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.

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.

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).

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.

[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 PFOA exposure on diminished ovarian reserve and its metabolism.

Owing to its difficulty in degrading and ease of accumulation in the body, perfluorooctanoic acid (PFOA) has a detrimental effect on reproduction. This study aimed to examine the effect of PFOA concentration in follicular fluid during ovulation stimulation on embryo quality and the impact of PFOA exposure on the metabolic components of follicular fluid. This was a single-center prospective study that included 25 patients with diminished ovarian reserve (DOR), 25 with normal ovarian reserve (NOR), and 25 with polycystic ovary syndrome (PCOS). Follicular fluid samples were analyzed using ultra-high performance liquid chromatography-tandem mass spectrometry. We demonstrated that the PFOA levels of follicular fluid in the DOR group were higher than those in the NOR group and PCOS group (P < 0.05). PFOA concentration in the PCOS group was negatively correlated with high-quality embryos (P < 0.05). To gain more insight into the impact of PFOA on the metabolic composition of follicular fluid, we classified the DOR group based on the PFOA concentration, for which metabolomic analysis was performed. In the high-concentration PFOA group, there was an increase and a decrease in three and nine metabolites, respectively, compared to that in the low-concentration group. These results suggest that PFOA may alter the metabolic composition of follicular fluid, thus, affecting ovarian reserve function.

The Effects of Combined Exposure to Bisphenols and Perfluoroalkyls on Human Perinatal Stem Cells and the Potential Implications for Health Outcomes.

The present study investigates the impact of two endocrine disruptors, namely Bisphenols (BPs) and Perfluoroalkyls (PFs), on human stem cells. These chemicals leach from plastic, and when ingested through contaminated food and water, they interfere with endogenous hormone signaling, causing various diseases. While the ability of BPs and PFs to cross the placental barrier and accumulate in fetal serum has been documented, the exact consequences for human development require further elucidation. The present research work explored the effects of combined exposure to BPs (BPA or BPS) and PFs (PFOS and PFOA) on human placenta (fetal membrane mesenchymal stromal cells, hFM-MSCs) and amniotic fluid (hAFSCs)-derived stem cells. The effects of the xenobiotics were assessed by analyzing cell proliferation, mitochondrial functionality, and the expression of genes involved in pluripotency and epigenetic regulation, which are crucial for early human development. Our findings demonstrate that antenatal exposure to BPs and/or PFs may alter the biological characteristics of perinatal stem cells and fetal epigenome, with potential implications for health outcomes at birth and in adulthood. Further research is necessary to comprehend the full extent of these effects and their long-term consequences.

Screening ionic liquids for efficiently extracting perfluoroalkyl chemicals (PFACs) from wastewater.

Liquid-liquid extraction (LLE) using ionic liquids (ILs)-based methods to remove perfluoroalkyl chemicals (PFACs), such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), from wastewater, is an important strategy. However, the lack of physicochemical and LLE data limits the selection of the most suitable ILs for the extraction of PFACs. In this work, 1763 ILs for PFACs extraction from water were systematically screened using COSMOtherm to estimate the infinite dilution activity coefficient (lnγ∞)of PFOA and PFOS in water and ILs. To evaluate the accuracy of COSMOtherm, 8 ILs with various lnγ∞ values were selected, and their extraction efficiency (E) and distribution coefficient (Dexp) were measured experimentally. The results showed that the predicted lnγ∞ decreased as the increase of experimental extraction efficiency of PFOA or PFOS, while the tendency of predicted distribution coefficient (Dpre) was consistent with the experimental (Dexp) results. This work provides an efficient basis for selecting ILs for the extraction of PFACs from wastewater.

Effects of Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonic Acid (PFOS) on Soil Microbial Community.

The extensive application of perfluoroalkyl and polyfluoroalkyl substances (PFASs) causes their frequent detection in various environments. In this work, two typical PFASs, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), are selected to investigate their effects on soil microorganisms. Microbial community structure and microbe-microbe relationships were investigated by high-throughput sequencing and co-occurrence network analysis. Under 90 days of exposure, the alpha-diversity of soil microbial communities was increased with the PFOS treatment, followed by the PFOA treatment. The exposure of PFASs substantially changed the compositions of soil microbial communities, leading to the enrichment of more PFASs-tolerant bacteria, such as Proteobacteria, Burkholderiales, and Rhodocyclales. Comparative co-occurrence networks were constructed to investigate the microbe-microbe interactions under different PFASs treatments. The majority of nodes in the PFOA and PFOS networks were associated with the genus Azospirillum and Hydrogenophaga, respectively. The LEfSe analysis further identified a set of biomarkers in the soil microbial communities, such as Azospirillum, Methyloversatilis, Hydrogenophaga, Pseudoxanthomonas, and Fusibacter. The relative abundances of these biomarkers were also changed by different PFASs treatments. Functional gene prediction suggested that the microbial metabolism processes, such as nucleotide transport and metabolism, cell motility, carbohydrate transport and metabolism, energy production and conversion, and secondary metabolites biosynthesis transport and catabolism, might be inhibited under PFAS exposure, which may further affect soil ecological services.

Chlorinated Polyfluorinated Ether Sulfonates and Thyroid Hormone Levels in Adults: Isomers of C8 Health Project in China.

Chlorinated polyfluorinated ether sulfonates (Cl-PFESAs) are one kind of replacement chemistry for perfluorooctanesulfonate (PFOS). Recent studies have shown that Cl-PFESAs could interfere with thyroid function in animal models. However, epidemiological evidence on the link between Cl-PFESAs and thyroid function remains scarce. In this study, we focused on two representative legacy perfluoroalkyl substances (PFAS), including PFOS and perfluorooctanoic acid (PFOA), and two PFOS alternatives (6:2 and 8:2 Cl-PFESAs) in the general adult population from a cross-sectional study, the "Isomers of C8 Health Project in China". Three serum thyroid hormones (THs), thyroid stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4), were measured. We fitted generalized linear regression, restricted cubic spline regression, and Bayesian kernel machine regression models to assess associations of individual Cl-PFESAs, legacy PFAS, and PFAS mixtures with THs, respectively. We found individual PFAS and their mixtures were nonlinearly associated with THs. The estimated changes of the TSH level (µIU/mL) at the 95th percentile of 6:2 Cl-PFESA and PFOS against the 5th percentile were -0.74 (95% CI: -0.94, -0.54) and -1.18 (95% CI: -1.37, -0.98), respectively. The present study provided epidemiological evidence for the association of 6:2 Cl-PFESA with thyroid hormone levels in the general adult population.

Comparison of sub-lethal metabolic perturbations of select legacy and novel perfluorinated alkyl substances (PFAS) in Daphnia magna.

Per- and polyfluoroalkyl substances (PFAS) are a class of pollutants of concern due to their ubiquitous presence, persistence, and toxicity in aquatic environments. Legacy PFAS pollutants such as perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) have been more widely studied in aquatic environments. However, replacement PFAS, such as ammonium perfluoro (2-methyl-3-oxahexanoate; GenX) are increasingly being detected with little known information surrounding their toxicity. Here, Daphnia magna, a model organism for freshwater ecotoxicology was used to compare the acute sub-lethal toxicity of PFOS, PFOA, GenX, and PFAS mixtures. Using liquid chromatography with tandem mass spectrometry (LC-MS/MS), the targeted polar metabolic profile extracted from single Daphnia was quantified to investigate perturbations in the exposure groups versus the unexposed organisms. Multivariate statistical analyses demonstrated significant non-monotonic separation in PFOA, GenX, and PFAS mixture exposures. Sub-lethal exposure to concentrations of PFOS did not lead to significant separation in multivariate analyses. Univariate statistics and pathway analyses were used to elucidate the mode of action of PFAS exposure. Exposure to all individual PFAS led to significant perturbations in many amino acids including cysteine, histidine, tryptophan, glycine, and serine. These perturbations are consistent with biochemical pathway disruptions in the pantothenate and Coenzyme A (CoA) biosynthesis, thiamine metabolism, histidine metabolism, and aminoacyl-tRNA biosynthesis pathways. Overall, the collected metabolomic data is consistent with disruptions in energy metabolism and protein synthesis as the primary mode of action of sub-lethal PFAS exposure. Secondary modes of action among individual pollutant exposures demonstrated that the structural properties (carboxylic acid vs. sulfonic acid group) may play a role in the metabolic perturbations observed. Sub-lethal exposure to PFAS mixtures highlighted a mixed response when compared to the individual pollutants (PFOS, PFOA, and GenX). Overall, this study emphasizes the niche capability of environmental metabolomics to differentiate secondary modes of action from metabolic perturbations in both single pollutant and pollutant mixtures within the same chemical class.

Effects of perfluoroalkyl substances (PFASs) and benzo[a]pyrene (BaP) co-exposure on phase I biotransformation in rainbow trout (Oncorhynchus mykiss).

The presence of perfluoroalkyl substances (PFASs) in the environment, especially in aquatic ecosystems, continues to be a significant concern for human and environmental health. Previous studies have suggested that several PFASs do not undergo biotransformation due to their chemical stability, yet perfluorooctanesulfonic acid (PFOS)- and perfluorooctanoic acid (PFOA)-exposed organisms have presented altered activity of important biotransformation pathways. Given the fundamental role of biotransformation in biological organisms and the significant distribution of PFAS in aquatic environments, the present study investigated the influence of PFOA and PFOS on phase I biotransformation enzymes in vitro using the rainbow trout liver RTL-W1 cell line and in vivo using juvenile rainbow trout. Cells and fish were exposed and co-exposed to environmentally relevant concentrations of PFOA, PFOS, and benzo[a]pyrene (BaP), for 72 h and 10 days, respectively, prior to measurements of cytotoxicity and biotransformation ability through measurements of CYP1A1-, CYP1A2-, and CYP3A4-like activities. Our results indicate that exposure to PFAS-BaP binary mixtures altered CYP1A-like activity in vivo; however, those alterations were not observed in vitro. Similarly, while BaP did not significantly induce CYP3A4 in vivo, exposure to the PFAS led to significantly lower enzymatic activity relative to basal levels. These observations may have implications for organisms simultaneously exposed to PFASs and other environmental pollutants for which biotransformation is necessary, especially in detoxification mechanisms. Furthermore, the interference with biotransformation pathways could potentially predispose exposed organisms to a compromised physiology, which may increase their vulnerability to other stressors and erode their survival fitness.

Contamination of perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in sediment of the Cau River, Vietnam.

Perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are recognized as emerging environmental pollutants because of their high persistence in various environmental matrices and toxic effects on humans and animals. In Vietnam, PFOA and PFOS have been detected in surface water and sediment in recent studies. The objectives of this study were to evaluate the spatial and vertical distribution, determine the factors affecting the sorption onto sediment, and assess the environmental risk of PFOS and PFOA in the sediment of the Cau River. The average concentrations of PFOS and PFOA in the surface sediment were 2.66 ng/g and 0.84 ng/g, respectively. The highest concentrations were recorded in the areas receiving wastewater from domestic and industrial activities. According to the depth, the contents of target chemicals in the surface sediments (0-5 cm) were lower than those in the second layer (5-10 cm). The remaining layers have decreasing concentration as the depth of the sediment increases. The water-sediment distribution coefficient was relatively different for PFOS and PFOA with log Kd values ranging from 1.31 to 1.86 and from 0.08 to 1.31, respectively. This study also demonstrated that the level of PFOS and PFOA in sediment is significantly correlated with total organic carbon content of sediment. No apparent relation was found between PFOS, PFOA concentration in sediment, and particle size distribution. Risk quotients of the two compounds were below 0.01, indicating that the environmental risk in the sediment is negligible at present. The results of this study provide an overview of PFOS and PFOA contamination in sediment in the Cau River, Vietnam.

Hydrodefluorination of Perfluorooctanoic Acid in the H2-Based Membrane Catalyst-Film Reactor with Platinum Group Metal Nanoparticles: Pathways and Optimal Conditions.

PFAAs (perfluorinated alkyl acids) have become a concern because of their widespread pollution and persistence. A previous study introduced a novel approach for removing and hydrodefluorinating perfluorooctanoic acid (PFOA) using palladium nanoparticles (Pd0NPs) in situ synthesized on H2-gas-transfer membranes. This work focuses on the products, pathways, and optimal catalyst conditions. Kinetic tests tracking PFOA removal, F- release, and hydrodefluorination intermediates documented that PFOA was hydrodefluorinated by a mixture of parallel and stepwise reactions on the Pd0NP surfaces. Slow desorption of defluorination products lowered the catalyst's activity for hydrodefluorination. Of the platinum group metals studied, Pd was overall superior to Pt, Rh, and Ru for hydrodefluorinating PFOA. pH had a strong influence on performance: PFOA was more strongly adsorbed at higher pH, but lower pH promoted defluorination. A membrane catalyst-film reactor (MCfR), containing an optimum loading of 1.2 g/m2 Pd0 for a total Pd amount of 22 mg, removed 3 mg/L PFOA during continuous flow for 90 days, and the removal flux was as high as 4 mg PFOA/m2/d at a steady state. The EPA health advisory level (70 ng/L) also was achieved over the 90 days with the influent PFOA at an environmentally relevant concentration of 500 ng/L. The results document a sustainable catalytic method for the detoxification of PFOA-contaminated water.

Per- and Polyfluoroalkyl Substances (PFAS) in Breast Milk: Concerning Trends for Current-Use PFAS.

This is the first study in the last 15 years to analyze per- and polyfluoroalkyl substances (PFAS) in breast milk collected from mothers (n = 50) in the United States, and our findings indicate that both legacy and current-use PFAS now contaminate breast milk, exposing nursing infants. Breast milk was analyzed for 39 PFAS, including 9 short-chain and 30 long-chain compounds, and 16 of these PFAS were detected in 4-100% of the samples. The ∑PFAS concentration in breast milk ranged from 52.0 to 1850 pg/mL with a median concentration of 121 pg/mL. Perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) were the most abundant PFAS in these samples (medians 30.4 and 13.9 pg/mL, respectively). Two short-chain PFAS, including perfluoro-n-hexanoic acid (PFHxA, C6) and perfluoro-n-heptanoic acid (PFHpA, C7), were detected in most of the samples with median concentrations of 9.69 and 6.10 pg/mL, respectively. Analysis of the available breast milk PFAS data from around the world over the period of 1996-2019 showed that while the levels of the phased-out PFOS and PFOA have been declining with halving times of 8.1 and 17 years, respectively, the detection frequencies of current-use short-chain PFAS have been increasing with a doubling time of 4.1 years.

Association between the total plasma isomers of per- and polyfluoroalkyl substances and erythrograms in young and middle-aged Taiwanese populations.

PURPOSE: Per- and polyfluoroalkyl substances (PFAS) are human-made chemicals used in daily use products. Recent studies have shown that different perfluorooctanoic acid (PFOA) and/or perfluorooctane sulfonate (PFOS) isomers may have different biological effects. In vitro studies have also reported that PFAS exposure can alter the structure of hemoglobin (Hb). In epidemiology, however, few studies have investigated the relationship between PFAS exposure and erythrocytes. Additionally, the correlation between PFOA/PFOS isomers and full erythrograms has never been explored. APPROACH AND RESULTS: In cohorts comprising young and middle-aged Taiwanese populations, we enrolled 1483 participants (aged between 12 and 63 years) to analyze the correlations between the plasma levels of PFOA/PFOS isomers and whole-blood erythrograms. The study comprised 868 men and 615 women with a mean age of 31.2 years. When all PFOA/PFOS isomers were entered into the multiple linear regression model, the linear PFOA (L-PFOA) levels were positively correlated with the Hb, hematocrit (HCT), mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH) levels while the branched PFOS (B-PFOS) levels were positively associated with the Hb, HCT, and mean corpuscular hemoglobin concentration (MCHC). The mean value of Hb was the highest (14.66 mg/dL (95% CI =14.52-14.80); P for trend <0.001) when both the L-PFOA and B-PFOS levels were above the 50th percentile. CONCLUSIONS: The results imply that PFOA/PFOS isomers may increase the weight and volume of Hb/RBC and that L-PFOA/B-PFOS may have an additive effect on the Hb levels. However, it is also possible PFAS detected at a higher concentration may due to its binding to higher levels of Hb. Further studies are needed to investigate the effects of PFOA/PFOS isomers on RBCs in humans.

Effect of soil organic matter on the plant uptake of perfluorooctanoic acid (PFOA) and perfluorooctanesulphonic acid (PFOS) in lettuce on granular activated carbon-applied soil.

The presence of perfluorooctanoic acid (PFOA) and perfluorooctanesulphonic acid (PFOS) in crops is an important consideration for food safety. The soil organic matter (SOM) content may affect the adsorption potential of PFOA and PFOS in water and soil and their subsequent uptake in crops. To better understand these dynamics, the adsorption and uptake of PFOA and PFOS in lettuce were investigated using granular activated carbon (GAC)-treated soils with varying SOM content. The adsorption potential of GAC was investigated, with maximum adsorption capacities for PFOA and PFOS calculated to be 9.091 mg g-1 and 27.778 mg g-1, respectively. These values decreased to 5.208 mg g-1 and 17.241 mg g-1, respectively, after the addition of 0.04 wt% humic acid. The average plant uptake factor (PUF) in low and high perfluoroalkyl and polyfluoroalkyl acid (PFAA)-contaminated soils with 4.0 wt% SOM was restricted to 0.353 for PFOA and 0.108 for PFOS. The PUFs were approximately two times lower than those for soil with 2.6 wt% SOM. Addition of 1 wt% GAC to the soil successfully reduced the PUF by up to 99.4%, with values of 0.006 (PFOA) and 0.005 (PFOS) in 2.6 wt% SOM-treated soil and 0.079 (PFOA) and 0.023 (PFOS) in 4.0 wt% SOM-treated soil. Although the PUF in the GAC-treated soil was drastically decreased, the PUF of the soil with 4.0 wt% SOM was at least four times higher than that with 2.6 wt% SOM. Therefore, SOM content is an important consideration in the remediation of PFOA- and PFOS-contaminated farmland soil using carbonaceous adsorbent.

The occurrence of per- and polyfluoroalkyl substances (PFASs) in fluoropolymer raw materials and products made in China.

Perfluorooctanoic acid (PFOA), its salts, and related compounds were listed as new persistent organic pollutants by the Stockholm Convention in 2019. In this study, the occurrence of residues of PFOA and other per- and polyfluoroalkyl substances (PFASs) in raw materials and fluoropolymer products from the Chinese fluoropolymer industries are reported for the first time. The PFOA concentrations in raw materials and fluoropolymer products were in the range of 6.7 to 1.1 × 106 ng/g, and

Perfluorinated alkylated substances serum concentration and breast cancer risk: Evidence from a nested case-control study in the French E3N cohort.

Endocrine-disrupting chemicals are proposed to increase breast cancer (BC) incidence. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), two perfluorinated alkylated substances (PFASs), are suspected to be ubiquitously present in the blood of human population worldwide. We investigated the associations between serum concentrations of these substances and BC risk. Etude Epidémiologique auprès de femmes de l'Education Nationale is a cohort of 98,995 French women born in 1925-1950 and followed up since 1990. We sampled 194 BC cases and 194 controls from women with available blood samples. Serum concentrations of PFASs were measured by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Adjusted conditional logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). All statistical tests were two sided. While PFASs concentrations were not associated with BC risk overall, we found positively linear associations between PFOS concentrations and the risk of ER+ (3rd quartile: OR = 2.22 [CI = 1.05-4.69]; 4th quartile: OR = 2.33 [CI = 1.11-4.90]); Ptrend = 0.04) and PR+ tumors (3rd quartile: OR = 2.47 [CI = 1.07-5.65]; 4th quartile: OR = 2.76 [CI = 1.21-6.30]; Ptrend = 0.02). When considering receptor-negative tumors, only the 2nd quartile of PFOS was associated with risk (ER-: OR = 15.40 [CI = 1.84-129.19]; PR-: OR = 3.47 [CI = 1.29-9.15]). While there was no association between PFOA and receptor-positive BC risk, the 2nd quartile of PFOA was positively associated with the risk of receptor-negative tumors (ER-: OR = 7.73 [CI = 1.46-41.08]; PR-: OR = 3.44 [CI = 1.30-9.10]). PFAS circulating levels were differentially associated with BC risk. While PFOS concentration was linearly associated with receptor-positive tumors, only low concentrations of PFOS and PFOA were associated with receptor-negative tumors. Our findings highlight the importance of considering exposure to PFASs as a potential risk factor for BC.