC are focused on the introduction of basicity to attract PFAS anions via electrostatic/chemical interactions, and those of MOF - on structural defects to increase the pore sizes. Based on the comparison of the performance and specifically adsorption forces provided by these two groups of materials, activated carbons were pointed out as worthy of further research efforts. This is because their surface, especially that in large pores, where dispersive forces are week and where extensive pore space might be utilized to adsorb more PFAS, can be further chemically modified and these modifications might be informed by the mechanisms of PFAS adsorption, which are specific for MOF. This review emphasizes the effects of these modifications on the adsorption mechanism and brings the critical assessment of the advantages/disadvantages of both groups as PFAS adsorbents.

Shift in the distribution and fate of perfluoroalkyl acids by sluice gates in the multi-environment media of rivers

The impact of sluice operations on the distribution and fate of perfluoroalkyl acids (PFAAs) remains poorly understood. In this study, the distribution of PFAAs was investigated in water, suspended particles, sediment, and pore water from the upstream and downstream sections of six sluice gates along the Wangyu River, China. The target PFAAs were widely distributed in the dissolved phase (∑PFAAs: 447.61 ± 180.26 ng/L), particle phase (∑PFAAs: 2040.95 ± 1870.88 ng/g dw), sedimentary phase (∑PFAAs: 39.42 ± 35.38 ng/g dw), and pore water phase (∑PFAAs: 8172.54 ± 4278.60 ng/L). Our data suggest predominant detections of short-chain PFAAs such as perfluorobutanoic acid (PFBA) and perfluorohexanoic acid (PFHxA) in the four environmental media. Sediment pore water appeared as an essential repository and potential source for PFAA re-release to the river environment. The levels of PFAAs in the dissolved and suspended particle phase upstream of the sluices were significantly lower than those downstream, while the situation in the sediment and pore water phase was the opposite. Sluice operation caused PFAA redistribution among the multi-environment media but did not change the PFAA composition, which had the significant effect on the partition behavior of perfluoroalkyl carboxylic acids (PFCAs) between particles and water, as well as changed the migration pattern of PFOA, PFNA and PFOS from equilibrium to the migration state. Quantitative prediction models were developed for simulating fate of PFAAs in gate-controlled river, and the major factors affecting the distribution and fate of PFAAs were identified. Our findings provide insights into the redistribution mechanisms of PFAAs and an understanding of their environmental fate.

Human exposure to F-53B in China and the evaluation of its potential toxicity: An overview

Chlorinated polyfluoroalkyl ether sulfonic acid (Cl-PFESAs, trade name F-53B), an alternative to perfluorooctane sulfonate (PFOS), has been widely used as a mist suppressant in the Chinese electroplating industry since the 1970 s. Due to greater restrictions on PFOS globally in recent years, the production and use of F-53B correspondingly increased, consequently causing more emissions into the environment. In China, an increasing number of studies report frequent detection and broad exposure to F-53B in the natural environment, various wildlife and the human body. In human blood, the detection rate of F-53B is almost 80%, accounting for 8.69 to 28% of ∑per- and polyfluoroalkyl substances (PFASs). F-53B is the most biopersistent PFAS in humans to date, with a half-life of 15.3 years. In addition, F-53B displays protein binding affinity and high human placental permeability. Recently, some epidemiological studies have reported the health risks associated with F-53B in humans, including abnormal serum lipid metabolism, vascular dysfunction, endocrine disorders and even adverse birth outcomes. Various in vivo and in vitro studies have demonstrated the toxicity of F-53B, such as hepatotoxicity, interference effects on the endocrine system, as well as reproductive and developmental toxicity. Our aims are to review studies on human F-53B exposure levels, trends and associated health effects; evaluate the potential toxicity; and predict directions for future research.

Distribution, sources, and dietetic-related health risk assessment of perfluoroalkyl acids (PFAAs) in the agricultural environment of an industrial-agricultural interaction region (IAIR), Changshu, East China

The exploration of the distribution and dietetic-related health risks of perfluoroalkyl acids (PFAAs) in industrial-agricultural interaction regions (IAIRs) is of significant importance, due to the transfer of many PFAA-related factories to developing countries with intensive agricultural activities. In the present study, based on the local diet, edible parts of rice, vegetables, fish, and their corresponding soils and irrigation/aquaculture water were investigated in a typical Chinese city (Changshu). The concentrations of total perfluoroalkyl acids (ΣPFAAs) in the edible parts of rice /vegetables and fish tissues ranged from 26.69 to 37.09 ng/g dw, 12.93 to 40.77 ng/g dw, and 13.27 to 29.82 ng/g ww, with perfluorohexanoic acid (PFPeA) and perfluorooctane sulfonic acid (PFOS) as the most dominant compounds. The PFAA concentrations in the corresponding rice soils, vegetable soils, irrigation water, and aquaculture water ranged from 11.99 to 26.33 ng/g dw, 14.06 to 36.19 ng/g dw, 141.36 to 297.00 ng/L, and 179.23 to 235.82 ng/L, respectively. Biota-sediment accumulation factor (BSAF) values for the plant-soil system were far greater than those for bioaccumulation factor (BAF) values for the plant-irrigation water system. PFAAs were more inclined to accumulate in the gills of fish as determined by their highest BAF values. Correlation analysis showed that PFAAs in root vegetables had a stronger correlation with those in soil compared with those in irrigation water. Source analysis showed that emissions from fluoride industries, textiles, and food industries may be the dominant sources of PFAAs in agricultural environments. The estimated dietary intake (EDI) for the selected diet was lower than that for rice/vegetables but was higher than that found in fish. Toddlers (2-5 years) had the highest exposure risk, and rural residents were more exposed to PFAAs than urban residents under the selected diet.

Source apportionment and health risk assessment of chemicals of concern in soil, water and sediment at a large strontium slag pile area

Strontium (Sr) is an alkaline earth metal that has adverse effects on bone tissue, but received little attention compared to other often-studied metals. This study analyzed the contents/concentrations of Sr, barium (Ba), sulfate (SO₄^2-), sulfide (S^2-), and six common metals in 209 multi-media samples, including slag, soil, groundwater, surface water, and sediment, collected at a large Sr slag pile area. Sr was the dominant chemical of concern (COC) in the soil and groundwater, with contents/concentrations being 35.50-32200 mg/kg and 0.57-152 mg/L, respectively, much higher than those reported in previous research. Contents/concentrations of all COCs in the surface water and sediment were relatively low, except Sr content in the sediment near the slag pile. The LogK_d value of Sr was calculated to be lower than those of common metals, indicating relatively high mobility of Sr in the aquatic environment. Contamination assessment using Nemerow index indicated near half of the soil and groundwater sampling locations, especially those within and near the slag pile, were heavily contaminated, and Sr was the dominant COC. The positive matrix factorization model suggested four sources for the COCs in soil, including Sr slag pile/SrCO₃ production, agricultural activities, industrial activities, and natural sources, with contribution rates of 66.88%, 5.28%, 7.5%, and 20.34%, respectively. Monte Carlo simulation-based probabilistic health risk assessment revealed that the non-carcinogenic risk of groundwater, and the carcinogenic risk of soil and groundwater, were unacceptable. Notably, Sr was the unique COC posing non-carcinogenic risk among the COCs studied. Our results provide the scientific support needed for managing Sr point source impacted area.

Perfluoroalkyl acids in dust on residential indoor/outdoor window glass in Chinese cities: occurrence, composition, and toddler exposure

The dust on indoor and outdoor surfaces of the window glasses were collected using sterile cotton balls in 11 cities from China. Two sampling campaigns were conducted with the time interval of 7 days to investigate the accumulation especially during the Spring festival holidays. Twenty-nine perfluoroalkyl acids (PFAA) were quantified to investigate concentration, composition, and toddlers' exposure. The concentrations of ∑PFAA ranged from no detection (nd) to 43 ng/m2 (mean 8.9 ± 10 ng/m2). Perfluorobutanoic acid (PFBA) was detected in 78% samples and accounted for 55 ± 21% of ∑PFAA concentrations. 6:2 fluorotelomer sulfonic acid (6:2 FTSA) and hexafluoropropylene oxide dimer acid (HFPO-DA) were detected in more than 50% samples indicating the use of alternatives. Fluorotelomer carboxylic acid (FTCA) and fluorotelomer unsaturated acid (FTUCA) were found in the dust, implying the degradation of fluorotelomer alcohols (FTOH). The highest concentration of ∑PFAA (43 ng/m2) was found in outdoor dust from Xinzhou, Shanxi Province. Higher ∑PFAA concentrations were found in indoor dust than outdoor in 6 paired samples (3 from Feb. 14 and 3 from Feb. 21). In Tianjin and Handan, the concentrations of ∑PFAA from outdoor surfaces were higher in sampling campaign I (SC I, Feb. 21) than in sampling campaign II (SC II, Feb. 14), implying intensive outdoor release. The exposure of 2-year-old toddlers to PFAA via hand-to-mouth ingestion and dermal absorption was estimated; the mean values of intake were 2.1 and 1.5 pg/kg body weight, respectively, assuming an exposure time of 1 h.

Anaerobic Microbial Dechlorination of 6:2 Chlorinated Polyfluorooctane Ether Sulfonate and the Underlying Mechanisms

The microbial transformation potential of 6:2 chlorinated polyfluorooctane ether sulfonate (6:2 Cl-PFESA) was explored in anaerobic microbial systems. Microbial communities from anaerobic wastewater sludge, an anaerobic digester, and anaerobic dechlorinating cultures enriched from aquifer materials reductively dechlorinated 6:2 Cl-PFESA to 6:2 hydrogen-substituted polyfluorooctane ether sulfonate (6:2 H-PFESA), which was identified as the sole metabolite by non-target analysis. Rapid and complete reductive dechlorination of 6:2 Cl-PFESA was achieved by the anaerobic dechlorinating cultures. The microbial community of the anaerobic dechlorinating cultures was impacted by 6:2 Cl-PFESA exposure. Organohalide-respiring bacteria originally present in the anaerobic dechlorinating cultures, including Geobacter, Dehalobacter, and Dehalococcoides, decreased in relative abundance over time. As the relative abundance of organohalide-respiring bacteria decreased, the rates of 6:2 Cl-PFESA dechlorination decreased, suggesting that the most likely mechanism for reductive dechlorination of 6:2 Cl-PFESA was co-metabolism rather than organohalide respiration. Reductive defluorination of 6:2 Cl-PFESA was not observed. Furthermore, 6:2 H-PFESA exhibited 5.5 times lower sorption affinity to the suspended biosolids than 6:2 Cl-PFESA, with the prospect of increased mobility in the environment. These results show the susceptibility of 6:2 Cl-PFESA to microbially mediated reductive dechlorination and the likely persistence of the product, 6:2 H-PFESA, in anaerobic environments.

Occurrence, distribution, and risk assessment of perfluoroalkyl acids in drinking water sources from the lower Yangtze River

The occurrence, spatial distribution, potential sources, and risk assessment of 14 perfluoroalkyl acids (PFAAs), including 11 perfluoroalkyl carboxylic acids and 3 perfluoroalkyl sulfonates acids, were investigated in 21 drinking water sources from the lower Yangtze River in November 2019. The total PFAAs (∑PFAAs) concentrations ranged from 39.3 to 220.3 ng/L, and perfluorooctanoic acid and perfluorooctanesulfonate were predominant with average concentrations of 19.4 and 15.4 ng/L, respectively. The higher ∑PFAAs concentrations in the southern shore and downstream could be attributed to industrial development and surface runoff/tide currents, respectively. Principal component analysis-multiple linear regression revealed that the primary sources of PFAAs were fluororesin coatings/metal plating, surface runoff/textile, effluent discharge/food packaging, and leather/fabrics. Human intake risks of PFAAs were assessed by target hazard quotient (THQ), which showed that human health risks of PFAAs decreased with increasing age, excluding 13-17 years age group. Moreover, the total exposure risks of PFOA/PFOS in all sampling sites to people aged over 18 years calculated based on contribution from drinking water were noted to be at safe level. The results obtained were helpful for improving our understanding of human health risks of PFAAs, and expanding our knowledge on PFAAs in drinking water.

Ship navigation disturbance alters multiphase distribution of perfluoroalkyl acids and increases their ecological risk in waterways

As a global persistent organic pollutant, perfluoroalkyl acids (PFAAs) have aroused great public concern. However, little is known regarding the effect of ship navigation disturbance on the transport and fate of PFAAs in inland waterways developed regions. In the present study, overlying water, pore water, suspended particulate matter (SPM), and sediment were collected from waterways (WWs), non-navigable channels (NCs), and ports (PTs) in Taihu Lake Basin. The results revealed that the total concentrations of PFAAs (ΣPFAAs) in WWs, NCs, and PTs varied considerably in different media. In overlying water, the mean ΣPFAAs in WWs were the highest, while those of NCs were relatively higher in the remaining three media. A comparison of PFAA distribution coefficients revealed that the values in NCs were generally higher than those of WWs and PTs, suggesting the critical role of ship navigation in PFAA transport. Furthermore, a structural equation model was applied to estimate direct and indirect effects of environmental factors on PFAA partitioning behavior. The results revealed that ship traffic volume (STV) exerted indirect effects on PFAA distribution between solid and dissolved phases by influencing dissolved oxygen, total suspended solid concentration, clay and sand contents, and median diameter. PFAAs were more readily to be released into overlying water from pore water than in sediment, and the ΣPFAAs carried per gram of SPM decreased with an increase in STV. Ecological risk assessment and Monte Carlo simulation results revealed that ship navigation could exert adverse effects on aquatic organisms, making the average probability of RQ_mix values to exceed corresponding risk values in WWs, which were 1.3-2-fold higher than in NCs. The present study provides crucial information for simulating the environmental behaviors of PFAAs under the influence of ship navigation and is significant for the integration of inland water transport development and aquatic environmental protection.

Legacy and emerging per- and polyfluoroalkyl substances (PFAS) in the Bohai Sea and its inflow rivers

In this study, the occurrence, distribution, sources, and risk of 29 legacy and emerging per- and polyfluoroalkyl substances (PFAS) in four kinds of environmental matrices in the Bohai Sea were investigated. The ∑PFAS concentrations were in the range of 0.40 ~ 61.4 ng/g dry weight (dw) in inflow river sediments, 0.48 ~ 61.4 ng/g dw in soil near river inflow, 0.37 ~ 4.18 ng/g dw in sea sediments, and 13.3 ~ 718 ng/L in seawater. PFAS with eight carbons accounted for > 62.2% by mass, in all samples. Perfluorooctanoic acid (PFOA) was the dominant PFAS both by mass and occurrence. Seawater from Laizhou Bay (south of the Bohai Sea) and sediments of Liaodong Bay (northeast of the Bohai Sea) had the highest levels of ∑PFAS. The sediment-water partition coefficient and organic carbon content normalized partition coefficient (log K_d and log K_oc) were calculated using measured PFAS concentrations to determine their distribution in seawater and sea sediments. The values of log K_d and log K_oc values increased with the increasing CF₂ units for perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkane sulfonic acids (PFSAs). Six primary sources were identified in this region, including aqueous film-forming foams (AFFF), metal plating, food packages, fluorine chemical industry, fluoropolymer manufacture, and domestic pollution. The risk quotient (RQ) values of PFAS were all < 1, indicating that organisms of the Bohai Sea were at low risk of PFAS exposure.

Legacy and alternative per- and polyfluoroalkyl substances (PFASs) in the West River and North River, south China: Occurrence, fate, spatio-temporal variations and potential sources

Poly- and perfluoroalkyl substances (PFASs) are contaminants of global concern. Studies in Pearl River, south China have focused on the delta area, while the upstream contributions are unclear. Here, we systematically investigated the fate, trends and potential sources of 57 PFASs in river water, sediment and fish of the North and West Rivers of the Pearl River system. Perfluorooctanoic acid (PFOA), Perfluorooctanesulfonic acid (PFOS) and 6:2 chlorinated polyfluoroalkyl ether sulfonate (6:2Cl-PFESA) were frequently found compounds in waters, sediments and fish, suggesting their wide usage in this area and potential for bioaccumulation. Waters showed a higher ∑PFASs in the wet season compared to the dry season, but sediments did not. The North River contributed higher PFAS loads to the Pearl River Delta. Our results also reflect the current shift in PFAS usage from legacy substances to alternatives. This study, for the first time, reports data on PFASs in two upstream rivers of the Pearl River and on alternative PFASs such as PFESA in this area, which can better the understanding of their use, fate, risk assessment and further controls and management.

Legacy and emerging per- and polyfluoroalkyl substances (PFAS) in sediments from the East China Sea and the Yellow Sea: Occurrence, source apportionment and environmental risk assessment

The Yellow Sea (YS), the East China Sea (ECS) and their coastal areas have undergone rapid urbanization and industrialization. These areas are important sinks for many persistent organic pollutants. In this study, the concentration of legacy and emerging per- and polyfluoroalkyl substances (PFAS) in marine sediments from the YS and ECS were investigated. Nineteen PFAS were identified, ranging in concentration from 0.21 ng/g to 4.74 ng/g (mean: 1.60 ng/g). Legacy long-chain PFAS [e.g., perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorooctane sulfonate (PFOS)] were the dominant contaminants. Alternative PFAS such as 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA) and 2,3,3,3-tetrafluoro-2-(1,1,2,2,3,3,3-heptafluoropropoxy) propanoic acid (HFPO-DA) were identified within the detection range of 16%-100%. HFPO-DA was measured in all sediments in equivalent levels to PFOS (0.119 ng/g and 0.139 ng/g, respectively). This is the first reported occurrence of perfluoro-1-butanesulfonamide (FBSA) and HFPO-DA in marine sediments, indicating a replacement in the production of PFAS from legacy to emerging ones along with eastern coastal cities of China. The results of the potential source identification demonstrated that metal plating plants, textile treatments, fluoropolymer products, food packaging, and the degradation of volatile precursor substances were the main sources of PFAS in the ECS and YS. The environmental risk assessment based on the risk quotient demonstrated that PFOA and PFOS in the ECS and YS may present a low to medium risk at most sampling points.

Distribution, partitioning behavior and potential source of legacy and alternative per- and polyfluoroalkyl substances (PFASs) in water and sediments from a subtropical Gulf, South China Sea

Legacy per- and polyfluoroalkyl acids (PFASs) have received global concern over the scientific and public community since this century. However, the information on alternative PFASs pollution in the marine environment, especially in the subtropical marine environment is extremely limited. This study investigated the occurrence, partitioning, potential sources, and ecological risks of PFASs, including perfluoroalkane sulfonic acids (PFSAs), perfluoroalkyl carboxylic acids (PFCAs), and alternative PFASs, in surface water and sediments from the subtropical Beibu Gulf, South China. Concentrations of total PFASs (∑PFASs) were in the range of 0.98-2.64 ng/L in water and 0.19-0.66 ng/g (dry weight, dw) in sediment, respectively. Perfluorooctanoic acid (PFOA) was the most abundant PFAS in water, while PFASs in sediment were dominated by perfluorooctanesulfonic acid (PFOS) and PFOA. Among investigated environmental parameters (total organic carbon (TOC), grain size, water pH, sediment pH, and salinity), TOC and salinity were the dominant factors influencing the sediment-water distribution coefficient (K_d) of PFOA, perfluorodecanoic acid (PFDA), and perfluorononanoic acid (PFNA). Log K_d and log soil organic carbon-water distribution coefficient (K_oc) both increase with increasing carbon chain length of PFASs. Significantly positive correlations between PFOS and perfluorohexanoic acid (PFHxA) (p < 0.05), PFOA and perfluoro-1-butane-sulfonamide (FBSA) were observed, suggesting that these PFASs might have similar sources and transport routes. Preliminary environmental risk assessment showed that PFOA and PFOS would not pose risks to the marine aquatic environment. This is the first comprehensive survey of legacy and alternative PFASs in a subtropical area of the Beibu Gulf, which provides significant data and scientific basis to better understand the fate of PFASs and pollution control management.

Occurrence and sources of per- and polyfluoroalkyl substances in the ice-melting lakes of Larsemann Hills, East Antarctica

The contamination and sources of per- and polyfluoroalkyl substances (PFASs) in the Antarctic continent have not been systematically investigated. In this study, 21 PFASs including some new emerging one, were measured in the surface waters collected from 21 ice-melting lakes next to the research stations in Larsemann Hills, East Antarctica (EA). All the PFASs had a median concentration lower than 26.7 pg/L, representing the background levels in EA. The contamination of PFASs in EA was generally lower than in West Antarctica (WA), which might be due to the less on-site human activities in EA than in WA. In the ice-melting lakes, perfluorooctane acid (PFOA) was predominant, and its concentrations in several lakes close to the research stations in EA could be up to 458 pg/L. For the first time, an emerging substitute of perfluorooctane sulfate (PFOS), 6:2 chlorinated polyfluorinated ether sulfonate (Cl-PFESA), was detected in several of the samples. Source apportionment methods including isomer profiling were applied, and the results collectively indicated that the PFASs in the melting lakes in EA were mainly derived from airborne input, but local discharge might also contribute to PFOA in some lakes. The results of this study supplied information about the sources of PFASs in Antarctica, and suggested that caution should be taken in future to control the local discharge due to increasing human activities in EA.

Are there risks induced by novel and legacy poly- and perfluoroalkyl substances in coastal aquaculture base in South China?

Perfluoroalkyl substances (PFASs) have raised great attention as emerging contaminants due to their persistent and bioaccumulative characteristics. Following the global actions to limit perfluorooctanesulfonic acid (PFOS) and its salts, chlorinated polyfluorinated ether sulfonate (F-53B), as an alternative perfluorochemical, has been a focus during this period. In this study, PFASs in coastal seawater, sediment, and seaweed from the significant aquaculture bases of Porphyra haitanensis in the southeast of China were investigated. Their bioaccumulation and ecological risk were elucidated and associated human exposures to PFASs with consumption of aquatic products for rural and urban groups were calculated. The total PFASs levels in seawater and sediment were 21.52-241.86 ng/L and 4.55-26.54 ng/g·dw, respectively. F-53B was found frequently and has relative high concentration in seawater (ND-2.13 ng/L). The Porphyra haitanensis and Siganus fuscescens were also analyzed, with PFASs concentrations ranging from 10.45 to 29.98 ng/g·dw and 7.17 to 25.43 ng/g·dw, respectively. The total logarithm BAF of F-53B and PFOS in two kinds of detected seafoods were within 0-2.94 and 2.01-3.25, these values did not vary in different sites. The estimated daily intake (EDI) of PFASs through aquatic products consumption in rural and urban residents were 0.03-26.50 ng/kg bw/day and 0.17-37.01 ng/kg bw/day, respectively, based on the Dietary Guidelines for Chinese residents. The total EDI of PFASs via Porphyra haitanensis and Siganus fuscescens in different groups were significantly lower than the suggested tolerable daily intake (PFOS, 150 ng/kg bw/day; PFOA, 1500 ng/kg bw/day), which indicates that PFASs did not induce health risks to the residents living around these aquaculture bases.