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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.

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.

[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]

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.

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).)

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.

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 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.

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.

Background: Perfluorooctanoic acid (PFOA) is a perfluoroalkyl acid found in > 99% of Americans. Its health effects are unknown. Prior estimates of serum half-life range from 2.3 to 3.8 years. Objectives: We assessed the impact of years of residence and years since residing in the study area on serum PFOA concentration in a sample of current and former residents who were exposed to PFOA emissions from an industrial facility in six water districts in West Virginia and Ohio. Methods: Serum samples and questionnaires, including residential history, were collected in 2005-2006. We modeled log serum PFOA (nanograms per milliliter) for current residents as a function of years of residence in a water district, adjusted for a variety of factors. We modeled the half-life in former residents who lived in two water districts with high exposure levels using a two-segment log-linear spline. Results: We modeled serum PFOA concentration in 17,516 current residents as a function of years of residence (R(2) = 0.68). Years of residence was significantly associated with PFOA concentration (1% increase in serum PFOA/year of residence), with significant heterogeneity by water district. Half-life was estimated in two water districts comprising a total of 1,573 individuals. For the participants included in our analyses, we found that years since residing in a water district was significantly associated with serum PFOA, which yielded half-lives of 2.9 and 8.5 years for water districts with higher and lower exposure levels, respectively. Conclusion: Years of residence in an exposed water district is positively associated with observed serum PFOA in 2005-2006. Differences in serum clearance rate between low-and high-exposure water districts suggest a possible concentration-dependent or time-dependent clearance process or inadequate adjustment for background exposures.

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]

Exposure to perfluoroalkyl substances (PFASs) is of public concern due to their persistent exposure and adverse health effects. Placental transfer of PFASs is an important excretion pathway of these chemicals in pregnant women and exposure route in fetuses. We measured PFAS concentrations in maternal, paternal, and umbilical cord serum collected from 62 pregnant Korean women and matched biological fathers of the fetuses. Placental transfer rates (cord to maternal serum ratio) of PFASs were also calculated. Demographics and pregnancy-related factors determining the placental transfer rates were identified using linear regression models. Maternal, paternal, and cord serum showed different PFASs compositions. Among the PFASs, perfluorooctane sulfonate (PFOS) showed the highest concentrations in maternal and paternal serum, while perfluorooctanoic acid (PFOA) showed the highest concentration in cord serum. There was a higher proportion of perfluoroalkyl carboxylic acids (PFCAs) with 9–12 carbon chains than those with 13–14 carbon chains in maternal and paternal serum, but this proportion was in the opposite direction in cord serum. PFOA and perfluorohexane sulfonate (PFHxS) had higher placental transfer rates (means of 0.32 and 0.36, respectively) than PFOS (mean of 0.12), which is in line with the results of previous studies. Gestational age and birth weight were positively associated with placental transfer rate of PFOA, PFHxS, and PFOS, while pre-pregnant BMI and weight were inversely associated with PFOS. This study showed that placental transfer of PFASs differs by compounds and is associated with pregnancy-related factors. Further studies on novel PFASs are warranted for Korean pregnant women.

Serum perfluoroalkyl acids (PFAAs) have been linked to disruption of maternal thyroid hormone homeostasis, but results have varied between studies which we hypothesized was due to timing of the thyroid hormone measurements, variability in PFAA isomer patterns, or presence of other stressors. In a longitudinal study design, we investigated the time-dependency of associations between PFAA isomers and thyroid hormones during pregnancy and post-partum while considering thyroid peroxidase antibody (TPOAb) status and mercury (Hg) co-exposure. In participants of a prospective Canadian birth cohort (n = 494), free thyroxine (FT4), free triiodothyronine (FT3), thyroid stimulating hormone (TSH) and TPOAb were quantified in maternal plasma collected in each trimester and 3-months postpartum, and 25 PFAAs (15 linear and 10 branched) and Hg were quantified in samples collected during the second trimester. Perfluorohexane sulfonate (PFHxS) and total branched isomers of perfluorooctane sulfonate (PFOS) were positively associated with TSH in mixed-effect models, with strongest associations early in gestation. Throughout pregnancy and post-partum, PFHxS was inversely associated with FT4, consistent with elevated TSH, while Hg was inversely associated with FT3. In TPOAb-positive women, negative associations were found between PFUnA and FT4, and 1 m -PFOS and TSH, supporting previous studies that thyroid disorder could increase susceptibility to PFAA-mediated hormone dysregulation. Hg did not confound associations but was a significant interaction term, revealing further positive associations between PFOS isomers (∑3 m +4 m -PFOS) and TSH. Higher perfluoroalkyl sulfonate exposures were associated with higher TSH and/or lower FT4, strongly suggestive that PFHxS and branched PFOS isomers are risk factors for subclinical maternal hypothyroidism. Isomer-specific analysis is important in future studies, as crude measures of 'total-PFOS' masked the associations of branched isomers. A concerning result was for PFHxS which had consistent negative associations with FT4 at all time points and a positive association with TSH in early pregnancy when fetal development is most sensitive to disruption. • Perfluoroalkyl acids were associated with thyroid hormones during and after pregnancy. • Associations were strongest in early pregnancy, a sensitive stage of neurodevelopment. • Evidence mounting for cause-effect relationship for perfluorohexane sulfonate • Isomer-specific associations for branched perfluorooctane sulfonate, not linear • Associations influenced by mercury co-exposure and thyroid peroxidase antibodies. [ABSTRACT FROM AUTHOR]

Associations between selected perfluoroalkyl acids (PFAAs) and biomarkers of renal function were evaluated for US adult aged ≥ 20 years (N = 8220) in the National Health and Nutrition Examination Survey for 2005–2014. Glomerular filtration (GF) stage-stratified regression models were classified by estimated glomerular filtration rate (eGFR) with GF-1 (eGFR > 90 mL/min/1.73 m2), GF-2 (eGFR 60–89 mL/min/1.73 m2), GF-3A (45–59 mL/min/1.73 m2), and GF-3B/4 (15–44 mL/min/1.73 m2). For GF-1, PFOA, PFOS, and PFHxS were positively and significantly associated with serum creatinine. Serum albumin levels were positively associated with the PFAA considered at all stages and most associations were significant. Further, PFAS serum concentration associations to serum albumin were about 2–3 times stronger at GF-3B/4 than at GF-1. In contrast, urine albumin was negatively and significantly associated with PFOA and PFHxS serum concentrations at all stages of renal function, while, PFOS and PFNA were negatively and significantly associated to urine albumin at GF-3A and GF-3B/4. Urine albumin/creatinine ratios were negatively and significantly associated with PFOA, PFOS, and, and PFHxS serum concentrations at all stages of renal function, as well as with PFNA and PFDA at GF-3A and GF-3B/4. Recent work revealed that serum PFAAs have an inverted U-shaped association to the calculated stages of renal failure based on eGFR; this work adds that albuminuria makes additional negative contributions to already existing negative associations of PFAA to eGFR in advancing stages of renal failure. We hypothesize that both progressive renal failure per se and especially renal failure with albuminuria cause the kidneys to reabsorb less and to excrete more of the PFAAs studied. We suspect this finding may generalize to some other perfluoroalkyl substances (PFAS). The findings also imply study design considerations for evaluating associations to diseases and biomarkers associated with renal failure, such as diabetes. • Negative associations between urinary albumin and UACR and PFAAs increased incrementally from GF-1 to GF-3B/4. • Albuminuria is associated with and may drive enhanced excretion of PFAAs as kidney function declines. • We illustrate how results have implications for study design of biomarkers associated with renal failure. [ABSTRACT FROM AUTHOR]

We analyzed paired serum, urine, and hair samples from 94 Korean children and adults to investigate levels of 11 perfluoroalkyl acids (PFAAs). The effects of demographic factors and dietary habits on PFAA exposure were also assessed based on the paired samples. The total PFAA concentrations were 2.4–31 ng/mL in serum, not detected–9.5 ng/mL in urine, and 0.48–15 ng/g in hair. Levels of perfluoropentanoic acid (PFPeA) and perfluorohexanoic acid (PFHxA), which have short carbon chains, were 1.5–5 fold higher in urine and hair than in serum. The PFAA concentrations in serum exhibited a decreasing trend with age from young childhood to adolescence, followed by an increasing trend after adolescence. For most PFAA species, concentrations in serum were higher in adult males than in adult females (p < 0.01). No sex difference was evident in the urine and hair samples. In addition, there was no age difference in the urine samples, but in the hair samples, we observed higher concentrations of PFAAs in children than in the other age groups (p < 0.01). The consumption rates of fish and water showed significant correlations with serum (positive correlation) and hair (negative) concentrations, respectively. No relationships between serum and hair/urine levels for most PFAAs were observed, except between serum and hair levels for perfluorooctanoic acid (PFOA). Image 1 • PFAAs concentrations in paired urine, hair and serum were assessed. • Short-chain PFAAs showed 1.5 times higher concentrations in urine and hair than in serum. • PFPeA and PFHxA were dominantly detected in urine and hair samples. • Consumption of fish and water showed negative correlation with PFOA in hair. • No correlation was observed for most of PFAAs between serum and hair or urine. Different perfluoroalkyl acid profiles were observed among serum, urine, and hair samples; in particular, higher proportions of perfluorocarboxylic acids (PFCAs) were present in urine and hair than in serum samples. [ABSTRACT FROM AUTHOR]

Abstract To investigate the distribution, partitioning, and inhalation exposure risks of perfluoroalkyl acids (PFAAs), gaseous and particulate samples were collected monthly between September 2013 and September 2015 in urban and rural areas near Lake Chaohu. Twelve PFAAs were determined by liquid chromatography-mass spectrometry. The mean concentrations of PFAAs in the gaseous phase and the particulate phase were 40.31 ± 31.47 pg/m3 and 63.26 ± 41.87 pg/m3, respectively. Perfluorobutanoic acid (PFBA) was the predominant contaminant in the gaseous phase (32.56% ± 9.28%), while perfluorooctanoic acid (PFOA) was the main contaminant in the particulate phase (33.21% ± 18.69%). The ratios of gaseous to particulate distribution ranged from 0.01 to 16.75. The gaseous-particulate partitioning coefficients, ranging from 0.01 to 23.41 ± 10−2 m3/μg, were significantly correlated with PM 10 concentrations and meteorological conditions, such as temperature and air pressure. The inhalation exposures of PFOA and PFOS were 1.94–60.2 pg/(kg·d) and 0.30–4.22 pg/(kg·d), respectively. The carcinogenic risk of PFOA for urban males was the highest and that for rural females was the lowest; the risks were lower than the acceptable level (10−6) defined by the US Environmental Protection Agency (USEPA). The non-carcinogenic risks of PFOA and PFOS were far below one. Graphical abstract Correlations between the gaseous-particulate partitioning coefficients (Kp) of PFOA and PFOS with the atmosphere environmental conditions such as PM10 concentrations and meteorological conditions (temperature and barometric pressure). Image 1 Highlights • PFBA and PFOA were predominant in the gaseous phase and the particulate phase, respectively. • The gaseous-particulate partitioning coefficients of PFOA and PFOS were correlated with meteorological conditions. • The inhalation exposures of PFOA and PFOS were 1.94–60.2 and 0.30–4.22 pg/(kg·d), respectively. • The carcinogenic risk of PFOA was lower than the acceptable level (10−6) defined by the USEPA. • The non-carcinogenic risks of PFOA and PFOS were far below one. [ABSTRACT FROM AUTHOR]

Perfluoroalkyl acid substances (PFAAs), such as perfluorobutanoic acid (PFBA), perfluorobutanoic sulfonic acid (PFBS), perfluorooctane acid (PFOA) and perfluoroooctane sulfonic acid (PFOS) are frequently detected in the global environment and can cause potential health hazards even at low levels. In this study, quantitative human health risk assessment was undertaken to derive soil generic assessment criteria (GAC) for four PFAAs under the agricultural land scenario in the evaluated Chinese regions, which considered multiple exposure pathways including vegetables consumption, dermal absorption, ingestion of soil and dust, and exposure from non-soil sources. It is showed that the calculated GAC for four PFAAs in Guangdong and Shandong Provinces were less stringent than those in Zhejiang and Jiangsu Provinces, and Shanghai City, owing to the low exposure from non-soil sources in former two provinces. In addition, GAC of PFOS were the most stringent in the range of 0.28–0.50 μg kg−1 in the studied regions, followed by PFOA (1.36–2.20 μg kg−1), PFBA (42.59–68.03 μg kg−1) and PFBS (474.59–749.60 μg kg−1), mainly attributable to significantly more stringent toxicological values of PFOA and PFOS. Correspondingly, the potential health hazards exist for PFOA in the studied regions except Guangdong Province, and PFOS only in Zhejiang and Jiangsu Provinces as indicated by the hazard quotients ranging from 1.04 to 19.49, but no health hazards are identified for PFBA and PFBS. The dominant exposure pathway was found to be consumption of vegetables and attached soil for PFBA and PFBS, contributing to more than 93% of the total exposure, compared to 49.91–76.69% for PFOA and PFOS due to significant exposure from non-soil sources levels. Overall, this study provides a technical reference on how to derive scientifically justifiable soil GAC for representative PFAAs for maintaining and assessing soil quality and food safety internationally under the agricultural land use. [Display omitted] • Spatial distribution of typical PFAAs were assessed in the selected regions of China. • The GAC of representative PFAAs were firstly derived under agricultural land use. • Dietary consumption of vegetables contributed significantly to the derived GAC. • Potential hazards are identified for PFOA and PFOS under agricultural land use. [ABSTRACT FROM AUTHOR]

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., Competing Interests: The authors declare no conflicts of interest., (© 2023 Published by Elsevier B.V. on behalf of Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment (MEE) & Nanjing University.)

Abstract Over the past decades, per- and polyfluoroalkyl substances (PFASs) found in environmental matrices worldwide have raised concerns due to their toxicity, ubiquity and persistence. A widespread pollution of groundwater and surface waters caused by PFASs in Northern Italy has been recently discovered, becoming a major environmental issue, also because the exact risk for humans and nature posed by this contamination is unclear. Here, the Po River in Northern Italy was selected as a study area to assess the ecological risk posed by perfluoroalkyl acids (PFAAs), a class of PFASs, considering the noticeable concentration of various PFAAs detected in the Po waters over the past years. Moreover, the Po has a large environmental and socio-economic importance: it is the largest Italian river and drains a densely inhabited, intensely cultivated and heavily industrialized watershed. Predicted no-effect concentrations (PNECs) were derived using two regulated methodologies, assessment factors (AFs) and species sensitivity distribution (SSD), which rely on published ecotoxicological laboratory tests. Results were compared to those of a novel methodology using the mechanistic ecosystem model AQUATOX to compute PNECs in an ecologically-sound manner, i.e. considering physical, chemical, biological and ecological processes in the river. The model was used to quantify how the biomasses of the modelled taxa in the river food web deviated from natural conditions due to varying inputs of the chemicals. PNEC for each chemical was defined as the lowest chemical concentration causing a non-negligible yearly biomass loss for a simulated taxon with respect to a control simulation. The investigated PFAAs were Perfluorooctanoic acid (PFOA) and Perfluorooctanesulfonic acid (PFOS) as long-chained compounds, and Perfluorobutanoic acid (PFBA) and Perfluorobutanesulfonic acid (PFBS) as short-chained homologues. Two emerging contaminants, Linear Alkylbenzene Sulfonate (LAS) and triclosan, were also studied to assess the performance of the three methodologies for chemicals whose ecotoxicology and environmental fate are well-studied. The most precautionary approach was the use of AFs generally followed by SSD and then AQUATOX, except for PFOS, for which AQUATOX yielded a much lower PNEC compared to the other approaches since, unlike the other two methodologies, it explicitly simulates sublethal toxicity and indirect ecological effects. Our findings highlight that neglecting the role of ecological processes when extrapolating from laboratory tests to ecosystems can result in under-protective threshold concentrations for chemicals. Ecosystem models can complement existing laboratory-based methodologies, and the use of multiple methods for deriving PNECs can help to clarify uncertainty in ecological risk estimates. Graphical abstract Unlabelled Image Highlights • Multiple methods for PNEC estimation can ensure higher confidence in results. • Assessment factor is usually the most protective ecological risk assessment method. • Ecological models allow insightful extrapolation from single-species to ecosystems. • Ignoring sublethal toxicity and ecological relationships can underestimate risk. • The AQUATOX-derived PNEC for PFOS is 3.6% of the currently accepted freshwater EQS. [ABSTRACT FROM AUTHOR]

Residual levels of perfluoroalkyl acids (PFAAs) in seven species of aquatic animals were analyzed by liquid chromatography-mass spectrometry. The distribution, composition, bioaccumulation, and biomagnification of PFAAs and their effect factors were studied. The results showed that: 1) Wet weight concentrations of 17 PFAAs in the aquatic animals ranged from 1.77 to 38.65 ng/g, with a mean value of 12.71 ± 9.21 ng/g. PFOS was the predominant contaminant (4.57 ± 4.57 ng/g, 6.76%–46.25%), followed by PFDA (1.95 ± 1.37 ng/g, 11.68%–21.25%) and PFUdA (1.84 ± 1.21 ng/g, 9.73%–35.34%. 2) PFAA residual levels in Culter erythropterus (30.98 ± 6.65 ng/g) were the highest, followed by Hemibarbus maculatus (16.79 ± 1.88 ng/g), while the PFAA levels in Carassius auratus were the lowest (2.22 ± 0.60 ng/g). 3) Biota-water bioaccumulation factors (BAFs), biota-suspended solid accumulation factors (BSSAFs) and biota-sediment accumulation factors (BSAFs) ranged from 0.35 to 12,370.51, 7.77 to 8452.92 and 9.10 to 6984.61, respectively. Bioaccumulation by shrimp and snails was significantly affected by Kow. 4) Food web magnification factors were greater than 1, indicating that biomagnification of PFAAs occurs across trophic levels. The bioaccumulation and biomagnification of PFAAs were significantly correlated with carbon chain length. [ABSTRACT FROM AUTHOR]

Perfluoroalkyl acids (PFAAs) are ubiquitous pollutants present in various environmental media, including marine sediments. A method was proposed for the determination of 17 target PFAA analytes in marine sediment samples ( n  = 49) collected from the Yangtze Estuary and East China Sea. The proposed method involves the use of an optimized pretreatment procedure and ultrahigh-performance liquid chromatography electrospray ionization–tandem mass spectrometry in dynamic multiple reaction monitoring mode. The method relied on extraction cycles using methanol followed by concentration, filtration, and small volume injection to UHPLC-MS/MS. The recovery, time efficiency, and detection limit of the proposed method are improved relative to those of traditional methods. Limits of detection varied from 0.003 to 0.045 ng/g, and spike recoveries to sediment ranged from 90% to 110% with suitable precisions (1.7%–14.6%). PFAAs were widely present in the samples, and ΣPFAAs ranged from 0.67 ng/g dw to 36.75 ng/g dw. Results indicated that terrigenous input strongly influences PFAA distribution in sediments from the study areas. Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) were identified as the dominant perfluorocarboxylic acid (PFCA) and perfluoroalkylsulfonate (PFSA) in sediment samples from the Yangtze Estuary and the East China Sea. Preliminary environmental risk assessment indicated that PFOS may pose a higher environmental risk than PFOA. Furthermore, risk quotient values indicated that PFOS poses a significant risk to the aquatic ecosystem of the study areas. [ABSTRACT FROM AUTHOR]

Perfluoroalkyl acids (PFAAs) have been suspected to act as endocrine disruptors and adversely affect human reproductive health. We aimed to investigate the association between PFAAs in blood and semen, explore a potential link between PFAAs exposure and semen quality in the population of the Pearl River Delta (PRD) region in China, one of the “world factories”. The monitoring results demonstrated that the population (103 male participants) from the PRD region in this study had higher PFAAs levels in blood and semen than some other areas in China. PFOS was found at the highest mean concentrations of 118.16 ng/mL in blood and 5.31 ng/mL in semen among the nine PFAAs. Significant associations were found between concentrations of several analytes in blood and semen, including Σ 9 PFAAs (r = 0.475, P < .01), PFOA (r = 0.215, P = .029), PFHS (r = 0.458, P < .01) and PFOS (r = 0.981, P < .01). BMI was the most important factor to PFAAs, but there was no significant difference in PFAAs concentrations in blood and semen collected from participants with different smoking and drinking habits, education background and occupations. Negative correlations were significantly observed between sperm motility and PFBA, PFPeA, PFHxA, PFBS, PFOA, PFHS, PFOS and Σ 9 PFAAs in semen. Therefore, exposure to PFAAs may result in a decline in semen mobility in participants from the PRD region. [ABSTRACT FROM AUTHOR]

Data from National Health and Nutrition Examination Survey for 2013–2014 for children aged 3–11 years (N = 639) were analyzed to evaluate the contribution of diet and other factors in variability associated with the observed levels of seven perfluoroalkyl acids in serum, namely, 2(N-methyl-perfluorooctane sulfonamide) acetic acid (MPAH), perfluorodecanoic acid (PFDE), perfluorononanoic acid (PFNA), perflurorohexane sulfonic acid (PFHxS), linear isomer of PFOA (NPFOA), linear isomer of PFOS (NPFOS), and monomethyl isomer of PFOS (MPFOS). Diet accounted for a low of 18.6% of the total explained variance in the adjusted levels of NPFOA and a high of 72.3% for PFNA. Consumption of meat other than fish and poultry was associated with increased levels of NPFOS (β = 0.00035, p < 0.01) and MPFOS (β = 0.00027, p=0.02). However, consumption of fish was associated with decreased levels of PFDE (β = − 0.00058, p=0.01). Consumption of eggs was associated with higher levels of PFDE (β = 0.00105, p=0.04). Higher levels of PFHxS were associated with consumption of fruits and juices (β = 0.00019, p = 0.03). Exposure to environmental tobacco smoke in indoor environments other than home was associated with 12.6% increase in the levels of NPFOA. Boys had higher adjusted geometric mean (AGM) than girls for MPAH (0.88 vs. 0.70 ng/mL, p = 0.04) and NPFOS (2.73 vs. 2.27 ng/mL, p = 0.04). Non-Hispanic white had higher AGMs than Hispanics for MPAH (0.15 vs. 0.07, p < 0.01), for NPFOA (1.98 vs. 1.64 ng/mL, p < 0.01), and MPFOS (1.39 vs. 1.18 ng/mL, p = 0.03). Non-Hispanic white also had higher AGM than non-Hispanic Asians and others for PFHxS (0.99 vs. 0.63 ng/mL, p < 0.01) and NPFOA (1.98 vs. 1.53 ng/mL, p < 0.01). [ABSTRACT FROM AUTHOR]

The occurrence of 17 target PFAA analytes was determined in surface sediments ( n = 37) of the East China Sea and potential influencing factors were examined. ΣPFAAs ranged from 0.41 ng/g dw to 3.06 ng/g dw, with perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) as the most abundant perfluorocarboxylic acid and perfluoroalkyl sulfonate, respectively. PFAAs in the sediments were strongly influenced by terrigenous input. Analysis of the relationship between dynamic influence factors and PFAA concentrations showed that the characteristics of PFAA distribution were rather complex. ΣPFAA concentrations and TOC were positively correlated ( p < 0.0001). Circumfluence also influenced the whole PFAA distribution and seasonal variation. In addition, correlation analysis suggested that log K oc values increased with increasing perfluoroalkyl chain length. Given the rapid economic development of eastern coastal cities of China, the environmental hazards of land source pollution cannot be ignored. [ABSTRACT FROM AUTHOR]

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. 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. 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. 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 1 m -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. 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. [ABSTRACT FROM AUTHOR]

[Display omitted] • COSMO-RS screening of 129 HDES constituents for PFOA/PFOS extraction. • Identification of 55 novel constituents from essential oils and plants. • Top constituents found to be primarily from terpene and terpenoid family. • Toxicity analysis and multicriteria evaluation for sustainable LLE process. • Reported framework can be considered as a robust selection tool. In this study, a molecular modeling approach was used to identify the most effective natural hydrophobic deep eutectic solvents (HDESs) for extracting the emerging pollutants, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) from synthetic wastewater. The use of HDESs for this purpose has not been reported in the literature, making this a pioneering contribution to the field. First, an extensive literature search was conducted to generate a list of 74 non-ionic HDES constituents. In the second step, a systematic screening of natural components was conducted to identify 55 new compounds that can be used for the synthesis of HDESs. The Conductor-like Screening Model for Real Solvents (COSMO-RS) was then used to screen the 129 potential HDES constituents based on three key performance indicators: distribution ratio, selectivity, and performance index at infinite dilution compared to the predicted performance of toluene as a benchmark, as the use of molecular solvents or DESs for this purpose has never been reported in the literature. The top 20 HDES constituents with the highest extraction performance were predominantly from the terpene and terpenoid families. The median lethal dose was also used to analyze toxicity. A multicriteria evaluation approach was adopted to evaluate several properties important to liquid–liquid extraction (LLE) processes, including the extraction performance, density, vapor pressure, water solubility, and leachability of DESs. Three HDESs, namely, trioctylphosphine oxide: 2-methylbenzothiazole (1:9), trioctylphosphine oxide: menthyl acetate (1:4), and 1,8-cineole: menthyl acetate (2.5:1), showed promising results. This study provides molecular insights on extracting PFOA/PFOS from wastewater using HDESs and emphasizes the need to evaluate LLE units using multicriteria. In addition, the results may serve as a starting point for further research, including the synthesis and characterization of novel HDES constituents and the development of optimized HDESs for the extraction of PFOA/PFOS from wastewater. [ABSTRACT FROM AUTHOR]

Bench- and pilot-scale sorption tests were used to probe the performance of several biochars at removing perfluoroalkyl acids (PFAA) from field waters, compared to granular activated carbon (GAC). Screening tests using organic matter-free water resulted in hardwood (HWC) ( K d = 41 L g −1 ) and pinewood (PWC) ( K d = 49 L g −1 ) biochars having the highest perfluorooctanoic acid (PFOA) removal performance that was comparable to bituminous coal GAC ( K d = 41 L g −1 ). PWC and HWC had a stronger affinity for PFOA sorbed in Lake Mead surface water (K F = 11 mg (1−n) L n g −1 ) containing a lower (2 mg L −1 ) dissolved organic carbon (DOC) concentration than in a tertiary-filtered wastewater (K F = 8 mg (1−n) L n g −1 ) with DOC of 4.9 mg L −1 . A pilot-scale study was performed using three parallel adsorbers (GAC, anthracite, and HWC biochar) treating the same tertiary-filtered wastewater. Compared to HWC, and anthracite, GAC was the most effective in mitigating perfluoropentanoic acid (PFPnA), perfluorohexanoic acid (PHxA), PFOA, perfluorooctane sulfonic acid (PFOS), and DOC (45–67% removed at 4354 bed volumes) followed by HWC, and then anthracite. Based on bench- and pilot-scale results, shorter-chain PFAA [perfluorobutanoic acid (PFBA), PFPnA, or PFHxA] were more difficult to remove with both biochar and GAC than the longer-chain, PFOS and PFOA. [ABSTRACT FROM AUTHOR]

Perfluoroalkyl acids (PFAAs) are highly persistent substances which have been detected in wildlife around the world, including birds. Although bird eggs have often been used to determine and monitor PFAAs levels in the marine environment, this has rarely been done in the terrestrial environment. In the present study we examined the concentrations and composition profile of 12 PFAAs (4 perfluoroalkyl sulfonic acids (PFSAs) and 8 perfluoroalkyl carboxylic acids (PFCAs) in the eggs of great tits ( Parus major ) collected at a fluorochemical plant and in three other areas, representing a gradient in distance from the pollution source (from 1 to 70 km), in Antwerp, Belgium. The PFSA concentrations measured at the site of the fluorochemical plant were among the highest ever reported in eggs with median concentrations of 10380 ng/g (extrapolated), 99.3 ng/g and 47.7 ng/g for PFOS, PFHxS and PFDS respectively. Furthermore, the median concentration of 19.8 ng/g for PFOA was also among the highest ever reported in bird eggs. Although these concentrations decreased sharply with distance from the fluorochemical plant, levels found in the adjacent sites were still high compared to what has been reported in literature. Moreover, based on what is known in literature, it is likely that these concentrations may cause toxicological effects. PFOS was the dominant contributor to the PFSA and PFAAs (63.4–97.6%) profile at each site, whereas for PFCAs this was PFOA at the plant site and the nearest locations (41.0–52.8%) but PFDoA (37.7%) at the farthest location. Although there is some evidence that PFAAs concentrations close to the plant site are decreasing in comparison with earlier measurements, which may be due to the phase out of PFOS, more research is necessary to understand the extent of the toxicological effects in the vicinity of this PFAAs hotspot. [ABSTRACT FROM AUTHOR]