Parabens as chemicals of emerging concern in the environment and humans: A review

Endocrine-disrupting chemicals in human adipose tissue and associations between exposure and obesity

Bio-accumulation of endocrine-disrupting chemicals (EDCs) in human body may result in various adverse health effects. This study measured the levels of 16 EDCs in the visceral adipose tissue of 55 participants in China and investigated their association with obesity. MeP, BPP, PrP, BPA, EtP, BPE, and BPC were frequently detected in more than 50 % of the adipose tissues. A positive correlation between bisphenol A and body mass index (BMI) was observed in both multivariate linear regression model (β = 0.87, 95 % confidence interval: 0.21-1.53, p = 0.011) and multivariate logistic regression analysis (odds ratio = 1.28, 95 % confidence interval: 1.01-1.62, 0.044). Restricted cubic spline regression analysis revealed a significant nonlinear association between bisphenol P and BMI. Weighted quantile sum regression and quantile-based g-computation revealed a slight positive trend between EDCs mixed exposure and BMI, with bisphenol A as the primary contributor to the positive correlation with BMI. Our findings suggest the extensive existence of environmental EDCs in the adipose tissue of the adult Chinese population and indicate that exposure to BPA in adipose tissue may be associated with the occurrence of obesity.

Multi-target analysis of synthetic phenolic compounds in human blood

Synthetic phenolic compounds are widely used in plastics and personal care products, leading to potential high human exposure. This study aimed to develop two multi-target analytical methods to quantify phenolic compounds in human serum, including free and conjugated synthetic phenolic antioxidants (SPAs), bisphenols, parabens, and UV filters. The two methods were applied to 30 human serum samples from young adults (15 females and 15 males) living in Stockholm, Sweden. An average recovery of 73 % (range 36-125 %) and good reproducibility (RSD <30 %) were established for 37 target analytes, and another four analytes were semi-quantified. Twenty-one target analytes were found above quantification levels. Notable, five SPAs, namely 2,2'-methylenebis(4-methyl-6-tert-butylphenol) (AO2246), 4,4'-methylenebis(2,6-di-tert-butylphenol) (AO4426), 4-tert octylphenol (4-tOP), butylade hydroxyanisole (BHA), butylated hydroxytoluene (BHT) were quantified in >93 % of samples, and with median concentrations between 1.4 (BHA) and 520 ng/g (AO2246). Other compounds quantified in the samples were bisphenol B (quantification frequency 57 %) and methylparaben (quantification frequency 87 %), with median concentrations of 0.38 and 1.6 ng/g respectively. Additionally, two features were semi-quantified using suspect screening: Fenozan (an SPA metabolite, 3-(3,5-Di-tert-butyl-4-hydroxyphenyl)propionic acid) and benzophenone-4 (a UV filter, 5-benzoyl-4-hydroxy-2-methoxybenzenesulfonic acid). To the best of our knowledge, this is the first time AO4426, 3,5-di-tert-butyl-4-hydroxybenzoic acid (BHT-COOH), 2-tert-butylbenzene-1,4-diol (TBHQ), bisphenol B, and Fenozan have been found in human blood. The finding of SPAs in human blood indicates high human exposure and needs further investigation.

Parabens exposure and its impact on diabesity: A review

Parabens are a family of alkyl esters of 4-hydroxybenzoic acid. The most commonly used include methylparaben, ethylparaben, propylparaben, and butylparaben. These compounds have been reported to disrupt the endocrine system and are believed to affect the central nervous, immune, and reproductive systems, as well as lipid homeostasis, glucose levels, and thyroid function. Given these effects, parabens pose potential health risks, including their possible link to conditions like diabesity - a term describing the dual condition of type 2 diabetes mellitus and obesity. This review explores current literature on how parabens may influence key mechanisms in diabesity, such as gluconeogenesis, glycogenolysis, adipogenesis, insulin resistance, and inflammation. Understanding their role in these metabolic pathways is critical for assessing their contribution to the diabesity epidemic and guiding future research for minimizing their harmful health impacts.

Zebrafish as a model for assessing biocide toxicity: A comprehensive review

The utilization of biocides in a myriad of products has become a widespread and critical practice in recent years. Among these, quaternary ammonium compounds, polyhexamethylene, parabens, and triclosan are notably prevalent across various industrial applications. However, the incorporation of these biocides raises significant concerns regarding their toxicological profile. Not only do these chemicals pose potential risks to consumers using biocide-containing products, but their environmental discharge also represents a substantial threat to the biosphere. In our meticulous review, we examined approximately 150 articles from esteemed databases including PubMed, MDPI, and Google Scholar, ultimately utilizing at least 88 of these articles to inform our analysis. Our investigation encompassed studies that probe general toxicity, behavioral toxicity, cardiovascular toxicity, and genotoxicity, among other toxicological impacts. With this comprehensive approach, we explore the zebrafish (Danio rerio) as a prominent model organism in toxicology research. This review article aims to synthesize research employing zebrafish to evaluate biocide toxicity and ascertain the suitability of this model for comprehensive analysis of biocidal agents and their associated products.

Raw sheep wool contamination with bisphenol A and parabens. An assessment of interregional differences

The objective of this work is to investigate for the first time the contamination of raw wool with endocrine disruptor compounds - bisphenol A (BPA) and parabens (PBs), as well as to conduct the first biomonitoring study on long-term sheep exposure to these substances. The levels of BPA, methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP) and butylparaben (BuP) were evaluated in wool samples (n = 100) from Kyrgyzstan and Poland using liquid chromatography-tandem mass spectrometry method. The highest levels were noted for BPA (range: 46.9-502 ng/g, mean 132 ± 70.5 ng/g) and MeP (range: 3.4 ng/g-71.1 ng/g, mean 19.9 ± 13.8 ng/g). Lower levels were found for EtP (range: Collapse

Key Words

• Biomonitoring
• Bisphenol A
• Endocrine disruptors
• Parabens
• Sheep wool

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MESH Headings

• Animals
• Benzhydryl Compounds/analysis
• Parabens/analysis
• Phenols/analysis
• Sheep
• Wool/chemistry
• Endocrine Disruptors/analysis
• Poland
• Environmental Pollutants/analysis
• Environmental Monitoring
• Bisphenol A Compounds

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Grants Collapse

Affiliation(s)

Sławomir Gonkowski Department of Clinical Physiology, University of Warmia and Mazury in Olsztyn, Faculty of Veterinary Medicine, Poland
Julia Martin Departamento de Química Analítica, Escuela Politécnica Superior, Universidad de Sevilla, Spain
Nariste Kadyralieva Department of Histology and Embryology, Kyrgyz-Turkish Manas University, Veterinary Faculty, Kyrgyzstan
Irene Aparicio Departamento de Química Analítica, Escuela Politécnica Superior, Universidad de Sevilla, Spain
Juan Luis Santos Departamento de Química Analítica, Escuela Politécnica Superior, Universidad de Sevilla, Spain
Esteban Alonso Departamento de Química Analítica, Escuela Politécnica Superior, Universidad de Sevilla, Spain
Liliana Rytel Department of Internal Diseases with Clinics, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Poland.

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Collaborators Collapse

Development and validation of an integrated UHPLC-MS/MS and GC-MS method for the simultaneous analysis of three categories of phenolic endocrine disrupting chemicals in surface water

The global concern over emerging contaminants, particularly endocrine-disrupting chemicals (EDCs), has driven the need for advanced detection methods. Phenolic EDCs, such as parabens, bisphenols, and synthetic phenolic antioxidants (SPAs), are widely distributed in the environment and pose risks to reproductive systems and metabolism. With ongoing advancements in research, the development of high-throughput technologies for the simultaneous detection of these phenolic EDCs has become a pressing priority. A sensitive method combining ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry (UHPLC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) was developed for the simultaneous determination of three typical classes of phenolic EDCs in aquatic environments, including parabens, bisphenols, and SPAs. Solid-phase extraction (SPE) parameters and instrumental conditions were optimized, achieving recoveries of 64.7%-123% and 64.0%-111% for blank spikes and matrix spikes, respectively, with relative standard deviation below 18%. Detection and quantification limits were determined to be 0.228-0.940 ng L-1 and 0.758-3.13 ng L-1, respectively. The method was successfully applied to 23 surface water samples, and 10 EDCs were detected. Notably, bisphenols and SPAs in the Qiantang River displayed a clear increasing trend toward the downstream. SPAs exhibited the highest concentrations, with oxidation by the π-system being the predominant pathway responsible for the transformation to degradants like BHT-Q and BHT-quinol. This method offers reliable detection and quantification of multiple phenolic EDCs in water, providing a valuable tool for environmental monitoring, risk assessment, and regulatory management of EDCs contamination.

Efficient enrichment and sensitive determination of endocrine disruptors in PPCPs by novel magnetic covalent organic framework extraction coupled with HPLC-MS/MS

Endocrine-disrupting chemicals (EDCs) are a growing class of pollutants commonly found in environmental matrices due to their extensive use in pharmaceuticals and personal care products (PPCPs). In this study, a novel magnetic covalent organic framework (COF), Fe3O4-COOH@TFP-BHBD, was successfully synthesized and utilized as an adsorbent for magnetic solid-phase extraction (MSPE) of EDCs from PPCPs. The core-shell structured adsorbent demonstrated a high specific surface area, strong magnetic responsiveness and excellent stability. A COF-MSPE-high-performance liquid chromatography-tandem mass spectrometry (COF-MSPE-HPLC-MS/MS) method was developed for the quantitative analysis of EDCs in PPCPs. Under the optimized condition, the detection and quantification limits of this method reached as low as 0.001-0.007 ng/mL and 0.004-0.025 ng/mL, respectively. This method was validated and proven capable to analyze real PPCP samples, while the spiked recovery rates in ranged from 85.62 to 107.83 % with RSD of 2.28-8.58 %. Moreover, the adsorption mechanism was investigated using density functional theory (DFT) calculations. The DFT results revealed that the efficient enrichment capacity of Fe3O4-COOH@TFP-BHBD for EDCs can be attributed to π-π interactions and hydrogen bondings. This proposed method provides excellent adsorption ability and sensitivity for the extraction and precise detection of EDCs in PPCPs.

The association between estrogenic activity evolution and the formation of different products during the photochemical transformation of parabens in water

Photochemical transformation is a critical factor influencing the environmental fate of pharmaceutical and personal care products in aquatic ecosystems. However, the relationship between toxicity evolution and the formation of various transformation products has been seldom explored. This study investigates the behavior and changes in estrogenic activity during the photochemical transformation of a series of typical endocrine-disrupting parabens (PBs), focusing on the effects of increasing alkyl-chain length (MPB, EPB, PPB and BPB). Based on MS/MS analysis, four types of transformation products were identified: (1) p-hydroxybenzoic acid (HB), which exhibits no estrogenic activity; (2) hydroxylated products (OH-PBs); (3) dimer products formed between HB and PBs (HB-PBs); and (4) dimer products formed from identical PBs (PBs-PBs), comprising three distinct isomers. In the absence of standard sample, OH-PBs were synthesized and their estrogenic activity was evaluated using a yeast two-hybrid reporter assay. The EC50 values were determined to be <1 × 10-3 M for OH-MPB, 2.05 × 10-4 M for OH-EPB, 5.05 × 10-5 M for OH-PPB, and 1.89 × 10-5 M for OH-BPB. These indicate that the estrogenic activity of OH-PBs is one order of magnitude lower than that of the corresponding PBs. Both HB-PBs and the three isomers of PBs-PBs exhibited significantly higher estrogenic activities than their corresponding parent compounds, increasing 9 - 14 and 32 - 184 times, respectively, based on theoretical calculations. Among the three PBs-PBs isomers, the highest estrogenic activity was observed in the ether dimer, followed by the biphenyl dimers. Consistent with the parent compounds, the estrogenic activities of OH-PBs, HB-PBs, and PBs-PBs increased with the length of the alkyl-chain. The estrogenic activity of MPB and EPB followed an overall downward trend during the photochemical transformation, whereas PPB and BPB remained stable initially before declining rapidly. This behavior was associated with the contributions of toxic transformation products. These findings elucidate the relationship between molecular structure, transformation products, and estrogenic activity, highlighting the importance of understanding estrogenic activity evolution during the photochemical transformation of PBs.

Overlooked Photochemical Risk of Antimicrobial Fragrances: Formation of Potent Allergens and Their Mechanistic Pathways

Antimicrobial fragrances, commonly found in household and personal care products, are frequently detected in water bodies, yet their environmental fate and transformation mechanisms remain inadequately explored. This study investigates the photochemical transformation of cinnamaldehyde (CA), a representative antimicrobial fragrance, and its consequence for toxicological effects. The results showed that under UV irradiation, 94.6% CA was eliminated within 60 min, with a degradation rate of 0.059 min-1. Laser flash photolysis, quenching experiments, and electron paramagnetic resonance spectra identified O2•- and 3CA* as the important species, contributing 29.4% and 33.6%, respectively, to the transformation process. Additionally, singlet oxygen (1O2), hydroxyl radicals (•OH), and solvated electrons (eaq-) were involved in mediating the oxidation reactions. These species facilitated photoionization and oxidation, resulting in the formation of five major transformation products, including cis-cinnamyl aldehyde, cinnamic acid, styrene, 1aH-indeno [1,2-b]oxirene), and 1-Oxo-1H-indene. Most of these products were persistent, and exhibited considerable ecotoxicological risks. Specifically, the cinnamic acid and 1-Oxo-1H-indene caused severe skin irritation, while cinnamic acid induced significant eye irritation. Notably, the transformation products demonstrated sensitizing effects on human skin. This study underscores the overlooked ecotoxicological risks associated with the photochemical transformation of antimicrobial fragrances, revealing their potential to generate potent allergens and other harmful byproducts.

Identifying Potential Chemicals of Concern in Children's Products in a Regulatory Context: A Systematic Evidence Mapping Approach

BACKGROUND

Children's vulnerability to chemical toxicant exposures demands strong consideration of the chemical composition of products designed for and marketed toward them. Inadequacies in health-protective legislation and lack of mandatory ingredient disclosure in most children's products have created significant gaps in protection and oversight. Scientific literature can provide insight into the chemical constituency of children's products that may be useful for prioritizing future regulatory efforts.

OBJECTIVE

We aimed to present a proof of concept for applying systematic evidence mapping methodology to identify which chemicals of potential concern have been reported in the scientific literature to be present in products marketed toward children, compile a compendium of data to inform future regulatory efforts, and identify research needs.

METHODS

We conducted a broad, all-encompassing survey of the available literature from four databases to identify chemicals present in children's products. Using systematic evidence mapping methodologies, we constructed a database of children's products and their chemical constituents (termed "product-chemical combinations") based on a broad survey of current and relevant environmental health literature. Our study focused on chemicals listed on the California Safer Consumer Products Program's Candidate Chemicals List, which includes chemicals with one or more known hazard traits. We then conducted an exploratory data analysis of product category and product-chemical combination frequencies to identify common chemicals in specific products.

RESULTS

Our systematic evidence mapping identified 206 potentially hazardous chemicals in children's products, 170 of which were found in toys. In total, we found 1,528 distinct product-chemical combinations; 582 product-chemical combinations included chemicals known to be hazardous or potentially hazardous. Ortho-phthalates in plastic toys, parabens in children's creams and lotions, and bisphenols in both baby bottles and teethers were the most frequently encountered product-chemical combinations of potential concern.

DISCUSSION

The frequently reported presence of endocrine-disrupting chemicals in multiple types of children's products raises concerns for aggregate exposures and reveals gaps in regulatory protections for this sensitive subpopulation. Our reproducible and systematic evidence-based approach serves as a case study that can guide other prioritization efforts for transparent regulatory action aimed at improving the safety of chemicals in consumer products. https://doi.org/10.1289/EHP15394.

Endocrine-Disrupting Chemicals and Persistent Nausea among Pregnant Women Enrolled in the Illinois Kids Development Study (I-KIDS)

BACKGROUND

Pregnant women are exposed to numerous endocrine-disrupting chemicals (EDCs). Pregnancy-related nausea likely has hormonal etiology and may persist beyond the first trimester.

OBJECTIVES

Therefore, we aimed to determine the relationship between EDC biomarkers and pregnancy nausea characteristics.

METHODS

Illinois Kids Development Study (I-KIDS) pregnant women (n = 467 ) reported nausea symptoms monthly from conception to delivery. We categorized women as never having nausea (9%) or as having typical (ends by 17 wk gestation; 42%), persistent (ends after 17 wk gestation; 25%), or irregular (24%) nausea. Women provided five urine samples across pregnancy, which we pooled and analyzed for phthalate/replacement, phenol, and triclocarban biomarkers. Using covariate-adjusted logistic regression, we evaluated relationships of EDCs with nausea and used quantile-based g-computation (QGComp) and Bayesian kernel machine regression (BKMR) to evaluate joint associations of EDCs with nausea symptoms. We also considered differences in associations by fetal sex.

RESULTS

Only the sum of urinary biomarkers of di(isononyl) cyclohexane-1,2-dicarboxylate (Σ DiNCH ) was associated with higher risk of persistent nausea compared to typical nausea [odds ratio (OR) = 1.18 ; 95% CI: 1.01, 1.37] in all women. However, using QGComp, a 10% higher concentration of the EDC mixture was associated with 14% higher risk of persistent nausea [relative risk (RR) = 1.14 ; 95% CI: 1.01, 1.30], due to Σ DiNCH , ethylparaben, and the sum of di-2-ethylhexyl phthalate (Σ DEHP ) metabolites. Similarly, using BMKR, the EDC mixture was associated with greater odds of persistent nausea in all women. In women carrying male offspring, ethylparaben was associated with persistent nausea, and a 10% higher concentration of the QGComp mixture was associated with 26% higher risk of persistent nausea (RR = 1.26 ; 95% CI:1.13, 1.41), driven by ethylparaben and Σ DiNCH . Consistently, using BKMR, EDCs were positively associated with persistent nausea in women carrying males. We did not identify associations between EDC biomarkers and persistent nausea in women carrying females or between EDC biomarkers and other nausea patterns.

DISCUSSION

Nonpersistent EDCs, modeled as a mixture, are associated with persistent nausea in pregnancy, primarily in women carrying males. Future work should explore possible mechanisms, clinical implications, and interventions to reduce exposures and symptoms. https://doi.org/10.1289/EHP15547.

Obesogenic effects of six classes of emerging contaminants

There is growing concern about the concept that exposure to environmental chemicals may be contributing to the obesity epidemic. However, there is no consensus on the obesogenic effects of emerging contaminants from a toxicological and environmental perspective. The potential human exposure and experimental evidence for obesogenic effects of emerging contaminants need to be systematically discussed. The main objective of this review is to provide recommendations for further subsequent policy development following a critical analysis of the literature for humans and experimental animals exposed to emerging contaminants. This article reviews human exposure to emerging contaminants (with a focus on antimicrobials, preservatives, water and oil repellents, flame retardants, antibiotics and bisphenols) and the impact of emerging contaminants on obesity. These emerging contaminants have been widely detected in human biological samples. Epidemiological studies provide evidence linking exposure to emerging contaminants to the risks of obesity in humans. Studies based on animal models and adipose cells show the obesogenic effects of emerging contaminants and identify modes of action by which contaminants may induce changes in body fat accumulation and lipid metabolic homeostasis. Some knowledge gaps in this area and future directions for further investigation are discussed.

Population-specific exposure risks from parabens and antimicrobials in cosmetics and personal care products: Insights from Korean usage patterns

The use of cosmetics and personal care products (CPCPs) is a significant source of human exposure to endocrine disrupting chemicals (EDCs). However, few studies have investigated EDC exposure through CPCP use based on realistic exposure factors of diverse population groups. In this study, 13 parabens and two antimicrobial agents were measured in 261 CPCPs categorized as leave-on, rinse-off, and baby care products. Methylparaben and propylparaben were the most prevalent parabens. Triclocarban was frequently found in rinse-off products, while triclosan was rarely detected, likely due to regulatory measures. Population-specific exposure assessments were conducted using measured EDC concentrations and exposure factors derived from surveys of 1,001 adults, 322 teenagers, and 719 mother-infant pairs in Korea. Dermal exposure doses (DEDs) of parabens were estimated at 11.4, 25.8, 25.1 and 0.03 µg/kg/day for males, females, mothers, and infants, respectively. For antimicrobial agents, DEDs were 0.20, 0.28, and 0.98 µg/kg/day for males, females, and mothers, respectively. Females had higher DEDs of parabens than males in both adults and teenagers, and mothers had higher DEDs of triclocarban. These findings emphasized the need to consider population-specific characteristics in exposure assessments. High-exposure scenarios resulted in DEDs 4-5 times higher than general-exposure scenarios. Skin care products, sunscreens, body and hand lotions were major contributors to paraben exposure, highlighting the need for targeted management to mitigate exposure from these products. This study provides realistic exposure data that can serve as a valuable reference for managing CPCP ingredients, particularly parabens and antimicrobial agents.

Urinary concentrations of early and mid-pregnancy parabens and gestational diabetes: A nested case-control study within the PETALS cohort

Parabens are widely used preservatives with endocrine-disrupting properties, but their role in glucose metabolism during pregnancy is unclear. This study examines prospective associations between urinary concentrations of four parabens in early and mid-pregnancy and gestational diabetes (GDM). A matched case-control study nested within a diverse longitudinal pregnancy cohort (PETALS) with universal GDM screening matched GDM cases to two controls (111 cases; 222 controls). Urine samples collected 2015-2017 in early (14 ± 2.3 weeks) and mid-pregnancy (20 ± 2.4 weeks) were analyzed for paraben concentrations with mass spectrometry. Area-under-the-time-concentration-curve (AUC) assessed cumulative exposure. Conditional logistic regression models evaluated associations between paraben concentrations and GDM, adjusting for covariates. We a priori examined effect modification by Asian/Pacific Islander (A/PI) race/ethnicity due to the case-control matching and GDM prevalence highest among A/PI. Participants were 31 ± 5 years old and 40 % A/PI, 33 % Hispanic, 14 % White and 9 % Black. Methylparaben and propylparaben had >94 % detection, while ethylparaben and butylparaben ranged from 22 %-51 %. Paraben exposure was not associated with GDM overall. Among A/PI, higher methylparaben concentrations exhibited higher odds of GDM: early-pregnancy OR 1.14 per IQR (95 % CI: 0.89,1.45) and AUC 1.07 (0.89,1.30) compared to non-A/PI (early-pregnancy 0.81 [0.62,1.06] and AUC 0.70 [0.44,1.12]; Pinteraction = 0.01 and 0.03, respectively). A/PI mid-pregnancy ethylparaben exposure (detectable vs non-detectable) was linked to higher GDM odds (2.00 [0.84,4.76] vs. non-A/PI 0.47 [0.17,1.27]; Pinteraction = 0.04) as was mid-pregnancy propylparaben exposure (Tertile 2 vs. 1: 3.67 [1.21,11.1] vs. non-A/PI 0.70 [0.22, 2.25]; Pinteraction = 0.04). Although overall paraben exposure was not associated with GDM, interactions by A/PI race/ethnicity suggested potential increased odds of GDM related to propylparaben, methylparaben, and ethylparaben exposure. Future studies should explore paraben exposure in diverse populations.

Covalent Organic Framework Nanofilm-Assisted Laser Desorption Ionization Mass Spectrometry for Rapid Screening of Parabens in Personal Care Products

RATIONAL

People are widely exposed to parabens in their daily life, but parabens are endocrine disrupting chemicals that pose a threat to human health. Therefore, establishing a rapid screening method to enhance monitoring of parabens is necessary. Herein, a covalent organic framework (COF) nanofilm-assisted laser desorption ionization mass spectrometry (LDI-MS) method was established to screen parabens in personal care products (PCPs).

METHODS

TAPB-TFPB-COF nanofilm was synthesized on indium tin oxide (ITO) glass and used as LDI-MS substrates. To observe the practicability of TAPB-TFPB-COF nanofilm-assisted LDI-MS, the results of this method for analyzing small molecules such as parabens, estrogens, and bisphenols were compared with those of the conventional organic matrix 9-aminoacridine (9-AA), and the reproducibility and detection limit were further verified. Finally, the method was applied to screen parabens in PCPs.

RESULTS

TAPB-TFPB-COF nanofilm-assisted LDI-MS analyzed small molecules such as parabens, estrogens, and bisphenols with higher mass spectral signals and cleaner mass spectral backgrounds compared with 9-AA. Meanwhile, the method analyzed methylparaben (MeP) with high reproducibility (RSD = 6.96%) and low detection limit (1.64 μM) and performed well for rapid screening of parabens in PCPs.

CONCLUSION

TAPB-TFPB-COF nanofilm-assisted LDI-MS for analyzing small molecules such as parabens, estrogens, and amino acids offered the advantages of rapid analysis, a clean background, and good reproducibility. The method was successfully applied to detecting parabens in PCPs, demonstrating the practical utility of LDI-MS based on TAPB-TFPB-COF nanofilm for analyzing parabens in complex samples.

Association between exposure to a mixture of dichlorophenol and parabens and lung function in adults from NHANES, 2007-2012

BACKGROUND

Few studies have examined the effects of dichlorophenol and parabens on lung function, with most focusing on individual chemicals.

OBJECTIVES

This study analyzes the effects of these chemicals on single or mixed exposures on lung function in adults.

METHODS

We utilized data from the 2007-2012 National Health and Nutrition Examination Survey (NHANES), focusing on urinary levels of dichlorophenol, parabens, and lung function measures. The generalized linear regression (GLM), weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) models were applied to assess the impact of chemical exposure on lung function.

RESULTS

A total of 2,599 adults with complete data were included in the analysis. Detection rates exceeding 75 % for 2,5-Dichlorophenol (2,5-DCP), 2,4-Dichlorophenol (2,4-DCP), methyl paraben, and propyl paraben were observed. In GLMs, 2,5-DCP was significantly negatively associated with forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1), either as a continuous (FVC: β = -0.012, 95 % CI = -0.018, -0.006; FEV1: β = -0.010, 95 % CI = -0.017, -0.004) or quartile variable (FVC: β = -0.027, 95 % CI = -0.039, -0.016; FEV1: β = -0.024, 95 % CI = -0.036, -0.011). The WQS regression confirmed a negative effect of the chemical mixture on lung function, with significant associations for both FVC (β = -0.013, 95 % CI = -0.018, -0.008) and FEV1 (β = -0.013, 95 % CI = -0.017, -0.007). These results were consistent in BKMR models.

CONCLUSION

Exposure to dichlorophenol and parabens, either individually or in combination, is associated with decreased lung function in humans.

Mediating effects of insulin resistance on lipid metabolism with elevated paraben exposure in the general Taiwan population

Introduction

Parabens are commonly used to prevent bacteria from growing in cosmetics and foodstuffs. Parabens have been reported to influence hormone regulation, potentially leading to metabolic anomalies, including insulin resistance and obesity. However, there is a paucity of knowledge regarding the relationship between urinary paraben levels and lipid metabolism in the general Taiwanese population. Therefore, the objective of this study was to determine whether the mediating role of insulin resistance exists between paraben exposure and lipid metabolism.

Methods

We selected the data of 264 adult participants from a representative survey in five major Taiwan area in 2013. UPLC tandem mass spectrometry was used to examine four urine parabens: methyl- (MeP), ethyl- (EtP), propyl- (PrP) and butyl- (BuP). Blood samples were analyzed for concentrations of glucose and lipid metabolic indices using the DxI 800 immunoassay analyzer and immunoradiometric assay kit. The relationship between urinary paraben levels and metabolism indices were evaluated through a multiple linear regression analysis. Finally, a mediation analysis was employed to understand the underlying mechanism by which paraben exposure influences lipid metabolism through insulin resistance.

Results

The significant positive association between MeP exposure and Castelli risk index I (CRI-I; β = 0.05, p = 0.049) was found, and also exhibited the similar associations between EtP exposure and low-density lipoprotein cholesterol (β = 0.10, p = 0.001), total cholesterol (β = 0.06, p = 0.003), and non-HDL cholesterol (NHC; β = 0.08, p = 0.005). EtP exhibited a significant positive association with triglyceride BMI (TyG-BMI; β = 0.02, p = 0.040). Additionally, TyG-BMI was positively associated with CRI-I (β = 0.98, p < 0.001), CRI-II (β = 1.03, p < 0.001) and NHC (β = 0.63, p < 0.001). Moreover, insulin resistance served as mediators for the effects of EtP exposure on lipid metabolism indices.

Discussion

The results indicate that changes in insulin resistance mediated the relationship between urinary paraben and lipid metabolism. Large-scale epidemiological and animal studies are warranted to identify biological mechanisms underlying validate these relationships.

Investigation of common and unreported parabens alongside other plastic-related contaminants in human milk using non-targeted strategies

Human milk studies analyzing widely used contaminants mainly utilize a targeted approach to screen and quantify a limited number of compounds. While targeted analysis allows health officials to quantify the levels of these chemicals in human milk, it fails to detect the presence of other unknowns that may be of equal importance. Hence, the objective of this study was to apply non-targeted analysis to detect and identify different prevalent contaminants, specifically common or unreported parabens as well as other plastic-related contaminants (PRCs) in human milk. Extracts of 594 human milk samples collected in Canada (Montreal) and South Africa (Vhembe and Pretoria) in 2018-2019 were analyzed using liquid chromatography-mass spectrometry to confirm the presence of methyl, ethyl and propyl parabens. Additional investigations revealed the presence of sulfated species of these parabens, suggesting their conjugation potential in human milk. Further analysis using in-source fragmentation, identified the presence of four other parabens in human milk, including phenyl paraben as well as 2-ethylhexyl 4-hydroxybenzoate, an unusual paraben exclusive to South African samples. Other PRCs that were detected included several phthalate metabolites, per- and poly-fluoroalkyl substances (PFAS) and 1,3 diphenyl guanidine, a tire-related chemical. This is the first study to have used different non-targeted analyses for the detection and confirmation of several common and unusual parabens alongside different PRCs in human milk.

ZIF-8 derived carbon@3D-printed columns as efficient continuous-flow adsorbents of parabens from water

In this study, we report a novel and cost-effective solution for removing parabens from water by combining MOF-derived porous carbons and 3D printing. In addition to being easy to prepare, the resulting 3D-printed device, with a cube-array structure, can also be fabricated in a robust column format for flow-through extraction of pollutants. Using an in-situ growth method, ZIF-8 MOF was directly deposited onto a 3D-printed device, achieving a stable and durable integration of the MOF onto the device. After the carbonization process, fully functional devices were obtained, entirely coated with a zinc-free carbon layer derived from ZIF-8, exhibiting both micro- and mesoporosity. c-ZIF-8@3D-printed cubes exhibited fast adsorption kinetics in batch conditions, achieving over 90 % extraction of ethylparaben within just 1 h, thanks to the mesoporosity of the obtained ZIF-8 derived carbon, as well as the possibility of establishing π-π interactions between it and the pollutant. Continuous-flow experiments demonstrated that c-ZIF-8@3D-printed columns showed high extraction efficiency for four parabens, maintaining removal rates between 83-92 % after 10 cycles. The columns also showed easy regeneration, enabling multiple uses of the 3D support and enhancing both the sustainability and efficiency of the water treatment process. Finally, the c-ZIF-8@3D-printed column was also tested for the simultaneous extraction of parabens from different real water samples with excellent results, confirming its potential for practical applications in water treatment.

Associations between phenol and paraben exposure and the risk of developing breast cancer in adult women: a cross-sectional study

Increasing evidence suggests that endocrine-disrupting chemicals (EDCs) have adverse effects on breast cancer (BC). The aim of this study was to assess the association between exposure to prevalent EDCs-phenols and parabens-and the risk of developing BC. Data on urinary bisphenol A (BPA), triclosan (TRS), benzophenone-3 (BP3), methyl paraben (MPB), ethyl paraben (EPB), propyl paraben (PPB), and butyl paraben (BUP) were obtained from the 2005-2014 National Health and Nutrition Examination Survey. A total of 4455 subjects were included in this cross-sectional study. The results from the weighted multivariable regression models indicated that exposure to elevated concentrations of TRS increased the risk of developing BC by 2.33 (Q2: 95% CI = 1.45-3.75, p < 0.001) and 1.94 times (Q3: 95% CI = 1.21-3.09, p = 0.006), respectively. The nonlinear association between TRS concentrations and the risk of developing BC was statistically significant (P nonlinear = 0.007), with the restricted cubic splines (RCS) curve exhibiting an inverted U shape. The association between TRS concentrations and the risk of developing BC was more pronounced among overweight individuals (BMI ≥ 25 kg/m2), those aged < 60 years, and white individuals. Weighted quantile sum (WQS) and Bayesian Kernel Machine Regression (BKMR) analysis revealed no significant overall association between mixtures of urinary phenol and paraben metabolites and BC risk. However, TRS exposure was the most influential, with higher TRS concentrations (both continuous and categorical) significantly associated with an increased BC risk, particularly in overweight individuals (BMI ≥ 25 kg/m2), those aged < 60 years, and white individuals.

Exploiting the synergistic effect of β-cyclodextrin functionalized-multi-walled carbon nanotubes and Zn-MOF for the detection of endocrine-disrupting chemical methylparaben

BACKGROUND

The buildup of methylparaben (MP), a broad-spectrum antimicrobial preservative with endocrine-disrupting properties, in environmental sources, especially aquatic systems, has become a significant concern due to its adverse health effects, including allergic reactions, promoting the risk of developing cancer, and inducing reproductive disorders. Hence, introducing inexpensive and easy-to-use monitoring devices for rapid, selective, and sensitive detection and quantification of MP is highly desirable. In this context, electrochemical platforms have proven to be attractive options due to their remarkable features, such as ease of fabrication and use, short response time, and acceptable sensitivity, accuracy, and selectivity.

RESULTS

In this regard, Zn-BTC metal-organic framework (MOF) and multi-walled carbon nanotubes (MWCNTs) functionalized with β-Cyclodextrin (β-CD) were utilized to modify the matrix of a carbon paste electrode (CPE). The morphological and electrochemical characteristics of β-CD-MWCNTs/Zn-BTC/CPE were evaluated using conventional material characterization techniques and electroanalytical methods. The sensor exhibited two linear current responses in concentration ranges of 0.01 mM-0.3 mM and 0.3 mM-6 mM. The limit of detection (LOD) and limit of quantification (LOQ) were calculated to be 3.8 μM and 11.5 μM, respectively. The device demonstrated excellent selectivity, repeatability, reproducibility, and stability over two weeks. Evaluating its applicability in real samples, including personal care products, tap and river water, and human blood serum, achieved recoveries in the range of 96.25 %-105 %, proving its reliability in environmental and industrial applications.

SIGNIFICANCE

Overall, the proposed modified graphitic platform is not only a cheaper and more easily fabricable and applicable option for MP detection compared to other reported conventional and electrochemical devices but also demonstrates exceptional selectivity and satisfactory sensitivity among various reported electrochemical sensors. In addition, the developed electroanalytical tool can be employed for MP measurement in a broader range of real sample matrixes compared to alternative electrochemical platforms.

Propylparaben-induced endoplasmic reticulum stress triggers G2/M phase cell cycle arrest and initiates caspase-3-dependent apoptosis in human lung cells

BACKGROUND

Propylparaben (PrP) is commonly used as an antimicrobial agent in food, cosmetics, and pharmaceuticals. While recent studies have shown that PrP exposure can cause various disruptions in cellular physiology, the precise mechanisms behind these effects remain unclear.

OBJECTIVE

In this study, we sought to examine the cytotoxic effects of PrP exposure on human lung cells in a dose- and time-dependent manner. We utilized flow cytometry to analyze the expression of proteins associated with the cell cycle and apoptosis at the single-cell level.

RESULTS

Our results showed that PrP treatment leads to a significant upregulation of genes related to ER stress. The activation of ER stress results in a decrease in cyclin B1 levels, which subsequently causes cell cycle arrest at the G2/M phase. After 48 h of PrP exposure, the unfolded protein response (UPR) triggers an apoptotic signaling pathway, increasing the number of cells undergoing caspase-3-mediated apoptosis. Together, these physiological changes lead to a reduction in cell viability in the presence of PrP.

CONCLUSION

These findings suggest that PrP exerts harmful effects on human lung cells by activating ER stress, which can lead to apoptosis and cell cycle arrest.

Contaminants of emerging concern in an endangered population of common eiders (Somateria mollissima) in the Baltic Sea

Contaminants of emerging concern (CECs) are ubiquitous in aquatic environments and pose a range of biological effects including endocrine disruption. Yet, knowledge of their occurrence in wildlife including seabirds remains scarce. We investigated the occurrence of selected bisphenols, benzophenones, phthalate metabolites, benzotriazoles, benzothiazoles, parabens, triclosan, and triclocarban in plasma of 18 breeding female common eiders (Somateria mollissima) from an endangered population in the Baltic Sea as most of these CECs have never before been examined in eiders. We sampled blood at the start (T1) and end (T2) of incubation to investigate concentration changes during incubation. As early- and late-breeding eiders tend to differ in how they finance reproduction (local vs stored nutrient reserves), we compared early and late breeders to assess whether CEC concentrations differed by breeding phenology. Of the 58 targeted CECs, 21 were detected in at least one female, with bisphenol A (BPA) and benzophenone-3 (BzP-3) occurring most frequently (T1: 78% and 61%; T2: 61% and 67%, respectively), while mono(2-ethyl-1-hexyl) phthalate (mEHP), BPA, and monoethyl phthalate (mEP) were detected in the highest concentrations (median concentrations 27.1, 12.7, and 11.2 ng/g wet weight, respectively, at T1). No CEC concentrations differed between early and late incubation. Late breeders had significantly higher concentrations of BzP-3, monomethyl phthalate (mMP), and mEP during early incubation (4.55 vs 1.24 ng/g ww, 7.05 vs 3.52, and 11.2 vs < limit of detection (LOD), respectively) and significantly higher concentrations of mMP and mEP during late incubation (6.16 vs  Collapse

Key Words

• Avian
• Blood
• Duck
• Personal care product
• Plasticizer
• UV filter

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MESH Headings

• Animals
• Female
• Water Pollutants, Chemical/analysis
• Endangered Species
• Environmental Monitoring/methods
• Phenols
• Benzhydryl Compounds
• Ducks
• Benzophenones
• Endocrine Disruptors/analysis
• Phthalic Acids

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Grants Collapse

Affiliation(s)

Amalie V Ask Department of Biology, University of Turku, FI-20014, Turku, Finland.
Veerle L B Jaspers Department of Biology, Norwegian University of Science and Technology (NTNU), NO-7491, Trondheim, Norway
Junjie Zhang Department of Chemistry, Norwegian University of Science and Technology (NTNU), NO-7491, Trondheim, Norway
Alexandros G Asimakopoulos Department of Chemistry, Norwegian University of Science and Technology (NTNU), NO-7491, Trondheim, Norway
Sunniva H Frøyland Department of Biology, Norwegian University of Science and Technology (NTNU), NO-7491, Trondheim, Norway
Juho Jolkkonen Department of Biological and Environmental Science, FI-40014, University of Jyväskylä, Finland
Wasique Z Prian Department of Biology, Norwegian University of Science and Technology (NTNU), NO-7491, Trondheim, Norway
Nora M Wilson Ab Bengtskär Oy, FI-25950, Rosala, Finland; Physics, Faculty of Science and Engineering, Åbo Akademi University, FI-20500, Turku, Finland
Christian Sonne Department of Ecoscience, Aarhus University, Arctic Research Centre (ARC), DK-4000, Roskilde, Denmark
Martin Hansen Department of Environmental Science, Aarhus University, DK-4000, Roskilde, Denmark
Markus Öst Environmental and Marine Biology, Åbo Akademi University, FI-20500, Turku, Finland
Sanna Koivisto Finnish Safety and Chemicals Agency, P.O. Box 66, FI-00521, Helsinki, Finland
Tapio Eeva Department of Biology, University of Turku, FI-20014, Turku, Finland
Farshad S Vakili Department of Biology, University of Turku, FI-20014, Turku, Finland
Céline Arzel Department of Biology, University of Turku, FI-20014, Turku, Finland

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A critical review of wastewater-based epidemiology as a tool to evaluate the unintentional human exposure to potentially harmful chemicals

Wastewater-based epidemiology (WBE) is a powerful tool to gather epidemiological insights at the community level, providing objective data on population exposure to harmful substances. A considerable portion of the human exposure to these potentially harmful chemicals occurs unintentionally, unlike substances such as pharmaceuticals, illicit drugs, or alcohol. In this context, this comprehensive review analyzes WBE studies focused on classes of organic chemicals to which humans are unintentionally exposed, namely organophosphorus flame retardants, per- and polyfluoroalkyl substances (PFAS), benzotriazoles and benzothiazoles, phthalates and terephthalates, benzophenones, pesticides, bisphenols, and parabens. The review highlights some advantages of WBE for public health surveillance, e.g., non-invasive analysis, predictive capability, nearly real-time data, population-wide insights, no ethical approval, and unbiased sampling. It also discusses challenges and future research directions in WBE regarding exposure to harmful chemicals from various sources. The review emphasizes the critical role of wastewater sampling, sample preparation, quality control, and instrumental analysis in achieving accurate and reliable results. Furthermore, it examines the selection of human biomarkers for WBE studies and explores strategies to link WBE with human biomonitoring (HBM), which together enhance both the precision and effectiveness of exposure assessments.

Propyl paraben removal using Cu2O/ZnO-NPs photocatalyst elaborated via green method

The aim of the present work is to investigate the photocatalytic degradation of propyl paraben (propyl para-hydroxybenzoate, PrP) using Cu2O-ZnO-NPs photocatalyst followed by the identification of the oxidation by-products. The Cu2O-ZnO-NPs material, synthesized using a green chemistry approach, was used as a photocatalyst for the removal of PrP. The nanoparticles were characterized by XRD, XRF, diffuse reflectance spectroscopy, ATG/DTG, FTIR, SEM-EDX, BET and FRX techniques. The XRD results showed that Cu2O-ZnO-NPs have a nanometer size of 24.13 nm. The DR-UV analysis showed that Cu2O-ZnO-NPs has an Eg of 2.35 eV which corresponds to the absorption of visible light. The SEM-EDX analysis showed that the ZnO has a hexagonal structure while the CuO has a monoclinic structure. The effect of variables such as propyl paraben concentration (PrP), hydrogen peroxide concentration (H2O2), catalyst dose, and the reaction temperature on the pseudo-first order reaction rate constant (kapp) of the reaction was evaluated. It was found that the degradation of PrP was governed by hydroxyl radical °OH attack and the pathways consisted of a cascade of reactions. The optimum photocatalytic degradation was obtained with an initial catalyst dose of 50 mg, pH 7, and PrP concentration of 10 mg/L. When the photocatalyst was irradiated, a significant PrP degradation was observed after 30 min of irradiation. The results suggest that Cu2O-ZnO-NPs act as a good photocatalyst for PrP degradation under visible light.

Bioaccumulation and ecotoxicity of parabens in aquatic organisms: Current status and trends

Parabens are preservatives widely used in personal care products, pharmaceuticals, and foodstuffs. However, they are still unregulated chemical compounds. Given their extensive use and presence in different environmental compartments, parabens can adversely affect animal health. Thus, the current study aimed to summarize and critically analyze the bioaccumulation and ecotoxicity of parabens in aquatic species. Studies have been mostly conducted in laboratory conditions (75%), using mainly fish and crustaceans. Field studies were carried out across 128 sampling sites in six countries. Paraben bioaccumulation was predominantly detected in fish muscle, liver, brain, gills, ovary, and testes. Among the parent parabens, methylparaben (MeP), ethylparaben (EtP), and propylparaben (PrP) have been detected frequently and more abundantly in tissues of marine and freshwater specimens, as well as the metabolite 4-hydroxybenzoic acid (4-HB). Parabens can induce lethal and sublethal effects on aquatic organisms, such as oxidative stress, endocrine disruption, neurotoxicity, behavioral changes, reproductive impairment, and developmental abnormalities. The toxicity of parabens varied according to species, taxonomic group, developmental stage, exposure time, and concentrations tested. This study highlights the potential bioaccumulation and ecotoxicological impacts of parabens and their metabolites on aquatic invertebrates and vertebrates. Additionally, future research recommendations are provided to evaluate the environmental risks posed by paraben contamination more effectively.

Mask Wearers at Risk of Inhaling Respirable Hazards from Leave-On Facial Cosmetics

Previous research has widely overlooked the respiratory risks associated with cosmetic powder, a type of mixed particulate matter with intricate chemical compositions, especially in the context of wearing masks. This study investigated the inhalation risks posed by five face powders, focusing on both particulate matter (minerals and primary microplastics) and soluble components (preservatives and organic UV filters). Wearing masks significantly increased the inhalation risk of face powders, with exposure levels influenced by factors such as particle size, density, and composition. Additionally, different samples demonstrated irregular behavioral patterns when exposed to various human tissue environments. Soluble components analysis revealed that multiple additives dissolved in six body fluids, with a higher degree of release observed in the respiratory tract fluid compared to the digestive tract fluid. The alveoli may serve as a specific target for exposure to organic UV filters due to the solubilization effect of pulmonary surfactants. These findings revealed the importance of considering both particulate matter and soluble components when assessing respiratory and digestive exposure risks from cosmetic powders. Furthermore, understanding the interactions between cosmetic particles and body fluids, as well as potential synergistic toxic effects, is crucial for ensuring the safety of cosmetic products and safeguarding public health.

Evolution of microbial community and resistance genes in denitrification system under single and combined exposure to benzethonium chloride and methylparaben

Benzethonium chloride (BZC) and methylparaben (MeP) are commonly added into cosmetics as preservatives, which are frequently detected in wastewater treatment plants. Different response patterns of denitrification system were proposed under single and combined exposure to BZC and MeP (0, 0.5, 5 mg/L) by evaluating system performance, functional genes, extracellular polymeric substance (EPS), cytotoxicity, microbial community structure and resistance genes (RGs). The inhibition effect of BZC on denitrification system was stronger than MeP, and the co-exposure of BZC and MeP showed synergistic effect, enhancing the inhibition effect of BZC single exposure. BZC and/or MeP could promote the diffusion of RGs in sludge, including intracellular RGs (si-RGs) and extracellular RGs (se-RGs). Moreover, the single exposure of BZC and co-exposure of BZC and MeP increased the dissemination risks of RGs in water (w-RGs). IntI1 and tnpA-04, mobile genetic elements (MGEs), correlated positively with diverse RGs from different fractions. Notably, the spread of RGs through horizontal gene transfer mediated by MGEs and the flow of si-RGs into extracellular and water were observed in this study.

Track of methylparaben in the bulk phase and on the extracellular matrix of dual-species biofilms: Biodegradation and bioaccumulation

Methylparaben (MP) is a preservative considered an environmental contaminant of emerging concern due to its persistence in water sources, including drinking water (DW). This study assesses the interaction between MP and dual-species biofilms of Acinetobacter calcoaceticus and Stenotrophomonas maltophilia. These biofilms were grown under realism-based conditions in a multiple-cylinder biofilm reactor on polypropylene (PPL) surfaces, for 7 days, and then exposed to MP at 0.5 mg/L for three consecutive days. S. maltophilia predominantly succeeds within these biofilms compared to A. calcoaceticus. Exposure to MP resulted in a 4-fold increase in the number of culturable cells and a 1.4-fold rise in polysaccharide content, suggesting that bacterial cells may utilize MP as a carbon source to enhance biofilm fitness. MP was found to adsorb to PPL with biofilms following a pseudo-second-order kinetic model. Circa 37 % of MP adsorbed to PPL after 3 days of exposure. Besides that, MP was biodegraded by biofilms following an apparent first-order kinetic model. Part (25 %) of the MP was biodegraded whereas only 0.02 % bioaccumulated on the biofilm matrix. Biodegradation was related to esterase and lipase activity. The results provide new insights into the interaction between MP with biofilms and materials used in DW industries.

Co-exposure to parabens, bisphenol A, and triclosan and the associations with dyslipidemia in Chinese older adults: The mediation effect of oxidative stress

Dyslipidemia is a prevalent metabolic disorder in older adults and has negative effects on cardiovascular health. However, the combined effect of paraben, bisphenol A (BPA), and triclosan (TCS) exposure on dyslipidemia and the underlying mechanisms remain unclear. This cross-sectional study recruited 486 individuals ≥60 years in Shenzhen, China. Morning spot urine samples were collected and analyzed for four parabens, BPA, TCS, and 8-hydroxy-2'-deoxyguanosine (8-OHdG), a typical biomarker for oxidative stress, using mass spectrometry. Blood samples were tested for lipid levels using an automated biochemical analyzer. Quantile-based g-computation (QGC) was used to assess the combined effects of exposures on dyslipidemia. Mediation analysis was applied to investigate the mediating role of 8-OHdG between exposure and dyslipidemia. QGC showed that co-exposure to parabens, BPA, and TCS was positively linked with hypercholesterolemia (OR: 1.17, 95%CI: 1.10-1.24, P < 0.001) and hyper-LDL-cholesterolemia (OR: 1.35, 95%CI: 1.05-1.75, P = 0.019). Methylparaben (MeP), n-propyl paraben (PrP), and butylparaben (BtP) were the major contributors. 8-OHdG mediated 6.5% and 13.0% of the overall effect of the examined chemicals on hypercholesterolemia and hyper-LDL-cholesterolemia, respectively (all P < 0.05). Our study indicated that co-exposure to parabens, BPA, and TCS is associated with dyslipidemia and oxidative stress partially mediate the association. Future research is needed to explore additional mechanisms underlying these relationships.

Potential antiandrogenic effects of parabens and benzophenone-type UV-filters by inhibition of 3α-hydroxysteroid dehydrogenases

Parabens and UV-filters are frequently used additives in cosmetics and body care products that prolong shelf-life. They are assessed for potential endocrine disrupting properties. Antiandrogenic effects of parabens and benzophenone-type UV-filters by blocking androgen receptor (AR) activity have been reported. Effects on local androgen formation received little attention. Local 5α-dihydrotestosterone (DHT) production with subsequent AR activation is required for male external genitalia formation during embryogenesis. We investigated whether parabens and benzophenone-type UV-filters might cause potential antiandrogenic effects by inhibiting oxidative 3α-hydroxysteroid dehydrogenases (3α-HSDs) involved in the backdoor pathway of DHT formation. Five different 3α-HSDs were assessed for their efficiency to catalyze the 3α-oxidation reaction to form DHT and activate AR. 17β-hydroxysteroid dehydrogenase type 6 (HSD17B6), retinol dehydrogenases type 5 and 16 were further assessed using a radiometric in vitro activity assay to determine the conversion of 5α-androstane-3α-ol-17-one to 5α-androstane-3,17-dione in lysates of overexpressing HEK-293 cells. All parabens tested, except p-hydroxybenzoic acid (a main metabolite) inhibited HSD17B6 activity. Hexyl- and heptylparaben, as well as benzophenone (BP)-1 and BP-2, showed the highest inhibitory potencies, with nanomolar IC50 values. Molecular modeling predicted binding modes for the inhibitory parabens and BPs and provided an explanation for the observed structure-activity-relationship. Our results propose a novel mechanism of antiandrogenic action for commercially used parabens and BP UV-filters by inhibiting HSD17B6 and lowering DHT synthesis. Follow-up studies should assess BP-3 metabolism after topical application and whether the identified inhibitors reach concentrations in liver, testis, or prostate to inhibit HSD17B6, thereby causing antiandrogenic effects.

Parabens as the double-edged sword: Understanding the benefits and potential health risks

Parabens are globally employed as important preservatives in pharmaceutical, food, and personal care products. Nonetheless, improper disposal of commercial products comprising parabens can potentially contaminate various environmental components, including the soil and water. Residues of parabens have been detected in surface water, ground water, packaged food materials, and other consumer items. Long-term exposure to parabens through numerous consumer products and contaminated water can harm human health. Paraben can modulate the hormonal and immune orchestra of the body. Recent findings have correlated paraben use with hypersensitivity, obesity, and infertility. Notably, parabens have also been detected in the samples of breast cancer patients, suggesting a potential cross-talk between parabens and carcinogenesis. Therefore, the present article aims to dissect the significance of parabens as a preservative in several consumer products and their impact of chronic exposure to human health. This review encompasses various facets of paraben, including its sources, mechanism of action at the molecular level, and sheds light on its toxicological implications on human health.

4-Hydroxybenzoic acid restrains Nlrp3 inflammasome priming and activation via disrupting PU.1 DNA binding activity and direct antioxidation

Reactive oxygen species (ROS) production is considered central to triggering the nucleotide-binding domain-like receptor family pyrin domain containing 3 (Nlrp3) inflammasome activation and the subsequent inflammatory responses. Coenzyme Q10 (CoQ10) plays a critical role in maintaining intracellular ROS homeostasis and inhibiting excessive Nlrp3 inflammasome activation. However, direct supplementation of CoQ10 showed unsatisfactory clinical improvement due to its limited absorption and bioavailability. Therefore, stimulating endogenous CoQ10 biosynthesis by supplementing CoQ10 precursors may provide a more promising therapeutic approach. In this study, we described the role of 4-hydroxybenzoic acid (4-HBA), a precursor of CoQ10, in attenuating excessive inflammatory responses. We found that while supplementation of 4-HBA inhibited the priming and activation of Nlrp3 inflammasome, this effect was independent of its metabolic transformation into CoQ10. 4-HBA itself exhibits antioxidative activities. Furthermore, 4-HBA can disrupt the binding activity of PU.1 on the promoters of Tlr4 and Md2, thereby directly suppressing Nlrp3 inflammasome priming during LPS-induced inflammatory responses. Therefore, strategically utilizing 4-HBA or increasing 4-HBA intake may represent a potential strategy for reducing excessive inflammation.

Estimation of suspected estrogenic transformation products generated during preservative butylparaben chlorination using a simplified effect-based analysis approach

Estrogenic transformation products (TPs) generated after water chlorination can be considered as an environmental and health concern, since they can retain and even increase the estrogenicity of the parent compound, thus posing possible risks to drinking water safety. Identification of the estrogenic TPs generated from estrogenic precursor during water chlorination is important. Herein, butylparaben (BuP), which was widely used as preservative in food, pharmaceuticals and personal care products (PPCPs), was selected for research. A simplified effect-based analysis (EDA) approach was applied for the identification of estrogenic TPs generated during BuP chlorination. Despite the removal of BuP corresponds to the decrease of estrogenicity in chlorinated samples, an significant increase of estrogenicity was observed (at T = 30 min, presented an estrogenicity equivalent to 17β-estradiol). Chemical analysis of the estrogenic chlorinated samples that have been previously subjected to biological analysis (in vitro assays), in combination with the principal component analysis (PCA) evaluation, followed by validating the estrogenic potency of most relevant estrogenic TPs through an in silico approach (molecular dynamics simulations), identified that the halogenated TP3 (3,5-Dichloro-butylparaben) increased by 62.5 % and 61.8 % of the estrogenic activity of the parent compound in samples chlorinated with 30 min and 1 h, respectively being classified as a potentially estrogenic activity driver after BuP chlorination. This study provides a scientific basis for the more comprehensive assessment of the environmental and health risk associated with BuP chlorination, highlighting the necessity of identifying the unknown estrogenic TPs generateded from estrogenic precursors chlorination.

Methylparaben changes the community composition, structure, and assembly processes of free-living bacteria, phytoplankton, and zooplankton

Parabens are common contaminants in river and lake environments. However, few studies have been conducted to determine the effects of parabens on bacteria, phytoplankton, and zooplankton communities in aquatic environments. In this study, the effect of methylparaben (MP) on the diversity and community structure of the aquatic plankton microbiome was investigated by incubating a microcosm with MP at 0.1, 1, 10, and 100 μg/L for 7 days. The results of the Simpson index showed that MP treatment altered the α-diversity of free-living bacteria (FL), phytoplankton, and zooplankton but had no significant effect on the α-diversity of particle-attached bacteria (PA). Further, the relative abundances of the sensitive bacteria Chitinophaga and Vibrionimonas declined after MP addition. Moreover, the relative abundances of Desmodesmus sp. HSJ717 and Scenedesmus armatus, of the phylum Chlorophyta, were significantly lower in the MP treatment group than in the control group. In addition, the relative abundance of Stoeckeria sp. SSMS0806, of the Dinophyta phylum, was higher than that in the control group. MP addition also increased the relative abundance of Arthropoda but decreased the relative abundance of Rotifera and Ciliophora. The β-diversity analysis showed that FL and phytoplankton communities were clustered separately after treatment with different MP concentrations. MP addition changed community assembly mechanisms in the microcosm, including increasing the stochastic processes for FL and the deterministic processes for PA and phytoplankton. Structural equation modeling analysis showed a significant negative relationship between bacteria richness and phytoplankton richness, and a significant positive relationship between phytoplankton (richness and community composition) and zooplankton. Overall, this study emphasizes that MP, at environmental concentrations, can change the diversity and structure of plankton microbial communities, which might have a negative effect on ecological systems.

Modelling of Cetylpyridinium Chloride Availability in Complex Mixtures for the Prediction of Anti-Microbial Activity Using Diffusion Ordered Spectroscopy, Saturation Transfer Difference and 1D NMR

Background/Objectives: A range of NMR techniques, including diffusion ordered spectroscopy (DOSY) were used to characterise complex micelles formed by the anti-microbial cationic surfactant cetylpyridium chloride and to quantify the degree of interaction between cetylpyridium chloride and hydroxyethyl cellulose in a variety of commercially relevant formulations as a model for the disk retention assay. Methods: This NMR-derived binding information was then compared with the results of formulation analysis by traditional disk retention assay (DRA) and anti-microbial activity assays to assess the suitability of these NMR techniques for the rapid identification of formulation components that could augment or retard antimicrobial activity DRA. Results: NMR showed a strong ability to predict anti-microbial activity for a diverse range of formulations containing cetylpyridinium chloride (CPC). Conclusions: This demonstrates the value of this NMR-based approach as a rapid, relatively non-destructive method for screening commercial experimental anti-microbial formulations for efficacy and further helps to understand the interplay of excipients and active ingredients.

Review of the Integrated Approaches for Monitoring and Treating Parabens in Water Matrices

Due to their antibacterial and antifungal properties, parabens are commonly used as biocides and preservatives in food, cosmetics, and pharmaceuticals. Parabens have been reported to exist in various water matrices at low concentrations, which renders the need for sample preparation before their quantification using analytical techniques. Thus, sample preparation methods such as solid-phase extraction (SPE), rotating-disk sorptive extraction (RDSE), and vortex-assisted dispersive liquid-liquid extraction (VA-DLLE) that are commonly used for parabens extraction and preconcentration have been discussed. As a result of sample preparation methods, analytical techniques now detect parabens at trace levels ranging from µg/L to ng/L. These compounds have been detected in water, air, soil, and human tissues. While the full impact of parabens on human health and ecosystems is still being debated in the scientific community, it is widely recognized that parabens can act as endocrine disruptors. Furthermore, some studies have suggested that parabens may have carcinogenic effects. The presence of parabens in the environment is primarily due to wastewater discharges, which result in widespread contamination and their concentrations increased during the COVID-19 pandemic waves. Neglecting the presence of parabens in water exposes humans to these compounds through contaminated food and drinking water. Although there are reviews that focus on the occurrence, fate, and behavior of parabens in the environment, they frequently overlook critical aspects such as removal methods, policy development, and regulatory frameworks. Addressing this gap, the effective treatment of parabens in water relies on combined approaches that address both cost and operational challenges. Membrane filtration methods, such as nanofiltration (NF) and reverse osmosis (RO), demonstrate high efficacy but are hindered by maintenance and energy costs due to extensive fouling. Innovations in anti-fouling and energy efficiency, coupled with pre-treatment methods like adsorption, help mitigate these costs and enhance scalability. Furthermore, combining adsorption with advanced oxidation processes (AOPs) or biological treatments significantly improves economic and energy efficiency. Integrating systems like O₃/UV with activated carbon, along with byproduct recovery strategies, further advances circular economy goals by minimizing waste and resource use. This review provides a thorough overview of paraben monitoring in wastewater, current treatment techniques, and the regulatory policies that govern their presence. Furthermore, it provides perspectives that are critical for future scientific investigations and shaping policies aimed at mitigating the risks of parabens in drinking water.

The impact of methylparaben and chlorine on the architecture of Stenotrophomonas maltophilia biofilms

The biofilm architecture is significantly influenced by external environmental conditions. Biofilms grown on drinking water distribution systems (DWDS) are exposed to environmental contaminants, including parabens, and disinfection strategies, such as chlorine. Although changes in biofilm density and culturability from chemical exposure are widely reported, little is known about the effects of parabens and chlorine on biofilm morphology and architecture. This is the first study evaluating architectural changes in Stenotrophomonas maltophilia colony biofilms (representatives of bacterial communities presented in DWDS) induced by the exposure to methylparaben (MP) at environmental (15 μg/L) and in-use (15 mg/L) concentrations, and chlorine at 5 mg/L, using widefield epi-fluorescence mesoscopy with Mesolens. The GFP fluorescence of colony biofilms allowed the visualization of internal structures and Nile Red fluorescence permitted the inspection of the distribution of lipids. Our data show that exposure to MP triggers physiological and morphological adaptation in mature colony biofilms by increasing the complexity of internal structures, which may confer protection to embedded cells from external chemical molecules. These architectural modifications include changes in lipid distribution as an adaptive response to MP exposure. Although chlorine exposure affected colony biofilm diameter and architecture, the colony roundness was completely affected by the simultaneous presence of MP and chlorine. This work is pioneer in using Mesolens to highlight the risks of exposure to emerging environmental contaminants (MP), by affecting the architecture of biofilms formed by drinking water (DW) bacteria, even when combined with routine disinfection strategies.

Effects of urinary organophosphate flame retardants in susceptibility to attention-deficit/hyperactivity disorder in school-age children

Our previous studies have revealed a correlation between urinary phthalates (PAE) metabolites and parabens and PM2.5 exposure and susceptibility to attention-deficit/hyperactivity disorder (ADHD) in school-age children. Our goal was to examine the relationships between urinary organophosphate flame retardants (OPFRs) and their metabolites and the susceptibility to ADHD in the same cohort of children. We recruited 186 school children, including 132 with ADHD and 54 normal controls, living in southern Taiwan to investigate five OPFRs (1,3-dichloro-2-propyl phosphate (TDCPP), tri-n-butyl phosphate (TnBP), tris (2-chloroethyl) phosphate (TCEP), tris(2-butoxyethyl) phosphate (TBEP), and triphenyl phosphate (TPHP)) and five OPFR metabolites (bis(1,3-dichloro-2-propyl) phosphate (BDCPP), di-n-butyl phosphate (DNBP), bis(2-chloroethyl) hydrogen phosphate (BCEP), di-(2-butoxyethyl) phosphate (DBEP), and diphenyl phosphate (DPHP)) in urine. ADHD patients' behavioral symptoms and neuropsychological function were assessed using the Swanson, Nolan, and Pelham Version IV Scale (SNAP-IV) and the Conners' Continuous Performance Test 3rd Edition (Conners CPT3), respectively. BCEP was predominant among urinary OPFRs and the metabolites in both the ADHD and control groups. ADHD children had significantly higher levels of urinary BDCPP, BCEP, DBEP, DPHP, TCEP, TBEP, TNBP, TPHP, and Σ10OPFR compared to the controls. After controlling for age, gender, body mass index, PM2.5 exposure scenarios, and urinary phthalate metabolites, parabens, bisphenol-A and creatinine, levels of urinary BDCPP, TDCPP, and TBEP in ADHD children showed significant and dose-dependent effects on core behavioral symptoms of inattention. DNBP levels were positively correlated with neuropsychological deficits (CPT detectability, omission, and commission), while urinary DPHP in ADHD children were negatively related to CPT detectability and commission. Hyperactivity and impulsivity were not correlated with urinary OPFRs and their metabolites in ADHD children. In conclusion, the ADHD symptom of inattention and CPT performance may be closely associated with certain urinary OPFRs and their metabolites, independent of urinary PAE metabolites, parabens, and bisphenol-A in school-age-ADHD children.

Parabens, triclosan, and triclocarban in aquatic products from Shenzhen, China and the relative health risk

The consumption of contaminated aquatic products may expose humans to residues of parabens, triclosan (TCS), and triclocarban (TCC). Despite its significance, empirical research on this issue remains limited. In this study, we employed high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to analyze extracts from 245 aquatic product samples collected randomly from local markets in Shenzhen, Guangdong Province. Our analysis detected at least one of the five parabens-methyl 4-hydroxybenzoate (MeP), ethyl 4-hydroxybenzoate (EtP), propyl 4-hydroxybenzoate (PrP), butyl 4-hydroxybenzoate (BuP), and benzyl 4-hydroxybenzoate (BeP)-in 88 samples (35.9%). TCS and TCC were found in 50.6% and 51.4% of the samples, respectively, with MeP being the most frequently detected paraben. Significant negative correlations were observed between TCS and MeP (r = -0.129, p < 0.05) and between TCC and MeP (r = -0.176, p < 0.05), indicating potential different sources for these contaminants. Residue levels varied among different types of aquatic products, with TCS and TCC concentrations being higher in fish compared to crustaceans and bivalves. The health risk associated with consuming these contaminants was found to be minimal for both males and females. This study provides valuable insights into the dietary risks associated with exposure to parabens, TCS, and TCC.

Parabens alter the surface characteristics and antibiotic susceptibility of drinking water bacteria

Parabens are markedly present in products of daily use, considered emerging environmental contaminants that can harm human health and aquatic life, due to their release into aquatic sources. The impact of the exposure of microbial communities to parabens remains unclear. This study investigates aspects of the mode of action of methylparaben (MP), propylparaben (PP), butylparaben (BP), and MIX at environmental (15 μg/L) and in-use (15000 μg/L) concentrations, against two bacterial strains of Acinetobacter calcoaceticus and Stenotrophomonas maltophilia previously isolated from drinking water (DW). BP showed the strongest antimicrobial activity, while MP exhibited the weakest. The mechanism of action of parabens at the selected concentrations was found to be related to perturbations on physicochemical bacterial cell surface properties and charge, by causing an increase of bacterial cell envelope hydrophilicity and zeta potential values. In addition, parabens may activate osmotic regulation mechanisms as observed by the increase in vacuole area for MP-exposed A. calcoaceticus. The bacterial metabolic activity as well as bacterial size was also affected by parabens exposure. MP exposure further enhanced the biofilm formation ability and increased bacterial tolerance to antibiotics. The results raise environmental implications, particularly concerning water quality and public health, as parabens exposure can potentiate the virulence of DW bacteria, increasing the risk of human exposure to harmful microorganisms.

Yeast surface display technology: Mechanisms, applications, and perspectives

Microbial cell surface display technology, which relies on genetically fusing heterologous target proteins to the cell wall through fusion with cell wall anchor proteins, has emerged as a promising and powerful method with diverse applications in biotechnology and biomedicine. Compared to classical intracellular or extracellular expression (secretion) systems, the cell surface display strategy stands out by eliminating the necessity for enzyme purification, overcoming substrate transport limitations, and demonstrating enhanced activity, stability, and selectivity. Unlike phage or bacterial surface display, the yeast surface display (YSD) system offers distinct advantages, including its large cell size, ease of culture and genetic manipulation, the use of generally regarded as safe (GRAS) host cell, the ability to ensure correct folding of complex eukaryotic proteins, and the potential for post-translational modifications. To date, YSD systems have found widespread applications in protein engineering, waste biorefineries, bioremediation, and the production of biocatalysts and biosensors. This review focuses on detailing various strategies and mechanisms for constructing YSD systems, providing a comprehensive overview of both fundamental principles and practical applications. Finally, the review outlines future perspectives for developing novel forms of YSD systems and explores potential applications in diverse fields.

Aromatase as a novel target of parabens in human and rat placentas: 3D-quantitative structure-activity relationship and docking analysis

Aromatase (CYP19A1), a pivotal enzyme in the biosynthesis of estradiol from testosterone, is predominantly expressed in reproductive tissues including placentas. This study investigated the effects of paraben acid and nine parabens on the activity of human and rat CYP19A1 using microsomes derived from human and rat placentas and on estradiol secretion in human choriocarcinoma BeWo cells. The results showed that propyl, butyl, hexyl, heptyl, and nonyl parabens significantly inhibited human CYP19A1 activity, with IC50 values of 66.37, 61.08, 55.65, 48.26, and 27.24 μM, respectively. In BeWo cells, these parabens notably diminished estradiol secretion at concentrations of 100 μM. Similarly, rat CYP19A1 was inhibited by these parabens, with IC50 values of 98.07, 70.10, 41.30, 27.93, and 6.33 μM for propyl, butyl, hexyl, heptyl, and nonyl parabens, respectively. Kinetic analysis identified these compounds as mixed inhibitors. Bivariate correlation analysis revealed a negative correlation between the partition coefficient value, molecular weight, the number of carbon atoms in the alcohol moiety, as well as heavy atom number and IC50 values. Three-dimensional quantitative structure-activity relationship analysis highlighted the critical role of hydrophobic regions in determining inhibitory potency. Docking studies suggested that parabens interact with the heme-iron binding site of both human and rat CYP19A1. This study elucidates the inhibitory effects of various parabens on CYP19A1 and their binding mechanisms, thereby providing a deeper understanding of their potential impact on estrogen biosynthesis.

Exploring the role of genetic variability and exposure to bisphenols and parabens on excess body weight in Spanish children

Gene-environment interaction studies are emerging as a promising tool to shed light on the reasons for the rapid increase in excess body weight (overweight and obesity). We aimed to investigate the influence of several polymorphisms on excess weight in Spanish children according to a short- and long-term exposure to bisphenols and parabens, combining individual approach with the joint effect of them. This case-control study included 144 controls and 98 cases children aged 3-12 years. Thirty SNPs in genes involved in obesity-related pathways, xenobiotic metabolism and hormone systems were genotyped using the GSA microchip technology and qPCRs with Taqman® probes. Levels of bisphenols and parabens in urine and hair were used to assess short- and long-term exposure, respectively, via UHPLC-MS/MS system. LEPR rs9436303 was identified as a relevant risk variant for excess weight (ORDom:AAvsAG+GG=2.65, p<0.001), and this effect persisted across exposure-stratified models. For long-term exposure, GPX1 rs1050450 was associated with increased excess weight at low single paraben exposure (ORGvsA=2.00, p=0.028, p-interaction=0.016), whereas LEPR rs1137101 exhibited a protective function at high co-exposure (ORDom:AAvsAG+GG=0.17, p=0.007, p-interaction=0.043). ESR2 rs3020450 (ORDom:GGvsAG+AA=5.17, p=0.020, p-interaction=0.028) and CYP2C19 rs4244285 (ORDom:GGvsAG+AA=3.54, p=0.039, p-interaction=0.285) were identified as predisposing variants at low and high co-exposure, respectively. In short-term exposure, higher odds were observed for INSIG2 rs7566605 at high bisphenol exposure (ORCvsG=2.97, p=0.035, p-interaction=0.017) and for GSTP1 rs1695 at low levels (ORDom:AAvsAG+GG=5.38, p=0.016, p-interaction=0.016). At low and medium co-exposure, SH2B1 rs7498665 (ORAvsG=0.17, p=0.015, p-interaction=0.085) and MC4R rs17782313 (ORAvsG=0.10, p=0.023, p-interaction=0.045) displayed a protective effect, whereas ESR2 rs3020450 maintained its contributing role (ORGvsA=3.12, p=0.030, p-interaction=0.010). Our findings demonstrate for the first time that understanding the genetic variation in excess weight and how the level of exposure to bisphenols and parabens might interact with it, is crucial for a more in-depth comprehension of the complex polygenic and multifactorial aetiology of overweight and obesity.

Solar-driven environmental fate of chlorinated parabens in natural and engineered water systems

Parabens are classified as emerging contaminants in global waters, and the ubiquitous emergence of their high-risk chlorinated products generated from chlorine-based wastewater disinfection has attracted increasing attention. However, rather limited information is available on their photofate after discharging into surface waters, and their degradation behavior after solar-based engineering water treatment is unclear. Herein, the reactivity of four chlorinated parabens with different photochemically produced reactive intermediates was measured. Quantitative contribution analysis in abating such compounds showed the dominance of direct photolysis in sunlit natural freshwaters. Introducing a technical solar/peroxymonosulfate (PMS) system could greatly improve the removal of chlorinated parabens. The economic analysis suggested that chlorinated parabens exhibited a minimum value of economic input as 93.41-158.04 kWh m-3 order-1 at 0.543-0.950 mM PMS. The high-resolution mass spectrometry analysis of the degradation products suggested that dechlorination, hydroxylation, and ester chain cleavage were the dominant transformation pathways during photolysis and solar/PMS treatment. Furthermore, the in silico prediction indicated severe aquatic toxicity of certain products but enhanced biodegradability. Overall, this investigation filled a knowledge gap on the reactivity of chlorinated parabens with diverse reactive transients and their quantitative contributions to the photolysis and solar/PMS treatment of emerging micropollutants in water.

Dose-dependent effects of different parabens on food waste biorefinery for volatile fatty acids production: Insight into specific fermentation processes, substrates transformation and microbial metabolic traits

Parabens are largely concentrated in food waste (FW) due to their large consumption as the widely used preservative. To date, whether and how they affect FW resource recovery via anaerobic fermentation is still largely unknown. This work unveiled the hormesis-like effects of two typical parabens (i.e., methylparaben and n-butylparaben) on VFAs production during FW anaerobic fermentation (i.e., parabens increased VFAs by 6.73-14.49 % at low dose but caused 82.51-87.74 % reduction at high dose). Mechanistic exploration revealed that the parabens facilitated the FW solubilization and enhanced the associated substrates' biodegradability. The low parabens enriched the functional microorganisms (e.g., Firmicutes and Actinobacteria) and upregulated those critical genes involved in VFAs biosynthesis (e.g., GCK and PK) by activating the microbial adaptive capacity (i.e., quorum sensing and two-component system). Consequently, the metabolism rates of fermentation substrates and subsequent VFAs production were accelerated. However, due to increased biotoxicity of high parabens, the functional microorganisms and relevant metabolic activities were depressed, resulting in the significant reduction of VFAs biosynthesis. Structural equation modeling clarified that microbial community was the predominant factor affecting VFAs generation, followed by metabolic pathways. This work elucidated the dose-dependent effects and underlying mechanisms of parabens on FW anaerobic fermentation, providing insights for the effective management of FW resource recovery.

A systematic review of the toxic potential of parabens in fish

Parabens are the most prevalent ingredients in cosmetics and personal care products (PCPs). They are colorless and tasteless and exhibit good stability when combined with other components. Because of these unique physicochemical properties, they are extensively used as antimicrobial and antifungal agents. Their release into the aquatic ecosystem poses potential threats to aquatic organisms, including fish. We conducted an electronic search in PubMed (http://www.ncbi.nlm.nih.gov/pubmed) using the search term parabens and fish and sorted 93 articles consisting of methyl paraben (MTP), ethyl paraben (ETP), propyl paraben (PPP), butyl paraben (BTP), and benzyl paraben (BNP) in several fish species. Furthermore, we confined our search to six fish species (common carp, Cyprinus carpio; fathead minnows, Pimephales promelas; Japanese medaka, Oryzias latipes; rainbow trout, Oncorhynchus mykiss; Nile tilapia, Oreochromis niloticus; and zebrafish, Danio rerio) and four common parabens (MTP, ETP, PPP, and BTP) and sorted 48 articles for review. Our search indicates that among all six fish, zebrafish was the most studied fish and the MTP was the most tested paraben in fish. Moreover, depending on the alkyl chain length and linearity, long-chained parabens were more toxic than the parabens with short chains. Parabens can be considered endocrine disruptors (EDs), targeting estrogen-androgen-thyroid-steroidogenesis (EATS) pathways, blocking the development and growth of gametes, and causing intergenerational toxicity to impact the viability of offspring/larvae. Paraben exposure can also induce behavioral changes and nervous system disorders in fish. Although the USEPA and EU limit the use of parabens in cosmetics and pharmaceuticals, their prolonged persistence in the environment may pose an additional health risk to humans.

Assessment of immunomodulatory effects of five commonly used parabens on human THP-1 derived macrophages: Implications for ecological and human health impacts

Parabens are widely used as broad-spectrum anti-microbials and preservatives in food, cosmetics, pharmaceuticals, and personal care products. Studies suggest that the utilization of parabens has substantially increased over the past years, particularly during the global pandemic of coronavirus disease 2019 (COVID-19). Although parabens are generally recognized as safe by the U.S. FDA, some concerns have been raised regarding the potential health effects of parabens associated with immunotoxicity. Herein, we comprehensively investigated several key characteristics of immunotoxicants of five commonly used parabens (methyl-, ethyl-, propyl-, butyl-, and benzyl parabens) in human THP-1 derived macrophages, which are effector cells serving as a first line of host defense against pathogens and tumor immunosurveillance. The results indicate parabens, at concentrations found in humans and biota, significantly dampened macrophage chemotaxis and secretion of major pro-inflammatory cytokines (TNF-α and IL-6) and anti-inflammatory cytokine (IL-10), corroborating the mRNA expression profile. Furthermore, some parabens were found to markedly alter macrophage adhesion and cell surface expression of costimulatory molecules, CD80+ and CD86+, and significantly increase macrophage phagocytosis. Collectively, these findings heighten awareness of potential immunotoxicity posed by paraben exposure at biologically relevant concentrations, providing implications for human health and ecological risks associated with immune dysfunctions.

Propylparaben exposure impairs G2/M and metaphase-anaphase transition during mouse oocyte maturation

Propylparaben (PrPB) is a known endocrine disrupting chemicals that is widely applied as preservative in pharmaceuticals, food and cosmetics. PrPB has been detected in human urine samples and human serum and has been proven to cause functional decline in reproduction. However, the direct effects of PrPB on mammalian oocyte are still unknown. Here, we demonstrationed that exposure to PrPB disturbed mouse oocyte maturation in vitro, causing meiotic resumption arrest and first polar body extrusion failure. Our results indicated that 600 μM PrPB reduced the rate of oocyte germinal vesicle breakdown (GVBD). Further research revealed that PrPB caused mitochondrial dysfunction and oxidative stress, which led to oocyte DNA damage. This damage further disturbed the activity of the maturation promoting factor (MPF) complex Cyclin B1/ Cyclin-dependent kinase 1 (CDK1) and induced G2/M arrest. Subsequent experiments revealed that PrPB exposure can lead to spindle morphology disorder and chromosome misalignment due to unstable microtubules. In addition, PrPB adversely affected the attachment between microtubules and kinetochore, resulting in persistent activation of BUB3 amd BubR1, which are two spindle-assembly checkpoint (SAC) protein. Taken together, our studies indicated that PrPB damaged mouse oocyte maturation via disrupting MPF related G2/M transition and SAC depended metaphase-anaphase transition.

Urinary paraben exposure increases the risk of a low estimated glomerular filtration rate in Taiwanese general population

BACKGROUND

The inconsistent relationship between chemical exposure and estimated glomerular filtration rate (eGFR) has been examined in only a few studies. We investigated the association between paraben exposure and indicators of renal function in a total of 361 individuals recruiting from a representative study.

METHOD

The levels of urinary parabens, including methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), and butylparaben (BuP), were measured using UPLC-MS/MS. The association between paraben exposure and indices of renal function was assessed using multiple logistic regression and Bayesian Kernel Machine Regression (BKMR).

RESULTS

The median levels of urinary parabens in the adult group were significantly higher than those in the minor group, that is, 397 vs. 148 ng/mL for MeP, 38.8 vs. 13.6 ng/mL for EtP, 117 vs. 57.7 ng/mL for PrP, and 6.61 vs. 2.79 ng/mL for BuP (all P < 0.001). In the adult group, multivariate regression models confirmed a positive association between the albumin-to-creatinine ratio and urinary MeP (β = 0.580) and a positive association of BUN (β = 0.061) and a negative association of eGFR (β = -0.051) with urinary EtP (all P < 0.001). In the adult group, compared with the lowest tertile group, the adjusted odds ratio in the third tertile (T3) of urinary EtP levels indicated a 3.08 times increased risk of eGFR abnormalities, followed by the second tertile (T2) with a 2.63 times increased risk. The generalized additive model (GAM) and BKMR models showed a non-linear correlation between urinary EtP levels and early CKD, as well as reduced eGFR. We observed a significant positive cumulative effect of urinary paraben on eGFR, and a significant positive single exposure effect of urinary EtP with eGFR abnormality.

CONCLUSION

We found a significant association between exposure to EtP and an increased risk of high BUN levels and decreased eGFR.