Perfluoroalkyl Substances Research Articles

Prenatal exposure to per- and polyfluoroalkyl substances (PFAS) and their influence on inflammatory biomarkers in pregnancy: Findings from the LIFECODES cohort

BackgroundPer- and polyfluoroalkyl substances (PFAS) are fluorinated chemicals linked to adverse pregnancy and birth outcomes. However, the underlying mechanisms, specifically their effects on maternal inflammatory processes, are not well characterized. ObjectiveWe examined associations between prenatal PFAS exposure and repeated measures of inflammatory biomarkers, including C-reactive protein (CRP) and four cytokines [Interleukin-10 (IL-10), IL-1β, IL-6, and tumor necrosis factor-α (TNF-α)]. MethodsWe analyzed data from 469 pregnant women in a nested case-control study of preterm birth at Brigham and Women’s Hospital in Boston, Massachusetts (2006–2008). We measured nine PFAS in early pregnancy plasma samples (median gestation: 10 weeks), with inflammatory biomarkers measured at median gestations of 10, 18, 26, and 35 weeks. We used linear mixed effects models for repeated measures and multivariable regression for visit-specific analysis to examine associations between each PFAS and inflammation biomarker, adjusting for maternal demographics, pre-pregnancy BMI, and parity. We examined PFAS mixture effects using sum of all PFAS (∑PFAS) and quantile-based g-computation approaches. ResultsWe observed consistent inverse associations between most PFAS and cytokines, specifically IL-10, IL-6, and TNF-α, in both single pollutant and mixture analyses. For example, an interquartile range increase in perfluorooctanesulfonic acid was associated with −10.87 (95% CI: −19.75, −0.99), −13.91 (95% CI: −24.11, −2.34), and −8.63 (95% CI: −14.51, −2.35) percent change in IL-10, IL-6, and TNF-α levels, respectively. Fetal sex, maternal race, and visit-specific analyses showed associations between most PFAS and cytokines were generally stronger in mid-pregnancy and among women who delivered males or identified as African American. ConclusionsThe observed suppression of both regulatory (IL-10) and pro-inflammatory (TNF-α) cytokines suggests that PFAS may alter maternal inflammatory processes or immune functions during pregnancy. Further research is needed to understand the effects of both legacy and newer PFAS on inflammatory pathways and their broader clinical implications.

Sorption of Per- and Polyfluoroalkyl Substances by Lignin in Pulp and Paper Wastewater

Per- and polyfluoroalkyl substances (PFAS) are anthropogenic chemicals commonly found in the environment. PFAS pose multifaceted challenges including identifying sources and exposure pathways, detecting and quantifying their presence, characterizing their fate and transport, and assessing their risks. PFAS and fluorotelomer polymers can be found in the pulp and paper (P&P) wastewater systems, but their behavior remains poorly understood. The constituents of P&P waste include lignin hydrolysis products, hence PFAS interactions with lignin likely affect PFAS removal efforts. This study employed quantitative ultra-performance liquid chromatography triple quadrupole mass spectrometry (UPLC-MS/MS) to investigate the sorption-desorption capacity and mechanisms of PFAS interaction with lignin. PFAS with sulfonate functional groups displayed higher affinity for lignin (solid phase) based on their partitioning coefficient (Kd), while PFAS with carboxylate head groups persisted in the P&P wastewater (aqueous phase). Sorption to lignin exhibited an increase with chain length (CF2)n among compounds with the same functional group. Long-chain (C ≥ 6) PFAS demonstrated higher sorption compared to short-chain (C ≤ 5) homologs. The sorption-desorption capacities, partitioning coefficients, and kinetics of PFAS reported in this study can facilitate predictive models for PFAS and assist in the development of efficient P&P waste treatment and management.

Kidney function mediates the association of per- and poly-fluoroalkyl substances (PFAS) and heavy metals with hepatic fibrosis risk

Heavy metals and per- and polyfluoroalkyl substances (PFAS) are significantly associated with the risk of hepatic fibrosis. However, the potential mediating effect of kidney function in the relationship between heavy metals, PFAS, and hepatic fibrosis risk remains unexplored. This research gap limits the development of hepatic fibrosis prevention and treatment strategies. To address this, this study conducts a cross-sectional analysis based on data from 10,870 participants in NHANES 2005-2018 to explore the relationship between heavy metals, PFAS, and the risk of hepatic fibrosis, as well as the mediating effect of kidney function. Participants with a Fibrosis-4 index <1.45 are defined as not having hepatic fibrosis in this study. Results from generalized linear regression models and weighted quantile sum regression models indicate that both individual and combined exposures to heavy metals and PFAS are positively associated with the risk of hepatic fibrosis. Nonlinear exposure-response functions suggest that there may be a threshold for the relationship between heavy metals (except mercury) and PFAS with the risk of hepatic fibrosis. Furthermore, heavy metals and PFAS increase the risk of kidney function impairment. After stratification by kidney function stage, the relationship between heavy metals (except lead) and proteinuria is not significant, while PFAS show a significant negative association with proteinuria. The decline in kidney function has a significant mediating effect in the relationship between heavy metals and PFAS and the risk of hepatic fibrosis, with mediation effect proportions all above 20%. The findings suggest that individual or combined exposure to heavy metals and PFAS does not increase the risk of hepatic fibrosis until a certain threshold is reached, and the mediating role of declining kidney function is very important. These results highlight the need to consider kidney function in the context of hepatic fibrosis risk assessment and management.

Tissue-specific distribution and fatty acid content of PFAS in the northern Bohai Sea fish: risk-benefit assessment of legacy PFAS and emerging alternatives

This study aimed to examine the distribution of poly- and perfluoroalkyl substances (PFAS) in 15 marine fish species from the northern Bohai Sea, investigate their sources of contamination, and evaluate the benefits-risks associated with the concurrent consumption of fish fatty acids and PFAS. The ∑PFAS concentrations in fish ranged from 9.38 to 262.92ng·g-1 (dry weight). The highest PFAS levels were found in the viscera and gills, while the lowest levels were found in the muscles. Industrial effluents and sewage treatment plant discharges were the primary sources of PFAS contamination. The individual PFAS concentrations in fish were insignificantly correlated with their trophic levels (p > 0.05). However, the concentrations of hexafluoropropylene oxide dimer acid (HFPO-DA) or long-chain PFAS (C > 8) significantly increased with fish size (e.g., total length, weight) and lipid content (p < 0.001). The benefit-risk analysis suggests that HPFO-DA poses a higher health risk than perfluorooctanoic acid (PFOA) in fish (p<0.05). Long-term consumption of contaminated fish may significantly increase human serum PFOA concentration and kidney cancer risk (p<0.05). Daily consumption of 5g (wet weight) muscle from Ditrema temmincki and Konosirus punctatus is recommended to meet the requirements for fatty acid supplementation without posing health risks.

Early pregnancy serum PFAS are associated with alterations in the maternal lipidome

Per- and polyfluoroalkyl substances (PFAS) have been detected in the blood of humans and animals worldwide. Exposure to some PFAS are associated with multiple adverse pregnancy outcomes. Existing literature has identified a strong association with PFAS exposure and metabolic dysfunction in humans, including modification of lipid metabolism. Using a subset of the Michigan Mother-Infant Pairs cohort (n=95), this study investigated associations between first trimester plasma levels of PFAS and maternal lipids and metabolites in the first trimester (T1), at the time of delivery (T3), and in the infant cord blood (CB) using untargeted shotgun lipidomics and metabolomics. Identifying PFAS-induced alterations in the maternal lipid- or metabolome at specific timepoints may help elucidate windows of susceptibility to adverse pregnancy outcomes. Out of 9 PFAS measured, 7 were detected in at least 20% of samples and were used for further analyses. PFOS and PFHxS were measured at the highest concentrations with medians of 5.76 ng/ml and 3.33 ng/ml, respectively. PFOA, PFNA, and PFDA had lower measured values with medians of < 1.2 ng/mL. PFHxS concentrations were positively associated with monounsaturated sphingomyelins (SMs) in T1 maternal plasma in adjusted models, determined by an adjusted p-value (q) < 0.1. PFHxS was positively associated with saturated and polyunsaturated SMs and inversely associated with saturated diacylglycerols in T1. Following metabolite-specific analysis, two mono-unsaturated diacylglycerols with carbon chain lengths of 32 and 35 were inversely associated with PFHxS in T1. In T3, only the association between PFHxS and SMs remained, but was attenuated. In addition, PFDA was associated with an increase in polyunsaturated plasmenyl-phosphatidylethanolamines in T3. No associations were identified between PFAS and infant cord blood lipids. Continued research into PFAS associated disruptions in lipid metabolism at sensitive stages of gestation may provide insight into the mechanisms that lead to adverse birth and pregnancy outcomes.

Uptake of per- and polyfluoroalkyl substances by Conservation Reserve Program’s seed mix in biosolids-amended soil

To test the effectiveness of phytoremediation of per- and polyfluoroalkyl substances (PFAS), we cultivated a mixture of nine grass-legume species native to Maine, US, in two types of soil amended with biosolids containing both pre-existing and spiked PFAS. To investigate how biochar amendment affects plant uptake of PFAS, two types of biochar at varying doses (i.e., 0%, 0.05%, 0.2%, 1%) were added to the biosolids before mixing with soil and cultivating plants. Our findings indicate that six representative PFAS, including short- and long-chain perfluoroalkyl carboxylic acids (PFCAs) (C6-C8) and perfluoroalkylsulfonic acids (PFSAs) (C4, C6, and C8), were effectively transferred from the biosolids amended soil (BAS) system to the harvestable grass-legume shoots. During the initial growth stage (Day 33), PFOA, PFHxS and PFOS were primarily detected in the grass shoots, showing a removal efficiency of 2-3%. As the growth period extended to Day 92, the uptake of short-chain PFBS, PFHxA, and PFHpA became increasingly dominant with an average removal efficiency of 5-20%. Notably, more than 10% of PFOA was uptaken by the shoots harvested from the Scantic soil amended with Biochar 2. These results were observed in grass-legume shoots when the soil was amended with a low dose of biochar (0.05%). However, when 1% biochar was added, PFAS were effectively stabilized, preventing their transfer to the above-ground plant compartments. Aside from different effect of different dose of the biochar, this study also revealed that plant’s uptake of PFAS is highly dependent on soil properties. Overall, this study demonstrated the feasibility of using a grass-legume mix for removing PFAS from contaminated soil and raised the need of developing site-specific treatment strategies to maximize the performance of phytoremediation.

PFAS, PCBs, PCDD/Fs, PAHs and extractable organic fluorine in bio-based fertilizers, amended soils and plants: Exposure assessment and temporal trends

Bio-based fertilizers (BBFs) produced from organic waste contribute to closed-loop nutrient cycles and circular agriculture. However, persistent organic contaminants, such as per- and poly-fluoroalkyl substances (PFAS), polychlorobiphenyls (PCBs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), as well as polyaromatic hydrocarbons (PAHs) can be present in organic waste or be formed during valorization processes. Consequently, these hazardous substances may be introduced into agricultural soils and the food chain via BBFs. This study assessed the exposure of 84 target substances and extractable organic fluorine (EOF) in 19 BBFs produced from different types of waste, including agricultural and food industrial waste, sewage sludge, and biowaste, and through various types of valorization methods, including hygienization at low temperatures (<150 °C) as well as pyrolysis and incineration at elevated temperatures (150–900 °C). The concentrations in BBFs (ΣPFOS & PFOA: <30 μg kg−1, Σ6PCBs: <15 μg kg−1, Σ11PAHs: <3 mg kg−1, Σ17PCDD/Fs: <4 ng TEQ kg−1) were found to be below the strictest thresholds used in individual EU countries, with only one exception (pyrolyzed sewage sludge, Σ11PAHs: 5.9 mg kg−1). Five BBFs produced from sewage sludge or chicken manure contained high concentrations of EOF (>140 μg kg−1), so monitoring of more PFAS is recommended. The calculated expected concentrations in soils after one BBF application (e.g. PFOS: <0.05 μg kg−1) fell below background contamination levels (PFOS: 2.7 μg kg−1) elsewhere in the literature. This was confirmed by the analysis of BBF-amended soils from field experiments (Finland and Austria). Studies on target legacy contaminants in sewage sludge were reviewed, indicating a general decreasing trend in concentration with an apparent half-life ranging from 4 (PFOS) to 9 (PCDD/Fs) years. Modelled cumulative concentrations of the target contaminants in agricultural soils indicated low long-term risks. Concentrations estimated and analyzed in edible plant part were low, indicating that exposure by plant consumption is well below tolerable daily intakes.

Fluorotelomer Alcohol (FTOH) Emission Rates from New and Old Rain Jackets to Air Determined by Iodide High-Resolution Chemical Ionization Mass Spectrometry

Per- and polyfluoroalkyl substances (PFAS), which include fluorotelomer alcohols (FTOHs), are synthetic chemicals used in consumer products because of their water-, stain-, and grease-repellent properties; thus, PFAS are commonly found in functional clothing such as rain jackets. To date, emissions of PFAS from products to indoor air have not been well characterized, although many PFAS-containing products are used and stored indoors. We used a test chamber connected to a high-resolution time-of-flight chemical ionization mass spectrometer equipped with iodide as a reagent ion (I-HR-ToF-CIMS) to measure emission rates for four FTOHs from 10 rain jackets and one backpack cover. The materials were categorized as old/used, new, or “PFAS-free”, and they were tested under two different scenarios, i.e., immediately out of package and after airing out. We observed real-time FTOH emissions from all materials. Under the out-of-package scenario, emissions of 6:2, 8:2 and 10:2 FTOH showed characteristics that indicate mass transfer is limited by internal diffusion, with a high initial peak followed by a lower steady-state emission rate. Peak emission rates correlated well with material-phase concentrations determined by an offline extractive gas chromatography-mass spectrometry (GC-MS) method. Our results further suggest that the old, used jackets had, on average, higher peak emission rates and higher material-phase concentrations than the new jackets, largely driven by 8:2 FTOH. “PFAS-free” materials had the overall lowest emission rates and material-phase concentrations. After airing out, emission rates were on average an order of magnitude lower than peak emission rates. Our findings emphasize the importance of considering consumer products like rain jackets as sources of indoor exposure to PFAS.

Occurrence of per- and polyfluoroalkyl substances in wheat, maize, rice, and soybean from chinese major grain producing regions.

Dietary exposure to per- and polyfluoroalkyl substances (PFAS) has been a concern for many years. Previous studies demonstrated that foods such as meat, milk, fish, vegetables, and tuber crops could be potential sources of human exposure to PFAS. However, research on PFAS contamination in grains remains limited. Therefore, this study conducted a comprehensive investigation of PFAS contamination in raw grains from major grain-producing regions in China. Among all grain species, soybeans exhibited the highest Σ16PFAS level (1.01ng/g dw), followed by rice (0.570ng/g dw), wheat (0.542ng/g dw), and maize (0.245ng/g dw). Short-chain perfluoroalkyl carboxylates (PFCAs) displayed higher detection frequencies compared to their long-chain homologues and perfluoroalkyl sulfonates (PFSAs). Perfluorobutanoic acid (PFBA) and perfluorooctanoic acid (PFOA) were dominant in wheat, maize, and soybean samples, while sodium p-perfluorous nonenoxybenzenesulfonate (OBS) was predominant in rice. OBS contributed approximately 70% to Σ16PFAS concentrations in rice. The concentration difference of OBS was not significant between indica rice and japonica rice, however, a disparity was observed between early indica rice and mid-late indica rice, suggesting that the growing period potentially affects OBS level in rice grains. Compared to other regions, east China displayed relatively higher PFAS concentrations in grain samples. This finding is consistent with previous studies and may be attributed to the intensive industrial and human activities. The estimated daily intake (EDI) of Σ16PFAS in grains from this study ranged from 0.0829 to 3.32ng/kg bw/day. The dietary health risks associated with PFOA in wheat and OBS in rice warrant further attention.

Occurrence, fate, and ecological risk of PAEs, PFASs, antibiotics in industrial, urban and rural WWTPs in Shaanxi Province, China

The wastewater treatment plants (WWTPs) were considered as a hub of transit from human activities as a source to the aquatic ecosystems as a sink of emerging contaminants (ECs). This study investigated the fate of phthalate esters (PAEs), per- and polyfluoroalkyl substances (PFASs) and antibiotics in the influent and effluent of WWTPs in industrial, urban and rural in Shaanxi province (China). The first most abundant monomer of these three types of ECs were the same in industrial, urban and rural WWTPs. The composition of PAEs in the influent of urban and rural WWTPs were quite different from that of industrial WWTPs. The removal efficiency of PAEs and PFASs in urban WWTPs were higher than those in rural and industrial WWTPs. The annual mass load of PFASs in rural WWTPs was lower than that in industrial and urban WWTPs. The risk quotient (RQ) of PAEs was high, with most of them exceeding 1. While the RQ of PFASs was low, exceeding 0.1 only in some industrial WWTPs. The frequency of high risk of total antibiotics in urban and rural WWTPs was higher than that in industrial WWTPs. This study provided field survey data and guidance to strengthen the management of ECs in the region.

The trends of per-and polyfluoroalkyl substances (pfas) in drinking water systems in Maryland United States

Per- and polyfluoroalkyl substances (PFAS) have become a major concern in water quality management because of their persistence in the environment and associated health risks. In Maryland, the diverse water resources and densely populated areas, faces unique challenges culminating from PFAS contamination. This research paper presents a comprehensive overview of PFAS contamination trends in Maryland's drinking water systems across four distinct phases, spanning from 2019 to 2022, it highlights the trends of PFAS contamination, environmental and public health risks, and strategies for effective management. Utilizing data from extensive monitoring efforts conducted in the state, the study reveals a persistent and evolving environmental health challenge characterized by the dominance of different PFAS compounds, particularly PFOS and PFOA, found at concerning concentrations. Mean concentrations of total PFOA/PFOS across the sampling periods were at 18.78 ng/L, 7.28 ng/L, 14.60 ng/L, 12.46 ng/L, significantly surpassing the EPA's 2024 maximum contaminant levels of 4 ng/L for PFOA and PFOS. Despite fluctuations observed across sampling phases, PFAS levels consistently surpass EPA health advisory levels, indicating widespread contamination. Potential sources, such as industrial sites and wastewater treatment plants, underscore the need for robust regulatory enforcement and innovative remediation strategies to safeguard public health. The findings emphasize the necessity for continuous monitoring and multi-faceted mitigation approaches to address PFAS contamination effectively, ensuring the safety of Maryland's water resources and the health of its residents.

Associations of per- and polyfluoroalkyl substances with human milk metabolomic profiles in a rural North American cohort.

Per- and polyfluoroalkyl substances (PFAS) are a class of persistent synthetic chemicals that are found in human milk and are associated with negative health effects. Research suggests that PFAS affect both lactation and the human metabolome. We measured perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) in the milk of 425 participants from the New Hampshire Birth Cohort Study using liquid chromatography-tandem mass spectrometry (LC-MS/MS). A nontargeted metabolomics assay was performed using LC with high-resolution MS, and metabolites were identified based on in-house database matching. We observed six metabolic profiles among our milk samples using self-organizing maps, and multinomial logistic regression was used to identify sociodemographic and perinatal predictors of these profiles, including infant sex, parity, participant body mass index, participant age, education, race, smoking status, gestational weight gain, and infant age at time of milk collection. Elevated PFOA was associated with profiles containing higher amounts of triglyceride fatty acids, glycerophospholipids and sphingolipids, and carnitine metabolites, as well as lower amounts of lactose and creatine phosphate. Lower concentrations of milk PFOS were associated with lower levels of fatty acids. Our findings suggest that elevated PFOA in human milk is related to metabolomic profiles consistent with enlarged milk fat globule membranes and altered fatty acid metabolism. Further, our study supports the theory that PFAS share mammary epithelial membrane transport mechanisms with fatty acids and associate with metabolic markers of reduced milk production.

Gene biomarkers in estuarine oysters indicate pollution profiles of metals, brominated flame retardants, and poly- and perfluoroalkyl substances in and near the Laizhou Bay

The Laizhou Bay (LZB) is of ecological and fishery importance. The discharge of effluents containing numerous pollutants into the LZB via rivers poses significant risks to ecosystem and human health. Estuarine biomonitoring is therefore crucial for assessing the contribution of rivers to coastal pollution and their impacts on species. Estuarine oyster Crassostrea gigas is a preferable bioindicator to pollution conditions. This study measured accumulation of contaminants and expression levels of gene biomarkers in the LZB and Northern Shandong Peninsula (NSP) oysters. The LZB oysters accumulated higher levels of brominated flame retardants (BFRs) and poly- and perfluoroalkyl substances (PFAS), while NSP oysters exhibited greater accumulation of heavy metals. Decabromodiphenyl ethane was the dominant BFR, while perfluorooctanoic acid and perfluoro-2-methoxyacetic acid were the dominant PFASs in oysters. The expression of gene biomarkers effectively distinguished the LZB and NSP oysters, with CYP2 subfamilies expression correlating with BFRs and PFASs and metallothionein expression indicating heavy metals. The reproductive endocrine and neuroendocrine-immune systems in oysters might be the targets of BFRs and heavy metal pollution, respectively. The negative correlation between contaminant accumulation and gene expression might be explained by adaptive evolution, emphasizing the need to consider genetic diversity in ecological risk assessments.

Concentration-dependent cellular responses of coontail (Ceratophyllum demersum) during the substitutions to perfluorooctanoic acid by its two alternatives

The substitutions of alternatives to legacy per- and polyfluoroalkyl substances (PFASs) may lead to unknown and variational joint toxicity on ecosystems. To comprehensively understand the effects of substitutions on aquatic ecosystems, the single and joint effects of perfluorooctanoic acid (PFOA) and its alternatives (perfluorobutanoic acid, PFBA; 2,3,3,3-tetrafluoro-2-(1,1,2,2,3,3,3,heptafluoropropoxy)propanoic acid, GenX) with various concentrations and compositions on a primary producer, coontail (Ceratophyllum demersum), were investigated at cellular level. Results showed that the substitutions of PFBA/GenX could alleviate the inhibition of PFOA on plant length, hydrogen peroxide accumulation, and chlorophyll b, due to the shifts of reactive oxygen species and their less toxicity to antioxidants. Significant up-regulations of superoxide dismutase, glutathione, and carotenoid implied their primary roles in defensing against PFASs (p<0.05). Catalase/peroxidase was significantly up-regulated in PFBA/GenX substitutions (p<0.05) to help alleviate stress. PFBA substitutions reduced 23.9% of PFOA in organelle and GenX reduced the subcellular concentrations of PFOA by 1.8%–17.4%. Redundancy analysis suggested that PFOA, PFBA, and GenX in cell wall and organelle, as well as GenX in soluble fractions, were responsible for the cellular responses. These findings were helpful to understand the integrated effects on aquatic ecosystems during the substitutions to legacy PFASs by alternatives.

Association between Serum Per- and polyfluoroalkyl Substances Levels and Metabolic Dysfunction-associated Steatotic Liver Disease

Experimental evidences have suggested that Per- and polyfluoroalkyl substances (PFASs) were hepatotoxicity, but epidemiologic inconsistencies. There were 1751 participants included in this study after excluding chronic hepatitis, cirrhosis, excessive alcohol drinkers, and those with missing key variables. Totally 30 PFASs were quantified using ultrahigh-pressure liquid chromatography tandem mass spectrometer (UPLC-MS). Metabolic dysfunction-associated steatotic liver disease (MASLD) defined as the presence of hepatic steatosis diagnosed on abdominal B-ultrasound in conjunction with at least one cardiometabolic risk factors (CMRF) and without other discernible cause. After multivariate adjustment, perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluoroalkyl carboxylates (ΣPFCAs), and perfluoroheptanoic acid (PFHpA) were positively associated with the risk of MASLD. Specifically, for each natural log-transformed unit increase in PFOA, PFNA, and ΣPFCAs, the risk of MASLD increased by 27% (95% confidence interval (CI): 1.09-1.48), 10% (95% CI: 0.99-1.23), and 29% (95% CI: 1.09-1.53), respectively. Compared with those in Tertile 1 of PFOA, PFNA, and ΣPFCAs, the risk of MASLD was increased by 35% (95% CI: 1.06-1.71, Ptrend = 0.019), 46% (95% CI: 1.15 - 1.85, Ptrend = 0.0018), and 43% (95% CI: 1.13-1.82, Ptrend = 0.0032) in Tertile 3, respectively. For PFHpA (detection rate: 14.79%), individuals with PFHpA levels above the detection limit had increased risk of MASLD by 54% (95% CI: 1.17-2.01) compared with those with PFHpA levels below the detection limit. While 8:2 chlorinated polyfluoroethersulfonic acid (8:2 Cl-PFESA) was inversely associated with steatotic liver disease (SLD) combined with 4 or 5 CMRFs (odds ratio per ln-unit = 0.87, 95% CI: 0.77-0.99). Mixed exposure analysis showed PFNA manifested a significant positive effect, while PFUdA had a significant negative effect. No association was found between other PFASs and MASLD prevalence. More prospective studies are needed to validate our conclusions.

Adsorption of perfluorosulfonic acids (PFSAs) on an ultrafine potato peel waste grafted β-cyclodextrin (UFPPW-β-CD)

Per- and polyfluoroalkyl substances are widely used in various consumer products. However, these compounds can cause various harm to the environment and health. Considering the high chemical stability, these compounds are not completely removed from the aqueous environment, and consequently, recent studies have detected their presence in water bodies. In this scenario, biomass-based adsorbents are promising. β-cyclodextrin (β-CD) was grafted in an ultrafine potato peel waste (UFPPW) to produce a novel, efficient and sustainable adsorbent (UFPPW-β-CD) that was used to remove three different perfluorosulfonic acids (PFSAs) from water. The efficient grafting was proved by several characterization techniques, which also demonstrated the main UFPPW-β-CD features. The UFPPW-β-CD was efficient for all PFSAs (perfluorohexanesulfonic acid (PFHxS), perfluoropentanesulfonic acid (PFPeS), and perfluorobutanesulfonic acid (PFBS)), with removal percentage higher than 74 %. The increase in the CF chain of PFSAs favored the adsorption due to the host–guest hydrophobic interactions between the CF chains of the adsorbates and the hydrophobic cavity of the β-CD. Removal percentages and adsorption capacities at pH 3.0 were 74.6 % (49.92 µg g−1) to the PFBS, 82.6 % (65.66 µg g−1) to the PFPeS, and 90 % (100.89 µg g−1) to the PFHxS. The kinetic followed the General order model, while the equilibrium agreed with the Sips isotherm. The adsorption capacity increased with the increase in the CF chain of the adsorbate, but the adsorption rate followed the opposite trend. PFSAs adsorption on the UFPPW-β-CD adsorbent was favorable and exothermic. UFPPW-β-CD could be used seven times, keeping its maximum adsorption capacity constant using ultrasound-assisted desorption. It can be concluded that UFPPW-β-CD is a sustainable adsorbent to uptake PFSAs from water, and this process is dependent on the size of the CF chains.

The oral acute toxicity of per- and polyfluoroalkyl compounds (PFASs) to Rat and Mouse: a mechanistic interpretation and prioritization analysis of untested PFASs by QSAR, q-RASAR and interspecies modelling methods

Per- and polyfluoroalkyl substances (PFASs) are widely used in modern industry, causing many adverse effects on both the environment and human health. In this study, for the first time, we followed OECD guidelines to systematically investigated the quantitative structure-activity relationship (QSAR) of the oral acute toxicity of PFASs to Rat and Mouse using simple 2D descriptors. The Read-Across similarity descriptors and 2D descriptors were also combined to develop the quantitative-read across structure activity relationship (q-RASAR) models. Interspecies toxicity (iST) correlation was also explored between the two rodent species. All developed QSAR, q-RASAR and iST models met the state-of-the-art validation criteria and were applied for toxicity predictions of hundreds of untested PFASs in true external sets. Subsequently, we performed the priority ranking of the untested PFASs based on the model predictions, with the mechanistic interpretation of the top 20 most toxic PFASs predicted by both QSAR and q-RASAR models. The two univariate iST models were also used for filling the interspecies toxicity data gap. Overall, the developed QSAR, q-RASAR and iST models can be used as effective tools for predicting the oral acute toxicity of untested PFASs to Rat and Mouse, thus being important for risk assessment of PFASs in ecological environment.

Association between per- and polyfluoroalkyl substance exposures and thyroid homeostasis parameters

Abstract Context Prevailing studies have shown the disruption effect of per- and polyfluoroalkyl substances (PFAS) on thyroid homeostasis. However, most studies focused on individual thyroid hormones. Objective To explore the associations between PFAS exposures and thyroid homeostasis parameters. Methods A total of 2386 adults from NHANES (2007-2008 and 2011-2012) were included. Thyroid homeostasis parameters included central and peripheral thyroid hormone sensitivity, calculated by thyroid hormones. Multivariable survey-weighted linear regressions were performed to determine the association between PFAS exposure and thyroid homeostasis parameters. The weighted quantile sum (WQS) and the quantile g-computation (QGC) models were used to estimate the mixed effects of co-exposures to PFAS. Results The ratio of free triiodothyronine/free thyroxine (FT3/FT4) and the sum activity of peripheral deiodinases (SPINA-GD) were positively associated with perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid, perfluorononanoic acid and perfluorohexane sulfonic acid, respectively. However, no significant associations were observed between PFAS exposure and central thyroid sensitivity parameters. PFAS co-exposures was positively associated with FT3/FT4 (β = 0.013, P &amp;lt; 0.001) and SPINA-GD (β = 1.230, P &amp;lt; 0.001) in WQS models. Consistently, PFAS concentrations per quantile was linked to an increase in FT3/FT4 (β = 0.004, P = 0.002) and SPINA-GD (β = 0.392, P = 0.008) in GQC models, with PFOA having the highest weight in all models. Conclusion This study revealed that PFAS exposures may affect peripheral thyroid hormone sensitivity instead of central among U.S. general adults, enhancing our understanding of the correlation between PFAS exposure and thyroid hormones and providing insights into potential health implications.

Sex-specific association of per- and polyfluoroalkyl substances (PFAS) exposure with vitamin D concentrations in older adults in the USA: an observational study

Sex-specific association of per- and polyfluoroalkyl substances (PFAS) exposure with vitamin D concentrations in older adults in the USA: an observational study

The efficacy of wastewater treatment plant on removal of perfluoroalkyl substances and their impacts on the coastal environment of False Bay, South Africa

AbstractPer- and polyfluoroalkyl substances (PFASs), which have their origins in both industrial processes and consumer products, can be detected at all treatment stages in wastewater treatment plants (WWTPs). Quantifying the emissions of PFAS from WWTPs into the marine environment is crucial because of their potential impacts on receiving aquatic ecosystems. In this study, the levels of five PFAS were measured in both influent and effluent sewage water samples obtained from a municipal WWTP, the discharges of which flow into False Bay, on the Indian Ocean coast of Cape Town, South Africa. Additionally, seawater, sediment, and biota samples from eight sites along the False Bay coast were also analysed. Results showed high prevalence of PFAS in the different environmental matrices. Perfluorononanoic acid was most dominant in all these matrices with maximum concentration in wastewater, 10.50 ng/L; seawater, 18.76 ng/L; marine sediment, 239.65 ng/g dry weight (dw); invertebrates, 0.72–2.45 µg/g dw; seaweed, 0.36–2.01 µg/g dw. The study used the chemical fingerprint of five PFASs detected in WWTP effluents to track their dispersion across a large, previously pristine marine environment and examined how each chemical accumulated in different marine organisms. The study also demonstrates that primary and secondary wastewater treatment processes cannot fully remove such compounds. There is thus a need to improve effluent quality before its release into the environment and promote continuous monitoring focusing on the sources of PFAS, including their potential transformation products, their environmental fate and ecological risks, particularly in areas receiving effluents from WWTP.