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Exposure to perfluoroalkyl acids (PFAAs) has been found to elicit a range of detrimental effects on human health. However, limited research has investigated the impact of PFAAs on immunity and immune disorders such as Sjogren's syndrome, with existing studies yielding inconsistent results. This study was conducted in Hangzhou, China, with an initial cohort comprising 156 healthy individuals and 162 patients diagnosed with Sjogren's syndrome. We quantified serum levels of PFAAs and examined associations between PFAAs and both susceptibilities to the development of Sjogren's syndrome and immune marker concentrations. Nine PFAAs were frequently detected in the serum, with perfluorooctanoate (PFOA) exhibiting the highest concentration, followed by perfluorooctanesulfonate (PFOS). Exposure to PFOA and perfluorotridecanoate (PFTrDA) was inversely associated with the disease. Furthermore, a negative correlation between PFOA and C-reactive protein (CRP) was observed. These findings suggest that exposure to specific PFAAs may impact the immune system and potentially influence the development of Sjogren's syndrome. [ABSTRACT FROM AUTHOR]

The detection of per- and polyfluoroalkyl substances (PFAS) in water presents a significant challenge for developing countries, requiring urgent attention. This review focuses on understanding the emergence of PFAS in drinking water, health concerns, and removal strategies for PFAS in water systems in developing countries. This review indicates the need for more studies to be conducted in many developing nations due to limited information on the environmental status and fate of PFAS. The health consequences of PFAS in water are enormous and cannot be overemphasized. Efforts are ongoing to legislate a national standard for PFAS in drinking water. Currently, there are few known mitigation efforts from African countries, in contrast to several developing nations in Asia. Therefore, there is an urgent need to develop economically viable techniques that could be integrated into large-scale operations to remove PFAS from water systems in the region. However, despite the success achieved with removing long-chain PFAS from water, more studies are required on strategies for eliminating short-chain moieties in water.

Plastic greenhouses play an important role in vegetable cultivation in China. While evaluations have attributed perfluoroalkyl acid contamination in greenhouse vegetables primarily to irrigation water, the potential contribution from greenhouse plastic films has consistently been overlooked, despite PFAAs' long-standing use as anti-fogging agents. In this study, a comprehensive assessment of PFAA contamination was conducted in greenhouses at the Shouguang vegetable base in China, based on extensive environmental and crop sample collection, followed by analysis using LC-MS/MS. PFAAs are still used in greenhouse plastic film, and their migration to the surface water mist and the air inside the greenhouse was also observed. Elevated levels of PFAA pollution were found near the corner areas of greenhouses with longer service times, leading to further pollution of the soil and nearby vegetables. This is considered as the primary source which may have been caused by PFAAs migrating with condensation from the plastic film and accumulating for decades. However, polluted irrigation water still remains the dominate source of PFAAs in other areas inside the greenhouse. Based on our analysis, we conclude that PFAAs present in plastic films could be the primary contaminant source for vegetables in specific zones. This underscores the urgent need for heightened vigilance towards environmental pollution within agricultural facilities, which currently represent the most prevalent mode of intensive vegetable cultivation in China. [ABSTRACT FROM AUTHOR]

Abstract Whether a family history of diabetes (FHD) and exposure to perfluoroalkyl acids (PFAAs) are correlated with an increased risk of developing arthritis remains unclear. This cross-sectional study was conducted to explore the correlations between FHD or exposure to PFAAs and arthritis as well as their interaction using the National Health and Nutrition Examination Survey (NHANES). In total, 6,194 participants aged ≥ 20 years from the 2011–2018 NHANES were enrolled. PFAAs are a cluster of synthetic chemicals, including perfluorononanoic acid (PFNA), perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorodecanoic acid (PFDA) and perfluorohexane sulfonic acid (PFHxS). FHD was evaluated using self-reported questionnaires. Arthritis was classified into three types, rheumatoid arthritis (RA), osteoarthritis (OA), and others, which were diagnosed using questionnaires. Generalized linear models (GLMs) were used to test the correlation between FHD and arthritis. To examine the joint effects of PFAAs and FHD on arthritis, interaction terms were applied in the GLM. Arthritis incidence was 26.7% among all participants. FHD was associated with both RA [OR = 1.70 (95% CI: 1.15–2.50)] and other types of arthritis [OR = 1.62 (95% CI: 1.21–2.16)]. However, the relationship between FHD and OA was not significant after adjustment (P = 0.18). Interaction outcomes indicated that higher PFDA levels increased the association between FHD and arthritis. FHD is associated with an increased incidence of arthritis, which may be increased by PFDA. Given the heavy burden of arthritis, preventive measures for arthritis and reduction of PFAAs exposure for patients with FHD are required.

Exposure to perfluoroalkyl acids (PFAAs) has been found to elicit a range of detrimental effects on human health. However, limited research has investigated the impact of PFAAs on immunity and immune disorders such as Sjogren’s syndrome, with existing studies yielding inconsistent results. This study was conducted in Hangzhou, China, with an initial cohort comprising 156 healthy individuals and 162 patients diagnosed with Sjogren’s syndrome. We quantified serum levels of PFAAs and examined associations between PFAAs and both susceptibilities to the development of Sjogren’s syndrome and immune marker concentrations. Nine PFAAs were frequently detected in the serum, with perfluorooctanoate (PFOA) exhibiting the highest concentration, followed by perfluorooctanesulfonate (PFOS). Exposure to PFOA and perfluorotridecanoate (PFTrDA) was inversely associated with the disease. Furthermore, a negative correlation between PFOA and C-reactive protein (CRP) was observed. These findings suggest that exposure to specific PFAAs may impact the immune system and potentially influence the development of Sjogren’s syndrome.

Whether a family history of diabetes (FHD) and exposure to perfluoroalkyl acids (PFAAs) are correlated with an increased risk of developing arthritis remains unclear. This cross-sectional study was conducted to explore the correlations between FHD or exposure to PFAAs and arthritis as well as their interaction using the National Health and Nutrition Examination Survey (NHANES). In total, 6,194 participants aged ≥ 20 years from the 2011–2018 NHANES were enrolled. PFAAs are a cluster of synthetic chemicals, including perfluorononanoic acid (PFNA), perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorodecanoic acid (PFDA) and perfluorohexane sulfonic acid (PFHxS). FHD was evaluated using self-reported questionnaires. Arthritis was classified into three types, rheumatoid arthritis (RA), osteoarthritis (OA), and others, which were diagnosed using questionnaires. Generalized linear models (GLMs) were used to test the correlation between FHD and arthritis. To examine the joint effects of PFAAs and FHD on arthritis, interaction terms were applied in the GLM. Arthritis incidence was 26.7% among all participants. FHD was associated with both RA [OR = 1.70 (95% CI: 1.15–2.50)] and other types of arthritis [OR = 1.62 (95% CI: 1.21–2.16)]. However, the relationship between FHD and OA was not significant after adjustment (P = 0.18). Interaction outcomes indicated that higher PFDA levels increased the association between FHD and arthritis. FHD is associated with an increased incidence of arthritis, which may be increased by PFDA. Given the heavy burden of arthritis, preventive measures for arthritis and reduction of PFAAs exposure for patients with FHD are required. [ABSTRACT FROM AUTHOR]

[Display omitted] Organically modified clays have been reported as a promising class of adsorbents for the treatment of per- and polyfluoroalkyl substances (PFAS), a group of emerging contaminants of widespread concerns. Here, we reported the development and evaluation of ionic liquid (IL)-modified clays prepared with various natural clays to explore the role of clay substrate in the adsorption of eight persistent perfluoroalkyl acids (PFAAs). Based on detailed adsorption isotherm study, we found that the adsorption capacities of PFAAs were closely related to the cation exchange capacities of the raw clays and correspondingly the IL loadings of the modified clays. Additionally, a positive correlation was observed between the adsorption affinity of PFAAs onto IL-modified clays and the octanol–water distribution coefficient (D ow) of PFAAs. Adsorption free energy analysis suggested that both electrostatic and hydrophobic interactions played important roles in the adsorption of PFAAs onto IL-modified clays. Although electrostatic interactions were more predominant, the contribution of hydrophobic interactions increased with the increasing carbon number of perfluoroalkyl moiety of PFAAs, resulting in more favorable adsorption of long-chain PFAAs than their short-chain homologs. The performance of IL-modified clays was further demonstrated for the removal of PFAA mixtures under environmentally relevant conditions. Overall, results of this work can provide important insights into guiding the design of organically modified clay adsorbents for PFAS treatment. [ABSTRACT FROM AUTHOR]

Plastic greenhouses play an important role in vegetable cultivation in China. While evaluations have attributed perfluoroalkyl acid contamination in greenhouse vegetables primarily to irrigation water, the potential contribution from greenhouse plastic films has consistently been overlooked, despite PFAAs’ long-standing use as anti-fogging agents. In this study, a comprehensive assessment of PFAA contamination was conducted in greenhouses at the Shouguang vegetable base in China, based on extensive environmental and crop sample collection, followed by analysis using LC-MS/MS. PFAAs are still used in greenhouse plastic film, and their migration to the surface water mist and the air inside the greenhouse was also observed. Elevated levels of PFAA pollution were found near the corner areas of greenhouses with longer service times, leading to further pollution of the soil and nearby vegetables. This is considered as the primary source which may have been caused by PFAAs migrating with condensation from the plastic film and accumulating for decades. However, polluted irrigation water still remains the dominate source of PFAAs in other areas inside the greenhouse. Based on our analysis, we conclude that PFAAs present in plastic films could be the primary contaminant source for vegetables in specific zones. This underscores the urgent need for heightened vigilance towards environmental pollution within agricultural facilities, which currently represent the most prevalent mode of intensive vegetable cultivation in China.

Perfluoroalkyl acids (PFAAs) are emerging pollutants that endangers food safety. Developing methods for the selective determination of trace PFAAs in complex samples remains challenging. Herein, an ionic liquid modified porous imprinted phenolic resin-dispersive filter extraction-liquid chromatography-tandem mass spectrometry (IL-PIPR−DFE−LC-MS/MS) method was developed for the determination of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in eggs. The new IL-PIPR adsorbent was prepared at room temperature, which avoids the disorder and instability of the template at high temperatures. The imprinting factor of IL-PIPR for PFOA and PFOS exceeded 7.3. DFE, combined with IL-PIPR (15 mg), was used to extract PFOA and PFOS from eggs within 15 min. The established method exhibits low limits of detection (0.01–0.02 ng/g) and high recoveries (84.7%–104.7%), which surpass those of previously reported methods. This work offers a new approach to explore advanced imprinted adsorbents for PFAAs, efficient sample pretreatment technique, and analytical method for pollutants in foods. [Display omitted] • Ionic liquid-porous imprinted resin (IL-PIPR) was synthesized at room temperature. • The imprinting factors of IL-PIPR for PFOA and PFOS is 7.3 and 8.9, respectively. • IL-PIPR has fast mass transfer (2 min) and the adsorption capacity exceeds 490 mg/g. • Extraction process (IL-PIPR-DFE) of PFOA and PFOA in egg sample within 15 min. • IL-PIPR-DFE-LC-MS/MS overcomes matrix interference and is accurate and rapid. [ABSTRACT FROM AUTHOR]

[Display omitted] • A series of unique imidazole-based mixed-ligand MOFs were synthesized. • Mixed-ligand strategy was verified to regulate the adsorption performance. • Zn(aIM + bIM) exhibited superior adsorption and removal efficiency for PFAAs. • Potential adsorption mechanisms were discussed through characterization and simulation. Metal-organic frameworks (MOFs) have been regarded as extremely promising adsorbent materials, with the repetitive coordination assembly of inorganic metal ions and organic ligands constituting their reticular structure and abundant pores. Herein, a ligand mixing approach to synthesizing and regulating MOFs is provided. By mixing multiple solvents and adding modifiers, imidazole-based linkers can be prepared MOFs with mixed ligand components at room temperature. In this study, we prepared four mixed-ligand MOFs: Zn(aIM + bIM), Zn(mIM + bIM), Zn(aIM + mIM), and Zn(mIM + 2-mbIM). Series of characterizations by SEM, XRD, NMR, etc. confirmed the successful preparation of mixed-ligand MOFs, and they exhibited the different surface areas, pore sizes, and surface properties. And the adsorption capabilities for perfluoroalkyl acids (PFAAs) were compared among the prepared MOFs adsorbents. Among them, Zn(aIM + bIM) consisting of benzimidazole and imidazole-2-formaldehyde linker possessed the optimum adsorption performance, with an equilibrium adsorption capacity q e of 245 mg/g for perfluorobutyric acid, and the calculated maximum adsorption capacity q m of 439 mg/g. And for the other chain lengths of perfluoroalkyl acids, the adsorption results are also acceptable. The potential adsorption mechanism and the reasons for the performance enhancement are discussed based on relevant characterization and simulation. It was proved that the ligand mixing strategy can provide new insights into the development of high-performance MOFs adsorbents for addressing environmental concerns. [ABSTRACT FROM AUTHOR]

• 145 ARG subtypes including high-risk ARGs were detected in the receiving waters. • ARG subtypes substantially decreased in receiving waters of PFAAs point source. • ARG profiles were significantly related to PFCAs and PFSAs. • Short-chain PFAAs had similar impacts on ARG profiles compared to long-chain PFAAs. The ecological risks posed by perfluoroalkyl acids (PFAAs) to the aquatic environment have recently been of great concern. However, little information was available on the impact of PFAAs on antibiotic resistance genes (ARGs) profiles. In this study, the receiving river of the largest fluoropolymer production facility in China was selected to investigate the effects of PFAAs on ARGs profiles. The highest PFAAs concentration for water samples near the industrial effluent discharge point was 310.9 μg/L, which was thousands times of higher than the average concentration collected at upstream sites. Perfluorooctanoic acid accounted for more than 67.2 % of ∑PFAAs concentration in water samples collected at the downstream sites, followed by perfluorohexanoic acid (3.6 %–15.9 %). 145 ARG subtypes including high-risk ARGs were detected by metagenomic technology. The results indicated that the discharge of PFAA-containing effluents had a significant impact on the abundance and diversity of ARGs in receiving waters, and PFAAs and water quality parameters (e.g., pH, NH 3 N, COD Mn , TP) could largely affect ARG profiles. Specifically, short-chain PFAAs had similar impacts on ARG profiles compared to the restricted long-chain PFAAs. This study confirmed the potential effects of PFAAs on ARGs in aquatic environment and provided more insights into the ecological risk raised by PFAAs. [Display omitted] [ABSTRACT FROM AUTHOR]

As the discharge of exogenous perfluoroalkyl acids (PFAAs) is gradually controlled, the secondary release of endogenous PFAAs is poised to become a major challenge. However, the effects of complex hydrodynamic conditions, such as disturbance from ship propeller jets, on PFAA release, are still poorly understood. In the present study, a propeller jet disturbance simulation experiment was carried out using an indoor flume to investigate the responses and mechanisms of PFAA release to the cumulative effects of jet force over time. Although an increase in jet action time (t) increased the total amount of dissolved PFAAs in the overlying water, PFAA dissolution intensity decreased. Conversely, increase in t induced a rise in both total PFAA amount adsorbed and adsorption intensity in suspended particulate matter (SPM). Moreover, differences in functional groups and carbon-fluorine chain lengths resulted in different types of PFAAs exhibiting different sensitivities to changes in t during dissolution and adsorption. During the jet disturbance, there were distinct shear zoning and pressure gradients in the flow field, contributing to the tendency of PFAAs to be distributed in the overlying water. However, after the disturbance, PFAAs tended to distribute in the SPM. Changes in t consistently affected the partition behavior of long-chain PFAAs (C ≥ 7), whereas the effect on the partition behavior of short-chain PFAAs (C < 7) was rather short-lived. In contrast, Perfluoroalkyl carboxylic acids were more readily released from the sediments and porewater than Perfluoroalkyl sulfonic acids; however, the difference decreased with increasing t. Both shear impulse and squeeze impulse showed a significant linear positive correlation with PFAA release (p < 0.05), but the effect of shear impulse was greater. The findings provide perspectives for further understanding of PFAA release under jet disturbance and could facilitate endogenous PFAA contamination control., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Per- and polyfluoroalkyl substances (PFAS) are widespread contaminants with adverse environmental and public health effects. Anion exchange (IX) processes can effectively remove many PFAS from water. Objectives of this research were to (1) quantify the effects of PFAS structure and background water matrix constituents [dissolved organic matter (DOM) and major inorganic anions (bicarbonate, chloride, sulfate, and nitrate)] on PFAS uptake capacity of IX resins (K IX ), and (2) develop models that predict PFAS breakthrough in packed bed IX columns from PFAS structure and background water matrix characteristics. Rapid small-scale column tests were conducted with two IX resins and 18 water matrices to determine breakthrough curves and K IX values for 23 PFAS. A quantitative structure-property relationship (QSPR) was developed that predicts K IX for different PFAS from a newly developed concept, the normalized chain length (NCL). NCL for each PFAS was calculated using a group contribution method, in which the contributions of PFAS structural fragments to NCL were normalized to that of -CF 2 -, which was assigned a value of 1.00. Relative to -CF 2 -, contributions of the structural fragments -O-, -CH 2 -, >CF-CF 3 , -CHF-, and -SO 3 H to NCL for the purposes of K IX prediction were 0.34, -1.87, 1.70, 0.00, and 3.65, respectively. DOM and nitrate adversely impacted PFAS removal, while chloride, sulfate, and bicarbonate, when added at concentrations of up to 3 meq/L above native background levels, had negligible effects on K IX . Based on the obtained water matrix effects, pseudo-single solute models were developed for the two tested IX resins, with which PFAS breakthrough curves for fixed bed IX columns can be predicted using only the NCL and the total organic carbon and nitrate concentrations of the influent water., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Studying the impacts of land use and river network structure on perfluoroalkyl acids (PFAAs) footprint in rivers is crucial for predicting the fate of PFAAs in aquatic environments. This study investigated the distribution, ecological risks, sources and influence factors of 17 PFAAs in water and sediments of rivers from hills to plain areas. The results showed that the detection frequencies were higher for short-chain PFAAs than long-chain PFAAs in water, whereas an opposite pattern was found in sediments. The concentration of ∑PFAAs ranged from 59.2 to 414 ng/L in water and from 1.4 to 60.1 ng/g in sediments. Perfluorohexanoic acid and perfluorooctanoic acid were identified as the main pollutants in the river. The average concentrations of PFAAs were higher in the aquaculture areas (water: 309.8 ng/L; sediments: 43.27 ng/g) than in residential areas (water: 206.03 ng/L; sediments: 11.7 ng/g) and farmland areas (water: 123.12 ng/L; sediments: 9.4 ng/g). Environmental risk assessment showed that PFAAs were mainly low risk or no risk in water, but were moderate risk and even high risk in sediments, especially for perfluorooctane sulfonate. Source apportionment found that PFAA sources were mostly from industry, wastewater discharge, and surface runoff. Dissolved oxygen, chemical oxygen demand, water system circularity, network connectivity and organic matter were significantly correlated to PFAA concentration, indicating that the physicochemical properties and river network might directly influence the environmental behavior of PFAAs. The built-up area was positively correlated with PFAAs. These findings indicated that a comprehensive understanding of the influences of land use and river network structure on PFAAs in rivers is essential for managers to formulate effective PFAA control strategies., Competing Interests: Declaration of competing interest The authors declare that they have no competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

[Display omitted] • A series of novel high-stability olefin chains with different OMe ratios were synthesized. • [OMe] 100 -COF can efficiently remove perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). • After soaking in DMF, methanol, water, HCl and NaOH solvents for 24 h, the sample still has high chemical stability. • The adsorption mechanism was characterized by theoretical and experimental data. Covalent organic frameworks (COFs) are promising adsorbents due to their designable functionality, but their applications are hampered by poor chemical stability. Herein, a series of novel high stability olefin-linked (C = C) COFs with different ratios of OMe, as the adsorbent to remove perfluoroalkyl acids (PFAAs), were firstly synthesized by a three-component strategy under solvothermal conditions. The synthesized COFs showed strong resistance toward acid (6 M HCl) and base (6 M NaOH) because of the robust C = C linkage which can be achieved reversibly under stringent synthetic conditions. Among the four [OMe] x -COF adsorbents, [OMe] 100 -COF exhibited the highest adsorption affinities and adsorption capacities for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). The theoretical maximum adsorption capacity of [OMe] 100 -COF for PFOA and PFOS, calculated by Langmuir isotherm, were 601.2 mg g−1 and 1106.1 mg g−1, respectively. This could be ascribed to the synergistic combination of electrostatic interaction and hydrophobic-hydrophobic interaction. Moreover, [OMe] 100 -COF can be efficiently regenerated during the adsorption–desorption cycles. This study provides a novel strategy to fabricate olefin-linked COFs for the effective adsorption of perfluorinated compounds in water. Perfluorinated compounds (PFAAs) were shortlisted for persistent organic pollutants (POPs) in 2009 due to their persistence, bioaccumulation, toxicity, and long-distance mobility. Adsorption is one of the promising ways with advantages of simplicity and low energy consumption for removing PFAAs from aqueous environment. Herein, a series of olefin-linked COFs with high chemical stability was synthesized using a three-component strategy. And they showed rapid uptake and high capacity for the removal of PFAAs. This study provides a novel strategy to fabricate olefin-linked COFs for the effective adsorption of perfluorinated compounds in water. [ABSTRACT FROM AUTHOR]

The detection of per- and polyfluoroalkyl substances (PFAS) in water presents a significant challenge for developing countries, requiring urgent attention. This review focuses on understanding the emergence of PFAS in drinking water, health concerns, and removal strategies for PFAS in water systems in developing countries. This review indicates the need for more studies to be conducted in many developing nations due to limited information on the environmental status and fate of PFAS. The health consequences of PFAS in water are enormous and cannot be overemphasized. Efforts are ongoing to legislate a national standard for PFAS in drinking water. Currently, there are few known mitigation efforts from African countries, in contrast to several developing nations in Asia. Therefore, there is an urgent need to develop economically viable techniques that could be integrated into large-scale operations to remove PFAS from water systems in the region. However, despite the success achieved with removing long-chain PFAS from water, more studies are required on strategies for eliminating short-chain moieties in water., Competing Interests: The authors have declared no conflicts of interest., (© 2024 The Author(s).)

This study assessed the occurrence, origins, and potential risks of emerging perfluoroalkyl acids (PFAAs) for the first time in drinking water resources of Khyber Pakhtunkhwa, Pakistan. In total, 13 perfluoroalkyl carboxylic acids (PFCAs) with carbon (C) chains C4-C18 and 4 perfluoroalkyl sulfonates (PFSAs) with C chains C4-C10 were tested in both surface and ground drinking water samples using a high-performance liquid chromatography system (HPLC) equipped with an Agilent 6460 Triple Quadrupole liquid chromatography-mass spectrometry (LC-MS) system. The concentrations of ∑PFCAs, ∑PFSAs, and ∑PFAAs in drinking water ranged from 1.46 to 72.85, 0.30-8.03, and 1.76-80.88 ng/L, respectively. Perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA), and perfluoropentanoic acid (PFPeA) were the dominant analytes in surface water followed by ground water, while the concentration of perfluorobutane sulfonate (PFBS), perfluorooctanoic acid (PFOA), perfluoroheptanoic acid (PFHpA), perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), and perfluorododecanoic acid (PFDoDA) were greater than long-chain PFOA and PFOS. The correlation statistics, which showed a strong correlation (p < 0.05) between the PFAA analytes, potentially indicated the fate of PFAAs in the area's drinking water sources, whereas the hierarchical cluster analysis (HCA) and principal component analysis (PCA) statistics identified industrial, domestic, agricultural, and commercial applications as potential point and non-point sources of PFAA contamination in the area. From risk perspectives, the overall PFAA toxicity in water resources was within the ecological health risk thresholds, where for the human population the hazard quotient (HQ) values of individual PFAAs were < 1, indicating no risk from the drinking water sources; however, the hazard index (HI) from the ∑PFAAs should not be underestimated, as it may significantly result in potential chronic toxicity to exposed adults, followed by children., Competing Interests: Declaration of competing interest The authors have no relevant financial or non-financial interests to disclose., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

• A scale-up approach was developed to predict pilot-scale PFAS removal from RSSCT data. • Crushing IX resins had little effect on total IX capacity and packed bed density. • PFAS breakthrough curves were independent of influent PFAS concentration. • Film diffusion was important in controlling PFAS uptake rates. • PFAS uptake capacity depended on Sherwood number and particle shape factor. Anion exchange (IX) is a readily implementable water treatment method that can effectively remove per- and polyfluoroalkyl substances (PFAS). The overarching objective of this research was to predict PFAS removal in full- or pilot-scale packed-bed IX resin contactors from rapid small-scale column test (RSSCT) data. Specific objectives were to (1) assess the effects of IX resin crushing on total anion exchange capacity and packed bed density, (2) determine the effects of initial PFAS concentration on PFAS uptake capacity, (3) determine the rate-limiting step controlling PFAS uptake kinetics, (4) determine the effects of hydraulic loading rate on PFAS uptake capacity, and (5) link constant diffusivity RSSCT data to pilot test data to develop a scale-up protocol. Experiments were conducted with two single-use IX resins and three water matrices, including coagulated surface water and groundwater. Crushing IX resin did not substantially change the bed density and total anion exchange capacity, but the morphology of particles changed from almost perfectly spherical to irregularly shaped. PFAS uptake capacity was independent of influent PFAS concentrations in the 30–300 ng/L range. This finding facilitated the development of an RSSCT scale-up approach because influent PFAS concentrations in RSSCTs and corresponding pilot tests often differ. Biot number values and data from interrupted RSSCTs demonstrated that film diffusion or a combination of film diffusion and intraparticle diffusion controls the rate of PFAS uptake by IX resins. From RSSCTs with identical empty bed contact times but different hydraulic loading rates (v f), PFAS uptake capacity was found to be a function of the square root of the product of Sherwood number and particle shape factor (S h × ϕ). Using a constant diffusivity RSSCT design with a reduced v f , full- or pilot-scale PFAS breakthrough data can therefore be predicted by multiplying the bed volumes of water treated in the RSSCT by a factor of (S h p i l o t × ϕ p i l o t ) / (S h R S S C T × ϕ R S S C T ) . This research will support the design of future IX treatment processes in the context of PFAS remediation and drinking water treatment. [Display omitted] [ABSTRACT FROM AUTHOR]

Perfluoroalkyl acids (PFAAs) are environmentally and biologically persistent chemicals. In this study, we investigated the concentrations of six PFAAs in dust samples collected from different indoor environments in a college campus in Tainan, Taiwan, and assessed the health risk of PFAAs exposure to college students. We also analyzed the effects of dust characteristics (total organic carbon, moisture content, and dust content) on PFAAs levels. With regard to the space type, the median of total PFAAs concentrations were in the order of laboratories (528.9 μg kg−1) > offices (304.2 μg kg−1) > dormitories (180.1 μg kg−1) > classrooms (105.1 μg kg−1). With regard to the height from the ground, the median total PFAAs concentrations were in the order of dust near the floors (>2 m; 383.6 μg kg−1) > near the ceiling (0–2 m; 202.5 μg kg−1) > on the ground (0 m; 145.6 μg kg−1). The main species of PFAAs, perfluorooctane sulfonate and short-chain perfluoroalkyl carboxylates, accounted for respectively 30%–60% and ∼20%–37% of total PFAAs pollution in the indoor space types and sampling heights under consideration. The average daily intake (ADI) values of six PFAAs for college students were found to be 0.059–0.126 ng kg−1 BW day−1 (BW: body weight), with dormitories and workplaces (i.e., laboratories and offices) accounting for over 40% and ∼50% of the ADI, respectively. The estimated hazard quotient ranged from 0.0029 to 0.0063, three orders of magnitude lower than 1, suggesting relatively low risks for college students exposed to the six PFAAs monitored in indoor dust. The analysis of dust characteristics revealed that total organic carbon did not have a significant effect on PFAAs levels as we expected. In contrast, dust moisture and cation content dominated PFAAs accumulation. [Display omitted] • PFAAs were found with a high detection frequency (98.1%) in indoor dust. • PFAAs median concentrations were found in labs > offices > dorms > classrooms. • PFAAs levels were in the order of near the floors > near the ceiling > on the ground. • The main species of PFAAs in indoor dust were PFOS and short-chain PFCAs. • Moisture and cation content dominate PFAAs accumulation rather than TOC. [ABSTRACT FROM AUTHOR]