A review of the pathways of human exposure to poly- and perfluoroalkyl substances (PFASs) and present understanding of health effects

Binary and quaternary mixtures of perfluoroalkyl substances (PFAS) differentially affect the immune response to influenza A virus infection

Per- and polyfluoroalkyl substances (PFAS) are anthropogenic organofluorine compounds that persist indefinitely in the environment and bioaccumulate throughout all trophic levels. Biomonitoring efforts have detected multiple PFAS in the serum of most people. Immune suppression has been among the most consistent effects of exposure to PFAS. PFAS often co-occur as mixtures in the environment, however, few studies have examined immunosuppression of PFAS mixtures or determined whether PFAS exposure affects immune function in the context of infection. In this study, mixtures containing two or four different PFAS and a mouse model of infection with influenza A virus (IAV) were used to assess immunotoxicity of PFAS mixtures. PFAS were administered via the drinking water as either a binary mixture of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) or quaternary mixture of PFOS, PFOA, perfluorohexane sulfonate (PFHxS), and perfluorononanoic acid (PFNA). The results indicated that the binary mixture affected the T-cell response, while the quaternary mixture affected the B-cell response to infection. These findings indicate that the immunomodulatory effects of PFAS mixtures are not simply additive, and that the sensitivity of immune responses to PFAS varies by cell type and mixture. The study also demonstrates the importance of studying adverse health effects of PFAS mixtures.

Association between PFAS exposure and thyroid health: A systematic review and meta-analysis for adolescents, pregnant women, adults and toxicological evidence

A burgeoning body of epidemiological and toxicological evidence suggests that thyroid health may be significantly impacted by exposure to both long- and short-chain perfluoroalkyl substances (PFAS) compounds. We conducted a meta-analysis to examine the association between 16 PFAS compounds and five thyroid hormones (TSH, TT3, TT4, FT3, and FT4) in the serum of a pregnant women, adolescents, and adults. The dose-response relationship between some PFAS and thyroid hormones in different population subpopulation was found and the model was fitted. We also amalgamated data from 18 animal experiments with previously published in vitro studies to elucidate the toxicological mechanisms underlying the impact of PFAS on the thyroid gland. The results of the study showed that (a) both conventional and emerging PFAS compounds were identified in human samples and exhibited associations with thyroid health outcomes; (b) in animal studies, PFAS have been found to impact thyroid gland health through two primary mechanisms: by influencing the hypothalamic-pituitary-thyroid axis and by binding to thyroid receptors. This study provides a systematic description of the health effects and risk assessment associated with PFAS exposure on the thyroid gland. Furthermore, dose-response relationships were established through the Hill model in python.

Exploring maternal and developmental toxicity of perfluoroalkyl ether acids PFO4DA and PFO5DoA using hepatic transcriptomics and serum metabolomics

Production of per- and polyfluoroalkyl substances (PFAS) has shifted from long-chain perfluoroalkyl acids to short-chain compounds and those with ether bonds in the carbon chain. Next-generation perfluoroalkylether PFAS include HFPO-DA ("GenX chemicals"), Nafion Byproducts, and the PFOx homologous series that includes perfluoro-3,5,7,9-butaoxadecanoic acid (PFO4DA) and perfluoro-3,5,7,9,11-pentaoxadodecanoic acid (PFO5DoA). PFO4DA and PFO5DoA have been detected in serum and/or tissues from humans and wildlife proximal to contamination point sources. However, toxicity data are extremely limited, with no in vivo developmental toxicology data. To address these data gaps, pregnant Sprague-Dawley rats were exposed via oral gavage to vehicle, PFO4DA, or PFO5DoA across a series of doses (0.1 to 62.5 mg/kg/day) from gestation day (GD) 18-22. Hepatic transcriptomics were assayed in dams and fetuses, and serum metabolomics in dams. These data were overlaid with serum PFO4DA and PFO5DoA concentrations to perform dose-response modeling. Both dams and fetuses exhibited dose-responsive disruption of hepatic gene expression in response to PFO4DA or PFO5DoA, with fetal expression disrupted at lower doses than dams. Several differentially expressed genes were upregulated by every dose of PFO5DoA in both maternal and fetal samples, including genes encoding enzymes that hydrolyze acyl-coA to free fatty acids. Maternal serum metabolomics revealed PFO4DA exposure did not induce significant changes at any tested dose, whereas PFO5DoA exposure resulted in dose-dependent differential metabolite abundance for 149 unique metabolites. Multi-omics pathway analyses of integrated maternal liver transcriptomics and serum metabolomics revealed significant convergent changes as low as 3 mg/kg/d PFO4DA and 0.3 mg/kg/d PFO5DoA exposure. Overall, transcriptomic and metabolomic effects of PFO4DA and PFO5DoA appear consistent with other carboxylic acid PFAS, with primary changes related to lipid metabolism, bile acids, cholesterol, and cellular stress. Importantly, PFO5DoA exposure more potently induced changes in maternal and fetal hepatic gene expression and maternal circulating metabolites, despite high structural similarity. Further, we report in vitro PPARα and PPARγ receptor activation for both compounds as putative molecular mechanisms. This work demonstrates the potential developmental toxicity of alternative moiety perfluoroethers and highlights the developing liver as particularly vulnerable to transcriptomic disruption. Synopsis: Developmental exposure to fluoroether carboxylic acids PFO4DA and PFO5DoA result in differential impacts on hepatic transcriptome in dams and offspring and circulating metabolome in dams, with PFO5DoA exhibiting higher potency than PFO4DA.

Metabolic changes associated with PFAS exposure in firefighters: A pilot study

This pilot study investigated the association between occupational exposure to per- and polyfluoroalkyl substances (PFASs) and metabolic profiles among two groups of aviation firefighters (n = 37), with an average of 6 and 31 years of working experience (here referred as junior and senior firefighters) at airports across Australia, with samples collected in 2013. PFAS levels in serum were determined in a previous study to be >17 times higher in the senior firefighter group, reflecting the difference in their occupational exposure to fluorosurfactants among the groups. The aim was to examine metabolic patterns across a broad range of PFAS exposure by comparing metabolic differences and their associations with PFAS levels. In this cross-sectional study, the length of firefighting experience and PFAS levels in serum were both further associated with changes in several classes of metabolites, including free fatty acids, bile acids, amino acids, lipids and metabolites related to gut microbial metabolism. The metabolites associated with the length of firefighting experience showed similarities with the metabolites associated with PFAS levels. A non-monotonic response to PFAS concentrations, particularly in saturated fatty acids, was also observed. In the junior firefighter group, the PFAS concentrations were positively associated with saturated fatty acids, i.e., the saturated fatty acid levels increased with increased PFAS levels. In the senior firefighter group, the trend was opposite, with saturated fatty acids decreasing with increasing levels of PFAS. Accounting for potential confounding factors such as BMI and age could not explain the results. While the study population was small, our results plausibly indicate that PFAS exposure can lead to a metabolic compensation strategy that is disrupted at high, long-term exposures. Our study also suggests that serum metabolites serve as better effect-based markers of the impact of exposure than the traditional clinical measurements alone, such as total triglycerides or total cholesterol.

Have per- and polyfluoroalkyl substances (PFAS) infiltrated Florida's freshwater springs?

The state of Florida contains over 1000 freshwater springs, fed by groundwater that provides 90 % of the drinking water for inhabitants. Freshwater springs are regarded as some of the cleanest water sources left on Earth, but recent studies regarding the extreme pervasiveness of per- and polyfluoroalkyl substances (PFAS) across the globe have called into question whether PFAS have infiltrated these vital water sources. In this study, 90 water samples (43 vents/40 runs/plus 7 additional surface samples) from 50 freshwater Florida springs were analyzed for the presence of 29 PFAS via ultra-high-performance liquid chromatography-tandem mass spectrometry. PFAS were detected in 63 % of the vent samples and 68 % of the run samples, with a total of 13 different quantifiable PFAS (>LOQ) present in at least one sample. Concentrations across samples ranged from 0.205 to 64.6 ng/L, with the most detected PFAS being perfluorobutanesulfonic acid (PFBS), perfluorooctanoic acid (PFOA), and perfluorooctanesulfonic acid (PFOS). This data highlights the presence of PFAS in Florida springs, representing a potential health concern for spring water users and drinking water consumers, and suggests the need for further research regarding the possible contamination pathways of Florida's freshwater springs.

Consolidating two-dimensional liquid chromatography-high-resolution tandem mass spectrometry (LC×LC-HRMS/MS) technique for the non-targeted analysis of poly- and perfluorinated substances: A trial on aqueous film-forming foams

To date, poly- and perfluoroalkyl substances (PFAS) represent a real threat for their environmental persistence, wide physicochemical variability, and their potential toxicity. Thus far a large portion of these chemicals remain structurally unknown. These chemicals, therefore, require the implementation of complex non-targeted analysis workflows using liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) for their comprehensive detection and monitoring. This approach, even though comprehensive, does not always provide the much-needed analytical resolution for the analysis of complex PFAS mixtures such as fire-fighting aqueous film-forming foams (AFFFs). This study consolidates the advantages of the LC×LC technique hyphenated with high-resolution tandem mass spectrometry (HRMS/MS) for the identification of PFAS in AFFF mixtures. A total of 57 PFAS homolog series (HS) were identified in 3M and Orchidee AFFF mixtures thanks to the (i) high chromatographic peak capacity (n'2D,c ~ 300) and the (i) increased mass domain resolution provided by the "remainder of Kendrick Mass" (RKM) analysis on the HRMS data. Then, we attempted to annotate the PFAS of each HS by exploiting the available reference standards and the FluoroMatch workflow in combination with the RKM defect by different fluorine repeating units, such as CF2, CF2O, and C2F4O. This approach resulted in 12 identified PFAS HS, including compounds belonging to the HS of perfluoroalkyl carboxylic acids (PFACAs), perfluoroalkyl sulfonic acids (PFASAs), (N-pentafluoro(5)sulfide)-perfluoroalkane sulfonates (SF5-PFASAs), N-sulfopropyldimethylammoniopropyl perfluoroalkane sulfonamides (N-SPAmP-FASA), and N-carboxymethyldimethylammoniopropyl perfluoroalkane sulfonamide (N-CMAmP-FASA). The annotated categories of perfluoroalkyl aldehydes and chlorinated PFASAs represent the first record of PFAS HS in the investigated AFFF samples.

SAP130 mediates crosstalk between hepatocyte ferroptosis and M1 macrophage polarization in PFOS-induced hepatotoxicity

Perfluorooctane sulfonate (PFOS) is a persistent organic pollutant widely utilized in industrial manufacturing and daily life, leading to significant environmental accumulation and various public health issues. This study aims to characterize spliceosome-associated protein 130 (SAP130) as a key mediator of crosstalk between hepatocytes and macrophages, elucidating its role in PFOS-induced liver inflammation. The data demonstrate that PFOS exposure induces ferroptosis in mouse liver and AML12 cells. During ferroptosis, SAP130 is released from injured hepatocytes into the microenvironment, binding to macrophage-inducible C-type lectin (Mincle) and activating the Mincle/Syk signaling pathway in macrophages, ultimately promoting M1 polarization and exacerbating liver injury. Treatment with the ferroptosis inhibitor Ferrostatin-1 reduces SAP130 release, inhibits Mincle/Syk signaling activation, and mitigates inflammatory response. Furthermore, siSAP130 suppresses the activation of the Mincle signaling pathway and M1 polarization in BMDM cells. Conversely, treatment with the ferroptosis agonist Erastin enhances paracrine secretion of SAP130 and exacerbates inflammation. These findings emphasize the significance of hepatocyte-macrophage crosstalk as a critical pathway for PFOS-induced liver injury in mice while highlighting SAP130 as a pivotal regulator of ferroptosis and inflammation, thereby elucidating the potential mechanism of PFOS-induced liver injury.

Innovative techniques for combating a common enemy forever chemicals: A comprehensive approach to mitigating per- and polyfluoroalkyl substances (PFAS) contamination

The pervasive presence of per and polyfluoroalkyl substances (PFAS), commonly referred to as "forever chemicals," in water systems poses a significant threat to both the environment and public health. PFAS are persistent organic pollutants that are incredibly resistant to degradation and have a tendency to accumulate in the environment, resulting in long-term contamination issues. This comprehensive review delves into the primary impacts of PFAS on both the environment and human health while also delving into advanced techniques aimed at addressing these concerns. The focus is on exploring the efficacy, practicality, and sustainability of these methods. The review outlines several key methods, such as advanced oxidation processes, novel materials adsorption, bioremediation, membrane filtration, and in-situ chemical oxidation, and evaluates their effectiveness in addressing PFAS contamination. By conducting a comparative analysis of these techniques, the study aims to provide a thorough understanding of current PFAS remediation technologies, as well as offer insights into integrated approaches for managing these persistent pollutants effectively. While acknowledging the high efficiency of adsorption and membrane filtration in reducing persistent organic pollutants due to their relatively low cost, versatility, and wide applicability, the review suggests that the integration of these methods could result in an overall enhancement of removal performance. Additionally, the study emphasizes the need for researcher attention in key areas and underscores the necessity of collaboration between researchers, industry, and regulatory authorities to address this complex challenge.

N-glucuronidation and Excretion of Perfluoroalkyl Sulfonamides in Mice Following Ingestion of Aqueous Film-Forming Foam

Perfluoroalkyl sulfonamides (FASAs) and other FASA-based per- and polyfluoroalkyl substances (PFASs) can transform into recalcitrant perfluoroalkyl sulfonates in vivo. We conducted high-resolution mass spectrometry suspect screening of urine and tissues (kidney and liver) from mice dosed with an electrochemically fluorinated aqueous film-forming foam (AFFF) to better understand the biological fate of AFFF-associated precursors. The B6C3F1 mice were dosed at five levels (0, 0.05, 0.5, 1, and 5 mg kg-1 day-1) based on perfluorooctane sulfonate and perfluorooctanoate content of the AFFF mixture. Dosing continued for 10 days followed by a 6-day depuration. Total oxidizable precursor assay of the AFFF suggested significant contributions from precursors with three to six perfluorinated carbons. We identified C4 to C6 FASAs and N-glucuronidated FASAs (FASA-N-glus) excreted in urine collected throughout dosing and depuration. Based on normalized relative abundance, FASA-N-glus accounted for up to 33% of the total excreted FASAs in mouse urine, highlighting the importance of phase II metabolic conjugation as a route of excretion. High-resolution mass spectrometry screening of liver and kidney tissue revealed accumulation of longer-chain (C7 and C8) FASAs not detected in urine. Chain-length-dependent conjugation of FASAs was also observed by incubating FASAs with mouse liver S9 fractions. Shorter-chain (C4) FASAs conjugated to a much greater extent over a 120-min incubation than longer-chain (C8) FASAs. Overall, this study highlights the significance of N-glucuronidation as an excretion mechanism for short-chain FASAs and suggests that monitoring urine for FASA-N-glus could contribute to a better understanding of PFAS exposure, as FASAs and their conjugates are often overlooked by traditional biomonitoring studies. Environ Toxicol Chem 2024;43:2274-2284. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

An in-depth examination of Per- and Polyfluoroalkyl (PFAS) effects on transporters, with emphasis on the ABC superfamily: A critical review

Per- and polyfluoroalkyl (PFAS) substances are a type of chemical compound unique for their multiple carbon-fluorine bonds, imbuing them with strength and environmental permanence. While legacy substances have been phased out due to human health risks, short-chain and alternative PFAS remain omnipresent. However, a detailed explanation for the pathways through which PFAS interact on a cellular and molecular level is still largely unknown, and the human health effects remain mechanistically unexplained. Of particular interest when focusing on this topic are the interactions between these exogenous chemicals and plasma and membrane proteins. Such proteins include serum albumin which can transport PFAS throughout the body, solute carrier proteins (SLC) and ATP binding cassette (ABC) transporters which are able to move PFAS into and out of cells, and proteins and nuclear receptors which interact with PFAS intracellularly. ABC transporters as a family have little available human data despite being responsible for the export of endogenous substances and drugs throughout the body. The multifactorial regulation of these crucial transporters is affected directly and indirectly by PFAS. Changes, which can include alterations to membrane transport activity and differences in protein expression, vary greatly depending on the specific PFAS and protein of interest. Together, the myriad of changes caused by understudied PFAS exposure to a class of understudied proteins crucial to cellular function and drug treatments has not been fully explored regarding human health and presents room for further exploration. This critical work aims to provide a novel framework of existing human data on PFAS and ABC transporters, allowing for future advancement and investigation into human transporter activity, mechanisms of regulation, and interactions with emerging contaminants.

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

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

Exposure of women undergoing in-vitro fertilization to per-and polyfluoroalkyl substances: Evidence on negative effects on fertilization and high-quality embryos

In April 2023, the World Health Organization (WHO) reported that 17.5% of the global adult population experience infertility. What may be the contribution of per-and polyfluoroalkyl (PFAS) to this global public health problem? This study explored the associations between in vitro fertilization (IVF) outcomes and plasma concentrations of individual PFAS and PFAS mixtures in women undergoing in vitro fertilization and embryo transfer (IVF-ET) and how these exposures might affect IVF outcomes. We analyzed 8 PFASs in plasma samples from women (N = 259) who underwent IVF treatment. In multivariable generalized linear mixed models, there were statistically significant associations of higher plasma concentrations of PFNA with reduced numbers of total retrieved oocytes [12.486 (95%CI: 0.446,25.418), p trend = 0.017], 2 PN zygotes [6.467(95%CI: 2.034,14.968), p trend = 0.007], and cleavage embryos [6.039(95%CI: 2.162,14.240), p trend = 0.008]. Similarly, there was a continuous decline in the numbers of retrieved 2 PN zygotes and cleavage embryos with increasing concentration of PFOS [6.467(95%CI: 2.034,14.968), p trend = 0.009 and 6.039(95%CI: 2.162,14.240), p trend = 0.031,respectively] and a negative association between PFHxS concentrations and clinical pregnancy during the initial cycles of frozen ET [0.525(95%CI:0.410,0.640), p trend = 0.021]. To investigate the joint effect of PFAS mixtures, a confounder-adjusted BKMR model analysis showed inverse relationship between PFAS mixtures and the number of high-quality embryos, 2 PN zygotes and cleavage embryos, to which the greatest contributors to the mixture effect are PFDeA and PFBS, respectively. It demonstrated that PFAS exposure might exert negative effects on oocyte yield, fertilization and high-quality embryo in women undergoing IVF. These findings suggest that exposure to PFAS may increase the risk of female infertility and further studies are needed to uncover the potential mechanisms underlying the reproductive effects associated with PFAS.

Influence of age on the concentrations of perfluoroalkyl acids (PFAA) in the tissues of perch (Percafluviatilis)

Globally, perfluoroalkyl acids (PFAA) are ubiquitous due to their almost unlimited applications in industry and households and are detected in a wide variety of matrices.Aquatic ecosystems are of particular importance due to the spread of PFAA via water fluxes. The majority of published studies describe PFAA concentrations in fish or aquatic mammals, but not the dependence of PFAA concentrations in tissues and organs in fish of different ages. Since this is very important for understanding the accumulation behavior of these substances our study systematically investigates the influence of age on the PFAA concentration in the tissues of 74 perches (Perca fluviatilis), a very popular edible fish. Fish are particularly suitable as indicators of PFAA contamination of water because of their uptake via water (gills and skin) and food (predominantly piscivorous diet). The mean total PFAA concentrations (as the sum of the individual concentrations of 11 compounds) were: 114 μg/kg (kidney), 112 μg/kg (heart), 79.9 μg/kg (liver), 78.4 μg/kg (spleen), 64.6 μg/kg (gills) and 21.7 μg/kg (muscle), with longer-chain compounds accounting for 90% of the substances. Perfluorooctanesulfoic acid (PFOS) accounted for the largest percentage of the total PFAA concentration in all tissues at 43-63%. With the exception of the heart and spleen, a significant increase in total concentrations was observed with increasing age of the perch. The strongest correlation was observed for the kidney, followed by the liver and gills. With regard to their consumption as human nutrition the tolerable weekly PFAA intake of 4.4 ng/kg bodyweight and week for the sum of the 4 EFSA PFAA in adults and children was exceeded many times over (860% and 1600% respectively) with an average fish consumption per week. The maximum PFAA levels set in the E.U. since January 2023 were exceeded five times.

Exposure to per- and polyfluoroalkyl substances and alterations in plasma microRNA profiles in children

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals that persist in the environment and can accumulate in humans, leading to adverse health effects. MicroRNAs (miRNAs) are emerging biomarkers that can advance the understanding of the mechanisms of PFAS effects on human health. However, little is known about the associations between PFAS exposures and miRNA alterations in humans.

OBJECTIVE

To investigate associations between PFAS concentrations and miRNA levels in children.

METHODS

Data from two distinct cohorts were utilized: 176 participants (average age 17.1 years; 75.6% female) from the Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) cohort in the United States, and 64 participants (average age 6.5 years, 39.1% female) from the Rhea study, a mother-child cohort in Greece. PFAS concentrations and miRNA levels were assessed in plasma samples from both studies. Associations between individual PFAS and plasma miRNA levels were examined after adjusting for covariates. Additionally, the cumulative effects of PFAS mixtures were evaluated using an exposure burden score. Ingenuity Pathways Analysis was employed to identify potential disease functions of PFAS-associated miRNAs.

RESULTS

Plasma PFAS concentrations were associated with alterations in 475 miRNAs in the Teen-LABs study and 5 miRNAs in the Rhea study (FDR p < 0.1). Specifically, plasma PFAS concentrations were consistently associated with decreased levels of miR-148b-3p and miR-29a-3p in both cohorts. Pathway analysis indicated that PFAS-related miRNAs were linked to numerous chronic disease pathways, including cardiovascular diseases, inflammatory conditions, and carcinogenesis.

CONCLUSION

Through miRNA screenings in two independent cohorts, this study identified both known and novel miRNAs associated with PFAS exposure in children. Pathway analysis revealed the involvement of these miRNAs in several cancer and inflammation-related pathways. Further studies are warranted to enhance our understanding of the relationships between PFAS exposure and disease risks, with miRNA emerging as potential biomarkers and/or mediators in these complex pathways.

Per and poly-fluoroalkyl substances and respiratory health in an Inuit community

BACKGROUND

Concentrations of plasma per and poly-fluoroalkyl substances (PFAS) are elevated in the Inuit population of Nunavik and may be causing adverse health effects. Respiratory health outcomes have been associated with PFAS, but have not been explored in Inuit communities. The aim of the study was to examine the association between PFAS and respiratory health outcomes, and the moderating role of nutritional biomarkers.

METHODS

We included up to 1298 participants of the Qanuilirpitaa? 2017 survey aged 16-80 years. Generalized regression models were used to estimate the associations between six individual PFAS congeners and four self-reported symptoms, four spirometry measures, and physician-diagnosed asthma. Outcomes associated with PFAS from single chemical models were further explored using Bayesian Kernel Machine Regression (BKMR). The modifying effect of n-3 PUFA in red blood cell quartiles and vitamin D deficiency were examined on the associations between PFAS and respiratory outcomes.

RESULTS

PFNA and PFOS were associated with asthma (odds ratio (OR) 1.61, 95% confidence interval (CI) 1.12, 2.32; OR 1.45 95% CI 1.04, 2.03). PFOA, PFNA, PFDA and PFHxS were associated with a decrease in the ratio between the forced expiratory volume in the first second and forced vital capacity (FEV1/FVC). No associations were observed with self-reported respiratory symptoms. No associations were observed between a PFAS mixture and asthma. Some associations were modified by nutritional factors, namely, stronger associations between PFOA and PFHxS and asthma with lower n-3 PUFA levels and stronger associations between PFDA, PFUnDA and PFOS and FEV1/FVC with vitamin D deficiency.

CONCLUSION

These findings add to the growing literature on the impacts of PFAS on respiratory health, and the importance of their global regulation. Associations were modified by nutritional factors pointing to the nutritional value of traditional Inuit foods.

Diet rich in soluble dietary fibres increases excretion of perfluorooctane sulfonic acid (PFOS) in male Sprague-Dawley rats

Perfluorooctane sulfonic acid (PFOS) belongs to a large group of anthropogenic compounds with high persistency named per- and polyfluorinated substances (PFAS). Widespread use from industry to household appliances and food-contact materials contributes to PFAS exposure with food as the primary source. Association studies suggest that vegetables and fibre rich diet may reduce PFOS levels in humans, but experimental data remain limited. Here, we investigated PFOS uptake and wash-out after seven days of PFOS (3 mg/kg/day) in two groups of rats (N=12 per group) fed diets either high (HF) or low (LF) in soluble dietary fibres. Two control groups (N=12/group) were fed the same diets without PFOS. Changes in pH and transit time were monitored alongside intestinal and faecal microbiota composition. We quantified systemic and excreted, linear and branched PFOS. Results revealed significantly lower pH and faster intestinal transit in the HF groups. Importantly, HF rats had lower serum PFOS concentrations and higher PFOS concentrations in caecal content and faeces, indicating a more efficient excretion on the fibre rich diet. In both dietary groups, PFOS affected the gut microbiota composition. Our results suggest that a diet rich in soluble dietary fibres accelerates excretion of PFOS and lowers PFOS concentration in serum.

Evaluation of per- and polyfluoroalkyl substances (PFAS) toxic effects on the acute inflammatory response in the medicinal leech Hirudo verbana

Per- and polyfluoroalkyl (PFAS) substances are a large group of chemicals with elevated water and oil-resistance properties, widely implicated in various applicative fields. Due to the extensive use and high resistance to degradative factors, these compounds pose a significant risk of environmental spreading, bioaccumulating also in living organisms. In this context, despite many researches have been performed to demonstrate "legacy" PFAS harmfulness, only few data are still available about all the emerging fluorinated molecules, industrially introduced to replace the previous ones. For this reason, we proposed the medicinal leech Hirudo verbana as consolidated invertebrate model to assess the effects of four different PFAS (HFPO-DA, PFMoBa, PFOA and PFMOPrA) following freshwater dispersion. Morphological, immunohistochemical and molecular analyses demonstrate that, despite all the compounds basically induce an acute inflammatory and oxidative stress response, a different cellular and molecular response has been observed. Whereas for PFOA and PFMOPrA an increase in the tested concentration leads to a corresponding rise in the immune response, HFPO-DA and PFMoBa trigger an entirely opposite effect. Indeed, the significant recruitment of both granulocytes and macrophage like cells, typically involved in the removal of non-self, is inhibited with increasing concentrations of these compounds. The data collected revealed a different sensitivity of the leech immune system following PFAS exposure, requiring to deepen the current knowledge on the potential toxicity of these compounds.

Uptake of Per- and Polyfluoroalkyl Substances in Mixed Forages on Biosolid-Amended Farm Fields

Models to predict perfluorooctanesulfonic acid (PFOS) concentrations in livestock based on soil concentrations are essential to guide decisions surrounding food testing and farm management. A key parameter in modeling soil-to-livestock exposure pathways is the plant transfer factor (TF) from soil into forages. Uptake of PFOS and other individual per- and polyfluoroalkyl substances (PFASs) were examined in perennial mixed grasses and legumes on PFAS-contaminated farm fields. In a field plot study, PFOS TFs were similar within each plot over three consecutive years but varied 10-fold among the four plots with mean TFs ranging from 0.026 to 0.27. In a multifarm field survey study, mean PFOS TFs ranged from 0.039 to 0.37. Increasing concentrations of two PFOS precursors in soil were significantly associated with increasing PFOS TFs. These data represent a substantial increase in empirical observations of PFAS TFs for grass-based forages for use in modeling soil-to-livestock exposure scenarios.

Serum per- and polyfluoroalkyl substance (PFAS) levels and health-related biomarkers in a pilot study of skiers in New England

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS), synthetic chemicals with adverse health effects, are used extensively in consumer products. Ski waxes, applied to the base of skis, contain up to 100% PFAS by mass, but exposure and health effects are poorly characterized.

OBJECTIVES

Our objectives were to quantify serum PFAS concentrations among skiers and explore associations with reported ski wax use and biomarkers of cardiometabolic, thyroid, and immune health.

METHODS

We recruited 30 active adult skiers to provide non-fasting blood samples and complete questionnaires. We quantified 18 PFAS using mass spectrometry, and measured serum lipids, thyroid hormones, and immunoglobulins. We explored associations of individual and aggregate measures of serum PFAS with wax use indicators and health biomarkers using multivariable regression models, adjusted for age and gender identity.

RESULTS

Nine PFAS (PFBS, PFHpS, PFHxS, Sm-PFOS, n-PFOS, PFDA, PFNA, PFUnDA, n-PFOA) were detected in 100% of participants, and MeFOSAA in 93%. Compared to NHANES, median serum concentrations (ng/ml) were similar, but higher in coaches (e.g., PFOAall: 1.1, PFOAcoaches: 2.7, PFOANHANES: 1.2; PFNAall: 0.5, PFNAcoaches: 1.7, PFNANHANES: 0.4). Factors reflecting wax exposure were positively associated with PFAS: e.g., >10 years as a snow sport athlete, compared to <10 years, was associated with 3.2 (95% CI: 0.7, 5.6) ng/ml higher aggregate PFAS, as defined by National Academies of Science, Engineering, and Medicine (NASEM). An IQR (6.3 ng/ml) increase in NASEM PFAS was associated with 32.1 (95% CI: 7.0, 57.2), 35.5 (13.5, 57.5), and 12.8 (0.6, 25.1) mg/dl higher total cholesterol, LDL-C, and sdLDL-C, respectively.

DISCUSSION

Our study provides early evidence that recreational skiers, particularly coaches, are exposed to PFAS through ski wax. Several PFAS were associated with higher serum lipids among these physically active adults. Interventions to remove PFAS from fluorinated wax could decrease direct exposure to skiers and reduce PFAS release into the environment.

Toxicokinetic of Perfluorinated Compounds - A Study of Liver Sequestration in Baltic Cod (Gadus morhua callarias) and Human Dietary Exposure

This study assessed the concentrations and temporal trends of perfluorinated compounds (PFCs) in the muscle and liver tissues of Baltic cod (Gadus morhua) from 2017 to 2023. The Environmental Quality Standard (EQS) for biota and the Estimated Weekly Intake (EWI) for human consumers were calculated to evaluate potential health risks associated with PFC exposure. Significant variations in PFC concentrations were observed across different compounds and sampling years. Perfluorooctanoic acid (PFOA) had a mean concentration ranging from 0.03 ng∙g⁻1 wet weight (ww) to 0.17 ng∙g⁻1 ww (mean: 0.093 ng∙g⁻1 ww), while perfluorononanoic acid (PFNA) ranged from 0.05 ng∙g⁻1 ww to 0.97 ng∙g⁻1 ww (mean: 0.46 ng∙g⁻1 ww). Perfluorooctane sulfonate (PFOS) demonstrated mean concentrations between 1.98 ng∙g⁻1 ww and 9.03 ng∙g⁻1 ww (mean: 4.78 ng∙g⁻1 ww). PFOSA exhibited the lowest liver sequestration factor, indicating a higher elimination potential. The EQS for biota, expressed in PFOA-equivalents, ranged from 9.36 ng∙g⁻1 ww to 28.5 ng∙g⁻1 ww (mean: 18.5 ng∙g⁻1 ww), showing an overall increasing trend over the study period. The EWI for Baltic cod muscle (ΣPFAS-4) indicated an average exposure of 1.84 ng∙kg⁻1 body weight (bw) per week for adults, with a maximum of 3.46 ng∙kg⁻1 bw per week. For cod liver consumers, the maximum exposure reached 6.45 ng∙kg⁻1 bw per week, exceeding the Tolerable Weekly Intake (TWI) in some cases. The rising PFC concentrations in Baltic cod, especially in liver tissues, pose health risks to consumers. Ongoing monitoring and risk assessments are essential to reduce the impacts of PFC exposure from seafood.

County-level associations between drinking water PFAS contamination and COVID-19 mortality in the United States

BACKGROUND

Epidemiologic and animal studies both support relationships between exposures to per- and polyfluoroalkyl substances (PFAS) and harmful effects on the immune system. Accordingly, PFAS have been identified as potential environmental risk factors for adverse COVID-19 outcomes.

OBJECTIVE

Here, we examine associations between PFAS contamination of U.S. community water systems (CWS) and county-level COVID-19 mortality records. Our analyses leverage two datasets: one at the subnational scale (5371 CWS serving 621 counties) and one at the national scale (4798 CWS serving 1677 counties). The subnational monitoring dataset was obtained from statewide drinking monitoring of PFAS (2016-2020) and the national monitoring dataset was obtained from a survey of unregulated contaminants (2013-2015).

METHODS

We conducted parallel analyses using multilevel quasi-Poisson regressions to estimate cumulative incidence ratios for the association between county-level measures of PFAS drinking water contamination and COVID-19 mortality prior to vaccination onset (Jan-Dec 2020). In the primary analyses, these regressions were adjusted for several county-level sociodemographic factors, days after the first reported case in the county, and total hospital beds.

RESULTS

In the subnational analysis, detection of at least one PFAS over 5 ng/L was associated with 12% higher [95% CI: 4%, 19%] COVID-19 mortality. In the national analysis, detection of at least one PFAS above the reporting limits (20-90 ng/L) was associated with 13% higher [95% CI: 8%, 19%] COVID-19 mortality.

IMPACT STATEMENT

Our findings provide evidence for an association between area-level drinking water PFAS contamination and higher COVID-19 mortality in the United States. These findings reinforce the importance of ongoing state and federal monitoring efforts supporting the U.S. Environmental Protection Agency's 2024 drinking water regulations for PFAS. More broadly, this example suggests that drinking water quality could play a role in infectious disease severity. Future research would benefit from study designs that combine area-level exposure measures with individual-level outcome data.

Comprehensive analysis of PFAS presence from environment to plate

Per- and polyfluoroalkyl substances (PFAS) pose an emerging environmental risk impacting food products and ecosystems. This study analyzes over 150,000 entries from food safety authorities and scientific publications from 2017 onwards. Our findings show that fish & seafood, and biota have the highest PFAS concentrations due to environmental contamination and bioaccumulation. Surface water samples also frequently contain PFAS, raising concerns about long-term ecological and human health effects. Comprehensive strategies are essential to mitigate these risks.

Antivirulence and antipathogenic activity of Mayan herbal remedies against Pseudomonas aeruginosa

ETHNOPHARMACOLOGICAL RELEVANCE

The Yucatan Peninsula has a privileged wealth of vascular plants with which various Mayan herbal formulations have been developed. However, studies on their antipathogenic and antivirulence properties are scarce.

AIM OF THE STUDY

Identify antivirulence properties in Mayan herbal remedies and determine their antipathogenic capacity in burn wounds infected with Pseudomonas aeruginosa.

MATERIALS AND METHODS

An ethnobotanical study was conducted in Mayan communities in central and southern Quintana Roo, Mexico. Furthermore, the antipathogenic capacity of three Mayan herbal remedies was analyzed using an animal model of thermal damage and P. aeruginosa infection. Antivirulence properties were determined by inhibiting phenotypes regulated by quorum sensing (pyocyanin, biofilm, and swarming) and by the secretion of the ExoU toxin. The chemical composition of the most active herbal remedy was analyzed using molecular network analysis.

RESULTS

It was found that topical administration of the remedy called "herbal soap" (HS) for eleven days maintained 100% survival of the animals, reduced establishment of the bacteria in the burn and prevented its systemic dispersion. Although no curative effect was recorded on tissue damaged by HS treatment, its herbal composition strongly reduced swarming and ExoU secretion. Through analysis of Molecular Networks, it was possible to carry out a global study of its chemical components, and identify the family of oxindole monoterpenoid alkaloids and carboline and tetrahydropyrididole alkaloids. In addition, flavonols, flavan-3-ols, and quinic acid derivatives were detected.

CONCLUSIONS

The antipathogenic and antivirulence capacity of ancient Mayan remedies makes them a potential resource for developing new antibacterial therapies to treat burns infected by P. aeruginosa.

Efficient removal of per- and polyfluoroalkyl substances (PFASs) from stored rainwater by composite metal salt /polydimethyldiallylammonium chloride coagulants

Stored rainwater, the primary source of drinking water in the villages and towns of the Loess Plateau in northwest China, has been found to contain per- and polyfluoroalkyl substances (PFASs) and lacks necessary treatment measures. Coagulation is a common water treatment process, and enhancing its efficacy in removing PFASs can significantly improve treatment efficiency, reduce costs, and minimize the environmental and health risks associated with perfluorinated compounds. This study investigated the removal efficiency of perfluorobutanoic acid (PFBA), perfluorobutanesulfonic acid (PFBS), perfluorooctanoic acid (PFOA), and perfluorooctanesulfonic acid (PFOS) using inorganic salt coagulants alone and in combination with polydimethyldiallylammonium chloride (PDMDAAC). The results indicated that the removal efficiencies of the four PFASs by polyferric chloride (PFCl) and polyaluminum chloride (PACl) increased with alkalinity. PDMDAAC significantly enhanced the coagulation removal efficiency of the four PFASs. The removal efficiency of the four PFASs was highest when the raw water pH was near 7. Within the molecular weight range of 0-500,000 for PDMDAAC, the removal efficiency of the four PFASs increased with increasing molecular weight. Charge neutralization is the primary coagulation mechanism for the removal of anionic PFASs. Therefore, this study provides guidance for selecting coagulants to remove PFASs from stored rainwater.

Pregnancy complications and birth outcomes following low-level exposure to per- and polyfluoroalkyl substances in the vitamin D antenatal asthma reduction trial

Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic, highly fluorinated aliphatic compounds, commonly utilised in a wide variety of consumer products with diverse applications. Since the genesis of these compounds, a growing body of evidence has demonstrated adverse health effects associated with PFAS exposure. In a racially diverse cohort of 459 pregnant mothers, demographically weighted towards minority representation (black 44.4%, white 38.4%, other 17.2%), across three major populous cities of the US, PFAS profiling was performed. Nine distinct PFAS species were quantified using mass spectrometry in plasma samples collected during the third trimester. Multivariable logistic and linear regression analyses were conducted to interrogate the associations of PFAS with gestational and birth outcomes: gestational diabetes, preeclampsia, gestational age at delivery, low birth weight, birth weight-, birth length- and head circumference-for-gestational-age. Detectable levels for eight out of nine profiled PFAS species were found in the plasma of pregnant mothers with a median range of 0.1-2.70 ng ml-1. Using a mixtures approach, we observe that increased quantile-based g-computation (Qg-comp) "total" PFAS levels were associated with increased newborn birth-weight-for-gestational-age (β 1.28; 95% CI 1.07-1.52; FDR p 0.006). In study centre-stratified analyses, we observed a similar trend in Boston pregnant mothers, with Qg-comp total PFAS associated with higher newborn birth-weight-for-gestational-age (β 1.39; 95% CI 1.01-1.92, FDR p 0.05). We additionally found elevated PFUA concentrations were associated with longer gestational terms in San Diego pregnant mothers (β 0.60; 95% CI 0.18-1.02, FDR p 0.05). In this multi-city study, we detected lower levels of PFAS than in many previous US environmental studies, concordant with current US trends indicating environmental PFAS levels are falling, and we note geographical variation in the associations between PFAS levels and birth outcomes.

The clinical, mechanistic, and social impacts of air pollution on atopic dermatitis

Atopic dermatitis (AD) is a complex disease characterized by dry, pruritic skin and significant atopic and psychological sequelae. Although AD has always been viewed as multifactorial, early research was dominated by overlapping genetic determinist views of either innate barrier defects leading to inflammation or innate inflammation eroding skin barrier function. Since 1970, however, the incidence of AD in the United States has increased at a pace that far exceeds genetic drift, thus suggesting a modern, environmental etiology. Another implicated factor is Staphylococcus aureus; however, a highly contagious microorganism is unlikely to be the primary etiology of a noncommunicable disease. Recently, the roles of the skin and gut microbiomes have received greater attention as potentially targetable drivers of AD. Here too, however, dysbiosis on a population scale would require induction by an environmental factor. In this review, we describe the evidence supporting the environmental hypothesis of AD etiology and detail the molecular mechanisms of each of the AD-relevant toxins. We also outline how a pollution-focused paradigm demands earnest engagement with environmental injustice if the field is to meaningfully address racial and geographic disparities. Identifying specific toxins and their mechanisms can also inform in-home and national mitigation strategies.

Phytoremediation Potential of Azolla filiculoides: Uptake and Toxicity of Seven Per- and Polyfluoroalkyl Substances (PFAS) at Environmentally Relevant Water Concentrations

Environmental contamination of aquatic systems by per- and polyfluoroalkyl substances (PFAS) has generated significant health concerns. Remediation of contaminated sites such as the fire-fighting emergency training grounds that use aqueous film-forming foams is a high priority. Phytoremediation may help play a part in removing PFAS from such contaminated waters. We investigated the potential of the water fern Azolla filiculoides, which is used for phytoremediation of a wide range of contaminants, to uptake seven common PFAS (perfluorobutanoic acid [PFBA], perfluorobutane sulfonic acid [PFBS], perfluoroheptanoic acid [PFHpA], perfluorohexanoic acid [PFHxA], perfluorohexane sulfonic acid [PFHxS], perfluorooctanoic acid [PFOA], and perfluoropentanoic acid [PFPeA]), during a 12-day exposure to environmentally relevant concentrations delivered as equimolar mixtures: low (∑PFAS = 0.0123 ± 1.89 μmol L-1), medium (∑PFAS = 0.123 ± 2.88 μmol L-1), and high (∑PFAS = 1.39 μmol L-1) treatments, equivalent to approximately 5, 50, and 500 µg L-1 total PFAS, respectively. The possible phytotoxic effects of PFAS were measured at 3-day intervals using chlorophyll a content, photosystem II efficiency (Fv/Fm), performance index, and specific growth rate. The PFAS concentrations in plant tissue and water were also measured every 3 days using ultra-high-performance liquid chromatography-tandem mass spectrometry. Treatments with PFAS did not lead to any detectable phytotoxic effects. All seven PFAS were detected in plant tissue, with the greatest uptake occurring during the first 6 days of exposure. After 12 days of exposure, a maximum bioconcentration factor was recorded for PFBA of 1.30 and a minimum of 0.192 for PFBS. Consequently, the application of Azolla spp. as a stand-alone system for phytoremediation of PFAS in aquatic environments is not sufficient to substantially reduce PFAS concentrations. Environ Toxicol Chem 2024;43:2157-2168. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Association of per- and polyfluoroalkyl substances with the antioxidant bilirubin across pregnancy

BACKGROUND

In mechanistic and preliminary human studies, prenatal exposure to per- and polyfluoroalkyl substances (PFAS) is associated with oxidative stress, a potential contributor to maternal liver disease. Bilirubin is an endogenous antioxidant abundant in the liver that may serve as a physiological modulator of oxidative stress in pregnant people. Hence, our objective was to estimate the association between repeated measures of PFAS and bilirubin during pregnancy.

METHODS

The study population included 332 participants in the Atlanta African American Maternal-Child Cohort between 2014 and 2020. Serum samples were collected up to two times (early pregnancy: 6-18 gestational weeks; late pregnancy: 21-36 gestational weeks) for the measurement of perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and total bilirubin. We analyzed single PFAS with linear mixed effect regression and a mixture of the four PFAS with quantile g-computation. Models were repeated with a multiplicative interaction term to explore effect modification by study visit.

RESULTS

Overall, PFHxS was positively associated with bilirubin (β = 0.08, 95 % CI = 0.01, 0.15). We also found during late pregnancy, there was a positive association of PFHxS and the PFAS mixture with bilirubin (β = 0.12, 95 % CI = 0.02, 0.22; ψ = 0.19, 95 % CI = 0.03, 0.34, respectively). Finally, study visit modified the PFOA-bilirubin association (interaction p-value = 0.09), which was greater during early pregnancy (β = 0.08, 95 % CI = 0.01, 0.15).

CONCLUSION

In a prospective cohort of pregnant African Americans, an increase in PFOA, PFHxS, and the PFAS mixture was associated with an increase in bilirubin. Our results suggest that, depending on pregnancy stage, prenatal PFAS exposure disrupts the maternal liver antioxidant capacity.

A toxicogenomics-based identification of potential mechanisms and signaling pathways involved in PFCs-induced cancer in human

Introduction

The number of new diagnosed cancer cases and cancer deaths are increasing worldwide. Perfluorinated compounds (PFCs) are synthetic chemicals, which are possible inducers of cancer in human and laboratory animals. Studies showed that PFCs induce breast, prostate, kidney, liver and pancreas cancer by inducing genes being involved in carcinogenic pathways.

Methodology

This study reviews the association between PFCs induced up-regulation/down-regulation of genes and signaling pathways that are important in promoting different types of cancer. To obtain chemical-gene interactions, an advanced search was performed in the Comparative Toxicogenomics Database platform.

Results

Five most prevalent cancers were studied and the maps of their signaling pathways were drawn, and colored borders indicate significantly differentially expressed genes if there had been reports of alterations in expression in the presence of PFCs.

Conclusion

In general, PFCs are capable of inducing cancer in human via altering PPARα and PI3K pathways, evading apoptosis, inducing sustained angiogenesis, alterations in proliferation and blocking differentiation. However, more epidemiological data and mechanistic studies are needed to better understand the carcinogenic effects of PFCs in human.

Soil amendments reduce PFAS bioaccumulation in Eisenia fetida following exposure to AFFF-impacted soil

The efficacy of RemBind® 300 to immobilize per- and polyfluoroalkyl substances (PFAS) in aqueous film forming foam (AFFF)-impacted soil (∑28 PFAS 1280-8130 ng g-1; n = 8) was assessed using leachability (ASLP) and bioaccumulation (Eisenia fetida) endpoints as the measure of efficacy. In unamended soil, ∑28 PFAS leachability ranged from 26.0 to 235 μg l-1, however, following the addition of 5% w/w RemBind® 300, ∑28 PFAS leachability was reduced by > 99%. Following exposure of E. fetida to unamended soil, ∑28 PFAS bioaccumulation ranged from 18,660-241,910 ng g-1 DW with PFOS accumulating to the greatest extent (15,150-212,120 ng g-1 DW). Biota soil accumulation factors (BSAF) were significantly (p < 0.05) higher for perfluoroalkyl sulfonic acids (PFSA; 13.2-50.9) compared to perfluoroalkyl carboxylic acids (PFCA; 1.2-12.7) while for individual PFSA, mean BSAF increased for C4 to C6 compounds (PFBS: 42.6; PFPeS: 52.7; PFHxS: 62.4). In contrast, when E. fetida were exposed to soil amended with 5% w/w RemBind® 300, significantly lower PFAS bioaccumulation occurred (∑28 PFAS: 339-3397 ng g-1 DW) with PFOS accumulation 23-246 fold lower compared to unamended soil. These results highlight the potential of soil amendments for reducing PFAS mobility and bioavailability, offering an immobilization-based risk management approach for AFFF-impacted soil.

In vitro cytotoxicity of six per- and polyfluoroalkyl substances (PFAS) in human immune cell lines

Per- and Polyfluoroalkyl substances (PFAS) are a group of persistent long-lived chemicals with global environmental contamination. The published literature is rife with confusing and sometimes contradictory effects of PFAS on animal and cell models, as well as epidemiological studies. Cytotoxicity studies are often used as an early indicator to guide safety requirements, regulation, and further studies and thus can be useful to understand important toxicity differences by various PFAS. Recent studies have found that PFAS are not equivalently toxic on all cell types, and that not all cell types exhibit the same sensitivity to individual PFAS. However, immune cells have not been well studied. As immune cells are important for regulating responses to environmental toxins, infection, and cancer, we sought to discover the sensitivity of these cells to various PFAS, including legacy and replacement compounds. We assessed a range of concentrations and found that immune cells are generally more robust when exposed to PFAS, and that Jurkat T-cells were more sensitive than THP-1 monocytes. As monocytes are critical for coordinating inflammatory responses to external threats with cell death cascades, we further investigated these cells. We discovered that THP-1 cells do not undergo organized or programmed death, such as apoptosis or pyroptosis, and instead PFAS exposure results in a more necrotic/lytic and unorganized death, likely contributing to potential inflammatory effects downstream.

A molecular metal-organic cage as a recyclable sponge for PFOS removal from water

A metal-organic cage (MOC) is shown to be an efficient molecular sponge for PFOS. A large association constant is observed for the 2 : 1 PFOS : MOC host-guest complex. Up to 12 equivalents of PFOS per MOC are removed from water. The recycling procedure developed allows for the recovery and reuse of the MOC.

Tissue distribution and temporal and spatial assessment of per- and polyfluoroalkyl substances (PFAS) in smallmouth bass (Micropterus dolomieu) in the mid-Atlantic United States

Per- and polyfluoroalkyl substances (PFAS) have become an environmental issue worldwide. A first step to assessing potential adverse effects on fish populations is to determine if concentrations of concern are present in a region and if so, in which watersheds. Hence, plasma from adult smallmouth bass Micropterus dolomieu collected at 10 sites within 4 river systems in the mid-Atlantic region of the United States, from 2014 to 2019, was analyzed for 13 PFAS. These analyses were directed at better understanding the presence and associations with land use attributes in an important sportfish. Four substances, PFOS, PFDA, PFUnA, and PFDoA, were detected in every plasma sample, with PFOS having the highest concentrations. Sites with mean plasma concentrations of PFOS below 100 ng/ml had the lowest percentage of developed landcover in the upstream catchments. Sites with moderate plasma concentrations (mean PFOS concentrations between 220 and 240 ng/ml) had low (< 7.0) percentages of developed land use but high (> 30) percentages of agricultural land use. Sites with mean plasma concentrations of PFOS > 350 ng/ml had the highest percentage of developed land use and the highest number PFAS facilities that included military installations and airports. Four of the sites were part of a long-term monitoring project, and PFAS concentrations of samples collected in spring 2017, 2018, and 2019 were compared. Significant annual differences in plasma concentrations were noted that may relate to sources and climatic factors. Samples were also collected at two sites for tissue (plasma, whole blood, liver, gonad, muscle) distribution analyses with an expanded analyte list of 28 PFAS. Relative tissue distributions were not consistent even within one species of similar ages. Although the long-chained legacy PFAS were generally detected more frequently and at higher concentrations, emerging compounds such as 6:2 FTS and GEN X were detected in a variety of tissues.

Association of perfluoroalkyl substances (PFAS) with liver function biomarkers in the highly exposed population of the Veneto Region

INTRODUCTION

Epidemiological studies highlight the presence of associations between per- and polyfluoroalkyl substances (PFAS) exposure with liver damage. In 2013, PFAS contamination was discovered in Veneto (Italy), leading to the implementation of a Surveillance Program (SP). Our objective is to investigate the association between PFAS exposure and biomarkers of liver function using single-pollutant and mixture approaches, while exploring the sex-specific differences and the mediating role of obesity in the association.

METHODS

The study included 42,094 subjects aged ≥20 years participating in the SP. We used generalized additive models to investigate the association between several PFAS and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, adjusting for possible confounders and stratifying by sex. Results were back-transformed to show predicted percentage changes in outcomes per ln-unit increase in PFAS levels; furthermore, we explored the role of BMI in the abovementioned causal pathway, considering it as a potential confounder or mediator PFAS joint effect was investigated using Quantile G-computation.

RESULTS

One ln-unit increase in PFHxS concentrations was associated with a 1.49% (95%CI: 0.87, 2.12) and a 0.84% (95% CI: 0.27, 1.40) increase in ALT levels, in males and females respectively; one ln-unit increase in PFOA concentrations was associated with a 1.03% (95%CI: 0.50, 1.55) increase in ALT levels in males, and a 0.52% (95% CI: 0.22, 0.82) and a 0.60% (95% CI: 0.25, 0.96) increase in AST levels in females and males. PFOS showed no association with ALT and AST levels. Quantile G-computation revealed that an interquartile increase in the PFAS mixture was associated with a 3.02% increase (95% CI: 1.65, 4.43) and a 1.65% (95% CI: 0.77, 2.5) increase in ALT levels, in females and males. Mediation analysis suggested that BMI suppressed the association between PFAS and ALT levels, with positive direct effects higher than the total effects.

CONCLUSION

Our findings suggest sex-specific associations between PFAS exposure and liver function biomarkers and underscore the need for additional studies on potential mediators.

Improved prediction of PFAS partitioning with PPLFERs and QSPRs

Per- and polyfluoroalkyl substances (PFAS) are chemicals of high concern and are undergoing hazard and risk assessment worldwide. Reliable physicochemical property (PCP) data are fundamental to assessments. However, experimental PCP data for PFAS are limited and property prediction tools such as quantitative structure-property relationships (QSPRs) therefore have poor predictive power for PFAS. New experimental data from Endo 2023 are used to improve QSPRs for predicting poly-parameter linear free energy relationship (PPLFER) descriptors for calculating water solubility (SW), vapor pressure (VP) and the octanol-water (KOW), octanol-air (KOA) and air-water (KAW) partition ratios. The new experimental data are only for neutral PFAS, and the QSPRs are only applicable to neutral chemicals. A key PPLFER descriptor for PFAS is the molar volume and this work compares different versions and makes recommendations for obtaining the best PCP predictions. The new models are included in the freely available IFSQSAR package (version 1.1.1), and property predictions are compared to those from the previous IFSQSAR (version 1.1.0) and from QSPRs in the US EPA's EPI Suite (version 4.11) and OPERA (version 2.9) models. The results from the new IFSQSAR models show improvements for predicting PFAS PCPs. The root mean squared error (RMSE) for predicting log KOWversus expected values from quantum chemical calculations was reduced by approximately 1 log unit whereas the RMSE for predicting log KAW and log KOA was reduced by 0.2 log units. IFSQSAR v.1.1.1 has an RMSE one or more log units lower than predictions from OPERA and EPI Suite when compared to expected values of log KOW, log KAW and log KOA for PFAS, except for EPI Suite predictions for log KOW which have a comparable RMSE. Recommendations for future experimental work for PPLFER descriptors for PFAS and future research to improve PCP predictions for PFAS are presented.

Molecular mechanism of immunotoxicity: Binding interaction between perfluorinated compounds and human immunoglobulin G

Perfluorinated compounds (PFCs) can induce immunotoxicity effect via binding with proteins. Immunoglobulin G (IgG) is a common four chain monomer protein in serum, and plays an important role in long-term body fluid immunity. Whether PFCs can bind with IgG and further induce immunotoxicity is not clear. Herein, fluorescence quenching assay was used to verify the PFCs-IgG binding interactions. The occurrence of fluorescence quenching phenomenon suggested that PFCs could bind to IgG. Linear fitting curves demonstrated that the binding constants (KA) for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) were 2.51 × 106 L/mol and 1.58 × 105 L/mol, respectively. UV-vis spectral analysis results showed that the PFCs-IgG interactions mainly proceeded via the intercalation binding mode. Fourier transform infrared spectroscopy results revealed that PFCs preferentially bound to the C=O/N-H of IgG structure. Circular dichroism results revealed that PFCs-IgG binding induced the decrease of α-helix. Moreover, hydrogen bonds and van der Waals force dominated PFCs-IgG binding interactions. This binding process was a stable process, and its stability depended on the number of hydrogen bonds formation. This study reveals the mechanism of interaction between PFCs and IgG at the molecular level, providing a theoretical basis for the immunotoxic mechanism of PFCs.

Mixed contaminant exposure in tapwater and the potential implications for human-health in disadvantaged communities in California

Water is an increasingly precious resource in California as years of drought, climate change, pollution, as well as an expanding population have all stressed the state's drinking water supplies. Currently, there are increasing concerns about whether regulated and unregulated contaminants in drinking water are linked to a variety of human-health outcomes particularly in socially disadvantaged communities with a history of health risks. To begin to address this data gap by broadly assessing contaminant mixture exposures, the current study was designed to collect tapwater samples from communities in Gold Country, the San Francisco Bay Area, two regions of the Central Valley (Merced/Fresno and Kern counties), and southeast Los Angeles for 251 organic chemicals and 32 inorganic constituents. Sampling prioritized low-income areas with suspected water quality challenges and elevated breast cancer rates. Results indicated that mixtures of regulated and unregulated contaminants were observed frequently in tapwater throughout the areas studied and the types and concentrations of detected contaminants varied by region, drinking-water source, and size of the public water system. Multiple exceedances of enforceable maximum contaminant level(s) (MCL), non-enforceable MCL goal(s) (MCLG), and other health advisories combined with frequent exceedances of benchmark-based hazard indices were also observed in samples collected in all five of the study regions. Given the current focus on improving water quality in socially disadvantaged communities, our study highlights the importance of assessing mixed-contaminant exposures in drinking water at the point of consumption to adequately address human-health concerns (e.g., breast cancer risk). Data from this pilot study provide a foundation for future studies across a greater number of communities in California to assess potential linkages between breast cancer rates and tapwater contaminants.

Per- and Polyfluoroalkyl (PFAS) Disruption of Thyroid Hormone Synthesis

Per- and polyfluoroalkyl substances (PFAS) are a group of environmental pollutants that have been linked to a variety of health problems in humans, including the disruption of thyroid functions. Herein, for the first time, the impact of PFAS on thyroid hormone synthesis is shown. Mid- to long-chain PFAS impact thyroid hormone synthesis by changing the local hydrogen bond network as well as the required orientation of hormonogenic residues, stopping the production of thyroxine (T4). Furthermore, the toxic effects of sulfonic PFAS are more prominent than those of carboxylic PFAS, highlighting that the exposure to these specific compounds can pose greater problems for thyroid homeostasis.

Antibody response to SARS-CoV-2 mRNA vaccination in Danish adults exposed to perfluoroalkyl substances (PFASs): The ENFORCE study

INTRODUCTION

Per- and polyfluoroalkyl substances (PFASs) have immunotoxic effects in children while studies in adults, including recent studies on the SARS-CoV-2 vaccine response have been less consistent. In a cohort of 50-69-year-olds repeatedly vaccinated against COVID-19 in Denmark from early 2021, we aimed to assess the association between serum-PFAS concentrations and SARS-CoV-2 antibody responses.

METHODS

We assessed serum-PFAS concentrations among 371 middle-aged adults from the National Cohort Study of Effectiveness and Safety of SARS-CoV-2 vaccines (ENFORCE) who had received their first vaccination against COVID-19. Following the second dose and the booster (third) Pfizer-BioNTech mRNA vaccination, we measured the specific spike IgG antibody response. Associations between serum-PFAS concentrations at inclusion and spike IgG antibody concentrations after vaccination were assessed using median regression, and analyses were adjusted for age, sex, presence of diabetes, number of vaccines received, and time since vaccination. We further examined the associations between serum-PFAS concentrations at inclusion and changes in spike IgG antibody concentration between the second dose and booster (third) vaccination.

RESULTS

Serum-PFAS concentrations were not associated with spike IgG antibody concentrations after the SARS-CoV-2 vaccinations, but the increase in response after the booster (third) vaccination compared to after the second vaccination was consistently lower at higher serum-PFAS concentrations. Each doubling in the concentration of seven serum-PFASs was associated with a 802 BAU/mL lower median increase in spike IgG antibody response after the booster (third) vaccination (95% CI: -1812; 208) adjusted for confounders.

DISCUSSION

As many adults were probably not immunological naïve prior to vaccination, our results were likely affected by individual variability in immune response to the vaccination. Despite this uncertainty, the diminished increase in SARS-CoV-2 spike antibody response after the booster (third) vaccination at higher PFAS exposure may potentially reflect an immunotoxic impact of the PFASs.

Carry-over rate of per- and polyfluoroalkyl substances to raw milk and human exposure risks in different regions of China

The widespread presence of per- and polyfluoroalkyl substances (PFAS) in various environmental matrices and their adverse health effects have gained worldwide attention. Therefore, numerous studies have focused on human exposure to PFAS through different pathways, such as fish and drinking water, and little attention has been paid to milk consumption. This study aimed to explore the transfer of PFAS by investigating the occurrence of PFAS in cow feed, drinking water, and raw milk from 20 regions of China and to assess the risk of human exposure to PFAS from raw milk. In total, 13, 15, and 7 PFAS were detected in cow feed, drinking water, and raw milk with total concentrations (∑PFAS) of 5.59 ± 2.91 ng/g (mean ± standard deviation), 11.91 ± 23.12 ng/L, and 0.15 ± 0.13 ng/mL, respectively. Perfluoropentanoic acid (PFPeA) was dominant with a concentration of 2.28 ± 1.75 ng/g, approximately 40.7 % of ∑PFAS in feed. Perfluorooctanoic acid (PFOA) and perfluorobutanoic acid (PFBA) were the dominant compounds found in drinking water at 4.80 ± 14.37 and 3.01 ± 6.06 ng/L, respectively. Additionally, PFOA (0.08 ± 0.09 ng/mL) was the most significant compound in raw milk, contributing 51.5 % of ∑PFAS. Moreover, the results of the carry-over rate (COR) were as follows: perfluorooctanesulfonic acid (PFOS, 29.58 %) > PFOA (15.78 %) > perfluorobutanesulfonic acid (PFBS, 9.45 %). According to the reference dose (RfD) established by the European Food Safety Authority (EFSA) in 2018, there is a potential toxicological hazard of PFOA exposure for preschool children through milk consumption. Notably, the health risk from PFOS for 1-year-old children in Central China exceeded that observed for humans in other regions and age groups. Our results showed that PFOS and PFOA were more likely to accumulate in cows and to be constantly transferred to milk, thus increasing the human health risk, especially in children.

Cross-cutting studies of per- and polyfluorinated alkyl substances (PFAS) in Arctic wildlife and humans

This cross-cutting review focuses on the presence and impacts of per- and polyfluoroalkyl substances (PFAS) in the Arctic. Several PFAS undergo long-range transport via atmospheric (volatile polyfluorinated compounds) and oceanic pathways (perfluorinated alkyl acids, PFAAs), causing widespread contamination of the Arctic. Beyond targeting a few well-known PFAS, applying sum parameters, suspect and non-targeted screening are promising approaches to elucidate predominant sources, transport, and pathways of PFAS in the Arctic environment, wildlife, and humans, and establish their time-trends. Across wildlife species, concentrations were dominated by perfluorooctane sulfonic acid (PFOS), followed by perfluorononanoic acid (PFNA); highest concentrations were present in mammalian livers and bird eggs. Time trends were similar for East Greenland ringed seals (Pusa hispida) and polar bears (Ursus maritimus). In polar bears, PFOS concentrations increased from the 1980s to 2006, with a secondary peak in 2014-2021, while PFNA increased regularly in the Canadian and Greenlandic ringed seals and polar bear livers. Human time trends vary regionally (though lacking for the Russian Arctic), and to the extent local Arctic human populations rely on traditional wildlife diets, such as marine mammals. Arctic human cohort studies implied that several PFAAs are immunotoxic, carcinogenic or contribute to carcinogenicity, and affect the reproductive, endocrine and cardiometabolic systems. Physiological, endocrine, and reproductive effects linked to PFAS exposure were largely similar among humans, polar bears, and Arctic seabirds. For most polar bear subpopulations across the Arctic, modeled serum concentrations exceeded PFOS levels in human populations, several of which already exceeded the established immunotoxic thresholds for the most severe risk category. Data is typically limited to the western Arctic region and populations. Monitoring of legacy and novel PFAS across the entire Arctic region, combined with proactive community engagement and international restrictions on PFAS production remain critical to mitigate PFAS exposure and its health impacts in the Arctic.

Per- and Polyfluoroalkyl Substances (PFAS) Affect Female Reproductive Health: Epidemiological Evidence and Underlying Mechanisms

PFAS (per- and polyfluoroalkyl substances) have been extensively used across numerous industries and consumer goods. Due to their high persistence and mobility, they are ubiquitous in the environment. Exposure to PFAS occurs in people via multiple pathways such as dermal contact, water supply, air inhalation, and dietary intake. Even if some PFAS are being phased out because of their persistent presence in the environment and harmful impacts on human health, mixes of replacement and legacy PFAS will continue to pollute the ecosystem. Numerous toxicological investigations have revealed harmful effects of PFAS exposure on female reproductive health, e.g., polycystic ovaries syndrome, premature ovarian failure, endometriosis, reproductive system tumors, pregnancy complications, and adverse pregnancy outcomes. Despite extensive epidemiological studies on the reproductive toxicity of PFAS, research findings remain inconsistent, and the underlying mechanisms are not well understood. In this review, we give an in-depth description of the sources and pathways of PFAS, and then review the reproductive toxicity of PFAS and its possible mechanisms.

Prenatal Exposure to Per- and Polyfluoroalkyl Substances and ASD-Related Symptoms in Early Childhood: Mediation Role of Steroids

Previous studies regarding the associations between perfluoroalkyl and polyfluoroalkyl substances (PFAS) and autism spectrum disorder (ASD) have yielded inconsistent results, with the underlying mechanisms remaining unknown. In this study, we quantified 13 PFAS in cord serum samples from 396 neonates and followed the children at age 4 to assess ASD-related symptoms. Our findings revealed associations between certain PFAS and ASD-related symptoms, with a doubling of perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA) concentrations associated with respective increases of 1.79, 1.62, and 1.45 units in language-related symptoms and PFDA exhibiting an association with higher score of sensory stimuli. Nonlinear associations were observed in the associations of 6:2 chlorinated polyfluorinated ether sulfonate (Cl-PFAES) and 8:2 Cl-PFAES with ASD-related symptoms. Employing weighted quantile sum (WQS) regression, we observed significant mixture effects of multiple PFAS on all domains of ASD-related symptoms, with PFNA emerging as the most substantial contributor. Assuming causality, we found that 39-40% of the estimated effect of long-chain PFAS (PFUnDA and PFDoDA) exposure on sensory stimuli was mediated by androstenedione. This study provides novel epidemiological data about prenatal PFAS mixture exposure and ASD-related symptoms.

Exploring the environmental contamination toxicity and potential carcinogenic pathways of perfluorinated and polyfluoroalkyl substances (PFAS): An integrated network toxicology and molecular docking strategy

The objective of this study was to investigate the potential carcinogenic toxicity and mechanisms of PFAS in thyroid, renal, and testicular cancers base on network toxicology and molecular docking techniques. Structural modeling was performed to predict relevant toxicity information, and compounds and cancer-related targets were screened in multiple databases. The interaction of PFAS with three cancers and their key protein targets were explored by combining protein network analysis, enrichment analysis and molecular docking techniques. PFOA, PFOS, and PFHXS exhibited significant carcinogenic and cytotoxic effects. These compounds may induce cancer by mediating active oxygen metabolism and the transduction of phosphatidylinositol 3-kinase/protein kinase B signaling pathway through genes such as ALB, mTOR, MDM2, and ERBB2. Furthermore, the underlying toxic mechanisms may be linked to the pathways in cancer, chemical carcinogenesis through reactive oxygen species/receptor activation, and the FoxO signaling pathway. The results contribute to a comprehensive understanding of the effects of these environmental pollutants on genes, proteins, and metabolic pathways in living organisms. It revealed their toxicity mechanisms in inducing thyroid, renal, and testicular cancers, and provided a solid theoretical foundation for designing new environmental control strategies and drug screening initiatives. Additionally, the integrated application of network toxicology and molecular docking technology can enhance our understanding of the toxicity and mechanisms of unknown environmental pollutants, which is beneficial for protecting the environment and human health.

Sex and obesity influence the relationship between perfluoroalkyl substances and lean body mass: NHANES 2011-2018

Objective

Polyfluoroalkyl substances (PFAS) are known endocrine disruptors, that have been the subject of limited research regarding their impact on human lean body mass. The aim of this study was to investigate the effects of PFAS exposure on lean body mass.

Methods

We performed a cross-sectional data analysis involving 1022 adolescents and 3274 adults from the National Health and Nutrition Examination Survey (NHANES) 2011-2018, whose lean body mass was measured by dual-energy X-ray absorptiometry. The lean mass index (LMI) was calculated as lean body mass dividing by the square of height. The association between PFAS and LMI was examined through a multivariate-adjusted weighted generalized linear model. Moreover, weighted quantile sum (WQS) regression models were employed to futher examine the relationship between the mixture of PFAS and LMI.

Results

Regression analyses revealed an inverse correlation between PFAS exposure and LMI after adjusting for potential covariates. Adults with higher serum PFAS concentrations manifested a reduction in whole LMI ( β  = -0.193, 95 % confidence interval (CI): -0.325 to -0.06). Notably, this correlation was particularly significant in adult females and individuals with obesity, and it was observed across diverse anatomical regions, including lower limbs, right arm, trunk, and whole lean body mass. In adult females, the association between PFAS and whole LMI was statistically significant ( β  = -0.294, 95 % CI: -0.495 to -0.094), and a similar trend was found in obese individuals ( β  = -0.512, 95 % CI: -0.762 to -0.261). WQS regression analyses supported the results obtained from weighted linear regression analyses.

Conclusions

Our study suggests that exposure to PFAS, whether individually or in combination, is associated with decreased lean body mass in specific body areas, with sex and obesity serving as major influencing factors.

Association between perfluoroalkyl substances and breast cancer on the National Health and Nutrition Examination Survey Database and meta-analysis

The relationship between perfluoroalkyl substances (PFASs) and the risk of breast cancer has been controversial. Here, we used the National Health and Nutrition Examination Survey (NHANES) database and a meta-analysis to examine the association between PFASs and breast cancer incidence. From the NHANES database, we obtained data on PFASs and breast cancer from 2003 to 2014. We searched PubMed, Web of Science, Scopus and PsycINFO from the establishment of the databases to August 24, 2023, for research on PFASs related to breast cancer. A meta-analysis was performed using Stata 12.0. A total of 1430 subjects aged 20 years or older were selected from the NHANES. The logistic regression results indicated that there was no correlation between breast cancer and PFASs (P > 0.05). The meta-analysis, included nine studies with a total of 2399 breast cancer patients, included in the meta-analysis, revealed no statistically significant association between PFASs and the risk of breast cancer (odds ratio = 1.04; 95 % confidence interval, 0.88-1.21; P > 0.05). The results show that PFASs are not associated with breast cancer risk.

Trends in Cancer Incidence and Mortality in US Adolescents and Young Adults, 2016-2021

(1) Background: The incidence rate of early onset-cancer (<50) has increased since 1995. Among younger people, cancers in AYAs (aged 15-39 y) are often biologically distinct tumors from those treated in the pediatric and older adult population. The current study describes trends in the United States for the most recent years including the first year of the COVID-19 epidemic. We aimed to describe the recent incidence and mortality trends of cancers in AYAs (aged 15-39 y). (2) Methods: We used data from the Surveillance, Epidemiology, and End Results (SEER 22) from 1 January 2016 to 31 December 2021. Age-adjusted incidence and mortality rates were assessed by SEER*Stat 8.4.3 for major cancer types by sex, race/ethnicity, age, and metropolitan/nonmetropolitan status. Time trends of age-adjusted incidence and mortality rates were examined by sex and metropolitan/nonmetropolitan status. (3) Results: Age-adjusted overall cancer incidence and mortality rates were stable during this study period. The age-adjusted incidence rates declined significantly for ependymoma, melanoma, carcinomas of lung, bronchus, and trachea, unspecified malignant neoplasms, and non-Hodgkin's lymphoma. Significant increases were found for gastrointestinal tract cancers and non-Kaposi sarcomas. The age-adjusted mortality rate decreased for acute myeloid leukemia, melanoma, carcinomas of liver and intrahepatic bile ducts, kidney and, in women, leukemia. For some cancers, rates differed by sex, race, ethnicity, and geography. Monitoring the rates and time trends of AYA cancer emphasizes the distinct health concern for this age group.

Male infertility and perfluoroalkyl and poly-fluoroalkyl substances: evidence for alterations in phosphorylation of proteins and fertility-related functional attributes in bull spermatozoa†

BACKGROUND

Perfluoroalkyl and poly-fluoroalkyl substances (PFAS) are pervasive environmental pollutants and potential threats to reproductive health. Epidemiological studies have established an association between PFAS and male infertility, but the underlying mechanisms are unclear.

OBJECTIVES

Investigate the effect of perfluorooctane sulfonic acid (PFOS), the most prevalent and representative PFAS, on bull sperm protein phosphorylation and function.

METHODS

We exposed bull sperm to PFOS at 10 (average population exposure) and 100 μM (high-exposure scenario), and analyzed global proteomic and phosphoproteomic analysis by TMT labeling and Nano LC-MS/MS. We also measured sperm fertility functions by flow cytometry.

RESULTS

PFOS at 10-μM altered sperm proteins linked to spermatogenesis and chromatin condensation, while at 100 μM, PFOS affected proteins associated with motility and fertility. We detected 299 phosphopeptides from 116 proteins, with 45 exhibiting differential expression between control and PFOS groups. PFOS dysregulated phosphorylation of key proteins (ACRBP, PRKAR2A, RAB2B, SPAG8, TUBB4B, ZPBP, and C2CD6) involved in sperm capacitation, acrosome reaction, sperm-egg interaction, and fertilization. PFOS also affected phosphorylation of other proteins (AQP7, HSBP9, IL4I1, PRKAR1A, and CCT8L2) related to sperm stress resistance and cryotolerance. Notably, four proteins (PRM1, ACRBP, TSSK1B, and CFAP45) exhibited differential regulation at both proteomic and phosphoproteomic levels. Flow cytometric analysis confirmed that PFOS increased protein phosphorylation in sperm and also decreased sperm motility, viability, calcium, and mitochondrial membrane potential and increased mitochondrial ROS in a dose-dependent manner.

CONCLUSIONS

This study demonstrates that PFOS exposure negatively affects phosphorylation of proteins vital for bull sperm function and fertilization.

Mapping Per- and Polyfluoroalkyl Substance Footprint from Cosmetics and Carpets across the Continental United States

Per- and polyfluoroalkyl substances (PFAS) released from common consumer products, such as cosmetics and carpets, are nonpoint sources of environmental contamination. However, detailed information on PFAS mass and emission rates from these products is limited. Here, we propose a methodology to develop PFAS footprint from the manufacturing and supply chain data of cosmetics and carpets. Our analysis combines geospatial and statistical assessments to understand how the production and consumption of these products contribute to existing PFAS contamination hotspots in the Continental United States (CONUS). Statewide mass estimations revealed that North Carolina and New York contribute to the major PFAS mass released from cosmetics, while Georgia and California contribute to the major PFAS mass released from carpets. The average per capita PFAS footprint from carpets and cosmetics is about 103 mg/year. Upon disposal, over 60% of the mass eventually ends up in landfills. The accumulation of PFAS stocks in landfills, primarily from carpets and to some extent from cosmetics, highlights the critical need to cease the production and use of PFAS in consumer products. Coastal counties are particularly vulnerable due to higher population and therefore higher consumption of these PFAS-tainted consumer products. Additionally, counties with densely populated areas and with preexisting contamination sources would face increased vulnerability to PFAS contamination released from various consumer products.

Microplastics and PFAS air-water interaction and deposition

Although microplastics (MPs) and per- and polyfluoroalkyl substances (PFAS) have received tremendous attention separately, understanding their ubiquitous presence in the environment, persistence and toxicity requires comprehensive study of the fate and transport of co-existing MPs and PFAS. MPs may have large sorption capacity and can serve as vectors for PFAS to undergo long-range transport in water. Atmospheric deposition of both PFAS and MPs has been reported in urban, rural, and remote areas. This review identifies types and levels of PFAS and MPs in air, their interactions, and environmental factors contributing to their air-water deposition. MPs in combination with PFAS may carry combined toxicity and pose elevated risks to ecosystems and human health. Our review shows that air-water deposition of MPs and PFAS can be governed by environmental factors including precipitation, humidity, UV, wind, and particulate matter levels in the air. Increasing humidity may increase MP particle size due to hygroscopic growth, which affects its distribution and deposition rate. Humidity has been observed to have both positive and negative impacts on PFAS partitioning onto MPs. More attention should be paid to MPs and PFAS co-occurrence when addressing their transport behavior in air and deposition to aquatic systems.