Perfluorohexanoic Acid Research Articles

Unveiling Priority Emerging PFAS in Taihu Lake Using Integrated Nontarget Screening, Target Analysis, and Risk Characterization.

Amidst tightening regulations, the proliferation of next-generation per- and polyfluoroalkyl substances (PFAS) necessitates a deeper understanding of their environmental fate and potential risks. Here, we conducted a comprehensive assessment of PFAS in the water and sediment of Taihu Lake, incorporating both nontarget and target screening, seasonal and geographical variation analysis, and risk prioritization. A total of 58 PFAS from 13 classes were identified, revealing complex PFAS contamination. In addition to short-chain perfluoroalkyl carboxylates (PFCAs) and sulfonates (PFSAs), bis(trifluoromethanesulfonyl)imide (Ntf2) and perfluoro-2,5-dimethyl-3,6-dioxo-heptanoic acid (C7 HFPO-TA) exhibited relatively high concentrations in water, with median values of 21.7 and 5.72 ng/L, respectively. Seasonal and geographical variation analysis revealed elevated levels of C7 HFPO-TA, Ntf2, and perfluorohexanoic acid (PFHxA) in the northeastern areas, suggesting transport via water diversion project. Multicriteria risk prioritization identified four high priority PFAS (Ntf2, C7 HFPO-TA, PFHxA, and perfluorooctanoic acid (PFOA)) in water and two high priority PFAS (hexafluoropropylene oxide dimer acid (HFPO-DA) and PFHxA) in sediment. Overall, this study revealed Ntf2 and C7 HFPO-TA as priority PFAS in Taihu Lake, underscoring the urgent necessity of evaluating risks associated with these emerging PFAS.

6669 Association Between Serum Levels of Thyroid Function and Per- and Polyfluoroalkyl Compounds Concentrations in Central Precocious Puberty in Girls

Abstract Disclosure: Y. Li: None. Y. Xing: None. X. Yin: None. J. Yang: None. S. Zang: None. T. Dong: None. Y. Pan: None. J. Dai: None. P. Li: None. Background: Exposure to per- and polyfluoroalkyl substances (PFASs) may interfere with thyroid function in the general population and disturb the timing of puberty onset. Objectives: We investigated the possible relationship between PFASs and thyroid hormone (THs) exposure in girls with central precocious puberty (CPP). Methods: In a prospective study initially established for assessing CPP, 627 serum samples were collected with (n = 226) and without (n = 401) CPP. The concentrations of 25 PFASs, thyroxin (T4), 3,5,3’-triiodothyronine (T3), and 3,3’,5’-triiodothyronine (rT3) were measured. We used logistic regression to examine the association of THs with the odds of having CPP and multiple linear regression to analyze the associations between THs and various PFASs in the CPP and control groups. Results: The levels of T4 in the CPP group were significantly lower than those in the control group, and the levels of T3 and rT3 were significantly higher than those in the control group. After adjusting for confounders, T3 concentrations were associated with 1.526-fold increased odds of having CPP [odds ratio (OR) = 1.526, 95% confidence interval (CI):1.216-1.914]. In the CPP cohort, perfluoroheptanoic acid (PFHpA), perfluoro (2-ethoxyethane) sulphonic acid (PFEESA), and fluorotelomer phosphate diester (6:2/8:2 diPAP) were inversely associated with T3; perfluorobutanoic acid (PFBA) was inversely associated with T4, and PFEESA and 6:2/8:2 diPAP positively associated with T4; PFBA was positively associated with rT3, and perfluorooctane sulfonic acid (PFOS) was inversely associated with rT. In the control cohort, perfluorobutanesulfonic acid (PFBS) was positively associated with T3, and PFEESA and 6:2/8:2 diPAP were inversely associated with T3, and these PFASs had an adverse association with T4. Perfluorohexanoic acid (PFHxA) was positively associated with rT3, and 6:2/8:2 diPAP was negatively associated with rT3. Conclusion: In this study, different measurements of PFASs and THs were observed in the CPP and control groups. Discrepancies in exposure to PFASs were associated with THs in the CPP cohort and healthy girls. Further research is necessary to investigate the mechanism by which PFASs affect the timing of puberty onset and thyroid function. Presentation: 6/1/2024

Enhancement of PFAS stress tolerance and wastewater treatment efficiency by arbuscular mycorrhizal fungi in constructed wetlands

This study aims to explore the effects of arbuscular mycorrhizal fungi (AMF) on the growth of Iris pseudacorus L. and treatment efficacy in constructed wetlands (CWs) subjected to stress from per-and poly-fluoroalkyl substances (PFASs). The findings reveal that PFASs exposure induces oxidative damage and inhibits the growth of I. pseudacorus. However, AMF symbiosis enhances plant tolerance to PFAS stress by modulating oxidative responses. AMF treatment not only promoted plant growth but also improved photosynthetic efficiency under PFAS exposure. Compared to non-AMF treatment, those with AMF treatment exhibited significantly increased levels of peroxidases and antioxidant enzymes, including peroxidase and superoxide dismutase, along with a notable reduction in lipid peroxidation. Additionally, AM symbiosis markedly enhanced the efficacy of CWs in the remediation of wastewater under PFASs-induced stress, with removal efficiencies for COD, TP, TN, and NH4+-N increasing by 19–34%, 67–180%, 106–137%, and 25–95%, respectively, compared to the AMF- treatments. In addition, the metabolic pathways of PFASs appeared to be influenced by their carbon chain length, with long-chain PFASs like perfluorooctanoic acid (PFOA) and perfluoro anionic acid (PFNA) exhibiting more complex pathways compared to short-chain PFASs such as perfluoro acetic acid (PFPeA), and perfluoro hexanoic acid (PFHpA). These results suggest that AMF-plant symbiosis can enhance plant resilience against PFAS-induced stress and improve the pollutant removal efficiency of CWs. This study highlights the significant potential of AMF in enhancing environmental remediation strategies, providing new insights for the more effective management of PFAS-contaminated ecosystems.

Skin Permeability of Perfluorocarboxylic Acids Using Flow-Through Diffusion on Porcine Skin.

Per- and polyfluoroalkyl substances (PFAS) are found in a variety of places including cosmetics, rain jackets, dust, and water. PFAS have also been applied to occupational gear to protect against water and oils. However, PFAS have been identified as immunosuppressants and perfluorooctanoic acid (PFOA), a specific PFAS, has been identified as carcinogenic. Since there is a risk for dermal exposure to these compounds, there is a need to characterize their dermal absorption. Using in vitro flow-through diffusion, skin permeabilities were determined for 14C-labeled perfluorooctanoic acid (PFOA), perfluorohexanoic acid (PFHxA), and perfluorobutanoic acid (PFBA) using porcine skin. Tests were conducted over 8 h with either acetone or artificial perspirant as the vehicle. PFBA was found to have greater permeability than PFHxA, likely due to having a smaller molecular weight. The dosing vehicle did not appear to impact permeability rates but impacted the disposition through the skin model. While these PFAS compounds showed a low permeability rate through the skin membranes, they can stay in the skin, acting as a reservoir.

Per- and polyfluoroalkyl substances (PFAS) in floor dust from different indoor environments in Australia: Levels, variation, and human exposure risks

Per-and polyfluoroalkyl substances (PFAS) have been a global concern in relation to human exposure. Dust has been proven to be an important source of human exposure to many groups of organic pollutants, however, no study so far has systematically evaluated human exposure to PFAS depending on time spent in different indoor environments i.e., houses, offices and public transport vehicles. Archived dust samples were collected from residential houses (n = 38), offices (n = 15), and public transport vehicles (n = 12) in Australia to assess human exposures to PFAS via dust ingestion and dermal contact. Amongst the 19 target analytes, 14 compounds were detected in >50% of the samples. Significantly higher PFAS concentrations were found in dust samples collected from offices with mean ± SD of 400 ± 810 ng/g than houses (170 ± 350 ng/g) and public transport vehicles (39 ± 33 ng/g). Composition patterns of PFAS varied among indoor environments with Perfluorohexanoic acid (PFHxA) (median 2.5 ng/g dust) and perfluorooctanoic acid (PFOA) (median 5.7 ng/g) were the most prevalent compounds detected (DF = 100%). PFOA was the dominant PFAS compound in both offices (median 11 ng/g) and houses (median 5.8 ng/g). Perfluorododecanoic acid (PFDoA) (median 3.6 ng/g) was found to be the most abundant compounds in public transport vehicles. Considering the time spent in indoor environments, relatively higher estimated daily intakes (EDIs) were identified in offices than in houses and public transport vehicles. EDIs for PFOA and perfluorooctane sulfonic acid (PFOS) for adults and toddlers were well below the acceptable levels of 20 ng/kg/day proposed by U.S Environmental Protection Agency (USEPA) and Food Standard Australia and New Zealand (USEPA, 2016; FSANZ et al. (2016)), suggesting low or negligible exposure pathways via dust ingestion and dermal contact.

Mechanism of selenium-enriched Bacillus subtilis alleviating perfluorohexanoic acid toxicity in Carassius auratus through the microbiota–gut–brain axis

The extensive production and use of perfluorohexanoic acid (PFHxA) have established it as an emerging environmental pollutant on a global scale. Selenium has been shown to exert substantial antagonistic effects on harmful substances. Concurrently, probiotics may confer advantageous effects on the host's brain function by orchestrating modulation within the microbiota–gut–brain axis. However, despite the promising properties of selenium-enriched Bacillus subtilis, uncertainties persist regarding its impact on PFHxA and underlying mechanisms. This study evaluated the potential alleviating effects of selenium-enriched B. subtilis on brain damage in Carassius auratus exposed to PFHxA from the perspective of the microbiota–gut–brain axis. Supplementation with selenium-enriched B. subtilis significantly mitigated brain damage and memory loss in C. auratus. Nissl staining of the brain revealed that selenium-enriched B. subtilis mitigated neuronal damage induced by PFHxA. TUNEL staining of the intestine showed that selenium-enriched B. subtilis mitigated PFHxA-induced apoptosis, thus mitigating intestinal injury. Moreover, our study uncovered additional layers of complexity in the microbiota–gut–brain axis, as enhancements were noted in the gut microbiota. Concurrently, alterations in the expression of neurotransmitters and biomarkers associated with emotions, such as 5-hydroxytryptamine, Dopamine, Corticotropin Releasing Factor, Substance p, and ghrelin, highlighted the profound impact of selenium-enriched B. subtilis on the intricate interplay between gut health and emotional well-being. Expanding our focus to the molecular level, we found that supplementation with selenium-enriched B. subtilis further inhibited cellular apoptosis through the brain-derived neurotrophic factor (BDNF) / Tyrosine Kinase receptor B (TrKB) / Protein Kinase B (AKT) / Glycogen synthase kinase3β (GSK-3β) pathway. In conclusion, supplementation with selenium-enriched B. subtilis is a promising strategy to mitigate PFHxA-induced brain damage in C. auratus, offering a multifaceted approach through the microbiota–gut–brain axis. In addition, our study introduces the potential of selenium-enriched B. subtilis as a valuable source of micronutrients for fish, opening new avenues for developmental considerations in aquaculture practices.

Occurrence, risk assessment and source apportionment of perfluoroalkyl acids in the river of a hill-plain intersection region: The impacts of land use and river network structure

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.

Co-accumulation characteristics and interaction mechanism of microplastics and PFASs in a large shallow lake

Microplastics (MPs) and per- and polyfluoroalkyl substances (PFASs) coexist widely in lakes and affect ecological security. The coexistence characteristics and adsorption-desorption mechanisms between MPs and typical PFASs were explored in a typical eutrophic shallow lake (Taihu Lake). Polyvinyl chloride (PVC) and polyethylene (PE) are the primary types of MPs in Taihu Lake, with average abundances in water and sediment of 18630 n/m3 and 584 n/kg, respectively. The average concentrations of PFASs in water and sediment are 288.93 ng/L and 4.33 ng/g, with short-chain PFASs (C4-C7) being the main pollutants. Perfluorobutanoic acid (PFBA) in both water and sediment contributed 38.48 % and 44.53 %, respectively, followed by hexafluoropropylene oxide dimer acid (HFPO-DA). The morphological characteristics of MPs influence the distribution of long-chain PFAS in lake water, while the presence of HFPO-DA and perfluorohexanoic acid (PFHxA) in sediment is directly linked to the concentration and size of MPs. A combination of field investigations and indoor experiments revealed that the irreversible adsorption characteristics between MPs and HFPO-DA may promote the high cumulative flux of HFPO-DA in sediment, and the biofilm on the surface of MPs significantly accelerates this accumulation process. The results provide a new perspective on the co-transport behavior of emerging pollutants in aquatic environments.

Toxicity prediction and risk assessment of per- and polyfluoroalkyl substances for threatened and endangered fishes

Per- and polyfluoroalkyl substances (PFASs) are severely polluted in aquatic environments and can harm aquatic organisms. Due to the limitation of conducting toxicity experiments directly on threatened and endangered (T&E) species, their toxicity data is scarce, hindering accurate risk assessments. The development of computational toxicology makes it possible to assess the risk of pollutants to T&E fishes. This study innovatively combined machine learning models, including random forest (RF), artificial neural network (ANN), and XGBoost, and the QSAR-ICE model to predict chronic developmental toxicity data of PFASs to T&E fishes. Among these, the XGBoost model exhibited superior performance, with R2 of 0.95 and 0.81 for the training and testing sets, respectively. Internal and external validation further confirmed that the XGBoost model is robust and reliable. Subsequently, it was used to predict chronic developmental toxicity data for seven priority PFASs to T&E fishes in the Yangtze River. Acipenseridae fishes (e.g., Acipenser dabryanus and Acipenser sinensis) showed high sensitivity to PFASs, possibly due to their unique lifestyle and physiological characteristics. Based on these data, the predicted no-effect concentration (PNEC) of individual PFASs was calculated, and the risk for T&E fishes in the Yangtze River was assessed. The results indicated that the risk of PFASs to T&E fishes is low (3.85 × 10−9∼8.20 × 10−4), with perfluorohexanoic acid (PFHxA) and perfluorooctanoic acid (PFOA) as the high-risk pollutants. The risk in the middle and lower reaches of the river is higher than in the upper reaches. This study provides a new approach for obtaining chronic toxicity data and conducting risk assessments for T&E species, advancing the protection of T&E species worldwide.

LP-20 Evaluation of the effect of perfluorohexanoic acid on selected cytotoxic and oxidative parameters in human peripheral blood mononuclear cells

LP-20 Evaluation of the effect of perfluorohexanoic acid on selected cytotoxic and oxidative parameters in human peripheral blood mononuclear cells

Distribution and seasonal variations of perfluoroalkyl substances (PFAS) in streams within the Changwon region

This study investigates the distribution and seasonal variations of Poly- and Perfluoroalkyl Substances (PFAS) concentrations in local streams within the Changwon area, aiming to quantify the total PFAS load entering Masan Bay. Using solid-phase extraction (SPE) cartridges for pretreatment, we analyzed 36 types of Perfluorinated carboxylic acids (PFCAs), Perfluorinated sulfonates (PFSAs), and precursor compounds via liquid chromatography-high resolution mass spectrometry (LC-HRMS). The study observed varying concentration levels across different streams, with notable detections of Perfluorohexanoic acid (PFHxA), Perfluorooctanoic acid (PFOA), Perfluorobutanesulfonic acid (PFBS), Perfluoropentanoic acid (PFPeA), and Perfluoroheptanoic acid (PFHpA) at quantifiable levels. Except for the Sogye Stream (SGC), PFCA-based compounds comprised over 50% of the total PFAS detected, predominantly featuring shorter-chain compounds with fewer than eight carbon atoms. Seasonal trends indicated that PFAS concentrations were lowest during the high rainfall period in summer and peaked in winter and spring. The Nam Stream (NC) contributed the highest PFAS inflow into Masan Bay, attributed to its elevated flow rates, while Sum B had high concentrations but lower emissions due to its limited flow. The total annual PFAS discharge was estimated at 1.9 kg. These findings highlight the urgent need for targeted management and comprehensive countermeasures to protect environmental health.

Differential uptake and translocation of perfluoroalkyl substances by vegetable roots and leaves: Insight into critical influencing factors

Crop contamination of perfluoroalkyl substances (PFASs) may threaten human health, with root and leaves representing the primary uptake pathways of PFASs in crops. Therefore, it is imperative to elucidate the uptake characteristics of PFASs by crop roots and leaves as well as the critical influencing factors. In this study, the uptake and translocation of PFASs by roots and leaves of pak choi and radish were systematically explored based on perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), and perfluorooctane sulfonate (PFOS). Additionally, the roles of root Casparian strips, leaf stomata, and PFAS structures in the aforementioned processes were elucidated. Compared with pak choi, PFASs are more easily transferred to leaves after root uptake in radish, resulting from the lack of root Casparian strips. In pak choi root, the bioaccumulation of C4-C8 perfluoroalkyl carboxylic acids (PFCAs) showed a U-shaped trend with the increase of their carbon chain lengths, and the translocation potentials of individual PFASs from root to leaves negatively correlated with their chain lengths. The leaf uptake of PFOA in pak choi and radish mainly depended on cuticle sorption, with the evidence of a slight decrease in the concentrations of PFOA in exposed leaves after stomatal closure induced by abscisic acid. The leaf bioaccumulation of C4-C8 PFCAs in pak choi exhibited an inverted U-shaped trend as their carbon chain lengths increased. PFASs in exposed leaves can be translocated to the root and then re-transferred to unexposed leaves in vegetables. The longer-chain PFASs showed higher translocation potentials from exposed leaves to root. PFOS demonstrated a higher bioaccumulation than PFOA in crop roots and leaves, mainly due to the greater hydrophobicity of PFOS. Planting root vegetables lacking Casparian strips is inadvisable in PFAS-contaminated environments, in view of their higher PFAS bioaccumulation and considerable human intake.

Current status and risk assessment of perfluoroalkyl acids in surface water and sediments of the Yellow River in Shandong, China

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.

Occurrence and potential ecological risks of PFAS in Pampulha Lake, Brazil, a UNESCO world heritage site

Per- and polyfluoroalkyl substances (PFAS) comprise >4000 synthetic substances used in industrial applications and consumer products. PFAS used daily in households and manufacturing plants end up in domestic sewage, and industrial effluents can be discharged to surface water. Urban watersheds located in low and middle-income countries (LMIC), which lack sanitation infrastructure, are potential recipients of waste containing PFAS. Yet, only a few studies report PFAS occurrence in urban reservoirs and lakes, especially those located in the Global South due to resource limitations. This is the first study aimed to assess PFAS occurrence and ecological risks in Pampulha Lake, Brazil, a site which represents the reality of many other urban watersheds in LMIC as it is surrounded by densely populated areas and manufacturing plants. Surface water samples were collected monthly for 1 year from four sampling points at Pampulha Lake. Sample analysis was based on US Environmental Protection Agency Method 1633, which employs solid phase extraction followed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Species sensitivity distribution (SSD) curves were built to identify potentially susceptible species based on detected water concentrations. Bioaccumulation was estimated for fish tissue. Short-chain (perfluorobutanesulfonic acid, PFBS and perfluorohexanoic acid, PFHxA) and long-chain PFAS (perfluorodecanoic acid, PFDA; perfluorooctanoic acid, PFOA; perfluorododecanoic acid, PFDoA; and perfluorooctanesulfonic acid, PFOS) were detected at the μg L−1 range. Total PFAS concentrations in the wet season were generally higher than in the dry season, likely due to limited capacity of the treatment plant processing water from tributaries which receive raw sewage. More than 5 % of aquatic species are potentially susceptible to chronic effects of PFOS at detected concentrations (0.2–2.2 μg L−1). Predicted bioaccumulation of PFOS in fish was above advisory diet intake levels for humans. Results emphasize the need for studies related to PFAS occurrence in watersheds located in LMIC.

An in silico insight on inhibitory potential of short-chain PFHxA and PFHxS against endogenous antioxidant enzymes

Per- and polyfluoroalkyl substances (PFAS) are a large group of synthetic chemicals that are globally used in various commercial products like cloths, carpets, cookware, firefighting foams, cosmetics, electronic products, etc. Inappropriate disposal of these consumer products could lead to environmental contamination with PFAS. Nowadays short-chain PFAS are substituting the long chain PFAS due to their short half-life. However, multiple studies have suggested that short-chain PFAS such as Perfluorohexanoic acid (PFHxA) and Perfluorohexanesulfonic acid (PFHxS) modulate antioxidant enzyme activities, induce Reactive Oxygen Species production, and contribute to oxidative stress in organisms. Notably, experimental set-ups aiming to investigate the mode of action of these compounds on antioxidants are entirely lacking. Hence in the present study, a ligand-docking approach was adopted to investigate the potential intermolecular interactions between short-chain PFAS and major antioxidants such as Glutathione peroxidase-4, Glutathione reductase, Glutathione S-Transferase, Catalase, and Superoxide dismutase-1. Three-dimensional structures of proteins were processed and docked individually with PFHxA and PFHxS using the AutoDock vina.. Results indicated significant binding affinities between various antioxidant proteins and PFAS. Interestingly, non-covalent interactions such as H-bonds, van der Waals, CH bonds, halogen bonds, and alkyl/pi-alkyl were apparent at protein-ligand interface. Hence, these results suggest that both PFHxA and PFHxS may potentially interact with the endogenous antioxidants and this outcome can be detrimental to the redox homeostasis of living organisms.

Quantifying levels of per- and polyfluoroalkyl Substances (PFAS) in water and serum after contamination from agricultural biosolid application

The National Academies of Sciences, Engineering, and Medicine recommends per- and polyfluoroalkyl substance (PFAS) blood testing for patients with risk of elevated exposure, and the Agency for Toxic Substances and Disease Registry (ATSDR) suggests PFAS blood testing based on exposure. Barriers to PFAS blood testing include cost, access to labs, and evolving laboratory methods. We quantify water and serum PFAS levels among a highly-exposed cohort in an area with groundwater contaminated by historical agricultural biosolid application. We compare the gold standard PFAS serum test with a commercial test and results from a one-compartment toxicokinetic model. Participants were adults (n = 30) whose household (n = 19) water had levels of the sum of six PFAS > 500 ng/L. Serum PFAS were measured using liquid chromatography-tandem mass spectrometry. Demographic and water consumption data were collected via telephone. Serum PFAS results from the commercial test were accessed via medical record. Statistical analysis included descriptive statistics and bivariate plots of serum levels. Perfluorohexanoic acid, perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorobutanesulfonic acid, perfluorohexanesulfonic acid (PFHxS), and perfluorooctanesulfonic acid (PFOS) were detected in 19 wells, and PFHpA, PFOA, PFNA, perfluorodecanoic acid, perfluoroundecanoic acid, PFHxS, and PFOS were detected in at least 19 participants’ serum. In well water, PFOA and PFOS levels had geometric means (GMs) of 1749 ng/L (geometric standard deviation [GSD] 2.4) and 887 ng/L (GSD 19.7), respectively. In serum, PFOA and PFOS had GMs of 116.2 µg/L (GSD 13.5) and 58.3 µg/L (GSD 13.8), respectively. Our results are comparable with and had a wider mix of PFAS than other high-exposure cohorts. There was good agreement between the commercial and gold standard tests for PFOA, PFNA, and PFHxS, and mixed agreement between the gold standard test and modeled predictions, suggesting water-based toxicokinetic models of serum PFAS may be inadequate for assessing exposure in this population.

Tracking the impact of perfluoroalkyl acid emissions on antibiotic resistance gene profiles in receiving water by metagenomic analysis

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, NH3N, CODMn, 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.

Legacy and alternative per- and polyfluoroalkyl substances (PFAS) alter the lipid profile of HepaRG cells

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals used in various industrial and consumer products. They have gained attention due to their ubiquitous occurrence in the environment and potential for adverse effects on human health, often linked to immune suppression, hepatotoxicity, and altered cholesterol metabolism. This study aimed to explore the impact of ten individual PFAS, 3 H-perfluoro-3-[(3-methoxypropoxy) propanoic acid] (PMPP/Adona), ammonium perfluoro-(2-methyl-3-oxahexanoate) (HFPO-DA/GenX), perfluorobutanoic acid (PFBA), perfluorobutanesulfonic acid (PFBS), perfluorodecanoic acid (PFDA), perfluorohexanoic acid (PFHxA), perfluorohexanesulfonate (PFHxS), perfluorononanoic acid (PFNA), perfluorooctanoic acid (PFOA), and perfluorooctanesulfonic acid (PFOS) on the lipid metabolism in human hepatocyte-like cells (HepaRG). These cells were exposed to different concentrations of PFAS ranging from 10 µM to 5000 µM. Lipids were extracted and analyzed using liquid chromatography coupled with mass spectrometry (LC- MS-QTOF). PFOS at 10 µM and PFOA at 25 µM increased the levels of ceramide (Cer), diacylglycerol (DAG), N-acylethanolamine (NAE), phosphatidylcholine (PC), and triacylglycerol (TAG) lipids, while PMPP/Adona, HFPO-DA/GenX, PFBA, PFBS, PFHxA, and PFHxS decreased the levels of these lipids. Furthermore, PFOA and PFOS markedly reduced the levels of palmitic acid (FA 16.0). The present study shows distinct concentration-dependent effects of PFAS on various lipid species, shedding light on the implications of PFAS for essential cellular functions. Our study revealed that the investigated legacy PFAS (PFOS, PFOA, PFBA, PFDA, PFHxA, PFHxS, and PFNA) and alternative PFAS (PMPP/Adona, HFPO-DA/GenX and PFBS) can potentially disrupt lipid homeostasis and metabolism in hepatic cells. This research offers a comprehensive insight into the impacts of legacy and alternative PFAS on lipid composition in HepaRG cells.

Spatial and temporal distribution of perfluoroalkyl substances (PFAS) detected after an aqueous film forming foam (AFFF) spill

In 2015, > 460,000 L of aqueous film-forming foam (AFFF) and fire suppressors containing per- and polyfluoroalkyl substances (PFAS) were used to combat a fire at a petrochemical fuel storage terminal in the Port of Santos (Brazil). Sediments from seven sites were sampled repeatedly from 2 weeks to 1 year after the fire (n = 30). Ʃ15PFAS concentrations ranged from 115 to 15,931 pg g−1 dry weight (dw). Perfluorooctane sulfonic acid (PFOS) was the most frequently detected compound with concentrations ranging from 363 to 4517 (average = 1603) pg g−1dw to <47.1 to 642 (average = 401) pg g−1 dw, followed by perfluorohexanoic acid (PFHxA) (from 38.8 to 219 (average = 162) pg g−1 dw after 15 days and from <20.8 to 161 (average = 101) pg g−1 dw one year later). Together, the hydrodynamics and fire events documented in the region were important features explaining the spread of PFAS.

The Transformation of Per- and Polyfluoroalkyl Substances in the Aquatic Environment of a Fluorochemical Industrial Park

Jiangsu High-Tech Fluorochemical Industrial Park in Changshu City, Jiangsu Province, is the largest fluorochemical industrial park in Asia. The occurrence of per- and polyfluoroalkyl substances (PFASs) in surface water and widespread local plants was investigated in Jiangsu High-Tech Fluorochemical Industrial Park. Thirty-two target PFASs were detected in dissolved-phase, particle-phase and plant samples. The concentrations of total PFASs ranged from 1650 to 8250 ng/L in the dissolved-phase samples, 132 to 6810 ng/g dw in the particle-phase samples and 25.8 to 9460 ng/g dw in different plant tissues. Perfluorohexanoic acid (PFHxA), Perfluorooctanoate acid (PFOA) and 6:2 fluorotelomer carboxylic acid (6:2 FTCA) were predominant PFASs and contributed 80−91% to ΣPFAS in water samples. A total of 67 emerging PFAS were identified in all samples using nontargeted analysis. Typha orientalis showed better accumulation ability, with an average ΣPFAS concentration of 3450 ng/g dw and the highest root concentration factor (RCF) of 171. Typha orientalis, Eichhornia crassipes and Alternanthera sessilis have potential for use in PFAS phytostabilization.