Per and poly-fluoroalkyl substances (PFAS) as a contaminant of emerging concern in surface water: A transboundary review of their occurrences and toxicity effects

Molecular docking-QSAR-Kronecker-regularized least squares-based multiple machine learning for assessment and prediction of PFAS-protein binding interactions

Ubiquitous per- and poly-fluoroalkyl substances (PFAS) threaten human's health and attract worldwide attention. PFAS-mediated toxicity involves adverse effects of PFAS on proteins, and assessment of PFAS-protein binding interactions helps to explain PFAS' adverse effects on human health. In-silico modeling can generate information and decrease experimental costs. Accordingly, in this study, molecular docking was used to determine the binding affinities of 430 PFAS with human serum albumin (HSA), peroxisome proliferator-activated receptor gamma (PPARγ), and transthyretin (TTR). Specifically, analytic hierarchy process, fuzzy comprehensive evaluation, and quantitative structure-activity relationship model were used to assess and predict the binding affinities between PFAS and HSA, PPARγ, and TTR. The binding patterns were determined by defining "PEOE_RPC-, E_vdw, MNDO_LUMO, and vsurf features" as key factors related to charge, energy and shape characteristic of PFAS. Finally, Kronecker-regularized least squares (Kron-RLS) model was applied to predict the binding affinities between PFAS- and G protein-coupled receptor 40 (GPR40), as a new target for prediction. Results showed that the Kron-RLS model exhibited good performance and generated precise predictions (R2 = 0.94). In conclusion, this study demonstrated that computational simulations could be used to aid the scientific management of the growing number of PFAS, and could be broadened to include a wide range of environmental contaminations.

A clustering approach based on high-resolution ecological vulnerability index reveals spatial patterns of per- and polyfluoroalkyl substances pollution in lakes on the Tibetan Plateau

Per- and polyfluoroalkyl substances (PFAS) are persistent organic pollutants (POPs) with toxicity, chemical stability, and long-range transport potential. The transport and accumulation mechanisms of PFAS in specific or typical lakes have been reported. In the wake of global PFAS pollution, it is more important to unravel the distribution patterns of PFAS across larger-scale, multi-lake systems. However, traditional lake classification methods are often overly simplistic and inflexible to adapt to large lake systems with complex ecological characteristics. Here, an improved ecological vulnerability index (EVI) was introduced and applied for the first time to classify lakes in a regional, multi-lake study of PFAS pollution. We evaluated the effectiveness of EVI that integrated multi-dimensional environmental factors in revealing PFAS distribution in 12 lakes on the Tibetan Plateau. The results showed that the composition, concentration, and diversity of PFAS in water and sediment samples significantly differed between high-vulnerability lakes (HVL) and low-vulnerability lakes (LVL) clustered by EVI. The linear regression of PFAS concentration and diversity on EVI was most pronounced at the 1-km buffer zone scale compared to larger scales. EVI was strongly associated with PFAS concentration and diversity in HVL dominated by natural factors, and these associations were weakened in LVL with prevalent human interference. Our findings indicate the greater potential of EVI to predict the spatial patterns of PFAS in lakes at smaller scales and across regions with comparable dominance of natural factors. The proposed clustering approach is adaptable, as the indicators and weights in the EVI system can be adjusted based on regional ecological characteristics. This study provides a tool for unveiling the distribution patterns of PFAS and their driving mechanisms in complex lake environments.

Unveiling the adsorption mechanism of perfluorooctane sulfonate onto polypropylene nanoplastics: A combined theoretical and experimental investigation

Polypropylene (PP) is a key component of nanoplastics detected globally in water, which can carry pollutants through co-transport. In this regard, the co-transport of perfluoroalkyl substances (PFAS) by nanoplastics (NPs) raises significant concern, as NPs can act as vectors that enhance PFAS uptake and bioaccumulation in organisms during co-exposure. In this context, research has shown interactions between NPs and PFAS, but the adsorption mechanism remains still unclear. In this work, a powerful synergic approach combining several computational and experimental techniques has been used to unveil the adsorption mechanism of perfluorooctanesulfonate (PFOS), which is one of the most widespread contaminants of emerging concerns (CECs) on PP nanoparticles. According to our DFT results, PFOS adsorbs onto the outer and inner surface of the nanoparticle, with a maximum adsorption energy of ≈ 18 kcal/mol and an adsorption mechanism mainly governed by dispersion forces between the two fragments. Batch experiments have confirmed that PFOS rapidly adsorbs on PP nanoparticle, showing that pH can reduce the adsorption capacity thus affecting the co-transport. Moreover, the dipole moment of the PFOS-nanoparticle complex has been found to be significantly larger as compared to the bare nanoparticle, resulting in a more pronounced transport in aqueous environment and making the PFOS-PP nanoparticle complex much more dangerous than the bare PP nanoparticle. Altogether, our results allowed us to disentangle the adsorption mechanism of PFAS on PP nanoparticles, which is a fundamental step to understand the co-occurrence of such dangerous pollutants in environmental matrices, as well as to obtain new information for toxicity and risk-models development.

Photocatalytic innovations in PFAS removal: Emerging trends and advances

Per- and polyfluoroalkyl substances (PFAS), such as perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), are persistent environmental pollutants posing significant risks to ecosystems, drinking water safety, and human health. Conventional PFAS removal methods effectively mitigate contamination but face challenges such as high operational costs, energy demands, and secondary waste production. Photocatalytic methods have emerged as a promising alternative, utilizing light-activated semiconductors to generate reactive oxygen species (ROS), which facilitate the efficient degradation of PFAS into non-toxic byproducts. Advanced photocatalysts, such as titanium dioxide (TiO2), demonstrate significant potential under UV and visible light, though challenges remain, including low activity under visible light, rapid recombination of photogenerated electron-hole pairs, and inefficient carrier utilization. To address these limitations, strategies such as non-metal and metal doping and combining wide- and narrow-bandgap semiconductors have been explored to enhance light absorption, photocatalytic efficiency, and stability. Recent developments in photocatalysts, including PMR technology (80 % PFOA removal in 2 h) (Junker et al., 2024b), Bi4O7-modified Ga2O3 (59.6 % defluorination) (Chen et al., 2024), and lead-doped TiO2/rGO (98 % PFOA removal in 24 h) (Chowdhury and Choi, 2023), have improved PFAS degradation by optimizing light absorption, charge separation, and surface adsorption. Hybrid systems integrating photocatalysis with other treatment methods, such as adsorption and electrochemical oxidation, offer a path toward sustainable, efficient PFAS remediation. This review explores the latest advancements in photocatalytic technologies and highlights future directions, including the development of cost-effective, environmentally friendly materials and field-scale validation. These efforts emphasize the potential of photocatalysis as a cornerstone in achieving sustainable water treatment solutions and protecting environmental and public health.

Celecoxib as a potential treatment for hepatocellular carcinoma in populations exposed to high PFAS levels

Per- and polyfluoroalkyl substances (PFAS), including perfluorooctane sulfonate and perfluorooctanoic acid, are associated with adverse human effects. However, few studies have assessed the effects of PFAS mixtures on hepatocellular carcinoma (HCC). In this study, we systematically investigated the effects and underlying mechanisms of PFAS mixtures on the proliferation, migration, and invasion of HCC cells (JHH-7 and Li-7) in vitro using a combination of biological techniques and high-coverage untargeted metabolomics. A six day exposure to a 5 μM PFAS mixture significantly enhanced the malignant progression of HCC in vitro. Metabolomic analysis identified the upregulation of prostaglandin E2 (PGE2) as a key factor associated with these effects. This hypothesis was further validated using celecoxib, a PGE2 inhibitor, which reduced PGE2 levels in HCC cells, consequently slowing their migration and invasion. Additionally, mice treated with celecoxib exhibited reduced tumor volumes compared with those treated with PFAS alone. These results suggest that PFAS exposure enhances HCC malignancy through the PI3K/AKT signaling pathway via increased PGE2 production. In conclusion, a 5 μM PFAS mixture accelerates HCC proliferation and invasion; moreover, celecoxib demonstrates potential as a therapeutic agent that inhibits these effects.

Furthering the Capabilities of Diffusive-Gradient Passive Samplers for Per- and Polyfluoroalkyl Substances

Per- and polyfluoroalkyl substances (PFAS) are chemical pollutants of growing concern for many stakeholders. Due to their ubiquity, persistence in the environment, and potential for toxicity at low environmental concentrations, it is necessary to have convenient and reliable methods to measure PFAS in natural waters. Passive sampling methods (in situ preconcentration of PFAS) may be suitable for monitoring situations. One passive sampling design successfully employed for other, well studied contaminants (e.g., methylmercury) is the diffusive gradient in thin film sampler (DGT). However, the application of DGT for PFAS requires development and validation. Here, we iterate on previous PFAS-DGT studies by introducing a redesigned diffusive gradient sampler for PFAS in water and show that it reliably measures 25 PFAS in water, consistent with diffusion theory. Diffusion and whole-sampler uptake rates consistently agreed with model predictions within ±50% relative difference, including when tested at cold temperature (5 °C). In field and laboratory deployments, DGT samplers measured PFAS concentrations within ±23% of grab sample results on average in each case─better performance than codeployed microporous polyethylene tube passive samplers. Based on the evidence in this study, the DGT passive sampler is a promising tool for consistently and accurately passively sampling PFAS in natural waters.

Hold My Beer: The Linkage between Municipal Water and Brewing Location on PFAS in Popular Beverages

Beer has been a popular beverage for millennia. As water is a main component of beer and the brewing process, we surmised that the polyfluoroalkyl substances (PFAS) presence and spatial variability in drinking water systems are a PFAS source in beers. This is the first study to adapt EPA Method 533 to measure PFAS in beer from various regions, brewery types, and water sources. Statistical analyses were conducted to correlate PFAS in state-reported drinking water, and beers were analyzed by brewing location. PFAS were detected in most beers, particularly from smaller scale breweries located near drinking water sources with known PFAS. Perfluorosulfonic acids, particularly PFOS, were frequently detected, with PFOA or PFOS above U.S. EPA's Maximum Contaminant Limits in some beers. There was also a county-level correlation between the total PFAS, PFOA, and PFBS concentrations in drinking water and beers. Given that approximately 18% of U.S. breweries are located within zip codes with detectable PFAS in municipal drinking water, our findings, which link PFAS in beer to the brewery water source, are intended to help inform data-driven policies on PFAS in beverages for governmental agencies, provide insights for brewers and water utilities on treatment needs, and support informed decision-making for consumers.

Critical role of pore size on perfluorooctanoic acid adsorption behaviors in carbonaceous sorbents

Per- and polyfluoroalkyl substances (PFAS) are an emergent threat to the environment due to their toxic, carcinogenic, and environmentally persistent nature. Commonly, these harmful micropollutants are removed from contaminated water sources through adsorption by porous sorbents such as activated carbon. While studies suggest a relationship between sorbent pore size and their PFAS remediation performance, the underlying mechanisms-particularly those related to sorbate morphology-have not been elucidated through direct experimental observations. This work investigates how pore size in carbonaceous sorbents impacts the morphology of adsorbed perfluorooctanoic acid (PFOA) aggregates and their sorption behavior, using microporous and mesoporous carbons as models. Contrast-matching small-angle neutron scattering (CM-SANS) is used to determine the structure of adsorbed PFOA molecules, supported by molecular dynamics simulations and physisorption experiments. Our findings reveal that the larger pore sizes in mesoporous sorbents enable the formation of PFOA assemblies during adsorption, which is hindered in microporous sorbents. Collectively, this work provides direct insights into the adsorption and assembly mechanisms of PFAS molecules within confined pores, offering important insights for the rational design of effective remediation systems.

Per- and polyfluoroalkyl substances (PFAS) in drinking water systems in the lower Yangtze River: source, fate, and health risk assessment

The Yangtze River is significantly impacted by industrial activities related to per- and polyfluoroalkyl substances (PFAS) in China, posing potential threats to drinking water safety. So far, our knowledge of PFAS occurrence in the river and their fate in the whole drinking water supply systems remains limited. We conducted a comprehensive investigation of PFAS in Jiangsu's drinking water systems, using the target screening method. 12 perfluoroalkyl acids (PFAAs) and 7 emerging PFAS were detected and precisely quantified in the whole treatment process water flows, as well as source water and household tap water with concentrations of 61.34-90.40 ng/L. PFAAs [PFOA (30.26 ng/L), PFBS (23.25 ng/L), PFBA (18.82 ng/L) and PFHxA (16.89 ng/L)] and 8:8 PFPiA (13.63 ng/L) were the dominant pollutants in the low Yangtze River. PFBA (19.92 ng/L), PFBS (15.02 ng/L) and PFOA (11.94 ng/L) were major contaminants in tap water. The powder activated carbon pre-treatment in DWTP-B could remove 21.36-65.84% of long-chain PFAS, especially PFOA. Ozonation achieved slight emerging PFAS removal (3.22-11.06%), while PFAAs concentrations exhibited an increase. Granular active carbon filtration was effective in removing long-chain PFAS, with DWTP-B outperforming DWTP-A. PFSAs (3.12-22.09%) had a better removal than PFCAs (- 0.62 to 19.54%). Infants and children face a moderate health risk of PFAS intake through drinking water, peaking at the age group of 9 months to 1 year (HQ = 2.45). These findings underscore the necessity for improved PFAS removal technologies and stricter regulation of PFAS contamination in the Yangtze River to reduce exposure.

Degradation and defluorination of C6F13 PFASs with different functional groups by VUV/UV-based reduction and oxidation processes

Structural diversity can affect the degradability of per- and polyfluoroalkyl substances (PFASs) during water treatment. Here, three PFASs with different functional groups-C6F13-R, PFHpA, PFHxS, and 6:2 FTS-were degraded using vacuum ultraviolet (VUV/UV)-based treatments. While fully fluorinated PFASs-PFHpA and PFHxS-were degraded faster in the VUV/UV/sulfite reaction than in VUV/UV photolysis, VUV/UV photolysis was more effective for degrading 6:2 FTS by OH radicals produced through photolysis of water. PFCAs such as PFHxA, PFPeA, and PFBA were formed by VUV/UV photolysis of PFHpA and 6:2 FTS, but the PFCA formation was inhibited in the VUV/UV/sulfite reaction. The degradation of the three PFASs in the VUV/UV/sulfite reaction was mainly carried out by H/F and SO3•-/F exchange mechanisms, mediated by hydrated electrons (eaq-) produced in the reaction. During the VUV/UV/sulfite reaction, PFCA precursors were first formed as transformation products, which were further transformed into PFCAs by the following VUV/UV/H2O2 reaction, implying enhanced defluorination of three PFASs. Our results indicate that VUV/UV-based treatments can be an option for PFAS degradation and defluorination by combining advanced reduction and oxidation processes and utilizing both eaq- and oxidative radicals.

Polystyrene nanoplastics amplify the toxic effects of PFOA on the Chinese mitten crab (Eriocheir sinensis)

Nanoplastics (NPs), the final form of degraded microplastics in the environment, can adsorb PFOA (an emerging organic pollutant in recent years) in several ways. Current research on these has focused on bony fishes and mollusks, however, the combined toxicity of PFOA and NPs remains unknown in Eriocheir sinensis. Therefore, the effects of single or combined exposure to PFOA and NPs were investigated. The results showed that NPs aggravated PFOA exposure-induced oxidative stress, serum lipid disorders, immune responses, and morphological damage. DEGs altered by NPs-PFOA exposure were predominantly enriched in GO terms for cell lumen, and organelle structure, and KEGG terms for spliceosome and endocrine disorders-related diseases. Notably, the apoptotic pathway plays a central role enriched under different exposure modes. PFOA or NPs-PFOA exposure disrupted the levels of lipids molecules-related metabolites by mediating the glycerophospholipid pathway, and the NPs mediated the ferroptosis pathway to exacerbate PFOA-induced metabolic toxicity. In addition, NPs exacerbated the inflammatory response and metabolic imbalance by mediating Fusobacterium ulcerans in the intestinal. In conclusion, this study provides a valuable reference for the characterization of NPs-PFOA combined pollution and a scientific basis for the development of environmental protection policies and pollution management strategies.

Current Approaches in the Classification of PFAS: An Overview

Perfluoroalkyl substances (PFAS) represent a broad group of synthetic chemicals that have raised concerns related to their long-term environmental persistence and potential health risks. Although several efforts have been dedicated to establishing international restrictions on their use, the definition of what qualifies as a PFAS remains a matter of debate among scientists, regulatory agencies, and industry. This article provides a brief overview of the different approaches proposed and adopted to date for identifying and grouping of these pollutants, either based on common structural motifs or on the combination of multiple factors, including functional uses, degradation behavior, physicochemical properties, and toxicity. The diversity and complexity of PFAS substances suggests the need of a multifaceted classification system that can guide regulatory efforts, risk assessment, and environmental monitoring through standardized criteria accepted on an international scale. A pivotal role in establishing a universal definition of PFAS will be played by the International Union of Pure and Applied Chemistry (IUPAC), which is currently supporting a project on the terminology and classification of these chemicals.

PFHxA and PFHxS promote breast cancer progression in 3D culture: MEX3C-associated immune infiltration revealed by bioinformatics and machine learning

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants with widespread use and bioaccumulative potential. Short-chain PFAS such as perfluorohexanoic acid (PFHxA) and perfluorohexane sulfonate (PFHxS) have been introduced as safer alternatives to long-chain PFAS, yet their toxicological impacts remain poorly defined. In this study, we employed a 3D Gelatin methacryloyl (GelMA) hydrogel model to mimic the tumor microenvironment and investigated the effects of PFHxA and PFHxS on triple-negative breast cancer (TNBC) progression. At environmentally relevant concentrations (0.1-10 μM), both compounds significantly enhanced proliferation, migration, and invasion of MDA-MB-231 cells. Transcriptomic and machine learning analyses identified MEX3C as a key gene upregulated by PFAS exposure. Gene set enrichment analysis (GSEA) revealed activation of the PI3K-AKT-mTOR signaling pathway, which was further supported by siRNA-mediated knockdown of MEX3C, leading to a marked reduction in the expression levels of phosphorylated PI3K, AKT, and mTOR proteins. Furthermore, immune cell co-culture experiments showed that MDA-MB-231 cells with high MEX3C expression promoted M2 macrophage polarization, suppressed M1 polarization, and enhanced macrophage chemotactic activity, the immunomodulatory effects were significantly attenuated upon MEX3C knockdown. These findings establish MEX3C as a central mediator of PFAS-induced tumor progression and immune remodeling. This study provides mechanistic insight into the carcinogenic potential of emerging short-chain PFAS and underscores the need for stricter regulation to safeguard public health.

Unveiling PFAS hazard in European surface waters using an interpretable machine-learning model

Per- and polyfluoroalkyl substances (PFAS), commonly known as "forever chemicals", are ubiquitous in surface waters and potentially threaten human health and ecosystems. Despite extensive monitoring efforts, PFAS risk in European surface waters remain poorly understood, as performing PFAS analyses in all surface waters is remarkably challenging. This study developed two machine-learning models to generate the first maps depicting the concentration levels and ecological risks of PFAS in continuous surface waters across 44 European countries, at a 2-km spatial resolution. We estimated that nearly eight thousand individuals were affected by surface waters with PFAS concentrations exceeding the European Drinking Water guideline of 100 ng/L. The prediction maps identified surface waters with high ecological risk and PFAS concentration (>100 ng/L), primarily in Germany, the Netherlands, Portugal, Spain, and Finland. Furthermore, we quantified the distance to the nearest PFAS point sources as the most critical factor (14%-19%) influencing the concentrations and ecological risks of PFAS. Importantly, we determined a threshold distance (4.1-4.9 km) from PFAS point sources, below which PFAS hazards in surface waters could be elevated. Our findings advance the understanding of spatial PFAS pollution in European surface waters and provide a guideline threshold to inform targeted regulatory measures aimed at mitigating PFAS hazards.

PFAS removal via adsorption: A synergistic review on advances of experimental and computational approaches

Per- and polyfluoroalkyl substances (PFAS), commonly known as "forever chemicals", have become a major focus of current research due to their toxicity and persistence in the environment. These synthetic compounds are notoriously difficult to degrade, accumulating in water systems and posing long-term health and environmental risks. Adsorption is one of the most investigated technologies for PFAS removal. This review comprehensively reviewed the PFAS adsorption process, focusing not only on the adsorption itself, but also on the behavior of PFAS in the aquatic environment prior to adsorption because these behaviors directly affect PFAS adsorption. Significantly, this review summarized in detail the advances made in PFAS adsorption from the computational approach and emphasized the importance of integrated experimental and computational studies in gaining molecular-level understanding on the adsorption mechanisms of PFAS. Toward the end, the review identified several critical research gaps and suggested key interdisciplinary research needs for further advancing our understanding on PFAS adsorption.

Unveiling the overlooked silent threat: High-throughput suspect screening of antibiotics and multidimensional heterogeneity in aquatic ecosystems of megacity

The environmental and health impacts of antibiotics (ABx) have garnered global attention. However, the issue of ABx contamination in aquatic ecosystems of densely populated megacities remains largely overlooked. Significant research gaps persist, particularly in understanding the full-chain pollution characteristics that span from urban aquatic environments to edible aquatic organisms, due in part to the lack of systematic monitoring data to support comprehensive assessments. To address this gap, this study conducts the first comprehensive screening of ABx in the aquatic ecosystems of a megacity, offering quantitative evaluations of ABx complexity and multidimensional heterogeneity. Over a one-year period, 406 samples were collected from four rivers and three lakes, and large-scale analyses identified 37 ABx compounds, with the overall detection rate of 30.05 %, with Sulfonamides (SAs), Quinolones (QNs), and Macrolides (MLs) being the most prevalent. Surface water samples contained the greatest number of ABx types, while amphibians exhibited the highest detection rate and concentrations. A pronounced increase in detections during the dry season (spring and winter) highlighted substantial spatio-temporal variation. Source-sink analysis revealed hospital effluents and wastewater treatment plants as primary pollution sources. Among the detected compounds, Nalidixic acid (NCA), Sulfamethazine (SMTZ), Flumequine (FQ), and Tylosin (TLS) posed the most significant ecological risks, with NCA identified as a priority for targeted control. This study establishes a novel framework for the high-throughput suspect screening, occurrence pattern analysis, and risk assessment of ABx in megacities worldwide.

Three-Dimensional Cultured Human Nasal Epithelial Cell Model for Testing Respiratory Toxicity and Neurotoxicity of Air Pollutants

Accumulating evidence suggests a strong correlation between air pollution and neurological disorders; however, appropriate models and methodologies are currently lacking. In this study, a human nasal RPMI 2650 cell model based on air-liquid interface culture was discovered to possess olfactory epithelial cells. Two short-chain per- and polyfluoroalkyl substances (PFAS), PFBA and PFHxA, were used to validate the performance of the model. RNA sequencing initially revealed the adverse effects of two PFAS at environmentally relevant concentrations. Their effects on key nasal epithelial cell functions, including barrier protection, solute transport, and neuronal activity, were separately investigated. Both PFBA and PFHxA disrupted membrane integrity and increased cellular transport capacity, as indicated by the upregulation of ABC transporters. Additionally, they inhibited tight junction proteins, including ZO-1, claudin-3, and occludin, while increasing mucin expression and mucus secretion. PFHxA exhibited stronger effects in most assays and uniquely induced a significant upregulation of NOTCH1 expression (p < 0.05), highlighting its potential hazards on olfactory neurons. This study proposed a novel in vitro test model with the matched respiratory epithelial and neuronal end points, which was expected to improve toxicological research and risk assessment of air pollutants.

Functional coatings for textiles: advancements in flame resistance, antimicrobial defense, and self-cleaning performance

The continuous evolution of textile technologies has led to innovative functional coatings that enhance protective textiles by integrating flame retardancy, antimicrobial efficacy, and self-cleaning properties. These multifunctional coatings address the growing demand for high-performance materials in healthcare, military, and industrial applications. This study reviews advancements in coating techniques, including dip-coating, spray-coating, sol-gel processes, and layer-by-layer assembly, highlighting their effectiveness in imparting durability, thermal stability, and biological activity to textile substrates. The incorporation of bioactive materials such as chitosan, silver nanoparticles, and plant-derived antimicrobials has demonstrated enhanced pathogen resistance and prolonged fabric functionality. Furthermore, recent developments in phosphorus-based flame retardants and photocatalytic self-cleaning agents, including titanium dioxide and silica nanoparticles, have contributed to the sustainability of functional textiles by reducing environmental impact. Challenges remain in achieving compatibility among diverse functional components while maintaining mechanical integrity and user comfort. Scalability and cost-efficiency also present barriers to commercialization, necessitating cross-disciplinary collaboration among material scientists, engineers, and regulatory experts. Future research should focus on biodegradable alternatives, smart-responsive coatings, and advanced nanomaterial integration to enhance the longevity and eco-friendliness of protective textiles. As industry standards shift towards sustainability, functional coatings are poised to redefine textile applications, offering tailored solutions that balance safety, performance, and environmental responsibility. This review underscores the transformative potential of multifunctional textile coatings and their role in advancing next-generation protective fabrics.

Health Impacts of Per- and Polyfluoroalkyl Substances (PFASs): A Comprehensive Review

Per- and polyfluoroalkyl substances (PFASs) are among the persistent organic pollutants characterized by their persistence in the environment, high mobility, and adverse impact not only on the ecosystem but also on human health. The biggest challenges in human biomonitoring are the low concentrations of PFASs in biological matrices and the presence of matrix interferents in samples. The combination of liquid chromatography with tandem mass spectrometry (LC-MS/MS) and solid-phase extraction (SPE) as a sample preparation technique appears to be the most suitable solution for achieving the desired selectivity and sensitivity in PFAS determination. The aim of this review is to describe possible sources of PFASs, their presence in various human matrices, analytical methods for determining PFASs in different biological matrices using various pretreatment techniques for complex samples, as well as adverse health risks associated with PFAS exposure. The most studied PFASs include PFOA and PFOS, which are most frequently detected in matrices such as plasma, serum, and breast milk. The average concentrations of PFOA range from 1.0 to 2.6 ng.mL-1 in plasma, 1.9 to 2.4 ng.mL-1 in serum, and 0.4 to 3.1 ng.mL-1 in breast milk. For PFOS, the average concentrations were 2.0-4.0 ng.mL-1, 3.7-4.6 ng.mL-1, and 3.6-4.8 ng.mL-1 for plasma, serum, and breast milk, respectively. The most significant health effects associated with exposure to long-chain PFASs (such as PFOA and PFOS) include lipid disorders, hypertension, diabetes mellitus, thyroid disorders, infertility, cancer, obesity, autism, neurodevelopmental issues, cardiovascular diseases, and kidney and liver disorders. It is of utmost importance to monitor PFAS exposure, predict their toxicity, and develop effective strategies to mitigate their potential effects on human health.

Safe Reuse of Treated Wastewater: Accumulation of Contaminants of Emerging Concern in Field-Grown Vegetables under Different Irrigation Schemes

The reuse of treated wastewater (TWW) for irrigation alleviates freshwater (FW) scarcity while supporting a circular economy. However, the potential human exposure to contaminants of emerging concern (CECs) through plant accumulation is a significant barrier. Currently, knowledge on CEC contamination of edible produce and effective mitigation strategies for the safe reuse of TWW is limited, particularly under field conditions. This study examined the accumulation of a representative set of CECs, including perfluoroalkyl and polyfluoroalkyl substances (PFAS), pharmaceuticals and personal care products, and tire wear particle (TWP) chemicals, in radish, lettuce, and tomato under three irrigation practices: FULL (continuous TWW irrigation), HALF (midseason switch from TWW to FW), and FW-only. Despite low PFAS concentrations (8.1-25.7 ng/L) in TWW, the plant uptake was consistently observed, including in tomato fruits. Alternating TWW with FW significantly reduced CEC accumulation in edible tissues, particularly for compounds with short half-lives, with reductions up to 82.4% even for persistent PFAS. For most CECs and plant species, edible tissue concentrations were similar between the HALF and FW treatments. These findings demonstrate the on-farm applicability of simple irrigation modifications to reduce food contamination and contribute to the promotion of safe reuse of nonconventional waters.

Multigeneration responses of Daphnia magna to short-chain per- and polyfluorinated substances (PFAS)

Short-chain per- and polyfluorinated substances (PFAS) are ubiquitous in the environment, but their chronic effects on aquatic organisms over multiple generations are often overlooked in environmental risk assessment. In this study, the ecotoxicity of perfluorobutane sulfonic acid (PFBS) and its precursor perfluorobutane sulfonamide (FBSA) to Daphnia magna was assessed under continuous exposure for six consecutive generations, with adult survival, reproduction, and population growth rate as endpoints. Observed effects were also related to internal PFAS concentrations in the daphnids. Compared to the first generation, both PFBS and FBSA showed intensified ecotoxicity over six generations, increasing by 1.8-3.0, and 3.6-6.4 times, respectively. Specifically, the EC50_r, water and LC50, water of PFBS decreased from 886 and > 1470 mg/L in the F0 generation to 470 and 483 mg/L, respectively in the F3 generation, while the EC50_r, water and EC50_repro, water of FBSA decreased from 12.4 and 7.08 mg/L in the F0 generation to 3.37 and 1.10 mg/L, respectively in the F5 generation. PFBS ecotoxicity increased as a result of elevated compound accumulation over generations, indicating a narcotic mode of action, whereas FBSA exerted specific reproductive toxicity, resulting in a more pronounced worsening of adverse effects over time. Compared to PFBS, FBSA was around 100 times more toxic in F0, escalating to over 435 times more toxic in F5, and also showed a higher bioaccumulation potential. These findings highlight that the conventional single-generation ecotoxicity tests underestimate PFAS ecotoxicity during multigeneration exposure, and that the environmental risks of PFAS cannot be reliably assessed by the current limited subset of studied compounds.

Phenolic Modified SiO2 Aerogel as a Hybrid Thermal Insulation Systems

SiO2 aerogel is a good thermal insulation material, but its porous nanostructure makes it brittle and has a poor mechanical property. SiO2 aerogel with a good elastic property was prepared by combining methyltrimethoxysilane (MTMS) and hexadecyltrimethoxysilane to form a composite organic silane precursor. However, its mechanical properties were not significantly improved. SiO2/phenolic-modified aerogel was prepared by modifying SiO2 aerogel with thermosetting phenolic resin, which effectively improved the mechanical properties of SiO2 aerogel. The results show that when the molar ratio of hexadecyltrimethoxysilane to MTMS is in the range of 0-0.05, the elastic properties of the aerogel continue to improve with the increase of the introduction of hexadecyltrimethoxysilane. The maximum compressive strength can reach 0.03 MPa, and the strain tolerance range is 10-18%. When the mass ratio of MTMS to phenolic resin is within the range of 0-5.5, the modified aerogel presents a nanoscale gel network structure. The maximum compressive strength can reach 0.048 MPa, which is nearly 60% higher than the maximum compressive strength of the aerogel before modification. The allowable strain range is 14.7-17.5%. After 20 stress-strain tests, the maximum compressive strength only decreases by 4%, indicating good stability. It simultaneously possessing low density (0.176 g/cm3), volume shrinkage rate, and low thermal conductivity. The thermal conductivity in an air atmosphere at 28 °C is 0.057 W/(m·K). The modified aerogel prepared by the sol-gel reaction and atmospheric drying process has broad application prospects.

Unique per- and polyfluoroalkyl substances (PFAS) source suggested by a Lake Trout (Salvelinus namaycush) PFAS profile in a temperate lake

Per- and polyfluoroalkyl substances (PFAS) are detected in pelagic freshwater fish and have deleterious effects on their health. It is unclear if traditional proxies for uptake of contaminants in fish (e.g., length, weight, age) predict fish PFAS concentrations. Here, we observe that summed PFAS concentrations are significantly higher in Lake Trout (Salvelinus namaycush) than other sportfish in Seneca Lake, New York. Carbon source (as proxied by δ13C) predicted variability within species, and trophic level (as proxied by δ15N) trended among species. A moderate inverse correlation (r = -0.51) was found between mercury and summed PFAS in Lake Trout. Summed PFAS concentrations and length, weight, or age were not statistically related, suggesting these characteristics are not reliable proxies for PFAS bioaccumulation. Length, weight, and age were significant predictors for mercury, indicating these drivers may be resulting in differential bioaccumulation in PFAS and mercury. In Seneca Lake, a unique PFAS composition was found for Lake Trout, where PFOS represents a lower proportion of summed PFAS than in other species in Seneca Lake, as well as relative to Lake Trout from other neighboring Finger Lakes. In addition, compared to Lake Erie and Lake Ontario, Lake Trout from Seneca Lake have higher concentrations of PFOA, PFNA, and PFDA, but lower proportions of PFOS. Lake Trout from Seneca Lake have a PFAS composition that consists almost exclusively of perfluoroalkyl carboxylic acids (PFCAs) and perfluorosulfonic acids (PFSAs), similar to the composition used in aqueous film forming foams (AFFF) before 2000 at a former military and current Superfund site in the lake's watershed.

Longitudinal trends of per- and poly-fluoroalkyl substances (PFAS) in nestling bald eagles (Haliaeetus leucocephalus) from Wisconsin

We analyzed concentrations and trends of per- and polyfluoroalkyl substances (PFAS) in 96 nestling bald eagles (Haliaeetus leucocephalus) at six study sites throughout Wisconsin from 2011 to 2017. Nestling blood plasma concentrations of the sum of 11 PFAS analytes (∑11 PFAS) differed among study locations: the highest concentration was in the industrialized Green Bay region at study area: Upper Green Bay/Lake Michigan (GBLM; estimated mean = 313.18 μg/L; range = 188.3-478.9 μg/L). For study locations with only one year of data, PFAS were highest at downstream Wisconsin River sites: Lower Wisconsin State River (LWSR; estimated mean = 646.7 μg/L; range 376.0-979.8 μg/L) and Middle Wisconsin River (MDWR; 659.6 μg/L; range = 209.3-928.6 μg/L). Overall, perfluoroctanesulfonate (PFOS) was the most abundant analyte at all study locations. Perfluoroundecanoate (PFUnDA) and perfluorodecanoate (PFDA) were the second and third highest concentration analytes at most sites. Temporal trends existed for ∑11 PFAS and all analytes for most of the study locations with more than one year of data - with patterns for analytes differing by study location. In addition, nestling age significantly altered plasma concentrations of ∑11 PFAS and PFOS - concentrations were higher in older nestlings, ranging from 3.77 to 4.38 μg/L per day of age difference, respectively. We have illustrated that bald eagles can be useful and reliable bioindicators of PFAS exposure and environmental change. The results from this study can be used by management and conservation agencies to highlight locations of concern that could be prioritized for remediation.

Per- and polyfluoroalkyl substances in environment and potential health impacts: Sources, remediation treatment and management, policy guidelines, destructive technologies, and techno-economic analysis

Per- and polyfluoroalkyl Substances (PFAS), also known as forever chemicals and ubiquitous persistence, pose significant public health challenges due to their potential toxicity, particularly in drinking water and soil contamination. However, PFAS occurrence and their concentrations in different environmental matrices vary globally, but factors influencing trends, transport, fate, toxicity, and interactions with co-contaminants remain largely unexplored. Therefore, this review critically examines the state-of-the-art worldwide PFAS sources, distribution, and pathways, and evaluates how PFASs are processed in wastewater treatment, generally, which causes severe problems with the quality and safety of drinking water. Importantly, the review also underscores health issues due to PFAS consumption and recent research trends on developing effective treatment strategies to manage PFAS contamination. Potential effects of PFAS were linked to urban land use and the proportion of wastewater effluent in streamflow. Besides, major emphasis was provided on challenges for conventional treatment, destructive technologies, environmental accumulation, precursor transformation, and cost-investment related to PFAS removal technologies. To combat PFAS contamination, this review proposes a framework that promotes the comprehensive identification of prevalent compounds, with a focus on their eradication through knowledge-based and targeted analysis. Additionally, it explores the ongoing debate surrounding PFAS laws and legal frameworks, offering ideas for enhancing contamination management. Lastly, this review provides a strategic plan for improving response and preparedness, serving as a foundation for addressing future environmental challenges and informing health risk assessments.

Cyclic removal and destruction of per- and polyfluoroalkyl substances from water using ion exchange, resin regeneration, and UV/sulfite reduction

Ion exchange (IX) can effectively remove per- and poly-fluoroalkyl substances (PFAS) from drinking water sources at ng/L to µg/L levels. However, adsorbed PFAS on spent resins should be further destructed for detoxification. Traditional resin incineration or landfilling may cause secondary pollution to the surrounding environment and cannot achieve resin reuse. This study explored three variations of a PFAS treatment train, aiming to completely defluorinate PFAS with different chain lengths and functional groups at environmentally relevant levels (ng/L) and to reuse the resins and solvents. The optimized treatment train includes IX, resin regeneration with 5 wt% NaCl and 60 % v/v methanol, distillation of waste regenerant, and advanced reduction by hydrated electrons (eaq-) generated during the ultraviolet/sulfite (UV/sulfite) treatment of still bottoms. Such a treatment train achieved nearly 100 % PFAS removal from surface water and groundwater using either PFAS-specific or generic resins, and almost 100 % defluorination of PFAS except a few short-chain fluorinated sulfonates and ethers. Regenerated resins had comparable PFAS removal to the pristine resins over three cycles. The generic resins (e.g., Dupont AmberLite™ IRA910) are easier to regenerate and thus are recommended for the treatment train over PFAS-selective resins (e.g., Purofine® PFA694E). Direct heterogenous defluorination on resins loaded with perfluorooctane sulfonate (PFOS) was ineffective, potentially due to the consumption of UV light/eaq- by the resins and insufficient contact between the UV light/eaq- with PFOS on the resin surface. Distillation of the waste regenerant successfully concentrated PFAS in the still bottoms, reduced the waste volume, and removed excess methanol, all essential for effective UV/sulfite treatment. Meanwhile, the produced condensate with high methanol contents and low PFAS levels can be reused for the next regeneration cycle. Findings from this study provide a timely and sustainable solution to the stringent and evolving regulations on PFAS and the resultant production of PFAS-laden resins as hazardous wastes.

Revealing hidden risks: in vitro analysis of PFAS hazards in Mytilus galloprovincialis gills and digestive gland

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals known for their persistence and bioaccumulation, leading to widespread environmental contamination. Despite their recognised environmental risks, particularly to aquatic wildlife, including marine invertebrates, detailed impact studies are limited. PFAS can be categorised according to the length of the compound chain, with short-chain PFAS announced as a safer alternative to the more commonly used long-chain PFAS. However, recent evidence suggests that also short-chain PFAS pose significant environmental risks. The present study evaluated the adverse effects of six PFAS compounds-two short-chain (PFHxA, 6:2 FTA) and four long-chain (PFUnDA, PFDoA, PFTriDA, PFTeDA)- on the digestive gland and gills of mussels, Mytilus galloprovincialis, using in vitro assays. The results showed organ-specific responses: the digestive gland was more sensitive to PFHxA, with increased catalase activity and decreased total antioxidant capacity, and cellular damage was observed only at higher concentrations of PFTriDA. Gills were more affected by PFDoA and PFTeDA, with inhibited antioxidant enzyme activity and increased oxidative stress. PFHxA and PFTriDA also showed inhibition of acetylcholinesterase activity. 6:2 FTA had the lowest effects for both organs, while PFHxA was the most harmful. These findings underscore the need for thorough risk assessments of PFAS, considering both chain length and organ-specific effects.

Unveiling the emerging concern of per- and polyfluoroalkyl substances (PFAS) and their potential impacts on estuarine ecosystems

Per- and polyfluoroalkyl substances (PFAS) have become ubiquitous chemicals that pose potentially serious threats to both human health and the integrity of the ecosystem. This review compiles current knowledge on PFAS contamination in estuaries, focusing on sources, abundance, distribution, fate, and toxic mechanisms. It also addresses the health risks associated with these compounds and identifies research gaps, offering recommendations for future studies. Estuaries are essential for maintaining biodiversity and serve as protective natural buffers against pollution flowing from land to sea. However, PFAS, known for their persistence and bioaccumulation potential, are detected in estuarine waters, sediments, and biota worldwide, with varying concentrations based on geographic locations and environmental matrices. Sources of PFAS in estuaries include routine items like nonstick kitchenware, industrial emissions, landfill sites, civilian and military airfields, and runoff from firefighting activities. The fate of PFAS in estuarine ecosystems is influenced by hydrology, biogeochemical interactions, and proximity to pollution sources.

The Environmental Impact of Medical Imaging Agents and the Roadmap to Sustainable Medical Imaging

Medical imaging agents, i.e., contrast agents for magnetic resonance imaging (MRI) and radiopharmaceuticals, play a vital role in the diagnosis of diseases. Yet, they mostly contain harmful and non-biodegradable substances, such as per- and polyfluoroalkyl substances (PFAS), heavy metals or radionuclides. As a result of their increasing clinical use, these agents are entering various water bodies and soil, posing risks to environment and human health. Here, the environmental effects of the application of imaging agents are outlined for the major imaging modalities, and the respective chemistry of the contrast agents with environmental implications is linked. Recommendations are introduced for the design and application of contrast agents: the 3Cs of imaging agents: control, change, and combine; and recent approaches for more sustainable imaging strategies are highlighted. This combination of measures should engage an open discussion, inspire solutions to reduce pollution by imaging agents, and increase awareness for the impact of toxic waste related to imaging agents.

Accumulation and trophic transfer of per- and polyfluoroalkyl substances (PFAS) in estuarine organisms determined via stable isotopes

Per- and polyfluoroalkyl substances (PFAS) are persistent organic pollutants in estuaries. In this study, 19 PFAS were quantified in surface waters, sediments, marine invertebrates (aquatic worms, Eastern oysters, and blue crab), and forage fish (Atlantic silverside, four-spine stickleback, mummichog, sheepshead minnow, and rainwater killifish) in an aqueous film forming foam (AFFF)-contaminated estuary, Georgica Pond (NY, USA). Carbon and nitrogen stable isotopes (δ13C and δ15N) were used to determine trophic position of organisms and to identify modes of PFAS exposure. The influence of salinity (8 to 26 practical salinity units, PSU) on the relative and absolute abundance of PFAS in all matrices was also investigated. Eleven long- and short-chain perfluoroalkyl acids (PFAAs) were found to have bioaccumulation potential (bioaccumulation factor, BAF; biota-sediment accumulation factor, BSAF) and were positively correlated with relative trophic position. Among these, long-chain PFAAs (perfluorohexanesulfonic acid, PFHxS; perfluorooctane sulfonic acid, PFOS; perfluorooctanoic acid, PFOA; perfluorononanoic acid, PFNA) were the greatest contributors to total body burden and bioaccumulated in all organisms, with PFOS (log BAF = 3.55 ± 0.83) and PFNA (log BAF = 3.17 ± 0.46) having the highest mean values of all compounds. PFOS was present in all biota samples and concentrations significantly increased with food web trophic position (ranging from 0.18 to 777 μg kg-1). Perfluorobutane sulfonic acid (PFBS) was also ubiquitous among all organisms, bioaccumulating in both invertebrate and vertebrate species. Total PFAS concentrations in aquatic worms were significantly higher in lower salinity water while the PFAS profile of Eastern oysters shifted from predominately perfluorocarboxylic acids (66 % of total composition) to perfluorosulfonic acids (62 %) as the ecosystem transitioned from low (9 PSU) to high (25 PSU) salinity. Collectively, this study demonstrates the utility of applying δ13C and δ15N to determine bioaccumulation patterns of both legacy PFAS and short-chain replacement compounds and underscores how shifts in salinity can alter the concentration and speciation of PFAS in estuaries.

Stormwater discharges affect PFAS occurrence, concentrations, and spatial distribution in water and bottom sediment of urban streams

Per- and polyfluoroalkyl substances (PFAS) are extensively used in urban environments and are, thus, found in urban stormwater. However, the relevance of stormwater as a pathway for PFAS to urban streams is largely unknown. This study evaluated the impact of urban stormwater runoff on PFAS concentrations and spatial distribution in three urban streams affected by stormwater discharges from separate sewer systems. River water was sampled during dry (DW) and wet weather (WW) upstream, immediately downstream, and further downstream of three urbanized areas with separate sewer systems and with and without point sources (i.e. waste water treatment plant, airports). Water samples were analyzed for 34 targeted PFAS compounds and sediment samples for 35 targeted PFAS and 30 PFAS compounds using a total oxidizable precursor assay. The sum of the quantified PFAS concentrations ranged from the reporting limit (RL) to 84.7 ng/L during DW and increased as the streams were affected by WW discharges (0.87 to 102.3 ng/L). The highest PFAS concentrations were found downstream of urban areas and/or point sources (i.e. airports) during WW, indicating a clear contribution from stormwater discharges. A consistent PFAS contribution from the WWTP was observed under both DW and WW conditions. During WW events, concentrations of perfluorooctanesulfonic acid (PFOS) and total PFAS (PFOA equivalents) exceeded the annual average environmental quality standards, which are an established limit of 0.65 ng/L for PFOS and a proposed limit of 4.4 ng/L for total PFAS. Notably, except for the legacy PFAS, PFOS and perfluorooctanoic acid (PFOA), the most frequently quantified PFAS during DW were short-chain. For WW, long-chain perfluorocarboxylic acids (PFCAs) and a precursor, 6:2 Fluorotelomer sulfonic acid (6:2 FTS), were more frequently quantified, suggesting stormwater is a source of these longer-chain and particle-associated PFAS. The detection of unregulated fluorotelomer sulfonates (FTSs) such as 6:2 and 8:2 FTS during WW suggests a need for regulatory action, as these compounds can degrade into more stable PFAS. In sediment, higher concentrations, and a greater variety of PFAS were found at sites with known point sources i.e. airports. Long-chain PFCAs (C7-C13), perfluoroalkyl sulfonates (PFSAs) (C6), and precursors (i.e. N-Ethyl perfluorooctane sulfonamidoacetic acid), were more prevalent in sediments than in the water. Notably, PFOS concentrations in sediment exceeded the lowest Predicted No-Effect Concentration (PNEC) across sites, posing a potential long-term environmental risk, though current PNECs for other PFAS may underestimate such risks. The findings of the study highlight urban stormwater as a source of PFAS to urban streams indicating the need to minimize PFAS sources in the urban environment and to effectively treat stormwater to protect receiving water bodies.

Modelling PFAS transport in Lake Ekoln: Implications for drinking water safety in the stockholm region

Per- and polyfluoroalkyl substances (PFAS) are found frequently in both groundwater and surface water sources across Sweden posing challenges to drinking water supply. Lake Ekoln is located south of Uppsala and is the basin of Lake Mälaren; Lake Mälaren is the third largest lake in Sweden and is the drinking water source for more than two million people. The aim of this study was to simulate the fate and transport of PFAS in Lake Ekoln during the period 2017-2020 using three-dimensional hydrodynamic modelling. The simulated water temperatures were in agreement with the observed water temperatures. The simulated PFAS concentrations were generally in agreement with the available measurements, but the lack of measurements made the comparison uncertain. The modelling results described the seasonal variations of PFAS in Lake Ekoln informing the operation of the drinking water treatment plants located downstream. The modelling results confirmed that the main inflow to the lake - the river Fyrisån - is the main source of PFAS to Lake Ekoln, highlighting the importance of mitigating this source in the context of ensuring safe drinking water supply in the Stockholm region. Regular monitoring of PFAS in the river Fyrisån is needed, and additional measurements in Lake Ekoln would facilitate further model development.

Environmental Issues in Global Pediatric Health: Technical Report

Pediatricians and pediatric trainees in North America are increasingly involved in caring for children and adolescents in or from low- and middle-income countries (LMICs). In many LMICs, toxic environmental exposures-notably outdoor and household air pollution, water pollution, lead, hazardous waste disposal, pesticides, and other manufactured chemicals-are highly prevalent and account for twice as great a proportion of disease and deaths among young children as in North America. Climate change will likely worsen these exposures. It is important that pediatricians and other pediatric health professionals from high-income countries who plan to work in LMICs be aware of the disproportionately severe impacts of environmental hazards, become knowledgeable about the major toxic threats to children's health in the countries and communities where they will be working, and consider environmental factors in their differential diagnoses. Likewise, pediatricians in high-income countries who care for children and adolescents who have emigrated from LMICs need to be aware that these children may be at elevated risk of diseases caused by past exposures to toxic environmental hazards in their countries of origin as well as ongoing exposures in products such as traditional foods, medications, and cosmetics imported from their original home countries. Because diseases of toxic environmental origin seldom have unique physical signatures, the environmental screening history, supplemented by laboratory testing, is the principal diagnostic tool. The goal of this technical report is to enhance pediatricians' ability to recognize, diagnose, and manage disease caused by hazardous environmental exposures, especially toxic chemical exposures, in all countries and especially in LMICs.

Per- and Poly-Fluoroalkyl Substances, and Organophosphate Flame Retardants in the Upper Yangtze River: Occurrence, Spatiotemporal Distribution, and Risk Assessment

Contaminants of Emerging Concern (CECs), including per- and polyfluoroalkyl substances (PFASs) and organophosphate flame retardants (OPFRs), have raised global concerns due to their persistence, bioaccumulation potential, and toxicity. This study presents a comprehensive investigation of the occurrence, spatiotemporal distribution, potential sources, and the ecological and human health risks associated with 18 PFASs and 9 OPFRs in the surface waters of the upper Yangtze River, China. The water samples were collected from the main stream and five major tributaries (Min, Jinsha, Tuo, Jialing, and Wu Rivers) in 2022 and 2023. The total concentration of PFASs and OPFRs ranged from 16.07 to 927.19 ng/L, and 17.36 to 190.42 ng/L, respectively, with a consistently higher concentration observed in the main stream compared to the tributaries. Ultra-short-chain PFASs (e.g., TFMS) and halogenated OPFRs (e.g., TCPP) were the predominant compounds, likely originating from industrial discharges, wastewater effluents, and other anthropogenic sources. Ecological risk assessments indicated low-to-moderate risks at most sampling sites, with higher risks near wastewater discharge points. Human health risk evaluations suggested negligible non-carcinogenic risks but identified potential carcinogenic risks from OPFR exposure for adults at specific locations, particularly in Leshan city. This study highlights the importance of understanding the fate and impacts of PFASs and OPFRs in the upper Yangtze River, and provides valuable insights for developing targeted pollution control strategies and risk management measures.

Ecological risks of PFAS in China's surface water: A machine learning approach

The persistence of per- and polyfluoroalkyl substances (PFAS) in surface water can pose risks to ecosystems, while due to data limitations, the occurrence, risks, and future trends of PFAS at large scales remain unknown. This study investigated the ecological risks of PFAS in surface water in China under different Shared Socioeconomic Pathways (SSPs) using machine learning modeling, based on concentration data collected from 167 published papers. The results indicated that long-chain PFAS currently dominated in most basins and posed significant risks, especially PFOA. Population density and temperature were key factors influencing risks of long-chain PFAS, while secondary industry and precipitation affected the risks of PFBS and PFHxS significantly, respectively. In the future, the ecological risks of long-chain PFAS would overall decrease, with risk probabilities of PFOA and PFOS decreasing significantly in SSP5 (8.15 % and 14.95 % reduction compared to 2020, respectively). The risks of short-chain PFAS were expected to increase, but stabilize in the late stage of SSP1. Nevertheless, the risks of long-chain PFAS would remain higher than those of short-chain PFAS, with high-risk areas concentrated in Southeast China. This study suggests changes in ecological risks of PFAS driven by future climate and human activities, providing new insights for risk management.

Presence and sources of per- and polyfluoroalkyl substances (PFASs) in the three major rivers on Hainan Island

Per- and polyfluoroalkyl substances (PFASs) have attracted considerable attention because of their toxicity, persistence and bioaccumulation potential. With the construction of the Hainan Free Trade Port and the rapid development of economy, environmental pollution on Hainan Island is becoming increasingly prominent. PFASs have been detected in the seawater and sediments of mangrove ecosystems on Hainan Island. As the receiving water of wastewater treatment plants (WWTPs) and industrial wastewater, rivers are inevitably contaminated by PFASs. However, few studies have focused on PFAS pollution in three large rivers (the Nandu, Changhua, and Wanquan rivers) on Hainan Island. In the present study, the pollution status, potential sources, and ecological risks of PFASs in these three major rivers were explored. Perfluorobutanonic acid (PFBA) (48.7%) was found to be the major PFASs in the surface waters, and perfluoroundecanoic acid (PFUnDA) (19.7%) was the major PFASs in the sediments of the three major rivers. The concentrations of ∑PFASs in the upper-midstream region were low due to minimal human influence and increased in the middle-lower reaches with increasing industrial activity and urbanization, whereas decreased at downstream sites near estuaries where river water was diluted with seawater. WWTP effluent, industrial wastewater discharge, the application and discharge of aqueous fire-fighting foam, storm runoff and landfill leachate were the major sources of PFASs in the three major rivers. In surface water, perfluorooctanoic acid (PFOA), perfluorooctane sulfonamide (PFOSA) and perfluorooctadecanoic acid (PFODA) posed low-moderate risks at 5.71-85.6% of the sampling sites. PFASs in the sediment posed no ecological risk. This study provides key data regarding the pollution status and potential sources of PFASs in large rivers on subtropical islands.

Occurrence of emerging and persistent organic pollutants in the rivers Cam, Ouse and Thames, UK

The widespread occurrence of new and emerging and persistent organic pollutants (NEPs and POPs) in surface water poses a risk to drinking water supply and consequently human health. The aim of this work was to investigate the occurrence and potential transport of 42 target NEPs and POPs (including per-and polyfluoroalkyl substances (PFAS), pharmaceuticals, pesticides and bisphenols) along the rural and urban environments of three rivers in England. The type and concentrations of pollutants varied between the sampling days and points. Two pharmaceuticals (diclofenac and ibuprofen), two pesticides (diethyl-meta-toluamide (DEET) and prosulfocarb) and a range of PFAS were detected above the method detection limit. The observed PFAS include restricted perfluorooctanoic acid (PFOA), and perfluorooctanesulfonic acid (PFOS) and a newer generation substitute 6:2 fluorotelomer sulfonate (6:2 FTS). The levels of PFOS and diclofenac observed in all studied rivers exceeded the European environmental quality standard (EQS). PFOS and diclofenac high detection frequency in the river Ouse suggests their persistence and potential to contaminate connecting tributaries. An assessment of the ecological risk of prosulfocarb levels in the samples from river Ouse, using the risk quotient method, showed a potential risk to algae, planktonic crustaceans, and fish. Our results suggest that the presence of 12 NEPs and POPs, could potentially be influenced by anthropogenic activities across urban and rural environments of the studied rivers. The study highlights the need for continuous monitoring of restricted and new-generation chemicals in the surface waters to understand their impact on the ecosystem and public health.

Sources and Pathways of PFAS Occurrence in Water Sources: Relative Contribution of Land-Applied Biosolids in an Agricultural Dominated Watershed

This study evaluated PFAS occurrence in rural well water and surface water relative to land application of biosolids in a tile-drained agriculture-dominated watershed. Spatial data were used to identify potentially vulnerable rural wells based on their proximity to biosolid-permitted land and location with respect to groundwater flow. Water was collected from 103 private wells in Greater Tippecanoe County Indiana and 168 surface water locations within the Region of the Great Bend of the Wabash River watershed. Overall, results indicate that surface water (∑PFAS ≤ 169.4 ng/L) is more vulnerable to PFAS contamination than well water (∑PFAS ≤ 15.7 ng/L). Short-chain perfluoroalkyl acids made up 72% of the ∑PFAS in both water sources. Nonetheless, long-chain homologues were detected more frequently in surface water (94%) than well water (82%). Hierarchical cluster analysis identified biosolid-applied fields, WTTPs, and industrial discharges as PFAS sources in first-order streams with high ∑PFAS. Temporal trends revealed an inverse relationship between streamflow and concentrations in surface water sites impacted by point discharges and vice versa for diffuse sources, thereby providing complementary evidence of potential sources. The well water data set did not show a distinct spatial trend between ∑PFAS and distance from biosolid application or well characteristics.

Bone cell differentiation and mineralization in wild-type and osteogenesis imperfecta zebrafish are compromised by per- and poly-fluoroalkyl substances (PFAS)

Perfluorinated compounds (PFAS) are well recognized toxic pollutants for humans, but if their effect is equally harmful for healthy and fragile people is unknown. Addressing this question represents a need for ensuring global health and wellbeing to all individuals in a world facing the progressive increase of aging and aging related diseases. This study aimed to evaluate the impact of perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorohexanoic acid (PFHxA) exposure on development and skeletal phenotype using the osteogenesis imperfecta (OI) zebrafish model Chihuahua (Chi/+), carrying a dominant glycine substitution in the α1 chain of collagen I and their wild-type (WT) littermates. To this purpose Chi/+ and WT zebrafish expressing the green fluorescent protein under the early osteoblast marker osterix were exposed from 1 to 6 days post fertilization to 0.36, 1.5 and 3.0 mg/L PFOS, 0.005 and 0.5 mg/L PFOA and 0.01, 0.48 and 16.0 mg/L PFHxA, and their development and skeletal phenotype investigated. Morphometric measurements, confocal microscopy evaluation of operculum area delimited by the fluorescent preosteoblasts and mineral deposition analysis following alizarin red staining were employed. PFOS and the highest concentration of PFHxA significantly impaired standard length in both genotypes. Osteoblast differentiation was significantly compromised by PFOS and by PFOA only in Chi/+. Limited to WT exposed to PFOA a reduced mineralization was also observed. No effect was detected after PFHxA exposure. Apoptosis was only activated by PFOA, specifically in Chi/+ mutant operculum osteoblasts. Interestingly, an altered lipid distribution in both WT and mutant fish was revealed after exposure to both pollutants. In conclusion, our data demonstrate that PFAS impair operculum development mainly compromising cell differentiation in mutant fish whereas alter lipid hepatic distribution in both genotypes with a more severe effect on Chi/+ preosteoblast survival. These results represent a first warning sign of the negative impact of PFAS exposure in presence of genetically determined skeletal fragility.

Per- and polyfluoroalkylated substances (PFAS) in the feathers and excreta of Gentoo penguins (Pygoscelis papua) from the Antarctic Peninsula

Per- and polyfluoroalkyl substances (PFAS) exhibit widespread global distribution, extending to remote regions including Antarctica. Despite potential adverse effects on seabirds, PFAS exposure among Antarctic penguins remains poorly studied. We investigated the occurrence of 29 PFAS compounds in feathers and excreta of Gentoo penguins (Pygoscelis papua) from Fildes Bay, Antarctica. Sample collection was conducted during the austral summer (February 2015) and analyzed by Ultra-performance liquid chromatography-tandem ES (-) mass spectrometry. The results showed that adults tend to accumulate more PFOA, PFPeS and NaDONA than chicks, with PFOA emerging as the predominant compound in feathers. The compounds PFHxA, PFDoDA, PFBS, PFOS, 4:2 FTS, 6:2 FTS, and PFEESA were only detected in penguin excreta, indicating that they are not absorbed into the organism. The detection of PFAS in penguin feathers and excreta not only indicates local contamination but also reaffirms the far-reaching impact of anthropogenic pollutants. This study presents the first documented occurrence of NaDONA in Antarctica, despite its status as a regulatory-compliant alternative to legacy PFAS compounds-a finding that needs deeper attention. The data can serve as a base for further research to understand the full extent of PFAS contamination and its implications for Antarctic wildlife and ecosystems.

Mobilization of poly- and perfluoroalkyl substances (PFAS) from heterogeneous soils: Desorption by ethanol/xanthan gum mixture

Remediating soils contaminated by per- and polyfluoroalkyl substances (PFAS) is a challenging task due to the unique properties of these compounds, such as variable solubility and resistance to degradation. In-situ soil flushing with solvents has been considered as a remediation technique for PFAS-contaminated soils. The use of non-Newtonian fluids, displaying variable viscosity depending on the applied shear rate, can offer certain advantages in improving the efficiency of the process, particularly in heterogeneous porous media. In this work, the efficacy of ethanol/xanthan mixture (XE) in the recovery of a mixture of perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonate (PFHxS), and perfluorobutane sulfonate (PFBS) from soil has been tested at lab-scale. XE's non-Newtonian behavior was examined through rheological measurements, confirming that ethanol did not affect xanthan gum's (XG) shear-thinning behavior. The recovery of PFAS in batch-desorption exceeded 95 % in ethanol, and 99 % in XE, except for PFBS which reached 94 %. 1D-column experiments revealed overshoots in PFAS breakthrough curves during ethanol and XE injection, due to over-solubilization. XE, (XG 0.05 % w/w) could recover 99 % PFOA, 98 % PFBS, 97 % PFHxS, and 92 % PFOS. Numerical modeling successfully reproduces breakthrough curves for PFOA, PFHxS, and PFBS with the convection-dispersion-sorption equation and Langmuir sorption isotherm.

Challenges Associated With PFAS Detection Method in Africa

Per- and polyfluoroalkyl substances (PFAS) are a group of man-made chemicals that are widely present in many industries. Monitoring and analyzing PFAS in Africa is challenging due to the limited availability of mass spectrometry (MS), which is an essential technique for detecting PFAS. This review assesses the scope and impact of the shortage of mass spectrometry instruments in Africa, emphasizing the resulting limitations in monitoring environmental and public health threats. The review analyzes the existing PFAS monitoring, the accessibility of MS instruments, and the technical capabilities within the continent. This study suggests that fewer African countries have sufficient MS instruments, resulting in significant underreport of environmental data and related public health issues. The review proposes financial support and programs to address these difficulties to provide necessary MS instruments. The review suggests that it is highly important to develop regional centers of excellence for PFAS monitoring using MS instruments and investing in training programs to address the gap in monitoring efforts. So, enhancing these are crucial for the successful management of the environment and safeguarding public health from the effects of PFAS contamination.

Bioconcentration, maternal transfer, and toxicokinetics of PFOS in a multi-generational zebrafish exposure

To enable risk characterization of perfluorooctane sulfonic acid (PFOS) in extended chronic and multi-generational exposures, we assessed PFOS bioconcentration in zebrafish (Danio rerio) exposed continuously to environmentally-relevant PFOS concentrations (0, 0.1, 0.6, 3.2, 20, and 100 µg/L PFOS) through 180 days postfertilization (dpf) in parental (P) and first filial generation (F1) fish. Exposures included five replicate tanks per treatment where whole-body PFOS concentrations were measured using 20-35 fish per replicate at 14 and 29 dpf in the P generation and one fish of each sex per replicate at 180 dpf for the P and F1 generations. Perfluorooctane sulfonic acid accumulation reached an apparent steady state at ≤ 14 dpf where whole-body wet-weight concentrations remained constant through 180 dpf in the P and F1 generations. The median bioconcentration factor (BCF) of 934 L/kg was observed for all PFOS exposures with a range from 255 to 2,136 L/kg which varied with PFOS exposure concentration and sex of adult fish. Significantly lower BCFs were observed in 20 and 100 µg/L PFOS exposures versus 0.1 and 0.6 µg/L indicating exposure-concentration dependance. Additionally, males had significantly increased (∼2×) PFOS accumulation and BCFs versus females in both P and F1 generations. Maternal transfer of PFOS was observed from P females to F1 eggs where maternal whole-body and egg PFOS burdens were equivalent, suggesting PFOS transfer to eggs was not a depuration pathway. Finally, a toxicokinetic model was developed that reliably reproduced PFOS whole-body burdens (data within 1.64-fold of predicted values) across all exposure durations spanning the P and F1 generations, providing a tool for PFOS bioaccumulation predictions relevant for risk assessment of acute, chronic, and multi-generational exposures.

Electrochemical advanced oxidation combined to electro-Fenton for effective treatment of perfluoroalkyl substances "PFAS" in water using a Magnéli phase-based anode

Per-and polyfluoroalkyl substances (PFAS), known as "forever chemicals", are posing a considerable threat to human health and the environment, that conventional treatment methods are unable to treat. In recent years, electrochemical advanced oxidation emerged as a promising technology for the degradation of recalcitrant pollutants such as PFAS. This work reports the degradation of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), using a Magnéli phase-based anode type Ti4O7 by electro-oxidation and electro-oxidation combined with electro-Fenton. First the Ti4O7 anode was prepared from Rutile TiO2 powder and characterized, the results showed that the Ti n O2n-1 phase is the dominant phase. Afterward, the degradation of PFOA and PFOS was evaluated on the developed anode. After 5 hours of treatment, 52% and 82% of PFOA and PFOS were removed respectively. To improve this results electro-oxidation was combined with electro-Fenton, the degradation of both pollutants increased, 92% of PFOA was degraded and PFOS was totally removed after 5 hours of treatment. The energy consumption was also evaluated at t 1/2 which is defined as the time when half of the initial concentration of PFOA and PFOS was degraded. Combining the two degradation approaches showed promising results that need to be further optimized for potential application at large volumes.

A quantitative classification method of land uses and assessment of per-and poly-fluoroalkyl substances (PFAS) occurrence in freshwater environments

We developed a quantitative method for classifying land uses for PFAS-related investigations in freshwater environments and determined PFAS ambient concentrations associated with specific land-use classes. Furthermore, our study presents a comprehensive assessment of the ambient occurrence and risks of PFAS mixtures beyond the usually studied PFOS-PFOA mixtures. Eighty-five inland (freshwater only) sites were sampled for water, sediment, and riparian soil in Victoria, south-east Australia, and analyzed for 33 PFAS. PFAS were detected in 91% of water samples, 34% of sediment samples, and 28% of riparian soil samples. Four land-use classes were defined: remote, agricultural, mixed, and urban. In the remote land-use class, only PFOS was detected at a low ambient concentration (0.0002 μg/L) in one water sample. Short-chain PFCA were frequently detected in the agricultural and mixed water samples. PFBA had the highest median ambient concentration in both land uses (ca. 0.01 μg/L), contributing to both ΣPFAS (40%) and ΣPFCA (50%) concentrations. In the urban land-use class, several congeners (PFBA, PFPeA, PFHxA, PFOA, PFHxS, and PFOS) had median ambient concentrations at or close to 0.01 μg/L and contributed similarly to ΣPFAS (10-20%). Elevated risk to the aquatic environment was found only for PFOS in two mixed and eight urban sites. This pattern was consistent with the finding for PFAS mixtures, where the elevated risk was driven by PFOS at those same sites. Our study provides critical information about environmentally relevant ambient concentrations and PFAS mixtures. This information, together with the land-use classification approach presented herein, can be used as reference levels for several critical purposes, including identifying PFAS-contaminated sites, informing land use planning and development decisions, setting standards and guidelines, and tracking changes over time.

Unraveling the long-term gastrointestinal impact of perinatal perfluorobutane sulfonate exposure on rat offspring: Intestinal barrier dysfunction and Th17/Treg imbalance

Per- and polyfluoroalkyl substances (PFAS), especially long-chain perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), are increasingly acknowledged as a potential inflammatory bowel diseases (IBD) risk factor. Perfluorobutane sulfonate (PFBS), one kind of shorter chain alternative, has been reported to exhibit similar health hazards to those long-chain PFAS. However, the underlying mechanism underpinning PFBS-induced colonic inflammation has not been sufficiently elucidated. The T-helper-17 (Th17)/regulatory T (Treg) imbalance is a crucial event for the pathogenesis of colonic inflammation. In this study, we aimed to reveal whether and how perinatal PFBS exposure leads to the Th17/Treg imbalance and colonic inflammation in offspring. We firstly demonstrated in vivo that early-life PFBS exposure (0.5 mg/kg, 5 mg/kg) led to increased intestinal permeability and colonic inflammation accompanied by decreased expressions of tight junction protein 1 (Tjp1) and claudin-4 (Cldn4) and increased expressions of interleukin 17A (IL-17A) in colon of rat offspring. Further results indicated that PFBS exposure induces the Th17/Treg imbalance through upregulating the expression of retinoic acid receptor-related orphan receptor gamma t (Ror-γt) and transforming growth factor beta (TGF-β) and downregulating of forkhead box protein 3 (Foxp3) and IL-10 in colon. Moreover, metabolomics analyses indicated that bile secretion metabolism was significantly altered under PFBS exposure. The reduction of lithocholic acid and deoxycholic acid was closely related to the changes of TGF-β and IL-10 in colon, and may contribute to the perturbation of Th17/Treg balance and colonic inflammation. These results provide evidences for the immunotoxicity of PFBS and reveal the potential contribution to colonic inflammation, which raises concern on the health effects and risk assessment of short-chain PFAS.

Legacy and alternative per- and polyfluoroalkyl substances spatiotemporal distribution in China: Human exposure, environmental media, and risk assessment

In recent decades, China's rapid development has led to significant environmental pollution from the widespread use of chemical products. Per- and polyfluoroalkyl substances (PFAS) are among the most concerning pollutants due to their persistence and bioaccumulation. This article assesses PFAS exposure levels, distribution, and health risks in Chinese blood, environment, and food. Out of 4037 papers retrieved from November 2022 to December 31, 2023, 351 articles met the criteria. Findings show perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) as the main PFAS in both Chinese populations and the environment. The highest PFOA levels in Chinese populations were in Shandong (53.868 ng/mL), while Hubei had the highest PFOS levels (43.874 ng/mL). Similarly, water samples from Sichuan (2115.204 ng/L) and Jiangsu (368.134 ng/L) had the highest PFOA and PFOS levels, respectively. Although localized areas showed high PFAS concentrations. Additionally, developed areas had higher PFAS contamination. The researches conducted in areas such as Qinghai and Hainan remain limited, underscoring the imperative for further investigation. Temporal analysis indicates declining levels of some PFAS, but emerging alternatives require more research. Limited studies on PFAS concentrations in soil, atmosphere, and food emphasize the need for comprehensive research to mitigate human exposure.

A novel high-throughput quantitative method for the determination of per- and poly-fluoroalkyl substances in human plasma based on UHPLC-Q/Orbitrap HRMS coupled with isotope internal standard

A novel method for the quantitative analysis of 56 per- and polyfluoroalkyl substances (PFASs) in human plasma was established on the basis of ultrahigh performance liquid chromatography tandem quadrupole Orbitrap high-resolution mass spectrometry (UHPLC-Q/Orbitrap HRMS) in combination with accurate customized mass databases and isotopic internal standards. A streamlined, high-throughput, and high-recovery (RE) sample pretreatment method was developed. The method's performance was evaluated in terms of linearity, limit of quantification, RE, repeatability, reproducibility, and matrix effect. The proposed method was applied in the simultaneous analysis of 56 PFASs in human plasma, and its results demonstrated high sensitivity, accuracy, and precision. The optimized method was implemented to analyze PFASs in 135 plasma samples, and 12 components were detected. The comparative analysis of the results from 135 plasma samples with domestic and international studies revealed elevated contents of PFOA, PFOS, PFBA, and PFTrDA, the moderate amounts of PFHxS, PFUdA, PFBS, and PFHpS, and the low concentrations of PFNA and PFDA. Notably, GenX was detected in human plasma for the first time. This finding suggests that the study region is contaminated with this substance. Correlation analysis revealed a strong relationship among PFNA, PFDA, and PFUdA, implying that these substances may have similar exposure sources.

Occurrence, transformation, and transport of PFAS entering, leaving, and flowing past wastewater treatment plants with diverse land uses

Per- and polyfluoroalkyl substances (PFAS) have been detected ubiquitously throughout the environment. Wastewater treatment plants (WWTPs) have been identified as potential hotspots for the introduction of PFAS into the environment. Therefore, the occurrence, transformation, and transport of 18 PFAS in two WWTPs with varying treatment processes, prevailing land uses, and during two distinct time periods were investigated. Polar Organic Chemical Integrative Samplers (POCIS) were installed at two WWTPs in Central Kentucky during April and July of 2022. PFAS concentrations typically increased from influent to effluent at both WWTPs, regardless of wastewater treatment processes, but changes in surface water concentrations from upstream to downstream of the effluent mixing zones varied. Both WWTPs discharged the 18 PFAS at higher loads than received, indicating prevalent transformation of PFAS precursors and non-measured PFAS analytes into measurable PFAS. Nearly all measured PFAS persisted in aqueous (86-98%) compartments rather than sediment or biosolids (2-14%). All biosolids had low content of PFAS with the dominant compound being PFOS (1.59-2.60 ng/g). Based on recent US EPA proposed maximum contaminant levels, hazard indexes for drinking water were exceeded in effluent and downstream surface waters at both WWTPs. The WWTP located in a heavily developed area and downstream from a firefighting training facility, had significantly higher concentrations of most PFAS species at most monitoring sites and was less impacted by sampling period compared to the WWTP located in a moderately developed, pastured area. Findings support the importance of WWTPs and land use practices as contributing to PFAS impact to downstream ecosystems along with potentially increasing strains on downstream drinking water source waters in regions that are surface water dependent.

Fate of per- and polyfluoroalkyl substances at a 40-year dedicated municipal biosolids land disposal site

The fate of per- and polyfluoroalkyl substances (PFAS) was evaluated at a site where municipal biosolids have been applied annually for 38 years as a waste management strategy. Soil cores (1.8 m in 30-cm sections), groundwater from four wells, and biosolids applied in 2022 were analyzed for PFAS (54 targeted, 17 semi-quantified) using liquid chromatography high resolution mass spectrometry including suspect screening. Total PFAS concentrations decreased with soil depth from 1700 ng/g to 2.06 ng/g. PFAS distribution in 2022 biosolids were 60 mol% perfluoroalkyl acid (PFAA) precursors and intermediates. The surface soil was dominated by long-chain PFAAs (67-76 mol%) reflecting precursor degradation after biosolids application. Presence of semi-quantified intermediates further reflects precursor degradation in surface soil. Long-chain PFAAs diminished with depth while short-chain PFAAs increased with up to 98 and 96 mol% short-chain PFAAs in the bottom depth and groundwater, respectively. PFAS distribution with depth is consistent with chain-length dependent sorption-impacted transport and the high organic carbon content of the surface soil (15.2 % OC) which subsequently decreased with depth (~2-3 % OC at >60 cm). High organic carbon content in the upper horizon is likely from decades of high biosolids application rates, which contributed to minimizing leaching of long-chain PFAS. While the well within the dedicated land disposal is not drinking water, for comparison only, PFAS concentrations in this well only marginally exceeded the EU drinking water directive for total PFAS and a few individual short-chain PFAS, but did exceed tenfold, the USEPA drinking water standard for PFOA.