Characteristic and health risk of per- and polyfluoroalkyl substances from cosmetics via dermal exposure

Target and suspect screening of per- and polyfluoroalkyl substances (PFASs) in consumer products using ion mobility separation high resolution mass spectrometry (IMS-HRMS)

This study aims to investigate the distribution of per- and polyfluoroalkyl substances (PFAS) and their precursors in 55 consumer products, including 27 personal care products (PCPs) from 7 categories and 28 household products (HPs) from 6 categories and analyze the correlation between them, by measuring PFASs using target analysis with LC-MS/MS and suspect screening using high-resolution mass spectrometry (HRMS) combined with ion mobility separation (IMS). In most products, perfluorocarboxylic acid (PFCA) concentrations (0.036-25.2 ng/g) exceeded perfluorosulfonic acid concentrations (n.d.-0.566 ng/g). In PCPs, the median concentrations of 12 PFASs and two fluorinated precursors (0.053-139 ng/g) were significantly higher than in HPs (0.012-76.0 ng/g) (p < 0.05). Across all PCP and HP types, short-chain PFASs (PFCAs ≤ C7; PFSAs ≤ C6) (1.68-46.9 ng/g) were also significantly higher than long-chain PFASs (0.071-6.86 ng/g) (p < 0.05). Suspect screening identified a total of 9 candidate PFASs, including the four PFCA precursors, all of which were assigned a confidence level of 3 or higher. The observed positive correlation between precursors and PFCAs (p < 0.05) suggests that precursors may be converted into PFCAs, thereby increasing PFCA concentrations, although the specific transformation pathways require further investigation. This study provides insights into the distribution of PFAS and their precursors in consumer products and demonstrates that IMS-HRMS-based suspect screening can be useful for distinguishing false positives in PFAS identification.

Dermal permeation of perfluoroalkyl substances in human skin - An in-vitro study

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous, persistent environmental contaminants, posing significant health risks to animals and humans. While dermal exposure to PFAS through daily contact with consumer products such as school uniforms and personal care items is common, the mechanisms and extent of skin uptake remain poorly understood. This study investigated the dermal penetration of 30 PFAS, both as mixtures and individual compounds, using in vitro human skin models in a Franz Diffusion Cell system. Results showed that in a mixture, short-chain PFAS, including FBSA, PFBA, PFPrS, and PFPeA, demonstrated permeation rates of 4.8 ± 2.5 %, 3.7 ± 0.3 %, 2.0 ± 0.1 %, and 1.1 ± 0.1 %, respectively, over 24 h. In contrast, none of the long-chain PFAS penetrated the skin in the same period. When tested individually in water, FBSA exhibited the highest permeation, achieving 7.0 ± 0.9 % (p < 0.05), underscoring its ability to cross the stratum corneum under simulated environmental conditions. These findings highlight that while permeation of long-chain PFAS could be slowed down by the skin barrier, certain short-chain PFAS, such as FBSA, can penetrate human skin in vitro. This study provides crucial preliminary data on PFAS dermal absorption, emphasizing the need for standardized experimental conditions that account for the chemical properties of PFAS and the physiological properties of human skin. Our findings suggest that further research is needed to elucidate the mechanisms of PFAS dermal absorption and better assess the risk of dermal exposure to PFAS.

Unveiling airborne threats: Vertical profiles of multiple emerging pollutants in PM2.5 across the urban atmosphere of Southern China

PM2.5 has a detrimental impact on human health and has become a focus of widespread concern. The tempo-spatial distribution of emerging pollutants has been extensively studied, while there is a scarcity of understanding their vertical distribution in atmospheric environment. Here we investigated the vertical profiles of phthalate esters (PAEs), organophosphate esters (OPEs), neonicotinoids (NEOs), and per-and polyfluorinated substances (PFASs) in PM2.5 at ground level (4.5 m), 118 m, and 488 m in an urban environment. Results reveal that the PAEs in PM2.5 had higher concentrations than OPEs, NEOs, and PFASs. Vertical pollutant distribution generally exhibits a decline in concentration with increasing altitude. However, the opposite pattern also occurs, especially for NEOs and PFASs. The underlying mechanisms are multifaceted, encompassing the physicochemical characteristics of pollutants, meteorological parameters, and air-mass trajectories, each contributing to the vertical profile in varying degree. Additionally, the indoor health risks posed by outdoor pollutants at 118 m and 488 m were evaluated and found to be comparable to the outdoor risks at the ground. To our knowledge, this is the first exploration of the vertical characteristics of emerging pollutants at heights exceeding 100 meters, which provides a crucial reference for the prevention and control of emerging pollutants.

Association between plasma perfluoroalkyl substances and high-grade serous ovarian cancer overall survival: A nested case-control study

BACKGROUND

Although evidence suggests that perfluoroalkyl and polyfluoroalkyl substances (PFASs) are positively correlated to several disease risks, no studies have proven if plasma PFASs are related to ovarian cancer survival.

OBJECTIVE

To explore the association between plasma PFASs and high-grade serous ovarian cancer (HGSOC) overall survival (OS) in the population who did not smoke.

METHODS

We conducted a nested case-control study within the Ovarian Cancer Follow-Up Study, matching 159 dead patients and 159 survival ones based on body mass index, sample date, and age at diagnosis. Nine plasma PFASs were extracted by solid phase extraction and measured using a liquid chromatography system coupled with tandem mass spectrometry. Baseline plasma concentrations of perfluorinated carboxylic acids (PFCAs) [perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroheptanoic acid (PFHpA)] and perfluorinated sulfonic acids (PFSAs) [perfluorooctane sulfonic acid (PFOS) and perfluorohexane sulfonic acid (PFHxS)] were calculated. Odds ratios (ORs) and corresponding 95 % confidence intervals (CIs) were calculated via conditional logistic regression models. To elucidate the combined effects, Bayesian kernel machine (BKMR), and regression quantile g-computation (QGC) models were utilized.

RESULT

In full-adjusted model, significant differences were observed between HGSOC survival and perfluorobutane sulfonic acid, PFHpA, PFHxS, PFOS, PFCA, and PFSA. ORs and 95 %CIs were 2.74 (1.41-5.31), 1.97 (1.03-3.76), 2.13 (1.15-3.95), 2.28 (1.16-4.47), 3.74 (1.78-7.85), and 2.56 (1.31-5.01), respectively for the highest tertile compared with the lowest tertile. The QGC and BKMR models indicated that elevated concentrations of PFAS mixtures were associated with poor OS in HGSOC.

CONCLUSIONS

Both individual and mixed plasma PFASs may relate to poor OS of HGSOC. Further research is necessary to establish causality, and it is recommended to reinforce environmental risk mitigation strategies to minimize PFAS exposure.

Leaching profile of per- and polyfluoroalkyl substances (PFAS) from biosolids after thickening, anaerobic digestion, and dewatering processes, and significance of protein, phosphorus, and selected ions

Batch leaching experiments were conducted to evaluate the release of forty per- and polyfluoroalkyl substances (PFAS) from sludge samples collected after thickening, anaerobic digestion, and dewatering processes at two wastewater treatment plants. The South District wastewater treatment plant (SDWWTP), which receives domestic wastewater and landfill leachate from a nearby landfill, and the Central District wastewater treatment plant (CDWWTP), which receives only domestic wastewater, were selected for this study. PFAS released into the aqueous phase were analyzed by sacrificial sampling after 1, 3, 7, 14, and 30 days. Results demonstrated rapid PFAS leaching, with the highest levels detected in biosolid leachates after just one day. Distinct differences were observed in PFAS composition and concentrations between the two treatment plants. Of the forty PFAS measured, nineteen were detected, with higher concentrations identified at SDWWTP. The input of landfill leachate to SDWWTP appears to have significantly contributed to the elevated levels of specific PFAS, particularly long-chain compounds, compared to the emerging short-chain PFAS found in biosolids. In addition to PFAS analysis, the compositions of the sludge samples, including total and volatile solids, protein, phosphorus (P), iron, aluminum, calcium, and magnesium, were also assessed. Spearman correlation analyses revealed moderate to strong relationships between PFAS levels in leachate and certain sludge components. For instance, correlations between P content and PFCAs and FTCAs were moderate (R2 = 0.45-0.76). In thickener sludge leachate, strong correlations were observed for FPrPA (3:3 FTCA), PFDA, and PFTrDA with P, with R2 values of 0.60, 0.53, and 0.54, respectively. In the digested sludge, correlations were found for PFHpA, PFDA, and PFNA (R2 = 0.45-0.76). Also, for digested sludge leachate, strong correlations were found between the individual compounds PFHpA, PFHxA, PFNA, PFOA, and PFPeA (R2 = 0.60-0.88). Predominant PFAS in leachate from biosolids were identified, including PFOS, FPePA (5:3 FTCA), PFPeA, PFBA, PFHxA, N-EtFOSAA, and 6-2 FTS.

Assessment of the Variability in the Occurrence of PFAS in Fish Tissues from Selected Fisheries in the Baltic Sea

In this study, the results of a comprehensive assessment of the variability in the occurrence of ten perfluorinated compounds (PFAS) in fish tissues originating from 2014 to 2019 from six fisheries in the Baltic Sea are presented. A total of 360 fish samples of three species (perch, herring and flatfish) were analysed. For the determination of PFAS, both linear and branched stereoisomers, LC-ESI-MS/MS technique preceded by simultaneous SPE isolation was validated and applied. The total concentration of all determined PFAS compounds shows that the highest levels were observed in the Szczecin Lagoon (4.8 ± 0.7 µg/kg) and the lowest in the Pomeranian Bay (1.9 ± 0.1 µg/kg). In most samples, the dominant compound was perfluorooctane sulfonic acid (PFOS). The present research enabled the assessment of the variability in the occurrence of PFAS stereoisomers in marine fish.

Occurrence, Fate, and Removal of Per- and Polyfluoroalkyl Substances (PFAS) in Small- and Large-Scale Municipal Wastewater Treatment Facilities in the United States

Wastewater treatment plants (WWTPs) could be conduits of polyfluoroalkyl substances (PFAS) contaminants in the environment. This study investigated the fate of 40 PFAS compounds across nine municipal WWTPs with varying treatment capacity and processes. High concentrations of perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) were detected in wastewater, with the ratio of their total concentrations (∑PFCAs/∑PFSAs) always greater than one. Transformation of precursors by activated sludge processes significantly increased the concentrations of short-chain PFCAs (e.g., perfluoropentanoic acid (PFPeA) and perfluorohexanoic acid (PFHxA)), while further advanced treatment processes offered minimal removal of perfluoroalkyl acids. Treatment capacity and PFAS removal efficiency showed no apparent correlation. The maximum possible PFAS loads discharged from WWTPs were 340-9645 g·year-1, similar to those entering the WWTPs. Among six regulated PFAS compounds, detection frequency was 100% for five (perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorononanoic acid (PFNA), perfluorobutanesulfonic acid (PFBS), and perfluorohexanesulfonic acid (PFHxS)) and 67% for hexafluoropropylene oxide dimer acid (HFPO-DA) (Gen-X). Concentrations of PFOA and PFOS in WWTP discharges consistently exceeded 4 ng·L-1. The hazard index (HI) for mixtures containing two or more of the four PFAS (PFNA, PFBS, PFHxS, and HFPO-DA) ranged from 0.2 to 6.1. These findings indicate that wastewater discharges may pose a risk, emphasizing the need for enhanced PFAS removal strategies in wastewater treatment processes.

Interference Mechanisms of Endocrine System and Other Systems of Endocrine-Disrupting Chemicals in Cosmetics-In Vitro Studies

Endocrine-disrupting chemicals (EDCs), found in various cosmetic products, interfere with the normal functioning of the endocrine system, impacting hormone regulation and posing risks to human health. Common cosmetic EDCs, such as ultraviolet (UV) filters, parabens, and triclosan, can enter the human body through different routes, including skin absorption. Their presence has been linked to adverse effects on reproduction, immune function, and development. High-throughput in vitro assays, using various human cell lines, were employed to assess the effects of common cosmetic EDCs such as ethylhexyl methoxycinnamate (EHMC), benzophenone-3 (BP-3), homosalate, and parabens. Despite ongoing regulatory efforts, gaps persist in understanding their long-term impacts, particularly when they are present as mixtures or degradation products in the environment. This study focuses on recent in vitro research to investigate the mechanisms through which cosmetic-related EDCs disrupt the endocrine system and other physiological systems. The in vitro findings highlight the broader systemic impact of these chemicals, extending beyond the endocrine system to include immune, reproductive, and cardiovascular effects. This research underscores the importance of developing safer cosmetic formulations and enhancing public health protection, emphasizing the need for stricter regulations.

Systemic and immunotoxicity induced by topical application of perfluoroheptane sulfonic acid (PFHpS) or perfluorooctane sulfonic acid (PFOS) in a murine model

Per- and polyfluoroalkyl substances (PFAS) are a large group of synthetic surfactants of over 12,000 compounds that are incorporated into numerous products for their chemical and physical properties. Studies have associated PFAS with adverse health effects. Although there is a high potential for dermal exposure, these studies are lacking. The present study evaluated the systemic and immunotoxicity of subchronic 28- or 10-days of dermal exposure, respectively, to PFHpS (0.3125-2.5% or 7.82-62.5 mg/kg/dose) or PFOS (0.5% or 12.5 mg/kg/dose) in a murine model. Elevated levels of PFHpS were detected in the serum and urine, suggesting that absorption is occurring through the dermal route. PFHpS induced significantly increased relative liver weight, significantly decreased relative spleen and thymus weight, altered serum chemistries, and altered histopathology. Additionally, PFHpS significantly reduced the humoral immune response and altered immune subsets in the spleen, suggesting immunosuppression. Gene expression changes were observed in the liver, skin, and spleen of genes involved in fatty acid metabolism, necrosis, and inflammation. Immune-cell phenotyping identified significant decreases in B-cells and CD11b+ monocyte and/or macrophages in the spleen along with decreases in eosinophils and dendritic cells in the skin. These findings support PFHpS absorption through the skin leading to liver damage and immune suppression.

Targeted investigation of per- and polyfluoroalkyl substances from domestic cosmetics and personal care products in China and its implications for human exposure

Per- and polyfluoroalkyl substances (PFASs) are synthetic chemicals reported in daily supplies, and skin absorption is one of the routes for human exposure to PFASs. This study aims to evaluate the potential risk of PFASs exposure from cosmetics and personal care products in China. A random sampling of 44 domestic cosmetics and personal care products, summarized into 6 categories, was conducted to investigate the concentrations of 24 target PFASs. PFASs concentrations of 86.4 % products were lower than 100 ng/g, and 34.2 % products were lower than 10 ng/g. PFCAs and PAPs were dominant. Keywords of "wear-resistant" and "long-lasting" may indicate the presence of PFASs in products. Disabled PFOA, PFOS, and PFHxS were not detected. Notably, the presence of PFHxA should be of concern, and its detection frequency reached 59.1 %, with the maximum concentration of 1274.77 ng/g. Further, the daily exposure dose (DED) of ∑PFASs from skin exposure through cosmetics and personal care products was evaluated to be 3.01 ng/kg-bw/day, which wasn't negligible compared to the prescribed acceptable intake value. Conclusively, this study emphasizes that cosmetics and personal care products are important sources leading to the PFASs skin exposure and provides a basis for future regulation of PFASs as product additive.

Threats of per- and poly-fluoroalkyl pollutants to susceptible populations

Environmental exposure to per- and poly-fluoroalkyl substances (PFAS) has raised significant global health concerns due to potential hazards in healthy adults. However, the impact of PFAS on susceptible populations, including pregnant individuals, newborns, the older people, and those with underlying health conditions, has been overlooked. These susceptible groups often have physiological changes that make them less resilient to the same exposures. Consequently, there is an urgent need for a comprehensive understanding of the health risks posed by PFAS exposure to these populations. In this review, we delve into the potential health risks of PFAS exposure in these susceptible populations. Equally important, we also examine and discuss the molecular mechanisms that underlie this susceptibility. These mechanisms include the induction of oxidative stress, disruption of the immune system, impairment of cellular metabolism, and alterations in gut microbiota, all of which contribute to the enhanced toxicity of PFAS in susceptible populations. Finally, we address the primary research challenges and unresolved issues that require further investigation. This discussion aims to foster research for a better understanding of how PFAS affect susceptible populations and to pave the way for strategies to minimize their adverse effects.