Sulfonic Acid Content Research Articles

Quantifying sources of variability in fish bioaccumulation factor estimates for perfluoro-n-octane sulfonic acid: study design effects and implications for water quality criteria

Abstract Numeric water quality criteria development approaches for the protection of aquatic life and human health incorporate bioaccumulation factors (BAFs) as key exposure pathways. These are typically derived from field-collected tissue and ambient water concentration data, and are often highly variable within and across species. Existing guidance for conducting BAF field studies is necessarily general to accommodate research objectives, ecosystem characteristics, and the chemicals and species of interest. However, the direction on evaluating study quality and understanding of the relative influence of study design components on BAFs is limited. We used a large, publicly available dataset of perfluoro-n-octane sulfonic acid (PFOS) concentrations in water and fish tissue to (1) evaluate overall patterns and drivers of water and fish tissue PFOS concentrations and derived BAFs, and (2) quantify how biological, environmental, and study design factors regarding water and tissue samples affect derived BAFs. PFOS tissue concentrations and BAFs differed significantly with species and, although variable, there was a significant positive relationship between PFOS water and fish tissue concentrations. Using biological, environmental, and study design variables, boosted regression tree analyses showed that spatial proximity between water and fish tissue sampling locations was the primary driver of BAF variability owing to large differences in water concentrations across hydraulically connected sites. Other variables, including temporal proximity between samples and biological and environmental factors, were less influential relative to spatial proximity. Our findings demonstrate that BAF study design decisions can have significant implications for key water quality criteria derivation components and highlight the need for sampling regimes that accurately characterize exposure to improve the quality of BAFs used in risk assessment and the development of regulatory standards.

Maternal transfer and sex-differences in brain bioaccumulation for Northern bobwhite quail (Colinus virginianus) exposed to per- and poly-fluoroalkyl substances

Per- and poly-fluoroalkyl substances (PFAS) are highly persistent chemicals commonly found in surface protectants, and class B aqueous film forming foams (AFFF), and many other consumer and industrial products. As a result of their widespread application and use, PFAS are now found in environmental media across the globe. Research has revealed that exposure to environmentally relevant concentrations of PFAS can reduce reproductive success and have immunological effects in laboratory animals, including birds. Further, PFAS can be passed down from parents to offspring, posing a threat to sensitive life stages. PFAS may enter the brain by disrupting tight junctions or binding to transporters, but our overall understanding of the interactions and accumulation of PFAS in the avian brain is limited due to the lack of data. We obtained archived samples of male-female pairs of Northern bobwhite quail (NBWQ) from chronic toxicity studies where adults were exposed to either individual PFAS or binary mixtures through drinking water for at least 60 days. PFAS were detected in the brains of exposed adult quail, while brains from control birds had only occasional detections of PFAS; mostly perfluorooctane sulfonic acid (PFOS), likely because our source of birds was pen-raised animals and many PFAS are ubiquitous. Despite similar average daily intake (ADI) for both males and females, we observed higher concentrations of most PFAS in the brains of male birds compared to female birds, with the exception of perfluoroheptanoic acid (PFHpA). For the binary mixture exposures, PFOS appeared to reduce brain concentrations of perfluorohexane sulfonic acid (PFHxS) in both males and females to levels that could not be explained by ADI differences alone. Collectively, study results demonstrated that brain accumulation of short-chain PFAS in birds was not significantly affected by sex, however, long-chain PFAS exposure resulted in avian brain accumulation with generally higher PFAS concentrations in males compared to females. The findings of this study offer insights into the accumulation of PFAS in the avian brain and suggest that there may be sex differences in potential risks associated with exposure to these pervasive chemicals.

Fate and partition of perfluoroalkyl acids (PFAAs) driven by particles in mangrove ecosystems: Mechanistic insights and environmental implications

A critical gap in understanding emerging pollutants in mangrove ecosystems should be addressed. Despite their ecological importance, the state of environmental quality in fragmented mangrove patches, especially emerging contaminants, remains largely uncharted. Our research presented an in-depth analysis of the distribution of perfluoroalkyl acids (PFAAs) across porewater, suspended particles, and sediment in these small, fragmented mangroves, revealing the mechanisms behind their distribution. The findings indicated that PFAA concentrations in sediments were generally lower than in suspended particles, except for C12–C14 perfluorinated carboxylic acids (PFCAs) and C4–C6 perfluorinated sulfonic acids (PFSAs). A comparison of contamination levels in different mangrove patches concurred with conventional water quality assessments and crab burrow surveys, showing that large artificially planted patches were less contaminated, while areas with intense human activity were more polluted. Notably, no significant differences were observed in the concentrations of long-chain PFAAs and PFCAs between patches (p > 0.1). Elevated crab burrowing activity and higher concentrations of perfluorobutanoic acid (PFBA) and perfluorohexane sulfonic acid (PFHxS) in suspended particles in low intertidal zones suggested that seafood, particularly crabs and shellfish, might be at risk of PFAA pollution. Rainfall-runoff was identified as the primary source of PFAA pollution in porewater and suspended particle systems in these areas. The transport of PFAAs and organic carbon in mangroves was influenced by the concentrations and properties of suspended particles. These insights were critical for developing targeted environmental management strategies to mitigate the impact of PFAAs and preserve the ecological integrity of mangrove ecosystems.

Conversion of chicory to valuable chemical LA and by-products with LABSA and BSA

This work examined the hydrothermal breakdown of biomass to platform chemicals, including acetic acid (AA), formic acid (FA), 5-hydroxy methylfurfural (5-HMF), and levulinic acid (LA). Chicory was selected as feedstock bacause of high potential to produce . Reactions were performed with BSA (Benzenesulfonic acid) and LABSA (Linear alkyl benzene sulfonic acid) as sulfonic acid catalysts. The studies were conducted with different catalyst concentrations (100, 300, and 600 mM) for 110 minutes at 200 °C with a biomass to solvent ratio of 1g/25 mL. The variation of product yield and composition on parameters such as time, sulfonic acid concentration and type were investigated. The maximum levulinic acid yields (wt.%) achieved through the experiments of this study were 23.95 wt.% (9.58 g/L) for 600 mM BSA and 85.93 wt.% (34.37 g/L) for 600 mM LABSA at 200 °C. Highest carbon-based yields of levulinic acid were obtained with 300 mM LABSA and 100 mM BSA.

Introducing sulfonic acid polymers into MOF nanochannels for ultra-high Ba2+ adsorption capacity and proton conductivity

Porous materials with a high concentration of sulfonic acid groups are highly desirable for applications such as radioactive Ba2+ adsorption, catalysis, and proton-conductive materials, but they are also challenging to synthesize. In this work, we introduce polymers containing sulfonic acid groups into the nanochannels of metal–organic frameworks (MOFs) through in-situ synthesis to enhance the sulfonic acid content. We use a alkene with sulfonic acid groups (2)-acrylamido-2-methylpropane sulfonic acid, AMPS) and a crosslinking agent N,N’-methylenebisacrylamide (MBAA) to synthesize two MOF composites, PAMPS@MIL-101 and PAMPS@MIL-101-SO3H, in the ultra-stable MIL-101 series through in-situ polymerization with free radical initiators. The two MOF composites have a high and uniform distribution of sulfonic acid groups in the MOF framework, which results in ultra-high barium ion adsorption capacity. The maximum adsorption amounts are 142.7 and 356.9 mg·g−1 for PAMPS@MIL-101 and PAMPS@MIL-101-SO3H, respectively, which are higher than those of most reported adsorbents. Importantly, the adsorption equilibrium can be achieved within 20 min. Moreover, both MOF composites, PAMPS@MIL-101 and PAMPS@MIL-101-SO3H, exhibit super proton conductivity, with values of 6.43 × 10−2 S·cm−1 and 1.43 × 10−1 S·cm−1 at 85 °C and 98 % RH, respectively. This method offers a new way of modifying MOF nanochannels with high sulfonic acid concentrations, and opens up new opportunities for developing radioactive Ba2+ adsorption materials and proton-conductive materials.

Assessment of World’s First Two Polymer Injectivity Tests Performed in Two Giant High-Temperature/High-Salinity Carbonate Reservoirs Using Single-Well Simulation Models and Pressure Falloff Tests Analysis

Summary Polymer flooding is a mature enhanced oil recovery (EOR) technology that has been widely implemented around the world for more than 60 years. Polymer flooding mostly targets medium- to high-permeability sandstone reservoirs with moderate salinity, hardness, and temperatures. However, in the last few years, the envelope of polymer flooding has been expanded to harsher reservoir conditions of high-temperature and high-salinity mixed-wet to oil-wet heterogeneous carbonate reservoirs. Development of novel polymers and innovative field application concepts has allowed for the reconsideration of polymer-based EOR as a promising technology to improve sweep efficiency for these challenging reservoirs. Polymer injectivity is one of the key challenges for polymer flooding projects and requires a rigorous derisking program that includes laboratory and field testing. A comprehensive laboratory program was designed to assess and investigate polymer thermal stability, polymer rheology in porous media, adsorption, and injectivity using reservoir core samples. In addition, two polymer injectivity tests (PITs) were performed in two giant light oil (0.3 cp) carbonate reservoirs in onshore Abu Dhabi under harsh conditions of high salinity (>200 g/L), high divalent ions (>20 g/L), high temperature (>250°F), and H2S concentration of up to 40 ppm. The polymer used during the two PITs (PIT 1 2019 and PIT 2 2021) is a new generation of EOR polymer (SAV 10) with high 2-acrylamido-tertiary-butyl sulfonic acid content that was specifically developed to tolerate such harsh conditions. This paper is focused on the interpretation of the PITs and lessons learned for future polymer-based EOR projects. The detailed data acquired in both tests were used to evaluate the polymer injectivity at representative field conditions and in-depth mobility reduction. The PITs together with the extensive laboratory studies are part of a thorough derisking program for the upcoming world’s first innovative hybrid EOR multiwell pilots—simultaneous injection of miscible gas and polymer (SIMGAP) and simultaneous injection of water and polymer (SIWAP). Both PITs are composed of three stages that include a multirate waterflood baseline, polymer injection using different rates, and polymer concentrations followed by extended chase waterflooding. In addition, a sequence of multiple pressure falloff (PFO) tests was acquired during the PIT executions and analyzed to obtain the required uncertainty parameters for the history-matching exercise. Polymer preshearing was considered as part of both PIT programs with the aim to homogenize the polymer molecular weight distribution and reduce possible shear-thickening effects near the wellbore as per laboratory measurements. Two single-well 3D simulation models were built to incorporate the information from polymer laboratory studies and to interpret the large field data sets acquired during the PITs. Lessons learned from PIT 1 allowed us to optimize the PIT 2 design program and achieve better understanding of polymer characteristics. The interpretation of the pressure transient analysis (PTA) of the PFO tests and the 3D simulation models of the two PITs confirmed the generation of polymer banks and demonstrated effective propagation of the polymer into the reservoirs at target concentrations and representative rates of the future SIWAP and SIMGAP interwell pilots.

Study of Electrical and Mechanical Properties of Polypyrrole-Coated Three-Dimensional Spacer Fabric

In this study, the liquid phase oxidative polymerization method was utilized to prepare polypyrrole conductive three-dimensional spacer fabrics. By controlling pyrrole solution, oxidant FeCl3 solution, dopant p-toluene sulfonic acid concentration and reaction time, the optimal process for the preparation of conductive spacer fabrics was obtained. This led to the best preparation process of polypyrrole-coated three-dimensional spacer conductive fabric (polypyrrole/three-dimensional spacer fabrics) being obtained. The results showed that the conductive properties of polypyrrole/three-dimensional spacer fabrics were the best when 0.10 mol/L pyrrole, 0.40 mol/L oxidant FeCl3 solution, and 0.40 mol/L dopant p-toluene sulfonic acid were prepared within a 2-h reaction time. The properties of polypyrrole/three-dimensional spacer fabrics were analyzed using the results from surface resistance, Fourier transform-infrared spectroscopy, mechanical properties, and stability tests. The results showed that polypyrrole was well attached to the three-dimensional spacer fabric surface, and the concentration of polypyrrole in the fabric exhibited an inverse correlation with changes in surface resistance. The mechanical properties of polypyrrole/three-dimensional spacer fabrics after treatment exhibit superior performance, with consistent changes in the meridional and zonal electrical properties during tensile testing and can maintain excellent long-term electrical stability in atmospheric environments.

Elevated levels of serum per- and poly-fluoroalkyl substances (PFAS) in contact lens users of U.S. young adults

Despite evidence indicating the presence of per- and poly-fluoroalkyl substances (PFAS) in contact lenses (CL), it remains unclear whether CL use increases PFAS exposure in the general population. We aimed to determine whether CL users have higher serum concentrations of PFAS than non-users, using data of 1660 adults aged 20–39 years participating in the National Health and Nutrition Examination Survey 1999–2000 and 2003–2008. We classified the individuals into CL users and non-users using the record of vision correction types during a vision test. Serum concentrations of six individual PFAS were measured, and the overall PFAS burden was calculated by item response theory scoring. Survey-weighted linear models were used to compare serum PFAS levels between CL users and non-users after adjusting for covariates. Distributions of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) concentrations were compared with reference values (e.g., human biomonitoring [HBM]-II values) indicating potential for adverse health effects. Survey-weighted linear models revealed that covariate-adjusted serum PFOA concentration was higher in CL users (geometric mean [GM]: 3.68 ng/mL; 95% CI: 3.00, 4.50) than in non-users (GM: 3.27 ng/mL; 95% CI: 2.81, 3.80; p = 0.02). Similarly, CL users had a significantly higher serum PFHxS concentration (GM: 1.58 ng/mL; 95% CI: 1.13, 2.20) than non-users (GM: 1.30 ng/mL; 95% CI: 1.10, 1.66; p = 0.03). CL users also had a significantly higher overall burden of PFAS than non-users. The differences in PFAS concentrations between CL users and non-users were more pronounced in females than in males. Moreover, a larger proportion of lens users (4.5%), compared to non-users (3.9%), had PFOA concentrations above the HBM-II, where adverse health effects are expected from PFOA exposure. This study suggests that CL use in general U.S. young adults may contribute significantly to PFAS body burden, which can potentially lead to public health problem.

Transport and dispersion of PFOA and PFOS in the Black Sea

A 3-D transport and dispersion model was applied to study the recent past and future dynamics of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) concentrations in the Black Sea for the 2016–2030 period. The modelled surface concentrations show a distinct seasonal behaviour, shaped by winter to spring convective mixing. A significant increasing long-term trend in PFOS concentrations is established, with concentrations in water layers 200 m below the surface increasing at 4–8% per year. Driving mechanisms for PFOA and PFOS transport and accumulation in the subsurface and deeper layers are the cooling of the surface water in winter and the transport of water masses from the North Western Shelf (NWS) of the Black Sea. A simulated 50% phase-out of PFOA and PFOS from 2020 to 2030 shows a 21% reduction in PFOA, while PFOS continues to increase.

Fast proton conductors for low humidity: hydrophilic sulfonated and phosphonated polysilsesquioxanes with Al-O-P crosslinks.

Proton-conducting polysilsesquioxane oligomers with core-shell structures consisting of hydrophilic silica-rich cores surrounded by an organic layer with sulfonic and phosphonic acid groups were synthesized. They were crosslinked by mixing with phosphoric acid and aluminum ions to form a hydrophilic Al-O-P framework. The resulting polymers were clear, uniform, flexible, and exhibited a high proton conductivity above 100 °C in non-humidified low-humidity air (∼22 mS cm-1 at 120 °C and ∼1%RH) because of their high sulfonic acid concentration and high water retention capability.

Interaction between the oxidative balance score and serum per- and poly-fluoroalkyl substances (PFASs) on liver health: analysis of the NHANES 2007-2018 dataset.

Per- and poly-fluoroalkyl substances (PFASs) are pervasive synthetic compounds, prompting investigations into their intricate interactions with lifestyle factors and health indicators because of their enduring environmental presence and bioaccumulation. This study aimed to explore the effects of the oxidative balance score (OBS) and PFAS on liver-related indices. Twenty dietary and lifestyle factors were used to calculate the OBS. The serum concentrations of PFASs were measured, and their sum was calculated for analysis. The levels of liver markers were also evaluated. Linear regression models and interaction analyses were used to assess the associations between OBS, PFAS concentrations, and liver indices. The results revealed an inverse association between high OBS and perfluorooctane sulfonic acid concentration, as well as the sum of PFAS concentrations. OBS was positively associated with liver markers. The PFAS concentrations were positively associated with total bilirubin, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels. Interaction analyses revealed significant interactions between OBS and specific PFASs for alkaline phosphatase (interaction P < 0.05). Possible interactions were also found between OBS and specific PFASs for ALT, and AST levels (interaction P < 0.10). This study clarified the association between total PFAS and OBS. This association was significant mainly for diet-related OBS. PFAS and OBS are associated with liver-related indicators in the blood.

Gel-state polybenzimidazole proton exchange membranes with flexible alkyl sulfonic acid side chains for a wider operating temperature range (25–240 °C)

High-temperature proton exchange membrane fuel cells (HT-PEMFC) possess distinct technical advantages of high output power, simplified water/heat management, increased tolerance to fuel impurities and diverse fuel sources, within the temperature range of 120–200 °C. However, for practical automobile applications, it was crucial to broaden their low-temperature operating window and enable cold start-up capability. Herein, gel-state phosphoric acid (PA) doped sulfonated polybenzimidazole (PBI) proton exchange membranes (PEMs) were designed and synthesized via PPA sol-gel process and in-situ sultone ring-opening reactions with various proton transport pathways based on absorbed PA, flexible alkyl chain connected sulfonic acid groups and imidazole sites. The effects of flexible alkyl sulfonic acid side chain length and content on PA doping level, proton conductivity, and membrane stability under different temperature and relative humidity (RH) were thoroughly investigated. The prepared gel-state membranes contained a self-assembled lamellar and porous structure that facilitated the absorption of a large amount of PA with rapid proton transporting mechanisms. At room temperature, the optimized membrane exhibited a proton conductivity of 0.069 S cm−1, which was further increased to 0.162 and 0.358 S cm−1 at 80 and 200 °C, respectively, without additional humidification. The most significant contribution of this work was demonstrating the feasibility of gel-state sulfonated PBI membranes in expanding HT-PEMFC application opportunities over a wider operating range of 25 to 240 °C.

Folate concentrations and serum perfluoroalkyl and polyfluoroalkyl substance concentrations in adolescents and adults in the USA (National Health and Nutrition Examination Study 2003–16): an observational study

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a family of highly fluorinated aliphatic compounds, which are widely used in commercial applications, including food packaging, textiles, and non-stick cookware. Folate might counteract the effects of environmental chemical exposures. We aimed to explore the relationship between blood folate biomarker concentrations and PFAS concentrations. This observational study pooled cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) 2003 to 2016 cycles. NHANES is a population-based national survey that measures the health and nutritional status of the US general population every 2 years by means of questionnaires, physical examination, and biospecimen collection. Folate concentrations in red blood cells and in serum, and perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS) concentrations in serum were examined. We used multivariable regression models to assess the percentage change in serum PFAS concentrations in relation to changes in folate biomarker concentrations. We additionally used models with restricted cubic splines to investigate the shape of these associations. This study included 2802 adolescents and 9159 adults who had complete data on PFAS concentrations, folate biomarkers, and covariates, were not pregnant, and had never had a cancer diagnosis at the time of the survey. The mean age was 15·4 years (SD 2·3) for adolescents and 45·5 years (17·5) for adults. The proportion of male participants was slightly higher in adolescents (1508 [54%] of 2802 participants) than in adults (3940 [49%] of 9159 participants). We found negative associations between red blood cell folate concentrations and serum concentrations of PFOS (percentage change for a 2·7 fold-increase in folate level -24·36%, 95% CI -33·21 to -14·34) and PFNA (-13·00%, -21·87 to -3·12) in adolescents, and PFOA (-12·45%, -17·28 to -7·35), PFOS (-25·30%, -29·67 to -20·65), PFNA (-21·65%, -26·19 to -16·82), and PFHxS (-11·70%, -17·32 to 5·70) in adults. Associations for serum folate concentrations and PFAS were in line with those found for red blood cell folate levels, although the magnitude of the effects was lower. Restricted cubic spline models suggested linearity of the observed associations, particularly for associations in adults. In this large-scale, nationally representative study, we found consistent inverse associations for most examined serum PFAS compounds in relation to folate concentrations measured in either red blood cells or serum among both adolescents and adults. These findings are supported by mechanistic in-vitro studies that show the potential of PFAS to compete with folate for several transporters implicated in PFAS toxicokinetics. If confirmed in experimental settings, these findings could have important implications for interventions to reduce the accumulated PFAS body burden and mitigate the related adverse health effects. United States National Institute of Environmental Health Sciences.

Associations of Gestational Perfluoroalkyl Substances Exposure with Early Childhood BMI -Scores and Risk of Overweight/Obesity: Results from the ECHO Cohorts.

Gestational per- and polyfluoroalkyl substances (PFAS) exposure may be associated with adiposity and increased risk of obesity among children and adolescents. However, results from epidemiological studies evaluating these associations are inconsistent. We estimated the associations of pregnancy PFAS concentrations with child body mass index (BMI) -scores and risk of overweight/obesity in eight U.S. cohorts. We used data from 1,391 mother-child pairs who enrolled in eight Environmental influences on Child Health Outcomes (ECHO) cohorts (enrolled: 1999-2019). We quantified concentrations of seven PFAS in maternal plasma or serum in pregnancy. We measured child weight and height between the ages of 2 and 5 y and calculated age- and sex-specific BMI -scores; 19.6% children had more than one BMI measurement. We estimated covariate-adjusted associations of individual PFAS and their mixture with child BMI -scores and risk of overweight/obesity using linear mixed models, modified Poisson regression models, and Bayesian approaches for mixtures. We explored whether child sex modified these associations. We observed a pattern of subtle positive associations of PFAS concentrations in pregnancy with BMI -scores and risk of overweight/obesity. For instance, each doubling in perfluorohexane sulfonic acid concentrations was associated with higher BMI -scores (; 95% CI: 0.01, 0.12). Each doubling in perfluroundecanoic acid [; 95% CI: 1.04, 1.16] and -methyl perfluorooctane sulfonamido acetic acid (; 95% CI: 1.00, 1.12) was associated with increased risk of overweight/obesity, with some evidence of a monotonic dose-response relation. We observed weaker and more imprecise associations of the PFAS mixture with BMI or risk of overweight/obesity. Associations did not differ by child sex. In eight U.S.-based prospective cohorts, gestational exposure to higher levels of PFAS were associated with slightly higher childhood BMI -score and risk of overweight or obesity. Future studies should examine associations of gestational exposure to PFAS with adiposity and related cardiometabolic consequences in older children. https://doi.org/10.1289/EHP11545.

Association of Early Pregnancy Perfluoroalkyl and Polyfluoroalkyl Substance Exposure With Birth Outcomes

Prenatal perfluoroalkyl and polyfluoroalkyl substances (PFAS) have been linked to adverse birth outcomes. Previous research showed that higher folate concentrations are associated with lower blood PFAS concentrations in adolescents and adults. Further studies are needed to explore whether prenatal folate status mitigates PFAS-related adverse birth outcomes. To examine whether prenatal folate status modifies the negative associations between pregnancy PFAS concentrations, birth weight, and gestational age previously observed in a US cohort. In a prospective design, a prebirth cohort of mothers or pregnant women was recruited between April 1999 and November 2002, in Project Viva, a study conducted in eastern Massachusetts. Statistical analyses were performed from May 24 and October 25, 2022. Plasma concentrations of 6 PFAS compounds were measured in early pregnancy (median gestational week, 9.6). Folate status was assessed through a food frequency questionnaire and measured in plasma samples collected in early pregnancy. Birth weight and gestational age, abstracted from delivery records; birth weight z score, standardized by gestational age and infant sex; low birth weight, defined as birth weight less than 2500 g; and preterm birth, defined as birth at less than 37 completed gestational weeks. The cohort included a total of 1400 mother-singleton pairs. The mean (SD) age of the mothers was 32.21 (4.89) years. Most of the mothers were White (73.2%) and had a college degree or higher (69.1%). Early pregnancy plasma perfluorooctanoic acid concentration was associated with lower birth weight and birth weight z score only among mothers whose dietary folate intake (birth weight: β, -89.13 g; 95% CI, -166.84 to -11.42 g; birth weight z score: -0.13; 95% CI, -0.26 to -0.003) or plasma folate concentration (birth weight: -87.03 g; 95% CI, -180.11 to 6.05 g; birth weight z score: -0.14; 95% CI, -0.30 to 0.02) were below the 25th percentile (dietary: 660 μg/d, plasma: 14 ng/mL). No associations were found among mothers in the higher folate level groups, although the tests for heterogeneity did not reject the null. Associations between plasma perfluorooctane sulfonic acid and perfluorononanoate (PFNA) concentrations and lower birth weight, and between PFNA and earlier gestational age were noted only among mothers whose prenatal dietary folate intake or plasma folate concentration was in the lowest quartile range. No associations were found among mothers in higher folate status quartile groups. In this large, US prebirth cohort, early pregnancy exposure to select PFAS compounds was associated with adverse birth outcomes only among mothers below the 25th percentile of prenatal dietary or plasma folate levels.

Association between prenatal or early postnatal exposure to perfluoroalkyl substances and language development in 18 to 36-month-old children from the Odense Child Cohort

BackgroundPerfluoroalkyl substances (PFAS) are persistent chemicals used in everyday consumer products leading to ubiquitous human exposure. Findings of impaired neurodevelopment after prenatal exposure to PFAS are contradictory and few studies have assessed the impact of postnatal PFAS exposure. Language development is a good early marker of neurodevelopment but only few studies have investigated this outcome separately. We therefore investigated the association between prenatal and early postnatal PFAS exposure and delayed language development in 18 to 36-month-old Danish children.MethodsThe Odense Child Cohort is a large prospective cohort. From 2010 to 2012 all newly pregnant women residing in the Municipality of Odense, Denmark was invited to participate. Concentration of perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA) were assessed in maternal serum collected in the 1st trimester of pregnancy and in child serum at 18 months. Parents responded to the Danish adaption of the MacArthur-Bates Communicative Development Inventories (MB-CDI) when their child was between 18 and 36 months. Language scores were converted into sex and age specific percentile scores and dichotomized to represent language scores above or below the 15th percentile. We applied Multiple Imputation by Chained Equation and conducted logistic regressions investigating the association between prenatal and early postnatal PFAS exposure and language development adjusting for maternal age, pre-pregnancy BMI, education and respectively fish intake in pregnancy or childhood and duration of breastfeeding in early postnatal PFAS exposure models.ResultsWe found no significant associations between neither prenatal nor early postnatal PFAS exposure and language development among 999 mother-child pairs.ConclusionIn this low-exposed cohort the finding of no association between early postnatal PFAS exposure and language development should be interpreted with caution as we were unable to separate the potential adverse effect of PFAS exposure from the well documented positive effect of breastfeeding on neurodevelopment. We, therefore, recommend assessment of child serum PFAS at an older age as development of the brain proceeds through childhood and even a small impact of PFAS on neurodevelopment would be of public health concern at population level due to the ubiquitous human exposure.

Newborn metabolomic signatures of maternal per- and polyfluoroalkyl substance exposure and reduced length of gestation

Marginalized populations experience disproportionate rates of preterm birth and early term birth. Exposure to per- and polyfluoroalkyl substances (PFAS) has been reported to reduce length of gestation, but the underlying mechanisms are unknown. In the present study, we characterized the molecular signatures of prenatal PFAS exposure and gestational age at birth outcomes in the newborn dried blood spot metabolome among 267 African American dyads in Atlanta, Georgia between 2016 and 2020. Pregnant people with higher serum perfluorooctanoic acid and perfluorohexane sulfonic acid concentrations had increased odds of an early birth. After false discovery rate correction, the effect of prenatal PFAS exposure on reduced length of gestation was associated with 8 metabolomic pathways and 52 metabolites in newborn dried blood spots, which suggested perturbed tissue neogenesis, neuroendocrine function, and redox homeostasis. These mechanisms explain how prenatal PFAS exposure gives rise to the leading cause of infant death in the United States.

Perfluorooctanoic acid dominates the molecular-level effects of a mixture of equal masses of perfluorooctanoic acid and perfluorooctane sulfonic acid in earthworm

Per- and polyfluoroalkyl substances (PFAS) are an important class of emerging contaminants in the environment. Most studies on the impact of PFAS mixtures considered phenotypic endpoints, which may not adequately reflect the sublethal effects on organisms. To fill this knowledge gap, we investigated the subchronic impact of environmentally relevant concentrations of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS)—as individual compounds and a mixture (PFOS+PFOA)—on earthworm (Eisenia fetida), using phenotypic and molecular endpoints. PFAS decreased the survival (12.2–16.3%), biomass (9.0–9.8%), and reproduction (15.6–19.8%) of E. fetida after 28 d of exposure. The bioaccumulation of PFOS after 28 d increased (from 2790.7 ng/g-dw to 5224.9 ng/g-dw) while that of PFOA decreased (from 780.2 ng/g-dw to 280.5 ng/g-dw) when E. fetida was exposed to the mixture compared to the individual compounds. These bioaccumulation trends were partly attributed to changes in the soil distribution coefficient (Kd) of PFOS and PFOA when present in the mixture. Eighty percent of the (p and FDR < 0.05) altered metabolites after 28 d were similarly perturbed by both PFOA and PFOS+PFOA. The pathways dysregulated are related to the metabolism of amino acids, energy, and sulfur. We showed that PFOA dominates the molecular-level impact of the binary PFAS mixture.

Distribution of per- and polyfluoroalkyl substances in blood, serum, and urine of patients with liver cancer and associations with liver function biomarkers

Studies have shown that per- and polyfluoroalkyl substances (PFASs) may be hepatotoxic in animals or humans. However, data on clinical epidemiology are very limited. In this study, 21 PFASs were determined in patients with liver diseases, with the highest median concentrations detected in the serum sample (26.7 ng/mL), followed by blood (10.7 ng/mL) and urine (5.02 ng/mL). Higher total PFAS concentrations were found in hepatocellular carcinoma (HCC) patients compared to non-HCC patients, with significant discrepancies in serum and blood samples. Besides, significant correlations were also found among PFAS concentrations and age, gender, body mass index (BMI), and liver function biomarkers levels. For example, PFAS concentrations are significantly higher in males than in females; Several serum PFASs concentrations increase with age and BMI, while the serum perfluorohexane sulfonic acid (PFHxS) concentrations are negatively correlated with age. In addition, multiple regression models adjusted for age, gender and BMI found that increased serum perfluorobutane sulfonic acid (PFBS), perfluoroheptane sulfonic acid (PFHpS) and perfluorohexylphosphonic acid (PFHxPA) conentrations are correlated with elevated alkaline phosphatase (ALP), aspartate aminotransferase (AST), and alpha-fetoprotein (AFP) (p < 0.05). Our results provide epidemiological support for the future study on the potential clinical hepatotoxicity of PFAS.

Association between prenatal and early postnatal exposure to perfluoroalkyl substances (PFAS) and IQ score in 7-year-old children from the Odense Child Cohort.

Perfluoroalkyl substances (PFAS) are persistent chemicals capable of crossing the placenta and passing into breastmilk. Evidence suggests that PFAS exposure may affect brain development. We investigated whether prenatal or early postnatal PFAS exposure was associated with IQ-scores in schoolchildren from the Odense Child Cohort, Denmark 2010 to 2020. We assessed perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA) concentrations in maternal serum collected in the 1st trimester of pregnancy and in child serum at age 18 months. At 7 years of age children completed an abbreviated version of Wechsler Intelligence Scale for Children version-V (WISC-V) from which Full Scale Intelligence Quotient (FSIQ) and Verbal Comprehension Index (VCI) were estimated. In multiple linear regressions among 967 mother-child pairs a doubling in maternal PFOS and PFNA concentrations was associated with lower FSIQ, while no significant associations were observed for PFOA, PFHxS or PFDA. PFAS concentrations at 18 months and duration of breastfeeding were strongly correlated and even in structural equation models it was not possible to differentiate the opposite effects of PFAS exposure and duration of breastfeeding on FSIQ. As PFAS exposure is ubiquitous association with even a small reduction in IQ is of public health concern.