Method of H2 Transfer Is Vital for Catalytic Hydrodefluorination of Perfluorooctanoic Acid (PFOA).

The efficient transfer of H2 plays a critical role in catalytic hydrogenation, particularly for the removal of recalcitrant contaminants from water. One of the most persistent contaminants, perfluorooctanoic acid (PFOA), was used to investigate how the method of H2 transfer affected the catalytic hydrodefluorination ability of elemental palladium nanoparticles (Pd0NPs). Pd0NPs were synthesized through an in situ autocatalytic reduction of Pd2+ driven by H2 from the membrane. The Pd0 nanoparticles were directly deposited onto the membrane fibers to form the catalyst film. Direct delivery of H2 to Pd0NPs through the walls of nonporous gas transfer membranes enhanced the hydrodefluorination of PFOA, compared to delivering H2 through the headspace. A higher H2 lumen pressure (20 vs 5 psig) also significantly increased the defluorination rate, although 5 psig H2 flux was sufficient for full reductive defluorination of PFOA. Calculations made using density functional theory (DFT) suggest that subsurface hydrogen delivered directly from the membrane increases and accelerates hydrodefluorination by creating a higher coverage of reactive hydrogen species on the Pd0NP catalyst compared to H2 delivery through the headspace. This study documents the crucial role of the H2 transfer method in the catalytic hydrogenation of PFOA and provides mechanistic insights into how membrane delivery accelerates hydrodefluorination.

The Total Mass of Per- and Polyfluoroalkyl Substances (PFASs) in California Cosmetics.

Cosmetics make up one of the consumer product categories most widely known to contain perfluoroalkyl and polyfluoroalkyl substances (PFASs), including precursors to perfluorooctanoic acid (PFOA) and other perfluoroalkyl acids (PFAAs). Because of the way cosmetics are used, most of the PFASs present in these products are likely to reach wastewater treatment plants (WWTPs), which suggests that cosmetics may contribute significantly to the load of PFOA and other PFASs at WWTPs. However, the majority of PFASs present as intentional ingredients in cosmetics cannot be quantified with the available analytical methods. To address this issue, we developed a methodology to estimate the total PFAS mass in cosmetics as well as the corresponding mass of total organic fluorine and of fluorinated side chains associated with PFAA precursors, using various ingredient databases and ingredient concentrations reported by manufacturers. Our results indicate that the cosmetics sold in California during a one-year period cumulatively contain 650-56 000 kg of total PFASs, 370-37 000 kg of organic fluorine, and 330-20 000 kg of fluorinated side chains associated with PFAA precursors. Among the 16 product subcategories considered, >90% of the PFAS mass came from shaving creams and gels, hair care products, facial cleansers, sun care products, and lotions and moisturizers, while the sum of all nine makeup subcategories accounted for <3%. Comparing our estimates to available WWTP influent data from the San Francisco Bay Area suggests that cosmetics may account for at least 4% of the precursor-derived PFAAs measured in wastewater. As the first study ever to estimate the total mass of PFASs contained in cosmetics sold in California, our results shed light on the significance of certain cosmetics as a source of PFASs to WWTPs and can inform effective source reduction efforts.

Visualization of PFOA accumulation and its effects on phospholipid in zebrafish liver by MALDI Imaging.

Exposure to poly- and perfluoroalkyl substances (PFASs) can result in bioaccumulation. Initial findings suggested that PFASs could accumulate in tissues rich in both phospholipids and proteins. However, our current understanding is limited to the average concentration of PFASs or phospholipid content across entire tissue matrices, leaving unresolved the spatial variations of lipid metabolism associated with PFOA in zebrafish tissue. To address gap, we developed a novel methodology for concurrent spatial profiling of perfluorooctanoic acid (PFOA) and individual phospholipids within zebrafish hepatic tissue sections, utilizing matrix-assisted laser desorption/ionization time of flight imaging mass spectrometry (MALDI-TOF-MSI). 5-diaminonapthalene (DAN) matrix and laser sensitivity of 50.0 were optimized for PFOA detection in MALDI-TOF-MSI analysis with high spatial resolution (25 µm). PFOA was observed to accumulate within zebrafish liver tissue. H&E staining results corroborating the damage inflicted by PFOA accumulation, consistent with MALDI MSI results. Significant up-regulation of 15 phospholipid species was observed in zebrafish groups exposed to PFOA, with these phospholipid demonstrating varied spatial distribution within the same tissue. Furthermore, co-localized imaging of distinct phospholipids and PFOA within identical tissue sections suggested there could be two distinct potential interactions between PFOA and phospholipids, which required further investigation. The MALDI-TOF-IMS provides a new tool to explore in situ spatial distributions and variations of the endogenous metabolites for the health risk assessment and ecotoxicology of emerging environmental pollutants.

Evidence on the genotoxic and ecotoxic effects of PFOA, PFOS and their mixture on human lymphocytes and bacteria.

Considering that the PFOA and PFOS are widely spread chemicals with harmful effects in human and environmental health as well as the increasing interest of the scientific community in the implications that might present especially when they co-exist, this study aims to assess their harmful impacts, both individually and as a mixture on human lymphocytes and aquatic microorganisms. The cytokinesis-block micronucleus (CBMN) assay was used to examine their potential for cytotoxicity and genotoxicity towards human cells, and Microtox assay using Aliivibrio fischeri assay was used to estimate the environmental risk. Regarding the human lymphocytes, the tested concentrations ranged between 250 and 1000 µg L-1, for all cases. PFOA increased slightly the frequency of micronuclei (MN) but without statistical significance. In the case of PFOS, our results showed a dose-dependent increase in the frequency of micronuclei which showed a statistically significant difference (p < 0.001) at 1000 µg L-1, which is the highest studied concentration. Regarding the CBPI index, statistically significant (p < 0.05, p < 0.01, and p < 0.001 respectively) differences were observed at all studied concentrations of PFOS, compared to the control. The mixture was found to be more cytotoxic and genotoxic than the individual tested compounds, causing a higher decrease at the CBPI index even in lower concentrations and increase at the MN frequencies. Aliivibrio fischeri was exposed to various concentrations in the range of 0.5 µg L-1- 20 mg L-1, for 5 and 15 min and significant increase in the inhibition percentage at the highest tested concentration of their mixture after 15 min was observed.

PFOA and testis cancer in the Veneto Region (Italy).

The largest documented episode of human contamination by PFOA in the world (approximately 150,000 actual residents on 1 January 2020) has occurred in Italy's Veneto Region. In this large, mostly flat plain area, a cluster of testicular cancers has also been observed. Preliminary data are reported, and the most relevant and recent recommendations regarding the health surveillance of exposed individuals are emphasized.

Sublethal perfluorooctanoic acid and perfluorooctanesulfonic acid delay C. elegans larval development and population growth but do not alter egg hatching.

Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) are polyfluoroalkyl substances (PFAS) used as surface coatings in manufacturing. Exposure to PFAS was shown to be correlated with infertility, low birth weight, and delayed aspects of pubertal development in mammals. Despite many correlational studies, there have been few direct investigations examining the link between PFAS exposure and early animal development. The aim of this study was to (1) examine the effects of PFOA on development and reproduction using the roundworm Caenorhabditis elegans, a model with a high predictive value for human reproductive toxicity and (2) compare observations to exposure to PFOS. PFAS exposure did not markedly alter egg hatching but delayed population growth, in part due to slower larval development. PFAS-exposed worms took longer to progress through larval stages to reach reproductive maturity, and this was not attributed to PFOA-induced toxicity to their food. Our results provide a robust benchmark for testing developmental and reproductive toxicity for other PFAS and PFAS-alternatives which continue to be used in manufacturing and released into the environment.

Extracorporeal Removal of Per- and Polyfluoroalkyl Substances by Hemoadsorption: In vitro Kinetic Model.

INTRODUCTION: Per- and polyfluoroalkyl substances (PFAS) are known water pollutants leading to potential public health consequences. High blood levels of PFAS have been associated with several pathological conditions including testicular and kidney cancer. Classic extracorporeal therapies have demonstrated limited efficiency, and new approaches should be explored. In this study, we studied the possible role of hemoadsorption to achieve a fast, safe, and effective removal of PFAS from blood in patients with high blood levels. METHODS: We developed an in vitro model of hemoadsorption to test the potential of PFAS removal by extracorporeal treatment. We recirculated a highly polluted batch of water (4 L) through a sorbent cartridge (Jafron Medical, Zhuhai, China) for 120 min at a flow of 150 mL/min. We collected samples at different time points and analyzed 39 different PFAS compounds. RESULTS: For the PFAS compounds with concentrations significantly above normal, we observed a removal ratio close to 90% already within the first 60 min of circulation leading to almost complete elimination of all pollutants at 120 min. CONCLUSIONS: The in vitro model of hemoadsorption suggests the possible application in vivo of this technique to reduce/normalize the concentrations of PFAS in patients exposed to water or environmental pollution.

Commentary: Understanding IARC's PFOA and PFOS carcinogenicity assessments.

In November 2023, the International Agency for Research on Cancer (IARC) classified PFOA as "carcinogenic to humans" (Group 1) and PFOS as "possibly carcinogenic to humans" (Group 2B). We evaluated these classifications, considering the epidemiology, experimental animal, and mechanistic evidence. It is our opinion that the IARC Working Group overstated the available evidence for the carcinogenicity of PFOA and PFOS. Epidemiology studies have shown weak and inconsistent associations across studies. Studies reporting increased incidences of tumors in experimental animals exposed to PFOA or PFOS had statistically significant results that were driven by the presence of benign adenomas. The IARC Working Group used the key characteristics of carcinogens (KCCs, which comprise 10 chemical and/or biological properties of known human carcinogens) approach to upgrade the carcinogenicity classifications for PFOA and PFOS from initially lower classifications that were based on the strength of the epidemiology and experimental animal evidence. However, this is not a robust assessment of mechanistic evidence, as it fails to consider the quality, external validity, and relevance of the evidence. Rather than use the KCCs as a checklist of potential carcinogenic mechanisms, IARC should use a rigorous method to evaluate the plausibility and human relevance of mechanistic evidence.

Perfluorooctanoic acid induces cardiac dysfunction in human induced pluripotent stem cell-derived cardiomyocytes.

Perfluorooctanoic acid (PFOA), commonly found in drinking water, leads to widespread exposure through skin contact, inhalation, and ingestion, resulting in detectable levels of PFOA in the bloodstream. In this study, we found that exposure to PFOA disrupts cardiac function in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). We observed reductions in field and action potentials in hiPSC-CMs exposed to PFOA. Furthermore, PFOA demonstrated a dose-dependent inhibitory effect on various ion channels, including the calcium, sodium, and potassium channels. Additionally, we noted dose-dependent inhibition of the expression of these ion channels in hiPSC-CMs following exposure to PFOA. These findings suggest that PFOA exposure can impair cardiac ion channel function and decrease the transcription of genes associated with these channels, potentially contributing to cardiac dysfunction such as arrhythmias. Our study sheds light on the electrophysiological and epigenetic consequences of PFOA-induced cardiac dysfunction, underscoring the importance of further research on the cardiovascular effects of perfluorinated compounds (PFCs).

Perfluorooctanoic acid inhibits androgen biosynthesis in rat immature Leydig cells.

Perfluorooctanoic acid (PFOA) is a commonly used short-chain synthetic perfluoroalkyl agent. Immature Leydig cells (ILCs) are localized in the testis and responsible for androgen biosynthesis and metabolism. Although PFOA shows toxicity in the reproductive system, it is not clear if it disrupts the function of ILCs. In the present study, primary ILCs were isolated from 35-day-old rats and exposed to a range of PFOA concentrations (0, 0.01, 0.1, or 1 µM). It was determined that 0.1 or 1 µM PFOA reduced total androgen biosynthesis in ILCs. Specifically, 22R-hydroxycholesterol (22R), and pregnenolone (P5) mediated androgen biosynthesis were reduced by 0.1 µM PFOA. PFOA also selectively downregulated mRNA and protein expressions of steroidogenic enzymes including LHCGR, CYP11A1, 3ß-HSD1, and NR5A1 at 0.01, 0.1, or 1 µM. Further analysis revealed that 0.1 µM PFOA inhibited CYP11A1 and 3ß-HSD1 enzyme activities. However, PFOA did not significantly affect androgen metabolism and turnover under any of the conditions tested. And PFOA gavaging to 35-day-old rats at 5 or 10 mg/kg for 7 or 14 days also reduced serum androgen levels secreted by ILCs. Moreover, PFOA gavaging also downregulated the mRNA and protein expression levels of LHCGR, CYP11A1, 3ß-HSD1, and NR5A1 in vivo. Taken together, these findings suggest that PFOA inhibits androgen biosynthesis in ILCs by selectively targeting key enzymes in the synthesis pathway.

Uptake of perfluoroalkyl substances PFOS and PFOA by free-floating hydrophytes Pistia stratiotes L. and Eichhornia crassipes (Mart.) Solms.

The phytoremediation potential of floating aquatic plants to accumulate and remove two common PFAS from contaminated water was investigated. Free-floating hydrophytes Eichhornia crassipes and Pistia stratiotes were grown in water spiked with 0.5, 1, or 2 ppm perfluorooctanoic acid (PFOA) or perfluorooctanesulfonic acid (PFOS) for seven days. Both species were able to accumulate PFOA and PFOS in this time frame, with translocation factors (TF) ranging from 0.13 to 0.57 for P. stratiotes and 0.18 to 0.45 for E. stratiotes, respectively. E. crassipes accumulated a greater amount of PFOA and PFOS than P. stratiotes, with 178.9 ug PFOA and 308.5 ug PFOS removed by E. crassipes and 98.9 ug PFOA and 137.8 ug PFOS removed by P. stratiotes at the highest concentrations. Root tissue contained a higher concentration of PFOA and PFOS than shoot tissue in both species, and the concentration of PFOS was generally significantly higher than PFOA in both E. crassipes and P. stratiotes, with concentrations of 15.39 and 27.32 ppb PFOA and 17.41 and 80.62 ppb PFOS in shoots and roots of P. stratiotes and 12.59 and 37.37 ppb PFOA and 39.92 and 83.40 ppb PFOS in shoots and roots of E. crassipes, respectively. Both species may be candidates for further phytoremediation studies in aquatic ecosystems.

This study investigates the feasibility of using wetland plants for the phytoremediation of PFAS. Prior published studies examine various plant interactions with PFAS but do not evaluate remediation potential of P. stratiotes.

Itaconic Acid Alleviates Perfluorooctanoic Acid-Induced Oxidative Stress and Intestinal Damage by Regulating the Keap1/Nrf2/Ho-1 Pathway and Reshaping the Gut Microbiota.

Itaconic acid (IA) is recognized for its potential application in treating intestinal diseases owing to the anti-inflammatory and antioxidant properties. Perfluorooctanoic acid (PFOA) can accumulate in animals and result in oxidative and inflammatory damages to multi-tissue and organ, particularly in the intestinal tract. This study aimed to explore whether IA could mitigate intestinal damage induced by PFOA exposure in laying hens and elucidate its potential underlying mechanisms. The results showed that IA improved the antioxidant capacity of laying hens and alleviated the oxidative damage induced by PFOA, as evidenced by the elevated activities of T-SOD, GSH-Px, and CAT, and the decreased MDA content in both the jejunum and serum. Furthermore, IA improved the intestinal morphological and structural integrity, notably attenuating PFOA-induced villus shedding, length reduction, and microvillus thinning. IA also upregulated the mRNA expression of ZO-1, Occludin, Claudin-1, and Mucin-2 in the jejunum, thereby restoring intestinal barrier function. Compared with the PF group, IA supplementation downregulated the gene expression of Keap1 and upregulated the HO-1, NQO1, SOD1, and GPX1 expression in the jejunum. Meanwhile, the PF + IA group exhibited lower expressions of inflammation-related genes (NF-κB, IL-1ß, IFN-γ, TNF-α, and IL-6) compared to the PF group. Moreover, IA reversed the PFOA-induced imbalance in gut microbiota by reducing the harmful bacteria such as Escherichia-Shigella, Clostridium innocuum, and Ruminococcus torques, while increasing the abundance of beneficial bacteria like Lactobacillus. Correlation analysis further revealed a significant association between gut microbes, inflammatory factors, and the Keap1/Nrf2/HO-1 pathway expression. In conclusion, dietary IA supplementation could alleviate the oxidative and inflammatory damage caused by PFOA exposure in the intestinal tract by reshaping the intestinal microbiota, modulating the Keap1/Nrf2/HO-1 pathway and reducing oxidative stress and inflammatory response, thereby promoting intestinal homeostasis.

Effective removal of perfluorooctanoic acid from water using PVA@UiO-66-NH2/GO composite materials via adsorption.

This study introduces an innovative approach using highly efficient nanocomposite materials to effectively remove PFAS from water, demonstrating remarkable adsorption capabilities. The nanocomposite was synthesized by integrating a zirconium-based metal-organic framework (MOF) called UiO-66 with graphene oxide (GO) within a polyvinyl alcohol (PVA) matrix. The resulting PVA@UiO-66/GO material features flower-like UiO-66 MOF crystals embedded in the PVA and GO matrix. Various kinetic models were applied to determine the rate constants and adsorption capacities, with the Langmuir isotherm indicating an adsorption capacity of 9.904 mg/g. Thermodynamic analysis confirmed the process's spontaneity and exothermic nature. The UiO-66-NH2/GO/PVA composite also demonstrated high reusability, maintaining substantial PFOA removal efficiency across multiple cycles, with optimal reduction occurring at approximately pH 5. Overall, the PVA@UiO-66/GO composites offer an effective, sustainable, and environmentally friendly solution for PFAS removal in water purification.

Perfluorooctanoic acid effect and microbial mechanism to methane production in anaerobic digestion.

Perfluorooctanoic acid (PFOA) as emerging pollutants was largely produced and stable in nature environment. Its fate and effect to the wasted sludge digestion process and corresponding microbial mechanism was rarely reported. This study investigated the different dose of PFOA to the wasted sludge digestion process, where the methane yield and microbial mechanism was illustrated. The PFOA added before digestion were 0-10000 µg/L, no significant variation in daily and accumulated methane production between each group. The 9th day methane yield was significantly higher than other days (p < 0.05). The soluble protein was significantly decreased after 76 days digestion (p < 0.001). The total PFOA in sludge (R2 = 0.8817) and liquid (R2 = 0.9083) phase after digestion was exponentially correlated with PFOA dosed. The PFOA in liquid phase was occupied 54.10 ± 18.38% of the total PFOA in all reactors. The dewatering rate was keep decreasing with the increase of PFOA added (R2 = 0.7748, p < 0.001). The mcrA abundance was significantly correlated with the pH value and organic matter concentration in the reactors. Chloroflexi was the predominant phyla, Aminicenantales, Bellilinea and Candidatus_Cloacimonas were predominant genera in all reactors. Candidatus_Methanofastidiosum and Methanolinea were predominant archaea in all reactors. The function prediction by FAPROTAX and Tax4fun implied that various PFOA dosage resulted in significant function variation. The fermentation and anaerobic chemoheterotrophy function were improved with the PFOA dose. Co-occurrence network implied the potent cooperation among the organic matter degradation and methanogenic microbe in the digestion system. PFOA has little impact to the methane generation while affect the microbe function significantly, its remaining in the digested sludge should be concerned to reduce its potential environmental risks.

Efficient electro-oxidation-based degradation of per- and polyfluoroalkyl (PFAS) persistent pollutants by using plasma torch synthesized pure-Magnéli phase-Ti4O7 anodes.

Pure Magnéli-phase Ti4O7 were prepared by means of a Plasma Torch (PT) coating method and integrated into an advanced electro-catalytic oxidation (AEO) process in order to degrade perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) persistent pollutants present in waters. The X-ray diffraction analysis confirmed the polycrystalline nature of the pure Magnéli phase PT-Ti4O7 coatings (∼100 µm thick)). The Raman spectra of the PT-Ti4O7 coatings also exhibited the two characteristic peaks (at 138 and 183 cm-1) of the PT-Ti4O7 Magnéli phase. Scanning electron microscopy revealed the nanostructured hierarchical morphology of the PT-Ti4O7 thus conferring them high surface area. The PT-Ti4O7 anodes are shown to achieve higher degradation efficiencies towards PFOA and PFOS in comparison with the conventional boron-doped diamond anodes. By investigating several AEO parameters (including current density, treatment time, nature of the anode material), we were able to optimise the AEO process. Thus, for both PFOA and PFOS (at an initial concentration of 500 ppb in synthetic wastewaters), degradation efficiencies as high as 96.6% and 99.7% were achieved, respectively, with a current density of 20 mA/cm2, a treatment time of 120 min and PT-Ti4O7 mesh-type anodes. PFOA and PFOS can be degraded by both direct anodic electrochemical oxidation (•OH radicals) and indirect electrochemical oxidation via mediators, such as persulphate acid (H2S2O8) generated by sulphate anodic oxidation. The degradation of both compounds followed pseudo-first-order kinetics. The reaction rate constant (k) for PFOS removal was 4.63 × 10-2 min-1, whereas 2.76 × 10-2 min-1 was recorded for PFOA removal. Subsequently, we have used the above optimal AEO operating conditions to treat real wastewater effluents (containing 17 types of PFAS molecules with a total content of 8500 ppb) and achieved a degradation rate of 39.1%-87.4% for eight of the 17 PFAS compounds. The degradation rate was found to be dependent on the chemical structure and chain length of each PFOA/PFOS component.

Elucidating the degradation mechanisms of perfluorooctanoic acid and perfluorooctane sulfonate in various environmental matrices: a review of green degradation pathways.

Given environmental persistence, potential for bioaccumulation, and toxicity of Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), the scientific community has increasingly focused on researching their toxicology and degradation methods. This paper presents a survey of recent research advances in the toxicological effects and degradation methods of PFOA and PFOS. Their adverse effects on the liver, nervous system, male reproductive system, genetics, and development are detailed. Additionally, the degradation techniques of PFOA and PFOS, including photochemical, photocatalytic, and electrochemical methods, are analyzed and compared, highlighted the potential of these technologies for environmental remediation. The biotransformation pathways and mechanisms of PFOA and PFOS involving microorganisms, plants, and enzymes are also presented. As the primary green degradation pathway for PFOA and PFOS, Biodegradation uses specific microorganisms, plants or enzymes to remove PFOA and PFOS from the environment through redox reactions, enzyme catalysis and other pathways. Currently, there has been a paucity of research conducted on the biodegradation of PFOA and PFOS. However, this degradation technology is promising owing to its specificity, cost-effectiveness, and ease of implementation. Furthermore, novel materials/methods for PFOA and PFOS degradation are presented in this paper. These novel materials/methods effectively improve the degradation efficiency of PFOA and PFOS and provide new ideas and tools for the degradation of PFOA and PFOS. This information can assist researchers in identifying flaws and gaps in the field, which can facilitate the formulation of innovative research ideas.

Role of ABCB1 and ABCB4 in renal and biliary excretion of perfluorooctanoic acid in mice.

BACKGROUND: Perfluorooctanoic acid (PFOA) is one of the major per- and polyfluoroalkyl substances. The role of ATP-binding cassette (ABC) transporters in PFOA toxicokinetics is unknown. METHODS: In this study, two ABC transporters, ABCB1 and ABCB4, were examined in mice with single intravenous PFOA administration (3.13 µmol/kg). To identify candidate renal PFOA transporters, we used a microarray approach to evaluate changes in gene expression of various kidney transporters in Abcb4 null mice. RESULTS: Biliary PFOA concentrations were lower in Abcb4 null mice (mean ± standard deviation: 0.25 ± 0.12 µg/mL) than in wild-type mice (0.87 ± 0.02 µg/mL). Immunohistochemically, ABCB4 expression was confirmed at the apical region of hepatocytes. However, renal clearance of PFOA was higher in Abcb4 null mice than in wild-type mice. Among 642 solute carrier and ABC transporters, 5 transporters showed significant differences in expression between wild-type and Abcb4 null mice. These candidates included two major xenobiotic transporters, multidrug resistance 1 (Abcb1) and organic anion transporter 3 (Slc22a8). Abcb1 mRNA levels were higher in Abcb4 null mice than in wild-type mice in kidney. In Abcb4 null mice, Abcb1b expression was enhanced in proximal tubules immunohistochemically, while that of Slc22a8 was not. Finally, in Abcb1a/b null mice, there was a significant decrease in the renal clearance of PFOA (0.69 ± 0.21 vs 1.1 mL ± 0.37/72 h in wild-type mice). A homology search of ABCB1 showed that several amino acids are mutated in humans compared with those in rodents and monkeys. CONCLUSIONS: These findings suggest that, in the mouse, Abcb4 and Abcb1 are excretory transporters of PFOA into bile and urine, respectively.

Impact of local food consumption on exposure to perfluorooctanoic acid and perfluorooctane sulfonate in a contaminated community in North-Eastern Italy.

OBJECTIVES: to estimate the contribution of locally-grown food consumption to perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) human exposure. DESIGN: residents of a PFAS-contaminated community of the Veneto Region (North-Eastern Italy) were categorized into two exposure groups, which refer to the period after the determination of serum levels of PFOA and PFOS conducted at baseline: 1. people drinking water filtered with double granular activated carbon (GAC) and not consuming locally-grown foods at all (reference group); 2. people drinking the same filtered water and which continue to consume only locally-grown foods. For each group, PFOA and PFOS daily intake rates (IR, ng/kg-day) were derived from measured PFOA and PFOS concentrations in treated water and local vegetable and animal food matrices. Then a one-compartment pharmacokinetic model was applied to predict PFOA and PFOS serum concentrations over time and the time needed to fall below a clinically significant threshold level of PFOA and PFOS (e.g., 20 ng/mL). SETTING AND PARTICIPANTS: the study area included 21 municipalities and 3 provinces (Vicenza, Verona, and Padua) located in the Veneto plain. Approximately 127,000 people lived in the most PFAS-contaminated areas on 31.12.2016; those aged 9 to 65 years were invited to participate in the Health Surveillance Plan (HPS), including laboratory tests and medical examination. MAIN OUTCOMES MEASURES: predicted PFOA and PFOS serum levels (ng/mL) among residents in the contaminated area. RESULTS: compared to the reference group, residents who continued to consume locally-grown foods had an approximately 24% higher IR of PFOA and PFOS and this resulted in 3 more years for their PFOA and PFOS concentrations to fall below the threshold level of 20 ng/mL. CONCLUSIONS: this study showed that the contribution of locally-grown food consumption cannot be ignored for people living in PFAS-contaminated areas.

[Determination of two perfluorinated compounds in urine by liquid chromatography-tandem mass spectrometry].

Objective: To establish a method for the determination of two perfluorinated compounds in urine by liquid chromatography-tandem mass spectrometry. Methods: In November 2022, urine samples were extracted by acidic methanol, purified by WAX solid phase extraction column, and eluted with methanol water, then Waters ACQUITY UPLC BEH C18 column (100 mm×2.1 mm, 1.7 µm) was used with 1.0 mmol/L ammonium acetate solution and methanol as mobile phase. The gradient elution was carried out, the detection was carried out by electrospray negative ion multiple response monitoring (MRM) mode, and the quantitative method was internal standard method. Results: Perfluorooctanoic acid and perfluorooctane sulfonic acid had a good linear relationship in the concentration range of 0.5-50.0 µg/L, and the correlation coefficient was >0.999. The limit of detection was 0.017 µg/L, and the limit of quantitation was 0.005 µg/L. The average recoveries were 96.3% and 101.8%, respectively. Days of precision were 3.5%-6.2% and 3.1%-7.4%, respectively, daytime precision were 4.3%-6.8% and 4.7%-8.1%, respectively. Conclusion: The established method of liquid chromatography-tandem mass spectrometry is high sensitivity and accuracy, and is suitable for the determination of perfluorooctanoic acid and perfluorooctane sulfonic acid in human urine.

Effect of pretreatment with a synbiotic on Perfluorooctanoic acid-induced liver damage after sub-acute oral exposure in C57BL/6J mice.

BACKGROUND: Perfluorooctanoic acid (PFOA(is used in several industrial applications, and serves as a surfactant. It is persistent in the environment and is resistant to typical environmental degradation processes. Exposure to this contaminant has been shown to reduce the normal gastrointestinal flora, especially Lactobacillus and Bifidobacterium. Since exposure to this contaminant still occurs and it has been suggested that gut microbiota imbalance might accelerate the progression of liver disorders, we aimed to study the effect of synbiotics pretreatment on PFOA-induced hepatotoxicity. METHOD AND MATERIALS: Herein, C57BL/6 J mice were administered 1, 5, 10, and 20 mg PFOA per kg body weight orally by gavage once daily up to 28 days. Another group was pretreated with synbiotic 4 h before receiving 10 mg PFOA/kg. Also, a control group received 2% Tween 80 orally as a vehicle of PFOA during the study. Plasma ALT, AST, TNF-α, HGF, IL-6, and IFN-γ were measured every week. In addition, a liver histopathological assessment was performed at the end of exposure studies. RESULTS: It was observed that exposure to PFOA can trigger inflammatory markers such as TNF-α, HGF, IL-6, and IFN-γ as well as hepatic enzymes AST and ALT in comparison with the control group. Synbiotic pretreatment prevented or statistically significant reduced the release of the inflammatory markers and the liver enzymes compared to PFOA only treated group. CONCLUSION: It could be inferred that having intact gut flora or even using synbiotic complements containing Lactobacillus, Bifidobacterium, and Streptococcus plus fructooligosaccharides as prebiotic is an appropriate strategy to reduce the negative effects of PFOA exposure.