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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]

The Yellow River is the main source of water for urban and rural area and agricultural irrigation in northern China. Herein, the distribution and risk assessment of perfluoroalkyl acids (PFAAs) were investigated from the Yellow River in Shandong Province, China. The total concentration of PFAAs (∑PFAAs) in surface water and sediments were 37.5–2128 ng/L (mean: 167 ng/L) and not detected−6.95 ng/g dry weight (dw) (mean: 1.02 ng/g dw), respectively. Short-chain PFAAs-perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA), and perfluorobutane sulfonic acid (PFBS) were the most prevalent PFAAs in surface water. Source analysis showed that firefighting foam (proportion: 31.3 %) and textile treatments and food packaging (proportion: 30.3 %) were the main sources of PFAAs in water. Based on the concentration of PFAAs in water, ecological and potential human health risks were assessed. Perfluorooctanoic acid (PFOA), perfluorononanoate (PFNA), perfluorodecanoate (PFDA) and perfluoroundecanoic acid (PFUnDA) posed nonnegligible ecological risk for some aquatic organisms. Levels of PFAAs (e.g., PFOA, PFNA, and PFDA etc.) in some water samples were higher than the advisory guidelines of PFAAs concentrations in water worldwide, indicating a potential human health risk. Therefore, PFOA, PFNA, PFDA, and PFUnDA are the key focus of pollutants in the water of the Yellow River in Shandong Province, and the standards and limits of these PFAAs in environments including surface water and sediment should be promoted.

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.

Perfluoroalkyl acids (PFAAs) are considered forever chemicals, gaining increasing attention for their hazardous impacts. However, the ecological effects of PFAAs remain unclear. Environmental DNA (eDNA), as the environmental gene pool, is often collected for evaluating the ecotoxicological effects of pollutants. In this study, we found that all PFAAs investigated, including perfluorohexanoic acid, perfluorooctanoic acid, perfluorononanoic acid, and perfluorooctane sulfonate, even at low concentrations (0.02 and 0.05 mg/L), expedited the enzymatic degradation of DNA in a nonlinear dose–effect relationship, with DNA degradation fragment sizes being lower than 1,000 bp and 200 bp after 15 and 30 min of degradation, respectively. This phenomenon was attributed to the binding interaction between PFAAs and AT bases in DNA via groove binding. van der Waals force (especially dispersion force) and hydrogen bonding are the main binding forces. DNA binding with PFAAs led to decreased base stacking and right-handed helicity, resulting in loose DNA structure exposing more digestion sites for degrading enzymes, and accelerating the enzymatic degradation of DNA. The global ecological risk evaluation results indicated that PFAA contamination could cause medium and high molecular ecological risk in 497 samples from 11 contamination-hot countries (such as the USA, Canada, and China). The findings of this study show new insights into the influence of PFAAs on the environmental fates of biomacromolecules and reveal the hidden molecular ecological effects of PFAAs in the environment.

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 (PFAA) in gas and particles were analyzed in southeast coastal and mountainous cities, including Fuzhou, Xiamen, Zhangzhou and Nanping, to study the pollution characteristics, particle size distribution, phase partitioning and atmospheric transport. PFAA ranged from 7.8 to 290 pg m−3 in gaseous phase, 27 − 1200 pg m−3 in particulate phase, and perfluorobutanoic acid (PFBA), perfluorooctanoic acid (PFOA) were main compounds. PFAA had the highest concentration in Nanping with perfluorohexanoic acid (PFHxA) dominant, which could be related to the emission of PFAS from local industrial plants. Perfluorocarboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) exhibited different particle size distribution characteristics, with PFSAs preferring to distribute on coarse particles, which could be affected by the salt, minerals and organic matter in different particle sizes. The gas − particle partitioning coefficient (KPA) had a line relationship with the fluorinated carbon chain length of PFAA, suggesting that long-chain PFAA tended to exist in particulate phase. The Winter Monsoon could transport to the study area and drive atmospheric PFAS to southern cities. Highlights: • Industrial plants contributed high concentrations of PFAA. • PFSAs tended to present in coarse particles. • Log KPA increased linearly with increasing carbon chain length of PFAA. • Winter Monsoon drove atmospheric PFAA to southern cities. [ABSTRACT FROM AUTHOR]

It is extremely important to analyze the contaminative behaviors of Perfluoroalkyl acids (PFAAs) due to their serious threats to urban environments which are closely related to humans. Current study aimed to explore the distribution, source apportionment and ecological risk assessment of PFAAs in surface water from Shijiazhuang, China. The concentrations of ∑PFAAs ranged from 19.5 to 125.9 ng/L in the investigation area. Perfluorobutanesulfonic acid (PFBS) and perfluoropentanoic acid (PFPeA) were the predominant contaminants (mean value: 14.3 ng/L and 16.6 ng/L, respectively). The distribution of PFAAs according to geospatial analysis and hierarchical clustering analysis (HCA) showed that higher levels of ∑PFAAs were detected in the southern surface water of Shijiazhuang and there was a stepwise decrease from the wet season to the dry season. Furthermore, based on source apportionment, the dominant potential sources were found to be wastewater treatment plant (WWTP) effluents and industrial discharge. The risk quotients (RQs) revealed low ecological risks of all PFAAs for aquatic organisms in Shijiazhuang surface water. Collectively, this study provided basic data for regulatory strategies for controlling PFAA pollutions in urban surface water. Graphical Abstract [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Perfluoroalkyl acids (PFAAs) within the broader class of per- and polyfluoroalkyl substances (PFAS) are present in human serum as isomer mixtures, but epidemiological studies have yet to address isomer-specific associations with child development and behavior. Objectives: To examine associations between prenatal exposure to 25 PFAAs, including perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) isomers, and child neurodevelopment among 490 mother–child pairs in a prospective Canadian birth cohort, the Alberta Pregnancy Outcomes and Nutrition (APrON) study. To consider the influence of a classic neurotoxicant, total mercury (THg), based on its likelihood of co-exposure with PFAAs from common dietary sources. Methods: Maternal blood samples were collected in the second trimester and child neurodevelopment was assessed at 2 years of age using the Bayley Scales of Infant and Toddler Development, 3rd Edition (Bayley-III). Linear or curvilinear multiple regression models were used to examine associations between exposures and neurodevelopment outcomes. Results: Select PFAAs were associated with lower Cognitive composite scores, including perfluoroheptanoate (PFHpA) (β = −0.88, 95% confidence interval (CI): −1.7, −0.06) and perfluorododecanoate (PFDoA) (β = −2.0, 95% CI: −3.9, −0.01). Non-linear relationships revealed associations of total PFOS (β = −4.4, 95% CI: −8.3, −0.43), and linear-PFOS (β = −4.0, 95% CI: −7.5, −0.57) and 1m-PFOS (β = −1.8, 95% CI: −3.3, −0.24) isomers with lower Language composite scores. Although there was no effect modification, including THg interaction terms in PFAA models revealed negative associations between perfluorononanoate (PFNA) and Motor (β = −3.3, 95% CI: −6.2, −0.33) and Social-Emotional (β = −3.0, 95% CI: −5.6, −0.40) composite scores. Discussion: These findings reinforce previous reports of adverse effects of maternal PFAA exposure during pregnancy on child neurodevelopment. The unique hazards posed from isomers of PFOS justify isomer-specific analysis in future studies. To control for possible confounding, mercury co-exposure may be considered in studies of PFAAs.

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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]

Herring gulls (Larus argentatus) are generalist feeders; contaminant levels in their eggs reflect chemical exposure and uptake due to foraging in both aquatic and terrestrial environments. Hence, contaminant levels in their eggs provide insights into sources and relative importance of aquatic versus terrestrial pathways of chemical transfer. Here, perfluoroalkyl acids (PFAAs) known to be bioaccumulative were measured in individual herring gull eggs from one site on Lake Superior, Ontario, Canada. Thirteen perfluorinated carboxylates (PFCA, C 4 -C 18) and four perfluorinated sulfonates (PFSA, C 4 -C 10) were measured. Total PFCA and total PFSA concentrations varied 4- and 5-fold, respectively, among eggs. To understand these differences, stable carbon and nitrogen isotopes and fatty acid dietary tracers were measured in the same eggs. Stable isotopes were not useful in explaining inter-egg differences in PFAA concentrations. However, a variety of omega 3 (n-3) and omega 6 (n-6) fatty acid measures were correlated with C 9 -C 13 PFCAs as well as the PFSAs: perfluoro-1-hexanesulfonic acid (PFHxS) and perfluoro-1-octanesulfonic acid (PFOS). In general, n-3 fatty acids were positively correlated with egg PFAA concentrations while only the n-6 fatty acids exhibited negative relationships with egg PFAA levels. Proportions of n-3 and n-6 fatty acids in eggs would be expected to increase and decrease, respectively, with increased aquatic food in the gull diet. Results indicate that increased use of aquatic food led to heightened PFAA exposure in these generalist consumers sampled in a relatively remote area. They also highlight the utility of employing a variety of dietary markers for understanding contaminant exposure and accumulation. [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.)

Na+/taurocholate cotransporting polypeptide (NTCP) is important for the enterohepatic circulation of bile acids, which has been suggested to contribute to the long serum elimination half-lives of perfluoroalkyl substances in humans. We demonstrated that some perfluoroalkyl sulfonates are transported by NTCP; however, little was known about carboxylates. The purpose of this study was to determine if perfluoroalkyl carboxylates would interact with NTCP and potentially act as substrates. Sodium-dependent transport of [3H]-taurocholate was measured in human embryonic kidney cells (HEK293) stably expressing NTCP in the absence or presence of perfluoroalkyl carboxylates with varying chain lengths. PFCAs with 8 (PFOA), 9 (PFNA), and 10 (PFDA) carbons were the strongest inhibitors. Inhibition kinetics demonstrated competitive inhibition and indicated that PFNA was the strongest inhibitor followed by PFDA and PFOA. All three compounds are transported by NTCP, and kinetics experiments revealed that PFOA had the highest affinity for NTCP with a Km value of 1.8 ± 0.4 mM. The Km value PFNA was estimated to be 5.3 ± 3.5 mM and the value for PFDA could not be determined due to limited solubility. In conclusion, our results suggest that, in addition to sulfonates, perfluorinated carboxylates are substrates of NTCP and have the potential to interact with NTCP-mediated transport.

Perfluoroalkyls acids (PFAAs) have been emitted in the environment either as manufacturing by products or through degradation of its precursors. Development of efficient identification and quantification of PFAAs in different environmental media is important for environmental and human health risk assessments. In this study, different extraction methods were developed to determine nine (9) different PFAAs in seawater and seawater sandworm Perinereis wilsoni. P. wilsoni extracted using two methods: manual extraction and accelerated solvent extraction (ASE). Solid phase extraction method was used for the clean-up and preconcentration of PFAAs from the marine water samples. High-performace liquid chromatography–tandem mass spectrometry was used to analyze PFAAs concentrations in the samples. Percent recoveries of surrogate (SUR) in marine water samples were between 52 to 72% (blank), 52 to 88% (1 ng), and 56 to 79% (10 ng). Manual extraction of sandworm resulted in 57 to 93% recovery of SUR compounds. ASE extraction gave higher recoveries of SUR compounds (62 to 92%). The developed analytical methods for seawater and sandworm extraction can assure production of good quality PFAAs data. [ABSTRACT FROM AUTHOR]

To study the contamination levels of perfluoroalkyl acids (PFAAs) in Chinese eggs and the effects of persistent organic pollutant (POP) amendments to the Stockholm Convention blacklist, 3200 eggs from 10 major producing areas were collected from June 2013 to May 2017. Seventeen PFAAs in eggs were analysed. Perfluorooctane sulphonic acid (PFOS), perfluoropentanoic acid (PFPeA) and perfluorooctanoic acid (PFOA) were the main PFAAs in eggs. Perfluoroalkyl carboxylic acids (PFCAs) and short-chain PFAAs levels in eggs decreased after the amendment was implemented in China (p <.05), but no significant difference was observed in PFOS. The average ΣPFAAs of eggs from 10 major producing areas was 0.23 ng/g (

[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]

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. [Display omitted] • Twelve perfluoroalkyl acids were detected in drinking water resources of Pakistan. • Perfluorobutanoic acid and Perfluorobutane sulfonate were the most abundant compounds. • Multivariate statistics identified anthropogenic activities as the potential sources. • Perfluoroalkyl acid levels were with in the world risk thresholds. • Perfluoroalkyl acid toxicity was substantially higher in children than in adults. [ABSTRACT FROM AUTHOR]

Perfluoroalkyl acids (PFAAs) are environmentally persistent components of surfactants that consist of fully fluorinated carbon chains and a terminal sulfonate or carboxylate polar head moiety. Due to their unique amphiphilic properties, PFAAs are used in the manufacturing of products such as aqueous film forming foams (AFFF). There is cause for concern for PFAA contamination resulting from runoff and groundwater infiltration of AFFF that were used during fire training. This study analyzed water and sediment samples that were collected over a 13-month sampling period from bayous upstream and downstream of two former fire training areas located near Barksdale Air Force Base (BAFB); the occurrence and magnitude of PFAAs supported an aquatic ecological risk assessment of potential impacts of PFAAs at the site. Liquid chromatography coupled with mass spectrometry was used for determination of 6 PFAAs listed under the third Unregulated Contaminant Monitoring Rule (UCMR 3). Total PFAA concentrations in surface water and sediment samples ranged from 0 (ND) 7.1 ng/mL and 0 (ND)31.4 ng/g, respectively. Perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) were the predominant PFAAs detected. In general, perfluorosulfonates were quantified more frequently and at higher concentrations than perfluorocarboxylates. The perfluoroalkyl chain length of PFAAs also showed significant influence on PFAA concentrations when analyzed by Spearman's rank correlation analysis. Some contamination we observed in surface water and sediment samples from reference locations could be a result of local runoff from the use of commercial products containing per- and poly-fluoroalkyl substances (PFAS), but AFFF appears to be the primary source given the close proximity of the historical fire training areas. [ABSTRACT FROM AUTHOR]

Perfluoroalkyl acids (PFAAs) are environmentally persistent components of surfactants that consist of fully fluorinated carbon chains and a terminal sulfonate or carboxylate polar head moiety. Due to their unique amphiphilic properties, PFAAs are used in the manufacturing of products such as aqueous film forming foams (AFFF). There is cause for concern for PFAA contamination resulting from runoff and groundwater infiltration of AFFF that were used during fire training. This study analyzed water and sediment samples that were collected over a 13-month sampling period from bayous upstream and downstream of two former fire training areas located near Barksdale Air Force Base (BAFB); the occurrence and magnitude of PFAAs supported an aquatic ecological risk assessment of potential impacts of PFAAs at the site. Liquid chromatography coupled with mass spectrometry was used for determination of 6 PFAAs listed under the third Unregulated Contaminant Monitoring Rule (UCMR 3). Total PFAA concentrations in surface water and sediment samples ranged from 0 (ND) −7.1 ng/mL and 0 (ND) −31.4 ng/g, respectively. Perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) were the predominant PFAAs detected. In general, perfluorosulfonates were quantified more frequently and at higher concentrations than perfluorocarboxylates. The perfluoroalkyl chain length of PFAAs also showed significant influence on PFAA concentrations when analyzed by Spearman’s rank correlation analysis. Some contamination we observed in surface water and sediment samples from reference locations could be a result of local runoff from the use of commercial products containing per- and poly-fluoroalkyl substances (PFAS), but AFFF appears to be the primary source given the close proximity of the historical fire training areas.

Perfluoroalkyl substances (PFASs), as coating materials, possess oil-resistant and waterproof properties. However, their persistency and toxicity have caused concerns. This study developed a method for determining five types of 20 PFASs with ultra-performance liquid chromatography/tandem mass spectrometry, and measured seven categories of 32 commercial samples of oil-resistant food packaging in Taiwan. The assay was validated according to the specification of Taiwan Food and Drug Administration (TFDA). Samples of 100 cm² were cut into pieces and were ultra-sonicated in 20-mL methanol at 50 °C for 45 minutes. The extracts were concentrated to 1 mL for instrumental analysis. Most matrix effect factors and extraction efficiencies of the analytes were 50%e80% and 52%e99%, respectively. Most limits of detection and limits of quantification were between 0.07e11.3 ng/dm² and 0.17e18.3 ng/dm², respectively. Most recoveries ranged from 70% to 117% at three tested levels, and the precisions (%RSD) were lower than 19%. Microwave popcorn paper contained more types and higher levels of PFASs than other packaging, with perfluoroalkyl acids at 8.3e1960 ng/dm² and fluorotelomer alcohols (FTOHs) at 9.7e7188 ng/dm². High concentrations of FTOHs were also observed in one oil-proof paper bag at 454¡2595 ng/dm² and in one French fries paper bag at 22.4e167 ng/dm². [ABSTRACT FROM AUTHOR]

The impacts of environmental chemicals on the decline of kidney function have been suggested by a limited number of statistical and animal studies. Thus, those exposures may be modifiable risk factors for chronic kidney disease. Some of the chemicals, such as Perfluoroalkyl acid (PFA), are pervasive throughout our environment, determining their health effects is an important public health concern. In this study, we examined cross-sectional data from the 2009–2010 cycle of the National Health and Nutrition Examination Survey (NHANES) using a statistical causal inference method-generalized propensity score method, to determine the links between concentrations of several major environmental chemicals and kidney function measured by the estimated glomerular filtration rate (eGFR). Various generalized propensity score estimation methods including Hirano-Imbens, additive spline, and a generalized additive model were compared. Among the examined environmental chemicals, each of the statistical models used associated an increase in PFA concentration with a decline in eGFR. We conclude that PFA is a modifiable risk factor for chronic kidney disease and the statistical causal method produces credible results in estimating the effect of chemical exposures on a continuous measure of kidney functions with an observational dataset.

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).)

For the first time (N = 6291), a study was undertaken to estimate associations between the concentratio ns of red blood cell folate (RBCF) and concentration of six perfluoroalkyl acids (PFAAs), namely, perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS), perfluorodecanoic acid (PFDA), perfluorononanoic acid (PFNA), and perfluoroundecanoic acid (PFUnDA) for US adults aged ≥20 years by fitting regression models for the data from National Health and Nutrition Examination Survey for 2007–2014. In almost consistent fashion, increasing concentrations of PFAAs were associated with decreasing concentrations of RBCF. For the total population, for a 10% increase in the concentrations of PFOA, PFOS, PFDA, PFHxS, PFNA, and PFUnDA, percent decreases in RBCF concentrations were found to be 0.33%, 0.66%, 0.83%, 0.16%, 0.89%, and 0.43%, respectively. RBCF concentrations of PFAAs were found to be 1104, 1042, 100, and 936 nmol/L across the four quartiles of PFOS; 112, 1068, 1009, and 948 nmol/L across the four quartiles of PFDA; 1125, 1054, 1005, and 967 nmol/L across the four quartiles of PFNA; and 1099, 1094, 989, and 952 nmol/L across the four quartiles of PFUnDA. Perfluorinated carboxylic acids with carbon chain length > 8 decreased concentrations of RBCF to a greater degree than those carbon chain length ≤ 8. Perfluorinated chemicals with a sulfonic group with carbon chain length > 6 decreased concentrations of RBCF to a greater degree than those carbon chain length ≤ 6. The degree to which concentrations of RBCF decrease varied by age, gender, and race/ethnicity. Non-Hispanic blacks as compared to non-Hispanic whites and Hispanics had the lowest decreases in RBCF concentrations. Mechanisms responsible for negative associations between RBCF and PFAA concentrations are not known and will need to be researched further. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFAS) have been extensively used as surfactants because of their high stability and good water/oil-repellent properties. PFASs, especially perfluoroalkyl acids (PFAAs), have long biological half-lives, and exposure may cause adverse health effects in humans. We assessed temporal trends of concentrations of eight PFAAs in serum of Swedish adolescents (age 16–21 years) from the general population, and estimated the stability of PFAAs and serum samples after 6 years of storage. Repeated cross-sectional sampling was performed on five occasions (covering in total 1213 individuals, 83% males) in southern Sweden between 2000 and 2017. We analyzed serum for perfluorohexane sulfonic acid (PFHxS), perfluorooctane sulfonic acid (PFOS), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), and perfluorododecanoic acid (PFDoDA) using liquid chromatography-tandem mass spectrometry. We assessed time trends using linear regression, long-term stability was assessed by reanalyzing samples collected 2013, and the comparison was done using Pearson correlation and Bland-Altman plots.PFHxS, PFOS, and PFOA decreased by 6.7% (CI: –7.0, –6.3%), 12.6% (CI: –12.9, –12.3%), and 6.5% (CI: –6.8, –6.1%) per year, respectively, and year of sampling explained 48–81% of the variation in concentrations. PFNA and PFDA seemed to increase up to 2009 and decrease thereafter. The trends were consistent after sensitivity analyses excluding women. Strong correlations of 94–97% were observed for concentrations of all compounds, except PFHxS, after storage. The observed trends closely followed the timing of manufacturers’ voluntary phase-out initiatives, and of regulatory measures governing the compounds implemented in the EU and USA. This indicates that these actions mitigated the population’s exposure to PFHxS, PFOS, and PFOA and, in recent years, to PFNA and PFDA, in southern Sweden. Furthermore, the results suggest that PFAAs remain stable in serum samples after long-term storage.

Per‐ and polyfluoroalkyl substances (PFAS) are organic pollutants that may have adverse effects on the ecosystem. Despite the global presence of PFAS, knowledge of PFAS on the African continent is limited because monitoring of PFAS is challenging and often not feasible owing to the lack of analytical capacity and high cost. However, it is necessary to understand the environmental risks posed by these chemicals in developing countries, because increasing urbanization will likely increase PFAS contamination in the environment. Although, as far as is known, PFAS concentrations in the African aquatic environment are generally lower than in more developed countries, exceedances of ecological quality standards (EQS) were reported in a few cases, providing evidence of potential ecological risks to these ecosystems. However, the number of ecosystems at risk will likely increase as urbanization and modernization increase in African countries. Therefore, environmental regulations should be updated and implemented to reduce further contamination of the aquatic environment with these chemicals. In addition, analytical laboratories in Africa should develop their capacity to detect PFAS and related compounds regularly and routinely. Local hot spots need to be identified, the influence of these hot spots on the PFAS burden in the environment should be investigated, and environmental regulations should be implemented for these hot spots to reduce their environmental impact. Therefore, we recommend a more routine monitoring of PFAS, including new PFAS that are currently used as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) alternatives, which are not regulated and environmentally concerning. Integr Environ Assess Manag 2021;17:726–732. © 2021 SETAC KEY POINTS: PFAS concentrations in the African aquatic environment are generally low compared to developed countries, but they sometimes do exceed ecological quality standard values, providing evidence for potential ecological risks at these ecosystems.Environmental regulations should be updated and implemented, as the number of ecosystems at risks will likely increase due to increasing urbanization and modernization of African countries, to reduce further contamination of the aquatic environment with PFAS.Analytical laboratories in Africa need to develop their capacity to detect PFAS and related compounds regularly and on a routine basis.Local hotspots need to be identified, the influence of these hotspots on the PFAS burden in the aquatic environment should be investigated, and environmental regulations should be implemented for these hotspots to reduce their environmental impact. [ABSTRACT FROM AUTHOR]

Data for 639 US children aged 3–11 years who participated in the National Health and Nutrition Examination Survey during 2013–2014 were analyzed by fitting regression models with log10-transformed values of blood lead and methyl and total mercury as dependent variables and log10-transformed values of perfluoroalkyl acids (PFAA) as one of the independent variables. PFAAs considered were 2-(N-methyl-perfluorooctane sulfonamido) acetic acid (MPAH), linear isomer of perfluorooctanoic acid (NPFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorohexane sulfonic acid (PFHxS), linear isomer of perfluorooctane sulfonic acid (NPFOS), and monomethyl branch isomer of perfluorooctane sulfonic acid (MPFOS). Adjusted regression slopes (β) indicating associations between the concentrations of PFAAs with blood lead and mercury were estimated. Statistically significant associations between concentrations of each PFAA and blood lead were observed. For 10% increases in concentrations of MPAH, NPFOA, PFNA, PFDA, PFHxS, NPFOS, and MPFOS, percent increases in the concentrations of blood lead were 0.45%, 1.59%, 0.78%, 0.32%, 0.65%, 1.32%, and 0.89% respectively. For 10% increases in concentrations of MPAH, PFNA, PFDA, and NPFOS, percent increases in the concentrations of total mercury in the blood were 1.62%, 1.44%, and 3.24% respectively. For 10% increases in concentrations of PFDA and NPFOS, percent increases in the concentrations of methyl mercury in the blood were 2.07% and 4.57% respectively. While concentrations of each of the seven PFAAs were positively associated with the concentrations of blood lead, concentrations of only PFDA and NPFOS were positively associated with increases in total and methyl mercury. PFAAs having positive associations with lead and mercury imply co-exposure and/or co-existence of high concentrations of PFAAs and lead/mercury. Since PFAAs as well as lead/mercury are known to be neurotoxic, nephrotoxic, and endocrine disruptors, their co-existence/co-exposure may lead to neurodevelopmental deficits that are additive/synergistic than neurodevelopmental deficits associated with exposures to PFAAs and lead/mercury alone. Future studies are needed to investigate additive/synergistic neurodevelopmental deficits associated with co-exposures to PFAAs and lead/mercury. [ABSTRACT FROM AUTHOR]

Data (N = 2552) from National Health and Nutrition Examination Survey for US adults aged ≥ 20 years for 2011–2016 were analyzed to estimate the associations between the concentrations of blood cadmium, lead, and total mercury and the concentrations of seven perfluoroalkyl acids (PFAA), namely, 2-(N-Methyl-perfluorooctane sulfonamido) acetic acid (MPAH), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonic acid (PFOS). Concentrations of blood cadmium were negatively associated with the concentrations of PFHxS (β = − 0.05428, p < 0.01) and PFOS (β = − 0.0212, p = 0.02). Concentrations of blood lead were positively associated with the concentrations of MPAH (β = 0.03301, p < 0.01), PFOA (β = 0.04783, p = 0.01), PFNA (β = 0.11761, p < 0.01), PFDA (β = 0.08007, p < 0.01), PFUA (β = 0.11382, p < 0.01), and PFOS (β = 0.04996, p = 0.02). Percent increases in the concentration of blood lead were 0.32%, 0.46%, 1.13%, 0.77%, 1.09%, and 0.48% for 10% increases in the concentrations of MPAH, PFOA, PFNA, PFDA, PFUA, and PFOS, respectively. Concentrations of blood total mercury were positively associated with the concentrations of PFNA (β = 0.37105, p < 0.01), PFDA (β = 0.46875, p < 0.01), PFUA (β = 0.56934, p < 0.01), and PFOS (β = 0.17557, p < 0.01). Percent increases in the concentration of blood total mercury were 3.6%, 4.57%, 5.58%, and 1.69% for 10% increases in the concentrations of PFNA, PFDA, PFUA, and PFOS, respectively. Associations between the concentrations of PFAAs with blood total mercury were substantially stronger than the concentrations with blood lead. Higher the carbon chain length for PFAAs, stronger were the associations between PFAAs with lead and mercury. [ABSTRACT FROM AUTHOR]

Introduction: The immunosuppressive properties of PFASs are widely recognized. Early-life exposure to PFAS has been linked to reduced immune response to childhood vaccinations and increased rates of common infectious diseases, but implications for hospitalizations are unclear. Objectives: To investigate the association between maternal serum concentrations of five PFASs during pregnancy and the child’s rate of hospitalization due to common infectious diseases between birth and 4 years of age. Methods: Serum samples from first trimester pregnant women from the Odense Child Cohort (OCC) collected in 2010–2012 were analyzed for concentrations of perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA) and three other PFASs. Data on child hospitalizations with an ICD-10 code for infectious disease was obtained from the Danish National Patient Register. The following were identified: upper respiratory tract infections (URTI), lower respiratory tract infections (LRTI), gastrointestinal infections (GI), and other infections. The Andersen-Gill Cox proportional hazard model for recurrent events was used to investigate the association between PFAS exposure and hospitalizations. The resulting estimates were hazard ratios (HRs), which express the relative change in the instantaneous risk of hospitalization with a doubling in maternal PFAS concentration. Results: A total of 1,503 mother–child pairs were included, and 26% of the children were hospitalized at least once for infectious disease. A doubling in maternal PFOS concentration was associated with a 23% increase in the risk of hospitalization due to any infection (HR: 1.23 (95% CI: 1.05, 1.44). There was indication of an interaction between child sex and PFOS (p = 0.07) and PFDA (p = 0.06), although in opposite directions. Further, every doubling of PFOA or PFOS increased the risk of LRTI by 27% (HR: 1.27 (1.01, 1.59)) and 54% (HR: 1.54 (1.11, 2.15)), respectively. Similar tendencies were seen for URTI and the group of other infections. For GIs, the opposite pattern of association was seen as HR’s were consistently below 1 (PFOA, HR: 0.55 (0.32, 0.95)). Discussion: We found an association between PFOS and the overall risk of infectious disease, and between PFOS and PFOA exposures and the risk of LRTI’s. These results are in agreement with previous findings from the OCC, in which maternal PFOS and PFOA concentrations were positively associated with the number of days that the children experienced fever, thereby suggesting that PFOS and PFOA may affect the prevalence of both mild and more severe infectious diseases even in a rather low-exposed population.

Data from the National Health and Nutrition Examination Survey (N = 6141) for the years 2003–2016 for US adults were analyzed to evaluate the impact of glomerular hyperfiltration on the observed concentrations of perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorodecanoic acid, perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA) for several disease groups. Hyperfiltrators were defined as having an estimated glomerular filtration rate (eGFR) ≥ 110 mL/min/1.73 m2, and normal filtrators were defined as those having an eGFR between 90 and 110 mL/min/1.73 m2. The seven disease groups for which the data were analyzed were as follows: those (i) without any diseases; (ii) with hypertension only; (iii) with albuminuria only; (iv) with anemia only; (v) with diabetes only; (vi) with hypertension and one or more of diabetes, anemia, and albuminuria; and (vii) with two or more of diabetes, anemia, and albuminuria without hypertension. For almost every PFAA, for all seven disease groups except the albuminuria only group, hyperfiltrators had lower adjusted geometric means (AGM) than normal filtrators. For example, for the disease group with hypertension only, for PFOS, the AGMs for hyperfiltrators and normal filtrators were 8.3 and 10.6 ng/mL, respectively, for the total population. For the group with albuminuria only, normal filtrators were found to have higher AGMs than hyperfiltrators for the total population and males. For example, for PFHxS, the AGMs for normal and hyperfiltrators were 0.98 and 1.05 ng/mL, respectively, for the total population. For females, these AGMs for normal and hyperfiltrators were 0.96 and 0.86 ng/mL respectively. Males usually had higher AGMs than females, but the reverse was also true occasionally. Usually, male–female differences were substantially narrower for normal filtrators than hyperfiltrators. Irrespective of the filtration status, the disease group with hypertension only had the highest AGMs for every PFAA. AGMs for the anemia only group were the lowest for every PFAA as compared with other disease groups among hyperfiltrators. [ABSTRACT FROM AUTHOR]

Perfluoroalkyl substances (PFAS) are surface‐active agents used in diverse industrial and commercial applications. They contaminate both freshwater and marine ecosystems, are highly persistent, and accumulate through trophic transfer. Seabirds are exposed to environmental contaminants due to their high trophic position in food webs and relatively long lifespan. We measured levels of 10 perfluoroalkyl acids (PFAAs) in egg yolks of yellow‐legged gulls (Larus michahellis) breeding in the northern Adriatic Sea (Northeast Italy). We examined variations in PFAAs within clutches (between eggs of different laying order) and among clutches. Perfluorooctane sulfonate (PFOS) was the most abundant yolk PFAA (mean = 42.0 ng/g wet wt), followed by perfluorooctanoic acid (PFOA; 3.8 ng/g wet wt) and perfluorododecanoic acid (PFDoDa; 2.8 ng/g wet wt). The ∑PFAAs averaged 57.4 ng/g wet weight, ranging between 26.5 and 115.0 ng/g wet weight. The PFAA levels varied substantially among clutches (0.29–0.79 of the total variation), whereas the effects of laying order were considerably weaker (0.01–0.13). Egg‐laying order effects were detected for ∑PFAAs, PFOS, perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnA), and PFDoDa, whereby the last‐laid eggs exhibited lower PFAA concentrations than early‐laid eggs. Our results indicate that seagulls from the northern Adriatic basin deposit measurable amounts of PFAAs in their eggs. The large among‐clutches differences in PFAAs suggest that exposure of yellow‐legged gull females to these compounds is highly variable. Environ Toxicol Chem 2021;40:744–753. © 2020 SETAC [ABSTRACT FROM AUTHOR]

Data for US adults aged ≥20 years from National Health and Nutrition Examination Survey for the years 2003–2014 were analyzed to evaluate how adjusted (N = 8481) and unadjusted (N = 9080) levels of selected perfluoroalkyl acids (PFAA) vary across the different stages of glomerular function (GF) among those who did not have diabetes, anemia, or albuminuria as compared to those who had diabetes only, anemia only, and albuminuria only. PFAAs selected for analyses were: perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorodecanoic acid (PFDA), perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA). Irrespective of GF stage, there was no noticeable evidence to suggest that adjusted levels of PFAA for those with diabetes only are any lower than those with no diabetes, no anemia, and no albuminuria. Those who had anemia only were found to have lower adjusted levels of at least PFOA, PFOS, PFDA, and PFHxS than those who had no diabetes, no anemia, and no albuminuria. These results were seen in the presence (eGFR 90 mL/min/1.73 m2), GF-2 (60 ≤ eGFR ≤ 90 mL/min/1.73 m2), and GF-3B/4 (15

Background: Studies exploring the associations between perfluoroalkyl acids (PFAAs) and type 2 diabetes mellitus (T2DM) are rather limited and have reported conflicting results. All studies to date, including prospective ones, have relied on a single blood sample to study this association. Similarly, studies investigating how T2DM status may influence the longitudinal changes in PFAA concentrations have not been previously performed. As PFAA concentrations in humans have changed considerably over the last two decades, and as individuals diagnosed with T2DM usually undergo lifestyle changes that could influence these concentrations, a single blood sample may not necessarily reflect the life-time exposure to PFAA concentrations. Hence, repeated measurements from the same individuals will extend our understanding of how PFAAs are associated with T2DM. The present study, therefore, aimed to explore associations between pre- and post-diagnostic PFAA blood profiles and T2DM and assess factors associated with longitudinal changes in PFAAs in T2DM cases and controls. Methods: Questionnaire data and blood samples from women participating in the Norwegian Women and Cancer study were used to conduct a nested case-control study among 46 T2DM cases matched to 85 non-diabetic controls. PFAAs were measured in blood samples collected prior to (2001/02) and after (2005/6) T2DM diagnosis. We investigated the association between PFAAs and incident and prevalent T2DM using conditional logistic regression. We assessed the longitudinal changes in PFAA concentrations within and between matched cases and controls using t-tests and linear regression models. Results: We observed no significant associations between pre-diagnostic PFAA concentrations and T2DM incidence. Similar results were observed for the post-diagnostic PFAA concentrations and T2DM prevalence. Decrease over time in PFAA concentrations were observed for PFOA and ∑PFOS concentrations, whereas increase over time were observed for PFNA, PFDA and PFUnDA concentrations. Longitudinal trends in PFAA concentrations among T2DM cases were similar to the changes observed in controls. Conclusions: The study did not find evidence of association between PFAAs and incident or prevalent T2DM. The longitudinal changes in PFAAs concentrations were not influenced by T2DM status.

Background: Perfluoroalkyl acids (PFAAs) are persistent and ubiquitous environmental contaminants that potentially disrupt endocrine system functions. While some PFAAs (perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA)) are regulated, currently used fluorotelomer alcohols (FTOHs) can be transported to the Arctic and are degraded in a number of PFAAs which biomagnify in Arctic wildlife (e.g. perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUdA)). Objectives: From 2004 to 2017, 279 pregnant Inuit women were recruited as part of biomonitoring projects in Nunavik. Our goal was to evaluate: (i) time-trends in plasma/serum PFAAs levels in pregnant Nunavimmiut women between 2004 and 2017; (ii) compare plasma/serum PFAAs levels in Nunavimmiut women in 2016–2017 to those measured in women of childbearing age in the Canadian Health Measure Survey (CHMS); and (iii) evaluate the associations of PFAAs levels with the consumption of country foods and pregnancy and maternal characteristics during pregnancy in the 97 participants recruited in 2016–2017. Methods: Individual blood sample were collected for serum or plasma PFAAs (PFOS, PFOA, pentafluorobenzoic acid (PFBA), perfluorohexanoic acid (PFHxA), perfluorobutanesulfonic acid (PFBS), perfluorohexane-1-sulfonic acid (PFHxS), PFNA, PFDA, PFUdA) analyses. Socio-demographic data, pregnancy and maternal characteristics and country foods consumption were documented using a questionnaire. Omega-3 and −6 polyunsaturated fatty acids (PUFA) were measured in red blood cell membranes and their ratio used as a biomarker of marine country foods consumption. Time-trends in PFAAs levels were evaluated using ANCOVA models adjusted for relevant co-variables. Serum/plasma levels of PFAAs in the 97 pregnant women aged 16 to 40 years old and recruited in 2016–2017 were compared to those measured in women aged 18 to 40 years old from the CHMS cycle 5 (2016–2017) using the geometric means (GM) and 95% confidence intervals (95% CI). Multivariate regression analyses were performed to examine associations between concentrations of PFAAs and country foods consumption data. Results: Statistically-significant downward time trends were noted for concentrations of PFOS, PFOA and PFHxS in pregnant Nunavik women between 2004 and 2017. Conversely, between 2011 and 2016–2017, PFNA, PFDA and PFUdA maternal serum levels increased by 19, 13 and 21% respectively. Among participants in 2016–2017, mean concentrations for PFNA (GM: 2.4 μg/L), PFDA (0.53 μg/L) and PFUdA (0.61 μg/L) were higher than those measured in women aged 18–40 years old in the Cycle 5 (2016–2017) of the CHMS. PFOA (0.53 μg/L) and PFHxS (0.26 μg/L) were lower than in CHMS, whereas PFBA, PFHxA and PFBS were not detected in 2016–2017. Ratios of serum/plasma levels of PFNA/PFOA, PFNA/PFOS, PFNA/PFHxS and PFUdA/PFDA were significantly higher in the 97 pregnant women from Nunavik recruited in 2016–2017 compared to CHMS, highlighting their distinct exposure profile. In multivariate models, PFHxS, PFOS, PFNA, PFDA and PFUdA levels in 2016–2017 were strongly associated with the omega-3/omega-6 PUFA ratio, indicating a positive association between marine country foods consumption and higher exposure to PFAAs. Conclusions: The exposure of pregnant women to long-chain PFAAs (PFNA, PFDA and PFUdA) increased from 2004 to 2017 in Nunavik. Associations noted between PFAAs levels and the omega-3/omega-6 ratio highlights the importance of implementing additional strict regulations on PFAAs and their precursors to protect the high nutritional quality and cultural importance of country foods in Nunavik.

Data (N = 10643) from National Health and Nutrition Examination Survey for US adults aged > = 20 years for 2003-2016 were analyzed to evaluate how concentrations of selected perfluoroalkyl acids (PFAA) vary among normotensives and hypertensives across various stages of glomerular function (GF) namely from stage 1 to stage 3B/4. Regression models stratified by GF stages and hypertension status were fitted for each of the five PFAAs, namely, PFOA, PFOS, PFDA, PFHxS, and PFNA. For the total population, hypertensives had higher adjusted levels than normotensives for GF-1, GF-2, and GF-3A with highest differences being at GF-3A for every PFAA. At GF-3B/4, hypertensives had lower adjusted geometric means (AGM) than normotensives. While AGMs for PFAA for hypertensives followed inverted U-shaped distributions with points of inflections at GF-3A, for normotensives the points of inflections were at GF-2 or GF-3A. [ABSTRACT FROM AUTHOR]

Background: The C8 Health Project was established in 2005 to collect data on perfluorooctanoic acid (PFOA, or C8) and human health in Ohio and West Virginia communities contaminated by a fluoropolymer production facility. Objective: We assessed PFOA exposure via contaminated drinking water in a subset of C8 Health Project participants who drank water from private wells. Methods: Participants provided demographic information and residential, occupational, and medical histories. Laboratory analyses were conducted to determine serum-PFOA concentrations. PFOA data were collected from 2001 through 2005 from 62 private drinking water wells. We examined the relationship between drinking water and PFOA levels in serum using robust regression methods. As a comparison with regression models, we used a first-order, single-compartment pharmacokinetic model to estimate the serum: drinking-water concentration ratio at steady state. Results: The median serum PFOA concentration in 108 study participants who used private wells was 75.7 mu g/L, approximately 20 times greater than the levels in the U. S. general population but similar to those of local residents who drank public water. Each 1 mu g/L increase in PFOA levels in drinking water was associated with an increase in serum concentrations of 141.5 mu g/L (95% confidence interval, 134.9-148.1). The serum: drinking-water concentration ratio for the steady-state pharmacokinetic model was 114. Conclusions: PFOA-contaminated drinking water is a significant contributor to PFOA levels in serum in the study population. Regression methods and pharmacokinetic modeling produced similar estimates of the relationship.