Targeted and Suspect Screening of Per- and Polyfluoroalkyl Substances in Cosmetics and Personal Care Products

Hair analysis as a non-invasive method for assessing the exposure of wildlife to per- and poly-fluoroalkyl substances (PFAS)

In mammals, exposure to PFAS is usually assessed by measuring burdens in internal organs (i.e., liver and brain) or plasma, while less emphasis is devoted to non-invasive and non-destructive methods. We assess the suitability of hair as a non-invasive matrix for monitoring the exposure of mammals to 33 PFAS, including perfluoroalkyl carboxylic acids (PFCAs), perfluoroalkane sulfonic acids (PFSAs), perfluoroalkylether carboxylic acids (PFECAs), perfluoroalkylether sulfonic acids (PFESAs), perfluoroalkane sulfonyl fluoride-based substances (PASFs), and fluorotelomers (FTs). The Red fox is chosen as the target species due to its apical position in the terrestrial food web of the study area, the Cavallino-Treporti peninsula in North-East Italy. All analysed samples (n = 24) are positive for PFAS, with eight compounds quantified in all samples, including PFHxA, PFOA, PFDA, PFUnDA, PFDoDA, PFTriDA, PFTeDA, and PFOS. The highest mean concentration in hair samples is measured for PFOS (1.40 ± 0.48 ng g-1 dw) followed by PFDoDA (0.31 ± 0.05 ng g-1 dw), and PFOA (0.31 ± 0.19 ng g-1 dw), while the mean ∑33PFAS was 3.41 ± 0.93 ng g-1 dw. The dominance of PFOS and long-chain PFAS in the PFAS profile and the occurrence of compounds with even-numbered carbon chains at higher concentrations than the odd-numbered compounds with a one-carbon longer chain (i.e., PFOA > PFNA, PFDA > PFUnDA, PFDoDA > PFTriDA) suggest the trophic transfer along the terrestrial food web as the primary exposure pathway in the study area. The data suggest hair analysis as a reliable, non-invasive method for assessing the possible exposure of mammals to PFAS and suggested that the Red fox can be used as a sentinel of the environment, embracing the One Health perspective.

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.

Evaluation of extraction methodologies for PFAS analysis in mascara: a comparative study of SPME and automated µSPE

Research efforts have primarily focused on identifying per- and polyfluoroalkyl substances (PFAS) in common environmental media like water, air, soil, and biological samples. However, there is limited research on PFAS detection in complex samples such as personal care products, including cosmetics. PFAS are used in cosmetics for emulsification, surfactant action, and stabilization, and have been detected in products such as foundation, powders, and nail polish. The complexity of cosmetic formulations, with various additives, makes the analysis of these samples extremely challenging. This study aimed to explore and develop convenient extraction methods to accurately quantify eight anionic PFAS in mascara products. Solid-phase microextraction (SPME) and automated micro solid-phase extraction (µSPE) were evaluated, and quantification was performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Six mascara products, including waterproof and non-waterproof types, were analyzed, optimizing methanol-water mixtures as dispersive media to maximize PFAS recovery. Elution solution composition, volume, and dispensing speed were optimized for the µSPE method to ensure quantitative elution of the PFAS from the extraction phase. For the SPME method, the extraction time was optimized to account for the varying diffusion behavior of PFAS in the mixed-phase medium. Both extraction methods were evaluated in terms of greenness and practicality, with SPME achieving the best overall scores. Method validation demonstrated good linearity (0.025 to 25 ng/g) for both protocols, with µSPE providing lower limits of quantification (LOQ) for the most hydrophobic PFAS. 6:2 diPAP was quantified in real samples at concentrations ranging from 1.26 to 3.48 ng/g in 4 of the 9 mascaras tested.

Per- and polyfluoroalkyl substances (PFAS): immunotoxicity at the primary sites of exposure

Per- and polyfluoroalkyl substances (PFAS) are persistent synthetic chemicals widely used in industrial and consumer products, leading to environmental contamination and human exposure. This review focuses on perfluoroalkyl acids, a subset of PFAS, which are primarily encountered through diet, including drinking water, and other pathways such as dust ingestion, and dermal contact. Impaired vaccine antibody response has been identified as the most critical effect for risk assessment by the European Food Safety Authority. Furthermore, human epidemiological studies have linked exposure to certain PFAS to various immune-related outcomes, such as asthma, allergies, and inflammatory bowel disease. This review examines potential immunomodulatory effects of perfluoroalkyl acids at the primary sites of exposure: lungs, intestines, and skin, using human epidemiological data as the basis for investigating these impacts. While animal studies are referenced for context, this paper highlights the need for further human-based research to address key questions about PFAS and their immunological impacts. The state of in vitro toxicity testing related to these effects is thoroughly reviewed and critical issues pertaining to this topic are discussed.

Associations between per-and polyfluoroalkyl substances (PFAS) and county-level cancer incidence between 2016 and 2021 and incident cancer burden attributable to PFAS in drinking water in the United States

BACKGROUND

Exposure to per- and polyfluoroalkyl substances (PFAS) has been linked with various cancers. Assessment of PFAS in drinking water and cancers can help inform biomonitoring and prevention efforts.

OBJECTIVE

To screen for incident cancer (2016-2021) and assess associations with PFAS contamination in drinking water in the US.

METHODS

We obtained county-level age-adjusted cancer incidence (2016-2021) from the Surveillance, Epidemiology, and End Results (SEER) Program. Data on PFAS levels in public drinking water systems were obtained from the Third (UCMR3; 2013-2015) and Fifth (UCMR5; 2023-2024) Unregulated Contaminant Monitoring Rule. UCMR3 measured PFOS, PFOA, PFNA, PFHxS, PFHpA, and PFBS. UCMR5 expanded measurements to include PFBA, PFHxA, PFPeA, and PFPeS. We created indicators of PFAS detection and, for UCMR5, concentrations above Maximum Contaminant Levels (MCLs). MCLs for PFOA and PFOS are 4 ng/L, and for PFNA and PFHxS are 10 ng/L. We used Poisson regression models to assess associations between PFAS detection or MCL violation and cancer incidence, adjusting for potential confounders. We estimated the number of attributable cancer cases.

RESULTS

PFAS in drinking water was associated with increased cancer incidence in the digestive, endocrine, oral cavity/pharynx, and respiratory systems. Incidence rate ratios (IRRs) ranged from 1.02 to 1.33. The strongest association was observed between PFBS and oral cavity/pharynx cancers (IRR: 1.33 [1.04, 1.71]). Among males, PFAS was associated with cancers in the urinary, brain, leukemia, and soft tissues. Among females, PFAS was associated with cancers in the thyroid, oral cavity/pharynx, and soft tissue. PFAS in drinking water is estimated to contribute to 4626 [95% CI: 1,377, 8046] incident cancer cases per year based on UCMR3 data and 6864 [95% CI: 991, 12,804] based on UCMR5.

IMPACT STATEMENT

The ecological study examined the associations between PFAS in drinking water measured in two waves (2013-2015 and 2023-2024) and cancer incidence between 2016 and 2021. We found that PFAS in drinking water was associated with cancers in the organ system including the oral cavity/pharynx, lung, digestive system, brain, urinary system, soft tissue, and thyroid. Some cancers have not been widely studied for their associations with PFAS. We also observed sex differences in the associations between PFAS and cancer risks. This is the first ecological study that examined PFAS exposure in drinking water and various cancer risks.

Exposure experiments and machine learning revealed that personal care products can significantly increase transdermal exposure of SVOCs from the environment

We investigated the impacts of personal care products (PCPs) on dermal exposure to semi-volatile organic compounds (SVOCs), including phthalates, organophosphate esters, polycyclic aromatic hydrocarbons (PAHs), ultraviolet filters, and p-phenylenediamines, through an experiment from volunteers, explored the impact mechanisms of PCP ingredients on dermal exposure, and predicted the PCP effects on SVOC concentrations in human serum using machine learning. After applying PCPs, namely lotion, baby oil, sunscreen, and blemish balm, the dermal adsorption of SVOCs increased significantly by 1.63 ± 0.62, 1.97 ± 0.73, 1.91 ± 0.48, and 2.03 ± 0.59 times, respectively, probably due to the absorption effects of PCP ingredients. Ingredient tocopherol can increase dermal adsorption of SVOCs by 2.59 ± 1.60 times. PCPs can either increase or decrease the SVOC transdermal exposure risks, depending on the properties of their ingredients. Blemish balm caused the highest hazard quotient for certain SVOCs, while tris(2-chloroethyl) phosphate (TCEP) exhibited the highest hazard quotient. We predicted the SVOC concentrations in serum before and after applying PCPs based on the PCP-increased skin permeation doses and machine learning. PCPs can significantly increase the serum concentrations of PAHs with 2-3 rings and TCEP. This study first revealed that PCPs can significantly increase the dermal exposure of SVOCs from the surroundings, resulting in potentially higher health risks.

Evaluating personal care product use by Environmental Working Group hazard scores in relation to consumers' sociodemographic characteristics, purchasing behaviors, and product safety perceptions

BACKGROUND

Personal care products (PCPs) are a source of environmental chemical exposures. Little research has examined the specific PCPs people use, the environmental hazards posed by those PCPs, and factors informing PCP selection.

OBJECTIVE

To examine chemical hazards of the specific products used in relation to sociodemographic factors, purchasing behaviors, and perceptions about PCP safety.

METHODS

In a cross-sectional, university-based sample (NJ, USA, N = 593), participants reported on sociodemographics, PCP purchasing behaviors and perceptions, and PCP use in the last 24-48 h (including brand and product name). Those PCPs were linked to product hazard scores (1=least hazardous, 10=most hazardous) in the Environmental Working Group's Skin Deep® database. For each participant, we calculated average hazard scores across all PCPs used and by category (e.g., haircare, skincare) and evaluated use of PCPs with high hazard scores (7-10). We fitted adjusted regression models examining associations of sociodemographic factors and participants' perceptions and purchasing behaviors with product hazard scores.

RESULTS

Of 9349 unique PCPs used by participants, 68% matched to Skin Deep®. Average hazard scores varied by participant characteristics (e.g., age) for perfumes/colognes, beauty, and skin care products. The relative risk (RR) of recent use of a hair product with a high hazard score was twice as high in non-Hispanic Black women compared to non-Hispanic White women (RR:1.99; 95%CI:1.37, 2.89). Frequent use of healthy product apps (β = -0.49, 95%CI:-0.77, -0.21), reading product ingredient labels (β = -0.26; 95%CI:-0.82, -0.30), and seeking eco-friendly products (β = -0.17; 95%CI:-0.36, -0.01) were associated with use of skin care products with lower hazard scores. Results for hair and beauty products were similar. Concerns about PCP health impacts and regulation were associated with using products with lower hazard scores.

IMPACT STATEMENT

Personal care products (PCPs) can contain numerous endocrine disrupting and carcinogenic chemicals. In a U.S. university-based sample, we linked the PCPs used by participants in the last 24-48 h to hazard scores in the Skin Deep® database. Average hazard scores of the PCPs used by participants varied by sociodemographic factors. Participant behaviors (e.g., use of healthy product apps) and perceptions of PCP safety and regulation were associated with the average hazard scores of the PCPs they used. Our findings suggest that education and tools to inform PCP choice may help consumers choose safer products and potentially, reduce chemical exposures.

Suspect and Nontarget Analysis of Per- and Polyfluoroalkyl Substances in Groundwater Underlying Different Land-Use Areas

Groundwater can be contaminated by PFAS emissions, yet research on the presence and associated risks of PFAS in groundwater underlying different land-use areas remains limited. Herein, high-resolution mass spectrometry-based suspect and nontarget analyses were performed to determine PFAS occurrence in groundwater samples obtained from a rural area, a planting region, and the vicinities of a pharmaceutical park, an airport, and an industrial park in Datong City, China. A total of 31 PFAS (16 emerging and 15 legacy PFAS) were identified, and the ΣPFAS concentrations ranged from 0.775 (rural area) to 80.7 ng/L (pharmaceutical park). In terms of the average concentration of ΣPFAS, legacy PFAS were predominant in rural groundwater, whereas emerging PFAS were predominant in the other four land-use areas. PFOA, PFDA, PFUnDA, and 6:2 FTS were detected in all groundwater samples. To further prioritize the risk of identified PFAS in groundwater, the detection frequency; concentration; and persistence, bioaccumulation, and toxicity attributes were adopted, which showed that high-risk compounds varied across different land-use areas. Our results further reveal the ubiquitous contamination of PFAS in groundwater environments, even in areas with limited human activity, and highlight the necessity of suspect and nontarget analysis for assessing PFAS exposure through groundwater.

Per- and polyfluoroalkyl substances (PFAS) accumulation in fish occupying different trophic positions from East Canyon Creek, a seasonally effluent-dominated river, Utah, USA

Fish and seafood are considered a major source of human dietary exposure to per- and polyfluoroalkyl substances (PFAS). In this study, we examined levels of 35 PFAS in fish samples of brown trout and mottled sculpin, which occupy different trophic positions, collected in 2014 from East Canyon Creek in Utah, USA. We observed 20 PFAS with ∑20PFAS ranging from 0.46-63.9 ng/g and from Collapse

Key Words

• Bioaccumulation
• Fish
• Food safety
• PFAS
• Trophic position

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MESH Headings

• Animals
• Utah
• Water Pollutants, Chemical/metabolism
• Water Pollutants, Chemical/analysis
• Fluorocarbons/metabolism
• Fluorocarbons/analysis
• Environmental Monitoring
• Rivers/chemistry
• Food Chain
• Fishes/metabolism
• Trout/metabolism

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Grants Collapse

Affiliation(s)

Yelena Sapozhnikova USDA, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, PA, USA.
Kevin M Stroski USDA, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, PA, USA; Center for Reservoir and Aquatic Systems Research, Department of Environmental Science, Baylor University, Waco, TX, USA
Samuel P Haddad Center for Reservoir and Aquatic Systems Research, Department of Environmental Science, Baylor University, Waco, TX, USA
S Rebekah Burket Center for Reservoir and Aquatic Systems Research, Department of Environmental Science, Baylor University, Waco, TX, USA
Michael Luers Snyderville Basin Water Reclamation District, Park City, UT, USA
Bryan W Brooks Center for Reservoir and Aquatic Systems Research, Department of Environmental Science, Baylor University, Waco, TX, USA

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Collaborators Collapse

A systematic review for non-targeted analysis of per- and polyfluoroalkyl substances (PFAS)

This review follows the PRISMA guidelines to provide a systematic review of 115 peer reviewed articles that used non-targeted analysis (NTA) methods to detect per- and polyfluoroalkylated substances (PFAS). This literature highlights the significant positive impact of NTA in understanding PFAS in the environment. Within the literature a geographical bias exists, with most NTA studies (∼60 %) conducted in the United States and China. Future studies in other regions (such as South America and Africa) are needed to gain a more global understanding. More research is required in marine environments and the atmosphere, as current studies focus mainly on freshwater, groundwater, soil, and sediments. The majority of studies focus on measuring PFAS in the environment, rather than in commercial products (with the exception of AFFF). Non-lethal blood sampling has been successful for NTA in humans and wildlife, but additional biomonitoring studies are required on exposed cohorts to understand health risks and PFAS biotransformation pathways. NTA methods mostly use liquid chromatography and negative ionisation, which biases the literature towards the detection of specific PFAS. Despite improvements in data reporting and quality assurance and control (QA/QC) procedures, factors such as false negative and false positive rates are often overlooked, and many NTA workflows remain highly subjective. Perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) are the most detected PFAS classes, identified in over 80 % of NTA studies, and are common in routine monitoring. However, our review identified >1000 PFAS from a total of 382 different PFAS classes, with over 300 classes found in fewer than 5 % of studies. This highlights the variety of different PFAS present in the environment, and the limitations of relying solely on targeted methods. Future monitoring programs and regulations would benefit from considering NTA methods to provide more comprehensive information on PFAS present in the environment.

Room-temperature synthesis of fluorinated covalent organic framework coupled with liquid chromatography-mass spectrometry for determination of per- and polyfluoroalkyl substances in drinking water

The routine monitoring of per- and polyfluoroalkyl substances (PFASs) in drinking water has become an important task in the field of public health. In this study, a fluorinated covalent organic framework (COF) was synthesized at room temperature using tetra-(4-aminophenyl) methane (TAM) and 2,3,5, 6-tetrafluoro-terephthalal (TFTA) as building blocks and named as TAM-TFTA-COF. The adsorption characteristics of PFASs on the TAM-TFTA-COF were investigated through adsorption model-fitting and molecular calculation. The TAM-TFTA-COF was served as the solid phase extraction (SPE) cartridge packing for the enrichment of PFASs. Combined with liquid chromatography-tandem mass spectrometry, the proposed method showed good linearity in the range of 1.25-375 ng·L-1, low limits of detection (0.03-0.24 ng·L-1), and excellent intraday and interday precisions with RSD <10.3 %. Furthermore, this analytical method can be utilized for the determination of PFASs in tap water, spring water, and lake water with satisfactory accuracy.

Examining disparities in PFAS plasma concentrations: Impact of drinking water contamination, food access, proximity to industrial facilities and superfund sites

BACKGROUND

Most of the US population is exposed to per- and polyfluorinated substances (PFAS) through various environmental media and these sources of PFAS exposure coupled with disproportionate co-localization of PFAS-polluting facilities in under-resourced communities may exacerbate disparities in PFAS-associated health risks.

METHOD

We leveraged two cohorts in Southern California with 8 PFAS concentrations measured in plasma. We obtained PFAS water testing data from the Third Unregulated Contaminant Monitoring Rule and state monitoring data, census tract-level information on food access using the Food Access Research Atlas, the location of Superfund sites on the National Priorities List, and data on facilities known to release PFAS pollutants. These data were then spatially linked to the participants' home addresses.

RESULTS

In the first cohort, we found that detections of PFOS, PFOA, and PFHxS in drinking water were associated with 1.54 ng/mL (95% CI: 0.77, 2.32), 0.47 ng/mL (0.25, 0.68), and 1.16 ng/mL (0.62, 1.71) increase in plasma PFOS, PFOA, and PFHxS. The presence of Superfund sites was associated with higher plasma concentrations of PFOS, PFHxS, PFPeS, and PFHpS (betas [95% CIs]: 0.96 [0.21, 1.71], 0.9 [0.22, 1.58], 0.04 [0.02, 0.06] and 0.05 [0.02, 0.09], respectively). Each additional PFAS-polluting facility present in the neighborhood was associated with a 0.9 ng/mL (0.03, 0.15) increase in the concentration of PFOS. In the other cohort, we found that the presence of Superfund sites was associated with higher plasma PFDA, PFHpS, PFOS (betas [95% CIs]: 0.03 [0.01, 0.06], 0.05 [0.01, 0.09], and 1.96 [0.31, 3.62]). Neighborhood low access to food was associated with a 2.51 ng/mL (0.7, 4.31) increase in plasma PFOS, 0.6 ng/mL (0.16, 1.06) increase in plasma PFOA and 0.06 (0.02, 0.1) increase in plasma PFHpS.

CONCLUSION

Reducing sources of PFAS exposure in under-resourced neighborhoods may help reduce disparities in human exposure levels.

City-scale impacts of PFAS from normal and elevated temperature landfill leachates on wastewater treatment plant influent

The influence of elevated temperatures on PFAS leaching in municipal solid waste (MSW) landfills has not been well characterized in the published scientific literature. This study systematically examined the compositions and concentrations of per- and polyfluoroalkyl substances (PFAS) and precursors content in both normal temperature landfill and elevated temperature landfill (ETLF) leachates and compared to a municipal wastewater and to a WWTP influent with and without introduced leachates. The characterization of the samples involved the analysis of 71 PFAS target compounds before and after applying the total oxidizable precursor (TOP) assay, along with measuring fluorotelomer alcohols (FTOHs) and adsorbable organofluorine (AOF) levels. Summed PFAS concentrations in leachates were driven largely by fluorotelomer carboxylic acids (FTCAs), short-chain and ultrashort-chain perfluorinated carboxylic acids and sulfonic acids. Summed PFAS concentrations in ETLF leachate were significantly higher than in normal leachate for precursors and terminal PFAS products. TOP assay data demonstrated that ETLF leachate contained significantly higher concentrations of oxidizable PFAS precursors than normal leachate. PFAS profiles in leachates were distinct from municipal wastewater and from WWTP influent, suggesting diverse PFAS inputs to the WWTP. The presence of unknown precursors revealed by the TOP assay and AOF analyses highlights the complexity of PFAS sources impacting sewer networks, warranting further study to better characterize PFAS inputs to the WWTP on a city-wide scale.

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.

Mass spectrometry in animal health laboratories: recent history, current applications, and future directions

Mass spectrometry (MS) has long been considered a cornerstone technique in analytical chemistry. However, the use of MS in animal health laboratories (AHLs) has been limited, however, largely because of the expense involved in purchasing and maintaining these systems. Nevertheless, since ~2020, the use of MS techniques has increased significantly in AHLs. As expected, developments in new instrumentation have shown significant benefits in veterinary analytical toxicology as well as bacteriology. Creative researchers continue to push the boundaries of MS analysis, and MS now promises to impact disciplines other than toxicology and bacteriology. I include a short discussion of MS instrumentation, more detailed discussions of the MS techniques introduced since ~2020, and a variety of new techniques that promise to bring the benefits of MS to disciplines such as virology and pathology.

Applying molecular oxygen for organic pollutant degradation: Strategies, mechanisms, and perspectives

Molecular oxygen (O2) is an environmentally friendly, cost-effective, and non-toxic oxidant. Activation of O2 generates various highly oxidative reactive oxygen species (ROS), which efficiently degrade pollutants with minimal environmental impact. Despite extensive research on the application of O2 activation in environmental remediation, a comprehensive review addressing this topic is currently lacking. This review provides an informative overview of recent advancements in O2 activation, focusing on three primary strategies: photocatalytic activation, chemical activation, and electrochemical activation of O2. We elucidate the respective mechanisms of these activation methods and discuss their advantages and disadvantages. Additionally, we thoroughly analyze the influence of oxygen supply, reactive temperature, and pH on the O2 activation process. From electron transfer and energy transfer perspectives, we explore the pathways for ROS generation during O2 activation. Finally, we address the challenges faced by researchers in this field and discuss future prospects for utilizing O2 activation in pollution control applications. This detailed analysis enhances our understanding and provides valuable insights for the practical implementation of organic pollutant degradation.

Personal care product use and per- and polyfluoroalkyl substances in pregnant and lactating people in the Maternal-Infant Research on Environmental Chemicals study

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous chemicals routinely detected in personal care products (PCPs). However, few studies have evaluated the impact of PCP use on PFAS concentrations in pregnant and lactating populations.

OBJECTIVE

We investigated associations between PCP use and PFAS concentrations in prenatal plasma and human milk.

METHODS

We leveraged the Maternal-Infant Research on Environmental Chemicals (MIREC) Study to evaluate the contribution of PCP use on PFAS concentrations in prenatal plasma (6 to 13 weeks' gestation; n = 1,940) and human-milk (2 to 10 weeks' postpartum; n = 664). Participants reported frequency of use across 8 PCP categories during the 1st and 3rd trimesters, 1 to 2 days postpartum, and 2 to 10 weeks' postpartum. We used adjusted linear regression models to quantify percent differences and corresponding 95 % confidence intervals.

RESULTS

In 1st trimester pregnant people, we found higher use of nailcare products (≥once a week vs. never: perfluorooctanoic acid (PFOA): 21 % [9.7 %, 32 %]; perfluorooctane-sulfonic acid (PFOS): 11 % [0.3 %, 23 %]), fragrances (daily vs. never: PFOA: 14 % [7.8 %, 21 %]; PFOS: 7.8 % [1.3 %, 15 %]), makeup (daily vs. never: PFOA: 14 % [5.8 %, 23 %]), hair dyes (never vs. 1-2 times during pregnancy: PFOA: 8.3 % [2.4 %, 15 %]), and hair sprays or gels (daily vs. never: PFOA: 12 % [5.0 %, 19 %], PFOS: 7.1 % [0.2 %, 15 %]) were associated with higher plasma PFAS concentrations. Similar results were observed for 3rd trimester PCP use and 2 to 10 weeks' postpartum human-milk PFAS concentrations. In addition, we also found that people using colored-permanent dye 1 to 2 days postpartum had higher Sm-PFOS (18 % [2.7 %, 35 %]), PFOA (16 % [4.3 %, 29 %]), and perfluorononanoic acid (17 % [3.6 %, 33 %]) postpartum human-milk concentrations.

CONCLUSIONS

Our results show that PCP use may be a modifiable source of PFAS exposure in pregnant and lactating populations. These results along with growing scientific evidence can help inform PFAS regulation and guide individual choices to reduce PFAS exposure.

Indoor air concentrations of PM2.5 quartz fiber filter-collected ionic PFAS and emissions to outdoor air: findings from the IPA campaign

Per- and polyfluoroalkyl substances (PFAS) are prevalent in consumer products used indoors. However, few measurements of ionic PFAS exist for indoor air. We analyzed samples collected on PM2.5 quartz fiber filters (QFFs) in 11 North Carolina homes 1-3 times in living rooms (two QFFs in series), and immediately outside each home (single QFF), for 26 ionic PFAS as part of the 9 months Indoor PFAS Assessment (IPA) Campaign. All targeted PFAS, except for PFDS and 8:2 monoPAP, were detected indoors. PFBA, PFHpA, PFHxA, PFOA, PFOS, and 6:2 diPAP were detected in >50% of indoor samples. PFHxA, PFOA, and PFOS had the highest detection frequency (DF = 80%; medians = 0.5-0.7 pg m-3), while median PFBA concentrations (3.6 pg m-3; DF = 67%) were highest indoors. Residential indoor air concentrations (sum of measured PFAS) were, on average, 3.4 times higher than residential outdoor air concentrations, and an order of magnitude higher than regional background concentrations. Indoor-to-outdoor emission rate estimates suggest that emissions from single unit homes could be a meaningful contributor to PFBA, PFOA, and PFOS emissions in populated areas far from major point sources. Backup QFFs were observed to adsorb some targeted PFAS from the gas-phase, making reported values upper-bounds for particle-phase and lower-bounds for total air (gas plus particle) concentrations. We found that higher concentrations of carbonaceous aerosol were associated with a shift in partitioning of short chain PFCAs and long chain PFSAs toward the particle phase.

Silicone Wristbands as a Personal Passive Sampler to Evaluate Indoor Exposure to Volatile and Non-volatile PFASs

Exposure to per- and polyfluoroalkyl substances (PFASs) primarily occurs via consumption of contaminated drinking water and food; however, individuals can also be exposed dermally and via inhalation indoors. This study developed an analytical method for measuring volatile PFASs in silicone wristbands and used them to assess personal exposure in a Midwestern community (n = 87). Paired samples of blood and wristbands were analyzed for PFASs using LC-MS/MS and GC-HRMS to monitor both non-volatile and volatile PFASs. The most frequently detected PFASs in wristbands were: 6:2 diPAP, 6:2 FTOH, MeFOSE and EtFOSE. Females had a 4-fold higher exposure to 6:2 diPAP compared to males and age-dependent differences in exposure to 6:2 FTOH, MeFOSE and EtFOSE were observed. Exposure to MeFOSE and EtFOSE differed based on the average time spent in the home. Frequently detected PFASs in blood were: PFOA, PFOS, PFHxS, PFHpS, and N-MeFOSAA. A strong correlation was found between MeFOSE in the wristbands and N-MeFOSAA in serum (rs = 0.90, p-value <0.001), suggesting exposure to this PFAS was primarily via inhalation and dermal exposure. These results demonstrate that wristbands can provide individual level data on exposure to some polyfluoroalkyl precursors present indoors that reflect serum levels of their suspected biotransformation products.

Concentration and health risk assessment of per- and polyfluoroalkyl substances in cosmetic and personal care products

Per and polyfluoroalkyl substances (PFAS) are toxicologically concerning because of their potential to bioaccumulate and their persistence in the environment and the human body. We determined PFAS levels in cosmetic and personal care products and assessed their health risks. We investigated the trends in concentrations and types of PFAS contaminants in cosmetic and personal care products before and after perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were added to the list of persistent organic pollutants. The total PFAS concentration ranged from 1.98 to 706.75 ng g-1. The hazard quotients (HQs) for PFOA, PFOS and perfluorobutanesulfonic acid (PFBS) were lower than 1, indicating no appreciable risk to consumers. Assuming the simultaneous use of all product types and the worst-case scenario for calculations, perfluoroalkyl carboxylic acids and perfluoroalkane sulfonic acids (PFSAs) also had hazard indices lower than 1. We found that adverse effects are unlikely to occur when each type of cosmetic is used separately, or even when all product types are used together. Nevertheless, the persistence and bioaccumulation characteristics of additional PFAS present in cosmetics continue to be a cause for concern. Further research is necessary to investigate the long-term impacts of using such cosmetics and the associated risks to human health.

Why are nH-perfluoroalkanoate ions more mobile than expected? Implications for identifying an emerging environmental pollutant

nH-Perfluoroalkyl carboxylic acids (nH-PFCAs) are emerging pollutants. Their identification by ion mobility is frustrated by the nH-PFCAs having unexpectedly small collision cross sections (CCS). Theory and experiment agree that this is because nH-PFCA ions undergo internal hydrogen bridging, and this insight will help guide the creation of more accurate methods for pollutant identification.

The Total Mass of Per- and Polyfluoroalkyl Substances (PFASs) in California Cosmetics

Cosmetics make up one of the consumer product categories most widely known to contain perfluoroalkyl and polyfluoroalkyl substances (PFASs), including precursors to perfluorooctanoic acid (PFOA) and other perfluoroalkyl acids (PFAAs). Because of the way cosmetics are used, most of the PFASs present in these products are likely to reach wastewater treatment plants (WWTPs), which suggests that cosmetics may contribute significantly to the load of PFOA and other PFASs at WWTPs. However, the majority of PFASs present as intentional ingredients in cosmetics cannot be quantified with the available analytical methods. To address this issue, we developed a methodology to estimate the total PFAS mass in cosmetics as well as the corresponding mass of total organic fluorine and of fluorinated side chains associated with PFAA precursors, using various ingredient databases and ingredient concentrations reported by manufacturers. Our results indicate that the cosmetics sold in California during a one-year period cumulatively contain 650-56 000 kg of total PFASs, 370-37 000 kg of organic fluorine, and 330-20 000 kg of fluorinated side chains associated with PFAA precursors. Among the 16 product subcategories considered, >90% of the PFAS mass came from shaving creams and gels, hair care products, facial cleansers, sun care products, and lotions and moisturizers, while the sum of all nine makeup subcategories accounted for <3%. Comparing our estimates to available WWTP influent data from the San Francisco Bay Area suggests that cosmetics may account for at least 4% of the precursor-derived PFAAs measured in wastewater. As the first study ever to estimate the total mass of PFASs contained in cosmetics sold in California, our results shed light on the significance of certain cosmetics as a source of PFASs to WWTPs and can inform effective source reduction efforts.

Simultaneous size and defect control of metal-organic framework by deep eutectic solvent for efficient perfluoroalkyl substances adsorption: Delving into mechanism

This study reports an environment-friendly protocol to prepare a metal-organic framework (MOF) with simultaneously controlled particle size and open metal site for adsorption removal of perfluoroalkyl substances (PFASs). The successful preparation of UiO-66 with defect and crystal size modulation was achieved using a green and straightforward method, adjusting the components and molar ratios of ammonium salt/glycolic acid deep eutectic solvents (DESs). The corresponding modulation mechanism primarily relied on the combined regulation of the deprotonation and competitive coordination abilities of the eutectic solvent components. The adsorption process was thoroughly examined using spectral analyses, adsorption behavior profiling, and ab initio molecular dynamics simulations. The results revealed that PFAS adsorption is driven by combined capturing effects, such as CF-π, acid/base coordination, C-F⋯Zr, hydrogen bonding, and hydrophobic interactions. Our findings were not thus that the smaller the crystal size of MOF and the higher the defect concentration in the material, the better the PFAS adsorption performance. The result demonstrated the combined effect of these adsorbent features on PFAS mixtures. Furthermore, they revealed unique differences in sorption properties between these targets with different carbon chain lengths. Extensive defects in DES-based UiO-66 led to larger pores, increasing the availability of many adsorption sites and aiding in PFAS adsorption and diffusion. Nevertheless, the surplus of larger pores in the substance increased the competitive adsorption, reducing the total quantity of PFASs absorbed. Furthermore, various interactions and a less restrictive configuration increased the contact of functional groups with adsorbates, substantially enhancing the adsorption. This study investigates the basic questions about how PFAS molecules are adsorbed on DES-based MOFs and the relationship among the structure, properties, and performance to improve the efficiency of this novel adsorbent.

Hepatotoxicity and lipid metabolism disorders of 8:2 polyfluoroalkyl phosphate diester in zebrafish: In vivo and in silico evidence

8:2 polyfluoroalkyl phosphate diester (8:2 diPAP) has been shown to accumulate in the liver, but whether it induces hepatotoxicity and lipid metabolism disorders remains largely unknown. In this study, zebrafish embryos were exposed to 8:2 diPAP for 7 d. Hepatocellular hypertrophy and karyolysis were noted after exposure to 0.5 ng/L 8:2 diPAP, suggesting suppressed liver development. Compared to the water control, 8:2 diPAP led to significantly higher triglyceride and total cholesterol levels, but markedly lower levels of low-density lipoprotein, implying disturbed lipid homeostasis. The levels of two peroxisome proliferator activated receptor (PPAR) subtypes (pparα and pparγ) involved in hepatotoxicity and lipid metabolism were significantly upregulated by 8:2 diPAP, consistent with their overexpression as determined by immunohistochemistry. In silico results showed that 8:2 diPAP formed hydrogen bonds with PPARα and PPARγ. Among seven machine learning models, Adaptive Boosting performed the best in predicting the binding affinities of PPARα and PPARγ on the test set. The predicted binding affinity of 8:2 diPAP to PPARα (7.12) was higher than that to PPARγ (6.97) by Adaptive Boosting, which matched well with the experimental results. Our results revealed PPAR - mediated adverse effects of 8:2 diPAP on the liver and lipid metabolism of zebrafish larvae.

Adsorption of perfluoroalkyl substances on deep eutectic solvent-based amorphous metal-organic framework: Structure and mechanism

Perfluoroalkyl substances (PFASs) are a class of emerging organic pollutants characterized by high toxicity, environmental persistence, and widespread detection in water sources. The removal of PFASs from water is a matter of global concern, given their detrimental impact on both the environment and public health. Many commonly used PFAS adsorbents demonstrate limited adsorption capacities and/or slow adsorption kinetics. Therefore, there is an urgent need for the development of efficient adsorbents. For the first time, this work systematically investigated the performance of a deep eutectic solvent (DES)-based amorphous metal-organic framework (MOF) for the adsorption of PFASs with different carbon-chain lengths under the state of the mixture in aquatic environments. The adsorption mechanism was probed by a suite of adsorption kinetics studies, adsorption isotherm profiling, spectral characterization, and ab initio molecular dynamics (AIMD) simulations, revealing that PFAS adsorption is driven by synergistic capturing effects including acid/base coordination, CF-π (carbon-fluorine-π), hydrogen bonding, and hydrophobic interactions. Furthermore, the adsorption processes of short-chain and long-chain targets were found to involve different rate-controlling steps and interaction sites. Hydrophobic interactions facilitated the swift arrival of long-chain PFASs at the coordinatively interacting sites between carboxyl termini and Lewis acid Zr unsaturated sites, thanks to their lower reaction barriers. On the other hand, the adsorption of short-chain PFASs primarily relied on a Zr hydroxyl-based ligand exchange force, which would take place at Brønsted acid sites. The existence of massive structural disorder in amorphous UiO-66 led to the development of larger pores, thus improving the accessibility of abundant adsorption sites and facilitating adsorption and diffusion. The presence of multiple types of interactions and flexible structure in defect-rich amorphous UiO-66 significantly increased the exposure of functional groups to the adsorbates. Additionally, this material possessed outstanding regeneration efficiency and outperformed other MOF-based adsorbents with high affinity for targets. It enhances our understanding of the adsorption performances and mechanisms of amorphous materials toward PFASs, thereby paving the way for designing more efficient PFAS adsorbents.

Bioaccumulation of Perfluoroalkyl Sulfonamides (FASA)

Hundreds of sites across the United States have high concentrations of perfluoroalkyl sulfonamides (FASA), but little is known about their propensity to accumulate in fish. FASA are precursors to terminal per- and polyfluoroalkyl substances (PFAS) that are abundant in diverse consumer products and aqueous film-forming foams manufactured using electrochemical fluorination (ECF AFFF). In this study, FASA with C3-C8 carbon chain lengths were detected in all fish samples from surface waters up to 8 km downstream of source zones with ECF AFFF contamination. Short-chain FASA ≤ C6 have rarely been included in routine screening for PFAS, but availability of new standards makes such analyses more feasible. Bioaccumulation factors (BAF) for FASA were between 1 and 3 orders of magnitude greater than their terminal perfluoroalkyl sulfonates. Across fish species, BAF for FASA were greater than for perfluorooctanesulfonate (PFOS), which is presently the focus of national advisory programs. Similar concentrations of the C6 FASA (<0.36-175 ng g-1) and PFOS (0.65-222 ng g-1) were detected in all fish species. No safety thresholds have been established for FASA. However, high concentrations in fish next to contaminated sites and preliminary findings on toxicity suggest an urgent need for consideration by fish advisory programs.

Predictors of Serum Per- and Polyfluoroalkyl Substances Concentrations among U.S. Couples Attending a Fertility Clinic

Previous studies have examined the predictors of PFAS concentrations among pregnant women and children. However, no study has explored the predictors of preconception PFAS concentrations among couples in the United States. This study included 572 females and 279 males (249 couples) who attended a U.S. fertility clinic between 2005 and 2019. Questionnaire information on demographics, reproductive history, and lifestyles and serum samples quantified for PFAS concentrations were collected at study enrollment. We examined the PFAS distribution and correlation within couples. We used Ridge regressions to predict the serum concentration of each PFAS in females and males using data of (1) socio-demographic and reproductive history, (2) diet, (3) behavioral factors, and (4) all factors included in (1) to (3) after accounting for temporal exposure trends. We used general linear models for univariate association of each factor with the PFAS concentration. We found moderate to high correlations for PFAS concentrations within couples. Among all examined factors, diet explained more of the variation in PFAS concentrations (1-48%), while behavioral factors explained the least (0-4%). Individuals reporting White race, with a higher body mass index, and nulliparous women had higher PFAS concentrations than others. Fish and shellfish consumption was positively associated with PFAS concentrations among both females and males, while intake of beans (females), peas (male), kale (females), and tortilla (both) was inversely associated with PFAS concentrations. Our findings provide important data for identifying sources of couples' PFAS exposure and informing interventions to reduce PFAS exposure in the preconception period.

Determination of per- and polyfluoroalkyl compounds in paper recycling grades using ultra-high-performance liquid chromatography-high-resolution mass spectrometry

Globally, per- and polyfluoroalkyl substances (PFAS)-related research on paper products has focused on food packaging with less consideration on the presence of PFAS at different stages of the paper recycling chain. This study analysed the prevalence of PFAS in paper grades used for the manufacture of recycled paperboard. The presence of PFAS was attributed to the use of PFAS-containing additives, consumer usage, exposure to packed goods as well as contamination during mingling, sorting, collection, and recovery of paper recycling material. Q Orbitrap mass spectrometry was used to analyse the paper samples after accelerated solvent extraction and solid phase extraction. The distribution and possible propagation of 22 PFAS were determined in pre-consumer, retail and post-consumer paper products. Post-consumer samples had the highest combined average concentration (ΣPFAS) at 213 ng/g, while the ΣPFAS in retail (159 ng/g) and pre-consumer samples (121 ng/g) was detected at lower concentrations. This study showed that waste collection and recycling protocols may influence PFAS propagation and that measures must be developed to minimise and possibly eliminate exposure opportunities.

Investigation of pH-dependent extraction methods for PFAS in (fluoropolymer-based) consumer products: A comparative study between targeted and sum parameter analysis

Here, we report a comparative study of different sum parameter analysis methods for the extraction of per- and polyfluoroalkyl substances (PFAS) from manufactured consumer products, which can be measured by combustion ion chromatography (CIC). Therefore, a hydrolysis-based extraction method was further developed, which accounts for the addition of hydrolyzable covalently bound polyfluoroalkylated side-chain polymers (SFPs) to the extractable organic fluorine portion of the mass balance proposed as "hydrolyzable organically bound fluorine" (HOF). To test this hypothesis, the method was applied to 39 different consumer products containing fluoropolymers or monomeric PFAS taken from four different categories: outdoor textiles, paper packaging, carpeting, and permanent baking sheets. We also evaluated the method's efficiency by extracting four synthesized fluorotelomer polyacrylate reference compounds. The total fluorine (TF) and extractable organically bound fluorine (EOF) values were measured through CIC using established protocols. The TF values ranged from sub-ppb to %-levels, depending on the compound class. All samples showed results for hydrolyzed organofluorine (HOF) between 0.03 and 76.3 μg/g, while most EOF values were lower ( Collapse

Key Words

• Combustion ion chromatography (CIC)
• Extractable organically bound fluorine (EOF)
• Hydrolytic extraction
• Per- and polyfluoroalkyl substances (PFAS) sum parameter
• Side-chain fluorinated polymers (SFPs)
• Solid-liquid extraction

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MESH Headings

• Fluorocarbon Polymers/analysis
• Fluorocarbons/analysis
• Chromatography, Liquid
• Fluorine/chemistry
• Tandem Mass Spectrometry
• Hydrogen-Ion Concentration

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Grants Collapse

Affiliation(s)

Philipp Roesch Federal Institute for Materials Research and Testing, Division 4.3 - Contaminant Transfer and Environmental Technologies, Unter den Eichen 87, 12205, Berlin, Germany.
Andrea Schinnen Federal Institute for Materials Research and Testing, Division 4.3 - Contaminant Transfer and Environmental Technologies, Unter den Eichen 87, 12205, Berlin, Germany
Maren Riedel Federal Institute for Materials Research and Testing, Division 4.3 - Contaminant Transfer and Environmental Technologies, Unter den Eichen 87, 12205, Berlin, Germany
Thomas Sommerfeld Federal Institute for Materials Research and Testing, Division 1.7 - Organic Trace and Food Analysis, Richard-Willstätter-Straße 11, 12489, Berlin, Germany
George Sawal German Environment Agency, Colditzstr. 34, 12099, Berlin, Germany
Nicole Bandow German Environment Agency, Colditzstr. 34, 12099, Berlin, Germany
Christian Vogel Federal Institute for Materials Research and Testing, Division 4.3 - Contaminant Transfer and Environmental Technologies, Unter den Eichen 87, 12205, Berlin, Germany
Ute Kalbe Federal Institute for Materials Research and Testing, Division 4.3 - Contaminant Transfer and Environmental Technologies, Unter den Eichen 87, 12205, Berlin, Germany
Franz-Georg Simon Federal Institute for Materials Research and Testing, Division 4.3 - Contaminant Transfer and Environmental Technologies, Unter den Eichen 87, 12205, Berlin, Germany

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Collaborators Collapse

Characterization and dermal bioaccessibility of residual- and listed PFAS ingredients in cosmetic products

As a large group of chemicals with diverse properties, per- and polyfluoroalkyl substances (PFAS) have found extensive application throughout consumer products, including cosmetics. Little is known about the importance of dermal uptake as a human exposure pathway for PFAS. Here we investigate a suite of listed-ingredient and residual PFAS in cosmetic products, along with their dermal bioaccessibility using in vitro incubations with artificial sweat. Concentrations of volatile listed ingredients (including cyclic perfluorinated alkanes, perfluorinated ethers, and polyfluorinated silanes) in three products ranged from 876-1323 μg g-1, while polar listed ingredients (i.e., polyfluoroalkyl phosphate esters [PAPs]) in a single product occurred at up to 2427 μg g-1 (6 : 2/6 : 2 diPAP)). Residual perfluoroalkyl carboxylic acids (PFCAs) were also measured at concentrations ranging from 0.02-29 μg g-1. When listed ingredients were included, our targeted analysis accounted for up to 103% of the total fluorine, while highlighting ambiguous and/or incorrect International Nomenclature of Cosmetic Ingredient (INCI) names used in several products. Bioaccessibility experiments revealed that residual PFCAs readily partitioned to artificial sweat (bioaccessible fractions ranging from 43-76% for detectable substances) while listed ingredients (i.e., PAPs and neutral/volatile PFAS) displayed negligible partitioning. This work provides new insight into the occurrence of PFAS in cosmetic products, while furthering our understanding on their mechanisms of dermal uptake.

Polyfluoroalkyl phosphate esters (PAPs) as PFAS substitutes and precursors: An overview

Polyfluoroalkyl phosphate esters (PAPs) are emerging substitutes for legacy per- and polyfluoroalkyl substances (PFAS), which are widely applied in consumer products and closely related to people's daily lives. Increasing concern has been raised about the safety of PAPs due to their metabolism into perfluorooctanoic acid (PFOA) and other perfluorinated carboxylates (PFCAs) in vivo. This review summarizes the current knowledge on PAPs and highlights the knowledge gaps. PAPs dominated the PFAS profiles in wastewater, sludge, household dust, food-contact materials, paper products, paints, and cosmetics. They exhibit biomagnification due to their higher levels in top predators. PAPs have been detected in human blood worldwide, with the highest mean levels being found in the United States (1.9 ng/mL) and China (0.4 ng/mL). 6:2 diPAP is the predominant PAP among all identified matrices, followed by 8:2 diPAP. Toxicokinetic studies suggest that after entering the body, most PAPs undergo biotransformation, generating phase Ⅰ (i.e., PFCAs), phase II, and intermediate products with toxicity to be verified. Several epidemiological and toxicological studies have reported the antiandrogenic effect, estrogenic effect, thyroid disruption, oxidative damage, and reproductive toxicity of PAPs. More research is urgently needed on the source and fate of PAPs, human exposure pathways, toxicity other than reproductive and endocrine systems, toxic effects of metabolites, and mixed exposure effects.

Assessing the performance of a targeted absolute quantification isotope dilution liquid chromatograhy tandem mass spectrometry assay versus a commercial nontargeted relative quantification assay for detection of three major perfluoroalkyls in human blood

Isotope dilution ultrahigh-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) is commonly used for trace analysis of polyfluoroalkyl and perfluoroalkyl substances (PFAS) in difficult matrices. Commercial nontargeted analysis of major PFAS where relative concentrations are obtained cost effectively is rapidly emerging and is claimed to provide comparable results to that of absolute quantification using matrix matched calibration and isotope dilution UHPLC-MS/MS. However, this remains to be demonstrated on a large scale. We aimed to assess the performance of a targeted absolute quantification isotope dilution LC-MS/MS assay versus a commercial nontargeted relative quantification assay for detection of three major PFAS in human blood. We evaluated a population-based cohort of 503 individuals. Correlations were assessed using Spearman's rank correlation coefficients (rho). Precision and bias were assessed using Bland-Altman plots. For perfluorooctane sulfonic acid, the median concentrations were 5.10 ng/mL (interquartile range [IQR] 3.50-7.24 ng/mL), the two assays correlated with rho 0.83. For perfluorooctanoic acid, the median concentrations were 2.14 ng/mL (IQR 1.60-3.0 ng/mL), the two assays correlated with rho 0.92. For perfluorohexanesulfonate, the median concentrations were 5.5 ng/mL (IQR 2.50-11.61 ng/mL), the two assays correlated with rho 0.96. The Bland-Altman statistical test showed agreement of the mean difference for the majority of samples (97-98%) between the two assays. Absolute plasma concentrations of PFAS obtained using matrix matched calibration and isotope dilution UHPLC-MS/MS show agreement with relative plasma concentrations from a nontargeted commercial platform by Metabolon. We observed striking consistency between the two assays when examining the associations of the three PFAS with cholesterol, offering additional confidence in the validity of utilizing the nontargeted approach for correlations with various health phenotypes.

Comparison of aggregated exposure to perfluorooctanoic acid (PFOA) from diet and personal care products with concentrations in blood using a PBPK model - Results from the Norwegian biomonitoring study in EuroMix

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) constitute a large group of compounds that are water, stain, and oil repellent. Numerous sources contribute to the blood levels of PFAS in the European population. The main contributor for perfluorooctanoic acid (PFOA) is food, house dust, consumer products and personal care products (PCPs).

OBJECTIVES

The purpose of the present work is to calculate the dietary and dermal external exposure to PFOA, estimate the aggregated internal exposure from diet and PCPs using a PBPK model, and compare estimates with measured concentrations.

METHODS

Detailed information on diet and PCP use from the EuroMix study is combined with concentration data of PFOA in food and PCPs in a probabilistic exposure assessment. A physiologically based pharmacokinetic model (PBPK) was further refined by incorporating a dermal exposure pathway, and changes in the kidney and faecal excretion.

RESULTS

The aggregated internal exposure using the PBPK model shows that the major contributor to the internal exposure is diet for both males and females. The estimated internal exposure of PFOA for the EuroMix population was in the same range but lower than the measured blood concentrations using the lower bound (LB) external exposure estimates, showing that the LB estimates are underestimations. For seven females the internal exposure of PFOA were higher from PCPs than from diet.

CONCLUSION

PCPs and diet contributed in the same range to the internal PFOA exposure for several women participating in EuroMix. This calls for additional studies on exposure to PFOA and possibly other PFAS from PCPs, especially for women. Overall, PBPK modelling was shown as valuable tool in understanding the sources of PFOA exposure and in guiding risk assessments and regulatory decisions.

Determination of polyfluoroalkyl substances in cosmetic products using dispersed liquid-liquid extraction coupled with UHPLC-MS/MS

Human exposure to polyfluoroalkyl substances (PFASs) via cosmetics has been of increasing concern due to the tremendous detrimental health impacts of PFASs. Developing an effective method for extracting and determining PFASs in cosmetics is crucial in accurately assessing their corresponding human exposure risk. Herein, this study developed a new sample pre-treatment method to address the challenges posed by the variety and complexity of cosmetic matrices. Seventeen PFASs in cosmetic products, including 9 perfluoro carboxylic acids and 8 perfluorosulfonic acids, were simultaneously determined using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The whole pre-treatment process can be divided into three steps. In step 1, cosmetics with diverse matrix types can be effectively dispersed during extraction by using saturated sodium chloride-acetonitrile and saturated sodium chloride-tetrahydrofuran as extraction solvents. In step 2, the pre-purification step employs a potassium ferrocyanide-zinc acetate co-precipitant to remove high molecular weight interferents from the extraction solution, thereby enhancing the efficiency of solid-phase extraction (SPE). In step 3, WAX-SPE is utilized to further eliminate interferents from the extraction solution while concentrating the analytes, meeting the trace analysis requirements for PFASs in cosmetics. The method detection limits were 0.09-0.26 ng g-1. The recoveries ranged from 70.1% to 114.7%, with relative standard deviations in the range of 2.0-19.1%. The method was applied to cosmetic samples in the Guangzhou market, and the total concentration of PFASs ranged from 0 to 10.8 ng g-1. This method has strong anti-interference ability, good applicability, high sensitivity, and good reproducibility, making it suitable for the analysis and detection of perfluorinated acids in cosmetic samples. It provides technical support for cosmetics safety regulation.

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

In this work, 45 cosmetic samples were collected from China, and 27 target per- and polyfluoroalkyl substances (PFAS) were analyzed by ultrahigh-performance liquid chromatography-high resolution mass spectrometry. PFAS were found in all samples, including the products marketed for pregnant women, and the total concentrations of PFAS measured in each sample were in the range of 4.05 - 94.9 ng/g. Short-chain perfluorinated carboxylic acids were the dominant compounds contributing to over 60% of the total content. Perfluorobutanoic acid, with high placental transfer efficiency, was the major PFAS in cosmetics for pregnant women. Three emerging PFAS, 2-perfluorohexyl ethanoic acid, 3-perfluoropentyl propanoic acid (5:3) and perfluoro-2-propoxypropanoic acid, were also identified in the cosmetic samples at quantifiable levels. Significantly, positive correlations between individual PFAS were observed, indicating that there may be a common source for PFAS in these samples. Statistical analyses suggested that using plastic containers and precursor substances may be potential sources of PFAS in terminal products, and product aging may increase PFAS levels. From the PFAS analysis of the cosmetics, the margin of safety (MoS) and hazard quotient (HQ) were calculated to assess human health risks through dermal exposure by using these products. Although the MoS and HQ values obtained were deemed acceptable, the cumulative effect caused by composite and long-term exposure to these contaminants needs to be given greater attention by health authorities.

Case-Cohort Study of the Association between PFAS and Selected Cancers among Participants in the American Cancer Society's Cancer Prevention Study II LifeLink Cohort

BACKGROUND

Previous epidemiological studies found associations between exposure to per- and polyfluoroalkyl substances (PFAS) and some cancer types. Many studies considered highly exposed populations, so relevance to less-exposed populations can be uncertain. Additionally, many studies considered only cancer site, not histology.

OBJECTIVES

We conducted a case-cohort study within the American Cancer Society's prospective Cancer Prevention Study II (CPS-II) LifeLink cohort to examine associations between PFAS exposure and risk of selected cancers, considering histologic subtypes.

METHODS

Serum specimens were collected from cohort participants during the period 1998-2001. This study included a subcohort (500 men, 499 women) randomly selected from participants without prior cancer diagnoses at serum collection, and all participants with incident (after serum collection) first cancers of the breast (females only, n = 786 ), bladder (n = 401 ), kidney (n = 158 ), pancreas (n = 172 ), prostate (males only, n = 1,610 ) or hematologic system (n = 635 ). PFAS concentrations [perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA)] were measured in stored serum. We assessed associations between PFAS concentrations and incident cancers, by site and histologic subtype, using multivariable Cox proportional hazards models stratified by sex and controlling for age and year at blood draw, education, race/ethnicity, smoking, and alcohol use.

RESULTS

Serum PFOA concentrations were positively associated with renal cell carcinoma of the kidney among women [hazard ratio (HR) and 95% confidence interval (CI) per PFOA doubling: 1.54 (95% CI: 1.05, 2.26)] but not men. Among men, we observed a positive association between PFHxS concentrations and chronic lymphocytic leukemia/small lymphocytic lymphoma [CLL/SLL, HR and 95% CI per PFHxS doubling: 1.34 (95% CI: 1.02, 1.75)]. We observed some heterogeneity of associations by histologic subtype within sites.

DISCUSSION

This study supports the previously observed association between PFOA and renal cell carcinoma among women and suggests an association between PFHxS and CLL/SLL among men. Consideration of histologic subtypes might be important in future studies of PFAS-cancer associations. https://doi.org/10.1289/EHP13174.

Target and nontarget analysis of per- and polyfluoroalkyl substances in surface water, groundwater and sediments of three typical fluorochemical industrial parks in China

The objectives of this study were to identify both legacy and emerging per- and polyfluoroalkyl substances (PFAS) from three typical fluoridated industrial parks (FIPs) in China, and to assess their environmental occurrence and fate. Complementary suspect target and nontarget screening were implemented, and a total of 111 emerging PFAS were identified. Based on the multi-mass scale analysis, 25 emerging PFAS were identified for the first time, including 24 per- and polyfluoroalkyl ether carboxylic acids (PFECAs) and 1 ultra-short chlorinated perfluoroalkyl carboxylic acids (Cl-PFCAs, C2), with a maximum percentage of 48.2 % in nontarget PFAS (exclude target PFAS). The composition of PFAS identified in different media was influenced by functional groups, carbon chain length, substituents and ether bond insertion, with poly-hydrogen substituted being preferably in water and a more diverse pattern of PFECAs in sediments. The patterns of PFAS homologs revealed distinct differences among the three typical FIPs in the shift of PFAS production patterns. The C4-PFAS and short-chain carboxylic acids (≤C6) were the main PFAS in the Fuxin and Changshu, respectively. In contrast, perfluorooctanoic acid (PFOA, C8) remained dominant in Zibo, and the highest point concentrations in water and sediment were up to 706 µg/L and 553 µg/g, respectively.

The wide presence of fluorinated compounds in common chemical products and the environment: a review

The C-F bonds, due to their many unique features, have been incorporated into numerous compounds in countless products and applications. These fluorinated compounds eventually are disposed of and released into the environment through different pathways. In this review, we analyzed the occurrence of these fluorinated compounds in seven types of products (i.e., refrigerants/propellants, aqueous film-forming foam, cosmetics, food packaging, agrochemicals, pharmaceuticals, coating materials) and discussed their fate in the environment. This is followed by describing the quantity of fluorinated compounds from each source based on available data. Total on- and off-site disposal or other releases of 536 fluorinated compounds in 2021 were analyzed using the data sourced from the U.S. EPA Toxics Release Inventory (TRI). Among the chemicals examined, chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) were the primary contributors in terms of total mass. Upon examining the seven sources of fluorinated compounds, it became evident that additional contributors are also responsible for the presence of organofluorine compounds in the environment. Although various toxic degradation products of fluorinated compounds could form in the environment, trifluoroacetic acid (TFA) was specifically highlighted in this review given the fact that it is a common dead-end degradation product of > 1 million chemicals. This paper ended with a discussion of several questions raised from this study. The path forward was elaborated as well for the purpose of protecting the environment and human health.

Environmental metabolomics uncovers oxidative stress, amino acid dysregulation, and energy impairment in Daphnia magna with exposure to industrial effluents

Anthropogenic activities are regarded as point sources of pollution entering freshwater bodies worldwide. With over 350,000 chemicals used in manufacturing, wastewater treatment and industrial effluents are comprised of complex mixtures of organic and inorganic pollutants of known and unknown origins. Consequently, their combined toxicity and mode of action are not well understood in aquatic organisms such as Daphnia magna. In this study, effluent samples from wastewater treatment and industrial sectors were used to examine molecular-level perturbations to the polar metabolic profile of D. magna. To determine if the industrial sector and/or the effluent chemistries played a role in the observed biochemical responses, Daphnia were acutely (48 h) exposed to undiluted (100%) and diluted (10, 25, and 50%) effluent samples. Endogenous metabolites were extracted from single daphnids and analyzed using targeted mass spectrometry-based metabolomics. The metabolic profile of Daphnia exposed to effluent samples resulted in significant separation compared to the unexposed controls. Linear regression analysis determined that no single pollutant detected in the effluents was significantly correlated with the responses of metabolites. Significant perturbations were uncovered across many classes of metabolites (amino acids, nucleosides, nucleotides, polyamines, and their derivatives) which serve as intermediates in keystone biochemical processes. The combined metabolic responses are consistent with oxidative stress, disruptions to energy metabolism, and protein dysregulation which were identified through biochemical pathway analysis. These results provide insight into the molecular processes driving stress responses in D. magna. Overall, we determined that the metabolic profile of Daphnia could not be predicted by the chemical composition of environmentally relevant mixtures. The findings of this study demonstrate the advantage of metabolomics in conjunction with chemical analyses to assess the interactions of industrial effluents. This work further demonstrates the ability of environmental metabolomics to characterize molecular-level perturbations in aquatic organisms exposed to complex chemical mixtures directly.

Non-targeted analysis (NTA) and suspect screening analysis (SSA): a review of examining the chemical exposome

Non-targeted analysis (NTA) and suspect screening analysis (SSA) are powerful techniques that rely on high-resolution mass spectrometry (HRMS) and computational tools to detect and identify unknown or suspected chemicals in the exposome. Fully understanding the chemical exposome requires characterization of both environmental media and human specimens. As such, we conducted a review to examine the use of different NTA and SSA methods in various exposure media and human samples, including the results and chemicals detected. The literature review was conducted by searching literature databases, such as PubMed and Web of Science, for keywords, such as "non-targeted analysis", "suspect screening analysis" and the exposure media. Sources of human exposure to environmental chemicals discussed in this review include water, air, soil/sediment, dust, and food and consumer products. The use of NTA for exposure discovery in human biospecimen is also reviewed. The chemical space that has been captured using NTA varies by media analyzed and analytical platform. In each media the chemicals that were frequently detected using NTA were: per- and polyfluoroalkyl substances (PFAS) and pharmaceuticals in water, pesticides and polyaromatic hydrocarbons (PAHs) in soil and sediment, volatile and semi-volatile organic compounds in air, flame retardants in dust, plasticizers in consumer products, and plasticizers, pesticides, and halogenated compounds in human samples. Some studies reviewed herein used both liquid chromatography (LC) and gas chromatography (GC) HRMS to increase the detected chemical space (16%); however, the majority (51%) only used LC-HRMS and fewer used GC-HRMS (32%). Finally, we identify knowledge and technology gaps that must be overcome to fully assess potential chemical exposures using NTA. Understanding the chemical space is essential to identifying and prioritizing gaps in our understanding of exposure sources and prior exposures. IMPACT STATEMENT: This review examines the results and chemicals detected by analyzing exposure media and human samples using high-resolution mass spectrometry based non-targeted analysis (NTA) and suspect screening analysis (SSA).

Environmental and health impacts of PFAS: Sources, distribution and sustainable management in North Carolina (USA)

Poly- and perfluoroalkyl substances (PFAS) are a class of manufactured chemicals that have recently attracted a great deal of attention from environmental regulators and the general public because of their high prevalence, resistance to degradation, and potential toxicity. This review summarizes the current state of PFAS and its effects on the environment of North Carolina, USA. Specific emphasis has been placed to identify i) the sources of PFAS in North Carolina ii) distribution of PFAS in different environmental segments of North Carolina, including surface water, groundwater, air, and sediment iii) drinking water contamination iv) impact of PFAS on human health v) PFAS accumulation in fish and other biota vi) status of PFAS removal from drinking water and finally vi) socioeconomic impact of PFAS uncertainties. Continuous discharges of PFAS occur in the North Carolina environment from direct and indirect sources, including manufacturing sites, firefighting foam, waste disposal and treatment plants, landfill leachate, and industrial emissions. PFAS are widespread in many environmental segments of North Carolina. They are more likely to be detected in surface and groundwater sediments and can enter aquatic bodies through direct discharge and wet and dry deposition of emissions. Eventually, some adverse effects of PFAS have already been reported in North Carolina residents who could have been exposed to the chemicals through contaminated drinking water. Furthermore, PFAS were also found in blood samples from fish and alligators. PFAS were confirmed to be present in water, sediment, organic compounds, and aquatic species at all levels of the food web. However, there is still a substantial amount of work to be done to understand the actual contamination by PFAS in North Carolina comprehensively.

Determinants of maternal and neonatal PFAS concentrations: a review

Per- and polyfluoroalkyl substances (PFAS) are used for their properties such as stain and water resistance. The substances have been associated with adverse health outcomes in both pregnant mothers and infants, including pre-eclampsia and low birthweight. A growing body of research suggests that PFAS are transferred from mother to fetus through the placenta, leading to in utero exposure. A systematic review was performed using the PubMed database to search for studies evaluating determinants of PFAS concentrations in blood matrices of pregnant mothers and neonates shortly after birth. Studies were included in this review if an observational study design was utilized, exposure to at least one PFAS analyte was measured, PFAS were measured in maternal or neonatal matrices, at least one determinant of PFAS concentrations was assessed, and results such as beta estimates were provided. We identified 35 studies for inclusion in the review and evaluated the PFAS and determinant relationships among the factors collected in these studies. Parity, breastfeeding history, maternal race and country of origin, and household income had the strongest and most consistent evidence to support their roles as determinants of certain PFAS concentrations in pregnant mothers. Reported study findings on smoking status, alcohol consumption, and pre-pregnancy body mass index (BMI) suggest that these factors are not important determinants of PFAS concentrations in pregnant mothers or neonates. Further study into informative factors such as consumer product use, detailed dietary information, and consumed water sources as potential determinants of maternal or neonatal PFAS concentrations is needed. Research on determinants of maternal or neonatal PFAS concentrations is critical to estimate past PFAS exposure, build improved exposure models, and further our understanding on dose-response relationships, which can influence epidemiological studies and risk assessment evaluations. Given the potential for adverse outcomes in pregnant mothers and neonates exposed to PFAS, it is important to identify and understand determinants of maternal and neonatal PFAS concentrations to better implement public health interventions in these populations.