Concentrations of environmental phenols and parabens in milk, urine and serum of lactating North Carolina women

Exposure to bisphenols, parabens, and benzophenones in colostrum breast milk of Panamanian women: A pilot study from the PA-MAMI cohort

BACKGROUND

Breast milk is the optimal source of nutrition for infants but can also expose them to endocrine-disrupting chemicals (EDCs), among other environmental contaminants.

AIM

To determine concentrations of non-persistent phenolic EDCs (three bisphenols, four parabens [PBs], and six benzophenones [BPs]), in colostrum samples from Panamanian mothers and to examine associated reproductive, sociodemographic, and life-style factors.

METHODS

Dispersive liquid-liquid microextraction was used to measure concentrations of bisphenol A (BPA), bisphenol F (BPF), bisphenol S (BPS), methyl- (MeP), ethyl- (EtP), propyl- (n-PrP), and butyl-paraben (n-BuP), and benzophenones BP-1, BP-2, BP-3, BP-6, BP-8, and 4-hydroxy-BP in colostrum milk samples from 36 mothers. An ad hoc questionnaire was used to collect data on potential influentially variables, and multiple linear and logistic regression analyses were conducted.

RESULTS

Two or more tested EDCs were detected in 36 colostrum samples (100 %), at least four in 14 samples (38.9 %), and at least six in 4 samples (11.1 %). The most frequently detected compounds were BPA (91.7 %), BP-8 (63.9 %), MeP (47.2 %), and BPF (41.7 %). The median concentration was 3.45 ng/mL for BP-8 and 1.37 ng/mL for BPA. No concentrations of n-PrP, BP-1, BP-6, or 4-hydroxy-BP were detected. Associations were observed between phenolic EDC concentrations and maternal place of residence, consumption frequency of poultry, fish, fresh cheese, fruit, yogurt and chocolate, intake of nutritional supplements, and application of some personal care products.

CONCLUSIONS

Bisphenols, parabens, and benzophenones were widely present in colostrum milk samples from Panamanian women. Preventive measures are needed to maximize the benefits of breastfeeding.

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.

Development of a robust non-targeted analysis approach for fast identification of endocrine disruptors and their metabolites in human urine for exposure assessment

Endocrine disrupting chemicals are of concern because of possible human health effects, thus they are frequently included in biomonitoring studies. Current analytical methods are focused on known chemicals and are incapable of identifying or quantifying other unknown chemicals and their metabolites. Non-targeted analysis (NTA) methods are advantageous since they allow for broad chemical screening, which provides a more comprehensive characterization of human chemical exposure, and can allow elucidation of metabolic pathways for unknown chemicals. There are still many challenges associated with NTA, which can impact the results obtained. The chemical space, i.e., the group of known and possible compounds within the scope of the method, must clearly be defined based on the sample preparation, as this is critical in identifying chemicals with confidence. Data acquisition modes and mobile phase additives used with liquid chromatography coupled to high-resolution mass-spectrometry can affect the chemicals ionized and structural identification based on the spectral quality. In this study, a sample preparation method was developed using a novel clean-up approach with CarbonS cartridges, for endocrine-disrupting chemicals in urine, including new bisphenol A analogues and benzophenone-based UV filters, like methyl bis (4-hydroxyphenyl acetate). The study showed that data dependent acquisition (DDA) had a lower identification rate (40%) at low spiking levels, i.e., 1 ng/mL, compared to data independent acquisition (DIA) (57%), when Compound Discoverer was used. In DDA, more compounds were identified using Compound Discoverer, with an identification rate of 95% when ammonium acetate was compared to acetic acid (82%) as a mobile phase additive. TraceFinder software had an identification rate of 53% at 1 ng/mL spiking level using the DDA data, compared to 40% using the DIA data. Using the developed method, 2,4 bisphenol F was identified for the first time in urine samples. The results show how NTA can provide human exposure information for risk assessment and regulatory action but standardized reporting of procedures is needed to ensure study results are reproducible and accurate. His Majesty the King in Right of Canada, as represented by the Minister of Health, 2024.

Human exposure characteristics of pharmaceutical and personal care product chemicals and associations with dietary habits

Considering the widespread presence of pharmaceutical and personal care products (PPCPs) in the environment and their adverse health effects, human exposure to PPCPs has caused worldwide concern. However, there remains insufficient information on the exposure assessment of the Chinese population. Based on this, the exposure levels of 13 PPCPs in the urine samples of 986 Chinese adults were measured, aiming to provide information on the prevalence of PPCP occurrence and investigate potential correlations between PPCP exposure and obesity. Results showed that the detection rates of these compounds in urine ranged from 28.12 % to 98.58 %, with median concentrations ranging below the limit of detection to 10.58 ng mL-1. Methyl-paraben (MeP) was the most dominant paraben and had the highest urinary concentration (median = 10.12 ng mL-1), while 4-hydroxy-benzophenone (4-OH-BP) was the dominant benzophenone derivative (median = 0.22 ng mL-1). In antibacterials, the urinary concentration of triclosan (mean = 42.00 ng mL-1) was much higher than that of triclocarban (mean = 0.63 ng mL-1). PPCP concentrations were significantly associated with sex, age, body mass index, education level, and annual household income (p < 0.050). Regression analysis of dietary habits showed that seafood and tea consumption may be significant exposure sources of PPCP exposure (p < 0.050). Furthermore, individual exposure to MeP (odds ratio (OR) < 1, p = 0.002) and 4-OH-BP (OR < 1, p = 0.009) exhibited a significantly negative association with obesity in females. Also, analysis results from quantile g-computation and Bayesian kernel machine regression models demonstrated that an inverse correlation between PPCP mixture exposure and obesity was significant in females. This study reports the extensive prevalence of PPCP exposure among adults from China, and may provide crucial insights into PPCP exposure dynamics. More epidemiological studies are need in the future, with a thorough knowledge of PPCP exposure.

Environmental phenol exposures in 6- to 12-week-old infants: The Infant Feeding and Early Development (IFED) study

BACKGROUND

Exposure to phenols, endocrine-disrupting chemicals used in personal care and consumer products, is widespread. Data on infant exposures are limited despite heightened sensitivity to endocrine disruption during this developmental period. We aimed to describe distributions and predictors of urinary phenol concentrations among U.S. infants ages 6-12 weeks.

METHODS

The Infant Feeding and Early Development (IFED) study is a prospective cohort study of healthy term infants enrolled during 2010-2013 in the Philadelphia region. We measured concentrations of seven phenols in 352 urine samples collected during the 6- or 8- and/or 12-week study visits from 199 infants. We used linear mixed models to estimate associations of maternal, sociodemographic, infant, and sample characteristics with natural-log transformed, creatinine-standardized phenol concentrations and present results as mean percent change from the reference level.

RESULTS

Median concentrations (μg/L) were 311 for methylparaben, 10.3 for propylparaben, 3.6 for benzophenone-3, 2.1 for triclosan, 1.0 for 2,5-dichlorophenol, 0.7 for BPA, and 0.3 for 2,4-dichlorophenol. Geometric mean methylparaben concentrations were approximately 10 times higher than published estimates for U.S. children ages 3-5 and 6-11 years, while propylparaben concentrations were 3-4 times higher. Infants of Black mothers had higher concentrations of BPA (83%), methylparaben (121%), propylparaben (218%), and 2,5-dichorophenol (287%) and lower concentrations of benzophenone-3 (-77%) and triclosan (-53%) than infants of White mothers. Triclosan concentrations were higher in breastfed infants (176%) and lower in infants whose mothers had a high school education or less (-62%). Phenol concentrations were generally higher in summer samples.

CONCLUSIONS

Widespread exposure to select environmental phenols among this cohort of healthy U.S. infants, including much higher paraben concentrations compared to those reported for U.S. children, supports the importance of expanding population-based biomonitoring programs to infants and toddlers. Future investigation of exposure sources is warranted to identify opportunities to minimize exposures during these sensitive periods of development.

The exposure to UV filters: Prevalence, effects, possible molecular mechanisms of action and interactions within mixtures

Substances that can absorb sunlight and harmful UV radiation such as organic UV filters are widely used in cosmetics and other personal care products. Since humans use a wide variety of chemicals for multiple purposes it is common for UV filters to co-occur with other substances either in human originating specimens or in the environment. There is increasing interest in understanding such co-occurrence in form of potential synergy, antagonist, or additive effects of biological systems. This review focuses on the collection of data about the simultaneous occurrence of UV filters oxybenzone (OXYB), ethylexyl-methoxycinnamate (EMC) and 4-methylbenzylidene camphor (4-MBC) as well as other classes of chemicals (such as pesticides, bisphenols, and parabens) to understand better any such interactions considering synergy, additive effect and antagonism. Our analysis identified >20 different confirmed synergies in 11 papers involving 16 compounds. We also highlight pathways (such as transcriptional activation of estrogen receptor, promotion of estradiol synthesis, hypothalamic-pituitary-gonadal (HPG) axis, and upregulation of thyroid-hormone synthesis) and proteins (such as Membrane Associated Progesterone Receptor (MAPR), cytochrome P450, and heat shock protein 70 (Hsp70)) that can act as important key nodes for such potential interactions. This article aims to provide insight into the molecular mechanisms on how commonly used UV filters act and may interact with other chemicals.

Parabens promotes invasive properties of multiple human cells: A potential cancer-associated adverse outcome pathway

Parabens are esters of p-hydroxybenzoic acid, which have been used as preservatives and considered safe for nearly a century, until the last two decades when concerns began to be raised about their association with cancers. Knowledge of the mode of action of parabens on the metastatic properties of different cancer cells is still very limited. In the present study, we investigated the effects of methylparaben (MP) and propylparaben (PP) on cell invasion and/or migration in multiple human cancerous and noncancerous cells, including hepatocellular carcinoma cells (HepG2), cervical carcinoma cells (HeLa), breast carcinoma cells (MCF-7), and human placental trophoblasts (HTR-8/SVneo). MP and PP at concentrations in a range of 5-500 μg/L significantly promoted the invasion of four cell lines, with a minimum effective concentration of 5 μg/L. MP and PP up-regulated the expression levels and enzymatic activities of matrix metalloproteinase 2 and 9 (MMP2 and MMP9), as well as altered the expression of the tissue inhibitors of metalloproteinase 1 and 2 (TIMP1 and TIMP2) in four cell lines, suggesting MMPs/TIMPs as potential key events (KEs) for paraben-induced cell invasion. Activation of the p38 mitogen-activated protein kinase (p38 MAPK) and c-Jun N-terminal protein kinases 1/2 (JNK1/2) signaling pathways was required for MP- and PP-promoted invasion of four cell lines, suggesting MAPK signaling pathways as candidates for KEs in cancer or noncancerous cells response to paraben exposure. This study showed for the first time that the two widely used parabens, MP and PP, promoted invasive capacity of multiple human cells through a common mode of action. This study provides evidence for the establishment of a potential cancer-associated AOP for parabens based on pathway-specific mechanism(s), which contributes towards assessing the health risks of these environmental chemicals.

Identifying critical windows of prenatal phenol, paraben, and pesticide exposure and child neurodevelopment: Findings from a prospective cohort study

BACKGROUND

This study aimed to investigate how exposure to a mixture of endocrine disrupting chemicals (EDCs) during two points in pregnancy affects early childhood neurodevelopment.

METHODS

We analyzed publicly-available data from a high-risk cohort of mothers and their children (2007-2014) that measured six EDCs including methyl-, ethyl- and propyl parabens (MEPB, ETPB, PRPB), Bisphenol-A (BPA), 3,5,6-trichloro-2-pyridinol (TCPy), 3-phenoxybenzoic acid (3-PBA) in prenatal urine samples during the second and third trimesters. Neurodevelopmental scores were assessed using Mullen Scales of Early Learning (MSEL) at age 3. We used mean field variational Bayes for lagged kernel machine regression (MFVB-LKMR) to investigate the association between trimester-specific co-exposure to the six EDCs and MSEL scores at age 3, stratified by sex.

RESULTS

The analysis included 130 children. For females, the relationship between BPA and 3PBA with MSEL score varied between the two trimesters. In the second trimester, effect estimates for BPA were null but inversely correlated with MSEL score in the third trimester. 3PBA had a negative relationship with MSEL in the second trimester and positive correlation in the third trimester. For males, effect estimates for all EDCs were in opposing directions across trimesters. MFVB-LKMR analysis identified significant two-way interaction between EDCs for MSEL scores in both trimesters. For example, in females, the MSEL scores associated with increased exposure to TCPy were 1.75 units (95%credible interval -0.04, -3.47) lower in the 2nd trimester and 4.61 (95%CI -3.39, -5.84) lower in the third trimester when PRPB was fixed at the 75th percentile compared to when PRPB was fixed at the 25th percentile.

CONCLUSION

Our study provides evidence that timing of EDC exposure within the prenatal period may impact neurodevelopmental outcomes in children. More of these varying effects were identified among females. Future research is needed to explore EDC mixtures and the timing of exposure during pregnancy to enhance our understanding of how these chemicals impact child health.

Bisphenol chemicals in colostrum from Shanghai, China during 2006-2019: Concentration, temporal variation, and potential influence on birth parameters

Bisphenol A (BPA) and its alternatives bisphenol S (BPS) and bisphenol F (BPF) are identified as endocrine disruptors that have negative impacts on infant growth. Their temporal variations in human milk and potential effects on fetal growth are not well known. In this study, colostrum collecting at four time points between 2006 and 2019 and paired urine in 2019 from Shanghai, China, were analyzed for eight bisphenols. The total concentrations in colostrum in 2019 were up to 3.43 ng/mL, with BPA being dominant, followed by BPS and BPF. BPA levels in colostrum noticeably decreased from 2010 to 2013. Additionally, obvious percentage changes in bisphenols were observed in 2019. The BPA concentrations in paired colostrum and urine were not significantly correlated. High levels of BPA in colostrum were linked to a significant reduction in birth head circumference in 2019 (p = 0.031). BPA and BPS in colostrum might have similar negative effect on fetal growth in 2019, but these effects were generally non-significant. Further studies are needed to testify the potential impact. The hazard indexes for infants in the first week of life were below 1, suggesting no obvious health risks. However, the high contribution from BPA still warrants further attention.

Research progress on mitochondrial damage and repairing in oocytes: A review

Oocytes are the female germ cells, which are susceptible to stress stimuli. The development of oocytes in the ovary is affected by many environmental and metabolic factors, food toxins, aging, and pathological factors. Mitochondria are the main target organelles of these factors, and the damage to mitochondrial structure and function can affect the production of ATP, the regulation of redox reactions, and apoptosis in oocytes. Mitochondrial damage is closely related to the decrease in oocyte quality and is the main factor leading to female infertility. Antioxidant foods or drugs have been used to prevent mitochondrial damage from some stressors or to repair damaged mitochondria, thereby improving oocyte development and female reproductive outcomes. In this paper, the damage of mitochondria during oocyte development by the above factors has been reviewed, and the relevant measures to alleviate the damage of mitochondria in oocytes have been discussed. Our findings may provide a theoretical basis and experimental basis for improving female fertility.

A review of sources, pathways, and toxic effects of human exposure to benzophenone ultraviolet light filters

Benzophenone ultraviolet light filters (BPs) are high-production-volume chemicals extensively used in personal care products, leading to widespread human exposure. Given their estrogenic properties, the potential health risks associated with exposure to BPs have become a public health concern. This review aims to summarize sources and pathways of exposure to BPs and associated health risks. Dermal exposure, primarily through the use of sunscreens, constitutes a major pathway for BP exposure. At a recommended application rate, dermal exposure of BP-3 via the application of sunscreens may reach or exceed the suggested reference dose. Other exposure pathways to BPs, such as drinking water, seafood, and packaged foods, contribute minimal to the overall dose. Inhalation is a minor pathway of exposure; however, its contribution cannot be ignored. Human exposure to BPs is an order of magnitude higher in North America than in Asia and Europe. Studies conducted on laboratory animals and cells have consistently demonstrated the toxic effects of BP exposure. BPs are estrogenic and elicit reproductive and developmental toxicities. Furthermore, neurotoxicity, hepatotoxicity, nephrotoxicity, and carcinogenicity have been reported from chronic BP exposure. In addition to animal and cell studies, epidemiological investigations have identified associations between BPs and couples' fecundity and other reproductive disorders, as well as adverse birth outcomes. Further studies are urgently needed to understand the risks posed by BPs on human health.

The association between prenatal exposure to bisphenol A and offspring obesity: A systematic review

In recent years, the global prevalence of childhood overweight and obesity has surged. Bisphenol A (BPA), prevalent in the manufacture of polycarbonate plastics and epoxy resins, is associated with this escalating obesity pattern. Both early life stages and pregnancy emerge as pivotal windows of vulnerability. This review systematically evaluates human studies to clarify the nexus between prenatal BPA exposure and offspring obesity. Our extensive literature search covered databases like PubMed, Web of Science, Cochrane Library, Embase, and Scopus, encompassing articles from their inception until July 2023. We utilized the Newcastle-Ottawa Scale (NOS) to evaluate the methodological rigor of the included studies, the Oxford Center for Evidence-Based Medicine Levels of Evidence Working Group (OCEBM) table to determine the level of the evidence, and the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) guidelines to evaluate the certainty of the evidence with statistical significance. We centered on primary studies investigating the link between urinary BPA levels during pregnancy and offspring obesity. Our analysis included thirteen studies, with participant counts ranging from 173 to 1124 mother-child dyads. Among them, eight studies conclusively linked prenatal BPA exposure to increased obesity in offspring. Evaluation metrics for the effect of prenatal BPA on offspring obesity comprised BMI z-score, waist circumference, overweight/obesity classification, aggregate skinfold thickness, body fat percentage, and more. Present findings indicate that prenatal BPA exposure amplifies offspring obesity risk, with potential effect variations by age and gender. Therefore, further research is needed to explore the causal link between prenatal BPA exposure and obesity at different developmental stages and genders, and to elucidate the underlying mechanisms.

Occurrence and bioaccumulation of parabens and their metabolites in the biota from a subtropical freshwater river ecosystem: Implications for human exposure

Widespread occurrence of parabens in the environment has been documented, whereas little information is available about the occurrence and bioaccumulation of parabens in the aquatic biota. In this study, plants (n = 14), plankton (n = 20), and fish muscle (n = 89) samples were collected from Dongjiang River Basin and analyzed for nine parabens and two of their metabolites using ultra-high performance liquid chromatogram-tandem mass spectrometry. All the samples contained notable concentrations of parabens and the metabolites, and the total concentrations of parabens (Σp-PBs; sum of nine parent compounds) ranged from 0.40 to 776 ng/g dry wt. MeP, EtP, and PrP were the predominant parent compounds in both plankton and fish, while in plants, MeP, BzP and EtP were the top three abundant chemicals. As the predominant metabolite, 4-HB was detected in 99% aquatic biota samples analyzed with the highest concentration (24800 ng/g, dry wt) detected in an alga. Significantly positively correlations among the concentrations of MeP, BzP, EtP and 4-HB in the fish muscle were found. Based on dry weight, bioaccumulation potentials of these chemical substances were estimated with bioaccumulation factor (BAF) values greater than 2000 L/kg, suggestive of bioaccumulative in aquatic biota. Based on the concentrations measured, the daily intake (EDI) of parabens through fish consumption was estimated with the mean EDIs as 4.20, 2.41, and 1.93 ng/kg bw/day for toddlers, children, and adults in urban, respectively. This study provides baseline information about the occurrence and fate of parabens in the aquatic environment.

Prenatal exposure to bisphenol A and neonatal health outcomes: A systematic review

Bisphenol A (BPA) is an endocrine-disrupting chemical substance responsible for the composition of polycarbonate plastics and epoxy resins. Early life and pregnancy are important windows of susceptibility. This review aimed to conduct a systematic assessment of human studies to comprehensively describe the association between prenatal BPA exposure and neonatal health outcomes. Literature was searched in Cochrane Library, Embase, PubMed, Scopus, and Web of Science published before November 2022, and were selected according to clear inclusion and exclusion criteria. The Newcastle-Ottawa scale (NOS) and Grades of Recommendation, Assessment, Development, and Evaluation guidelines (GRADE) were followed to grade the methodological quality of studies and the certainty of the evidence respectively. As a result, a total of 22259 participants from 45 trials were included. And the potential associations of prenatal exposure to BPA and neonatal health outcomes were mainly shown in four aspects: gestational age/preterm birth, physical health at birth, the incidence of systemic abnormalities or diseases, and other health outcomes. Although the certainty of the evidence was low to very low, the methodological quality of the included studies was high. Prenatal BPA exposure tended to have negative effects on most of the health outcomes in neonates but showed inconsistent results on physical health at birth. This systematic review is the first to comprehensively synthesize the existing evidence on the association between prenatal BPA exposure and neonatal health outcomes. In the future, further studies are still needed to verify these effects and elucidate the underlying mechanisms.

Exposure to Butylparaben Induces Craniofacial Bone Developmental Toxicity in Zebrafish (Danio rerio) Embryos

Butylparaben (BuP) is a common antibacterial preservative utilized extensively in food, medical supplies, cosmetics, and personal care products. The current study reports the use of Zebrafish (Danio rerio) embryos to investigate potential developmental toxicity caused by exposure to BuP. The development of Neural crest cells (NCCs) is highly active during gastrulation in Zebrafish embryos. Thus, we utilized 0.5 mg/L, 0.75 mg/L, and 1 mg/L BuP solutions, respectively, in accordance with the international safety standard dosage. We observed severe craniofacial cartilage deformities, periocular edema, cardiac dysplasia, and delayed otolith development in the Zebrafish larvae 5 days after exposure. The oxidative stress response was significantly enhanced. In addition, the biochemical analysis revealed that the activities of catalase (CAT) and superoxide dismutase (SOD) were significantly reduced relative to the control group, whereas the concentration of malondialdehyde (MDA) was significantly elevated. Furthermore, ALP activity, a marker of osteoblast activity, was also reduced. Moreover, the RT-qPCR results indicated that the expression of chondrocyte marker genes sox9a, sox9b, and col2a1a was down-regulated. In addition, the morphology of maxillofacial chondrocytes was altered in Zebrafish larvae, and the proliferation of cranial NCCs was inhibited. Accordingly, our findings indicate that strong oxidative stress induced by BuP inhibits the proliferation of NCCs in larval Zebrafish, leading to craniofacial deformities.

Urinary Paraben Concentrations and Associations with the Periconceptional Urinary Metabolome: Untargeted and Targeted Metabolomics Analyses of Participants from the Early Pregnancy Study

BACKGROUND

Parabens, found in everyday items from personal care products to foods, are chemicals with endocrine-disrupting activity, which has been shown to influence reproductive function.

OBJECTIVES

This study investigated whether urinary concentrations of methylparaben, propylparaben, or butylparaben were associated with the urinary metabolome during the periconceptional period, a critical window for female reproductive function. Changes to the periconceptional urinary metabolome could provide insights into the mechanisms by which parabens could impact fertility.

METHODS

Urinary paraben concentrations were measured in paired pre- and postconception urine samples from 42 participants in the Early Pregnancy Study, a prospective cohort of 221 women attempting to conceive. We performed untargeted and targeted metabolomics analyses using ultrahigh-performance liquid chromatography quadrupole time-of-flight mass spectrometry. We used principal component analysis, orthogonal partial least-squares discriminant analysis, and permutation testing, coupled with univariate statistical analyses, to find metabolites associated with paraben concentration at the two time points. Potential confounders were identified with a directed acyclic graph and used to adjust results with multivariable linear regression. Metabolites were identified using fragmentation data.

RESULTS

Seven metabolites were associated with paraben concentration (variable importance to projection score > 1 , false discovery rate-corrected q -value < 0.1 ). We identified four diet-related metabolites to the Metabolomics Standards Initiative (MSI) certainty of identification level 2, including metabolites from smoke flavoring, grapes, and olive oil. One metabolite was identified to the class level only (MSI level 3). Two metabolites were unidentified (MSI level 4). After adjustment, three metabolites remained associated with methylparaben and propylparaben, two of which were diet-related. No metabolomic markers of endocrine disruption were associated with paraben concentrations.

DISCUSSION

This study identified novel relationships between urinary paraben concentrations and diet-related metabolites but not with metabolites on endocrine-disrupting pathways, as hypothesized. It demonstrates the feasibility of integrating untargeted metabolomics data with environmental exposure information and epidemiological adjustment for confounders. The findings underscore a potentially important connection between diet and paraben exposure, with applications to nutritional epidemiology and dietary exposure assessment. https://doi.org/10.1289/EHP12125.

Rhus tripartite methanolic extract alleviates propylparaben-induced reproductive toxicity via anti-inflammatory, antioxidant, 5-α reductase in male rats

Evidence showed that herbal medicine could be beneficial for protection against diseases that may be exist in consequence of exposure to environmental toxicants. Propylparaben (PrP) is used as preservative in food, pharmaceuticals, and cosmetics. It is classified as one of endocrine disruptive chemicals (EDCs). This study evaluated the protective effect of Rhus tripartita methanolic extract (RTME) against reproductive toxicity induced by PrP in male rats. A total of 60 Wister albino rats were divided into four groups (15 rats for each group). Group I (control): rats received the vehicle (DMSO), group II: normal rats received RTME (10 mg/kg/day), group III: rats received PrP (10 mg/kg/day), and group IV: rats received PrP (10 mg/kg/day) and RTME (10 mg/kg/day) for 4 weeks. At the end of experiment, levels of testosterone, dihydrotestosterone (DHT), and 5α-reductase were analyzed in sera. Data obtained showed a significant reduction in the levels of testosterone, dihydrotestosterone (DHT), and 5α- reductase in rats given PrP versus control (p < 0.001) and RTME treatment improved these parameters but not returned to normal. Data obtained showed a significant elevation in levels of IL-6 and TNF-α in the testis of rats given PrP versus control (p < 0.001), these inflammatory mediators were significant reduced in rats treated with RTME compared with untreated rats (p < 0.001). There was a positive correlation between level of DHT and antioxidant enzymes activities (r = 0.56). A significant elevation in the levels of MDA with reduction in the activities of GST, GSPx, SOD, and catalase (p < 0.001) in rat testicular tissues of PrP group versus control (p < 0.001) was found. Treatment with RTME significantly reduced the levels of MDA and enhanced activities of GST, GSPx, SOD, and catalase (p < 0.001) compared to untreated group (p < 0.001). In conclusion, the active ingredient components of RTME abrogate the toxicity of PrP by exhibiting antioxidative and anti-inflammatory effects, enhancing 5-α reductase with improved hormonal status against PrP- induced testicular damage. Toxicity of propylparaben, and effect of Rhus tripartita methanolic extract.

Endocrine Disruption of Propylparaben in the Male Mosquitofish (Gambusia affinis): Tissue Injuries and Abnormal Gene Expressions of Hypothalamic-Pituitary-Gonadal-Liver Axis

Propylparaben (PrP) is a widely used preservative that is constantly detected in aquatic environments and poses a potential threat to aquatic ecosystems. In the present work, adult male mosquitofish were acutely (4d) and chronically (32d) exposed to environmentally and humanly realistic concentrations of PrP (0, 0.15, 6.00 and 240 μg/L), aimed to investigate the toxic effects, endocrine disruption and possible mechanisms of PrP. Histological analysis showed time- and dose-dependent manners in the morphological injuries of brain, liver and testes. Histopathological alterations in the liver were found in 4d and severe damage was identified in 32d, including hepatic sinus dilatation, cytoplasmic vacuolation, cytolysis and nuclear aggregation. Tissue impairments in the brain and testes were detected in 32d; cell cavitation, cytomorphosis and blurred cell boundaries appeared in the brain, while the testes lesions contained spermatogenic cell lesion, decreased mature seminal vesicle, sperm cells gathering, seminiferous tubules disorder and dilated intercellular space. Furthermore, delayed spermatogenesis had occurred. The transcriptional changes of 19 genes along the hypothalamus-pituitary-gonadal-liver (HPGL) axis were investigated across the three organs. The disrupted expression of genes such as Ers, Ars, Vtgs, cyp19a, star, hsd3b, hsd17b3 and shh indicated the possible abnormal steroidogenesis, estrogenic or antiandrogen effects of PrP. Overall, the present results provided evidences for the toxigenicity and endocrine disruptive effects on the male mosquitofish of chronic PrP exposure, which highlights the need for more investigations of its potential health risks.

Embryonic benzophenone-3 exposure inhibited fertility in later-life female zebrafish and altered developmental morphology in offspring embryos

Benzophenone-3 (BP3), an organic UV filter widely used in personal care products, is ubiquitous in aquatic environments. Previous studies have shown that BP3 can interfere with oocytes development in the ovary. The current study was conducted to evaluate the effects of embryonic BP3 exposure on reproductive outcomes in later life. Zebrafish embryos were exposed to different concentrations of BP3 (0, 1, 10, 100 μg/L) for 5 days in the developmental stage and subsequently fed for 4 months without any toxins. The body length, body weight, and ovary weight in F0 female adult zebrafish and morphology indices in F1 offspring embryos were measured. The reproductive behaviors of adult zebrafish were recorded by a digital camera. HE staining was used to estimate the development of oocytes and the proportion of different phases was calculated. qPCR was used to detect the expression levels of reproduction-related genes of the hypothalamic-pituitary-gonadal (HPG) axis. Our findings revealed that the body length and body weight were not changed with embryonic BP3 exposure, but BP3 exposure inhibited the development and maturation of ovaries in later-life female zebrafish, accompanied by an increased proportion of follicles in the primary growth and early vitellogenic stages, and a decline in the full-growth stage in ovaries. Meanwhile, reduced egg production, delayed hatching rate, altered somite count and increased mortality rate were observed at 100 μg/L in offspring embryos. Behavioral results showed that BP3 exposure reduced the frequency of chasing, touching, entering the spawning area, and the duration of fish entering the spawning area later in life, qPCR analysis showed that the expression levels of reproduction-related genes of the HPG axis were downregulated in females, following a decreasing trend in plasma E2 and 11-KT levels. These results suggested that embryonic BP3 exposure negatively affected the fertility of fish and the development of their offspring embryos, which may cause potential risks to aquatic ecosystems and human health.

Urinary phenol concentrations and fecundability and early pregnancy loss

STUDY QUESTION

Are urinary phenol concentrations of methylparaben, propylparaben, butylparaben, triclosan, benzophenone-3, 2,4-dichlorophenol or 2,5-dichlorophenol associated with fecundability and early pregnancy loss?

SUMMARY ANSWER

2,5-dichlorophenol concentrations were associated with an increased odds of early pregnancy loss, and higher concentrations of butylparaben and triclosan were associated with an increase in fecundability.

WHAT IS KNOWN ALREADY

Phenols are chemicals with endocrine-disrupting potential found in everyday products. Despite plausible mechanisms of phenol reproductive toxicity, there are inconsistent results across few epidemiologic studies examining phenol exposure and reproductive function in non-fertility treatment populations.

STUDY DESIGN, SIZE, DURATION

Specimens and data were from the North Carolina Early Pregnancy Study prospective cohort of 221 women attempting to conceive naturally from 1982 to 1986. This analysis includes data from 221 participants across 706 menstrual cycles, with 135 live births, 15 clinical miscarriages and 48 early pregnancy losses (before 42 days after the last menstrual period).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants collected daily first-morning urine specimens. For each menstrual cycle, aliquots from three daily specimens across the cycle were pooled within individuals and analyzed for phenol concentrations. To assess sample repeatability, we calculated intraclass correlation coefficients (ICCs) for each phenol. We evaluated associations between phenol concentrations from pooled samples and time to pregnancy using discrete-time logistic regression and generalized estimating equations (GEE), and early pregnancy loss using multivariable logistic regression and GEE.

MAIN RESULTS AND THE ROLE OF CHANCE

ICCs for within-person variability across menstrual cycles in pooled phenol concentrations ranged from 0.42 to 0.75. There was an increased odds of early pregnancy loss with 2,5-dichlorophenol concentrations although the CIs were wide (5th vs 1st quintile odds ratio (OR): 4.79; 95% CI: 1.06, 21.59). There was an increased per-cycle odds of conception at higher concentrations of butylparaben (OR: 1.62; 95% CI: 1.08, 2.44) and triclosan (OR: 1.49; 95% CI: 0.99, 2.26) compared to non-detectable concentrations. No associations were observed between these endpoints and concentrations of other phenols examined.

LIMITATIONS, REASONS FOR CAUTION

Limitations include the absence of phenol measurements for male partners and a limited sample size, especially for the outcome of early pregnancy loss, which reduced our power to detect associations.

WIDER IMPLICATIONS OF THE FINDINGS

This study is the first to use repeated pooled measures to summarize phenol exposure and the first to investigate associations with fecundability and early pregnancy loss. Within-person phenol concentration variability underscores the importance of collecting repeated samples for future studies. Exposure misclassification could contribute to differences between the findings of this study and those of other studies, all of which used one urine sample to assess phenol exposure. This study also contributes to the limited literature probing potential associations between environmental exposures and early pregnancy loss, which is a challenging outcome to study as it typically occurs before a pregnancy is clinically recognized.

STUDY FUNDING/COMPETING INTEREST(S)

This research was supported by the National Institute of Environmental Health Sciences of the National Institutes of Health (award number F31ES030594), the Intramural Research Program of the National Institutes of Health, the National Institute of Environmental Health Sciences (project numbers ES103333 and ES103086) and a doctoral fellowship at the Yale School of Public Health. The authors declare they have no competing interests to disclose.

TRIAL REGISTRATION NUMBER

N/A.

Phenols, Parabens, Phthalates and Puberty: a Systematic Review of Synthetic Chemicals Commonly Found in Personal Care Products and Girls' Pubertal Development

PURPOSE OF REVIEW

Exposure to endocrine disrupting chemicals through personal care products (PCPs) is widespread and may disrupt hormone-sensitive endpoints, such as timing of puberty. Given the well-documented (and ongoing) decline in age at menarche in many populations, we conducted a systematic review of the epidemiological literature on exposure to chemicals commonly found in PCPs (including certain phthalates, phenols, and parabens) in relation to girls' pubertal development.

RECENT FINDINGS

The preponderance of research on this topic has examined phthalate exposures with the strongest evidence indicating that prenatal monoethyl phthalate (MEP) concentrations may be associated with slightly earlier timing of puberty, including age at menarche. Findings examining peri-pubertal phthalate exposures and pubertal outcomes were less consistent as were studies of prenatal and peri-pubertal phenol exposures. Very few studies had examined parabens in relation to girls' pubertal development. Common study limitations included potential exposure misclassification related to use of spot samples and/or mistimed biomarker assessment with respect to the outcomes. The role of body size as a mediator in these relationships remains unresolved. Overall, evidence of associations between chemical exposures in PCPs and girls' pubertal development was conflicting. When associations were observed, effect sizes were small. Nevertheless, given the many environmental, social, and behavioral factors in the modern environment that may act synergistically to accelerate timing of puberty, even marginal changes may be cause for concern, with implications for cancer risk, mental health, and cardiometabolic disease in later life.

Assessment of human exposure to benzophenone-type UV filters: A review

To avoid the harmful effects of UV radiation, benzophenone-type UV filters (BPs) are widely used in personal care products and other synthetic products. Biomonitoring studies have shown the presence of BPs in various human biological samples, raising health concerns. However, there is a paucity of data on the global human exposure to this group of contaminants. In this study, we compiled data on the body burden of BPs along with the possible exposure routes and biotransformation pathways. BPs can easily penetrate the skin barrier and thus, they can be absorbed through the skin. In the human body, BPs can undergo Phase I (mainly demethylation and hydroxylation) and Phase II (mainly glucuronidation and sulfation) biotransformations. From a total of 158 studies, most of the studies are related to urine (concentration up to 92.7 mg L^-1), followed by those reported in blood (up to 0.9 mg L^-1) and milk (up to 0.8 mg L^-1). Among BPs, benzophenone-1 and benzophenone-3 are the most commonly detected congeners. The body burden of BPs is associated with various factors, including the country of residence, lifestyle, income, education level, and ethnicity. The presence of BPs in maternal urine (up to 1.1 mg L^-1), placenta (up to 9.8 ng g^-1), and amniotic fluid (up to 15.7 μg L^-1) suggests potential risks of prenatal exposure. In addition, transplacental transfer of BPs is possible, as demonstrated by their presence in maternal serum and cord serum. The possible association of BPs exposure and health effects was discussed. Future human biomonitoring studies and studies on the potential health effects are warranted. Overall, this review provides a summary of the global human exposure to BPs and can serve as supporting evidence to guide usage in order to protect humans from being exposed to BPs.

Glyphosate and AMPA in Human Urine of HBM4EU Aligned Studies: Part A Children

Few data are available on the exposure of children to glyphosate (Gly) in Europe. Within HBM4EU, new HBM exposure data were collected from aligned studies at five sampling sites distributed over Europe (studies: SLO CRP (SI); ORGANIKO (CY); GerES V-sub (DE); 3XG (BE); ESTEBAN (FR)). Median Gly concentrations in urine were below or around the detection limit (0.1 µg/L). The 95th percentiles ranged between 0.18 and 1.03 µg Gly/L. The ratio of AMPA (aminomethylphosphonic acid; main metabolite of Gly) to Gly at molar basis was on average 2.2 and the ratio decreased with higher Gly concentrations, suggesting that other sources of AMPA, independent of metabolism of Gly to AMPA in the monitored participants, may concurrently operate. Using reverse dosimetry and HBM exposure data from five European countries (east, west and south Europe) combined with the proposed ADI (acceptable daily intake) of EFSA for Gly of 0.1 mg/kg bw/day (based on histopathological findings in the salivary gland of rats) indicated no human health risks for Gly in the studied populations at the moment. However, the absence of a group ADI for Gly+AMPA and ongoing discussions on e.g., endocrine disrupting effects cast some uncertainty in relation to the current single substance ADI for Gly. The carcinogenic effects of Gly are still debated in the scientific community. These outcomes would influence the risk conclusions presented here. Finally, regression analyses did not find clear associations between urinary exposure biomarkers and analyzed potential exposure determinants. More information from questionnaires targeting exposure-related behavior just before the sampling is needed.

Comparative cytotoxicity induced by parabens and their halogenated byproducts in human and fish cell lines

Parabens are a group of para-hydroxybenzoic acid (p-HBA) esters widely used in pharmaceutical industries. Their safety is well documented in mammalian models, but little is known about their toxicity in non-mammal species. In addition, chlorinated and brominated parabens resulting from wastewater treatment have been identified in effluents. In the present study, we explored the cytotoxic effects (EC₅₀) of five parabens: methylparaben (MP), ethylparaben (EP), propylparaben (PP), butylparaben (BuP), and benzylparaben (BeP); the primary metabolite, 4-hydroxybenzoic acid (4-HBA), and three of the wastewater chlorinated/brominated byproducts on fish and human cell lines. In general, higher cytotoxicity was observed with increased paraben chain length. The tested compounds induced toxicity in the order of 4-HBA < MP < EP < PP < BuP < BeP. The halogenated byproducts led to higher toxicity with the addition of second chlorine. The longer chain-parabens (BuP and BeP) caused a concentration-dependent decrease in cell viability in fish cell lines. Intriguingly, the main paraben metabolite, 4-HBA, proved to be more toxic to fish hepatocytes than human hepatocytes by 100-fold. Our study demonstrated that the cytotoxicity of some of these compounds appears to be tissue-dependent. These observations provide valuable information for early cellular responses in human and non-mammalian models upon exposure to paraben congeners.

Biomonitoring bisphenols, parabens, and benzophenones in breast milk from a human milk bank in Southern Spain

BACKGROUND

Human breast milk is considered the optimal source of nutrition for infants. Milk from breast milk banks offers an alternative to infant formulas for vulnerable hospitalized neonates most likely to benefit from exclusive human milk feeding. However, breast milk can also be a source of exposure to environmental contaminants, including endocrine-disrupting chemicals (EDCs).

AIM

To evaluate concentrations of phenolic EDCs, including bisphenols, parabens (PBs), and benzophenones (BPs), in samples from a human milk bank in Granada, Southern Spain and to explore sociodemographic, reproductive, and lifestyle factors related to their concentrations in the milk.

METHODS

Concentrations of three bisphenols [bisphenol A (BPA), bisphenol F (BPF), and bisphenol S (BPS)], four PBs [methyl- (MeP), ethyl- (EtP), propyl- (n-PrP), and butyl-paraben (n-BuP)], and six BPs [BP-1, BP-2, BP-3, BP-6, BP-8, and 4-hydroxy-BP] were determined in milk samples from 83 donors. Information on potential explanatory variables was gathered using the milk bank donor form and an ad hoc questionnaire. Multiple linear and logistic regression models were fitted.

RESULTS

Detectable concentrations were found of at least one of the analyzed compounds in all donor breast milk samples and at least five compounds in one-fifth of them. The most frequently detected compounds were MeP (90.5%), BP-3 (75.0%), EtP (51.2%), n-PrP (46.4%), and BPA (41.7%). Median concentrations ranged between <0.10 ng/mL (n-PrP, n-BuP, BP-1) and 0.59 ng/mL (BP-3). No sample contained detectable concentrations of BPF, BPS, or most BPs (BP-2, BP-6, BP-8, and 4- hydroxy-BP). Breast milk phenol concentrations were associated with parity, the utilization of deodorants, mouthwash, skin care products, and cosmetics, and the intake of nutritional supplements.

CONCLUSIONS

Results reveal the widespread presence of BPA, PBs, and BP-3 in donor breast milk samples, highlighting the need for preventive measures to enhance the benefits of breast milk from milk banks and from breastfeeding women in general.

Endocrine-Disrupting Effects of Bisphenol A on the Cardiovascular System: A Review

Currently, the plastic monomer and plasticizer bisphenol A (BPA) is one of the most widely used chemicals. BPA is present in polycarbonate plastics and epoxy resins, commonly used in food storage and industrial or medical products. However, the use of this synthetic compound is a growing concern, as BPA is an endocrine-disrupting compound and can bind mainly to estrogen receptors, interfering with different functions at the cardiovascular level. Several studies have investigated the disruptive effects of BPA; however, its cardiotoxicity remains unclear. Therefore, this review’s purpose is to address the most recent studies on the implications of BPA on the cardiovascular system. Our findings suggest that BPA impairs cardiac excitability through intracellular mechanisms, involving the inhibition of the main ion channels, changes in Ca²⁺ handling, the induction of oxidative stress, and epigenetic modifications. Our data support that BPA exposure increases the risk of developing cardiovascular diseases (CVDs) including atherosclerosis and its risk factors such as hypertension and diabetes. Furthermore, BPA exposure is also particularly harmful in pregnancy, promoting the development of hypertensive disorders during pregnancy. In summary, BPA exposure compromises human health, promoting the development and progression of CVDs and risk factors. Further studies are needed to clarify the human health effects of BPA-induced cardiotoxicity.

Environmental Phenol and Paraben Exposure Risks and Their Potential Influence on the Gene Expression Involved in the Prognosis of Prostate Cancer

Prostate cancer (PCa) is one of the leading malignant tumors in US men. The lack of understanding of the molecular pathology on the risk of food supply chain exposures of environmental phenol (EP) and paraben (PB) chemicals limits the prevention, diagnosis, and treatment options. This research aims to utilize a risk assessment approach to demonstrate the association of EP and PB exposures detected in the urine samples along with PCa in US men (NHANES data 2005−2015). Further, we employ integrated bioinformatics to examine how EP and PB exposure influences the molecular pathways associated with the progression of PCa. The odds ratio, multiple regression model, and Pearson coefficients were used to evaluate goodness-of-fit analyses. The results demonstrated associations of EPs, PBs, and their metabolites, qualitative and quantitative variables, with PCa. The genes responsive to EP and PB exposures were identified using the Comparative Toxicogenomic Database (CTD). DAVID.6.8, GO, and KEGG enrichment analyses were used to delineate their roles in prostate carcinogenesis. The plug-in CytoHubba and MCODE completed identification of the hub genes in Cytoscape software for their roles in the PCa prognosis. It was then validated by using the UALCAN database by evaluating the expression levels and predictive values of the identified hub genes in prostate cancer prognosis using TCGA data. We demonstrate a significant association of higher levels of EPs and PBs in the urine samples, categorical and numerical confounders, with self-reported PCa cases. The higher expression levels of the hub genes (BUB1B, TOP2A, UBE2C, RRM2, and CENPF) in the aggressive stages (Gleason score > 8) of PCa tissues indicate their potential role(s) in the carcinogenic pathways. Our results present an innovative approach to extrapolate and validate hub genes responsive to the EPs and PBs, which may contribute to the severity of the disease prognosis, especially in the older population of US men.

Estimation of parabens and bisphenols in maternal products and urinary concentrations in Indian pregnant women: daily intake and health risk assessment

The presence of parabens and bisphenols in maternal products and usage during pregnancy have raised serious concern about their possible harm to pregnant women. The concentrations of six parabens and eight bisphenols were quantified by high-performance liquid chromatography-tandem mass spectrometry in the samples of commercially available herbal-based ayurvedic maternal products and urine of healthy pregnant women from Assam, India. Methyl paraben (MP) and bisphenol AF (BPAF) were found to be more dominant in the maternal products, whereas MP, bisphenol A (BPA), and BPAF were dominant in urine samples of healthy pregnant women. The sum of the mean concentrations of all forms of parabens and bisphenols in maternal products were 48,308.50 ng/g and 542.42 ng/g, respectively, and urine 101.33 ng/mL and 23.42 ng/mL, respectively. The estimated daily intake (EDI) of total parabens and bisphenols in maternal products were 7378.02 and 19.78 ng/kg body weight/day, respectively. EDI of total parabens and bisphenols from urinary concentrations were 690.12 and 111.33 μg/kg body weight/day, respectively. The concentrations of butyl (BP) and heptyl (HP) parabens have a significant positive correlation with birth weight. The hazard quotient (HQ) value of MP, EP, and BPA was less than 1, and margin of exposure (MOE) identified potential risk associated with propyl paraben. Results from Monte-Carlo risk assessment analysis did not exceed the acceptable daily intake (ADI). Our results showed that higher concentrations of parabens and bisphenols are present in maternal products and the urine of healthy pregnant women. Hence maternal products containing bisphenols and parabens should be used cautiously during pregnancy to avoid maternal and fetal complications.

Early-Life Environment Influence on Late-Onset Alzheimer's Disease

With the expand of the population's average age, the incidence of neurodegenerative disorders has dramatically increased over the last decades. Alzheimer disease (AD) which is the most prevalent neurodegenerative disease is mostly sporadic and primarily characterized by cognitive deficits and neuropathological lesions such as amyloid -β (Aβ) plaques and neurofibrillary tangles composed of hyper- and/or abnormally phosphorylated Tau protein. AD is considered a complex disease that arises from the interaction between environmental and genetic factors, modulated by epigenetic mechanisms. Besides the well-described cognitive decline, AD patients also exhibit metabolic impairments. Metabolic and cognitive perturbations are indeed frequently observed in the Developmental Origin of Health and Diseases (DOHaD) field of research which proposes that environmental perturbations during the perinatal period determine the susceptibility to pathological conditions later in life. In this review, we explored the potential influence of early environmental exposure to risk factors (maternal stress, malnutrition, xenobiotics, chemical factors … ) and the involvement of epigenetic mechanisms on the programming of late-onset AD. Animal models indicate that offspring exposed to early-life stress during gestation and/or lactation increase both AD lesions, lead to defects in synaptic plasticity and finally to cognitive impairments. This long-lasting epigenetic programming could be modulated by factors such as nutriceuticals, epigenetic modifiers or psychosocial behaviour, offering thus future therapeutic opportunity to protect from AD development.

Biomonitoring parabens in dogs using fur sample analysis - Preliminary studies

Parabens are widely used in the food, cosmetics and pharmaceutical industry and are widespread in the environment. As endocrine disruptors, parabens have adverse effects on living organisms. However, knowledge of the exposure of domestic animals to parabens is extremely scarce. Therefore, this study assessed the exposure level of dogs to three parabens commonly used in industry (i.e. methylparaben - MeP, ethylparaben - EtP and propylparaben - PrP) using fur sample analysis in liquid chromatography-tandem mass spectrometry. The presence of parabens has been noted in the samples collected from all dogs included in the study (n = 30). Mean concentrations of MeP, EtP and PrP in the fur of dogs were 176 (relative standard deviation - RSD = 127.48%) ng/g dry weight (dw), 48.4 (RSD = 163.64%) ng/g dw and 79.8 ng/g dw (RSD = 151.89%), respectively. The highest concentrations were found for MeP (up to 1023 ng/g dw). Concentrations of MeP and EtP in males were statistically higher than those in females (p < 0.05). Statistically significantly higher concentration levels of PrP in young animals (up to three years old) were also found. This is the first study concerning the use of fur samples to evaluate the exposure of domestic animals to parabens. The results indicate that an analysis of the fur may be a useful tool of paraben biomonitoring in dogs. The presence of parabens in the canine fur also suggests that these substances may play a role in veterinary toxicology. However, many aspects connected with this issue are not clear and require further study.

Concentrations of bisphenols, parabens, and benzophenones in human breast milk: A systematic review and meta-analysis

BACKGROUND

Breast milk is the main source of nutrition for infants but may be responsible for their exposure to environmental chemicals, including endocrine-disrupting chemicals.

AIM

To review available evidence on the presence and concentrations of bisphenols, parabens (PBs), and benzophenones (BPs) in human milk and to explore factors related to exposure levels.

METHODS

A systematic review was carried out using Medline, Web of Science, and Scopus databases, conducting a comprehensive search of peer-reviewed original articles published during the period 2000-2020, including epidemiological and methodological studies. Inclusion criteria were met by 50 studies, which were compiled by calculating weighted detection frequencies and arithmetic mean concentrations of the chemicals. Their risk of bias was assessed using the ROBINS-I checklist.

RESULTS

Among the 50 reviewed studies, concentrations of bisphenols were assessed by 37 (74.0%), PBs by 21 (42.0%), and BPs by 10 (20.0%). Weighted detection frequencies were 63.6% for bisphenol-A (BPA), 27.9-63.4% for PBs, and 39.5% for benzophenone-3 (BP-3). Weighted mean concentrations were 1.4 ng/mL for BPA, 0.2-14.2 ng/mL for PBs, and 24.4 ng/mL for BP-3. Mean concentrations ranged among studies from 0.1 to 3.9 ng/mL for BPA, 0.1 to 1063.6 ng/mL for PBs, and 0.5 to 72.4 ng/mL for BP-3. The highest concentrations of BPA and PBs were reported in samples from Asia (versus America and Europe). Higher BPA and lower methyl-paraben concentrations were observed in samples collected after 2010. Elevated concentrations of these chemicals were associated with socio-demographic and lifestyle factors in eight studies (16.0%). Two epidemiological studies showed moderate/serious risk of bias.

CONCLUSIONS

This systematic review contributes the first overview of the widespread presence and concentrations of bisphenols, PBs, and BPs in human breast milk, revealing geographical and temporal variations. The methodological heterogeneity of published studies underscores the need for well-conducted studies to assess the magnitude of exposure to these chemicals from human milk.

Influence of BPA exposure, measured in saliva, on childhood weight

INTRODUCTION

Endocrine disruptors such as bisphenol A (BPA), BPA glycidyl methacrylate, and other BPA acrylate-based derivatives have been related to type 2 diabetes, the metabolic syndrome, and obesity, among other metabolic disorders. The objective of this study is to examine the influence of BPA exposure by saliva analysis and daily physical activity on the risk of overweight/obesity in schoolchildren from southern Spain.

METHODS

The study included 300 children (53.5% girls) aged 7-10 years. Participants completed a questionnaire with four sections: participant data, including demographic information and life and family habits; semi-quantitative food frequency questionnaire; anthropometric variables; and physical activity variables. All participants underwent dental examination, when the presence of sealants/composites in each tooth and other dental alterations was recorded, and samples of whole saliva were collected for UHPLC-MS/MS analyses.

RESULTS

Risk of overweight/obesity was significantly influenced by body fat composition (OR = 10.77), not walking to and from school (OR = 1.38), lesser energy expenditure in sedentary activities (OR = 12.71), greater energy expenditure in sports (OR =1.62), and exposure to BPA from dental sealants/composites (OR = 1.38; p = 0.058).

DISCUSSION

Further research is warranted on this issue in children, who may be especially vulnerable to the negative health effects of endocrine disruption.

Evaluation of human exposure to parabens in north eastern Poland through hair sample analysis

Parabens (PBs) are a group of substances commonly used in industry. They also pollute the environment, penetrate into living organisms and adversely affect various internal organs. During this study, the degree of exposure of people living in Olsztyn, a city in north eastern Poland, to selected parabens most often used in industry was studied. The chemicals under investigation included: methyl paraben—MePB, ethyl paraben—EtPB, propyl paraben—PrPB, benzyl paraben BePB and butyl paraben -BuPB. To this aim, hair samples collected from the scalps of 30 volunteers were analyzed using a liquid chromatography–mass spectrometry technique. All PBs studied were present in a high percentage of analyzed samples (from 76.7% in the case of BePB to 100% in the case of MePB and PrPB). The mean concentration levels were 4425.3 pg/mg for MeBP, 704.0 pg/mg for EtPB, 825.7 pg/mg for PrPB, 135.2 pg/mg for BePB and 154.5 pg/mg for BuPB. Significant differences in PB concentration levels between particular persons were visible. On the other hand, gender, age and artificial hair coloring did not cause statistically significant differences in PB levels. Obtained results have clearly indicated that people living in north eastern Poland are exposed to various PBs, and therefore these substances may affect their health status. However, the evaluation of PBs influence on human health requires further research.

Fetoplacental vasculature as a model to study human cardiovascular endocrine disruption

Increasing evidence has associated the exposure of endocrine-disrupting chemicals (EDCs) with the cardiovascular (CV) system. This exposure is particularly problematic in a sensitive window of development, pregnancy. Pregnancy exposome can affect the overall health of the pregnancy by dramatic changes in vascular physiology and endocrine activity, increasing maternal susceptibility. Moreover, fetoplacental vascular function is generally altered, increasing the risk of developing pregnancy complications (including cardiovascular diseases, CVD) and predisposing the foetus to adverse health risks later in life. Thus, our review summarizes the existing literature on exposures to EDCs during pregnancy and adverse maternal health outcomes, focusing on the human placenta, vein, and umbilical artery associated with pregnancy complications. The purpose of this review is to highlight the role of fetoplacental vasculature as a model for the study of human cardiovascular endocrine disruption. Therefore, we emphasize that the placenta, together with the umbilical arteries and veins, allows a better characterization of the pregnant woman's exposome. Consequently, it contributes to the protection of the mother and foetus against CV disorders in life.

Identifying the link between chemical exposures and breast cancer in African American women via integrated in vitro and exposure biomarker data

Among women, breast cancer is the most prevalent form of cancer worldwide and has the second highest mortality rate of any cancer in the United States. The breast cancer related death rate is 40 % higher in non-Hispanic Black women compared to non-Hispanic White women. The incidence of triple negative breast cancer (TNBC), an aggressive subtype of breast cancer for which there is no targeted therapy, is also approximately three times higher for Black, relative to, White women. The drivers of these differences are poorly understood. Here, we aimed to identify chemical exposures which play a role in breast cancer disparities. Using chemical biomonitoring data from the National Health and Nutrition Examination Survey (NHANES) and biological activity data from the EPA's ToxCast program, we assessed the toxicological profiles of chemicals to which US Black women are disproportionately exposed. We conducted a literature search to identify breast cancer targets in ToxCast to analyze the response of chemicals with exposure disparities in these assays. Forty-three chemical biomarkers are significantly higher in Black women. Investigation of these chemicals in ToxCast resulted in 32,683 assays for analysis, 5172 of which contained nonzero values for the concentration at which the dose-response fitted model reaches the cutoff considered "active". Of these chemicals BPA, PFOS, and thiram are most comprehensively assayed. 2,5-dichlorophenol, 1,4-dichlorobenzene, and methyl and propyl parabens had higher biomarker concentrations in Black women and moderate testing and activity in ToxCast. The distribution of active concentrations for these chemicals in ToxCast assays are comparable to biomarker concentrations in Black women NHANES participants. Through this integrated analysis, we identify that multiple chemicals, including thiram, propylparaben, and p,p' DDE, have disproportionate exposures in Black women and have breast cancer associated biological activity at human exposure relevant doses.

Benzophenone-3 induced abnormal development of enteric nervous system in zebrafish through MAPK/ERK signaling pathway

Hirschsprung disease (HSCR) is a congenital disease characterized by the absence of enteric neurons, which is derived from the failure of the proliferation, differentiation or migration of the enteric neural crest cells (ENCCs). HSCR is associated with multiple risk factors, including polygenic inheritance factors and environmental factors. Genetic studies have been extensively performed, whereas studies related to environmental factors remain insufficient. Benzophenone-3 (BP-3), one important component of the ultraviolet (UV) filters, has been proved to have cytotoxicity and neurotoxicity which might be associated with HSCR. In this study, we used zebrafish as a model to investigate the relationship between BP-3 exposure and the development of the enteric nervous system (ENS) in vivo. Embryos exposed to BP-3 showed an average of 46% reduction of the number of the enteric neurons number. Besides, the ENCCs specific markers (ret and hand2) were downregulated upon BP-3 exposure. Moreover, we identified potential targets of BP-3 through Network Pharmacology Analysis and Autodock and demonstrated that the attenuation of the MAPK/ERK signaling might be the potential mechanism underlying the inhibition of the ENS development by BP-3. Importantly, MAPK/ERK signaling agonist could be used to rescue the ENS defects of zebrafish induced by BP-3. Overall, we characterized the influence of BP-3 on ENS development in vivo and explored possible molecular mechanisms.

Estimation of lactating mothers' daily intakes of bisphenol A using breast milk

Breast milk is a unique biological sample that reflects the exposure levels of both lactating mothers and infants. The exposure levels of BPA due to breast milk consumption for infants can be estimated easily, but the method to estimate the total daily intake (TDI) of lactating mothers from breast milk has not yet been established. In this study, BPA concentrations were detected in breast milk samples from 149 lactating mothers from Hunan, China. The median concentration of BPA in breast milk was 0.053 μg/L with a range of 0.001-2.535 μg/L, and a temporal decline trend was found for BPA concentrations in breast milk (p < 0.05). The median intake of BPA via breast milk was 26.8 ng/kg bw/day for 0-3-month-old infants and 7.0 ng/kg bw/day for 4-12-month-old infants. Based on the predicted concentrations of BPA in urine and blood via the conversion coefficients from breast milk, the TDIs of lactating mothers were estimated. The TDIs estimated from the simulated urine concentration were 84.0 ± 175.2 ng/kg bw/day for 0-3-month-old infants' mothers and 36.9 ± 80.8 ng/kg bw/day for 4-12-month-old infants' mothers. The dietary daily intakes estimated from the simulated blood concentration were 579.6 ± 370.8 ng/kg bw/day for 0-3-month-old infants' mothers and 280.1 ± 195.2 ng/kg bw/day for 4-12-month-old infants' mothers. When assuming the dietary daily intakes in Hunan of the fifth total diet study (TDS) as the "true" total dietary intake of our population, the contribution of diet was estimated to be 63.7%, which suggested that non-dietary BPA exposure may be underestimated.

Development of a sensitive analytical method for the simultaneous analysis of Benzophenone-type UV filters and paraben preservatives in umbilical cord blood

UV filters and parabens are compounds used in large quantities in modern societies and have become ubiquitous in the environment. They are considered compounds of emerging concern due to the unwanted effects they cause in the environment and their bioaccumulation potential in humans. Considering their endocrine disrupting activity and their so far unknown effects in newborns, a continuous monitoring of these substances is required. In this work, we developed and validated a new sensitive methodology for the analysis of 8 UV filters and metabolites, and 4 parabens in umbilical cord blood samples. The method consisted of a liquid-liquid extraction and phase separation by freezing. Then, the organic extract was further analyzed at alkaline pH using liquid chromatography coupled to tandem-mass spectrometry (LC-MS/MS) using a QqLIT hybrid mass spectrometer as analyzer. The low limits of detection achieved (0.01–0.42 ng/mL) allowed the reliable simultaneous quantification of UV filters and parabens in this complex biological matrix.•

Simple, fast and sensitive analysis of UV filters and parabens in cord blood samples.

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First simultaneous analysis of UV filters and parabens in cord blood.

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Allows the evaluation of perinatal transfer of UV filters and parabens from the mother to the fetus.

Propylparaben concentrations in the urine of women and adverse effects on ovarian function in mice in vivo and ovarian cells in vitro

Female reproduction is precisely regulated by hormones, and the ovary is easily affected by environmental endocrine disruptors (EDCs), which are ubiquitous in industrialized societies. Parabens are EDCs that are used as antibacterial preservatives in cosmetics, personal care products (PCPs), medicines, and food. We used ultrahigh-performance liquid chromatography-mass spectrometry to quantitatively detect methyl-, ethyl-, butyl-, and propylparaben (PP) concentrations in urine samples from 74 women of childbearing age. Balb/c mice were subcutaneously injected with 100 mg/kg/day of PP for 21 consecutive days or 100 or 1,000 mg/kg/day of PP during superovulation. Various concentrations of PP (ranging from 1 to 1,000 nM) were added to a human ovarian granulosa tumor-derived cell line (KGN) culture for 24 h. The urinary paraben concentrations of women who used cosmetics and other PCPs within 48 h prior to sample collection were significantly elevated, and the PP concentration was significantly positively correlated with the basal estradiol concentration. After PP injection, the mouse serum estradiol concentrations were significantly increased, estrus cycles were disordered, corpus luteum number was reduced, and number of oocytes retrieved was significantly reduced. In in vitro experiments, PP treatment increased estradiol synthesis and the expression levels of aromatase enzyme (CYP19A1) and steroidogenic acute regulatory protein. This study demonstrates the adverse effects of PP on ovarian estradiol secretion and ovulation, further evaluates the safety of PP as a preservative, and provides guidance for the use of PCPs and cosmetics by women of childbearing age.

The degradation of paraben preservatives: Recent progress and sustainable approaches toward photocatalysis

Parabens are a class of compounds primarily used as antimicrobial preservatives in pharmaceutical products, cosmetics, and foodstuff. Their widely used field leads to increasing concentrations detected in various environmental matrices like water, soil, and sludges, even detected in human tissue, blood, and milk. Treatment techniques, including chemical advanced oxidation, biological degradation, and physical adsorption processes, have been widely used to complete mineralization or to degrade parabens into less complicated byproducts. All kinds of processes were reviewed to give a completed picture of parabens removal. In light of these treatment techniques, advanced photocatalysis, which is emerging rapidly and widely as an economical, efficient, and environmentally-friendly technique, has received considerable attention. TiO₂-based and non-TiO₂-based photocatalysts play an essential role in parabens degradation. The effect of experimental parameters, such as the concentration of targeted parabens, concentration of photocatalyst, reaction time, and initial solution pH, even the presence of radical scavengers, are surveyed and compared from the literature. Some representative parabens such as methylparaben, propylparaben, and benzylparaben have been successfully studied the reaction pathways and their intermediates in their degradation process. As reported in the literature, the degradation of parabens involves the production of highly reactive species, mainly hydroxyl radicals. These reactive radicals would attack the paraben preservatives, break, and finally mineralize them into simpler inorganic and nontoxic molecules. Concluding perspectives on the challenges and opportunities for photocatalysis toward parabens remediation are also intensively highlighted.

Correlation study of parabens in urine, serum, and seminal plasma of adult men in Beijing, China

The adverse effects of parabens raise concerns about their extensive use as preservatives in consumer products, especially in cosmetics. Until now, their distribution and excretion in humans have attracted little attention. Here, we quantified various agents including, for the first time, methyl-; ethyl-; n-propyl-; n-butyl-, and i-butylparaben (MeP, EtP, PrP, n-BuP, i-BuP); methyl- and ethyl-protocatechuate (OH-MeP and OH-EtP); hydroxybenzoic acid (4-HB); and 3,4-dihydroxybenzoic acid (3,4-DHB) in urine, serum, and seminal plasma samples from 50 healthy Chinese men in Beijing, China. Urine paraben concentrations were 1-2 orders of magnitudes higher than those in serum and seminal plasma. MeP and PrP were predominant and correlated with each other in the urine, serum, and seminal plasma. In urine, we observed a significant correlation between MeP and OH-MeP; EtP and OH-EtP; and 4-HB and 3,4-DHB concentrations. All these results provide new information on parabens as biomarkers for the assessment of exposure.

Exposure to environmental phenols and parabens, and relation to body mass index, eczema and respiratory outcomes in the Norwegian RHINESSA study

BACKGROUND

Many phenols and parabens are applied in cosmetics, pharmaceuticals and food, to prevent growth of bacteria and fungi. Whether these chemicals affect inflammatory diseases like allergies and overweight is largely unexplored. We aimed to assess the associations of use of personal care products with urine biomarkers levels of phenols and paraben exposure, and whether urine levels (reflecting body burden of this chemical exposures) are associated with eczema, rhinitis, asthma, specific IgE and body mass index.

METHODS

Demographics, clinical variables, and self-report of personal care products use along with urine samples were collected concurrently from 496 adults (48% females, median age: 28 years) and 90 adolescents (10-17 years of age) from the RHINESSA study in Bergen, Norway. Urine biomarkers of triclosan (TCS), triclocarban (TCC), parabens and benzophenone-3, bisphenols and dichlorophenols (DCP) were quantified by mass spectrometry.

RESULTS

Detection of the urine biomarkers varied according to chemical type and demographics. TCC was detected in 5% of adults and in 45% of adolescents, while propyl (PPB) and methyl (MPB) parabens were detected in 95% of adults and in 94% (PPB) and 99% (MPB) of adolescents. Women had higher median urine concentrations of phenolic chemicals and reported a higher frequency of use of personal care products than men. Urine concentration of MPB increased in a dose-dependent manner with increased frequency of use of several cosmetic products. Overall, urinary biomarker levels of parabens were lower in those with current eczema. The biomarker concentrations of bisphenol S was higher in participants with positive specific IgE and females with current asthma, but did not differ by eczema or rhinitis status. MPB, ethylparaben (EPB), 2,4-DCP and TCS were inversely related to BMI in adults; interaction by gender were not significant.

CONCLUSIONS

Reported frequency of use of personal care products correlated very well with urine biomarker levels of paraben and phenols. Several chemicals were inversley related to BMI, and lower levels of parabens was observed for participants with current eczema. There is a need for further studies of health effects of chemicals from personal care products, in particular in longitudinally designed studies.

Review of the safety of application of cosmetic products containing parabens

Cosmetics are a source of lifetime exposure to various substances including parabens, being the most popular synthetic preservatives. Because the use of cosmetics shows an increasing trend and some adverse health outcomes of parabens present in these products have been reported, the present review focused on the safety of dermal application of these compounds. Special attention has been paid to the absorption of parabens and their retention in the human body in the intact form, as well as to their toxicological characteristics. Particular emphasis has been placed on the estrogenic potential of parabens. Based on the available published data of the concentrations of parabens in various kinds of cosmetics, the average ranges of systemic exposure dose (SED) for methylparaben, ethylparaben, propylparaben, and butylparaben have been calculated. Safety evaluations [margin of safety (MoS)] for these compounds, based on their aggregate exposure, have also been performed. Moreover, evidence for the negative impact of methylparaben on skin cells has been provided, and the main factors that may intensify dermal absorption of parabens and their impact on the skin have been described. Summarizing, the use of single cosmetics containing parabens should not pose a hazard for human health; however, using excessive quantities of cosmetic preparations containing these compounds may lead to the development of unfavorable health outcomes. Due to the real risk of estrogenic effects, as a result of exposure to parabens in cosmetics, simultaneous use of many cosmetic products containing these preservatives should be avoided.

Experimental design approaches to optimize ultrasound-assisted simultaneous-silylation dispersive liquid-liquid microextraction for the rapid determination of parabens in water samples

This work describes a rapid solvent-minimized process to effectively determine four common paraben preservatives (methyl-, ethyl-, propyl- and butyl-paraben) in surface water samples. The method involved the use of a combination of a novel ultrasound-assisted simultaneous-silylation within dispersive liquid–liquid microextraction (UASS-DLLME) with detection by gas chromatography-tandem mass spectrometry (GC-MS/MS). To overcome the challenges related to the different experimental conditions, multivariate experimental design approaches conducted by means of a multilevel categorical design and a Box–Behnken design were utilized to screen and optimize parameters that have significant influences on the efficiency of silylation and extraction. The method was then validated and shown to provide low limits of quantitation (LOQs; 1–5 ng L⁻¹), high precision (3–11%), and satisfactory mean spiked recoveries (accuracy; 79–101%). Upon analyzing samples of surface water obtained from the field, we found that, in total, there was a relatively high concentration of the target parabens ranging from 200 to 1389 ng L⁻¹. The sources of the elevated levels of these parabens may be from the release of untreated municipal wastewater in this region, and also due to the widespread application of parabens in personal care and food products.

This work describes a rapid solvent-minimized process to effectively determine four common paraben preservatives (methyl-, ethyl-, propyl- and butyl-paraben) in surface water samples.

Mixtures modeling identifies chemical inducers versus repressors of toxicity associated with wildfire smoke

Exposure to wildfire smoke continues to be a growing threat to public health, yet the chemical components in wildfire smoke that primarily drive toxicity and associated disease are largely unknown. This study utilized a suite of computational approaches to identify groups of chemicals induced by variable biomass burn conditions that were associated with biological responses in the mouse lung, including pulmonary immune response and injury markers. Smoke condensate samples were collected and characterized, resulting in chemical distribution information for 86 constituents across ten different exposures. Mixtures-relevant statistical methods included (i) a chemical clustering and data-reduction method, weighted chemical co-expression network analysis (WCCNA), (ii) a quantile g-computation approach to address the joint effect of multiple chemicals in different groupings, and (iii) a correlation analysis to compare mixtures modeling results against individual chemical relationships. Seven chemical groups were identified using WCCNA based on co-occurrence showing both positive and negative relationships with biological responses. A group containing methoxyphenols (e.g., coniferyl aldehyde, eugenol, guaiacol, and vanillin) displayed highly significant, negative relationships with several biological responses, including cytokines and lung injury markers. This group was further shown through quantile g-computation methods to associate with reduced biological responses. Specifically, mixtures modeling based on all chemicals excluding those in the methoxyphenol group demonstrated more significant, positive relationships with several biological responses; whereas mixtures modeling based on just those in the methoxyphenol group demonstrated significant negative relationships with several biological responses, suggesting potential protective effects. Mixtures-based analyses also identified other groups consisting of inorganic elements and ionic constituents showing positive relationships with several biological responses, including markers of inflammation. Many of the effects identified through mixtures modeling in this analysis were not captured through individual chemical analyses. Together, this study demonstrates the utility of mixtures-based approaches to identify potential drivers and inhibitors of toxicity relevant to wildfire exposures.

Maternal Bisphenol A (BPA) Exposure Alters Cerebral Cortical Morphogenesis and Synaptic Function in Mice

Early-life exposure to bisphenol A (BPA), synthetic compound used in polycarbonate plastic, is associated with altered cognitive and emotional behavior later in life. However, the brain mechanism underlying the behavioral deficits is unknown. Here, we show that maternal BPA exposure disrupted self-renewal and differentiation of neural progenitors during cortical development. The BPA exposure reduced the neuron number, whereas it increased glial cells in the cerebral cortex. Also, synaptic formation and transmission in the cerebral cortex were suppressed after maternal BPA exposure. These changes appeared to be associated with autophagy as a gene ontology analysis of RNA-seq identified an autophagy domain in the BPA condition. Mouse behavioral tests revealed that maternal BPA caused hyperactivity and social deficits in adult offspring. Together, these results suggest that maternal BPA exposure leads to abnormal cortical architecture and function likely by activating autophagy.